[PATCH 2/5] x86, sleep: always save the value of EFER

H. Peter Anvin
2009-11-13T23:28:26Z

Always save the value of EFER, regardless of the state of NX. Since
EFER may not actually exist, use rdmsr_safe() to do so.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Nigel Cunningham <nigel@tuxonice.net>
---
arch/x86/kernel/acpi/sleep.c | 9 +++------
1 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/acpi/sleep.c b/arch/x86/kernel/acpi/sleep.c
index ca93638..c2e4455 100644
--- a/arch/x86/kernel/acpi/sleep.c
+++ b/arch/x86/kernel/acpi/sleep.c
@@ -78,12 +78,9 @@ int acpi_save_state_mem(void)
#ifndef CONFIG_64BIT
store_gdt((struct desc_ptr *)&header->pmode_gdt);

- header->pmode_efer_low = nx_enabled;
- if (header->pmode_efer_low & 1) {
- /* This is strange, why not save efer, always? */
- rdmsr(MSR_EFER, header->pmode_efer_low,
- header->pmode_efer_high);
- }
+ header->pmode_efer_low = header->pmode_efer_high = 0;
+ rdmsr_safe(MSR_EFER,
+ &header->pmode_efer_low, &header->pmode_efer_high);
#endif /* !CONFIG_64BIT */

header->pmode_cr0 = read_cr0();
--
1.6.2.5