[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20150824134408.be0ffaa654f7d26802119b81@linux-foundation.org>
Date: Mon, 24 Aug 2015 13:44:08 -0700
From: Andrew Morton <akpm@...ux-foundation.org>
To: Sean Fu <fxinrong@...il.com>
Cc: "Eric W. Biederman" <ebiederm@...ssion.com>,
Andrey Ryabinin <ryabinin.a.a@...il.com>,
Ulrich Obergfell <uobergfe@...hat.com>,
"Steven Rostedt (Red Hat)" <rostedt@...dmis.org>,
Prarit Bhargava <prarit@...hat.com>,
Eric B Munson <emunson@...mai.com>,
"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>,
Johannes Weiner <hannes@...xchg.org>,
Thomas Gleixner <tglx@...utronix.de>,
Don Zickus <dzickus@...hat.com>,
Heinrich Schuchardt <xypron.glpk@....de>,
David Rientjes <rientjes@...gle.com>,
linux-kernel@...r.kernel.org
Subject: Re: [PATCH] kernel/sysctl.c: If "count" including the terminating
byte '\0' the write system call should retrun success.
On Mon, 24 Aug 2015 23:33:58 +0800 Sean Fu <fxinrong@...il.com> wrote:
> On Mon, Aug 24, 2015 at 8:27 PM, Eric W. Biederman
> <ebiederm@...ssion.com> wrote:
> >
> >
> > On August 24, 2015 1:56:13 AM PDT, Sean Fu <fxinrong@...il.com> wrote:
> >>when the input argument "count" including the terminating byte "\0",
> >>The write system call return EINVAL on proc file.
> >>But it return success on regular file.
> >
> > Nonsense. It will write the '\0' to a regular file because it is just data.
> >
> > Integers in proc are more than data.
> >
> > So I see no justification for this change.
> In fact, "write(fd, "1\0", 2)" on Integers proc file return success on
> 2.6 kernel. I already tested it on 2.6.6.60 kernel.
>
> So, The latest behavior of "write(fd, "1\0", 2)" is different from old
> kernel(2.6).
> This maybe impact the compatibility of some user space program.
2.6 was a long time ago. If this behaviour change has happened in the
last 1-2 kernel releases then there would be a case to consider making
changes. But if the kernel has been this way for two years then it's
too late to bother switching back to the old (and strange) behaviour.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists