Re: [PATCH] libbpf: Use the correct fd when attaching to perf events
From: Andrii Nakryiko <hidden>
Date: 2021-03-13 01:32:39
Also in:
bpf, lkml
On Fri, Mar 12, 2021 at 1:43 PM Sultan Alsawaf [off-list ref] wrote:
From: Sultan Alsawaf <redacted> We should be using the program fd here, not the perf event fd.
Why? Can you elaborate on what issue you ran into with the current code?
quoted hunk ↗ jump to hunk
Fixes: 63f2f5ee856ba ("libbpf: add ability to attach/detach BPF program to perf event") Signed-off-by: Sultan Alsawaf <redacted> --- tools/lib/bpf/libbpf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index d43cc3f29dae..3d20d57d4af5 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c@@ -9538,7 +9538,7 @@ struct bpf_link *bpf_program__attach_perf_event(struct bpf_program *prog, if (!link) return ERR_PTR(-ENOMEM); link->detach = &bpf_link__detach_perf_event; - link->fd = pfd; + link->fd = prog_fd; if (ioctl(pfd, PERF_EVENT_IOC_SET_BPF, prog_fd) < 0) { err = -errno; --2.30.2