Re: [PATCH bpf-next] libbpf: fix bail out from 'ringbuf_process_ring()' on error
From: Andrii Nakryiko <hidden>
Date: 2021-03-26 04:32:31
Also in:
bpf, lkml
On Thu, Mar 25, 2021 at 8:02 AM Pedro Tammela [off-list ref] wrote:
The current code bails out with negative and positive returns. If the callback returns a positive return code, 'ring_buffer__consume()' and 'ring_buffer__poll()' will return a spurious number of records consumed, but mostly important will continue the processing loop. This patch makes positive returns from the callback a no-op. Signed-off-by: Pedro Tammela <redacted> --- tools/lib/bpf/ringbuf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
Thanks. Applied to bpf tree and added:
Fixes: bf99c936f947 ("libbpf: Add BPF ring buffer support")
quoted hunk ↗ jump to hunk
diff --git a/tools/lib/bpf/ringbuf.c b/tools/lib/bpf/ringbuf.c index 8caaafe7e312..e7a8d847161f 100644 --- a/tools/lib/bpf/ringbuf.c +++ b/tools/lib/bpf/ringbuf.c@@ -227,7 +227,7 @@ static int ringbuf_process_ring(struct ring* r) if ((len & BPF_RINGBUF_DISCARD_BIT) == 0) { sample = (void *)len_ptr + BPF_RINGBUF_HDR_SZ; err = r->sample_cb(r->ctx, sample, len); - if (err) { + if (err < 0) { /* update consumer pos and bail out */ smp_store_release(r->consumer_pos, cons_pos); --2.25.1