11da177e4SLinus Torvalds /* 21da177e4SLinus Torvalds * mm/mprotect.c 31da177e4SLinus Torvalds * 41da177e4SLinus Torvalds * (C) Copyright 1994 Linus Torvalds 51da177e4SLinus Torvalds * (C) Copyright 2002 Christoph Hellwig 61da177e4SLinus Torvalds * 7046c6884SAlan Cox * Address space accounting code <alan@lxorguk.ukuu.org.uk> 81da177e4SLinus Torvalds * (C) Copyright 2002 Red Hat Inc, All Rights Reserved 91da177e4SLinus Torvalds */ 101da177e4SLinus Torvalds 111da177e4SLinus Torvalds #include <linux/mm.h> 121da177e4SLinus Torvalds #include <linux/hugetlb.h> 131da177e4SLinus Torvalds #include <linux/shm.h> 141da177e4SLinus Torvalds #include <linux/mman.h> 151da177e4SLinus Torvalds #include <linux/fs.h> 161da177e4SLinus Torvalds #include <linux/highmem.h> 171da177e4SLinus Torvalds #include <linux/security.h> 181da177e4SLinus Torvalds #include <linux/mempolicy.h> 191da177e4SLinus Torvalds #include <linux/personality.h> 201da177e4SLinus Torvalds #include <linux/syscalls.h> 210697212aSChristoph Lameter #include <linux/swap.h> 220697212aSChristoph Lameter #include <linux/swapops.h> 23cddb8a5cSAndrea Arcangeli #include <linux/mmu_notifier.h> 2464cdd548SKOSAKI Motohiro #include <linux/migrate.h> 25cdd6c482SIngo Molnar #include <linux/perf_event.h> 26*64a9a34eSMel Gorman #include <linux/ksm.h> 271da177e4SLinus Torvalds #include <asm/uaccess.h> 281da177e4SLinus Torvalds #include <asm/pgtable.h> 291da177e4SLinus Torvalds #include <asm/cacheflush.h> 301da177e4SLinus Torvalds #include <asm/tlbflush.h> 311da177e4SLinus Torvalds 321c12c4cfSVenki Pallipadi #ifndef pgprot_modify 331c12c4cfSVenki Pallipadi static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot) 341c12c4cfSVenki Pallipadi { 351c12c4cfSVenki Pallipadi return newprot; 361c12c4cfSVenki Pallipadi } 371c12c4cfSVenki Pallipadi #endif 381c12c4cfSVenki Pallipadi 394b10e7d5SMel Gorman static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd, 40c1e6098bSPeter Zijlstra unsigned long addr, unsigned long end, pgprot_t newprot, 410f19c179SMel Gorman int dirty_accountable, int prot_numa) 421da177e4SLinus Torvalds { 434b10e7d5SMel Gorman struct mm_struct *mm = vma->vm_mm; 440697212aSChristoph Lameter pte_t *pte, oldpte; 45705e87c0SHugh Dickins spinlock_t *ptl; 467da4d641SPeter Zijlstra unsigned long pages = 0; 471da177e4SLinus Torvalds 48705e87c0SHugh Dickins pte = pte_offset_map_lock(mm, pmd, addr, &ptl); 496606c3e0SZachary Amsden arch_enter_lazy_mmu_mode(); 501da177e4SLinus Torvalds do { 510697212aSChristoph Lameter oldpte = *pte; 520697212aSChristoph Lameter if (pte_present(oldpte)) { 531da177e4SLinus Torvalds pte_t ptent; 544b10e7d5SMel Gorman bool updated = false; 551da177e4SLinus Torvalds 564b10e7d5SMel Gorman if (!prot_numa) { 570c5f83c2SMel Gorman ptent = ptep_modify_prot_start(mm, addr, pte); 581667918bSMel Gorman if (pte_numa(ptent)) 591667918bSMel