diff options
Diffstat (limited to 'mm/mprotect.c')
| -rw-r--r-- | mm/mprotect.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/mm/mprotect.c b/mm/mprotect.c index ec39f730a0bf..e3309fcf586b 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -84,6 +84,11 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd, if (!page || PageKsm(page)) continue; + /* Also skip shared copy-on-write pages */ + if (is_cow_mapping(vma->vm_flags) && + page_mapcount(page) != 1) + continue; + /* Avoid TLB flush if possible */ if (pte_protnone(oldpte)) continue; @@ -166,7 +171,7 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma, next = pmd_addr_end(addr, end); if (!is_swap_pmd(*pmd) && !pmd_trans_huge(*pmd) && !pmd_devmap(*pmd) && pmd_none_or_clear_bad(pmd)) - continue; + goto next; /* invoke the mmu notifier if the pmd is populated */ if (!mni_start) { @@ -188,7 +193,7 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma, } /* huge pmd was handled */ - continue; + goto next; } } /* fall through, the trans huge pmd just split */ @@ -196,6 +201,8 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma, this_pages = change_pte_range(vma, pmd, addr, next, newprot, dirty_accountable, prot_numa); pages += this_pages; +next: + cond_resched(); } while (pmd++, addr = next, addr != end); if (mni_start) |