Re: [PATCHv4, REBASED 1/4] x86/mm/ident_map: Fix virtual address wrap to zero

From: Borislav Petkov
Date: Thu Oct 31 2024 - 10:00:01 EST


On Thu, Oct 31, 2024 at 12:11:52PM +0200, Kirill A. Shutemov wrote:
> Do we have magic words for that?

No clue.

> I tried to express that in the second paragraph: "no such users in the
> upstream".

Right, so perhaps better to spell it out explicitly:

"Backporter's note:

This fixes a theoretical issue only and there's no need to backport it to
stable."

at the end of the commit message.

> > And which commit is it fixing?
> >
> > aece27851d44 ("x86, 64bit, mm: Add generic kernel/ident mapping helper")
> > perhaps?
>
> This one is closer:
>
> e4630fdd4763 ("x86/power/64: Always create temporary identity mapping correctly")
>
> It adds x86_mapping_info::offset.

But aece27851d44 has the faulty check...

--
Regards/Gruss,
Boris.

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