* [PATCH v3 bpf-next 1/7] bpf: add a __btf_get_by_fd helper
2024-11-29 13:28 [PATCH v3 bpf-next 0/7] Add fd_array_cnt attribute for BPF_PROG_LOAD Anton Protopopov
@ 2024-11-29 13:28 ` Anton Protopopov
2024-11-29 13:28 ` [PATCH v3 bpf-next 2/7] bpf: move map/prog compatibility checks Anton Protopopov
` (5 subsequent siblings)
6 siblings, 0 replies; 14+ messages in thread
From: Anton Protopopov @ 2024-11-29 13:28 UTC (permalink / raw)
To: bpf; +Cc: Anton Protopopov
Add a new helper to get a pointer to a struct btf from a file
descriptor. This helper doesn't increase a refcnt. Add a comment
explaining this and pointing to a corresponding function which
does take a reference.
Signed-off-by: Anton Protopopov <aspsk@isovalent.com>
---
include/linux/bpf.h | 17 +++++++++++++++++
include/linux/btf.h | 2 ++
kernel/bpf/btf.c | 13 ++++---------
3 files changed, 23 insertions(+), 9 deletions(-)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 3ace0d6227e3..fcb4ecd9d1fd 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -2294,6 +2294,14 @@ void __bpf_obj_drop_impl(void *p, const struct btf_record *rec, bool percpu);
struct bpf_map *bpf_map_get(u32 ufd);
struct bpf_map *bpf_map_get_with_uref(u32 ufd);
+/*
+ * The __bpf_map_get() and __btf_get_by_fd() functions parse a file
+ * descriptor and return a corresponding map or btf object.
+ * Their names are double underscored to emphasize the fact that they
+ * do not increase refcnt. To also increase refcnt use corresponding
+ * bpf_map_get() and btf_get_by_fd() functions.
+ */
+
static inline struct bpf_map *__bpf_map_get(struct fd f)
{
if (fd_empty(f))
@@ -2303,6 +2311,15 @@ static inline struct bpf_map *__bpf_map_get(struct fd f)
return fd_file(f)->private_data;
}
+static inline struct btf *__btf_get_by_fd(struct fd f)
+{
+ if (fd_empty(f))
+ return ERR_PTR(-EBADF);
+ if (unlikely(fd_file(f)->f_op != &btf_fops))
+ return ERR_PTR(-EINVAL);
+ return fd_file(f)->private_data;
+}
+
void bpf_map_inc(struct bpf_map *map);
void bpf_map_inc_with_uref(struct bpf_map *map);
struct bpf_map *__bpf_map_inc_not_zero(struct bpf_map *map, bool uref);
diff --git a/include/linux/btf.h b/include/linux/btf.h
index 4214e76c9168..69159e649675 100644
--- a/include/linux/btf.h
+++ b/include/linux/btf.h
@@ -4,6 +4,7 @@
#ifndef _LINUX_BTF_H
#define _LINUX_BTF_H 1
+#include <linux/file.h>
#include <linux/types.h>
#include <linux/bpfptr.h>
#include <linux/bsearch.h>
@@ -143,6 +144,7 @@ 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,
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index e7a59e6462a9..ad5310fa1d3b 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -7743,17 +7743,12 @@ int btf_new_fd(const union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size)
struct btf *btf_get_by_fd(int fd)
{
- struct btf *btf;
CLASS(fd, f)(fd);
+ struct btf *btf;
- if (fd_empty(f))
- return ERR_PTR(-EBADF);
-
- if (fd_file(f)->f_op != &btf_fops)
- return ERR_PTR(-EINVAL);
-
- btf = fd_file(f)->private_data;
- refcount_inc(&btf->refcnt);
+ btf = __btf_get_by_fd(f);
+ if (!IS_ERR(btf))
+ refcount_inc(&btf->refcnt);
return btf;
}
--
2.34.1
^ permalink raw reply related [flat|nested] 14+ messages in thread* [PATCH v3 bpf-next 2/7] bpf: move map/prog compatibility checks
2024-11-29 13:28 [PATCH v3 bpf-next 0/7] Add fd_array_cnt attribute for BPF_PROG_LOAD Anton Protopopov
2024-11-29 13:28 ` [PATCH v3 bpf-next 1/7] bpf: add a __btf_get_by_fd helper Anton Protopopov
@ 2024-11-29 13:28 ` Anton Protopopov
2024-11-29 13:28 ` [PATCH v3 bpf-next 3/7] bpf: add fd_array_cnt attribute for prog_load Anton Protopopov
` (4 subsequent siblings)
6 siblings, 0 replies; 14+ messages in thread
From: Anton Protopopov @ 2024-11-29 13:28 UTC (permalink / raw)
To: bpf; +Cc: Anton Protopopov, Andrii Nakryiko
Move some inlined map/prog compatibility checks from the
resolve_pseudo_ldimm64() function to the dedicated
check_map_prog_compatibility() function. Call the latter function
from the add_used_map_from_fd() function directly.
This simplifies code and optimizes logic a bit, as before these
changes the check_map_prog_compatibility() function was executed on
every map usage, which doesn't make sense, as it doesn't include any
per-instruction checks, only map type vs. prog type.
(This patch also simplifies a consequent patch which will call the
add_used_map_from_fd() function from another code path.)
Signed-off-by: Anton Protopopov <aspsk@isovalent.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
---
kernel/bpf/verifier.c | 101 +++++++++++++++++++-----------------------
1 file changed, 46 insertions(+), 55 deletions(-)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 1c4ebb326785..8e034a22aa2a 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -19064,6 +19064,12 @@ static bool is_tracing_prog_type(enum bpf_prog_type type)
}
}
+static bool bpf_map_is_cgroup_storage(struct bpf_map *map)
+{
+ return (map->map_type == BPF_MAP_TYPE_CGROUP_STORAGE ||
+ map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE);
+}
+
static int check_map_prog_compatibility(struct bpf_verifier_env *env,
struct bpf_map *map,
struct bpf_prog *prog)
@@ -19142,25 +19148,48 @@ static int check_map_prog_compatibility(struct bpf_verifier_env *env,
return -EINVAL;
}
- return 0;
-}
+ if (bpf_map_is_cgroup_storage(map) &&
+ bpf_cgroup_storage_assign(env->prog->aux, map)) {
+ verbose(env, "only one cgroup storage of each type is allowed\n");
+ return -EBUSY;
+ }
-static bool bpf_map_is_cgroup_storage(struct bpf_map *map)
-{
- return (map->map_type == BPF_MAP_TYPE_CGROUP_STORAGE ||
- map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE);
+ if (map->map_type == BPF_MAP_TYPE_ARENA) {
+ if (env->prog->aux->arena) {
+ verbose(env, "Only one arena per program\n");
+ return -EBUSY;
+ }
+ if (!env->allow_ptr_leaks || !env->bpf_capable) {
+ verbose(env, "CAP_BPF and CAP_PERFMON are required to use arena\n");
+ return -EPERM;
+ }
+ if (!env->prog->jit_requested) {
+ verbose(env, "JIT is required to use arena\n");
+ return -EOPNOTSUPP;
+ }
+ if (!bpf_jit_supports_arena()) {
+ verbose(env, "JIT doesn't support arena\n");
+ return -EOPNOTSUPP;
+ }
+ env->prog->aux->arena = (void *)map;
+ if (!bpf_arena_get_user_vm_start(env->prog->aux->arena)) {
+ verbose(env, "arena's user address must be set via map_extra or mmap()\n");
+ return -EINVAL;
+ }
+ }
+
+ return 0;
}
/* Add map behind fd to used maps list, if it's not already there, and return
- * its index. Also set *reused to true if this map was already in the list of
- * used maps.
+ * its index.
* Returns <0 on error, or >= 0 index, on success.
