From: Pedro Tammela pctammela@gmail.com
commit 6032ebb54c60cae24329f6aba3ce0c1ca8ad6abe upstream.
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.
Fixes: bf99c936f947 ("libbpf: Add BPF ring buffer support") Signed-off-by: Pedro Tammela pctammela@mojatatu.com Signed-off-by: Andrii Nakryiko andrii@kernel.org Link: https://lore.kernel.org/bpf/20210325150115.138750-1-pctammela@mojatatu.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- tools/lib/bpf/ringbuf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/tools/lib/bpf/ringbuf.c +++ b/tools/lib/bpf/ringbuf.c @@ -227,7 +227,7 @@ static int ringbuf_process_ring(struct 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);