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> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 26 | #include <asm/uaccess.h> |
| 27 | #include <asm/pgtable.h> |
| 28 | #include <asm/cacheflush.h> |
| 29 | #include <asm/tlbflush.h> |
| 30 | |
Venki Pallipadi | 1c12c4c | 2008-05-14 16:05:51 -0700 | [diff] [blame] | 31 | #ifndef pgprot_modify |
| 32 | static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot) |
| 33 | { |
| 34 | return newprot; |
| 35 | } |
| 36 | #endif |
| 37 | |
Mel Gorman | 4b10e7d | 2012-10-25 14:16:32 +0200 | [diff] [blame] | 38 | 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] | 39 | unsigned long addr, unsigned long end, pgprot_t newprot, |
Mel Gorman | b795854 | 2013-10-07 11:29:07 +0100 | [diff] [blame] | 40 | int dirty_accountable, int prot_numa, bool *ret_all_same_nidpid) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | { |
Mel Gorman | 4b10e7d | 2012-10-25 14:16:32 +0200 | [diff] [blame] | 42 | struct mm_struct *mm = vma->vm_mm; |
Christoph Lameter | 0697212 | 2006-06-23 02:03:35 -0700 | [diff] [blame] | 43 | pte_t *pte, oldpte; |
Hugh Dickins | 705e87c | 2005-10-29 18:16:27 -0700 | [diff] [blame] | 44 | spinlock_t *ptl; |
Peter Zijlstra | 7da4d64 | 2012-11-19 03:14:23 +0100 | [diff] [blame] | 45 | unsigned long pages = 0; |
Mel Gorman | b795854 | 2013-10-07 11:29:07 +0100 | [diff] [blame] | 46 | bool all_same_nidpid = true; |
Mel Gorman | 9532fec | 2012-11-15 01:24:32 +0000 | [diff] [blame] | 47 | int last_nid = -1; |
Mel Gorman | b795854 | 2013-10-07 11:29:07 +0100 | [diff] [blame] | 48 | int last_pid = -1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 49 | |
Hugh Dickins | 705e87c | 2005-10-29 18:16:27 -0700 | [diff] [blame] | 50 | pte = pte_offset_map_lock(mm, pmd, addr, &ptl); |
Zachary Amsden | 6606c3e | 2006-09-30 23:29:33 -0700 | [diff] [blame] | 51 | arch_enter_lazy_mmu_mode(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 52 | do { |
Christoph Lameter | 0697212 | 2006-06-23 02:03:35 -0700 | [diff] [blame] | 53 | oldpte = *pte; |
| 54 | if (pte_present(oldpte)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 55 | pte_t ptent; |
Mel Gorman | 4b10e7d | 2012-10-25 14:16:32 +0200 | [diff] [blame] | 56 | bool updated = false; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 57 | |
Jeremy Fitzhardinge | 1ea0704 | 2008-06-16 04:30:00 -0700 | [diff] [blame] | 58 | ptent = ptep_modify_prot_start(mm, addr, pte); |
Mel Gorman | 4b10e7d | 2012-10-25 14:16:32 +0200 | [diff] [blame] | 59 | if (!prot_numa) { |
| 60 | ptent = pte_modify(ptent, newprot); |
| 61 | updated = true; |
| 62 | } else { |
| 63 | struct page *page; |
| 64 | |
| 65 | page = vm_normal_page(vma, addr, oldpte); |
| 66 | if (page) { |
Mel Gorman | b795854 | 2013-10-07 11:29:07 +0100 | [diff] [blame] | 67 | int nidpid = page_nidpid_last(page); |
| 68 | int this_nid = nidpid_to_nid(nidpid); |
| 69 | int this_pid = nidpid_to_pid(nidpid); |
| 70 | |
Mel Gorman | 9532fec | 2012-11-15 01:24:32 +0000 | [diff] [blame] | 71 | if (last_nid == -1) |
| 72 | last_nid = this_nid; |
Mel Gorman | b795854 | 2013-10-07 11:29:07 +0100 | [diff] [blame] | 73 | if (last_pid == -1) |