*/
-static int add_used_map_from_fd(struct bpf_verifier_env *env, int fd, bool *reused)
+static int add_used_map_from_fd(struct bpf_verifier_env *env, int fd)
{
CLASS(fd, f)(fd);
struct bpf_map *map;
- int i;
+ int i, err;
map = __bpf_map_get(f);
if (IS_ERR(map)) {
@@ -19169,12 +19198,9 @@ static int add_used_map_from_fd(struct bpf_verifier_env *env, int fd, bool *reus
}
/* check whether we recorded this map already */
- for (i = 0; i < env->used_map_cnt; i++) {
- if (env->used_maps[i] == map) {
- *reused = true;
+ for (i = 0; i < env->used_map_cnt; i++)
+ if (env->used_maps[i] == map)
return i;
- }
- }
if (env->used_map_cnt >= MAX_USED_MAPS) {
verbose(env, "The total number of maps per program has reached the limit of %u\n",
@@ -19182,6 +19208,10 @@ static int add_used_map_from_fd(struct bpf_verifier_env *env, int fd, bool *reus
return -E2BIG;
}
+ err = check_map_prog_compatibility(env, map, env->prog);
+ if (err)
+ return err;
+
if (env->prog->sleepable)
atomic64_inc(&map->sleepable_refcnt);
@@ -19192,7 +19222,6 @@ static int add_used_map_from_fd(struct bpf_verifier_env *env, int fd, bool *reus
*/
bpf_map_inc(map);
- *reused = false;
env->used_maps[env->used_map_cnt++] = map;
return env->used_map_cnt - 1;
@@ -19229,7 +19258,6 @@ static int resolve_pseudo_ldimm64(struct bpf_verifier_env *env)
int map_idx;
u64 addr;
u32 fd;
- bool reused;
if (i == insn_cnt - 1 || insn[1].code != 0 ||
insn[1].dst_reg != 0 || insn[1].src_reg != 0 ||
@@ -19290,7 +19318,7 @@ static int resolve_pseudo_ldimm64(struct bpf_verifier_env *env)
break;
}
- map_idx = add_used_map_from_fd(env, fd, &reused);
+ map_idx = add_used_map_from_fd(env, fd);
if (map_idx < 0)
return map_idx;
map = env->used_maps[map_idx];
@@ -19298,10 +19326,6 @@ static int resolve_pseudo_ldimm64(struct bpf_verifier_env *env)
aux = &env->insn_aux_data[i];
aux->map_index = map_idx;
- err = check_map_prog_compatibility(env, map, env->prog);
- if (err)
- return err;
-
if (insn[0].src_reg == BPF_PSEUDO_MAP_FD ||
insn[0].src_reg == BPF_PSEUDO_MAP_IDX) {
addr = (unsigned long)map;
@@ -19332,39 +19356,6 @@ static int resolve_pseudo_ldimm64(struct bpf_verifier_env *env)
insn[0].imm = (u32)addr;
insn[1].imm = addr >> 32;
- /* proceed with extra checks only if its newly added used map */
- if (reused)
- goto next_insn;
-
- if (bpf_map_is_cgroup_storage(map) &&
- bpf_cgroup_storage_assign(env->prog->aux, map)) {
- verbose(env, "only one cgroup storage of each type is allowed\n");
- return -EBUSY;
- }
- if (map->map_type == BPF_MAP_TYPE_ARENA) {
- if (env->prog->aux->arena) {
- verbose(env, "Only one arena per program\n");
- return -EBUSY;
- }
- if (!env->allow_ptr_leaks || !env->bpf_capable) {
- verbose(env, "CAP_BPF and CAP_PERFMON are required to use arena\n");
- return -EPERM;
- }
- if (!env->prog->jit_requested) {
- verbose(env, "JIT is required to use arena\n");
- return -EOPNOTSUPP;
- }
- if (!bpf_jit_supports_arena()) {
- verbose(env, "JIT doesn't support arena\n");
- return -EOPNOTSUPP;
- }
- env->prog->aux->arena = (void *)map;
- if (!bpf_arena_get_user_vm_start(env->prog->aux->arena)) {
- verbose(env, "arena's user address must be set via map_extra or mmap()\n");
- return -EINVAL;
- }
- }
-
next_insn:
insn++;
i++;
--
2.34.1
^ permalink raw reply related [flat|nested] 14+ messages in thread* [PATCH v3 bpf-next 3/7] bpf: add fd_array_cnt attribute for prog_load
2024-11-29 13:28 [PATCH v3 bpf-next 0/7] Add fd_array_cnt attribute for BPF_PROG_LOAD Anton Protopopov
2024-11-29 13:28 ` [PATCH v3 bpf-next 1/7] bpf: add a __btf_get_by_fd helper Anton Protopopov
2024-11-29 13:28 ` [PATCH v3 bpf-next 2/7] bpf: move map/prog compatibility checks Anton Protopopov
@ 2024-11-29 13:28 ` Anton Protopopov
2024-12-03 2:26 ` Alexei Starovoitov
2024-11-29 13:28 ` [PATCH v3 bpf-next 4/7] libbpf: prog load: allow to use fd_array_cnt Anton Protopopov
` (3 subsequent siblings)
6 siblings, 1 reply; 14+ messages in thread
From: Anton Protopopov @ 2024-11-29 13:28 UTC (permalink / raw)
To: bpf; +Cc: Anton Protopopov
The fd_array attribute of the BPF_PROG_LOAD syscall may contain a set
of file descriptors: maps or btfs. This field was introduced as a
sparse array. Introduce a new attribute, fd_array_cnt, which, if
present, indicates that the fd_array is a continuous array of the
corresponding length.
If fd_array_cnt is non-zero, then every map in the fd_array will be
bound to the program, as if it was used by the program. This
functionality is similar to the BPF_PROG_BIND_MAP syscall, but such
maps can be used by the verifier during the program load.
Signed-off-by: Anton Protopopov <aspsk@isovalent.com>
---
include/uapi/linux/bpf.h | 10 ++++
kernel/bpf/syscall.c | 2 +-
kernel/bpf/verifier.c | 94 ++++++++++++++++++++++++++++------
tools/include/uapi/linux/bpf.h | 10 ++++
4 files changed, 100 insertions(+), 16 deletions(-)
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 4162afc6b5d0..2acf9b336371 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -1573,6 +1573,16 @@ union bpf_attr {
* If provided, prog_flags should have BPF_F_TOKEN_FD flag set.
*/
__s32 prog_token_fd;
+ /* The fd_array_cnt can be used to pass the length of the
+ * fd_array array. In this case all the [map] file descriptors
+ * passed in this array will be bound to the program, even if
+ * the maps are not referenced directly. The functionality is
+ * similar to the BPF_PROG_BIND_MAP syscall, but maps can be
+ * used by the verifier during the program load. If provided,
+ * then the fd_array[0,...,fd_array_cnt-1] is expected to be
+ * continuous.
+ */
+ __u32 fd_array_cnt;
};
struct { /* anonymous struct used by BPF_OBJ_* commands */
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 58190ca724a2..7e3fbc23c742 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -2729,7 +2729,7 @@ static bool is_perfmon_prog_type(enum bpf_prog_type prog_type)
}
/* last field in 'union bpf_attr' used by this command */
-#define BPF_PROG_LOAD_LAST_FIELD prog_token_fd
+#define BPF_PROG_LOAD_LAST_FIELD fd_array_cnt
static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size)
{
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 8e034a22aa2a..d172f6974fd7 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -19181,22 +19181,10 @@ static int check_map_prog_compatibility(struct bpf_verifier_env *env,
return 0;
}
-/* Add map behind fd to used maps list, if it's not already there, and return
- * its index.
- * Returns <0 on error, or >= 0 index, on success.
- */
-static int add_used_map_from_fd(struct bpf_verifier_env *env, int fd)
+static int __add_used_map(struct bpf_verifier_env *env, struct bpf_map *map)
{
- CLASS(fd, f)(fd);
- struct bpf_map *map;
int i, err;
- map = __bpf_map_get(f);
- if (IS_ERR(map)) {
- verbose(env, "fd %d is not pointing to valid bpf_map\n", fd);
- return PTR_ERR(map);
- }
-
/* check whether we recorded this map already */
for (i = 0; i < env->used_map_cnt; i++)
if (env->used_maps[i] == map)
@@ -19227,6 +19215,24 @@ static int add_used_map_from_fd(struct bpf_verifier_env *env, int fd)
return env->used_map_cnt - 1;
}
+/* Add map behind fd to used maps list, if it's not already there, and return
+ * its index.
+ * Returns <0 on error, or >= 0 index, on success.
+ */
+static int add_used_map(struct bpf_verifier_env *env, int fd)
+{
+ struct bpf_map *map;
+ CLASS(fd, f)(fd);
+
+ map = __bpf_map_get(f);
+ if (IS_ERR(map)) {
+ verbose(env, "fd %d is not pointing to valid bpf_map\n", fd);
+ return PTR_ERR(map);
+ }
+
+ return __add_used_map(env, map);
+}
+
/* find and rewrite pseudo imm in ld_imm64 instructions:
*
* 1. if it accesses map FD, replace it with actual map pointer.
@@ -19318,7 +19324,7 @@ static int resolve_pseudo_ldimm64(struct bpf_verifier_env *env)
break;
}
- map_idx = add_used_map_from_fd(env, fd);
+ map_idx = add_used_map(env, fd);
if (map_idx < 0)
return map_idx;
map = env->used_maps[map_idx];
@@ -22526,6 +22532,61 @@ struct btf *bpf_get_btf_vmlinux(void)
return btf_vmlinux;
}
+/*
+ * The add_fd_from_fd_array() is executed only if fd_array_cnt is given. In
+ * this case expect that every file descriptor in the array is either a map or
+ * a BTF, or a hole (0). Everything else is considered to be trash.
+ */
+static int add_fd_from_fd_array(struct bpf_verifier_env *env, int fd)
+{
+ struct bpf_map *map;
+ CLASS(fd, f)(fd);
+ int ret;
+
+ map = __bpf_map_get(f);
+ if (!IS_ERR(map)) {
+ ret = __add_used_map(env, map);
+ if (ret < 0)
+ return ret;
+ return 0;
+ }
+
+ if (!IS_ERR(__btf_get_by_fd(f)))
+ return 0;
+
+ verbose(env, "fd %d is not pointing to valid bpf_map or btf\n", fd);
+ return PTR_ERR(map);
+}
+
+static int init_fd_array(struct bpf_verifier_env *env, union bpf_attr *attr, bpfptr_t uattr)
+{
+ size_t size = sizeof(int);
+ int ret;
+ int fd;
+ u32 i;
+
+ env->fd_array = make_bpfptr(attr->fd_array, uattr.is_kernel);
+
+ /*
+ * The only difference between old (no fd_array_cnt is given) and new
+ * APIs is that in the latter case the fd_array is expected to be
+ * continuous and is scanned for map fds right away
+ */
+ if (!attr->fd_array_cnt)
+ return 0;
+
+ for (i = 0; i < attr->fd_array_cnt; i++) {
+ if (copy_from_bpfptr_offset(&fd, env->fd_array, i * size, size))
+ return -EFAULT;
+
+ ret = add_fd_from_fd_array(env, fd);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr, __u32 uattr_size)
{
u64 start_time = ktime_get_ns();
@@ -22557,7 +22618,9 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr, __u3
env->insn_aux_data[i].orig_idx = i;
env->prog = *prog;
env->ops = bpf_verifier_ops[env->prog->type];
- env->fd_array = make_bpfptr(attr->fd_array, uattr.is_kernel);
+ ret = init_fd_array(env, attr, uattr);
+ if (ret)
+ goto err_free_aux_data;
env->allow_ptr_leaks = bpf_allow_ptr_leaks(env->prog->aux->token);
env->allow_uninit_stack = bpf_allow_uninit_stack(env->prog->aux->token);
@@ -22775,6 +22838,7 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr, __u3
err_unlock:
if (!is_priv)
mutex_unlock(&bpf_verifier_lock);
+err_free_aux_data:
vfree(env->insn_aux_data);
kvfree(env->insn_hist);
err_free_env:
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 4162afc6b5d0..2acf9b336371 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -1573,6 +1573,16 @@ union bpf_attr {
* If provided, prog_flags should have BPF_F_TOKEN_FD flag set.
