On 06/16/2015 12:05 PM, Pavel Machek wrote: > >> diff --git a/arch/x86/kernel/acpi/wakeup_32.S >> b/arch/x86/kernel/acpi/wakeup_32.S >> index 665c6b7..eef2bd3 100644 >> --- a/arch/x86/kernel/acpi/wakeup_32.S >> +++ b/arch/x86/kernel/acpi/wakeup_32.S >> @@ -31,17 +31,11 @@ wakeup_pmode_return: >> >> movl %cs:saved_magic, %eax >> cmpl $0x12345678, %eax >> - jne bogus_magic >> - >> - # jump to place where we left off >> - movl saved_eip, %eax >> - jmp *%eax >> - >> + je ret_point >> bogus_magic: > > Longjump is supposed to flush the prefetch, but hopefully nothing > depends on that detail... ... > > no. > > https://en.wikibooks.org/wiki/X86_Assembly/Protected_Mode#Entering_Protected_Mode > > longjump is supposed to be there. Sorry about that. I guess indirect > jump is not neccessary, and we should add a comment there.
What "long jump"? It's not a far (segment:offset) jump, it's a near jump (one which only changes the offset), indirect one through a register. And we aren't switching to or from protected mode here. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