| 74 | last_pid = this_pid; |
| 75 | if (last_nid != this_nid || |
| 76 | last_pid != this_pid) { |
| 77 | all_same_nidpid = false; |
| 78 | } |
Mel Gorman | 9532fec | 2012-11-15 01:24:32 +0000 | [diff] [blame] | 79 | |
Mel Gorman | 1bc115d | 2013-10-07 11:29:05 +0100 | [diff] [blame] | 80 | if (!pte_numa(oldpte)) { |
Mel Gorman | 4b10e7d | 2012-10-25 14:16:32 +0200 | [diff] [blame] | 81 | ptent = pte_mknuma(ptent); |
| 82 | updated = true; |
| 83 | } |
| 84 | } |
| 85 | } |
Jeremy Fitzhardinge | 1ea0704 | 2008-06-16 04:30:00 -0700 | [diff] [blame] | 86 | |
Peter Zijlstra | c1e6098 | 2006-09-25 23:30:59 -0700 | [diff] [blame] | 87 | /* |
| 88 | * Avoid taking write faults for pages we know to be |
| 89 | * dirty. |
| 90 | */ |
Mel Gorman | 4b10e7d | 2012-10-25 14:16:32 +0200 | [diff] [blame] | 91 | if (dirty_accountable && pte_dirty(ptent)) { |
Peter Zijlstra | c1e6098 | 2006-09-25 23:30:59 -0700 | [diff] [blame] | 92 | ptent = pte_mkwrite(ptent); |
Mel Gorman | 4b10e7d | 2012-10-25 14:16:32 +0200 | [diff] [blame] | 93 | updated = true; |
| 94 | } |
Jeremy Fitzhardinge | 1ea0704 | 2008-06-16 04:30:00 -0700 | [diff] [blame] | 95 | |
Mel Gorman | 4b10e7d | 2012-10-25 14:16:32 +0200 | [diff] [blame] | 96 | if (updated) |
| 97 | pages++; |
Jeremy Fitzhardinge | 1ea0704 | 2008-06-16 04:30:00 -0700 | [diff] [blame] | 98 | ptep_modify_prot_commit(mm, addr, pte, ptent); |
Konstantin Khlebnikov | ce1744f | 2012-03-21 16:33:59 -0700 | [diff] [blame] | 99 | } else if (IS_ENABLED(CONFIG_MIGRATION) && !pte_file(oldpte)) { |
Christoph Lameter | 0697212 | 2006-06-23 02:03:35 -0700 | [diff] [blame] | 100 | swp_entry_t entry = pte_to_swp_entry(oldpte); |
| 101 | |
| 102 | if (is_write_migration_entry(entry)) { |
| 103 | /* |
| 104 | * A protection check is difficult so |
| 105 | * just be safe and disable write |
| 106 | */ |
| 107 | make_migration_entry_read(&entry); |
| 108 | set_pte_at(mm, addr, pte, |
| 109 | swp_entry_to_pte(entry)); |
Mel Gorman | e920e14 | 2013-10-07 11:28:48 +0100 | [diff] [blame] | 110 | |
| 111 | pages++; |
Christoph Lameter | 0697212 | 2006-06-23 02:03:35 -0700 | [diff] [blame] | 112 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 113 | } |
| 114 | } while (pte++, addr += PAGE_SIZE, addr != end); |
Zachary Amsden | 6606c3e | 2006-09-30 23:29:33 -0700 | [diff] [blame] | 115 | arch_leave_lazy_mmu_mode(); |
Hugh Dickins | 705e87c | 2005-10-29 18:16:27 -0700 | [diff] [blame] | 116 | pte_unmap_unlock(pte - 1, ptl); |
Peter Zijlstra | 7da4d64 | 2012-11-19 03:14:23 +0100 | [diff] [blame] | 117 | |
Mel Gorman | b795854 | 2013-10-07 11:29:07 +0100 | [diff] [blame] | 118 | *ret_all_same_nidpid = all_same_nidpid; |
Peter Zijlstra | 7da4d64 | 2012-11-19 03:14:23 +0100 | [diff] [blame] | 119 | return pages; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 120 | } |
| 121 | |
Mel Gorman | 4b10e7d | 2012-10-25 14:16:32 +0200 | [diff] [blame] | 122 | #ifdef CONFIG_NUMA_BALANCING |
| 123 | static inline void change_pmd_protnuma(struct mm_struct *mm, unsigned long addr, |
Andrew Morton | 7d12efa | 2012-12-18 14:23:17 -0800 | [diff] [blame] | 124 | pmd_t *pmd) |
