From mboxrd@z Thu Jan 1 00:00:00 1970 From: Srinivas Pandruvada Subject: [PATCH] x86: General protection fault after STR (32 bit systems only) Date: Thu, 11 Jun 2015 16:45:38 -0700 Message-ID: <1434066338-6619-1-git-send-email-srinivas.pandruvada@linux.intel.com> Return-path: Received: from mga01.intel.com ([192.55.52.88]:49828 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752390AbbFKXsE (ORCPT ); Thu, 11 Jun 2015 19:48:04 -0400 Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: mingo@redhat.com, tglx@linutronix.de, hpa@zytor.com, pavel@ucw.cz, rjw@rjwysocki.net Cc: x86@kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Srinivas Pandruvada Suspend to RAM process is returning to userspsace with DS set to KERNEL_DS after resume, this cause general protection fault. This is very difficult to reproduce, but this does happen on 32 bit systems. This crash is not reproduced after save/restore DS during calls to _save_processor_state/ __restore_processor_state respectively. Similar issue was reported in the past https://bugzilla.kernel.org/show_bug.cgi?id=61781, for which the root cause was not identified. Signed-off-by: Srinivas Pandruvada Reviewed-by: Andi Kleen --- arch/x86/include/asm/suspend_32.h | 2 +- arch/x86/power/cpu.c | 2 ++ 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/suspend_32.h b/arch/x86/include/asm/suspend_32.h index 552d6c9..3503d0b 100644 --- a/arch/x86/include/asm/suspend_32.h +++ b/arch/x86/include/asm/suspend_32.h @@ -11,7 +11,7 @@ /* image of the saved processor state */ struct saved_context { - u16 es, fs, gs, ss; + u16 ds, es, fs, gs, ss; unsigned long cr0, cr2, cr3, cr4; u64 misc_enable; bool misc_enable_saved; diff --git a/arch/x86/power/cpu.c b/arch/x86/power/cpu.c index 757678f..e0dfb01 100644 --- a/arch/x86/power/cpu.c +++ b/arch/x86/power/cpu.c @@ -79,6 +79,7 @@ static void __save_processor_state(struct saved_context *ctxt) * segment registers */ #ifdef CONFIG_X86_32 + savesegment(ds, ctxt->ds); savesegment(es, ctxt->es); savesegment(fs, ctxt->fs); savesegment(gs, ctxt->gs); @@ -198,6 +199,7 @@ static void notrace __restore_processor_state(struct saved_context *ctxt) * segment registers */ #ifdef CONFIG_X86_32 + loadsegment(ds, ctxt->ds); loadsegment(es, ctxt->es); loadsegment(fs, ctxt->fs); loadsegment(gs, ctxt->gs); -- 1.9.3