bpf: Update the struct_ops of a bpf_link.

By improving the BPF_LINK_UPDATE command of bpf(), it should allow you
to conveniently switch between different struct_ops on a single
bpf_link. This would enable smoother transitions from one struct_ops
to another.

The struct_ops maps passing along with BPF_LINK_UPDATE should have the
BPF_F_LINK flag.

Signed-off-by: Kui-Feng Lee <kuifeng@meta.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230323032405.3735486-6-kuifeng@meta.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
This commit is contained in:
Kui-Feng Lee
2023-03-22 20:24:02 -07:00
committed by Martin KaFai Lau
parent 8d1608d709
commit aef56f2e91
6 changed files with 122 additions and 11 deletions

View File

@@ -1555,12 +1555,23 @@ union bpf_attr {
struct { /* struct used by BPF_LINK_UPDATE command */
__u32 link_fd; /* link fd */
/* new program fd to update link with */
__u32 new_prog_fd;
union {
/* new program fd to update link with */
__u32 new_prog_fd;
/* new struct_ops map fd to update link with */
__u32 new_map_fd;
};
__u32 flags; /* extra flags */
/* expected link's program fd; is specified only if
* BPF_F_REPLACE flag is set in flags */
__u32 old_prog_fd;
union {
/* expected link's program fd; is specified only if
* BPF_F_REPLACE flag is set in flags.
*/
__u32 old_prog_fd;
/* expected link's map fd; is specified only
* if BPF_F_REPLACE flag is set.
*/
__u32 old_map_fd;
};
} link_update;
struct {