[thirdparty/kernel/linux.git] / include / linux / btf.h

/* SPDX-License-Identifier: GPL-2.0 */
/* Copyright (c) 2018 Facebook */

#ifndef _LINUX_BTF_H
#define _LINUX_BTF_H 1

#include <linux/types.h>
#include <uapi/linux/btf.h>
#include <uapi/linux/bpf.h>

#define BTF_TYPE_EMIT(type) ((void)(type *)0)

struct btf;
struct btf_member;
struct btf_type;
union bpf_attr;
struct btf_show;

extern const struct file_operations btf_fops;

void btf_put(struct btf *btf);
int btf_new_fd(const union bpf_attr *attr);
struct btf *btf_get_by_fd(int fd);
int btf_get_info_by_fd(const struct btf *btf,
		       const union bpf_attr *attr,
		       union bpf_attr __user *uattr);
/* Figure out the size of a type_id.  If type_id is a modifier
 * (e.g. const), it will be resolved to find out the type with size.
 *
 * For example:
 * In describing "const void *",  type_id is "const" and "const"
 * refers to "void *".  The return type will be "void *".
 *
 * If type_id is a simple "int", then return type will be "int".
 *
 * @btf: struct btf object
 * @type_id: Find out the size of type_id. The type_id of the return
 *           type is set to *type_id.
 * @ret_size: It can be NULL.  If not NULL, the size of the return
 *            type is set to *ret_size.
 * Return: The btf_type (resolved to another type with size info if needed).
 *         NULL is returned if type_id itself does not have size info
 *         (e.g. void) or it cannot be resolved to another type that
 *         has size info.
 *         *type_id and *ret_size will not be changed in the
 *         NULL return case.
 */
const struct btf_type *btf_type_id_size(const struct btf *btf,
					u32 *type_id,
					u32 *ret_size);

/*
 * Options to control show behaviour.
 *	- BTF_SHOW_COMPACT: no formatting around type information
 *	- BTF_SHOW_NONAME: no struct/union member names/types
 *	- BTF_SHOW_PTR_RAW: show raw (unobfuscated) pointer values;
 *	  equivalent to %px.
 *	- BTF_SHOW_ZERO: show zero-valued struct/union members; they
 *	  are not displayed by default
 *	- BTF_SHOW_UNSAFE: skip use of bpf_probe_read() to safely read
 *	  data before displaying it.
 */
#define BTF_SHOW_COMPACT	BTF_F_COMPACT
#define BTF_SHOW_NONAME		BTF_F_NONAME
#define BTF_SHOW_PTR_RAW	BTF_F_PTR_RAW
#define BTF_SHOW_ZERO		BTF_F_ZERO
#define BTF_SHOW_UNSAFE		(1ULL << 4)

void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj,
		       struct seq_file *m);
int btf_type_seq_show_flags(const struct btf *btf, u32 type_id, void *obj,
			    struct seq_file *m, u64 flags);

/*
 * Copy len bytes of string representation of obj of BTF type_id into buf.
 *
 * @btf: struct btf object
 * @type_id: type id of type obj points to
 * @obj: pointer to typed data
 * @buf: buffer to write to
 * @len: maximum length to write to buf
 * @flags: show options (see above)
 *
 * Return: length that would have been/was copied as per snprintf, or
 *	   negative error.
 */
int btf_type_snprintf_show(const struct btf *btf, u32 type_id, void *obj,
			   char *buf, int len, u64 flags);

int btf_get_fd_by_id(u32 id);
u32 btf_id(const struct btf *btf);
bool btf_member_is_reg_int(const struct btf *btf, const struct btf_type *s,
			   const struct btf_member *m,
			   u32 expected_offset, u32 expected_size);
int btf_find_spin_lock(const struct btf *btf, const struct btf_type *t);
bool btf_type_is_void(const struct btf_type *t);
s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind);
const struct btf_type *btf_type_skip_modifiers(const struct btf *btf,
					       u32 id, u32 *res_id);
const struct btf_type *btf_type_resolve_ptr(const struct btf *btf,
					    u32 id, u32 *res_id);
const struct btf_type *btf_type_resolve_func_ptr(const struct btf *btf,
						 u32 id, u32 *res_id);
const struct btf_type *
btf_resolve_size(const struct btf *btf, const struct btf_type *type,
		 u32 *type_size);