*/
__s32 prog_token_fd;
+ /* The fd_array_cnt can be used to pass the length of the
+ * fd_array array. In this case all the [map] file descriptors
+ * passed in this array will be bound to the program, even if
+ * the maps are not referenced directly. The functionality is
+ * similar to the BPF_PROG_BIND_MAP syscall, but maps can be
+ * used by the verifier during the program load. If provided,
+ * then the fd_array[0,...,fd_array_cnt-1] is expected to be
+ * continuous.
+ */
+ __u32 fd_array_cnt;
};
struct { /* anonymous struct used by BPF_OBJ_* commands */
--
2.34.1
^ permalink raw reply related [flat|nested] 14+ messages in thread* Re: [PATCH v3 bpf-next 3/7] bpf: add fd_array_cnt attribute for prog_load
2024-11-29 13:28 ` [PATCH v3 bpf-next 3/7] bpf: add fd_array_cnt attribute for prog_load Anton Protopopov
@ 2024-12-03 2:26 ` Alexei Starovoitov
2024-12-03 10:31 ` Anton Protopopov
0 siblings, 1 reply; 14+ messages in thread
From: Alexei Starovoitov @ 2024-12-03 2:26 UTC (permalink / raw)
To: Anton Protopopov; +Cc: bpf
On Fri, Nov 29, 2024 at 5:26 AM Anton Protopopov <aspsk@isovalent.com> wrote:
>
> The fd_array attribute of the BPF_PROG_LOAD syscall may contain a set
> of file descriptors: maps or btfs. This field was introduced as a
> sparse array. Introduce a new attribute, fd_array_cnt, which, if
> present, indicates that the fd_array is a continuous array of the
> corresponding length.
>
> If fd_array_cnt is non-zero, then every map in the fd_array will be
> bound to the program, as if it was used by the program. This
> functionality is similar to the BPF_PROG_BIND_MAP syscall, but such
> maps can be used by the verifier during the program load.
>
> Signed-off-by: Anton Protopopov <aspsk@isovalent.com>
> ---
> include/uapi/linux/bpf.h | 10 ++++
> kernel/bpf/syscall.c | 2 +-
> kernel/bpf/verifier.c | 94 ++++++++++++++++++++++++++++------
> tools/include/uapi/linux/bpf.h | 10 ++++
> 4 files changed, 100 insertions(+), 16 deletions(-)
>
> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> index 4162afc6b5d0..2acf9b336371 100644
> --- a/include/uapi/linux/bpf.h
> +++ b/include/uapi/linux/bpf.h
> @@ -1573,6 +1573,16 @@ union bpf_attr {
> * If provided, prog_flags should have BPF_F_TOKEN_FD flag set.
> */
> __s32 prog_token_fd;
> + /* The fd_array_cnt can be used to pass the length of the
> + * fd_array array. In this case all the [map] file descriptors
> + * passed in this array will be bound to the program, even if
> + * the maps are not referenced directly. The functionality is
> + * similar to the BPF_PROG_BIND_MAP syscall, but maps can be
> + * used by the verifier during the program load. If provided,
> + * then the fd_array[0,...,fd_array_cnt-1] is expected to be
> + * continuous.
> + */
> + __u32 fd_array_cnt;
> };
>
> struct { /* anonymous struct used by BPF_OBJ_* commands */
> diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
> index 58190ca724a2..7e3fbc23c742 100644
> --- a/kernel/bpf/syscall.c
> +++ b/kernel/bpf/syscall.c
> @@ -2729,7 +2729,7 @@ static bool is_perfmon_prog_type(enum bpf_prog_type prog_type)
> }
>
> /* last field in 'union bpf_attr' used by this command */
> -#define BPF_PROG_LOAD_LAST_FIELD prog_token_fd
> +#define BPF_PROG_LOAD_LAST_FIELD fd_array_cnt
>
> static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size)
> {
> diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
> index 8e034a22aa2a..d172f6974fd7 100644
> --- a/kernel/bpf/verifier.c
> +++ b/kernel/bpf/verifier.c
> @@ -19181,22 +19181,10 @@ static int check_map_prog_compatibility(struct bpf_verifier_env *env,
> return 0;
> }
>
> -/* Add map behind fd to used maps list, if it's not already there, and return
> - * its index.
> - * Returns <0 on error, or >= 0 index, on success.
> - */
> -static int add_used_map_from_fd(struct bpf_verifier_env *env, int fd)
> +static int __add_used_map(struct bpf_verifier_env *env, struct bpf_map *map)
> {
> - CLASS(fd, f)(fd);
> - struct bpf_map *map;
> int i, err;
>
> - map = __bpf_map_get(f);
> - if (IS_ERR(map)) {
> - verbose(env, "fd %d is not pointing to valid bpf_map\n", fd);
> - return PTR_ERR(map);
> - }
> -
> /* check whether we recorded this map already */
> for (i = 0; i < env->used_map_cnt; i++)
> if (env->used_maps[i] == map)
> @@ -19227,6 +19215,24 @@ static int add_used_map_from_fd(struct bpf_verifier_env *env, int fd)
> return env->used_map_cnt - 1;
> }
>
> +/* Add map behind fd to used maps list, if it's not already there, and return
> + * its index.
> + * Returns <0 on error, or >= 0 index, on success.
> + */
> +static int add_used_map(struct bpf_verifier_env *env, int fd)
> +{
> + struct bpf_map *map;
> + CLASS(fd, f)(fd);
> +
> + map = __bpf_map_get(f);
> + if (IS_ERR(map)) {
> + verbose(env, "fd %d is not pointing to valid bpf_map\n", fd);
> + return PTR_ERR(map);
> + }
> +
> + return __add_used_map(env, map);
> +}
> +
> /* find and rewrite pseudo imm in ld_imm64 instructions:
> *
> * 1. if it accesses map FD, replace it with actual map pointer.
> @@ -19318,7 +19324,7 @@ static int resolve_pseudo_ldimm64(struct bpf_verifier_env *env)
> break;
> }
>
> - map_idx = add_used_map_from_fd(env, fd);
> + map_idx = add_used_map(env, fd);
> if (map_idx < 0)
> return map_idx;
> map = env->used_maps[map_idx];
> @@ -22526,6 +22532,61 @@ struct btf *bpf_get_btf_vmlinux(void)
> return btf_vmlinux;
> }
>
> +/*
> + * The add_fd_from_fd_array() is executed only if fd_array_cnt is given. In
> + * this case expect that every file descriptor in the array is either a map or
> + * a BTF, or a hole (0). Everything else is considered to be trash.
> + */
The comment is now incorrect. 0 is not a valid hole.
No holes are allowed. And no trash.
> +static int add_fd_from_fd_array(struct bpf_verifier_env *env, int fd)
> +{
> + struct bpf_map *map;
> + CLASS(fd, f)(fd);
> + int ret;
> +
> + map = __bpf_map_get(f);
> + if (!IS_ERR(map)) {
> + ret = __add_used_map(env, map);
> + if (ret < 0)
> + return ret;
> + return 0;
> + }
> +
> + if (!IS_ERR(__btf_get_by_fd(f)))
> + return 0;
It is quite asymmetrical that maps get refcnted and saved
while BTFs just checked for existence and not refcnted.
A comment is necessary.
> +
> + verbose(env, "fd %d is not pointing to valid bpf_map or btf\n", fd);
> + return PTR_ERR(map);
> +}
> +
> +static int init_fd_array(struct bpf_verifier_env *env, union bpf_attr *attr, bpfptr_t uattr)
The name still bothers me.
The fd_array in the env and in uattr is not initialized.
Maybe process_fd_array() ?
pw-bot: cr
^ permalink raw reply [flat|nested] 14+ messages in thread* Re: [PATCH v3 bpf-next 3/7] bpf: add fd_array_cnt attribute for prog_load
2024-12-03 2:26 ` Alexei Starovoitov
@ 2024-12-03 10:31 ` Anton Protopopov
0 siblings, 0 replies; 14+ messages in thread
From: Anton Protopopov @ 2024-12-03 10:31 UTC (permalink / raw)
To: Alexei Starovoitov; +Cc: bpf
On 24/12/02 06:26PM, Alexei Starovoitov wrote:
> On Fri, Nov 29, 2024 at 5:26 AM Anton Protopopov <aspsk@isovalent.com> wrote:
> >
> > The fd_array attribute of the BPF_PROG_LOAD syscall may contain a set
> > of file descriptors: maps or btfs. This field was introduced as a
> > sparse array. Introduce a new attribute, fd_array_cnt, which, if
> > present, indicates that the fd_array is a continuous array of the
> > corresponding length.
> >
> > If fd_array_cnt is non-zero, then every map in the fd_array will be
> > bound to the program, as if it was used by the program. This
> > functionality is similar to the BPF_PROG_BIND_MAP syscall, but such
> > maps can be used by the verifier during the program load.
> >
> > Signed-off-by: Anton Protopopov <aspsk@isovalent.com>
> > ---
> > include/uapi/linux/bpf.h | 10 ++++
> > kernel/bpf/syscall.c | 2 +-
> > kernel/bpf/verifier.c | 94 ++++++++++++++++++++++++++++------
> > tools/include/uapi/linux/bpf.h | 10 ++++
> > 4 files changed, 100 insertions(+), 16 deletions(-)
> >
> > diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> > index 4162afc6b5d0..2acf9b336371 100644
> > --- a/include/uapi/linux/bpf.h
> > +++ b/include/uapi/linux/bpf.h
> > @@ -1573,6 +1573,16 @@ union bpf_attr {
> > * If provided, prog_flags should have BPF_F_TOKEN_FD flag set.
> > */
> > __s32 prog_token_fd;
> > + /* The fd_array_cnt can be used to pass the length of the
> > + * fd_array array. In this case all the [map] file descriptors
> > + * passed in this array will be bound to the program, even if
> > + * the maps are not referenced directly. The functionality is
> > + * similar to the BPF_PROG_BIND_MAP syscall, but maps can be
> > + * used by the verifier during the program load. If provided,
> > + * then the fd_array[0,...,fd_array_cnt-1] is expected to be
> > + * continuous.
