Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * mm/mprotect.c |
| 3 | * |
| 4 | * (C) Copyright 1994 Linus Torvalds |
| 5 | * (C) Copyright 2002 Christoph Hellwig |
| 6 | * |
Alan Cox | 046c688 | 2009-01-05 14:06:29 +0000 | [diff] [blame] | 7 | * Address space accounting code <alan@lxorguk.ukuu.org.uk> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 8 | * (C) Copyright 2002 Red Hat Inc, All Rights Reserved |
| 9 | */ |
| 10 | |
| 11 | #include <linux/mm.h> |
| 12 | #include <linux/hugetlb.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 13 | #include <linux/shm.h> |
| 14 | #include <linux/mman.h> |
| 15 | #include <linux/fs.h> |
| 16 | #include <linux/highmem.h> |
| 17 | #include <linux/security.h> |
| 18 | #include <linux/mempolicy.h> |
| 19 | #include <linux/personality.h> |
| 20 | #include <linux/syscalls.h> |
Christoph Lameter | 0697212 | 2006-06-23 02:03:35 -0700 | [diff] [blame] | 21 | #include <linux/swap.h> |
| 22 | #include <linux/swapops.h> |
Andrea Arcangeli | cddb8a5 | 2008-07-28 15:46:29 -0700 | [diff] [blame] | 23 | #include <linux/mmu_notifier.h> |
KOSAKI Motohiro | 64cdd54 | 2009-01-06 14:39:16 -0800 | [diff] [blame] | 24 | #include <linux/migrate.h> |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 25 | #include <linux/perf_event.h> |
Dave Hansen | e8c24d3 | 2016-07-29 09:30:15 -0700 | [diff] [blame] | 26 | #include <linux/pkeys.h> |
Mel Gorman | 64a9a34 | 2014-01-21 15:51:02 -0800 | [diff] [blame] | 27 | #include <linux/ksm.h> |
Linus Torvalds | 7c0f6ba | 2016-12-24 11:46:01 -0800 | [diff] [blame] | 28 | #include <linux/uaccess.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | #include <asm/pgtable.h> |
| 30 | #include <asm/cacheflush.h> |
Dave Hansen | e8c24d3 | 2016-07-29 09:30:15 -0700 | [diff] [blame] | 31 | #include <asm/mmu_context.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | #include <asm/tlbflush.h> |
| 33 | |
Kirill A. Shutemov | 36f8818 | 2015-06-24 16:56:10 -0700 | [diff] [blame] | 34 | #include "internal.h" |
| 35 | |
Mel Gorman | 4b10e7d | 2012-10-25 14:16:32 +0200 | [diff] [blame] | 36 | static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd, |
Peter Zijlstra | c1e6098 | 2006-09-25 23:30:59 -0700 | [diff] [blame] | 37 | unsigned long addr, unsigned long end, pgprot_t newprot, |
Mel Gorman | 0f19c17 | 2013-10-07 11:29:25 +0100 | [diff] [blame] | 38 | int dirty_accountable, int prot_numa) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 39 | { |
Mel Gorman | 4b10e7d | 2012-10-25 14:16:32 +0200 | [diff] [blame] | 40 | struct mm_struct *mm = vma->vm_mm; |
Christoph Lameter | 0697212 | 2006-06-23 02:03:35 -0700 | [diff] [blame] | 41 | pte_t *pte, oldpte; |
Hugh Dickins | 705e87c | 2005-10-29 18:16:27 -0700 | [diff] [blame] | 42 | spinlock_t *ptl; |
Peter Zijlstra | 7da4d64 | 2012-11-19 03:14:23 +0100 | [diff] [blame] | 43 | unsigned long pages = 0; |
Andi Kleen | 3e32158 | 2016-12-12 16:41:47 -0800 | [diff] [blame] | 44 | int target_node = NUMA_NO_NODE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 45 | |
Andrea Arcangeli | 175ad4f | 2017-02-22 15:44:12 -0800 | [diff] [blame] | 46 | /* |
| 47 | * Can be called with only the mmap_sem for reading by |
| 48 | * prot_numa so we must check the pmd isn't constantly |
| 49 | * changing from under us from pmd_none to pmd_trans_huge |
| 50 | * and/or the other way around. |
| 51 | */ |
| 52 | if (pmd_trans_unstable(pmd)) |
| 53 | return 0; |
| 54 | |
| 55 | /* |
| 56 | * The pmd points to a regular pte so the pmd can't change |
| 57 | * from under us even if the mmap_sem is only hold for |
| 58 | * reading. |
| 59 | */ |
| 60 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); |
Mel Gorman | 1ad9f62 | 2014-04-07 15:36:56 -0700 | [diff] [blame] | 61 | if (!pte) |
| 62 | return 0; |
| 63 | |
