From: Andrey Konovalov <andreyknvl@gmail.com>
To: David Hildenbrand <david@redhat.com>,
Sergei Trofimovich <slyfox@gentoo.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Linux Memory Management List <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>,
Vlastimil Babka <vbabka@suse.cz>
Subject: Re: [PATCH] mm: page_alloc: ignore init_on_free=1 for page alloc
Date: Fri, 26 Mar 2021 16:00:34 +0100 [thread overview]
Message-ID: <CA+fCnZeC8AWearU9CQaYrFM-ZCUaQpX1e7vBkRMNtqqf_=ucGA@mail.gmail.com> (raw)
In-Reply-To: <4e23d404-5125-6c9c-4aa7-5eff0fa1ba33@redhat.com>
On Fri, Mar 26, 2021 at 2:49 PM David Hildenbrand <david@redhat.com> wrote:
>
> > I observed use of poisoned pages as the crash on ia64 booted with
> > init_on_free=1 init_on_alloc=1 (CONFIG_PAGE_POISONING=y config).
> > There pmd page contained 0xaaaaaaaa poison pages and led to early crash.
> >
> > The change drops the assumption that init_on_free=1 guarantees free
> > pages to contain zeros.
> >
> > Alternative would be to make interaction between runtime poisoning and
> > sanitizing options and build-time debug flags like CONFIG_PAGE_POISONING
> > more coherent. I took the simpler path.
> >
>
> I thought latest work be Vlastimil tried to tackle that. To me, it feels
> like page_poison=on and init_on_free=1 should bail out and disable one
> of both things. Having both at the same time doesn't sound helpful.
This is exactly how it works, see init_mem_debugging_and_hardening().
Sergei, could you elaborate more on what kind of crash this patch is
trying to fix? Where does it happen and why?
next prev parent reply other threads:[~2021-03-26 15:00 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-26 11:26 [PATCH] mm: page_alloc: ignore init_on_free=1 for page alloc Sergei Trofimovich
2021-03-26 13:48 ` David Hildenbrand
2021-03-26 15:00 ` Andrey Konovalov [this message]
2021-03-26 16:42 ` Sergei Trofimovich
2021-03-29 12:10 ` Vlastimil Babka
2021-03-29 22:00 ` Andrey Konovalov
2021-03-29 22:07 ` Vlastimil Babka
2021-03-30 14:48 ` Andrey Konovalov
2021-03-26 14:17 ` Vlastimil Babka
2021-03-26 17:25 ` Sergei Trofimovich
2021-03-27 18:03 ` Sergei Trofimovich
2021-03-27 18:21 ` [PATCH v2] mm: page_alloc: ignore init_on_free=1 for debug_pagealloc=1 Sergei Trofimovich
2021-03-29 9:23 ` David Hildenbrand
2021-03-29 11:59 ` Vlastimil Babka
2021-03-29 22:25 ` [PATCH v3] " Sergei Trofimovich
2021-03-30 8:39 ` David Hildenbrand
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