Gorman ptent = pte_mknonnuma(ptent); 60c1e6098bSPeter Zijlstra ptent = pte_modify(ptent, newprot); 614b10e7d5SMel Gorman updated = true; 624b10e7d5SMel Gorman } else { 634b10e7d5SMel Gorman struct page *page; 644b10e7d5SMel Gorman 650c5f83c2SMel Gorman ptent = *pte; 664b10e7d5SMel Gorman page = vm_normal_page(vma, addr, oldpte); 67*64a9a34eSMel Gorman if (page && !PageKsm(page)) { 681bc115d8SMel Gorman if (!pte_numa(oldpte)) { 694b10e7d5SMel Gorman ptent = pte_mknuma(ptent); 700c5f83c2SMel Gorman set_pte_at(mm, addr, pte, ptent); 714b10e7d5SMel Gorman updated = true; 724b10e7d5SMel Gorman } 734b10e7d5SMel Gorman } 744b10e7d5SMel Gorman } 751ea0704eSJeremy Fitzhardinge 76c1e6098bSPeter Zijlstra /* 77c1e6098bSPeter Zijlstra * Avoid taking write faults for pages we know to be 78c1e6098bSPeter Zijlstra * dirty. 79c1e6098bSPeter Zijlstra */ 804b10e7d5SMel Gorman if (dirty_accountable && pte_dirty(ptent)) { 81c1e6098bSPeter Zijlstra ptent = pte_mkwrite(ptent); 824b10e7d5SMel Gorman updated = true; 834b10e7d5SMel Gorman } 841ea0704eSJeremy Fitzhardinge 854b10e7d5SMel Gorman if (updated) 864b10e7d5SMel Gorman pages++; 870c5f83c2SMel Gorman 880c5f83c2SMel Gorman /* Only !prot_numa always clears the pte */ 890c5f83c2SMel Gorman if (!prot_numa) 901ea0704eSJeremy Fitzhardinge ptep_modify_prot_commit(mm, addr, pte, ptent); 91ce1744f4SKonstantin Khlebnikov } else if (IS_ENABLED(CONFIG_MIGRATION) && !pte_file(oldpte)) { 920697212aSChristoph Lameter swp_entry_t entry = pte_to_swp_entry(oldpte); 930697212aSChristoph Lameter 940697212aSChristoph Lameter if (is_write_migration_entry(entry)) { 95c3d16e16SCyrill Gorcunov pte_t newpte; 960697212aSChristoph Lameter /* 970697212aSChristoph Lameter * A protection check is difficult so 980697212aSChristoph Lameter * just be safe and disable write 990697212aSChristoph Lameter */ 1000697212aSChristoph Lameter make_migration_entry_read(&entry); 101c3d16e16SCyrill Gorcunov newpte = swp_entry_to_pte(entry); 102c3d16e16SCyrill Gorcunov if (pte_swp_soft_dirty(oldpte)) 103c3d16e16SCyrill Gorcunov newpte = pte_swp_mksoft_dirty(newpte); 104c3d16e16SCyrill Gorcunov set_pte_at(mm, addr, pte, newpte); 105e920e14cSMel Gorman 1067da4d641SPeter Zijlstra pages++; 1070697212aSChristoph Lameter } 108e920e14cSMel Gorman } 1091da177e4SLinus Torvalds } while (pte++, addr += PAGE_SIZE, addr != end); 1106606c3e0SZachary Amsden arch_leave_lazy_mmu_mode(); 111705e87c0SHugh Dickins pte_unmap_unlock(pte - 1, ptl); 1127da4d641SPeter Zijlstra 1137da4d641SPeter Zijlstra return pages; 1141da177e4SLinus Torvalds } 1151da177e4SLinus Torvalds 1167d12efaeSAndrew Morton static inline unsigned long change_pmd_range(struct vm_area_struct *vma, 1177d12efaeSAndrew Morton pud_t *pud, unsigned long addr, unsigned long end, 1187d12efaeSAndrew Morton pgprot_t newprot, int dirty_accountable, int prot_numa) 1191da177e4SLinus