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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT 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 82CD4C56202 for ; Mon, 23 Nov 2020 12:47:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3541D2100A for ; Mon, 23 Nov 2020 12:47:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="KoX+aHuV" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732751AbgKWMqd (ORCPT ); Mon, 23 Nov 2020 07:46:33 -0500 Received: from mail.kernel.org ([198.145.29.99]:60066 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732740AbgKWMq3 (ORCPT ); Mon, 23 Nov 2020 07:46:29 -0500 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id F0EE3208C3; Mon, 23 Nov 2020 12:46:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1606135588; bh=YhRyQ/YJFXdK7Ox66tX6f5/svd923I0mNeQygINnzZc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KoX+aHuVRxIB0T4YUXAfDx85qZNjLVCRJjoFQqYHJYMZH2YFDUpPHjbO58fgqF6RY UZNRJ9pAALC1EGpYzyNokYCxbRrZIX4hXitsqSQjJthif3HI7Wh4Ymz5UqXTLAe1sx D4LE3nSeIwS45gaWiMwxbgxVB/7Xg+px923/DWPA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Leo Yan , Jiri Olsa , Arnaldo Carvalho de Melo , Sasha Levin Subject: [PATCH 5.9 123/252] perf lock: Dont free "lock_seq_stat" if read_count isnt zero Date: Mon, 23 Nov 2020 13:21:13 +0100 Message-Id: <20201123121841.528847251@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201123121835.580259631@linuxfoundation.org> References: <20201123121835.580259631@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Leo Yan [ Upstream commit b0e5a05cc9e37763c7f19366d94b1a6160c755bc ] When execute command "perf lock report", it hits failure and outputs log as follows: perf: builtin-lock.c:623: report_lock_release_event: Assertion `!(seq->read_count < 0)' failed. Aborted This is an imbalance issue. The locking sequence structure "lock_seq_stat" contains the reader counter and it is used to check if the locking sequence is balance or not between acquiring and releasing. If the tool wrongly frees "lock_seq_stat" when "read_count" isn't zero, the "read_count" will be reset to zero when allocate a new structure at the next time; thus it causes the wrong counting for reader and finally results in imbalance issue. To fix this issue, if detects "read_count" is not zero (means still have read user in the locking sequence), goto the "end" tag to skip freeing structure "lock_seq_stat". Fixes: e4cef1f65061 ("perf lock: Fix state machine to recognize lock sequence") Signed-off-by: Leo Yan Acked-by: Jiri Olsa Link: https://lore.kernel.org/r/20201104094229.17509-2-leo.yan@linaro.org Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin --- tools/perf/builtin-lock.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/perf/builtin-lock.c b/tools/perf/builtin-lock.c index 5cecc1ad78e1f..a2f1e53f37a7a 100644 --- a/tools/perf/builtin-lock.c +++ b/tools/perf/builtin-lock.c @@ -621,7 +621,7 @@ static int report_lock_release_event(struct evsel *evsel, case SEQ_STATE_READ_ACQUIRED: seq->read_count--; BUG_ON(seq->read_count < 0); - if (!seq->read_count) { + if (seq->read_count) { ls->nr_release++; goto end; } -- 2.27.0