> > + */
> > + __u32 fd_array_cnt;
> > };
> >
> > struct { /* anonymous struct used by BPF_OBJ_* commands */
> > diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
> > index 58190ca724a2..7e3fbc23c742 100644
> > --- a/kernel/bpf/syscall.c
> > +++ b/kernel/bpf/syscall.c
> > @@ -2729,7 +2729,7 @@ static bool is_perfmon_prog_type(enum bpf_prog_type prog_type)
> > }
> >
> > /* last field in 'union bpf_attr' used by this command */
> > -#define BPF_PROG_LOAD_LAST_FIELD prog_token_fd
> > +#define BPF_PROG_LOAD_LAST_FIELD fd_array_cnt
> >
> > static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size)
> > {
> > diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
> > index 8e034a22aa2a..d172f6974fd7 100644
> > --- a/kernel/bpf/verifier.c
> > +++ b/kernel/bpf/verifier.c
> > @@ -19181,22 +19181,10 @@ static int check_map_prog_compatibility(struct bpf_verifier_env *env,
> > return 0;
> > }
> >
> > -/* Add map behind fd to used maps list, if it's not already there, and return
> > - * its index.
> > - * Returns <0 on error, or >= 0 index, on success.
> > - */
> > -static int add_used_map_from_fd(struct bpf_verifier_env *env, int fd)
> > +static int __add_used_map(struct bpf_verifier_env *env, struct bpf_map *map)
> > {
> > - CLASS(fd, f)(fd);
> > - struct bpf_map *map;
> > int i, err;
> >
> > - map = __bpf_map_get(f);
> > - if (IS_ERR(map)) {
> > - verbose(env, "fd %d is not pointing to valid bpf_map\n", fd);
> > - return PTR_ERR(map);
> > - }
> > -
> > /* check whether we recorded this map already */
> > for (i = 0; i < env->used_map_cnt; i++)
> > if (env->used_maps[i] == map)
> > @@ -19227,6 +19215,24 @@ static int add_used_map_from_fd(struct bpf_verifier_env *env, int fd)
> > return env->used_map_cnt - 1;
> > }
> >
> > +/* Add map behind fd to used maps list, if it's not already there, and return
> > + * its index.
> > + * Returns <0 on error, or >= 0 index, on success.
> > + */
> > +static int add_used_map(struct bpf_verifier_env *env, int fd)
> > +{
> > + struct bpf_map *map;
> > + CLASS(fd, f)(fd);
> > +
> > + map = __bpf_map_get(f);
> > + if (IS_ERR(map)) {
> > + verbose(env, "fd %d is not pointing to valid bpf_map\n", fd);
> > + return PTR_ERR(map);
> > + }
> > +
> > + return __add_used_map(env, map);
> > +}
> > +
> > /* find and rewrite pseudo imm in ld_imm64 instructions:
> > *
> > * 1. if it accesses map FD, replace it with actual map pointer.
> > @@ -19318,7 +19324,7 @@ static int resolve_pseudo_ldimm64(struct bpf_verifier_env *env)
> > break;
> > }
> >
> > - map_idx = add_used_map_from_fd(env, fd);
> > + map_idx = add_used_map(env, fd);
> > if (map_idx < 0)
> > return map_idx;
> > map = env->used_maps[map_idx];
> > @@ -22526,6 +22532,61 @@ struct btf *bpf_get_btf_vmlinux(void)
> > return btf_vmlinux;
> > }
> >
> > +/*
> > + * The add_fd_from_fd_array() is executed only if fd_array_cnt is given. In
> > + * this case expect that every file descriptor in the array is either a map or
> > + * a BTF, or a hole (0). Everything else is considered to be trash.
> > + */
>
> The comment is now incorrect. 0 is not a valid hole.
> No holes are allowed. And no trash.
Thanks, fixed.
> > +static int add_fd_from_fd_array(struct bpf_verifier_env *env, int fd)
> > +{
> > + struct bpf_map *map;
> > + CLASS(fd, f)(fd);
> > + int ret;
> > +
> > + map = __bpf_map_get(f);
> > + if (!IS_ERR(map)) {
> > + ret = __add_used_map(env, map);
> > + if (ret < 0)
> > + return ret;
> > + return 0;
> > + }
> > +
> > + if (!IS_ERR(__btf_get_by_fd(f)))
> > + return 0;
>
> It is quite asymmetrical that maps get refcnted and saved
> while BTFs just checked for existence and not refcnted.
> A comment is necessary.
Added.
>
> > +
> > + verbose(env, "fd %d is not pointing to valid bpf_map or btf\n", fd);
> > + return PTR_ERR(map);
> > +}
> > +
> > +static int init_fd_array(struct bpf_verifier_env *env, union bpf_attr *attr, bpfptr_t uattr)
>
> The name still bothers me.
> The fd_array in the env and in uattr is not initialized.
>
> Maybe process_fd_array() ?
Sure, 'process_fd_array' looks fine for me.
> pw-bot: cr
^ permalink raw reply [flat|nested] 14+ messages in thread
* [PATCH v3 bpf-next 4/7] libbpf: prog load: allow to use fd_array_cnt
2024-11-29 13:28 [PATCH v3 bpf-next 0/7] Add fd_array_cnt attribute for BPF_PROG_LOAD Anton Protopopov
` (2 preceding siblings ...)
2024-11-29 13:28 ` [PATCH v3 bpf-next 3/7] bpf: add fd_array_cnt attribute for prog_load Anton Protopopov
@ 2024-11-29 13:28 ` Anton Protopopov
2024-12-03 2:34 ` Alexei Starovoitov
2024-11-29 13:28 ` [PATCH v3 bpf-next 5/7] selftests/bpf: Add tests for fd_array_cnt Anton Protopopov
` (2 subsequent siblings)
6 siblings, 1 reply; 14+ messages in thread
From: Anton Protopopov @ 2024-11-29 13:28 UTC (permalink / raw)
To: bpf; +Cc: Anton Protopopov
Add new fd_array_cnt field to bpf_prog_load_opts
and pass it in bpf_attr, if set.
Signed-off-by: Anton Protopopov <aspsk@isovalent.com>
---
tools/lib/bpf/bpf.c | 5 +++--
tools/lib/bpf/bpf.h | 5 ++++-
tools/lib/bpf/features.c | 2 +-
3 files changed, 8 insertions(+), 4 deletions(-)
diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index becdfa701c75..0e7f59224936 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -105,7 +105,7 @@ int sys_bpf_prog_load(union bpf_attr *attr, unsigned int size, int attempts)
*/
int probe_memcg_account(int token_fd)
{
- const size_t attr_sz = offsetofend(union bpf_attr, prog_token_fd);
+ const size_t attr_sz = offsetofend(union bpf_attr, fd_array_cnt);
struct bpf_insn insns[] = {
BPF_EMIT_CALL(BPF_FUNC_ktime_get_coarse_ns),
BPF_EXIT_INSN(),
@@ -238,7 +238,7 @@ int bpf_prog_load(enum bpf_prog_type prog_type,
const struct bpf_insn *insns, size_t insn_cnt,
struct bpf_prog_load_opts *opts)
{
- const size_t attr_sz = offsetofend(union bpf_attr, prog_token_fd);
+ const size_t attr_sz = offsetofend(union bpf_attr, fd_array_cnt);
void *finfo = NULL, *linfo = NULL;
const char *func_info, *line_info;
__u32 log_size, log_level, attach_prog_fd, attach_btf_obj_fd;
@@ -311,6 +311,7 @@ int bpf_prog_load(enum bpf_prog_type prog_type,
attr.line_info_cnt = OPTS_GET(opts, line_info_cnt, 0);
attr.fd_array = ptr_to_u64(OPTS_GET(opts, fd_array, NULL));
+ attr.fd_array_cnt = OPTS_GET(opts, fd_array_cnt, 0);
if (log_level) {
attr.log_buf = ptr_to_u64(log_buf);
diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
index a4a7b1ad1b63..435da95d2058 100644
--- a/tools/lib/bpf/bpf.h
+++ b/tools/lib/bpf/bpf.h
@@ -107,9 +107,12 @@ struct bpf_prog_load_opts {
*/
__u32 log_true_size;
__u32 token_fd;
+
+ /* if set, provides the length of fd_array */
+ __u32 fd_array_cnt;
size_t :0;
};
-#define bpf_prog_load_opts__last_field token_fd
+#define bpf_prog_load_opts__last_field fd_array_cnt
LIBBPF_API int bpf_prog_load(enum bpf_prog_type prog_type,
const char *prog_name, const char *license,
diff --git a/tools/lib/bpf/features.c b/tools/lib/bpf/features.c
index 760657f5224c..5afc9555d9ac 100644
--- a/tools/lib/bpf/features.c
+++ b/tools/lib/bpf/features.c
@@ -22,7 +22,7 @@ int probe_fd(int fd)
static int probe_kern_prog_name(int token_fd)
{
- const size_t attr_sz = offsetofend(union bpf_attr, prog_token_fd);
+ const size_t attr_sz = offsetofend(union bpf_attr, fd_array_cnt);
struct bpf_insn insns[] = {
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
--
2.34.1
^ permalink raw reply related [flat|nested] 14+ messages in thread* Re: [PATCH v3 bpf-next 4/7] libbpf: prog load: allow to use fd_array_cnt
2024-11-29 13:28 ` [PATCH v3 bpf-next 4/7] libbpf: prog load: allow to use fd_array_cnt Anton Protopopov
@ 2024-12-03 2:34 ` Alexei Starovoitov
2024-12-03 10:23 ` Anton Protopopov
0 siblings, 1 reply; 14+ messages in thread
From: Alexei Starovoitov @ 2024-12-03 2:34 UTC (permalink / raw)
To: Anton Protopopov; +Cc: bpf
On Fri, Nov 29, 2024 at 5:29 AM Anton Protopopov <aspsk@isovalent.com> wrote:
>
> Add new fd_array_cnt field to bpf_prog_load_opts
> and pass it in bpf_attr, if set.
