diff options
Diffstat (limited to 'mm/memory.c')
| -rw-r--r-- | mm/memory.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/mm/memory.c b/mm/memory.c index 6ef014220e09..f2f7dc215b6b 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -6353,6 +6353,20 @@ fail: #endif #ifdef CONFIG_PER_VMA_LOCK +void __vma_start_write(struct vm_area_struct *vma, unsigned int mm_lock_seq) +{ + down_write(&vma->vm_lock.lock); + /* + * We should use WRITE_ONCE() here because we can have concurrent reads + * from the early lockless pessimistic check in vma_start_read(). + * We don't really care about the correctness of that early check, but + * we should use WRITE_ONCE() for cleanliness and to keep KCSAN happy. + */ + WRITE_ONCE(vma->vm_lock_seq, mm_lock_seq); + up_write(&vma->vm_lock.lock); +} +EXPORT_SYMBOL_GPL(__vma_start_write); + /* * Lookup and lock a VMA under RCU protection. Returned VMA is guaranteed to be * stable and not isolated. If the VMA is not found or is being modified the |