Commit a3d63e85 authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Alexei Starovoitov
Browse files

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: default avatarAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20240124022127.2379740-15-andrii@kernel.org
parent 364f8483

tools/lib/bpf/bpf.c

+5 −1
Original line number Diff line number Diff line
@@ -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

tools/lib/bpf/bpf.h

+4 −1
Original line number Diff line number Diff line
@@ -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);