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| author | H. Peter Anvin <hpa@zytor.com> | 2009-11-14 00:28:14 +0100 |
|---|---|---|
| committer | H. Peter Anvin <hpa@zytor.com> | 2009-11-16 22:44:57 +0100 |
| commit | a7c4c0d934c6cbc58de262d090d4a715445453f0 (patch) | |
| tree | f321fc60984d17c57a65bac6820a12b61d6ed8d4 /arch | |
| parent | x86-32: Use symbolic constants, safer CPUID when enabling EFER.NX (diff) | |
| download | linux-a7c4c0d934c6cbc58de262d090d4a715445453f0.tar.xz linux-a7c4c0d934c6cbc58de262d090d4a715445453f0.zip | |
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 <hpa@zytor.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Nigel Cunningham <nigel@tuxonice.net>
LKML-Reference: <1258154897-6770-3-git-send-email-hpa@zytor.com>
Acked-by: Kees Cook <kees.cook@canonical.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | 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 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(); |