#define for_each_member(i, struct_type, member)			\
	for (i = 0, member = btf_type_member(struct_type);	\
	     i < btf_type_vlen(struct_type);			\
	     i++, member++)

static inline bool btf_type_is_ptr(const struct btf_type *t)
{
	return BTF_INFO_KIND(t->info) == BTF_KIND_PTR;
}

static inline bool btf_type_is_int(const struct btf_type *t)
{
	return BTF_INFO_KIND(t->info) == BTF_KIND_INT;
}

static inline bool btf_type_is_small_int(const struct btf_type *t)
{
	return btf_type_is_int(t) && t->size <= sizeof(u64);
}

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_type_is_typedef(const struct btf_type *t)
{
	return BTF_INFO_KIND(t->info) == BTF_KIND_TYPEDEF;
}

static inline bool btf_type_is_func(const struct btf_type *t)
{
	return BTF_INFO_KIND(t->info) == BTF_KIND_FUNC;
}

static inline bool btf_type_is_func_proto(const struct btf_type *t)
{
	return BTF_INFO_KIND(t->info) == BTF_KIND_FUNC_PROTO;
}

static inline bool btf_type_is_var(const struct btf_type *t)
{
	return BTF_INFO_KIND(t->info) == BTF_KIND_VAR;
}

/* union is only a special case of struct:
 * all its offsetof(member) == 0
 */
static inline bool btf_type_is_struct(const struct btf_type *t)
{
	u8 kind = BTF_INFO_KIND(t->info);

	return kind == BTF_KIND_STRUCT || kind == BTF_KIND_UNION;
}

static inline u16 btf_type_vlen(const struct btf_type *t)
{
	return BTF_INFO_VLEN(t->info);
}

static inline u16 btf_func_linkage(const struct btf_type *t)
{
	return BTF_INFO_VLEN(t->info);
}

static inline bool btf_type_kflag(const struct btf_type *t)
{
	return BTF_INFO_KFLAG(t->info);
}

static inline u32 btf_member_bit_offset(const struct btf_type *struct_type,
					const struct btf_member *member)
{
	return btf_type_kflag(struct_type) ? BTF_MEMBER_BIT_OFFSET(member->offset)
					   : member->offset;
}

static inline u32 btf_member_bitfield_size(const struct btf_type *struct_type,
					   const struct btf_member *member)
{
	return btf_type_kflag(struct_type) ? BTF_MEMBER_BITFIELD_SIZE(member->offset)
					   : 0;
}

static inline const struct btf_member *btf_type_member(const struct btf_type *t)
{
	return (const struct btf_member *)(t + 1);
}

#ifdef CONFIG_BPF_SYSCALL
const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id);
const char *btf_name_by_offset(const struct btf *btf, u32 offset);
struct btf *btf_parse_vmlinux(void);
struct btf *bpf_prog_get_target_btf(const struct bpf_prog *prog);
#else
static inline const struct btf_type *btf_type_by_id(const struct btf *btf,
						    u32 type_id)
{
	return NULL;
}
static inline const char *btf_name_by_offset(const struct btf *btf,
					     u32 offset)
{
	return NULL;
}
#endif

