Re: [PATCH] x86: fix early boot crash on gcc-10

From: Jakub Jelinek
Date: Tue Mar 17 2020 - 10:39:35 EST


On Tue, Mar 17, 2020 at 03:36:02PM +0100, Borislav Petkov wrote:
> On Mon, Mar 16, 2020 at 07:03:03PM +0100, Jakub Jelinek wrote:
> > On Mon, Mar 16, 2020 at 06:54:50PM +0100, Borislav Petkov wrote:
> > > So having a way to state "do not add stack canary checking to this
> > > particular function" would be optimal. And since you already have the
> > > "stack_protect" function attribute I figure adding a "no_stack_protect"
> > > one should be easy...
> >
> > Easy, but a waste when GCC already has the optimize attribute that can
> > handle also ~450 other options that are per-function rather than per-TU.
>
> Ok, Micha explained to me what you mean here and I did:
>
> static void __attribute__((optimize("no-stack-protect"))) notrace start_secondary(void *unused)
> {
>
> but it said

That is because the option is called -fno-stack-protector, so one needs to
use __attribute__((optimize("no-stack-protector")))

Jakub