Andi Kleen | 3e32158 | 2016-12-12 16:41:47 -0800 | [diff] [blame] | 64 | /* Get target node for single threaded private VMAs */ |
| 65 | if (prot_numa && !(vma->vm_flags & VM_SHARED) && |
| 66 | atomic_read(&vma->vm_mm->mm_users) == 1) |
| 67 | target_node = numa_node_id(); |
| 68 | |
Zachary Amsden | 6606c3e | 2006-09-30 23:29:33 -0700 | [diff] [blame] | 69 | arch_enter_lazy_mmu_mode(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 70 | do { |
Christoph Lameter | 0697212 | 2006-06-23 02:03:35 -0700 | [diff] [blame] | 71 | oldpte = *pte; |
| 72 | if (pte_present(oldpte)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 73 | pte_t ptent; |
Mel Gorman | b191f9b | 2015-03-25 15:55:40 -0700 | [diff] [blame] | 74 | bool preserve_write = prot_numa && pte_write(oldpte); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 75 | |
Mel Gorman | e944fd6 | 2015-02-12 14:58:35 -0800 | [diff] [blame] | 76 | /* |
| 77 | * Avoid trapping faults against the zero or KSM |
| 78 | * pages. See similar comment in change_huge_pmd. |
| 79 | */ |
| 80 | if (prot_numa) { |
| 81 | struct page *page; |
| 82 | |
| 83 | page = vm_normal_page(vma, addr, oldpte); |
| 84 | if (!page || PageKsm(page)) |
| 85 | continue; |
Mel Gorman | 10c1045 | 2015-02-12 14:58:44 -0800 | [diff] [blame] | 86 | |
| 87 | /* Avoid TLB flush if possible */ |
| 88 | if (pte_protnone(oldpte)) |
| 89 | continue; |
Andi Kleen | 3e32158 | 2016-12-12 16:41:47 -0800 | [diff] [blame] | 90 | |
| 91 | /* |
| 92 | * Don't mess with PTEs if page is already on the node |
| 93 | * a single-threaded process is running on. |
| 94 | */ |
| 95 | if (target_node == page_to_nid(page)) |
| 96 | continue; |
Mel Gorman | e944fd6 | 2015-02-12 14:58:35 -0800 | [diff] [blame] | 97 | } |
| 98 | |
Mel Gorman | 8a0516e | 2015-02-12 14:58:22 -0800 | [diff] [blame] | 99 | ptent = ptep_modify_prot_start(mm, addr, pte); |
| 100 | ptent = pte_modify(ptent, newprot); |
Mel Gorman | b191f9b | 2015-03-25 15:55:40 -0700 | [diff] [blame] | 101 | if (preserve_write) |
Aneesh Kumar K.V | 288bc54 | 2017-02-24 14:59:16 -0800 | [diff] [blame] | 102 | ptent = pte_mk_savedwrite(ptent); |
Mel Gorman | 4b10e7d | 2012-10-25 14:16:32 +0200 | [diff] [blame] | 103 | |
Mel Gorman | 8a0516e | 2015-02-12 14:58:22 -0800 | [diff] [blame] | 104 | /* Avoid taking write faults for known dirty pages */ |
| 105 | if (dirty_accountable && pte_dirty(ptent) && |
| 106 | (pte_soft_dirty(ptent) || |
| 107 | !(vma->vm_flags & VM_SOFTDIRTY))) { |
| 108 | ptent = pte_mkwrite(ptent); |
Mel Gorman | 4b10e7d | 2012-10-25 14:16:32 +0200 | [diff] [blame] | 109 | } |
Mel Gorman | 8a0516e | 2015-02-12 14:58:22 -0800 | [diff] [blame] | 110 | ptep_modify_prot_commit(mm, addr, pte, ptent); |
| 111 | pages++; |
Kirill A. Shutemov | 0661a33 | 2015-02-10 14:10:04 -0800 | [diff] [blame] | 112 | } else if (IS_ENABLED(CONFIG_MIGRATION)) { |
Christoph Lameter | 0697212 | 2006-06-23 02:03:35 -0700 | [diff] [blame] | 113 | swp_entry_t entry = pte_to_swp_entry(oldpte); |
| 114 | |
| 115 | if (is_write_migration_entry(entry)) { |
Cyrill Gorcunov | c3d16e1 | 2013-10-16 13:46:51 -0700 | [diff] [blame] | 116 | pte_t newpte; |
Christoph Lameter | 0697212 | 2006-06-23 02:03:35 -0700 | [diff] [blame] | 117 | /* |
| 118 | * A protection check is difficult so |
| 119 | * just be safe and disable write |
| 120 | */ |
| 121 | make_migration_entry_read(&entry); |
Cyrill Gorcunov | c3d16e1 | 2013-10-16 13:46:51 -0700 | [diff] [blame] | 122 | newpte = swp_entry_to_pte(entry); |
| 123 | if (pte_swp_soft_dirty(oldpte)) |
| 124 | newpte = pte_swp_mksoft_dirty(newpte); |
| 125 | set_pte_at(mm, addr, pte, newpte); |
Mel Gorman | e920e14 | 2013-10-07 11:28:48 +0100 | [diff] [blame] | 126 | |
| 127 | pages++; |
Christoph Lameter | 0697212 | 2006-06-23 02:03:35 -0700 | [diff] [blame] | 128 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 129 | } |
