| Message ID | 20190808154240.9384-4-hch@lst.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/3] mm: split out a new pagewalk.h header from mm.h | expand |
On Thu, Aug 08, 2019 at 06:42:40PM +0300, Christoph Hellwig wrote: > Use lockdep to check for held locks instead of using home grown > asserts. > > @@ -319,7 +319,7 @@ int walk_page_range(struct mm_struct *mm, unsigned long start, > if (!walk.mm) > return -EINVAL; > > - VM_BUG_ON_MM(!rwsem_is_locked(&walk.mm->mmap_sem), walk.mm); > + lockdep_assert_held(&walk.mm->mmap_sem); It occurs to me that this is exactly the pattern that lockdep_pin_lock() was designed for. I'm pretty sure things will go badly if any callee unlocks then relocks the lock.
diff --git a/mm/pagewalk.c b/mm/pagewalk.c index 28510fc0dde1..9ec1885ceed7 100644 --- a/mm/pagewalk.c +++ b/mm/pagewalk.c @@ -319,7 +319,7 @@ int walk_page_range(struct mm_struct *mm, unsigned long start, if (!walk.mm) return -EINVAL; - VM_BUG_ON_MM(!rwsem_is_locked(&walk.mm->mmap_sem), walk.mm); + lockdep_assert_held(&walk.mm->mmap_sem); vma = find_vma(walk.mm, start); do { @@ -369,7 +369,7 @@ int walk_page_vma(struct vm_area_struct *vma, const struct mm_walk_ops *ops, if (!walk.mm) return -EINVAL; - VM_BUG_ON(!rwsem_is_locked(&vma->vm_mm->mmap_sem)); + lockdep_assert_held(&walk.mm->mmap_sem); err = walk_page_test(vma->vm_start, vma->vm_end, &walk); if (err > 0)
Use lockdep to check for held locks instead of using home grown asserts. Signed-off-by: Christoph Hellwig <hch@lst.de> --- mm/pagewalk.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)