Re: [PATCH v3 35/75] x86/head/64: Build k/head64.c with -fno-stack-protector

From: Brian Gerst
Date: Wed Jun 03 2020 - 13:14:25 EST


On Wed, Jun 3, 2020 at 11:18 AM Joerg Roedel <joro@xxxxxxxxxx> wrote:
>
> On Tue, May 19, 2020 at 09:58:18AM -0400, Brian Gerst wrote:
> > On Tue, Apr 28, 2020 at 11:28 AM Joerg Roedel <joro@xxxxxxxxxx> wrote:
>
> > The proper fix would be to initialize MSR_GS_BASE earlier.
>
> That'll mean to initialize it two times during boot, as the first C
> function with stack-protection is called before the kernel switches to
> its high addresses (early_idt_setup call-path). But okay, I can do that.

Good point. Since this is boot code which isn't subject to stack
smashing attacks, disabling stack protector is probably the simpler
option.

--
Brian Gerst