| 130 | } while (pte++, addr += PAGE_SIZE, addr != end); |
Zachary Amsden | 6606c3e | 2006-09-30 23:29:33 -0700 | [diff] [blame] | 131 | arch_leave_lazy_mmu_mode(); |
Hugh Dickins | 705e87c | 2005-10-29 18:16:27 -0700 | [diff] [blame] | 132 | pte_unmap_unlock(pte - 1, ptl); |
Peter Zijlstra | 7da4d64 | 2012-11-19 03:14:23 +0100 | [diff] [blame] | 133 | |
| 134 | return pages; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 135 | } |
| 136 | |
Andrew Morton | 7d12efa | 2012-12-18 14:23:17 -0800 | [diff] [blame] | 137 | static inline unsigned long change_pmd_range(struct vm_area_struct *vma, |
| 138 | pud_t *pud, unsigned long addr, unsigned long end, |
| 139 | pgprot_t newprot, int dirty_accountable, int prot_numa) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 140 | { |
| 141 | pmd_t *pmd; |
Rik van Riel | a533809 | 2014-04-07 15:36:57 -0700 | [diff] [blame] | 142 | struct mm_struct *mm = vma->vm_mm; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 143 | unsigned long next; |
Peter Zijlstra | 7da4d64 | 2012-11-19 03:14:23 +0100 | [diff] [blame] | 144 | unsigned long pages = 0; |
Mel Gorman | 72403b4 | 2013-11-12 15:08:32 -0800 | [diff] [blame] | 145 | unsigned long nr_huge_updates = 0; |
Rik van Riel | a533809 | 2014-04-07 15:36:57 -0700 | [diff] [blame] | 146 | unsigned long mni_start = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 147 | |
| 148 | pmd = pmd_offset(pud, addr); |
| 149 | do { |
Mel Gorman | 25cbbef | 2013-10-07 11:29:14 +0100 | [diff] [blame] | 150 | unsigned long this_pages; |
| 151 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 152 | next = pmd_addr_end(addr, end); |
Dan Williams | 5c7fb56 | 2016-01-15 16:56:52 -0800 | [diff] [blame] | 153 | if (!pmd_trans_huge(*pmd) && !pmd_devmap(*pmd) |
| 154 | && pmd_none_or_clear_bad(pmd)) |
Rik van Riel | 88a9ab6 | 2014-04-07 15:36:55 -0700 | [diff] [blame] | 155 | continue; |
Rik van Riel | a533809 | 2014-04-07 15:36:57 -0700 | [diff] [blame] | 156 | |
| 157 | /* invoke the mmu notifier if the pmd is populated */ |
| 158 | if (!mni_start) { |
| 159 | mni_start = addr; |
| 160 | mmu_notifier_invalidate_range_start(mm, mni_start, end); |
| 161 | } |
| 162 | |
Dan Williams | 5c7fb56 | 2016-01-15 16:56:52 -0800 | [diff] [blame] | 163 | if (pmd_trans_huge(*pmd) || pmd_devmap(*pmd)) { |
Kirill A. Shutemov | 6b9116a | 2016-02-11 16:13:03 -0800 | [diff] [blame] | 164 | if (next - addr != HPAGE_PMD_SIZE) { |
David Rientjes | fd60775 | 2016-12-12 16:42:20 -0800 | [diff] [blame] | 165 | __split_huge_pmd(vma, pmd, addr, false, NULL); |
Kirill A. Shutemov | 6b9116a | 2016-02-11 16:13:03 -0800 | [diff] [blame] | 166 | } else { |
Mel Gorman | f123d74 | 2013-10-07 11:28:49 +0100 | [diff] [blame] | 167 | int nr_ptes = change_huge_pmd(vma, pmd, addr, |
Mel Gorman | e944fd6 | 2015-02-12 14:58:35 -0800 | [diff] [blame] | 168 | newprot, prot_numa); |
Mel Gorman | f123d74 | 2013-10-07 11:28:49 +0100 | [diff] [blame] | 169 | |
| 170 | if (nr_ptes) { |
Mel Gorman | 72403b4 | 2013-11-12 15:08:32 -0800 | [diff] [blame] | 171 | if (nr_ptes == HPAGE_PMD_NR) { |
| 172 | pages += HPAGE_PMD_NR; |
| 173 | nr_huge_updates++; |
| 174 | } |
Mel Gorman | 1ad9f62 | 2014-04-07 15:36:56 -0700 | [diff] [blame] | 175 | |
| 176 | /* huge pmd was handled */ |
Mel Gorman | f123d74 | 2013-10-07 11:28:49 +0100 | [diff] [blame] | 177 | continue; |
| 178 | } |
Peter Zijlstra | 7da4d64 | 2012-11-19 03:14:23 +0100 | [diff] [blame] | 179 | } |
Rik van Riel | 88a9ab6 | 2014-04-07 15:36:55 -0700 | [diff] [blame] | 180 | /* fall through, the trans huge pmd just split */ |
Johannes Weiner | cd7548a | 2011-01-13 15:47:04 -0800 | [diff] [blame] | 181 | } |
Mel Gorman | 25cbbef | 2013-10-07 11:29:14 +0100 | [diff] [blame] | 182 | this_pages = change_pte_range(vma, pmd, addr, next, newprot, |
