Re: [RESEND][patch V3 03/23] vmlinux.lds.h: Create section for protection against instrumentation

From: Borislav Petkov
Date: Tue Mar 24 2020 - 08:26:13 EST


Just typos:

On Fri, Mar 20, 2020 at 06:59:59PM +0100, Thomas Gleixner wrote:
> Some code pathes, especially the low level entry code, must be protected

s/pathes/paths/

> against instrumentation for various reasons:
>
> - Low level entry code can be a fragile beast, especially on x86.
>
> - With NO_HZ_FULL RCU state needs to be established before using it.
>
> Having a dedicated section for such code allows to validate with tooling
> that no unsafe functions are invoked.
>
> Add the .noinstr.text section and the noinstr attribute to mark
> functions. noinstr implies notrace. Kprobes will gain a section check
> later.
>
> Provide also two sets of markers:
>
> - instr_begin()/end()
>
> This is used to mark code inside in a noinstr function which calls

s/in //

> into regular instrumentable text section as safe.
>
> - noinstr_call_begin()/end()
>
> Same as above but used to mark indirect calls which cannot be tracked by
> tooling and need to be audited manually.

--
Regards/Gruss,
Boris.

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