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Commit a3f916f2 authored by Dominik Brodowski's avatar Dominik Brodowski
Browse files

pcmcia: disable pcmcia ioctl for !ARM, prepare for removal 

The PCMCIA ioctl -- deprecated for years -- suffers from insufficient
locking. As it already has been deprecated for years, with its removal
long overdue, limit it to !SMP and !PREEMPT.

Furthermore, the last legitimate use of the ioctl to be reported
relates to the ARM architecture in 2008.[1] Attempts to resolve
this issue turned out unsuccessful so far.[2] Other usages have only
been reported as hear-say. If there are any legitiate and necessary
use-cases remaining, please speak out before the end of the grace
period until 2.6.3{5,6}(-rc1).

[1] http://lists.infradead.org/pipermail/linux-pcmcia/2008-April/005440.html
    see also: http://lkml.org/lkml/2008/2/27/291
[2] http://lists.infradead.org/pipermail/linux-pcmcia/2008-April/005450.html
    http://lists.infradead.org/pipermail/linux-pcmcia/2010-January/006740.html
    see also: http://lists.infradead.org/pipermail/linux-pcmcia/2008-April/005453.html



CC: Russell King <rmk+kernel@arm.linux.org.uk>
CC: Alan Cox <alan@lxorguk.ukuu.org.uk>
CC: Robert P. J. Day <rpjday@crashcourse.ca>
CC: Jaswinder Singh Rajput <jaswinder@kernel.org>
CC: linux-kernel@vger.kernel.org
Signed-off-by: default avatarDominik Brodowski <linux@dominikbrodowski.net>
parent 6e83ee07

Documentation/feature-removal-schedule.txt

+9 −3
Original line number Diff line number Diff line
@@ -138,19 +138,25 @@ Who: Mauro Carvalho Chehab <mchehab@infradead.org> 
---------------------------



What:	PCMCIA control ioctl (needed for pcmcia-cs [cardmgr, cardctl])

When:	November 2005

When:	2.6.35/2.6.36

Files:	drivers/pcmcia/: pcmcia_ioctl.c

Why:	With the 16-bit PCMCIA subsystem now behaving (almost) like a

	normal hotpluggable bus, and with it using the default kernel

	infrastructure (hotplug, driver core, sysfs) keeping the PCMCIA

	control ioctl needed by cardmgr and cardctl from pcmcia-cs is

	unnecessary, and makes further cleanups and integration of the

	unnecessary and potentially harmful (it does not provide for

	proper locking), and makes further cleanups and integration of the

	PCMCIA subsystem into the Linux kernel device driver model more

	difficult. The features provided by cardmgr and cardctl are either

	handled by the kernel itself now or are available in the new

	pcmciautils package available at

	http://kernel.org/pub/linux/utils/kernel/pcmcia/

Who:	Dominik Brodowski <linux@brodo.de>



	For all architectures except ARM, the associated config symbol

	has been removed from kernel 2.6.34; for ARM, it will be likely

	be removed from kernel 2.6.35. The actual code will then likely

	be removed from kernel 2.6.36.

Who:	Dominik Brodowski <linux@dominikbrodowski.net>



---------------------------

drivers/pcmcia/Kconfig

+10 −4
Original line number Diff line number Diff line
@@ -51,17 +51,23 @@ config PCMCIA_LOAD_CIS 


config PCMCIA_IOCTL

	bool "PCMCIA control ioctl (obsolete)"

	depends on PCMCIA

	depends on PCMCIA && ARM && !SMP && !PREEMPT

	default y

	help

	  If you say Y here, the deprecated ioctl interface to the PCMCIA

	  subsystem will be built. It is needed by cardmgr and cardctl

	  (pcmcia-cs) to function properly.

	  subsystem will be built. It is needed by the deprecated pcmcia-cs

	  tools (cardmgr, cardctl) to function properly.



	  You should use the new pcmciautils package instead (see

	  <file:Documentation/Changes> for location and details).



	  If unsure, say Y.

	  This config option will most likely be removed from kernel 2.6.35,

	  the associated code from kernel 2.6.36.



	  As the PCMCIA ioctl is not locking safe, it depends on !SMP and

	  !PREEMPT.



	  If unsure, say N.



config CARDBUS

	bool "32-bit CardBus support"