[PATCH bpf-next v4 00/18] bpf: Add 64bit enum value support

[PATCH bpf-next v4 00/18] bpf: Add 64bit enum value support

[Yonghong Song]

Currently, btf only supports upto 32bit enum value with BTF_KIND_ENUM.
But in kernel, some enum has 64bit values, e.g., in uapi bpf.h, we have
  enum {
        BPF_F_INDEX_MASK                = 0xffffffffULL,
        BPF_F_CURRENT_CPU               = BPF_F_INDEX_MASK,
        BPF_F_CTXLEN_MASK               = (0xfffffULL << 32),
  };
With BTF_KIND_ENUM, the value for BPF_F_CTXLEN_MASK will be encoded
as 0 which is incorrect.

To solve this problem, BTF_KIND_ENUM64 is proposed in this patch set
to support enum 64bit values. Also, since sometimes there is a need
to generate C code from btf, e.g., vmlinux.h, btf kflag support
is also added for BTF_KIND_ENUM and BTF_KIND_ENUM64 to indicate
signedness, helping proper value printout.

Changelog:
  v3 -> v4:
    - rename btf_type_is_any_enum() to btf_is_any_enum() to favor
      consistency in libbpf.
    - fix sign extension issue in btf_dump_get_enum_value().
    - fix BPF_CORE_FIELD_SIGNED signedness issue in bpf_core_calc_field_relo().
  v2 -> v3:
    - Implement separate btf_equal_enum()/btf_equal_enum64() and
      btf_compat_enum()/btf_compat_enum64().
    - Add a new enum64 placeholder type dynamicly for enum64 sanitization.
    - For bpftool output and unit selftest, printed out signed/unsigned
      encoding as well.
    - fix some issues with BTF_KIND_ENUM is doc and clarified sign extension
      rules for enum values.
  v1 -> v2:
    - Changed kflag default from signed to unsigned
    - Fixed sanitization issue
    - Broke down libbpf related patches for easier review
    - Added more tests
    - More code refactorization
    - Corresponding llvm patch (to support enum64) is also updated

Yonghong Song (18):
  bpf: Add btf enum64 support
  libbpf: Permit 64bit relocation value
  libbpf: Fix an error in 64bit relocation value computation
  libbpf: Refactor btf__add_enum() for future code sharing
  libbpf: Add enum64 parsing and new enum64 public API
  libbpf: Add enum64 deduplication support
  libbpf: Add enum64 support for btf_dump
  libbpf: Add enum64 sanitization
  libbpf: Add enum64 support for bpf linking
  libbpf: Add enum64 relocation support
  bpftool: Add btf enum64 support
  selftests/bpf: Fix selftests failure
  selftests/bpf: Test new enum kflag and enum64 API functions
  selftests/bpf: Add BTF_KIND_ENUM64 unit tests
  selftests/bpf: Test BTF_KIND_ENUM64 for deduplication
  selftests/bpf: Add a test for enum64 value relocations
  selftests/bpf: Clarify llvm dependency with possible selftest failures
  docs/bpf: Update documentation for BTF_KIND_ENUM64 support

 Documentation/bpf/btf.rst                     |  43 +++-
 include/linux/btf.h                           |  28 +++
 include/uapi/linux/btf.h                      |  17 +-
 kernel/bpf/btf.c                              | 142 +++++++++++--
 kernel/bpf/verifier.c                         |   2 +-
 tools/bpf/bpftool/btf.c                       |  57 ++++-
 tools/bpf/bpftool/btf_dumper.c                |  29 +++
 tools/bpf/bpftool/gen.c                       |   1 +
 tools/include/uapi/linux/btf.h                |  17 +-
 tools/lib/bpf/btf.c                           | 201 ++++++++++++++++--
 tools/lib/bpf/btf.h                           |  32 ++-
 tools/lib/bpf/btf_dump.c                      | 137 +++++++++---
 tools/lib/bpf/libbpf.c                        |  63 +++++-
 tools/lib/bpf/libbpf.map                      |   2 +
 tools/lib/bpf/libbpf_internal.h               |   2 +
 tools/lib/bpf/linker.c                        |   2 +
 tools/lib/bpf/relo_core.c                     | 105 +++++----
 tools/lib/bpf/relo_core.h                     |   4 +-
 tools/testing/selftests/bpf/README.rst        |  18 ++
 tools/testing/selftests/bpf/btf_helpers.c     |  25 ++-
 tools/testing/selftests/bpf/prog_tests/btf.c  | 153 +++++++++++--
 .../selftests/bpf/prog_tests/btf_write.c      | 126 ++++++++---
 .../selftests/bpf/prog_tests/core_reloc.c     |  58 +++++
 .../bpf/progs/btf__core_reloc_enum64val.c     |   3 +
 .../progs/btf__core_reloc_enum64val___diff.c  |   3 +
 .../btf__core_reloc_enum64val___err_missing.c |   3 +
 ...btf__core_reloc_enum64val___val3_missing.c |   3 +
 .../selftests/bpf/progs/core_reloc_types.h    |  78 +++++++
 .../bpf/progs/test_core_reloc_enum64val.c     |  70 ++++++
 tools/testing/selftests/bpf/test_btf.h        |   1 +
 30 files changed, 1235 insertions(+), 190 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_enum64val.c
 create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_enum64val___diff.c
 create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_enum64val___err_missing.c
 create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_enum64val___val3_missing.c
 create mode 100644 tools/testing/selftests/bpf/progs/test_core_reloc_enum64val.c

-- 
2.30.2

[PATCH bpf-next v4 01/18] bpf: Add btf enum64 support

[Yonghong Song]

Currently, BTF only supports upto 32bit enum value with BTF_KIND_ENUM.
But in kernel, some enum indeed has 64bit values, e.g.,
in uapi bpf.h, we have
  enum {
        BPF_F_INDEX_MASK                = 0xffffffffULL,
        BPF_F_CURRENT_CPU               = BPF_F_INDEX_MASK,
        BPF_F_CTXLEN_MASK               = (0xfffffULL << 32),
  };
In this case, BTF_KIND_ENUM will encode the value of BPF_F_CTXLEN_MASK
as 0, which certainly is incorrect.

This patch added a new btf kind, BTF_KIND_ENUM64, which permits
64bit value to cover the above use case. The BTF_KIND_ENUM64 has
the following three fields followed by the common type:
  struct bpf_enum64 {
    __u32 nume_off;
    __u32 val_lo32;
    __u32 val_hi32;
  };
Currently, btf type section has an alignment of 4 as all element types
are u32. Representing the value with __u64 will introduce a pad
for bpf_enum64 and may also introduce misalignment for the 64bit value.
Hence, two members of val_hi32 and val_lo32 are chosen to avoid these issues.

The kflag is also introduced for BTF_KIND_ENUM and BTF_KIND_ENUM64
to indicate whether the value is signed or unsigned. The kflag intends
to provide consistent output of BTF C fortmat with the original
source code. For example, the original BTF_KIND_ENUM bit value is 0xffffffff.
The format C has two choices, printing out 0xffffffff or -1 and current libbpf
prints out as unsigned value. But if the signedness is preserved in btf,
the value can be printed the same as the original source code.
The kflag value 0 means unsigned values, which is consistent to the default
by libbpf and should also cover most cases as well.

The new BTF_KIND_ENUM64 is intended to support the enum value represented as
64bit value. But it can represent all BTF_KIND_ENUM values as well.
The compiler ([1]) and pahole will generate BTF_KIND_ENUM64 only if the value has
to be represented with 64 bits.

In addition, a static inline function btf_kind_core_compat() is introduced which
will be used later when libbpf relo_core.c changed. Here the kernel shares the
same relo_core.c with libbpf.

  [1] https://reviews.llvm.org/D124641

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Yonghong Song <yhs@fb.com>
---
 include/linux/btf.h            |  28 +++++++
 include/uapi/linux/btf.h       |  17 +++-
 kernel/bpf/btf.c               | 142 +++++++++++++++++++++++++++++----
 kernel/bpf/verifier.c          |   2 +-
 tools/include/uapi/linux/btf.h |  17 +++-
 5 files changed, 185 insertions(+), 21 deletions(-)

diff --git a/include/linux/btf.h b/include/linux/btf.h
index 2611cea2c2b6..1bfed7fa0428 100644
--- a/include/linux/btf.h
+++ b/include/linux/btf.h
@@ -177,6 +177,19 @@ static inline bool btf_type_is_enum(const struct btf_type *t)
 	return BTF_INFO_KIND(t->info) == BTF_KIND_ENUM;
 }
 
+static inline bool btf_is_any_enum(const struct btf_type *t)
+{
+	return BTF_INFO_KIND(t->info) == BTF_KIND_ENUM ||
+	       BTF_INFO_KIND(t->info) == BTF_KIND_ENUM64;
+}
+
+static inline bool btf_kind_core_compat(const struct btf_type *t1,
+					const struct btf_type *t2)
+{
+	return BTF_INFO_KIND(t1->info) == BTF_INFO_KIND(t2->info) ||
+	       (btf_is_any_enum(t1) && btf_is_any_enum(t2));
+}
+
 static inline bool str_is_empty(const char *s)
 {
 	return !s || !s[0];
@@ -192,6 +205,16 @@ static inline bool btf_is_enum(const struct btf_type *t)
 	return btf_kind(t) == BTF_KIND_ENUM;
 }
 
+static inline bool btf_is_enum64(const struct btf_type *t)
+{
+	return btf_kind(t) == BTF_KIND_ENUM64;
+}
+
+static inline u64 btf_enum64_value(const struct btf_enum64 *e)
+{
+	return ((u64)e->val_hi32 << 32) | e->val_lo32;
+}
+
 static inline bool btf_is_composite(const struct btf_type *t)
 {
 	u16 kind = btf_kind(t);
@@ -332,6 +355,11 @@ static inline struct btf_enum *btf_enum(const struct btf_type *t)
 	return (struct btf_enum *)(t + 1);
 }
 
+static inline struct btf_enum64 *btf_enum64(const struct btf_type *t)
+{
+	return (struct btf_enum64 *)(t + 1);
+}
+
 static inline const struct btf_var_secinfo *btf_type_var_secinfo(
 		const struct btf_type *t)
 {
diff --git a/include/uapi/linux/btf.h b/include/uapi/linux/btf.h
index a9162a6c0284..ec1798b6d3ff 100644
--- a/include/uapi/linux/btf.h
+++ b/include/uapi/linux/btf.h
@@ -36,10 +36,10 @@ struct btf_type {
 	 * bits 24-28: kind (e.g. int, ptr, array...etc)
 	 * bits 29-30: unused
 	 * bit     31: kind_flag, currently used by
-	 *             struct, union and fwd
+	 *             struct, union, enum, fwd and enum64
 	 */
 	__u32 info;
-	/* "size" is used by INT, ENUM, STRUCT, UNION and DATASEC.
+	/* "size" is used by INT, ENUM, STRUCT, UNION, DATASEC and ENUM64.
 	 * "size" tells the size of the type it is describing.
 	 *
 	 * "type" is used by PTR, TYPEDEF, VOLATILE, CONST, RESTRICT,
@@ -63,7 +63,7 @@ enum {
 	BTF_KIND_ARRAY		= 3,	/* Array	*/
 	BTF_KIND_STRUCT		= 4,	/* Struct	*/
 	BTF_KIND_UNION		= 5,	/* Union	*/
-	BTF_KIND_ENUM		= 6,	/* Enumeration	*/
+	BTF_KIND_ENUM		= 6,	/* Enumeration up to 32-bit values */
 	BTF_KIND_FWD		= 7,	/* Forward	*/
 	BTF_KIND_TYPEDEF	= 8,	/* Typedef	*/
 	BTF_KIND_VOLATILE	= 9,	/* Volatile	*/
@@ -76,6 +76,7 @@ enum {
 	BTF_KIND_FLOAT		= 16,	/* Floating point	*/
 	BTF_KIND_DECL_TAG	= 17,	/* Decl Tag */
 	BTF_KIND_TYPE_TAG	= 18,	/* Type Tag */
+	BTF_KIND_ENUM64		= 19,	/* Enumeration up to 64-bit values */
 
 	NR_BTF_KINDS,
 	BTF_KIND_MAX		= NR_BTF_KINDS - 1,
@@ -186,4 +187,14 @@ struct btf_decl_tag {
        __s32   component_idx;
 };
 
+/* BTF_KIND_ENUM64 is followed by multiple "struct btf_enum64".
+ * The exact number of btf_enum64 is stored in the vlen (of the
+ * info in "struct btf_type").
+ */
+struct btf_enum64 {
+	__u32	name_off;
+	__u32	val_lo32;
+	__u32	val_hi32;
+};
+
 #endif /* _UAPI__LINUX_BTF_H__ */
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 7bccaa4646e5..6c0d8480e15c 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -309,6 +309,7 @@ static const char * const btf_kind_str[NR_BTF_KINDS] = {
 	[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)
@@ -666,6 +667,7 @@ static bool btf_type_has_size(const struct btf_type *t)
 	case BTF_KIND_ENUM:
 	case BTF_KIND_DATASEC:
 	case BTF_KIND_FLOAT:
+	case BTF_KIND_ENUM64:
 		return true;
 	}
 
@@ -711,6 +713,11 @@ static 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)];
@@ -1019,6 +1026,7 @@ static const char *btf_show_name(struct btf_show *show)
 			parens = "{";
 		break;
 	case BTF_KIND_ENUM:
+	case BTF_KIND_ENUM64:
 		prefix = "enum";
 		break;
 	default:
@@ -1834,6 +1842,7 @@ __btf_resolve_size(const struct btf *btf, const struct btf_type *type,
 		case BTF_KIND_UNION:
 		case BTF_KIND_ENUM:
 		case BTF_KIND_FLOAT:
+		case BTF_KIND_ENUM64:
 			size = type->size;
 			goto resolved;
 
@@ -3670,6 +3679,7 @@ static s32 btf_enum_check_meta(struct btf_verifier_env *env,
 {
 	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;
 
@@ -3683,11 +3693,6 @@ static s32 btf_enum_check_meta(struct btf_verifier_env *env,
 		return -EINVAL;
 	}
 
-	if (btf_type_kflag(t)) {
-		btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
-		return -EINVAL;
-	}
-
 	if (t->size > 8 || !is_power_of_2(t->size)) {
 		btf_verifier_log_type(env, t, "Unexpected size");
 		return -EINVAL;
@@ -3718,7 +3723,8 @@ static s32 btf_enum_check_meta(struct btf_verifier_env *env,
 
 		if (env->log.level == BPF_LOG_KERNEL)
 			continue;
-		btf_verifier_log(env, "\t%s val=%d\n",
+		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);
 	}
@@ -3759,7 +3765,10 @@ static void btf_enum_show(const struct btf *btf, const struct btf_type *t,
 		return;
 	}
 
-	btf_show_type_value(show, "%d", v);
+	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);
 }
 
@@ -3772,6 +3781,109 @@ static struct btf_kind_operations enum_ops = {
 	.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 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)
@@ -4438,6 +4550,7 @@ static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS] = {
 	[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,
@@ -5299,7 +5412,7 @@ bool btf_ctx_access(int off, int size, enum bpf_access_type type,
 	/* skip modifiers */
 	while (btf_type_is_modifier(t))
 		t = btf_type_by_id(btf, t->type);
-	if (btf_type_is_small_int(t) || btf_type_is_enum(t))
+	if (btf_type_is_small_int(t) || btf_is_any_enum(t))
 		/* accessing a scalar */
 		return true;
 	if (!btf_type_is_ptr(t)) {
@@ -5763,7 +5876,7 @@ static int __get_type_size(struct btf *btf, u32 btf_id,
 	if (btf_type_is_ptr(t))
 		/* kernel size of pointer. Not BPF's size of pointer*/
 		return sizeof(void *);
-	if (btf_type_is_int(t) || btf_type_is_enum(t))
+	if (btf_type_is_int(t) || btf_is_any_enum(t))
 		return t->size;
 	*bad_type = t;
 	return -EINVAL;
@@ -5911,7 +6024,7 @@ static int btf_check_func_type_match(struct bpf_verifier_log *log,
 		 * to context only. And only global functions can be replaced.
 		 * Hence type check only those types.
 		 */
-		if (btf_type_is_int(t1) || btf_type_is_enum(t1))
+		if (btf_type_is_int(t1) || btf_is_any_enum(t1))
 			continue;
 		if (!btf_type_is_ptr(t1)) {
 			bpf_log(log,
@@ -6408,7 +6521,7 @@ int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog,
 	t = btf_type_by_id(btf, t->type);
 	while (btf_type_is_modifier(t))
 		t = btf_type_by_id(btf, t->type);
-	if (!btf_type_is_int(t) && !btf_type_is_enum(t)) {
+	if (!btf_type_is_int(t) && !btf_is_any_enum(t)) {
 		bpf_log(log,
 			"Global function %s() doesn't return scalar. Only those are supported.\n",
 			tname);
@@ -6423,7 +6536,7 @@ int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog,
 		t = btf_type_by_id(btf, args[i].type);
 		while (btf_type_is_modifier(t))
 			t = btf_type_by_id(btf, t->type);
-		if (btf_type_is_int(t) || btf_type_is_enum(t)) {
+		if (btf_type_is_int(t) || btf_is_any_enum(t)) {
 			reg->type = SCALAR_VALUE;
 			continue;
 		}
@@ -7335,6 +7448,7 @@ int __bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id,
 	case BTF_KIND_UNION:
 	case BTF_KIND_ENUM:
 	case BTF_KIND_FWD:
+	case BTF_KIND_ENUM64:
 		return 1;
 	case BTF_KIND_INT:
 		/* just reject deprecated bitfield-like integers; all other
@@ -7387,10 +7501,10 @@ int __bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id,
  * field-based relocations. This function assumes that root types were already
  * checked for name match. Beyond that initial root-level name check, names
  * are completely ignored. Compatibility rules are as follows:
- *   - any two STRUCTs/UNIONs/FWDs/ENUMs/INTs are considered compatible, but
+ *   - any two STRUCTs/UNIONs/FWDs/ENUMs/INTs/ENUM64s are considered compatible, but
  *     kind should match for local and target types (i.e., STRUCT is not
  *     compatible with UNION);
- *   - for ENUMs, the size is ignored;
+ *   - for ENUMs/ENUM64s, the size is ignored;
  *   - for INT, size and signedness are ignored;
  *   - for ARRAY, dimensionality is ignored, element types are checked for
  *     compatibility recursively;
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index aedac2ac02b9..2d2872682278 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -10901,7 +10901,7 @@ static int check_btf_func(struct bpf_verifier_env *env,
 			goto err_free;
 		ret_type = btf_type_skip_modifiers(btf, func_proto->type, NULL);
 		scalar_return =
-			btf_type_is_small_int(ret_type) || btf_type_is_enum(ret_type);
+			btf_type_is_small_int(ret_type) || btf_is_any_enum(ret_type);
 		if (i && !scalar_return && env->subprog_info[i].has_ld_abs) {
 			verbose(env, "LD_ABS is only allowed in functions that return 'int'.\n");
 			goto err_free;
diff --git a/tools/include/uapi/linux/btf.h b/tools/include/uapi/linux/btf.h
index a9162a6c0284..ec1798b6d3ff 100644
--- a/tools/include/uapi/linux/btf.h
+++ b/tools/include/uapi/linux/btf.h
@@ -36,10 +36,10 @@ struct btf_type {
 	 * bits 24-28: kind (e.g. int, ptr, array...etc)
 	 * bits 29-30: unused
 	 * bit     31: kind_flag, currently used by
-	 *             struct, union and fwd
+	 *             struct, union, enum, fwd and enum64
 	 */
 	__u32 info;
-	/* "size" is used by INT, ENUM, STRUCT, UNION and DATASEC.
+	/* "size" is used by INT, ENUM, STRUCT, UNION, DATASEC and ENUM64.
 	 * "size" tells the size of the type it is describing.
 	 *
 	 * "type" is used by PTR, TYPEDEF, VOLATILE, CONST, RESTRICT,
@@ -63,7 +63,7 @@ enum {
 	BTF_KIND_ARRAY		= 3,	/* Array	*/
 	BTF_KIND_STRUCT		= 4,	/* Struct	*/
 	BTF_KIND_UNION		= 5,	/* Union	*/
-	BTF_KIND_ENUM		= 6,	/* Enumeration	*/
+	BTF_KIND_ENUM		= 6,	/* Enumeration up to 32-bit values */
 	BTF_KIND_FWD		= 7,	/* Forward	*/
 	BTF_KIND_TYPEDEF	= 8,	/* Typedef	*/
 	BTF_KIND_VOLATILE	= 9,	/* Volatile	*/
@@ -76,6 +76,7 @@ enum {
 	BTF_KIND_FLOAT		= 16,	/* Floating point	*/
 	BTF_KIND_DECL_TAG	= 17,	/* Decl Tag */
 	BTF_KIND_TYPE_TAG	= 18,	/* Type Tag */
+	BTF_KIND_ENUM64		= 19,	/* Enumeration up to 64-bit values */
 
