gcc-7 complains that wl3501_cs passes NULL into a function that then uses the argument as the input for memcpy: drivers/net/wireless/wl3501_cs.c: In function 'wl3501_get_scan': include/net/iw_handler.h:559:3: error: argument 2 null where non-null expected [-Werror=nonnull] memcpy(stream + point_len, extra, iwe->u.data.length); This works fine here because iwe->u.data.length is guaranteed to be NULL, and the memcpy doesn't actually have an effect. Making the length check explicit avoids the warning and should have no other effect here. Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> --- include/net/iw_handler.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/include/net/iw_handler.h b/include/net/iw_handler.h index e0f4109e64c6..1a41043688bc 100644 --- a/include/net/iw_handler.h +++ b/include/net/iw_handler.h @@ -556,7 +556,8 @@ iwe_stream_add_point(struct iw_request_info *info, char *stream, char *ends, memcpy(stream + lcp_len, ((char *) &iwe->u) + IW_EV_POINT_OFF, IW_EV_POINT_PK_LEN - IW_EV_LCP_PK_LEN); - memcpy(stream + point_len, extra, iwe->u.data.length); + if (iwe->u.data.length) + memcpy(stream + point_len, extra, iwe->u.data.length); stream += event_len; } return stream; -- 2.9.0