tools/lib/bpf/bpf.c

Source file repositories/reference/linux-study-clean/tools/lib/bpf/bpf.c

File Facts

System
Linux kernel
Corpus path
tools/lib/bpf/bpf.c
Extension
.c
Size
42948 bytes
Lines
1485
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: implementation source
Status
source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

if (!finfo) {
				errno = E2BIG;
				goto done;
			}

			attr.func_info = ptr_to_u64(finfo);
			attr.func_info_rec_size = func_info_rec_size;
		} else if (!linfo && attr.line_info_cnt &&
			   attr.line_info_rec_size < line_info_rec_size) {
			linfo = alloc_zero_tailing_info(line_info,
							attr.line_info_cnt,
							line_info_rec_size,
							attr.line_info_rec_size);
			if (!linfo) {
				errno = E2BIG;
				goto done;
			}

			attr.line_info = ptr_to_u64(linfo);
			attr.line_info_rec_size = line_info_rec_size;
		} else {
			break;
		}

		fd = sys_bpf_prog_load(&attr, attr_sz, attempts);
		OPTS_SET(opts, log_true_size, attr.log_true_size);
		if (fd >= 0)
			goto done;
	}

	if (log_level == 0 && log_buf) {
		/* log_level == 0 with non-NULL log_buf requires retrying on error
		 * with log_level == 1 and log_buf/log_buf_size set, to get details of
		 * failure
		 */
		attr.log_buf = ptr_to_u64(log_buf);
		attr.log_size = log_size;
		attr.log_level = 1;

		fd = sys_bpf_prog_load(&attr, attr_sz, attempts);
		OPTS_SET(opts, log_true_size, attr.log_true_size);
	}
done:
	/* free() doesn't affect errno, so we don't need to restore it */
	free(finfo);
	free(linfo);
	return libbpf_err_errno(fd);
}

int bpf_map_update_elem(int fd, const void *key, const void *value,
			__u64 flags)
{
	const size_t attr_sz = offsetofend(union bpf_attr, flags);
	union bpf_attr attr;
	int ret;

	memset(&attr, 0, attr_sz);
	attr.map_fd = fd;
	attr.key = ptr_to_u64(key);
	attr.value = ptr_to_u64(value);
	attr.flags = flags;

	ret = sys_bpf(BPF_MAP_UPDATE_ELEM, &attr, attr_sz);
	return libbpf_err_errno(ret);
}

int bpf_map_lookup_elem(int fd, const void *key, void *value)
{
	const size_t attr_sz = offsetofend(union bpf_attr, flags);
	union bpf_attr attr;
	int ret;

	memset(&attr, 0, attr_sz);
	attr.map_fd = fd;
	attr.key = ptr_to_u64(key);
	attr.value = ptr_to_u64(value);

	ret = sys_bpf(BPF_MAP_LOOKUP_ELEM, &attr, attr_sz);
	return libbpf_err_errno(ret);
}

int bpf_map_lookup_elem_flags(int fd, const void *key, void *value, __u64 flags)
{
	const size_t attr_sz = offsetofend(union bpf_attr, flags);
	union bpf_attr attr;
	int ret;

	memset(&attr, 0, attr_sz);
	attr.map_fd = fd;
	attr.key = ptr_to_u64(key);

Annotation

Implementation Notes