Mel Gorman | 4b10e7d | 2012-10-25 14:16:32 +0200 | [diff] [blame] | 125 | { |
| 126 | spin_lock(&mm->page_table_lock); |
| 127 | set_pmd_at(mm, addr & PMD_MASK, pmd, pmd_mknuma(*pmd)); |
| 128 | spin_unlock(&mm->page_table_lock); |
| 129 | } |
| 130 | #else |
| 131 | static inline void change_pmd_protnuma(struct mm_struct *mm, unsigned long addr, |
Andrew Morton | 7d12efa | 2012-12-18 14:23:17 -0800 | [diff] [blame] | 132 | pmd_t *pmd) |
Mel Gorman | 4b10e7d | 2012-10-25 14:16:32 +0200 | [diff] [blame] | 133 | { |
| 134 | BUG(); |
| 135 | } |
| 136 | #endif /* CONFIG_NUMA_BALANCING */ |
| 137 | |
Andrew Morton | 7d12efa | 2012-12-18 14:23:17 -0800 | [diff] [blame] | 138 | static inline unsigned long change_pmd_range(struct vm_area_struct *vma, |
| 139 | pud_t *pud, unsigned long addr, unsigned long end, |
| 140 | pgprot_t newprot, int dirty_accountable, int prot_numa) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 141 | { |
| 142 | pmd_t *pmd; |
| 143 | unsigned long next; |
Peter Zijlstra | 7da4d64 | 2012-11-19 03:14:23 +0100 | [diff] [blame] | 144 | unsigned long pages = 0; |
Mel Gorman | b795854 | 2013-10-07 11:29:07 +0100 | [diff] [blame] | 145 | bool all_same_nidpid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 146 | |
| 147 | pmd = pmd_offset(pud, addr); |
| 148 | do { |
| 149 | next = pmd_addr_end(addr, end); |
Johannes Weiner | cd7548a | 2011-01-13 15:47:04 -0800 | [diff] [blame] | 150 | if (pmd_trans_huge(*pmd)) { |
| 151 | if (next - addr != HPAGE_PMD_SIZE) |
Kirill A. Shutemov | e180377 | 2012-12-12 13:50:59 -0800 | [diff] [blame] | 152 | split_huge_page_pmd(vma, addr, pmd); |
Mel Gorman | f123d74 | 2013-10-07 11:28:49 +0100 | [diff] [blame] | 153 | else { |
| 154 | int nr_ptes = change_huge_pmd(vma, pmd, addr, |
| 155 | newprot, prot_numa); |
| 156 | |
| 157 | if (nr_ptes) { |
| 158 | if (nr_ptes == HPAGE_PMD_NR) |
| 159 | pages++; |
| 160 | |
| 161 | continue; |
| 162 | } |
Peter Zijlstra | 7da4d64 | 2012-11-19 03:14:23 +0100 | [diff] [blame] | 163 | } |
Johannes Weiner | cd7548a | 2011-01-13 15:47:04 -0800 | [diff] [blame] | 164 | /* fall through */ |
| 165 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 166 | if (pmd_none_or_clear_bad(pmd)) |
| 167 | continue; |
Mel Gorman | 4b10e7d | 2012-10-25 14:16:32 +0200 | [diff] [blame] | 168 | pages += change_pte_range(vma, pmd, addr, next, newprot, |
Mel Gorman | b795854 | 2013-10-07 11:29:07 +0100 | [diff] [blame] | 169 | dirty_accountable, prot_numa, &all_same_nidpid); |
Mel Gorman | 4b10e7d | 2012-10-25 14:16:32 +0200 | [diff] [blame] | 170 | |
Mel Gorman | 9532fec | 2012-11-15 01:24:32 +0000 | [diff] [blame] | 171 | /* |
| 172 | * If we are changing protections for NUMA hinting faults then |
| 173 | * set pmd_numa if the examined pages were all on the same |
| 174 | * node. This allows a regular PMD to be handled as one fault |
| 175 | * and effectively batches the taking of the PTL |
| 176 | */ |
Mel Gorman | b795854 | 2013-10-07 11:29:07 +0100 | [diff] [blame] | 177 | if (prot_numa && all_same_nidpid) |
