On 12/15/24 11:34 AM, Leo Yan wrote:
The bpf_perf_event_aux_pause kfunc will be used to control the Perf AUX area to pause or resume. An example use-case is attaching eBPF to Ftrace tracepoints. When a tracepoint is hit, the associated eBPF program will be executed. The eBPF program can invoke bpf_perf_event_aux_pause() to pause or resume AUX trace. This is useful for fine-grained tracing by combining Perf and eBPF. This commit implements the bpf_perf_event_aux_pause kfunc, and make it pass the eBPF verifier.
The subject and commit message mentions to implement a kfunc, but actually you implemented a uapi helper. Please implement a kfunc instead (searching __bpf_kfunc in kernel/bpf directory).
Signed-off-by: Leo Yan <leo....@arm.com> --- include/uapi/linux/bpf.h | 21 ++++++++++++++++ kernel/bpf/verifier.c | 2 ++ kernel/trace/bpf_trace.c | 52 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 75 insertions(+) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 4162afc6b5d0..678278c91ce2 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -5795,6 +5795,26 @@ union bpf_attr { * 0 on success. * * **-ENOENT** if the bpf_local_storage cannot be found. + * + * long bpf_perf_event_aux_pause(struct bpf_map *map, u64 flags, u32 pause) + * Description + * Pause or resume an AUX area trace associated to the perf event. + * + * The *flags* argument is specified as the key value for + * retrieving event pointer from the passed *map*. + * + * The *pause* argument controls AUX trace pause or resume. + * Non-zero values (true) are to pause the AUX trace and the zero + * value (false) is for re-enabling the AUX trace. + * Return + * 0 on success. + * + * **-ENOENT** if not found event in the events map. + * + * **-E2BIG** if the event index passed in the *flags* parameter + * is out-of-range of the map. + * + * **-EINVAL** if the flags passed is an invalid value. */ #define ___BPF_FUNC_MAPPER(FN, ctx...) \ FN(unspec, 0, ##ctx) \ @@ -6009,6 +6029,7 @@ union bpf_attr { FN(user_ringbuf_drain, 209, ##ctx) \ FN(cgrp_storage_get, 210, ##ctx) \ FN(cgrp_storage_delete, 211, ##ctx) \ + FN(perf_event_aux_pause, 212, ##ctx) \ /* *//* backwards-compatibility macros for users of __BPF_FUNC_MAPPER that don't
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