 	NR_BTF_KINDS,
 	BTF_KIND_MAX		= NR_BTF_KINDS - 1,
@@ -186,4 +187,14 @@ struct btf_decl_tag {
        __s32   component_idx;
 };
 
+/* BTF_KIND_ENUM64 is followed by multiple "struct btf_enum64".
+ * The exact number of btf_enum64 is stored in the vlen (of the
+ * info in "struct btf_type").
+ */
+struct btf_enum64 {
+	__u32	name_off;
+	__u32	val_lo32;
+	__u32	val_hi32;
+};
+
 #endif /* _UAPI__LINUX_BTF_H__ */
-- 
2.30.2

[PATCH bpf-next v4 02/18] libbpf: Permit 64bit relocation value

[Yonghong Song]

Currently, the libbpf limits the relocation value to be 32bit
since all current relocations have such a limit. But with
BTF_KIND_ENUM64 support, the enum value could be 64bit.
So let us permit 64bit relocation value in libbpf.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Yonghong Song <yhs@fb.com>
---
 tools/lib/bpf/relo_core.c | 49 +++++++++++++++++++++------------------
 tools/lib/bpf/relo_core.h |  4 ++--
 2 files changed, 29 insertions(+), 24 deletions(-)

diff --git a/tools/lib/bpf/relo_core.c b/tools/lib/bpf/relo_core.c
index d8ab4c61cb61..0dce5644877b 100644
--- a/tools/lib/bpf/relo_core.c
+++ b/tools/lib/bpf/relo_core.c
@@ -583,7 +583,7 @@ static int bpf_core_spec_match(struct bpf_core_spec *local_spec,
 static int bpf_core_calc_field_relo(const char *prog_name,
 				    const struct bpf_core_relo *relo,
 				    const struct bpf_core_spec *spec,
-				    __u32 *val, __u32 *field_sz, __u32 *type_id,
+				    __u64 *val, __u32 *field_sz, __u32 *type_id,
 				    bool *validate)
 {
 	const struct bpf_core_accessor *acc;
@@ -708,7 +708,7 @@ static int bpf_core_calc_field_relo(const char *prog_name,
 
 static int bpf_core_calc_type_relo(const struct bpf_core_relo *relo,
 				   const struct bpf_core_spec *spec,
-				   __u32 *val, bool *validate)
+				   __u64 *val, bool *validate)
 {
 	__s64 sz;
 
@@ -751,7 +751,7 @@ static int bpf_core_calc_type_relo(const struct bpf_core_relo *relo,
 
 static int bpf_core_calc_enumval_relo(const struct bpf_core_relo *relo,
 				      const struct bpf_core_spec *spec,
-				      __u32 *val)
+				      __u64 *val)
 {
 	const struct btf_type *t;
 	const struct btf_enum *e;
@@ -929,7 +929,7 @@ int bpf_core_patch_insn(const char *prog_name, struct bpf_insn *insn,
 			int insn_idx, const struct bpf_core_relo *relo,
 			int relo_idx, const struct bpf_core_relo_res *res)
 {
-	__u32 orig_val, new_val;
+	__u64 orig_val, new_val;
 	__u8 class;
 
 	class = BPF_CLASS(insn->code);
@@ -954,28 +954,30 @@ int bpf_core_patch_insn(const char *prog_name, struct bpf_insn *insn,
 		if (BPF_SRC(insn->code) != BPF_K)
 			return -EINVAL;
 		if (res->validate && insn->imm != orig_val) {
-			pr_warn("prog '%s': relo #%d: unexpected insn #%d (ALU/ALU64) value: got %u, exp %u -> %u\n",
+			pr_warn("prog '%s': relo #%d: unexpected insn #%d (ALU/ALU64) value: got %u, exp %llu -> %llu\n",
 				prog_name, relo_idx,
-				insn_idx, insn->imm, orig_val, new_val);
+				insn_idx, insn->imm, (unsigned long long)orig_val,
+				(unsigned long long)new_val);
 			return -EINVAL;
 		}
 		orig_val = insn->imm;
 		insn->imm = new_val;
-		pr_debug("prog '%s': relo #%d: patched insn #%d (ALU/ALU64) imm %u -> %u\n",
+		pr_debug("prog '%s': relo #%d: patched insn #%d (ALU/ALU64) imm %llu -> %llu\n",
 			 prog_name, relo_idx, insn_idx,
-			 orig_val, new_val);
+			 (unsigned long long)orig_val, (unsigned long long)new_val);
 		break;
 	case BPF_LDX:
 	case BPF_ST:
 	case BPF_STX:
 		if (res->validate && insn->off != orig_val) {
-			pr_warn("prog '%s': relo #%d: unexpected insn #%d (LDX/ST/STX) value: got %u, exp %u -> %u\n",
-				prog_name, relo_idx, insn_idx, insn->off, orig_val, new_val);
+			pr_warn("prog '%s': relo #%d: unexpected insn #%d (LDX/ST/STX) value: got %u, exp %llu -> %llu\n",
+				prog_name, relo_idx, insn_idx, insn->off, (unsigned long long)orig_val,
+				(unsigned long long)new_val);
 			return -EINVAL;
 		}
 		if (new_val > SHRT_MAX) {
-			pr_warn("prog '%s': relo #%d: insn #%d (LDX/ST/STX) value too big: %u\n",
-				prog_name, relo_idx, insn_idx, new_val);
+			pr_warn("prog '%s': relo #%d: insn #%d (LDX/ST/STX) value too big: %llu\n",
+				prog_name, relo_idx, insn_idx, (unsigned long long)new_val);
 			return -ERANGE;
 		}
 		if (res->fail_memsz_adjust) {
@@ -987,8 +989,9 @@ int bpf_core_patch_insn(const char *prog_name, struct bpf_insn *insn,
 
 		orig_val = insn->off;
 		insn->off = new_val;
-		pr_debug("prog '%s': relo #%d: patched insn #%d (LDX/ST/STX) off %u -> %u\n",
-			 prog_name, relo_idx, insn_idx, orig_val, new_val);
+		pr_debug("prog '%s': relo #%d: patched insn #%d (LDX/ST/STX) off %llu -> %llu\n",
+			 prog_name, relo_idx, insn_idx, (unsigned long long)orig_val,
+			 (unsigned long long)new_val);
 
 		if (res->new_sz != res->orig_sz) {
 			int insn_bytes_sz, insn_bpf_sz;
@@ -1026,18 +1029,18 @@ int bpf_core_patch_insn(const char *prog_name, struct bpf_insn *insn,
 
 		imm = insn[0].imm + ((__u64)insn[1].imm << 32);
 		if (res->validate && imm != orig_val) {
-			pr_warn("prog '%s': relo #%d: unexpected insn #%d (LDIMM64) value: got %llu, exp %u -> %u\n",
+			pr_warn("prog '%s': relo #%d: unexpected insn #%d (LDIMM64) value: got %llu, exp %llu -> %llu\n",
 				prog_name, relo_idx,
 				insn_idx, (unsigned long long)imm,
-				orig_val, new_val);
+				(unsigned long long)orig_val, (unsigned long long)new_val);
 			return -EINVAL;
 		}
 
 		insn[0].imm = new_val;
-		insn[1].imm = 0; /* currently only 32-bit values are supported */
-		pr_debug("prog '%s': relo #%d: patched insn #%d (LDIMM64) imm64 %llu -> %u\n",
+		insn[1].imm = new_val >> 32;
+		pr_debug("prog '%s': relo #%d: patched insn #%d (LDIMM64) imm64 %llu -> %llu\n",
 			 prog_name, relo_idx, insn_idx,
-			 (unsigned long long)imm, new_val);
+			 (unsigned long long)imm, (unsigned long long)new_val);
 		break;
 	}
 	default:
@@ -1261,10 +1264,12 @@ int bpf_core_calc_relo_insn(const char *prog_name,
 			 * decision and value, otherwise it's dangerous to
 			 * proceed due to ambiguity
 			 */
-			pr_warn("prog '%s': relo #%d: relocation decision ambiguity: %s %u != %s %u\n",
+			pr_warn("prog '%s': relo #%d: relocation decision ambiguity: %s %llu != %s %llu\n",
 				prog_name, relo_idx,
-				cand_res.poison ? "failure" : "success", cand_res.new_val,
-				targ_res->poison ? "failure" : "success", targ_res->new_val);
+				cand_res.poison ? "failure" : "success",
+				(unsigned long long)cand_res.new_val,
+				targ_res->poison ? "failure" : "success",
+				(unsigned long long)targ_res->new_val);
 			return -EINVAL;
 		}
 
diff --git a/tools/lib/bpf/relo_core.h b/tools/lib/bpf/relo_core.h
index 073039d8ca4f..7df0da082f2c 100644
--- a/tools/lib/bpf/relo_core.h
+++ b/tools/lib/bpf/relo_core.h
@@ -46,9 +46,9 @@ struct bpf_core_spec {
 
 struct bpf_core_relo_res {
 	/* expected value in the instruction, unless validate == false */
-	__u32 orig_val;
+	__u64 orig_val;
 	/* new value that needs to be patched up to */
-	__u32 new_val;
+	__u64 new_val;
 	/* relocation unsuccessful, poison instruction, but don't fail load */
 	bool poison;
 	/* some relocations can't be validated against orig_val */
-- 
2.30.2

[PATCH bpf-next v4 03/18] libbpf: Fix an error in 64bit relocation value computation

[Yonghong Song]

Currently, the 64bit relocation value in the instruction
is computed as follows:
  __u64 imm = insn[0].imm + ((__u64)insn[1].imm << 32)

Suppose insn[0].imm = -1 (0xffffffff) and insn[1].imm = 1.
With the above computation, insn[0].imm will first sign-extend
to 64bit -1 (0xffffffffFFFFFFFF) and then add 0x1FFFFFFFF,
producing incorrect value 0xFFFFFFFF. The correct value
should be 0x1FFFFFFFF.

Changing insn[0].imm to __u32 first will prevent 64bit sign
extension and fix the issue. Merging high and low 32bit values
also changed from '+' to '|' to be consistent with other
similar occurences in kernel and libbpf.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Dave Marchevsky <davemarchevsky@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
---
 tools/lib/bpf/relo_core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/lib/bpf/relo_core.c b/tools/lib/bpf/relo_core.c
index 0dce5644877b..073a54ed7432 100644
--- a/tools/lib/bpf/relo_core.c
+++ b/tools/lib/bpf/relo_core.c
@@ -1027,7 +1027,7 @@ int bpf_core_patch_insn(const char *prog_name, struct bpf_insn *insn,
 			return -EINVAL;
 		}
 
-		imm = insn[0].imm + ((__u64)insn[1].imm << 32);
+		imm = (__u32)insn[0].imm | ((__u64)insn[1].imm << 32);
 		if (res->validate && imm != orig_val) {
 			pr_warn("prog '%s': relo #%d: unexpected insn #%d (LDIMM64) value: got %llu, exp %llu -> %llu\n",
 				prog_name, relo_idx,
-- 
2.30.2

[PATCH bpf-next v4 04/18] libbpf: Refactor btf__add_enum() for future code sharing

[Yonghong Song]

Refactor btf__add_enum() function to create a separate
function btf_add_enum_common() so later the common function
can be used to add enum64 btf type. There is no functionality
change for this patch.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Yonghong Song <yhs@fb.com>
---
 tools/lib/bpf/btf.c | 36 +++++++++++++++++++++---------------
 1 file changed, 21 insertions(+), 15 deletions(-)

diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index 2e9c23bcdc67..1972d0c65e0c 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -2129,20 +2129,8 @@ int btf__add_field(struct btf *btf, const char *name, int type_id,
 	return 0;
 }
 
-/*
- * Append new BTF_KIND_ENUM type with:
- *   - *name* - name of the enum, can be NULL or empty for anonymous enums;
- *   - *byte_sz* - size of the enum, in bytes.
- *
- * Enum initially has no enum values in it (and corresponds to enum forward
- * declaration). Enumerator values can be added by btf__add_enum_value()
- * immediately after btf__add_enum() succeeds.
- *
- * Returns:
- *   - >0, type ID of newly added BTF type;
- *   - <0, on error.
- */
-int btf__add_enum(struct btf *btf, const char *name, __u32 byte_sz)
+static int btf_add_enum_common(struct btf *btf, const char *name, __u32 byte_sz,
+			       bool is_signed, __u8 kind)
 {
 	struct btf_type *t;
 	int sz, name_off = 0;
@@ -2167,12 +2155,30 @@ int btf__add_enum(struct btf *btf, const char *name, __u32 byte_sz)
 
 	/* start out with vlen=0; it will be adjusted when adding enum values */
 	t->name_off = name_off;
-	t->info = btf_type_info(BTF_KIND_ENUM, 0, 0);
+	t->info = btf_type_info(kind, 0, is_signed);
 	t->size = byte_sz;
 
 	return btf_commit_type(btf, sz);
 }
 
+/*
+ * Append new BTF_KIND_ENUM type with:
+ *   - *name* - name of the enum, can be NULL or empty for anonymous enums;
+ *   - *byte_sz* - size of the enum, in bytes.
+ *
+ * Enum initially has no enum values in it (and corresponds to enum forward
+ * declaration). Enumerator values can be added by btf__add_enum_value()
+ * immediately after btf__add_enum() succeeds.
+ *
+ * Returns:
+ *   - >0, type ID of newly added BTF type;
+ *   - <0, on error.
+ */
+int btf__add_enum(struct btf *btf, const char *name, __u32 byte_sz)
+{
+	return btf_add_enum_common(btf, name, byte_sz, false, BTF_KIND_ENUM);
+}
+
 /*
  * Append new enum value for the current ENUM type with:
  *   - *name* - name of the enumerator value, can't be NULL or empty;
-- 
2.30.2

[PATCH bpf-next v4 05/18] libbpf: Add enum64 parsing and new enum64 public API

[Yonghong Song]

Add enum64 parsing support and two new enum64 public APIs:
  btf__add_enum64
  btf__add_enum64_value

Also add support of signedness for BTF_KIND_ENUM. The
BTF_KIND_ENUM API signatures are not changed. The signedness
will be changed from unsigned to signed if btf__add_enum_value()
finds any negative values.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Yonghong Song <yhs@fb.com>
---
 tools/lib/bpf/btf.c      | 103 +++++++++++++++++++++++++++++++++++++++
 tools/lib/bpf/btf.h      |  12 +++++
 tools/lib/bpf/libbpf.map |   2 +
 3 files changed, 117 insertions(+)

diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index 1972d0c65e0c..8676efb2baba 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -305,6 +305,8 @@ static int btf_type_size(const struct btf_type *t)
 		return base_size + sizeof(__u32);
 	case BTF_KIND_ENUM:
 		return base_size + vlen * sizeof(struct btf_enum);
+	case BTF_KIND_ENUM64:
+		return base_size + vlen * sizeof(struct btf_enum64);
 	case BTF_KIND_ARRAY:
 		return base_size + sizeof(struct btf_array);
 	case BTF_KIND_STRUCT:
@@ -334,6 +336,7 @@ static void btf_bswap_type_base(struct btf_type *t)
 static int btf_bswap_type_rest(struct btf_type *t)
 {
 	struct btf_var_secinfo *v;
+	struct btf_enum64 *e64;
 	struct btf_member *m;
 	struct btf_array *a;
 	struct btf_param *p;
@@ -361,6 +364,13 @@ static int btf_bswap_type_rest(struct btf_type *t)
 			e->val = bswap_32(e->val);
 		}
 		return 0;
+	case BTF_KIND_ENUM64:
+		for (i = 0, e64 = btf_enum64(t); i < vlen; i++, e64++) {
+			e64->name_off = bswap_32(e64->name_off);
+			e64->val_lo32 = bswap_32(e64->val_lo32);
+			e64->val_hi32 = bswap_32(e64->val_hi32);
+		}
+		return 0;
 	case BTF_KIND_ARRAY:
 		a = btf_array(t);
 		a->type = bswap_32(a->type);
@@ -611,6 +621,7 @@ __s64 btf__resolve_size(const struct btf *btf, __u32 type_id)
 		case BTF_KIND_STRUCT:
 		case BTF_KIND_UNION:
 		case BTF_KIND_ENUM:
+		case BTF_KIND_ENUM64:
 		case BTF_KIND_DATASEC:
 		case BTF_KIND_FLOAT:
 			size = t->size;
@@ -658,6 +669,7 @@ int btf__align_of(const struct btf *btf, __u32 id)
 	switch (kind) {
 	case BTF_KIND_INT:
 	case BTF_KIND_ENUM:
+	case BTF_KIND_ENUM64:
 	case BTF_KIND_FLOAT:
 		return min(btf_ptr_sz(btf), (size_t)t->size);
 	case BTF_KIND_PTR:
@@ -2176,6 +2188,10 @@ static int btf_add_enum_common(struct btf *btf, const char *name, __u32 byte_sz,
  */
 int btf__add_enum(struct btf *btf, const char *name, __u32 byte_sz)
 {
+	/*
+	 * set the signedness to be unsigned, it will change to signed
+	 * if any later enumerator is negative.
+	 */
 	return btf_add_enum_common(btf, name, byte_sz, false, BTF_KIND_ENUM);
 }
 
