From: Rafael J. Wysocki <rjw@xxxxxxx> 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 <rjw@xxxxxxx> Reported-and-tested-by: Andy Wettstein <ajw1980@xxxxxxxxx> --- 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 <linux/dmi.h> #include <linux/cpumask.h> #include <asm/segment.h> +#include <asm/desc.h> #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; _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
