Subject: Re: [PATCH v2 0/2] vfs: Define new syscall getumask.
To: "Theodore Ts'o" <tytso@mit.edu>,
        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
        "Richard W.M. Jones" <rjones@redhat.com>, linux-kernel@vger.kernel.org,
        Thomas Gleixner <tglx@linutronix.de>, mingo@redhat.com,
        Andrew Morton <akpm@linux-foundation.org>, luto@kernel.org,
        viro@zeniv.linux.org.uk, zab <zab@redhat.com>, emunson@akamai.com,
        "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
        Andrea Arcangeli <aarcange@redhat.com>, josh@joshtriplett.org,
        Pavel Emelyanov <xemul@parallels.com>, sfr@canb.auug.org.au,
        Milosz Tanski <milosz@adfin.com>, rostedt <rostedt@goodmis.org>,
        arnd@arndb.de, ebiederm@xmission.com, gorcunov <gorcunov@openvz.org>,
        iulia manda21 <iulia.manda21@gmail.com>,
        dave hansen <dave.hansen@linux.intel.com>, mguzik <mguzik@redhat.com>,
        adobriyan@gmail.com, Davidlohr Bueso <dave@stgolabs.net>,
        linux-api <linux-api@vger.kernel.org>, gorcunov@gmail.com,
        fw@deneb.enyo.de, Linus Torvalds <torvalds@linux-foundation.org>
References: <1460552272-15985-1-git-send-email-rjones@redhat.com>
 <2143735451.55767.1460561962122.JavaMail.zimbra@efficios.com>
 <1736004700.56566.1460581285951.JavaMail.zimbra@efficios.com>
 <20160414021348.GB16656@thunk.org>
From: "H. Peter Anvin" <hpa@zytor.com>
Message-ID: <57142C80.6070005@zytor.com>
Date: Sun, 17 Apr 2016 17:38:24 -0700
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101
 Thunderbird/38.7.1
MIME-Version: 1.0
In-Reply-To: <20160414021348.GB16656@thunk.org>
Content-Type: text/plain; charset=windows-1252
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 915
Lines: 22

On 04/13/16 19:13, Theodore Ts'o wrote:
> 
> One other reason to suggest using a /proc file is that you're not at
> the mercy of the glibc folks to wire up a new system call.  (Glibc has
> been refusing to wire up getrandom(2), for example.   Grrrr.....)
> 

This brings right back up the libinux idea.  There are continued
concerns about type compatibility, but saying "oh, use syscall(3)
instead" has worse properties than a Linux-kernel-team maintained
libinux.  Last I heard the glibc team had (reluctantly?) agreed to do
something to deal with linux-specific system calls, but last I heard
nothing had happened.  The last discussion I see on the glibc mailing
list dates back to November, and that thread seems to have died from
bikeshedding, again.

There aren't a *lot* of such system calls, but even in that thread the
"oh, only two applications need this, let them use syscall(3)" seems to
remain.

	-hpa