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-rw-r--r--tools/lib/bpf/btf.h217
1 files changed, 129 insertions, 88 deletions
diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h
index 061839f04525..cc01494d6210 100644
--- a/tools/lib/bpf/btf.h
+++ b/tools/lib/bpf/btf.h
@@ -18,6 +18,7 @@ extern "C" {
#define BTF_ELF_SEC ".BTF"
#define BTF_EXT_ELF_SEC ".BTF.ext"
+#define BTF_BASE_ELF_SEC ".BTF.base"
#define MAPS_ELF_SEC ".maps"
struct btf;
@@ -93,6 +94,7 @@ LIBBPF_API struct btf *btf__new_empty(void);
* @brief **btf__new_empty_split()** creates an unpopulated BTF object from an
* ELF BTF section except with a base BTF on top of which split BTF should be
* based
+ * @param base_btf base BTF object
* @return new BTF object instance which has to be eventually freed with
* **btf__free()**
*
@@ -107,6 +109,31 @@ LIBBPF_API struct btf *btf__new_empty(void);
*/
LIBBPF_API struct btf *btf__new_empty_split(struct btf *base_btf);
+/**
+ * @brief **btf__distill_base()** creates new versions of the split BTF
+ * *src_btf* and its base BTF. The new base BTF will only contain the types
+ * needed to improve robustness of the split BTF to small changes in base BTF.
+ * When that split BTF is loaded against a (possibly changed) base, this
+ * distilled base BTF will help update references to that (possibly changed)
+ * base BTF.
+ * @param src_btf source split BTF object
+ * @param new_base_btf pointer to where the new base BTF object pointer will be stored
+ * @param new_split_btf pointer to where the new split BTF object pointer will be stored
+ * @return 0 on success; negative error code, otherwise
+ *
+ * Both the new split and its associated new base BTF must be freed by
+ * the caller.
+ *
+ * If successful, 0 is returned and **new_base_btf** and **new_split_btf**
+ * will point at new base/split BTF. Both the new split and its associated
+ * new base BTF must be freed by the caller.
+ *
+ * A negative value is returned on error and the thread-local `errno` variable
+ * is set to the error code as well.
+ */
+LIBBPF_API int btf__distill_base(const struct btf *src_btf, struct btf **new_base_btf,
+ struct btf **new_split_btf);
+
LIBBPF_API struct btf *btf__parse(const char *path, struct btf_ext **btf_ext);
LIBBPF_API struct btf *btf__parse_split(const char *path, struct btf *base_btf);
LIBBPF_API struct btf *btf__parse_elf(const char *path, struct btf_ext **btf_ext);
@@ -116,24 +143,15 @@ LIBBPF_API struct btf *btf__parse_raw_split(const char *path, struct btf *base_b
LIBBPF_API struct btf *btf__load_vmlinux_btf(void);
LIBBPF_API struct btf *btf__load_module_btf(const char *module_name, struct btf *vmlinux_btf);
-LIBBPF_API struct btf *libbpf_find_kernel_btf(void);
LIBBPF_API struct btf *btf__load_from_kernel_by_id(__u32 id);
LIBBPF_API struct btf *btf__load_from_kernel_by_id_split(__u32 id, struct btf *base_btf);
-LIBBPF_DEPRECATED_SINCE(0, 6, "use btf__load_from_kernel_by_id instead")
-LIBBPF_API int btf__get_from_id(__u32 id, struct btf **btf);
-LIBBPF_DEPRECATED_SINCE(0, 6, "intended for internal libbpf use only")
-LIBBPF_API int btf__finalize_data(struct bpf_object *obj, struct btf *btf);
-LIBBPF_DEPRECATED_SINCE(0, 6, "use btf__load_into_kernel instead")
-LIBBPF_API int btf__load(struct btf *btf);
LIBBPF_API int btf__load_into_kernel(struct btf *btf);
LIBBPF_API __s32 btf__find_by_name(const struct btf *btf,
const char *type_name);
LIBBPF_API __s32 btf__find_by_name_kind(const struct btf *btf,
const char *type_name, __u32 kind);
