Re: [PATCH V2 04/41] x86/entry: Introduce __entry_text for entry code written in C

From: Borislav Petkov
Date: Thu Sep 30 2021 - 07:49:30 EST


On Sun, Sep 26, 2021 at 11:08:01PM +0800, Lai Jiangshan wrote:
> From: Lai Jiangshan <laijs@xxxxxxxxxxxxxxxxx>
>
> Some entry code will be implemented in C files. We need __entry_text

Who's "we"?

> to set them in .entry.text section. __entry_text disables instruments

s/instruments/instrumentation/

> like noinstr, but it doesn't disable stack protector since not all
> compiler supported by kernel supporting function level granular
> attribute to disable stack protector. It will be disabled by C file
> level.
>
> Signed-off-by: Lai Jiangshan <laijs@xxxxxxxxxxxxxxxxx>
> ---
> arch/x86/include/asm/idtentry.h | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h
> index 1345088e9902..6779def97591 100644
> --- a/arch/x86/include/asm/idtentry.h
> +++ b/arch/x86/include/asm/idtentry.h
> @@ -11,6 +11,9 @@
>
> #include <asm/irq_stack.h>
>
> +/* Entry code written in C. */
> +#define __entry_text __noinstr_section(".entry.text")

I'm assuming that __noinstr_section() is defined somewhere, maybe in
patch 3, which I don't have in my mbox.

Yah, the 0th message says:

" compiler_types.h: Add __noinstr_section() for noinstr"

Aha, I see why: you haven't CCed me on that one so I don't have it:

https://lkml.kernel.org/r/20210926150838.197719-4-jiangshanlai@xxxxxxxxx

I have all the remaining 40 but not that one.

On your next submission, please make sure you CC x86@xxxxxxxxxx so that
all x86 people get the whole patchset.

Thx.

--
Regards/Gruss,
Boris.

https://people.kernel.org/tglx/notes-about-netiquette