From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6F629C3A5A7 for ; Wed, 4 Sep 2019 09:04:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 47C9422CF7 for ; Wed, 4 Sep 2019 09:04:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727741AbfIDJEN (ORCPT ); Wed, 4 Sep 2019 05:04:13 -0400 Received: from lb2-smtp-cloud8.xs4all.net ([194.109.24.25]:55389 "EHLO lb2-smtp-cloud8.xs4all.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727348AbfIDJEN (ORCPT ); Wed, 4 Sep 2019 05:04:13 -0400 Received: from [IPv6:2001:420:44c1:2579:89b1:cff7:3961:1f3f] ([IPv6:2001:420:44c1:2579:89b1:cff7:3961:1f3f]) by smtp-cloud8.xs4all.net with ESMTPA id 5RCyi5WhKMK4h5RD1iCmiJ; Wed, 04 Sep 2019 11:04:12 +0200 To: Linux Media Mailing List Cc: Dan Carpenter From: Hans Verkuil Subject: [PATCH for v5.3] videobuf-core.c: poll_wait needs a non-NULL buf pointer Message-ID: Date: Wed, 4 Sep 2019 11:04:07 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.5.1 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-CMAE-Envelope: MS4wfIpGoDXWxuH+bY1piwdWUAFLi/m9avsHqBsiaVdRiljwRioAVjeOzR3fM+750hrko6Q5vDTmOp/edT60hJ2ahyXufGdFjv3EmU4vxAUD2lRmEI5CoGtV UoAwI/gLZZ7MMDJeJvsaSWy4Q06r5qemkGf3yXbd9HWurilUje5dQWjiDijLq8QJpE8N5wuK8cFkv+o4gr54dVQO1zxXRvPaHMNiOAfrSS2nar3oxVrJ0MSn EpDzWxW34q0FcaDJj3qzrVmMMPGMOmu/ghgUg4/59mBTLpHqqem43y4xdAw3CThO2tMwjaHI6DbDUw64GltgYARpU47uBEdYqRVeyfpI9YE= Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org poll_wait uses &buf->done, but buf is NULL. Move the poll_wait to later in the function once buf is correctly set and only call it if it is non-NULL. Signed-off-by: Hans Verkuil Reported-by: Dan Carpenter Fixes: bb436cbeb918 ("media: videobuf: fix epoll() by calling poll_wait first") Cc: # for v5.1 and up --- diff --git a/drivers/media/v4l2-core/videobuf-core.c b/drivers/media/v4l2-core/videobuf-core.c index 7ef3e4d22bf6..939fc11cf080 100644 --- a/drivers/media/v4l2-core/videobuf-core.c +++ b/drivers/media/v4l2-core/videobuf-core.c @@ -1123,7 +1123,6 @@ __poll_t videobuf_poll_stream(struct file *file, struct videobuf_buffer *buf = NULL; __poll_t rc = 0; - poll_wait(file, &buf->done, wait); videobuf_queue_lock(q); if (q->streaming) { if (!list_empty(&q->stream)) @@ -1143,7 +1142,9 @@ __poll_t videobuf_poll_stream(struct file *file, } buf = q->read_buf; } - if (!buf) + if (buf) + poll_wait(file, &buf->done, wait); + else rc = EPOLLERR; if (0 == rc) {