Mel Gorman | 4b10e7d | 2012-10-25 14:16:32 +0200 | [diff] [blame] | 178 | change_pmd_protnuma(vma->vm_mm, addr, pmd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 179 | } while (pmd++, addr = next, addr != end); |
Peter Zijlstra | 7da4d64 | 2012-11-19 03:14:23 +0100 | [diff] [blame] | 180 | |
| 181 | return pages; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 182 | } |
| 183 | |
Andrew Morton | 7d12efa | 2012-12-18 14:23:17 -0800 | [diff] [blame] | 184 | static inline unsigned long change_pud_range(struct vm_area_struct *vma, |
| 185 | pgd_t *pgd, unsigned long addr, unsigned long end, |
| 186 | pgprot_t newprot, int dirty_accountable, int prot_numa) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 187 | { |
| 188 | pud_t *pud; |
| 189 | unsigned long next; |
Peter Zijlstra | 7da4d64 | 2012-11-19 03:14:23 +0100 | [diff] [blame] | 190 | unsigned long pages = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 191 | |
| 192 | pud = pud_offset(pgd, addr); |
| 193 | do { |
| 194 | next = pud_addr_end(addr, end); |
| 195 | if (pud_none_or_clear_bad(pud)) |
| 196 | continue; |
Peter Zijlstra | 7da4d64 | 2012-11-19 03:14:23 +0100 | [diff] [blame] | 197 | pages += change_pmd_range(vma, pud, addr, next, newprot, |
Mel Gorman | 4b10e7d | 2012-10-25 14:16:32 +0200 | [diff] [blame] | 198 | dirty_accountable, prot_numa); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 199 | } while (pud++, addr = next, addr != end); |
Peter Zijlstra | 7da4d64 | 2012-11-19 03:14:23 +0100 | [diff] [blame] | 200 | |
| 201 | return pages; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 202 | } |
| 203 | |
Peter Zijlstra | 7da4d64 | 2012-11-19 03:14:23 +0100 | [diff] [blame] | 204 | static unsigned long change_protection_range(struct vm_area_struct *vma, |
Peter Zijlstra | c1e6098 | 2006-09-25 23:30:59 -0700 | [diff] [blame] | 205 | unsigned long addr, unsigned long end, pgprot_t newprot, |
Mel Gorman | 4b10e7d | 2012-10-25 14:16:32 +0200 | [diff] [blame] | 206 | int dirty_accountable, int prot_numa) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 207 | { |
| 208 | struct mm_struct *mm = vma->vm_mm; |
| 209 | pgd_t *pgd; |
| 210 | unsigned long next; |
| 211 | unsigned long start = addr; |
Peter Zijlstra | 7da4d64 | 2012-11-19 03:14:23 +0100 | [diff] [blame] | 212 | unsigned long pages = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 213 | |
| 214 | BUG_ON(addr >= end); |
| 215 | pgd = pgd_offset(mm, addr); |
| 216 | flush_cache_range(vma, addr, end); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 217 | do { |
| 218 | next = pgd_addr_end(addr, end); |
| 219 | if (pgd_none_or_clear_bad(pgd)) |
| 220 | continue; |
Peter Zijlstra | 7da4d64 | 2012-11-19 03:14:23 +0100 | [diff] [blame] | 221 | pages += change_pud_range(vma, pgd, addr, next, newprot, |
Mel Gorman | 4b10e7d | 2012-10-25 14:16:32 +0200 | [diff] [blame] | 222 | dirty_accountable, prot_numa); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 223 | } while (pgd++, addr = next, addr != end); |
Peter Zijlstra | 7da4d64 | 2012-11-19 03:14:23 +0100 | [diff] [blame] | 224 | |
Ingo Molnar | 1233d58 | 2012-11-19 03:14:24 +0100 | [diff] [blame] | 225 | /* Only flush the TLB if we actually modified any entries: */ |