Mel Gorman | 0f19c17 | 2013-10-07 11:29:25 +0100 | [diff] [blame] | 183 | dirty_accountable, prot_numa); |
Mel Gorman | 25cbbef | 2013-10-07 11:29:14 +0100 | [diff] [blame] | 184 | pages += this_pages; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 185 | } while (pmd++, addr = next, addr != end); |
Peter Zijlstra | 7da4d64 | 2012-11-19 03:14:23 +0100 | [diff] [blame] | 186 | |
Rik van Riel | a533809 | 2014-04-07 15:36:57 -0700 | [diff] [blame] | 187 | if (mni_start) |
| 188 | mmu_notifier_invalidate_range_end(mm, mni_start, end); |
| 189 | |
Mel Gorman | 72403b4 | 2013-11-12 15:08:32 -0800 | [diff] [blame] | 190 | if (nr_huge_updates) |
| 191 | count_vm_numa_events(NUMA_HUGE_PTE_UPDATES, nr_huge_updates); |
Peter Zijlstra | 7da4d64 | 2012-11-19 03:14:23 +0100 | [diff] [blame] | 192 | return pages; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 193 | } |
| 194 | |
Andrew Morton | 7d12efa | 2012-12-18 14:23:17 -0800 | [diff] [blame] | 195 | static inline unsigned long change_pud_range(struct vm_area_struct *vma, |
Kirill A. Shutemov | c2febaf | 2017-03-09 17:24:07 +0300 | [diff] [blame] | 196 | p4d_t *p4d, unsigned long addr, unsigned long end, |
Andrew Morton | 7d12efa | 2012-12-18 14:23:17 -0800 | [diff] [blame] | 197 | pgprot_t newprot, int dirty_accountable, int prot_numa) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 198 | { |
| 199 | pud_t *pud; |
| 200 | unsigned long next; |
Peter Zijlstra | 7da4d64 | 2012-11-19 03:14:23 +0100 | [diff] [blame] | 201 | unsigned long pages = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 202 | |
Kirill A. Shutemov | c2febaf | 2017-03-09 17:24:07 +0300 | [diff] [blame] | 203 | pud = pud_offset(p4d, addr); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 204 | do { |
| 205 | next = pud_addr_end(addr, end); |
| 206 | if (pud_none_or_clear_bad(pud)) |
| 207 | continue; |
Peter Zijlstra | 7da4d64 | 2012-11-19 03:14:23 +0100 | [diff] [blame] | 208 | pages += change_pmd_range(vma, pud, addr, next, newprot, |
Mel Gorman | 4b10e7d | 2012-10-25 14:16:32 +0200 | [diff] [blame] | 209 | dirty_accountable, prot_numa); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 210 | } while (pud++, addr = next, addr != end); |
Peter Zijlstra | 7da4d64 | 2012-11-19 03:14:23 +0100 | [diff] [blame] | 211 | |
| 212 | return pages; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 213 | } |
| 214 | |
Kirill A. Shutemov | c2febaf | 2017-03-09 17:24:07 +0300 | [diff] [blame] | 215 | static inline unsigned long change_p4d_range(struct vm_area_struct *vma, |
| 216 | pgd_t *pgd, unsigned long addr, unsigned long end, |
| 217 | pgprot_t newprot, int dirty_accountable, int prot_numa) |
| 218 | { |
| 219 | p4d_t *p4d; |
| 220 | unsigned long next; |
| 221 | unsigned long pages = 0; |
| 222 | |
| 223 | p4d = p4d_offset(pgd, addr); |
| 224 | do { |
| 225 | next = p4d_addr_end(addr, end); |
| 226 | if (p4d_none_or_clear_bad(p4d)) |
| 227 | continue; |
| 228 | pages += change_pud_range(vma, p4d, addr, next, newprot, |
| 229 | dirty_accountable, prot_numa); |
| 230 | } while (p4d++, addr = next, addr != end); |
| 231 | |
| 232 | return pages; |
| 233 | } |
| 234 | |
Peter Zijlstra | 7da4d64 | 2012-11-19 03:14:23 +0100 | [diff] [blame] | 235 | static unsigned long change_protection_range(struct vm_area_struct *vma, |
Peter Zijlstra | c1e6098 | 2006-09-25 23:30:59 -0700 | [diff] [blame] | 236 | unsigned long addr, unsigned long end, pgprot_t newprot, |
Mel Gorman | 4b10e7d | 2012-10-25 14:16:32 +0200 | [diff] [blame] | 237 | int dirty_accountable, int prot_numa) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 238 | { |
| 239 | struct mm_struct *mm = vma->vm_mm; |
| 240 | pgd_t *pgd; |
| 241 | unsigned long next; |
| 242 | unsigned long start = addr; |