-LIBBPF_DEPRECATED_SINCE(0, 7, "use btf__type_cnt() instead; note that btf__get_nr_types() == btf__type_cnt() - 1")
-LIBBPF_API __u32 btf__get_nr_types(const struct btf *btf);
LIBBPF_API __u32 btf__type_cnt(const struct btf *btf);
LIBBPF_API const struct btf *btf__base_btf(const struct btf *btf);
LIBBPF_API const struct btf_type *btf__type_by_id(const struct btf *btf,
@@ -147,32 +165,16 @@ LIBBPF_API int btf__resolve_type(const struct btf *btf, __u32 type_id);
LIBBPF_API int btf__align_of(const struct btf *btf, __u32 id);
LIBBPF_API int btf__fd(const struct btf *btf);
LIBBPF_API void btf__set_fd(struct btf *btf, int fd);
-LIBBPF_DEPRECATED_SINCE(0, 7, "use btf__raw_data() instead")
-LIBBPF_API const void *btf__get_raw_data(const struct btf *btf, __u32 *size);
LIBBPF_API const void *btf__raw_data(const struct btf *btf, __u32 *size);
LIBBPF_API const char *btf__name_by_offset(const struct btf *btf, __u32 offset);
LIBBPF_API const char *btf__str_by_offset(const struct btf *btf, __u32 offset);
-LIBBPF_API int btf__get_map_kv_tids(const struct btf *btf, const char *map_name,
- __u32 expected_key_size,
- __u32 expected_value_size,
- __u32 *key_type_id, __u32 *value_type_id);
LIBBPF_API struct btf_ext *btf_ext__new(const __u8 *data, __u32 size);
LIBBPF_API void btf_ext__free(struct btf_ext *btf_ext);
-LIBBPF_API const void *btf_ext__get_raw_data(const struct btf_ext *btf_ext,
- __u32 *size);
-LIBBPF_API LIBBPF_DEPRECATED("btf_ext__reloc_func_info was never meant as a public API and has wrong assumptions embedded in it; it will be removed in the future libbpf versions")
-int btf_ext__reloc_func_info(const struct btf *btf,
- const struct btf_ext *btf_ext,
- const char *sec_name, __u32 insns_cnt,
- void **func_info, __u32 *cnt);
-LIBBPF_API LIBBPF_DEPRECATED("btf_ext__reloc_line_info was never meant as a public API and has wrong assumptions embedded in it; it will be removed in the future libbpf versions")
-int btf_ext__reloc_line_info(const struct btf *btf,
- const struct btf_ext *btf_ext,
- const char *sec_name, __u32 insns_cnt,
- void **line_info, __u32 *cnt);
-LIBBPF_API __u32 btf_ext__func_info_rec_size(const struct btf_ext *btf_ext);
-LIBBPF_API __u32 btf_ext__line_info_rec_size(const struct btf_ext *btf_ext);
+LIBBPF_API const void *btf_ext__raw_data(const struct btf_ext *btf_ext, __u32 *size);
+LIBBPF_API enum btf_endianness btf_ext__endianness(const struct btf_ext *btf_ext);
+LIBBPF_API int btf_ext__set_endianness(struct btf_ext *btf_ext,
+ enum btf_endianness endian);
LIBBPF_API int btf__find_str(struct btf *btf, const char *s);
LIBBPF_API int btf__add_str(struct btf *btf, const char *s);
@@ -215,6 +217,8 @@ 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,
@@ -228,6 +232,7 @@ LIBBPF_API int btf__add_volatile(struct btf *btf, int ref_type_id);
LIBBPF_API int btf__add_const(struct btf *btf, int ref_type_id);
LIBBPF_API int btf__add_restrict(struct btf *btf, int ref_type_id);
LIBBPF_API int btf__add_type_tag(struct btf *btf, const char *value, int ref_type_id);
+LIBBPF_API int btf__add_type_attr(struct btf *btf, const char *value, int ref_type_id);
/* func and func_proto construction APIs */
LIBBPF_API int btf__add_func(struct btf *btf, const char *name,
@@ -244,6 +249,8 @@ LIBBPF_API int btf__add_datasec_var_info(struct btf *btf, int var_type_id,
/* tag construction API */
LIBBPF_API int btf__add_decl_tag(struct btf *btf, const char *value, int ref_type_id,
int component_idx);
