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=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 07FC4C282CE for ; Wed, 24 Apr 2019 17:46:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C4270218B0 for ; Wed, 24 Apr 2019 17:46:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556128014; bh=STQznUZze8QDmSf8B+bOGRIkORWLMlYfOgqYld8MiaA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=tkpv1TpGyuR3sTrMos5pq9h0xea3UN2l3cCP8wV7J9F1CnxBXgr5SO6dm5PhX6aT6 NA00wNwiD2DM8N3Gl33r4V69meMA5ediSiPEWfSjeKAwwXR+5JBVO68AUyCH1rFkXA Xy2EIHQ8K3IUT0WAc4o9vMrI/7CSSGhZ0TN3TIz8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391621AbfDXRqs (ORCPT ); Wed, 24 Apr 2019 13:46:48 -0400 Received: from mail.kernel.org ([198.145.29.99]:58970 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389873AbfDXRcU (ORCPT ); Wed, 24 Apr 2019 13:32:20 -0400 Received: from localhost (62-193-50-229.as16211.net [62.193.50.229]) (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 76EC72190A; Wed, 24 Apr 2019 17:32:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556127140; bh=STQznUZze8QDmSf8B+bOGRIkORWLMlYfOgqYld8MiaA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Wmn1kUc5+QAUGFlE3QDlRm7SFwPEvhe90IIj3AUPmcZeYu6kxj34hHNQlItz5lA8T QSE4OcObsR11VyFPVCosGzvgohtlJwz/uFUDWX8veIF+sEmsonscYs1YmMigsbS3a1 NCPmn8BkpG7EzDOW0WcUWAx3kRjbKm1m6lyLBpHo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Chang-An Chen , Thomas Gleixner , Frederic Weisbecker , Matthias Brugger , John Stultz , Kees Cook , Corey Minyard , linux-mediatek@lists.infradead.org, linux-arm-kernel@lists.infradead.org, Stanley Chu , kuohong.wang@mediatek.com, freddy.hsin@mediatek.com Subject: [PATCH 4.19 76/96] timers/sched_clock: Prevent generic sched_clock wrap caused by tick_freeze() Date: Wed, 24 Apr 2019 19:10:21 +0200 Message-Id: <20190424170924.889524656@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190424170919.829037226@linuxfoundation.org> References: <20190424170919.829037226@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Chang-An Chen commit 3f2552f7e9c5abef2775c53f7af66532f8bf65bc upstream. tick_freeze() introduced by suspend-to-idle in commit 124cf9117c5f ("PM / sleep: Make it possible to quiesce timers during suspend-to-idle") uses timekeeping_suspend() instead of syscore_suspend() during suspend-to-idle. As a consequence generic sched_clock will keep going because sched_clock_suspend() and sched_clock_resume() are not invoked during suspend-to-idle which can result in a generic sched_clock wrap. On a ARM system with suspend-to-idle enabled, sched_clock is registered as "56 bits at 13MHz, resolution 76ns, wraps every 4398046511101ns", which means the real wrapping duration is 8796093022202ns. [ 134.551779] suspend-to-idle suspend (timekeeping_suspend()) [ 1204.912239] suspend-to-idle resume (timekeeping_resume()) ...... [ 1206.912239] suspend-to-idle suspend (timekeeping_suspend()) [ 5880.502807] suspend-to-idle resume (timekeeping_resume()) ...... [ 6000.403724] suspend-to-idle suspend (timekeeping_suspend()) [ 8035.753167] suspend-to-idle resume (timekeeping_resume()) ...... [ 8795.786684] (2)[321:charger_thread]...... [ 8795.788387] (2)[321:charger_thread]...... [ 0.057226] (0)[0:swapper/0]...... [ 0.061447] (2)[0:swapper/2]...... sched_clock was not stopped during suspend-to-idle, and sched_clock_poll hrtimer was not expired because timekeeping_suspend() was invoked during suspend-to-idle. It makes sched_clock wrap at kernel time 8796s. To prevent this, invoke sched_clock_suspend() and sched_clock_resume() in tick_freeze() together with timekeeping_suspend() and timekeeping_resume(). Fixes: 124cf9117c5f (PM / sleep: Make it possible to quiesce timers during suspend-to-idle) Signed-off-by: Chang-An Chen Signed-off-by: Thomas Gleixner Cc: Frederic Weisbecker Cc: Matthias Brugger Cc: John Stultz Cc: Kees Cook Cc: Corey Minyard Cc: Cc: Cc: Stanley Chu Cc: Cc: Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/1553828349-8914-1-git-send-email-chang-an.chen@mediatek.com Signed-off-by: Greg Kroah-Hartman --- kernel/time/sched_clock.c | 4 ++-- kernel/time/tick-common.c | 2 ++ kernel/time/timekeeping.h | 7 +++++++ 3 files changed, 11 insertions(+), 2 deletions(-) --- a/kernel/time/sched_clock.c +++ b/kernel/time/sched_clock.c @@ -275,7 +275,7 @@ static u64 notrace suspended_sched_clock return cd.read_data[seq & 1].epoch_cyc; } -static int sched_clock_suspend(void) +int sched_clock_suspend(void) { struct clock_read_data *rd = &cd.read_data[0]; @@ -286,7 +286,7 @@ static int sched_clock_suspend(void) return 0; } -static void sched_clock_resume(void) +void sched_clock_resume(void) { struct clock_read_data *rd = &cd.read_data[0]; --- a/kernel/time/tick-common.c +++ b/kernel/time/tick-common.c @@ -491,6 +491,7 @@ void tick_freeze(void) trace_suspend_resume(TPS("timekeeping_freeze"), smp_processor_id(), true); system_state = SYSTEM_SUSPEND; + sched_clock_suspend(); timekeeping_suspend(); } else { tick_suspend_local(); @@ -514,6 +515,7 @@ void tick_unfreeze(void) if (tick_freeze_depth == num_online_cpus()) { timekeeping_resume(); + sched_clock_resume(); system_state = SYSTEM_RUNNING; trace_suspend_resume(TPS("timekeeping_freeze"), smp_processor_id(), false); --- a/kernel/time/timekeeping.h +++ b/kernel/time/timekeeping.h @@ -14,6 +14,13 @@ extern u64 timekeeping_max_deferment(voi extern void timekeeping_warp_clock(void); extern int timekeeping_suspend(void); extern void timekeeping_resume(void); +#ifdef CONFIG_GENERIC_SCHED_CLOCK +extern int sched_clock_suspend(void); +extern void sched_clock_resume(void); +#else +static inline int sched_clock_suspend(void) { return 0; } +static inline void sched_clock_resume(void) { } +#endif extern void do_timer(unsigned long ticks); extern void update_wall_time(void);