| 226 | if (pages) |
| 227 | flush_tlb_range(vma, start, end); |
Peter Zijlstra | 7da4d64 | 2012-11-19 03:14:23 +0100 | [diff] [blame] | 228 | |
| 229 | return pages; |
| 230 | } |
| 231 | |
| 232 | unsigned long change_protection(struct vm_area_struct *vma, unsigned long start, |
| 233 | unsigned long end, pgprot_t newprot, |
Mel Gorman | 4b10e7d | 2012-10-25 14:16:32 +0200 | [diff] [blame] | 234 | int dirty_accountable, int prot_numa) |
Peter Zijlstra | 7da4d64 | 2012-11-19 03:14:23 +0100 | [diff] [blame] | 235 | { |
| 236 | struct mm_struct *mm = vma->vm_mm; |
| 237 | unsigned long pages; |
| 238 | |
| 239 | mmu_notifier_invalidate_range_start(mm, start, end); |
| 240 | if (is_vm_hugetlb_page(vma)) |
| 241 | pages = hugetlb_change_protection(vma, start, end, newprot); |
| 242 | else |
Mel Gorman | 4b10e7d | 2012-10-25 14:16:32 +0200 | [diff] [blame] | 243 | pages = change_protection_range(vma, start, end, newprot, dirty_accountable, prot_numa); |
Peter Zijlstra | 7da4d64 | 2012-11-19 03:14:23 +0100 | [diff] [blame] | 244 | mmu_notifier_invalidate_range_end(mm, start, end); |
| 245 | |
| 246 | return pages; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 247 | } |
| 248 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 249 | int |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 250 | mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev, |
| 251 | unsigned long start, unsigned long end, unsigned long newflags) |
| 252 | { |
| 253 | struct mm_struct *mm = vma->vm_mm; |
| 254 | unsigned long oldflags = vma->vm_flags; |
| 255 | long nrpages = (end - start) >> PAGE_SHIFT; |
| 256 | unsigned long charged = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 257 | pgoff_t pgoff; |
| 258 | int error; |
Peter Zijlstra | c1e6098 | 2006-09-25 23:30:59 -0700 | [diff] [blame] | 259 | int dirty_accountable = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 260 | |
| 261 | if (newflags == oldflags) { |
| 262 | *pprev = vma; |
| 263 | return 0; |
| 264 | } |
| 265 | |
| 266 | /* |
| 267 | * If we make a private mapping writable we increase our commit; |
| 268 | * but (without finer accounting) cannot reduce our commit if we |
Mel Gorman | 5a6fe12 | 2009-02-10 14:02:27 +0000 | [diff] [blame] | 269 | * make it unwritable again. hugetlb mapping were accounted for |
| 270 | * 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] | 271 | */ |
| 272 | if (newflags & VM_WRITE) { |
Mel Gorman | 5a6fe12 | 2009-02-10 14:02:27 +0000 | [diff] [blame] | 273 | if (!(oldflags & (VM_ACCOUNT|VM_WRITE|VM_HUGETLB| |
Andy Whitcroft | cdfd432 | 2008-07-23 21:27:28 -0700 | [diff] [blame] | 274 | VM_SHARED|VM_NORESERVE))) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 275 | charged = nrpages; |
Al Viro | 191c542 | 2012-02-13 03:58:52 +0000 | [diff] [blame] | 276 | if (security_vm_enough_memory_mm(mm, charged)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 277 | return -ENOMEM; |
| 278 | newflags |= VM_ACCOUNT; |
| 279 | } |
| 280 | } |
| 281 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 282 | /* |
| 283 | * First try to merge with previous and/or next vma. |
| 284 | */ |
