From: "Kirill A. Shutemov" <kirill@shutemov.name>
To: Li Xinhai <lixinhai.lxh@gmail.com>
Cc: linux-mm@kvack.org, akpm@linux-foundation.org,
Rik van Riel <riel@redhat.com>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Matthew Wilcox <willy@infradead.org>
Subject: Re: [PATCH 1/3] mm: don't prepare anon_vma if vma has VM_WIPEONFORK
Date: Thu, 2 Apr 2020 16:45:37 +0300 [thread overview]
Message-ID: <20200402134537.avk5p7247zqwp4cg@box> (raw)
In-Reply-To: <1581150928-3214-2-git-send-email-lixinhai.lxh@gmail.com>
On Sat, Feb 08, 2020 at 08:35:26AM +0000, Li Xinhai wrote:
> In dup_mmap(), anon_vma_prepare() is called for vma has VM_WIPEONFORK,
> and parameter 'tmp' (i.e., the new vma of child) has same ->vm_next and
> ->vm_prev as its parent vma. That allows anon_vma used by parent been
> mistakenly shared by child (find_mergeable_anon_vma() will do this reuse
> work).
>
> Besides this issue, call anon_vma_prepare() should be avoided because we
> don't copy page for this vma. Preparing anon_vma will be handled during
> fault.
>
> Fixes: d2cd9ede6e19 ("mm,fork: introduce MADV_WIPEONFORK")
> Signed-off-by: Li Xinhai <lixinhai.lxh@gmail.com>
> Cc: Rik van Riel <riel@redhat.com>
> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> Cc: Matthew Wilcox <willy@infradead.org>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
--
Kirill A. Shutemov
next prev parent reply other threads:[~2020-04-02 13:45 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-08 8:35 [PATCH 0/3] mm: Fix misuse of parent anon_vma in dup_mmap path Li Xinhai
2020-02-08 8:35 ` [PATCH 1/3] mm: don't prepare anon_vma if vma has VM_WIPEONFORK Li Xinhai
2020-02-08 8:53 ` Li Xinhai
2020-04-02 13:45 ` Kirill A. Shutemov [this message]
2020-02-08 8:35 ` [PATCH 2/3] Revert "mm/rmap.c: reuse mergeable anon_vma as parent when fork" Li Xinhai
2020-04-02 13:59 ` Kirill A. Shutemov
2020-04-03 3:08 ` Li Xinhai
2020-04-05 1:26 ` Li Xinhai
2020-02-08 8:35 ` [PATCH 3/3] mm: set vm_next and vm_prev to NULL in vm_area_dup() Li Xinhai
2020-04-02 14:07 ` Kirill A. Shutemov
2020-02-10 0:52 ` [PATCH 0/3] mm: Fix misuse of parent anon_vma in dup_mmap path Andrew Morton
2020-02-10 2:15 ` Li Xinhai
2020-04-20 12:06 ` Michal Hocko
2020-04-21 3:53 ` Li Xinhai
2020-04-21 7:26 ` Michal Hocko
2020-04-02 1:25 ` Andrew Morton
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