linux/arch/frv/mm
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
..
cache-page.c frv: remove the second parameter of kmap_atomic_primary() 2012-07-23 14:11:22 +08:00
dma-alloc.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
elf-fdpic.c mm: use vm_unmapped_area() on frv architecture 2013-02-27 19:10:09 -08:00
extable.c arch/frv/mm/extable.c: remove unused function 2015-02-12 18:54:12 -08:00
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
init.c mm/frv: prepare for removing num_physpages and simplify mem_init() 2013-07-03 16:07:36 -07:00
kmap.c Disintegrate asm/system.h for FRV 2012-03-28 18:30:02 +01:00
Makefile frv: unbreak misalignment handling changes 2008-05-01 08:03:58 -07:00
mmu-context.c frv: use find_task_by_vpid in cxn_pin_by_pid 2008-02-05 09:44:20 -08:00
pgalloc.c frv: handle pgtable_page_ctor() fail 2013-11-15 09:32:17 +09:00
tlb-flush.S Remove obsolete #include <linux/config.h> 2006-06-30 19:25:36 +02:00
tlb-miss.S Rename special text sections in arch/frv from .text.XXX to .text..XXX. 2010-03-03 11:26:01 +01:00