* [RFC] btf: split core BTF parsing out of BPF subsystem into kernel/btf/
2026-03-24 18:44 ` Sasha Levin
@ 2026-03-25 1:18 ` Sasha Levin
2026-03-25 2:15 ` bot+bpf-ci
0 siblings, 1 reply; 18+ messages in thread
From: Sasha Levin @ 2026-03-25 1:18 UTC (permalink / raw)
To: sashal
Cc: James.Bottomley, adobriyan, akpm, alexei.starovoitov, ast, bp,
bpf, corbet, dave.hansen, davidgow, deller, geert, gregkh, hpa,
jgross, jpoimboe, kees, laurent.pinchart, linux-doc, linux-kbuild,
linux-kernel, linux-modules, masahiroy, mcgrof, mingo, nathan,
nsc, peterz, petr.pavlu, pmladek, rdunlap, rostedt, tglx, vbabka,
x86
Move BTF type format parsing and inspection code out of the BPF
subsystem into its own kernel/btf/ directory, separating core BTF
functionality from BPF-specific extensions.
CONFIG_DEBUG_INFO_BTF currently depends on CONFIG_BPF_SYSCALL, which
prevents embedded, automotive, and safety-critical environments from
using BTF. These platforms often disable BPF for security and size
reasons but would benefit from BTF type information for crash
diagnostics and debugging.
Introduce CONFIG_BTF for the core BTF runtime support (type parsing,
lookup, and display) which can be enabled independently of
CONFIG_BPF_SYSCALL, and remove the BPF_SYSCALL dependency from
CONFIG_DEBUG_INFO_BTF. The code is split into:
kernel/btf/btf.c - Core BTF: parsing, verification, type lookup,
display infrastructure. No BPF dependencies.
kernel/btf/bpf.c - BPF extensions: kfunc registration, struct_ops,
verifier integration, FD interface, module BTF.
kernel/btf/btf.h - Internal shared header.
When CONFIG_BPF_SYSCALL=n, only btf.c is compiled, providing the
minimal BTF API. When CONFIG_BPF_SYSCALL=y, both files are compiled
and bpf.c overrides weak symbols in btf.c for BPF-specific cleanup
(IDR management, RCU-deferred freeing, kfunc/struct_ops tab cleanup).
No functional change when CONFIG_BPF_SYSCALL=y.
Assisted-by: Claude:claude-opus-4-6
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
include/linux/btf.h | 80 +-
kernel/Makefile | 1 +
kernel/bpf/Makefile | 2 +-
kernel/btf/Makefile | 4 +
kernel/{bpf/btf.c => btf/bpf.c} | 6386 ++++---------------------------
kernel/btf/btf.c | 4803 +++++++++++++++++++++++
kernel/btf/btf.h | 135 +
lib/Kconfig.debug | 15 +-
8 files changed, 5796 insertions(+), 5630 deletions(-)
create mode 100644 kernel/btf/Makefile
rename kernel/{bpf/btf.c => btf/bpf.c} (50%)
create mode 100644 kernel/btf/btf.c
create mode 100644 kernel/btf/btf.h
diff --git a/include/linux/btf.h b/include/linux/btf.h
index 48108471c5b13..d4d64878324ff 100644
--- a/include/linux/btf.h
+++ b/include/linux/btf.h
@@ -139,17 +139,11 @@ struct btf_struct_metas {
struct btf_struct_meta types[];
};
-extern const struct file_operations btf_fops;
-
const char *btf_get_name(const struct btf *btf);
void btf_get(struct btf *btf);
void btf_put(struct btf *btf);
const struct btf_header *btf_header(const struct btf *btf);
-int btf_new_fd(const union bpf_attr *attr, bpfptr_t uattr, u32 uattr_sz);
-struct btf *btf_get_by_fd(int fd);
-int btf_get_info_by_fd(const struct btf *btf,
- const union bpf_attr *attr,
- union bpf_attr __user *uattr);
+
/* Figure out the size of a type_id. If type_id is a modifier
* (e.g. const), it will be resolved to find out the type with size.
*
@@ -213,12 +207,9 @@ int btf_type_seq_show_flags(const struct btf *btf, u32 type_id, void *obj,
int btf_type_snprintf_show(const struct btf *btf, u32 type_id, void *obj,
char *buf, int len, u64 flags);
-int btf_get_fd_by_id(u32 id);
-u32 btf_obj_id(const struct btf *btf);
bool btf_is_kernel(const struct btf *btf);
bool btf_is_module(const struct btf *btf);
bool btf_is_vmlinux(const struct btf *btf);
-struct module *btf_try_get_module(const struct btf *btf);
u32 btf_nr_types(const struct btf *btf);
u32 btf_named_start_id(const struct btf *btf, bool own);
struct btf *btf_base_btf(const struct btf *btf);
@@ -228,12 +219,8 @@ bool btf_type_is_primitive(const struct btf_type *t);
bool btf_member_is_reg_int(const struct btf *btf, const struct btf_type *s,
const struct btf_member *m,
u32 expected_offset, u32 expected_size);
-struct btf_record *btf_parse_fields(const struct btf *btf, const struct btf_type *t,
- u32 field_mask, u32 value_size);
-int btf_check_and_fixup_fields(const struct btf *btf, struct btf_record *rec);
bool btf_type_is_void(const struct btf_type *t);
s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind);
-s32 bpf_find_btf_id(const char *name, u32 kind, struct btf **btf_p);
const struct btf_type *btf_type_skip_modifiers(const struct btf *btf,
u32 id, u32 *res_id);
const struct btf_type *btf_type_resolve_ptr(const struct btf *btf,
@@ -245,6 +232,20 @@ btf_resolve_size(const struct btf *btf, const struct btf_type *type,
u32 *type_size);
const char *btf_type_str(const struct btf_type *t);
+/* BPF-specific declarations */
+extern const struct file_operations btf_fops;
+int btf_new_fd(const union bpf_attr *attr, bpfptr_t uattr, u32 uattr_sz);
+struct btf *btf_get_by_fd(int fd);
+int btf_get_info_by_fd(const struct btf *btf,
+ const union bpf_attr *attr,
+ union bpf_attr __user *uattr);
+int btf_get_fd_by_id(u32 id);
+u32 btf_obj_id(const struct btf *btf);
+struct btf_record *btf_parse_fields(const struct btf *btf, const struct btf_type *t,
+ u32 field_mask, u32 value_size);
+int btf_check_and_fixup_fields(const struct btf *btf, struct btf_record *rec);
+s32 bpf_find_btf_id(const char *name, u32 kind, struct btf **btf_p);
+
#define for_each_member(i, struct_type, member) \
for (i = 0, member = btf_type_member(struct_type); \
i < btf_type_vlen(struct_type); \
@@ -524,9 +525,6 @@ static inline void *btf_id_set8_contains(const struct btf_id_set8 *set, u32 id)
bool btf_param_match_suffix(const struct btf *btf,
const struct btf_param *arg,
const char *suffix);
-int btf_ctx_arg_offset(const struct btf *btf, const struct btf_type *func_proto,
- u32 arg_no);
-u32 btf_ctx_arg_idx(struct btf *btf, const struct btf_type *func_proto, int off);
struct bpf_verifier_log;
@@ -564,16 +562,39 @@ struct btf_field_iter {
int vlen;
};
-#ifdef CONFIG_BPF_SYSCALL
+#ifdef CONFIG_BTF
const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id);
void btf_set_base_btf(struct btf *btf, const struct btf *base_btf);
+const char *btf_name_by_offset(const struct btf *btf, u32 offset);
+const char *btf_str_by_offset(const struct btf *btf, u32 offset);
+#else
+static inline const struct btf_type *btf_type_by_id(const struct btf *btf,
+ u32 type_id)
+{
+ return NULL;
+}
+
+static inline void btf_set_base_btf(struct btf *btf, const struct btf *base_btf)
+{
+}
+
+static inline const char *btf_name_by_offset(const struct btf *btf,
+ u32 offset)
+{
+ return NULL;
+}
+#endif /* CONFIG_BTF */
+
+#ifdef CONFIG_BPF_SYSCALL
+struct module *btf_try_get_module(const struct btf *btf);
int btf_relocate(struct btf *btf, const struct btf *base_btf, __u32 **map_ids);
int btf_field_iter_init(struct btf_field_iter *it, struct btf_type *t,
enum btf_field_iter_kind iter_kind);
__u32 *btf_field_iter_next(struct btf_field_iter *it);
-const char *btf_name_by_offset(const struct btf *btf, u32 offset);
-const char *btf_str_by_offset(const struct btf *btf, u32 offset);
+int btf_ctx_arg_offset(const struct btf *btf, const struct btf_type *func_proto,
+ u32 arg_no);
+u32 btf_ctx_arg_idx(struct btf *btf, const struct btf_type *func_proto, int off);
struct btf *btf_parse_vmlinux(void);
struct btf *bpf_prog_get_target_btf(const struct bpf_prog *prog);
u32 *btf_kfunc_flags(const struct btf *btf, u32 kfunc_btf_id, const struct bpf_prog *prog);
@@ -606,17 +627,7 @@ static inline bool btf_type_is_struct_ptr(struct btf *btf, const struct btf_type
return btf_type_is_struct(t);
}
#else
-static inline const struct btf_type *btf_type_by_id(const struct btf *btf,
- u32 type_id)
-{
- return NULL;
-}
-
-static inline void btf_set_base_btf(struct btf *btf, const struct btf *base_btf)
-{
-}
-
-static inline int btf_relocate(void *log, struct btf *btf, const struct btf *base_btf,
+static inline int btf_relocate(struct btf *btf, const struct btf *base_btf,
__u32 **map_ids)
{
return -EOPNOTSUPP;
@@ -633,11 +644,6 @@ static inline __u32 *btf_field_iter_next(struct btf_field_iter *it)
return NULL;
}
-static inline const char *btf_name_by_offset(const struct btf *btf,
- u32 offset)
-{
- return NULL;
-}
static inline u32 *btf_kfunc_id_set_contains(const struct btf *btf,
u32 kfunc_btf_id,
struct bpf_prog *prog)
@@ -683,5 +689,5 @@ static inline int btf_check_iter_arg(struct btf *btf, const struct btf_type *fun
{
return -EOPNOTSUPP;
}
-#endif
+#endif /* CONFIG_BPF_SYSCALL */
#endif
diff --git a/kernel/Makefile b/kernel/Makefile
index 6785982013dce..d09d7f102c335 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -121,6 +121,7 @@ obj-$(CONFIG_RETHOOK) += trace/
obj-$(CONFIG_IRQ_WORK) += irq_work.o
obj-$(CONFIG_CPU_PM) += cpu_pm.o
obj-$(CONFIG_BPF) += bpf/
+obj-$(CONFIG_BTF) += btf/
obj-$(CONFIG_KCSAN) += kcsan/
obj-$(CONFIG_SHADOW_CALL_STACK) += scs.o
obj-$(CONFIG_HAVE_STATIC_CALL) += static_call.o
diff --git a/kernel/bpf/Makefile b/kernel/bpf/Makefile
index 79cf22860a99b..37d7ebf4808f3 100644
--- a/kernel/bpf/Makefile
+++ b/kernel/bpf/Makefile
@@ -14,7 +14,7 @@ obj-$(CONFIG_BPF_SYSCALL) += bpf_local_storage.o bpf_task_storage.o
obj-${CONFIG_BPF_LSM} += bpf_inode_storage.o
obj-$(CONFIG_BPF_SYSCALL) += disasm.o mprog.o
obj-$(CONFIG_BPF_JIT) += trampoline.o
-obj-$(CONFIG_BPF_SYSCALL) += btf.o memalloc.o rqspinlock.o stream.o
+obj-$(CONFIG_BPF_SYSCALL) += memalloc.o rqspinlock.o stream.o
ifeq ($(CONFIG_MMU)$(CONFIG_64BIT),yy)
obj-$(CONFIG_BPF_SYSCALL) += arena.o range_tree.o
endif
diff --git a/kernel/btf/Makefile b/kernel/btf/Makefile
new file mode 100644
index 0000000000000..e0365d5c7e9bd
--- /dev/null
+++ b/kernel/btf/Makefile
@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_BTF) += btf.o
+obj-$(CONFIG_BPF_SYSCALL) += bpf.o
diff --git a/kernel/bpf/btf.c b/kernel/btf/bpf.c
similarity index 50%
rename from kernel/bpf/btf.c
rename to kernel/btf/bpf.c
index 71f9143fe90f3..986d29f4bc3ba 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/btf/bpf.c
@@ -1,33 +1,35 @@
// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2018 Facebook */
+/* BPF-specific BTF extensions */
#include <uapi/linux/btf.h>
#include <uapi/linux/bpf.h>
-#include <uapi/linux/bpf_perf_event.h>
#include <uapi/linux/types.h>
-#include <linux/seq_file.h>
#include <linux/compiler.h>
#include <linux/ctype.h>
#include <linux/errno.h>
#include <linux/slab.h>
-#include <linux/anon_inodes.h>
#include <linux/file.h>
-#include <linux/uaccess.h>
#include <linux/kernel.h>
-#include <linux/idr.h>
#include <linux/sort.h>
+#include <linux/seq_file.h>
#include <linux/bpf_verifier.h>
#include <linux/btf.h>
#include <linux/btf_ids.h>
+#include <linux/bsearch.h>
+#include <linux/string.h>
+#include <linux/overflow.h>
+#include <linux/kobject.h>
+
+#include <uapi/linux/bpf_perf_event.h>
+#include <linux/anon_inodes.h>
+#include <linux/uaccess.h>
+#include <linux/idr.h>
#include <linux/bpf.h>
#include <linux/bpf_lsm.h>
#include <linux/skmsg.h>
#include <linux/perf_event.h>
-#include <linux/bsearch.h>
-#include <linux/kobject.h>
-#include <linux/string.h>
#include <linux/sysfs.h>
-#include <linux/overflow.h>
#include <net/netfilter/nf_bpf_link.h>
@@ -35,173 +37,7 @@
#include <net/xdp.h>
#include "../tools/lib/bpf/relo_core.h"
-/* BTF (BPF Type Format) is the meta data format which describes
- * the data types of BPF program/map. Hence, it basically focus
- * on the C programming language which the modern BPF is primary
- * using.
- *
- * ELF Section:
- * ~~~~~~~~~~~
- * The BTF data is stored under the ".BTF" ELF section
- *
- * struct btf_type:
- * ~~~~~~~~~~~~~~~
- * Each 'struct btf_type' object describes a C data type.
- * Depending on the type it is describing, a 'struct btf_type'
- * object may be followed by more data. F.e.
- * To describe an array, 'struct btf_type' is followed by
- * 'struct btf_array'.
- *
- * 'struct btf_type' and any extra data following it are
- * 4 bytes aligned.
- *
- * Type section:
- * ~~~~~~~~~~~~~
- * The BTF type section contains a list of 'struct btf_type' objects.
- * Each one describes a C type. Recall from the above section
- * that a 'struct btf_type' object could be immediately followed by extra
- * data in order to describe some particular C types.
- *
- * type_id:
- * ~~~~~~~
- * Each btf_type object is identified by a type_id. The type_id
- * is implicitly implied by the location of the btf_type object in
- * the BTF type section. The first one has type_id 1. The second
- * one has type_id 2...etc. Hence, an earlier btf_type has
- * a smaller type_id.
- *
- * A btf_type object may refer to another btf_type object by using
- * type_id (i.e. the "type" in the "struct btf_type").
- *
- * NOTE that we cannot assume any reference-order.
- * A btf_type object can refer to an earlier btf_type object
- * but it can also refer to a later btf_type object.
- *
- * For example, to describe "const void *". A btf_type
- * object describing "const" may refer to another btf_type
- * object describing "void *". This type-reference is done
- * by specifying type_id:
- *
- * [1] CONST (anon) type_id=2
- * [2] PTR (anon) type_id=0
- *
- * The above is the btf_verifier debug log:
- * - Each line started with "[?]" is a btf_type object
- * - [?] is the type_id of the btf_type object.
- * - CONST/PTR is the BTF_KIND_XXX
- * - "(anon)" is the name of the type. It just
- * happens that CONST and PTR has no name.
- * - type_id=XXX is the 'u32 type' in btf_type
- *
- * NOTE: "void" has type_id 0
- *
- * String section:
- * ~~~~~~~~~~~~~~
- * The BTF string section contains the names used by the type section.
- * Each string is referred by an "offset" from the beginning of the
- * string section.
- *
- * Each string is '\0' terminated.
- *
- * The first character in the string section must be '\0'
- * which is used to mean 'anonymous'. Some btf_type may not
- * have a name.
- */
-
-/* BTF verification:
- *
- * To verify BTF data, two passes are needed.
- *
- * Pass #1
- * ~~~~~~~
- * The first pass is to collect all btf_type objects to
- * an array: "btf->types".
- *
- * Depending on the C type that a btf_type is describing,
- * a btf_type may be followed by extra data. We don't know
- * how many btf_type is there, and more importantly we don't
- * know where each btf_type is located in the type section.
- *
- * Without knowing the location of each type_id, most verifications
- * cannot be done. e.g. an earlier btf_type may refer to a later
- * btf_type (recall the "const void *" above), so we cannot
- * check this type-reference in the first pass.
- *
- * In the first pass, it still does some verifications (e.g.
- * checking the name is a valid offset to the string section).
- *
- * Pass #2
- * ~~~~~~~
- * The main focus is to resolve a btf_type that is referring
- * to another type.
- *
- * We have to ensure the referring type:
- * 1) does exist in the BTF (i.e. in btf->types[])
- * 2) does not cause a loop:
- * struct A {
- * struct B b;
- * };
- *
- * struct B {
- * struct A a;
- * };
- *
- * btf_type_needs_resolve() decides if a btf_type needs
- * to be resolved.
- *
- * The needs_resolve type implements the "resolve()" ops which
- * essentially does a DFS and detects backedge.
- *
- * During resolve (or DFS), different C types have different
- * "RESOLVED" conditions.
- *
- * When resolving a BTF_KIND_STRUCT, we need to resolve all its
- * members because a member is always referring to another
- * type. A struct's member can be treated as "RESOLVED" if
- * it is referring to a BTF_KIND_PTR. Otherwise, the
- * following valid C struct would be rejected:
- *
- * struct A {
- * int m;
- * struct A *a;
- * };
- *
- * When resolving a BTF_KIND_PTR, it needs to keep resolving if
- * it is referring to another BTF_KIND_PTR. Otherwise, we cannot
- * detect a pointer loop, e.g.:
- * BTF_KIND_CONST -> BTF_KIND_PTR -> BTF_KIND_CONST -> BTF_KIND_PTR +
- * ^ |
- * +-----------------------------------------+
- *
- */
-
-#define BITS_PER_U128 (sizeof(u64) * BITS_PER_BYTE * 2)
-#define BITS_PER_BYTE_MASK (BITS_PER_BYTE - 1)
-#define BITS_PER_BYTE_MASKED(bits) ((bits) & BITS_PER_BYTE_MASK)
-#define BITS_ROUNDDOWN_BYTES(bits) ((bits) >> 3)
-#define BITS_ROUNDUP_BYTES(bits) \
- (BITS_ROUNDDOWN_BYTES(bits) + !!BITS_PER_BYTE_MASKED(bits))
-
-#define BTF_INFO_MASK 0x9f00ffff
-#define BTF_INT_MASK 0x0fffffff
-#define BTF_TYPE_ID_VALID(type_id) ((type_id) <= BTF_MAX_TYPE)
-#define BTF_STR_OFFSET_VALID(name_off) ((name_off) <= BTF_MAX_NAME_OFFSET)
-
-/* 16MB for 64k structs and each has 16 members and
- * a few MB spaces for the string section.
- * The hard limit is S32_MAX.
- */
-#define BTF_MAX_SIZE (16 * 1024 * 1024)
-
-#define for_each_member_from(i, from, struct_type, member) \
- for (i = from, member = btf_type_member(struct_type) + from; \
- i < btf_type_vlen(struct_type); \
- i++, member++)
-
-#define for_each_vsi_from(i, from, struct_type, member) \
- for (i = from, member = btf_type_var_secinfo(struct_type) + from; \
- i < btf_type_vlen(struct_type); \
- i++, member++)
+#include "btf.h"
DEFINE_IDR(btf_idr);
DEFINE_SPINLOCK(btf_idr_lock);
@@ -250,431 +86,12 @@ struct btf_struct_ops_tab {
u32 capacity;
struct bpf_struct_ops_desc ops[];
};
-
-struct btf {
- void *data;
- struct btf_type **types;
- u32 *resolved_ids;
- u32 *resolved_sizes;
- const char *strings;
- void *nohdr_data;
- struct btf_header hdr;
- u32 nr_types; /* includes VOID for base BTF */
- u32 named_start_id;
- u32 types_size;
- u32 data_size;
- refcount_t refcnt;
u32 id;
struct rcu_head rcu;
struct btf_kfunc_set_tab *kfunc_set_tab;
struct btf_id_dtor_kfunc_tab *dtor_kfunc_tab;
struct btf_struct_metas *struct_meta_tab;
struct btf_struct_ops_tab *struct_ops_tab;
-
- /* split BTF support */
- struct btf *base_btf;
- u32 start_id; /* first type ID in this BTF (0 for base BTF) */
- u32 start_str_off; /* first string offset (0 for base BTF) */
- char name[MODULE_NAME_LEN];
- bool kernel_btf;
- __u32 *base_id_map; /* map from distilled base BTF -> vmlinux BTF ids */
-};
-
-enum verifier_phase {
- CHECK_META,
- CHECK_TYPE,
-};
-
-struct resolve_vertex {
- const struct btf_type *t;
- u32 type_id;
- u16 next_member;
-};
-
-enum visit_state {
- NOT_VISITED,
- VISITED,
- RESOLVED,
-};
-
-enum resolve_mode {
- RESOLVE_TBD, /* To Be Determined */
- RESOLVE_PTR, /* Resolving for Pointer */
- RESOLVE_STRUCT_OR_ARRAY, /* Resolving for struct/union
- * or array
- */
-};
-
-#define MAX_RESOLVE_DEPTH 32
-
-struct btf_sec_info {
- u32 off;
- u32 len;
-};
-
-struct btf_verifier_env {
- struct btf *btf;
- u8 *visit_states;
- struct resolve_vertex stack[MAX_RESOLVE_DEPTH];
- struct bpf_verifier_log log;
- u32 log_type_id;
- u32 top_stack;
- enum verifier_phase phase;
- enum resolve_mode resolve_mode;
-};
-
-static const char * const btf_kind_str[NR_BTF_KINDS] = {
- [BTF_KIND_UNKN] = "UNKNOWN",
- [BTF_KIND_INT] = "INT",
- [BTF_KIND_PTR] = "PTR",
- [BTF_KIND_ARRAY] = "ARRAY",
- [BTF_KIND_STRUCT] = "STRUCT",
- [BTF_KIND_UNION] = "UNION",
- [BTF_KIND_ENUM] = "ENUM",
- [BTF_KIND_FWD] = "FWD",
- [BTF_KIND_TYPEDEF] = "TYPEDEF",
- [BTF_KIND_VOLATILE] = "VOLATILE",
- [BTF_KIND_CONST] = "CONST",
- [BTF_KIND_RESTRICT] = "RESTRICT",
- [BTF_KIND_FUNC] = "FUNC",
- [BTF_KIND_FUNC_PROTO] = "FUNC_PROTO",
- [BTF_KIND_VAR] = "VAR",
- [BTF_KIND_DATASEC] = "DATASEC",
- [BTF_KIND_FLOAT] = "FLOAT",
- [BTF_KIND_DECL_TAG] = "DECL_TAG",
- [BTF_KIND_TYPE_TAG] = "TYPE_TAG",
- [BTF_KIND_ENUM64] = "ENUM64",
-};
-
-const char *btf_type_str(const struct btf_type *t)
-{
- return btf_kind_str[BTF_INFO_KIND(t->info)];
-}
-
-/* Chunk size we use in safe copy of data to be shown. */
-#define BTF_SHOW_OBJ_SAFE_SIZE 32
-
-/*
- * This is the maximum size of a base type value (equivalent to a
- * 128-bit int); if we are at the end of our safe buffer and have
- * less than 16 bytes space we can't be assured of being able
- * to copy the next type safely, so in such cases we will initiate
- * a new copy.
- */
-#define BTF_SHOW_OBJ_BASE_TYPE_SIZE 16
-
-/* Type name size */
-#define BTF_SHOW_NAME_SIZE 80
-
-/*
- * The suffix of a type that indicates it cannot alias another type when
- * comparing BTF IDs for kfunc invocations.
- */
-#define NOCAST_ALIAS_SUFFIX "___init"
-
-/*
- * Common data to all BTF show operations. Private show functions can add
- * their own data to a structure containing a struct btf_show and consult it
- * in the show callback. See btf_type_show() below.
- *
- * One challenge with showing nested data is we want to skip 0-valued
- * data, but in order to figure out whether a nested object is all zeros
- * we need to walk through it. As a result, we need to make two passes
- * when handling structs, unions and arrays; the first path simply looks
- * for nonzero data, while the second actually does the display. The first
- * pass is signalled by show->state.depth_check being set, and if we
- * encounter a non-zero value we set show->state.depth_to_show to
- * the depth at which we encountered it. When we have completed the
- * first pass, we will know if anything needs to be displayed if
- * depth_to_show > depth. See btf_[struct,array]_show() for the
- * implementation of this.
- *
- * Another problem is we want to ensure the data for display is safe to
- * access. To support this, the anonymous "struct {} obj" tracks the data
- * object and our safe copy of it. We copy portions of the data needed
- * to the object "copy" buffer, but because its size is limited to
- * BTF_SHOW_OBJ_COPY_LEN bytes, multiple copies may be required as we
- * traverse larger objects for display.
- *
- * The various data type show functions all start with a call to
- * btf_show_start_type() which returns a pointer to the safe copy
- * of the data needed (or if BTF_SHOW_UNSAFE is specified, to the
- * raw data itself). btf_show_obj_safe() is responsible for
- * using copy_from_kernel_nofault() to update the safe data if necessary
- * as we traverse the object's data. skbuff-like semantics are
- * used:
- *
- * - obj.head points to the start of the toplevel object for display
- * - obj.size is the size of the toplevel object
- * - obj.data points to the current point in the original data at
- * which our safe data starts. obj.data will advance as we copy
- * portions of the data.
- *
- * In most cases a single copy will suffice, but larger data structures
- * such as "struct task_struct" will require many copies. The logic in
- * btf_show_obj_safe() handles the logic that determines if a new
- * copy_from_kernel_nofault() is needed.
- */
-struct btf_show {
- u64 flags;
- void *target; /* target of show operation (seq file, buffer) */
- __printf(2, 0) void (*showfn)(struct btf_show *show, const char *fmt, va_list args);
- const struct btf *btf;
- /* below are used during iteration */
- struct {
- u8 depth;
- u8 depth_to_show;
- u8 depth_check;
- u8 array_member:1,
- array_terminated:1;
- u16 array_encoding;
- u32 type_id;
- int status; /* non-zero for error */
- const struct btf_type *type;
- const struct btf_member *member;
- char name[BTF_SHOW_NAME_SIZE]; /* space for member name/type */
- } state;
- struct {
- u32 size;
- void *head;
- void *data;
- u8 safe[BTF_SHOW_OBJ_SAFE_SIZE];
- } obj;
-};
-
-struct btf_kind_operations {
- s32 (*check_meta)(struct btf_verifier_env *env,
- const struct btf_type *t,
- u32 meta_left);
- int (*resolve)(struct btf_verifier_env *env,
- const struct resolve_vertex *v);
- int (*check_member)(struct btf_verifier_env *env,
- const struct btf_type *struct_type,
- const struct btf_member *member,
- const struct btf_type *member_type);
- int (*check_kflag_member)(struct btf_verifier_env *env,
- const struct btf_type *struct_type,
- const struct btf_member *member,
- const struct btf_type *member_type);
- void (*log_details)(struct btf_verifier_env *env,
- const struct btf_type *t);
- void (*show)(const struct btf *btf, const struct btf_type *t,
- u32 type_id, void *data, u8 bits_offsets,
- struct btf_show *show);
-};
-
-static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS];
-static struct btf_type btf_void;
-
-static int btf_resolve(struct btf_verifier_env *env,
- const struct btf_type *t, u32 type_id);
-
-static int btf_func_check(struct btf_verifier_env *env,
- const struct btf_type *t);
-
-static bool btf_type_is_modifier(const struct btf_type *t)
-{
- /* Some of them is not strictly a C modifier
- * but they are grouped into the same bucket
- * for BTF concern:
- * A type (t) that refers to another
- * type through t->type AND its size cannot
- * be determined without following the t->type.
- *
- * ptr does not fall into this bucket
- * because its size is always sizeof(void *).
- */
- switch (BTF_INFO_KIND(t->info)) {
- case BTF_KIND_TYPEDEF:
- case BTF_KIND_VOLATILE:
- case BTF_KIND_CONST:
- case BTF_KIND_RESTRICT:
- case BTF_KIND_TYPE_TAG:
- return true;
- }
-
- return false;
-}
-
-static int btf_start_id(const struct btf *btf)
-{
- return btf->start_id + (btf->base_btf ? 0 : 1);
-}
-
-bool btf_type_is_void(const struct btf_type *t)
-{
- return t == &btf_void;
-}
-
-static bool btf_type_is_datasec(const struct btf_type *t)
-{
- return BTF_INFO_KIND(t->info) == BTF_KIND_DATASEC;
-}
-
-static bool btf_type_is_decl_tag(const struct btf_type *t)
-{
- return BTF_INFO_KIND(t->info) == BTF_KIND_DECL_TAG;
-}
-
-static bool btf_type_nosize(const struct btf_type *t)
-{
- return btf_type_is_void(t) || btf_type_is_fwd(t) ||
- btf_type_is_func(t) || btf_type_is_func_proto(t) ||
- btf_type_is_decl_tag(t);
-}
-
-static bool btf_type_nosize_or_null(const struct btf_type *t)
-{
- return !t || btf_type_nosize(t);
-}
-
-static bool btf_type_is_decl_tag_target(const struct btf_type *t)
-{
- return btf_type_is_func(t) || btf_type_is_struct(t) ||
- btf_type_is_var(t) || btf_type_is_typedef(t);
-}
-
-bool btf_is_vmlinux(const struct btf *btf)
-{
- return btf->kernel_btf && !btf->base_btf;
-}
-
-u32 btf_nr_types(const struct btf *btf)
-{
- u32 total = 0;
-
- while (btf) {
- total += btf->nr_types;
- btf = btf->base_btf;
- }
-
- return total;
-}
-
-/*
- * Note that vmlinux and kernel module BTFs are always sorted
- * during the building phase.
- */
-static void btf_check_sorted(struct btf *btf)
-{
- u32 i, n, named_start_id = 0;
-
- n = btf_nr_types(btf);
- if (btf_is_vmlinux(btf)) {
- for (i = btf_start_id(btf); i < n; i++) {
- const struct btf_type *t = btf_type_by_id(btf, i);
- const char *n = btf_name_by_offset(btf, t->name_off);
-
- if (n[0] != '\0') {
- btf->named_start_id = i;
- return;
- }
- }
- return;
- }
-
- for (i = btf_start_id(btf) + 1; i < n; i++) {
- const struct btf_type *ta = btf_type_by_id(btf, i - 1);
- const struct btf_type *tb = btf_type_by_id(btf, i);
- const char *na = btf_name_by_offset(btf, ta->name_off);
- const char *nb = btf_name_by_offset(btf, tb->name_off);
-
- if (strcmp(na, nb) > 0)
- return;
-
- if (named_start_id == 0 && na[0] != '\0')
- named_start_id = i - 1;
- if (named_start_id == 0 && nb[0] != '\0')
- named_start_id = i;
- }
-
- if (named_start_id)
- btf->named_start_id = named_start_id;
-}
-
-/*
- * btf_named_start_id - Get the named starting ID for the BTF
- * @btf: Pointer to the target BTF object
- * @own: Flag indicating whether to query only the current BTF (true = current BTF only,
- * false = recursively traverse the base BTF chain)
- *
- * Return value rules:
- * 1. For a sorted btf, return its named_start_id
- * 2. Else for a split BTF, return its start_id
- * 3. Else for a base BTF, return 1
- */
-u32 btf_named_start_id(const struct btf *btf, bool own)
-{
- const struct btf *base_btf = btf;
-
- while (!own && base_btf->base_btf)
- base_btf = base_btf->base_btf;
-
- return base_btf->named_start_id ?: (base_btf->start_id ?: 1);
-}
-
-static s32 btf_find_by_name_kind_bsearch(const struct btf *btf, const char *name)
-{
- const struct btf_type *t;
- const char *tname;
- s32 l, r, m;
-
- l = btf_named_start_id(btf, true);
- r = btf_nr_types(btf) - 1;
- while (l <= r) {
- m = l + (r - l) / 2;
- t = btf_type_by_id(btf, m);
- tname = btf_name_by_offset(btf, t->name_off);
- if (strcmp(tname, name) >= 0) {
- if (l == r)
- return r;
- r = m;
- } else {
- l = m + 1;
- }
- }
-
- return btf_nr_types(btf);
-}
-
-s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind)
-{
- const struct btf *base_btf = btf_base_btf(btf);
- const struct btf_type *t;
- const char *tname;
- s32 id, total;
-
- if (base_btf) {
- id = btf_find_by_name_kind(base_btf, name, kind);
- if (id > 0)
- return id;
- }
-
- total = btf_nr_types(btf);
- if (btf->named_start_id > 0 && name[0]) {
- id = btf_find_by_name_kind_bsearch(btf, name);
- for (; id < total; id++) {
- t = btf_type_by_id(btf, id);
- tname = btf_name_by_offset(btf, t->name_off);
- if (strcmp(tname, name) != 0)
- return -ENOENT;
- if (BTF_INFO_KIND(t->info) == kind)
- return id;
- }
- } else {
- for (id = btf_start_id(btf); id < total; id++) {
- t = btf_type_by_id(btf, id);
- if (BTF_INFO_KIND(t->info) != kind)
- continue;
- tname = btf_name_by_offset(btf, t->name_off);
- if (strcmp(tname, name) == 0)
- return id;
- }
- }
-
- return -ENOENT;
-}
-
s32 bpf_find_btf_id(const char *name, u32 kind, struct btf **btf_p)
{
struct btf *btf;
@@ -719,4964 +136,976 @@ s32 bpf_find_btf_id(const char *name, u32 kind, struct btf **btf_p)
return ret;
}
EXPORT_SYMBOL_GPL(bpf_find_btf_id);
-
-const struct btf_type *btf_type_skip_modifiers(const struct btf *btf,
- u32 id, u32 *res_id)
+static int btf_alloc_id(struct btf *btf)
{
- const struct btf_type *t = btf_type_by_id(btf, id);
+ int id;
- while (btf_type_is_modifier(t)) {
- id = t->type;
- t = btf_type_by_id(btf, t->type);
- }
+ idr_preload(GFP_KERNEL);
+ spin_lock_bh(&btf_idr_lock);
+ id = idr_alloc_cyclic(&btf_idr, btf, 1, INT_MAX, GFP_ATOMIC);
+ if (id > 0)
+ btf->id = id;
+ spin_unlock_bh(&btf_idr_lock);
+ idr_preload_end();
- if (res_id)
- *res_id = id;
+ if (WARN_ON_ONCE(!id))
+ return -ENOSPC;
- return t;
+ return id > 0 ? 0 : id;
}
-const struct btf_type *btf_type_resolve_ptr(const struct btf *btf,
- u32 id, u32 *res_id)
+static void btf_free_id(struct btf *btf)
{
- const struct btf_type *t;
-
- t = btf_type_skip_modifiers(btf, id, NULL);
- if (!btf_type_is_ptr(t))
- return NULL;
+ unsigned long flags;
- return btf_type_skip_modifiers(btf, t->type, res_id);
+ /*
+ * In map-in-map, calling map_delete_elem() on outer
+ * map will call bpf_map_put on the inner map.
+ * It will then eventually call btf_free_id()
+ * on the inner map. Some of the map_delete_elem()
+ * implementation may have irq disabled, so
+ * we need to use the _irqsave() version instead
+ * of the _bh() version.
+ */
+ spin_lock_irqsave(&btf_idr_lock, flags);
+ if (btf->id) {
+ idr_remove(&btf_idr, btf->id);
+ /*
+ * Clear the id here to make this function idempotent, since it will get
+ * called a couple of times for module BTFs: on module unload, and then
+ * the final btf_put(). btf_alloc_id() starts IDs with 1, so we can use
+ * 0 as sentinel value.
+ */
+ WRITE_ONCE(btf->id, 0);
+ }
+ spin_unlock_irqrestore(&btf_idr_lock, flags);
}
-const struct btf_type *btf_type_resolve_func_ptr(const struct btf *btf,
- u32 id, u32 *res_id)
+static void btf_free_kfunc_set_tab(struct btf *btf)
{
- const struct btf_type *ptype;
-
- ptype = btf_type_resolve_ptr(btf, id, res_id);
- if (ptype && btf_type_is_func_proto(ptype))
- return ptype;
+ struct btf_kfunc_set_tab *tab = btf->kfunc_set_tab;
+ int hook;
- return NULL;
+ if (!tab)
+ return;
+ for (hook = 0; hook < ARRAY_SIZE(tab->sets); hook++)
+ kfree(tab->sets[hook]);
+ kfree(tab);
+ btf->kfunc_set_tab = NULL;
}
-/* Types that act only as a source, not sink or intermediate
- * type when resolving.
- */
-static bool btf_type_is_resolve_source_only(const struct btf_type *t)
+static void btf_free_dtor_kfunc_tab(struct btf *btf)
{
- return btf_type_is_var(t) ||
- btf_type_is_decl_tag(t) ||
- btf_type_is_datasec(t);
+ struct btf_id_dtor_kfunc_tab *tab = btf->dtor_kfunc_tab;
+
+ if (!tab)
+ return;
+ kfree(tab);
+ btf->dtor_kfunc_tab = NULL;
}
-/* What types need to be resolved?
- *
- * btf_type_is_modifier() is an obvious one.
- *
- * btf_type_is_struct() because its member refers to
- * another type (through member->type).
- *
- * btf_type_is_var() because the variable refers to
- * another type. btf_type_is_datasec() holds multiple
- * btf_type_is_var() types that need resolving.
- *
- * btf_type_is_array() because its element (array->type)
- * refers to another type. Array can be thought of a
- * special case of struct while array just has the same
- * member-type repeated by array->nelems of times.
- */
-static bool btf_type_needs_resolve(const struct btf_type *t)
+static void btf_struct_metas_free(struct btf_struct_metas *tab)
{
- return btf_type_is_modifier(t) ||
- btf_type_is_ptr(t) ||
- btf_type_is_struct(t) ||
- btf_type_is_array(t) ||
- btf_type_is_var(t) ||
- btf_type_is_func(t) ||
- btf_type_is_decl_tag(t) ||
- btf_type_is_datasec(t);
+ int i;
+
+ if (!tab)
+ return;
+ for (i = 0; i < tab->cnt; i++)
+ btf_record_free(tab->types[i].record);
+ kfree(tab);
}
-/* t->size can be used */
-static bool btf_type_has_size(const struct btf_type *t)
+static void btf_free_struct_meta_tab(struct btf *btf)
{
- switch (BTF_INFO_KIND(t->info)) {
- case BTF_KIND_INT:
- case BTF_KIND_STRUCT:
- case BTF_KIND_UNION:
- case BTF_KIND_ENUM:
- case BTF_KIND_DATASEC:
- case BTF_KIND_FLOAT:
- case BTF_KIND_ENUM64:
- return true;
- }
+ struct btf_struct_metas *tab = btf->struct_meta_tab;
- return false;
+ btf_struct_metas_free(tab);
+ btf->struct_meta_tab = NULL;
}
-static const char *btf_int_encoding_str(u8 encoding)
+static void btf_free_struct_ops_tab(struct btf *btf)
{
- if (encoding == 0)
- return "(none)";
- else if (encoding == BTF_INT_SIGNED)
- return "SIGNED";
- else if (encoding == BTF_INT_CHAR)
- return "CHAR";
- else if (encoding == BTF_INT_BOOL)
- return "BOOL";
- else
- return "UNKN";
-}
+ struct btf_struct_ops_tab *tab = btf->struct_ops_tab;
+ u32 i;
-static u32 btf_type_int(const struct btf_type *t)
-{
- return *(u32 *)(t + 1);
-}
+ if (!tab)
+ return;
-static const struct btf_array *btf_type_array(const struct btf_type *t)
-{
- return (const struct btf_array *)(t + 1);
-}
+ for (i = 0; i < tab->cnt; i++)
+ bpf_struct_ops_desc_release(&tab->ops[i]);
-static const struct btf_enum *btf_type_enum(const struct btf_type *t)
-{
- return (const struct btf_enum *)(t + 1);
+ kfree(tab);
+ btf->struct_ops_tab = NULL;
}
-static const struct btf_var *btf_type_var(const struct btf_type *t)
+void btf_free_bpf_data(struct btf *btf)
{
- return (const struct btf_var *)(t + 1);
+ btf_free_struct_meta_tab(btf);
+ btf_free_dtor_kfunc_tab(btf);
+ btf_free_kfunc_set_tab(btf);
+ btf_free_struct_ops_tab(btf);
}
-static const struct btf_decl_tag *btf_type_decl_tag(const struct btf_type *t)
+static void btf_free_rcu(struct rcu_head *rcu)
{
- return (const struct btf_decl_tag *)(t + 1);
-}
+ struct btf *btf = container_of(rcu, struct btf, rcu);
-static const struct btf_enum64 *btf_type_enum64(const struct btf_type *t)
-{
- return (const struct btf_enum64 *)(t + 1);
+ btf_free(btf);
}
-static const struct btf_kind_operations *btf_type_ops(const struct btf_type *t)
+void btf_put_bpf(struct btf *btf)
{
- return kind_ops[BTF_INFO_KIND(t->info)];
+ btf_free_id(btf);
+ call_rcu(&btf->rcu, btf_free_rcu);
}
+enum {
+ BTF_FIELD_IGNORE = 0,
+ BTF_FIELD_FOUND = 1,
+};
-static bool btf_name_offset_valid(const struct btf *btf, u32 offset)
-{
- if (!BTF_STR_OFFSET_VALID(offset))
- return false;
-
- while (offset < btf->start_str_off)
- btf = btf->base_btf;
-
- offset -= btf->start_str_off;
- return offset < btf->hdr.str_len;
-}
+struct btf_field_info {
+ enum btf_field_type type;
+ u32 off;
+ union {
+ struct {
+ u32 type_id;
+ } kptr;
+ struct {
+ const char *node_name;
+ u32 value_btf_id;
+ } graph_root;
+ };
+};
-static bool __btf_name_char_ok(char c, bool first)
+static int btf_find_struct(const struct btf *btf, const struct btf_type *t,
+ u32 off, int sz, enum btf_field_type field_type,
+ struct btf_field_info *info)
{
- if ((first ? !isalpha(c) :
- !isalnum(c)) &&
- c != '_' &&
- c != '.')
- return false;
- return true;
+ if (!__btf_type_is_struct(t))
+ return BTF_FIELD_IGNORE;
+ if (t->size != sz)
+ return BTF_FIELD_IGNORE;
+ info->type = field_type;
+ info->off = off;
+ return BTF_FIELD_FOUND;
}
-const char *btf_str_by_offset(const struct btf *btf, u32 offset)
+static int btf_find_kptr(const struct btf *btf, const struct btf_type *t,
+ u32 off, int sz, struct btf_field_info *info, u32 field_mask)
{
- while (offset < btf->start_str_off)
- btf = btf->base_btf;
-
- offset -= btf->start_str_off;
- if (offset < btf->hdr.str_len)
- return &btf->strings[offset];
-
- return NULL;
-}
+ enum btf_field_type type;
+ const char *tag_value;
+ bool is_type_tag;
+ u32 res_id;
-static bool btf_name_valid_identifier(const struct btf *btf, u32 offset)
-{
- /* offset must be valid */
- const char *src = btf_str_by_offset(btf, offset);
- const char *src_limit;
+ /* Permit modifiers on the pointer itself */
+ if (btf_type_is_volatile(t))
+ t = btf_type_by_id(btf, t->type);
+ /* For PTR, sz is always == 8 */
+ if (!btf_type_is_ptr(t))
+ return BTF_FIELD_IGNORE;
+ t = btf_type_by_id(btf, t->type);
+ is_type_tag = btf_type_is_type_tag(t) && !btf_type_kflag(t);
+ if (!is_type_tag)
+ return BTF_FIELD_IGNORE;
+ /* Reject extra tags */
+ if (btf_type_is_type_tag(btf_type_by_id(btf, t->type)))
+ return -EINVAL;
+ tag_value = __btf_name_by_offset(btf, t->name_off);
+ if (!strcmp("kptr_untrusted", tag_value))
+ type = BPF_KPTR_UNREF;
+ else if (!strcmp("kptr", tag_value))
+ type = BPF_KPTR_REF;
+ else if (!strcmp("percpu_kptr", tag_value))
+ type = BPF_KPTR_PERCPU;
+ else if (!strcmp("uptr", tag_value))
+ type = BPF_UPTR;
+ else
+ return -EINVAL;
- if (!__btf_name_char_ok(*src, true))
- return false;
+ if (!(type & field_mask))
+ return BTF_FIELD_IGNORE;
- /* set a limit on identifier length */
- src_limit = src + KSYM_NAME_LEN;
- src++;
- while (*src && src < src_limit) {
- if (!__btf_name_char_ok(*src, false))
- return false;
- src++;
- }
+ /* Get the base type */
+ t = btf_type_skip_modifiers(btf, t->type, &res_id);
+ /* Only pointer to struct is allowed */
+ if (!__btf_type_is_struct(t))
+ return -EINVAL;
- return !*src;
+ info->type = type;
+ info->off = off;
+ info->kptr.type_id = res_id;
+ return BTF_FIELD_FOUND;
}
-/* Allow any printable character in DATASEC names */
-static bool btf_name_valid_section(const struct btf *btf, u32 offset)
+int btf_find_next_decl_tag(const struct btf *btf, const struct btf_type *pt,
+ int comp_idx, const char *tag_key, int last_id)
{
- /* offset must be valid */
- const char *src = btf_str_by_offset(btf, offset);
- const char *src_limit;
+ int len = strlen(tag_key);
+ int i, n;
- if (!*src)
- return false;
+ for (i = last_id + 1, n = btf_nr_types(btf); i < n; i++) {
+ const struct btf_type *t = btf_type_by_id(btf, i);
- /* set a limit on identifier length */
- src_limit = src + KSYM_NAME_LEN;
- while (*src && src < src_limit) {
- if (!isprint(*src))
- return false;
- src++;
+ if (!btf_type_is_decl_tag(t))
+ continue;
+ if (pt != btf_type_by_id(btf, t->type))
+ continue;
+ if (btf_type_decl_tag(t)->component_idx != comp_idx)
+ continue;
+ if (strncmp(__btf_name_by_offset(btf, t->name_off), tag_key, len))
+ continue;
+ return i;
}
-
- return !*src;
-}
-
-static const char *__btf_name_by_offset(const struct btf *btf, u32 offset)
-{
- const char *name;
-
- if (!offset)
- return "(anon)";
-
- name = btf_str_by_offset(btf, offset);
- return name ?: "(invalid-name-offset)";
+ return -ENOENT;
}
-const char *btf_name_by_offset(const struct btf *btf, u32 offset)
+const char *btf_find_decl_tag_value(const struct btf *btf, const struct btf_type *pt,
+ int comp_idx, const char *tag_key)
{
- return btf_str_by_offset(btf, offset);
-}
+ const char *value = NULL;
+ const struct btf_type *t;
+ int len, id;
-const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id)
-{
- while (type_id < btf->start_id)
- btf = btf->base_btf;
+ id = btf_find_next_decl_tag(btf, pt, comp_idx, tag_key,
+ btf_named_start_id(btf, false) - 1);
+ if (id < 0)
+ return ERR_PTR(id);
- type_id -= btf->start_id;
- if (type_id >= btf->nr_types)
- return NULL;
- return btf->types[type_id];
-}
-EXPORT_SYMBOL_GPL(btf_type_by_id);
-
-/*
- * Check that the type @t is a regular int. This means that @t is not
- * a bit field and it has the same size as either of u8/u16/u32/u64
- * or __int128. If @expected_size is not zero, then size of @t should
- * be the same. A caller should already have checked that the type @t
- * is an integer.
