Re: [PATCH v5 32/32] x86/mm: Add support to make use of Secure Memory Encryption

Tom Lendacky
2017-05-30T15:48:51Z

On 5/19/2017 3:16 PM, Josh Poimboeuf wrote:
> On Fri, May 19, 2017 at 01:30:05PM +0200, Borislav Petkov wrote:
>>> it is called so early. I can get past it by adding:
>>>
>>> CFLAGS_mem_encrypt.o := $(nostackp)
>>>
>>> in the arch/x86/mm/Makefile, but that obviously eliminates the support
>>> for the whole file. Would it be better to split out the sme_enable()
>>> and other boot routines into a separate file or just apply the
>>> $(nostackp) to the whole file?
>>
>> Josh might have a better idea here... CCed.
>
> I'm the stack validation guy, not the stack protection guy :-)
>
> But there is a way to disable compiler options on a per-function basis
> with the gcc __optimize__ function attribute. For example:
>
> __attribute__((__optimize__("no-stack-protector")))
>

I'll look at doing that instead of removing the support for the whole
file.

Thanks,
Tom