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
..
elf.c	tile/elf: reorganize notify_exec()	2015-04-17 12:58:31 -04:00
extable.c	arch/tile: core support for Tilera 32-bit chips.	2010-06-04 17:11:18 -04:00
fault.c	mm/fault, arch: Use pagefault_disable() to check for disabled pagefaults in the handler	2015-05-19 08:39:15 +02:00
highmem.c	sched/preempt, mm/kmap: Explicitly disable/enable preemption in kmap_atomic_*	2015-05-19 08:39:14 +02:00
homecache.c	tile: use %*pb[l] to print bitmaps including cpumasks and nodemasks	2015-02-13 21:21:37 -08:00
hugetlbpage.c	mm/hugetlb: reduce arch dependent code around follow_huge_*	2015-02-11 17:06:01 -08:00
init.c	tile: map data region shadow of kernel as R/W	2015-04-17 14:01:35 -04:00
Makefile	arch/tile: core support for Tilera 32-bit chips.	2010-06-04 17:11:18 -04:00
migrate_32.S	tile: provide traceability for hypervisor calls	2013-08-13 16:26:31 -04:00
migrate_64.S	tile: provide traceability for hypervisor calls	2013-08-13 16:26:31 -04:00
migrate.h	arch/tile: use interrupt critical sections less	2012-05-25 12:48:20 -04:00
mmap.c	tile: support ASLR fully	2013-08-30 11:56:25 -04:00
pgtable.c	tile: Use the more common pr_warn instead of pr_warning	2014-11-11 15:51:42 -05:00