- */
-static bool __btf_type_int_is_regular(const struct btf_type *t, size_t expected_size)
-{
- u32 int_data = btf_type_int(t);
- u8 nr_bits = BTF_INT_BITS(int_data);
- u8 nr_bytes = BITS_ROUNDUP_BYTES(nr_bits);
-
- return BITS_PER_BYTE_MASKED(nr_bits) == 0 &&
- BTF_INT_OFFSET(int_data) == 0 &&
- (nr_bytes <= 16 && is_power_of_2(nr_bytes)) &&
- (expected_size == 0 || nr_bytes == expected_size);
-}
+ t = btf_type_by_id(btf, id);
+ len = strlen(tag_key);
+ value = __btf_name_by_offset(btf, t->name_off) + len;
-static bool btf_type_int_is_regular(const struct btf_type *t)
-{
- return __btf_type_int_is_regular(t, 0);
-}
+ /* Prevent duplicate entries for same type */
+ id = btf_find_next_decl_tag(btf, pt, comp_idx, tag_key, id);
+ if (id >= 0)
+ return ERR_PTR(-EEXIST);
-bool btf_type_is_i32(const struct btf_type *t)
-{
- return btf_type_is_int(t) && __btf_type_int_is_regular(t, 4);
+ return value;
}
-bool btf_type_is_i64(const struct btf_type *t)
+static int
+btf_find_graph_root(const struct btf *btf, const struct btf_type *pt,
+ const struct btf_type *t, int comp_idx, u32 off,
+ int sz, struct btf_field_info *info,
+ enum btf_field_type head_type)
{
- return btf_type_is_int(t) && __btf_type_int_is_regular(t, 8);
-}
+ const char *node_field_name;
+ const char *value_type;
+ s32 id;
-bool btf_type_is_primitive(const struct btf_type *t)
-{
- return (btf_type_is_int(t) && btf_type_int_is_regular(t)) ||
- btf_is_any_enum(t);
+ if (!__btf_type_is_struct(t))
+ return BTF_FIELD_IGNORE;
+ if (t->size != sz)
+ return BTF_FIELD_IGNORE;
+ value_type = btf_find_decl_tag_value(btf, pt, comp_idx, "contains:");
+ if (IS_ERR(value_type))
+ return -EINVAL;
+ node_field_name = strstr(value_type, ":");
+ if (!node_field_name)
+ return -EINVAL;
+ value_type = kstrndup(value_type, node_field_name - value_type,
+ GFP_KERNEL_ACCOUNT | __GFP_NOWARN);
+ if (!value_type)
+ return -ENOMEM;
+ id = btf_find_by_name_kind(btf, value_type, BTF_KIND_STRUCT);
+ kfree(value_type);
+ if (id < 0)
+ return id;
+ node_field_name++;
+ if (str_is_empty(node_field_name))
+ return -EINVAL;
+ info->type = head_type;
+ info->off = off;
+ info->graph_root.value_btf_id = id;
+ info->graph_root.node_name = node_field_name;
+ return BTF_FIELD_FOUND;
}
-/*
- * Check that given struct member is a regular int with expected
- * offset and size.
- */
-bool btf_member_is_reg_int(const struct btf *btf, const struct btf_type *s,
- const struct btf_member *m,
- u32 expected_offset, u32 expected_size)
+static int btf_get_field_type(const struct btf *btf, const struct btf_type *var_type,
+ u32 field_mask, u32 *seen_mask, int *align, int *sz)
{
- const struct btf_type *t;
- u32 id, int_data;
- u8 nr_bits;
+ const struct {
+ enum btf_field_type type;
+ const char *const name;
+ const bool is_unique;
+ } field_types[] = {
+ { BPF_SPIN_LOCK, "bpf_spin_lock", true },
+ { BPF_RES_SPIN_LOCK, "bpf_res_spin_lock", true },
+ { BPF_TIMER, "bpf_timer", true },
+ { BPF_WORKQUEUE, "bpf_wq", true },
+ { BPF_TASK_WORK, "bpf_task_work", true },
+ { BPF_LIST_HEAD, "bpf_list_head", false },
+ { BPF_LIST_NODE, "bpf_list_node", false },
+ { BPF_RB_ROOT, "bpf_rb_root", false },
+ { BPF_RB_NODE, "bpf_rb_node", false },
+ { BPF_REFCOUNT, "bpf_refcount", false },
+ };
+ int type = 0, i;
+ const char *name = __btf_name_by_offset(btf, var_type->name_off);
+ const char *field_type_name;
+ enum btf_field_type field_type;
+ bool is_unique;
- id = m->type;
- t = btf_type_id_size(btf, &id, NULL);
- if (!t || !btf_type_is_int(t))
- return false;
+ for (i = 0; i < ARRAY_SIZE(field_types); ++i) {
+ field_type = field_types[i].type;
+ field_type_name = field_types[i].name;
+ is_unique = field_types[i].is_unique;
+ if (!(field_mask & field_type) || strcmp(name, field_type_name))
+ continue;
+ if (is_unique) {
+ if (*seen_mask & field_type)
+ return -E2BIG;
+ *seen_mask |= field_type;
+ }
+ type = field_type;
+ goto end;
+ }
- int_data = btf_type_int(t);
- nr_bits = BTF_INT_BITS(int_data);
- if (btf_type_kflag(s)) {
- u32 bitfield_size = BTF_MEMBER_BITFIELD_SIZE(m->offset);
- u32 bit_offset = BTF_MEMBER_BIT_OFFSET(m->offset);
-
- /* if kflag set, int should be a regular int and
- * bit offset should be at byte boundary.
- */
- return !bitfield_size &&
- BITS_ROUNDUP_BYTES(bit_offset) == expected_offset &&
- BITS_ROUNDUP_BYTES(nr_bits) == expected_size;
- }
-
- if (BTF_INT_OFFSET(int_data) ||
- BITS_PER_BYTE_MASKED(m->offset) ||
- BITS_ROUNDUP_BYTES(m->offset) != expected_offset ||
- BITS_PER_BYTE_MASKED(nr_bits) ||
- BITS_ROUNDUP_BYTES(nr_bits) != expected_size)
- return false;
-
- return true;
-}
-
-/* Similar to btf_type_skip_modifiers() but does not skip typedefs. */
-static const struct btf_type *btf_type_skip_qualifiers(const struct btf *btf,
- u32 id)
-{
- const struct btf_type *t = btf_type_by_id(btf, id);
-
- while (btf_type_is_modifier(t) &&
- BTF_INFO_KIND(t->info) != BTF_KIND_TYPEDEF) {
- t = btf_type_by_id(btf, t->type);
+ /* Only return BPF_KPTR when all other types with matchable names fail */
+ if (field_mask & (BPF_KPTR | BPF_UPTR) && !__btf_type_is_struct(var_type)) {
+ type = BPF_KPTR_REF;
+ goto end;
}
-
- return t;
+ return 0;
+end:
+ *sz = btf_field_type_size(type);
+ *align = btf_field_type_align(type);
+ return type;
}
-#define BTF_SHOW_MAX_ITER 10
-
-#define BTF_KIND_BIT(kind) (1ULL << kind)
-
-/*
- * Populate show->state.name with type name information.
- * Format of type name is
+/* Repeat a number of fields for a specified number of times.
*
- * [.member_name = ] (type_name)
+ * Copy the fields starting from the first field and repeat them for
+ * repeat_cnt times. The fields are repeated by adding the offset of each
+ * field with
+ * (i + 1) * elem_size
+ * where i is the repeat index and elem_size is the size of an element.
*/
-static const char *btf_show_name(struct btf_show *show)
+static int btf_repeat_fields(struct btf_field_info *info, int info_cnt,
+ u32 field_cnt, u32 repeat_cnt, u32 elem_size)
{
- /* BTF_MAX_ITER array suffixes "[]" */
- const char *array_suffixes = "[][][][][][][][][][]";
- const char *array_suffix = &array_suffixes[strlen(array_suffixes)];
- /* BTF_MAX_ITER pointer suffixes "*" */
- const char *ptr_suffixes = "**********";
- const char *ptr_suffix = &ptr_suffixes[strlen(ptr_suffixes)];
- const char *name = NULL, *prefix = "", *parens = "";
- const struct btf_member *m = show->state.member;
- const struct btf_type *t;
- const struct btf_array *array;
- u32 id = show->state.type_id;
- const char *member = NULL;
- bool show_member = false;
- u64 kinds = 0;
- int i;
-
- show->state.name[0] = '\0';
-
- /*
- * Don't show type name if we're showing an array member;
- * in that case we show the array type so don't need to repeat
- * ourselves for each member.
- */
- if (show->state.array_member)
- return "";
-
- /* Retrieve member name, if any. */
- if (m) {
- member = btf_name_by_offset(show->btf, m->name_off);
- show_member = strlen(member) > 0;
- id = m->type;
- }
-
- /*
- * Start with type_id, as we have resolved the struct btf_type *
- * via btf_modifier_show() past the parent typedef to the child
- * struct, int etc it is defined as. In such cases, the type_id
- * still represents the starting type while the struct btf_type *
- * in our show->state points at the resolved type of the typedef.
- */
- t = btf_type_by_id(show->btf, id);
- if (!t)
- return "";
+ u32 i, j;
+ u32 cur;
- /*
- * The goal here is to build up the right number of pointer and
- * array suffixes while ensuring the type name for a typedef
- * is represented. Along the way we accumulate a list of
- * BTF kinds we have encountered, since these will inform later
- * display; for example, pointer types will not require an
- * opening "{" for struct, we will just display the pointer value.
- *
- * We also want to accumulate the right number of pointer or array
- * indices in the format string while iterating until we get to
- * the typedef/pointee/array member target type.
- *
- * We start by pointing at the end of pointer and array suffix
- * strings; as we accumulate pointers and arrays we move the pointer
- * or array string backwards so it will show the expected number of
- * '*' or '[]' for the type. BTF_SHOW_MAX_ITER of nesting of pointers
- * and/or arrays and typedefs are supported as a precaution.
- *
- * We also want to get typedef name while proceeding to resolve
- * type it points to so that we can add parentheses if it is a
- * "typedef struct" etc.
- */
- for (i = 0; i < BTF_SHOW_MAX_ITER; i++) {
-
- switch (BTF_INFO_KIND(t->info)) {
- case BTF_KIND_TYPEDEF:
- if (!name)
- name = btf_name_by_offset(show->btf,
- t->name_off);
- kinds |= BTF_KIND_BIT(BTF_KIND_TYPEDEF);
- id = t->type;
- break;
- case BTF_KIND_ARRAY:
- kinds |= BTF_KIND_BIT(BTF_KIND_ARRAY);
- parens = "[";
- if (!t)
- return "";
- array = btf_type_array(t);
- if (array_suffix > array_suffixes)
- array_suffix -= 2;
- id = array->type;
- break;
- case BTF_KIND_PTR:
- kinds |= BTF_KIND_BIT(BTF_KIND_PTR);
- if (ptr_suffix > ptr_suffixes)
- ptr_suffix -= 1;
- id = t->type;
+ /* Ensure not repeating fields that should not be repeated. */
+ for (i = 0; i < field_cnt; i++) {
+ switch (info[i].type) {
+ case BPF_KPTR_UNREF:
+ case BPF_KPTR_REF:
+ case BPF_KPTR_PERCPU:
+ case BPF_UPTR:
+ case BPF_LIST_HEAD:
+ case BPF_RB_ROOT:
break;
default:
- id = 0;
- break;
+ return -EINVAL;
}
- if (!id)
- break;
- t = btf_type_skip_qualifiers(show->btf, id);
- }
- /* We may not be able to represent this type; bail to be safe */
- if (i == BTF_SHOW_MAX_ITER)
- return "";
-
- if (!name)
- name = btf_name_by_offset(show->btf, t->name_off);
-
- switch (BTF_INFO_KIND(t->info)) {
- case BTF_KIND_STRUCT:
- case BTF_KIND_UNION:
- prefix = BTF_INFO_KIND(t->info) == BTF_KIND_STRUCT ?
- "struct" : "union";
- /* if it's an array of struct/union, parens is already set */
- if (!(kinds & (BTF_KIND_BIT(BTF_KIND_ARRAY))))
- parens = "{";
- break;
- case BTF_KIND_ENUM:
- case BTF_KIND_ENUM64:
- prefix = "enum";
- break;
- default:
- break;
}
- /* pointer does not require parens */
- if (kinds & BTF_KIND_BIT(BTF_KIND_PTR))
- parens = "";
- /* typedef does not require struct/union/enum prefix */
- if (kinds & BTF_KIND_BIT(BTF_KIND_TYPEDEF))
- prefix = "";
-
- if (!name)
- name = "";
-
- /* Even if we don't want type name info, we want parentheses etc */
- if (show->flags & BTF_SHOW_NONAME)
- snprintf(show->state.name, sizeof(show->state.name), "%s",
- parens);
- else
- snprintf(show->state.name, sizeof(show->state.name),
- "%s%s%s(%s%s%s%s%s%s)%s",
- /* first 3 strings comprise ".member = " */
- show_member ? "." : "",
- show_member ? member : "",
- show_member ? " = " : "",
- /* ...next is our prefix (struct, enum, etc) */
- prefix,
- strlen(prefix) > 0 && strlen(name) > 0 ? " " : "",
- /* ...this is the type name itself */
- name,
- /* ...suffixed by the appropriate '*', '[]' suffixes */
- strlen(ptr_suffix) > 0 ? " " : "", ptr_suffix,
- array_suffix, parens);
-
- return show->state.name;
-}
+ /* The type of struct size or variable size is u32,
+ * so the multiplication will not overflow.
+ */
+ if (field_cnt * (repeat_cnt + 1) > info_cnt)
+ return -E2BIG;
-static const char *__btf_show_indent(struct btf_show *show)
-{
- const char *indents = " ";
- const char *indent = &indents[strlen(indents)];
+ cur = field_cnt;
+ for (i = 0; i < repeat_cnt; i++) {
+ memcpy(&info[cur], &info[0], field_cnt * sizeof(info[0]));
+ for (j = 0; j < field_cnt; j++)
+ info[cur++].off += (i + 1) * elem_size;
+ }
- if ((indent - show->state.depth) >= indents)
- return indent - show->state.depth;
- return indents;
+ return 0;
}
-static const char *btf_show_indent(struct btf_show *show)
-{
- return show->flags & BTF_SHOW_COMPACT ? "" : __btf_show_indent(show);
-}
+static int btf_find_struct_field(const struct btf *btf,
+ const struct btf_type *t, u32 field_mask,
+ struct btf_field_info *info, int info_cnt,
+ u32 level);
-static const char *btf_show_newline(struct btf_show *show)
+/* Find special fields in the struct type of a field.
+ *
+ * This function is used to find fields of special types that is not a
+ * global variable or a direct field of a struct type. It also handles the
+ * repetition if it is the element type of an array.
+ */
+static int btf_find_nested_struct(const struct btf *btf, const struct btf_type *t,
+ u32 off, u32 nelems,
+ u32 field_mask, struct btf_field_info *info,
+ int info_cnt, u32 level)
{
- return show->flags & BTF_SHOW_COMPACT ? "" : "\n";
-}
+ int ret, err, i;
-static const char *btf_show_delim(struct btf_show *show)
-{
- if (show->state.depth == 0)
- return "";
+ level++;
+ if (level >= MAX_RESOLVE_DEPTH)
+ return -E2BIG;
- if ((show->flags & BTF_SHOW_COMPACT) && show->state.type &&
- BTF_INFO_KIND(show->state.type->info) == BTF_KIND_UNION)
- return "|";
+ ret = btf_find_struct_field(btf, t, field_mask, info, info_cnt, level);
- return ",";
-}
+ if (ret <= 0)
+ return ret;
-__printf(2, 3) static void btf_show(struct btf_show *show, const char *fmt, ...)
-{
- va_list args;
+ /* Shift the offsets of the nested struct fields to the offsets
+ * related to the container.
+ */
+ for (i = 0; i < ret; i++)
+ info[i].off += off;
- if (!show->state.depth_check) {
- va_start(args, fmt);
- show->showfn(show, fmt, args);
- va_end(args);
+ if (nelems > 1) {
+ err = btf_repeat_fields(info, info_cnt, ret, nelems - 1, t->size);
+ if (err == 0)
+ ret *= nelems;
+ else
+ ret = err;
}
-}
-
-/* Macros are used here as btf_show_type_value[s]() prepends and appends
- * format specifiers to the format specifier passed in; these do the work of
- * adding indentation, delimiters etc while the caller simply has to specify
- * the type value(s) in the format specifier + value(s).
- */
-#define btf_show_type_value(show, fmt, value) \
- do { \
- if ((value) != (__typeof__(value))0 || \
- (show->flags & BTF_SHOW_ZERO) || \
- show->state.depth == 0) { \
- btf_show(show, "%s%s" fmt "%s%s", \
- btf_show_indent(show), \
- btf_show_name(show), \
- value, btf_show_delim(show), \
- btf_show_newline(show)); \
- if (show->state.depth > show->state.depth_to_show) \
- show->state.depth_to_show = show->state.depth; \
- } \
- } while (0)
-
-#define btf_show_type_values(show, fmt, ...) \
- do { \
- btf_show(show, "%s%s" fmt "%s%s", btf_show_indent(show), \
- btf_show_name(show), \
- __VA_ARGS__, btf_show_delim(show), \
- btf_show_newline(show)); \
- if (show->state.depth > show->state.depth_to_show) \
- show->state.depth_to_show = show->state.depth; \
- } while (0)
-
-/* How much is left to copy to safe buffer after @data? */
-static int btf_show_obj_size_left(struct btf_show *show, void *data)
-{
- return show->obj.head + show->obj.size - data;
-}
-
-/* Is object pointed to by @data of @size already copied to our safe buffer? */
-static bool btf_show_obj_is_safe(struct btf_show *show, void *data, int size)
-{
- return data >= show->obj.data &&
- (data + size) < (show->obj.data + BTF_SHOW_OBJ_SAFE_SIZE);
-}
-/*
- * If object pointed to by @data of @size falls within our safe buffer, return
- * the equivalent pointer to the same safe data. Assumes
- * copy_from_kernel_nofault() has already happened and our safe buffer is
- * populated.
- */
-static void *__btf_show_obj_safe(struct btf_show *show, void *data, int size)
-{
- if (btf_show_obj_is_safe(show, data, size))
- return show->obj.safe + (data - show->obj.data);
- return NULL;
+ return ret;
}
-/*
- * Return a safe-to-access version of data pointed to by @data.
- * We do this by copying the relevant amount of information
- * to the struct btf_show obj.safe buffer using copy_from_kernel_nofault().
- *
- * If BTF_SHOW_UNSAFE is specified, just return data as-is; no
- * safe copy is needed.
- *
- * Otherwise we need to determine if we have the required amount
- * of data (determined by the @data pointer and the size of the
- * largest base type we can encounter (represented by
- * BTF_SHOW_OBJ_BASE_TYPE_SIZE). Having that much data ensures
- * that we will be able to print some of the current object,
- * and if more is needed a copy will be triggered.
- * Some objects such as structs will not fit into the buffer;
- * in such cases additional copies when we iterate over their
- * members may be needed.
- *
- * btf_show_obj_safe() is used to return a safe buffer for
- * btf_show_start_type(); this ensures that as we recurse into
- * nested types we always have safe data for the given type.
- * This approach is somewhat wasteful; it's possible for example
- * that when iterating over a large union we'll end up copying the
- * same data repeatedly, but the goal is safety not performance.
- * We use stack data as opposed to per-CPU buffers because the
- * iteration over a type can take some time, and preemption handling
- * would greatly complicate use of the safe buffer.
- */
-static void *btf_show_obj_safe(struct btf_show *show,
- const struct btf_type *t,
- void *data)
+static int btf_find_field_one(const struct btf *btf,
+ const struct btf_type *var,
+ const struct btf_type *var_type,
+ int var_idx,
+ u32 off, u32 expected_size,
+ u32 field_mask, u32 *seen_mask,
+ struct btf_field_info *info, int info_cnt,
+ u32 level)
{
- const struct btf_type *rt;
- int size_left, size;
- void *safe = NULL;
-
- if (show->flags & BTF_SHOW_UNSAFE)
- return data;
-
- rt = btf_resolve_size(show->btf, t, &size);
- if (IS_ERR(rt)) {
- show->state.status = PTR_ERR(rt);
- return NULL;
- }
+ int ret, align, sz, field_type;
+ struct btf_field_info tmp;
+ const struct btf_array *array;
+ u32 i, nelems = 1;
- /*
- * Is this toplevel object? If so, set total object size and
- * initialize pointers. Otherwise check if we still fall within
- * our safe object data.
+ /* Walk into array types to find the element type and the number of
+ * elements in the (flattened) array.
*/
- if (show->state.depth == 0) {
- show->obj.size = size;
- show->obj.head = data;
- } else {
- /*
- * If the size of the current object is > our remaining
- * safe buffer we _may_ need to do a new copy. However
- * consider the case of a nested struct; it's size pushes
- * us over the safe buffer limit, but showing any individual
- * struct members does not. In such cases, we don't need
- * to initiate a fresh copy yet; however we definitely need
- * at least BTF_SHOW_OBJ_BASE_TYPE_SIZE bytes left
- * in our buffer, regardless of the current object size.
- * The logic here is that as we resolve types we will
- * hit a base type at some point, and we need to be sure
- * the next chunk of data is safely available to display
- * that type info safely. We cannot rely on the size of
- * the current object here because it may be much larger
- * than our current buffer (e.g. task_struct is 8k).
- * All we want to do here is ensure that we can print the
- * next basic type, which we can if either
- * - the current type size is within the safe buffer; or
- * - at least BTF_SHOW_OBJ_BASE_TYPE_SIZE bytes are left in
- * the safe buffer.
- */
- safe = __btf_show_obj_safe(show, data,
- min(size,
- BTF_SHOW_OBJ_BASE_TYPE_SIZE));
+ for (i = 0; i < MAX_RESOLVE_DEPTH && btf_type_is_array(var_type); i++) {
+ array = btf_array(var_type);
+ nelems *= array->nelems;
+ var_type = btf_type_by_id(btf, array->type);
}
+ if (i == MAX_RESOLVE_DEPTH)
+ return -E2BIG;
+ if (nelems == 0)
+ return 0;
- /*
- * We need a new copy to our safe object, either because we haven't
- * yet copied and are initializing safe data, or because the data
- * we want falls outside the boundaries of the safe object.
- */
- if (!safe) {
- size_left = btf_show_obj_size_left(show, data);
- if (size_left > BTF_SHOW_OBJ_SAFE_SIZE)
- size_left = BTF_SHOW_OBJ_SAFE_SIZE;
- show->state.status = copy_from_kernel_nofault(show->obj.safe,
- data, size_left);
- if (!show->state.status) {
- show->obj.data = data;
- safe = show->obj.safe;
- }
+ field_type = btf_get_field_type(btf, var_type,
+ field_mask, seen_mask, &align, &sz);
+ /* Look into variables of struct types */
+ if (!field_type && __btf_type_is_struct(var_type)) {
+ sz = var_type->size;
+ if (expected_size && expected_size != sz * nelems)
+ return 0;
+ ret = btf_find_nested_struct(btf, var_type, off, nelems, field_mask,
+ &info[0], info_cnt, level);
+ return ret;
}
- return safe;
-}
+ if (field_type == 0)
+ return 0;
+ if (field_type < 0)
+ return field_type;
-/*
- * Set the type we are starting to show and return a safe data pointer
- * to be used for showing the associated data.
- */
-static void *btf_show_start_type(struct btf_show *show,
- const struct btf_type *t,
- u32 type_id, void *data)
-{
- show->state.type = t;
- show->state.type_id = type_id;
- show->state.name[0] = '\0';
+ if (expected_size && expected_size != sz * nelems)
+ return 0;
+ if (off % align)
+ return 0;
- return btf_show_obj_safe(show, t, data);
-}
+ switch (field_type) {
+ case BPF_SPIN_LOCK:
+ case BPF_RES_SPIN_LOCK:
+ case BPF_TIMER:
+ case BPF_WORKQUEUE:
+ case BPF_LIST_NODE:
+ case BPF_RB_NODE:
+ case BPF_REFCOUNT:
+ case BPF_TASK_WORK:
+ ret = btf_find_struct(btf, var_type, off, sz, field_type,
+ info_cnt ? &info[0] : &tmp);
+ if (ret < 0)
+ return ret;
+ break;
+ case BPF_KPTR_UNREF:
+ case BPF_KPTR_REF:
+ case BPF_KPTR_PERCPU:
+ case BPF_UPTR:
+ ret = btf_find_kptr(btf, var_type, off, sz,
+ info_cnt ? &info[0] : &tmp, field_mask);
+ if (ret < 0)
+ return ret;
+ break;
+ case BPF_LIST_HEAD:
+ case BPF_RB_ROOT:
+ ret = btf_find_graph_root(btf, var, var_type,
+ var_idx, off, sz,
+ info_cnt ? &info[0] : &tmp,
+ field_type);
+ if (ret < 0)
+ return ret;
+ break;
+ default:
+ return -EFAULT;
+ }
-static void btf_show_end_type(struct btf_show *show)
-{
- show->state.type = NULL;
- show->state.type_id = 0;
- show->state.name[0] = '\0';
+ if (ret == BTF_FIELD_IGNORE)
+ return 0;
+ if (!info_cnt)
+ return -E2BIG;
+ if (nelems > 1) {
+ ret = btf_repeat_fields(info, info_cnt, 1, nelems - 1, sz);
+ if (ret < 0)
+ return ret;
+ }
+ return nelems;
}
-static void *btf_show_start_aggr_type(struct btf_show *show,
- const struct btf_type *t,
- u32 type_id, void *data)
+static int btf_find_struct_field(const struct btf *btf,
+ const struct btf_type *t, u32 field_mask,
+ struct btf_field_info *info, int info_cnt,
+ u32 level)
{
- void *safe_data = btf_show_start_type(show, t, type_id, data);
-
- if (!safe_data)
- return safe_data;
+ int ret, idx = 0;
+ const struct btf_member *member;
+ u32 i, off, seen_mask = 0;
- btf_show(show, "%s%s%s", btf_show_indent(show),
- btf_show_name(show),
- btf_show_newline(show));
- show->state.depth++;
- return safe_data;
-}
+ for_each_member(i, t, member) {
+ const struct btf_type *member_type = btf_type_by_id(btf,
+ member->type);
-static void btf_show_end_aggr_type(struct btf_show *show,
- const char *suffix)
-{
- show->state.depth--;
- btf_show(show, "%s%s%s%s", btf_show_indent(show), suffix,
- btf_show_delim(show), btf_show_newline(show));
- btf_show_end_type(show);
-}
-
-static void btf_show_start_member(struct btf_show *show,
- const struct btf_member *m)
-{
- show->state.member = m;
-}
-
-static void btf_show_start_array_member(struct btf_show *show)
-{
- show->state.array_member = 1;
- btf_show_start_member(show, NULL);
-}
-
-static void btf_show_end_member(struct btf_show *show)
-{
- show->state.member = NULL;
-}
-
-static void btf_show_end_array_member(struct btf_show *show)
-{
- show->state.array_member = 0;
- btf_show_end_member(show);
-}
+ off = __btf_member_bit_offset(t, member);
+ if (off % 8)
+ /* valid C code cannot generate such BTF */
+ return -EINVAL;
+ off /= 8;
-static void *btf_show_start_array_type(struct btf_show *show,
- const struct btf_type *t,
- u32 type_id,
- u16 array_encoding,
- void *data)
-{
- show->state.array_encoding = array_encoding;
- show->state.array_terminated = 0;
- return btf_show_start_aggr_type(show, t, type_id, data);
+ ret = btf_find_field_one(btf, t, member_type, i,
+ off, 0,
+ field_mask, &seen_mask,
+ &info[idx], info_cnt - idx, level);
+ if (ret < 0)
+ return ret;
+ idx += ret;
+ }
+ return idx;
}
-static void btf_show_end_array_type(struct btf_show *show)
+static int btf_find_datasec_var(const struct btf *btf, const struct btf_type *t,
+ u32 field_mask, struct btf_field_info *info,
+ int info_cnt, u32 level)
{
- show->state.array_encoding = 0;
- show->state.array_terminated = 0;
- btf_show_end_aggr_type(show, "]");
-}
+ int ret, idx = 0;
+ const struct btf_var_secinfo *vsi;
+ u32 i, off, seen_mask = 0;
-static void *btf_show_start_struct_type(struct btf_show *show,
- const struct btf_type *t,
- u32 type_id,
- void *data)
-{
- return btf_show_start_aggr_type(show, t, type_id, data);
-}
+ for_each_vsi(i, t, vsi) {
+ const struct btf_type *var = btf_type_by_id(btf, vsi->type);
+ const struct btf_type *var_type = btf_type_by_id(btf, var->type);
-static void btf_show_end_struct_type(struct btf_show *show)
-{
- btf_show_end_aggr_type(show, "}");
+ off = vsi->offset;
+ ret = btf_find_field_one(btf, var, var_type, -1, off, vsi->size,
+ field_mask, &seen_mask,
+ &info[idx], info_cnt - idx,
+ level);
+ if (ret < 0)
+ return ret;
+ idx += ret;
+ }
+ return idx;
}
-__printf(2, 3) static void __btf_verifier_log(struct bpf_verifier_log *log,
- const char *fmt, ...)
+static int btf_find_field(const struct btf *btf, const struct btf_type *t,
+ u32 field_mask, struct btf_field_info *info,
+ int info_cnt)
{
- va_list args;
-
- va_start(args, fmt);
- bpf_verifier_vlog(log, fmt, args);
- va_end(args);
+ if (__btf_type_is_struct(t))
+ return btf_find_struct_field(btf, t, field_mask, info, info_cnt, 0);
+ else if (btf_type_is_datasec(t))
+ return btf_find_datasec_var(btf, t, field_mask, info, info_cnt, 0);
+ return -EINVAL;
}
-__printf(2, 3) static void btf_verifier_log(struct btf_verifier_env *env,
- const char *fmt, ...)
+/* Callers have to ensure the life cycle of btf if it is program BTF */
+static int btf_parse_kptr(const struct btf *btf, struct btf_field *field,
+ struct btf_field_info *info)
{
- struct bpf_verifier_log *log = &env->log;
- va_list args;
-
- if (!bpf_verifier_log_needed(log))
- return;
+ struct module *mod = NULL;
+ const struct btf_type *t;
+ /* If a matching btf type is found in kernel or module BTFs, kptr_ref
+ * is that BTF, otherwise it's program BTF
+ */
+ struct btf *kptr_btf;
+ int ret;
+ s32 id;
- va_start(args, fmt);
- bpf_verifier_vlog(log, fmt, args);
- va_end(args);
-}
+ /* Find type in map BTF, and use it to look up the matching type
+ * in vmlinux or module BTFs, by name and kind.
+ */
+ t = btf_type_by_id(btf, info->kptr.type_id);
+ id = bpf_find_btf_id(__btf_name_by_offset(btf, t->name_off), BTF_INFO_KIND(t->info),
+ &kptr_btf);
+ if (id == -ENOENT) {
+ /* btf_parse_kptr should only be called w/ btf = program BTF */
+ WARN_ON_ONCE(btf_is_kernel(btf));
-__printf(4, 5) static void __btf_verifier_log_type(struct btf_verifier_env *env,
- const struct btf_type *t,
- bool log_details,
- const char *fmt, ...)
-{
- struct bpf_verifier_log *log = &env->log;
- struct btf *btf = env->btf;
- va_list args;
+ /* Type exists only in program BTF. Assume that it's a MEM_ALLOC
+ * kptr allocated via bpf_obj_new
+ */
+ field->kptr.dtor = NULL;
+ id = info->kptr.type_id;
+ kptr_btf = (struct btf *)btf;
+ goto found_dtor;
+ }
+ if (id < 0)
+ return id;
- if (!bpf_verifier_log_needed(log))
- return;
+ /* Find and stash the function pointer for the destruction function that
+ * needs to be eventually invoked from the map free path.
+ */
+ if (info->type == BPF_KPTR_REF) {
+ const struct btf_type *dtor_func;
+ const char *dtor_func_name;
+ unsigned long addr;
+ s32 dtor_btf_id;
- if (log->level == BPF_LOG_KERNEL) {
- /* btf verifier prints all types it is processing via
- * btf_verifier_log_type(..., fmt = NULL).
- * Skip those prints for in-kernel BTF verification.
+ /* This call also serves as a whitelist of allowed objects that
+ * can be used as a referenced pointer and be stored in a map at
+ * the same time.
*/
- if (!fmt)
- return;
-
- /* Skip logging when loading module BTF with mismatches permitted */
- if (env->btf->base_btf && IS_ENABLED(CONFIG_MODULE_ALLOW_BTF_MISMATCH))
- return;
- }
+ dtor_btf_id = btf_find_dtor_kfunc(kptr_btf, id);
+ if (dtor_btf_id < 0) {
+ ret = dtor_btf_id;
+ goto end_btf;
+ }
- __btf_verifier_log(log, "[%u] %s %s%s",
- env->log_type_id,
- btf_type_str(t),
- __btf_name_by_offset(btf, t->name_off),
- log_details ? " " : "");
+ dtor_func = btf_type_by_id(kptr_btf, dtor_btf_id);
+ if (!dtor_func) {
+ ret = -ENOENT;
+ goto end_btf;
+ }
- if (log_details)
- btf_type_ops(t)->log_details(env, t);
+ if (btf_is_module(kptr_btf)) {
+ mod = btf_try_get_module(kptr_btf);
+ if (!mod) {
+ ret = -ENXIO;
+ goto end_btf;
+ }
+ }
- if (fmt && *fmt) {
- __btf_verifier_log(log, " ");
- va_start(args, fmt);
- bpf_verifier_vlog(log, fmt, args);
- va_end(args);
+ /* We already verified dtor_func to be btf_type_is_func
+ * in register_btf_id_dtor_kfuncs.
+ */
+ dtor_func_name = __btf_name_by_offset(kptr_btf, dtor_func->name_off);
+ addr = kallsyms_lookup_name(dtor_func_name);
+ if (!addr) {
+ ret = -EINVAL;
+ goto end_mod;
+ }
+ field->kptr.dtor = (void *)addr;
}
- __btf_verifier_log(log, "\n");
+found_dtor:
+ field->kptr.btf_id = id;
+ field->kptr.btf = kptr_btf;
+ field->kptr.module = mod;
+ return 0;
+end_mod:
+ module_put(mod);
+end_btf:
+ btf_put(kptr_btf);
+ return ret;
}
-#define btf_verifier_log_type(env, t, ...) \
- __btf_verifier_log_type((env), (t), true, __VA_ARGS__)
-#define btf_verifier_log_basic(env, t, ...) \
- __btf_verifier_log_type((env), (t), false, __VA_ARGS__)
-
-__printf(4, 5)
-static void btf_verifier_log_member(struct btf_verifier_env *env,
- const struct btf_type *struct_type,
- const struct btf_member *member,
- const char *fmt, ...)
+static int btf_parse_graph_root(const struct btf *btf,
+ struct btf_field *field,
+ struct btf_field_info *info,
+ const char *node_type_name,
+ size_t node_type_align)
{
- struct bpf_verifier_log *log = &env->log;
- struct btf *btf = env->btf;
- va_list args;
-
- if (!bpf_verifier_log_needed(log))
- return;
-
- if (log->level == BPF_LOG_KERNEL) {
- if (!fmt)
- return;
-
- /* Skip logging when loading module BTF with mismatches permitted */
- if (env->btf->base_btf && IS_ENABLED(CONFIG_MODULE_ALLOW_BTF_MISMATCH))
- return;
- }
+ const struct btf_type *t, *n = NULL;
+ const struct btf_member *member;
+ u32 offset;
+ int i;
- /* The CHECK_META phase already did a btf dump.
- *
- * If member is logged again, it must hit an error in
- * parsing this member. It is useful to print out which
- * struct this member belongs to.
+ t = btf_type_by_id(btf, info->graph_root.value_btf_id);
+ /* We've already checked that value_btf_id is a struct type. We
+ * just need to figure out the offset of the list_node, and
+ * verify its type.
*/
- if (env->phase != CHECK_META)
- btf_verifier_log_type(env, struct_type, NULL);
-
- if (btf_type_kflag(struct_type))
- __btf_verifier_log(log,
- "\t%s type_id=%u bitfield_size=%u bits_offset=%u",
- __btf_name_by_offset(btf, member->name_off),
- member->type,
- BTF_MEMBER_BITFIELD_SIZE(member->offset),
- BTF_MEMBER_BIT_OFFSET(member->offset));
- else
- __btf_verifier_log(log, "\t%s type_id=%u bits_offset=%u",
- __btf_name_by_offset(btf, member->name_off),
- member->type, member->offset);
+ for_each_member(i, t, member) {
+ if (strcmp(info->graph_root.node_name,
+ __btf_name_by_offset(btf, member->name_off)))
+ continue;
+ /* Invalid BTF, two members with same name */
+ if (n)
+ return -EINVAL;
+ n = btf_type_by_id(btf, member->type);
+ if (!__btf_type_is_struct(n))
+ return -EINVAL;
+ if (strcmp(node_type_name, __btf_name_by_offset(btf, n->name_off)))
+ return -EINVAL;
+ offset = __btf_member_bit_offset(n, member);
+ if (offset % 8)
+ return -EINVAL;
+ offset /= 8;
+ if (offset % node_type_align)
+ return -EINVAL;
- if (fmt && *fmt) {
- __btf_verifier_log(log, " ");
- va_start(args, fmt);
- bpf_verifier_vlog(log, fmt, args);
- va_end(args);
+ field->graph_root.btf = (struct btf *)btf;
+ field->graph_root.value_btf_id = info->graph_root.value_btf_id;
+ field->graph_root.node_offset = offset;
}
-
- __btf_verifier_log(log, "\n");
+ if (!n)
+ return -ENOENT;
+ return 0;
}
-__printf(4, 5)
-static void btf_verifier_log_vsi(struct btf_verifier_env *env,
- const struct btf_type *datasec_type,
- const struct btf_var_secinfo *vsi,
- const char *fmt, ...)
+static int btf_parse_list_head(const struct btf *btf, struct btf_field *field,
+ struct btf_field_info *info)
{
- struct bpf_verifier_log *log = &env->log;
- va_list args;
-
- if (!bpf_verifier_log_needed(log))
- return;
- if (log->level == BPF_LOG_KERNEL && !fmt)
- return;
- if (env->phase != CHECK_META)
- btf_verifier_log_type(env, datasec_type, NULL);
-
- __btf_verifier_log(log, "\t type_id=%u offset=%u size=%u",
- vsi->type, vsi->offset, vsi->size);
- if (fmt && *fmt) {
- __btf_verifier_log(log, " ");
- va_start(args, fmt);
- bpf_verifier_vlog(log, fmt, args);
- va_end(args);
- }
-
- __btf_verifier_log(log, "\n");
+ return btf_parse_graph_root(btf, field, info, "bpf_list_node",
+ __alignof__(struct bpf_list_node));
}
-static void btf_verifier_log_hdr(struct btf_verifier_env *env,
- u32 btf_data_size)
+static int btf_parse_rb_root(const struct btf *btf, struct btf_field *field,
+ struct btf_field_info *info)
{
- struct bpf_verifier_log *log = &env->log;
- const struct btf *btf = env->btf;
- const struct btf_header *hdr;
-
- if (!bpf_verifier_log_needed(log))
- return;
-
- if (log->level == BPF_LOG_KERNEL)
- return;
- hdr = &btf->hdr;
- __btf_verifier_log(log, "magic: 0x%x\n", hdr->magic);
- __btf_verifier_log(log, "version: %u\n", hdr->version);
- __btf_verifier_log(log, "flags: 0x%x\n", hdr->flags);
- __btf_verifier_log(log, "hdr_len: %u\n", hdr->hdr_len);
- __btf_verifier_log(log, "type_off: %u\n", hdr->type_off);
- __btf_verifier_log(log, "type_len: %u\n", hdr->type_len);
- __btf_verifier_log(log, "str_off: %u\n", hdr->str_off);
- __btf_verifier_log(log, "str_len: %u\n", hdr->str_len);
- __btf_verifier_log(log, "btf_total_size: %u\n", btf_data_size);
+ return btf_parse_graph_root(btf, field, info, "bpf_rb_node",
+ __alignof__(struct bpf_rb_node));
}
-static int btf_add_type(struct btf_verifier_env *env, struct btf_type *t)
+static int btf_field_cmp(const void *_a, const void *_b, const void *priv)
{
- struct btf *btf = env->btf;
-
- if (btf->types_size == btf->nr_types) {
- /* Expand 'types' array */
-
- struct btf_type **new_types;
- u32 expand_by, new_size;
-
- if (btf->start_id + btf->types_size == BTF_MAX_TYPE) {
- btf_verifier_log(env, "Exceeded max num of types");
- return -E2BIG;
- }
-
- expand_by = max_t(u32, btf->types_size >> 2, 16);
- new_size = min_t(u32, BTF_MAX_TYPE,
- btf->types_size + expand_by);
-
- new_types = kvzalloc_objs(*new_types, new_size,
- GFP_KERNEL | __GFP_NOWARN);
- if (!new_types)
- return -ENOMEM;
-
- if (btf->nr_types == 0) {
- if (!btf->base_btf) {
- /* lazily init VOID type */
- new_types[0] = &btf_void;
- btf->nr_types++;
- }
- } else {
- memcpy(new_types, btf->types,
- sizeof(*btf->types) * btf->nr_types);
- }
-
- kvfree(btf->types);
- btf->types = new_types;
- btf->types_size = new_size;
- }
-
- btf->types[btf->nr_types++] = t;
+ const struct btf_field *a = (const struct btf_field *)_a;
+ const struct btf_field *b = (const struct btf_field *)_b;
+ if (a->offset < b->offset)
+ return -1;
+ else if (a->offset > b->offset)
+ return 1;
return 0;
}
-static int btf_alloc_id(struct btf *btf)
+struct btf_record *btf_parse_fields(const struct btf *btf, const struct btf_type *t,
+ u32 field_mask, u32 value_size)
{
- int id;
+ struct btf_field_info info_arr[BTF_FIELDS_MAX];
+ u32 next_off = 0, field_type_size;
+ struct btf_record *rec;
+ int ret, i, cnt;
- idr_preload(GFP_KERNEL);
- spin_lock_bh(&btf_idr_lock);
- id = idr_alloc_cyclic(&btf_idr, btf, 1, INT_MAX, GFP_ATOMIC);
- if (id > 0)
- btf->id = id;
- spin_unlock_bh(&btf_idr_lock);
- idr_preload_end();
+ ret = btf_find_field(btf, t, field_mask, info_arr, ARRAY_SIZE(info_arr));
+ if (ret < 0)
+ return ERR_PTR(ret);
+ if (!ret)
+ return NULL;
- if (WARN_ON_ONCE(!id))
- return -ENOSPC;
-
- return id > 0 ? 0 : id;
-}
-
-static void btf_free_id(struct btf *btf)
-{
- unsigned long flags;
-
- /*
- * In map-in-map, calling map_delete_elem() on outer
- * map will call bpf_map_put on the inner map.
- * It will then eventually call btf_free_id()
- * on the inner map. Some of the map_delete_elem()
- * implementation may have irq disabled, so
- * we need to use the _irqsave() version instead
- * of the _bh() version.
- */
- spin_lock_irqsave(&btf_idr_lock, flags);
- if (btf->id) {
- idr_remove(&btf_idr, btf->id);
- /*
- * Clear the id here to make this function idempotent, since it will get
- * called a couple of times for module BTFs: on module unload, and then
- * the final btf_put(). btf_alloc_id() starts IDs with 1, so we can use
- * 0 as sentinel value.
- */
- WRITE_ONCE(btf->id, 0);
- }
- spin_unlock_irqrestore(&btf_idr_lock, flags);
-}
-
-static void btf_free_kfunc_set_tab(struct btf *btf)
-{
- struct btf_kfunc_set_tab *tab = btf->kfunc_set_tab;
- int hook;
-
- if (!tab)
- return;
- for (hook = 0; hook < ARRAY_SIZE(tab->sets); hook++)
- kfree(tab->sets[hook]);
- kfree(tab);
- btf->kfunc_set_tab = NULL;
-}
-
-static void btf_free_dtor_kfunc_tab(struct btf *btf)
-{
- struct btf_id_dtor_kfunc_tab *tab = btf->dtor_kfunc_tab;
-
- if (!tab)
- return;
- kfree(tab);
- btf->dtor_kfunc_tab = NULL;
-}
-
-static void btf_struct_metas_free(struct btf_struct_metas *tab)
-{
- int i;
-
- if (!tab)
- return;
- for (i = 0; i < tab->cnt; i++)
- btf_record_free(tab->types[i].record);
- kfree(tab);
-}
-
-static void btf_free_struct_meta_tab(struct btf *btf)
-{
- struct btf_struct_metas *tab = btf->struct_meta_tab;
-
- btf_struct_metas_free(tab);
- btf->struct_meta_tab = NULL;
-}
-
-static void btf_free_struct_ops_tab(struct btf *btf)
-{
- struct btf_struct_ops_tab *tab = btf->struct_ops_tab;
- u32 i;
-
- if (!tab)
- return;
-
- for (i = 0; i < tab->cnt; i++)
- bpf_struct_ops_desc_release(&tab->ops[i]);
-
- kfree(tab);
- btf->struct_ops_tab = NULL;
-}
-
-static void btf_free(struct btf *btf)
-{
- btf_free_struct_meta_tab(btf);
- btf_free_dtor_kfunc_tab(btf);
- btf_free_kfunc_set_tab(btf);
- btf_free_struct_ops_tab(btf);
- kvfree(btf->types);
- kvfree(btf->resolved_sizes);
- kvfree(btf->resolved_ids);
- /* vmlinux does not allocate btf->data, it simply points it at
- * __start_BTF.
+ cnt = ret;
+ /* This needs to be kzalloc to zero out padding and unused fields, see
+ * comment in btf_record_equal.
*/
- if (!btf_is_vmlinux(btf))
- kvfree(btf->data);
- kvfree(btf->base_id_map);
- kfree(btf);
-}
-
-static void btf_free_rcu(struct rcu_head *rcu)
-{
- struct btf *btf = container_of(rcu, struct btf, rcu);
-
- btf_free(btf);
-}
-
-const char *btf_get_name(const struct btf *btf)
-{
- return btf->name;
-}
-
-void btf_get(struct btf *btf)
-{
- refcount_inc(&btf->refcnt);
-}
-
-void btf_put(struct btf *btf)
-{
- if (btf && refcount_dec_and_test(&btf->refcnt)) {
- btf_free_id(btf);
- call_rcu(&btf->rcu, btf_free_rcu);
- }
-}
-
-struct btf *btf_base_btf(const struct btf *btf)
-{
- return btf->base_btf;
-}
-
-const struct btf_header *btf_header(const struct btf *btf)
-{
- return &btf->hdr;
-}
-
-void btf_set_base_btf(struct btf *btf, const struct btf *base_btf)
-{
- btf->base_btf = (struct btf *)base_btf;
- btf->start_id = btf_nr_types(base_btf);
- btf->start_str_off = base_btf->hdr.str_len;
-}
-
-static int env_resolve_init(struct btf_verifier_env *env)
-{
- struct btf *btf = env->btf;
- u32 nr_types = btf->nr_types;
- u32 *resolved_sizes = NULL;
- u32 *resolved_ids = NULL;
- u8 *visit_states = NULL;
-
- resolved_sizes = kvcalloc(nr_types, sizeof(*resolved_sizes),
- GFP_KERNEL | __GFP_NOWARN);
- if (!resolved_sizes)
- goto nomem;
-
- resolved_ids = kvcalloc(nr_types, sizeof(*resolved_ids),
- GFP_KERNEL | __GFP_NOWARN);
- if (!resolved_ids)
- goto nomem;
-
- visit_states = kvcalloc(nr_types, sizeof(*visit_states),
- GFP_KERNEL | __GFP_NOWARN);
- if (!visit_states)
- goto nomem;
-
- btf->resolved_sizes = resolved_sizes;
- btf->resolved_ids = resolved_ids;
- env->visit_states = visit_states;
-
- return 0;
-
-nomem:
- kvfree(resolved_sizes);
- kvfree(resolved_ids);
- kvfree(visit_states);
- return -ENOMEM;
-}
-
-static void btf_verifier_env_free(struct btf_verifier_env *env)
-{
- kvfree(env->visit_states);
- kfree(env);
-}
-
-static bool env_type_is_resolve_sink(const struct btf_verifier_env *env,
- const struct btf_type *next_type)
-{
- switch (env->resolve_mode) {
- case RESOLVE_TBD:
- /* int, enum or void is a sink */
- return !btf_type_needs_resolve(next_type);
- case RESOLVE_PTR:
- /* int, enum, void, struct, array, func or func_proto is a sink
- * for ptr
- */
- return !btf_type_is_modifier(next_type) &&
- !btf_type_is_ptr(next_type);
- case RESOLVE_STRUCT_OR_ARRAY:
- /* int, enum, void, ptr, func or func_proto is a sink
- * for struct and array
- */
- return !btf_type_is_modifier(next_type) &&
- !btf_type_is_array(next_type) &&
- !btf_type_is_struct(next_type);
- default:
- BUG();
- }
-}
-
-static bool env_type_is_resolved(const struct btf_verifier_env *env,
- u32 type_id)
-{
- /* base BTF types should be resolved by now */
- if (type_id < env->btf->start_id)
- return true;
-
- return env->visit_states[type_id - env->btf->start_id] == RESOLVED;
-}
-
-static int env_stack_push(struct btf_verifier_env *env,
- const struct btf_type *t, u32 type_id)
-{
- const struct btf *btf = env->btf;
- struct resolve_vertex *v;
-
- if (env->top_stack == MAX_RESOLVE_DEPTH)
- return -E2BIG;
-
- if (type_id < btf->start_id
- || env->visit_states[type_id - btf->start_id] != NOT_VISITED)
- return -EEXIST;
-
- env->visit_states[type_id - btf->start_id] = VISITED;
-
- v = &env->stack[env->top_stack++];
- v->t = t;
- v->type_id = type_id;
- v->next_member = 0;
-
- if (env->resolve_mode == RESOLVE_TBD) {
- if (btf_type_is_ptr(t))
- env->resolve_mode = RESOLVE_PTR;
- else if (btf_type_is_struct(t) || btf_type_is_array(t))
- env->resolve_mode = RESOLVE_STRUCT_OR_ARRAY;
- }
-
- return 0;
-}
-
-static void env_stack_set_next_member(struct btf_verifier_env *env,
- u16 next_member)
-{
- env->stack[env->top_stack - 1].next_member = next_member;
-}
-
-static void env_stack_pop_resolved(struct btf_verifier_env *env,
- u32 resolved_type_id,
- u32 resolved_size)
-{
- u32 type_id = env->stack[--(env->top_stack)].type_id;
- struct btf *btf = env->btf;
+ rec = kzalloc_flex(*rec, fields, cnt, GFP_KERNEL_ACCOUNT | __GFP_NOWARN);
+ if (!rec)
+ return ERR_PTR(-ENOMEM);
- type_id -= btf->start_id; /* adjust to local type id */
- btf->resolved_sizes[type_id] = resolved_size;
- btf->resolved_ids[type_id] = resolved_type_id;
- env->visit_states[type_id] = RESOLVED;
-}
+ rec->spin_lock_off = -EINVAL;
+ rec->res_spin_lock_off = -EINVAL;
+ rec->timer_off = -EINVAL;
+ rec->wq_off = -EINVAL;
+ rec->refcount_off = -EINVAL;
+ rec->task_work_off = -EINVAL;
+ for (i = 0; i < cnt; i++) {
+ field_type_size = btf_field_type_size(info_arr[i].type);
+ if (info_arr[i].off + field_type_size > value_size) {
+ WARN_ONCE(1, "verifier bug off %d size %d", info_arr[i].off, value_size);
+ ret = -EFAULT;
+ goto end;
+ }
+ if (info_arr[i].off < next_off) {
+ ret = -EEXIST;
+ goto end;
+ }
+ next_off = info_arr[i].off + field_type_size;
-static const struct resolve_vertex *env_stack_peak(struct btf_verifier_env *env)
-{
- return env->top_stack ? &env->stack[env->top_stack - 1] : NULL;
-}
+ rec->field_mask |= info_arr[i].type;
+ rec->fields[i].offset = info_arr[i].off;
+ rec->fields[i].type = info_arr[i].type;
+ rec->fields[i].size = field_type_size;
-/* Resolve the size of a passed-in "type"
- *
- * type: is an array (e.g. u32 array[x][y])
- * return type: type "u32[x][y]", i.e. BTF_KIND_ARRAY,
- * *type_size: (x * y * sizeof(u32)). Hence, *type_size always
- * corresponds to the return type.
