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
..
configs	arch/um: make it work with defconfig and x86_64	2013-11-17 11:31:48 +01:00
drivers	uml: Fix unsafe pid reference to foreground process group	2014-11-05 16:26:13 -08:00
include	Merge branch 'exec_domain_rip_v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc	2015-04-15 13:53:55 -07:00
kernel	mm/fault, arch: Use pagefault_disable() to check for disabled pagefaults in the handler	2015-05-19 08:39:15 +02:00
os-Linux	um: Move uml_postsetup in the init_thread stack	2015-04-13 21:17:44 +02:00
scripts	um: Preinclude include/linux/kern_levels.h	2012-09-27 20:20:09 +02:00
.gitignore
Kconfig.char	um: remove used STDIO_CONSOLE Kconfig param	2013-11-17 11:32:27 +01:00
Kconfig.common	um: Skip futex_atomic_cmpxchg_inatomic() test	2015-01-04 14:20:26 +01:00
Kconfig.debug	lib: consolidate DEBUG_STACK_USAGE option	2011-05-25 08:39:54 -07:00
Kconfig.net	arch/um: remove depends on CONFIG_EXPERIMENTAL	2013-01-11 11:38:04 -08:00
Kconfig.rest	um: switch to use of drivers/Kconfig	2011-11-02 14:15:41 +01:00
Kconfig.um	Merge tag 'for-linus-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml	2015-04-15 13:49:27 -07:00
Makefile	kbuild: use relative path more to include Makefile	2015-04-02 16:42:08 +02:00
Makefile-os-Linux
Makefile-skas