From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:45277 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758107AbcC2UFA (ORCPT ); Tue, 29 Mar 2016 16:05:00 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Rafael J. Wysocki" , "Todd E Brandt" Date: Tue, 29 Mar 2016 20:18:22 +0100 Message-ID: Subject: [PATCH 3.2 53/62] PM / sleep / x86: Fix crash on graph trace through x86 suspend In-Reply-To: Sender: stable-owner@vger.kernel.org List-ID: 3.2.79-rc1 review patch. If anyone has any objections, please let me know. ------------------ 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 [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings --- arch/x86/kernel/acpi/sleep.c | 7 +++++++ 1 file changed, 7 insertions(+) --- a/arch/x86/kernel/acpi/sleep.c +++ b/arch/x86/kernel/acpi/sleep.c @@ -15,6 +15,7 @@ #include #include +#include #include "realmode/wakeup.h" #include "sleep.h" @@ -102,7 +103,13 @@ int 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; }