- * *elem_type: u32
- * *elem_id: id of u32
- * *total_nelems: (x * y). Hence, individual elem size is
- * (*type_size / *total_nelems)
- * *type_id: id of type if it's changed within the function, 0 if not
- *
- * type: is not an array (e.g. const struct X)
- * return type: type "struct X"
- * *type_size: sizeof(struct X)
- * *elem_type: same as return type ("struct X")
- * *elem_id: 0
- * *total_nelems: 1
- * *type_id: id of type if it's changed within the function, 0 if not
- */
-static const struct btf_type *
-__btf_resolve_size(const struct btf *btf, const struct btf_type *type,
- u32 *type_size, const struct btf_type **elem_type,
- u32 *elem_id, u32 *total_nelems, u32 *type_id)
-{
- const struct btf_type *array_type = NULL;
- const struct btf_array *array = NULL;
- u32 i, size, nelems = 1, id = 0;
-
- for (i = 0; i < MAX_RESOLVE_DEPTH; i++) {
- switch (BTF_INFO_KIND(type->info)) {
- /* type->size can be used */
- case BTF_KIND_INT:
- case BTF_KIND_STRUCT:
- case BTF_KIND_UNION:
- case BTF_KIND_ENUM:
- case BTF_KIND_FLOAT:
- case BTF_KIND_ENUM64:
- size = type->size;
- goto resolved;
-
- case BTF_KIND_PTR:
- size = sizeof(void *);
- goto resolved;
-
- /* Modifiers */
- case BTF_KIND_TYPEDEF:
- case BTF_KIND_VOLATILE:
- case BTF_KIND_CONST:
- case BTF_KIND_RESTRICT:
- case BTF_KIND_TYPE_TAG:
- id = type->type;
- type = btf_type_by_id(btf, type->type);
+ switch (info_arr[i].type) {
+ case BPF_SPIN_LOCK:
+ WARN_ON_ONCE(rec->spin_lock_off >= 0);
+ /* Cache offset for faster lookup at runtime */
+ rec->spin_lock_off = rec->fields[i].offset;
break;
-
- case BTF_KIND_ARRAY:
- if (!array_type)
- array_type = type;
- array = btf_type_array(type);
- if (nelems && array->nelems > U32_MAX / nelems)
- return ERR_PTR(-EINVAL);
- nelems *= array->nelems;
- type = btf_type_by_id(btf, array->type);
+ case BPF_RES_SPIN_LOCK:
+ WARN_ON_ONCE(rec->spin_lock_off >= 0);
+ /* Cache offset for faster lookup at runtime */
+ rec->res_spin_lock_off = rec->fields[i].offset;
+ break;
+ case BPF_TIMER:
+ WARN_ON_ONCE(rec->timer_off >= 0);
+ /* Cache offset for faster lookup at runtime */
+ rec->timer_off = rec->fields[i].offset;
+ break;
+ case BPF_WORKQUEUE:
+ WARN_ON_ONCE(rec->wq_off >= 0);
+ /* Cache offset for faster lookup at runtime */
+ rec->wq_off = rec->fields[i].offset;
+ break;
+ case BPF_TASK_WORK:
+ WARN_ON_ONCE(rec->task_work_off >= 0);
+ rec->task_work_off = rec->fields[i].offset;
+ break;
+ case BPF_REFCOUNT:
+ WARN_ON_ONCE(rec->refcount_off >= 0);
+ /* Cache offset for faster lookup at runtime */
+ rec->refcount_off = rec->fields[i].offset;
+ break;
+ case BPF_KPTR_UNREF:
+ case BPF_KPTR_REF:
+ case BPF_KPTR_PERCPU:
+ case BPF_UPTR:
+ ret = btf_parse_kptr(btf, &rec->fields[i], &info_arr[i]);
+ if (ret < 0)
+ goto end;
+ break;
+ case BPF_LIST_HEAD:
+ ret = btf_parse_list_head(btf, &rec->fields[i], &info_arr[i]);
+ if (ret < 0)
+ goto end;
+ break;
+ case BPF_RB_ROOT:
+ ret = btf_parse_rb_root(btf, &rec->fields[i], &info_arr[i]);
+ if (ret < 0)
+ goto end;
+ break;
+ case BPF_LIST_NODE:
+ case BPF_RB_NODE:
break;
-
- /* type without size */
default:
- return ERR_PTR(-EINVAL);
+ ret = -EFAULT;
+ goto end;
}
+ rec->cnt++;
}
- return ERR_PTR(-EINVAL);
-
-resolved:
- if (nelems && size > U32_MAX / nelems)
- return ERR_PTR(-EINVAL);
-
- *type_size = nelems * size;
- if (total_nelems)
- *total_nelems = nelems;
- if (elem_type)
- *elem_type = type;
- if (elem_id)
- *elem_id = array ? array->type : 0;
- if (type_id && id)
- *type_id = id;
-
- return array_type ? : type;
-}
-
-const struct btf_type *
-btf_resolve_size(const struct btf *btf, const struct btf_type *type,
- u32 *type_size)
-{
- return __btf_resolve_size(btf, type, type_size, NULL, NULL, NULL, NULL);
-}
-
-static u32 btf_resolved_type_id(const struct btf *btf, u32 type_id)
-{
- while (type_id < btf->start_id)
- btf = btf->base_btf;
-
- return btf->resolved_ids[type_id - btf->start_id];
-}
-
-/* The input param "type_id" must point to a needs_resolve type */
-static const struct btf_type *btf_type_id_resolve(const struct btf *btf,
- u32 *type_id)
-{
- *type_id = btf_resolved_type_id(btf, *type_id);
- return btf_type_by_id(btf, *type_id);
-}
-
-static u32 btf_resolved_type_size(const struct btf *btf, u32 type_id)
-{
- while (type_id < btf->start_id)
- btf = btf->base_btf;
-
- return btf->resolved_sizes[type_id - btf->start_id];
-}
-
-const struct btf_type *btf_type_id_size(const struct btf *btf,
- u32 *type_id, u32 *ret_size)
-{
- const struct btf_type *size_type;
- u32 size_type_id = *type_id;
- u32 size = 0;
-
- size_type = btf_type_by_id(btf, size_type_id);
- if (btf_type_nosize_or_null(size_type))
- return NULL;
-
- if (btf_type_has_size(size_type)) {
- size = size_type->size;
- } else if (btf_type_is_array(size_type)) {
- size = btf_resolved_type_size(btf, size_type_id);
- } else if (btf_type_is_ptr(size_type)) {
- size = sizeof(void *);
- } else {
- if (WARN_ON_ONCE(!btf_type_is_modifier(size_type) &&
- !btf_type_is_var(size_type)))
- return NULL;
-
- size_type_id = btf_resolved_type_id(btf, size_type_id);
- size_type = btf_type_by_id(btf, size_type_id);
- if (btf_type_nosize_or_null(size_type))
- return NULL;
- else if (btf_type_has_size(size_type))
- size = size_type->size;
- else if (btf_type_is_array(size_type))
- size = btf_resolved_type_size(btf, size_type_id);
- else if (btf_type_is_ptr(size_type))
- size = sizeof(void *);
- else
- return NULL;
- }
-
- *type_id = size_type_id;
- if (ret_size)
- *ret_size = size;
-
- return size_type;
-}
-
-static int btf_df_check_member(struct btf_verifier_env *env,
- const struct btf_type *struct_type,
- const struct btf_member *member,
- const struct btf_type *member_type)
-{
- btf_verifier_log_basic(env, struct_type,
- "Unsupported check_member");
- return -EINVAL;
-}
-
-static int btf_df_check_kflag_member(struct btf_verifier_env *env,
- const struct btf_type *struct_type,
- const struct btf_member *member,
- const struct btf_type *member_type)
-{
- btf_verifier_log_basic(env, struct_type,
- "Unsupported check_kflag_member");
- return -EINVAL;
-}
-
-/* Used for ptr, array struct/union and float type members.
- * int, enum and modifier types have their specific callback functions.
- */
-static int btf_generic_check_kflag_member(struct btf_verifier_env *env,
- const struct btf_type *struct_type,
- const struct btf_member *member,
- const struct btf_type *member_type)
-{
- if (BTF_MEMBER_BITFIELD_SIZE(member->offset)) {
- btf_verifier_log_member(env, struct_type, member,
- "Invalid member bitfield_size");
- return -EINVAL;
- }
-
- /* bitfield size is 0, so member->offset represents bit offset only.
- * It is safe to call non kflag check_member variants.
- */
- return btf_type_ops(member_type)->check_member(env, struct_type,
- member,
- member_type);
-}
-
-static int btf_df_resolve(struct btf_verifier_env *env,
- const struct resolve_vertex *v)
-{
- btf_verifier_log_basic(env, v->t, "Unsupported resolve");
- return -EINVAL;
-}
-
-static void btf_df_show(const struct btf *btf, const struct btf_type *t,
- u32 type_id, void *data, u8 bits_offsets,
- struct btf_show *show)
-{
- btf_show(show, "<unsupported kind:%u>", BTF_INFO_KIND(t->info));
-}
-
-static int btf_int_check_member(struct btf_verifier_env *env,
- const struct btf_type *struct_type,
- const struct btf_member *member,
- const struct btf_type *member_type)
-{
- u32 int_data = btf_type_int(member_type);
- u32 struct_bits_off = member->offset;
- u32 struct_size = struct_type->size;
- u32 nr_copy_bits;
- u32 bytes_offset;
-
- if (U32_MAX - struct_bits_off < BTF_INT_OFFSET(int_data)) {
- btf_verifier_log_member(env, struct_type, member,
- "bits_offset exceeds U32_MAX");
- return -EINVAL;
- }
-
- struct_bits_off += BTF_INT_OFFSET(int_data);
- bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
- nr_copy_bits = BTF_INT_BITS(int_data) +
- BITS_PER_BYTE_MASKED(struct_bits_off);
-
- if (nr_copy_bits > BITS_PER_U128) {
- btf_verifier_log_member(env, struct_type, member,
- "nr_copy_bits exceeds 128");
- return -EINVAL;
- }
-
- if (struct_size < bytes_offset ||
- struct_size - bytes_offset < BITS_ROUNDUP_BYTES(nr_copy_bits)) {
- btf_verifier_log_member(env, struct_type, member,
- "Member exceeds struct_size");
- return -EINVAL;
- }
-
- return 0;
-}
-
-static int btf_int_check_kflag_member(struct btf_verifier_env *env,
- const struct btf_type *struct_type,
- const struct btf_member *member,
- const struct btf_type *member_type)
-{
- u32 struct_bits_off, nr_bits, nr_int_data_bits, bytes_offset;
- u32 int_data = btf_type_int(member_type);
- u32 struct_size = struct_type->size;
- u32 nr_copy_bits;
-
- /* a regular int type is required for the kflag int member */
- if (!btf_type_int_is_regular(member_type)) {
- btf_verifier_log_member(env, struct_type, member,
- "Invalid member base type");
- return -EINVAL;
- }
-
- /* check sanity of bitfield size */
- nr_bits = BTF_MEMBER_BITFIELD_SIZE(member->offset);
- struct_bits_off = BTF_MEMBER_BIT_OFFSET(member->offset);
- nr_int_data_bits = BTF_INT_BITS(int_data);
- if (!nr_bits) {
- /* Not a bitfield member, member offset must be at byte
- * boundary.
- */
- if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
- btf_verifier_log_member(env, struct_type, member,
- "Invalid member offset");
- return -EINVAL;
- }
-
- nr_bits = nr_int_data_bits;
- } else if (nr_bits > nr_int_data_bits) {
- btf_verifier_log_member(env, struct_type, member,
- "Invalid member bitfield_size");
- return -EINVAL;
- }
-
- bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
- nr_copy_bits = nr_bits + BITS_PER_BYTE_MASKED(struct_bits_off);
- if (nr_copy_bits > BITS_PER_U128) {
- btf_verifier_log_member(env, struct_type, member,
- "nr_copy_bits exceeds 128");
- return -EINVAL;
- }
-
- if (struct_size < bytes_offset ||
- struct_size - bytes_offset < BITS_ROUNDUP_BYTES(nr_copy_bits)) {
- btf_verifier_log_member(env, struct_type, member,
- "Member exceeds struct_size");
- return -EINVAL;
- }
-
- return 0;
-}
-
-static s32 btf_int_check_meta(struct btf_verifier_env *env,
- const struct btf_type *t,
- u32 meta_left)
-{
- u32 int_data, nr_bits, meta_needed = sizeof(int_data);
- u16 encoding;
-
- if (meta_left < meta_needed) {
- btf_verifier_log_basic(env, t,
- "meta_left:%u meta_needed:%u",
- meta_left, meta_needed);
- return -EINVAL;
- }
-
- if (btf_type_vlen(t)) {
- btf_verifier_log_type(env, t, "vlen != 0");
- return -EINVAL;
- }
-
- if (btf_type_kflag(t)) {
- btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
- return -EINVAL;
- }
-
- int_data = btf_type_int(t);
- if (int_data & ~BTF_INT_MASK) {
- btf_verifier_log_basic(env, t, "Invalid int_data:%x",
- int_data);
- return -EINVAL;
- }
-
- nr_bits = BTF_INT_BITS(int_data) + BTF_INT_OFFSET(int_data);
-
- if (nr_bits > BITS_PER_U128) {
- btf_verifier_log_type(env, t, "nr_bits exceeds %zu",
- BITS_PER_U128);
- return -EINVAL;
- }
-
- if (BITS_ROUNDUP_BYTES(nr_bits) > t->size) {
- btf_verifier_log_type(env, t, "nr_bits exceeds type_size");
- return -EINVAL;
- }
-
- /*
- * Only one of the encoding bits is allowed and it
- * should be sufficient for the pretty print purpose (i.e. decoding).
- * Multiple bits can be allowed later if it is found
- * to be insufficient.
- */
- encoding = BTF_INT_ENCODING(int_data);
- if (encoding &&
- encoding != BTF_INT_SIGNED &&
- encoding != BTF_INT_CHAR &&
- encoding != BTF_INT_BOOL) {
- btf_verifier_log_type(env, t, "Unsupported encoding");
- return -ENOTSUPP;
- }
-
- btf_verifier_log_type(env, t, NULL);
-
- return meta_needed;
-}
-
-static void btf_int_log(struct btf_verifier_env *env,
- const struct btf_type *t)
-{
- int int_data = btf_type_int(t);
-
- btf_verifier_log(env,
- "size=%u bits_offset=%u nr_bits=%u encoding=%s",
- t->size, BTF_INT_OFFSET(int_data),
- BTF_INT_BITS(int_data),
- btf_int_encoding_str(BTF_INT_ENCODING(int_data)));
-}
-
-static void btf_int128_print(struct btf_show *show, void *data)
-{
- /* data points to a __int128 number.
- * Suppose
- * int128_num = *(__int128 *)data;
- * The below formulas shows what upper_num and lower_num represents:
- * upper_num = int128_num >> 64;
- * lower_num = int128_num & 0xffffffffFFFFFFFFULL;
- */
- u64 upper_num, lower_num;
-
-#ifdef __BIG_ENDIAN_BITFIELD
- upper_num = *(u64 *)data;
- lower_num = *(u64 *)(data + 8);
-#else
- upper_num = *(u64 *)(data + 8);
- lower_num = *(u64 *)data;
-#endif
- if (upper_num == 0)
- btf_show_type_value(show, "0x%llx", lower_num);
- else
- btf_show_type_values(show, "0x%llx%016llx", upper_num,
- lower_num);
-}
-
-static void btf_int128_shift(u64 *print_num, u16 left_shift_bits,
- u16 right_shift_bits)
-{
- u64 upper_num, lower_num;
-
-#ifdef __BIG_ENDIAN_BITFIELD
- upper_num = print_num[0];
- lower_num = print_num[1];
-#else
- upper_num = print_num[1];
- lower_num = print_num[0];
-#endif
-
- /* shake out un-needed bits by shift/or operations */
- if (left_shift_bits >= 64) {
- upper_num = lower_num << (left_shift_bits - 64);
- lower_num = 0;
- } else {
- upper_num = (upper_num << left_shift_bits) |
- (lower_num >> (64 - left_shift_bits));
- lower_num = lower_num << left_shift_bits;
- }
-
- if (right_shift_bits >= 64) {
- lower_num = upper_num >> (right_shift_bits - 64);
- upper_num = 0;
- } else {
- lower_num = (lower_num >> right_shift_bits) |
- (upper_num << (64 - right_shift_bits));
- upper_num = upper_num >> right_shift_bits;
- }
-
-#ifdef __BIG_ENDIAN_BITFIELD
- print_num[0] = upper_num;
- print_num[1] = lower_num;
-#else
- print_num[0] = lower_num;
- print_num[1] = upper_num;
-#endif
-}
-
-static void btf_bitfield_show(void *data, u8 bits_offset,
- u8 nr_bits, struct btf_show *show)
-{
- u16 left_shift_bits, right_shift_bits;
- u8 nr_copy_bytes;
- u8 nr_copy_bits;
- u64 print_num[2] = {};
-
- nr_copy_bits = nr_bits + bits_offset;
- nr_copy_bytes = BITS_ROUNDUP_BYTES(nr_copy_bits);
-
- memcpy(print_num, data, nr_copy_bytes);
-
-#ifdef __BIG_ENDIAN_BITFIELD
- left_shift_bits = bits_offset;
-#else
- left_shift_bits = BITS_PER_U128 - nr_copy_bits;
-#endif
- right_shift_bits = BITS_PER_U128 - nr_bits;
-
- btf_int128_shift(print_num, left_shift_bits, right_shift_bits);
- btf_int128_print(show, print_num);
-}
-
-
-static void btf_int_bits_show(const struct btf *btf,
- const struct btf_type *t,
- void *data, u8 bits_offset,
- struct btf_show *show)
-{
- u32 int_data = btf_type_int(t);
- u8 nr_bits = BTF_INT_BITS(int_data);
- u8 total_bits_offset;
-
- /*
- * bits_offset is at most 7.
- * BTF_INT_OFFSET() cannot exceed 128 bits.
- */
- total_bits_offset = bits_offset + BTF_INT_OFFSET(int_data);
- data += BITS_ROUNDDOWN_BYTES(total_bits_offset);
- bits_offset = BITS_PER_BYTE_MASKED(total_bits_offset);
- btf_bitfield_show(data, bits_offset, nr_bits, show);
-}
-
-static void btf_int_show(const struct btf *btf, const struct btf_type *t,
- u32 type_id, void *data, u8 bits_offset,
- struct btf_show *show)
-{
- u32 int_data = btf_type_int(t);
- u8 encoding = BTF_INT_ENCODING(int_data);
- bool sign = encoding & BTF_INT_SIGNED;
- u8 nr_bits = BTF_INT_BITS(int_data);
- void *safe_data;
-
- safe_data = btf_show_start_type(show, t, type_id, data);
- if (!safe_data)
- return;
-
- if (bits_offset || BTF_INT_OFFSET(int_data) ||
- BITS_PER_BYTE_MASKED(nr_bits)) {
- btf_int_bits_show(btf, t, safe_data, bits_offset, show);
- goto out;
- }
-
- switch (nr_bits) {
- case 128:
- btf_int128_print(show, safe_data);
- break;
- case 64:
- if (sign)
- btf_show_type_value(show, "%lld", *(s64 *)safe_data);
- else
- btf_show_type_value(show, "%llu", *(u64 *)safe_data);
- break;
- case 32:
- if (sign)
- btf_show_type_value(show, "%d", *(s32 *)safe_data);
- else
- btf_show_type_value(show, "%u", *(u32 *)safe_data);
- break;
- case 16:
- if (sign)
- btf_show_type_value(show, "%d", *(s16 *)safe_data);
- else
- btf_show_type_value(show, "%u", *(u16 *)safe_data);
- break;
- case 8:
- if (show->state.array_encoding == BTF_INT_CHAR) {
- /* check for null terminator */
- if (show->state.array_terminated)
- break;
- if (*(char *)data == '\0') {
- show->state.array_terminated = 1;
- break;
- }
- if (isprint(*(char *)data)) {
- btf_show_type_value(show, "'%c'",
- *(char *)safe_data);
- break;
- }
- }
- if (sign)
- btf_show_type_value(show, "%d", *(s8 *)safe_data);
- else
- btf_show_type_value(show, "%u", *(u8 *)safe_data);
- break;
- default:
- btf_int_bits_show(btf, t, safe_data, bits_offset, show);
- break;
- }
-out:
- btf_show_end_type(show);
-}
-
-static const struct btf_kind_operations int_ops = {
- .check_meta = btf_int_check_meta,
- .resolve = btf_df_resolve,
- .check_member = btf_int_check_member,
- .check_kflag_member = btf_int_check_kflag_member,
- .log_details = btf_int_log,
- .show = btf_int_show,
-};
-
-static int btf_modifier_check_member(struct btf_verifier_env *env,
- const struct btf_type *struct_type,
- const struct btf_member *member,
- const struct btf_type *member_type)
-{
- const struct btf_type *resolved_type;
- u32 resolved_type_id = member->type;
- struct btf_member resolved_member;
- struct btf *btf = env->btf;
-
- resolved_type = btf_type_id_size(btf, &resolved_type_id, NULL);
- if (!resolved_type) {
- btf_verifier_log_member(env, struct_type, member,
- "Invalid member");
- return -EINVAL;
- }
-
- resolved_member = *member;
- resolved_member.type = resolved_type_id;
-
- return btf_type_ops(resolved_type)->check_member(env, struct_type,
- &resolved_member,
- resolved_type);
-}
-
-static int btf_modifier_check_kflag_member(struct btf_verifier_env *env,
- const struct btf_type *struct_type,
- const struct btf_member *member,
- const struct btf_type *member_type)
-{
- const struct btf_type *resolved_type;
- u32 resolved_type_id = member->type;
- struct btf_member resolved_member;
- struct btf *btf = env->btf;
-
- resolved_type = btf_type_id_size(btf, &resolved_type_id, NULL);
- if (!resolved_type) {
- btf_verifier_log_member(env, struct_type, member,
- "Invalid member");
- return -EINVAL;
- }
-
- resolved_member = *member;
- resolved_member.type = resolved_type_id;
-
- return btf_type_ops(resolved_type)->check_kflag_member(env, struct_type,
- &resolved_member,
- resolved_type);
-}
-
-static int btf_ptr_check_member(struct btf_verifier_env *env,
- const struct btf_type *struct_type,
- const struct btf_member *member,
- const struct btf_type *member_type)
-{
- u32 struct_size, struct_bits_off, bytes_offset;
-
- struct_size = struct_type->size;
- struct_bits_off = member->offset;
- bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
-
- if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
- btf_verifier_log_member(env, struct_type, member,
- "Member is not byte aligned");
- return -EINVAL;
- }
-
- if (struct_size - bytes_offset < sizeof(void *)) {
- btf_verifier_log_member(env, struct_type, member,
- "Member exceeds struct_size");
- return -EINVAL;
- }
-
- return 0;
-}
-
-static int btf_ref_type_check_meta(struct btf_verifier_env *env,
- const struct btf_type *t,
- u32 meta_left)
-{
- const char *value;
-
- if (btf_type_vlen(t)) {
- btf_verifier_log_type(env, t, "vlen != 0");
- return -EINVAL;
- }
-
- if (btf_type_kflag(t) && !btf_type_is_type_tag(t)) {
- btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
- return -EINVAL;
- }
-
- if (!BTF_TYPE_ID_VALID(t->type)) {
- btf_verifier_log_type(env, t, "Invalid type_id");
- return -EINVAL;
- }
-
- /* typedef/type_tag type must have a valid name, and other ref types,
- * volatile, const, restrict, should have a null name.
- */
- if (BTF_INFO_KIND(t->info) == BTF_KIND_TYPEDEF) {
- if (!t->name_off ||
- !btf_name_valid_identifier(env->btf, t->name_off)) {
- btf_verifier_log_type(env, t, "Invalid name");
- return -EINVAL;
- }
- } else if (BTF_INFO_KIND(t->info) == BTF_KIND_TYPE_TAG) {
- value = btf_name_by_offset(env->btf, t->name_off);
- if (!value || !value[0]) {
- btf_verifier_log_type(env, t, "Invalid name");
- return -EINVAL;
- }
- } else {
- if (t->name_off) {
- btf_verifier_log_type(env, t, "Invalid name");
- return -EINVAL;
- }
- }
-
- btf_verifier_log_type(env, t, NULL);
-
- return 0;
-}
-
-static int btf_modifier_resolve(struct btf_verifier_env *env,
- const struct resolve_vertex *v)
-{
- const struct btf_type *t = v->t;
- const struct btf_type *next_type;
- u32 next_type_id = t->type;
- struct btf *btf = env->btf;
-
- next_type = btf_type_by_id(btf, next_type_id);
- if (!next_type || btf_type_is_resolve_source_only(next_type)) {
- btf_verifier_log_type(env, v->t, "Invalid type_id");
- return -EINVAL;
- }
-
- if (!env_type_is_resolve_sink(env, next_type) &&
- !env_type_is_resolved(env, next_type_id))
- return env_stack_push(env, next_type, next_type_id);
-
- /* Figure out the resolved next_type_id with size.
- * They will be stored in the current modifier's
- * resolved_ids and resolved_sizes such that it can
- * save us a few type-following when we use it later (e.g. in
- * pretty print).
- */
- if (!btf_type_id_size(btf, &next_type_id, NULL)) {
- if (env_type_is_resolved(env, next_type_id))
- next_type = btf_type_id_resolve(btf, &next_type_id);
-
- /* "typedef void new_void", "const void"...etc */
- if (!btf_type_is_void(next_type) &&
- !btf_type_is_fwd(next_type) &&
- !btf_type_is_func_proto(next_type)) {
- btf_verifier_log_type(env, v->t, "Invalid type_id");
- return -EINVAL;
- }
- }
-
- env_stack_pop_resolved(env, next_type_id, 0);
-
- return 0;
-}
-
-static int btf_var_resolve(struct btf_verifier_env *env,
- const struct resolve_vertex *v)
-{
- const struct btf_type *next_type;
- const struct btf_type *t = v->t;
- u32 next_type_id = t->type;
- struct btf *btf = env->btf;
-
- next_type = btf_type_by_id(btf, next_type_id);
- if (!next_type || btf_type_is_resolve_source_only(next_type)) {
- btf_verifier_log_type(env, v->t, "Invalid type_id");
- return -EINVAL;
- }
-
- if (!env_type_is_resolve_sink(env, next_type) &&
- !env_type_is_resolved(env, next_type_id))
- return env_stack_push(env, next_type, next_type_id);
-
- if (btf_type_is_modifier(next_type)) {
- const struct btf_type *resolved_type;
- u32 resolved_type_id;
-
- resolved_type_id = next_type_id;
- resolved_type = btf_type_id_resolve(btf, &resolved_type_id);
-
- if (btf_type_is_ptr(resolved_type) &&
- !env_type_is_resolve_sink(env, resolved_type) &&
- !env_type_is_resolved(env, resolved_type_id))
- return env_stack_push(env, resolved_type,
- resolved_type_id);
- }
-
- /* We must resolve to something concrete at this point, no
- * forward types or similar that would resolve to size of
- * zero is allowed.
- */
- if (!btf_type_id_size(btf, &next_type_id, NULL)) {
- btf_verifier_log_type(env, v->t, "Invalid type_id");
- return -EINVAL;
- }
-
- env_stack_pop_resolved(env, next_type_id, 0);
-
- return 0;
-}
-
-static int btf_ptr_resolve(struct btf_verifier_env *env,
- const struct resolve_vertex *v)
-{
- const struct btf_type *next_type;
- const struct btf_type *t = v->t;
- u32 next_type_id = t->type;
- struct btf *btf = env->btf;
-
- next_type = btf_type_by_id(btf, next_type_id);
- if (!next_type || btf_type_is_resolve_source_only(next_type)) {
- btf_verifier_log_type(env, v->t, "Invalid type_id");
- return -EINVAL;
- }
-
- if (!env_type_is_resolve_sink(env, next_type) &&
- !env_type_is_resolved(env, next_type_id))
- return env_stack_push(env, next_type, next_type_id);
-
- /* If the modifier was RESOLVED during RESOLVE_STRUCT_OR_ARRAY,
- * the modifier may have stopped resolving when it was resolved
- * to a ptr (last-resolved-ptr).
- *
- * We now need to continue from the last-resolved-ptr to
- * ensure the last-resolved-ptr will not referring back to
- * the current ptr (t).
- */
- if (btf_type_is_modifier(next_type)) {
- const struct btf_type *resolved_type;
- u32 resolved_type_id;
-
- resolved_type_id = next_type_id;
- resolved_type = btf_type_id_resolve(btf, &resolved_type_id);
-
- if (btf_type_is_ptr(resolved_type) &&
- !env_type_is_resolve_sink(env, resolved_type) &&
- !env_type_is_resolved(env, resolved_type_id))
- return env_stack_push(env, resolved_type,
- resolved_type_id);
- }
-
- if (!btf_type_id_size(btf, &next_type_id, NULL)) {
- if (env_type_is_resolved(env, next_type_id))
- next_type = btf_type_id_resolve(btf, &next_type_id);
-
- if (!btf_type_is_void(next_type) &&
- !btf_type_is_fwd(next_type) &&
- !btf_type_is_func_proto(next_type)) {
- btf_verifier_log_type(env, v->t, "Invalid type_id");
- return -EINVAL;
- }
- }
-
- env_stack_pop_resolved(env, next_type_id, 0);
-
- return 0;
-}
-
-static void btf_modifier_show(const struct btf *btf,
- const struct btf_type *t,
- u32 type_id, void *data,
- u8 bits_offset, struct btf_show *show)
-{
- if (btf->resolved_ids)
- t = btf_type_id_resolve(btf, &type_id);
- else
- t = btf_type_skip_modifiers(btf, type_id, NULL);
-
- btf_type_ops(t)->show(btf, t, type_id, data, bits_offset, show);
-}
-
-static void btf_var_show(const struct btf *btf, const struct btf_type *t,
- u32 type_id, void *data, u8 bits_offset,
- struct btf_show *show)
-{
- t = btf_type_id_resolve(btf, &type_id);
-
- btf_type_ops(t)->show(btf, t, type_id, data, bits_offset, show);
-}
-
-static void btf_ptr_show(const struct btf *btf, const struct btf_type *t,
- u32 type_id, void *data, u8 bits_offset,
- struct btf_show *show)
-{
- void *safe_data;
-
- safe_data = btf_show_start_type(show, t, type_id, data);
- if (!safe_data)
- return;
-
- /* It is a hashed value unless BTF_SHOW_PTR_RAW is specified */
- if (show->flags & BTF_SHOW_PTR_RAW)
- btf_show_type_value(show, "0x%px", *(void **)safe_data);
- else
- btf_show_type_value(show, "0x%p", *(void **)safe_data);
- btf_show_end_type(show);
-}
-
-static void btf_ref_type_log(struct btf_verifier_env *env,
- const struct btf_type *t)
-{
- btf_verifier_log(env, "type_id=%u", t->type);
-}
-
-static const struct btf_kind_operations modifier_ops = {
- .check_meta = btf_ref_type_check_meta,
- .resolve = btf_modifier_resolve,
- .check_member = btf_modifier_check_member,
- .check_kflag_member = btf_modifier_check_kflag_member,
- .log_details = btf_ref_type_log,
- .show = btf_modifier_show,
-};
-
-static const struct btf_kind_operations ptr_ops = {
- .check_meta = btf_ref_type_check_meta,
- .resolve = btf_ptr_resolve,
- .check_member = btf_ptr_check_member,
- .check_kflag_member = btf_generic_check_kflag_member,
- .log_details = btf_ref_type_log,
- .show = btf_ptr_show,
-};
-
-static s32 btf_fwd_check_meta(struct btf_verifier_env *env,
- const struct btf_type *t,
- u32 meta_left)
-{
- if (btf_type_vlen(t)) {
- btf_verifier_log_type(env, t, "vlen != 0");
- return -EINVAL;
- }
-
- if (t->type) {
- btf_verifier_log_type(env, t, "type != 0");
- return -EINVAL;
- }
-
- /* fwd type must have a valid name */
- if (!t->name_off ||
- !btf_name_valid_identifier(env->btf, t->name_off)) {
- btf_verifier_log_type(env, t, "Invalid name");
- return -EINVAL;
- }
-
- btf_verifier_log_type(env, t, NULL);
-
- return 0;
-}
-
-static void btf_fwd_type_log(struct btf_verifier_env *env,
- const struct btf_type *t)
-{
- btf_verifier_log(env, "%s", btf_type_kflag(t) ? "union" : "struct");
-}
-
-static const struct btf_kind_operations fwd_ops = {
- .check_meta = btf_fwd_check_meta,
- .resolve = btf_df_resolve,
- .check_member = btf_df_check_member,
- .check_kflag_member = btf_df_check_kflag_member,
- .log_details = btf_fwd_type_log,
- .show = btf_df_show,
-};
-
-static int btf_array_check_member(struct btf_verifier_env *env,
- const struct btf_type *struct_type,
- const struct btf_member *member,
- const struct btf_type *member_type)
-{
- u32 struct_bits_off = member->offset;
- u32 struct_size, bytes_offset;
- u32 array_type_id, array_size;
- struct btf *btf = env->btf;
-
- if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
- btf_verifier_log_member(env, struct_type, member,
- "Member is not byte aligned");
- return -EINVAL;
- }
-
- array_type_id = member->type;
- btf_type_id_size(btf, &array_type_id, &array_size);
- struct_size = struct_type->size;
- bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
- if (struct_size - bytes_offset < array_size) {
- btf_verifier_log_member(env, struct_type, member,
- "Member exceeds struct_size");
- return -EINVAL;
- }
-
- return 0;
-}
-
-static s32 btf_array_check_meta(struct btf_verifier_env *env,
- const struct btf_type *t,
- u32 meta_left)
-{
- const struct btf_array *array = btf_type_array(t);
- u32 meta_needed = sizeof(*array);
-
- if (meta_left < meta_needed) {
- btf_verifier_log_basic(env, t,
- "meta_left:%u meta_needed:%u",
- meta_left, meta_needed);
- return -EINVAL;
- }
-
- /* array type should not have a name */
- if (t->name_off) {
- btf_verifier_log_type(env, t, "Invalid name");
- return -EINVAL;
- }
-
- if (btf_type_vlen(t)) {
- btf_verifier_log_type(env, t, "vlen != 0");
- return -EINVAL;
- }
-
- if (btf_type_kflag(t)) {
- btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
- return -EINVAL;
- }
-
- if (t->size) {
- btf_verifier_log_type(env, t, "size != 0");
- return -EINVAL;
- }
-
- /* Array elem type and index type cannot be in type void,
- * so !array->type and !array->index_type are not allowed.
- */
- if (!array->type || !BTF_TYPE_ID_VALID(array->type)) {
- btf_verifier_log_type(env, t, "Invalid elem");
- return -EINVAL;
- }
-
- if (!array->index_type || !BTF_TYPE_ID_VALID(array->index_type)) {
- btf_verifier_log_type(env, t, "Invalid index");
- return -EINVAL;
- }
-
- btf_verifier_log_type(env, t, NULL);
-
- return meta_needed;
-}
-
-static int btf_array_resolve(struct btf_verifier_env *env,
- const struct resolve_vertex *v)
-{
- const struct btf_array *array = btf_type_array(v->t);
- const struct btf_type *elem_type, *index_type;
- u32 elem_type_id, index_type_id;
- struct btf *btf = env->btf;
- u32 elem_size;
-
- /* Check array->index_type */
- index_type_id = array->index_type;
- index_type = btf_type_by_id(btf, index_type_id);
- if (btf_type_nosize_or_null(index_type) ||
- btf_type_is_resolve_source_only(index_type)) {
- btf_verifier_log_type(env, v->t, "Invalid index");
- return -EINVAL;
- }
-
- if (!env_type_is_resolve_sink(env, index_type) &&
- !env_type_is_resolved(env, index_type_id))
- return env_stack_push(env, index_type, index_type_id);
-
- index_type = btf_type_id_size(btf, &index_type_id, NULL);
- if (!index_type || !btf_type_is_int(index_type) ||
- !btf_type_int_is_regular(index_type)) {
- btf_verifier_log_type(env, v->t, "Invalid index");
- return -EINVAL;
- }
-
- /* Check array->type */
- elem_type_id = array->type;
- elem_type = btf_type_by_id(btf, elem_type_id);
- if (btf_type_nosize_or_null(elem_type) ||
- btf_type_is_resolve_source_only(elem_type)) {
- btf_verifier_log_type(env, v->t,
- "Invalid elem");
- return -EINVAL;
- }
-
- if (!env_type_is_resolve_sink(env, elem_type) &&
- !env_type_is_resolved(env, elem_type_id))
- return env_stack_push(env, elem_type, elem_type_id);
-
- elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size);
- if (!elem_type) {
- btf_verifier_log_type(env, v->t, "Invalid elem");
- return -EINVAL;
- }
-
- if (btf_type_is_int(elem_type) && !btf_type_int_is_regular(elem_type)) {
- btf_verifier_log_type(env, v->t, "Invalid array of int");
- return -EINVAL;
- }
-
- if (array->nelems && elem_size > U32_MAX / array->nelems) {
- btf_verifier_log_type(env, v->t,
- "Array size overflows U32_MAX");
- return -EINVAL;
- }
-
- env_stack_pop_resolved(env, elem_type_id, elem_size * array->nelems);
-
- return 0;
-}
-
-static void btf_array_log(struct btf_verifier_env *env,
- const struct btf_type *t)
-{
- const struct btf_array *array = btf_type_array(t);
-
- btf_verifier_log(env, "type_id=%u index_type_id=%u nr_elems=%u",
- array->type, array->index_type, array->nelems);
-}
-
-static void __btf_array_show(const struct btf *btf, const struct btf_type *t,
- u32 type_id, void *data, u8 bits_offset,
- struct btf_show *show)
-{
- const struct btf_array *array = btf_type_array(t);
- const struct btf_kind_operations *elem_ops;
- const struct btf_type *elem_type;
- u32 i, elem_size = 0, elem_type_id;
- u16 encoding = 0;
-
- elem_type_id = array->type;
- elem_type = btf_type_skip_modifiers(btf, elem_type_id, NULL);
- if (elem_type && btf_type_has_size(elem_type))
- elem_size = elem_type->size;
-
- if (elem_type && btf_type_is_int(elem_type)) {
- u32 int_type = btf_type_int(elem_type);
-
- encoding = BTF_INT_ENCODING(int_type);
-
- /*
- * BTF_INT_CHAR encoding never seems to be set for
- * char arrays, so if size is 1 and element is
- * printable as a char, we'll do that.
- */
- if (elem_size == 1)
- encoding = BTF_INT_CHAR;
- }
-
- if (!btf_show_start_array_type(show, t, type_id, encoding, data))
- return;
-
- if (!elem_type)
- goto out;
- elem_ops = btf_type_ops(elem_type);
-
- for (i = 0; i < array->nelems; i++) {
-
- btf_show_start_array_member(show);
-
- elem_ops->show(btf, elem_type, elem_type_id, data,
- bits_offset, show);
- data += elem_size;
-
- btf_show_end_array_member(show);
-
- if (show->state.array_terminated)
- break;
- }
-out:
- btf_show_end_array_type(show);
-}
-
-static void btf_array_show(const struct btf *btf, const struct btf_type *t,
- u32 type_id, void *data, u8 bits_offset,
- struct btf_show *show)
-{
- const struct btf_member *m = show->state.member;
-
- /*
- * First check if any members would be shown (are non-zero).
- * See comments above "struct btf_show" definition for more
- * details on how this works at a high-level.
- */
- if (show->state.depth > 0 && !(show->flags & BTF_SHOW_ZERO)) {
- if (!show->state.depth_check) {
- show->state.depth_check = show->state.depth + 1;
- show->state.depth_to_show = 0;
- }
- __btf_array_show(btf, t, type_id, data, bits_offset, show);
- show->state.member = m;
-
- if (show->state.depth_check != show->state.depth + 1)
- return;
- show->state.depth_check = 0;
-
- if (show->state.depth_to_show <= show->state.depth)
- return;
- /*
- * Reaching here indicates we have recursed and found
- * non-zero array member(s).
- */
- }
- __btf_array_show(btf, t, type_id, data, bits_offset, show);
-}
-
-static const struct btf_kind_operations array_ops = {
- .check_meta = btf_array_check_meta,
- .resolve = btf_array_resolve,
- .check_member = btf_array_check_member,
- .check_kflag_member = btf_generic_check_kflag_member,
- .log_details = btf_array_log,
- .show = btf_array_show,
-};
-
-static int btf_struct_check_member(struct btf_verifier_env *env,
- const struct btf_type *struct_type,
- const struct btf_member *member,
- const struct btf_type *member_type)
-{
- u32 struct_bits_off = member->offset;
- u32 struct_size, bytes_offset;
-
- if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
- btf_verifier_log_member(env, struct_type, member,
- "Member is not byte aligned");
- return -EINVAL;
- }
-
- struct_size = struct_type->size;
- bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
- if (struct_size - bytes_offset < member_type->size) {
- btf_verifier_log_member(env, struct_type, member,
- "Member exceeds struct_size");
- return -EINVAL;
- }
-
- return 0;
-}
-
-static s32 btf_struct_check_meta(struct btf_verifier_env *env,
- const struct btf_type *t,
- u32 meta_left)
-{
- bool is_union = BTF_INFO_KIND(t->info) == BTF_KIND_UNION;
- const struct btf_member *member;
- u32 meta_needed, last_offset;
- struct btf *btf = env->btf;
- u32 struct_size = t->size;
- u32 offset;
- u16 i;
-
- meta_needed = btf_type_vlen(t) * sizeof(*member);
- if (meta_left < meta_needed) {
- btf_verifier_log_basic(env, t,
- "meta_left:%u meta_needed:%u",
- meta_left, meta_needed);
- return -EINVAL;
- }
-
- /* struct type either no name or a valid one */
- if (t->name_off &&
- !btf_name_valid_identifier(env->btf, t->name_off)) {
- btf_verifier_log_type(env, t, "Invalid name");
- return -EINVAL;
- }
-
- btf_verifier_log_type(env, t, NULL);
-
- last_offset = 0;
- for_each_member(i, t, member) {
- if (!btf_name_offset_valid(btf, member->name_off)) {
- btf_verifier_log_member(env, t, member,
- "Invalid member name_offset:%u",
- member->name_off);
- return -EINVAL;
- }
-
- /* struct member either no name or a valid one */
- if (member->name_off &&
- !btf_name_valid_identifier(btf, member->name_off)) {
- btf_verifier_log_member(env, t, member, "Invalid name");
- return -EINVAL;
- }
- /* A member cannot be in type void */
- if (!member->type || !BTF_TYPE_ID_VALID(member->type)) {
- btf_verifier_log_member(env, t, member,
- "Invalid type_id");
- return -EINVAL;
- }
-
- offset = __btf_member_bit_offset(t, member);
- if (is_union && offset) {
- btf_verifier_log_member(env, t, member,
- "Invalid member bits_offset");
- return -EINVAL;
- }
-
- /*
- * ">" instead of ">=" because the last member could be
- * "char a[0];"
- */
- if (last_offset > offset) {
- btf_verifier_log_member(env, t, member,
- "Invalid member bits_offset");
- return -EINVAL;
- }
-
- if (BITS_ROUNDUP_BYTES(offset) > struct_size) {
- btf_verifier_log_member(env, t, member,
- "Member bits_offset exceeds its struct size");
- return -EINVAL;
- }
-
- btf_verifier_log_member(env, t, member, NULL);
- last_offset = offset;
- }
-
- return meta_needed;
-}
-
-static int btf_struct_resolve(struct btf_verifier_env *env,
- const struct resolve_vertex *v)
-{
- const struct btf_member *member;
- int err;
- u16 i;
-
- /* Before continue resolving the next_member,
- * ensure the last member is indeed resolved to a
- * type with size info.
