linux_dsm_epyc7002/tools/lib/bpf/btf.h
KP Singh 454fb20747 libbpf: Add explicit padding to btf_dump_emit_type_decl_opts
[ Upstream commit ea24b19562fe5f72c78319dbb347b701818956d9 ]

Similar to
https://lore.kernel.org/bpf/20210313210920.1959628-2-andrii@kernel.org/

When DECLARE_LIBBPF_OPTS is used with inline field initialization, e.g:

  DECLARE_LIBBPF_OPTS(btf_dump_emit_type_decl_opts, opts,
    .field_name = var_ident,
    .indent_level = 2,
    .strip_mods = strip_mods,
  );

and compiled in debug mode, the compiler generates code which
leaves the padding uninitialized and triggers errors within libbpf APIs
which require strict zero initialization of OPTS structs.

Adding anonymous padding field fixes the issue.

Fixes: 9f81654eeb ("libbpf: Expose BTF-to-C type declaration emitting API")
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: KP Singh <kpsingh@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210319192117.2310658-1-kpsingh@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-14 09:50:30 +02:00

362 lines
11 KiB
C

/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
/* Copyright (c) 2018 Facebook */
#ifndef __LIBBPF_BTF_H
#define __LIBBPF_BTF_H
#include <stdarg.h>
#include <stdbool.h>
#include <linux/btf.h>
#include <linux/types.h>
#include "libbpf_common.h"
#ifdef __cplusplus
extern "C" {
#endif
#define BTF_ELF_SEC ".BTF"
#define BTF_EXT_ELF_SEC ".BTF.ext"
#define MAPS_ELF_SEC ".maps"
struct btf;
struct btf_ext;
struct btf_type;
struct bpf_object;
enum btf_endianness {
BTF_LITTLE_ENDIAN = 0,
BTF_BIG_ENDIAN = 1,
};
LIBBPF_API void btf__free(struct btf *btf);
LIBBPF_API struct btf *btf__new(const void *data, __u32 size);
LIBBPF_API struct btf *btf__new_empty(void);
LIBBPF_API struct btf *btf__parse(const char *path, struct btf_ext **btf_ext);
LIBBPF_API struct btf *btf__parse_elf(const char *path, struct btf_ext **btf_ext);
LIBBPF_API struct btf *btf__parse_raw(const char *path);
LIBBPF_API int btf__finalize_data(struct bpf_object *obj, struct btf *btf);
LIBBPF_API int btf__load(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_API __u32 btf__get_nr_types(const struct btf *btf);
LIBBPF_API const struct btf_type *btf__type_by_id(const struct btf *btf,
__u32 id);
LIBBPF_API size_t btf__pointer_size(const struct btf *btf);
LIBBPF_API int btf__set_pointer_size(struct btf *btf, size_t ptr_sz);
LIBBPF_API enum btf_endianness btf__endianness(const struct btf *btf);
LIBBPF_API int btf__set_endianness(struct btf *btf, enum btf_endianness endian);
LIBBPF_API __s64 btf__resolve_size(const struct btf *btf, __u32 type_id);
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_API const void *btf__get_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_from_id(__u32 id, struct btf **btf);
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(__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 struct btf *libbpf_find_kernel_btf(void);
LIBBPF_API int btf__find_str(struct btf *btf, const char *s);
LIBBPF_API int btf__add_str(struct btf *btf, const char *s);
LIBBPF_API int btf__add_int(struct btf *btf, const char *name, size_t byte_sz, int encoding);
LIBBPF_API int btf__add_ptr(struct btf *btf, int ref_type_id);
LIBBPF_API int btf__add_array(struct btf *btf,
int index_type_id, int elem_type_id, __u32 nr_elems);
