Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759317AbcCVK6d (ORCPT ); Tue, 22 Mar 2016 06:58:33 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:56890 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932585AbcCVKmy (ORCPT ); Tue, 22 Mar 2016 06:42:54 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Todd Brandt , "Rafael J. Wysocki" , Luis Henriques Subject: [PATCH 3.16.y-ckt 105/142] PM / sleep / x86: Fix crash on graph trace through x86 suspend Date: Tue, 22 Mar 2016 10:40:34 +0000 Message-Id: <1458643271-4227-106-git-send-email-luis.henriques@canonical.com> In-Reply-To: <1458643271-4227-1-git-send-email-luis.henriques@canonical.com> References: <1458643271-4227-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1685 Lines: 51 3.16.7-ckt26 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: Todd E Brandt commit 92f9e179a702a6adbc11e2fedc76ecd6ffc9e3f7 upstream. Pause/unpause graph tracing around do_suspend_lowlevel as it has inconsistent call/return info after it jumps to the wakeup vector. The graph trace buffer will otherwise become misaligned and may eventually crash and hang on suspend. To reproduce the issue and test the fix: Run a function_graph trace over suspend/resume and set the graph function to suspend_devices_and_enter. This consistently hangs the system without this fix. Signed-off-by: Todd Brandt Signed-off-by: Rafael J. Wysocki Signed-off-by: Luis Henriques --- arch/x86/kernel/acpi/sleep.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/arch/x86/kernel/acpi/sleep.c b/arch/x86/kernel/acpi/sleep.c index 31368207837c..8255d2fe8cfa 100644 --- a/arch/x86/kernel/acpi/sleep.c +++ b/arch/x86/kernel/acpi/sleep.c @@ -16,6 +16,7 @@ #include #include +#include #include "../../realmode/rm/wakeup.h" #include "sleep.h" @@ -107,7 +108,13 @@ int x86_acpi_suspend_lowlevel(void) saved_magic = 0x123456789abcdef0L; #endif /* CONFIG_64BIT */ + /* + * Pause/unpause graph tracing around do_suspend_lowlevel as it has + * inconsistent call/return info after it jumps to the wakeup vector. + */ + pause_graph_tracing(); do_suspend_lowlevel(); + unpause_graph_tracing(); return 0; }