Fix: handle writes of length 0

[lttng-ust.git] / libringbuffer / backend.h

diff --git a/libringbuffer/backend.h b/libringbuffer/backend.h
index 125d0a50117097b344f12e28147c1cc1d41cdec6..feefc7a3229f1314cf6813b1f05178a0cc6176e8 100644 (file)
--- a/libringbuffer/backend.h
+++ b/libringbuffer/backend.h
@@ -84,6 +84,8 @@ void lib_ring_buffer_write(const struct lttng_ust_lib_ring_buffer_config *config
        struct lttng_ust_lib_ring_buffer_backend_pages_shmp *rpages;
        unsigned long sb_bindex, id;
 
+       if (caa_unlikely(!len))
+               return;
        offset &= chanb->buf_size - 1;
        sbidx = offset >> chanb->subbuf_size_order;
        id = shmp_index(handle, bufb->buf_wsb, sbidx)->id;