/* struct/union construction APIs */
LIBBPF_API int btf__add_struct(struct btf *btf, const char *name, __u32 sz);
LIBBPF_API int btf__add_union(struct btf *btf, const char *name, __u32 sz);
LIBBPF_API int btf__add_field(struct btf *btf, const char *name, int field_type_id,
__u32 bit_offset, __u32 bit_size);
/* 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);
enum btf_fwd_kind {
BTF_FWD_STRUCT = 0,
BTF_FWD_UNION = 1,
BTF_FWD_ENUM = 2,
};
LIBBPF_API int btf__add_fwd(struct btf *btf, const char *name, enum btf_fwd_kind fwd_kind);
LIBBPF_API int btf__add_typedef(struct btf *btf, const char *name, int ref_type_id);
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);
/* func and func_proto construction APIs */
LIBBPF_API int btf__add_func(struct btf *btf, const char *name,
enum btf_func_linkage linkage, int proto_type_id);
LIBBPF_API int btf__add_func_proto(struct btf *btf, int ret_type_id);
LIBBPF_API int btf__add_func_param(struct btf *btf, const char *name, int type_id);
/* var & datasec construction APIs */
LIBBPF_API int btf__add_var(struct btf *btf, const char *name, int linkage, int type_id);
LIBBPF_API int btf__add_datasec(struct btf *btf, const char *name, __u32 byte_sz);
LIBBPF_API int btf__add_datasec_var_info(struct btf *btf, int var_type_id,
__u32 offset, __u32 byte_sz);
struct btf_dedup_opts {
unsigned int dedup_table_size;
bool dont_resolve_fwds;
};
LIBBPF_API int btf__dedup(struct btf *btf, struct btf_ext *btf_ext,
const struct btf_dedup_opts *opts);
struct btf_dump;
struct btf_dump_opts {
void *ctx;
};
typedef void (*btf_dump_printf_fn_t)(void *ctx, const char *fmt, va_list args);
LIBBPF_API struct btf_dump *btf_dump__new(const struct btf *btf,
const struct btf_ext *btf_ext,
const struct btf_dump_opts *opts,
btf_dump_printf_fn_t printf_fn);
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_t sz;
/* optional field name for type declaration, e.g.:
* - struct my_struct <FNAME>
* - void (*<FNAME>)(int)
* - char (*<FNAME>)[123]
*/
const char *field_name;
/* extra indentation level (in number of tabs) to emit for multi-line
* type declarations (e.g., anonymous struct); applies for lines
* starting from the second one (first line is assumed to have
* necessary indentation already
*/
int indent_level;
/* strip all the const/volatile/restrict mods */
bool strip_mods;
size_t :0;
};
#define btf_dump_emit_type_decl_opts__last_field strip_mods
LIBBPF_API int
btf_dump__emit_type_decl(struct btf_dump *d, __u32 id,
const struct btf_dump_emit_type_decl_opts *opts);
/*
* A set of helpers for easier BTF types handling
*/
static inline __u16 btf_kind(const struct btf_type *t)
{
return BTF_INFO_KIND(t->info);
}
static inline __u16 btf_vlen(const struct btf_type *t)
{
return BTF_INFO_VLEN(t->info);
}
static inline bool btf_kflag(const struct btf_type *t)
{
return BTF_INFO_KFLAG(t->info);
}
static inline bool btf_is_void(const struct btf_type *t)
{
return btf_kind(t) == BTF_KIND_UNKN;
}
static inline bool btf_is_int(const struct btf_type *t)
{
return btf_kind(t) == BTF_KIND_INT;
}
static inline bool btf_is_ptr(const struct btf_type *t)
{
return btf_kind(t) == BTF_KIND_PTR;
}
static inline bool btf_is_array(const struct btf_type *t)
{
return btf_kind(t) == BTF_KIND_ARRAY;
}
