linux-kernel - Re: [PATCH] mm: mempolicy: keep VMA walk if both MPOL_MF_STRICT and MPOL_MF

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: <20230928093809.75de08561b0fa1af03bf4a89@linux-foundation.org>
Date:   Thu, 28 Sep 2023 09:38:09 -0700
From:   Andrew Morton <akpm@...ux-foundation.org>
To:     Suren Baghdasaryan <surenb@...gle.com>
Cc:     Yang Shi <yang@...amperecomputing.com>, hughd@...gle.com,
        willy@...radead.org, mhocko@...e.com, vbabka@...e.cz,
        osalvador@...e.de, aquini@...hat.com, kirill@...temov.name,
        rientjes@...gle.com, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org, stable@...r.kernel.org
Subject: Re: [PATCH] mm: mempolicy: keep VMA walk if both MPOL_MF_STRICT and
 MPOL_MF_MOVE are specified

On Wed, 27 Sep 2023 14:39:21 -0700 Suren Baghdasaryan <surenb@...gle.com> wrote:

> > >
> > >> The code should conceptually do:
> > >>
> > >>   if (MPOL_MF_MOVE|MOVEALL)
> > >>       scan all vmas
> > >>       try to migrate the existing pages
> > >>       return success
> > >>   else if (MPOL_MF_MOVE* | MPOL_MF_STRICT)
> > >>       scan all vmas
> > >>       try to migrate the existing pages
> > >>       return -EIO if unmovable or migration failed
> > >>   else /* MPOL_MF_STRICT alone */
> > >>       break early if meets unmovable and don't call mbind_range() at all
> > >>   else /* none of those flags */
> > >>       check the ranges in test_walk, EFAULT without mbind_range() if discontig.
> 
> With this change I think my temporary fix at
> https://lore.kernel.org/all/20230918211608.3580629-1-surenb@google.com/
> can be removed because we either scan all vmas (which means we locked
> them all) or we break early and do not call mbind_range() at all (in
> which case we don't need vmas to be locked).

Thanks, I dropped "mm: lock VMAs skipped by a failed queue_pages_range()"