@@ -2226,6 +2242,82 @@ int btf__add_enum_value(struct btf *btf, const char *name, __s64 value)
 	t = btf_last_type(btf);
 	btf_type_inc_vlen(t);
 
+	/* if negative value, set signedness to signed */
+	if (value < 0)
+		t->info = btf_type_info(btf_kind(t), btf_vlen(t), true);
+
+	btf->hdr->type_len += sz;
+	btf->hdr->str_off += sz;
+	return 0;
+}
+
+/*
+ * Append new BTF_KIND_ENUM64 type with:
+ *   - *name* - name of the enum, can be NULL or empty for anonymous enums;
+ *   - *byte_sz* - size of the enum, in bytes.
+ *   - *is_signed* - whether the enum values are signed or not;
+ *
+ * Enum initially has no enum values in it (and corresponds to enum forward
+ * declaration). Enumerator values can be added by btf__add_enum64_value()
+ * immediately after btf__add_enum64() succeeds.
+ *
+ * Returns:
+ *   - >0, type ID of newly added BTF type;
+ *   - <0, on error.
+ */
+int btf__add_enum64(struct btf *btf, const char *name, __u32 byte_sz,
+		    bool is_signed)
+{
+	return btf_add_enum_common(btf, name, byte_sz, is_signed,
+				   BTF_KIND_ENUM64);
+}
+
+/*
+ * Append new enum value for the current ENUM64 type with:
+ *   - *name* - name of the enumerator value, can't be NULL or empty;
+ *   - *value* - integer value corresponding to enum value *name*;
+ * Returns:
+ *   -  0, on success;
+ *   - <0, on error.
+ */
+int btf__add_enum64_value(struct btf *btf, const char *name, __u64 value)
+{
+	struct btf_enum64 *v;
+	struct btf_type *t;
+	int sz, name_off;
+
+	/* last type should be BTF_KIND_ENUM64 */
+	if (btf->nr_types == 0)
+		return libbpf_err(-EINVAL);
+	t = btf_last_type(btf);
+	if (!btf_is_enum64(t))
+		return libbpf_err(-EINVAL);
+
+	/* non-empty name */
+	if (!name || !name[0])
+		return libbpf_err(-EINVAL);
+
+	/* decompose and invalidate raw data */
+	if (btf_ensure_modifiable(btf))
+		return libbpf_err(-ENOMEM);
+
+	sz = sizeof(struct btf_enum64);
+	v = btf_add_type_mem(btf, sz);
+	if (!v)
+		return libbpf_err(-ENOMEM);
+
+	name_off = btf__add_str(btf, name);
+	if (name_off < 0)
+		return name_off;
+
+	v->name_off = name_off;
+	v->val_lo32 = (__u32)value;
+	v->val_hi32 = value >> 32;
+
+	/* update parent type's vlen */
+	t = btf_last_type(btf);
+	btf_type_inc_vlen(t);
+
 	btf->hdr->type_len += sz;
 	btf->hdr->str_off += sz;
 	return 0;
@@ -4737,6 +4829,7 @@ int btf_type_visit_type_ids(struct btf_type *t, type_id_visit_fn visit, void *ct
 	case BTF_KIND_INT:
 	case BTF_KIND_FLOAT:
 	case BTF_KIND_ENUM:
+	case BTF_KIND_ENUM64:
 		return 0;
 
 	case BTF_KIND_FWD:
@@ -4831,6 +4924,16 @@ int btf_type_visit_str_offs(struct btf_type *t, str_off_visit_fn visit, void *ct
 		}
 		break;
 	}
+	case BTF_KIND_ENUM64: {
+		struct btf_enum64 *m = btf_enum64(t);
+
+		for (i = 0, n = btf_vlen(t); i < n; i++, m++) {
+			err = visit(&m->name_off, ctx);
+			if (err)
+				return err;
+		}
+		break;
+	}
 	case BTF_KIND_FUNC_PROTO: {
 		struct btf_param *m = btf_params(t);
 
diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h
index 951ac7475794..a41463bf9060 100644
--- a/tools/lib/bpf/btf.h
+++ b/tools/lib/bpf/btf.h
@@ -215,6 +215,8 @@ LIBBPF_API int btf__add_field(struct btf *btf, const char *name, int field_type_
 /* enum construction APIs */
 LIBBPF_API int btf__add_enum(struct btf *btf, const char *name, __u32 bytes_sz);
 LIBBPF_API int btf__add_enum_value(struct btf *btf, const char *name, __s64 value);
+LIBBPF_API int btf__add_enum64(struct btf *btf, const char *name, __u32 bytes_sz, bool is_signed);
+LIBBPF_API int btf__add_enum64_value(struct btf *btf, const char *name, __u64 value);
 
 enum btf_fwd_kind {
 	BTF_FWD_STRUCT = 0,
@@ -454,6 +456,11 @@ static inline bool btf_is_enum(const struct btf_type *t)
 	return btf_kind(t) == BTF_KIND_ENUM;
 }
 
+static inline bool btf_is_enum64(const struct btf_type *t)
+{
+	return btf_kind(t) == BTF_KIND_ENUM64;
+}
+
 static inline bool btf_is_fwd(const struct btf_type *t)
 {
 	return btf_kind(t) == BTF_KIND_FWD;
@@ -549,6 +556,11 @@ static inline struct btf_enum *btf_enum(const struct btf_type *t)
 	return (struct btf_enum *)(t + 1);
 }
 
+static inline struct btf_enum64 *btf_enum64(const struct btf_type *t)
+{
+	return (struct btf_enum64 *)(t + 1);
+}
+
 static inline struct btf_member *btf_members(const struct btf_type *t)
 {
 	return (struct btf_member *)(t + 1);
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index 38e284ff057d..116a2a8ee7c2 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -462,6 +462,8 @@ LIBBPF_0.8.0 {
 
 LIBBPF_1.0.0 {
 	global:
+		btf__add_enum64;
+		btf__add_enum64_value;
 		libbpf_bpf_attach_type_str;
 		libbpf_bpf_link_type_str;
 		libbpf_bpf_map_type_str;
-- 
2.30.2

[PATCH bpf-next v4 06/18] libbpf: Add enum64 deduplication support

[Yonghong Song]

Add enum64 deduplication support. BTF_KIND_ENUM64 handling
is very similar to BTF_KIND_ENUM.

Signed-off-by: Yonghong Song <yhs@fb.com>
---
 tools/lib/bpf/btf.c | 62 +++++++++++++++++++++++++++++++++++++++++++--
 tools/lib/bpf/btf.h |  5 ++++
 2 files changed, 65 insertions(+), 2 deletions(-)

diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index 8676efb2baba..ae1520f7e1b0 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -3582,7 +3582,7 @@ static bool btf_equal_int_tag(struct btf_type *t1, struct btf_type *t2)
 	return info1 == info2;
 }
 
-/* Calculate type signature hash of ENUM. */
+/* Calculate type signature hash of ENUM/ENUM64. */
 static long btf_hash_enum(struct btf_type *t)
 {
 	long h;
@@ -3616,9 +3616,31 @@ static bool btf_equal_enum(struct btf_type *t1, struct btf_type *t2)
 	return true;
 }
 
+static bool btf_equal_enum64(struct btf_type *t1, struct btf_type *t2)
+{
+	const struct btf_enum64 *m1, *m2;
+	__u16 vlen;
+	int i;
+
+	if (!btf_equal_common(t1, t2))
+		return false;
+
+	vlen = btf_vlen(t1);
+	m1 = btf_enum64(t1);
+	m2 = btf_enum64(t2);
+	for (i = 0; i < vlen; i++) {
+		if (m1->name_off != m2->name_off || m1->val_lo32 != m2->val_lo32 ||
+		    m1->val_hi32 != m2->val_hi32)
+			return false;
+		m1++;
+		m2++;
+	}
+	return true;
+}
+
 static inline bool btf_is_enum_fwd(struct btf_type *t)
 {
-	return btf_is_enum(t) && btf_vlen(t) == 0;
+	return btf_is_any_enum(t) && btf_vlen(t) == 0;
 }
 
 static bool btf_compat_enum(struct btf_type *t1, struct btf_type *t2)
@@ -3631,6 +3653,17 @@ static bool btf_compat_enum(struct btf_type *t1, struct btf_type *t2)
 	       t1->size == t2->size;
 }
 
+static bool btf_compat_enum64(struct btf_type *t1, struct btf_type *t2)
+{
+	if (!btf_is_enum_fwd(t1) && !btf_is_enum_fwd(t2))
+		return btf_equal_enum64(t1, t2);
+
+	/* ignore vlen when comparing */
+	return t1->name_off == t2->name_off &&
+	       (t1->info & ~0xffff) == (t2->info & ~0xffff) &&
+	       t1->size == t2->size;
+}
+
 /*
  * Calculate type signature hash of STRUCT/UNION, ignoring referenced type IDs,
  * as referenced type IDs equivalence is established separately during type
@@ -3843,6 +3876,7 @@ static int btf_dedup_prep(struct btf_dedup *d)
 			h = btf_hash_int_decl_tag(t);
 			break;
 		case BTF_KIND_ENUM:
+		case BTF_KIND_ENUM64:
 			h = btf_hash_enum(t);
 			break;
 		case BTF_KIND_STRUCT:
@@ -3932,6 +3966,27 @@ static int btf_dedup_prim_type(struct btf_dedup *d, __u32 type_id)
 		}
 		break;
 
+	case BTF_KIND_ENUM64:
+		h = btf_hash_enum(t);
+		for_each_dedup_cand(d, hash_entry, h) {
+			cand_id = (__u32)(long)hash_entry->value;
+			cand = btf_type_by_id(d->btf, cand_id);
+			if (btf_equal_enum64(t, cand)) {
+				new_id = cand_id;
+				break;
+			}
+			if (btf_compat_enum64(t, cand)) {
+				if (btf_is_enum_fwd(t)) {
+					/* resolve fwd to full enum */
+					new_id = cand_id;
+					break;
+				}
+				/* resolve canonical enum fwd to full enum */
+				d->map[cand_id] = type_id;
+			}
+		}
+		break;
+
 	case BTF_KIND_FWD:
 	case BTF_KIND_FLOAT:
 		h = btf_hash_common(t);
@@ -4227,6 +4282,9 @@ static int btf_dedup_is_equiv(struct btf_dedup *d, __u32 cand_id,
 	case BTF_KIND_ENUM:
 		return btf_compat_enum(cand_type, canon_type);
 
+	case BTF_KIND_ENUM64:
+		return btf_compat_enum64(cand_type, canon_type);
+
 	case BTF_KIND_FWD:
 	case BTF_KIND_FLOAT:
 		return btf_equal_common(cand_type, canon_type);
diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h
index a41463bf9060..c7e8b1fdfe24 100644
--- a/tools/lib/bpf/btf.h
+++ b/tools/lib/bpf/btf.h
@@ -531,6 +531,11 @@ static inline bool btf_is_type_tag(const struct btf_type *t)
 	return btf_kind(t) == BTF_KIND_TYPE_TAG;
 }
 
+static inline bool btf_is_any_enum(const struct btf_type *t)
+{
+	return btf_is_enum(t) || btf_is_enum64(t);
+}
+
 static inline __u8 btf_int_encoding(const struct btf_type *t)
 {
 	return BTF_INT_ENCODING(*(__u32 *)(t + 1));
-- 
2.30.2

Re: [PATCH bpf-next v4 06/18] libbpf: Add enum64 deduplication support

[Andrii Nakryiko]

On Thu, Jun 2, 2022 at 6:59 PM Yonghong Song <yhs@fb.com> wrote:
>
> Add enum64 deduplication support. BTF_KIND_ENUM64 handling
> is very similar to BTF_KIND_ENUM.
>
> Signed-off-by: Yonghong Song <yhs@fb.com>
> ---

LGTM

Acked-by: Andrii Nakryiko <andrii@kernel.org>

>  tools/lib/bpf/btf.c | 62 +++++++++++++++++++++++++++++++++++++++++++--
>  tools/lib/bpf/btf.h |  5 ++++
>  2 files changed, 65 insertions(+), 2 deletions(-)
>

[...]

[PATCH bpf-next v4 07/18] libbpf: Add enum64 support for btf_dump

[Yonghong Song]

Add enum64 btf dumping support. For long long and unsigned long long
dump, suffixes 'LL' and 'ULL' are added to avoid compilation errors
in some cases.

Signed-off-by: Yonghong Song <yhs@fb.com>
---
 tools/lib/bpf/btf.h      |   5 ++
 tools/lib/bpf/btf_dump.c | 137 +++++++++++++++++++++++++++++----------
 2 files changed, 108 insertions(+), 34 deletions(-)

diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h
index c7e8b1fdfe24..dcb3f575a281 100644
--- a/tools/lib/bpf/btf.h
+++ b/tools/lib/bpf/btf.h
@@ -566,6 +566,11 @@ static inline struct btf_enum64 *btf_enum64(const struct btf_type *t)
 	return (struct btf_enum64 *)(t + 1);
 }
 
+static inline __u64 btf_enum64_value(const struct btf_enum64 *e)
+{
+	return ((__u64)e->val_hi32 << 32) | e->val_lo32;
+}
+
 static inline struct btf_member *btf_members(const struct btf_type *t)
 {
 	return (struct btf_member *)(t + 1);
diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c
index 6b1bc1f43728..f5275f819027 100644
--- a/tools/lib/bpf/btf_dump.c
+++ b/tools/lib/bpf/btf_dump.c
@@ -318,6 +318,7 @@ static int btf_dump_mark_referenced(struct btf_dump *d)
 		switch (btf_kind(t)) {
 		case BTF_KIND_INT:
 		case BTF_KIND_ENUM:
+		case BTF_KIND_ENUM64:
 		case BTF_KIND_FWD:
 		case BTF_KIND_FLOAT:
 			break;
@@ -538,6 +539,7 @@ static int btf_dump_order_type(struct btf_dump *d, __u32 id, bool through_ptr)
 		return 1;
 	}
 	case BTF_KIND_ENUM:
+	case BTF_KIND_ENUM64:
 	case BTF_KIND_FWD:
 		/*
 		 * non-anonymous or non-referenced enums are top-level
@@ -739,6 +741,7 @@ static void btf_dump_emit_type(struct btf_dump *d, __u32 id, __u32 cont_id)
 		tstate->emit_state = EMITTED;
 		break;
 	case BTF_KIND_ENUM:
+	case BTF_KIND_ENUM64:
 		if (top_level_def) {
 			btf_dump_emit_enum_def(d, id, t, 0);
 			btf_dump_printf(d, ";\n\n");
@@ -989,38 +992,81 @@ static void btf_dump_emit_enum_fwd(struct btf_dump *d, __u32 id,
 	btf_dump_printf(d, "enum %s", btf_dump_type_name(d, id));
 }
 
-static void btf_dump_emit_enum_def(struct btf_dump *d, __u32 id,
-				   const struct btf_type *t,
-				   int lvl)
+static void btf_dump_emit_enum32_val(struct btf_dump *d,
+				     const struct btf_type *t,
+				     int lvl, __u16 vlen)
 {
 	const struct btf_enum *v = btf_enum(t);
-	__u16 vlen = btf_vlen(t);
+	bool is_signed = btf_kflag(t);
+	const char *fmt_str;
 	const char *name;
 	size_t dup_cnt;
 	int i;
 
+	for (i = 0; i < vlen; i++, v++) {
+		name = btf_name_of(d, v->name_off);
+		/* enumerators share namespace with typedef idents */
+		dup_cnt = btf_dump_name_dups(d, d->ident_names, name);
+		if (dup_cnt > 1) {
+			fmt_str = is_signed ? "\n%s%s___%zd = %d," : "\n%s%s___%zd = %u,";
+			btf_dump_printf(d, fmt_str, pfx(lvl + 1), name, dup_cnt, v->val);
+		} else {
+			fmt_str = is_signed ? "\n%s%s = %d," : "\n%s%s = %u,";
+			btf_dump_printf(d, fmt_str, pfx(lvl + 1), name, v->val);
+		}
+	}
+}
+
+static void btf_dump_emit_enum64_val(struct btf_dump *d,
+				     const struct btf_type *t,
+				     int lvl, __u16 vlen)
+{
+	const struct btf_enum64 *v = btf_enum64(t);
+	bool is_signed = btf_kflag(t);
+	const char *fmt_str;
+	const char *name;
+	size_t dup_cnt;
+	__u64 val;
+	int i;
+
+	for (i = 0; i < vlen; i++, v++) {
+		name = btf_name_of(d, v->name_off);
+		dup_cnt = btf_dump_name_dups(d, d->ident_names, name);
+		val = btf_enum64_value(v);
+		if (dup_cnt > 1) {
+			fmt_str = is_signed ? "\n%s%s___%zd = %lldLL,"
+					    : "\n%s%s___%zd = %lluULL,";
+			btf_dump_printf(d, fmt_str,
+					pfx(lvl + 1), name, dup_cnt,
+					(unsigned long long)val);
+		} else {
+			fmt_str = is_signed ? "\n%s%s = %lldLL,"
+					    : "\n%s%s = %lluULL,";
+			btf_dump_printf(d, fmt_str,
+					pfx(lvl + 1), name,
+					(unsigned long long)val);
+		}
+	}
+}
+static void btf_dump_emit_enum_def(struct btf_dump *d, __u32 id,
+				   const struct btf_type *t,
+				   int lvl)
+{
+	__u16 vlen = btf_vlen(t);
+
 	btf_dump_printf(d, "enum%s%s",
 			t->name_off ? " " : "",
 			btf_dump_type_name(d, id));
 
