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bh=jgiR0d8hUFYk52IUlDU+5+WUlWzBEfGIiyIxt9qM28M=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=ULxhZQ8c8CFbkpJnZkQWozl7DcYVx5jaXu3rzUm9YEUVUUBF3LoSFC62/+TJOYZaR XqOGcbMw9b1nL+CccygWmx/zE9bKSUO+vNPz8Irpn2cZdIGClGOwo3gE90ADY2+Gol bLVO3uhuoeYOQb1698Ohp0oHoLXvcFQkBDfiZnyc= Date: Wed, 25 Jan 2023 16:21:59 -0800 From: Andrew Morton To: Suren Baghdasaryan Cc: michel@lespinasse.org, jglisse@google.com, mhocko@suse.com, vbabka@suse.cz, hannes@cmpxchg.org, mgorman@techsingularity.net, dave@stgolabs.net, willy@infradead.org, liam.howlett@oracle.com, peterz@infradead.org, ldufour@linux.ibm.com, paulmck@kernel.org, mingo@redhat.com, will@kernel.org, luto@kernel.org, songliubraving@fb.com, peterx@redhat.com, david@redhat.com, dhowells@redhat.com, hughd@google.com, bigeasy@linutronix.de, kent.overstreet@linux.dev, punit.agrawal@bytedance.com, lstoakes@gmail.com, peterjung1337@gmail.com, rientjes@google.com, axelrasmussen@google.com, joelaf@google.com, minchan@google.com, jannh@google.com, shakeelb@google.com, tatashin@google.com, edumazet@google.com, gthelen@google.com, gurua@google.com, arjunroy@google.com, soheil@google.com, hughlynch@google.com, leewalsh@google.com, posk@google.com, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, x86@kernel.org, linux-kernel@vger.kernel.org, kernel-team@android.com Subject: Re: [PATCH v3 1/7] kernel/fork: convert vma assignment to a memcpy Message-Id: <20230125162159.a66e5ef05fecb405e85ffec9@linux-foundation.org> In-Reply-To: <20230125233554.153109-2-surenb@google.com> References: <20230125233554.153109-1-surenb@google.com> <20230125233554.153109-2-surenb@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-Rspam-User: X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 12A161C0008 X-Stat-Signature: c6knhdgjy3oybn3tnqb6stwjcnsh5qw5 X-HE-Tag: 1674692524-129252 X-HE-Meta: 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 Ct3Hpo86 KYFINyOOpSYPlAxekKUCWmouo2rJZ9osHa5O+pLTrQVjsA1afaMoDYIs6D2aJZzzfxpEsTCQNuUaQGLzSCgiuBpnOsLFDYaWgMf7HfZlfTrFR9Ky+QR0QH54rZlHjpXx/JnYRa8F4lkMujHYPXIsAECAL5IpK+vEYI7iAnkbmjywjo1BA9zMmOwhXhXmAeF7T4LxzPay6/jC3cmfmk4s6qCCZpqgO8Cs5mdHJa3kZNcowynk4n5N2mBubYN7Q8+C64K+y4740QL9maplGyyR+vlrhayH5EEqGwiCAiXeljygynwhPD62Y47YTkwwjCaMepiEiWOPhWZeqBvO610/jTgjWTIN6fWuluvSSw016RIkwMG+aulgF5l+8hg== 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, 25 Jan 2023 15:35:48 -0800 Suren Baghdasaryan wrote: > Convert vma assignment in vm_area_dup() to a memcpy() to prevent compiler > errors when we add a const modifier to vma->vm_flags. > > ... > > --- a/kernel/fork.c > +++ b/kernel/fork.c > @@ -482,7 +482,7 @@ struct vm_area_struct *vm_area_dup(struct vm_area_struct *orig) > * orig->shared.rb may be modified concurrently, but the clone > * will be reinitialized. > */ > - *new = data_race(*orig); > + memcpy(new, orig, sizeof(*new)); The data_race() removal is unchangelogged? > INIT_LIST_HEAD(&new->anon_vma_chain); > dup_anon_vma_name(orig, new); > }