Re: [PATCH] arch: x86: power: cpu: init %gs before __restore_processor_state (clang)

[Roman Kiryanov]

On Tue, Sep 15, 2020 at 11:52 AM Borislav Petkov <bp@xxxxxxxxx> wrote:
>
> On Tue, Sep 15, 2020 at 11:36:13AM -0700, Roman Kiryanov wrote:
> > This is fair. Unfortunately I am not an x86 asm expert. I expect the proper
> > fix should land into arch/x86/kernel/acpi/wakeup_64.S to init %gs
> > (maybe some more registers) before "jmp restore_processor_state".
>
> ... because "LLVM appears to be inlining functions with stack protectors
> into functions compiled with -fno-stack-protector" and now the *kernel*
> needs to init %gs?
>
> How about LLVM stops doing those wrong inlining decisions?

This will remove the issue for a while until clang/gcc/other decides to use
%gs for other purposes before the kernel initializes it.

Regards,
Roman.