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Date: Wed, 26 Aug 2015 23:48:01 +0800
Message-ID: <CAGk-QBte6bWGWWYGy=UmyqFuchy_94pr2o7B9p1tK=dgU+CK1Q@mail.gmail.com>
Subject: Re: [PATCH] kernel/sysctl.c: If "count" including the terminating
 byte '\0' the write system call should retrun success.
From: Sean Fu <fxinrong@gmail.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Austin S Hemmelgarn <ahferroin7@gmail.com>,
        "Eric W. Biederman" <ebiederm@xmission.com>,
        Andrey Ryabinin <ryabinin.a.a@gmail.com>,
        Ulrich Obergfell <uobergfe@redhat.com>,
        Prarit Bhargava <prarit@redhat.com>,
        Eric B Munson <emunson@akamai.com>,
        "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Thomas Gleixner <tglx@linutronix.de>, Don Zickus <dzickus@redhat.com>,
        Heinrich Schuchardt <xypron.glpk@gmx.de>,
        David Rientjes <rientjes@google.com>, linux-kernel@vger.kernel.org
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On Wed, Aug 26, 2015 at 3:05 AM, Steven Rostedt <rostedt@goodmis.org> wrote:
> On Tue, 25 Aug 2015 13:33:57 -0400
> Austin S Hemmelgarn <ahferroin7@gmail.com> wrote:
>
>> >> How do you know that?
>> > I will prove that all other write usage is not impacted later.
>> Except that you can only really do this for programs that you have
>> access to, and by definition you can not have access to every program
>> ever written that writes to /proc.
>>
>> If you were going to do this, it would need to be itself controlled by
>> another sysctl to toggle the behavior, which would need to default to
>> the current behavior.
>
> Defending the patch, I can't imagine any user space code expecting the
> current behavior. The current behavior is that if you write "1\0" it
> will error out instead of accepting the "1". I can't come up with a
> scenario that would require userspace to expect "1\0" to fail. Can you?
Thanks
>
>
> -- Steve
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