Files
linux/include/linux
David Hildenbrand 70ffdb9393 mm/fault, arch: Use pagefault_disable() to check for disabled pagefaults in the handler
Introduce faulthandler_disabled() and use it to check for irq context and
disabled pagefaults (via pagefault_disable()) in the pagefault handlers.

Please note that we keep the in_atomic() checks in place - to detect
whether in irq context (in which case preemption is always properly
disabled).

In contrast, preempt_disable() should never be used to disable pagefaults.
With !CONFIG_PREEMPT_COUNT, preempt_disable() doesn't modify the preempt
counter, and therefore the result of in_atomic() differs.
We validate that condition by using might_fault() checks when calling
might_sleep().

Therefore, add a comment to faulthandler_disabled(), describing why this
is needed.

faulthandler_disabled() and pagefault_disable() are defined in
linux/uaccess.h, so let's properly add that include to all relevant files.

This patch is based on a patch from Thomas Gleixner.

Reviewed-and-tested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: David.Laight@ACULAB.COM
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: airlied@linux.ie
Cc: akpm@linux-foundation.org
Cc: benh@kernel.crashing.org
Cc: bigeasy@linutronix.de
Cc: borntraeger@de.ibm.com
Cc: daniel.vetter@intel.com
Cc: heiko.carstens@de.ibm.com
Cc: herbert@gondor.apana.org.au
Cc: hocko@suse.cz
Cc: hughd@google.com
Cc: mst@redhat.com
Cc: paulus@samba.org
Cc: ralf@linux-mips.org
Cc: schwidefsky@de.ibm.com
Cc: yang.shi@windriver.com
Link: http://lkml.kernel.org/r/1431359540-32227-7-git-send-email-dahi@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-19 08:39:15 +02:00
..
2015-03-29 16:17:10 +01:00
2015-04-07 11:17:34 +02:00
2015-03-25 20:28:11 -04:00
2015-04-17 09:03:53 -04:00
2015-05-04 13:09:55 -06:00
2015-04-17 08:31:12 -06:00
2015-03-11 15:56:59 -07:00
2015-04-16 12:33:51 +09:30
2015-02-12 18:54:15 -08:00
2015-03-02 16:43:41 -05:00
2015-05-14 17:55:51 -07:00
2015-03-16 21:45:54 +11:00
2015-04-03 16:18:02 +02:00
2015-02-13 21:21:36 -08:00
2015-05-14 17:55:51 -07:00
2015-04-14 16:49:05 -07:00
2015-03-25 11:44:52 +01:00
2015-04-17 09:04:07 -04:00
2015-03-31 12:04:12 +02:00
2015-04-23 14:36:28 -04:00
2015-03-11 17:56:28 -04:00
2015-04-12 21:03:31 +02:00
2015-02-17 14:34:52 -08:00
2015-02-24 08:44:16 +01:00
2015-03-26 18:18:20 +01:00
2015-04-25 15:49:49 -04:00
2015-02-13 21:21:41 -08:00
2015-03-11 21:55:28 -04:00
2015-04-11 15:53:35 -04:00
2015-02-13 21:21:35 -08:00
2015-03-25 13:28:58 +01:00
2015-04-29 17:10:37 -04:00
2015-05-10 19:26:37 +02:00
2015-04-11 22:29:44 -04:00
2015-03-24 09:48:14 -07:00
2015-04-15 16:35:20 -07:00