Re: [PATCH 3/4] x86: open-code register save/restore in trace_hardirqs thunks

From: Denys Vlasenko
Date: Sat Jan 10 2015 - 17:03:30 EST


On Sat, Jan 10, 2015 at 11:00 PM, Borislav Petkov <bp@xxxxxxxxx> wrote:
>> --- a/arch/x86/lib/thunk_64.S
>> +++ b/arch/x86/lib/thunk_64.S
>> @@ -17,9 +17,27 @@
>> CFI_STARTPROC
>>
>> /* this one pushes 9 elems, the next one would be %rIP */
>> - SAVE_ARGS
>> + pushq_cfi %rdi
>> + CFI_REL_OFFSET rdi, 0
>
> Btw, why the second CFI annotation?
>
> pushq_cfi does already CFI_ADJUST_CFA_OFFSET 8. Can't we use one and
> hide it in the macro?

We probably should.

Since thunk_32.S uses the very same construct, I think it should be fixed
in both files by one patch.
--
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/