From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: [PATCH] x86 ACPI: Fix breakage of resume on 64-bit UP systems with SMP kernel Date: Fri, 17 Oct 2008 01:26:27 +0200 Message-ID: <200810170126.27890.rjw@sisk.pl> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-2" Content-Transfer-Encoding: 7bit Return-path: Received: from ogre.sisk.pl ([217.79.144.158]:60569 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756883AbYJPXWR (ORCPT ); Thu, 16 Oct 2008 19:22:17 -0400 Content-Disposition: inline Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Ingo Molnar Cc: ACPI Devel Maling List , Andrew Morton , LKML , Pavel Machek , pm list From: Rafael J. Wysocki x86 ACPI: Fix breakage of resume on 64-bit UP systems with SMP kernel We are now using per CPU GDT tables in head_64.S and the original early_gdt_descr.address is invalidated after boot by setup_per_cpu_areas(). This breaks resume from suspend to RAM on x86_64 UP systems using SMP kernels, because this part of head_64.S is also executed during the resume and the invalid GDT address causes the system to crash. It doesn't break on 'true' SMP systems, because early_gdt_descr.address is modified every time native_cpu_up() runs. However, during resume it should point to the GDT of the boot CPU rather than to another CPU's GDT. For this reason, during suspend to RAM always make early_gdt_descr.address point to the boot CPU's GDT. This fixes http://bugzilla.kernel.org/show_bug.cgi?id=11568, which is a regression from 2.6.26. Signed-off-by: Rafael J. Wysocki Reported-and-tested-by: Andy Wettstein --- arch/x86/kernel/acpi/sleep.c | 3 +++ 1 file changed, 3 insertions(+) Index: linux-2.6/arch/x86/kernel/acpi/sleep.c =================================================================== --- linux-2.6.orig/arch/x86/kernel/acpi/sleep.c +++ linux-2.6/arch/x86/kernel/acpi/sleep.c @@ -10,6 +10,7 @@ #include #include #include +#include #include "realmode/wakeup.h" #include "sleep.h" @@ -100,6 +101,8 @@ int acpi_save_state_mem(void) header->trampoline_segment = setup_trampoline() >> 4; #ifdef CONFIG_SMP stack_start.sp = temp_stack + 4096; + early_gdt_descr.address = + (unsigned long)get_cpu_gdt_table(smp_processor_id()); #endif initial_code = (unsigned long)wakeup_long64; saved_magic = 0x123456789abcdef0;