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From: Kees Cook <keescook@chromium.org>
To: Matthew Wilcox <willy@infradead.org>
Cc: Yu Zhao <yuzhao@google.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	dev@der-flo.net, Linux-MM <linux-mm@kvack.org>,
	Uladzislau Rezki <urezki@gmail.com>,
	bugzilla-daemon@kernel.org
Subject: Re: [Bug 216489] New: Machine freezes due to memory lock
Date: Fri, 16 Sep 2022 07:42:07 -0700	[thread overview]
Message-ID: <202209160739.ADFB98C3@keescook> (raw)
In-Reply-To: <YySE6VV23JkwonyQ@casper.infradead.org>

On Fri, Sep 16, 2022 at 03:15:05PM +0100, Matthew Wilcox wrote:
> Right, and Ulad is right about it beig callable from any context.  I think
> the longterm solution is to make the vmap_area_root tree walkable under
> RCU protection.

Agreed, I've updated my proposed patch.

> For now, let's have a distinct return code (ERR_PTR(-EAGAIN), perhaps?) to
> indicate that we've hit contention.  It generally won't matter if we
> hit it in process context because hardening doesn't have to be 100%
> reliable to be useful.

Right, as I note in the series[1], hardening shouldn't be getting called
_at all_ in this path. :P

-Kees

[1] https://lore.kernel.org/linux-hardening/20220916135953.1320601-1-keescook@chromium.org/

-- 
Kees Cook


  reply	other threads:[~2022-09-16 14:42 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <bug-216489-27@https.bugzilla.kernel.org/>
2022-09-15 20:39 ` Andrew Morton
2022-09-15 22:42   ` Matthew Wilcox
2022-09-15 23:59     ` Yu Zhao
2022-09-16  8:38       ` Matthew Wilcox
2022-09-16  9:46         ` Kees Cook
2022-09-16 12:28           ` Uladzislau Rezki
2022-09-16 12:32             ` Uladzislau Rezki
2022-09-16 14:15           ` Matthew Wilcox
2022-09-16 14:42             ` Kees Cook [this message]
2022-09-16 18:47             ` Uladzislau Rezki

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