Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751986Ab0HRXDV (ORCPT ); Wed, 18 Aug 2010 19:03:21 -0400 Received: from mga09.intel.com ([134.134.136.24]:37213 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751621Ab0HRXC5 (ORCPT ); Wed, 18 Aug 2010 19:02:57 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.56,229,1280732400"; d="scan'208";a="546610547" From: "Fenghua Yu" To: "Rudolf Marek" , "Huaxu Wan" , "H Peter Anvin" , "Chen Gong" , "Jean Delvare" Cc: "linux-kernel" , "lm-sensors" , Fenghua Yu Subject: [PATCH] drivers/hwmon/pkgtemp: Fix improper locking in CPU hot remove Date: Wed, 18 Aug 2010 15:53:47 -0700 Message-Id: <1282172027-640-3-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 1.7.2 In-Reply-To: <1282172027-640-1-git-send-email-fenghua.yu@intel.com> References: <1282172027-640-1-git-send-email-fenghua.yu@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2114 Lines: 74 From: Fenghua Yu When a sibling is added to dev_list after a cpu is hot-removed, pdev_list_mutex has been locked already. But pkgtemp_device_add() tries to lock pdev_list_mutex again. This is incorrect. The patch fixes this issue. The patch also removes __cpuinit for pkgtemp_device_add() to avoid section mismatch warning. Signed-off-by: Fenghua Yu --- drivers/hwmon/pkgtemp.c | 18 +++++++++++++----- 1 files changed, 13 insertions(+), 5 deletions(-) diff --git a/drivers/hwmon/pkgtemp.c b/drivers/hwmon/pkgtemp.c index 74157fc..928a016 100644 --- a/drivers/hwmon/pkgtemp.c +++ b/drivers/hwmon/pkgtemp.c @@ -276,7 +276,7 @@ struct pdev_entry { static LIST_HEAD(pdev_list); static DEFINE_MUTEX(pdev_list_mutex); -static int __cpuinit pkgtemp_device_add(unsigned int cpu) +static int pkgtemp_device_add(unsigned int cpu) { int err; struct platform_device *pdev; @@ -341,26 +341,34 @@ static void pkgtemp_device_remove(unsigned int cpu) { struct pdev_entry *p, *n; unsigned int i; - int err; - mutex_lock(&pdev_list_mutex); list_for_each_entry_safe(p, n, &pdev_list, list) { if (p->cpu != cpu) continue; + mutex_lock(&pdev_list_mutex); platform_device_unregister(p->pdev); list_del(&p->list); kfree(p); + mutex_unlock(&pdev_list_mutex); + /* + * Select one of removed cpu's siblings to represent sensor + * for this package. + * If there is no more running sibling in a package, the + * package sensor for this package is not available to user + * space any more. + */ for_each_cpu(i, cpu_core_mask(cpu)) { + int err; + if (i != cpu) { err = pkgtemp_device_add(i); if (!err) break; } } - break; + return; } - mutex_unlock(&pdev_list_mutex); } static int __cpuinit pkgtemp_cpu_callback(struct notifier_block *nfb, -- 1.6.0.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/