linux/include
Michael S. Tsirkin 662bbcb274 mm, sched: Allow uaccess in atomic with pagefault_disable()
This changes might_fault() so that it does not
trigger a false positive diagnostic for e.g. the following
sequence:

	spin_lock_irqsave()
	pagefault_disable()
	copy_to_user()
	pagefault_enable()
	spin_unlock_irqrestore()

In particular vhost wants to do this, to call
socket ops from under a lock.

There are 3 cases to consider:

 - CONFIG_PROVE_LOCKING - might_fault is non-inline
   so it's easy to move the in_atomic test to fix
   up the false positive warning.

 - CONFIG_DEBUG_ATOMIC_SLEEP - might_fault
   is currently inline, but we are calling a
   non-inline __might_sleep anyway,
   so let's use the non-line version of might_fault
   that does the right thing.

 - !CONFIG_DEBUG_ATOMIC_SLEEP && !CONFIG_PROVE_LOCKING
   __might_sleep is a nop so might_fault is a nop.

Make this explicit.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1369577426-26721-11-git-send-email-mst@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-05-28 09:41:11 +02:00
..
acpi ACPI / PM: Allow device power states to be used for CONFIG_PM unset 2013-05-22 00:19:28 +02:00
asm-generic asm-generic: uaccess s/might_sleep/might_fault/ 2013-05-28 09:41:05 +02:00
clocksource ARM: late Exynos multiplatform changes 2013-05-07 11:28:42 -07:00
crypto crypto: sha512 - Expose generic sha512 routine to be callable from other modules 2013-04-25 21:00:57 +08:00
drm Merge branch 'drm-radeon-sun-hainan' of git://people.freedesktop.org/~airlied/linux 2013-05-21 08:50:57 -07:00
dt-bindings
keys
linux mm, sched: Allow uaccess in atomic with pagefault_disable() 2013-05-28 09:41:11 +02:00
math-emu
media Merge branch 'topic/omap3isp' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media 2013-05-01 09:57:04 -07:00
memory
misc
net Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless into for-davem 2013-05-20 15:19:01 -04:00
pcmcia
ras
rdma
rxrpc
scsi Merge branch 'postmerge' into for-linus 2013-05-10 07:54:01 -07:00
sound sound fixes for v3.10-rc1 2013-05-10 07:51:56 -07:00
target target: removed unused transport_state flag 2013-05-15 01:46:53 -07:00
trace Fixed regressions (two stability regressions and a performance 2013-05-14 09:30:54 -07:00
uapi virtio_console: fix uapi header 2013-05-20 10:25:28 +09:30
video Merge branch 'late/clksrc' into late/cleanup 2013-05-06 23:43:45 +02:00
xen Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2013-05-01 14:08:52 -07:00
Kbuild UAPI: remove empty Kbuild files 2013-04-30 17:04:09 -07:00