-	if (vlen) {
-		btf_dump_printf(d, " {");
-		for (i = 0; i < vlen; i++, v++) {
-			name = btf_name_of(d, v->name_off);
-			/* enumerators share namespace with typedef idents */
-			dup_cnt = btf_dump_name_dups(d, d->ident_names, name);
-			if (dup_cnt > 1) {
-				btf_dump_printf(d, "\n%s%s___%zu = %u,",
-						pfx(lvl + 1), name, dup_cnt,
-						(__u32)v->val);
-			} else {
-				btf_dump_printf(d, "\n%s%s = %u,",
-						pfx(lvl + 1), name,
-						(__u32)v->val);
-			}
-		}
-		btf_dump_printf(d, "\n%s}", pfx(lvl));
-	}
+	if (!vlen)
+		return;
+
+	btf_dump_printf(d, " {");
+	if (btf_is_enum(t))
+		btf_dump_emit_enum32_val(d, t, lvl, vlen);
+	else
+		btf_dump_emit_enum64_val(d, t, lvl, vlen);
+	btf_dump_printf(d, "\n%s}", pfx(lvl));
 }
 
 static void btf_dump_emit_fwd_def(struct btf_dump *d, __u32 id,
@@ -1178,6 +1224,7 @@ static void btf_dump_emit_type_decl(struct btf_dump *d, __u32 id,
 			break;
 		case BTF_KIND_INT:
 		case BTF_KIND_ENUM:
+		case BTF_KIND_ENUM64:
 		case BTF_KIND_FWD:
 		case BTF_KIND_STRUCT:
 		case BTF_KIND_UNION:
@@ -1312,6 +1359,7 @@ static void btf_dump_emit_type_chain(struct btf_dump *d,
 				btf_dump_emit_struct_fwd(d, id, t);
 			break;
 		case BTF_KIND_ENUM:
+		case BTF_KIND_ENUM64:
 			btf_dump_emit_mods(d, decls);
 			/* inline anonymous enum */
 			if (t->name_off == 0 && !d->skip_anon_defs)
@@ -1988,7 +2036,8 @@ static int btf_dump_get_enum_value(struct btf_dump *d,
 				   __u32 id,
 				   __s64 *value)
 {
-	/* handle unaligned enum value */
+	bool is_signed = btf_kflag(t);
+
 	if (!ptr_is_aligned(d->btf, id, data)) {
 		__u64 val;
 		int err;
@@ -2005,13 +2054,13 @@ static int btf_dump_get_enum_value(struct btf_dump *d,
 		*value = *(__s64 *)data;
 		return 0;
 	case 4:
-		*value = *(__s32 *)data;
+		*value = is_signed ? *(__s32 *)data : *(__u32 *)data;
 		return 0;
 	case 2:
-		*value = *(__s16 *)data;
+		*value = is_signed ? *(__s16 *)data : *(__u16 *)data;
 		return 0;
 	case 1:
-		*value = *(__s8 *)data;
+		*value = is_signed ? *(__s8 *)data : *(__u8 *)data;
 		return 0;
 	default:
 		pr_warn("unexpected size %d for enum, id:[%u]\n", t->size, id);
@@ -2024,7 +2073,7 @@ static int btf_dump_enum_data(struct btf_dump *d,
 			      __u32 id,
 			      const void *data)
 {
-	const struct btf_enum *e;
+	bool is_signed;
 	__s64 value;
 	int i, err;
 
@@ -2032,14 +2081,31 @@ static int btf_dump_enum_data(struct btf_dump *d,
 	if (err)
 		return err;
 
-	for (i = 0, e = btf_enum(t); i < btf_vlen(t); i++, e++) {
-		if (value != e->val)
-			continue;
-		btf_dump_type_values(d, "%s", btf_name_of(d, e->name_off));
-		return 0;
-	}
+	is_signed = btf_kflag(t);
+	if (btf_is_enum(t)) {
+		const struct btf_enum *e;
+
+		for (i = 0, e = btf_enum(t); i < btf_vlen(t); i++, e++) {
+			if (value != e->val)
+				continue;
+			btf_dump_type_values(d, "%s", btf_name_of(d, e->name_off));
+			return 0;
+		}
 
-	btf_dump_type_values(d, "%d", value);
+		btf_dump_type_values(d, is_signed ? "%d" : "%u", value);
+	} else {
+		const struct btf_enum64 *e;
+
+		for (i = 0, e = btf_enum64(t); i < btf_vlen(t); i++, e++) {
+			if (value != btf_enum64_value(e))
+				continue;
+			btf_dump_type_values(d, "%s", btf_name_of(d, e->name_off));
+			return 0;
+		}
+
+		btf_dump_type_values(d, is_signed ? "%lldLL" : "%lluULL",
+				     (unsigned long long)value);
+	}
 	return 0;
 }
 
@@ -2099,6 +2165,7 @@ static int btf_dump_type_data_check_overflow(struct btf_dump *d,
 	case BTF_KIND_FLOAT:
 	case BTF_KIND_PTR:
 	case BTF_KIND_ENUM:
+	case BTF_KIND_ENUM64:
 		if (data + bits_offset / 8 + size > d->typed_dump->data_end)
 			return -E2BIG;
 		break;
@@ -2203,6 +2270,7 @@ static int btf_dump_type_data_check_zero(struct btf_dump *d,
 		return -ENODATA;
 	}
 	case BTF_KIND_ENUM:
+	case BTF_KIND_ENUM64:
 		err = btf_dump_get_enum_value(d, t, data, id, &value);
 		if (err)
 			return err;
@@ -2275,6 +2343,7 @@ static int btf_dump_dump_type_data(struct btf_dump *d,
 		err = btf_dump_struct_data(d, t, id, data);
 		break;
 	case BTF_KIND_ENUM:
+	case BTF_KIND_ENUM64:
 		/* handle bitfield and int enum values */
 		if (bit_sz) {
 			__u64 print_num;
-- 
2.30.2

Re: [PATCH bpf-next v4 07/18] libbpf: Add enum64 support for btf_dump

[Andrii Nakryiko]

On Thu, Jun 2, 2022 at 6:59 PM Yonghong Song <yhs@fb.com> wrote:
>
> Add enum64 btf dumping support. For long long and unsigned long long
> dump, suffixes 'LL' and 'ULL' are added to avoid compilation errors
> in some cases.
>
> Signed-off-by: Yonghong Song <yhs@fb.com>
> ---
>  tools/lib/bpf/btf.h      |   5 ++
>  tools/lib/bpf/btf_dump.c | 137 +++++++++++++++++++++++++++++----------
>  2 files changed, 108 insertions(+), 34 deletions(-)
>

LGTM, thanks for the fix!

Acked-by: Andrii Nakryiko <andrii@kernel.org>

> diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h
> index c7e8b1fdfe24..dcb3f575a281 100644
> --- a/tools/lib/bpf/btf.h
> +++ b/tools/lib/bpf/btf.h
> @@ -566,6 +566,11 @@ static inline struct btf_enum64 *btf_enum64(const struct btf_type *t)
>         return (struct btf_enum64 *)(t + 1);
>  }

[...]

[PATCH bpf-next v4 08/18] libbpf: Add enum64 sanitization

[Yonghong Song]

When old kernel does not support enum64 but user space btf
contains non-zero enum kflag or enum64, libbpf needs to
do proper sanitization so modified btf can be accepted
by the kernel.

Sanitization for enum kflag can be achieved by clearing
the kflag bit. For enum64, the type is replaced with an
union of integer member types and the integer member size
must be smaller than enum64 size. If such an integer
type cannot be found, a new type is created and used
for union members.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Yonghong Song <yhs@fb.com>
---
 tools/lib/bpf/btf.h             |  3 +-
 tools/lib/bpf/libbpf.c          | 56 ++++++++++++++++++++++++++++++---
 tools/lib/bpf/libbpf_internal.h |  2 ++
 3 files changed, 56 insertions(+), 5 deletions(-)

diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h
index dcb3f575a281..83312c34007a 100644
--- a/tools/lib/bpf/btf.h
+++ b/tools/lib/bpf/btf.h
@@ -395,9 +395,10 @@ btf_dump__dump_type_data(struct btf_dump *d, __u32 id,
 #ifndef BTF_KIND_FLOAT
 #define BTF_KIND_FLOAT		16	/* Floating point	*/
 #endif
-/* The kernel header switched to enums, so these two were never #defined */
+/* The kernel header switched to enums, so the following were never #defined */
 #define BTF_KIND_DECL_TAG	17	/* Decl Tag */
 #define BTF_KIND_TYPE_TAG	18	/* Type Tag */
+#define BTF_KIND_ENUM64		19	/* Enum for up-to 64bit values */
 
 static inline __u16 btf_kind(const struct btf_type *t)
 {
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 5afe4cbd684f..c4e3e2355a53 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -2242,6 +2242,7 @@ static const char *__btf_kind_str(__u16 kind)
 	case BTF_KIND_FLOAT: return "float";
 	case BTF_KIND_DECL_TAG: return "decl_tag";
 	case BTF_KIND_TYPE_TAG: return "type_tag";
+	case BTF_KIND_ENUM64: return "enum64";
 	default: return "unknown";
 	}
 }
@@ -2770,12 +2771,13 @@ static bool btf_needs_sanitization(struct bpf_object *obj)
 	bool has_func = kernel_supports(obj, FEAT_BTF_FUNC);
 	bool has_decl_tag = kernel_supports(obj, FEAT_BTF_DECL_TAG);
 	bool has_type_tag = kernel_supports(obj, FEAT_BTF_TYPE_TAG);
+	bool has_enum64 = kernel_supports(obj, FEAT_BTF_ENUM64);
 
 	return !has_func || !has_datasec || !has_func_global || !has_float ||
-	       !has_decl_tag || !has_type_tag;
+	       !has_decl_tag || !has_type_tag || !has_enum64;
 }
 
-static void bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *btf)
+static int bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *btf)
 {
 	bool has_func_global = kernel_supports(obj, FEAT_BTF_GLOBAL_FUNC);
 	bool has_datasec = kernel_supports(obj, FEAT_BTF_DATASEC);
@@ -2783,6 +2785,8 @@ static void bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *btf)
 	bool has_func = kernel_supports(obj, FEAT_BTF_FUNC);
 	bool has_decl_tag = kernel_supports(obj, FEAT_BTF_DECL_TAG);
 	bool has_type_tag = kernel_supports(obj, FEAT_BTF_TYPE_TAG);
+	bool has_enum64 = kernel_supports(obj, FEAT_BTF_ENUM64);
+	__u32 enum64_placeholder_id = 0;
 	struct btf_type *t;
 	int i, j, vlen;
 
@@ -2845,8 +2849,32 @@ static void bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *btf)
 			/* replace TYPE_TAG with a CONST */
 			t->name_off = 0;
 			t->info = BTF_INFO_ENC(BTF_KIND_CONST, 0, 0);
-		}
+		} else if (!has_enum64 && btf_is_enum(t)) {
+			/* clear the kflag */
+			t->info = btf_type_info(btf_kind(t), btf_vlen(t), false);
+		} else if (!has_enum64 && btf_is_enum64(t)) {
+			/* replace ENUM64 with a union */
+			struct btf_member *m;
+
+			if (enum64_placeholder_id == 0) {
+				enum64_placeholder_id = btf__add_int(btf, "enum64_placeholder", 1, 0);
+				if (enum64_placeholder_id < 0)
+					return enum64_placeholder_id;
+
+				t = (struct btf_type *)btf__type_by_id(btf, i);
+			}
+
+			m = btf_members(t);
+			vlen = btf_vlen(t);
+			t->info = BTF_INFO_ENC(BTF_KIND_UNION, 0, vlen);
+			for (j = 0; j < vlen; j++, m++) {
+				m->type = enum64_placeholder_id;
+				m->offset = 0;
+			}
+                }
 	}
+
+	return 0;
 }
 
 static bool libbpf_needs_btf(const struct bpf_object *obj)
@@ -3184,7 +3212,9 @@ static int bpf_object__sanitize_and_load_btf(struct bpf_object *obj)
 
 		/* enforce 8-byte pointers for BPF-targeted BTFs */
 		btf__set_pointer_size(obj->btf, 8);
-		bpf_object__sanitize_btf(obj, kern_btf);
+		err = bpf_object__sanitize_btf(obj, kern_btf);
+		if (err)
+			return err;
 	}
 
 	if (obj->gen_loader) {
@@ -3691,6 +3721,10 @@ static enum kcfg_type find_kcfg_type(const struct btf *btf, int id,
 		if (strcmp(name, "libbpf_tristate"))
 			return KCFG_UNKNOWN;
 		return KCFG_TRISTATE;
+	case BTF_KIND_ENUM64:
+		if (strcmp(name, "libbpf_tristate"))
+			return KCFG_UNKNOWN;
+		return KCFG_TRISTATE;
 	case BTF_KIND_ARRAY:
 		if (btf_array(t)->nelems == 0)
 			return KCFG_UNKNOWN;
@@ -4874,6 +4908,17 @@ static int probe_kern_bpf_cookie(void)
 	return probe_fd(ret);
 }
 
+static int probe_kern_btf_enum64(void)
+{
+	static const char strs[] = "\0enum64";
+	__u32 types[] = {
+		BTF_TYPE_ENC(1, BTF_INFO_ENC(BTF_KIND_ENUM64, 0, 0), 8),
+	};
+
+	return probe_fd(libbpf__load_raw_btf((char *)types, sizeof(types),
+					     strs, sizeof(strs)));
+}
+
 enum kern_feature_result {
 	FEAT_UNKNOWN = 0,
 	FEAT_SUPPORTED = 1,
@@ -4939,6 +4984,9 @@ static struct kern_feature_desc {
 	[FEAT_BPF_COOKIE] = {
 		"BPF cookie support", probe_kern_bpf_cookie,
 	},
+	[FEAT_BTF_ENUM64] = {
+		"BTF_KIND_ENUM64 support", probe_kern_btf_enum64,
+	},
 };
 
 bool kernel_supports(const struct bpf_object *obj, enum kern_feature_id feat_id)
diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h
index 4abdbe2fea9d..10c16acfa8ae 100644
--- a/tools/lib/bpf/libbpf_internal.h
+++ b/tools/lib/bpf/libbpf_internal.h
@@ -351,6 +351,8 @@ enum kern_feature_id {
 	FEAT_MEMCG_ACCOUNT,
 	/* BPF cookie (bpf_get_attach_cookie() BPF helper) support */
 	FEAT_BPF_COOKIE,
+	/* BTF_KIND_ENUM64 support and BTF_KIND_ENUM kflag support */
+	FEAT_BTF_ENUM64,
 	__FEAT_CNT,
 };
 
-- 
2.30.2

[PATCH bpf-next v4 09/18] libbpf: Add enum64 support for bpf linking

[Yonghong Song]

Add BTF_KIND_ENUM64 support for bpf linking, which is
very similar to BTF_KIND_ENUM.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Yonghong Song <yhs@fb.com>
---
 tools/lib/bpf/linker.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/lib/bpf/linker.c b/tools/lib/bpf/linker.c
index 9aa016fb55aa..979b150affb9 100644
--- a/tools/lib/bpf/linker.c
+++ b/tools/lib/bpf/linker.c
@@ -1340,6 +1340,7 @@ static bool glob_sym_btf_matches(const char *sym_name, bool exact,
 	case BTF_KIND_STRUCT:
 	case BTF_KIND_UNION:
 	case BTF_KIND_ENUM:
+	case BTF_KIND_ENUM64:
 	case BTF_KIND_FWD:
 	case BTF_KIND_FUNC:
 	case BTF_KIND_VAR:
@@ -1362,6 +1363,7 @@ static bool glob_sym_btf_matches(const char *sym_name, bool exact,
 	case BTF_KIND_INT:
 	case BTF_KIND_FLOAT:
 	case BTF_KIND_ENUM:
+	case BTF_KIND_ENUM64:
 		/* ignore encoding for int and enum values for enum */
 		if (t1->size != t2->size) {
 			pr_warn("global '%s': incompatible %s '%s' size %u and %u\n",
-- 
2.30.2

[PATCH bpf-next v4 10/18] libbpf: Add enum64 relocation support

[Yonghong Song]

The enum64 relocation support is added. The bpf local type
could be either enum or enum64 and the remote type could be
either enum or enum64 too. The all combinations of local enum/enum64
and remote enum/enum64 are supported.

Signed-off-by: Yonghong Song <yhs@fb.com>
---
 tools/lib/bpf/btf.h       |  7 +++++
 tools/lib/bpf/libbpf.c    |  7 ++---
 tools/lib/bpf/relo_core.c | 54 +++++++++++++++++++++++++++------------
 3 files changed, 48 insertions(+), 20 deletions(-)

diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h
index 83312c34007a..9fb416eb5644 100644
--- a/tools/lib/bpf/btf.h
+++ b/tools/lib/bpf/btf.h
@@ -537,6 +537,13 @@ static inline bool btf_is_any_enum(const struct btf_type *t)
 	return btf_is_enum(t) || btf_is_enum64(t);
 }
 
+static inline bool btf_kind_core_compat(const struct btf_type *t1,
+					const struct btf_type *t2)
+{
+	return btf_kind(t1) == btf_kind(t2) ||
+	       (btf_is_any_enum(t1) && btf_is_any_enum(t2));
+}
+
 static inline __u8 btf_int_encoding(const struct btf_type *t)
 {
 	return BTF_INT_ENCODING(*(__u32 *)(t + 1));
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index c4e3e2355a53..decf04f30250 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -5529,7 +5529,7 @@ int bpf_core_add_cands(struct bpf_core_cand *local_cand,
 	n = btf__type_cnt(targ_btf);
 	for (i = targ_start_id; i < n; i++) {
 		t = btf__type_by_id(targ_btf, i);
-		if (btf_kind(t) != btf_kind(local_t))
+		if (!btf_kind_core_compat(t, local_t))
 			continue;
 
 		targ_name = btf__name_by_offset(targ_btf, t->name_off);
@@ -5743,7 +5743,7 @@ int bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id,
 	/* caller made sure that names match (ignoring flavor suffix) */
 	local_type = btf__type_by_id(local_btf, local_id);
 	targ_type = btf__type_by_id(targ_btf, targ_id);
-	if (btf_kind(local_type) != btf_kind(targ_type))
+	if (!btf_kind_core_compat(local_type, targ_type))
 		return 0;
 
 recur:
@@ -5756,7 +5756,7 @@ int bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id,
 	if (!local_type || !targ_type)
 		return -EINVAL;
 
-	if (btf_kind(local_type) != btf_kind(targ_type))
+	if (!btf_kind_core_compat(local_type, targ_type))
 		return 0;
 
 	switch (btf_kind(local_type)) {
@@ -5764,6 +5764,7 @@ int bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id,
 	case BTF_KIND_STRUCT:
 	case BTF_KIND_UNION:
 	case BTF_KIND_ENUM:
+	case BTF_KIND_ENUM64:
 	case BTF_KIND_FWD:
 		return 1;
 	case BTF_KIND_INT:
diff --git a/tools/lib/bpf/relo_core.c b/tools/lib/bpf/relo_core.c
index 073a54ed7432..6ad3c3891a9a 100644
--- a/tools/lib/bpf/relo_core.c
+++ b/tools/lib/bpf/relo_core.c
@@ -186,7 +186,7 @@ int bpf_core_parse_spec(const char *prog_name, const struct btf *btf,
 	struct bpf_core_accessor *acc;
 	const struct btf_type *t;
 	const char *name, *spec_str;
-	__u32 id;
+	__u32 id, name_off;
 	__s64 sz;
 
 	spec_str = btf__name_by_offset(btf, relo->access_str_off);
@@ -231,11 +231,13 @@ int bpf_core_parse_spec(const char *prog_name, const struct btf *btf,
 	spec->len++;
 
 	if (core_relo_is_enumval_based(relo->kind)) {
-		if (!btf_is_enum(t) || spec->raw_len > 1 || access_idx >= btf_vlen(t))
+		if (!btf_is_any_enum(t) || spec->raw_len > 1 || access_idx >= btf_vlen(t))
 			return -EINVAL;
 
 		/* record enumerator name in a first accessor */
-		acc->name = btf__name_by_offset(btf, btf_enum(t)[access_idx].name_off);
+		name_off = btf_is_enum(t) ? btf_enum(t)[access_idx].name_off
+					  : btf_enum64(t)[access_idx].name_off;
+		acc->name = btf__name_by_offset(btf, name_off);
 		return 0;
 	}
 
