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From:   Linus Torvalds <torvalds@linux-foundation.org>
Date:   Tue, 8 Mar 2022 13:22:11 -0800
Message-ID: <CAHk-=wiA0KMVbLacK-Gi5_ZsZhXVi++6ePTtPrJkgf0az7r2ww@mail.gmail.com>
Subject: Re: [PATCH v1 00/15] mm: COW fixes part 2: reliable GUP pins of
 anonymous pages
To:     David Hildenbrand <david@redhat.com>
Cc:     Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Hugh Dickins <hughd@google.com>,
        David Rientjes <rientjes@google.com>,
        Shakeel Butt <shakeelb@google.com>,
        John Hubbard <jhubbard@nvidia.com>,
        Jason Gunthorpe <jgg@nvidia.com>,
        Mike Kravetz <mike.kravetz@oracle.com>,
        Mike Rapoport <rppt@linux.ibm.com>,
        Yang Shi <shy828301@gmail.com>,
        "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
        Matthew Wilcox <willy@infradead.org>,
        Vlastimil Babka <vbabka@suse.cz>, Jann Horn <jannh@google.com>,
        Michal Hocko <mhocko@kernel.org>,
        Nadav Amit <namit@vmware.com>, Rik van Riel <riel@surriel.com>,
        Roman Gushchin <guro@fb.com>,
        Andrea Arcangeli <aarcange@redhat.com>,
        Peter Xu <peterx@redhat.com>,
        Donald Dutile <ddutile@redhat.com>,
        Christoph Hellwig <hch@lst.de>,
        Oleg Nesterov <oleg@redhat.com>, Jan Kara <jack@suse.cz>,
        Liang Zhang <zhangliang5@huawei.com>,
        Pedro Gomes <pedrodemargomes@gmail.com>,
        Oded Gabbay <oded.gabbay@gmail.com>,
        Linux-MM <linux-mm@kvack.org>,
        Khalid Aziz <khalid.aziz@oracle.com>
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On Tue, Mar 8, 2022 at 6:14 AM David Hildenbrand <david@redhat.com> wrote:
>
> This series fixes memory corruptions when a GUP pin (FOLL_PIN) was taken
> on an anonymous page and COW logic fails to detect exclusivity of the page
> to then replacing the anonymous page by a copy in the page table [...]

From a cursory scan of the patches, this looks sane.

I'm not sure what the next step should be, but I really would like the
people who do a lot of pinning stuff to give it a good shake-down.
Including both looking at the patches, but very much actually running
it on whatever test-cases etc you people have.

Please?

                 Linus