From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:56413 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752597AbcI1IiC (ORCPT ); Wed, 28 Sep 2016 04:38:02 -0400 Subject: Patch "PM / hibernate: Restore processor state before using per-CPU variables" has been added to the 4.4-stable tree To: thgarnie@google.com, bp@suse.de, gregkh@linuxfoundation.org, jikos@kernel.org, jkosina@suse.cz, pavel@ucw.cz, rafael.j.wysocki@intel.com, rafael@kernel.org Cc: , From: Date: Wed, 28 Sep 2016 10:38:03 +0200 Message-ID: <147505188384173@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled PM / hibernate: Restore processor state before using per-CPU variables to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: pm-hibernate-restore-processor-state-before-using-per-cpu-variables.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 62822e2ec4ad091ba31f823f577ef80db52e3c2c Mon Sep 17 00:00:00 2001 From: Thomas Garnier Date: Thu, 11 Aug 2016 14:49:29 -0700 Subject: PM / hibernate: Restore processor state before using per-CPU variables From: Thomas Garnier commit 62822e2ec4ad091ba31f823f577ef80db52e3c2c upstream. Restore the processor state before calling any other functions to ensure per-CPU variables can be used with KASLR memory randomization. Tracing functions use per-CPU variables (GS based on x86) and one was called just before restoring the processor state fully. It resulted in a double fault when both the tracing & the exception handler functions tried to use a per-CPU variable. Fixes: bb3632c6101b (PM / sleep: trace events for suspend/resume) Reported-and-tested-by: Borislav Petkov Reported-by: Jiri Kosina Tested-by: Rafael J. Wysocki Tested-by: Jiri Kosina Signed-off-by: Thomas Garnier Acked-by: Pavel Machek Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman --- kernel/power/hibernate.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -299,12 +299,12 @@ static int create_image(int platform_mod save_processor_state(); trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, true); error = swsusp_arch_suspend(); + /* Restore control flow magically appears here */ + restore_processor_state(); trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, false); if (error) printk(KERN_ERR "PM: Error %d creating hibernation image\n", error); - /* Restore control flow magically appears here */ - restore_processor_state(); if (!in_suspend) events_check_enabled = false; Patches currently in stable-queue which might be from thgarnie@google.com are queue-4.4/pm-hibernate-restore-processor-state-before-using-per-cpu-variables.patch