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authorDavid Fries <david@fries.net>2008-08-17 23:03:40 -0500
committerIngo Molnar <mingo@elte.hu>2008-08-18 08:50:19 +0200
commite532c06f2a835b5cc4f4166f467437d9b09c1d0e (patch)
tree762fa0f0c22dc1af7d9d6e918f4d48ced8910a4e /arch/x86/kernel/acpi/sleep.c
parent39e00fe20aaad4326ed5e0e3221451732bc7f679 (diff)
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x86: fix i486 suspend to disk CR4 oops
arch/x86/power/cpu_32.c __save_processor_state calls read_cr4() only a i486 CPU doesn't have the CR4 register. Trying to read it produces an invalid opcode oops during suspend to disk. Use the safe rc4 reading op instead. If the value to be written is zero the write is skipped. arch/x86/power/hibernate_asm_32.S done: swapped the use of %eax and %ecx to use jecxz for the zero test and jump over store to %cr4. restore_image: s/%ecx/%eax/ to be consistent with done: In addition to __save_processor_state, acpi_save_state_mem, efi_call_phys_prelog, and efi_call_phys_epilog had checks added (acpi restore was in assembly and already had a check for non-zero). There were other reads and writes of CR4, but MCE and virtualization shouldn't be executed on a i486 anyway. Signed-off-by: David Fries <david@fries.net> Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/acpi/sleep.c')
-rw-r--r--arch/x86/kernel/acpi/sleep.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kernel/acpi/sleep.c b/arch/x86/kernel/acpi/sleep.c
index 81e5ab6542d..426e5d91b63 100644
--- a/arch/x86/kernel/acpi/sleep.c
+++ b/arch/x86/kernel/acpi/sleep.c
@@ -86,7 +86,7 @@ int acpi_save_state_mem(void)
#endif /* !CONFIG_64BIT */
header->pmode_cr0 = read_cr0();
- header->pmode_cr4 = read_cr4();
+ header->pmode_cr4 = read_cr4_safe();
header->realmode_flags = acpi_realmode_flags;
header->real_magic = 0x12345678;