@@ -340,7 +342,7 @@ static int bpf_core_fields_are_compat(const struct btf *local_btf,
 
 	if (btf_is_composite(local_type) && btf_is_composite(targ_type))
 		return 1;
-	if (btf_kind(local_type) != btf_kind(targ_type))
+	if (!btf_kind_core_compat(local_type, targ_type))
 		return 0;
 
 	switch (btf_kind(local_type)) {
@@ -348,6 +350,7 @@ static int bpf_core_fields_are_compat(const struct btf *local_btf,
 	case BTF_KIND_FLOAT:
 		return 1;
 	case BTF_KIND_FWD:
+	case BTF_KIND_ENUM64:
 	case BTF_KIND_ENUM: {
 		const char *local_name, *targ_name;
 		size_t local_len, targ_len;
@@ -477,6 +480,7 @@ static int bpf_core_spec_match(struct bpf_core_spec *local_spec,
 	const struct bpf_core_accessor *local_acc;
 	struct bpf_core_accessor *targ_acc;
 	int i, sz, matched;
+	__u32 name_off;
 
 	memset(targ_spec, 0, sizeof(*targ_spec));
 	targ_spec->btf = targ_btf;
@@ -494,18 +498,22 @@ static int bpf_core_spec_match(struct bpf_core_spec *local_spec,
 
 	if (core_relo_is_enumval_based(local_spec->relo_kind)) {
 		size_t local_essent_len, targ_essent_len;
-		const struct btf_enum *e;
 		const char *targ_name;
 
 		/* has to resolve to an enum */
 		targ_type = skip_mods_and_typedefs(targ_spec->btf, targ_id, &targ_id);
-		if (!btf_is_enum(targ_type))
+		if (!btf_is_any_enum(targ_type))
 			return 0;
 
 		local_essent_len = bpf_core_essential_name_len(local_acc->name);
 
-		for (i = 0, e = btf_enum(targ_type); i < btf_vlen(targ_type); i++, e++) {
-			targ_name = btf__name_by_offset(targ_spec->btf, e->name_off);
+		for (i = 0; i < btf_vlen(targ_type); i++) {
+			if (btf_is_enum(targ_type))
+				name_off = btf_enum(targ_type)[i].name_off;
+			else
+				name_off = btf_enum64(targ_type)[i].name_off;
+
+			targ_name = btf__name_by_offset(targ_spec->btf, name_off);
 			targ_essent_len = bpf_core_essential_name_len(targ_name);
 			if (targ_essent_len != local_essent_len)
 				continue;
@@ -680,8 +688,7 @@ static int bpf_core_calc_field_relo(const char *prog_name,
 		*val = byte_sz;
 		break;
 	case BPF_CORE_FIELD_SIGNED:
-		/* enums will be assumed unsigned */
-		*val = btf_is_enum(mt) ||
+		*val = (btf_is_any_enum(mt) && BTF_INFO_KFLAG(mt->info)) ||
 		       (btf_int_encoding(mt) & BTF_INT_SIGNED);
 		if (validate)
 			*validate = true; /* signedness is never ambiguous */
@@ -754,7 +761,6 @@ static int bpf_core_calc_enumval_relo(const struct bpf_core_relo *relo,
 				      __u64 *val)
 {
 	const struct btf_type *t;
-	const struct btf_enum *e;
 
 	switch (relo->kind) {
 	case BPF_CORE_ENUMVAL_EXISTS:
@@ -764,8 +770,10 @@ static int bpf_core_calc_enumval_relo(const struct bpf_core_relo *relo,
 		if (!spec)
 			return -EUCLEAN; /* request instruction poisoning */
 		t = btf_type_by_id(spec->btf, spec->spec[0].type_id);
-		e = btf_enum(t) + spec->spec[0].idx;
-		*val = e->val;
+		if (btf_is_enum(t))
+			*val = btf_enum(t)[spec->spec[0].idx].val;
+		else
+			*val = btf_enum64_value(btf_enum64(t) + spec->spec[0].idx);
 		break;
 	default:
 		return -EOPNOTSUPP;
@@ -1060,7 +1068,6 @@ int bpf_core_patch_insn(const char *prog_name, struct bpf_insn *insn,
 int bpf_core_format_spec(char *buf, size_t buf_sz, const struct bpf_core_spec *spec)
 {
 	const struct btf_type *t;
-	const struct btf_enum *e;
 	const char *s;
 	__u32 type_id;
 	int i, len = 0;
@@ -1089,10 +1096,23 @@ int bpf_core_format_spec(char *buf, size_t buf_sz, const struct bpf_core_spec *s
 
 	if (core_relo_is_enumval_based(spec->relo_kind)) {
 		t = skip_mods_and_typedefs(spec->btf, type_id, NULL);
-		e = btf_enum(t) + spec->raw_spec[0];
-		s = btf__name_by_offset(spec->btf, e->name_off);
+		if (btf_is_enum(t)) {
+			const struct btf_enum *e;
+			const char *fmt_str;
+
+			e = btf_enum(t) + spec->raw_spec[0];
+			s = btf__name_by_offset(spec->btf, e->name_off);
+			fmt_str = BTF_INFO_KFLAG(t->info) ? "::%s = %d" : "::%s = %u";
+			append_buf(fmt_str, s, e->val);
+		} else {
+			const struct btf_enum64 *e;
+			const char *fmt_str;
 
-		append_buf("::%s = %u", s, e->val);
+			e = btf_enum64(t) + spec->raw_spec[0];
+			s = btf__name_by_offset(spec->btf, e->name_off);
+			fmt_str = BTF_INFO_KFLAG(t->info) ? "::%s = %lld" : "::%s = %llu";
+			append_buf(fmt_str, s, (unsigned long long)btf_enum64_value(e));
+		}
 		return len;
 	}
 
-- 
2.30.2

Re: [PATCH bpf-next v4 10/18] libbpf: Add enum64 relocation support

[Andrii Nakryiko]

On Thu, Jun 2, 2022 at 6:59 PM Yonghong Song <yhs@fb.com> wrote:
>
> The enum64 relocation support is added. The bpf local type
> could be either enum or enum64 and the remote type could be
> either enum or enum64 too. The all combinations of local enum/enum64
> and remote enum/enum64 are supported.
>
> Signed-off-by: Yonghong Song <yhs@fb.com>
> ---
>  tools/lib/bpf/btf.h       |  7 +++++
>  tools/lib/bpf/libbpf.c    |  7 ++---
>  tools/lib/bpf/relo_core.c | 54 +++++++++++++++++++++++++++------------
>  3 files changed, 48 insertions(+), 20 deletions(-)
>

Acked-by: Andrii Nakryiko <andrii@kernel.org>

> diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h
> index 83312c34007a..9fb416eb5644 100644
> --- a/tools/lib/bpf/btf.h
> +++ b/tools/lib/bpf/btf.h
> @@ -537,6 +537,13 @@ static inline bool btf_is_any_enum(const struct btf_type *t)
>         return btf_is_enum(t) || btf_is_enum64(t);
>  }
>

[...]

[PATCH bpf-next v4 11/18] bpftool: Add btf enum64 support

[Yonghong Song]

Add BTF_KIND_ENUM64 support.
For example, the following enum is defined in uapi bpf.h.
  $ cat core.c
  enum A {
        BPF_F_INDEX_MASK                = 0xffffffffULL,
        BPF_F_CURRENT_CPU               = BPF_F_INDEX_MASK,
        BPF_F_CTXLEN_MASK               = (0xfffffULL << 32),
  } g;
Compiled with
  clang -target bpf -O2 -g -c core.c
Using bpftool to dump types and generate format C file:
  $ bpftool btf dump file core.o
  ...
  [1] ENUM64 'A' encoding=UNSIGNED size=8 vlen=3
        'BPF_F_INDEX_MASK' val=4294967295ULL
        'BPF_F_CURRENT_CPU' val=4294967295ULL
        'BPF_F_CTXLEN_MASK' val=4503595332403200ULL
  $ bpftool btf dump file core.o format c
  ...
  enum A {
        BPF_F_INDEX_MASK = 4294967295ULL,
        BPF_F_CURRENT_CPU = 4294967295ULL,
        BPF_F_CTXLEN_MASK = 4503595332403200ULL,
  };
  ...

Note that for raw btf output, the encoding (UNSIGNED or SIGNED)
is printed out as well. The 64bit value is also represented properly
in BTF and C dump.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Yonghong Song <yhs@fb.com>
---
 tools/bpf/bpftool/btf.c        | 57 ++++++++++++++++++++++++++++++++--
 tools/bpf/bpftool/btf_dumper.c | 29 +++++++++++++++++
 tools/bpf/bpftool/gen.c        |  1 +
 3 files changed, 84 insertions(+), 3 deletions(-)

diff --git a/tools/bpf/bpftool/btf.c b/tools/bpf/bpftool/btf.c
index 7e6accb9d9f7..0744bd1150be 100644
--- a/tools/bpf/bpftool/btf.c
+++ b/tools/bpf/bpftool/btf.c
@@ -40,6 +40,7 @@ static const char * const btf_kind_str[NR_BTF_KINDS] = {
 	[BTF_KIND_FLOAT]	= "FLOAT",
 	[BTF_KIND_DECL_TAG]	= "DECL_TAG",
 	[BTF_KIND_TYPE_TAG]	= "TYPE_TAG",
+	[BTF_KIND_ENUM64]	= "ENUM64",
 };
 
 struct btf_attach_point {
@@ -212,26 +213,76 @@ static int dump_btf_type(const struct btf *btf, __u32 id,
 	case BTF_KIND_ENUM: {
 		const struct btf_enum *v = (const void *)(t + 1);
 		__u16 vlen = BTF_INFO_VLEN(t->info);
+		const char *encoding;
 		int i;
 
+		encoding = btf_kflag(t) ? "SIGNED" : "UNSIGNED";
 		if (json_output) {
+			jsonw_string_field(w, "encoding", encoding);
 			jsonw_uint_field(w, "size", t->size);
 			jsonw_uint_field(w, "vlen", vlen);
 			jsonw_name(w, "values");
 			jsonw_start_array(w);
 		} else {
-			printf(" size=%u vlen=%u", t->size, vlen);
+			printf(" encoding=%s size=%u vlen=%u", encoding, t->size, vlen);
+		}
+		for (i = 0; i < vlen; i++, v++) {
+			const char *name = btf_str(btf, v->name_off);
+
+			if (json_output) {
+				jsonw_start_object(w);
+				jsonw_string_field(w, "name", name);
+				if (btf_kflag(t))
+					jsonw_int_field(w, "val", v->val);
+				else
+					jsonw_uint_field(w, "val", v->val);
+				jsonw_end_object(w);
+			} else {
+				if (btf_kflag(t))
+					printf("\n\t'%s' val=%d", name, v->val);
+				else
+					printf("\n\t'%s' val=%u", name, v->val);
+			}
+		}
+		if (json_output)
+			jsonw_end_array(w);
+		break;
+	}
+	case BTF_KIND_ENUM64: {
+		const struct btf_enum64 *v = btf_enum64(t);
+		__u16 vlen = btf_vlen(t);
+		const char *encoding;
+		int i;
+
+		encoding = btf_kflag(t) ? "SIGNED" : "UNSIGNED";
+		if (json_output) {
+			jsonw_string_field(w, "encoding", encoding);
+			jsonw_uint_field(w, "size", t->size);
+			jsonw_uint_field(w, "vlen", vlen);
+			jsonw_name(w, "values");
+			jsonw_start_array(w);
+		} else {
+			printf(" encoding=%s size=%u vlen=%u", encoding, t->size, vlen);
 		}
 		for (i = 0; i < vlen; i++, v++) {
 			const char *name = btf_str(btf, v->name_off);
+			__u64 val = ((__u64)v->val_hi32 << 32) | v->val_lo32;
 
 			if (json_output) {
 				jsonw_start_object(w);
 				jsonw_string_field(w, "name", name);
-				jsonw_uint_field(w, "val", v->val);
+				if (btf_kflag(t))
+					jsonw_int_field(w, "val", val);
+				else
+					jsonw_uint_field(w, "val", val);
 				jsonw_end_object(w);
 			} else {
-				printf("\n\t'%s' val=%u", name, v->val);
+				if (btf_kflag(t))
+					printf("\n\t'%s' val=%lldLL", name,
+					       (unsigned long long)val);
+				else
+					printf("\n\t'%s' val=%lluULL", name,
+					       (unsigned long long)val);
 			}
 		}
 		if (json_output)
diff --git a/tools/bpf/bpftool/btf_dumper.c b/tools/bpf/bpftool/btf_dumper.c
index f5dddf8ef404..125798b0bc5d 100644
--- a/tools/bpf/bpftool/btf_dumper.c
+++ b/tools/bpf/bpftool/btf_dumper.c
@@ -182,6 +182,32 @@ static int btf_dumper_enum(const struct btf_dumper *d,
 	return 0;
 }
 
+static int btf_dumper_enum64(const struct btf_dumper *d,
+			     const struct btf_type *t,
+			     const void *data)
+{
+	const struct btf_enum64 *enums = btf_enum64(t);
+	__u32 val_lo32, val_hi32;
+	__u64 value;
+	__u16 i;
+
+	value = *(__u64 *)data;
+	val_lo32 = (__u32)value;
+	val_hi32 = value >> 32;
+
+	for (i = 0; i < btf_vlen(t); i++) {
+		if (val_lo32 == enums[i].val_lo32 && val_hi32 == enums[i].val_hi32) {
+			jsonw_string(d->jw,
+				     btf__name_by_offset(d->btf,
+							 enums[i].name_off));
+			return 0;
+		}
+	}
+
+	jsonw_int(d->jw, value);
+	return 0;
+}
+
 static bool is_str_array(const struct btf *btf, const struct btf_array *arr,
 			 const char *s)
 {
@@ -542,6 +568,8 @@ static int btf_dumper_do_type(const struct btf_dumper *d, __u32 type_id,
 		return btf_dumper_array(d, type_id, data);
 	case BTF_KIND_ENUM:
 		return btf_dumper_enum(d, t, data);
+	case BTF_KIND_ENUM64:
+		return btf_dumper_enum64(d, t, data);
 	case BTF_KIND_PTR:
 		btf_dumper_ptr(d, t, data);
 		return 0;
@@ -618,6 +646,7 @@ static int __btf_dumper_type_only(const struct btf *btf, __u32 type_id,
 			      btf__name_by_offset(btf, t->name_off));
 		break;
 	case BTF_KIND_ENUM:
+	case BTF_KIND_ENUM64:
 		BTF_PRINT_ARG("enum %s ",
 			      btf__name_by_offset(btf, t->name_off));
 		break;
diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c
index f158dc1c2149..480cbd859359 100644
--- a/tools/bpf/bpftool/gen.c
+++ b/tools/bpf/bpftool/gen.c
@@ -1750,6 +1750,7 @@ btfgen_mark_type(struct btfgen_info *info, unsigned int type_id, bool follow_poi
 	case BTF_KIND_INT:
 	case BTF_KIND_FLOAT:
 	case BTF_KIND_ENUM:
+	case BTF_KIND_ENUM64:
 	case BTF_KIND_STRUCT:
 	case BTF_KIND_UNION:
 		break;
-- 
2.30.2

[PATCH bpf-next v4 12/18] selftests/bpf: Fix selftests failure

[Yonghong Song]

The kflag is supported now for BTF_KIND_ENUM.
So remove the test which tests verifier failure
due to existence of kflag.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Yonghong Song <yhs@fb.com>
---
 tools/testing/selftests/bpf/prog_tests/btf.c | 20 --------------------
 1 file changed, 20 deletions(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/btf.c b/tools/testing/selftests/bpf/prog_tests/btf.c
index ba5bde53d418..8e068e06b3e8 100644
--- a/tools/testing/selftests/bpf/prog_tests/btf.c
+++ b/tools/testing/selftests/bpf/prog_tests/btf.c
@@ -2896,26 +2896,6 @@ static struct btf_raw_test raw_tests[] = {
 	.err_str = "Invalid btf_info kind_flag",
 },
 
-{
-	.descr = "invalid enum kind_flag",
-	.raw_types = {
-		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),		/* [1] */
-		BTF_TYPE_ENC(0, BTF_INFO_ENC(BTF_KIND_ENUM, 1, 1), 4),	/* [2] */
-		BTF_ENUM_ENC(NAME_TBD, 0),
-		BTF_END_RAW,
-	},
-	BTF_STR_SEC("\0A"),
-	.map_type = BPF_MAP_TYPE_ARRAY,
-	.map_name = "enum_type_check_btf",
-	.key_size = sizeof(int),
-	.value_size = sizeof(int),
-	.key_type_id = 1,
-	.value_type_id = 1,
-	.max_entries = 4,
-	.btf_load_err = true,
-	.err_str = "Invalid btf_info kind_flag",
-},
-
 {
 	.descr = "valid fwd kind_flag",
 	.raw_types = {
-- 
2.30.2

[PATCH bpf-next v4 13/18] selftests/bpf: Test new enum kflag and enum64 API functions

[Yonghong Song]

Add tests to use the new enum kflag and enum64 API functions
in selftest btf_write.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Yonghong Song <yhs@fb.com>
---
 tools/testing/selftests/bpf/btf_helpers.c     |  25 +++-
 .../selftests/bpf/prog_tests/btf_write.c      | 126 +++++++++++++-----
 2 files changed, 114 insertions(+), 37 deletions(-)

diff --git a/tools/testing/selftests/bpf/btf_helpers.c b/tools/testing/selftests/bpf/btf_helpers.c
index b5941d514e17..1c1c2c26690a 100644
--- a/tools/testing/selftests/bpf/btf_helpers.c
+++ b/tools/testing/selftests/bpf/btf_helpers.c
@@ -26,11 +26,12 @@ static const char * const btf_kind_str_mapping[] = {
 	[BTF_KIND_FLOAT]	= "FLOAT",
 	[BTF_KIND_DECL_TAG]	= "DECL_TAG",
 	[BTF_KIND_TYPE_TAG]	= "TYPE_TAG",
+	[BTF_KIND_ENUM64]	= "ENUM64",
 };
 
 static const char *btf_kind_str(__u16 kind)
 {
-	if (kind > BTF_KIND_TYPE_TAG)
+	if (kind > BTF_KIND_ENUM64)
 		return "UNKNOWN";
 	return btf_kind_str_mapping[kind];
 }
@@ -139,14 +140,32 @@ int fprintf_btf_type_raw(FILE *out, const struct btf *btf, __u32 id)
 	}
 	case BTF_KIND_ENUM: {
 		const struct btf_enum *v = btf_enum(t);
+		const char *fmt_str;
 
