bpf handlers for perf events other than tracepoints, kprobes or uprobes are attached to the overflow_handler of the perf event. Perf events of type software/dummy are placeholder events. So when attaching a bpf handle to an overflow_handler of such an event, the bpf handler will not be triggered. This fix returns the error EOPNOTSUPP to indicate that attaching a bpf handler to a perf event of type software/dummy is not supported. Signed-off-by: Florian Lehner <dev@xxxxxxxxxxx> --- kernel/events/core.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/events/core.c b/kernel/events/core.c index da467e1dd49a..4e8846b7ceda 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -9668,6 +9668,10 @@ static int perf_event_set_bpf_handler(struct perf_event *event, u32 prog_fd) if (event->prog) return -EEXIST; + if (event->attr.type == PERF_TYPE_SOFTWARE && + event->attr.config == PERF_COUNT_SW_DUMMY) + return -EOPNOTSUPP; + prog = bpf_prog_get_type(prog_fd, BPF_PROG_TYPE_PERF_EVENT); if (IS_ERR(prog)) return PTR_ERR(prog); -- 2.28.0
