linux/arch/s390
Martin Schwidefsky b6d09449d5 [PATCH] s390: pfault interrupt race
There is a race in pfault_interrupt.  That function gets called two times for
each pfault notification.  Once with a subcode of 0 to indicate that a real
page is not available and once with a subcode of 0x80 to indicate that the
page is present again.

Since the two external interrupts can be delivered on two different cpus the
order in which the two calls are made is unpredictable.  It is possible that
the subcode 0x80 interrupt is completed before the subcode 0x00 interrupt has
done the wake_up() call.

To avoid calling wake_up() on an already removed task structure proper task
structure reference counting is needed.  Increase the reference counter in the
subcode 0x00 interrupt before setting pfault_wait to zero and return the
reference after the wake_up call.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05 00:06:28 -07:00
..
appldata [PATCH] s390: fix inline assembly in appldata 2005-07-29 15:01:15 -07:00
boot [PATCH] use ${CROSS_COMPILE}installkernel in arch/*/boot/install.sh 2005-06-23 09:45:07 -07:00
crypto Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
kernel [PATCH] s390: debug feature changes 2005-09-05 00:06:26 -07:00
lib [PATCH] s390: spin lock retry 2005-07-27 16:26:04 -07:00
math-emu Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
mm [PATCH] s390: pfault interrupt race 2005-09-05 00:06:28 -07:00
oprofile Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
defconfig [PATCH] s390: default configuration 2005-07-29 15:01:14 -07:00
Kconfig [NET]: add a top-level Networking menu to *config 2005-07-11 21:03:49 -07:00
Kconfig.debug Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
Makefile Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00