-		fprintf(out, " size=%u vlen=%u", t->size, vlen);
+		fmt_str = btf_kflag(t) ? "\n\t'%s' val=%d" : "\n\t'%s' val=%u";
+		fprintf(out, " encoding=%s size=%u vlen=%u",
+			btf_kflag(t) ? "SIGNED" : "UNSIGNED", t->size, vlen);
 		for (i = 0; i < vlen; i++, v++) {
-			fprintf(out, "\n\t'%s' val=%u",
+			fprintf(out, fmt_str,
 				btf_str(btf, v->name_off), v->val);
 		}
 		break;
 	}
+	case BTF_KIND_ENUM64: {
+		const struct btf_enum64 *v = btf_enum64(t);
+		const char *fmt_str;
+
+		fmt_str = btf_kflag(t) ? "\n\t'%s' val=%lld" : "\n\t'%s' val=%llu";
+
+		fprintf(out, " encoding=%s size=%u vlen=%u",
+			btf_kflag(t) ? "SIGNED" : "UNSIGNED", t->size, vlen);
+		for (i = 0; i < vlen; i++, v++) {
+			fprintf(out, fmt_str,
+				btf_str(btf, v->name_off),
+				((__u64)v->val_hi32 << 32) | v->val_lo32);
+		}
+		break;
+	}
 	case BTF_KIND_FWD:
 		fprintf(out, " fwd_kind=%s", btf_kflag(t) ? "union" : "struct");
 		break;
diff --git a/tools/testing/selftests/bpf/prog_tests/btf_write.c b/tools/testing/selftests/bpf/prog_tests/btf_write.c
index addf99c05896..6e36de1302fc 100644
--- a/tools/testing/selftests/bpf/prog_tests/btf_write.c
+++ b/tools/testing/selftests/bpf/prog_tests/btf_write.c
@@ -9,6 +9,7 @@ static void gen_btf(struct btf *btf)
 	const struct btf_var_secinfo *vi;
 	const struct btf_type *t;
 	const struct btf_member *m;
+	const struct btf_enum64 *v64;
 	const struct btf_enum *v;
 	const struct btf_param *p;
 	int id, err, str_off;
@@ -171,7 +172,7 @@ static void gen_btf(struct btf *btf)
 	ASSERT_STREQ(btf__str_by_offset(btf, v->name_off), "v2", "v2_name");
 	ASSERT_EQ(v->val, 2, "v2_val");
 	ASSERT_STREQ(btf_type_raw_dump(btf, 9),
-		     "[9] ENUM 'e1' size=4 vlen=2\n"
+		     "[9] ENUM 'e1' encoding=UNSIGNED size=4 vlen=2\n"
 		     "\t'v1' val=1\n"
 		     "\t'v2' val=2", "raw_dump");
 
@@ -202,7 +203,7 @@ static void gen_btf(struct btf *btf)
 	ASSERT_EQ(btf_vlen(t), 0, "enum_fwd_kind");
 	ASSERT_EQ(t->size, 4, "enum_fwd_sz");
 	ASSERT_STREQ(btf_type_raw_dump(btf, 12),
-		     "[12] ENUM 'enum_fwd' size=4 vlen=0", "raw_dump");
+		     "[12] ENUM 'enum_fwd' encoding=UNSIGNED size=4 vlen=0", "raw_dump");
 
 	/* TYPEDEF */
 	id = btf__add_typedef(btf, "typedef1", 1);
@@ -307,6 +308,48 @@ static void gen_btf(struct btf *btf)
 	ASSERT_EQ(t->type, 1, "tag_type");
 	ASSERT_STREQ(btf_type_raw_dump(btf, 20),
 		     "[20] TYPE_TAG 'tag1' type_id=1", "raw_dump");
+
+	/* ENUM64 */
+	id = btf__add_enum64(btf, "e1", 8, true);
+	ASSERT_EQ(id, 21, "enum64_id");
+	err = btf__add_enum64_value(btf, "v1", -1);
+	ASSERT_OK(err, "v1_res");
+	err = btf__add_enum64_value(btf, "v2", 0x123456789); /* 4886718345 */
+	ASSERT_OK(err, "v2_res");
+	t = btf__type_by_id(btf, 21);
+	ASSERT_STREQ(btf__str_by_offset(btf, t->name_off), "e1", "enum64_name");
+	ASSERT_EQ(btf_kind(t), BTF_KIND_ENUM64, "enum64_kind");
+	ASSERT_EQ(btf_vlen(t), 2, "enum64_vlen");
+	ASSERT_EQ(t->size, 8, "enum64_sz");
+	v64 = btf_enum64(t) + 0;
+	ASSERT_STREQ(btf__str_by_offset(btf, v64->name_off), "v1", "v1_name");
+	ASSERT_EQ(v64->val_hi32, 0xffffffff, "v1_val");
+	ASSERT_EQ(v64->val_lo32, 0xffffffff, "v1_val");
+	v64 = btf_enum64(t) + 1;
+	ASSERT_STREQ(btf__str_by_offset(btf, v64->name_off), "v2", "v2_name");
+	ASSERT_EQ(v64->val_hi32, 0x1, "v2_val");
+	ASSERT_EQ(v64->val_lo32, 0x23456789, "v2_val");
+	ASSERT_STREQ(btf_type_raw_dump(btf, 21),
+		     "[21] ENUM64 'e1' encoding=SIGNED size=8 vlen=2\n"
+		     "\t'v1' val=-1\n"
+		     "\t'v2' val=4886718345", "raw_dump");
+
+	id = btf__add_enum64(btf, "e1", 8, false);
+	ASSERT_EQ(id, 22, "enum64_id");
+	err = btf__add_enum64_value(btf, "v1", 0xffffffffFFFFFFFF); /* 18446744073709551615 */
+	ASSERT_OK(err, "v1_res");
+	t = btf__type_by_id(btf, 22);
+	ASSERT_STREQ(btf__str_by_offset(btf, t->name_off), "e1", "enum64_name");
+	ASSERT_EQ(btf_kind(t), BTF_KIND_ENUM64, "enum64_kind");
+	ASSERT_EQ(btf_vlen(t), 1, "enum64_vlen");
+	ASSERT_EQ(t->size, 8, "enum64_sz");
+	v64 = btf_enum64(t) + 0;
+	ASSERT_STREQ(btf__str_by_offset(btf, v64->name_off), "v1", "v1_name");
+	ASSERT_EQ(v64->val_hi32, 0xffffffff, "v1_val");
+	ASSERT_EQ(v64->val_lo32, 0xffffffff, "v1_val");
+	ASSERT_STREQ(btf_type_raw_dump(btf, 22),
+		     "[22] ENUM64 'e1' encoding=UNSIGNED size=8 vlen=1\n"
+		     "\t'v1' val=18446744073709551615", "raw_dump");
 }
 
 static void test_btf_add()
@@ -332,12 +375,12 @@ static void test_btf_add()
 		"\t'f2' type_id=1 bits_offset=32 bitfield_size=16",
 		"[8] UNION 'u1' size=8 vlen=1\n"
 		"\t'f1' type_id=1 bits_offset=0 bitfield_size=16",
-		"[9] ENUM 'e1' size=4 vlen=2\n"
+		"[9] ENUM 'e1' encoding=UNSIGNED size=4 vlen=2\n"
 		"\t'v1' val=1\n"
 		"\t'v2' val=2",
 		"[10] FWD 'struct_fwd' fwd_kind=struct",
 		"[11] FWD 'union_fwd' fwd_kind=union",
-		"[12] ENUM 'enum_fwd' size=4 vlen=0",
+		"[12] ENUM 'enum_fwd' encoding=UNSIGNED size=4 vlen=0",
 		"[13] TYPEDEF 'typedef1' type_id=1",
 		"[14] FUNC 'func1' type_id=15 linkage=global",
 		"[15] FUNC_PROTO '(anon)' ret_type_id=1 vlen=2\n"
@@ -348,7 +391,12 @@ static void test_btf_add()
 		"\ttype_id=1 offset=4 size=8",
 		"[18] DECL_TAG 'tag1' type_id=16 component_idx=-1",
 		"[19] DECL_TAG 'tag2' type_id=14 component_idx=1",
-		"[20] TYPE_TAG 'tag1' type_id=1");
+		"[20] TYPE_TAG 'tag1' type_id=1",
+		"[21] ENUM64 'e1' encoding=SIGNED size=8 vlen=2\n"
+		"\t'v1' val=-1\n"
+		"\t'v2' val=4886718345",
+		"[22] ENUM64 'e1' encoding=UNSIGNED size=8 vlen=1\n"
+		"\t'v1' val=18446744073709551615");
 
 	btf__free(btf);
 }
@@ -370,7 +418,7 @@ static void test_btf_add_btf()
 	gen_btf(btf2);
 
 	id = btf__add_btf(btf1, btf2);
-	if (!ASSERT_EQ(id, 21, "id"))
+	if (!ASSERT_EQ(id, 23, "id"))
 		goto cleanup;
 
 	VALIDATE_RAW_BTF(
@@ -386,12 +434,12 @@ static void test_btf_add_btf()
 		"\t'f2' type_id=1 bits_offset=32 bitfield_size=16",
 		"[8] UNION 'u1' size=8 vlen=1\n"
 		"\t'f1' type_id=1 bits_offset=0 bitfield_size=16",
-		"[9] ENUM 'e1' size=4 vlen=2\n"
+		"[9] ENUM 'e1' encoding=UNSIGNED size=4 vlen=2\n"
 		"\t'v1' val=1\n"
 		"\t'v2' val=2",
 		"[10] FWD 'struct_fwd' fwd_kind=struct",
 		"[11] FWD 'union_fwd' fwd_kind=union",
-		"[12] ENUM 'enum_fwd' size=4 vlen=0",
+		"[12] ENUM 'enum_fwd' encoding=UNSIGNED size=4 vlen=0",
 		"[13] TYPEDEF 'typedef1' type_id=1",
 		"[14] FUNC 'func1' type_id=15 linkage=global",
 		"[15] FUNC_PROTO '(anon)' ret_type_id=1 vlen=2\n"
@@ -403,36 +451,46 @@ static void test_btf_add_btf()
 		"[18] DECL_TAG 'tag1' type_id=16 component_idx=-1",
 		"[19] DECL_TAG 'tag2' type_id=14 component_idx=1",
 		"[20] TYPE_TAG 'tag1' type_id=1",
+		"[21] ENUM64 'e1' encoding=SIGNED size=8 vlen=2\n"
+		"\t'v1' val=-1\n"
+		"\t'v2' val=4886718345",
+		"[22] ENUM64 'e1' encoding=UNSIGNED size=8 vlen=1\n"
+		"\t'v1' val=18446744073709551615",
 
 		/* types appended from the second BTF */
-		"[21] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
-		"[22] PTR '(anon)' type_id=21",
-		"[23] CONST '(anon)' type_id=25",
-		"[24] VOLATILE '(anon)' type_id=23",
-		"[25] RESTRICT '(anon)' type_id=24",
-		"[26] ARRAY '(anon)' type_id=22 index_type_id=21 nr_elems=10",
-		"[27] STRUCT 's1' size=8 vlen=2\n"
-		"\t'f1' type_id=21 bits_offset=0\n"
-		"\t'f2' type_id=21 bits_offset=32 bitfield_size=16",
-		"[28] UNION 'u1' size=8 vlen=1\n"
-		"\t'f1' type_id=21 bits_offset=0 bitfield_size=16",
-		"[29] ENUM 'e1' size=4 vlen=2\n"
+		"[23] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
+		"[24] PTR '(anon)' type_id=23",
+		"[25] CONST '(anon)' type_id=27",
+		"[26] VOLATILE '(anon)' type_id=25",
+		"[27] RESTRICT '(anon)' type_id=26",
+		"[28] ARRAY '(anon)' type_id=24 index_type_id=23 nr_elems=10",
+		"[29] STRUCT 's1' size=8 vlen=2\n"
+		"\t'f1' type_id=23 bits_offset=0\n"
+		"\t'f2' type_id=23 bits_offset=32 bitfield_size=16",
+		"[30] UNION 'u1' size=8 vlen=1\n"
+		"\t'f1' type_id=23 bits_offset=0 bitfield_size=16",
+		"[31] ENUM 'e1' encoding=UNSIGNED size=4 vlen=2\n"
 		"\t'v1' val=1\n"
 		"\t'v2' val=2",
-		"[30] FWD 'struct_fwd' fwd_kind=struct",
-		"[31] FWD 'union_fwd' fwd_kind=union",
-		"[32] ENUM 'enum_fwd' size=4 vlen=0",
-		"[33] TYPEDEF 'typedef1' type_id=21",
-		"[34] FUNC 'func1' type_id=35 linkage=global",
-		"[35] FUNC_PROTO '(anon)' ret_type_id=21 vlen=2\n"
-		"\t'p1' type_id=21\n"
-		"\t'p2' type_id=22",
-		"[36] VAR 'var1' type_id=21, linkage=global-alloc",
-		"[37] DATASEC 'datasec1' size=12 vlen=1\n"
-		"\ttype_id=21 offset=4 size=8",
-		"[38] DECL_TAG 'tag1' type_id=36 component_idx=-1",
-		"[39] DECL_TAG 'tag2' type_id=34 component_idx=1",
-		"[40] TYPE_TAG 'tag1' type_id=21");
+		"[32] FWD 'struct_fwd' fwd_kind=struct",
+		"[33] FWD 'union_fwd' fwd_kind=union",
+		"[34] ENUM 'enum_fwd' encoding=UNSIGNED size=4 vlen=0",
+		"[35] TYPEDEF 'typedef1' type_id=23",
+		"[36] FUNC 'func1' type_id=37 linkage=global",
+		"[37] FUNC_PROTO '(anon)' ret_type_id=23 vlen=2\n"
+		"\t'p1' type_id=23\n"
+		"\t'p2' type_id=24",
+		"[38] VAR 'var1' type_id=23, linkage=global-alloc",
+		"[39] DATASEC 'datasec1' size=12 vlen=1\n"
+		"\ttype_id=23 offset=4 size=8",
+		"[40] DECL_TAG 'tag1' type_id=38 component_idx=-1",
+		"[41] DECL_TAG 'tag2' type_id=36 component_idx=1",
+		"[42] TYPE_TAG 'tag1' type_id=23",
+		"[43] ENUM64 'e1' encoding=SIGNED size=8 vlen=2\n"
+		"\t'v1' val=-1\n"
+		"\t'v2' val=4886718345",
+		"[44] ENUM64 'e1' encoding=UNSIGNED size=8 vlen=1\n"
+		"\t'v1' val=18446744073709551615");
 
 cleanup:
 	btf__free(btf1);
-- 
2.30.2

[PATCH bpf-next v4 14/18] selftests/bpf: Add BTF_KIND_ENUM64 unit tests

[Yonghong Song]

Add unit tests for basic BTF_KIND_ENUM64 encoding.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Yonghong Song <yhs@fb.com>
---
 tools/testing/selftests/bpf/prog_tests/btf.c | 36 ++++++++++++++++++++
 tools/testing/selftests/bpf/test_btf.h       |  1 +
 2 files changed, 37 insertions(+)

diff --git a/tools/testing/selftests/bpf/prog_tests/btf.c b/tools/testing/selftests/bpf/prog_tests/btf.c
index 8e068e06b3e8..a986ee56c5f7 100644
--- a/tools/testing/selftests/bpf/prog_tests/btf.c
+++ b/tools/testing/selftests/bpf/prog_tests/btf.c
@@ -4052,6 +4052,42 @@ static struct btf_raw_test raw_tests[] = {
 	.btf_load_err = true,
 	.err_str = "Type tags don't precede modifiers",
 },
+{
+	.descr = "enum64 test #1, unsigned, size 8",
+	.raw_types = {
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),			/* [1] */
+		BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_ENUM64, 0, 2), 8),	/* [2] */
+		BTF_ENUM64_ENC(NAME_TBD, 0, 0),
+		BTF_ENUM64_ENC(NAME_TBD, 1, 1),
+		BTF_END_RAW,
+	},
+	BTF_STR_SEC("\0a\0b\0c"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = "tag_type_check_btf",
+	.key_size = sizeof(int),
+	.value_size = 8,
+	.key_type_id = 1,
+	.value_type_id = 2,
+	.max_entries = 1,
+},
+{
+	.descr = "enum64 test #2, signed, size 4",
+	.raw_types = {
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),			/* [1] */
+		BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_ENUM64, 1, 2), 4),	/* [2] */
+		BTF_ENUM64_ENC(NAME_TBD, -1, 0),
+		BTF_ENUM64_ENC(NAME_TBD, 1, 0),
+		BTF_END_RAW,
+	},
+	BTF_STR_SEC("\0a\0b\0c"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = "tag_type_check_btf",
+	.key_size = sizeof(int),
+	.value_size = 4,
+	.key_type_id = 1,
+	.value_type_id = 2,
+	.max_entries = 1,
+},
 
 }; /* struct btf_raw_test raw_tests[] */
 
diff --git a/tools/testing/selftests/bpf/test_btf.h b/tools/testing/selftests/bpf/test_btf.h
index 128989bed8b7..38782bd47fdc 100644
--- a/tools/testing/selftests/bpf/test_btf.h
+++ b/tools/testing/selftests/bpf/test_btf.h
@@ -39,6 +39,7 @@
 #define BTF_MEMBER_ENC(name, type, bits_offset)	\
 	(name), (type), (bits_offset)
 #define BTF_ENUM_ENC(name, val) (name), (val)
+#define BTF_ENUM64_ENC(name, val_lo32, val_hi32) (name), (val_lo32), (val_hi32)
 #define BTF_MEMBER_OFFSET(bitfield_size, bits_offset) \
 	((bitfield_size) << 24 | (bits_offset))
 
-- 
2.30.2

[PATCH bpf-next v4 15/18] selftests/bpf: Test BTF_KIND_ENUM64 for deduplication

[Yonghong Song]

