From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [134.134.136.65]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id ABB56179AB; Thu, 25 Jan 2024 08:00:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=134.134.136.65 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706169604; cv=none; b=cgpsSUFYtllLSP1r7BYP9yOmvJPGoMaGIrlLb0I+DmdZ/d2C0DfoqjU1xLwMjjAbVX9EML9ybjvKY/4j9JFFBecX5Pe2avGP8hm3L2fh5lVe2UugHL0NRjd8AGwZb+NrZGr47ZzMXhrtTYOYbjPPlxYTXeNKpmXl/pxV4RD7HRU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706169604; c=relaxed/simple; bh=z+VAqBghFB7YwJJVRmjHIb/J1jBpR0/SN3VAkD9JHMA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=j4eK/IeBJIb4TWIpYq00wEociohm5GW6Hb7Jm1QbAS52EgrBEOYKnuNWxzXA7T0iZ2Qnh1olZttGp3CJ5CF+EUhU7PA2EXhhZziBoHetU9Qi2FfqwLCS1OEyk/TrQRrKMheBZWFEDi8lFRhmXa36ROAQO3y3jPvn+qLCXbU3io4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=Svi2Txuq; arc=none smtp.client-ip=134.134.136.65 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="Svi2Txuq" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1706169602; x=1737705602; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=z+VAqBghFB7YwJJVRmjHIb/J1jBpR0/SN3VAkD9JHMA=; b=Svi2TxuqvyaboLK0avbQqYUpArqnY+B21wZmanEK7CNlX93KkdU+np7S ntqxcC9CAAzm+AvzfCvrIxd8/szj55C1rbFXxGKh3jVtxIz9RTGgUm7G3 DYShK2tq0zDhZFyonEDVQaD/TFqfg1emZDwdSoqZyqKdgTIBtQV4pglBT jr5IEsAi6+mYcfrhnFP+9C+UeJYvW+N/PR970GdxNqF2Rpnca3PskFFmK esMeiTwKcPUfNGujRMgW/srHMSp8cOFoPY2MBMCBJww0eSFHYJ1I6Zcun VBAt15tBp/0j4ug+vvbTx6kS/HI/Gw2fOHav6hkxykPGE7tc8tt4ILjCS w==; X-IronPort-AV: E=McAfee;i="6600,9927,10962"; a="405838370" X-IronPort-AV: E=Sophos;i="6.05,216,1701158400"; d="scan'208";a="405838370" Received: from orviesa002.jf.intel.com ([10.64.159.142]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Jan 2024 00:00:01 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.05,216,1701158400"; d="scan'208";a="28399670" Received: from sgruszka-mobl.ger.corp.intel.com (HELO localhost) ([10.252.58.119]) by orviesa002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Jan 2024 00:00:00 -0800 Date: Thu, 25 Jan 2024 08:59:57 +0100 From: Stanislaw Gruszka To: "Rafael J. Wysocki" Cc: Linux PM , LKML , Ulf Hansson Subject: Re: [PATCH v1 08/12] PM: sleep: stats: Use locking in dpm_save_failed_dev() Message-ID: References: <5760158.DvuYhMxLoT@kreacher> <3798847.kQq0lBPeGt@kreacher> Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3798847.kQq0lBPeGt@kreacher> On Mon, Jan 22, 2024 at 12:33:53PM +0100, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki > > Because dpm_save_failed_dev() may be called simultaneously by multiple > failing device PM functions, the state of the suspend_stats fields > updated by it may become inconsistent. > > Prevent that from happening by using a lock in dpm_save_failed_dev(). > > Signed-off-by: Rafael J. Wysocki Reviewed-by: Stanislaw Gruszka > --- > kernel/power/main.c | 5 +++++ > 1 file changed, 5 insertions(+) > > Index: linux-pm/kernel/power/main.c > =================================================================== > --- linux-pm.orig/kernel/power/main.c > +++ linux-pm/kernel/power/main.c > @@ -323,13 +323,18 @@ struct suspend_stats { > }; > > static struct suspend_stats suspend_stats; > +static DEFINE_MUTEX(suspend_stats_lock); > > void dpm_save_failed_dev(const char *name) > { > + mutex_lock(&suspend_stats_lock); > + > strscpy(suspend_stats.failed_devs[suspend_stats.last_failed_dev], > name, sizeof(suspend_stats.failed_devs[0])); > suspend_stats.last_failed_dev++; > suspend_stats.last_failed_dev %= REC_FAILED_NUM; > + > + mutex_unlock(&suspend_stats_lock); > } > > void dpm_save_failed_step(enum suspend_stat_step step) > > > >