- */
- if (v->next_member) {
- const struct btf_type *last_member_type;
- const struct btf_member *last_member;
- u32 last_member_type_id;
-
- last_member = btf_type_member(v->t) + v->next_member - 1;
- last_member_type_id = last_member->type;
- if (WARN_ON_ONCE(!env_type_is_resolved(env,
- last_member_type_id)))
- return -EINVAL;
-
- last_member_type = btf_type_by_id(env->btf,
- last_member_type_id);
- if (btf_type_kflag(v->t))
- err = btf_type_ops(last_member_type)->check_kflag_member(env, v->t,
- last_member,
- last_member_type);
- else
- err = btf_type_ops(last_member_type)->check_member(env, v->t,
- last_member,
- last_member_type);
- if (err)
- return err;
- }
-
- for_each_member_from(i, v->next_member, v->t, member) {
- u32 member_type_id = member->type;
- const struct btf_type *member_type = btf_type_by_id(env->btf,
- member_type_id);
-
- if (btf_type_nosize_or_null(member_type) ||
- btf_type_is_resolve_source_only(member_type)) {
- btf_verifier_log_member(env, v->t, member,
- "Invalid member");
- return -EINVAL;
- }
-
- if (!env_type_is_resolve_sink(env, member_type) &&
- !env_type_is_resolved(env, member_type_id)) {
- env_stack_set_next_member(env, i + 1);
- return env_stack_push(env, member_type, member_type_id);
- }
-
- if (btf_type_kflag(v->t))
- err = btf_type_ops(member_type)->check_kflag_member(env, v->t,
- member,
- member_type);
- else
- err = btf_type_ops(member_type)->check_member(env, v->t,
- member,
- member_type);
- if (err)
- return err;
- }
-
- env_stack_pop_resolved(env, 0, 0);
-
- return 0;
-}
-
-static void btf_struct_log(struct btf_verifier_env *env,
- const struct btf_type *t)
-{
- btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t));
-}
-
-enum {
- BTF_FIELD_IGNORE = 0,
- BTF_FIELD_FOUND = 1,
-};
-
-struct btf_field_info {
- enum btf_field_type type;
- u32 off;
- union {
- struct {
- u32 type_id;
- } kptr;
- struct {
- const char *node_name;
- u32 value_btf_id;
- } graph_root;
- };
-};
-
-static int btf_find_struct(const struct btf *btf, const struct btf_type *t,
- u32 off, int sz, enum btf_field_type field_type,
- struct btf_field_info *info)
-{
- if (!__btf_type_is_struct(t))
- return BTF_FIELD_IGNORE;
- if (t->size != sz)
- return BTF_FIELD_IGNORE;
- info->type = field_type;
- info->off = off;
- return BTF_FIELD_FOUND;
-}
-
-static int btf_find_kptr(const struct btf *btf, const struct btf_type *t,
- u32 off, int sz, struct btf_field_info *info, u32 field_mask)
-{
- enum btf_field_type type;
- const char *tag_value;
- bool is_type_tag;
- u32 res_id;
-
- /* Permit modifiers on the pointer itself */
- if (btf_type_is_volatile(t))
- t = btf_type_by_id(btf, t->type);
- /* For PTR, sz is always == 8 */
- if (!btf_type_is_ptr(t))
- return BTF_FIELD_IGNORE;
- t = btf_type_by_id(btf, t->type);
- is_type_tag = btf_type_is_type_tag(t) && !btf_type_kflag(t);
- if (!is_type_tag)
- return BTF_FIELD_IGNORE;
- /* Reject extra tags */
- if (btf_type_is_type_tag(btf_type_by_id(btf, t->type)))
- return -EINVAL;
- tag_value = __btf_name_by_offset(btf, t->name_off);
- if (!strcmp("kptr_untrusted", tag_value))
- type = BPF_KPTR_UNREF;
- else if (!strcmp("kptr", tag_value))
- type = BPF_KPTR_REF;
- else if (!strcmp("percpu_kptr", tag_value))
- type = BPF_KPTR_PERCPU;
- else if (!strcmp("uptr", tag_value))
- type = BPF_UPTR;
- else
- return -EINVAL;
-
- if (!(type & field_mask))
- return BTF_FIELD_IGNORE;
-
- /* Get the base type */
- t = btf_type_skip_modifiers(btf, t->type, &res_id);
- /* Only pointer to struct is allowed */
- if (!__btf_type_is_struct(t))
- return -EINVAL;
-
- info->type = type;
- info->off = off;
- info->kptr.type_id = res_id;
- return BTF_FIELD_FOUND;
-}
-
-int btf_find_next_decl_tag(const struct btf *btf, const struct btf_type *pt,
- int comp_idx, const char *tag_key, int last_id)
-{
- int len = strlen(tag_key);
- int i, n;
-
- for (i = last_id + 1, n = btf_nr_types(btf); i < n; i++) {
- const struct btf_type *t = btf_type_by_id(btf, i);
-
- if (!btf_type_is_decl_tag(t))
- continue;
- if (pt != btf_type_by_id(btf, t->type))
- continue;
- if (btf_type_decl_tag(t)->component_idx != comp_idx)
- continue;
- if (strncmp(__btf_name_by_offset(btf, t->name_off), tag_key, len))
- continue;
- return i;
- }
- return -ENOENT;
-}
-
-const char *btf_find_decl_tag_value(const struct btf *btf, const struct btf_type *pt,
- int comp_idx, const char *tag_key)
-{
- const char *value = NULL;
- const struct btf_type *t;
- int len, id;
-
- id = btf_find_next_decl_tag(btf, pt, comp_idx, tag_key,
- btf_named_start_id(btf, false) - 1);
- if (id < 0)
- return ERR_PTR(id);
-
- t = btf_type_by_id(btf, id);
- len = strlen(tag_key);
- value = __btf_name_by_offset(btf, t->name_off) + len;
-
- /* Prevent duplicate entries for same type */
- id = btf_find_next_decl_tag(btf, pt, comp_idx, tag_key, id);
- if (id >= 0)
- return ERR_PTR(-EEXIST);
-
- return value;
-}
-
-static int
-btf_find_graph_root(const struct btf *btf, const struct btf_type *pt,
- const struct btf_type *t, int comp_idx, u32 off,
- int sz, struct btf_field_info *info,
- enum btf_field_type head_type)
-{
- const char *node_field_name;
- const char *value_type;
- s32 id;
-
- if (!__btf_type_is_struct(t))
- return BTF_FIELD_IGNORE;
- if (t->size != sz)
- return BTF_FIELD_IGNORE;
- value_type = btf_find_decl_tag_value(btf, pt, comp_idx, "contains:");
- if (IS_ERR(value_type))
- return -EINVAL;
- node_field_name = strstr(value_type, ":");
- if (!node_field_name)
- return -EINVAL;
- value_type = kstrndup(value_type, node_field_name - value_type,
- GFP_KERNEL_ACCOUNT | __GFP_NOWARN);
- if (!value_type)
- return -ENOMEM;
- id = btf_find_by_name_kind(btf, value_type, BTF_KIND_STRUCT);
- kfree(value_type);
- if (id < 0)
- return id;
- node_field_name++;
- if (str_is_empty(node_field_name))
- return -EINVAL;
- info->type = head_type;
- info->off = off;
- info->graph_root.value_btf_id = id;
- info->graph_root.node_name = node_field_name;
- return BTF_FIELD_FOUND;
-}
-
-static int btf_get_field_type(const struct btf *btf, const struct btf_type *var_type,
- u32 field_mask, u32 *seen_mask, int *align, int *sz)
-{
- const struct {
- enum btf_field_type type;
- const char *const name;
- const bool is_unique;
- } field_types[] = {
- { BPF_SPIN_LOCK, "bpf_spin_lock", true },
- { BPF_RES_SPIN_LOCK, "bpf_res_spin_lock", true },
- { BPF_TIMER, "bpf_timer", true },
- { BPF_WORKQUEUE, "bpf_wq", true },
- { BPF_TASK_WORK, "bpf_task_work", true },
- { BPF_LIST_HEAD, "bpf_list_head", false },
- { BPF_LIST_NODE, "bpf_list_node", false },
- { BPF_RB_ROOT, "bpf_rb_root", false },
- { BPF_RB_NODE, "bpf_rb_node", false },
- { BPF_REFCOUNT, "bpf_refcount", false },
- };
- int type = 0, i;
- const char *name = __btf_name_by_offset(btf, var_type->name_off);
- const char *field_type_name;
- enum btf_field_type field_type;
- bool is_unique;
-
- for (i = 0; i < ARRAY_SIZE(field_types); ++i) {
- field_type = field_types[i].type;
- field_type_name = field_types[i].name;
- is_unique = field_types[i].is_unique;
- if (!(field_mask & field_type) || strcmp(name, field_type_name))
- continue;
- if (is_unique) {
- if (*seen_mask & field_type)
- return -E2BIG;
- *seen_mask |= field_type;
- }
- type = field_type;
- goto end;
- }
-
- /* Only return BPF_KPTR when all other types with matchable names fail */
- if (field_mask & (BPF_KPTR | BPF_UPTR) && !__btf_type_is_struct(var_type)) {
- type = BPF_KPTR_REF;
- goto end;
- }
- return 0;
-end:
- *sz = btf_field_type_size(type);
- *align = btf_field_type_align(type);
- return type;
-}
-
-/* Repeat a number of fields for a specified number of times.
- *
- * Copy the fields starting from the first field and repeat them for
- * repeat_cnt times. The fields are repeated by adding the offset of each
- * field with
- * (i + 1) * elem_size
- * where i is the repeat index and elem_size is the size of an element.
- */
-static int btf_repeat_fields(struct btf_field_info *info, int info_cnt,
- u32 field_cnt, u32 repeat_cnt, u32 elem_size)
-{
- u32 i, j;
- u32 cur;
-
- /* Ensure not repeating fields that should not be repeated. */
- for (i = 0; i < field_cnt; i++) {
- switch (info[i].type) {
- case BPF_KPTR_UNREF:
- case BPF_KPTR_REF:
- case BPF_KPTR_PERCPU:
- case BPF_UPTR:
- case BPF_LIST_HEAD:
- case BPF_RB_ROOT:
- break;
- default:
- return -EINVAL;
- }
- }
-
- /* The type of struct size or variable size is u32,
- * so the multiplication will not overflow.
- */
- if (field_cnt * (repeat_cnt + 1) > info_cnt)
- return -E2BIG;
-
- cur = field_cnt;
- for (i = 0; i < repeat_cnt; i++) {
- memcpy(&info[cur], &info[0], field_cnt * sizeof(info[0]));
- for (j = 0; j < field_cnt; j++)
- info[cur++].off += (i + 1) * elem_size;
- }
-
- return 0;
-}
-
-static int btf_find_struct_field(const struct btf *btf,
- const struct btf_type *t, u32 field_mask,
- struct btf_field_info *info, int info_cnt,
- u32 level);
-
-/* Find special fields in the struct type of a field.
- *
- * This function is used to find fields of special types that is not a
- * global variable or a direct field of a struct type. It also handles the
- * repetition if it is the element type of an array.
- */
-static int btf_find_nested_struct(const struct btf *btf, const struct btf_type *t,
- u32 off, u32 nelems,
- u32 field_mask, struct btf_field_info *info,
- int info_cnt, u32 level)
-{
- int ret, err, i;
-
- level++;
- if (level >= MAX_RESOLVE_DEPTH)
- return -E2BIG;
-
- ret = btf_find_struct_field(btf, t, field_mask, info, info_cnt, level);
-
- if (ret <= 0)
- return ret;
-
- /* Shift the offsets of the nested struct fields to the offsets
- * related to the container.
- */
- for (i = 0; i < ret; i++)
- info[i].off += off;
-
- if (nelems > 1) {
- err = btf_repeat_fields(info, info_cnt, ret, nelems - 1, t->size);
- if (err == 0)
- ret *= nelems;
- else
- ret = err;
- }
-
- return ret;
-}
-
-static int btf_find_field_one(const struct btf *btf,
- const struct btf_type *var,
- const struct btf_type *var_type,
- int var_idx,
- u32 off, u32 expected_size,
- u32 field_mask, u32 *seen_mask,
- struct btf_field_info *info, int info_cnt,
- u32 level)
-{
- int ret, align, sz, field_type;
- struct btf_field_info tmp;
- const struct btf_array *array;
- u32 i, nelems = 1;
-
- /* Walk into array types to find the element type and the number of
- * elements in the (flattened) array.
- */
- for (i = 0; i < MAX_RESOLVE_DEPTH && btf_type_is_array(var_type); i++) {
- array = btf_array(var_type);
- nelems *= array->nelems;
- var_type = btf_type_by_id(btf, array->type);
- }
- if (i == MAX_RESOLVE_DEPTH)
- return -E2BIG;
- if (nelems == 0)
- return 0;
-
- field_type = btf_get_field_type(btf, var_type,
- field_mask, seen_mask, &align, &sz);
- /* Look into variables of struct types */
- if (!field_type && __btf_type_is_struct(var_type)) {
- sz = var_type->size;
- if (expected_size && expected_size != sz * nelems)
- return 0;
- ret = btf_find_nested_struct(btf, var_type, off, nelems, field_mask,
- &info[0], info_cnt, level);
- return ret;
- }
-
- if (field_type == 0)
- return 0;
- if (field_type < 0)
- return field_type;
-
- if (expected_size && expected_size != sz * nelems)
- return 0;
- if (off % align)
- return 0;
-
- switch (field_type) {
- case BPF_SPIN_LOCK:
- case BPF_RES_SPIN_LOCK:
- case BPF_TIMER:
- case BPF_WORKQUEUE:
- case BPF_LIST_NODE:
- case BPF_RB_NODE:
- case BPF_REFCOUNT:
- case BPF_TASK_WORK:
- ret = btf_find_struct(btf, var_type, off, sz, field_type,
- info_cnt ? &info[0] : &tmp);
- if (ret < 0)
- return ret;
- break;
- case BPF_KPTR_UNREF:
- case BPF_KPTR_REF:
- case BPF_KPTR_PERCPU:
- case BPF_UPTR:
- ret = btf_find_kptr(btf, var_type, off, sz,
- info_cnt ? &info[0] : &tmp, field_mask);
- if (ret < 0)
- return ret;
- break;
- case BPF_LIST_HEAD:
- case BPF_RB_ROOT:
- ret = btf_find_graph_root(btf, var, var_type,
- var_idx, off, sz,
- info_cnt ? &info[0] : &tmp,
- field_type);
- if (ret < 0)
- return ret;
- break;
- default:
- return -EFAULT;
- }
-
- if (ret == BTF_FIELD_IGNORE)
- return 0;
- if (!info_cnt)
- return -E2BIG;
- if (nelems > 1) {
- ret = btf_repeat_fields(info, info_cnt, 1, nelems - 1, sz);
- if (ret < 0)
- return ret;
- }
- return nelems;
-}
-
-static int btf_find_struct_field(const struct btf *btf,
- const struct btf_type *t, u32 field_mask,
- struct btf_field_info *info, int info_cnt,
- u32 level)
-{
- int ret, idx = 0;
- const struct btf_member *member;
- u32 i, off, seen_mask = 0;
-
- for_each_member(i, t, member) {
- const struct btf_type *member_type = btf_type_by_id(btf,
- member->type);
-
- off = __btf_member_bit_offset(t, member);
- if (off % 8)
- /* valid C code cannot generate such BTF */
- return -EINVAL;
- off /= 8;
-
- ret = btf_find_field_one(btf, t, member_type, i,
- off, 0,
- field_mask, &seen_mask,
- &info[idx], info_cnt - idx, level);
- if (ret < 0)
- return ret;
- idx += ret;
- }
- return idx;
-}
-
-static int btf_find_datasec_var(const struct btf *btf, const struct btf_type *t,
- u32 field_mask, struct btf_field_info *info,
- int info_cnt, u32 level)
-{
- int ret, idx = 0;
- const struct btf_var_secinfo *vsi;
- u32 i, off, seen_mask = 0;
-
- for_each_vsi(i, t, vsi) {
- const struct btf_type *var = btf_type_by_id(btf, vsi->type);
- const struct btf_type *var_type = btf_type_by_id(btf, var->type);
-
- off = vsi->offset;
- ret = btf_find_field_one(btf, var, var_type, -1, off, vsi->size,
- field_mask, &seen_mask,
- &info[idx], info_cnt - idx,
- level);
- if (ret < 0)
- return ret;
- idx += ret;
- }
- return idx;
-}
-
-static int btf_find_field(const struct btf *btf, const struct btf_type *t,
- u32 field_mask, struct btf_field_info *info,
- int info_cnt)
-{
- if (__btf_type_is_struct(t))
- return btf_find_struct_field(btf, t, field_mask, info, info_cnt, 0);
- else if (btf_type_is_datasec(t))
- return btf_find_datasec_var(btf, t, field_mask, info, info_cnt, 0);
- return -EINVAL;
-}
-
-/* Callers have to ensure the life cycle of btf if it is program BTF */
-static int btf_parse_kptr(const struct btf *btf, struct btf_field *field,
- struct btf_field_info *info)
-{
- struct module *mod = NULL;
- const struct btf_type *t;
- /* If a matching btf type is found in kernel or module BTFs, kptr_ref
- * is that BTF, otherwise it's program BTF
- */
- struct btf *kptr_btf;
- int ret;
- s32 id;
-
- /* Find type in map BTF, and use it to look up the matching type
- * in vmlinux or module BTFs, by name and kind.
- */
- t = btf_type_by_id(btf, info->kptr.type_id);
- id = bpf_find_btf_id(__btf_name_by_offset(btf, t->name_off), BTF_INFO_KIND(t->info),
- &kptr_btf);
- if (id == -ENOENT) {
- /* btf_parse_kptr should only be called w/ btf = program BTF */
- WARN_ON_ONCE(btf_is_kernel(btf));
-
- /* Type exists only in program BTF. Assume that it's a MEM_ALLOC
- * kptr allocated via bpf_obj_new
- */
- field->kptr.dtor = NULL;
- id = info->kptr.type_id;
- kptr_btf = (struct btf *)btf;
- goto found_dtor;
- }
- if (id < 0)
- return id;
-
- /* Find and stash the function pointer for the destruction function that
- * needs to be eventually invoked from the map free path.
- */
- if (info->type == BPF_KPTR_REF) {
- const struct btf_type *dtor_func;
- const char *dtor_func_name;
- unsigned long addr;
- s32 dtor_btf_id;
-
- /* This call also serves as a whitelist of allowed objects that
- * can be used as a referenced pointer and be stored in a map at
- * the same time.
- */
- dtor_btf_id = btf_find_dtor_kfunc(kptr_btf, id);
- if (dtor_btf_id < 0) {
- ret = dtor_btf_id;
- goto end_btf;
- }
-
- dtor_func = btf_type_by_id(kptr_btf, dtor_btf_id);
- if (!dtor_func) {
- ret = -ENOENT;
- goto end_btf;
- }
-
- if (btf_is_module(kptr_btf)) {
- mod = btf_try_get_module(kptr_btf);
- if (!mod) {
- ret = -ENXIO;
- goto end_btf;
- }
- }
-
- /* We already verified dtor_func to be btf_type_is_func
- * in register_btf_id_dtor_kfuncs.
- */
- dtor_func_name = __btf_name_by_offset(kptr_btf, dtor_func->name_off);
- addr = kallsyms_lookup_name(dtor_func_name);
- if (!addr) {
- ret = -EINVAL;
- goto end_mod;
- }
- field->kptr.dtor = (void *)addr;
- }
-
-found_dtor:
- field->kptr.btf_id = id;
- field->kptr.btf = kptr_btf;
- field->kptr.module = mod;
- return 0;
-end_mod:
- module_put(mod);
-end_btf:
- btf_put(kptr_btf);
- return ret;
-}
-
-static int btf_parse_graph_root(const struct btf *btf,
- struct btf_field *field,
- struct btf_field_info *info,
- const char *node_type_name,
- size_t node_type_align)
-{
- const struct btf_type *t, *n = NULL;
- const struct btf_member *member;
- u32 offset;
- int i;
-
- t = btf_type_by_id(btf, info->graph_root.value_btf_id);
- /* We've already checked that value_btf_id is a struct type. We
- * just need to figure out the offset of the list_node, and
- * verify its type.
- */
- for_each_member(i, t, member) {
- if (strcmp(info->graph_root.node_name,
- __btf_name_by_offset(btf, member->name_off)))
- continue;
- /* Invalid BTF, two members with same name */
- if (n)
- return -EINVAL;
- n = btf_type_by_id(btf, member->type);
- if (!__btf_type_is_struct(n))
- return -EINVAL;
- if (strcmp(node_type_name, __btf_name_by_offset(btf, n->name_off)))
- return -EINVAL;
- offset = __btf_member_bit_offset(n, member);
- if (offset % 8)
- return -EINVAL;
- offset /= 8;
- if (offset % node_type_align)
- return -EINVAL;
-
- field->graph_root.btf = (struct btf *)btf;
- field->graph_root.value_btf_id = info->graph_root.value_btf_id;
- field->graph_root.node_offset = offset;
- }
- if (!n)
- return -ENOENT;
- return 0;
-}
-
-static int btf_parse_list_head(const struct btf *btf, struct btf_field *field,
- struct btf_field_info *info)
-{
- return btf_parse_graph_root(btf, field, info, "bpf_list_node",
- __alignof__(struct bpf_list_node));
-}
-
-static int btf_parse_rb_root(const struct btf *btf, struct btf_field *field,
- struct btf_field_info *info)
-{
- return btf_parse_graph_root(btf, field, info, "bpf_rb_node",
- __alignof__(struct bpf_rb_node));
-}
-
-static int btf_field_cmp(const void *_a, const void *_b, const void *priv)
-{
- const struct btf_field *a = (const struct btf_field *)_a;
- const struct btf_field *b = (const struct btf_field *)_b;
-
- if (a->offset < b->offset)
- return -1;
- else if (a->offset > b->offset)
- return 1;
- return 0;
-}
-
-struct btf_record *btf_parse_fields(const struct btf *btf, const struct btf_type *t,
- u32 field_mask, u32 value_size)
-{
- struct btf_field_info info_arr[BTF_FIELDS_MAX];
- u32 next_off = 0, field_type_size;
- struct btf_record *rec;
- int ret, i, cnt;
-
- ret = btf_find_field(btf, t, field_mask, info_arr, ARRAY_SIZE(info_arr));
- if (ret < 0)
- return ERR_PTR(ret);
- if (!ret)
- return NULL;
-
- cnt = ret;
- /* This needs to be kzalloc to zero out padding and unused fields, see
- * comment in btf_record_equal.
- */
- rec = kzalloc_flex(*rec, fields, cnt, GFP_KERNEL_ACCOUNT | __GFP_NOWARN);
- if (!rec)
- return ERR_PTR(-ENOMEM);
-
- rec->spin_lock_off = -EINVAL;
- rec->res_spin_lock_off = -EINVAL;
- rec->timer_off = -EINVAL;
- rec->wq_off = -EINVAL;
- rec->refcount_off = -EINVAL;
- rec->task_work_off = -EINVAL;
- for (i = 0; i < cnt; i++) {
- field_type_size = btf_field_type_size(info_arr[i].type);
- if (info_arr[i].off + field_type_size > value_size) {
- WARN_ONCE(1, "verifier bug off %d size %d", info_arr[i].off, value_size);
- ret = -EFAULT;
- goto end;
- }
- if (info_arr[i].off < next_off) {
- ret = -EEXIST;
- goto end;
- }
- next_off = info_arr[i].off + field_type_size;
-
- rec->field_mask |= info_arr[i].type;
- rec->fields[i].offset = info_arr[i].off;
- rec->fields[i].type = info_arr[i].type;
- rec->fields[i].size = field_type_size;
-
- switch (info_arr[i].type) {
- case BPF_SPIN_LOCK:
- WARN_ON_ONCE(rec->spin_lock_off >= 0);
- /* Cache offset for faster lookup at runtime */
- rec->spin_lock_off = rec->fields[i].offset;
- break;
- case BPF_RES_SPIN_LOCK:
- WARN_ON_ONCE(rec->spin_lock_off >= 0);
- /* Cache offset for faster lookup at runtime */
- rec->res_spin_lock_off = rec->fields[i].offset;
- break;
- case BPF_TIMER:
- WARN_ON_ONCE(rec->timer_off >= 0);
- /* Cache offset for faster lookup at runtime */
- rec->timer_off = rec->fields[i].offset;
- break;
- case BPF_WORKQUEUE:
- WARN_ON_ONCE(rec->wq_off >= 0);
- /* Cache offset for faster lookup at runtime */
- rec->wq_off = rec->fields[i].offset;
- break;
- case BPF_TASK_WORK:
- WARN_ON_ONCE(rec->task_work_off >= 0);
- rec->task_work_off = rec->fields[i].offset;
- break;
- case BPF_REFCOUNT:
- WARN_ON_ONCE(rec->refcount_off >= 0);
- /* Cache offset for faster lookup at runtime */
- rec->refcount_off = rec->fields[i].offset;
- break;
- case BPF_KPTR_UNREF:
- case BPF_KPTR_REF:
- case BPF_KPTR_PERCPU:
- case BPF_UPTR:
- ret = btf_parse_kptr(btf, &rec->fields[i], &info_arr[i]);
- if (ret < 0)
- goto end;
- break;
- case BPF_LIST_HEAD:
- ret = btf_parse_list_head(btf, &rec->fields[i], &info_arr[i]);
- if (ret < 0)
- goto end;
- break;
- case BPF_RB_ROOT:
- ret = btf_parse_rb_root(btf, &rec->fields[i], &info_arr[i]);
- if (ret < 0)
- goto end;
- break;
- case BPF_LIST_NODE:
- case BPF_RB_NODE:
- break;
- default:
- ret = -EFAULT;
- goto end;
- }
- rec->cnt++;
- }
-
- if (rec->spin_lock_off >= 0 && rec->res_spin_lock_off >= 0) {
- ret = -EINVAL;
- goto end;
- }
-
- /* bpf_{list_head, rb_node} require bpf_spin_lock */
- if ((btf_record_has_field(rec, BPF_LIST_HEAD) ||
- btf_record_has_field(rec, BPF_RB_ROOT)) &&
- (rec->spin_lock_off < 0 && rec->res_spin_lock_off < 0)) {
- ret = -EINVAL;
- goto end;
- }
-
- if (rec->refcount_off < 0 &&
- btf_record_has_field(rec, BPF_LIST_NODE) &&
- btf_record_has_field(rec, BPF_RB_NODE)) {
- ret = -EINVAL;
- goto end;
- }
-
- sort_r(rec->fields, rec->cnt, sizeof(struct btf_field), btf_field_cmp,
- NULL, rec);
-
- return rec;
-end:
- btf_record_free(rec);
- return ERR_PTR(ret);
-}
-
-int btf_check_and_fixup_fields(const struct btf *btf, struct btf_record *rec)
-{
- int i;
-
- /* There are three types that signify ownership of some other type:
- * kptr_ref, bpf_list_head, bpf_rb_root.
- * kptr_ref only supports storing kernel types, which can't store
- * references to program allocated local types.
- *
- * Hence we only need to ensure that bpf_{list_head,rb_root} ownership
- * does not form cycles.
- */
- if (IS_ERR_OR_NULL(rec) || !(rec->field_mask & (BPF_GRAPH_ROOT | BPF_UPTR)))
- return 0;
- for (i = 0; i < rec->cnt; i++) {
- struct btf_struct_meta *meta;
- const struct btf_type *t;
- u32 btf_id;
-
- if (rec->fields[i].type == BPF_UPTR) {
- /* The uptr only supports pinning one page and cannot
- * point to a kernel struct
- */
- if (btf_is_kernel(rec->fields[i].kptr.btf))
- return -EINVAL;
- t = btf_type_by_id(rec->fields[i].kptr.btf,
- rec->fields[i].kptr.btf_id);
- if (!t->size)
- return -EINVAL;
- if (t->size > PAGE_SIZE)
- return -E2BIG;
- continue;
- }
-
- if (!(rec->fields[i].type & BPF_GRAPH_ROOT))
- continue;
- btf_id = rec->fields[i].graph_root.value_btf_id;
- meta = btf_find_struct_meta(btf, btf_id);
- if (!meta)
- return -EFAULT;
- rec->fields[i].graph_root.value_rec = meta->record;
-
- /* We need to set value_rec for all root types, but no need
- * to check ownership cycle for a type unless it's also a
- * node type.
- */
- if (!(rec->field_mask & BPF_GRAPH_NODE))
- continue;
-
- /* We need to ensure ownership acyclicity among all types. The
- * proper way to do it would be to topologically sort all BTF
- * IDs based on the ownership edges, since there can be multiple
- * bpf_{list_head,rb_node} in a type. Instead, we use the
- * following resaoning:
- *
- * - A type can only be owned by another type in user BTF if it
- * has a bpf_{list,rb}_node. Let's call these node types.
- * - A type can only _own_ another type in user BTF if it has a
- * bpf_{list_head,rb_root}. Let's call these root types.
- *
- * We ensure that if a type is both a root and node, its
- * element types cannot be root types.
- *
- * To ensure acyclicity:
- *
- * When A is an root type but not a node, its ownership
- * chain can be:
- * A -> B -> C
- * Where:
- * - A is an root, e.g. has bpf_rb_root.
- * - B is both a root and node, e.g. has bpf_rb_node and
- * bpf_list_head.
- * - C is only an root, e.g. has bpf_list_node
- *
- * When A is both a root and node, some other type already
- * owns it in the BTF domain, hence it can not own
- * another root type through any of the ownership edges.
- * A -> B
- * Where:
- * - A is both an root and node.
- * - B is only an node.
- */
- if (meta->record->field_mask & BPF_GRAPH_ROOT)
- return -ELOOP;
- }
- return 0;
-}
-
-static void __btf_struct_show(const struct btf *btf, const struct btf_type *t,
- u32 type_id, void *data, u8 bits_offset,
- struct btf_show *show)
-{
- const struct btf_member *member;
- void *safe_data;
- u32 i;
-
- safe_data = btf_show_start_struct_type(show, t, type_id, data);
- if (!safe_data)
- return;
-
- for_each_member(i, t, member) {
- const struct btf_type *member_type = btf_type_by_id(btf,
- member->type);
- const struct btf_kind_operations *ops;
- u32 member_offset, bitfield_size;
- u32 bytes_offset;
- u8 bits8_offset;
-
- btf_show_start_member(show, member);
-
- member_offset = __btf_member_bit_offset(t, member);
- bitfield_size = __btf_member_bitfield_size(t, member);
- bytes_offset = BITS_ROUNDDOWN_BYTES(member_offset);
- bits8_offset = BITS_PER_BYTE_MASKED(member_offset);
- if (bitfield_size) {
- safe_data = btf_show_start_type(show, member_type,
- member->type,
- data + bytes_offset);
- if (safe_data)
- btf_bitfield_show(safe_data,
- bits8_offset,
- bitfield_size, show);
- btf_show_end_type(show);
- } else {
- ops = btf_type_ops(member_type);
- ops->show(btf, member_type, member->type,
- data + bytes_offset, bits8_offset, show);
- }
-
- btf_show_end_member(show);
- }
-
- btf_show_end_struct_type(show);
-}
-
-static void btf_struct_show(const struct btf *btf, const struct btf_type *t,
- u32 type_id, void *data, u8 bits_offset,
- struct btf_show *show)
-{
- const struct btf_member *m = show->state.member;
-
- /*
- * First check if any members would be shown (are non-zero).
- * See comments above "struct btf_show" definition for more
- * details on how this works at a high-level.
- */
- if (show->state.depth > 0 && !(show->flags & BTF_SHOW_ZERO)) {
- if (!show->state.depth_check) {
- show->state.depth_check = show->state.depth + 1;
- show->state.depth_to_show = 0;
- }
- __btf_struct_show(btf, t, type_id, data, bits_offset, show);
- /* Restore saved member data here */
- show->state.member = m;
- if (show->state.depth_check != show->state.depth + 1)
- return;
- show->state.depth_check = 0;
-
- if (show->state.depth_to_show <= show->state.depth)
- return;
- /*
- * Reaching here indicates we have recursed and found
- * non-zero child values.
- */
- }
-
- __btf_struct_show(btf, t, type_id, data, bits_offset, show);
-}
-
-static const struct btf_kind_operations struct_ops = {
- .check_meta = btf_struct_check_meta,
- .resolve = btf_struct_resolve,
- .check_member = btf_struct_check_member,
- .check_kflag_member = btf_generic_check_kflag_member,
- .log_details = btf_struct_log,
- .show = btf_struct_show,
-};
-
-static int btf_enum_check_member(struct btf_verifier_env *env,
- const struct btf_type *struct_type,
- const struct btf_member *member,
- const struct btf_type *member_type)
-{
- u32 struct_bits_off = member->offset;
- u32 struct_size, bytes_offset;
-
- if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
- btf_verifier_log_member(env, struct_type, member,
- "Member is not byte aligned");
- return -EINVAL;
- }
-
- struct_size = struct_type->size;
- bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
- if (struct_size - bytes_offset < member_type->size) {
- btf_verifier_log_member(env, struct_type, member,
- "Member exceeds struct_size");
- return -EINVAL;
- }
-
- return 0;
-}
-
-static int btf_enum_check_kflag_member(struct btf_verifier_env *env,
- const struct btf_type *struct_type,
- const struct btf_member *member,
- const struct btf_type *member_type)
-{
- u32 struct_bits_off, nr_bits, bytes_end, struct_size;
- u32 int_bitsize = sizeof(int) * BITS_PER_BYTE;
-
- struct_bits_off = BTF_MEMBER_BIT_OFFSET(member->offset);
- nr_bits = BTF_MEMBER_BITFIELD_SIZE(member->offset);
- if (!nr_bits) {
- if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
- btf_verifier_log_member(env, struct_type, member,
- "Member is not byte aligned");
- return -EINVAL;
- }
-
- nr_bits = int_bitsize;
- } else if (nr_bits > int_bitsize) {
- btf_verifier_log_member(env, struct_type, member,
- "Invalid member bitfield_size");
- return -EINVAL;
- }
-
- struct_size = struct_type->size;
- bytes_end = BITS_ROUNDUP_BYTES(struct_bits_off + nr_bits);
- if (struct_size < bytes_end) {
- btf_verifier_log_member(env, struct_type, member,
- "Member exceeds struct_size");
- return -EINVAL;
- }
-
- return 0;
-}
-
-static s32 btf_enum_check_meta(struct btf_verifier_env *env,
- const struct btf_type *t,
- u32 meta_left)
-{
- const struct btf_enum *enums = btf_type_enum(t);
- struct btf *btf = env->btf;
- const char *fmt_str;
- u16 i, nr_enums;
- u32 meta_needed;
-
- nr_enums = btf_type_vlen(t);
- meta_needed = nr_enums * sizeof(*enums);
-
- if (meta_left < meta_needed) {
- btf_verifier_log_basic(env, t,
- "meta_left:%u meta_needed:%u",
- meta_left, meta_needed);
- return -EINVAL;
- }
-
- if (t->size > 8 || !is_power_of_2(t->size)) {
- btf_verifier_log_type(env, t, "Unexpected size");
- return -EINVAL;
- }
-
- /* enum type either no name or a valid one */
- if (t->name_off &&
- !btf_name_valid_identifier(env->btf, t->name_off)) {
- btf_verifier_log_type(env, t, "Invalid name");
- return -EINVAL;
- }
-
- btf_verifier_log_type(env, t, NULL);
-
- for (i = 0; i < nr_enums; i++) {
- if (!btf_name_offset_valid(btf, enums[i].name_off)) {
- btf_verifier_log(env, "\tInvalid name_offset:%u",
- enums[i].name_off);
- return -EINVAL;
- }
-
- /* enum member must have a valid name */
- if (!enums[i].name_off ||
- !btf_name_valid_identifier(btf, enums[i].name_off)) {
- btf_verifier_log_type(env, t, "Invalid name");
- return -EINVAL;
- }
-
- if (env->log.level == BPF_LOG_KERNEL)
- continue;
- fmt_str = btf_type_kflag(t) ? "\t%s val=%d\n" : "\t%s val=%u\n";
- btf_verifier_log(env, fmt_str,
- __btf_name_by_offset(btf, enums[i].name_off),
- enums[i].val);
- }
-
- return meta_needed;
-}
-
-static void btf_enum_log(struct btf_verifier_env *env,
- const struct btf_type *t)
-{
- btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t));
-}
-
-static void btf_enum_show(const struct btf *btf, const struct btf_type *t,
- u32 type_id, void *data, u8 bits_offset,
- struct btf_show *show)
-{
- const struct btf_enum *enums = btf_type_enum(t);
- u32 i, nr_enums = btf_type_vlen(t);
- void *safe_data;
- int v;
-
- safe_data = btf_show_start_type(show, t, type_id, data);
- if (!safe_data)
- return;
-
- v = *(int *)safe_data;
-
- for (i = 0; i < nr_enums; i++) {
- if (v != enums[i].val)
- continue;
-
- btf_show_type_value(show, "%s",
- __btf_name_by_offset(btf,
- enums[i].name_off));
-
- btf_show_end_type(show);
- return;
- }
-
- if (btf_type_kflag(t))
- btf_show_type_value(show, "%d", v);
- else
- btf_show_type_value(show, "%u", v);
- btf_show_end_type(show);
-}
-
-static const struct btf_kind_operations enum_ops = {
- .check_meta = btf_enum_check_meta,
- .resolve = btf_df_resolve,
- .check_member = btf_enum_check_member,
- .check_kflag_member = btf_enum_check_kflag_member,
- .log_details = btf_enum_log,
- .show = btf_enum_show,
-};
-
-static s32 btf_enum64_check_meta(struct btf_verifier_env *env,
- const struct btf_type *t,
- u32 meta_left)
-{
- const struct btf_enum64 *enums = btf_type_enum64(t);
- struct btf *btf = env->btf;
- const char *fmt_str;
- u16 i, nr_enums;
- u32 meta_needed;
-
- nr_enums = btf_type_vlen(t);
- meta_needed = nr_enums * sizeof(*enums);
-
- if (meta_left < meta_needed) {
- btf_verifier_log_basic(env, t,
- "meta_left:%u meta_needed:%u",
- meta_left, meta_needed);
- return -EINVAL;
- }
-
- if (t->size > 8 || !is_power_of_2(t->size)) {
- btf_verifier_log_type(env, t, "Unexpected size");
- return -EINVAL;
- }
-
- /* enum type either no name or a valid one */
- if (t->name_off &&
- !btf_name_valid_identifier(env->btf, t->name_off)) {
- btf_verifier_log_type(env, t, "Invalid name");
- return -EINVAL;
- }
-
- btf_verifier_log_type(env, t, NULL);
-
- for (i = 0; i < nr_enums; i++) {
- if (!btf_name_offset_valid(btf, enums[i].name_off)) {
- btf_verifier_log(env, "\tInvalid name_offset:%u",
- enums[i].name_off);
- return -EINVAL;
- }
-
- /* enum member must have a valid name */
- if (!enums[i].name_off ||
- !btf_name_valid_identifier(btf, enums[i].name_off)) {
- btf_verifier_log_type(env, t, "Invalid name");
- return -EINVAL;
- }
-
- if (env->log.level == BPF_LOG_KERNEL)
- continue;
-
- fmt_str = btf_type_kflag(t) ? "\t%s val=%lld\n" : "\t%s val=%llu\n";
- btf_verifier_log(env, fmt_str,
- __btf_name_by_offset(btf, enums[i].name_off),
- btf_enum64_value(enums + i));
- }
-
- return meta_needed;
-}
-
-static void btf_enum64_show(const struct btf *btf, const struct btf_type *t,
- u32 type_id, void *data, u8 bits_offset,
- struct btf_show *show)
-{
- const struct btf_enum64 *enums = btf_type_enum64(t);
- u32 i, nr_enums = btf_type_vlen(t);
- void *safe_data;
- s64 v;
-
- safe_data = btf_show_start_type(show, t, type_id, data);
- if (!safe_data)
- return;
-
- v = *(u64 *)safe_data;
-
- for (i = 0; i < nr_enums; i++) {
- if (v != btf_enum64_value(enums + i))
- continue;
-
- btf_show_type_value(show, "%s",
- __btf_name_by_offset(btf,
- enums[i].name_off));
-
- btf_show_end_type(show);
- return;
- }
-
- if (btf_type_kflag(t))
- btf_show_type_value(show, "%lld", v);
- else
- btf_show_type_value(show, "%llu", v);
- btf_show_end_type(show);
-}
-
-static const struct btf_kind_operations enum64_ops = {
- .check_meta = btf_enum64_check_meta,
- .resolve = btf_df_resolve,
- .check_member = btf_enum_check_member,
- .check_kflag_member = btf_enum_check_kflag_member,
- .log_details = btf_enum_log,
- .show = btf_enum64_show,
-};
-
-static s32 btf_func_proto_check_meta(struct btf_verifier_env *env,
- const struct btf_type *t,
- u32 meta_left)
-{
- u32 meta_needed = btf_type_vlen(t) * sizeof(struct btf_param);
-
- if (meta_left < meta_needed) {
- btf_verifier_log_basic(env, t,
- "meta_left:%u meta_needed:%u",
- meta_left, meta_needed);
- return -EINVAL;
- }
-
- if (t->name_off) {
- btf_verifier_log_type(env, t, "Invalid name");
- return -EINVAL;
- }
-
- if (btf_type_kflag(t)) {
- btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
- return -EINVAL;
- }
-
- btf_verifier_log_type(env, t, NULL);
-
- return meta_needed;
-}
-
-static void btf_func_proto_log(struct btf_verifier_env *env,
- const struct btf_type *t)
-{
- const struct btf_param *args = (const struct btf_param *)(t + 1);
- u16 nr_args = btf_type_vlen(t), i;
-
- btf_verifier_log(env, "return=%u args=(", t->type);
- if (!nr_args) {
- btf_verifier_log(env, "void");
- goto done;
- }
-
- if (nr_args == 1 && !args[0].type) {
- /* Only one vararg */
- btf_verifier_log(env, "vararg");
- goto done;
- }
-
- btf_verifier_log(env, "%u %s", args[0].type,
- __btf_name_by_offset(env->btf,
- args[0].name_off));
- for (i = 1; i < nr_args - 1; i++)
- btf_verifier_log(env, ", %u %s", args[i].type,
- __btf_name_by_offset(env->btf,
- args[i].name_off));
-
- if (nr_args > 1) {
- const struct btf_param *last_arg = &args[nr_args - 1];
-
- if (last_arg->type)
- btf_verifier_log(env, ", %u %s", last_arg->type,
- __btf_name_by_offset(env->btf,
- last_arg->name_off));
- else
- btf_verifier_log(env, ", vararg");
- }
-
-done:
- btf_verifier_log(env, ")");
-}
-
-static const struct btf_kind_operations func_proto_ops = {
- .check_meta = btf_func_proto_check_meta,
- .resolve = btf_df_resolve,
- /*
- * BTF_KIND_FUNC_PROTO cannot be directly referred by
- * a struct's member.
- *
- * It should be a function pointer instead.
- * (i.e. struct's member -> BTF_KIND_PTR -> BTF_KIND_FUNC_PROTO)
- *
- * Hence, there is no btf_func_check_member().
- */
- .check_member = btf_df_check_member,
- .check_kflag_member = btf_df_check_kflag_member,
- .log_details = btf_func_proto_log,
- .show = btf_df_show,
-};
-
-static s32 btf_func_check_meta(struct btf_verifier_env *env,
- const struct btf_type *t,
- u32 meta_left)
-{
- if (!t->name_off ||
- !btf_name_valid_identifier(env->btf, t->name_off)) {
- btf_verifier_log_type(env, t, "Invalid name");
- return -EINVAL;
- }
-
- if (btf_type_vlen(t) > BTF_FUNC_GLOBAL) {
- btf_verifier_log_type(env, t, "Invalid func linkage");
- return -EINVAL;
- }
-
- if (btf_type_kflag(t)) {
- btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
- return -EINVAL;
- }
-
- btf_verifier_log_type(env, t, NULL);
-
- return 0;
-}
-
-static int btf_func_resolve(struct btf_verifier_env *env,
- const struct resolve_vertex *v)
-{
- const struct btf_type *t = v->t;
- u32 next_type_id = t->type;
- int err;
-
- err = btf_func_check(env, t);
- if (err)
- return err;
-
- env_stack_pop_resolved(env, next_type_id, 0);
- return 0;
-}
-
-static const struct btf_kind_operations func_ops = {
- .check_meta = btf_func_check_meta,
- .resolve = btf_func_resolve,
- .check_member = btf_df_check_member,
- .check_kflag_member = btf_df_check_kflag_member,
- .log_details = btf_ref_type_log,
- .show = btf_df_show,
-};
-
-static s32 btf_var_check_meta(struct btf_verifier_env *env,
- const struct btf_type *t,
- u32 meta_left)
-{
- const struct btf_var *var;
- u32 meta_needed = sizeof(*var);
-
- if (meta_left < meta_needed) {
- btf_verifier_log_basic(env, t,
- "meta_left:%u meta_needed:%u",
- meta_left, meta_needed);
- return -EINVAL;
- }
-
- if (btf_type_vlen(t)) {
- btf_verifier_log_type(env, t, "vlen != 0");
- return -EINVAL;
- }
-
- if (btf_type_kflag(t)) {
- btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
- return -EINVAL;
- }
-
- if (!t->name_off ||
- !btf_name_valid_identifier(env->btf, t->name_off)) {
- btf_verifier_log_type(env, t, "Invalid name");
- return -EINVAL;
- }
-
- /* A var cannot be in type void */
- if (!t->type || !BTF_TYPE_ID_VALID(t->type)) {
- btf_verifier_log_type(env, t, "Invalid type_id");
- return -EINVAL;
- }
-
- var = btf_type_var(t);
- if (var->linkage != BTF_VAR_STATIC &&
- var->linkage != BTF_VAR_GLOBAL_ALLOCATED) {
- btf_verifier_log_type(env, t, "Linkage not supported");
- return -EINVAL;
- }
-
- btf_verifier_log_type(env, t, NULL);
-
- return meta_needed;
-}
-
-static void btf_var_log(struct btf_verifier_env *env, const struct btf_type *t)
-{
- const struct btf_var *var = btf_type_var(t);
-
- btf_verifier_log(env, "type_id=%u linkage=%u", t->type, var->linkage);
-}
-
-static const struct btf_kind_operations var_ops = {
- .check_meta = btf_var_check_meta,
- .resolve = btf_var_resolve,
- .check_member = btf_df_check_member,
- .check_kflag_member = btf_df_check_kflag_member,
- .log_details = btf_var_log,
- .show = btf_var_show,
-};
-
-static s32 btf_datasec_check_meta(struct btf_verifier_env *env,
- const struct btf_type *t,
- u32 meta_left)
-{
- const struct btf_var_secinfo *vsi;
- u64 last_vsi_end_off = 0, sum = 0;
- u32 i, meta_needed;
-
- meta_needed = btf_type_vlen(t) * sizeof(*vsi);
- if (meta_left < meta_needed) {
- btf_verifier_log_basic(env, t,
- "meta_left:%u meta_needed:%u",
- meta_left, meta_needed);
- return -EINVAL;
- }
-
- if (!t->size) {
- btf_verifier_log_type(env, t, "size == 0");
- return -EINVAL;
- }
-
- if (btf_type_kflag(t)) {
- btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
- return -EINVAL;
- }
-
- if (!t->name_off ||
- !btf_name_valid_section(env->btf, t->name_off)) {
- btf_verifier_log_type(env, t, "Invalid name");
- return -EINVAL;
- }
-
- btf_verifier_log_type(env, t, NULL);
-
- for_each_vsi(i, t, vsi) {
- /* A var cannot be in type void */
- if (!vsi->type || !BTF_TYPE_ID_VALID(vsi->type)) {
- btf_verifier_log_vsi(env, t, vsi,
- "Invalid type_id");
- return -EINVAL;
- }
-
- if (vsi->offset < last_vsi_end_off || vsi->offset >= t->size) {
- btf_verifier_log_vsi(env, t, vsi,
- "Invalid offset");
- return -EINVAL;
- }
-
- if (!vsi->size || vsi->size > t->size) {
- btf_verifier_log_vsi(env, t, vsi,
- "Invalid size");
- return -EINVAL;
- }
-
- last_vsi_end_off = vsi->offset + vsi->size;
- if (last_vsi_end_off > t->size) {
- btf_verifier_log_vsi(env, t, vsi,
- "Invalid offset+size");
- return -EINVAL;
- }
-
- btf_verifier_log_vsi(env, t, vsi, NULL);
- sum += vsi->size;
- }
-
- if (t->size < sum) {
- btf_verifier_log_type(env, t, "Invalid btf_info size");
- return -EINVAL;
- }
-
- return meta_needed;
-}
-
-static int btf_datasec_resolve(struct btf_verifier_env *env,
- const struct resolve_vertex *v)
-{
- const struct btf_var_secinfo *vsi;
- struct btf *btf = env->btf;
- u16 i;
-
- env->resolve_mode = RESOLVE_TBD;
- for_each_vsi_from(i, v->next_member, v->t, vsi) {
- u32 var_type_id = vsi->type, type_id, type_size = 0;
- const struct btf_type *var_type = btf_type_by_id(env->btf,
- var_type_id);
- if (!var_type || !btf_type_is_var(var_type)) {
- btf_verifier_log_vsi(env, v->t, vsi,
- "Not a VAR kind member");
- return -EINVAL;
- }
-
- if (!env_type_is_resolve_sink(env, var_type) &&
- !env_type_is_resolved(env, var_type_id)) {
- env_stack_set_next_member(env, i + 1);
- return env_stack_push(env, var_type, var_type_id);
- }
-
- type_id = var_type->type;
- if (!btf_type_id_size(btf, &type_id, &type_size)) {
- btf_verifier_log_vsi(env, v->t, vsi, "Invalid type");
- return -EINVAL;
- }
-
- if (vsi->size < type_size) {
- btf_verifier_log_vsi(env, v->t, vsi, "Invalid size");
- return -EINVAL;
- }
- }
-
- env_stack_pop_resolved(env, 0, 0);
- return 0;
-}
-
-static void btf_datasec_log(struct btf_verifier_env *env,
- const struct btf_type *t)
-{
- btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t));
-}
-
-static void btf_datasec_show(const struct btf *btf,
- const struct btf_type *t, u32 type_id,
- void *data, u8 bits_offset,
- struct btf_show *show)
-{
- const struct btf_var_secinfo *vsi;
- const struct btf_type *var;
- u32 i;
-
- if (!btf_show_start_type(show, t, type_id, data))
- return;
-
- btf_show_type_value(show, "section (\"%s\") = {",
- __btf_name_by_offset(btf, t->name_off));
- for_each_vsi(i, t, vsi) {
- var = btf_type_by_id(btf, vsi->type);
- if (i)
- btf_show(show, ",");
- btf_type_ops(var)->show(btf, var, vsi->type,
- data + vsi->offset, bits_offset, show);
- }
- btf_show_end_type(show);
-}
-
-static const struct btf_kind_operations datasec_ops = {
- .check_meta = btf_datasec_check_meta,
- .resolve = btf_datasec_resolve,
- .check_member = btf_df_check_member,
- .check_kflag_member = btf_df_check_kflag_member,
- .log_details = btf_datasec_log,
- .show = btf_datasec_show,
-};
-
-static s32 btf_float_check_meta(struct btf_verifier_env *env,
- const struct btf_type *t,
- u32 meta_left)
-{
- if (btf_type_vlen(t)) {
- btf_verifier_log_type(env, t, "vlen != 0");
- return -EINVAL;
- }
-
- if (btf_type_kflag(t)) {
- btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
- return -EINVAL;
- }
-
- if (t->size != 2 && t->size != 4 && t->size != 8 && t->size != 12 &&
- t->size != 16) {
- btf_verifier_log_type(env, t, "Invalid type_size");
- return -EINVAL;
- }
-
- btf_verifier_log_type(env, t, NULL);
-
- return 0;
-}
-
-static int btf_float_check_member(struct btf_verifier_env *env,
- const struct btf_type *struct_type,
- const struct btf_member *member,
- const struct btf_type *member_type)
-{
- u64 start_offset_bytes;
- u64 end_offset_bytes;
- u64 misalign_bits;
- u64 align_bytes;
- u64 align_bits;
-
- /* Different architectures have different alignment requirements, so
- * here we check only for the reasonable minimum. This way we ensure
- * that types after CO-RE can pass the kernel BTF verifier.
