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[209.85.167.44]) by smtp.gmail.com with ESMTPSA id y23-v6sm13011951ljk.95.2019.01.05.11.46.49 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 05 Jan 2019 11:46:50 -0800 (PST) Received: by mail-lf1-f44.google.com with SMTP id y14so8630522lfg.13 for ; Sat, 05 Jan 2019 11:46:49 -0800 (PST) X-Received: by 2002:a19:3fcf:: with SMTP id m198mr26611229lfa.106.1546717609589; Sat, 05 Jan 2019 11:46:49 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: From: Linus Torvalds Date: Sat, 5 Jan 2019 11:46:33 -0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH] mm/mincore: allow for making sys_mincore() privileged To: Jiri Kosina Cc: Andrew Morton , Greg KH , Peter Zijlstra , Michal Hocko , linux-mm@kvack.org, Linux List Kernel Mailing , linux-api@vger.kernel.org Content-Type: text/plain; charset="UTF-8" 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: Message-ID: <20190105194633._Y2tMRRkoSKmpfdkl-WYqhuIjVbST_Q_N74fl49HWbM@z> On Sat, Jan 5, 2019 at 9:27 AM Jiri Kosina wrote: > > From: Jiri Kosina > > There are possibilities [1] how mincore() could be used as a converyor of > a sidechannel information about pagecache metadata. Can we please just limit it to vma's that are either anonymous, or map a file that the user actually owns? Then the capability check could be for "override the file owner check" instead, which makes tons of sense. No new sysctl's for something like this, please. Linus