#endif
Commit	Line	Data
eb3f595d MKL	1	/* SPDX-License-Identifier: GPL-2.0 */
	2	/* Copyright (c) 2018 Facebook */
	3
	4	#ifndef _LINUX_BTF_H
	5	#define _LINUX_BTF_H 1
	6
	7	#include <linux/types.h>
38207291	8	#include <uapi/linux/btf.h>
c4d0bfb4	9	#include <uapi/linux/bpf.h>
eb3f595d	10
85d33df3 MKL	11	#define BTF_TYPE_EMIT(type) ((void)(type *)0)
85d33df3 MKL	12
eb3f595d	13	struct btf;
ffa0c1cf	14	struct btf_member;
eb3f595d	15	struct btf_type;
f56a653c	16	union bpf_attr;
31d0bc81	17	struct btf_show;
eb3f595d	18
60197cfb MKL	19	extern const struct file_operations btf_fops;
60197cfb MKL	20
f56a653c MKL	21	void btf_put(struct btf *btf);
	22	int btf_new_fd(const union bpf_attr *attr);
	23	struct btf *btf_get_by_fd(int fd);
60197cfb MKL	24	int btf_get_info_by_fd(const struct btf *btf,
	25	const union bpf_attr *attr,
	26	union bpf_attr __user *uattr);
eb3f595d MKL	27	/* Figure out the size of a type_id. If type_id is a modifier
	28	* (e.g. const), it will be resolved to find out the type with size.
	29	*
	30	* For example:
	31	* In describing "const void *", type_id is "const" and "const"
	32	* refers to "void ". The return type will be "void ".
	33	*
	34	* If type_id is a simple "int", then return type will be "int".
	35	*
	36	* @btf: struct btf object
	37	* @type_id: Find out the size of type_id. The type_id of the return
	38	* type is set to *type_id.
	39	* @ret_size: It can be NULL. If not NULL, the size of the return
	40	* type is set to *ret_size.
	41	* Return: The btf_type (resolved to another type with size info if needed).
	42	* NULL is returned if type_id itself does not have size info
	43	* (e.g. void) or it cannot be resolved to another type that
	44	* has size info.
	45	* type_id and ret_size will not be changed in the
	46	* NULL return case.
	47	*/
	48	const struct btf_type btf_type_id_size(const struct btf btf,
	49	u32 *type_id,
	50	u32 *ret_size);
31d0bc81 AM	51
	52	/*
	53	* Options to control show behaviour.
	54	* - BTF_SHOW_COMPACT: no formatting around type information
	55	* - BTF_SHOW_NONAME: no struct/union member names/types
	56	* - BTF_SHOW_PTR_RAW: show raw (unobfuscated) pointer values;
	57	* equivalent to %px.
	58	* - BTF_SHOW_ZERO: show zero-valued struct/union members; they
	59	* are not displayed by default
	60	* - BTF_SHOW_UNSAFE: skip use of bpf_probe_read() to safely read
	61	* data before displaying it.
	62	*/
c4d0bfb4 AM	63	#define BTF_SHOW_COMPACT BTF_F_COMPACT
	64	#define BTF_SHOW_NONAME BTF_F_NONAME
	65	#define BTF_SHOW_PTR_RAW BTF_F_PTR_RAW
	66	#define BTF_SHOW_ZERO BTF_F_ZERO
31d0bc81 AM	67	#define BTF_SHOW_UNSAFE (1ULL << 4)
31d0bc81 AM	68
b00b8dae MKL	69	void btf_type_seq_show(const struct btf btf, u32 type_id, void obj,
b00b8dae MKL	70	struct seq_file *m);
eb411377 AM	71	int btf_type_seq_show_flags(const struct btf btf, u32 type_id, void obj,
eb411377 AM	72	struct seq_file *m, u64 flags);
31d0bc81 AM	73
	74	/*
	75	* Copy len bytes of string representation of obj of BTF type_id into buf.
	76	*
	77	* @btf: struct btf object
	78	* @type_id: type id of type obj points to
	79	* @obj: pointer to typed data
	80	* @buf: buffer to write to
	81	* @len: maximum length to write to buf
	82	* @flags: show options (see above)
	83	*
	84	* Return: length that would have been/was copied as per snprintf, or
	85	* negative error.
	86	*/
	87	int btf_type_snprintf_show(const struct btf btf, u32 type_id, void obj,
	88	char *buf, int len, u64 flags);
	89
78958fca MKL	90	int btf_get_fd_by_id(u32 id);
78958fca MKL	91	u32 btf_id(const struct btf *btf);
ffa0c1cf YS	92	bool btf_member_is_reg_int(const struct btf btf, const struct btf_type s,
	93	const struct btf_member *m,
	94	u32 expected_offset, u32 expected_size);
d83525ca	95	int btf_find_spin_lock(const struct btf btf, const struct btf_type t);
2824ecb7	96	bool btf_type_is_void(const struct btf_type *t);