| 285 | pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT); |
| 286 | *pprev = vma_merge(mm, *pprev, start, end, newflags, |
| 287 | vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma)); |
| 288 | if (*pprev) { |
| 289 | vma = *pprev; |
| 290 | goto success; |
| 291 | } |
| 292 | |
| 293 | *pprev = vma; |
| 294 | |
| 295 | if (start != vma->vm_start) { |
| 296 | error = split_vma(mm, vma, start, 1); |
| 297 | if (error) |
| 298 | goto fail; |
| 299 | } |
| 300 | |
| 301 | if (end != vma->vm_end) { |
| 302 | error = split_vma(mm, vma, end, 0); |
| 303 | if (error) |
| 304 | goto fail; |
| 305 | } |
| 306 | |
| 307 | success: |
| 308 | /* |
| 309 | * vm_flags and vm_page_prot are protected by the mmap_sem |
| 310 | * held in write mode. |
| 311 | */ |
| 312 | vma->vm_flags = newflags; |
Venki Pallipadi | 1c12c4c | 2008-05-14 16:05:51 -0700 | [diff] [blame] | 313 | vma->vm_page_prot = pgprot_modify(vma->vm_page_prot, |
| 314 | vm_get_page_prot(newflags)); |
| 315 | |
Peter Zijlstra | c1e6098 | 2006-09-25 23:30:59 -0700 | [diff] [blame] | 316 | if (vma_wants_writenotify(vma)) { |
Hugh Dickins | 1ddd439 | 2007-10-22 20:45:12 -0700 | [diff] [blame] | 317 | vma->vm_page_prot = vm_get_page_prot(newflags & ~VM_SHARED); |
Peter Zijlstra | c1e6098 | 2006-09-25 23:30:59 -0700 | [diff] [blame] | 318 | dirty_accountable = 1; |
| 319 | } |
Peter Zijlstra | d08b385 | 2006-09-25 23:30:57 -0700 | [diff] [blame] | 320 | |
Andrew Morton | 7d12efa | 2012-12-18 14:23:17 -0800 | [diff] [blame] | 321 | change_protection(vma, start, end, vma->vm_page_prot, |
| 322 | dirty_accountable, 0); |
Peter Zijlstra | 7da4d64 | 2012-11-19 03:14:23 +0100 | [diff] [blame] | 323 | |
Hugh Dickins | ab50b8e | 2005-10-29 18:15:56 -0700 | [diff] [blame] | 324 | vm_stat_account(mm, oldflags, vma->vm_file, -nrpages); |
| 325 | vm_stat_account(mm, newflags, vma->vm_file, nrpages); |
Pekka Enberg | 63bfd73 | 2010-11-08 21:29:07 +0200 | [diff] [blame] | 326 | perf_event_mmap(vma); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 327 | return 0; |
| 328 | |
| 329 | fail: |
| 330 | vm_unacct_memory(charged); |
| 331 | return error; |
| 332 | } |
| 333 | |
Heiko Carstens | 6a6160a | 2009-01-14 14:14:15 +0100 | [diff] [blame] | 334 | SYSCALL_DEFINE3(mprotect, unsigned long, start, size_t, len, |
| 335 | unsigned long, prot) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 336 | { |
| 337 | unsigned long vm_flags, nstart, end, tmp, reqprot; |
| 338 | struct vm_area_struct *vma, *prev; |
| 339 | int error = -EINVAL; |
| 340 | const int grows = prot & (PROT_GROWSDOWN|PROT_GROWSUP); |
| 341 | prot &= ~(PROT_GROWSDOWN|PROT_GROWSUP); |
| 342 | if (grows == (PROT_GROWSDOWN|PROT_GROWSUP)) /* can't be both */ |
| 343 | return -EINVAL; |
| 344 | |
| 345 | if (start & ~PAGE_MASK) |
| 346 | return -EINVAL; |
| 347 | if (!len) |
| 348 | return 0; |
| 349 | len = PAGE_ALIGN(len); |
| 350 | end = start + len; |
| 351 | if (end <= start) |
| 352 | return -ENOMEM; |
Dave Kleikamp | b845f31 | 2008-07-08 00:28:51 +1000 | [diff] [blame] | 353 | if (!arch_validate_prot(prot)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 354 | return -EINVAL; |