Peter Zijlstra | 7da4d64 | 2012-11-19 03:14:23 +0100 | [diff] [blame] | 243 | unsigned long pages = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 244 | |
| 245 | BUG_ON(addr >= end); |
| 246 | pgd = pgd_offset(mm, addr); |
| 247 | flush_cache_range(vma, addr, end); |
Rik van Riel | 2084140 | 2013-12-18 17:08:44 -0800 | [diff] [blame] | 248 | set_tlb_flush_pending(mm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 249 | do { |
| 250 | next = pgd_addr_end(addr, end); |
| 251 | if (pgd_none_or_clear_bad(pgd)) |
| 252 | continue; |
Kirill A. Shutemov | c2febaf | 2017-03-09 17:24:07 +0300 | [diff] [blame] | 253 | pages += change_p4d_range(vma, pgd, addr, next, newprot, |
Mel Gorman | 4b10e7d | 2012-10-25 14:16:32 +0200 | [diff] [blame] | 254 | dirty_accountable, prot_numa); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 255 | } while (pgd++, addr = next, addr != end); |
Peter Zijlstra | 7da4d64 | 2012-11-19 03:14:23 +0100 | [diff] [blame] | 256 | |
Ingo Molnar | 1233d58 | 2012-11-19 03:14:24 +0100 | [diff] [blame] | 257 | /* Only flush the TLB if we actually modified any entries: */ |
| 258 | if (pages) |
| 259 | flush_tlb_range(vma, start, end); |
Rik van Riel | 2084140 | 2013-12-18 17:08:44 -0800 | [diff] [blame] | 260 | clear_tlb_flush_pending(mm); |
Peter Zijlstra | 7da4d64 | 2012-11-19 03:14:23 +0100 | [diff] [blame] | 261 | |
| 262 | return pages; |
| 263 | } |
| 264 | |
| 265 | unsigned long change_protection(struct vm_area_struct *vma, unsigned long start, |
| 266 | unsigned long end, pgprot_t newprot, |
Mel Gorman | 4b10e7d | 2012-10-25 14:16:32 +0200 | [diff] [blame] | 267 | int dirty_accountable, int prot_numa) |
Peter Zijlstra | 7da4d64 | 2012-11-19 03:14:23 +0100 | [diff] [blame] | 268 | { |
Peter Zijlstra | 7da4d64 | 2012-11-19 03:14:23 +0100 | [diff] [blame] | 269 | unsigned long pages; |
| 270 | |
Peter Zijlstra | 7da4d64 | 2012-11-19 03:14:23 +0100 | [diff] [blame] | 271 | if (is_vm_hugetlb_page(vma)) |
| 272 | pages = hugetlb_change_protection(vma, start, end, newprot); |
| 273 | else |
Mel Gorman | 4b10e7d | 2012-10-25 14:16:32 +0200 | [diff] [blame] | 274 | pages = change_protection_range(vma, start, end, newprot, dirty_accountable, prot_numa); |
Peter Zijlstra | 7da4d64 | 2012-11-19 03:14:23 +0100 | [diff] [blame] | 275 | |
| 276 | return pages; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 277 | } |
| 278 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 279 | int |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 280 | mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev, |
| 281 | unsigned long start, unsigned long end, unsigned long newflags) |
| 282 | { |
| 283 | struct mm_struct *mm = vma->vm_mm; |
| 284 | unsigned long oldflags = vma->vm_flags; |
| 285 | long nrpages = (end - start) >> PAGE_SHIFT; |
| 286 | unsigned long charged = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 287 | pgoff_t pgoff; |
| 288 | int error; |
Peter Zijlstra | c1e6098 | 2006-09-25 23:30:59 -0700 | [diff] [blame] | 289 | int dirty_accountable = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 290 | |
| 291 | if (newflags == oldflags) { |
| 292 | *pprev = vma; |
| 293 | return 0; |
| 294 | } |
| 295 | |
| 296 | /* |
| 297 | * If we make a private mapping writable we increase our commit; |
| 298 | * but (without finer accounting) cannot reduce our commit if we |
Mel Gorman | 5a6fe12 | 2009-02-10 14:02:27 +0000 | [diff] [blame] | 299 | * make it unwritable again. hugetlb mapping were accounted for |
| 300 | * even if read-only so there is no need to account for them here |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 301 | */ |
| 302 | if (newflags & VM_WRITE) { |
Konstantin Khlebnikov | 8463833 | 2016-01-14 15:22:07 -0800 | [diff] [blame] | 303 | /* Check space limits when area turns into data. */ |