>
> Signed-off-by: Anton Protopopov <aspsk@isovalent.com>
> ---
> tools/lib/bpf/bpf.c | 5 +++--
> tools/lib/bpf/bpf.h | 5 ++++-
> tools/lib/bpf/features.c | 2 +-
> 3 files changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
> index becdfa701c75..0e7f59224936 100644
> --- a/tools/lib/bpf/bpf.c
> +++ b/tools/lib/bpf/bpf.c
> @@ -105,7 +105,7 @@ int sys_bpf_prog_load(union bpf_attr *attr, unsigned int size, int attempts)
> */
> int probe_memcg_account(int token_fd)
> {
> - const size_t attr_sz = offsetofend(union bpf_attr, prog_token_fd);
> + const size_t attr_sz = offsetofend(union bpf_attr, fd_array_cnt);
Thankfully this function doesn't set fd_array_cnt below.
Otherwise the detection of memcg would fail on older kernels.
Let's avoid people mindlessly adding init of fd_array_cnt here by accident.
Simply keep this line as-is.
offsetofend(.., prog_token_fd) is fine.
> struct bpf_insn insns[] = {
> BPF_EMIT_CALL(BPF_FUNC_ktime_get_coarse_ns),
> BPF_EXIT_INSN(),
> @@ -238,7 +238,7 @@ int bpf_prog_load(enum bpf_prog_type prog_type,
> const struct bpf_insn *insns, size_t insn_cnt,
> struct bpf_prog_load_opts *opts)
> {
> - const size_t attr_sz = offsetofend(union bpf_attr, prog_token_fd);
> + const size_t attr_sz = offsetofend(union bpf_attr, fd_array_cnt);
> void *finfo = NULL, *linfo = NULL;
> const char *func_info, *line_info;
> __u32 log_size, log_level, attach_prog_fd, attach_btf_obj_fd;
> @@ -311,6 +311,7 @@ int bpf_prog_load(enum bpf_prog_type prog_type,
> attr.line_info_cnt = OPTS_GET(opts, line_info_cnt, 0);
>
> attr.fd_array = ptr_to_u64(OPTS_GET(opts, fd_array, NULL));
> + attr.fd_array_cnt = OPTS_GET(opts, fd_array_cnt, 0);
>
> if (log_level) {
> attr.log_buf = ptr_to_u64(log_buf);
> diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
> index a4a7b1ad1b63..435da95d2058 100644
> --- a/tools/lib/bpf/bpf.h
> +++ b/tools/lib/bpf/bpf.h
> @@ -107,9 +107,12 @@ struct bpf_prog_load_opts {
> */
> __u32 log_true_size;
> __u32 token_fd;
> +
> + /* if set, provides the length of fd_array */
> + __u32 fd_array_cnt;
> size_t :0;
> };
> -#define bpf_prog_load_opts__last_field token_fd
> +#define bpf_prog_load_opts__last_field fd_array_cnt
>
> LIBBPF_API int bpf_prog_load(enum bpf_prog_type prog_type,
> const char *prog_name, const char *license,
> diff --git a/tools/lib/bpf/features.c b/tools/lib/bpf/features.c
> index 760657f5224c..5afc9555d9ac 100644
> --- a/tools/lib/bpf/features.c
> +++ b/tools/lib/bpf/features.c
> @@ -22,7 +22,7 @@ int probe_fd(int fd)
>
> static int probe_kern_prog_name(int token_fd)
> {
> - const size_t attr_sz = offsetofend(union bpf_attr, prog_token_fd);
> + const size_t attr_sz = offsetofend(union bpf_attr, fd_array_cnt);
Same here. Don't change it.
^ permalink raw reply [flat|nested] 14+ messages in thread* Re: [PATCH v3 bpf-next 4/7] libbpf: prog load: allow to use fd_array_cnt
2024-12-03 2:34 ` Alexei Starovoitov
@ 2024-12-03 10:23 ` Anton Protopopov
0 siblings, 0 replies; 14+ messages in thread
From: Anton Protopopov @ 2024-12-03 10:23 UTC (permalink / raw)
To: Alexei Starovoitov; +Cc: bpf
On 24/12/02 06:34PM, Alexei Starovoitov wrote:
> On Fri, Nov 29, 2024 at 5:29 AM Anton Protopopov <aspsk@isovalent.com> wrote:
> >
> > Add new fd_array_cnt field to bpf_prog_load_opts
> > and pass it in bpf_attr, if set.
> >
> > Signed-off-by: Anton Protopopov <aspsk@isovalent.com>
> > ---
> > tools/lib/bpf/bpf.c | 5 +++--
> > tools/lib/bpf/bpf.h | 5 ++++-
> > tools/lib/bpf/features.c | 2 +-
> > 3 files changed, 8 insertions(+), 4 deletions(-)
> >
> > diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
> > index becdfa701c75..0e7f59224936 100644
> > --- a/tools/lib/bpf/bpf.c
> > +++ b/tools/lib/bpf/bpf.c
> > @@ -105,7 +105,7 @@ int sys_bpf_prog_load(union bpf_attr *attr, unsigned int size, int attempts)
> > */
> > int probe_memcg_account(int token_fd)
> > {
> > - const size_t attr_sz = offsetofend(union bpf_attr, prog_token_fd);
> > + const size_t attr_sz = offsetofend(union bpf_attr, fd_array_cnt);
>
> Thankfully this function doesn't set fd_array_cnt below.
> Otherwise the detection of memcg would fail on older kernels.
> Let's avoid people mindlessly adding init of fd_array_cnt here by accident.
> Simply keep this line as-is.
> offsetofend(.., prog_token_fd) is fine.
Ok, thanks, reverted (as with the one you've mentioned below)
> > struct bpf_insn insns[] = {
> > BPF_EMIT_CALL(BPF_FUNC_ktime_get_coarse_ns),
> > BPF_EXIT_INSN(),
> > @@ -238,7 +238,7 @@ int bpf_prog_load(enum bpf_prog_type prog_type,
> > const struct bpf_insn *insns, size_t insn_cnt,
> > struct bpf_prog_load_opts *opts)
> > {
> > - const size_t attr_sz = offsetofend(union bpf_attr, prog_token_fd);
> > + const size_t attr_sz = offsetofend(union bpf_attr, fd_array_cnt);
> > void *finfo = NULL, *linfo = NULL;
> > const char *func_info, *line_info;
> > __u32 log_size, log_level, attach_prog_fd, attach_btf_obj_fd;
> > @@ -311,6 +311,7 @@ int bpf_prog_load(enum bpf_prog_type prog_type,
> > attr.line_info_cnt = OPTS_GET(opts, line_info_cnt, 0);
> >
> > attr.fd_array = ptr_to_u64(OPTS_GET(opts, fd_array, NULL));
> > + attr.fd_array_cnt = OPTS_GET(opts, fd_array_cnt, 0);
> >
> > if (log_level) {
> > attr.log_buf = ptr_to_u64(log_buf);
> > diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
> > index a4a7b1ad1b63..435da95d2058 100644
> > --- a/tools/lib/bpf/bpf.h
> > +++ b/tools/lib/bpf/bpf.h
> > @@ -107,9 +107,12 @@ struct bpf_prog_load_opts {
> > */
> > __u32 log_true_size;
> > __u32 token_fd;
> > +
> > + /* if set, provides the length of fd_array */
> > + __u32 fd_array_cnt;
> > size_t :0;
> > };
> > -#define bpf_prog_load_opts__last_field token_fd
> > +#define bpf_prog_load_opts__last_field fd_array_cnt
> >
> > LIBBPF_API int bpf_prog_load(enum bpf_prog_type prog_type,
> > const char *prog_name, const char *license,
> > diff --git a/tools/lib/bpf/features.c b/tools/lib/bpf/features.c
> > index 760657f5224c..5afc9555d9ac 100644
> > --- a/tools/lib/bpf/features.c
> > +++ b/tools/lib/bpf/features.c
> > @@ -22,7 +22,7 @@ int probe_fd(int fd)
> >
> > static int probe_kern_prog_name(int token_fd)
> > {
> > - const size_t attr_sz = offsetofend(union bpf_attr, prog_token_fd);
> > + const size_t attr_sz = offsetofend(union bpf_attr, fd_array_cnt);
>
> Same here. Don't change it.
^ permalink raw reply [flat|nested] 14+ messages in thread
* [PATCH v3 bpf-next 5/7] selftests/bpf: Add tests for fd_array_cnt
2024-11-29 13:28 [PATCH v3 bpf-next 0/7] Add fd_array_cnt attribute for BPF_PROG_LOAD Anton Protopopov
` (3 preceding siblings ...)
2024-11-29 13:28 ` [PATCH v3 bpf-next 4/7] libbpf: prog load: allow to use fd_array_cnt Anton Protopopov
@ 2024-11-29 13:28 ` Anton Protopopov
2024-12-03 2:37 ` Alexei Starovoitov
2024-11-29 13:28 ` [PATCH v3 bpf-next 6/7] bpf: fix potential error return Anton Protopopov
2024-11-29 13:28 ` [PATCH v3 bpf-next 7/7] selftest/bpf: replace magic constants by macros Anton Protopopov
6 siblings, 1 reply; 14+ messages in thread
From: Anton Protopopov @ 2024-11-29 13:28 UTC (permalink / raw)
To: bpf; +Cc: Anton Protopopov
Add a new set of tests to test the new field in PROG_LOAD-related
part of bpf_attr: fd_array_cnt.
Add the following test cases:
* fd_array_cnt/no-fd-array: program is loaded in a normal
way, without any fd_array present
* fd_array_cnt/fd-array-ok: pass two extra non-used maps,
check that they're bound to the program
* fd_array_cnt/fd-array-dup-input: pass a few extra maps,
only two of which are unique
* fd_array_cnt/fd-array-ref-maps-in-array: pass a map in
fd_array which is also referenced from within the program
* fd_array_cnt/fd-array-trash-input: pass array with some trash
* fd_array_cnt/fd-array-with-holes: pass an array with holes (fd=0)
* fd_array_cnt/fd-array-2big: pass too large array
All the tests above are using the bpf(2) syscall directly,
no libbpf involved.
