Commit ef20a9b2 authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Alexei Starovoitov
Browse files

libbpf: add helpers for working with BTF types 



Add lots of frequently used helpers that simplify working with BTF
types.

Signed-off-by: default avatarAndrii Nakryiko <andriin@fb.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 682cdbdc

tools/lib/bpf/btf.h

+178 −0
Original line number Diff line number Diff line
@@ -5,6 +5,7 @@ 
#define __LIBBPF_BTF_H



#include <stdarg.h>

#include <linux/btf.h>

#include <linux/types.h>



#ifdef __cplusplus
@@ -120,6 +121,183 @@ LIBBPF_API void btf_dump__free(struct btf_dump *d); 


LIBBPF_API int btf_dump__dump_type(struct btf_dump *d, __u32 id);



/*

 * 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_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