- */
- align_bytes = min_t(u64, sizeof(void *), member_type->size);
- align_bits = align_bytes * BITS_PER_BYTE;
- div64_u64_rem(member->offset, align_bits, &misalign_bits);
- if (misalign_bits) {
- btf_verifier_log_member(env, struct_type, member,
- "Member is not properly aligned");
- return -EINVAL;
- }
-
- start_offset_bytes = member->offset / BITS_PER_BYTE;
- end_offset_bytes = start_offset_bytes + member_type->size;
- if (end_offset_bytes > struct_type->size) {
- btf_verifier_log_member(env, struct_type, member,
- "Member exceeds struct_size");
- return -EINVAL;
- }
-
- return 0;
-}
-
-static void btf_float_log(struct btf_verifier_env *env,
- const struct btf_type *t)
-{
- btf_verifier_log(env, "size=%u", t->size);
-}
-
-static const struct btf_kind_operations float_ops = {
- .check_meta = btf_float_check_meta,
- .resolve = btf_df_resolve,
- .check_member = btf_float_check_member,
- .check_kflag_member = btf_generic_check_kflag_member,
- .log_details = btf_float_log,
- .show = btf_df_show,
-};
-
-static s32 btf_decl_tag_check_meta(struct btf_verifier_env *env,
- const struct btf_type *t,
- u32 meta_left)
-{
- const struct btf_decl_tag *tag;
- u32 meta_needed = sizeof(*tag);
- s32 component_idx;
- const char *value;
-
- if (meta_left < meta_needed) {
- btf_verifier_log_basic(env, t,
- "meta_left:%u meta_needed:%u",
- meta_left, meta_needed);
- return -EINVAL;
- }
-
- value = btf_name_by_offset(env->btf, t->name_off);
- if (!value || !value[0]) {
- btf_verifier_log_type(env, t, "Invalid value");
- return -EINVAL;
- }
-
- if (btf_type_vlen(t)) {
- btf_verifier_log_type(env, t, "vlen != 0");
- return -EINVAL;
- }
-
- component_idx = btf_type_decl_tag(t)->component_idx;
- if (component_idx < -1) {
- btf_verifier_log_type(env, t, "Invalid component_idx");
- return -EINVAL;
- }
-
- btf_verifier_log_type(env, t, NULL);
-
- return meta_needed;
-}
-
-static int btf_decl_tag_resolve(struct btf_verifier_env *env,
- const struct resolve_vertex *v)
-{
- const struct btf_type *next_type;
- const struct btf_type *t = v->t;
- u32 next_type_id = t->type;
- struct btf *btf = env->btf;
- s32 component_idx;
- u32 vlen;
-
- next_type = btf_type_by_id(btf, next_type_id);
- if (!next_type || !btf_type_is_decl_tag_target(next_type)) {
- btf_verifier_log_type(env, v->t, "Invalid type_id");
- return -EINVAL;
- }
-
- if (!env_type_is_resolve_sink(env, next_type) &&
- !env_type_is_resolved(env, next_type_id))
- return env_stack_push(env, next_type, next_type_id);
-
- component_idx = btf_type_decl_tag(t)->component_idx;
- if (component_idx != -1) {
- if (btf_type_is_var(next_type) || btf_type_is_typedef(next_type)) {
- btf_verifier_log_type(env, v->t, "Invalid component_idx");
- return -EINVAL;
- }
-
- if (btf_type_is_struct(next_type)) {
- vlen = btf_type_vlen(next_type);
- } else {
- /* next_type should be a function */
- next_type = btf_type_by_id(btf, next_type->type);
- vlen = btf_type_vlen(next_type);
- }
-
- if ((u32)component_idx >= vlen) {
- btf_verifier_log_type(env, v->t, "Invalid component_idx");
- return -EINVAL;
- }
- }
-
- env_stack_pop_resolved(env, next_type_id, 0);
-
- return 0;
-}
-
-static void btf_decl_tag_log(struct btf_verifier_env *env, const struct btf_type *t)
-{
- btf_verifier_log(env, "type=%u component_idx=%d", t->type,
- btf_type_decl_tag(t)->component_idx);
-}
-
-static const struct btf_kind_operations decl_tag_ops = {
- .check_meta = btf_decl_tag_check_meta,
- .resolve = btf_decl_tag_resolve,
- .check_member = btf_df_check_member,
- .check_kflag_member = btf_df_check_kflag_member,
- .log_details = btf_decl_tag_log,
- .show = btf_df_show,
-};
-
-static int btf_func_proto_check(struct btf_verifier_env *env,
- const struct btf_type *t)
-{
- const struct btf_type *ret_type;
- const struct btf_param *args;
- const struct btf *btf;
- u16 nr_args, i;
- int err;
-
- btf = env->btf;
- args = (const struct btf_param *)(t + 1);
- nr_args = btf_type_vlen(t);
-
- /* Check func return type which could be "void" (t->type == 0) */
- if (t->type) {
- u32 ret_type_id = t->type;
-
- ret_type = btf_type_by_id(btf, ret_type_id);
- if (!ret_type) {
- btf_verifier_log_type(env, t, "Invalid return type");
- return -EINVAL;
- }
-
- if (btf_type_is_resolve_source_only(ret_type)) {
- btf_verifier_log_type(env, t, "Invalid return type");
- return -EINVAL;
- }
-
- if (btf_type_needs_resolve(ret_type) &&
- !env_type_is_resolved(env, ret_type_id)) {
- err = btf_resolve(env, ret_type, ret_type_id);
- if (err)
- return err;
- }
-
- /* Ensure the return type is a type that has a size */
- if (!btf_type_id_size(btf, &ret_type_id, NULL)) {
- btf_verifier_log_type(env, t, "Invalid return type");
- return -EINVAL;
- }
- }
-
- if (!nr_args)
- return 0;
-
- /* Last func arg type_id could be 0 if it is a vararg */
- if (!args[nr_args - 1].type) {
- if (args[nr_args - 1].name_off) {
- btf_verifier_log_type(env, t, "Invalid arg#%u",
- nr_args);
- return -EINVAL;
- }
- nr_args--;
- }
-
- for (i = 0; i < nr_args; i++) {
- const struct btf_type *arg_type;
- u32 arg_type_id;
-
- arg_type_id = args[i].type;
- arg_type = btf_type_by_id(btf, arg_type_id);
- if (!arg_type) {
- btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1);
- return -EINVAL;
- }
-
- if (btf_type_is_resolve_source_only(arg_type)) {
- btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1);
- return -EINVAL;
- }
-
- if (args[i].name_off &&
- (!btf_name_offset_valid(btf, args[i].name_off) ||
- !btf_name_valid_identifier(btf, args[i].name_off))) {
- btf_verifier_log_type(env, t,
- "Invalid arg#%u", i + 1);
- return -EINVAL;
- }
-
- if (btf_type_needs_resolve(arg_type) &&
- !env_type_is_resolved(env, arg_type_id)) {
- err = btf_resolve(env, arg_type, arg_type_id);
- if (err)
- return err;
- }
-
- if (!btf_type_id_size(btf, &arg_type_id, NULL)) {
- btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1);
- return -EINVAL;
- }
- }
-
- return 0;
-}
-
-static int btf_func_check(struct btf_verifier_env *env,
- const struct btf_type *t)
-{
- const struct btf_type *proto_type;
- const struct btf_param *args;
- const struct btf *btf;
- u16 nr_args, i;
-
- btf = env->btf;
- proto_type = btf_type_by_id(btf, t->type);
-
- if (!proto_type || !btf_type_is_func_proto(proto_type)) {
- btf_verifier_log_type(env, t, "Invalid type_id");
- return -EINVAL;
- }
-
- args = (const struct btf_param *)(proto_type + 1);
- nr_args = btf_type_vlen(proto_type);
- for (i = 0; i < nr_args; i++) {
- if (!args[i].name_off && args[i].type) {
- btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1);
- return -EINVAL;
- }
- }
-
- return 0;
-}
-
-static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS] = {
- [BTF_KIND_INT] = &int_ops,
- [BTF_KIND_PTR] = &ptr_ops,
- [BTF_KIND_ARRAY] = &array_ops,
- [BTF_KIND_STRUCT] = &struct_ops,
- [BTF_KIND_UNION] = &struct_ops,
- [BTF_KIND_ENUM] = &enum_ops,
- [BTF_KIND_FWD] = &fwd_ops,
- [BTF_KIND_TYPEDEF] = &modifier_ops,
- [BTF_KIND_VOLATILE] = &modifier_ops,
- [BTF_KIND_CONST] = &modifier_ops,
- [BTF_KIND_RESTRICT] = &modifier_ops,
- [BTF_KIND_FUNC] = &func_ops,
- [BTF_KIND_FUNC_PROTO] = &func_proto_ops,
- [BTF_KIND_VAR] = &var_ops,
- [BTF_KIND_DATASEC] = &datasec_ops,
- [BTF_KIND_FLOAT] = &float_ops,
- [BTF_KIND_DECL_TAG] = &decl_tag_ops,
- [BTF_KIND_TYPE_TAG] = &modifier_ops,
- [BTF_KIND_ENUM64] = &enum64_ops,
-};
-
-static s32 btf_check_meta(struct btf_verifier_env *env,
- const struct btf_type *t,
- u32 meta_left)
-{
- u32 saved_meta_left = meta_left;
- s32 var_meta_size;
-
- if (meta_left < sizeof(*t)) {
- btf_verifier_log(env, "[%u] meta_left:%u meta_needed:%zu",
- env->log_type_id, meta_left, sizeof(*t));
- return -EINVAL;
- }
- meta_left -= sizeof(*t);
-
- if (t->info & ~BTF_INFO_MASK) {
- btf_verifier_log(env, "[%u] Invalid btf_info:%x",
- env->log_type_id, t->info);
- return -EINVAL;
- }
-
- if (BTF_INFO_KIND(t->info) > BTF_KIND_MAX ||
- BTF_INFO_KIND(t->info) == BTF_KIND_UNKN) {
- btf_verifier_log(env, "[%u] Invalid kind:%u",
- env->log_type_id, BTF_INFO_KIND(t->info));
- return -EINVAL;
- }
-
- if (!btf_name_offset_valid(env->btf, t->name_off)) {
- btf_verifier_log(env, "[%u] Invalid name_offset:%u",
- env->log_type_id, t->name_off);
- return -EINVAL;
- }
-
- var_meta_size = btf_type_ops(t)->check_meta(env, t, meta_left);
- if (var_meta_size < 0)
- return var_meta_size;
-
- meta_left -= var_meta_size;
-
- return saved_meta_left - meta_left;
-}
-
-static int btf_check_all_metas(struct btf_verifier_env *env)
-{
- struct btf *btf = env->btf;
- struct btf_header *hdr;
- void *cur, *end;
-
- hdr = &btf->hdr;
- cur = btf->nohdr_data + hdr->type_off;
- end = cur + hdr->type_len;
-
- env->log_type_id = btf->base_btf ? btf->start_id : 1;
- while (cur < end) {
- struct btf_type *t = cur;
- s32 meta_size;
-
- meta_size = btf_check_meta(env, t, end - cur);
- if (meta_size < 0)
- return meta_size;
-
- btf_add_type(env, t);
- cur += meta_size;
- env->log_type_id++;
- }
-
- return 0;
-}
-
-static bool btf_resolve_valid(struct btf_verifier_env *env,
- const struct btf_type *t,
- u32 type_id)
-{
- struct btf *btf = env->btf;
-
- if (!env_type_is_resolved(env, type_id))
- return false;
-
- if (btf_type_is_struct(t) || btf_type_is_datasec(t))
- return !btf_resolved_type_id(btf, type_id) &&
- !btf_resolved_type_size(btf, type_id);
-
- if (btf_type_is_decl_tag(t) || btf_type_is_func(t))
- return btf_resolved_type_id(btf, type_id) &&
- !btf_resolved_type_size(btf, type_id);
-
- if (btf_type_is_modifier(t) || btf_type_is_ptr(t) ||
- btf_type_is_var(t)) {
- t = btf_type_id_resolve(btf, &type_id);
- return t &&
- !btf_type_is_modifier(t) &&
- !btf_type_is_var(t) &&
- !btf_type_is_datasec(t);
- }
-
- if (btf_type_is_array(t)) {
- const struct btf_array *array = btf_type_array(t);
- const struct btf_type *elem_type;
- u32 elem_type_id = array->type;
- u32 elem_size;
-
- elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size);
- return elem_type && !btf_type_is_modifier(elem_type) &&
- (array->nelems * elem_size ==
- btf_resolved_type_size(btf, type_id));
- }
-
- return false;
-}
-
-static int btf_resolve(struct btf_verifier_env *env,
- const struct btf_type *t, u32 type_id)
-{
- u32 save_log_type_id = env->log_type_id;
- const struct resolve_vertex *v;
- int err = 0;
-
- env->resolve_mode = RESOLVE_TBD;
- env_stack_push(env, t, type_id);
- while (!err && (v = env_stack_peak(env))) {
- env->log_type_id = v->type_id;
- err = btf_type_ops(v->t)->resolve(env, v);
- }
-
- env->log_type_id = type_id;
- if (err == -E2BIG) {
- btf_verifier_log_type(env, t,
- "Exceeded max resolving depth:%u",
- MAX_RESOLVE_DEPTH);
- } else if (err == -EEXIST) {
- btf_verifier_log_type(env, t, "Loop detected");
- }
-
- /* Final sanity check */
- if (!err && !btf_resolve_valid(env, t, type_id)) {
- btf_verifier_log_type(env, t, "Invalid resolve state");
- err = -EINVAL;
- }
-
- env->log_type_id = save_log_type_id;
- return err;
-}
-
-static int btf_check_all_types(struct btf_verifier_env *env)
-{
- struct btf *btf = env->btf;
- const struct btf_type *t;
- u32 type_id, i;
- int err;
-
- err = env_resolve_init(env);
- if (err)
- return err;
-
- env->phase++;
- for (i = btf->base_btf ? 0 : 1; i < btf->nr_types; i++) {
- type_id = btf->start_id + i;
- t = btf_type_by_id(btf, type_id);
-
- env->log_type_id = type_id;
- if (btf_type_needs_resolve(t) &&
- !env_type_is_resolved(env, type_id)) {
- err = btf_resolve(env, t, type_id);
- if (err)
- return err;
- }
-
- if (btf_type_is_func_proto(t)) {
- err = btf_func_proto_check(env, t);
- if (err)
- return err;
- }
- }
-
- return 0;
-}
-
-static int btf_parse_type_sec(struct btf_verifier_env *env)
-{
- const struct btf_header *hdr = &env->btf->hdr;
- int err;
-
- /* Type section must align to 4 bytes */
- if (hdr->type_off & (sizeof(u32) - 1)) {
- btf_verifier_log(env, "Unaligned type_off");
- return -EINVAL;
- }
-
- if (!env->btf->base_btf && !hdr->type_len) {
- btf_verifier_log(env, "No type found");
- return -EINVAL;
- }
-
- err = btf_check_all_metas(env);
- if (err)
- return err;
-
- return btf_check_all_types(env);
-}
-
-static int btf_parse_str_sec(struct btf_verifier_env *env)
-{
- const struct btf_header *hdr;
- struct btf *btf = env->btf;
- const char *start, *end;
-
- hdr = &btf->hdr;
- start = btf->nohdr_data + hdr->str_off;
- end = start + hdr->str_len;
-
- if (end != btf->data + btf->data_size) {
- btf_verifier_log(env, "String section is not at the end");
- return -EINVAL;
- }
-
- btf->strings = start;
-
- if (btf->base_btf && !hdr->str_len)
- return 0;
- if (!hdr->str_len || hdr->str_len - 1 > BTF_MAX_NAME_OFFSET || end[-1]) {
- btf_verifier_log(env, "Invalid string section");
- return -EINVAL;
- }
- if (!btf->base_btf && start[0]) {
- btf_verifier_log(env, "Invalid string section");
- return -EINVAL;
- }
-
- return 0;
-}
-
-static const size_t btf_sec_info_offset[] = {
- offsetof(struct btf_header, type_off),
- offsetof(struct btf_header, str_off),
-};
-
-static int btf_sec_info_cmp(const void *a, const void *b)
-{
- const struct btf_sec_info *x = a;
- const struct btf_sec_info *y = b;
-
- return (int)(x->off - y->off) ? : (int)(x->len - y->len);
-}
+ if (rec->spin_lock_off >= 0 && rec->res_spin_lock_off >= 0) {
+ ret = -EINVAL;
+ goto end;
+ }
-static int btf_check_sec_info(struct btf_verifier_env *env,
- u32 btf_data_size)
-{
- struct btf_sec_info secs[ARRAY_SIZE(btf_sec_info_offset)];
- u32 total, expected_total, i;
- const struct btf_header *hdr;
- const struct btf *btf;
-
- btf = env->btf;
- hdr = &btf->hdr;
-
- /* Populate the secs from hdr */
- for (i = 0; i < ARRAY_SIZE(btf_sec_info_offset); i++)
- secs[i] = *(struct btf_sec_info *)((void *)hdr +
- btf_sec_info_offset[i]);
-
- sort(secs, ARRAY_SIZE(btf_sec_info_offset),
- sizeof(struct btf_sec_info), btf_sec_info_cmp, NULL);
-
- /* Check for gaps and overlap among sections */
- total = 0;
- expected_total = btf_data_size - hdr->hdr_len;
- for (i = 0; i < ARRAY_SIZE(btf_sec_info_offset); i++) {
- if (expected_total < secs[i].off) {
- btf_verifier_log(env, "Invalid section offset");
- return -EINVAL;
- }
- if (total < secs[i].off) {
- /* gap */
- btf_verifier_log(env, "Unsupported section found");
- return -EINVAL;
- }
- if (total > secs[i].off) {
- btf_verifier_log(env, "Section overlap found");
- return -EINVAL;
- }
- if (expected_total - total < secs[i].len) {
- btf_verifier_log(env,
- "Total section length too long");
- return -EINVAL;
- }
- total += secs[i].len;
+ /* bpf_{list_head, rb_node} require bpf_spin_lock */
+ if ((btf_record_has_field(rec, BPF_LIST_HEAD) ||
+ btf_record_has_field(rec, BPF_RB_ROOT)) &&
+ (rec->spin_lock_off < 0 && rec->res_spin_lock_off < 0)) {
+ ret = -EINVAL;
+ goto end;
}
- /* There is data other than hdr and known sections */
- if (expected_total != total) {
- btf_verifier_log(env, "Unsupported section found");
- return -EINVAL;
+ if (rec->refcount_off < 0 &&
+ btf_record_has_field(rec, BPF_LIST_NODE) &&
+ btf_record_has_field(rec, BPF_RB_NODE)) {
+ ret = -EINVAL;
+ goto end;
}
- return 0;
+ sort_r(rec->fields, rec->cnt, sizeof(struct btf_field), btf_field_cmp,
+ NULL, rec);
+
+ return rec;
+end:
+ btf_record_free(rec);
+ return ERR_PTR(ret);
}
-static int btf_parse_hdr(struct btf_verifier_env *env)
+int btf_check_and_fixup_fields(const struct btf *btf, struct btf_record *rec)
{
- u32 hdr_len, hdr_copy, btf_data_size;
- const struct btf_header *hdr;
- struct btf *btf;
-
- btf = env->btf;
- btf_data_size = btf->data_size;
-
- if (btf_data_size < offsetofend(struct btf_header, hdr_len)) {
- btf_verifier_log(env, "hdr_len not found");
- return -EINVAL;
- }
-
- hdr = btf->data;
- hdr_len = hdr->hdr_len;
- if (btf_data_size < hdr_len) {
- btf_verifier_log(env, "btf_header not found");
- return -EINVAL;
- }
+ int i;
- /* Ensure the unsupported header fields are zero */
- if (hdr_len > sizeof(btf->hdr)) {
- u8 *expected_zero = btf->data + sizeof(btf->hdr);
- u8 *end = btf->data + hdr_len;
+ /* There are three types that signify ownership of some other type:
+ * kptr_ref, bpf_list_head, bpf_rb_root.
+ * kptr_ref only supports storing kernel types, which can't store
+ * references to program allocated local types.
+ *
+ * Hence we only need to ensure that bpf_{list_head,rb_root} ownership
+ * does not form cycles.
+ */
+ if (IS_ERR_OR_NULL(rec) || !(rec->field_mask & (BPF_GRAPH_ROOT | BPF_UPTR)))
+ return 0;
+ for (i = 0; i < rec->cnt; i++) {
+ struct btf_struct_meta *meta;
+ const struct btf_type *t;
+ u32 btf_id;
- for (; expected_zero < end; expected_zero++) {
- if (*expected_zero) {
- btf_verifier_log(env, "Unsupported btf_header");
+ if (rec->fields[i].type == BPF_UPTR) {
+ /* The uptr only supports pinning one page and cannot
+ * point to a kernel struct
+ */
+ if (btf_is_kernel(rec->fields[i].kptr.btf))
+ return -EINVAL;
+ t = btf_type_by_id(rec->fields[i].kptr.btf,
+ rec->fields[i].kptr.btf_id);
+ if (!t->size)
+ return -EINVAL;
+ if (t->size > PAGE_SIZE)
return -E2BIG;
- }
+ continue;
}
- }
-
- hdr_copy = min_t(u32, hdr_len, sizeof(btf->hdr));
- memcpy(&btf->hdr, btf->data, hdr_copy);
- hdr = &btf->hdr;
-
- btf_verifier_log_hdr(env, btf_data_size);
-
- if (hdr->magic != BTF_MAGIC) {
- btf_verifier_log(env, "Invalid magic");
- return -EINVAL;
- }
-
- if (hdr->version != BTF_VERSION) {
- btf_verifier_log(env, "Unsupported version");
- return -ENOTSUPP;
- }
+ if (!(rec->fields[i].type & BPF_GRAPH_ROOT))
+ continue;
+ btf_id = rec->fields[i].graph_root.value_btf_id;
+ meta = btf_find_struct_meta(btf, btf_id);
+ if (!meta)
+ return -EFAULT;
+ rec->fields[i].graph_root.value_rec = meta->record;
- if (hdr->flags) {
- btf_verifier_log(env, "Unsupported flags");
- return -ENOTSUPP;
- }
+ /* We need to set value_rec for all root types, but no need
+ * to check ownership cycle for a type unless it's also a
+ * node type.
+ */
+ if (!(rec->field_mask & BPF_GRAPH_NODE))
+ continue;
- if (!btf->base_btf && btf_data_size == hdr->hdr_len) {
- btf_verifier_log(env, "No data");
- return -EINVAL;
+ /* We need to ensure ownership acyclicity among all types. The
+ * proper way to do it would be to topologically sort all BTF
+ * IDs based on the ownership edges, since there can be multiple
+ * bpf_{list_head,rb_node} in a type. Instead, we use the
+ * following resaoning:
+ *
+ * - A type can only be owned by another type in user BTF if it
+ * has a bpf_{list,rb}_node. Let's call these node types.
+ * - A type can only _own_ another type in user BTF if it has a
+ * bpf_{list_head,rb_root}. Let's call these root types.
+ *
+ * We ensure that if a type is both a root and node, its
+ * element types cannot be root types.
+ *
+ * To ensure acyclicity:
+ *
+ * When A is an root type but not a node, its ownership
+ * chain can be:
+ * A -> B -> C
+ * Where:
+ * - A is an root, e.g. has bpf_rb_root.
+ * - B is both a root and node, e.g. has bpf_rb_node and
+ * bpf_list_head.
+ * - C is only an root, e.g. has bpf_list_node
+ *
+ * When A is both a root and node, some other type already
+ * owns it in the BTF domain, hence it can not own
+ * another root type through any of the ownership edges.
+ * A -> B
+ * Where:
+ * - A is both an root and node.
+ * - B is only an node.
+ */
+ if (meta->record->field_mask & BPF_GRAPH_ROOT)
+ return -ELOOP;
}
-
- return btf_check_sec_info(env, btf_data_size);
+ return 0;
}
-
static const char *alloc_obj_fields[] = {
"bpf_spin_lock",
"bpf_list_head",
@@ -5818,54 +1247,6 @@ struct btf_struct_meta *btf_find_struct_meta(const struct btf *btf, u32 btf_id)
return NULL;
return bsearch(&btf_id, tab->types, tab->cnt, sizeof(tab->types[0]), btf_id_cmp_func);
}
-
-static int btf_check_type_tags(struct btf_verifier_env *env,
- struct btf *btf, int start_id)
-{
- int i, n, good_id = start_id - 1;
- bool in_tags;
-
- n = btf_nr_types(btf);
- for (i = start_id; i < n; i++) {
- const struct btf_type *t;
- int chain_limit = 32;
- u32 cur_id = i;
-
- t = btf_type_by_id(btf, i);
- if (!t)
- return -EINVAL;
- if (!btf_type_is_modifier(t))
- continue;
-
- cond_resched();
-
- in_tags = btf_type_is_type_tag(t);
- while (btf_type_is_modifier(t)) {
- if (!chain_limit--) {
- btf_verifier_log(env, "Max chain length or cycle detected");
- return -ELOOP;
- }
- if (btf_type_is_type_tag(t)) {
- if (!in_tags) {
- btf_verifier_log(env, "Type tags don't precede modifiers");
- return -EINVAL;
- }
- } else if (in_tags) {
- in_tags = false;
- }
- if (cur_id <= good_id)
- break;
- /* Move to next type */
- cur_id = t->type;
- t = btf_type_by_id(btf, cur_id);
- if (!t)
- return -EINVAL;
- }
- good_id = i;
- }
- return 0;
-}
-
static int finalize_log(struct bpf_verifier_log *log, bpfptr_t uattr, u32 uattr_size)
{
u32 log_true_size;
@@ -6313,60 +1694,6 @@ int get_kern_ctx_btf_id(struct bpf_verifier_log *log, enum bpf_prog_type prog_ty
}
BTF_ID_LIST_SINGLE(bpf_ctx_convert_btf_id, struct, bpf_ctx_convert)
-
-static struct btf *btf_parse_base(struct btf_verifier_env *env, const char *name,
- void *data, unsigned int data_size)
-{
- struct btf *btf = NULL;
- int err;
-
- if (!IS_ENABLED(CONFIG_DEBUG_INFO_BTF))
- return ERR_PTR(-ENOENT);
-
- btf = kzalloc_obj(*btf, GFP_KERNEL | __GFP_NOWARN);
- if (!btf) {
- err = -ENOMEM;
- goto errout;
- }
- env->btf = btf;
-
- btf->data = data;
- btf->data_size = data_size;
- btf->kernel_btf = true;
- btf->named_start_id = 0;
- strscpy(btf->name, name);
-
- err = btf_parse_hdr(env);
- if (err)
- goto errout;
-
- btf->nohdr_data = btf->data + btf->hdr.hdr_len;
-
- err = btf_parse_str_sec(env);
- if (err)
- goto errout;
-
- err = btf_check_all_metas(env);
- if (err)
- goto errout;
-
- err = btf_check_type_tags(env, btf, 1);
- if (err)
- goto errout;
-
- btf_check_sorted(btf);
- refcount_set(&btf->refcnt, 1);
-
- return btf;
-
-errout:
- if (btf) {
- kvfree(btf->types);
- kfree(btf);
- }
- return ERR_PTR(err);
-}
-
struct btf *btf_parse_vmlinux(void)
{
struct btf_verifier_env *env = NULL;
@@ -8029,96 +3356,6 @@ int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog)
return 0;
}
-
-static void btf_type_show(const struct btf *btf, u32 type_id, void *obj,
- struct btf_show *show)
-{
- const struct btf_type *t = btf_type_by_id(btf, type_id);
-
- show->btf = btf;
- memset(&show->state, 0, sizeof(show->state));
- memset(&show->obj, 0, sizeof(show->obj));
-
- btf_type_ops(t)->show(btf, t, type_id, obj, 0, show);
-}
-
-__printf(2, 0) static void btf_seq_show(struct btf_show *show, const char *fmt,
- va_list args)
-{
- seq_vprintf((struct seq_file *)show->target, fmt, args);
-}
-
-int btf_type_seq_show_flags(const struct btf *btf, u32 type_id,
- void *obj, struct seq_file *m, u64 flags)
-{
- struct btf_show sseq;
-
- sseq.target = m;
- sseq.showfn = btf_seq_show;
- sseq.flags = flags;
-
- btf_type_show(btf, type_id, obj, &sseq);
-
- return sseq.state.status;
-}
-
-void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj,
- struct seq_file *m)
-{
- (void) btf_type_seq_show_flags(btf, type_id, obj, m,
- BTF_SHOW_NONAME | BTF_SHOW_COMPACT |
- BTF_SHOW_ZERO | BTF_SHOW_UNSAFE);
-}
-
-struct btf_show_snprintf {
- struct btf_show show;
- int len_left; /* space left in string */
- int len; /* length we would have written */
-};
-
-__printf(2, 0) static void btf_snprintf_show(struct btf_show *show, const char *fmt,
- va_list args)
-{
- struct btf_show_snprintf *ssnprintf = (struct btf_show_snprintf *)show;
- int len;
-
- len = vsnprintf(show->target, ssnprintf->len_left, fmt, args);
-
- if (len < 0) {
- ssnprintf->len_left = 0;
- ssnprintf->len = len;
- } else if (len >= ssnprintf->len_left) {
- /* no space, drive on to get length we would have written */
- ssnprintf->len_left = 0;
- ssnprintf->len += len;
- } else {
- ssnprintf->len_left -= len;
- ssnprintf->len += len;
- show->target += len;
- }
-}
-
-int btf_type_snprintf_show(const struct btf *btf, u32 type_id, void *obj,
- char *buf, int len, u64 flags)
-{
- struct btf_show_snprintf ssnprintf;
-
- ssnprintf.show.target = buf;
- ssnprintf.show.flags = flags;
- ssnprintf.show.showfn = btf_snprintf_show;
- ssnprintf.len_left = len;
- ssnprintf.len = 0;
-
- btf_type_show(btf, type_id, obj, (struct btf_show *)&ssnprintf);
-
- /* If we encountered an error, return it. */
- if (ssnprintf.show.state.status)
- return ssnprintf.show.state.status;
-
- /* Otherwise return length we would have written */
- return ssnprintf.len;
-}
-
#ifdef CONFIG_PROC_FS
static void bpf_btf_show_fdinfo(struct seq_file *m, struct file *filp)
{
@@ -8271,17 +3508,6 @@ u32 btf_obj_id(const struct btf *btf)
{
return READ_ONCE(btf->id);
}
-
-bool btf_is_kernel(const struct btf *btf)
-{
- return btf->kernel_btf;
-}
-
-bool btf_is_module(const struct btf *btf)
-{
- return btf->kernel_btf && strcmp(btf->name, "vmlinux") != 0;
-}
-
enum {
BTF_MODULE_F_LIVE = (1 << 0),
};
@@ -9740,21 +4966,3 @@ int __register_bpf_struct_ops(struct bpf_struct_ops *st_ops)
}
EXPORT_SYMBOL_GPL(__register_bpf_struct_ops);
#endif
-
-bool btf_param_match_suffix(const struct btf *btf,
- const struct btf_param *arg,
- const char *suffix)
-{
- int suffix_len = strlen(suffix), len;
- const char *param_name;
-
- /* In the future, this can be ported to use BTF tagging */
- param_name = btf_name_by_offset(btf, arg->name_off);
- if (str_is_empty(param_name))
- return false;
- len = strlen(param_name);
- if (len <= suffix_len)
- return false;
- param_name += len - suffix_len;
- return !strncmp(param_name, suffix, suffix_len);
-}
diff --git a/kernel/btf/btf.c b/kernel/btf/btf.c
new file mode 100644
index 0000000000000..0eb383926b7d3
--- /dev/null
+++ b/kernel/btf/btf.c
@@ -0,0 +1,4803 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2018 Facebook */
+
+#include <uapi/linux/btf.h>
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/types.h>
+#include <linux/seq_file.h>
+#include <linux/compiler.h>
+#include <linux/ctype.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/file.h>
+#include <linux/kernel.h>
+#include <linux/sort.h>
+#include <linux/bpf_verifier.h>
+#include <linux/btf.h>
+#include <linux/btf_ids.h>
+#include <linux/bsearch.h>
+#include <linux/kobject.h>
+#include <linux/string.h>
+#include <linux/overflow.h>
+#include "btf.h"
+
+#ifndef CONFIG_BPF_SYSCALL
+/*
+ * When CONFIG_BPF_SYSCALL is not set, log.c is not compiled, so
+ * bpf_verifier_vlog() is unavailable. Provide a simple implementation
+ * that handles the BPF_LOG_KERNEL case (pr_err), which is the only
+ * log level used by the core BTF verifier for kernel BTF parsing.
+ */
+void bpf_verifier_vlog(struct bpf_verifier_log *log, const char *fmt,
+ va_list args)
+{
+ char buf[256];
+
+ vscnprintf(buf, sizeof(buf), fmt, args);
+ if (log->level == BPF_LOG_KERNEL)
+ pr_err("BPF: %s", buf);
+}
+
+__printf(2, 3) void bpf_log(struct bpf_verifier_log *log,
+ const char *fmt, ...)
+{
+ va_list args;
+
+ if (!bpf_verifier_log_needed(log))
+ return;
+
+ va_start(args, fmt);
+ bpf_verifier_vlog(log, fmt, args);
+ va_end(args);
+}
+#endif /* !CONFIG_BPF_SYSCALL */
+
+/* BTF (BPF Type Format) is the meta data format which describes
+ * the data types of BPF program/map. Hence, it basically focus
+ * on the C programming language which the modern BPF is primary
+ * using.
+ *
+ * ELF Section:
+ * ~~~~~~~~~~~
+ * The BTF data is stored under the ".BTF" ELF section
+ *
+ * struct btf_type:
+ * ~~~~~~~~~~~~~~~
+ * Each 'struct btf_type' object describes a C data type.
+ * Depending on the type it is describing, a 'struct btf_type'
+ * object may be followed by more data. F.e.
+ * To describe an array, 'struct btf_type' is followed by
+ * 'struct btf_array'.
+ *
+ * 'struct btf_type' and any extra data following it are
+ * 4 bytes aligned.
+ *
+ * Type section:
+ * ~~~~~~~~~~~~~
+ * The BTF type section contains a list of 'struct btf_type' objects.
+ * Each one describes a C type. Recall from the above section
+ * that a 'struct btf_type' object could be immediately followed by extra
+ * data in order to describe some particular C types.
+ *
+ * type_id:
+ * ~~~~~~~
+ * Each btf_type object is identified by a type_id. The type_id
+ * is implicitly implied by the location of the btf_type object in
+ * the BTF type section. The first one has type_id 1. The second
+ * one has type_id 2...etc. Hence, an earlier btf_type has
+ * a smaller type_id.
+ *
+ * A btf_type object may refer to another btf_type object by using
+ * type_id (i.e. the "type" in the "struct btf_type").
+ *
+ * NOTE that we cannot assume any reference-order.
+ * A btf_type object can refer to an earlier btf_type object
+ * but it can also refer to a later btf_type object.
+ *
+ * For example, to describe "const void *". A btf_type
+ * object describing "const" may refer to another btf_type
+ * object describing "void *". This type-reference is done
+ * by specifying type_id:
+ *
+ * [1] CONST (anon) type_id=2
+ * [2] PTR (anon) type_id=0
+ *
+ * The above is the btf_verifier debug log:
+ * - Each line started with "[?]" is a btf_type object
+ * - [?] is the type_id of the btf_type object.
+ * - CONST/PTR is the BTF_KIND_XXX
+ * - "(anon)" is the name of the type. It just
+ * happens that CONST and PTR has no name.
+ * - type_id=XXX is the 'u32 type' in btf_type
+ *
+ * NOTE: "void" has type_id 0
+ *
+ * String section:
+ * ~~~~~~~~~~~~~~
+ * The BTF string section contains the names used by the type section.
+ * Each string is referred by an "offset" from the beginning of the
+ * string section.
+ *
+ * Each string is '\0' terminated.
+ *
+ * The first character in the string section must be '\0'
+ * which is used to mean 'anonymous'. Some btf_type may not
+ * have a name.
+ */
+
+/* BTF verification:
+ *
+ * To verify BTF data, two passes are needed.
+ *
+ * Pass #1
+ * ~~~~~~~
+ * The first pass is to collect all btf_type objects to
+ * an array: "btf->types".
+ *
+ * Depending on the C type that a btf_type is describing,
+ * a btf_type may be followed by extra data. We don't know
+ * how many btf_type is there, and more importantly we don't
+ * know where each btf_type is located in the type section.
+ *
+ * Without knowing the location of each type_id, most verifications
+ * cannot be done. e.g. an earlier btf_type may refer to a later
+ * btf_type (recall the "const void *" above), so we cannot
+ * check this type-reference in the first pass.
+ *
+ * In the first pass, it still does some verifications (e.g.
+ * checking the name is a valid offset to the string section).
+ *
+ * Pass #2
+ * ~~~~~~~
+ * The main focus is to resolve a btf_type that is referring
+ * to another type.
+ *
+ * We have to ensure the referring type:
+ * 1) does exist in the BTF (i.e. in btf->types[])
+ * 2) does not cause a loop:
+ * struct A {
+ * struct B b;
+ * };
+ *
+ * struct B {
+ * struct A a;
+ * };
+ *
+ * btf_type_needs_resolve() decides if a btf_type needs
+ * to be resolved.
+ *
+ * The needs_resolve type implements the "resolve()" ops which
+ * essentially does a DFS and detects backedge.
+ *
+ * During resolve (or DFS), different C types have different
+ * "RESOLVED" conditions.
+ *
+ * When resolving a BTF_KIND_STRUCT, we need to resolve all its
+ * members because a member is always referring to another
+ * type. A struct's member can be treated as "RESOLVED" if
+ * it is referring to a BTF_KIND_PTR. Otherwise, the
+ * following valid C struct would be rejected:
+ *
+ * struct A {
+ * int m;
+ * struct A *a;
+ * };
+ *
+ * When resolving a BTF_KIND_PTR, it needs to keep resolving if
+ * it is referring to another BTF_KIND_PTR. Otherwise, we cannot
+ * detect a pointer loop, e.g.:
+ * BTF_KIND_CONST -> BTF_KIND_PTR -> BTF_KIND_CONST -> BTF_KIND_PTR +
+ * ^ |
+ * +-----------------------------------------+
+ *
+ */
+
+#define BITS_PER_U128 (sizeof(u64) * BITS_PER_BYTE * 2)
+
+#define BTF_INFO_MASK 0x9f00ffff
+#define BTF_INT_MASK 0x0fffffff
+#define BTF_TYPE_ID_VALID(type_id) ((type_id) <= BTF_MAX_TYPE)
+#define BTF_STR_OFFSET_VALID(name_off) ((name_off) <= BTF_MAX_NAME_OFFSET)
+
+
+#define for_each_member_from(i, from, struct_type, member) \
+ for (i = from, member = btf_type_member(struct_type) + from; \
+ i < btf_type_vlen(struct_type); \
+ i++, member++)
+
+#define for_each_vsi_from(i, from, struct_type, member) \
+ for (i = from, member = btf_type_var_secinfo(struct_type) + from; \
+ i < btf_type_vlen(struct_type); \
+ i++, member++)
+
+
+
+
+enum visit_state {
+ NOT_VISITED,
+ VISITED,
+ RESOLVED,
+};
+
+struct btf_sec_info {
+ u32 off;
+ u32 len;
+};
+
+const char * const btf_kind_str[NR_BTF_KINDS] = {
+ [BTF_KIND_UNKN] = "UNKNOWN",
+ [BTF_KIND_INT] = "INT",
+ [BTF_KIND_PTR] = "PTR",
+ [BTF_KIND_ARRAY] = "ARRAY",
+ [BTF_KIND_STRUCT] = "STRUCT",
+ [BTF_KIND_UNION] = "UNION",
+ [BTF_KIND_ENUM] = "ENUM",
+ [BTF_KIND_FWD] = "FWD",
+ [BTF_KIND_TYPEDEF] = "TYPEDEF",
+ [BTF_KIND_VOLATILE] = "VOLATILE",
+ [BTF_KIND_CONST] = "CONST",
+ [BTF_KIND_RESTRICT] = "RESTRICT",
+ [BTF_KIND_FUNC] = "FUNC",
+ [BTF_KIND_FUNC_PROTO] = "FUNC_PROTO",
+ [BTF_KIND_VAR] = "VAR",
+ [BTF_KIND_DATASEC] = "DATASEC",
+ [BTF_KIND_FLOAT] = "FLOAT",
+ [BTF_KIND_DECL_TAG] = "DECL_TAG",
+ [BTF_KIND_TYPE_TAG] = "TYPE_TAG",
+ [BTF_KIND_ENUM64] = "ENUM64",
+};
+
+const char *btf_type_str(const struct btf_type *t)
+{
+ return btf_kind_str[BTF_INFO_KIND(t->info)];
+}
+
+/* Chunk size we use in safe copy of data to be shown. */
+#define BTF_SHOW_OBJ_SAFE_SIZE 32
+
+/*
+ * This is the maximum size of a base type value (equivalent to a
+ * 128-bit int); if we are at the end of our safe buffer and have
+ * less than 16 bytes space we can't be assured of being able
+ * to copy the next type safely, so in such cases we will initiate
+ * a new copy.
+ */
+#define BTF_SHOW_OBJ_BASE_TYPE_SIZE 16
+
+/* Type name size */
+#define BTF_SHOW_NAME_SIZE 80
+
+
+/*
+ * Common data to all BTF show operations. Private show functions can add
+ * their own data to a structure containing a struct btf_show and consult it
+ * in the show callback. See btf_type_show() below.
+ *
+ * One challenge with showing nested data is we want to skip 0-valued
+ * data, but in order to figure out whether a nested object is all zeros
+ * we need to walk through it. As a result, we need to make two passes
+ * when handling structs, unions and arrays; the first path simply looks
+ * for nonzero data, while the second actually does the display. The first
+ * pass is signalled by show->state.depth_check being set, and if we
+ * encounter a non-zero value we set show->state.depth_to_show to
+ * the depth at which we encountered it. When we have completed the
+ * first pass, we will know if anything needs to be displayed if
+ * depth_to_show > depth. See btf_[struct,array]_show() for the
+ * implementation of this.
+ *
+ * Another problem is we want to ensure the data for display is safe to
+ * access. To support this, the anonymous "struct {} obj" tracks the data
+ * object and our safe copy of it. We copy portions of the data needed
+ * to the object "copy" buffer, but because its size is limited to
+ * BTF_SHOW_OBJ_COPY_LEN bytes, multiple copies may be required as we
+ * traverse larger objects for display.
+ *
+ * The various data type show functions all start with a call to
+ * btf_show_start_type() which returns a pointer to the safe copy
+ * of the data needed (or if BTF_SHOW_UNSAFE is specified, to the
+ * raw data itself). btf_show_obj_safe() is responsible for
+ * using copy_from_kernel_nofault() to update the safe data if necessary
+ * as we traverse the object's data. skbuff-like semantics are
+ * used:
+ *
+ * - obj.head points to the start of the toplevel object for display
+ * - obj.size is the size of the toplevel object
+ * - obj.data points to the current point in the original data at
+ * which our safe data starts. obj.data will advance as we copy
+ * portions of the data.
+ *
+ * In most cases a single copy will suffice, but larger data structures
+ * such as "struct task_struct" will require many copies. The logic in
+ * btf_show_obj_safe() handles the logic that determines if a new
+ * copy_from_kernel_nofault() is needed.
+ */
+struct btf_show {
+ u64 flags;
+ void *target; /* target of show operation (seq file, buffer) */
+ __printf(2, 0) void (*showfn)(struct btf_show *show, const char *fmt, va_list args);
+ const struct btf *btf;
+ /* below are used during iteration */
+ struct {
+ u8 depth;
+ u8 depth_to_show;
+ u8 depth_check;
+ u8 array_member:1,
+ array_terminated:1;
+ u16 array_encoding;
+ u32 type_id;
+ int status; /* non-zero for error */
+ const struct btf_type *type;
+ const struct btf_member *member;
+ char name[BTF_SHOW_NAME_SIZE]; /* space for member name/type */
+ } state;
+ struct {
+ u32 size;
+ void *head;
+ void *data;
+ u8 safe[BTF_SHOW_OBJ_SAFE_SIZE];
+ } obj;
+};
+
+struct btf_kind_operations {
+ s32 (*check_meta)(struct btf_verifier_env *env,
+ const struct btf_type *t,
+ u32 meta_left);
+ int (*resolve)(struct btf_verifier_env *env,
+ const struct resolve_vertex *v);
+ int (*check_member)(struct btf_verifier_env *env,
+ const struct btf_type *struct_type,
+ const struct btf_member *member,
+ const struct btf_type *member_type);
+ int (*check_kflag_member)(struct btf_verifier_env *env,
+ const struct btf_type *struct_type,
+ const struct btf_member *member,
+ const struct btf_type *member_type);
+ void (*log_details)(struct btf_verifier_env *env,
+ const struct btf_type *t);
+ void (*show)(const struct btf *btf, const struct btf_type *t,
+ u32 type_id, void *data, u8 bits_offsets,
+ struct btf_show *show);
+};
+
+static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS];
+static struct btf_type btf_void;
+
+static int btf_resolve(struct btf_verifier_env *env,
+ const struct btf_type *t, u32 type_id);
+
+static int btf_func_check(struct btf_verifier_env *env,
+ const struct btf_type *t);
+
+bool btf_type_is_modifier(const struct btf_type *t)
+{
+ /* Some of them is not strictly a C modifier
+ * but they are grouped into the same bucket
+ * for BTF concern:
+ * A type (t) that refers to another
+ * type through t->type AND its size cannot
+ * be determined without following the t->type.
+ *
+ * ptr does not fall into this bucket
+ * because its size is always sizeof(void *).
+ */
+ switch (BTF_INFO_KIND(t->info)) {
+ case BTF_KIND_TYPEDEF:
+ case BTF_KIND_VOLATILE:
+ case BTF_KIND_CONST:
+ case BTF_KIND_RESTRICT:
+ case BTF_KIND_TYPE_TAG:
+ return true;
+ }
+
+ return false;
+}
+
+static int btf_start_id(const struct btf *btf)
+{
+ return btf->start_id + (btf->base_btf ? 0 : 1);
+}
+
+bool btf_type_is_void(const struct btf_type *t)
+{
+ return t == &btf_void;
+}
+
+bool btf_type_is_datasec(const struct btf_type *t)
+{
+ return BTF_INFO_KIND(t->info) == BTF_KIND_DATASEC;
+}
+
+bool btf_type_is_decl_tag(const struct btf_type *t)
+{
+ return BTF_INFO_KIND(t->info) == BTF_KIND_DECL_TAG;
+}
+
+static bool btf_type_nosize(const struct btf_type *t)
+{
+ return btf_type_is_void(t) || btf_type_is_fwd(t) ||
+ btf_type_is_func(t) || btf_type_is_func_proto(t) ||
+ btf_type_is_decl_tag(t);
+}
+
+static bool btf_type_nosize_or_null(const struct btf_type *t)
+{
+ return !t || btf_type_nosize(t);
+}
+
+static bool btf_type_is_decl_tag_target(const struct btf_type *t)
+{
+ return btf_type_is_func(t) || btf_type_is_struct(t) ||
+ btf_type_is_var(t) || btf_type_is_typedef(t);
+}
+
+bool btf_is_vmlinux(const struct btf *btf)
+{
+ return btf->kernel_btf && !btf->base_btf;
+}
+
+u32 btf_nr_types(const struct btf *btf)
+{
+ u32 total = 0;
+
+ while (btf) {
+ total += btf->nr_types;
+ btf = btf->base_btf;
+ }
+
+ return total;
+}
+
+/*
+ * Note that vmlinux and kernel module BTFs are always sorted
+ * during the building phase.
