From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf1-f198.google.com (mail-pf1-f198.google.com [209.85.210.198]) by kanga.kvack.org (Postfix) with ESMTP id 7C6C46B1D54 for ; Tue, 21 Aug 2018 02:40:19 -0400 (EDT) Received: by mail-pf1-f198.google.com with SMTP id p5-v6so9149071pfh.11 for ; Mon, 20 Aug 2018 23:40:19 -0700 (PDT) Received: from ozlabs.org (ozlabs.org. [2401:3900:2:1::2]) by mx.google.com with ESMTPS id k193-v6si7070824pge.4.2018.08.20.23.40.18 for (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 20 Aug 2018 23:40:18 -0700 (PDT) From: Michael Ellerman Subject: Re: Odd SIGSEGV issue introduced by commit 6b31d5955cb29 ("mm, oom: fix potential data corruption when oom_reaper races with writer") In-Reply-To: <7767bdf4-a034-ecb9-1ac8-4fa87f335818@c-s.fr> References: <7767bdf4-a034-ecb9-1ac8-4fa87f335818@c-s.fr> Date: Tue, 21 Aug 2018 16:40:15 +1000 Message-ID: <871sasmddc.fsf@concordia.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain Sender: owner-linux-mm@kvack.org List-ID: To: Christophe LEROY , Michal Hocko , Ram Pai , Andrew Morton Cc: "linuxppc-dev@lists.ozlabs.org" , linux-mm Christophe LEROY 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