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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, 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 A0BF0C2D0CE for ; Fri, 24 Jan 2020 07:03:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7C4E6208C4 for ; Fri, 24 Jan 2020 07:03:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730868AbgAXHDv (ORCPT ); Fri, 24 Jan 2020 02:03:51 -0500 Received: from relay.sw.ru ([185.231.240.75]:53208 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730779AbgAXHDu (ORCPT ); Fri, 24 Jan 2020 02:03:50 -0500 Received: from vvs-ws.sw.ru ([172.16.24.21]) by relay.sw.ru with esmtp (Exim 4.92.3) (envelope-from ) id 1iuszj-00086M-3X; Fri, 24 Jan 2020 10:03:07 +0300 From: Vasily Averin Subject: [PATCH 6/7] trigger_next should increase position index To: linux-kernel@vger.kernel.org Cc: Andrew Morton , NeilBrown , Waiman Long , Steven Rostedt , Ingo Molnar , Peter Oberparleiter Message-ID: <3c35ee24-dd3a-8119-9c19-552ed253388a@virtuozzo.com> Date: Fri, 24 Jan 2020 10:03:06 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org if seq_file .next fuction does not change position index, read after some lseek can generate unexpected output. https://bugzilla.kernel.org/show_bug.cgi?id=206283 Signed-off-by: Vasily Averin --- kernel/trace/trace_events_trigger.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c index 2cd53ca..d5f5e5c 100644 --- a/kernel/trace/trace_events_trigger.c +++ b/kernel/trace/trace_events_trigger.c @@ -116,9 +116,10 @@ static void *trigger_next(struct seq_file *m, void *t, loff_t *pos) { struct trace_event_file *event_file = event_file_data(m->private); - if (t == SHOW_AVAILABLE_TRIGGERS) + if (t == SHOW_AVAILABLE_TRIGGERS) { + (*pos)++; return NULL; - + } return seq_list_next(t, &event_file->triggers, pos); } -- 1.8.3.1