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Shutemov" , "Zach O'Keefe" , linux-kernel@vger.kernel.org, David Hildenbrand , Yang Shi , linux-mm@kvack.org Subject: Re: [PATCH] mm/khugepaged: Fix ->anon_vma race Message-Id: <20230117145532.94132510f8bc538d5465fd43@linux-foundation.org> In-Reply-To: References: <20230111133351.807024-1-jannh@google.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 0AEE7140010 X-Stat-Signature: qriqwkjnsmzsqio1fpcdaioqze3687js X-Rspam-User: X-Rspamd-Server: rspam08 X-HE-Tag: 1673996134-686003 X-HE-Meta: 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 W8ZrkycS 3iVcwFwsL6Axh7iq3e6OCkpAD38qnh5bf9NaYzLw6SoZxcQz2+NkV76ns3XVWgUoJEWrDsB1qVdALPA2q+sG8yW+iUB4i8GSskmUe5Ii4NqD1E6MtrQ6KTMaQBQ== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, 17 Jan 2023 20:12:49 +0100 Jann Horn wrote: > On Wed, Jan 11, 2023 at 2:33 PM Jann Horn wrote: > > If an ->anon_vma is attached to the VMA, collapse_and_free_pmd() requires > > it to be locked. retract_page_tables() bails out if an ->anon_vma is > > attached, but does this check before holding the mmap lock (as the comment > > above the check explains). > > @akpm please replace the commit message with the following, and maybe > also add a "Link:" entry pointing to > https://lore.kernel.org/linux-mm/CAG48ez3434wZBKFFbdx4M9j6eUwSUVPd4dxhzW_k_POneSDF+A@mail.gmail.com/ > for the reproducer. Done, thanks.