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References: <2e5e80481533e73876d5d187d1f278f9656df73a.1617118134.git.andreyknvl@google.com>
 <115c3cd4-a5ec-ea4c-fdc8-a17a0990bd30@suse.cz>
In-Reply-To: <115c3cd4-a5ec-ea4c-fdc8-a17a0990bd30@suse.cz>
From:   Andrey Konovalov <andreyknvl@google.com>
Date:   Tue, 30 Mar 2021 18:37:39 +0200
Message-ID: <CAAeHK+yHcPQFP83p7-gPS4zC0NmhSWasxtoQU+Lz+py=QvKV-g@mail.gmail.com>
Subject: Re: [PATCH mm] mm, kasan: fix for "integrate page_alloc init with HW_TAGS"
To:     Vlastimil Babka <vbabka@suse.cz>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Sergei Trofimovich <slyfox@gentoo.org>,
        Alexander Potapenko <glider@google.com>,
        Marco Elver <elver@google.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        Andrey Ryabinin <aryabinin@virtuozzo.com>,
        Andrey Konovalov <andreyknvl@gmail.com>,
        kasan-dev <kasan-dev@googlegroups.com>,
        Linux Memory Management List <linux-mm@kvack.org>,
        LKML <linux-kernel@vger.kernel.org>
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On Tue, Mar 30, 2021 at 5:54 PM Vlastimil Babka <vbabka@suse.cz> wrote:
>
> On 3/30/21 5:31 PM, Andrey Konovalov wrote:
> > My commit "integrate page_alloc init with HW_TAGS" changed the order of
> > kernel_unpoison_pages() and kernel_init_free_pages() calls. This leads
> > to __GFP_ZERO allocations being incorrectly poisoned when page poisoning
> > is enabled.
>
> Correction: This leads to check_poison_mem() complain about memory corruption
> because the poison pattern has already been overwritten by zeroes.

Ah, indeed. Will send v2. Thanks!