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

From: Josh Poimboeuf
Date: Fri May 19 2017 - 16:18:03 EST


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")))

--
Josh