Torvalds { 1201da177e4SLinus Torvalds pmd_t *pmd; 1211da177e4SLinus Torvalds unsigned long next; 1227da4d641SPeter Zijlstra unsigned long pages = 0; 12372403b4aSMel Gorman unsigned long nr_huge_updates = 0; 1241da177e4SLinus Torvalds 1251da177e4SLinus Torvalds pmd = pmd_offset(pud, addr); 1261da177e4SLinus Torvalds do { 12725cbbef1SMel Gorman unsigned long this_pages; 12825cbbef1SMel Gorman 1291da177e4SLinus Torvalds next = pmd_addr_end(addr, end); 130cd7548abSJohannes Weiner if (pmd_trans_huge(*pmd)) { 131cd7548abSJohannes Weiner if (next - addr != HPAGE_PMD_SIZE) 132e180377fSKirill A. Shutemov split_huge_page_pmd(vma, addr, pmd); 133f123d74aSMel Gorman else { 134f123d74aSMel Gorman int nr_ptes = change_huge_pmd(vma, pmd, addr, 135f123d74aSMel Gorman newprot, prot_numa); 136f123d74aSMel Gorman 137f123d74aSMel Gorman if (nr_ptes) { 13872403b4aSMel Gorman if (nr_ptes == HPAGE_PMD_NR) { 13972403b4aSMel Gorman pages += HPAGE_PMD_NR; 14072403b4aSMel Gorman nr_huge_updates++; 14172403b4aSMel Gorman } 142cd7548abSJohannes Weiner continue; 1437da4d641SPeter Zijlstra } 144f123d74aSMel Gorman } 145cd7548abSJohannes Weiner /* fall through */ 146cd7548abSJohannes Weiner } 1471da177e4SLinus Torvalds if (pmd_none_or_clear_bad(pmd)) 1481da177e4SLinus Torvalds continue; 14925cbbef1SMel Gorman this_pages = change_pte_range(vma, pmd, addr, next, newprot, 1500f19c179SMel Gorman dirty_accountable, prot_numa); 15125cbbef1SMel Gorman pages += this_pages; 1521da177e4SLinus Torvalds } while (pmd++, addr = next, addr != end); 1537da4d641SPeter Zijlstra 15472403b4aSMel Gorman if (nr_huge_updates) 15572403b4aSMel Gorman count_vm_numa_events(NUMA_HUGE_PTE_UPDATES, nr_huge_updates); 1567da4d641SPeter Zijlstra return pages; 1571da177e4SLinus Torvalds } 1581da177e4SLinus Torvalds 1597d12efaeSAndrew Morton static inline unsigned long change_pud_range(struct vm_area_struct *vma, 1607d12efaeSAndrew Morton pgd_t *pgd, unsigned long addr, unsigned long end, 1617d12efaeSAndrew Morton pgprot_t newprot, int dirty_accountable, int prot_numa) 1621da177e4SLinus Torvalds { 1631da177e4SLinus Torvalds pud_t *pud; 1641da177e4SLinus Torvalds unsigned long next; 1657da4d641SPeter Zijlstra unsigned long pages = 0; 1661da177e4SLinus Torvalds 1671da177e4SLinus Torvalds pud = pud_offset(pgd, addr); 1681da177e4SLinus Torvalds do { 1691da177e4SLinus Torvalds next = pud_addr_end(addr, end); 1701da177e4SLinus Torvalds if (pud_none_or_clear_bad(pud)) 1711da177e4SLinus Torvalds continue; 1727da4d641SPeter Zijlstra pages += change_pmd_range(vma, pud, addr, next, newprot, 1734b10e7d5SMel Gorman dirty_accountable, prot_numa); 1741da177e4SLinus Torvalds } while (pud++, addr = next, addr != end); 1757da4d641SPeter Zijlstra 1767da4d641SPeter Zijlstra return pages; 1771da177e4SLinus Torvalds } 1781da177e4SLinus Torvalds 1797da4d641SPeter Zijlstra static