linux-kernel - Re: [PATCH 04/13] mm: Fix pmd_read

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <Y1ZIU8eL3ieeXmDS@hirez.programming.kicks-ass.net>
Date:   Mon, 24 Oct 2022 10:09:55 +0200
From:   Peter Zijlstra <peterz@...radead.org>
To:     Linus Torvalds <torvalds@...ux-foundation.org>
Cc:     x86@...nel.org, willy@...radead.org, akpm@...ux-foundation.org,
        linux-kernel@...r.kernel.org, linux-mm@...ck.org,
        aarcange@...hat.com, kirill.shutemov@...ux.intel.com,
        jroedel@...e.de, ubizjak@...il.com
Subject: Re: [PATCH 04/13] mm: Fix pmd_read_atomic()

On Sat, Oct 22, 2022 at 10:30:51AM -0700, Linus Torvalds wrote:
> On Sat, Oct 22, 2022 at 4:48 AM Peter Zijlstra <peterz@...radead.org> wrote:
> >
> > --- a/include/linux/pgtable.h
> > +++ b/include/linux/pgtable.h
> > @@ -258,6 +258,13 @@ static inline pte_t ptep_get(pte_t *ptep
> >  }
> >  #endif
> >
> > +#ifndef __HAVE_ARCH_PMDP_GET
> > +static inline pmd_t pmdp_get(pmd_t *pmdp)
> > +{
> > +       return READ_ONCE(*pmdp);
> > +}
> > +#endif
> 
> What, what, what?
> 
> Where did that __HAVE_ARCH_PMDP_GET come from?

Copy/paste like from ptep_get(), that has __HAVE_ARCH_PTEP_GET (which
does appear to get used, once).

Do I break the pattern and simply leave this off, or do I stay
consistent even though we hate it a little? ;-)