From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760770Ab2C3MW3 (ORCPT ); Fri, 30 Mar 2012 08:22:29 -0400 Received: from vms173011pub.verizon.net ([206.46.173.11]:48615 "EHLO vms173011pub.verizon.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760594Ab2C3MSY (ORCPT ); Fri, 30 Mar 2012 08:18:24 -0400 From: Len Brown To: linux-acpi@vger.kernel.org, linux-pm@lists.linux-foundation.org Cc: linux-kernel@vger.kernel.org, "Paul E. McKenney" , "Paul E. McKenney" , Len Brown Subject: [PATCH 69/76] ACPI: Fix unprotected smp_processor_id() in acpi_processor_cst_has_changed() Date: Fri, 30 Mar 2012 06:14:12 -0400 Message-id: <9505626d7bfeb5bd4b85acb483831ac640b2a5e8.1333101989.git.len.brown@intel.com> X-Mailer: git-send-email 1.7.10.rc2.19.gfae9d In-reply-to: <1333102459-23750-1-git-send-email-lenb@kernel.org> References: <1333102459-23750-1-git-send-email-lenb@kernel.org> In-reply-to: <09f98a825a821f7a3f1b162f9ed023f37213a63b.1333101989.git.len.brown@intel.com> References: <09f98a825a821f7a3f1b162f9ed023f37213a63b.1333101989.git.len.brown@intel.com> Reply-to: Len Brown Organization: Intel Open Source Technology Center Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Paul E. McKenney" The acpi_processor_cst_has_changed() function is invoked from a CPU_ONLINE or CPU_DEAD function, which might well execute on CPU 0 even though the CPU being hotplugged is some other CPU. In addition, acpi_processor_cst_has_changed() invokes smp_processor_id() without protection, resulting in splats when onlining CPUs. This commit therefore changes the smp_processor_id() to pr->id, as is used elsewhere in the code, for example, in acpi_processor_add(). Signed-off-by: Paul E. McKenney Signed-off-by: Paul E. McKenney Reviewed-by: Srivatsa S. Bhat Tested-by: Yong Zhang Acked-by: Rafael J. Wysocki Signed-off-by: Len Brown --- drivers/acpi/processor_idle.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 0e8e2de..9e57b06 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -1159,8 +1159,7 @@ int acpi_processor_cst_has_changed(struct acpi_processor *pr) * to make the code that updates C-States be called once. */ - if (smp_processor_id() == 0 && - cpuidle_get_driver() == &acpi_idle_driver) { + if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) { cpuidle_pause_and_lock(); /* Protect against cpu-hotplug */ -- 1.7.10.rc2.19.gfae9d