unsigned long change_protection_range(struct vm_area_struct *vma, 180c1e6098bSPeter Zijlstra unsigned long addr, unsigned long end, pgprot_t newprot, 1814b10e7d5SMel Gorman int dirty_accountable, int prot_numa) 1821da177e4SLinus Torvalds { 1831da177e4SLinus Torvalds struct mm_struct *mm = vma->vm_mm; 1841da177e4SLinus Torvalds pgd_t *pgd; 1851da177e4SLinus Torvalds unsigned long next; 1861da177e4SLinus Torvalds unsigned long start = addr; 1877da4d641SPeter Zijlstra unsigned long pages = 0; 1881da177e4SLinus Torvalds 1891da177e4SLinus Torvalds BUG_ON(addr >= end); 1901da177e4SLinus Torvalds pgd = pgd_offset(mm, addr); 1911da177e4SLinus Torvalds flush_cache_range(vma, addr, end); 19220841405SRik van Riel set_tlb_flush_pending(mm); 1931da177e4SLinus Torvalds do { 1941da177e4SLinus Torvalds next = pgd_addr_end(addr, end); 1951da177e4SLinus Torvalds if (pgd_none_or_clear_bad(pgd)) 1961da177e4SLinus Torvalds continue; 1977da4d641SPeter Zijlstra pages += change_pud_range(vma, pgd, addr, next, newprot, 1984b10e7d5SMel Gorman dirty_accountable, prot_numa); 1991da177e4SLinus Torvalds } while (pgd++, addr = next, addr != end); 2007da4d641SPeter Zijlstra 2011233d588SIngo Molnar /* Only flush the TLB if we actually modified any entries: */ 2021233d588SIngo Molnar if (pages) 2031da177e4SLinus Torvalds flush_tlb_range(vma, start, end); 20420841405SRik van Riel clear_tlb_flush_pending(mm); 2057da4d641SPeter Zijlstra 2067da4d641SPeter Zijlstra return pages; 2077da4d641SPeter Zijlstra } 2087da4d641SPeter Zijlstra 2097da4d641SPeter Zijlstra unsigned long change_protection(struct vm_area_struct *vma, unsigned long start, 2107da4d641SPeter Zijlstra unsigned long end, pgprot_t newprot, 2114b10e7d5SMel Gorman int dirty_accountable, int prot_numa) 2127da4d641SPeter Zijlstra { 2137da4d641SPeter Zijlstra struct mm_struct *mm = vma->vm_mm; 2147da4d641SPeter Zijlstra unsigned long pages; 2157da4d641SPeter Zijlstra 2167da4d641SPeter Zijlstra mmu_notifier_invalidate_range_start(mm, start, end); 2177da4d641SPeter Zijlstra if (is_vm_hugetlb_page(vma)) 2187da4d641SPeter Zijlstra pages = hugetlb_change_protection(vma, start, end, newprot); 2197da4d641SPeter Zijlstra else 2204b10e7d5SMel Gorman pages = change_protection_range(vma, start, end, newprot, dirty_accountable, prot_numa); 2217da4d641SPeter Zijlstra mmu_notifier_invalidate_range_end(mm, start, end); 2227da4d641SPeter Zijlstra 2237da4d641SPeter Zijlstra return pages; 2241da177e4SLinus Torvalds } 2251da177e4SLinus Torvalds 226b6a2fea3SOllie Wild int 2271da177e4SLinus Torvalds mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev, 2281da177e4SLinus Torvalds unsigned long start, unsigned long end, unsigned long newflags) 2291da177e4SLinus Torvalds { 2301da177e4SLinus Torvalds struct mm_struct *mm = vma->vm_mm; 2311da177e4SLinus Torvalds unsigned long oldflags = vma->vm_flags; 