From a7c4c0d934c6cbc58de262d090d4a715445453f0 Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Fri, 13 Nov 2009 15:28:14 -0800 Subject: [PATCH] x86, sleep: Always save the value of EFER Always save the value of EFER, regardless of the state of NX. Since EFER may not actually exist, use rdmsr_safe() to do so. v2: check the return value from rdmsr_safe() instead of relying on the output values being unchanged on error. Signed-off-by: H. Peter Anvin Acked-by: Rafael J. Wysocki Cc: Pavel Machek Cc: Nigel Cunningham LKML-Reference: <1258154897-6770-3-git-send-email-hpa@zytor.com> Acked-by: Kees Cook --- arch/x86/kernel/acpi/sleep.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) diff --git a/arch/x86/kernel/acpi/sleep.c b/arch/x86/kernel/acpi/sleep.c index 4a411450dfa0..82e508677b91 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); - } + if (rdmsr_safe(MSR_EFER, &header->pmode_efer_low, + &header->pmode_efer_high)) + header->pmode_efer_low = header->pmode_efer_high = 0; #endif /* !CONFIG_64BIT */ header->pmode_cr0 = read_cr0(); -- 2.39.5