diff options
| author | Andrii Nakryiko <andrii@kernel.org> | 2021-08-15 00:05:57 -0700 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2021-08-17 00:45:07 +0200 |
| commit | b89fbfbb854c9afc3047e8273cc3a694650b802e (patch) | |
| tree | c7b3624e206ecc2f865cefb688bcdbf173c1beaa /include/linux/bpf_types.h | |
| parent | 652c1b17b85b9c195978c051aa283027529db1fe (diff) | |
bpf: Implement minimal BPF perf link
Introduce a new type of BPF link - BPF perf link. This brings perf_event-based
BPF program attachments (perf_event, tracepoints, kprobes, and uprobes) into
the common BPF link infrastructure, allowing to list all active perf_event
based attachments, auto-detaching BPF program from perf_event when link's FD
is closed, get generic BPF link fdinfo/get_info functionality.
BPF_LINK_CREATE command expects perf_event's FD as target_fd. No extra flags
are currently supported.
Force-detaching and atomic BPF program updates are not yet implemented, but
with perf_event-based BPF links we now have common framework for this without
the need to extend ioctl()-based perf_event interface.
One interesting consideration is a new value for bpf_attach_type, which
BPF_LINK_CREATE command expects. Generally, it's either 1-to-1 mapping from
bpf_attach_type to bpf_prog_type, or many-to-1 mapping from a subset of
bpf_attach_types to one bpf_prog_type (e.g., see BPF_PROG_TYPE_SK_SKB or
BPF_PROG_TYPE_CGROUP_SOCK). In this case, though, we have three different
program types (KPROBE, TRACEPOINT, PERF_EVENT) using the same perf_event-based
mechanism, so it's many bpf_prog_types to one bpf_attach_type. I chose to
define a single BPF_PERF_EVENT attach type for all of them and adjust
link_create()'s logic for checking correspondence between attach type and
program type.
The alternative would be to define three new attach types (e.g., BPF_KPROBE,
BPF_TRACEPOINT, and BPF_PERF_EVENT), but that seemed like unnecessary overkill
and BPF_KPROBE will cause naming conflicts with BPF_KPROBE() macro, defined by
libbpf. I chose to not do this to avoid unnecessary proliferation of
bpf_attach_type enum values and not have to deal with naming conflicts.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/bpf/20210815070609.987780-5-andrii@kernel.org
Diffstat (limited to 'include/linux/bpf_types.h')
| -rw-r--r-- | include/linux/bpf_types.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/include/linux/bpf_types.h b/include/linux/bpf_types.h index ae3ac3a2018c..9c81724e4b98 100644 --- a/include/linux/bpf_types.h +++ b/include/linux/bpf_types.h @@ -136,3 +136,6 @@ BPF_LINK_TYPE(BPF_LINK_TYPE_ITER, iter) BPF_LINK_TYPE(BPF_LINK_TYPE_NETNS, netns) BPF_LINK_TYPE(BPF_LINK_TYPE_XDP, xdp) #endif +#ifdef CONFIG_PERF_EVENTS +BPF_LINK_TYPE(BPF_LINK_TYPE_PERF_EVENT, perf) +#endif |