Commit 395fc4fa authored by Joe Burton's avatar Joe Burton Committed by Andrii Nakryiko
Browse files

libbpf: Add bpf_obj_get_opts() 



Add an extensible variant of bpf_obj_get() capable of setting the
`file_flags` parameter.

This parameter is needed to enable unprivileged access to BPF maps.
Without a method like this, users must manually make the syscall.

Signed-off-by: default avatarJoe Burton <jevburton@google.com>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220729202727.3311806-1-jevburton.kernel@gmail.com
parent d0b80a9e

tools/lib/bpf/bpf.c

+9 −0
Original line number Diff line number Diff line
@@ -578,12 +578,21 @@ int bpf_obj_pin(int fd, const char *pathname) 
}



int bpf_obj_get(const char *pathname)

{

	return bpf_obj_get_opts(pathname, NULL);

}



int bpf_obj_get_opts(const char *pathname, const struct bpf_obj_get_opts *opts)

{

	union bpf_attr attr;

	int fd;



	if (!OPTS_VALID(opts, bpf_obj_get_opts))

		return libbpf_err(-EINVAL);



	memset(&attr, 0, sizeof(attr));

	attr.pathname = ptr_to_u64((void *)pathname);

	attr.file_flags = OPTS_GET(opts, file_flags, 0);



	fd = sys_bpf_fd(BPF_OBJ_GET, &attr, sizeof(attr));

	return libbpf_err_errno(fd);

tools/lib/bpf/bpf.h

+11 −0
Original line number Diff line number Diff line
@@ -270,8 +270,19 @@ LIBBPF_API int bpf_map_update_batch(int fd, const void *keys, const void *values 
				    __u32 *count,

				    const struct bpf_map_batch_opts *opts);



struct bpf_obj_get_opts {

	size_t sz; /* size of this struct for forward/backward compatibility */



	__u32 file_flags;



	size_t :0;

};

#define bpf_obj_get_opts__last_field file_flags



LIBBPF_API int bpf_obj_pin(int fd, const char *pathname);

LIBBPF_API int bpf_obj_get(const char *pathname);

LIBBPF_API int bpf_obj_get_opts(const char *pathname,

				const struct bpf_obj_get_opts *opts);



struct bpf_prog_attach_opts {

	size_t sz; /* size of this struct for forward/backward compatibility */

tools/lib/bpf/libbpf.map

+1 −0
Original line number Diff line number Diff line
@@ -355,6 +355,7 @@ LIBBPF_0.8.0 { 


LIBBPF_1.0.0 {

	global:

		bpf_obj_get_opts;

		bpf_prog_query_opts;

		bpf_program__attach_ksyscall;

		btf__add_enum64;