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
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configs	netpoll: delete defconfig references to obsolete NETPOLL_TRAP	2014-11-29 21:13:48 -08:00
gxio	ptp: tilegx: convert to the 64 bit get/set time methods.	2015-03-31 12:01:18 -04:00
include	mm/uaccess, mm/fault: Clarify that uaccess may only sleep if pagefaults are enabled	2015-05-19 08:39:14 +02:00
kernel	tile: properly use node_isset() on a nodemask_t	2015-04-28 10:36:45 -04:00
kvm	rcu: Make SRCU optional by using CONFIG_SRCU	2015-01-06 11:04:29 -08:00
lib	tile: include: asm: use 'long long' instead of 'u64' for atomic64_t and its related functions	2013-09-27 16:08:56 -04:00
mm	mm/fault, arch: Use pagefault_disable() to check for disabled pagefaults in the handler	2015-05-19 08:39:15 +02:00
Kbuild	arch/tile: core support for Tilera 32-bit chips.	2010-06-04 17:11:18 -04:00
Kconfig	Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile	2015-04-17 16:03:05 -04:00
Kconfig.debug	tile: remove DEBUG_EXTRA_FLAGS kernel config option	2013-09-03 14:52:17 -04:00
Makefile	tile: remove DEBUG_EXTRA_FLAGS kernel config option	2013-09-03 14:52:17 -04:00