| 304 | if (!may_expand_vm(mm, newflags, nrpages) && |
| 305 | may_expand_vm(mm, oldflags, nrpages)) |
| 306 | return -ENOMEM; |
Mel Gorman | 5a6fe12 | 2009-02-10 14:02:27 +0000 | [diff] [blame] | 307 | if (!(oldflags & (VM_ACCOUNT|VM_WRITE|VM_HUGETLB| |
Andy Whitcroft | cdfd432 | 2008-07-23 21:27:28 -0700 | [diff] [blame] | 308 | VM_SHARED|VM_NORESERVE))) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 309 | charged = nrpages; |
Al Viro | 191c542 | 2012-02-13 03:58:52 +0000 | [diff] [blame] | 310 | if (security_vm_enough_memory_mm(mm, charged)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 311 | return -ENOMEM; |
| 312 | newflags |= VM_ACCOUNT; |
| 313 | } |
| 314 | } |
| 315 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 316 | /* |
| 317 | * First try to merge with previous and/or next vma. |
| 318 | */ |
| 319 | pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT); |
| 320 | *pprev = vma_merge(mm, *pprev, start, end, newflags, |
Andrea Arcangeli | 19a809a | 2015-09-04 15:46:24 -0700 | [diff] [blame] | 321 | vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma), |
| 322 | vma->vm_userfaultfd_ctx); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 323 | if (*pprev) { |
| 324 | vma = *pprev; |
Andrea Arcangeli | e86f15e | 2016-10-07 17:01:28 -0700 | [diff] [blame] | 325 | VM_WARN_ON((vma->vm_flags ^ newflags) & ~VM_SOFTDIRTY); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 326 | goto success; |
| 327 | } |
| 328 | |
| 329 | *pprev = vma; |
| 330 | |
| 331 | if (start != vma->vm_start) { |
| 332 | error = split_vma(mm, vma, start, 1); |
| 333 | if (error) |
| 334 | goto fail; |
| 335 | } |
| 336 | |
| 337 | if (end != vma->vm_end) { |
| 338 | error = split_vma(mm, vma, end, 0); |
| 339 | if (error) |
| 340 | goto fail; |
| 341 | } |
| 342 | |
| 343 | success: |
| 344 | /* |
| 345 | * vm_flags and vm_page_prot are protected by the mmap_sem |
| 346 | * held in write mode. |
| 347 | */ |
| 348 | vma->vm_flags = newflags; |
Andrea Arcangeli | 6d2329f | 2016-10-07 17:01:22 -0700 | [diff] [blame] | 349 | dirty_accountable = vma_wants_writenotify(vma, vma->vm_page_prot); |
Peter Feiner | 64e4550 | 2014-10-13 15:55:46 -0700 | [diff] [blame] | 350 | vma_set_page_prot(vma); |
Peter Zijlstra | d08b385 | 2006-09-25 23:30:57 -0700 | [diff] [blame] | 351 | |
Andrew Morton | 7d12efa | 2012-12-18 14:23:17 -0800 | [diff] [blame] | 352 | change_protection(vma, start, end, vma->vm_page_prot, |
| 353 | dirty_accountable, 0); |
Peter Zijlstra | 7da4d64 | 2012-11-19 03:14:23 +0100 | [diff] [blame] | 354 | |
Kirill A. Shutemov | 36f8818 | 2015-06-24 16:56:10 -0700 | [diff] [blame] | 355 | /* |
| 356 | * Private VM_LOCKED VMA becoming writable: trigger COW to avoid major |
| 357 | * fault on access. |
| 358 | */ |
| 359 | if ((oldflags & (VM_WRITE | VM_SHARED | VM_LOCKED)) == VM_LOCKED && |
| 360 | (newflags & VM_WRITE)) { |
| 361 | populate_vma_page_range(vma, start, end, NULL); |
| 362 | } |
| 363 | |
Konstantin Khlebnikov | 8463833 | 2016-01-14 15:22:07 -0800 | [diff] [blame] | 364 | vm_stat_account(mm, oldflags, -nrpages); |
| 365 | vm_stat_account(mm, newflags, nrpages); |
Pekka Enberg | 63bfd73 | 2010-11-08 21:29:07 +0200 | [diff] [blame] | 366 | perf_event_mmap(vma); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 367 | return 0; |
| 368 | |
| 369 | fail: |
| 370 | vm_unacct_memory(charged); |
| 371 | return error; |
| 372 | } |
| 373 | |
Dave Hansen | 7d06d9c | 2016-07-29 09:30:12 -0700 | [diff] [blame] | 374 | /* |
| 375 | * pkey==-1 when doing a legacy mprotect() |
| 376 | */ |
| 377 | static int do_mprotect_pkey(unsigned long start, size_t len, |
| 378 | unsigned long prot, int pkey) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 379 | { |
