huge pagecache: mmap_sem is unlocked when truncation splits pmd

[deliverable/linux.git] / mm / memory.c

diff --git a/mm/memory.c b/mm/memory.c
index 305537fc86406076ba07b3cdfeb6bf7affbc8ff6..52c218e2b724cdb8db1678c4070f31ab033daf65 100644 (file)
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1222,15 +1222,8 @@ static inline unsigned long zap_pmd_range(struct mmu_gather *tlb,
                next = pmd_addr_end(addr, end);
                if (pmd_trans_huge(*pmd) || pmd_devmap(*pmd)) {
                        if (next - addr != HPAGE_PMD_SIZE) {
-#ifdef CONFIG_DEBUG_VM
-                               if (!rwsem_is_locked(&tlb->mm->mmap_sem)) {
-                                       pr_err("%s: mmap_sem is unlocked! addr=0x%lx end=0x%lx vma->vm_start=0x%lx vma->vm_end=0x%lx\n",
-                                               __func__, addr, end,
-                                               vma->vm_start,
-                                               vma->vm_end);
-                                       BUG();
-                               }
-#endif
+                               VM_BUG_ON_VMA(vma_is_anonymous(vma) &&
+                                   !rwsem_is_locked(&tlb->mm->mmap_sem), vma);
                                split_huge_pmd(vma, pmd, addr);
                        } else if (zap_huge_pmd(tlb, vma, pmd, addr))
                                goto next;