+LIBBPF_API int btf__add_decl_attr(struct btf *btf, const char *value, int ref_type_id,
+ int component_idx);
struct btf_dedup_opts {
size_t sz;
@@ -257,22 +264,29 @@ struct btf_dedup_opts {
LIBBPF_API int btf__dedup(struct btf *btf, const struct btf_dedup_opts *opts);
-LIBBPF_API int btf__dedup_v0_6_0(struct btf *btf, const struct btf_dedup_opts *opts);
-
-LIBBPF_DEPRECATED_SINCE(0, 7, "use btf__dedup() instead")
-LIBBPF_API int btf__dedup_deprecated(struct btf *btf, struct btf_ext *btf_ext, const void *opts);
-#define btf__dedup(...) ___libbpf_overload(___btf_dedup, __VA_ARGS__)
-#define ___btf_dedup3(btf, btf_ext, opts) btf__dedup_deprecated(btf, btf_ext, opts)
-#define ___btf_dedup2(btf, opts) btf__dedup(btf, opts)
+/**
+ * @brief **btf__relocate()** will check the split BTF *btf* for references
+ * to base BTF kinds, and verify those references are compatible with
+ * *base_btf*; if they are, *btf* is adjusted such that is re-parented to
+ * *base_btf* and type ids and strings are adjusted to accommodate this.
+ * @param btf split BTF object to relocate
+ * @param base_btf base BTF object
+ * @return 0 on success; negative error code, otherwise
+ *
+ * If successful, 0 is returned and **btf** now has **base_btf** as its
+ * base.
+ *
+ * A negative value is returned on error and the thread-local `errno` variable
+ * is set to the error code as well.
+ */
+LIBBPF_API int btf__relocate(struct btf *btf, const struct btf *base_btf);
struct btf_dump;
struct btf_dump_opts {
- union {
- size_t sz;
- void *ctx; /* DEPRECATED: will be gone in v1.0 */
- };
+ size_t sz;
};
+#define btf_dump_opts__last_field sz
typedef void (*btf_dump_printf_fn_t)(void *ctx, const char *fmt, va_list args);
@@ -281,57 +295,12 @@ LIBBPF_API struct btf_dump *btf_dump__new(const struct btf *btf,
void *ctx,
const struct btf_dump_opts *opts);
-LIBBPF_API struct btf_dump *btf_dump__new_v0_6_0(const struct btf *btf,
- btf_dump_printf_fn_t printf_fn,
- void *ctx,
- const struct btf_dump_opts *opts);
-
-LIBBPF_API struct btf_dump *btf_dump__new_deprecated(const struct btf *btf,
- const struct btf_ext *btf_ext,
- const struct btf_dump_opts *opts,
- btf_dump_printf_fn_t printf_fn);
-
-/* Choose either btf_dump__new() or btf_dump__new_deprecated() based on the
- * type of 4th argument. If it's btf_dump's print callback, use deprecated
- * API; otherwise, choose the new btf_dump__new(). ___libbpf_override()
- * doesn't work here because both variants have 4 input arguments.
- *
- * (void *) casts are necessary to avoid compilation warnings about type
- * mismatches, because even though __builtin_choose_expr() only ever evaluates
- * one side the other side still has to satisfy type constraints (this is
- * compiler implementation limitation which might be lifted eventually,
- * according to the documentation). So passing struct btf_ext in place of
- * btf_dump_printf_fn_t would be generating compilation warning. Casting to
- * void * avoids this issue.
- *
- * Also, two type compatibility checks for a function and function pointer are
- * required because passing function reference into btf_dump__new() as
- * btf_dump__new(..., my_callback, ...) and as btf_dump__new(...,
- * &my_callback, ...) (not explicit ampersand in the latter case) actually
- * differs as far as __builtin_types_compatible_p() is concerned. Thus two
- * checks are combined to detect callback argument.
- *
- * The rest works just like in case of ___libbpf_override() usage with symbol
- * versioning.
