diff options
| author | Toke Høiland-Jørgensen <toke@redhat.com> | 2020-09-29 14:45:51 +0200 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2020-09-29 13:09:24 -0700 |
| commit | 4a1e7c0c63e02daad751842b7880f9bbcdfb6e89 (patch) | |
| tree | 889732ecf7e8ffe11000a93435bcae1ac68a554b /tools | |
| parent | 3aac1ead5eb6b76f3d2b8d111e6de1c2de23fb34 (diff) | |
bpf: Support attaching freplace programs to multiple attach points
This enables support for attaching freplace programs to multiple attach
points. It does this by amending the UAPI for bpf_link_Create with a target
btf ID that can be used to supply the new attachment point along with the
target program fd. The target must be compatible with the target that was
supplied at program load time.
The implementation reuses the checks that were factored out of
check_attach_btf_id() to ensure compatibility between the BTF types of the
old and new attachment. If these match, a new bpf_tracing_link will be
created for the new attach target, allowing multiple attachments to
co-exist simultaneously.
The code could theoretically support multiple-attach of other types of
tracing programs as well, but since I don't have a use case for any of
those, there is no API support for doing so.
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/160138355169.48470.17165680973640685368.stgit@toke.dk
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/include/uapi/linux/bpf.h | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 96ddb00b91dc..2b1d3f16cbd1 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -639,8 +639,13 @@ union bpf_attr { }; __u32 attach_type; /* attach type */ __u32 flags; /* extra flags */ - __aligned_u64 iter_info; /* extra bpf_iter_link_info */ - __u32 iter_info_len; /* iter_info length */ + union { + __u32 target_btf_id; /* btf_id of target to attach to */ + struct { + __aligned_u64 iter_info; /* extra bpf_iter_link_info */ + __u32 iter_info_len; /* iter_info length */ + }; + }; } link_create; struct { /* struct used by BPF_LINK_UPDATE command */ |