Commit e859e429 authored by Yafang Shao's avatar Yafang Shao Committed by Alexei Starovoitov
Browse files

bpf: Show target_{obj,btf}_id in tracing link fdinfo 



The target_btf_id can help us understand which kernel function is
linked by a tracing prog. The target_btf_id and target_obj_id have
already been exposed to userspace, so we just need to show them.

The result as follows,

$ cat /proc/10673/fdinfo/10
pos:    0
flags:  02000000
mnt_id: 15
ino:    2094
link_type:      tracing
link_id:        2
prog_tag:       a04f5eef06a7f555
prog_id:        13
attach_type:    24
target_obj_id:  1
target_btf_id:  13964

Signed-off-by: default avatarYafang Shao <laoar.shao@gmail.com>
Acked-by: default avatarSong Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230517103126.68372-2-laoar.shao@gmail.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent effcf624

kernel/bpf/syscall.c

+9 −2
Original line number Diff line number Diff line
@@ -2968,10 +2968,17 @@ static void bpf_tracing_link_show_fdinfo(const struct bpf_link *link, 
{

	struct bpf_tracing_link *tr_link =

		container_of(link, struct bpf_tracing_link, link.link);

	u32 target_btf_id, target_obj_id;



	bpf_trampoline_unpack_key(tr_link->trampoline->key,

				  &target_obj_id, &target_btf_id);

	seq_printf(seq,

		   "attach_type:\t%d\n",

		   tr_link->attach_type);

		   "attach_type:\t%d\n"

		   "target_obj_id:\t%u\n"

		   "target_btf_id:\t%u\n",

		   tr_link->attach_type,

		   target_obj_id,

		   target_btf_id);

}



static int bpf_tracing_link_fill_link_info(const struct bpf_link *link,