| 355 | |
| 356 | reqprot = prot; |
| 357 | /* |
| 358 | * Does the application expect PROT_READ to imply PROT_EXEC: |
| 359 | */ |
Hua Zhong | b344e05 | 2006-06-23 02:03:23 -0700 | [diff] [blame] | 360 | if ((prot & PROT_READ) && (current->personality & READ_IMPLIES_EXEC)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 361 | prot |= PROT_EXEC; |
| 362 | |
| 363 | vm_flags = calc_vm_prot_bits(prot); |
| 364 | |
| 365 | down_write(¤t->mm->mmap_sem); |
| 366 | |
Linus Torvalds | 097d591 | 2012-03-06 18:23:36 -0800 | [diff] [blame] | 367 | vma = find_vma(current->mm, start); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 368 | error = -ENOMEM; |
| 369 | if (!vma) |
| 370 | goto out; |
Linus Torvalds | 097d591 | 2012-03-06 18:23:36 -0800 | [diff] [blame] | 371 | prev = vma->vm_prev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 372 | if (unlikely(grows & PROT_GROWSDOWN)) { |
| 373 | if (vma->vm_start >= end) |
| 374 | goto out; |
| 375 | start = vma->vm_start; |
| 376 | error = -EINVAL; |
| 377 | if (!(vma->vm_flags & VM_GROWSDOWN)) |
| 378 | goto out; |
Andrew Morton | 7d12efa | 2012-12-18 14:23:17 -0800 | [diff] [blame] | 379 | } else { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 380 | if (vma->vm_start > start) |
| 381 | goto out; |
| 382 | if (unlikely(grows & PROT_GROWSUP)) { |
| 383 | end = vma->vm_end; |
| 384 | error = -EINVAL; |
| 385 | if (!(vma->vm_flags & VM_GROWSUP)) |
| 386 | goto out; |
| 387 | } |
| 388 | } |
| 389 | if (start > vma->vm_start) |
| 390 | prev = vma; |
| 391 | |
| 392 | for (nstart = start ; ; ) { |
| 393 | unsigned long newflags; |
| 394 | |
Andrew Morton | 7d12efa | 2012-12-18 14:23:17 -0800 | [diff] [blame] | 395 | /* Here we know that vma->vm_start <= nstart < vma->vm_end. */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 396 | |
Andrew Morton | 7d12efa | 2012-12-18 14:23:17 -0800 | [diff] [blame] | 397 | newflags = vm_flags; |
| 398 | newflags |= (vma->vm_flags & ~(VM_READ | VM_WRITE | VM_EXEC)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 399 | |
Paolo 'Blaisorblade' Giarrusso | 7e2cff4 | 2005-09-21 09:55:39 -0700 | [diff] [blame] | 400 | /* newflags >> 4 shift VM_MAY% in place of VM_% */ |
| 401 | if ((newflags & ~(newflags >> 4)) & (VM_READ | VM_WRITE | VM_EXEC)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 402 | error = -EACCES; |
| 403 | goto out; |
| 404 | } |
| 405 | |
| 406 | error = security_file_mprotect(vma, reqprot, prot); |
| 407 | if (error) |
| 408 | goto out; |
| 409 | |
| 410 | tmp = vma->vm_end; |
| 411 | if (tmp > end) |
| 412 | tmp = end; |
| 413 | error = mprotect_fixup(vma, &prev, nstart, tmp, newflags); |
| 414 | if (error) |
| 415 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 416 | nstart = tmp; |
| 417 | |
| 418 | if (nstart < prev->vm_end) |
| 419 | nstart = prev->vm_end; |
| 420 | if (nstart >= end) |
| 421 | goto out; |
| 422 | |
| 423 | vma = prev->vm_next; |
| 424 | if (!vma || vma->vm_start != nstart) { |
| 425 | error = -ENOMEM; |
| 426 | goto out; |
| 427 | } |
| 428 | } |
| 429 | out: |
| 430 | up_write(¤t->mm->mmap_sem); |
| 431 | return error; |
| 432 | } |