+ */
+void btf_check_sorted(struct btf *btf)
+{
+ u32 i, n, named_start_id = 0;
+
+ n = btf_nr_types(btf);
+ if (btf_is_vmlinux(btf)) {
+ for (i = btf_start_id(btf); i < n; i++) {
+ const struct btf_type *t = btf_type_by_id(btf, i);
+ const char *n = btf_name_by_offset(btf, t->name_off);
+
+ if (n[0] != '\0') {
+ btf->named_start_id = i;
+ return;
+ }
+ }
+ return;
+ }
+
+ for (i = btf_start_id(btf) + 1; i < n; i++) {
+ const struct btf_type *ta = btf_type_by_id(btf, i - 1);
+ const struct btf_type *tb = btf_type_by_id(btf, i);
+ const char *na = btf_name_by_offset(btf, ta->name_off);
+ const char *nb = btf_name_by_offset(btf, tb->name_off);
+
+ if (strcmp(na, nb) > 0)
+ return;
+
+ if (named_start_id == 0 && na[0] != '\0')
+ named_start_id = i - 1;
+ if (named_start_id == 0 && nb[0] != '\0')
+ named_start_id = i;
+ }
+
+ if (named_start_id)
+ btf->named_start_id = named_start_id;
+}
+
+/*
+ * btf_named_start_id - Get the named starting ID for the BTF
+ * @btf: Pointer to the target BTF object
+ * @own: Flag indicating whether to query only the current BTF (true = current BTF only,
+ * false = recursively traverse the base BTF chain)
+ *
+ * Return value rules:
+ * 1. For a sorted btf, return its named_start_id
+ * 2. Else for a split BTF, return its start_id
+ * 3. Else for a base BTF, return 1
+ */
+u32 btf_named_start_id(const struct btf *btf, bool own)
+{
+ const struct btf *base_btf = btf;
+
+ while (!own && base_btf->base_btf)
+ base_btf = base_btf->base_btf;
+
+ return base_btf->named_start_id ?: (base_btf->start_id ?: 1);
+}
+
+static s32 btf_find_by_name_kind_bsearch(const struct btf *btf, const char *name)
+{
+ const struct btf_type *t;
+ const char *tname;
+ s32 l, r, m;
+
+ l = btf_named_start_id(btf, true);
+ r = btf_nr_types(btf) - 1;
+ while (l <= r) {
+ m = l + (r - l) / 2;
+ t = btf_type_by_id(btf, m);
+ tname = btf_name_by_offset(btf, t->name_off);
+ if (strcmp(tname, name) >= 0) {
+ if (l == r)
+ return r;
+ r = m;
+ } else {
+ l = m + 1;
+ }
+ }
+
+ return btf_nr_types(btf);
+}
+
+s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind)
+{
+ const struct btf *base_btf = btf_base_btf(btf);
+ const struct btf_type *t;
+ const char *tname;
+ s32 id, total;
+
+ if (base_btf) {
+ id = btf_find_by_name_kind(base_btf, name, kind);
+ if (id > 0)
+ return id;
+ }
+
+ total = btf_nr_types(btf);
+ if (btf->named_start_id > 0 && name[0]) {
+ id = btf_find_by_name_kind_bsearch(btf, name);
+ for (; id < total; id++) {
+ t = btf_type_by_id(btf, id);
+ tname = btf_name_by_offset(btf, t->name_off);
+ if (strcmp(tname, name) != 0)
+ return -ENOENT;
+ if (BTF_INFO_KIND(t->info) == kind)
+ return id;
+ }
+ } else {
+ for (id = btf_start_id(btf); id < total; id++) {
+ t = btf_type_by_id(btf, id);
+ if (BTF_INFO_KIND(t->info) != kind)
+ continue;
+ tname = btf_name_by_offset(btf, t->name_off);
+ if (strcmp(tname, name) == 0)
+ return id;
+ }
+ }
+
+ return -ENOENT;
+}
+
+
+const struct btf_type *btf_type_skip_modifiers(const struct btf *btf,
+ u32 id, u32 *res_id)
+{
+ const struct btf_type *t = btf_type_by_id(btf, id);
+
+ while (btf_type_is_modifier(t)) {
+ id = t->type;
+ t = btf_type_by_id(btf, t->type);
+ }
+
+ if (res_id)
+ *res_id = id;
+
+ return t;
+}
+
+const struct btf_type *btf_type_resolve_ptr(const struct btf *btf,
+ u32 id, u32 *res_id)
+{
+ const struct btf_type *t;
+
+ t = btf_type_skip_modifiers(btf, id, NULL);
+ if (!btf_type_is_ptr(t))
+ return NULL;
+
+ return btf_type_skip_modifiers(btf, t->type, res_id);
+}
+
+const struct btf_type *btf_type_resolve_func_ptr(const struct btf *btf,
+ u32 id, u32 *res_id)
+{
+ const struct btf_type *ptype;
+
+ ptype = btf_type_resolve_ptr(btf, id, res_id);
+ if (ptype && btf_type_is_func_proto(ptype))
+ return ptype;
+
+ return NULL;
+}
+
+/* Types that act only as a source, not sink or intermediate
+ * type when resolving.
+ */
+static bool btf_type_is_resolve_source_only(const struct btf_type *t)
+{
+ return btf_type_is_var(t) ||
+ btf_type_is_decl_tag(t) ||
+ btf_type_is_datasec(t);
+}
+
+/* What types need to be resolved?
+ *
+ * btf_type_is_modifier() is an obvious one.
+ *
+ * btf_type_is_struct() because its member refers to
+ * another type (through member->type).
+ *
+ * btf_type_is_var() because the variable refers to
+ * another type. btf_type_is_datasec() holds multiple
+ * btf_type_is_var() types that need resolving.
+ *
+ * btf_type_is_array() because its element (array->type)
+ * refers to another type. Array can be thought of a
+ * special case of struct while array just has the same
+ * member-type repeated by array->nelems of times.
+ */
+static bool btf_type_needs_resolve(const struct btf_type *t)
+{
+ return btf_type_is_modifier(t) ||
+ btf_type_is_ptr(t) ||
+ btf_type_is_struct(t) ||
+ btf_type_is_array(t) ||
+ btf_type_is_var(t) ||
+ btf_type_is_func(t) ||
+ btf_type_is_decl_tag(t) ||
+ btf_type_is_datasec(t);
+}
+
+/* t->size can be used */
+bool btf_type_has_size(const struct btf_type *t)
+{
+ switch (BTF_INFO_KIND(t->info)) {
+ case BTF_KIND_INT:
+ case BTF_KIND_STRUCT:
+ case BTF_KIND_UNION:
+ case BTF_KIND_ENUM:
+ case BTF_KIND_DATASEC:
+ case BTF_KIND_FLOAT:
+ case BTF_KIND_ENUM64:
+ return true;
+ }
+
+ return false;
+}
+
+static const char *btf_int_encoding_str(u8 encoding)
+{
+ if (encoding == 0)
+ return "(none)";
+ else if (encoding == BTF_INT_SIGNED)
+ return "SIGNED";
+ else if (encoding == BTF_INT_CHAR)
+ return "CHAR";
+ else if (encoding == BTF_INT_BOOL)
+ return "BOOL";
+ else
+ return "UNKN";
+}
+
+static u32 btf_type_int(const struct btf_type *t)
+{
+ return *(u32 *)(t + 1);
+}
+
+static const struct btf_array *btf_type_array(const struct btf_type *t)
+{
+ return (const struct btf_array *)(t + 1);
+}
+
+static const struct btf_enum *btf_type_enum(const struct btf_type *t)
+{
+ return (const struct btf_enum *)(t + 1);
+}
+
+static const struct btf_var *btf_type_var(const struct btf_type *t)
+{
+ return (const struct btf_var *)(t + 1);
+}
+
+const struct btf_decl_tag *btf_type_decl_tag(const struct btf_type *t)
+{
+ return (const struct btf_decl_tag *)(t + 1);
+}
+
+static const struct btf_enum64 *btf_type_enum64(const struct btf_type *t)
+{
+ return (const struct btf_enum64 *)(t + 1);
+}
+
+static const struct btf_kind_operations *btf_type_ops(const struct btf_type *t)
+{
+ return kind_ops[BTF_INFO_KIND(t->info)];
+}
+
+static bool btf_name_offset_valid(const struct btf *btf, u32 offset)
+{
+ if (!BTF_STR_OFFSET_VALID(offset))
+ return false;
+
+ while (offset < btf->start_str_off)
+ btf = btf->base_btf;
+
+ offset -= btf->start_str_off;
+ return offset < btf->hdr.str_len;
+}
+
+static bool __btf_name_char_ok(char c, bool first)
+{
+ if ((first ? !isalpha(c) :
+ !isalnum(c)) &&
+ c != '_' &&
+ c != '.')
+ return false;
+ return true;
+}
+
+const char *btf_str_by_offset(const struct btf *btf, u32 offset)
+{
+ while (offset < btf->start_str_off)
+ btf = btf->base_btf;
+
+ offset -= btf->start_str_off;
+ if (offset < btf->hdr.str_len)
+ return &btf->strings[offset];
+
+ return NULL;
+}
+
+static bool btf_name_valid_identifier(const struct btf *btf, u32 offset)
+{
+ /* offset must be valid */
+ const char *src = btf_str_by_offset(btf, offset);
+ const char *src_limit;
+
+ if (!__btf_name_char_ok(*src, true))
+ return false;
+
+ /* set a limit on identifier length */
+ src_limit = src + KSYM_NAME_LEN;
+ src++;
+ while (*src && src < src_limit) {
+ if (!__btf_name_char_ok(*src, false))
+ return false;
+ src++;
+ }
+
+ return !*src;
+}
+
+/* Allow any printable character in DATASEC names */
+static bool btf_name_valid_section(const struct btf *btf, u32 offset)
+{
+ /* offset must be valid */
+ const char *src = btf_str_by_offset(btf, offset);
+ const char *src_limit;
+
+ if (!*src)
+ return false;
+
+ /* set a limit on identifier length */
+ src_limit = src + KSYM_NAME_LEN;
+ while (*src && src < src_limit) {
+ if (!isprint(*src))
+ return false;
+ src++;
+ }
+
+ return !*src;
+}
+
+const char *__btf_name_by_offset(const struct btf *btf, u32 offset)
+{
+ const char *name;
+
+ if (!offset)
+ return "(anon)";
+
+ name = btf_str_by_offset(btf, offset);
+ return name ?: "(invalid-name-offset)";
+}
+
+const char *btf_name_by_offset(const struct btf *btf, u32 offset)
+{
+ return btf_str_by_offset(btf, offset);
+}
+
+const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id)
+{
+ while (type_id < btf->start_id)
+ btf = btf->base_btf;
+
+ type_id -= btf->start_id;
+ if (type_id >= btf->nr_types)
+ return NULL;
+ return btf->types[type_id];
+}
+EXPORT_SYMBOL_GPL(btf_type_by_id);
+
+/*
+ * Check that the type @t is a regular int. This means that @t is not
+ * a bit field and it has the same size as either of u8/u16/u32/u64
+ * or __int128. If @expected_size is not zero, then size of @t should
+ * be the same. A caller should already have checked that the type @t
+ * is an integer.
+ */
+static bool __btf_type_int_is_regular(const struct btf_type *t, size_t expected_size)
+{
+ u32 int_data = btf_type_int(t);
+ u8 nr_bits = BTF_INT_BITS(int_data);
+ u8 nr_bytes = BITS_ROUNDUP_BYTES(nr_bits);
+
+ return BITS_PER_BYTE_MASKED(nr_bits) == 0 &&
+ BTF_INT_OFFSET(int_data) == 0 &&
+ (nr_bytes <= 16 && is_power_of_2(nr_bytes)) &&
+ (expected_size == 0 || nr_bytes == expected_size);
+}
+
+static bool btf_type_int_is_regular(const struct btf_type *t)
+{
+ return __btf_type_int_is_regular(t, 0);
+}
+
+bool btf_type_is_i32(const struct btf_type *t)
+{
+ return btf_type_is_int(t) && __btf_type_int_is_regular(t, 4);
+}
+
+bool btf_type_is_i64(const struct btf_type *t)
+{
+ return btf_type_is_int(t) && __btf_type_int_is_regular(t, 8);
+}
+
+bool btf_type_is_primitive(const struct btf_type *t)
+{
+ return (btf_type_is_int(t) && btf_type_int_is_regular(t)) ||
+ btf_is_any_enum(t);
+}
+
+/*
+ * Check that given struct member is a regular int with expected
+ * offset and size.
+ */
+bool btf_member_is_reg_int(const struct btf *btf, const struct btf_type *s,
+ const struct btf_member *m,
+ u32 expected_offset, u32 expected_size)
+{
+ const struct btf_type *t;
+ u32 id, int_data;
+ u8 nr_bits;
+
+ id = m->type;
+ t = btf_type_id_size(btf, &id, NULL);
+ if (!t || !btf_type_is_int(t))
+ return false;
+
+ int_data = btf_type_int(t);
+ nr_bits = BTF_INT_BITS(int_data);
+ if (btf_type_kflag(s)) {
+ u32 bitfield_size = BTF_MEMBER_BITFIELD_SIZE(m->offset);
+ u32 bit_offset = BTF_MEMBER_BIT_OFFSET(m->offset);
+
+ /* if kflag set, int should be a regular int and
+ * bit offset should be at byte boundary.
+ */
+ return !bitfield_size &&
+ BITS_ROUNDUP_BYTES(bit_offset) == expected_offset &&
+ BITS_ROUNDUP_BYTES(nr_bits) == expected_size;
+ }
+
+ if (BTF_INT_OFFSET(int_data) ||
+ BITS_PER_BYTE_MASKED(m->offset) ||
+ BITS_ROUNDUP_BYTES(m->offset) != expected_offset ||
+ BITS_PER_BYTE_MASKED(nr_bits) ||
+ BITS_ROUNDUP_BYTES(nr_bits) != expected_size)
+ return false;
+
+ return true;
+}
+
+/* Similar to btf_type_skip_modifiers() but does not skip typedefs. */
+static const struct btf_type *btf_type_skip_qualifiers(const struct btf *btf,
+ u32 id)
+{
+ const struct btf_type *t = btf_type_by_id(btf, id);
+
+ while (btf_type_is_modifier(t) &&
+ BTF_INFO_KIND(t->info) != BTF_KIND_TYPEDEF) {
+ t = btf_type_by_id(btf, t->type);
+ }
+
+ return t;
+}
+
+#define BTF_SHOW_MAX_ITER 10
+
+#define BTF_KIND_BIT(kind) (1ULL << kind)
+
+/*
+ * Populate show->state.name with type name information.
+ * Format of type name is
+ *
+ * [.member_name = ] (type_name)
+ */
+static const char *btf_show_name(struct btf_show *show)
+{
+ /* BTF_MAX_ITER array suffixes "[]" */
+ const char *array_suffixes = "[][][][][][][][][][]";
+ const char *array_suffix = &array_suffixes[strlen(array_suffixes)];
+ /* BTF_MAX_ITER pointer suffixes "*" */
+ const char *ptr_suffixes = "**********";
+ const char *ptr_suffix = &ptr_suffixes[strlen(ptr_suffixes)];
+ const char *name = NULL, *prefix = "", *parens = "";
+ const struct btf_member *m = show->state.member;
+ const struct btf_type *t;
+ const struct btf_array *array;
+ u32 id = show->state.type_id;
+ const char *member = NULL;
+ bool show_member = false;
+ u64 kinds = 0;
+ int i;
+
+ show->state.name[0] = '\0';
+
+ /*
+ * Don't show type name if we're showing an array member;
+ * in that case we show the array type so don't need to repeat
+ * ourselves for each member.
+ */
+ if (show->state.array_member)
+ return "";
+
+ /* Retrieve member name, if any. */
+ if (m) {
+ member = btf_name_by_offset(show->btf, m->name_off);
+ show_member = strlen(member) > 0;
+ id = m->type;
+ }
+
+ /*
+ * Start with type_id, as we have resolved the struct btf_type *
+ * via btf_modifier_show() past the parent typedef to the child
+ * struct, int etc it is defined as. In such cases, the type_id
+ * still represents the starting type while the struct btf_type *
+ * in our show->state points at the resolved type of the typedef.
+ */
+ t = btf_type_by_id(show->btf, id);
+ if (!t)
+ return "";
+
+ /*
+ * The goal here is to build up the right number of pointer and
+ * array suffixes while ensuring the type name for a typedef
+ * is represented. Along the way we accumulate a list of
+ * BTF kinds we have encountered, since these will inform later
+ * display; for example, pointer types will not require an
+ * opening "{" for struct, we will just display the pointer value.
+ *
+ * We also want to accumulate the right number of pointer or array
+ * indices in the format string while iterating until we get to
+ * the typedef/pointee/array member target type.
+ *
+ * We start by pointing at the end of pointer and array suffix
+ * strings; as we accumulate pointers and arrays we move the pointer
+ * or array string backwards so it will show the expected number of
+ * '*' or '[]' for the type. BTF_SHOW_MAX_ITER of nesting of pointers
+ * and/or arrays and typedefs are supported as a precaution.
+ *
+ * We also want to get typedef name while proceeding to resolve
+ * type it points to so that we can add parentheses if it is a
+ * "typedef struct" etc.
+ */
+ for (i = 0; i < BTF_SHOW_MAX_ITER; i++) {
+
+ switch (BTF_INFO_KIND(t->info)) {
+ case BTF_KIND_TYPEDEF:
+ if (!name)
+ name = btf_name_by_offset(show->btf,
+ t->name_off);
+ kinds |= BTF_KIND_BIT(BTF_KIND_TYPEDEF);
+ id = t->type;
+ break;
+ case BTF_KIND_ARRAY:
+ kinds |= BTF_KIND_BIT(BTF_KIND_ARRAY);
+ parens = "[";
+ if (!t)
+ return "";
+ array = btf_type_array(t);
+ if (array_suffix > array_suffixes)
+ array_suffix -= 2;
+ id = array->type;
+ break;
+ case BTF_KIND_PTR:
+ kinds |= BTF_KIND_BIT(BTF_KIND_PTR);
+ if (ptr_suffix > ptr_suffixes)
+ ptr_suffix -= 1;
+ id = t->type;
+ break;
+ default:
+ id = 0;
+ break;
+ }
+ if (!id)
+ break;
+ t = btf_type_skip_qualifiers(show->btf, id);
+ }
+ /* We may not be able to represent this type; bail to be safe */
+ if (i == BTF_SHOW_MAX_ITER)
+ return "";
+
+ if (!name)
+ name = btf_name_by_offset(show->btf, t->name_off);
+
+ switch (BTF_INFO_KIND(t->info)) {
+ case BTF_KIND_STRUCT:
+ case BTF_KIND_UNION:
+ prefix = BTF_INFO_KIND(t->info) == BTF_KIND_STRUCT ?
+ "struct" : "union";
+ /* if it's an array of struct/union, parens is already set */
+ if (!(kinds & (BTF_KIND_BIT(BTF_KIND_ARRAY))))
+ parens = "{";
+ break;
+ case BTF_KIND_ENUM:
+ case BTF_KIND_ENUM64:
+ prefix = "enum";
+ break;
+ default:
+ break;
+ }
+
+ /* pointer does not require parens */
+ if (kinds & BTF_KIND_BIT(BTF_KIND_PTR))
+ parens = "";
+ /* typedef does not require struct/union/enum prefix */
+ if (kinds & BTF_KIND_BIT(BTF_KIND_TYPEDEF))
+ prefix = "";
+
+ if (!name)
+ name = "";
+
+ /* Even if we don't want type name info, we want parentheses etc */
+ if (show->flags & BTF_SHOW_NONAME)
+ snprintf(show->state.name, sizeof(show->state.name), "%s",
+ parens);
+ else
+ snprintf(show->state.name, sizeof(show->state.name),
+ "%s%s%s(%s%s%s%s%s%s)%s",
+ /* first 3 strings comprise ".member = " */
+ show_member ? "." : "",
+ show_member ? member : "",
+ show_member ? " = " : "",
+ /* ...next is our prefix (struct, enum, etc) */
+ prefix,
+ strlen(prefix) > 0 && strlen(name) > 0 ? " " : "",
+ /* ...this is the type name itself */
+ name,
+ /* ...suffixed by the appropriate '*', '[]' suffixes */
+ strlen(ptr_suffix) > 0 ? " " : "", ptr_suffix,
+ array_suffix, parens);
+
+ return show->state.name;
+}
+
+static const char *__btf_show_indent(struct btf_show *show)
+{
+ const char *indents = " ";
+ const char *indent = &indents[strlen(indents)];
+
+ if ((indent - show->state.depth) >= indents)
+ return indent - show->state.depth;
+ return indents;
+}
+
+static const char *btf_show_indent(struct btf_show *show)
+{
+ return show->flags & BTF_SHOW_COMPACT ? "" : __btf_show_indent(show);
+}
+
+static const char *btf_show_newline(struct btf_show *show)
+{
+ return show->flags & BTF_SHOW_COMPACT ? "" : "\n";
+}
+
+static const char *btf_show_delim(struct btf_show *show)
+{
+ if (show->state.depth == 0)
+ return "";
+
+ if ((show->flags & BTF_SHOW_COMPACT) && show->state.type &&
+ BTF_INFO_KIND(show->state.type->info) == BTF_KIND_UNION)
+ return "|";
+
+ return ",";
+}
+
+__printf(2, 3) static void btf_show(struct btf_show *show, const char *fmt, ...)
+{
+ va_list args;
+
+ if (!show->state.depth_check) {
+ va_start(args, fmt);
+ show->showfn(show, fmt, args);
+ va_end(args);
+ }
+}
+
+/* Macros are used here as btf_show_type_value[s]() prepends and appends
+ * format specifiers to the format specifier passed in; these do the work of
+ * adding indentation, delimiters etc while the caller simply has to specify
+ * the type value(s) in the format specifier + value(s).
+ */
+#define btf_show_type_value(show, fmt, value) \
+ do { \
+ if ((value) != (__typeof__(value))0 || \
+ (show->flags & BTF_SHOW_ZERO) || \
+ show->state.depth == 0) { \
+ btf_show(show, "%s%s" fmt "%s%s", \
+ btf_show_indent(show), \
+ btf_show_name(show), \
+ value, btf_show_delim(show), \
+ btf_show_newline(show)); \
+ if (show->state.depth > show->state.depth_to_show) \
+ show->state.depth_to_show = show->state.depth; \
+ } \
+ } while (0)
+
+#define btf_show_type_values(show, fmt, ...) \
+ do { \
+ btf_show(show, "%s%s" fmt "%s%s", btf_show_indent(show), \
+ btf_show_name(show), \
+ __VA_ARGS__, btf_show_delim(show), \
+ btf_show_newline(show)); \
+ if (show->state.depth > show->state.depth_to_show) \
+ show->state.depth_to_show = show->state.depth; \
+ } while (0)
+
+/* How much is left to copy to safe buffer after @data? */
+static int btf_show_obj_size_left(struct btf_show *show, void *data)
+{
+ return show->obj.head + show->obj.size - data;
+}
+
+/* Is object pointed to by @data of @size already copied to our safe buffer? */
+static bool btf_show_obj_is_safe(struct btf_show *show, void *data, int size)
+{
+ return data >= show->obj.data &&
+ (data + size) < (show->obj.data + BTF_SHOW_OBJ_SAFE_SIZE);
+}
+
+/*
+ * If object pointed to by @data of @size falls within our safe buffer, return
+ * the equivalent pointer to the same safe data. Assumes
+ * copy_from_kernel_nofault() has already happened and our safe buffer is
+ * populated.
+ */
+static void *__btf_show_obj_safe(struct btf_show *show, void *data, int size)
+{
+ if (btf_show_obj_is_safe(show, data, size))
+ return show->obj.safe + (data - show->obj.data);
+ return NULL;
+}
+
+/*
+ * Return a safe-to-access version of data pointed to by @data.
+ * We do this by copying the relevant amount of information
+ * to the struct btf_show obj.safe buffer using copy_from_kernel_nofault().
+ *
+ * If BTF_SHOW_UNSAFE is specified, just return data as-is; no
+ * safe copy is needed.
+ *
+ * Otherwise we need to determine if we have the required amount
+ * of data (determined by the @data pointer and the size of the
+ * largest base type we can encounter (represented by
+ * BTF_SHOW_OBJ_BASE_TYPE_SIZE). Having that much data ensures
+ * that we will be able to print some of the current object,
+ * and if more is needed a copy will be triggered.
+ * Some objects such as structs will not fit into the buffer;
+ * in such cases additional copies when we iterate over their
+ * members may be needed.
+ *
+ * btf_show_obj_safe() is used to return a safe buffer for
+ * btf_show_start_type(); this ensures that as we recurse into
+ * nested types we always have safe data for the given type.
+ * This approach is somewhat wasteful; it's possible for example
+ * that when iterating over a large union we'll end up copying the
+ * same data repeatedly, but the goal is safety not performance.
+ * We use stack data as opposed to per-CPU buffers because the
+ * iteration over a type can take some time, and preemption handling
+ * would greatly complicate use of the safe buffer.
+ */
+static void *btf_show_obj_safe(struct btf_show *show,
+ const struct btf_type *t,
+ void *data)
+{
+ const struct btf_type *rt;
+ int size_left, size;
+ void *safe = NULL;
+
+ if (show->flags & BTF_SHOW_UNSAFE)
+ return data;
+
+ rt = btf_resolve_size(show->btf, t, &size);
+ if (IS_ERR(rt)) {
+ show->state.status = PTR_ERR(rt);
+ return NULL;
+ }
+
+ /*
+ * Is this toplevel object? If so, set total object size and
+ * initialize pointers. Otherwise check if we still fall within
+ * our safe object data.
+ */
+ if (show->state.depth == 0) {
+ show->obj.size = size;
+ show->obj.head = data;
+ } else {
+ /*
+ * If the size of the current object is > our remaining
+ * safe buffer we _may_ need to do a new copy. However
+ * consider the case of a nested struct; it's size pushes
+ * us over the safe buffer limit, but showing any individual
+ * struct members does not. In such cases, we don't need
+ * to initiate a fresh copy yet; however we definitely need
+ * at least BTF_SHOW_OBJ_BASE_TYPE_SIZE bytes left
+ * in our buffer, regardless of the current object size.
+ * The logic here is that as we resolve types we will
+ * hit a base type at some point, and we need to be sure
+ * the next chunk of data is safely available to display
+ * that type info safely. We cannot rely on the size of
+ * the current object here because it may be much larger
+ * than our current buffer (e.g. task_struct is 8k).
+ * All we want to do here is ensure that we can print the
+ * next basic type, which we can if either
+ * - the current type size is within the safe buffer; or
+ * - at least BTF_SHOW_OBJ_BASE_TYPE_SIZE bytes are left in
+ * the safe buffer.
+ */
+ safe = __btf_show_obj_safe(show, data,
+ min(size,
+ BTF_SHOW_OBJ_BASE_TYPE_SIZE));
+ }
+
+ /*
+ * We need a new copy to our safe object, either because we haven't
+ * yet copied and are initializing safe data, or because the data
+ * we want falls outside the boundaries of the safe object.
+ */
+ if (!safe) {
+ size_left = btf_show_obj_size_left(show, data);
+ if (size_left > BTF_SHOW_OBJ_SAFE_SIZE)
+ size_left = BTF_SHOW_OBJ_SAFE_SIZE;
+ show->state.status = copy_from_kernel_nofault(show->obj.safe,
+ data, size_left);
+ if (!show->state.status) {
+ show->obj.data = data;
+ safe = show->obj.safe;
+ }
+ }
+
+ return safe;
+}
+
+/*
+ * Set the type we are starting to show and return a safe data pointer
+ * to be used for showing the associated data.
+ */
+static void *btf_show_start_type(struct btf_show *show,
+ const struct btf_type *t,
+ u32 type_id, void *data)
+{
+ show->state.type = t;
+ show->state.type_id = type_id;
+ show->state.name[0] = '\0';
+
+ return btf_show_obj_safe(show, t, data);
+}
+
+static void btf_show_end_type(struct btf_show *show)
+{
+ show->state.type = NULL;
+ show->state.type_id = 0;
+ show->state.name[0] = '\0';
+}
+
+static void *btf_show_start_aggr_type(struct btf_show *show,
+ const struct btf_type *t,
+ u32 type_id, void *data)
+{
+ void *safe_data = btf_show_start_type(show, t, type_id, data);
+
+ if (!safe_data)
+ return safe_data;
+
+ btf_show(show, "%s%s%s", btf_show_indent(show),
+ btf_show_name(show),
+ btf_show_newline(show));
+ show->state.depth++;
+ return safe_data;
+}
+
+static void btf_show_end_aggr_type(struct btf_show *show,
+ const char *suffix)
+{
+ show->state.depth--;
+ btf_show(show, "%s%s%s%s", btf_show_indent(show), suffix,
+ btf_show_delim(show), btf_show_newline(show));
+ btf_show_end_type(show);
+}
+
+static void btf_show_start_member(struct btf_show *show,
+ const struct btf_member *m)
+{
+ show->state.member = m;
+}
+
+static void btf_show_start_array_member(struct btf_show *show)
+{
+ show->state.array_member = 1;
+ btf_show_start_member(show, NULL);
+}
+
+static void btf_show_end_member(struct btf_show *show)
+{
+ show->state.member = NULL;
+}
+
+static void btf_show_end_array_member(struct btf_show *show)
+{
+ show->state.array_member = 0;
+ btf_show_end_member(show);
+}
+
+static void *btf_show_start_array_type(struct btf_show *show,
+ const struct btf_type *t,
+ u32 type_id,
+ u16 array_encoding,
+ void *data)
+{
+ show->state.array_encoding = array_encoding;
+ show->state.array_terminated = 0;
+ return btf_show_start_aggr_type(show, t, type_id, data);
+}
+
+static void btf_show_end_array_type(struct btf_show *show)
+{
+ show->state.array_encoding = 0;
+ show->state.array_terminated = 0;
+ btf_show_end_aggr_type(show, "]");
+}
+
+static void *btf_show_start_struct_type(struct btf_show *show,
+ const struct btf_type *t,
+ u32 type_id,
+ void *data)
+{
+ return btf_show_start_aggr_type(show, t, type_id, data);
+}
+
+static void btf_show_end_struct_type(struct btf_show *show)
+{
+ btf_show_end_aggr_type(show, "}");
+}
+
+__printf(2, 3) static void __btf_verifier_log(struct bpf_verifier_log *log,
+ const char *fmt, ...)
+{
+ va_list args;
+
+ va_start(args, fmt);
+ bpf_verifier_vlog(log, fmt, args);
+ va_end(args);
+}
+
+__printf(2, 3) static void btf_verifier_log(struct btf_verifier_env *env,
+ const char *fmt, ...)
+{
+ struct bpf_verifier_log *log = &env->log;
+ va_list args;
+
+ if (!bpf_verifier_log_needed(log))
+ return;
+
+ va_start(args, fmt);
+ bpf_verifier_vlog(log, fmt, args);
+ va_end(args);
+}
+
+__printf(4, 5) static void __btf_verifier_log_type(struct btf_verifier_env *env,
+ const struct btf_type *t,
+ bool log_details,
+ const char *fmt, ...)
+{
+ struct bpf_verifier_log *log = &env->log;
+ struct btf *btf = env->btf;
+ va_list args;
+
+ if (!bpf_verifier_log_needed(log))
+ return;
+
+ if (log->level == BPF_LOG_KERNEL) {
+ /* btf verifier prints all types it is processing via
+ * btf_verifier_log_type(..., fmt = NULL).
+ * Skip those prints for in-kernel BTF verification.
+ */
+ if (!fmt)
+ return;
+
+ /* Skip logging when loading module BTF with mismatches permitted */
+ if (env->btf->base_btf && IS_ENABLED(CONFIG_MODULE_ALLOW_BTF_MISMATCH))
+ return;
+ }
+
+ __btf_verifier_log(log, "[%u] %s %s%s",
+ env->log_type_id,
+ btf_type_str(t),
+ __btf_name_by_offset(btf, t->name_off),
+ log_details ? " " : "");
+
+ if (log_details)
+ btf_type_ops(t)->log_details(env, t);
+
+ if (fmt && *fmt) {
+ __btf_verifier_log(log, " ");
+ va_start(args, fmt);
+ bpf_verifier_vlog(log, fmt, args);
+ va_end(args);
+ }
+
+ __btf_verifier_log(log, "\n");
+}
+
+#define btf_verifier_log_type(env, t, ...) \
+ __btf_verifier_log_type((env), (t), true, __VA_ARGS__)
+#define btf_verifier_log_basic(env, t, ...) \
+ __btf_verifier_log_type((env), (t), false, __VA_ARGS__)
+
+__printf(4, 5)
+static void btf_verifier_log_member(struct btf_verifier_env *env,
+ const struct btf_type *struct_type,
+ const struct btf_member *member,
+ const char *fmt, ...)
+{
+ struct bpf_verifier_log *log = &env->log;
+ struct btf *btf = env->btf;
+ va_list args;
+
+ if (!bpf_verifier_log_needed(log))
+ return;
+
+ if (log->level == BPF_LOG_KERNEL) {
+ if (!fmt)
+ return;
+
+ /* Skip logging when loading module BTF with mismatches permitted */
+ if (env->btf->base_btf && IS_ENABLED(CONFIG_MODULE_ALLOW_BTF_MISMATCH))
+ return;
+ }
+
+ /* The CHECK_META phase already did a btf dump.
+ *
+ * If member is logged again, it must hit an error in
+ * parsing this member. It is useful to print out which
+ * struct this member belongs to.
+ */
+ if (env->phase != CHECK_META)
+ btf_verifier_log_type(env, struct_type, NULL);
+
+ if (btf_type_kflag(struct_type))
+ __btf_verifier_log(log,
+ "\t%s type_id=%u bitfield_size=%u bits_offset=%u",
+ __btf_name_by_offset(btf, member->name_off),
+ member->type,
+ BTF_MEMBER_BITFIELD_SIZE(member->offset),
+ BTF_MEMBER_BIT_OFFSET(member->offset));
+ else
+ __btf_verifier_log(log, "\t%s type_id=%u bits_offset=%u",
+ __btf_name_by_offset(btf, member->name_off),
+ member->type, member->offset);
+
+ if (fmt && *fmt) {
+ __btf_verifier_log(log, " ");
+ va_start(args, fmt);
+ bpf_verifier_vlog(log, fmt, args);
+ va_end(args);
+ }
+
+ __btf_verifier_log(log, "\n");
+}
+
+__printf(4, 5)
+static void btf_verifier_log_vsi(struct btf_verifier_env *env,
+ const struct btf_type *datasec_type,
+ const struct btf_var_secinfo *vsi,
+ const char *fmt, ...)
+{
+ struct bpf_verifier_log *log = &env->log;
+ va_list args;
+
+ if (!bpf_verifier_log_needed(log))
+ return;
+ if (log->level == BPF_LOG_KERNEL && !fmt)
+ return;
+ if (env->phase != CHECK_META)
+ btf_verifier_log_type(env, datasec_type, NULL);
+
+ __btf_verifier_log(log, "\t type_id=%u offset=%u size=%u",
+ vsi->type, vsi->offset, vsi->size);
+ if (fmt && *fmt) {
+ __btf_verifier_log(log, " ");
+ va_start(args, fmt);
+ bpf_verifier_vlog(log, fmt, args);
+ va_end(args);
+ }
+
+ __btf_verifier_log(log, "\n");
+}
+
+static void btf_verifier_log_hdr(struct btf_verifier_env *env,
+ u32 btf_data_size)
+{
+ struct bpf_verifier_log *log = &env->log;
+ const struct btf *btf = env->btf;
+ const struct btf_header *hdr;
+
+ if (!bpf_verifier_log_needed(log))
+ return;
+
+ if (log->level == BPF_LOG_KERNEL)
+ return;
+ hdr = &btf->hdr;
+ __btf_verifier_log(log, "magic: 0x%x\n", hdr->magic);
+ __btf_verifier_log(log, "version: %u\n", hdr->version);
+ __btf_verifier_log(log, "flags: 0x%x\n", hdr->flags);
+ __btf_verifier_log(log, "hdr_len: %u\n", hdr->hdr_len);
+ __btf_verifier_log(log, "type_off: %u\n", hdr->type_off);
+ __btf_verifier_log(log, "type_len: %u\n", hdr->type_len);
+ __btf_verifier_log(log, "str_off: %u\n", hdr->str_off);
+ __btf_verifier_log(log, "str_len: %u\n", hdr->str_len);
+ __btf_verifier_log(log, "btf_total_size: %u\n", btf_data_size);
+}
+
+static int btf_add_type(struct btf_verifier_env *env, struct btf_type *t)
+{
+ struct btf *btf = env->btf;
+
+ if (btf->types_size == btf->nr_types) {
+ /* Expand 'types' array */
+
+ struct btf_type **new_types;
+ u32 expand_by, new_size;
+
+ if (btf->start_id + btf->types_size == BTF_MAX_TYPE) {
+ btf_verifier_log(env, "Exceeded max num of types");
+ return -E2BIG;
+ }
+
+ expand_by = max_t(u32, btf->types_size >> 2, 16);
+ new_size = min_t(u32, BTF_MAX_TYPE,
+ btf->types_size + expand_by);
+
+ new_types = kvzalloc_objs(*new_types, new_size,
+ GFP_KERNEL | __GFP_NOWARN);
+ if (!new_types)
+ return -ENOMEM;
+
+ if (btf->nr_types == 0) {
+ if (!btf->base_btf) {
+ /* lazily init VOID type */
+ new_types[0] = &btf_void;
+ btf->nr_types++;
+ }
+ } else {
+ memcpy(new_types, btf->types,
+ sizeof(*btf->types) * btf->nr_types);
+ }
+
+ kvfree(btf->types);
+ btf->types = new_types;
+ btf->types_size = new_size;
+ }
+
+ btf->types[btf->nr_types++] = t;
+
+ return 0;
+}
+
+
+void __weak btf_free_bpf_data(struct btf *btf)
+{
+}
+
+void btf_free(struct btf *btf)
+{
+ btf_free_bpf_data(btf);
+ kvfree(btf->types);
+ kvfree(btf->resolved_sizes);
+ kvfree(btf->resolved_ids);
+ /* vmlinux does not allocate btf->data, it simply points it at
+ * __start_BTF.
+ */
+ if (!btf_is_vmlinux(btf))
+ kvfree(btf->data);
+ kvfree(btf->base_id_map);
+ kfree(btf);
+}
+
+
+const char *btf_get_name(const struct btf *btf)
+{
+ return btf->name;
+}
+
+void btf_get(struct btf *btf)
+{
+ refcount_inc(&btf->refcnt);
+}
+
+void __weak btf_put_bpf(struct btf *btf)
+{
+ btf_free(btf);
+}
+
+void btf_put(struct btf *btf)
+{
+ if (btf && refcount_dec_and_test(&btf->refcnt)) {
+ btf_put_bpf(btf);
+ }
+}
+
+struct btf *btf_base_btf(const struct btf *btf)
+{
+ return btf->base_btf;
+}
+
+const struct btf_header *btf_header(const struct btf *btf)
+{
+ return &btf->hdr;
+}
+
+void btf_set_base_btf(struct btf *btf, const struct btf *base_btf)
+{
+ btf->base_btf = (struct btf *)base_btf;
+ btf->start_id = btf_nr_types(base_btf);
+ btf->start_str_off = base_btf->hdr.str_len;
+}
+
+static int env_resolve_init(struct btf_verifier_env *env)
+{
+ struct btf *btf = env->btf;
+ u32 nr_types = btf->nr_types;
+ u32 *resolved_sizes = NULL;
+ u32 *resolved_ids = NULL;
+ u8 *visit_states = NULL;
+
+ resolved_sizes = kvcalloc(nr_types, sizeof(*resolved_sizes),
+ GFP_KERNEL | __GFP_NOWARN);
+ if (!resolved_sizes)
+ goto nomem;
+
+ resolved_ids = kvcalloc(nr_types, sizeof(*resolved_ids),
+ GFP_KERNEL | __GFP_NOWARN);
+ if (!resolved_ids)
+ goto nomem;
+
+ visit_states = kvcalloc(nr_types, sizeof(*visit_states),
+ GFP_KERNEL | __GFP_NOWARN);
+ if (!visit_states)
+ goto nomem;
+
+ btf->resolved_sizes = resolved_sizes;
+ btf->resolved_ids = resolved_ids;
+ env->visit_states = visit_states;
+
+ return 0;
+
+nomem:
+ kvfree(resolved_sizes);
+ kvfree(resolved_ids);
+ kvfree(visit_states);
+ return -ENOMEM;
+}
+
+void btf_verifier_env_free(struct btf_verifier_env *env)
+{
+ kvfree(env->visit_states);
+ kfree(env);
+}
+
+static bool env_type_is_resolve_sink(const struct btf_verifier_env *env,
+ const struct btf_type *next_type)
+{
+ switch (env->resolve_mode) {
+ case RESOLVE_TBD:
+ /* int, enum or void is a sink */
+ return !btf_type_needs_resolve(next_type);
+ case RESOLVE_PTR:
+ /* int, enum, void, struct, array, func or func_proto is a sink
+ * for ptr
+ */
+ return !btf_type_is_modifier(next_type) &&
+ !btf_type_is_ptr(next_type);
+ case RESOLVE_STRUCT_OR_ARRAY:
+ /* int, enum, void, ptr, func or func_proto is a sink
+ * for struct and array
+ */
+ return !btf_type_is_modifier(next_type) &&
+ !btf_type_is_array(next_type) &&
+ !btf_type_is_struct(next_type);
+ default:
+ BUG();
+ }
+}
+
+static bool env_type_is_resolved(const struct btf_verifier_env *env,
+ u32 type_id)
+{
+ /* base BTF types should be resolved by now */
+ if (type_id < env->btf->start_id)
+ return true;
+
+ return env->visit_states[type_id - env->btf->start_id] == RESOLVED;
+}
+
+static int env_stack_push(struct btf_verifier_env *env,
+ const struct btf_type *t, u32 type_id)
+{
+ const struct btf *btf = env->btf;
+ struct resolve_vertex *v;
+
+ if (env->top_stack == MAX_RESOLVE_DEPTH)
+ return -E2BIG;
+
+ if (type_id < btf->start_id
+ || env->visit_states[type_id - btf->start_id] != NOT_VISITED)
+ return -EEXIST;
+
+ env->visit_states[type_id - btf->start_id] = VISITED;
+
+ v = &env->stack[env->top_stack++];
+ v->t = t;
+ v->type_id = type_id;
+ v->next_member = 0;
+
+ if (env->resolve_mode == RESOLVE_TBD) {
+ if (btf_type_is_ptr(t))
+ env->resolve_mode = RESOLVE_PTR;
+ else if (btf_type_is_struct(t) || btf_type_is_array(t))
+ env->resolve_mode = RESOLVE_STRUCT_OR_ARRAY;
+ }
+
+ return 0;
+}
+
+static void env_stack_set_next_member(struct btf_verifier_env *env,
+ u16 next_member)
+{
+ env->stack[env->top_stack - 1].next_member = next_member;
+}
+
+static void env_stack_pop_resolved(struct btf_verifier_env *env,
+ u32 resolved_type_id,
+ u32 resolved_size)
+{
+ u32 type_id = env->stack[--(env->top_stack)].type_id;
+ struct btf *btf = env->btf;
+
+ type_id -= btf->start_id; /* adjust to local type id */
+ btf->resolved_sizes[type_id] = resolved_size;
+ btf->resolved_ids[type_id] = resolved_type_id;
+ env->visit_states[type_id] = RESOLVED;
+}
+
+static const struct resolve_vertex *env_stack_peak(struct btf_verifier_env *env)
+{
+ return env->top_stack ? &env->stack[env->top_stack - 1] : NULL;
+}
+
+/* Resolve the size of a passed-in "type"
+ *
+ * type: is an array (e.g. u32 array[x][y])
+ * return type: type "u32[x][y]", i.e. BTF_KIND_ARRAY,
+ * *type_size: (x * y * sizeof(u32)). Hence, *type_size always
+ * corresponds to the return type.
+ * *elem_type: u32
+ * *elem_id: id of u32
+ * *total_nelems: (x * y). Hence, individual elem size is
+ * (*type_size / *total_nelems)
+ * *type_id: id of type if it's changed within the function, 0 if not
+ *
+ * type: is not an array (e.g. const struct X)
+ * return type: type "struct X"
+ * *type_size: sizeof(struct X)
+ * *elem_type: same as return type ("struct X")
+ * *elem_id: 0
+ * *total_nelems: 1
+ * *type_id: id of type if it's changed within the function, 0 if not
+ */
+const struct btf_type *
+__btf_resolve_size(const struct btf *btf, const struct btf_type *type,
+ u32 *type_size, const struct btf_type **elem_type,
+ u32 *elem_id, u32 *total_nelems, u32 *type_id)
+{
+ const struct btf_type *array_type = NULL;
+ const struct btf_array *array = NULL;
+ u32 i, size, nelems = 1, id = 0;
+
+ for (i = 0; i < MAX_RESOLVE_DEPTH; i++) {
+ switch (BTF_INFO_KIND(type->info)) {
+ /* type->size can be used */
+ case BTF_KIND_INT:
+ case BTF_KIND_STRUCT:
+ case BTF_KIND_UNION:
+ case BTF_KIND_ENUM:
+ case BTF_KIND_FLOAT:
+ case BTF_KIND_ENUM64:
+ size = type->size;
+ goto resolved;
+
+ case BTF_KIND_PTR:
+ size = sizeof(void *);
+ goto resolved;
+
+ /* Modifiers */
+ case BTF_KIND_TYPEDEF:
+ case BTF_KIND_VOLATILE:
+ case BTF_KIND_CONST:
+ case BTF_KIND_RESTRICT:
+ case BTF_KIND_TYPE_TAG:
+ id = type->type;
+ type = btf_type_by_id(btf, type->type);
+ break;
+
+ case BTF_KIND_ARRAY:
+ if (!array_type)
+ array_type = type;
+ array = btf_type_array(type);
+ if (nelems && array->nelems > U32_MAX / nelems)
+ return ERR_PTR(-EINVAL);
+ nelems *= array->nelems;
+ type = btf_type_by_id(btf, array->type);
+ break;
+
+ /* type without size */
+ default:
+ return ERR_PTR(-EINVAL);
+ }
+ }
+
+ return ERR_PTR(-EINVAL);
+
+resolved:
+ if (nelems && size > U32_MAX / nelems)
+ return ERR_PTR(-EINVAL);
+
+ *type_size = nelems * size;
+ if (total_nelems)
+ *total_nelems = nelems;
+ if (elem_type)
+ *elem_type = type;
+ if (elem_id)
+ *elem_id = array ? array->type : 0;
+ if (type_id && id)
+ *type_id = id;
+
+ return array_type ? : type;
+}
+
+const struct btf_type *
+btf_resolve_size(const struct btf *btf, const struct btf_type *type,
+ u32 *type_size)
+{
+ return __btf_resolve_size(btf, type, type_size, NULL, NULL, NULL, NULL);
+}
+
+static u32 btf_resolved_type_id(const struct btf *btf, u32 type_id)
+{
+ while (type_id < btf->start_id)
+ btf = btf->base_btf;
+
+ return btf->resolved_ids[type_id - btf->start_id];
+}
+
+/* The input param "type_id" must point to a needs_resolve type */
+static const struct btf_type *btf_type_id_resolve(const struct btf *btf,
+ u32 *type_id)
+{
+ *type_id = btf_resolved_type_id(btf, *type_id);
+ return btf_type_by_id(btf, *type_id);
+}
+
+static u32 btf_resolved_type_size(const struct btf *btf, u32 type_id)
+{
+ while (type_id < btf->start_id)
+ btf = btf->base_btf;
+
+ return btf->resolved_sizes[type_id - btf->start_id];
+}
+
+const struct btf_type *btf_type_id_size(const struct btf *btf,
+ u32 *type_id, u32 *ret_size)
+{
+ const struct btf_type *size_type;
+ u32 size_type_id = *type_id;
+ u32 size = 0;
+
+ size_type = btf_type_by_id(btf, size_type_id);
+ if (btf_type_nosize_or_null(size_type))
+ return NULL;
+
+ if (btf_type_has_size(size_type)) {
+ size = size_type->size;
+ } else if (btf_type_is_array(size_type)) {
+ size = btf_resolved_type_size(btf, size_type_id);
+ } else if (btf_type_is_ptr(size_type)) {
+ size = sizeof(void *);
+ } else {
+ if (WARN_ON_ONCE(!btf_type_is_modifier(size_type) &&
+ !btf_type_is_var(size_type)))
+ return NULL;
+
+ size_type_id = btf_resolved_type_id(btf, size_type_id);
+ size_type = btf_type_by_id(btf, size_type_id);
+ if (btf_type_nosize_or_null(size_type))
+ return NULL;
+ else if (btf_type_has_size(size_type))
+ size = size_type->size;
+ else if (btf_type_is_array(size_type))
+ size = btf_resolved_type_size(btf, size_type_id);
+ else if (btf_type_is_ptr(size_type))
+ size = sizeof(void *);
+ else
+ return NULL;
+ }
+
+ *type_id = size_type_id;
+ if (ret_size)
+ *ret_size = size;
+
+ return size_type;
+}
+
+static int btf_df_check_member(struct btf_verifier_env *env,
+ const struct btf_type *struct_type,
+ const struct btf_member *member,
+ const struct btf_type *member_type)
+{
+ btf_verifier_log_basic(env, struct_type,
+ "Unsupported check_member");
+ return -EINVAL;
+}
+
+static int btf_df_check_kflag_member(struct btf_verifier_env *env,
+ const struct btf_type *struct_type,
+ const struct btf_member *member,
+ const struct btf_type *member_type)
+{
+ btf_verifier_log_basic(env, struct_type,
+ "Unsupported check_kflag_member");
+ return -EINVAL;
+}
+
+/* Used for ptr, array struct/union and float type members.
