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From: Arnd Bergmann <arndbergmann@googlemail.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: LKML <linux-kernel@vger.kernel.org>, Ingo Molnar <mingo@elte.hu>,
	ALan Cox <alan@lxorguk.ukuu.org.uk>,
	Frederic Weisbecker <fweisbec@gmail.com>,
	Jeff Dike <jdike@addtoit.com>
Subject: Re: [patch 6/7] um: Convert mmapper to unlocked_ioctl
Date: Thu, 15 Oct 2009 15:00:34 +0200	[thread overview]
Message-ID: <200910151500.34820.arnd@arndb.de> (raw)
In-Reply-To: <20091015083933.997426614@linutronix.de>

On Thursday 15 October 2009, Thomas Gleixner wrote:
> The ioctl is empty and needs no serialization. We might remove it
> completely but that would change the return value from -ENOIOCTLCMD to
> -ENOTTY.
> 
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> Cc: Jeff Dike <jdike@addtoit.com>

This one is tricky if you want to get it right according to the
book. ENOIOCTLCMD is never a valid return code for user space,
but sys_ioctl passes it down anyway.

However, returning -ENOIOCTLCMD from an *unlocked_ioctl* function
automatically gets turned into -EINVAL. It does this to allow
the same functions to be used for unlocked_ioctl and compat_ioctl.
In effect, this patch is functionally identical to removing the
ioctl function, which I think is what should be done here.

	Arnd <><

  reply	other threads:[~2009-10-15 13:01 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-10-15  8:42 [patch 0/7] BKL the next lot Thomas Gleixner
2009-10-15  8:42 ` [patch 1/7] ia64: Remove the BKL from perfmon Thomas Gleixner
2009-10-15  8:42 ` [patch 2/7] m68k: Remove BKL from rtc implementations Thomas Gleixner
2010-03-07 12:40   ` Geert Uytterhoeven
2009-10-15  8:42 ` [patch 3/7] powerpc: Use unlocked ioctl in nvram_64 Thomas Gleixner
2009-10-15  8:42 ` [patch 4/7] sh: Remove BKL from landisk gio Thomas Gleixner
2009-10-16  6:18   ` Paul Mundt
2009-10-15  8:42 ` [patch 5/7] um: Convert hostaudio to unlocked ioctl Thomas Gleixner
2009-10-15  8:42 ` [patch 6/7] um: Convert mmapper to unlocked_ioctl Thomas Gleixner
2009-10-15 13:00   ` Arnd Bergmann [this message]
2009-10-15 14:50     ` Thomas Gleixner
2009-10-15 15:29     ` Alan Cox
2009-10-16 19:42       ` Arnd Bergmann
2009-10-17  2:58         ` Thomas Gleixner
2009-10-15  8:42 ` [patch 7/7] um: Remove BKL from harddog Thomas Gleixner

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