Signed-off-by: Anton Protopopov <aspsk@isovalent.com>
---
kernel/bpf/verifier.c | 30 +-
.../selftests/bpf/prog_tests/fd_array.c | 340 ++++++++++++++++++
2 files changed, 355 insertions(+), 15 deletions(-)
create mode 100644 tools/testing/selftests/bpf/prog_tests/fd_array.c
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index d172f6974fd7..7102d85f580d 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -22620,7 +22620,7 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr, __u3
env->ops = bpf_verifier_ops[env->prog->type];
ret = init_fd_array(env, attr, uattr);
if (ret)
- goto err_free_aux_data;
+ goto err_release_maps;
env->allow_ptr_leaks = bpf_allow_ptr_leaks(env->prog->aux->token);
env->allow_uninit_stack = bpf_allow_uninit_stack(env->prog->aux->token);
@@ -22773,11 +22773,11 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr, __u3
copy_to_bpfptr_offset(uattr, offsetof(union bpf_attr, log_true_size),
&log_true_size, sizeof(log_true_size))) {
ret = -EFAULT;
- goto err_release_maps;
+ goto err_ext;
}
if (ret)
- goto err_release_maps;
+ goto err_ext;
if (env->used_map_cnt) {
/* if program passed verifier, update used_maps in bpf_prog_info */
@@ -22787,7 +22787,7 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr, __u3
if (!env->prog->aux->used_maps) {
ret = -ENOMEM;
- goto err_release_maps;
+ goto err_ext;
}
memcpy(env->prog->aux->used_maps, env->used_maps,
@@ -22801,7 +22801,7 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr, __u3
GFP_KERNEL);
if (!env->prog->aux->used_btfs) {
ret = -ENOMEM;
- goto err_release_maps;
+ goto err_ext;
}
memcpy(env->prog->aux->used_btfs, env->used_btfs,
@@ -22817,15 +22817,7 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr, __u3
adjust_btf_func(env);
-err_release_maps:
- if (!env->prog->aux->used_maps)
- /* if we didn't copy map pointers into bpf_prog_info, release
- * them now. Otherwise free_used_maps() will release them.
- */
- release_maps(env);
- if (!env->prog->aux->used_btfs)
- release_btfs(env);
-
+err_ext:
/* extension progs temporarily inherit the attach_type of their targets
for verification purposes, so set it back to zero before returning
*/
@@ -22838,7 +22830,15 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr, __u3
err_unlock:
if (!is_priv)
mutex_unlock(&bpf_verifier_lock);
-err_free_aux_data:
+err_release_maps:
+ if (!env->prog->aux->used_maps)
+ /* if we didn't copy map pointers into bpf_prog_info, release
+ * them now. Otherwise free_used_maps() will release them.
+ */
+ release_maps(env);
+ if (!env->prog->aux->used_btfs)
+ release_btfs(env);
+
vfree(env->insn_aux_data);
kvfree(env->insn_hist);
err_free_env:
diff --git a/tools/testing/selftests/bpf/prog_tests/fd_array.c b/tools/testing/selftests/bpf/prog_tests/fd_array.c
new file mode 100644
index 000000000000..1d4bff4a1269
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/fd_array.c
@@ -0,0 +1,340 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <test_progs.h>
+
+#include <linux/btf.h>
+#include <bpf/bpf.h>
+
+#include "../test_btf.h"
+
+static inline int new_map(void)
+{
+ LIBBPF_OPTS(bpf_map_create_opts, opts);
+ const char *name = NULL;
+ __u32 max_entries = 1;
+ __u32 value_size = 8;
+ __u32 key_size = 4;
+
+ return bpf_map_create(BPF_MAP_TYPE_ARRAY, name,
+ key_size, value_size,
+ max_entries, &opts);
+}
+
+static int new_btf(void)
+{
+ LIBBPF_OPTS(bpf_btf_load_opts, opts);
+ struct btf_blob {
+ struct btf_header btf_hdr;
+ __u32 types[8];
+ __u32 str;
+ } raw_btf = {
+ .btf_hdr = {
+ .magic = BTF_MAGIC,
+ .version = BTF_VERSION,
+ .hdr_len = sizeof(struct btf_header),
+ .type_len = sizeof(raw_btf.types),
+ .str_off = offsetof(struct btf_blob, str) - offsetof(struct btf_blob, types),
+ .str_len = sizeof(raw_btf.str),
+ },
+ .types = {
+ /* long */
+ BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 64, 8), /* [1] */
+ /* unsigned long */
+ BTF_TYPE_INT_ENC(0, 0, 0, 64, 8), /* [2] */
+ },
+ };
+
+ return bpf_btf_load(&raw_btf, sizeof(raw_btf), &opts);
+}
+
+static bool map_exists(__u32 id)
+{
+ int fd;
+
+ fd = bpf_map_get_fd_by_id(id);
+ if (fd >= 0) {
+ close(fd);
+ return true;
+ }
+ return false;
+}
+
+static inline int bpf_prog_get_map_ids(int prog_fd, __u32 *nr_map_ids, __u32 *map_ids)
+{
+ __u32 len = sizeof(struct bpf_prog_info);
+ struct bpf_prog_info info = {
+ .nr_map_ids = *nr_map_ids,
+ .map_ids = ptr_to_u64(map_ids),
+ };
+ int err;
+
+ err = bpf_prog_get_info_by_fd(prog_fd, &info, &len);
+ if (!ASSERT_OK(err, "bpf_prog_get_info_by_fd"))
+ return -1;
+
+ *nr_map_ids = info.nr_map_ids;
+
+ return 0;
+}
+
+static int __load_test_prog(int map_fd, const int *fd_array, int fd_array_cnt)
+{
+ /* A trivial program which uses one map */
+ struct bpf_insn insns[] = {
+ BPF_LD_MAP_FD(BPF_REG_1, map_fd),
+ BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ };
+ LIBBPF_OPTS(bpf_prog_load_opts, opts);
+
+ opts.fd_array = fd_array;
+ opts.fd_array_cnt = fd_array_cnt;
+
+ return bpf_prog_load(BPF_PROG_TYPE_XDP, NULL, "GPL", insns, ARRAY_SIZE(insns), &opts);
+}
+
+static int load_test_prog(const int *fd_array, int fd_array_cnt)
+{
+ int map_fd;
+ int ret;
+
+ map_fd = new_map();
+ if (!ASSERT_GE(map_fd, 0, "new_map"))
+ return map_fd;
+
+ ret = __load_test_prog(map_fd, fd_array, fd_array_cnt);
+ close(map_fd);
+
+ /* switch back to returning the actual value */
+ if (ret < 0)
+ return -errno;
+ return ret;
+}
+
+static bool check_expected_map_ids(int prog_fd, int expected, __u32 *map_ids, __u32 *nr_map_ids)
+{
+ int err;
+
+ err = bpf_prog_get_map_ids(prog_fd, nr_map_ids, map_ids);
+ if (!ASSERT_OK(err, "bpf_prog_get_map_ids"))
+ return false;
+ if (!ASSERT_EQ(*nr_map_ids, expected, "unexpected nr_map_ids"))
+ return false;
+
+ return true;
+}
+
+/*
+ * Load a program, which uses one map. No fd_array maps are present.
+ * On return only one map is expected to be bound to prog.
+ */
+static void check_fd_array_cnt__no_fd_array(void)
+{
+ __u32 map_ids[16];
+ __u32 nr_map_ids;
+ int prog_fd = -1;
+
+ prog_fd = load_test_prog(NULL, 0);
+ if (!ASSERT_GE(prog_fd, 0, "BPF_PROG_LOAD"))
+ return;
+ nr_map_ids = ARRAY_SIZE(map_ids);
+ check_expected_map_ids(prog_fd, 1, map_ids, &nr_map_ids);
+ close(prog_fd);
+}
+
+/*
+ * Load a program, which uses one map, and pass two extra, non-equal, maps in
+ * fd_array with fd_array_cnt=2. On return three maps are expected to be bound
+ * to the program.
+ */
+static void check_fd_array_cnt__fd_array_ok(void)
+{
+ int extra_fds[2] = { -1, -1 };
+ __u32 map_ids[16];
+ __u32 nr_map_ids;
+ int prog_fd = -1;
+
+ extra_fds[0] = new_map();
+ if (!ASSERT_GE(extra_fds[0], 0, "new_map"))
+ goto cleanup;
+ extra_fds[1] = new_map();
+ if (!ASSERT_GE(extra_fds[1], 0, "new_map"))
+ goto cleanup;
+ prog_fd = load_test_prog(extra_fds, 2);
+ if (!ASSERT_GE(prog_fd, 0, "BPF_PROG_LOAD"))
+ goto cleanup;
+ nr_map_ids = ARRAY_SIZE(map_ids);
+ if (!check_expected_map_ids(prog_fd, 3, map_ids, &nr_map_ids))
+ goto cleanup;
+
+ /* maps should still exist when original file descriptors are closed */
+ close(extra_fds[0]);
+ close(extra_fds[1]);
+ if (!ASSERT_EQ(map_exists(map_ids[0]), true, "map_ids[0] should exist"))
+ goto cleanup;
+ if (!ASSERT_EQ(map_exists(map_ids[1]), true, "map_ids[1] should exist"))
+ goto cleanup;
+
+ /* some fds might be invalid, so ignore return codes */
+cleanup:
+ close(extra_fds[1]);
+ close(extra_fds[0]);
+ close(prog_fd);
+}
+
+/*
+ * Load a program with a few extra maps duplicated in the fd_array.
+ * After the load maps should only be referenced once.
+ */
+static void check_fd_array_cnt__duplicated_maps(void)
+{
+ int extra_fds[4] = { -1, -1, -1, -1 };
+ __u32 map_ids[16];
+ __u32 nr_map_ids;
+ int prog_fd = -1;
+
+ extra_fds[0] = extra_fds[2] = new_map();
+ if (!ASSERT_GE(extra_fds[0], 0, "new_map"))
+ goto cleanup;
+ extra_fds[1] = extra_fds[3] = new_map();
+ if (!ASSERT_GE(extra_fds[1], 0, "new_map"))
+ goto cleanup;
+ prog_fd = load_test_prog(extra_fds, 4);
+ if (!ASSERT_GE(prog_fd, 0, "BPF_PROG_LOAD"))
+ goto cleanup;
+ nr_map_ids = ARRAY_SIZE(map_ids);
+ if (!check_expected_map_ids(prog_fd, 3, map_ids, &nr_map_ids))
+ goto cleanup;
+
+ /* maps should still exist when original file descriptors are closed */
+ close(extra_fds[0]);
+ close(extra_fds[1]);
+ if (!ASSERT_EQ(map_exists(map_ids[0]), true, "map should exist"))
+ goto cleanup;
+ if (!ASSERT_EQ(map_exists(map_ids[1]), true, "map should exist"))
+ goto cleanup;
+
+ /* some fds might be invalid, so ignore return codes */
+cleanup:
+ close(extra_fds[1]);
+ close(extra_fds[0]);
+ close(prog_fd);
+}
+
+/*
+ * Check that if maps which are referenced by a program are
+ * passed in fd_array, then they will be referenced only once
+ */
+static void check_fd_array_cnt__referenced_maps_in_fd_array(void)
+{
+ int extra_fds[1] = { -1 };
+ __u32 map_ids[16];
+ __u32 nr_map_ids;
+ int prog_fd = -1;
+
+ extra_fds[0] = new_map();
+ if (!ASSERT_GE(extra_fds[0], 0, "new_map"))
+ goto cleanup;
+ prog_fd = __load_test_prog(extra_fds[0], extra_fds, 1);
+ if (!ASSERT_GE(prog_fd, 0, "BPF_PROG_LOAD"))
+ goto cleanup;
+ nr_map_ids = ARRAY_SIZE(map_ids);
+ if (!check_expected_map_ids(prog_fd, 1, map_ids, &nr_map_ids))
+ goto cleanup;
+
+ /* map should still exist when original file descriptor is closed */
+ close(extra_fds[0]);
+ if (!ASSERT_EQ(map_exists(map_ids[0]), true, "map should exist"))
+ goto cleanup;
+
+ /* some fds might be invalid, so ignore return codes */
+cleanup:
+ close(extra_fds[0]);
+ close(prog_fd);
+}
+
+/*
+ * Test that a program with trash in fd_array can't be loaded:
+ * only map and BTF file descriptors should be accepted.
+ */
+static void check_fd_array_cnt__fd_array_with_trash(void)
+{
+ int extra_fds[3] = { -1, -1, -1 };
+ int prog_fd = -1;
+
+ extra_fds[0] = new_map();
+ if (!ASSERT_GE(extra_fds[0], 0, "new_map"))
+ goto cleanup;
+ extra_fds[1] = new_btf();
+ if (!ASSERT_GE(extra_fds[1], 0, "new_btf"))
+ goto cleanup;
+
+ /* trash 1: not a file descriptor */
+ extra_fds[2] = 0xbeef;
+ prog_fd = load_test_prog(extra_fds, 3);
+ if (!ASSERT_EQ(prog_fd, -EBADF, "prog should have been rejected with -EBADF"))
+ goto cleanup;
+
+ /* trash 2: not a map or btf */
+ extra_fds[2] = socket(AF_INET, SOCK_STREAM, 0);
+ if (!ASSERT_GE(extra_fds[2], 0, "socket"))
+ goto cleanup;
+
+ prog_fd = load_test_prog(extra_fds, 3);
+ if (!ASSERT_EQ(prog_fd, -EINVAL, "prog should have been rejected with -EINVAL"))
+ goto cleanup;
+
+ /* some fds might be invalid, so ignore return codes */
+cleanup:
+ close(extra_fds[2]);
+ close(extra_fds[1]);
+ close(extra_fds[0]);
+}
+
+/*
+ * Test that a program with too big fd_array can't be loaded.
+ */
+static void check_fd_array_cnt__fd_array_too_big(void)
+{
+ int extra_fds[65];
+ int prog_fd = -1;
+ int i;
+
+ for (i = 0; i < 65; i++) {
+ extra_fds[i] = new_map();
+ if (!ASSERT_GE(extra_fds[i], 0, "new_map"))
+ goto cleanup_fds;
+ }
+
+ prog_fd = load_test_prog(extra_fds, 65);
+ ASSERT_EQ(prog_fd, -E2BIG, "prog should have been rejected with -E2BIG");
+
+cleanup_fds:
+ while (i > 0)
+ close(extra_fds[--i]);
+}
+
+void test_fd_array_cnt(void)
+{
+ if (test__start_subtest("no-fd-array"))
+ check_fd_array_cnt__no_fd_array();
+
+ if (test__start_subtest("fd-array-ok"))
+ check_fd_array_cnt__fd_array_ok();
+
+ if (test__start_subtest("fd-array-dup-input"))
+ check_fd_array_cnt__duplicated_maps();
+
+ if (test__start_subtest("fd-array-ref-maps-in-array"))
+ check_fd_array_cnt__referenced_maps_in_fd_array();
+
+ if (test__start_subtest("fd-array-trash-input"))
+ check_fd_array_cnt__fd_array_with_trash();
+
+ if (test__start_subtest("fd-array-2big"))
+ check_fd_array_cnt__fd_array_too_big();
+}
--
2.34.1
^ permalink raw reply related [flat|nested] 14+ messages in thread* Re: [PATCH v3 bpf-next 5/7] selftests/bpf: Add tests for fd_array_cnt
2024-11-29 13:28 ` [PATCH v3 bpf-next 5/7] selftests/bpf: Add tests for fd_array_cnt Anton Protopopov
@ 2024-12-03 2:37 ` Alexei Starovoitov
2024-12-03 10:25 ` Anton Protopopov
0 siblings, 1 reply; 14+ messages in thread
From: Alexei Starovoitov @ 2024-12-03 2:37 UTC (permalink / raw)
To: Anton Protopopov; +Cc: bpf
On Fri, Nov 29, 2024 at 5:29 AM Anton Protopopov <aspsk@isovalent.com> wrote:
>
> Add a new set of tests to test the new field in PROG_LOAD-related
> part of bpf_attr: fd_array_cnt.
>
> Add the following test cases:
>
> * fd_array_cnt/no-fd-array: program is loaded in a normal
> way, without any fd_array present
>
> * fd_array_cnt/fd-array-ok: pass two extra non-used maps,
> check that they're bound to the program
>
> * fd_array_cnt/fd-array-dup-input: pass a few extra maps,
> only two of which are unique
>
> * fd_array_cnt/fd-array-ref-maps-in-array: pass a map in
> fd_array which is also referenced from within the program
>
> * fd_array_cnt/fd-array-trash-input: pass array with some trash
>
> * fd_array_cnt/fd-array-with-holes: pass an array with holes (fd=0)
>
> * fd_array_cnt/fd-array-2big: pass too large array
>
> All the tests above are using the bpf(2) syscall directly,
> no libbpf involved.
>
> Signed-off-by: Anton Protopopov <aspsk@isovalent.com>
> ---
> kernel/bpf/verifier.c | 30 +-
> .../selftests/bpf/prog_tests/fd_array.c | 340 ++++++++++++++++++
> 2 files changed, 355 insertions(+), 15 deletions(-)
> create mode 100644 tools/testing/selftests/bpf/prog_tests/fd_array.c
>
> diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
> index d172f6974fd7..7102d85f580d 100644
> --- a/kernel/bpf/verifier.c
> +++ b/kernel/bpf/verifier.c
> @@ -22620,7 +22620,7 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr, __u3
> env->ops = bpf_verifier_ops[env->prog->type];
> ret = init_fd_array(env, attr, uattr);
> if (ret)
> - goto err_free_aux_data;
> + goto err_release_maps;
>
> env->allow_ptr_leaks = bpf_allow_ptr_leaks(env->prog->aux->token);
> env->allow_uninit_stack = bpf_allow_uninit_stack(env->prog->aux->token);
> @@ -22773,11 +22773,11 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr, __u3
> copy_to_bpfptr_offset(uattr, offsetof(union bpf_attr, log_true_size),
> &log_true_size, sizeof(log_true_size))) {
> ret = -EFAULT;
> - goto err_release_maps;
> + goto err_ext;
> }
>
> if (ret)
> - goto err_release_maps;
> + goto err_ext;
>
> if (env->used_map_cnt) {
> /* if program passed verifier, update used_maps in bpf_prog_info */
> @@ -22787,7 +22787,7 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr, __u3
>
> if (!env->prog->aux->used_maps) {
> ret = -ENOMEM;
> - goto err_release_maps;
> + goto err_ext;
> }
>
> memcpy(env->prog->aux->used_maps, env->used_maps,
> @@ -22801,7 +22801,7 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr, __u3
> GFP_KERNEL);
> if (!env->prog->aux->used_btfs) {
> ret = -ENOMEM;
> - goto err_release_maps;
> + goto err_ext;
> }
>
> memcpy(env->prog->aux->used_btfs, env->used_btfs,
> @@ -22817,15 +22817,7 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr, __u3
>
> adjust_btf_func(env);
>
> -err_release_maps:
> - if (!env->prog->aux->used_maps)
> - /* if we didn't copy map pointers into bpf_prog_info, release
> - * them now. Otherwise free_used_maps() will release them.
> - */
> - release_maps(env);
> - if (!env->prog->aux->used_btfs)
> - release_btfs(env);
> -
> +err_ext:
> /* extension progs temporarily inherit the attach_type of their targets
> for verification purposes, so set it back to zero before returning
> */
> @@ -22838,7 +22830,15 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr, __u3
> err_unlock:
> if (!is_priv)
> mutex_unlock(&bpf_verifier_lock);
> -err_free_aux_data:
> +err_release_maps:
> + if (!env->prog->aux->used_maps)
> + /* if we didn't copy map pointers into bpf_prog_info, release
> + * them now. Otherwise free_used_maps() will release them.
