libbpf: Add BPF token support to bpf_btf_load() API

Allow user to specify token_fd for bpf_btf_load() API that wraps
kernel's BPF_BTF_LOAD command. This allows loading BTF from unprivileged
process as long as it has BPF token allowing BPF_BTF_LOAD command, which
can be created and delegated by privileged process.

Wire through new btf_flags as well, so that user can provide
BPF_F_TOKEN_FD flag, if necessary.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20240124022127.2379740-15-andrii@kernel.org
This commit is contained in:
Andrii Nakryiko 2024-01-23 18:21:11 -08:00 committed by Alexei Starovoitov
parent 364f848375
commit a3d63e8525
2 changed files with 9 additions and 2 deletions

View file

@ -1185,7 +1185,7 @@ int bpf_raw_tracepoint_open(const char *name, int prog_fd)
int bpf_btf_load(const void *btf_data, size_t btf_size, struct bpf_btf_load_opts *opts)
{
const size_t attr_sz = offsetofend(union bpf_attr, btf_log_true_size);
const size_t attr_sz = offsetofend(union bpf_attr, btf_token_fd);
union bpf_attr attr;
char *log_buf;
size_t log_size;
@ -1210,6 +1210,10 @@ int bpf_btf_load(const void *btf_data, size_t btf_size, struct bpf_btf_load_opts
attr.btf = ptr_to_u64(btf_data);
attr.btf_size = btf_size;
attr.btf_flags = OPTS_GET(opts, btf_flags, 0);
attr.btf_token_fd = OPTS_GET(opts, token_fd, 0);
/* log_level == 0 and log_buf != NULL means "try loading without
* log_buf, but retry with log_buf and log_level=1 on error", which is
* consistent across low-level and high-level BTF and program loading

View file

@ -134,9 +134,12 @@ struct bpf_btf_load_opts {
* If kernel doesn't support this feature, log_size is left unchanged.
*/
__u32 log_true_size;
__u32 btf_flags;
__u32 token_fd;
size_t :0;
};
#define bpf_btf_load_opts__last_field log_true_size
#define bpf_btf_load_opts__last_field token_fd
LIBBPF_API int bpf_btf_load(const void *btf_data, size_t btf_size,
struct bpf_btf_load_opts *opts);