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Shutemov" Cc: akpm@linux-foundation.org, linux-mm@kvack.org, chenqiwu Subject: Re: [PATCH] mm/rmap: ensure the validity of mapping vma which referenced an anon page Message-ID: <20200311103137.GA32509@cqw-OptiPlex-7050> References: <1583912713-30778-1-git-send-email-qiwuchen55@gmail.com> <20200311091943.szpvgb3tsc6ss74z@box> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200311091943.szpvgb3tsc6ss74z@box> User-Agent: Mutt/1.5.21 (2010-09-15) 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 Wed, Mar 11, 2020 at 12:19:43PM +0300, Kirill A. Shutemov wrote: > On Wed, Mar 11, 2020 at 03:45:13PM +0800, qiwuchen55@gmail.com wrote: > > From: chenqiwu > > > > When finding all the mapping vmas for an anon page by anon_vma, there > > is a panic risk that one mapping vma or its vm_mm has been released by > > someone. > > What? Who would be able to release the VMA or the mm_struct? We hold > anon_vma lock. It doesn't make sense to me. Something else is broken. > There is only log (no kdump) in my hand. It's hard to say who released the VMA's mm_struct before we hold the anon_vma lock.