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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7FA4AC6FA9D for ; Wed, 1 Mar 2023 18:12:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230044AbjCASMR (ORCPT ); Wed, 1 Mar 2023 13:12:17 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46700 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230045AbjCASMQ (ORCPT ); Wed, 1 Mar 2023 13:12:16 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3293B4AFE7 for ; Wed, 1 Mar 2023 10:12:14 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id BFCDA6144F for ; Wed, 1 Mar 2023 18:12:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D2B00C433D2; Wed, 1 Mar 2023 18:12:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1677694332; bh=KHecUUfMefPZbkB5lscasoLHLCIIaq3jElsS3EtgwUA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ksou9u4gFkwwORyQ69IuTGV3lpC1LccBVYDipqgYzMPiMZIuY3mW3XGc4WUF1e6aZ 20aOPHfoPiXB2B9/NPsKsKkDjaVP4JcrWJOM11KVLpdAyf3WWEdz8jCDkcghWPg3JZ e6DmlTDHbbWfP1IUAMOfg5NzZqQpgmw3Wf9b21UY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= , "Rafael J. Wysocki" , Petr Mladek , Paul Menzel Subject: [PATCH 6.1 24/42] PM: sleep: Avoid using pr_cont() in the tasks freezing code Date: Wed, 1 Mar 2023 19:08:45 +0100 Message-Id: <20230301180658.122122337@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230301180657.003689969@linuxfoundation.org> References: <20230301180657.003689969@linuxfoundation.org> User-Agent: quilt/0.67 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: Rafael J. Wysocki commit a449dfbfc0894676ad0aa1873383265047529e3a upstream. Using pr_cont() in the tasks freezing code related to system-wide suspend and hibernation is problematic, because the continuation messages printed there are susceptible to interspersing with other unrelated messages which results in output that is hard to understand. Address this issue by modifying try_to_freeze_tasks() to print messages that don't require continuations and adjusting its callers accordingly. Reported-by: Thomas Weißschuh Signed-off-by: Rafael J. Wysocki Reviewed-by: Petr Mladek Cc: Paul Menzel Signed-off-by: Greg Kroah-Hartman --- kernel/power/process.c | 21 ++++++++------------- 1 file changed, 8 insertions(+), 13 deletions(-) --- a/kernel/power/process.c +++ b/kernel/power/process.c @@ -27,6 +27,8 @@ unsigned int __read_mostly freeze_timeou static int try_to_freeze_tasks(bool user_only) { + const char *what = user_only ? "user space processes" : + "remaining freezable tasks"; struct task_struct *g, *p; unsigned long end_time; unsigned int todo; @@ -36,6 +38,8 @@ static int try_to_freeze_tasks(bool user bool wakeup = false; int sleep_usecs = USEC_PER_MSEC; + pr_info("Freezing %s\n", what); + start = ktime_get_boottime(); end_time = jiffies + msecs_to_jiffies(freeze_timeout_msecs); @@ -82,7 +86,6 @@ static int try_to_freeze_tasks(bool user elapsed_msecs = ktime_to_ms(elapsed); if (todo) { - pr_cont("\n"); pr_err("Freezing of tasks %s after %d.%03d seconds " "(%d tasks refusing to freeze, wq_busy=%d):\n", wakeup ? "aborted" : "failed", @@ -101,8 +104,8 @@ static int try_to_freeze_tasks(bool user read_unlock(&tasklist_lock); } } else { - pr_cont("(elapsed %d.%03d seconds) ", elapsed_msecs / 1000, - elapsed_msecs % 1000); + pr_info("Freezing %s completed (elapsed %d.%03d seconds)\n", + what, elapsed_msecs / 1000, elapsed_msecs % 1000); } return todo ? -EBUSY : 0; @@ -130,14 +133,11 @@ int freeze_processes(void) static_branch_inc(&freezer_active); pm_wakeup_clear(0); - pr_info("Freezing user space processes ... "); pm_freezing = true; error = try_to_freeze_tasks(true); - if (!error) { + if (!error) __usermodehelper_set_disable_depth(UMH_DISABLED); - pr_cont("done."); - } - pr_cont("\n"); + BUG_ON(in_atomic()); /* @@ -166,14 +166,9 @@ int freeze_kernel_threads(void) { int error; - pr_info("Freezing remaining freezable tasks ... "); - pm_nosig_freezing = true; error = try_to_freeze_tasks(false); - if (!error) - pr_cont("done."); - pr_cont("\n"); BUG_ON(in_atomic()); if (error)