Re: [PATCH 1/3] x86, acpi: Eliminate saved_eip

From: Pavel Machek
Date: Tue Jun 16 2015 - 06:06:01 EST



> 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.

Thanks,
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/