Dave Hansen | 62b5f7d | 2016-02-12 13:02:40 -0800 | [diff] [blame] | 380 | unsigned long nstart, end, tmp, reqprot; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 381 | struct vm_area_struct *vma, *prev; |
| 382 | int error = -EINVAL; |
| 383 | const int grows = prot & (PROT_GROWSDOWN|PROT_GROWSUP); |
Piotr Kwapulinski | f138556 | 2016-03-22 14:27:51 -0700 | [diff] [blame] | 384 | const bool rier = (current->personality & READ_IMPLIES_EXEC) && |
| 385 | (prot & PROT_READ); |
| 386 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 387 | prot &= ~(PROT_GROWSDOWN|PROT_GROWSUP); |
| 388 | if (grows == (PROT_GROWSDOWN|PROT_GROWSUP)) /* can't be both */ |
| 389 | return -EINVAL; |
| 390 | |
| 391 | if (start & ~PAGE_MASK) |
| 392 | return -EINVAL; |
| 393 | if (!len) |
| 394 | return 0; |
| 395 | len = PAGE_ALIGN(len); |
| 396 | end = start + len; |
| 397 | if (end <= start) |
| 398 | return -ENOMEM; |
Dave Kleikamp | b845f31 | 2008-07-08 00:28:51 +1000 | [diff] [blame] | 399 | if (!arch_validate_prot(prot)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 400 | return -EINVAL; |
| 401 | |
| 402 | reqprot = prot; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 403 | |
Michal Hocko | dc0ef0d | 2016-05-23 16:25:27 -0700 | [diff] [blame] | 404 | if (down_write_killable(¤t->mm->mmap_sem)) |
| 405 | return -EINTR; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 406 | |
Dave Hansen | e8c24d3 | 2016-07-29 09:30:15 -0700 | [diff] [blame] | 407 | /* |
| 408 | * If userspace did not allocate the pkey, do not let |
| 409 | * them use it here. |
| 410 | */ |
| 411 | error = -EINVAL; |
| 412 | if ((pkey != -1) && !mm_pkey_is_allocated(current->mm, pkey)) |
| 413 | goto out; |
| 414 | |
Linus Torvalds | 097d591 | 2012-03-06 18:23:36 -0800 | [diff] [blame] | 415 | vma = find_vma(current->mm, start); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 416 | error = -ENOMEM; |
| 417 | if (!vma) |
| 418 | goto out; |
Linus Torvalds | 097d591 | 2012-03-06 18:23:36 -0800 | [diff] [blame] | 419 | prev = vma->vm_prev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 420 | if (unlikely(grows & PROT_GROWSDOWN)) { |
| 421 | if (vma->vm_start >= end) |
| 422 | goto out; |
| 423 | start = vma->vm_start; |
| 424 | error = -EINVAL; |
| 425 | if (!(vma->vm_flags & VM_GROWSDOWN)) |
| 426 | goto out; |
Andrew Morton | 7d12efa | 2012-12-18 14:23:17 -0800 | [diff] [blame] | 427 | } else { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 428 | if (vma->vm_start > start) |
| 429 | goto out; |
| 430 | if (unlikely(grows & PROT_GROWSUP)) { |
| 431 | end = vma->vm_end; |
| 432 | error = -EINVAL; |
| 433 | if (!(vma->vm_flags & VM_GROWSUP)) |
| 434 | goto out; |
| 435 | } |
| 436 | } |
| 437 | if (start > vma->vm_start) |
| 438 | prev = vma; |
| 439 | |
| 440 | for (nstart = start ; ; ) { |
Dave Hansen | a8502b6 | 2016-07-29 09:30:13 -0700 | [diff] [blame] | 441 | unsigned long mask_off_old_flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 442 | unsigned long newflags; |
Dave Hansen | 7d06d9c | 2016-07-29 09:30:12 -0700 | [diff] [blame] | 443 | int new_vma_pkey; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 444 | |
Andrew Morton | 7d12efa | 2012-12-18 14:23:17 -0800 | [diff] [blame] | 445 | /* Here we know that vma->vm_start <= nstart < vma->vm_end. */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 446 | |
Piotr Kwapulinski | f138556 | 2016-03-22 14:27:51 -0700 | [diff] [blame] | 447 | /* Does the application expect PROT_READ to imply PROT_EXEC */ |
| 448 | if (rier && (vma->vm_flags & VM_MAYEXEC)) |
| 449 | prot |= PROT_EXEC; |
| 450 | |
Dave Hansen | a8502b6 | 2016-07-29 09:30:13 -0700 | [diff] [blame] | 451 | /* |
| 452 | * Each mprotect() call explicitly passes r/w/x permissions. |
| 453 | * If a permission is not passed to mprotect(), it must be |
| 454 | * cleared from the VMA. |