Add a few unit tests for BTF_KIND_ENUM64 deduplication.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Yonghong Song <yhs@fb.com>
---
 tools/testing/selftests/bpf/prog_tests/btf.c | 97 +++++++++++++++++++-
 1 file changed, 95 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/btf.c b/tools/testing/selftests/bpf/prog_tests/btf.c
index a986ee56c5f7..edb387163baa 100644
--- a/tools/testing/selftests/bpf/prog_tests/btf.c
+++ b/tools/testing/selftests/bpf/prog_tests/btf.c
@@ -7016,9 +7016,12 @@ static struct btf_dedup_test dedup_tests[] = {
 			BTF_DECL_TAG_ENC(NAME_TBD, 13, 1),				/* [16] decl_tag */
 			BTF_DECL_TAG_ENC(NAME_TBD, 7, -1),				/* [17] decl_tag */
 			BTF_TYPE_TAG_ENC(NAME_TBD, 8),					/* [18] type_tag */
+			BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_ENUM64, 0, 2), 8),	/* [19] enum64 */
+				BTF_ENUM64_ENC(NAME_TBD, 0, 0),
+				BTF_ENUM64_ENC(NAME_TBD, 1, 1),
 			BTF_END_RAW,
 		},
-		BTF_STR_SEC("\0A\0B\0C\0D\0E\0F\0G\0H\0I\0J\0K\0L\0M\0N\0O\0P\0Q\0R"),
+		BTF_STR_SEC("\0A\0B\0C\0D\0E\0F\0G\0H\0I\0J\0K\0L\0M\0N\0O\0P\0Q\0R\0S\0T\0U"),
 	},
 	.expect = {
 		.raw_types = {
@@ -7046,9 +7049,12 @@ static struct btf_dedup_test dedup_tests[] = {
 			BTF_DECL_TAG_ENC(NAME_TBD, 13, 1),				/* [16] decl_tag */
 			BTF_DECL_TAG_ENC(NAME_TBD, 7, -1),				/* [17] decl_tag */
 			BTF_TYPE_TAG_ENC(NAME_TBD, 8),					/* [18] type_tag */
+			BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_ENUM64, 0, 2), 8),	/* [19] enum64 */
+				BTF_ENUM64_ENC(NAME_TBD, 0, 0),
+				BTF_ENUM64_ENC(NAME_TBD, 1, 1),
 			BTF_END_RAW,
 		},
-		BTF_STR_SEC("\0A\0B\0C\0D\0E\0F\0G\0H\0I\0J\0K\0L\0M\0N\0O\0P\0Q\0R"),
+		BTF_STR_SEC("\0A\0B\0C\0D\0E\0F\0G\0H\0I\0J\0K\0L\0M\0N\0O\0P\0Q\0R\0S\0T\0U"),
 	},
 },
 {
@@ -7509,6 +7515,91 @@ static struct btf_dedup_test dedup_tests[] = {
 		BTF_STR_SEC("\0tag1\0t\0m"),
 	},
 },
+{
+	.descr = "dedup: enum64, standalone",
+	.input = {
+		.raw_types = {
+			BTF_TYPE_ENC(NAME_NTH(1), BTF_INFO_ENC(BTF_KIND_ENUM64, 0, 1), 8),
+				BTF_ENUM64_ENC(NAME_NTH(2), 1, 123),
+			BTF_TYPE_ENC(NAME_NTH(1), BTF_INFO_ENC(BTF_KIND_ENUM64, 0, 1), 8),
+				BTF_ENUM64_ENC(NAME_NTH(2), 1, 123),
+			BTF_END_RAW,
+		},
+		BTF_STR_SEC("\0e1\0e1_val"),
+	},
+	.expect = {
+		.raw_types = {
+			BTF_TYPE_ENC(NAME_NTH(1), BTF_INFO_ENC(BTF_KIND_ENUM64, 0, 1), 8),
+				BTF_ENUM64_ENC(NAME_NTH(2), 1, 123),
+			BTF_END_RAW,
+		},
+		BTF_STR_SEC("\0e1\0e1_val"),
+	},
+},
+{
+	.descr = "dedup: enum64, fwd resolution",
+	.input = {
+		.raw_types = {
+			/* [1] fwd enum64 'e1' before full enum */
+			BTF_TYPE_ENC(NAME_NTH(1), BTF_INFO_ENC(BTF_KIND_ENUM64, 0, 0), 8),
+			/* [2] full enum64 'e1' after fwd */
+			BTF_TYPE_ENC(NAME_NTH(1), BTF_INFO_ENC(BTF_KIND_ENUM64, 0, 1), 8),
+				BTF_ENUM64_ENC(NAME_NTH(2), 1, 123),
+			/* [3] full enum64 'e2' before fwd */
+			BTF_TYPE_ENC(NAME_NTH(3), BTF_INFO_ENC(BTF_KIND_ENUM64, 0, 1), 8),
+				BTF_ENUM64_ENC(NAME_NTH(4), 0, 456),
+			/* [4] fwd enum64 'e2' after full enum */
+			BTF_TYPE_ENC(NAME_NTH(3), BTF_INFO_ENC(BTF_KIND_ENUM64, 0, 0), 8),
+			/* [5] incompatible full enum64 with different value */
+			BTF_TYPE_ENC(NAME_NTH(1), BTF_INFO_ENC(BTF_KIND_ENUM64, 0, 1), 8),
+				BTF_ENUM64_ENC(NAME_NTH(2), 0, 321),
+			BTF_END_RAW,
+		},
+		BTF_STR_SEC("\0e1\0e1_val\0e2\0e2_val"),
+	},
+	.expect = {
+		.raw_types = {
+			/* [1] full enum64 'e1' */
+			BTF_TYPE_ENC(NAME_NTH(1), BTF_INFO_ENC(BTF_KIND_ENUM64, 0, 1), 8),
+				BTF_ENUM64_ENC(NAME_NTH(2), 1, 123),
+			/* [2] full enum64 'e2' */
+			BTF_TYPE_ENC(NAME_NTH(3), BTF_INFO_ENC(BTF_KIND_ENUM64, 0, 1), 8),
+				BTF_ENUM64_ENC(NAME_NTH(4), 0, 456),
+			/* [3] incompatible full enum64 with different value */
+			BTF_TYPE_ENC(NAME_NTH(1), BTF_INFO_ENC(BTF_KIND_ENUM64, 0, 1), 8),
+				BTF_ENUM64_ENC(NAME_NTH(2), 0, 321),
+			BTF_END_RAW,
+		},
+		BTF_STR_SEC("\0e1\0e1_val\0e2\0e2_val"),
+	},
+},
+{
+	.descr = "dedup: enum and enum64, no dedup",
+	.input = {
+		.raw_types = {
+			/* [1] enum 'e1' */
+			BTF_TYPE_ENC(NAME_NTH(1), BTF_INFO_ENC(BTF_KIND_ENUM, 0, 1), 4),
+				BTF_ENUM_ENC(NAME_NTH(2), 1),
+			/* [2] enum64 'e1' */
+			BTF_TYPE_ENC(NAME_NTH(1), BTF_INFO_ENC(BTF_KIND_ENUM64, 0, 1), 4),
+				BTF_ENUM64_ENC(NAME_NTH(2), 1, 0),
+			BTF_END_RAW,
+		},
+		BTF_STR_SEC("\0e1\0e1_val"),
+	},
+	.expect = {
+		.raw_types = {
+			/* [1] enum 'e1' */
+			BTF_TYPE_ENC(NAME_NTH(1), BTF_INFO_ENC(BTF_KIND_ENUM, 0, 1), 4),
+				BTF_ENUM_ENC(NAME_NTH(2), 1),
+			/* [2] enum64 'e1' */
+			BTF_TYPE_ENC(NAME_NTH(1), BTF_INFO_ENC(BTF_KIND_ENUM64, 0, 1), 4),
+				BTF_ENUM64_ENC(NAME_NTH(2), 1, 0),
+			BTF_END_RAW,
+		},
+		BTF_STR_SEC("\0e1\0e1_val"),
+	},
+},
 
 };
 
@@ -7533,6 +7624,8 @@ static int btf_type_size(const struct btf_type *t)
 		return base_size + sizeof(__u32);
 	case BTF_KIND_ENUM:
 		return base_size + vlen * sizeof(struct btf_enum);
+	case BTF_KIND_ENUM64:
+		return base_size + vlen * sizeof(struct btf_enum64);
 	case BTF_KIND_ARRAY:
 		return base_size + sizeof(struct btf_array);
 	case BTF_KIND_STRUCT:
-- 
2.30.2

[PATCH bpf-next v4 16/18] selftests/bpf: Add a test for enum64 value relocations

[Yonghong Song]

Add a test for enum64 value relocations.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Yonghong Song <yhs@fb.com>
---
 .../selftests/bpf/prog_tests/core_reloc.c     | 58 ++++++++++++++
 .../bpf/progs/btf__core_reloc_enum64val.c     |  3 +
 .../progs/btf__core_reloc_enum64val___diff.c  |  3 +
 .../btf__core_reloc_enum64val___err_missing.c |  3 +
 ...btf__core_reloc_enum64val___val3_missing.c |  3 +
 .../selftests/bpf/progs/core_reloc_types.h    | 78 +++++++++++++++++++
 .../bpf/progs/test_core_reloc_enum64val.c     | 70 +++++++++++++++++
 7 files changed, 218 insertions(+)
 create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_enum64val.c
 create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_enum64val___diff.c
 create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_enum64val___err_missing.c
 create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_enum64val___val3_missing.c
 create mode 100644 tools/testing/selftests/bpf/progs/test_core_reloc_enum64val.c

diff --git a/tools/testing/selftests/bpf/prog_tests/core_reloc.c b/tools/testing/selftests/bpf/prog_tests/core_reloc.c
index 3712dfe1be59..47c1ef117275 100644
--- a/tools/testing/selftests/bpf/prog_tests/core_reloc.c
+++ b/tools/testing/selftests/bpf/prog_tests/core_reloc.c
@@ -363,6 +363,25 @@ static int duration = 0;
 	.fails = true,							\
 }
 
+#define ENUM64VAL_CASE_COMMON(name)					\
+	.case_name = #name,						\
+	.bpf_obj_file = "test_core_reloc_enum64val.o",			\
+	.btf_src_file = "btf__core_reloc_" #name ".o",			\
+	.raw_tp_name = "sys_enter",					\
+	.prog_name = "test_core_enum64val"
+
+#define ENUM64VAL_CASE(name, ...) {					\
+	ENUM64VAL_CASE_COMMON(name),					\
+	.output = STRUCT_TO_CHAR_PTR(core_reloc_enum64val_output)	\
+			__VA_ARGS__,					\
+	.output_len = sizeof(struct core_reloc_enum64val_output),	\
+}
+
+#define ENUM64VAL_ERR_CASE(name) {					\
+	ENUM64VAL_CASE_COMMON(name),					\
+	.fails = true,							\
+}
+
 struct core_reloc_test_case;
 
 typedef int (*setup_test_fn)(struct core_reloc_test_case *test);
@@ -831,6 +850,45 @@ static const struct core_reloc_test_case test_cases[] = {
 		.anon_val2 = 0x222,
 	}),
 	ENUMVAL_ERR_CASE(enumval___err_missing),
+
+	/* 64bit enumerator value existence and value relocations */
+	ENUM64VAL_CASE(enum64val, {
+		.unsigned_val1_exists = true,
+		.unsigned_val2_exists = true,
+		.unsigned_val3_exists = true,
+		.signed_val1_exists = true,
+		.signed_val2_exists = true,
+		.signed_val3_exists = true,
+		.unsigned_val1 = 0x1ffffffffULL,
+		.unsigned_val2 = 0x2,
+		.signed_val1 = 0x1ffffffffLL,
+		.signed_val2 = -2,
+	}),
+	ENUM64VAL_CASE(enum64val___diff, {
+		.unsigned_val1_exists = true,
+		.unsigned_val2_exists = true,
+		.unsigned_val3_exists = true,
+		.signed_val1_exists = true,
+		.signed_val2_exists = true,
+		.signed_val3_exists = true,
+		.unsigned_val1 = 0x101ffffffffULL,
+		.unsigned_val2 = 0x202ffffffffULL,
+		.signed_val1 = -101,
+		.signed_val2 = -202,
+	}),
+	ENUM64VAL_CASE(enum64val___val3_missing, {
+		.unsigned_val1_exists = true,
+		.unsigned_val2_exists = true,
+		.unsigned_val3_exists = false,
+		.signed_val1_exists = true,
+		.signed_val2_exists = true,
+		.signed_val3_exists = false,
+		.unsigned_val1 = 0x111ffffffffULL,
+		.unsigned_val2 = 0x222,
+		.signed_val1 = 0x111ffffffffLL,
+		.signed_val2 = -222,
+	}),
+	ENUM64VAL_ERR_CASE(enum64val___err_missing),
 };
 
 struct data {
diff --git a/tools/testing/selftests/bpf/progs/btf__core_reloc_enum64val.c b/tools/testing/selftests/bpf/progs/btf__core_reloc_enum64val.c
new file mode 100644
index 000000000000..888e79db6a77
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/btf__core_reloc_enum64val.c
@@ -0,0 +1,3 @@
+#include "core_reloc_types.h"
+
+void f(struct core_reloc_enum64val x) {}
diff --git a/tools/testing/selftests/bpf/progs/btf__core_reloc_enum64val___diff.c b/tools/testing/selftests/bpf/progs/btf__core_reloc_enum64val___diff.c
new file mode 100644
index 000000000000..194749130d87
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/btf__core_reloc_enum64val___diff.c
@@ -0,0 +1,3 @@
+#include "core_reloc_types.h"
+
+void f(struct core_reloc_enum64val___diff x) {}
diff --git a/tools/testing/selftests/bpf/progs/btf__core_reloc_enum64val___err_missing.c b/tools/testing/selftests/bpf/progs/btf__core_reloc_enum64val___err_missing.c
new file mode 100644
index 000000000000..3d732d4193e4
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/btf__core_reloc_enum64val___err_missing.c
@@ -0,0 +1,3 @@
+#include "core_reloc_types.h"
+
+void f(struct core_reloc_enum64val___err_missing x) {}
diff --git a/tools/testing/selftests/bpf/progs/btf__core_reloc_enum64val___val3_missing.c b/tools/testing/selftests/bpf/progs/btf__core_reloc_enum64val___val3_missing.c
new file mode 100644
index 000000000000..17cf5d6a848d
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/btf__core_reloc_enum64val___val3_missing.c
@@ -0,0 +1,3 @@
+#include "core_reloc_types.h"
+
+void f(struct core_reloc_enum64val___val3_missing x) {}
diff --git a/tools/testing/selftests/bpf/progs/core_reloc_types.h b/tools/testing/selftests/bpf/progs/core_reloc_types.h
index f9dc9766546e..26e103302c05 100644
--- a/tools/testing/selftests/bpf/progs/core_reloc_types.h
+++ b/tools/testing/selftests/bpf/progs/core_reloc_types.h
@@ -1117,6 +1117,20 @@ struct core_reloc_enumval_output {
 	int anon_val2;
 };
 
+struct core_reloc_enum64val_output {
+	bool unsigned_val1_exists;
+	bool unsigned_val2_exists;
+	bool unsigned_val3_exists;
+	bool signed_val1_exists;
+	bool signed_val2_exists;
+	bool signed_val3_exists;
+
+	long unsigned_val1;
+	long unsigned_val2;
+	long signed_val1;
+	long signed_val2;
+};
+
 enum named_enum {
 	NAMED_ENUM_VAL1 = 1,
 	NAMED_ENUM_VAL2 = 2,
@@ -1134,6 +1148,23 @@ struct core_reloc_enumval {
 	anon_enum f2;
 };
 
+enum named_unsigned_enum64 {
+	UNSIGNED_ENUM64_VAL1 = 0x1ffffffffULL,
+	UNSIGNED_ENUM64_VAL2 = 0x2,
+	UNSIGNED_ENUM64_VAL3 = 0x3ffffffffULL,
+};
+
+enum named_signed_enum64 {
+	SIGNED_ENUM64_VAL1 = 0x1ffffffffLL,
+	SIGNED_ENUM64_VAL2 = -2,
+	SIGNED_ENUM64_VAL3 = 0x3ffffffffLL,
+};
+
+struct core_reloc_enum64val {
+	enum named_unsigned_enum64 f1;
+	enum named_signed_enum64 f2;
+};
+
 /* differing enumerator values */
 enum named_enum___diff {
 	NAMED_ENUM_VAL1___diff = 101,
@@ -1152,6 +1183,23 @@ struct core_reloc_enumval___diff {
 	anon_enum___diff f2;
 };
 
+enum named_unsigned_enum64___diff {
+	UNSIGNED_ENUM64_VAL1___diff = 0x101ffffffffULL,
+	UNSIGNED_ENUM64_VAL2___diff = 0x202ffffffffULL,
+	UNSIGNED_ENUM64_VAL3___diff = 0x303ffffffffULL,
+};
+
+enum named_signed_enum64___diff {
+	SIGNED_ENUM64_VAL1___diff = -101,
+	SIGNED_ENUM64_VAL2___diff = -202,
+	SIGNED_ENUM64_VAL3___diff = -303,
+};
+
+struct core_reloc_enum64val___diff {
+	enum named_unsigned_enum64___diff f1;
+	enum named_signed_enum64___diff f2;
+};
+
 /* missing (optional) third enum value */
 enum named_enum___val3_missing {
 	NAMED_ENUM_VAL1___val3_missing = 111,
@@ -1168,6 +1216,21 @@ struct core_reloc_enumval___val3_missing {
 	anon_enum___val3_missing f2;
 };
 
+enum named_unsigned_enum64___val3_missing {
+	UNSIGNED_ENUM64_VAL1___val3_missing = 0x111ffffffffULL,
+	UNSIGNED_ENUM64_VAL2___val3_missing = 0x222,
+};
+
+enum named_signed_enum64___val3_missing {
+	SIGNED_ENUM64_VAL1___val3_missing = 0x111ffffffffLL,
+	SIGNED_ENUM64_VAL2___val3_missing = -222,
+};
+
+struct core_reloc_enum64val___val3_missing {
+	enum named_unsigned_enum64___val3_missing f1;
+	enum named_signed_enum64___val3_missing f2;
+};
+
 /* missing (mandatory) second enum value, should fail */
 enum named_enum___err_missing {
 	NAMED_ENUM_VAL1___err_missing = 1,
@@ -1183,3 +1246,18 @@ struct core_reloc_enumval___err_missing {
 	enum named_enum___err_missing f1;
 	anon_enum___err_missing f2;
 };
+
+enum named_unsigned_enum64___err_missing {
+	UNSIGNED_ENUM64_VAL1___err_missing = 0x1ffffffffULL,
+	UNSIGNED_ENUM64_VAL3___err_missing = 0x3ffffffffULL,
+};
+
+enum named_signed_enum64___err_missing {
+	SIGNED_ENUM64_VAL1___err_missing = 0x1ffffffffLL,
+	SIGNED_ENUM64_VAL3___err_missing = -3,
+};
+
+struct core_reloc_enum64val___err_missing {
+	enum named_unsigned_enum64___err_missing f1;
+	enum named_signed_enum64___err_missing f2;
+};
diff --git a/tools/testing/selftests/bpf/progs/test_core_reloc_enum64val.c b/tools/testing/selftests/bpf/progs/test_core_reloc_enum64val.c
new file mode 100644
index 000000000000..820f4e1b8f30
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_core_reloc_enum64val.c
@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */
+
+#include <linux/bpf.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_core_read.h>
+
+char _license[] SEC("license") = "GPL";
+
+struct {
+	char in[256];
+	char out[256];
+	bool skip;
+} data = {};
+
+enum named_unsigned_enum64 {
+	UNSIGNED_ENUM64_VAL1 = 0x1ffffffffULL,
+	UNSIGNED_ENUM64_VAL2 = 0x2ffffffffULL,
+	UNSIGNED_ENUM64_VAL3 = 0x3ffffffffULL,
+};
+
+enum named_signed_enum64 {
+	SIGNED_ENUM64_VAL1 = 0x1ffffffffLL,
+	SIGNED_ENUM64_VAL2 = -2,
+	SIGNED_ENUM64_VAL3 = 0x3ffffffffLL,
+};
+
+struct core_reloc_enum64val_output {
+	bool unsigned_val1_exists;
+	bool unsigned_val2_exists;
+	bool unsigned_val3_exists;
+	bool signed_val1_exists;
+	bool signed_val2_exists;
+	bool signed_val3_exists;
+
+	long unsigned_val1;
+	long unsigned_val2;
+	long signed_val1;
+	long signed_val2;
+};
+
+SEC("raw_tracepoint/sys_enter")
+int test_core_enum64val(void *ctx)
+{
+#if __has_builtin(__builtin_preserve_enum_value)
+	struct core_reloc_enum64val_output *out = (void *)&data.out;
+	enum named_unsigned_enum64 named_unsigned = 0;
+	enum named_signed_enum64 named_signed = 0;
+
+	out->unsigned_val1_exists = bpf_core_enum_value_exists(named_unsigned, UNSIGNED_ENUM64_VAL1);
+	out->unsigned_val2_exists = bpf_core_enum_value_exists(enum named_unsigned_enum64, UNSIGNED_ENUM64_VAL2);
+	out->unsigned_val3_exists = bpf_core_enum_value_exists(enum named_unsigned_enum64, UNSIGNED_ENUM64_VAL3);
+	out->signed_val1_exists = bpf_core_enum_value_exists(named_signed, SIGNED_ENUM64_VAL1);
+	out->signed_val2_exists = bpf_core_enum_value_exists(enum named_signed_enum64, SIGNED_ENUM64_VAL2);
+	out->signed_val3_exists = bpf_core_enum_value_exists(enum named_signed_enum64, SIGNED_ENUM64_VAL3);
+
+	out->unsigned_val1 = bpf_core_enum_value(named_unsigned, UNSIGNED_ENUM64_VAL1);
+	out->unsigned_val2 = bpf_core_enum_value(named_unsigned, UNSIGNED_ENUM64_VAL2);
+	out->signed_val1 = bpf_core_enum_value(named_signed, SIGNED_ENUM64_VAL1);
+	out->signed_val2 = bpf_core_enum_value(named_signed, SIGNED_ENUM64_VAL2);
+	/* NAMED_ENUM64_VAL3 value is optional */
+
+#else
+	data.skip = true;
+#endif
+
+	return 0;
+}
-- 
2.30.2

