diff options
| -rw-r--r-- | mm/mprotect.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/mm/mprotect.c b/mm/mprotect.c index b94fbb45d5c7..03e2cec3e669 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -608,8 +608,11 @@ mprotect_fixup(struct vma_iterator *vmi, struct mmu_gather *tlb, /* * If we make a private mapping writable we increase our commit; * but (without finer accounting) cannot reduce our commit if we - * make it unwritable again. hugetlb mapping were accounted for - * even if read-only so there is no need to account for them here + * make it unwritable again except in the anonymous case where no + * anon_vma has yet to be assigned. + * + * hugetlb mapping were accounted for even if read-only so there is + * no need to account for them here. */ if (newflags & VM_WRITE) { /* Check space limits when area turns into data. */ @@ -623,6 +626,9 @@ mprotect_fixup(struct vma_iterator *vmi, struct mmu_gather *tlb, return -ENOMEM; newflags |= VM_ACCOUNT; } + } else if ((oldflags & VM_ACCOUNT) && vma_is_anonymous(vma) && + !vma->anon_vma) { + newflags &= ~VM_ACCOUNT; } /* @@ -665,6 +671,9 @@ success: change_protection(tlb, vma, start, end, mm_cp_flags); + if ((oldflags & VM_ACCOUNT) && !(newflags & VM_ACCOUNT)) + vm_unacct_memory(nrpages); + /* * Private VM_LOCKED VMA becoming writable: trigger COW to avoid major * fault on access. |