+ * int, enum and modifier types have their specific callback functions.
+ */
+static int btf_generic_check_kflag_member(struct btf_verifier_env *env,
+ const struct btf_type *struct_type,
+ const struct btf_member *member,
+ const struct btf_type *member_type)
+{
+ if (BTF_MEMBER_BITFIELD_SIZE(member->offset)) {
+ btf_verifier_log_member(env, struct_type, member,
+ "Invalid member bitfield_size");
+ return -EINVAL;
+ }
+
+ /* bitfield size is 0, so member->offset represents bit offset only.
+ * It is safe to call non kflag check_member variants.
+ */
+ return btf_type_ops(member_type)->check_member(env, struct_type,
+ member,
+ member_type);
+}
+
+static int btf_df_resolve(struct btf_verifier_env *env,
+ const struct resolve_vertex *v)
+{
+ btf_verifier_log_basic(env, v->t, "Unsupported resolve");
+ return -EINVAL;
+}
+
+static void btf_df_show(const struct btf *btf, const struct btf_type *t,
+ u32 type_id, void *data, u8 bits_offsets,
+ struct btf_show *show)
+{
+ btf_show(show, "<unsupported kind:%u>", BTF_INFO_KIND(t->info));
+}
+
+static int btf_int_check_member(struct btf_verifier_env *env,
+ const struct btf_type *struct_type,
+ const struct btf_member *member,
+ const struct btf_type *member_type)
+{
+ u32 int_data = btf_type_int(member_type);
+ u32 struct_bits_off = member->offset;
+ u32 struct_size = struct_type->size;
+ u32 nr_copy_bits;
+ u32 bytes_offset;
+
+ if (U32_MAX - struct_bits_off < BTF_INT_OFFSET(int_data)) {
+ btf_verifier_log_member(env, struct_type, member,
+ "bits_offset exceeds U32_MAX");
+ return -EINVAL;
+ }
+
+ struct_bits_off += BTF_INT_OFFSET(int_data);
+ bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
+ nr_copy_bits = BTF_INT_BITS(int_data) +
+ BITS_PER_BYTE_MASKED(struct_bits_off);
+
+ if (nr_copy_bits > BITS_PER_U128) {
+ btf_verifier_log_member(env, struct_type, member,
+ "nr_copy_bits exceeds 128");
+ return -EINVAL;
+ }
+
+ if (struct_size < bytes_offset ||
+ struct_size - bytes_offset < BITS_ROUNDUP_BYTES(nr_copy_bits)) {
+ btf_verifier_log_member(env, struct_type, member,
+ "Member exceeds struct_size");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int btf_int_check_kflag_member(struct btf_verifier_env *env,
+ const struct btf_type *struct_type,
+ const struct btf_member *member,
+ const struct btf_type *member_type)
+{
+ u32 struct_bits_off, nr_bits, nr_int_data_bits, bytes_offset;
+ u32 int_data = btf_type_int(member_type);
+ u32 struct_size = struct_type->size;
+ u32 nr_copy_bits;
+
+ /* a regular int type is required for the kflag int member */
+ if (!btf_type_int_is_regular(member_type)) {
+ btf_verifier_log_member(env, struct_type, member,
+ "Invalid member base type");
+ return -EINVAL;
+ }
+
+ /* check sanity of bitfield size */
+ nr_bits = BTF_MEMBER_BITFIELD_SIZE(member->offset);
+ struct_bits_off = BTF_MEMBER_BIT_OFFSET(member->offset);
+ nr_int_data_bits = BTF_INT_BITS(int_data);
+ if (!nr_bits) {
+ /* Not a bitfield member, member offset must be at byte
+ * boundary.
+ */
+ if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
+ btf_verifier_log_member(env, struct_type, member,
+ "Invalid member offset");
+ return -EINVAL;
+ }
+
+ nr_bits = nr_int_data_bits;
+ } else if (nr_bits > nr_int_data_bits) {
+ btf_verifier_log_member(env, struct_type, member,
+ "Invalid member bitfield_size");
+ return -EINVAL;
+ }
+
+ bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
+ nr_copy_bits = nr_bits + BITS_PER_BYTE_MASKED(struct_bits_off);
+ if (nr_copy_bits > BITS_PER_U128) {
+ btf_verifier_log_member(env, struct_type, member,
+ "nr_copy_bits exceeds 128");
+ return -EINVAL;
+ }
+
+ if (struct_size < bytes_offset ||
+ struct_size - bytes_offset < BITS_ROUNDUP_BYTES(nr_copy_bits)) {
+ btf_verifier_log_member(env, struct_type, member,
+ "Member exceeds struct_size");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static s32 btf_int_check_meta(struct btf_verifier_env *env,
+ const struct btf_type *t,
+ u32 meta_left)
+{
+ u32 int_data, nr_bits, meta_needed = sizeof(int_data);
+ u16 encoding;
+
+ if (meta_left < meta_needed) {
+ btf_verifier_log_basic(env, t,
+ "meta_left:%u meta_needed:%u",
+ meta_left, meta_needed);
+ return -EINVAL;
+ }
+
+ if (btf_type_vlen(t)) {
+ btf_verifier_log_type(env, t, "vlen != 0");
+ return -EINVAL;
+ }
+
+ if (btf_type_kflag(t)) {
+ btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
+ return -EINVAL;
+ }
+
+ int_data = btf_type_int(t);
+ if (int_data & ~BTF_INT_MASK) {
+ btf_verifier_log_basic(env, t, "Invalid int_data:%x",
+ int_data);
+ return -EINVAL;
+ }
+
+ nr_bits = BTF_INT_BITS(int_data) + BTF_INT_OFFSET(int_data);
+
+ if (nr_bits > BITS_PER_U128) {
+ btf_verifier_log_type(env, t, "nr_bits exceeds %zu",
+ BITS_PER_U128);
+ return -EINVAL;
+ }
+
+ if (BITS_ROUNDUP_BYTES(nr_bits) > t->size) {
+ btf_verifier_log_type(env, t, "nr_bits exceeds type_size");
+ return -EINVAL;
+ }
+
+ /*
+ * Only one of the encoding bits is allowed and it
+ * should be sufficient for the pretty print purpose (i.e. decoding).
+ * Multiple bits can be allowed later if it is found
+ * to be insufficient.
+ */
+ encoding = BTF_INT_ENCODING(int_data);
+ if (encoding &&
+ encoding != BTF_INT_SIGNED &&
+ encoding != BTF_INT_CHAR &&
+ encoding != BTF_INT_BOOL) {
+ btf_verifier_log_type(env, t, "Unsupported encoding");
+ return -ENOTSUPP;
+ }
+
+ btf_verifier_log_type(env, t, NULL);
+
+ return meta_needed;
+}
+
+static void btf_int_log(struct btf_verifier_env *env,
+ const struct btf_type *t)
+{
+ int int_data = btf_type_int(t);
+
+ btf_verifier_log(env,
+ "size=%u bits_offset=%u nr_bits=%u encoding=%s",
+ t->size, BTF_INT_OFFSET(int_data),
+ BTF_INT_BITS(int_data),
+ btf_int_encoding_str(BTF_INT_ENCODING(int_data)));
+}
+
+static void btf_int128_print(struct btf_show *show, void *data)
+{
+ /* data points to a __int128 number.
+ * Suppose
+ * int128_num = *(__int128 *)data;
+ * The below formulas shows what upper_num and lower_num represents:
+ * upper_num = int128_num >> 64;
+ * lower_num = int128_num & 0xffffffffFFFFFFFFULL;
+ */
+ u64 upper_num, lower_num;
+
+#ifdef __BIG_ENDIAN_BITFIELD
+ upper_num = *(u64 *)data;
+ lower_num = *(u64 *)(data + 8);
+#else
+ upper_num = *(u64 *)(data + 8);
+ lower_num = *(u64 *)data;
+#endif
+ if (upper_num == 0)
+ btf_show_type_value(show, "0x%llx", lower_num);
+ else
+ btf_show_type_values(show, "0x%llx%016llx", upper_num,
+ lower_num);
+}
+
+static void btf_int128_shift(u64 *print_num, u16 left_shift_bits,
+ u16 right_shift_bits)
+{
+ u64 upper_num, lower_num;
+
+#ifdef __BIG_ENDIAN_BITFIELD
+ upper_num = print_num[0];
+ lower_num = print_num[1];
+#else
+ upper_num = print_num[1];
+ lower_num = print_num[0];
+#endif
+
+ /* shake out un-needed bits by shift/or operations */
+ if (left_shift_bits >= 64) {
+ upper_num = lower_num << (left_shift_bits - 64);
+ lower_num = 0;
+ } else {
+ upper_num = (upper_num << left_shift_bits) |
+ (lower_num >> (64 - left_shift_bits));
+ lower_num = lower_num << left_shift_bits;
+ }
+
+ if (right_shift_bits >= 64) {
+ lower_num = upper_num >> (right_shift_bits - 64);
+ upper_num = 0;
+ } else {
+ lower_num = (lower_num >> right_shift_bits) |
+ (upper_num << (64 - right_shift_bits));
+ upper_num = upper_num >> right_shift_bits;
+ }
+
+#ifdef __BIG_ENDIAN_BITFIELD
+ print_num[0] = upper_num;
+ print_num[1] = lower_num;
+#else
+ print_num[0] = lower_num;
+ print_num[1] = upper_num;
+#endif
+}
+
+static void btf_bitfield_show(void *data, u8 bits_offset,
+ u8 nr_bits, struct btf_show *show)
+{
+ u16 left_shift_bits, right_shift_bits;
+ u8 nr_copy_bytes;
+ u8 nr_copy_bits;
+ u64 print_num[2] = {};
+
+ nr_copy_bits = nr_bits + bits_offset;
+ nr_copy_bytes = BITS_ROUNDUP_BYTES(nr_copy_bits);
+
+ memcpy(print_num, data, nr_copy_bytes);
+
+#ifdef __BIG_ENDIAN_BITFIELD
+ left_shift_bits = bits_offset;
+#else
+ left_shift_bits = BITS_PER_U128 - nr_copy_bits;
+#endif
+ right_shift_bits = BITS_PER_U128 - nr_bits;
+
+ btf_int128_shift(print_num, left_shift_bits, right_shift_bits);
+ btf_int128_print(show, print_num);
+}
+
+
+static void btf_int_bits_show(const struct btf *btf,
+ const struct btf_type *t,
+ void *data, u8 bits_offset,
+ struct btf_show *show)
+{
+ u32 int_data = btf_type_int(t);
+ u8 nr_bits = BTF_INT_BITS(int_data);
+ u8 total_bits_offset;
+
+ /*
+ * bits_offset is at most 7.
+ * BTF_INT_OFFSET() cannot exceed 128 bits.
+ */
+ total_bits_offset = bits_offset + BTF_INT_OFFSET(int_data);
+ data += BITS_ROUNDDOWN_BYTES(total_bits_offset);
+ bits_offset = BITS_PER_BYTE_MASKED(total_bits_offset);
+ btf_bitfield_show(data, bits_offset, nr_bits, show);
+}
+
+static void btf_int_show(const struct btf *btf, const struct btf_type *t,
+ u32 type_id, void *data, u8 bits_offset,
+ struct btf_show *show)
+{
+ u32 int_data = btf_type_int(t);
+ u8 encoding = BTF_INT_ENCODING(int_data);
+ bool sign = encoding & BTF_INT_SIGNED;
+ u8 nr_bits = BTF_INT_BITS(int_data);
+ void *safe_data;
+
+ safe_data = btf_show_start_type(show, t, type_id, data);
+ if (!safe_data)
+ return;
+
+ if (bits_offset || BTF_INT_OFFSET(int_data) ||
+ BITS_PER_BYTE_MASKED(nr_bits)) {
+ btf_int_bits_show(btf, t, safe_data, bits_offset, show);
+ goto out;
+ }
+
+ switch (nr_bits) {
+ case 128:
+ btf_int128_print(show, safe_data);
+ break;
+ case 64:
+ if (sign)
+ btf_show_type_value(show, "%lld", *(s64 *)safe_data);
+ else
+ btf_show_type_value(show, "%llu", *(u64 *)safe_data);
+ break;
+ case 32:
+ if (sign)
+ btf_show_type_value(show, "%d", *(s32 *)safe_data);
+ else
+ btf_show_type_value(show, "%u", *(u32 *)safe_data);
+ break;
+ case 16:
+ if (sign)
+ btf_show_type_value(show, "%d", *(s16 *)safe_data);
+ else
+ btf_show_type_value(show, "%u", *(u16 *)safe_data);
+ break;
+ case 8:
+ if (show->state.array_encoding == BTF_INT_CHAR) {
+ /* check for null terminator */
+ if (show->state.array_terminated)
+ break;
+ if (*(char *)data == '\0') {
+ show->state.array_terminated = 1;
+ break;
+ }
+ if (isprint(*(char *)data)) {
+ btf_show_type_value(show, "'%c'",
+ *(char *)safe_data);
+ break;
+ }
+ }
+ if (sign)
+ btf_show_type_value(show, "%d", *(s8 *)safe_data);
+ else
+ btf_show_type_value(show, "%u", *(u8 *)safe_data);
+ break;
+ default:
+ btf_int_bits_show(btf, t, safe_data, bits_offset, show);
+ break;
+ }
+out:
+ btf_show_end_type(show);
+}
+
+static const struct btf_kind_operations int_ops = {
+ .check_meta = btf_int_check_meta,
+ .resolve = btf_df_resolve,
+ .check_member = btf_int_check_member,
+ .check_kflag_member = btf_int_check_kflag_member,
+ .log_details = btf_int_log,
+ .show = btf_int_show,
+};
+
+static int btf_modifier_check_member(struct btf_verifier_env *env,
+ const struct btf_type *struct_type,
+ const struct btf_member *member,
+ const struct btf_type *member_type)
+{
+ const struct btf_type *resolved_type;
+ u32 resolved_type_id = member->type;
+ struct btf_member resolved_member;
+ struct btf *btf = env->btf;
+
+ resolved_type = btf_type_id_size(btf, &resolved_type_id, NULL);
+ if (!resolved_type) {
+ btf_verifier_log_member(env, struct_type, member,
+ "Invalid member");
+ return -EINVAL;
+ }
+
+ resolved_member = *member;
+ resolved_member.type = resolved_type_id;
+
+ return btf_type_ops(resolved_type)->check_member(env, struct_type,
+ &resolved_member,
+ resolved_type);
+}
+
+static int btf_modifier_check_kflag_member(struct btf_verifier_env *env,
+ const struct btf_type *struct_type,
+ const struct btf_member *member,
+ const struct btf_type *member_type)
+{
+ const struct btf_type *resolved_type;
+ u32 resolved_type_id = member->type;
+ struct btf_member resolved_member;
+ struct btf *btf = env->btf;
+
+ resolved_type = btf_type_id_size(btf, &resolved_type_id, NULL);
+ if (!resolved_type) {
+ btf_verifier_log_member(env, struct_type, member,
+ "Invalid member");
+ return -EINVAL;
+ }
+
+ resolved_member = *member;
+ resolved_member.type = resolved_type_id;
+
+ return btf_type_ops(resolved_type)->check_kflag_member(env, struct_type,
+ &resolved_member,
+ resolved_type);
+}
+
+static int btf_ptr_check_member(struct btf_verifier_env *env,
+ const struct btf_type *struct_type,
+ const struct btf_member *member,
+ const struct btf_type *member_type)
+{
+ u32 struct_size, struct_bits_off, bytes_offset;
+
+ struct_size = struct_type->size;
+ struct_bits_off = member->offset;
+ bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
+
+ if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
+ btf_verifier_log_member(env, struct_type, member,
+ "Member is not byte aligned");
+ return -EINVAL;
+ }
+
+ if (struct_size - bytes_offset < sizeof(void *)) {
+ btf_verifier_log_member(env, struct_type, member,
+ "Member exceeds struct_size");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int btf_ref_type_check_meta(struct btf_verifier_env *env,
+ const struct btf_type *t,
+ u32 meta_left)
+{
+ const char *value;
+
+ if (btf_type_vlen(t)) {
+ btf_verifier_log_type(env, t, "vlen != 0");
+ return -EINVAL;
+ }
+
+ if (btf_type_kflag(t) && !btf_type_is_type_tag(t)) {
+ btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
+ return -EINVAL;
+ }
+
+ if (!BTF_TYPE_ID_VALID(t->type)) {
+ btf_verifier_log_type(env, t, "Invalid type_id");
+ return -EINVAL;
+ }
+
+ /* typedef/type_tag type must have a valid name, and other ref types,
+ * volatile, const, restrict, should have a null name.
+ */
+ if (BTF_INFO_KIND(t->info) == BTF_KIND_TYPEDEF) {
+ if (!t->name_off ||
+ !btf_name_valid_identifier(env->btf, t->name_off)) {
+ btf_verifier_log_type(env, t, "Invalid name");
+ return -EINVAL;
+ }
+ } else if (BTF_INFO_KIND(t->info) == BTF_KIND_TYPE_TAG) {
+ value = btf_name_by_offset(env->btf, t->name_off);
+ if (!value || !value[0]) {
+ btf_verifier_log_type(env, t, "Invalid name");
+ return -EINVAL;
+ }
+ } else {
+ if (t->name_off) {
+ btf_verifier_log_type(env, t, "Invalid name");
+ return -EINVAL;
+ }
+ }
+
+ btf_verifier_log_type(env, t, NULL);
+
+ return 0;
+}
+
+static int btf_modifier_resolve(struct btf_verifier_env *env,
+ const struct resolve_vertex *v)
+{
+ const struct btf_type *t = v->t;
+ const struct btf_type *next_type;
+ u32 next_type_id = t->type;
+ struct btf *btf = env->btf;
+
+ next_type = btf_type_by_id(btf, next_type_id);
+ if (!next_type || btf_type_is_resolve_source_only(next_type)) {
+ btf_verifier_log_type(env, v->t, "Invalid type_id");
+ return -EINVAL;
+ }
+
+ if (!env_type_is_resolve_sink(env, next_type) &&
+ !env_type_is_resolved(env, next_type_id))
+ return env_stack_push(env, next_type, next_type_id);
+
+ /* Figure out the resolved next_type_id with size.
+ * They will be stored in the current modifier's
+ * resolved_ids and resolved_sizes such that it can
+ * save us a few type-following when we use it later (e.g. in
+ * pretty print).
+ */
+ if (!btf_type_id_size(btf, &next_type_id, NULL)) {
+ if (env_type_is_resolved(env, next_type_id))
+ next_type = btf_type_id_resolve(btf, &next_type_id);
+
+ /* "typedef void new_void", "const void"...etc */
+ if (!btf_type_is_void(next_type) &&
+ !btf_type_is_fwd(next_type) &&
+ !btf_type_is_func_proto(next_type)) {
+ btf_verifier_log_type(env, v->t, "Invalid type_id");
+ return -EINVAL;
+ }
+ }
+
+ env_stack_pop_resolved(env, next_type_id, 0);
+
+ return 0;
+}
+
+static int btf_var_resolve(struct btf_verifier_env *env,
+ const struct resolve_vertex *v)
+{
+ const struct btf_type *next_type;
+ const struct btf_type *t = v->t;
+ u32 next_type_id = t->type;
+ struct btf *btf = env->btf;
+
+ next_type = btf_type_by_id(btf, next_type_id);
+ if (!next_type || btf_type_is_resolve_source_only(next_type)) {
+ btf_verifier_log_type(env, v->t, "Invalid type_id");
+ return -EINVAL;
+ }
+
+ if (!env_type_is_resolve_sink(env, next_type) &&
+ !env_type_is_resolved(env, next_type_id))
+ return env_stack_push(env, next_type, next_type_id);
+
+ if (btf_type_is_modifier(next_type)) {
+ const struct btf_type *resolved_type;
+ u32 resolved_type_id;
+
+ resolved_type_id = next_type_id;
+ resolved_type = btf_type_id_resolve(btf, &resolved_type_id);
+
+ if (btf_type_is_ptr(resolved_type) &&
+ !env_type_is_resolve_sink(env, resolved_type) &&
+ !env_type_is_resolved(env, resolved_type_id))
+ return env_stack_push(env, resolved_type,
+ resolved_type_id);
+ }
+
+ /* We must resolve to something concrete at this point, no
+ * forward types or similar that would resolve to size of
+ * zero is allowed.
+ */
+ if (!btf_type_id_size(btf, &next_type_id, NULL)) {
+ btf_verifier_log_type(env, v->t, "Invalid type_id");
+ return -EINVAL;
+ }
+
+ env_stack_pop_resolved(env, next_type_id, 0);
+
+ return 0;
+}
+
+static int btf_ptr_resolve(struct btf_verifier_env *env,
+ const struct resolve_vertex *v)
+{
+ const struct btf_type *next_type;
+ const struct btf_type *t = v->t;
+ u32 next_type_id = t->type;
+ struct btf *btf = env->btf;
+
+ next_type = btf_type_by_id(btf, next_type_id);
+ if (!next_type || btf_type_is_resolve_source_only(next_type)) {
+ btf_verifier_log_type(env, v->t, "Invalid type_id");
+ return -EINVAL;
+ }
+
+ if (!env_type_is_resolve_sink(env, next_type) &&
+ !env_type_is_resolved(env, next_type_id))
+ return env_stack_push(env, next_type, next_type_id);
+
+ /* If the modifier was RESOLVED during RESOLVE_STRUCT_OR_ARRAY,
+ * the modifier may have stopped resolving when it was resolved
+ * to a ptr (last-resolved-ptr).
+ *
+ * We now need to continue from the last-resolved-ptr to
+ * ensure the last-resolved-ptr will not referring back to
+ * the current ptr (t).
+ */
+ if (btf_type_is_modifier(next_type)) {
+ const struct btf_type *resolved_type;
+ u32 resolved_type_id;
+
+ resolved_type_id = next_type_id;
+ resolved_type = btf_type_id_resolve(btf, &resolved_type_id);
+
+ if (btf_type_is_ptr(resolved_type) &&
+ !env_type_is_resolve_sink(env, resolved_type) &&
+ !env_type_is_resolved(env, resolved_type_id))
+ return env_stack_push(env, resolved_type,
+ resolved_type_id);
+ }
+
+ if (!btf_type_id_size(btf, &next_type_id, NULL)) {
+ if (env_type_is_resolved(env, next_type_id))
+ next_type = btf_type_id_resolve(btf, &next_type_id);
+
+ if (!btf_type_is_void(next_type) &&
+ !btf_type_is_fwd(next_type) &&
+ !btf_type_is_func_proto(next_type)) {
+ btf_verifier_log_type(env, v->t, "Invalid type_id");
+ return -EINVAL;
+ }
+ }
+
+ env_stack_pop_resolved(env, next_type_id, 0);
+
+ return 0;
+}
+
+static void btf_modifier_show(const struct btf *btf,
+ const struct btf_type *t,
+ u32 type_id, void *data,
+ u8 bits_offset, struct btf_show *show)
+{
+ if (btf->resolved_ids)
+ t = btf_type_id_resolve(btf, &type_id);
+ else
+ t = btf_type_skip_modifiers(btf, type_id, NULL);
+
+ btf_type_ops(t)->show(btf, t, type_id, data, bits_offset, show);
+}
+
+static void btf_var_show(const struct btf *btf, const struct btf_type *t,
+ u32 type_id, void *data, u8 bits_offset,
+ struct btf_show *show)
+{
+ t = btf_type_id_resolve(btf, &type_id);
+
+ btf_type_ops(t)->show(btf, t, type_id, data, bits_offset, show);
+}
+
+static void btf_ptr_show(const struct btf *btf, const struct btf_type *t,
+ u32 type_id, void *data, u8 bits_offset,
+ struct btf_show *show)
+{
+ void *safe_data;
+
+ safe_data = btf_show_start_type(show, t, type_id, data);
+ if (!safe_data)
+ return;
+
+ /* It is a hashed value unless BTF_SHOW_PTR_RAW is specified */
+ if (show->flags & BTF_SHOW_PTR_RAW)
+ btf_show_type_value(show, "0x%px", *(void **)safe_data);
+ else
+ btf_show_type_value(show, "0x%p", *(void **)safe_data);
+ btf_show_end_type(show);
+}
+
+static void btf_ref_type_log(struct btf_verifier_env *env,
+ const struct btf_type *t)
+{
+ btf_verifier_log(env, "type_id=%u", t->type);
+}
+
+static const struct btf_kind_operations modifier_ops = {
+ .check_meta = btf_ref_type_check_meta,
+ .resolve = btf_modifier_resolve,
+ .check_member = btf_modifier_check_member,
+ .check_kflag_member = btf_modifier_check_kflag_member,
+ .log_details = btf_ref_type_log,
+ .show = btf_modifier_show,
+};
+
+static const struct btf_kind_operations ptr_ops = {
+ .check_meta = btf_ref_type_check_meta,
+ .resolve = btf_ptr_resolve,
+ .check_member = btf_ptr_check_member,
+ .check_kflag_member = btf_generic_check_kflag_member,
+ .log_details = btf_ref_type_log,
+ .show = btf_ptr_show,
+};
+
+static s32 btf_fwd_check_meta(struct btf_verifier_env *env,
+ const struct btf_type *t,
+ u32 meta_left)
+{
+ if (btf_type_vlen(t)) {
+ btf_verifier_log_type(env, t, "vlen != 0");
+ return -EINVAL;
+ }
+
+ if (t->type) {
+ btf_verifier_log_type(env, t, "type != 0");
+ return -EINVAL;
+ }
+
+ /* fwd type must have a valid name */
+ if (!t->name_off ||
+ !btf_name_valid_identifier(env->btf, t->name_off)) {
+ btf_verifier_log_type(env, t, "Invalid name");
+ return -EINVAL;
+ }
+
+ btf_verifier_log_type(env, t, NULL);
+
+ return 0;
+}
+
+static void btf_fwd_type_log(struct btf_verifier_env *env,
+ const struct btf_type *t)
+{
+ btf_verifier_log(env, "%s", btf_type_kflag(t) ? "union" : "struct");
+}
+
+static const struct btf_kind_operations fwd_ops = {
+ .check_meta = btf_fwd_check_meta,
+ .resolve = btf_df_resolve,
+ .check_member = btf_df_check_member,
+ .check_kflag_member = btf_df_check_kflag_member,
+ .log_details = btf_fwd_type_log,
+ .show = btf_df_show,
+};
+
+static int btf_array_check_member(struct btf_verifier_env *env,
+ const struct btf_type *struct_type,
+ const struct btf_member *member,
+ const struct btf_type *member_type)
+{
+ u32 struct_bits_off = member->offset;
+ u32 struct_size, bytes_offset;
+ u32 array_type_id, array_size;
+ struct btf *btf = env->btf;
+
+ if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
+ btf_verifier_log_member(env, struct_type, member,
+ "Member is not byte aligned");
+ return -EINVAL;
+ }
+
+ array_type_id = member->type;
+ btf_type_id_size(btf, &array_type_id, &array_size);
+ struct_size = struct_type->size;
+ bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
+ if (struct_size - bytes_offset < array_size) {
+ btf_verifier_log_member(env, struct_type, member,
+ "Member exceeds struct_size");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static s32 btf_array_check_meta(struct btf_verifier_env *env,
+ const struct btf_type *t,
+ u32 meta_left)
+{
+ const struct btf_array *array = btf_type_array(t);
+ u32 meta_needed = sizeof(*array);
+
+ if (meta_left < meta_needed) {
+ btf_verifier_log_basic(env, t,
+ "meta_left:%u meta_needed:%u",
+ meta_left, meta_needed);
+ return -EINVAL;
+ }
+
+ /* array type should not have a name */
+ if (t->name_off) {
+ btf_verifier_log_type(env, t, "Invalid name");
+ return -EINVAL;
+ }
+
+ if (btf_type_vlen(t)) {
+ btf_verifier_log_type(env, t, "vlen != 0");
+ return -EINVAL;
+ }
+
+ if (btf_type_kflag(t)) {
+ btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
+ return -EINVAL;
+ }
+
+ if (t->size) {
+ btf_verifier_log_type(env, t, "size != 0");
+ return -EINVAL;
+ }
+
+ /* Array elem type and index type cannot be in type void,
+ * so !array->type and !array->index_type are not allowed.
+ */
+ if (!array->type || !BTF_TYPE_ID_VALID(array->type)) {
+ btf_verifier_log_type(env, t, "Invalid elem");
+ return -EINVAL;
+ }
+
+ if (!array->index_type || !BTF_TYPE_ID_VALID(array->index_type)) {
+ btf_verifier_log_type(env, t, "Invalid index");
+ return -EINVAL;
+ }
+
+ btf_verifier_log_type(env, t, NULL);
+
+ return meta_needed;
+}
+
+static int btf_array_resolve(struct btf_verifier_env *env,
+ const struct resolve_vertex *v)
+{
+ const struct btf_array *array = btf_type_array(v->t);
+ const struct btf_type *elem_type, *index_type;
+ u32 elem_type_id, index_type_id;
+ struct btf *btf = env->btf;
+ u32 elem_size;
+
+ /* Check array->index_type */
+ index_type_id = array->index_type;
+ index_type = btf_type_by_id(btf, index_type_id);
+ if (btf_type_nosize_or_null(index_type) ||
+ btf_type_is_resolve_source_only(index_type)) {
+ btf_verifier_log_type(env, v->t, "Invalid index");
+ return -EINVAL;
+ }
+
+ if (!env_type_is_resolve_sink(env, index_type) &&
+ !env_type_is_resolved(env, index_type_id))
+ return env_stack_push(env, index_type, index_type_id);
+
+ index_type = btf_type_id_size(btf, &index_type_id, NULL);
+ if (!index_type || !btf_type_is_int(index_type) ||
+ !btf_type_int_is_regular(index_type)) {
+ btf_verifier_log_type(env, v->t, "Invalid index");
+ return -EINVAL;
+ }
+
+ /* Check array->type */
+ elem_type_id = array->type;
+ elem_type = btf_type_by_id(btf, elem_type_id);
+ if (btf_type_nosize_or_null(elem_type) ||
+ btf_type_is_resolve_source_only(elem_type)) {
+ btf_verifier_log_type(env, v->t,
+ "Invalid elem");
+ return -EINVAL;
+ }
+
+ if (!env_type_is_resolve_sink(env, elem_type) &&
+ !env_type_is_resolved(env, elem_type_id))
+ return env_stack_push(env, elem_type, elem_type_id);
+
+ elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size);
+ if (!elem_type) {
+ btf_verifier_log_type(env, v->t, "Invalid elem");
+ return -EINVAL;
+ }
+
+ if (btf_type_is_int(elem_type) && !btf_type_int_is_regular(elem_type)) {
+ btf_verifier_log_type(env, v->t, "Invalid array of int");
+ return -EINVAL;
+ }
+
+ if (array->nelems && elem_size > U32_MAX / array->nelems) {
+ btf_verifier_log_type(env, v->t,
+ "Array size overflows U32_MAX");
+ return -EINVAL;
+ }
+
+ env_stack_pop_resolved(env, elem_type_id, elem_size * array->nelems);
+
+ return 0;
+}
+
+static void btf_array_log(struct btf_verifier_env *env,
+ const struct btf_type *t)
+{
+ const struct btf_array *array = btf_type_array(t);
+
+ btf_verifier_log(env, "type_id=%u index_type_id=%u nr_elems=%u",
+ array->type, array->index_type, array->nelems);
+}
+
+static void __btf_array_show(const struct btf *btf, const struct btf_type *t,
+ u32 type_id, void *data, u8 bits_offset,
+ struct btf_show *show)
+{
+ const struct btf_array *array = btf_type_array(t);
+ const struct btf_kind_operations *elem_ops;
+ const struct btf_type *elem_type;
+ u32 i, elem_size = 0, elem_type_id;
+ u16 encoding = 0;
+
+ elem_type_id = array->type;
+ elem_type = btf_type_skip_modifiers(btf, elem_type_id, NULL);
+ if (elem_type && btf_type_has_size(elem_type))
+ elem_size = elem_type->size;
+
+ if (elem_type && btf_type_is_int(elem_type)) {
+ u32 int_type = btf_type_int(elem_type);
+
+ encoding = BTF_INT_ENCODING(int_type);
+
+ /*
+ * BTF_INT_CHAR encoding never seems to be set for
+ * char arrays, so if size is 1 and element is
+ * printable as a char, we'll do that.
+ */
+ if (elem_size == 1)
+ encoding = BTF_INT_CHAR;
+ }
+
+ if (!btf_show_start_array_type(show, t, type_id, encoding, data))
+ return;
+
+ if (!elem_type)
+ goto out;
+ elem_ops = btf_type_ops(elem_type);
+
+ for (i = 0; i < array->nelems; i++) {
+
+ btf_show_start_array_member(show);
+
+ elem_ops->show(btf, elem_type, elem_type_id, data,
+ bits_offset, show);
+ data += elem_size;
+
+ btf_show_end_array_member(show);
+
+ if (show->state.array_terminated)
+ break;
+ }
+out:
+ btf_show_end_array_type(show);
+}
+
+static void btf_array_show(const struct btf *btf, const struct btf_type *t,
+ u32 type_id, void *data, u8 bits_offset,
+ struct btf_show *show)
+{
+ const struct btf_member *m = show->state.member;
+
+ /*
+ * First check if any members would be shown (are non-zero).
+ * See comments above "struct btf_show" definition for more
+ * details on how this works at a high-level.
+ */
+ if (show->state.depth > 0 && !(show->flags & BTF_SHOW_ZERO)) {
+ if (!show->state.depth_check) {
+ show->state.depth_check = show->state.depth + 1;
+ show->state.depth_to_show = 0;
+ }
+ __btf_array_show(btf, t, type_id, data, bits_offset, show);
+ show->state.member = m;
+
+ if (show->state.depth_check != show->state.depth + 1)
+ return;
+ show->state.depth_check = 0;
+
+ if (show->state.depth_to_show <= show->state.depth)
+ return;
+ /*
+ * Reaching here indicates we have recursed and found
+ * non-zero array member(s).
+ */
+ }
+ __btf_array_show(btf, t, type_id, data, bits_offset, show);
+}
+
+static const struct btf_kind_operations array_ops = {
+ .check_meta = btf_array_check_meta,
+ .resolve = btf_array_resolve,
+ .check_member = btf_array_check_member,
+ .check_kflag_member = btf_generic_check_kflag_member,
+ .log_details = btf_array_log,
+ .show = btf_array_show,
+};
+
+static int btf_struct_check_member(struct btf_verifier_env *env,
+ const struct btf_type *struct_type,
+ const struct btf_member *member,
+ const struct btf_type *member_type)
+{
+ u32 struct_bits_off = member->offset;
+ u32 struct_size, bytes_offset;
+
+ if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
+ btf_verifier_log_member(env, struct_type, member,
+ "Member is not byte aligned");
+ return -EINVAL;
+ }
+
+ struct_size = struct_type->size;
+ bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
+ if (struct_size - bytes_offset < member_type->size) {
+ btf_verifier_log_member(env, struct_type, member,
+ "Member exceeds struct_size");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static s32 btf_struct_check_meta(struct btf_verifier_env *env,
+ const struct btf_type *t,
+ u32 meta_left)
+{
+ bool is_union = BTF_INFO_KIND(t->info) == BTF_KIND_UNION;
+ const struct btf_member *member;
+ u32 meta_needed, last_offset;
+ struct btf *btf = env->btf;
+ u32 struct_size = t->size;
+ u32 offset;
+ u16 i;
+
+ meta_needed = btf_type_vlen(t) * sizeof(*member);
+ if (meta_left < meta_needed) {
+ btf_verifier_log_basic(env, t,
+ "meta_left:%u meta_needed:%u",
+ meta_left, meta_needed);
+ return -EINVAL;
+ }
+
+ /* struct type either no name or a valid one */
+ if (t->name_off &&
+ !btf_name_valid_identifier(env->btf, t->name_off)) {
+ btf_verifier_log_type(env, t, "Invalid name");
+ return -EINVAL;
+ }
+
+ btf_verifier_log_type(env, t, NULL);
+
+ last_offset = 0;
+ for_each_member(i, t, member) {
+ if (!btf_name_offset_valid(btf, member->name_off)) {
+ btf_verifier_log_member(env, t, member,
+ "Invalid member name_offset:%u",
+ member->name_off);
+ return -EINVAL;
+ }
+
+ /* struct member either no name or a valid one */
+ if (member->name_off &&
+ !btf_name_valid_identifier(btf, member->name_off)) {
+ btf_verifier_log_member(env, t, member, "Invalid name");
+ return -EINVAL;
+ }
+ /* A member cannot be in type void */
+ if (!member->type || !BTF_TYPE_ID_VALID(member->type)) {
+ btf_verifier_log_member(env, t, member,
+ "Invalid type_id");
+ return -EINVAL;
+ }
+
+ offset = __btf_member_bit_offset(t, member);
+ if (is_union && offset) {
+ btf_verifier_log_member(env, t, member,
+ "Invalid member bits_offset");
+ return -EINVAL;
+ }
+
+ /*
+ * ">" instead of ">=" because the last member could be
+ * "char a[0];"
+ */
+ if (last_offset > offset) {
+ btf_verifier_log_member(env, t, member,
+ "Invalid member bits_offset");
+ return -EINVAL;
+ }
+
+ if (BITS_ROUNDUP_BYTES(offset) > struct_size) {
+ btf_verifier_log_member(env, t, member,
+ "Member bits_offset exceeds its struct size");
+ return -EINVAL;
+ }
+
+ btf_verifier_log_member(env, t, member, NULL);
+ last_offset = offset;
+ }
+
+ return meta_needed;
+}
+
+static int btf_struct_resolve(struct btf_verifier_env *env,
+ const struct resolve_vertex *v)
+{
+ const struct btf_member *member;
+ int err;
+ u16 i;
+
+ /* Before continue resolving the next_member,
+ * ensure the last member is indeed resolved to a
+ * type with size info.
+ */
+ if (v->next_member) {
+ const struct btf_type *last_member_type;
+ const struct btf_member *last_member;
+ u32 last_member_type_id;
+
+ last_member = btf_type_member(v->t) + v->next_member - 1;
+ last_member_type_id = last_member->type;
+ if (WARN_ON_ONCE(!env_type_is_resolved(env,
+ last_member_type_id)))
+ return -EINVAL;
+
+ last_member_type = btf_type_by_id(env->btf,
+ last_member_type_id);
+ if (btf_type_kflag(v->t))
+ err = btf_type_ops(last_member_type)->check_kflag_member(env, v->t,
+ last_member,
+ last_member_type);
+ else
+ err = btf_type_ops(last_member_type)->check_member(env, v->t,
+ last_member,
+ last_member_type);
+ if (err)
+ return err;
+ }
+
+ for_each_member_from(i, v->next_member, v->t, member) {
+ u32 member_type_id = member->type;
+ const struct btf_type *member_type = btf_type_by_id(env->btf,
+ member_type_id);
+
+ if (btf_type_nosize_or_null(member_type) ||
+ btf_type_is_resolve_source_only(member_type)) {
+ btf_verifier_log_member(env, v->t, member,
+ "Invalid member");
+ return -EINVAL;
+ }
+
+ if (!env_type_is_resolve_sink(env, member_type) &&
+ !env_type_is_resolved(env, member_type_id)) {
+ env_stack_set_next_member(env, i + 1);
+ return env_stack_push(env, member_type, member_type_id);
+ }
+
+ if (btf_type_kflag(v->t))
+ err = btf_type_ops(member_type)->check_kflag_member(env, v->t,
+ member,
+ member_type);
+ else
+ err = btf_type_ops(member_type)->check_member(env, v->t,
+ member,
+ member_type);
+ if (err)
+ return err;
+ }
+
+ env_stack_pop_resolved(env, 0, 0);
+
+ return 0;
+}
+
+static void btf_struct_log(struct btf_verifier_env *env,
+ const struct btf_type *t)
+{
+ btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t));
+}
+
+
+static void __btf_struct_show(const struct btf *btf, const struct btf_type *t,
+ u32 type_id, void *data, u8 bits_offset,
+ struct btf_show *show)
+{
+ const struct btf_member *member;
+ void *safe_data;
+ u32 i;
+
+ safe_data = btf_show_start_struct_type(show, t, type_id, data);
+ if (!safe_data)
+ return;
+
+ for_each_member(i, t, member) {
+ const struct btf_type *member_type = btf_type_by_id(btf,
+ member->type);
+ const struct btf_kind_operations *ops;
+ u32 member_offset, bitfield_size;
+ u32 bytes_offset;
+ u8 bits8_offset;
+
+ btf_show_start_member(show, member);
+
+ member_offset = __btf_member_bit_offset(t, member);
+ bitfield_size = __btf_member_bitfield_size(t, member);
+ bytes_offset = BITS_ROUNDDOWN_BYTES(member_offset);
+ bits8_offset = BITS_PER_BYTE_MASKED(member_offset);
+ if (bitfield_size) {
+ safe_data = btf_show_start_type(show, member_type,
+ member->type,
+ data + bytes_offset);
+ if (safe_data)
+ btf_bitfield_show(safe_data,
+ bits8_offset,
+ bitfield_size, show);
+ btf_show_end_type(show);
+ } else {
+ ops = btf_type_ops(member_type);
+ ops->show(btf, member_type, member->type,
+ data + bytes_offset, bits8_offset, show);
+ }
+
+ btf_show_end_member(show);
+ }
+
+ btf_show_end_struct_type(show);
+}
+
+static void btf_struct_show(const struct btf *btf, const struct btf_type *t,
+ u32 type_id, void *data, u8 bits_offset,
+ struct btf_show *show)
+{
+ const struct btf_member *m = show->state.member;
+
+ /*
+ * First check if any members would be shown (are non-zero).
+ * See comments above "struct btf_show" definition for more
+ * details on how this works at a high-level.
+ */
+ if (show->state.depth > 0 && !(show->flags & BTF_SHOW_ZERO)) {
+ if (!show->state.depth_check) {
+ show->state.depth_check = show->state.depth + 1;
+ show->state.depth_to_show = 0;
+ }
+ __btf_struct_show(btf, t, type_id, data, bits_offset, show);
+ /* Restore saved member data here */
+ show->state.member = m;
+ if (show->state.depth_check != show->state.depth + 1)
+ return;
+ show->state.depth_check = 0;
+
+ if (show->state.depth_to_show <= show->state.depth)
+ return;
+ /*
+ * Reaching here indicates we have recursed and found
+ * non-zero child values.
+ */
+ }
+
+ __btf_struct_show(btf, t, type_id, data, bits_offset, show);
+}
+
+static const struct btf_kind_operations struct_ops = {
+ .check_meta = btf_struct_check_meta,
+ .resolve = btf_struct_resolve,
+ .check_member = btf_struct_check_member,
+ .check_kflag_member = btf_generic_check_kflag_member,
+ .log_details = btf_struct_log,
+ .show = btf_struct_show,
+};
+
+static int btf_enum_check_member(struct btf_verifier_env *env,
+ const struct btf_type *struct_type,
+ const struct btf_member *member,
+ const struct btf_type *member_type)
+{
+ u32 struct_bits_off = member->offset;
+ u32 struct_size, bytes_offset;
+
+ if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
+ btf_verifier_log_member(env, struct_type, member,
+ "Member is not byte aligned");
+ return -EINVAL;
+ }
+
+ struct_size = struct_type->size;
+ bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
+ if (struct_size - bytes_offset < member_type->size) {
+ btf_verifier_log_member(env, struct_type, member,
+ "Member exceeds struct_size");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int btf_enum_check_kflag_member(struct btf_verifier_env *env,
+ const struct btf_type *struct_type,
+ const struct btf_member *member,
+ const struct btf_type *member_type)
+{
+ u32 struct_bits_off, nr_bits, bytes_end, struct_size;
+ u32 int_bitsize = sizeof(int) * BITS_PER_BYTE;
+
+ struct_bits_off = BTF_MEMBER_BIT_OFFSET(member->offset);
+ nr_bits = BTF_MEMBER_BITFIELD_SIZE(member->offset);
+ if (!nr_bits) {
+ if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
+ btf_verifier_log_member(env, struct_type, member,
+ "Member is not byte aligned");
+ return -EINVAL;
+ }
+
+ nr_bits = int_bitsize;
+ } else if (nr_bits > int_bitsize) {
+ btf_verifier_log_member(env, struct_type, member,
+ "Invalid member bitfield_size");
+ return -EINVAL;
+ }
+
+ struct_size = struct_type->size;
+ bytes_end = BITS_ROUNDUP_BYTES(struct_bits_off + nr_bits);
+ if (struct_size < bytes_end) {
+ btf_verifier_log_member(env, struct_type, member,
+ "Member exceeds struct_size");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static s32 btf_enum_check_meta(struct btf_verifier_env *env,
+ const struct btf_type *t,
+ u32 meta_left)
+{
+ const struct btf_enum *enums = btf_type_enum(t);
+ struct btf *btf = env->btf;
+ const char *fmt_str;
+ u16 i, nr_enums;
+ u32 meta_needed;
+
+ nr_enums = btf_type_vlen(t);
+ meta_needed = nr_enums * sizeof(*enums);
+
+ if (meta_left < meta_needed) {
+ btf_verifier_log_basic(env, t,
+ "meta_left:%u meta_needed:%u",
+ meta_left, meta_needed);
+ return -EINVAL;
+ }
+
+ if (t->size > 8 || !is_power_of_2(t->size)) {
+ btf_verifier_log_type(env, t, "Unexpected size");
+ return -EINVAL;
+ }
+
+ /* enum type either no name or a valid one */
+ if (t->name_off &&
+ !btf_name_valid_identifier(env->btf, t->name_off)) {
+ btf_verifier_log_type(env, t, "Invalid name");
+ return -EINVAL;
+ }
+
+ btf_verifier_log_type(env, t, NULL);
+
+ for (i = 0; i < nr_enums; i++) {
+ if (!btf_name_offset_valid(btf, enums[i].name_off)) {
+ btf_verifier_log(env, "\tInvalid name_offset:%u",
+ enums[i].name_off);
+ return -EINVAL;
+ }
+
+ /* enum member must have a valid name */
+ if (!enums[i].name_off ||
+ !btf_name_valid_identifier(btf, enums[i].name_off)) {
+ btf_verifier_log_type(env, t, "Invalid name");
+ return -EINVAL;
+ }
+
+ if (env->log.level == BPF_LOG_KERNEL)
+ continue;
+ fmt_str = btf_type_kflag(t) ? "\t%s val=%d\n" : "\t%s val=%u\n";
+ btf_verifier_log(env, fmt_str,
+ __btf_name_by_offset(btf, enums[i].name_off),
+ enums[i].val);
+ }
+
+ return meta_needed;
+}
+
+static void btf_enum_log(struct btf_verifier_env *env,
+ const struct btf_type *t)
+{
+ btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t));
+}
+
+static void btf_enum_show(const struct btf *btf, const struct btf_type *t,
+ u32 type_id, void *data, u8 bits_offset,
+ struct btf_show *show)
+{
+ const struct btf_enum *enums = btf_type_enum(t);
+ u32 i, nr_enums = btf_type_vlen(t);
+ void *safe_data;
+ int v;
+
+ safe_data = btf_show_start_type(show, t, type_id, data);
+ if (!safe_data)
+ return;
+
+ v = *(int *)safe_data;
+
+ for (i = 0; i < nr_enums; i++) {
+ if (v != enums[i].val)
+ continue;
+
+ btf_show_type_value(show, "%s",
+ __btf_name_by_offset(btf,
+ enums[i].name_off));
+
+ btf_show_end_type(show);
+ return;
+ }
+
+ if (btf_type_kflag(t))
+ btf_show_type_value(show, "%d", v);
+ else
+ btf_show_type_value(show, "%u", v);
+ btf_show_end_type(show);
+}
+
+static const struct btf_kind_operations enum_ops = {
+ .check_meta = btf_enum_check_meta,
+ .resolve = btf_df_resolve,
+ .check_member = btf_enum_check_member,
+ .check_kflag_member = btf_enum_check_kflag_member,
+ .log_details = btf_enum_log,
+ .show = btf_enum_show,
+};
+
+static s32 btf_enum64_check_meta(struct btf_verifier_env *env,
+ const struct btf_type *t,
+ u32 meta_left)
+{
+ const struct btf_enum64 *enums = btf_type_enum64(t);
+ struct btf *btf = env->btf;
+ const char *fmt_str;
+ u16 i, nr_enums;
+ u32 meta_needed;
+
+ nr_enums = btf_type_vlen(t);
+ meta_needed = nr_enums * sizeof(*enums);
+
+ if (meta_left < meta_needed) {
+ btf_verifier_log_basic(env, t,
+ "meta_left:%u meta_needed:%u",
+ meta_left, meta_needed);
+ return -EINVAL;
+ }
+
+ if (t->size > 8 || !is_power_of_2(t->size)) {
+ btf_verifier_log_type(env, t, "Unexpected size");
+ return -EINVAL;
+ }
+
+ /* enum type either no name or a valid one */
+ if (t->name_off &&
+ !btf_name_valid_identifier(env->btf, t->name_off)) {
+ btf_verifier_log_type(env, t, "Invalid name");
+ return -EINVAL;
+ }
+
+ btf_verifier_log_type(env, t, NULL);
+
+ for (i = 0; i < nr_enums; i++) {
+ if (!btf_name_offset_valid(btf, enums[i].name_off)) {
+ btf_verifier_log(env, "\tInvalid name_offset:%u",
+ enums[i].name_off);
+ return -EINVAL;
+ }
+
+ /* enum member must have a valid name */
+ if (!enums[i].name_off ||
+ !btf_name_valid_identifier(btf, enums[i].name_off)) {
+ btf_verifier_log_type(env, t, "Invalid name");
+ return -EINVAL;
+ }
+
+ if (env->log.level == BPF_LOG_KERNEL)
+ continue;
+
+ fmt_str = btf_type_kflag(t) ? "\t%s val=%lld\n" : "\t%s val=%llu\n";
+ btf_verifier_log(env, fmt_str,
+ __btf_name_by_offset(btf, enums[i].name_off),
+ btf_enum64_value(enums + i));
+ }
+
+ return meta_needed;
+}
+
+static void btf_enum64_show(const struct btf *btf, const struct btf_type *t,
+ u32 type_id, void *data, u8 bits_offset,
+ struct btf_show *show)
+{
+ const struct btf_enum64 *enums = btf_type_enum64(t);
+ u32 i, nr_enums = btf_type_vlen(t);
+ void *safe_data;
+ s64 v;
+
+ safe_data = btf_show_start_type(show, t, type_id, data);
+ if (!safe_data)
+ return;
+
+ v = *(u64 *)safe_data;
+
+ for (i = 0; i < nr_enums; i++) {
+ if (v != btf_enum64_value(enums + i))
+ continue;
+
+ btf_show_type_value(show, "%s",
+ __btf_name_by_offset(btf,
+ enums[i].name_off));
+
+ btf_show_end_type(show);
+ return;
+ }
+
+ if (btf_type_kflag(t))
+ btf_show_type_value(show, "%lld", v);
+ else
+ btf_show_type_value(show, "%llu", v);
+ btf_show_end_type(show);
+}
+
+static const struct btf_kind_operations enum64_ops = {
+ .check_meta = btf_enum64_check_meta,
+ .resolve = btf_df_resolve,
+ .check_member = btf_enum_check_member,
+ .check_kflag_member = btf_enum_check_kflag_member,
+ .log_details = btf_enum_log,
+ .show = btf_enum64_show,
+};
+
+static s32 btf_func_proto_check_meta(struct btf_verifier_env *env,
+ const struct btf_type *t,
+ u32 meta_left)
+{
+ u32 meta_needed = btf_type_vlen(t) * sizeof(struct btf_param);
+
+ if (meta_left < meta_needed) {
+ btf_verifier_log_basic(env, t,
+ "meta_left:%u meta_needed:%u",
+ meta_left, meta_needed);
+ return -EINVAL;
+ }
+
+ if (t->name_off) {
+ btf_verifier_log_type(env, t, "Invalid name");
+ return -EINVAL;
+ }
+
+ if (btf_type_kflag(t)) {
+ btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
+ return -EINVAL;
+ }
+
+ btf_verifier_log_type(env, t, NULL);
+
+ return meta_needed;
+}
+
+static void btf_func_proto_log(struct btf_verifier_env *env,
+ const struct btf_type *t)
+{
+ const struct btf_param *args = (const struct btf_param *)(t + 1);
+ u16 nr_args = btf_type_vlen(t), i;
+
+ btf_verifier_log(env, "return=%u args=(", t->type);
+ if (!nr_args) {
+ btf_verifier_log(env, "void");
+ goto done;
+ }
+
+ if (nr_args == 1 && !args[0].type) {
+ /* Only one vararg */
+ btf_verifier_log(env, "vararg");
+ goto done;
+ }
+
+ btf_verifier_log(env, "%u %s", args[0].type,
+ __btf_name_by_offset(env->btf,
+ args[0].name_off));
+ for (i = 1; i < nr_args - 1; i++)
+ btf_verifier_log(env, ", %u %s", args[i].type,
+ __btf_name_by_offset(env->btf,
+ args[i].name_off));
+
+ if (nr_args > 1) {
+ const struct btf_param *last_arg = &args[nr_args - 1];
+
+ if (last_arg->type)
+ btf_verifier_log(env, ", %u %s", last_arg->type,
+ __btf_name_by_offset(env->btf,
+ last_arg->name_off));
+ else
+ btf_verifier_log(env, ", vararg");
+ }
+
+done:
+ btf_verifier_log(env, ")");
+}
+
+static const struct btf_kind_operations func_proto_ops = {
+ .check_meta = btf_func_proto_check_meta,
+ .resolve = btf_df_resolve,
+ /*
+ * BTF_KIND_FUNC_PROTO cannot be directly referred by
+ * a struct's member.