Re: [PATCH bpf-next v4 16/18] selftests/bpf: Add a test for enum64 value relocations

[Alexei Starovoitov]

On Fri, Jun 3, 2022 at 4:00 AM Yonghong Song <yhs@fb.com> wrote:
> +
> +SEC("raw_tracepoint/sys_enter")
> +int test_core_enum64val(void *ctx)
> +{
> +#if __has_builtin(__builtin_preserve_enum_value)
> +       struct core_reloc_enum64val_output *out = (void *)&data.out;
> +       enum named_unsigned_enum64 named_unsigned = 0;
> +       enum named_signed_enum64 named_signed = 0;

libbpf: prog 'test_core_enum64val': relo #0: unexpected insn #0
(LDIMM64) value: got 8589934591, exp 18446744073709551615 ->
18446744073709551615
libbpf: prog 'test_core_enum64val': relo #0: failed to patch insn #0: -22
libbpf: failed to perform CO-RE relocations: -22
libbpf: failed to load object 'test_core_reloc_enum64val.o'

Is it failing in CI because clang is too old?
CI will pick up newer clang sooner or later,
but the users will be confused.
The patch 17/18 that updates README certainly helps,
but I was wondering whether we can do a similar trick
to what Andrii did in libbpf and make the error more human readable?

Re: [PATCH bpf-next v4 16/18] selftests/bpf: Add a test for enum64 value relocations

[Andrii Nakryiko]

On Fri, Jun 3, 2022 at 8:14 AM Alexei Starovoitov
<alexei.starovoitov@gmail.com> wrote:
>
> On Fri, Jun 3, 2022 at 4:00 AM Yonghong Song <yhs@fb.com> wrote:
> > +
> > +SEC("raw_tracepoint/sys_enter")
> > +int test_core_enum64val(void *ctx)
> > +{
> > +#if __has_builtin(__builtin_preserve_enum_value)
> > +       struct core_reloc_enum64val_output *out = (void *)&data.out;
> > +       enum named_unsigned_enum64 named_unsigned = 0;
> > +       enum named_signed_enum64 named_signed = 0;
>
> libbpf: prog 'test_core_enum64val': relo #0: unexpected insn #0
> (LDIMM64) value: got 8589934591, exp 18446744073709551615 ->
> 18446744073709551615
> libbpf: prog 'test_core_enum64val': relo #0: failed to patch insn #0: -22
> libbpf: failed to perform CO-RE relocations: -22
> libbpf: failed to load object 'test_core_reloc_enum64val.o'
>
> Is it failing in CI because clang is too old?

Hm... doesn't seem so. I pulled Yonghong's patches locally, built the
very latest Clang, rebuilt selftests from scratch and I get the same
error.

Yonghong, do you get the same error in your setup? If not, what am I
missing in mine?


> CI will pick up newer clang sooner or later,
> but the users will be confused.
> The patch 17/18 that updates README certainly helps,
> but I was wondering whether we can do a similar trick
> to what Andrii did in libbpf and make the error more human readable?

Re: [PATCH bpf-next v4 16/18] selftests/bpf: Add a test for enum64 value relocations

[Andrii Nakryiko]

On Fri, Jun 3, 2022 at 1:22 PM Andrii Nakryiko
<andrii.nakryiko@gmail.com> wrote:
>
> On Fri, Jun 3, 2022 at 8:14 AM Alexei Starovoitov
> <alexei.starovoitov@gmail.com> wrote:
> >
> > On Fri, Jun 3, 2022 at 4:00 AM Yonghong Song <yhs@fb.com> wrote:
> > > +
> > > +SEC("raw_tracepoint/sys_enter")
> > > +int test_core_enum64val(void *ctx)
> > > +{
> > > +#if __has_builtin(__builtin_preserve_enum_value)
> > > +       struct core_reloc_enum64val_output *out = (void *)&data.out;
> > > +       enum named_unsigned_enum64 named_unsigned = 0;
> > > +       enum named_signed_enum64 named_signed = 0;
> >
> > libbpf: prog 'test_core_enum64val': relo #0: unexpected insn #0
> > (LDIMM64) value: got 8589934591, exp 18446744073709551615 ->
> > 18446744073709551615
> > libbpf: prog 'test_core_enum64val': relo #0: failed to patch insn #0: -22
> > libbpf: failed to perform CO-RE relocations: -22
> > libbpf: failed to load object 'test_core_reloc_enum64val.o'
> >
> > Is it failing in CI because clang is too old?
>
> Hm... doesn't seem so. I pulled Yonghong's patches locally, built the
> very latest Clang, rebuilt selftests from scratch and I get the same
> error.
>
> Yonghong, do you get the same error in your setup? If not, what am I
> missing in mine?

and confirming that Clang doesn't generate ENUM64:


$ tools/build/bpftool/bootstrap/bpftool btf dump file
btf__core_reloc_enum64val___diff.o
[1] INT 'long' size=8 bits_offset=0 nr_bits=64 encoding=SIGNED
[2] FUNC_PROTO '(anon)' ret_type_id=0 vlen=1
        'x' type_id=1
[3] FUNC 'preserce_ptr_sz_fn' type_id=2 linkage=global
[4] STRUCT 'core_reloc_enum64val___diff' size=16 vlen=2
        'f1' type_id=5 bits_offset=0
        'f2' type_id=6 bits_offset=64
[5] ENUM 'named_unsigned_enum64___diff' encoding=UNSIGNED size=8 vlen=3
        'UNSIGNED_ENUM64_VAL1___diff' val=4294967295
        'UNSIGNED_ENUM64_VAL2___diff' val=4294967295
        'UNSIGNED_ENUM64_VAL3___diff' val=4294967295
[6] ENUM 'named_signed_enum64___diff' encoding=UNSIGNED size=4 vlen=3
        'SIGNED_ENUM64_VAL1___diff' val=4294967195
        'SIGNED_ENUM64_VAL2___diff' val=4294967094
        'SIGNED_ENUM64_VAL3___diff' val=4294966993
[7] FUNC_PROTO '(anon)' ret_type_id=0 vlen=1
        'x' type_id=4
[8] FUNC 'f' type_id=7 linkage=global


>
>
> > CI will pick up newer clang sooner or later,
> > but the users will be confused.
> > The patch 17/18 that updates README certainly helps,
> > but I was wondering whether we can do a similar trick
> > to what Andrii did in libbpf and make the error more human readable?

Re: [PATCH bpf-next v4 16/18] selftests/bpf: Add a test for enum64 value relocations

[Yonghong Song]

On 6/3/22 8:14 AM, Alexei Starovoitov wrote:
> On Fri, Jun 3, 2022 at 4:00 AM Yonghong Song <yhs@fb.com> wrote:
>> +
>> +SEC("raw_tracepoint/sys_enter")
>> +int test_core_enum64val(void *ctx)
>> +{
>> +#if __has_builtin(__builtin_preserve_enum_value)
>> +       struct core_reloc_enum64val_output *out = (void *)&data.out;
>> +       enum named_unsigned_enum64 named_unsigned = 0;
>> +       enum named_signed_enum64 named_signed = 0;
> 
> libbpf: prog 'test_core_enum64val': relo #0: unexpected insn #0
> (LDIMM64) value: got 8589934591, exp 18446744073709551615 ->
> 18446744073709551615
> libbpf: prog 'test_core_enum64val': relo #0: failed to patch insn #0: -22
> libbpf: failed to perform CO-RE relocations: -22
> libbpf: failed to load object 'test_core_reloc_enum64val.o'
> 
> Is it failing in CI because clang is too old?

Yes, the failure is due to that the llvm patch to support enum64
is not merged. The llvm patch is not merged because otherwise
people using latest compiler (with llvm patch) may fail to
latest libbpf.

> CI will pick up newer clang sooner or later,
> but the users will be confused.
> The patch 17/18 that updates README certainly helps,
> but I was wondering whether we can do a similar trick
> to what Andrii did in libbpf and make the error more human readable?

I think the above information is what current libbpf did for
relocation errors.

Unless I missed something, Andrii's commit 9fdc4273b8da ("libbpf: Fix up 
verifier log for unguarded failed CO-RE relos") is to improve kernel 
verifier log w.r.t. relocation failures.

Re: [PATCH bpf-next v4 16/18] selftests/bpf: Add a test for enum64 value relocations

[Alexei Starovoitov]

On Sat, Jun 4, 2022 at 4:51 AM Yonghong Song <yhs@fb.com> wrote:
>
>
>
> On 6/3/22 8:14 AM, Alexei Starovoitov wrote:
> > On Fri, Jun 3, 2022 at 4:00 AM Yonghong Song <yhs@fb.com> wrote:
> >> +
> >> +SEC("raw_tracepoint/sys_enter")
> >> +int test_core_enum64val(void *ctx)
> >> +{
> >> +#if __has_builtin(__builtin_preserve_enum_value)
> >> +       struct core_reloc_enum64val_output *out = (void *)&data.out;
> >> +       enum named_unsigned_enum64 named_unsigned = 0;
> >> +       enum named_signed_enum64 named_signed = 0;
> >
> > libbpf: prog 'test_core_enum64val': relo #0: unexpected insn #0
> > (LDIMM64) value: got 8589934591, exp 18446744073709551615 ->
> > 18446744073709551615
> > libbpf: prog 'test_core_enum64val': relo #0: failed to patch insn #0: -22
> > libbpf: failed to perform CO-RE relocations: -22
> > libbpf: failed to load object 'test_core_reloc_enum64val.o'
> >
> > Is it failing in CI because clang is too old?
>
> Yes, the failure is due to that the llvm patch to support enum64
> is not merged. The llvm patch is not merged because otherwise
> people using latest compiler (with llvm patch) may fail to
> latest libbpf.
>
> > CI will pick up newer clang sooner or later,
> > but the users will be confused.
> > The patch 17/18 that updates README certainly helps,
> > but I was wondering whether we can do a similar trick
> > to what Andrii did in libbpf and make the error more human readable?
>
> I think the above information is what current libbpf did for
> relocation errors.
>
> Unless I missed something, Andrii's commit 9fdc4273b8da ("libbpf: Fix up
> verifier log for unguarded failed CO-RE relos") is to improve kernel
> verifier log w.r.t. relocation failures.

Right. I was referring to the spirit of that commit.
libbpf can probably print more user friendly message and point out
that enum64 is potentially missing in the clang?

[PATCH bpf-next v4 17/18] selftests/bpf: Clarify llvm dependency with possible selftest failures

[Yonghong Song]

Certain subtests in selftests core_reloc and core_reloc_btfgen
requires llvm ENUM64 support in llvm15. If an older compiler
is used, these subtests will fail. Make this requirement clear
in selftests README.rst file.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Yonghong Song <yhs@fb.com>
---
 tools/testing/selftests/bpf/README.rst | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/tools/testing/selftests/bpf/README.rst b/tools/testing/selftests/bpf/README.rst
index eb1b7541f39d..a83d78a58014 100644
--- a/tools/testing/selftests/bpf/README.rst
+++ b/tools/testing/selftests/bpf/README.rst
@@ -266,3 +266,21 @@ from running test_progs will look like:
   test_xdpwall:FAIL:Does LLVM have https://reviews.llvm.org/D109073? unexpected error: -4007
 
 __ https://reviews.llvm.org/D109073
+
+ENUM64 support and Clang version
+================================
+
+There are a few selftests requiring LLVM ENUM64 support. The LLVM ENUM64 is
+introduced in `Clang 15` [0_]. Without proper compiler support, the following selftests
+will fail:
+
+.. code-block:: console
+
+  #45 /73    core_reloc/enum64val:FAIL
+  #45 /74    core_reloc/enum64val___diff:FAIL
+  #45 /75    core_reloc/enum64val___val3_missing:FAIL
+  #46 /73    core_reloc_btfgen/enum64val:FAIL
+  #46 /74    core_reloc_btfgen/enum64val___diff:FAIL
+  #46 /75    core_reloc_btfgen/enum64val___val3_missing:FAIL
+
+.. _0: https://reviews.llvm.org/D124641
-- 
2.30.2

[PATCH bpf-next v4 18/18] docs/bpf: Update documentation for BTF_KIND_ENUM64 support

[Yonghong Song]

Add BTF_KIND_ENUM64 documentation in btf.rst.
Also fixed a typo for section number for BTF_KIND_TYPE_TAG
from 2.2.17 to 2.2.18, and fixed a type size issue for
BTF_KIND_ENUM.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Yonghong Song <yhs@fb.com>
---
 Documentation/bpf/btf.rst | 43 +++++++++++++++++++++++++++++++++------
 1 file changed, 37 insertions(+), 6 deletions(-)

diff --git a/Documentation/bpf/btf.rst b/Documentation/bpf/btf.rst
index 7940da9bc6c1..f49aeef62d0c 100644
--- a/Documentation/bpf/btf.rst
+++ b/Documentation/bpf/btf.rst
@@ -74,7 +74,7 @@ sequentially and type id is assigned to each recognized type starting from id
     #define BTF_KIND_ARRAY          3       /* Array        */
     #define BTF_KIND_STRUCT         4       /* Struct       */
     #define BTF_KIND_UNION          5       /* Union        */
-    #define BTF_KIND_ENUM           6       /* Enumeration  */
+    #define BTF_KIND_ENUM           6       /* Enumeration up to 32-bit values */
     #define BTF_KIND_FWD            7       /* Forward      */
     #define BTF_KIND_TYPEDEF        8       /* Typedef      */
     #define BTF_KIND_VOLATILE       9       /* Volatile     */
@@ -87,6 +87,7 @@ sequentially and type id is assigned to each recognized type starting from id
     #define BTF_KIND_FLOAT          16      /* Floating point       */
     #define BTF_KIND_DECL_TAG       17      /* Decl Tag     */
     #define BTF_KIND_TYPE_TAG       18      /* Type Tag     */
+    #define BTF_KIND_ENUM64         19      /* Enumeration up to 64-bit values */
 
 Note that the type section encodes debug info, not just pure types.
 ``BTF_KIND_FUNC`` is not a type, and it represents a defined subprogram.
@@ -101,10 +102,10 @@ Each type contains the following common data::
          * bits 24-28: kind (e.g. int, ptr, array...etc)
          * bits 29-30: unused
          * bit     31: kind_flag, currently used by
-         *             struct, union and fwd
+         *             struct, union, fwd, enum and enum64.
          */
         __u32 info;
-        /* "size" is used by INT, ENUM, STRUCT and UNION.
+        /* "size" is used by INT, ENUM, STRUCT, UNION and ENUM64.
          * "size" tells the size of the type it is describing.
          *
          * "type" is used by PTR, TYPEDEF, VOLATILE, CONST, RESTRICT,
@@ -281,10 +282,10 @@ modes exist:
 
 ``struct btf_type`` encoding requirement:
   * ``name_off``: 0 or offset to a valid C identifier
-  * ``info.kind_flag``: 0
+  * ``info.kind_flag``: 0 for unsigned, 1 for signed
   * ``info.kind``: BTF_KIND_ENUM
   * ``info.vlen``: number of enum values
-  * ``size``: 4
+  * ``size``: 1/2/4/8
 
 ``btf_type`` is followed by ``info.vlen`` number of ``struct btf_enum``.::
 
@@ -297,6 +298,10 @@ The ``btf_enum`` encoding:
   * ``name_off``: offset to a valid C identifier
   * ``val``: any value
 
+If the original enum value is signed and the size is less than 4,
+that value will be sign extended into 4 bytes. If the size is 8,
+the value will be truncated into 4 bytes.
+
 2.2.7 BTF_KIND_FWD
 ~~~~~~~~~~~~~~~~~~
 
@@ -493,7 +498,7 @@ the attribute is applied to a ``struct``/``union`` member or
 a ``func`` argument, and ``btf_decl_tag.component_idx`` should be a
 valid index (starting from 0) pointing to a member or an argument.
 
-2.2.17 BTF_KIND_TYPE_TAG
+2.2.18 BTF_KIND_TYPE_TAG
 ~~~~~~~~~~~~~~~~~~~~~~~~
 
 ``struct btf_type`` encoding requirement:
@@ -516,6 +521,32 @@ type_tag, then zero or more const/volatile/restrict/typedef
 and finally the base type. The base type is one of
 int, ptr, array, struct, union, enum, func_proto and float types.
 
+2.2.19 BTF_KIND_ENUM64
+~~~~~~~~~~~~~~~~~~~~~~
+
+``struct btf_type`` encoding requirement:
+  * ``name_off``: 0 or offset to a valid C identifier
+  * ``info.kind_flag``: 0 for unsigned, 1 for signed
+  * ``info.kind``: BTF_KIND_ENUM64
+  * ``info.vlen``: number of enum values
+  * ``size``: 1/2/4/8
+
+``btf_type`` is followed by ``info.vlen`` number of ``struct btf_enum64``.::
+
+    struct btf_enum64 {
+        __u32   name_off;
+        __u32   val_lo32;
+        __u32   val_hi32;
+    };
+
+The ``btf_enum64`` encoding:
+  * ``name_off``: offset to a valid C identifier
+  * ``val_lo32``: lower 32-bit value for a 64-bit value
+  * ``val_hi32``: high 32-bit value for a 64-bit value
+
+If the original enum value is signed and the size is less than 8,
+that value will be sign extended into 8 bytes.
+
 3. BTF Kernel API
 =================
 
-- 
2.30.2