> + */
> + release_maps(env);
> + if (!env->prog->aux->used_btfs)
> + release_btfs(env);
> +
> vfree(env->insn_aux_data);
> kvfree(env->insn_hist);
verifier.c hunk shouldn't be mixed with the selftests.
Looks like it should be in patch 3?
Not sure what it does though.
^ permalink raw reply [flat|nested] 14+ messages in thread* Re: [PATCH v3 bpf-next 5/7] selftests/bpf: Add tests for fd_array_cnt
2024-12-03 2:37 ` Alexei Starovoitov
@ 2024-12-03 10:25 ` Anton Protopopov
0 siblings, 0 replies; 14+ messages in thread
From: Anton Protopopov @ 2024-12-03 10:25 UTC (permalink / raw)
To: Alexei Starovoitov; +Cc: bpf
On 24/12/02 06:37PM, Alexei Starovoitov wrote:
> On Fri, Nov 29, 2024 at 5:29 AM Anton Protopopov <aspsk@isovalent.com> wrote:
> >
> > Add a new set of tests to test the new field in PROG_LOAD-related
> > part of bpf_attr: fd_array_cnt.
> >
> > Add the following test cases:
> >
> > * fd_array_cnt/no-fd-array: program is loaded in a normal
> > way, without any fd_array present
> >
> > * fd_array_cnt/fd-array-ok: pass two extra non-used maps,
> > check that they're bound to the program
> >
> > * fd_array_cnt/fd-array-dup-input: pass a few extra maps,
> > only two of which are unique
> >
> > * fd_array_cnt/fd-array-ref-maps-in-array: pass a map in
> > fd_array which is also referenced from within the program
> >
> > * fd_array_cnt/fd-array-trash-input: pass array with some trash
> >
> > * fd_array_cnt/fd-array-with-holes: pass an array with holes (fd=0)
> >
> > * fd_array_cnt/fd-array-2big: pass too large array
> >
> > All the tests above are using the bpf(2) syscall directly,
> > no libbpf involved.
> >
> > Signed-off-by: Anton Protopopov <aspsk@isovalent.com>
> > ---
> > kernel/bpf/verifier.c | 30 +-
> > .../selftests/bpf/prog_tests/fd_array.c | 340 ++++++++++++++++++
> > 2 files changed, 355 insertions(+), 15 deletions(-)
> > create mode 100644 tools/testing/selftests/bpf/prog_tests/fd_array.c
> >
> > diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
> > index d172f6974fd7..7102d85f580d 100644
> > --- a/kernel/bpf/verifier.c
> > +++ b/kernel/bpf/verifier.c
> > @@ -22620,7 +22620,7 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr, __u3
> > env->ops = bpf_verifier_ops[env->prog->type];
> > ret = init_fd_array(env, attr, uattr);
> > if (ret)
> > - goto err_free_aux_data;
> > + goto err_release_maps;
> >
> > env->allow_ptr_leaks = bpf_allow_ptr_leaks(env->prog->aux->token);
> > env->allow_uninit_stack = bpf_allow_uninit_stack(env->prog->aux->token);
> > @@ -22773,11 +22773,11 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr, __u3
> > copy_to_bpfptr_offset(uattr, offsetof(union bpf_attr, log_true_size),
> > &log_true_size, sizeof(log_true_size))) {
> > ret = -EFAULT;
> > - goto err_release_maps;
> > + goto err_ext;
> > }
> >
> > if (ret)
> > - goto err_release_maps;
> > + goto err_ext;
> >
> > if (env->used_map_cnt) {
> > /* if program passed verifier, update used_maps in bpf_prog_info */
> > @@ -22787,7 +22787,7 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr, __u3
> >
> > if (!env->prog->aux->used_maps) {
> > ret = -ENOMEM;
> > - goto err_release_maps;
> > + goto err_ext;
> > }
> >
> > memcpy(env->prog->aux->used_maps, env->used_maps,
> > @@ -22801,7 +22801,7 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr, __u3
> > GFP_KERNEL);
> > if (!env->prog->aux->used_btfs) {
> > ret = -ENOMEM;
> > - goto err_release_maps;
> > + goto err_ext;
> > }
> >
> > memcpy(env->prog->aux->used_btfs, env->used_btfs,
> > @@ -22817,15 +22817,7 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr, __u3
> >
> > adjust_btf_func(env);
> >
> > -err_release_maps:
> > - if (!env->prog->aux->used_maps)
> > - /* if we didn't copy map pointers into bpf_prog_info, release
> > - * them now. Otherwise free_used_maps() will release them.
> > - */
> > - release_maps(env);
> > - if (!env->prog->aux->used_btfs)
> > - release_btfs(env);
> > -
> > +err_ext:
> > /* extension progs temporarily inherit the attach_type of their targets
> > for verification purposes, so set it back to zero before returning
> > */
> > @@ -22838,7 +22830,15 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr, __u3
> > err_unlock:
> > if (!is_priv)
> > mutex_unlock(&bpf_verifier_lock);
> > -err_free_aux_data:
> > +err_release_maps:
> > + if (!env->prog->aux->used_maps)
> > + /* if we didn't copy map pointers into bpf_prog_info, release
> > + * them now. Otherwise free_used_maps() will release them.
> > + */
> > + release_maps(env);
> > + if (!env->prog->aux->used_btfs)
> > + release_btfs(env);
> > +
> > vfree(env->insn_aux_data);
> > kvfree(env->insn_hist);
>
> verifier.c hunk shouldn't be mixed with the selftests.
>
> Looks like it should be in patch 3?
Sorry, wrong `rebase -i`
> Not sure what it does though.
Yeah, thanks. I've simplified this part of Patch 3,
this diff will not appear in v4
^ permalink raw reply [flat|nested] 14+ messages in thread
* [PATCH v3 bpf-next 6/7] bpf: fix potential error return
2024-11-29 13:28 [PATCH v3 bpf-next 0/7] Add fd_array_cnt attribute for BPF_PROG_LOAD Anton Protopopov
` (4 preceding siblings ...)
2024-11-29 13:28 ` [PATCH v3 bpf-next 5/7] selftests/bpf: Add tests for fd_array_cnt Anton Protopopov
@ 2024-11-29 13:28 ` Anton Protopopov
2024-11-29 13:28 ` [PATCH v3 bpf-next 7/7] selftest/bpf: replace magic constants by macros Anton Protopopov
6 siblings, 0 replies; 14+ messages in thread
From: Anton Protopopov @ 2024-11-29 13:28 UTC (permalink / raw)
To: bpf; +Cc: Anton Protopopov, Jiri Olsa
The bpf_remove_insns() function returns WARN_ON_ONCE(error), where
error is a result of bpf_adj_branches(), and thus should be always 0
However, if for any reason it is not 0, then it will be converted to
boolean by WARN_ON_ONCE and returned to user space as 1, not an actual
error value. Fix this by returning the original err after the WARN check.
Signed-off-by: Anton Protopopov <aspsk@isovalent.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
---
kernel/bpf/core.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 14d9288441f2..35a306ce9d94 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -539,6 +539,8 @@ struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
int bpf_remove_insns(struct bpf_prog *prog, u32 off, u32 cnt)
{
+ int err;
+
/* Branch offsets can't overflow when program is shrinking, no need
* to call bpf_adj_branches(..., true) here
*/
@@ -546,7 +548,9 @@ int bpf_remove_insns(struct bpf_prog *prog, u32 off, u32 cnt)
sizeof(struct bpf_insn) * (prog->len - off - cnt));
prog->len -= cnt;
- return WARN_ON_ONCE(bpf_adj_branches(prog, off, off + cnt, off, false));
+ err = bpf_adj_branches(prog, off, off + cnt, off, false);
+ WARN_ON_ONCE(err);
+ return err;
}
static void bpf_prog_kallsyms_del_subprogs(struct bpf_prog *fp)
--
2.34.1
^ permalink raw reply related [flat|nested] 14+ messages in thread* [PATCH v3 bpf-next 7/7] selftest/bpf: replace magic constants by macros
2024-11-29 13:28 [PATCH v3 bpf-next 0/7] Add fd_array_cnt attribute for BPF_PROG_LOAD Anton Protopopov
` (5 preceding siblings ...)
2024-11-29 13:28 ` [PATCH v3 bpf-next 6/7] bpf: fix potential error return Anton Protopopov
@ 2024-11-29 13:28 ` Anton Protopopov
6 siblings, 0 replies; 14+ messages in thread
From: Anton Protopopov @ 2024-11-29 13:28 UTC (permalink / raw)
To: bpf; +Cc: Anton Protopopov, Eduard Zingerman
Replace magic constants in a BTF structure initialization code by
proper macros, as is done in other similar selftests.
Signed-off-by: Anton Protopopov <aspsk@isovalent.com>
Suggested-by: Eduard Zingerman <eddyz87@gmail.com>
---
tools/testing/selftests/bpf/progs/syscall.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/tools/testing/selftests/bpf/progs/syscall.c b/tools/testing/selftests/bpf/progs/syscall.c
index 0f4dfb770c32..b698cc62a371 100644
--- a/tools/testing/selftests/bpf/progs/syscall.c
+++ b/tools/testing/selftests/bpf/progs/syscall.c
@@ -76,9 +76,9 @@ static int btf_load(void)
.magic = BTF_MAGIC,
.version = BTF_VERSION,
.hdr_len = sizeof(struct btf_header),
- .type_len = sizeof(__u32) * 8,
- .str_off = sizeof(__u32) * 8,
- .str_len = sizeof(__u32),
+ .type_len = sizeof(raw_btf.types),
+ .str_off = offsetof(struct btf_blob, str) - offsetof(struct btf_blob, types),
+ .str_len = sizeof(raw_btf.str),
},
.types = {
/* long */
--
2.34.1
^ permalink raw reply related [flat|nested] 14+ messages in thread