xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

bpf: Add BPF_MAP_GET_FD_BY_ID

Browse Source 
Add BPF_MAP_GET_FD_BY_ID command to allow user to get a fd
from a bpf_map's ID.

bpf_map_inc_not_zero() is added and is called with map_idr_lock
held.

__bpf_map_put() is also added which has the 'bool do_idr_lock'
param to decide if the map_idr_lock should be acquired when
freeing the map->id.

In the error path of bpf_map_inc_not_zero(), it may have to
call __bpf_map_put(map, false) which does not need
to take the map_idr_lock when freeing the map->id.

It is currently limited to CAP_SYS_ADMIN which we can
consider to lift it in followup patches.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Martin KaFai Lau
2017-06-05 12:15:50 -07:00
committed by David S. Miller
parent b16d9aa4c2
commit bd5f5f4ecb
2 changed files with 87 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
include/uapi/linux/bpf.h
View File

@@ -85,6 +85,7 @@ enum bpf_cmd {
BPF_PROG_GET_NEXT_ID,
BPF_MAP_GET_NEXT_ID,
BPF_PROG_GET_FD_BY_ID,
BPF_MAP_GET_FD_BY_ID,
};
enum bpf_map_type {
@@ -217,6 +218,7 @@ union bpf_attr {
union {
__u32 start_id;
__u32 prog_id;
__u32 map_id;
};
__u32 next_id;
};