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
..
extable.c	sparc: Add module.h to files previously implicitly using it.	2011-10-31 19:30:54 -04:00
fault_32.c	mm/fault, arch: Use pagefault_disable() to check for disabled pagefaults in the handler	2015-05-19 08:39:15 +02:00
fault_64.c	mm/fault, arch: Use pagefault_disable() to check for disabled pagefaults in the handler	2015-05-19 08:39:15 +02:00
gup.c	mm: gup: use get_user_pages_unlocked within get_user_pages_fast	2015-02-11 17:06:05 -08:00
highmem.c	sched/preempt, mm/kmap: Explicitly disable/enable preemption in kmap_atomic_*	2015-05-19 08:39:14 +02:00
hugetlbpage.c	mm/hugetlb: reduce arch dependent code around follow_huge_*	2015-02-11 17:06:01 -08:00
hypersparc.S	[PATCH] sparc32: vm_area_struct access for old Sun SPARCs.	2013-07-10 13:56:10 -07:00
init_32.c	sparc32: fix sparse warning in devices.c	2014-04-29 01:12:26 -04:00
init_64.c	mm/fault, arch: Use pagefault_disable() to check for disabled pagefaults in the handler	2015-05-19 08:39:15 +02:00
init_64.h	sparc64: Use kernel page tables for vmemmap.	2014-10-05 16:53:39 -07:00
io-unit.c	sparc32: fix sparse warning in io-unit.c	2014-05-18 19:01:26 -07:00
iommu.c	sparc32: fix sparse warning in iommu.c	2014-05-18 19:01:26 -07:00
leon_mm.c	sparc32: fix sparse "Should it be static?" in mm/	2014-04-29 01:12:25 -04:00
Makefile	sparc32: introduce run-time patching of srmmu access functions	2012-05-27 23:52:49 -07:00
mm_32.h	sparc32: fix sparse "Should it be static?" in mm/	2014-04-29 01:12:25 -04:00
srmmu_access.S	sparc32: introduce run-time patching of srmmu access functions	2012-05-27 23:52:49 -07:00
srmmu.c	sparc32: destroy_context() and switch_mm() needs to disable interrupts.	2014-12-18 12:47:54 -05:00
swift.S	[PATCH] sparc32: vm_area_struct access for old Sun SPARCs.	2013-07-10 13:56:10 -07:00
tlb.c	sparc: Replace __get_cpu_var uses	2014-08-26 13:45:55 -04:00
tsb.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-next	2014-06-19 07:50:07 -10:00
tsunami.S	[PATCH] sparc32: vm_area_struct access for old Sun SPARCs.	2013-07-10 13:56:10 -07:00
ultra.S	sparc64: Make PAGE_OFFSET variable.	2013-11-12 15:22:34 -08:00
viking.S	[PATCH] sparc32: vm_area_struct access for old Sun SPARCs.	2013-07-10 13:56:10 -07:00