static inline bool btf_is_struct(const struct btf_type *t)
{
return btf_kind(t) == BTF_KIND_STRUCT;
}
static inline bool btf_is_union(const struct btf_type *t)
{
return btf_kind(t) == BTF_KIND_UNION;
}
static inline bool btf_is_composite(const struct btf_type *t)
{
__u16 kind = btf_kind(t);
return kind == BTF_KIND_STRUCT || kind == BTF_KIND_UNION;
}
static inline bool btf_is_enum(const struct btf_type *t)
{
return btf_kind(t) == BTF_KIND_ENUM;
}
static inline bool btf_is_fwd(const struct btf_type *t)
{
return btf_kind(t) == BTF_KIND_FWD;
}
static inline bool btf_is_typedef(const struct btf_type *t)
{
return btf_kind(t) == BTF_KIND_TYPEDEF;
}
static inline bool btf_is_volatile(const struct btf_type *t)
{
return btf_kind(t) == BTF_KIND_VOLATILE;
}
static inline bool btf_is_const(const struct btf_type *t)
{
return btf_kind(t) == BTF_KIND_CONST;
}
static inline bool btf_is_restrict(const struct btf_type *t)
{
return btf_kind(t) == BTF_KIND_RESTRICT;
}
static inline bool btf_is_mod(const struct btf_type *t)
{
__u16 kind = btf_kind(t);
return kind == BTF_KIND_VOLATILE ||
kind == BTF_KIND_CONST ||
kind == BTF_KIND_RESTRICT;
}
static inline bool btf_is_func(const struct btf_type *t)
{
return btf_kind(t) == BTF_KIND_FUNC;
}
static inline bool btf_is_func_proto(const struct btf_type *t)
{
return btf_kind(t) == BTF_KIND_FUNC_PROTO;
}
static inline bool btf_is_var(const struct btf_type *t)
{
return btf_kind(t) == BTF_KIND_VAR;
}
static inline bool btf_is_datasec(const struct btf_type *t)
{
return btf_kind(t) == BTF_KIND_DATASEC;
}
static inline __u8 btf_int_encoding(const struct btf_type *t)
{
return BTF_INT_ENCODING(*(__u32 *)(t + 1));
}
static inline __u8 btf_int_offset(const struct btf_type *t)
{
return BTF_INT_OFFSET(*(__u32 *)(t + 1));
}
static inline __u8 btf_int_bits(const struct btf_type *t)
{
return BTF_INT_BITS(*(__u32 *)(t + 1));
}
static inline struct btf_array *btf_array(const struct btf_type *t)
{
return (struct btf_array *)(t + 1);
}
static inline struct btf_enum *btf_enum(const struct btf_type *t)
{
return (struct btf_enum *)(t + 1);
}
static inline struct btf_member *btf_members(const struct btf_type *t)
{
return (struct btf_member *)(t + 1);
}
/* Get bit offset of a member with specified index. */
static inline __u32 btf_member_bit_offset(const struct btf_type *t,
__u32 member_idx)
{
const struct btf_member *m = btf_members(t) + member_idx;
bool kflag = btf_kflag(t);
return kflag ? BTF_MEMBER_BIT_OFFSET(m->offset) : m->offset;
}
/*
* Get bitfield size of a member, assuming t is BTF_KIND_STRUCT or
* BTF_KIND_UNION. If member is not a bitfield, zero is returned.
*/
static inline __u32 btf_member_bitfield_size(const struct btf_type *t,
__u32 member_idx)
{
const struct btf_member *m = btf_members(t) + member_idx;
bool kflag = btf_kflag(t);
return kflag ? BTF_MEMBER_BITFIELD_SIZE(m->offset) : 0;
}
static inline struct btf_param *btf_params(const struct btf_type *t)
{
return (struct btf_param *)(t + 1);
}
static inline struct btf_var *btf_var(const struct btf_type *t)
{
return (struct btf_var *)(t + 1);
}
static inline struct btf_var_secinfo *
btf_var_secinfos(const struct btf_type *t)
{
return (struct btf_var_secinfo *)(t + 1);
}
#ifdef __cplusplus
} /* extern "C" */
#endif
#endif /* __LIBBPF_BTF_H */