From: Andy Lutomirski <luto@kernel.org>
To: Dan Williams <dan.j.williams@intel.com>
Cc: "Darrick J. Wong" <darrick.wong@oracle.com>,
Jan Kara <jack@suse.cz>, Arnd Bergmann <arnd@arndb.de>,
linux-nvdimm <linux-nvdimm@lists.01.org>,
Linux API <linux-api@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
linux-xfs@vger.kernel.org,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
Andrew Lutomirski <luto@kernel.org>,
Linux FS Devel <linux-fsdevel@vger.kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH v4 2/3] mm: introduce MAP_VALIDATE a mechanism for adding new mmap flags
Date: Tue, 15 Aug 2017 09:28:21 -0700 [thread overview]
Message-ID: <CALCETrU811Ac+DpiUP8MdayA6cD3Jk+Dd0RXAqk5YM6Lj9YsDQ@mail.gmail.com> (raw)
In-Reply-To: <150277753660.23945.11500026891611444016.stgit@dwillia2-desk3.amr.corp.intel.com>
On Mon, Aug 14, 2017 at 11:12 PM, Dan Williams <dan.j.williams@intel.com> wrote:
> The mmap syscall suffers from the ABI anti-pattern of not validating
> unknown flags. However, proposals like MAP_SYNC and MAP_DIRECT need a
> mechanism to define new behavior that is known to fail on older kernels
> without the feature. Use the fact that specifying MAP_SHARED and
> MAP_PRIVATE at the same time is invalid as a cute hack to allow a new
> set of validated flags to be introduced.
While this is cute, is it actually better than a new syscall?
next prev parent reply other threads:[~2017-08-15 16:28 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-15 6:12 [PATCH v4 0/3] MAP_DIRECT and block-map sealed files Dan Williams
2017-08-15 6:12 ` [PATCH v4 1/3] fs, xfs: introduce S_IOMAP_SEALED Dan Williams
[not found] ` <150277752553.23945.13932394738552748440.stgit-p8uTFz9XbKj2zm6wflaqv1nYeNYlB/vhral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
2017-08-15 6:12 ` [PATCH v4 2/3] mm: introduce MAP_VALIDATE a mechanism for adding new mmap flags Dan Williams
2017-08-15 12:27 ` Jan Kara
[not found] ` <20170815122701.GF27505-4I4JzKEfoa/jFM9bn6wA6Q@public.gmane.org>
2017-08-15 16:24 ` Dan Williams
2017-09-17 3:44 ` Dan Williams
[not found] ` <CAA9_cmc0vejxCsc1NWp5b4C0CSsO5xetF3t6LCoCuEYB6yPiwQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2017-09-17 17:39 ` Christoph Hellwig
[not found] ` <20170917173945.GA22200-jcswGhMUV9g@public.gmane.org>
2017-09-18 9:31 ` Jan Kara
2017-09-18 15:47 ` Dan Williams
2017-09-18 9:26 ` Jan Kara
2017-08-15 16:28 ` Andy Lutomirski [this message]
2017-08-15 22:31 ` Dan Williams
2017-08-17 8:06 ` kbuild test robot
2017-08-15 6:12 ` [PATCH v4 3/3] fs, xfs: introduce MAP_DIRECT for creating block-map-sealed file ranges Dan Williams
2017-08-15 9:18 ` Kirill A. Shutemov
2017-08-15 17:11 ` Dan Williams
2017-08-16 10:25 ` Kirill A. Shutemov
[not found] ` <150277754211.23945.458876600578531019.stgit-p8uTFz9XbKj2zm6wflaqv1nYeNYlB/vhral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
2017-08-15 12:42 ` Jan Kara
[not found] ` <20170815124250.GG27505-4I4JzKEfoa/jFM9bn6wA6Q@public.gmane.org>
2017-08-15 16:29 ` Dan Williams
[not found] ` <CAPcyv4h01os0Gc6bYmaGdMXt5q4G4zfirNRPWG3=gQi5POrpmg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2017-08-16 1:15 ` Dan Williams
2017-08-17 8:49 ` kbuild test robot
2017-08-15 9:01 ` [PATCH v4 0/3] MAP_DIRECT and block-map sealed files Dave Chinner
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