+ *
+ * It should be a function pointer instead.
+ * (i.e. struct's member -> BTF_KIND_PTR -> BTF_KIND_FUNC_PROTO)
+ *
+ * Hence, there is no btf_func_check_member().
+ */
+ .check_member = btf_df_check_member,
+ .check_kflag_member = btf_df_check_kflag_member,
+ .log_details = btf_func_proto_log,
+ .show = btf_df_show,
+};
+
+static s32 btf_func_check_meta(struct btf_verifier_env *env,
+ const struct btf_type *t,
+ u32 meta_left)
+{
+ if (!t->name_off ||
+ !btf_name_valid_identifier(env->btf, t->name_off)) {
+ btf_verifier_log_type(env, t, "Invalid name");
+ return -EINVAL;
+ }
+
+ if (btf_type_vlen(t) > BTF_FUNC_GLOBAL) {
+ btf_verifier_log_type(env, t, "Invalid func linkage");
+ return -EINVAL;
+ }
+
+ if (btf_type_kflag(t)) {
+ btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
+ return -EINVAL;
+ }
+
+ btf_verifier_log_type(env, t, NULL);
+
+ return 0;
+}
+
+static int btf_func_resolve(struct btf_verifier_env *env,
+ const struct resolve_vertex *v)
+{
+ const struct btf_type *t = v->t;
+ u32 next_type_id = t->type;
+ int err;
+
+ err = btf_func_check(env, t);
+ if (err)
+ return err;
+
+ env_stack_pop_resolved(env, next_type_id, 0);
+ return 0;
+}
+
+static const struct btf_kind_operations func_ops = {
+ .check_meta = btf_func_check_meta,
+ .resolve = btf_func_resolve,
+ .check_member = btf_df_check_member,
+ .check_kflag_member = btf_df_check_kflag_member,
+ .log_details = btf_ref_type_log,
+ .show = btf_df_show,
+};
+
+static s32 btf_var_check_meta(struct btf_verifier_env *env,
+ const struct btf_type *t,
+ u32 meta_left)
+{
+ const struct btf_var *var;
+ u32 meta_needed = sizeof(*var);
+
+ if (meta_left < meta_needed) {
+ btf_verifier_log_basic(env, t,
+ "meta_left:%u meta_needed:%u",
+ meta_left, meta_needed);
+ return -EINVAL;
+ }
+
+ if (btf_type_vlen(t)) {
+ btf_verifier_log_type(env, t, "vlen != 0");
+ return -EINVAL;
+ }
+
+ if (btf_type_kflag(t)) {
+ btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
+ return -EINVAL;
+ }
+
+ if (!t->name_off ||
+ !btf_name_valid_identifier(env->btf, t->name_off)) {
+ btf_verifier_log_type(env, t, "Invalid name");
+ return -EINVAL;
+ }
+
+ /* A var cannot be in type void */
+ if (!t->type || !BTF_TYPE_ID_VALID(t->type)) {
+ btf_verifier_log_type(env, t, "Invalid type_id");
+ return -EINVAL;
+ }
+
+ var = btf_type_var(t);
+ if (var->linkage != BTF_VAR_STATIC &&
+ var->linkage != BTF_VAR_GLOBAL_ALLOCATED) {
+ btf_verifier_log_type(env, t, "Linkage not supported");
+ return -EINVAL;
+ }
+
+ btf_verifier_log_type(env, t, NULL);
+
+ return meta_needed;
+}
+
+static void btf_var_log(struct btf_verifier_env *env, const struct btf_type *t)
+{
+ const struct btf_var *var = btf_type_var(t);
+
+ btf_verifier_log(env, "type_id=%u linkage=%u", t->type, var->linkage);
+}
+
+static const struct btf_kind_operations var_ops = {
+ .check_meta = btf_var_check_meta,
+ .resolve = btf_var_resolve,
+ .check_member = btf_df_check_member,
+ .check_kflag_member = btf_df_check_kflag_member,
+ .log_details = btf_var_log,
+ .show = btf_var_show,
+};
+
+static s32 btf_datasec_check_meta(struct btf_verifier_env *env,
+ const struct btf_type *t,
+ u32 meta_left)
+{
+ const struct btf_var_secinfo *vsi;
+ u64 last_vsi_end_off = 0, sum = 0;
+ u32 i, meta_needed;
+
+ meta_needed = btf_type_vlen(t) * sizeof(*vsi);
+ if (meta_left < meta_needed) {
+ btf_verifier_log_basic(env, t,
+ "meta_left:%u meta_needed:%u",
+ meta_left, meta_needed);
+ return -EINVAL;
+ }
+
+ if (!t->size) {
+ btf_verifier_log_type(env, t, "size == 0");
+ return -EINVAL;
+ }
+
+ if (btf_type_kflag(t)) {
+ btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
+ return -EINVAL;
+ }
+
+ if (!t->name_off ||
+ !btf_name_valid_section(env->btf, t->name_off)) {
+ btf_verifier_log_type(env, t, "Invalid name");
+ return -EINVAL;
+ }
+
+ btf_verifier_log_type(env, t, NULL);
+
+ for_each_vsi(i, t, vsi) {
+ /* A var cannot be in type void */
+ if (!vsi->type || !BTF_TYPE_ID_VALID(vsi->type)) {
+ btf_verifier_log_vsi(env, t, vsi,
+ "Invalid type_id");
+ return -EINVAL;
+ }
+
+ if (vsi->offset < last_vsi_end_off || vsi->offset >= t->size) {
+ btf_verifier_log_vsi(env, t, vsi,
+ "Invalid offset");
+ return -EINVAL;
+ }
+
+ if (!vsi->size || vsi->size > t->size) {
+ btf_verifier_log_vsi(env, t, vsi,
+ "Invalid size");
+ return -EINVAL;
+ }
+
+ last_vsi_end_off = vsi->offset + vsi->size;
+ if (last_vsi_end_off > t->size) {
+ btf_verifier_log_vsi(env, t, vsi,
+ "Invalid offset+size");
+ return -EINVAL;
+ }
+
+ btf_verifier_log_vsi(env, t, vsi, NULL);
+ sum += vsi->size;
+ }
+
+ if (t->size < sum) {
+ btf_verifier_log_type(env, t, "Invalid btf_info size");
+ return -EINVAL;
+ }
+
+ return meta_needed;
+}
+
+static int btf_datasec_resolve(struct btf_verifier_env *env,
+ const struct resolve_vertex *v)
+{
+ const struct btf_var_secinfo *vsi;
+ struct btf *btf = env->btf;
+ u16 i;
+
+ env->resolve_mode = RESOLVE_TBD;
+ for_each_vsi_from(i, v->next_member, v->t, vsi) {
+ u32 var_type_id = vsi->type, type_id, type_size = 0;
+ const struct btf_type *var_type = btf_type_by_id(env->btf,
+ var_type_id);
+ if (!var_type || !btf_type_is_var(var_type)) {
+ btf_verifier_log_vsi(env, v->t, vsi,
+ "Not a VAR kind member");
+ return -EINVAL;
+ }
+
+ if (!env_type_is_resolve_sink(env, var_type) &&
+ !env_type_is_resolved(env, var_type_id)) {
+ env_stack_set_next_member(env, i + 1);
+ return env_stack_push(env, var_type, var_type_id);
+ }
+
+ type_id = var_type->type;
+ if (!btf_type_id_size(btf, &type_id, &type_size)) {
+ btf_verifier_log_vsi(env, v->t, vsi, "Invalid type");
+ return -EINVAL;
+ }
+
+ if (vsi->size < type_size) {
+ btf_verifier_log_vsi(env, v->t, vsi, "Invalid size");
+ return -EINVAL;
+ }
+ }
+
+ env_stack_pop_resolved(env, 0, 0);
+ return 0;
+}
+
+static void btf_datasec_log(struct btf_verifier_env *env,
+ const struct btf_type *t)
+{
+ btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t));
+}
+
+static void btf_datasec_show(const struct btf *btf,
+ const struct btf_type *t, u32 type_id,
+ void *data, u8 bits_offset,
+ struct btf_show *show)
+{
+ const struct btf_var_secinfo *vsi;
+ const struct btf_type *var;
+ u32 i;
+
+ if (!btf_show_start_type(show, t, type_id, data))
+ return;
+
+ btf_show_type_value(show, "section (\"%s\") = {",
+ __btf_name_by_offset(btf, t->name_off));
+ for_each_vsi(i, t, vsi) {
+ var = btf_type_by_id(btf, vsi->type);
+ if (i)
+ btf_show(show, ",");
+ btf_type_ops(var)->show(btf, var, vsi->type,
+ data + vsi->offset, bits_offset, show);
+ }
+ btf_show_end_type(show);
+}
+
+static const struct btf_kind_operations datasec_ops = {
+ .check_meta = btf_datasec_check_meta,
+ .resolve = btf_datasec_resolve,
+ .check_member = btf_df_check_member,
+ .check_kflag_member = btf_df_check_kflag_member,
+ .log_details = btf_datasec_log,
+ .show = btf_datasec_show,
+};
+
+static s32 btf_float_check_meta(struct btf_verifier_env *env,
+ const struct btf_type *t,
+ u32 meta_left)
+{
+ if (btf_type_vlen(t)) {
+ btf_verifier_log_type(env, t, "vlen != 0");
+ return -EINVAL;
+ }
+
+ if (btf_type_kflag(t)) {
+ btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
+ return -EINVAL;
+ }
+
+ if (t->size != 2 && t->size != 4 && t->size != 8 && t->size != 12 &&
+ t->size != 16) {
+ btf_verifier_log_type(env, t, "Invalid type_size");
+ return -EINVAL;
+ }
+
+ btf_verifier_log_type(env, t, NULL);
+
+ return 0;
+}
+
+static int btf_float_check_member(struct btf_verifier_env *env,
+ const struct btf_type *struct_type,
+ const struct btf_member *member,
+ const struct btf_type *member_type)
+{
+ u64 start_offset_bytes;
+ u64 end_offset_bytes;
+ u64 misalign_bits;
+ u64 align_bytes;
+ u64 align_bits;
+
+ /* Different architectures have different alignment requirements, so
+ * here we check only for the reasonable minimum. This way we ensure
+ * that types after CO-RE can pass the kernel BTF verifier.
+ */
+ align_bytes = min_t(u64, sizeof(void *), member_type->size);
+ align_bits = align_bytes * BITS_PER_BYTE;
+ div64_u64_rem(member->offset, align_bits, &misalign_bits);
+ if (misalign_bits) {
+ btf_verifier_log_member(env, struct_type, member,
+ "Member is not properly aligned");
+ return -EINVAL;
+ }
+
+ start_offset_bytes = member->offset / BITS_PER_BYTE;
+ end_offset_bytes = start_offset_bytes + member_type->size;
+ if (end_offset_bytes > struct_type->size) {
+ btf_verifier_log_member(env, struct_type, member,
+ "Member exceeds struct_size");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static void btf_float_log(struct btf_verifier_env *env,
+ const struct btf_type *t)
+{
+ btf_verifier_log(env, "size=%u", t->size);
+}
+
+static const struct btf_kind_operations float_ops = {
+ .check_meta = btf_float_check_meta,
+ .resolve = btf_df_resolve,
+ .check_member = btf_float_check_member,
+ .check_kflag_member = btf_generic_check_kflag_member,
+ .log_details = btf_float_log,
+ .show = btf_df_show,
+};
+
+static s32 btf_decl_tag_check_meta(struct btf_verifier_env *env,
+ const struct btf_type *t,
+ u32 meta_left)
+{
+ const struct btf_decl_tag *tag;
+ u32 meta_needed = sizeof(*tag);
+ s32 component_idx;
+ const char *value;
+
+ if (meta_left < meta_needed) {
+ btf_verifier_log_basic(env, t,
+ "meta_left:%u meta_needed:%u",
+ meta_left, meta_needed);
+ return -EINVAL;
+ }
+
+ value = btf_name_by_offset(env->btf, t->name_off);
+ if (!value || !value[0]) {
+ btf_verifier_log_type(env, t, "Invalid value");
+ return -EINVAL;
+ }
+
+ if (btf_type_vlen(t)) {
+ btf_verifier_log_type(env, t, "vlen != 0");
+ return -EINVAL;
+ }
+
+ component_idx = btf_type_decl_tag(t)->component_idx;
+ if (component_idx < -1) {
+ btf_verifier_log_type(env, t, "Invalid component_idx");
+ return -EINVAL;
+ }
+
+ btf_verifier_log_type(env, t, NULL);
+
+ return meta_needed;
+}
+
+static int btf_decl_tag_resolve(struct btf_verifier_env *env,
+ const struct resolve_vertex *v)
+{
+ const struct btf_type *next_type;
+ const struct btf_type *t = v->t;
+ u32 next_type_id = t->type;
+ struct btf *btf = env->btf;
+ s32 component_idx;
+ u32 vlen;
+
+ next_type = btf_type_by_id(btf, next_type_id);
+ if (!next_type || !btf_type_is_decl_tag_target(next_type)) {
+ btf_verifier_log_type(env, v->t, "Invalid type_id");
+ return -EINVAL;
+ }
+
+ if (!env_type_is_resolve_sink(env, next_type) &&
+ !env_type_is_resolved(env, next_type_id))
+ return env_stack_push(env, next_type, next_type_id);
+
+ component_idx = btf_type_decl_tag(t)->component_idx;
+ if (component_idx != -1) {
+ if (btf_type_is_var(next_type) || btf_type_is_typedef(next_type)) {
+ btf_verifier_log_type(env, v->t, "Invalid component_idx");
+ return -EINVAL;
+ }
+
+ if (btf_type_is_struct(next_type)) {
+ vlen = btf_type_vlen(next_type);
+ } else {
+ /* next_type should be a function */
+ next_type = btf_type_by_id(btf, next_type->type);
+ vlen = btf_type_vlen(next_type);
+ }
+
+ if ((u32)component_idx >= vlen) {
+ btf_verifier_log_type(env, v->t, "Invalid component_idx");
+ return -EINVAL;
+ }
+ }
+
+ env_stack_pop_resolved(env, next_type_id, 0);
+
+ return 0;
+}
+
+static void btf_decl_tag_log(struct btf_verifier_env *env, const struct btf_type *t)
+{
+ btf_verifier_log(env, "type=%u component_idx=%d", t->type,
+ btf_type_decl_tag(t)->component_idx);
+}
+
+static const struct btf_kind_operations decl_tag_ops = {
+ .check_meta = btf_decl_tag_check_meta,
+ .resolve = btf_decl_tag_resolve,
+ .check_member = btf_df_check_member,
+ .check_kflag_member = btf_df_check_kflag_member,
+ .log_details = btf_decl_tag_log,
+ .show = btf_df_show,
+};
+
+static int btf_func_proto_check(struct btf_verifier_env *env,
+ const struct btf_type *t)
+{
+ const struct btf_type *ret_type;
+ const struct btf_param *args;
+ const struct btf *btf;
+ u16 nr_args, i;
+ int err;
+
+ btf = env->btf;
+ args = (const struct btf_param *)(t + 1);
+ nr_args = btf_type_vlen(t);
+
+ /* Check func return type which could be "void" (t->type == 0) */
+ if (t->type) {
+ u32 ret_type_id = t->type;
+
+ ret_type = btf_type_by_id(btf, ret_type_id);
+ if (!ret_type) {
+ btf_verifier_log_type(env, t, "Invalid return type");
+ return -EINVAL;
+ }
+
+ if (btf_type_is_resolve_source_only(ret_type)) {
+ btf_verifier_log_type(env, t, "Invalid return type");
+ return -EINVAL;
+ }
+
+ if (btf_type_needs_resolve(ret_type) &&
+ !env_type_is_resolved(env, ret_type_id)) {
+ err = btf_resolve(env, ret_type, ret_type_id);
+ if (err)
+ return err;
+ }
+
+ /* Ensure the return type is a type that has a size */
+ if (!btf_type_id_size(btf, &ret_type_id, NULL)) {
+ btf_verifier_log_type(env, t, "Invalid return type");
+ return -EINVAL;
+ }
+ }
+
+ if (!nr_args)
+ return 0;
+
+ /* Last func arg type_id could be 0 if it is a vararg */
+ if (!args[nr_args - 1].type) {
+ if (args[nr_args - 1].name_off) {
+ btf_verifier_log_type(env, t, "Invalid arg#%u",
+ nr_args);
+ return -EINVAL;
+ }
+ nr_args--;
+ }
+
+ for (i = 0; i < nr_args; i++) {
+ const struct btf_type *arg_type;
+ u32 arg_type_id;
+
+ arg_type_id = args[i].type;
+ arg_type = btf_type_by_id(btf, arg_type_id);
+ if (!arg_type) {
+ btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1);
+ return -EINVAL;
+ }
+
+ if (btf_type_is_resolve_source_only(arg_type)) {
+ btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1);
+ return -EINVAL;
+ }
+
+ if (args[i].name_off &&
+ (!btf_name_offset_valid(btf, args[i].name_off) ||
+ !btf_name_valid_identifier(btf, args[i].name_off))) {
+ btf_verifier_log_type(env, t,
+ "Invalid arg#%u", i + 1);
+ return -EINVAL;
+ }
+
+ if (btf_type_needs_resolve(arg_type) &&
+ !env_type_is_resolved(env, arg_type_id)) {
+ err = btf_resolve(env, arg_type, arg_type_id);
+ if (err)
+ return err;
+ }
+
+ if (!btf_type_id_size(btf, &arg_type_id, NULL)) {
+ btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1);
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+
+static int btf_func_check(struct btf_verifier_env *env,
+ const struct btf_type *t)
+{
+ const struct btf_type *proto_type;
+ const struct btf_param *args;
+ const struct btf *btf;
+ u16 nr_args, i;
+
+ btf = env->btf;
+ proto_type = btf_type_by_id(btf, t->type);
+
+ if (!proto_type || !btf_type_is_func_proto(proto_type)) {
+ btf_verifier_log_type(env, t, "Invalid type_id");
+ return -EINVAL;
+ }
+
+ args = (const struct btf_param *)(proto_type + 1);
+ nr_args = btf_type_vlen(proto_type);
+ for (i = 0; i < nr_args; i++) {
+ if (!args[i].name_off && args[i].type) {
+ btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1);
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+
+static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS] = {
+ [BTF_KIND_INT] = &int_ops,
+ [BTF_KIND_PTR] = &ptr_ops,
+ [BTF_KIND_ARRAY] = &array_ops,
+ [BTF_KIND_STRUCT] = &struct_ops,
+ [BTF_KIND_UNION] = &struct_ops,
+ [BTF_KIND_ENUM] = &enum_ops,
+ [BTF_KIND_FWD] = &fwd_ops,
+ [BTF_KIND_TYPEDEF] = &modifier_ops,
+ [BTF_KIND_VOLATILE] = &modifier_ops,
+ [BTF_KIND_CONST] = &modifier_ops,
+ [BTF_KIND_RESTRICT] = &modifier_ops,
+ [BTF_KIND_FUNC] = &func_ops,
+ [BTF_KIND_FUNC_PROTO] = &func_proto_ops,
+ [BTF_KIND_VAR] = &var_ops,
+ [BTF_KIND_DATASEC] = &datasec_ops,
+ [BTF_KIND_FLOAT] = &float_ops,
+ [BTF_KIND_DECL_TAG] = &decl_tag_ops,
+ [BTF_KIND_TYPE_TAG] = &modifier_ops,
+ [BTF_KIND_ENUM64] = &enum64_ops,
+};
+
+static s32 btf_check_meta(struct btf_verifier_env *env,
+ const struct btf_type *t,
+ u32 meta_left)
+{
+ u32 saved_meta_left = meta_left;
+ s32 var_meta_size;
+
+ if (meta_left < sizeof(*t)) {
+ btf_verifier_log(env, "[%u] meta_left:%u meta_needed:%zu",
+ env->log_type_id, meta_left, sizeof(*t));
+ return -EINVAL;
+ }
+ meta_left -= sizeof(*t);
+
+ if (t->info & ~BTF_INFO_MASK) {
+ btf_verifier_log(env, "[%u] Invalid btf_info:%x",
+ env->log_type_id, t->info);
+ return -EINVAL;
+ }
+
+ if (BTF_INFO_KIND(t->info) > BTF_KIND_MAX ||
+ BTF_INFO_KIND(t->info) == BTF_KIND_UNKN) {
+ btf_verifier_log(env, "[%u] Invalid kind:%u",
+ env->log_type_id, BTF_INFO_KIND(t->info));
+ return -EINVAL;
+ }
+
+ if (!btf_name_offset_valid(env->btf, t->name_off)) {
+ btf_verifier_log(env, "[%u] Invalid name_offset:%u",
+ env->log_type_id, t->name_off);
+ return -EINVAL;
+ }
+
+ var_meta_size = btf_type_ops(t)->check_meta(env, t, meta_left);
+ if (var_meta_size < 0)
+ return var_meta_size;
+
+ meta_left -= var_meta_size;
+
+ return saved_meta_left - meta_left;
+}
+
+int btf_check_all_metas(struct btf_verifier_env *env)
+{
+ struct btf *btf = env->btf;
+ struct btf_header *hdr;
+ void *cur, *end;
+
+ hdr = &btf->hdr;
+ cur = btf->nohdr_data + hdr->type_off;
+ end = cur + hdr->type_len;
+
+ env->log_type_id = btf->base_btf ? btf->start_id : 1;
+ while (cur < end) {
+ struct btf_type *t = cur;
+ s32 meta_size;
+
+ meta_size = btf_check_meta(env, t, end - cur);
+ if (meta_size < 0)
+ return meta_size;
+
+ btf_add_type(env, t);
+ cur += meta_size;
+ env->log_type_id++;
+ }
+
+ return 0;
+}
+
+static bool btf_resolve_valid(struct btf_verifier_env *env,
+ const struct btf_type *t,
+ u32 type_id)
+{
+ struct btf *btf = env->btf;
+
+ if (!env_type_is_resolved(env, type_id))
+ return false;
+
+ if (btf_type_is_struct(t) || btf_type_is_datasec(t))
+ return !btf_resolved_type_id(btf, type_id) &&
+ !btf_resolved_type_size(btf, type_id);
+
+ if (btf_type_is_decl_tag(t) || btf_type_is_func(t))
+ return btf_resolved_type_id(btf, type_id) &&
+ !btf_resolved_type_size(btf, type_id);
+
+ if (btf_type_is_modifier(t) || btf_type_is_ptr(t) ||
+ btf_type_is_var(t)) {
+ t = btf_type_id_resolve(btf, &type_id);
+ return t &&
+ !btf_type_is_modifier(t) &&
+ !btf_type_is_var(t) &&
+ !btf_type_is_datasec(t);
+ }
+
+ if (btf_type_is_array(t)) {
+ const struct btf_array *array = btf_type_array(t);
+ const struct btf_type *elem_type;
+ u32 elem_type_id = array->type;
+ u32 elem_size;
+
+ elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size);
+ return elem_type && !btf_type_is_modifier(elem_type) &&
+ (array->nelems * elem_size ==
+ btf_resolved_type_size(btf, type_id));
+ }
+
+ return false;
+}
+
+static int btf_resolve(struct btf_verifier_env *env,
+ const struct btf_type *t, u32 type_id)
+{
+ u32 save_log_type_id = env->log_type_id;
+ const struct resolve_vertex *v;
+ int err = 0;
+
+ env->resolve_mode = RESOLVE_TBD;
+ env_stack_push(env, t, type_id);
+ while (!err && (v = env_stack_peak(env))) {
+ env->log_type_id = v->type_id;
+ err = btf_type_ops(v->t)->resolve(env, v);
+ }
+
+ env->log_type_id = type_id;
+ if (err == -E2BIG) {
+ btf_verifier_log_type(env, t,
+ "Exceeded max resolving depth:%u",
+ MAX_RESOLVE_DEPTH);
+ } else if (err == -EEXIST) {
+ btf_verifier_log_type(env, t, "Loop detected");
+ }
+
+ /* Final sanity check */
+ if (!err && !btf_resolve_valid(env, t, type_id)) {
+ btf_verifier_log_type(env, t, "Invalid resolve state");
+ err = -EINVAL;
+ }
+
+ env->log_type_id = save_log_type_id;
+ return err;
+}
+
+static int btf_check_all_types(struct btf_verifier_env *env)
+{
+ struct btf *btf = env->btf;
+ const struct btf_type *t;
+ u32 type_id, i;
+ int err;
+
+ err = env_resolve_init(env);
+ if (err)
+ return err;
+
+ env->phase++;
+ for (i = btf->base_btf ? 0 : 1; i < btf->nr_types; i++) {
+ type_id = btf->start_id + i;
+ t = btf_type_by_id(btf, type_id);
+
+ env->log_type_id = type_id;
+ if (btf_type_needs_resolve(t) &&
+ !env_type_is_resolved(env, type_id)) {
+ err = btf_resolve(env, t, type_id);
+ if (err)
+ return err;
+ }
+
+ if (btf_type_is_func_proto(t)) {
+ err = btf_func_proto_check(env, t);
+ if (err)
+ return err;
+ }
+ }
+
+ return 0;
+}
+
+int btf_parse_type_sec(struct btf_verifier_env *env)
+{
+ const struct btf_header *hdr = &env->btf->hdr;
+ int err;
+
+ /* Type section must align to 4 bytes */
+ if (hdr->type_off & (sizeof(u32) - 1)) {
+ btf_verifier_log(env, "Unaligned type_off");
+ return -EINVAL;
+ }
+
+ if (!env->btf->base_btf && !hdr->type_len) {
+ btf_verifier_log(env, "No type found");
+ return -EINVAL;
+ }
+
+ err = btf_check_all_metas(env);
+ if (err)
+ return err;
+
+ return btf_check_all_types(env);
+}
+
+int btf_parse_str_sec(struct btf_verifier_env *env)
+{
+ const struct btf_header *hdr;
+ struct btf *btf = env->btf;
+ const char *start, *end;
+
+ hdr = &btf->hdr;
+ start = btf->nohdr_data + hdr->str_off;
+ end = start + hdr->str_len;
+
+ if (end != btf->data + btf->data_size) {
+ btf_verifier_log(env, "String section is not at the end");
+ return -EINVAL;
+ }
+
+ btf->strings = start;
+
+ if (btf->base_btf && !hdr->str_len)
+ return 0;
+ if (!hdr->str_len || hdr->str_len - 1 > BTF_MAX_NAME_OFFSET || end[-1]) {
+ btf_verifier_log(env, "Invalid string section");
+ return -EINVAL;
+ }
+ if (!btf->base_btf && start[0]) {
+ btf_verifier_log(env, "Invalid string section");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static const size_t btf_sec_info_offset[] = {
+ offsetof(struct btf_header, type_off),
+ offsetof(struct btf_header, str_off),
+};
+
+static int btf_sec_info_cmp(const void *a, const void *b)
+{
+ const struct btf_sec_info *x = a;
+ const struct btf_sec_info *y = b;
+
+ return (int)(x->off - y->off) ? : (int)(x->len - y->len);
+}
+
+static int btf_check_sec_info(struct btf_verifier_env *env,
+ u32 btf_data_size)
+{
+ struct btf_sec_info secs[ARRAY_SIZE(btf_sec_info_offset)];
+ u32 total, expected_total, i;
+ const struct btf_header *hdr;
+ const struct btf *btf;
+
+ btf = env->btf;
+ hdr = &btf->hdr;
+
+ /* Populate the secs from hdr */
+ for (i = 0; i < ARRAY_SIZE(btf_sec_info_offset); i++)
+ secs[i] = *(struct btf_sec_info *)((void *)hdr +
+ btf_sec_info_offset[i]);
+
+ sort(secs, ARRAY_SIZE(btf_sec_info_offset),
+ sizeof(struct btf_sec_info), btf_sec_info_cmp, NULL);
+
+ /* Check for gaps and overlap among sections */
+ total = 0;
+ expected_total = btf_data_size - hdr->hdr_len;
+ for (i = 0; i < ARRAY_SIZE(btf_sec_info_offset); i++) {
+ if (expected_total < secs[i].off) {
+ btf_verifier_log(env, "Invalid section offset");
+ return -EINVAL;
+ }
+ if (total < secs[i].off) {
+ /* gap */
+ btf_verifier_log(env, "Unsupported section found");
+ return -EINVAL;
+ }
+ if (total > secs[i].off) {
+ btf_verifier_log(env, "Section overlap found");
+ return -EINVAL;
+ }
+ if (expected_total - total < secs[i].len) {
+ btf_verifier_log(env,
+ "Total section length too long");
+ return -EINVAL;
+ }
+ total += secs[i].len;
+ }
+
+ /* There is data other than hdr and known sections */
+ if (expected_total != total) {
+ btf_verifier_log(env, "Unsupported section found");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+int btf_parse_hdr(struct btf_verifier_env *env)
+{
+ u32 hdr_len, hdr_copy, btf_data_size;
+ const struct btf_header *hdr;
+ struct btf *btf;
+
+ btf = env->btf;
+ btf_data_size = btf->data_size;
+
+ if (btf_data_size < offsetofend(struct btf_header, hdr_len)) {
+ btf_verifier_log(env, "hdr_len not found");
+ return -EINVAL;
+ }
+
+ hdr = btf->data;
+ hdr_len = hdr->hdr_len;
+ if (btf_data_size < hdr_len) {
+ btf_verifier_log(env, "btf_header not found");
+ return -EINVAL;
+ }
+
+ /* Ensure the unsupported header fields are zero */
+ if (hdr_len > sizeof(btf->hdr)) {
+ u8 *expected_zero = btf->data + sizeof(btf->hdr);
+ u8 *end = btf->data + hdr_len;
+
+ for (; expected_zero < end; expected_zero++) {
+ if (*expected_zero) {
+ btf_verifier_log(env, "Unsupported btf_header");
+ return -E2BIG;
+ }
+ }
+ }
+
+ hdr_copy = min_t(u32, hdr_len, sizeof(btf->hdr));
+ memcpy(&btf->hdr, btf->data, hdr_copy);
+
+ hdr = &btf->hdr;
+
+ btf_verifier_log_hdr(env, btf_data_size);
+
+ if (hdr->magic != BTF_MAGIC) {
+ btf_verifier_log(env, "Invalid magic");
+ return -EINVAL;
+ }
+
+ if (hdr->version != BTF_VERSION) {
+ btf_verifier_log(env, "Unsupported version");
+ return -ENOTSUPP;
+ }
+
+ if (hdr->flags) {
+ btf_verifier_log(env, "Unsupported flags");
+ return -ENOTSUPP;
+ }
+
+ if (!btf->base_btf && btf_data_size == hdr->hdr_len) {
+ btf_verifier_log(env, "No data");
+ return -EINVAL;
+ }
+
+ return btf_check_sec_info(env, btf_data_size);
+}
+
+
+int btf_check_type_tags(struct btf_verifier_env *env,
+ struct btf *btf, int start_id)
+{
+ int i, n, good_id = start_id - 1;
+ bool in_tags;
+
+ n = btf_nr_types(btf);
+ for (i = start_id; i < n; i++) {
+ const struct btf_type *t;
+ int chain_limit = 32;
+ u32 cur_id = i;
+
+ t = btf_type_by_id(btf, i);
+ if (!t)
+ return -EINVAL;
+ if (!btf_type_is_modifier(t))
+ continue;
+
+ cond_resched();
+
+ in_tags = btf_type_is_type_tag(t);
+ while (btf_type_is_modifier(t)) {
+ if (!chain_limit--) {
+ btf_verifier_log(env, "Max chain length or cycle detected");
+ return -ELOOP;
+ }
+ if (btf_type_is_type_tag(t)) {
+ if (!in_tags) {
+ btf_verifier_log(env, "Type tags don't precede modifiers");
+ return -EINVAL;
+ }
+ } else if (in_tags) {
+ in_tags = false;
+ }
+ if (cur_id <= good_id)
+ break;
+ /* Move to next type */
+ cur_id = t->type;
+ t = btf_type_by_id(btf, cur_id);
+ if (!t)
+ return -EINVAL;
+ }
+ good_id = i;
+ }
+ return 0;
+}
+
+
+struct btf *
+btf_parse_base(struct btf_verifier_env *env, const char *name,
+ void *data, unsigned int data_size)
+{
+ struct btf *btf = NULL;
+ int err;
+
+ if (!IS_ENABLED(CONFIG_DEBUG_INFO_BTF))
+ return ERR_PTR(-ENOENT);
+
+ btf = kzalloc_obj(*btf, GFP_KERNEL | __GFP_NOWARN);
+ if (!btf) {
+ err = -ENOMEM;
+ goto errout;
+ }
+ env->btf = btf;
+
+ btf->data = data;
+ btf->data_size = data_size;
+ btf->kernel_btf = true;
+ btf->named_start_id = 0;
+ strscpy(btf->name, name);
+
+ err = btf_parse_hdr(env);
+ if (err)
+ goto errout;
+
+ btf->nohdr_data = btf->data + btf->hdr.hdr_len;
+
+ err = btf_parse_str_sec(env);
+ if (err)
+ goto errout;
+
+ err = btf_check_all_metas(env);
+ if (err)
+ goto errout;
+
+ err = btf_check_type_tags(env, btf, 1);
+ if (err)
+ goto errout;
+
+ btf_check_sorted(btf);
+ refcount_set(&btf->refcnt, 1);
+
+ return btf;
+
+errout:
+ if (btf) {
+ kvfree(btf->types);
+ kfree(btf);
+ }
+ return ERR_PTR(err);
+}
+
+
+static void btf_type_show(const struct btf *btf, u32 type_id, void *obj,
+ struct btf_show *show)
+{
+ const struct btf_type *t = btf_type_by_id(btf, type_id);
+
+ show->btf = btf;
+ memset(&show->state, 0, sizeof(show->state));
+ memset(&show->obj, 0, sizeof(show->obj));
+
+ btf_type_ops(t)->show(btf, t, type_id, obj, 0, show);
+}
+
+__printf(2, 0) static void btf_seq_show(struct btf_show *show, const char *fmt,
+ va_list args)
+{
+ seq_vprintf((struct seq_file *)show->target, fmt, args);
+}
+
+int btf_type_seq_show_flags(const struct btf *btf, u32 type_id,
+ void *obj, struct seq_file *m, u64 flags)
+{
+ struct btf_show sseq;
+
+ sseq.target = m;
+ sseq.showfn = btf_seq_show;
+ sseq.flags = flags;
+
+ btf_type_show(btf, type_id, obj, &sseq);
+
+ return sseq.state.status;
+}
+
+void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj,
+ struct seq_file *m)
+{
+ (void) btf_type_seq_show_flags(btf, type_id, obj, m,
+ BTF_SHOW_NONAME | BTF_SHOW_COMPACT |
+ BTF_SHOW_ZERO | BTF_SHOW_UNSAFE);
+}
+
+struct btf_show_snprintf {
+ struct btf_show show;
+ int len_left; /* space left in string */
+ int len; /* length we would have written */
+};
+
+__printf(2, 0) static void btf_snprintf_show(struct btf_show *show, const char *fmt,
+ va_list args)
+{
+ struct btf_show_snprintf *ssnprintf = (struct btf_show_snprintf *)show;
+ int len;
+
+ len = vsnprintf(show->target, ssnprintf->len_left, fmt, args);
+
+ if (len < 0) {
+ ssnprintf->len_left = 0;
+ ssnprintf->len = len;
+ } else if (len >= ssnprintf->len_left) {
+ /* no space, drive on to get length we would have written */
+ ssnprintf->len_left = 0;
+ ssnprintf->len += len;
+ } else {
+ ssnprintf->len_left -= len;
+ ssnprintf->len += len;
+ show->target += len;
+ }
+}
+
+int btf_type_snprintf_show(const struct btf *btf, u32 type_id, void *obj,
+ char *buf, int len, u64 flags)
+{
+ struct btf_show_snprintf ssnprintf;
+
+ ssnprintf.show.target = buf;
+ ssnprintf.show.flags = flags;
+ ssnprintf.show.showfn = btf_snprintf_show;
+ ssnprintf.len_left = len;
+ ssnprintf.len = 0;
+
+ btf_type_show(btf, type_id, obj, (struct btf_show *)&ssnprintf);
+
+ /* If we encountered an error, return it. */
+ if (ssnprintf.show.state.status)
+ return ssnprintf.show.state.status;
+
+ /* Otherwise return length we would have written */
+ return ssnprintf.len;
+}
+
+
+bool btf_is_kernel(const struct btf *btf)
+{
+ return btf->kernel_btf;
+}
+
+bool btf_is_module(const struct btf *btf)
+{
+ return btf->kernel_btf && strcmp(btf->name, "vmlinux") != 0;
+}
+
+
+bool btf_param_match_suffix(const struct btf *btf,
+ const struct btf_param *arg,
+ const char *suffix)
+{
+ int suffix_len = strlen(suffix), len;
+ const char *param_name;
+
+ /* In the future, this can be ported to use BTF tagging */
+ param_name = btf_name_by_offset(btf, arg->name_off);
+ if (str_is_empty(param_name))
+ return false;
+ len = strlen(param_name);
+ if (len <= suffix_len)
+ return false;
+ param_name += len - suffix_len;
+ return !strncmp(param_name, suffix, suffix_len);
+}
diff --git a/kernel/btf/btf.h b/kernel/btf/btf.h
new file mode 100644
index 0000000000000..f66d9300adb31
--- /dev/null
+++ b/kernel/btf/btf.h
@@ -0,0 +1,135 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) 2018 Facebook */
+/* Internal BTF header for kernel/btf/ */
+
+#ifndef _KERNEL_BTF_BTF_H
+#define _KERNEL_BTF_BTF_H
+
+#include <linux/types.h>
+#include <linux/btf.h>
+#include <linux/bpf_verifier.h>
+#include <linux/module.h>
+#include <linux/rculist.h>
+
+/* Forward declarations */
+struct btf_show;
+struct btf_struct_metas;
+
+/* btf_verifier_env and its dependencies (needed by both btf.c and bpf.c) */
+enum verifier_phase {
+ CHECK_META,
+ CHECK_TYPE,
+};
+
+struct resolve_vertex {
+ const struct btf_type *t;
+ u32 type_id;
+ u16 next_member;
+};
+
+enum resolve_mode {
+ RESOLVE_TBD, /* To Be Determined */
+ RESOLVE_PTR, /* Resolving for Pointer */
+ RESOLVE_STRUCT_OR_ARRAY, /* Resolving for struct/union
+ * or array
+ */
+};
+
+#define MAX_RESOLVE_DEPTH 32
+
+struct btf_verifier_env {
+ struct btf *btf;
+ u8 *visit_states;
+ struct resolve_vertex stack[MAX_RESOLVE_DEPTH];
+ struct bpf_verifier_log log;
+ u32 log_type_id;
+ u32 top_stack;
+ enum verifier_phase phase;
+ enum resolve_mode resolve_mode;
+};
+
+#ifdef CONFIG_BPF_SYSCALL
+struct btf_kfunc_set_tab;
+struct btf_id_dtor_kfunc_tab;
+struct btf_struct_ops_tab;
+#endif
+
+struct btf {
+ void *data;
+ struct btf_type **types;
+ u32 *resolved_ids;
+ u32 *resolved_sizes;
+ const char *strings;
+ void *nohdr_data;
+ struct btf_header hdr;
+ u32 nr_types; /* includes VOID for base BTF */
+ u32 named_start_id;
+ u32 types_size;
+ u32 data_size;
+ refcount_t refcnt;
+#ifdef CONFIG_BPF_SYSCALL
+ u32 id;
+ struct rcu_head rcu;
+ struct btf_kfunc_set_tab *kfunc_set_tab;
+ struct btf_id_dtor_kfunc_tab *dtor_kfunc_tab;
+ struct btf_struct_metas *struct_meta_tab;
+ struct btf_struct_ops_tab *struct_ops_tab;
+#endif
+
+ /* split BTF support */
+ struct btf *base_btf;
+ u32 start_id; /* first type ID in this BTF (0 for base BTF) */
+ u32 start_str_off; /* first string offset (0 for base BTF) */
+ char name[MODULE_NAME_LEN];
+ bool kernel_btf;
+ __u32 *base_id_map; /* map from distilled base BTF -> vmlinux BTF ids */
+};
+
+#define BITS_PER_BYTE_MASK (BITS_PER_BYTE - 1)
+#define BITS_PER_BYTE_MASKED(bits) ((bits) & BITS_PER_BYTE_MASK)
+#define BITS_ROUNDDOWN_BYTES(bits) ((bits) >> 3)
+#define BITS_ROUNDUP_BYTES(bits) \
+ (BITS_ROUNDDOWN_BYTES(bits) + !!BITS_PER_BYTE_MASKED(bits))
+
+/* 16MB for 64k structs and each has 16 members and
+ * a few MB spaces for the string section.
+ * The hard limit is S32_MAX.
+ */
+#define BTF_MAX_SIZE (16 * 1024 * 1024)
+
+/*
+ * The suffix of a type that indicates it cannot alias another type when
+ * comparing BTF IDs for kfunc invocations.
+ */
+#define NOCAST_ALIAS_SUFFIX "___init"
+
+/* Core BTF functions needed by bpf.c */
+const char *__btf_name_by_offset(const struct btf *btf, u32 offset);
+const struct btf_type *
+__btf_resolve_size(const struct btf *btf, const struct btf_type *type,
+ u32 *type_size, const struct btf_type **elem_type,
+ u32 *elem_id, u32 *total_nelems, u32 *type_id);
+int btf_check_all_metas(struct btf_verifier_env *env);
+void btf_check_sorted(struct btf *btf);
+int btf_check_type_tags(struct btf_verifier_env *env,
+ struct btf *btf, int start_id);
+void btf_free(struct btf *btf);
+struct btf *btf_parse_base(struct btf_verifier_env *env, const char *name,
+ void *data, unsigned int data_size);
+int btf_parse_hdr(struct btf_verifier_env *env);
+int btf_parse_str_sec(struct btf_verifier_env *env);
+int btf_parse_type_sec(struct btf_verifier_env *env);
+const struct btf_decl_tag *btf_type_decl_tag(const struct btf_type *t);
+bool btf_type_has_size(const struct btf_type *t);
+bool btf_type_is_datasec(const struct btf_type *t);
+bool btf_type_is_decl_tag(const struct btf_type *t);
+bool btf_type_is_modifier(const struct btf_type *t);
+void btf_verifier_env_free(struct btf_verifier_env *env);
+
+extern const char * const btf_kind_str[NR_BTF_KINDS];
+
+/* Weak symbols - overridden by bpf.c when CONFIG_BPF_SYSCALL=y */
+void btf_free_bpf_data(struct btf *btf);
+void btf_put_bpf(struct btf *btf);
+
+#endif /* _KERNEL_BTF_BTF_H */
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 93f356d2b3d95..0009a7ac78462 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -395,14 +395,23 @@ config DEBUG_INFO_SPLIT
to know about the .dwo files and include them.
Incompatible with older versions of ccache.
-config DEBUG_INFO_BTF
- bool "Generate BTF type information"
+config BTF
+ bool "BTF type information support"
depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED
depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST
- depends on BPF_SYSCALL
depends on PAHOLE_VERSION >= 122
# pahole uses elfutils, which does not have support for Hexagon relocations
depends on !HEXAGON
+ help
+ Enable the core BTF (BPF Type Format) infrastructure. This provides
+ BTF parsing, type lookup, and display functionality used by BPF and
+ other kernel subsystems.
+
+ This option is typically selected automatically by DEBUG_INFO_BTF.
+
+config DEBUG_INFO_BTF
+ bool "Generate BTF type information"
+ select BTF
help
Generate deduplicated BTF type information from DWARF debug info.
Turning this on requires pahole v1.22 or later, which will convert
--
2.51.0
^ permalink raw reply related [flat|nested] 18+ messages in thread