include/linux/btf.h

Source file repositories/reference/linux-study-clean/include/linux/btf.h

File Facts

System
Linux kernel
Corpus path
include/linux/btf.h
Extension
.h
Size
21190 bytes
Lines
689
Domain
Core OS
Bucket
Core Kernel Interface
Inferred role
Core OS: operation-table or driver-model contract
Status
pattern implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

extern const struct file_operations btf_fops;

const char *btf_get_name(const struct btf *btf);
void btf_get(struct btf *btf);
void btf_put(struct btf *btf);
const struct btf_header *btf_header(const struct btf *btf);
struct bpf_log_attr;
int btf_new_fd(const union bpf_attr *attr, bpfptr_t uattr, struct bpf_log_attr *attr_log);
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_obj_id(const struct btf *btf);
bool btf_is_kernel(const struct btf *btf);
bool btf_is_module(const struct btf *btf);
bool btf_is_vmlinux(const struct btf *btf);
struct module *btf_try_get_module(const struct btf *btf);
u32 btf_nr_types(const struct btf *btf);
u32 btf_named_start_id(const struct btf *btf, bool own);
struct btf *btf_base_btf(const struct btf *btf);
bool btf_type_is_i32(const struct btf_type *t);
bool btf_type_is_i64(const struct btf_type *t);
bool btf_type_is_primitive(const struct btf_type *t);
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);

Annotation

Implementation Notes