- *
- * C++ compilers don't support __builtin_types_compatible_p(), so at least
- * don't screw up compilation for them and let C++ users pick btf_dump__new
- * vs btf_dump__new_deprecated explicitly.
- */
-#ifndef __cplusplus
-#define btf_dump__new(a1, a2, a3, a4) __builtin_choose_expr( \
- __builtin_types_compatible_p(typeof(a4), btf_dump_printf_fn_t) || \
- __builtin_types_compatible_p(typeof(a4), void(void *, const char *, va_list)), \
- btf_dump__new_deprecated((void *)a1, (void *)a2, (void *)a3, (void *)a4), \
- btf_dump__new((void *)a1, (void *)a2, (void *)a3, (void *)a4))
-#endif
-
LIBBPF_API void btf_dump__free(struct btf_dump *d);
LIBBPF_API int btf_dump__dump_type(struct btf_dump *d, __u32 id);
struct btf_dump_emit_type_decl_opts {
- /* size of this struct, for forward/backward compatiblity */
+ /* size of this struct, for forward/backward compatibility */
size_t sz;
/* optional field name for type declaration, e.g.:
* - struct my_struct <FNAME>
@@ -365,9 +334,10 @@ struct btf_dump_type_data_opts {
bool compact; /* no newlines/indentation */
bool skip_names; /* skip member/type names */
bool emit_zeroes; /* show 0-valued fields */
+ bool emit_strings; /* print char arrays as strings */
size_t :0;
};
-#define btf_dump_type_data_opts__last_field emit_zeroes
+#define btf_dump_type_data_opts__last_field emit_strings
LIBBPF_API int
btf_dump__dump_type_data(struct btf_dump *d, __u32 id,
@@ -375,8 +345,29 @@ btf_dump__dump_type_data(struct btf_dump *d, __u32 id,
const struct btf_dump_type_data_opts *opts);
/*
- * A set of helpers for easier BTF types handling
+ * A set of helpers for easier BTF types handling.
+ *
+ * The inline functions below rely on constants from the kernel headers which
+ * may not be available for applications including this header file. To avoid
+ * compilation errors, we define all the constants here that were added after
+ * the initial introduction of the BTF_KIND* constants.
*/
+#ifndef BTF_KIND_FUNC
+#define BTF_KIND_FUNC 12 /* Function */
+#define BTF_KIND_FUNC_PROTO 13 /* Function Proto */
+#endif
+#ifndef BTF_KIND_VAR
+#define BTF_KIND_VAR 14 /* Variable */
+#define BTF_KIND_DATASEC 15 /* Section */
+#endif
+#ifndef BTF_KIND_FLOAT
+#define BTF_KIND_FLOAT 16 /* Floating point */
+#endif
+/* 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)
{
return BTF_INFO_KIND(t->info);
@@ -434,6 +425,11 @@ 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;
@@ -504,6 +500,18 @@ 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 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));
@@ -529,6 +537,39 @@ static inline struct btf_enum *btf_enum(const struct btf_type *t)
return (struct btf_enum *)(t + 1);
}
+struct btf_enum64;
+
+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)
+{
+ /* struct btf_enum64 is introduced in Linux 6.0, which is very
+ * bleeding-edge. Here we are avoiding relying on struct btf_enum64
+ * definition coming from kernel UAPI headers to support wider range
+ * of system-wide kernel headers.
+ *
+ * Given this header can be also included from C++ applications, that
+ * further restricts C tricks we can use (like using compatible
+ * anonymous struct). So just treat struct btf_enum64 as
+ * a three-element array of u32 and access second (lo32) and third
+ * (hi32) elements directly.
+ *
+ * For reference, here is a struct btf_enum64 definition:
+ *
+ * const struct btf_enum64 {
+ * __u32 name_off;
+ * __u32 val_lo32;
+ * __u32 val_hi32;
+ * };
+ */
+ const __u32 *e64 = (const __u32 *)e;
+
+ return ((__u64)e64[2] << 32) | e64[1];
+}
+
static inline struct btf_member *btf_members(const struct btf_type *t)
{
return (struct btf_member *)(t + 1);
generated by cgit (git 2.34.1) at 2025-12-25 09:23:39 +0000