2321da177e4SLinus Torvalds long nrpages = (end - start) >> PAGE_SHIFT; 2331da177e4SLinus Torvalds unsigned long charged = 0; 2341da177e4SLinus Torvalds pgoff_t pgoff; 2351da177e4SLinus Torvalds int error; 236c1e6098bSPeter Zijlstra int dirty_accountable = 0; 2371da177e4SLinus Torvalds 2381da177e4SLinus Torvalds if (newflags == oldflags) { 2391da177e4SLinus Torvalds *pprev = vma; 2401da177e4SLinus Torvalds return 0; 2411da177e4SLinus Torvalds } 2421da177e4SLinus Torvalds 2431da177e4SLinus Torvalds /* 2441da177e4SLinus Torvalds * If we make a private mapping writable we increase our commit; 2451da177e4SLinus Torvalds * but (without finer accounting) cannot reduce our commit if we 2465a6fe125SMel Gorman * make it unwritable again. hugetlb mapping were accounted for 2475a6fe125SMel Gorman * even if read-only so there is no need to account for them here 2481da177e4SLinus Torvalds */ 2491da177e4SLinus Torvalds if (newflags & VM_WRITE) { 2505a6fe125SMel Gorman if (!(oldflags & (VM_ACCOUNT|VM_WRITE|VM_HUGETLB| 251cdfd4325SAndy Whitcroft VM_SHARED|VM_NORESERVE))) { 2521da177e4SLinus Torvalds charged = nrpages; 253191c5424SAl Viro if (security_vm_enough_memory_mm(mm, charged)) 2541da177e4SLinus Torvalds return -ENOMEM; 2551da177e4SLinus Torvalds newflags |= VM_ACCOUNT; 2561da177e4SLinus Torvalds } 2571da177e4SLinus Torvalds } 2581da177e4SLinus Torvalds 2591da177e4SLinus Torvalds /* 2601da177e4SLinus Torvalds * First try to merge with previous and/or next vma. 2611da177e4SLinus Torvalds */ 2621da177e4SLinus Torvalds pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT); 2631da177e4SLinus Torvalds *pprev = vma_merge(mm, *pprev, start, end, newflags, 2641da177e4SLinus Torvalds vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma)); 2651da177e4SLinus Torvalds if (*pprev) { 2661da177e4SLinus Torvalds vma = *pprev; 2671da177e4SLinus Torvalds goto success; 2681da177e4SLinus Torvalds } 2691da177e4SLinus Torvalds 2701da177e4SLinus Torvalds *pprev = vma; 2711da177e4SLinus Torvalds 2721da177e4SLinus Torvalds if (start != vma->vm_start) { 2731da177e4SLinus Torvalds error = split_vma(mm, vma, start, 1); 2741da177e4SLinus Torvalds if (error) 2751da177e4SLinus Torvalds goto fail; 2761da177e4SLinus Torvalds } 2771da177e4SLinus Torvalds 2781da177e4SLinus Torvalds if (end != vma->vm_end) { 2791da177e4SLinus Torvalds error = split_vma(mm, vma, end, 0); 2801da177e4SLinus Torvalds if (error) 2811da177e4SLinus Torvalds goto fail; 2821da177e4SLinus Torvalds } 2831da177e4SLinus Torvalds 2841da177e4SLinus Torvalds success: 2851da177e4SLinus Torvalds /* 2861da177e4SLinus Torvalds * vm_flags and vm_page_prot are protected by the mmap_sem 2871da177e4SLinus Torvalds * held in write mode. 2881da177e4SLinus Torvalds */ 2891da177e4SLinus Torvalds vma->vm_flags = newflags; 2901c12c4cfSVenki Pallipadi vma->vm_page_prot = pgprot_modify(vma->vm_page_prot, 2911c12c4cfSVenki Pallipadi vm_get_page_prot(newflags)); 2921c12c4cfSVenki Pallipadi 293c1e6098bSPeter Zijlstra if (vma_wants_writenotify(vma)) { 2941ddd439eSHugh Dickins vma->vm_page_prot = vm_get_page_prot(newflags & ~VM_SHARED); 295c1e6098bSPeter Zijlstra dirty_accountable = 1; 296c1e6098bSPeter Zijlstra } 297d08b3851SPeter Zijlstra 2987d12efaeSAndrew Morton change_protection(vma, start, end, vma->vm_page_prot, 2997d12efaeSAndrew Morton dirty_accountable, 0); 3007da4d641SPeter Zijlstra 301ab50b8edSHugh Dickins vm_stat_account(mm, oldflags, vma->vm_file, -nrpages); 302ab50b8edSHugh Dickins vm_stat_account(mm, newflags, vma->vm_file, nrpages); 30363bfd738SPekka Enberg perf_event_mmap(vma); 3041da177e4SLinus Torvalds return 0; 3051da177e4SLinus Torvalds 3061da177e4SLinus Torvalds fail: 3071da177e4SLinus Torvalds vm_unacct_memory(charged); 3081da177e4SLinus Torvalds return error; 3091da177e4SLinus Torvalds } 3101da177e4SLinus Torvalds 3116a6160a7SHeiko Carstens SYSCALL_DEFINE3(mprotect, unsigned long, start, size_t, len, 3126a6160a7SHeiko Carstens unsigned long, prot) 3131da177e4SLinus Torvalds { 3141da177e4SLinus Torvalds unsigned long vm_flags, nstart, end, tmp, reqprot; 3151da177e4SLinus Torvalds struct vm_area_struct *vma, *prev; 3161da177e4SLinus Torvalds int error = -EINVAL; 3171da177e4SLinus Torvalds const int grows = prot & (PROT_GROWSDOWN|PROT_GROWSUP); 3181da177e4SLinus Torvalds prot &= ~(PROT_GROWSDOWN|PROT_GROWSUP); 3191da177e4SLinus Torvalds if (grows == (PROT_GROWSDOWN|PROT_GROWSUP)) /* can't be both */ 3201da177e4SLinus Torvalds return -EINVAL; 3211da177e4SLinus Torvalds 3221da177e4SLinus Torvalds if (start & ~PAGE_MASK) 3231da177e4SLinus Torvalds return -EINVAL; 3241da177e4SLinus Torvalds if (!len) 3251da177e4SLinus Torvalds return 0; 3261da177e4SLinus Torvalds len = PAGE_ALIGN(len); 3271da177e4SLinus Torvalds end = start + len; 3281da177e4SLinus Torvalds if (end <= start) 3291da177e4SLinus Torvalds return -ENOMEM; 330b845f313SDave Kleikamp if (!arch_validate_prot(prot)) 3311da177e4SLinus Torvalds return -EINVAL; 3321da177e4SLinus Torvalds 3331da177e4SLinus Torvalds reqprot = prot; 3341da177e4SLinus Torvalds /* 3351da177e4SLinus Torvalds * Does the application expect PROT_READ to imply PROT_EXEC: 3361da177e4SLinus Torvalds */ 337b344e05cSHua Zhong if ((prot & PROT_READ) && (current->personality & READ_IMPLIES_EXEC)) 3381da177e4SLinus Torvalds prot |= PROT_EXEC; 3391da177e4SLinus Torvalds 3401da177e4SLinus Torvalds vm_flags = calc_vm_prot_bits(prot); 3411da177e4SLinus Torvalds 3421da177e4SLinus Torvalds down_write(¤t->mm->mmap_sem); 3431da177e4SLinus Torvalds 344097d5910SLinus Torvalds vma = find_vma(current->mm, start); 3451da177e4SLinus Torvalds error = -ENOMEM; 3461da177e4SLinus Torvalds if (!vma) 3471da177e4SLinus Torvalds goto out; 348097d5910SLinus Torvalds prev = vma->vm_prev; 3491da177e4SLinus Torvalds if (unlikely(grows & PROT_GROWSDOWN)) { 3501da177e4SLinus Torvalds if (vma->vm_start >= end) 3511da177e4SLinus Torvalds goto out; 3521da177e4SLinus Torvalds start = vma->vm_start; 3531da177e4SLinus Torvalds error = -EINVAL; 3541da177e4SLinus Torvalds if (!