From patchwork Tue Sep 1 15:10:04 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 310563 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=-13.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, 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 27CB8C433E2 for ; Tue, 1 Sep 2020 15:15:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EF68E206FA for ; Tue, 1 Sep 2020 15:15:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598973341; bh=y7+3mb3F1IV1P7eyHp4J62UIqOIDN8ka/C+d2ylHIHE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=XHsMY/Jb+rFuDFfJIcqeRfDju2QBLqSJKQMGaBRqvJTL+xx82t0voKXHUJvj6qvbP c02f/4Mlg1BtItO0AMWn36eEseSE+jBIdLrXVWyhky8948fIxkXhebvbsUaHe/YayS o60i9ebV4rsZsb3+Jh1x3Gad6kS8ZFw/HMTSRfAo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728808AbgIAPPk (ORCPT ); Tue, 1 Sep 2020 11:15:40 -0400 Received: from mail.kernel.org ([198.145.29.99]:59804 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729208AbgIAPPg (ORCPT ); Tue, 1 Sep 2020 11:15:36 -0400 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 258E3206FA; Tue, 1 Sep 2020 15:15:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598973328; bh=y7+3mb3F1IV1P7eyHp4J62UIqOIDN8ka/C+d2ylHIHE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tP2al5vRdw06hXPz/obVU2eXQxNB7iQ7Tr1Xt0vAiUCORoVsW4Nazh+hG1UADNpAz llRzxpBt+rrIEN9Tj8MMxLcsoPtBgH7pFV4bJgk5L8YIFNenhZNLhWFysli0tQctie 8yX1xm5eYMl7QYylnCsA4eQD8Qx8y9sTfOSoDeH8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Chris Wilson , Ingo Molnar , Peter Zijlstra , Sasha Levin Subject: [PATCH 4.9 28/78] locking/lockdep: Fix overflow in presentation of average lock-time Date: Tue, 1 Sep 2020 17:10:04 +0200 Message-Id: <20200901150926.151655527@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200901150924.680106554@linuxfoundation.org> References: <20200901150924.680106554@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Chris Wilson [ Upstream commit a7ef9b28aa8d72a1656fa6f0a01bbd1493886317 ] Though the number of lock-acquisitions is tracked as unsigned long, this is passed as the divisor to div_s64() which interprets it as a s32, giving nonsense values with more than 2 billion acquisitons. E.g. acquisitions holdtime-min holdtime-max holdtime-total holdtime-avg ------------------------------------------------------------------------- 2350439395 0.07 353.38 649647067.36 0.-32 Signed-off-by: Chris Wilson Signed-off-by: Ingo Molnar Cc: Peter Zijlstra Link: https://lore.kernel.org/r/20200725185110.11588-1-chris@chris-wilson.co.uk Signed-off-by: Sasha Levin --- kernel/locking/lockdep_proc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/locking/lockdep_proc.c b/kernel/locking/lockdep_proc.c index 75d80809c48c9..09bad6cbb95cf 100644 --- a/kernel/locking/lockdep_proc.c +++ b/kernel/locking/lockdep_proc.c @@ -425,7 +425,7 @@ static void seq_lock_time(struct seq_file *m, struct lock_time *lt) seq_time(m, lt->min); seq_time(m, lt->max); seq_time(m, lt->total); - seq_time(m, lt->nr ? div_s64(lt->total, lt->nr) : 0); + seq_time(m, lt->nr ? div64_u64(lt->total, lt->nr) : 0); } static void seq_stats(struct seq_file *m, struct lock_stat_data *data)