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From: Michael Ellerman <mpe@ellerman.id.au>
To: Christophe LEROY <christophe.leroy@c-s.fr>,
	Michal Hocko <mhocko@kernel.org>, Ram Pai <linuxram@us.ibm.com>,
	Andrew Morton <akpm@linux-foundation.org>
Cc: "linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>,
	linux-mm <linux-mm@kvack.org>
Subject: Re: Odd SIGSEGV issue introduced by commit 6b31d5955cb29 ("mm, oom: fix potential data corruption when oom_reaper races with writer")
Date: Tue, 21 Aug 2018 16:40:15 +1000	[thread overview]
Message-ID: <871sasmddc.fsf@concordia.ellerman.id.au> (raw)
In-Reply-To: <7767bdf4-a034-ecb9-1ac8-4fa87f335818@c-s.fr>

Christophe LEROY <christophe.leroy@c-s.fr> writes:
...
>
> And I bisected its disappearance with commit 99cd1302327a2 ("powerpc: 
> Deliver SEGV signal on pkey violation")

Whoa that's weird.

> Looking at those two commits, especially the one which makes it 
> dissapear, I'm quite sceptic. Any idea on what could be the cause and/or 
> how to investigate further ?

Are you sure it's not some corruption that just happens to be masked by
that commit? I can't see anything in that commit that could explain that
change in behaviour.

The only real change is if you're hitting DSISR_KEYFAULT isn't it?

What happens if you take 087003e9ef7c and apply the various hunks from
99cd1302327a2 gradually (or those that you can anyway)?

cheers

  parent reply	other threads:[~2018-08-21  6:40 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-08-20 15:23 Christophe LEROY
2018-08-20 16:01 ` Michal Hocko
2018-08-20 16:04   ` Christophe LEROY
2018-08-21  6:40 ` Michael Ellerman [this message]
2018-08-21 17:50   ` Ram Pai
2018-08-22  8:19     ` Christophe LEROY
2018-08-22 22:55       ` Ram Pai
2018-08-23  1:25 ` Michael Ellerman

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