| 455 | */ |
| 456 | mask_off_old_flags = VM_READ | VM_WRITE | VM_EXEC | |
| 457 | ARCH_VM_PKEY_FLAGS; |
| 458 | |
Dave Hansen | 7d06d9c | 2016-07-29 09:30:12 -0700 | [diff] [blame] | 459 | new_vma_pkey = arch_override_mprotect_pkey(vma, prot, pkey); |
| 460 | newflags = calc_vm_prot_bits(prot, new_vma_pkey); |
Dave Hansen | a8502b6 | 2016-07-29 09:30:13 -0700 | [diff] [blame] | 461 | newflags |= (vma->vm_flags & ~mask_off_old_flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 462 | |
Paolo 'Blaisorblade' Giarrusso | 7e2cff4 | 2005-09-21 09:55:39 -0700 | [diff] [blame] | 463 | /* newflags >> 4 shift VM_MAY% in place of VM_% */ |
| 464 | if ((newflags & ~(newflags >> 4)) & (VM_READ | VM_WRITE | VM_EXEC)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 465 | error = -EACCES; |
| 466 | goto out; |
| 467 | } |
| 468 | |
| 469 | error = security_file_mprotect(vma, reqprot, prot); |
| 470 | if (error) |
| 471 | goto out; |
| 472 | |
| 473 | tmp = vma->vm_end; |
| 474 | if (tmp > end) |
| 475 | tmp = end; |
| 476 | error = mprotect_fixup(vma, &prev, nstart, tmp, newflags); |
| 477 | if (error) |
| 478 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 479 | nstart = tmp; |
| 480 | |
| 481 | if (nstart < prev->vm_end) |
| 482 | nstart = prev->vm_end; |
| 483 | if (nstart >= end) |
| 484 | goto out; |
| 485 | |
| 486 | vma = prev->vm_next; |
| 487 | if (!vma || vma->vm_start != nstart) { |
| 488 | error = -ENOMEM; |
| 489 | goto out; |
| 490 | } |
Piotr Kwapulinski | f138556 | 2016-03-22 14:27:51 -0700 | [diff] [blame] | 491 | prot = reqprot; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 492 | } |
| 493 | out: |
| 494 | up_write(¤t->mm->mmap_sem); |
| 495 | return error; |
| 496 | } |
Dave Hansen | 7d06d9c | 2016-07-29 09:30:12 -0700 | [diff] [blame] | 497 | |
| 498 | SYSCALL_DEFINE3(mprotect, unsigned long, start, size_t, len, |
| 499 | unsigned long, prot) |
| 500 | { |
| 501 | return do_mprotect_pkey(start, len, prot, -1); |
| 502 | } |
| 503 | |
Heiko Carstens | c7142ae | 2016-12-12 16:43:09 -0800 | [diff] [blame] | 504 | #ifdef CONFIG_ARCH_HAS_PKEYS |
| 505 | |
Dave Hansen | 7d06d9c | 2016-07-29 09:30:12 -0700 | [diff] [blame] | 506 | SYSCALL_DEFINE4(pkey_mprotect, unsigned long, start, size_t, len, |
| 507 | unsigned long, prot, int, pkey) |
| 508 | { |
| 509 | return do_mprotect_pkey(start, len, prot, pkey); |
| 510 | } |
Dave Hansen | e8c24d3 | 2016-07-29 09:30:15 -0700 | [diff] [blame] | 511 | |
| 512 | SYSCALL_DEFINE2(pkey_alloc, unsigned long, flags, unsigned long, init_val) |
| 513 | { |
| 514 | int pkey; |
| 515 | int ret; |
| 516 | |
| 517 | /* No flags supported yet. */ |
| 518 | if (flags) |
| 519 | return -EINVAL; |
| 520 | /* check for unsupported init values */ |
| 521 | if (init_val & ~PKEY_ACCESS_MASK) |
| 522 | return -EINVAL; |
| 523 | |
| 524 | down_write(¤t->mm->mmap_sem); |
| 525 | pkey = mm_pkey_alloc(current->mm); |
| 526 | |
| 527 | ret = -ENOSPC; |
| 528 | if (pkey == -1) |
| 529 | goto out; |
| 530 | |
| 531 | ret = arch_set_user_pkey_access(current, pkey, init_val); |
| 532 | if (ret) { |
| 533 | mm_pkey_free(current->mm, pkey); |
| 534 | goto out; |
| 535 | } |
| 536 | ret = pkey; |
| 537 | out: |
| 538 | up_write(¤t->mm->mmap_sem); |
| 539 | return ret; |
| 540 | } |
| 541 | |
| 542 | SYSCALL_DEFINE1(pkey_free, int, pkey) |
| 543 | { |
| 544 | int ret; |
| 545 | |
| 546 | down_write(¤t->mm->mmap_sem); |
| 547 | ret = mm_pkey_free(current->mm, pkey); |
| 548 | up_write(¤t->mm->mmap_sem); |
| 549 | |
| 550 | /* |
| 551 | * We could provie warnings or errors if any VMA still |
| 552 | * has the pkey set here. |
| 553 | */ |
| 554 | return ret; |
| 555 | } |
Heiko Carstens | c7142ae | 2016-12-12 16:43:09 -0800 | [diff] [blame] | 556 | |
| 557 | #endif /* CONFIG_ARCH_HAS_PKEYS */ |