27ae7997 MKL	97	s32 btf_find_by_name_kind(const struct btf btf, const char name, u8 kind);
	98	const struct btf_type btf_type_skip_modifiers(const struct btf btf,
	99	u32 id, u32 *res_id);
	100	const struct btf_type btf_type_resolve_ptr(const struct btf btf,
	101	u32 id, u32 *res_id);
	102	const struct btf_type btf_type_resolve_func_ptr(const struct btf btf,
	103	u32 id, u32 *res_id);
85d33df3 MKL	104	const struct btf_type *
85d33df3 MKL	105	btf_resolve_size(const struct btf btf, const struct btf_type type,
6298399b	106	u32 *type_size);
27ae7997 MKL	107
	108	#define for_each_member(i, struct_type, member) \
	109	for (i = 0, member = btf_type_member(struct_type); \
	110	i < btf_type_vlen(struct_type); \
	111	i++, member++)
f6161a8f	112
38207291 MKL	113	static inline bool btf_type_is_ptr(const struct btf_type *t)
	114	{
	115	return BTF_INFO_KIND(t->info) == BTF_KIND_PTR;
	116	}
	117
	118	static inline bool btf_type_is_int(const struct btf_type *t)
	119	{
	120	return BTF_INFO_KIND(t->info) == BTF_KIND_INT;
	121	}
	122
a9b59159 JF	123	static inline bool btf_type_is_small_int(const struct btf_type *t)
	124	{
	125	return btf_type_is_int(t) && t->size <= sizeof(u64);
	126	}
	127
38207291 MKL	128	static inline bool btf_type_is_enum(const struct btf_type *t)
	129	{
	130	return BTF_INFO_KIND(t->info) == BTF_KIND_ENUM;
	131	}
	132
	133	static inline bool btf_type_is_typedef(const struct btf_type *t)
	134	{
	135	return BTF_INFO_KIND(t->info) == BTF_KIND_TYPEDEF;
	136	}
	137
	138	static inline bool btf_type_is_func(const struct btf_type *t)
	139	{
	140	return BTF_INFO_KIND(t->info) == BTF_KIND_FUNC;
	141	}
	142
	143	static inline bool btf_type_is_func_proto(const struct btf_type *t)
	144	{
	145	return BTF_INFO_KIND(t->info) == BTF_KIND_FUNC_PROTO;
	146	}
	147
4976b718 HL	148	static inline bool btf_type_is_var(const struct btf_type *t)
	149	{
	150	return BTF_INFO_KIND(t->info) == BTF_KIND_VAR;
	151	}
	152
	153	/* union is only a special case of struct:
	154	* all its offsetof(member) == 0
	155	*/
	156	static inline bool btf_type_is_struct(const struct btf_type *t)
	157	{
	158	u8 kind = BTF_INFO_KIND(t->info);
	159
	160	return kind == BTF_KIND_STRUCT \|\| kind == BTF_KIND_UNION;
	161	}
	162
27ae7997 MKL	163	static inline u16 btf_type_vlen(const struct btf_type *t)
	164	{
	165	return BTF_INFO_VLEN(t->info);
	166	}
	167
be8704ff AS	168	static inline u16 btf_func_linkage(const struct btf_type *t)
	169	{
	170	return BTF_INFO_VLEN(t->info);
	171	}
	172
27ae7997 MKL	173	static inline bool btf_type_kflag(const struct btf_type *t)
	174	{
	175	return BTF_INFO_KFLAG(t->info);
	176	}
	177
85d33df3 MKL	178	static inline u32 btf_member_bit_offset(const struct btf_type *struct_type,
	179	const struct btf_member *member)
	180	{
	181	return btf_type_kflag(struct_type) ? BTF_MEMBER_BIT_OFFSET(member->offset)
	182	: member->offset;
	183	}
	184
27ae7997 MKL	185	static inline u32 btf_member_bitfield_size(const struct btf_type *struct_type,
	186	const struct btf_member *member)
	187	{
	188	return btf_type_kflag(struct_type) ? BTF_MEMBER_BITFIELD_SIZE(member->offset)
	189	: 0;
	190	}
	191
	192	static inline const struct btf_member btf_type_member(const struct btf_type t)
	193	{
	194	return (const struct btf_member *)(t + 1);
	195	}
	196
f6161a8f	197	#ifdef CONFIG_BPF_SYSCALL
838e9690 YS	198	const struct btf_type btf_type_by_id(const struct btf btf, u32 type_id);
838e9690 YS	199	const char btf_name_by_offset(const struct btf btf, u32 offset);
8580ac94	200	struct btf *btf_parse_vmlinux(void);
5b92a28a	201	struct btf bpf_prog_get_target_btf(const struct bpf_prog prog);
f6161a8f YS	202	#else
	203	static inline const struct btf_type btf_type_by_id(const struct btf btf,
	204	u32 type_id)
	205	{
	206	return NULL;
	207	}
	208	static inline const char btf_name_by_offset(const struct btf btf,
	209	u32 offset)
	210	{
	211	return NULL;
	212	}
	213	#endif
eb3f595d MKL	214
eb3f595d MKL	215	#endif