mm/mmu_notifiers: annotate with might_sleep()

Since mmu notifiers don't exist for many processes, but could block in
interesting places, add some annotations. This should help make sure the
core mm keeps up its end of the mmu notifier contract.

The checks here are outside of all notifier checks because of that.
They compile away without CONFIG_DEBUG_ATOMIC_SLEEP.

Link: https://lore.kernel.org/r/20190826201425.17547-6-daniel.vetter@ffwll.ch
Suggested-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
This commit is contained in:
Daniel Vetter 2019-08-26 22:14:25 +02:00 committed by Jason Gunthorpe
parent 66204f1d2d
commit 810e24e009

View File

@ -343,6 +343,8 @@ static inline void mmu_notifier_change_pte(struct mm_struct *mm,
static inline void
mmu_notifier_invalidate_range_start(struct mmu_notifier_range *range)
{
might_sleep();
lock_map_acquire(&__mmu_notifier_invalidate_range_start_map);
if (mm_has_notifiers(range->mm)) {
range->flags |= MMU_NOTIFIER_RANGE_BLOCKABLE;
@ -368,6 +370,9 @@ mmu_notifier_invalidate_range_start_nonblock(struct mmu_notifier_range *range)
static inline void
mmu_notifier_invalidate_range_end(struct mmu_notifier_range *range)
{
if (mmu_notifier_range_blockable(range))
might_sleep();
if (mm_has_notifiers(range->mm))
__mmu_notifier_invalidate_range_end(range, false);
}