(vma->vm_flags & VM_GROWSDOWN)) 3551da177e4SLinus Torvalds goto out; 3567d12efaeSAndrew Morton } else { 3571da177e4SLinus Torvalds if (vma->vm_start > start) 3581da177e4SLinus Torvalds goto out; 3591da177e4SLinus Torvalds if (unlikely(grows & PROT_GROWSUP)) { 3601da177e4SLinus Torvalds end = vma->vm_end; 3611da177e4SLinus Torvalds error = -EINVAL; 3621da177e4SLinus Torvalds if (!(vma->vm_flags & VM_GROWSUP)) 3631da177e4SLinus Torvalds goto out; 3641da177e4SLinus Torvalds } 3651da177e4SLinus Torvalds } 3661da177e4SLinus Torvalds if (start > vma->vm_start) 3671da177e4SLinus Torvalds prev = vma; 3681da177e4SLinus Torvalds 3691da177e4SLinus Torvalds for (nstart = start ; ; ) { 3701da177e4SLinus Torvalds unsigned long newflags; 3711da177e4SLinus Torvalds 3721da177e4SLinus Torvalds /* Here we know that vma->vm_start <= nstart < vma->vm_end. */ 3731da177e4SLinus Torvalds 3747d12efaeSAndrew Morton newflags = vm_flags; 3757d12efaeSAndrew Morton newflags |= (vma->vm_flags & ~(VM_READ | VM_WRITE | VM_EXEC)); 3761da177e4SLinus Torvalds 3777e2cff42SPaolo 'Blaisorblade' Giarrusso /* newflags >> 4 shift VM_MAY% in place of VM_% */ 3787e2cff42SPaolo 'Blaisorblade' Giarrusso if ((newflags & ~(newflags >> 4)) & (VM_READ | VM_WRITE | VM_EXEC)) { 3791da177e4SLinus Torvalds error = -EACCES; 3801da177e4SLinus Torvalds goto out; 3811da177e4SLinus Torvalds } 3821da177e4SLinus Torvalds 3831da177e4SLinus Torvalds error = security_file_mprotect(vma, reqprot, prot); 3841da177e4SLinus Torvalds if (error) 3851da177e4SLinus Torvalds goto out; 3861da177e4SLinus Torvalds 3871da177e4SLinus Torvalds tmp = vma->vm_end; 3881da177e4SLinus Torvalds if (tmp > end) 3891da177e4SLinus Torvalds tmp = end; 3901da177e4SLinus Torvalds error = mprotect_fixup(vma, &prev, nstart, tmp, newflags); 3911da177e4SLinus Torvalds if (error) 3921da177e4SLinus Torvalds goto out; 3931da177e4SLinus Torvalds nstart = tmp; 3941da177e4SLinus Torvalds 3951da177e4SLinus Torvalds if (nstart < prev->vm_end) 3961da177e4SLinus Torvalds nstart = prev->vm_end; 3971da177e4SLinus Torvalds if (nstart >= end) 3981da177e4SLinus Torvalds goto out; 3991da177e4SLinus Torvalds 4001da177e4SLinus Torvalds vma = prev->vm_next; 4011da177e4SLinus Torvalds if (!vma || vma->vm_start != nstart) { 4021da177e4SLinus Torvalds error = -ENOMEM; 4031da177e4SLinus Torvalds goto out; 4041da177e4SLinus Torvalds } 4051da177e4SLinus Torvalds } 4061da177e4SLinus Torvalds out: 4071da177e4SLinus Torvalds up_write(¤t->mm->mmap_sem); 4081da177e4SLinus Torvalds return error; 4091da177e4SLinus Torvalds } 410