blob: ef5be8eaab001792b469fac1bd5b43cb139d1b0b [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * mm/mprotect.c
3 *
4 * (C) Copyright 1994 Linus Torvalds
5 * (C) Copyright 2002 Christoph Hellwig
6 *
Alan Cox046c6882009-01-05 14:06:29 +00007 * Address space accounting code <alan@lxorguk.ukuu.org.uk>
Linus Torvalds1da177e2005-04-16 15:20:36 -07008 * (C) Copyright 2002 Red Hat Inc, All Rights Reserved
9 */
10
11#include <linux/mm.h>
12#include <linux/hugetlb.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070013#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 Lameter06972122006-06-23 02:03:35 -070021#include <linux/swap.h>
22#include <linux/swapops.h>
Andrea Arcangelicddb8a52008-07-28 15:46:29 -070023#include <linux/mmu_notifier.h>
KOSAKI Motohiro64cdd542009-01-06 14:39:16 -080024#include <linux/migrate.h>
Ingo Molnarcdd6c482009-09-21 12:02:48 +020025#include <linux/perf_event.h>
Mel Gorman64a9a342014-01-21 15:51:02 -080026#include <linux/ksm.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070027#include <asm/uaccess.h>
28#include <asm/pgtable.h>
29#include <asm/cacheflush.h>
30#include <asm/tlbflush.h>
31
Kirill A. Shutemov36f88182015-06-24 16:56:10 -070032#include "internal.h"
33
Mel Gorman1ad9f622014-04-07 15:36:56 -070034/*
35 * For a prot_numa update we only hold mmap_sem for read so there is a
36 * potential race with faulting where a pmd was temporarily none. This
37 * function checks for a transhuge pmd under the appropriate lock. It
38 * returns a pte if it was successfully locked or NULL if it raced with
39 * a transhuge insertion.
40 */
41static pte_t *lock_pte_protection(struct vm_area_struct *vma, pmd_t *pmd,
42 unsigned long addr, int prot_numa, spinlock_t **ptl)
43{
44 pte_t *pte;
45 spinlock_t *pmdl;
46
47 /* !prot_numa is protected by mmap_sem held for write */
48 if (!prot_numa)
49 return pte_offset_map_lock(vma->vm_mm, pmd, addr, ptl);
50
51 pmdl = pmd_lock(vma->vm_mm, pmd);
52 if (unlikely(pmd_trans_huge(*pmd) || pmd_none(*pmd))) {
53 spin_unlock(pmdl);
54 return NULL;
55 }
56
57 pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, ptl);
58 spin_unlock(pmdl);
59 return pte;
60}
61
Mel Gorman4b10e7d2012-10-25 14:16:32 +020062static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
Peter Zijlstrac1e60982006-09-25 23:30:59 -070063 unsigned long addr, unsigned long end, pgprot_t newprot,
Mel Gorman0f19c172013-10-07 11:29:25 +010064 int dirty_accountable, int prot_numa)
Linus Torvalds1da177e2005-04-16 15:20:36 -070065{
Mel Gorman4b10e7d2012-10-25 14:16:32 +020066 struct mm_struct *mm = vma->vm_mm;
Christoph Lameter06972122006-06-23 02:03:35 -070067 pte_t *pte, oldpte;
Hugh Dickins705e87c2005-10-29 18:16:27 -070068 spinlock_t *ptl;
Peter Zijlstra7da4d642012-11-19 03:14:23 +010069 unsigned long pages = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -070070
Mel Gorman1ad9f622014-04-07 15:36:56 -070071 pte = lock_pte_protection(vma, pmd, addr, prot_numa, &ptl);
72 if (!pte)
73 return 0;
74
Zachary Amsden6606c3e2006-09-30 23:29:33 -070075 arch_enter_lazy_mmu_mode();
Linus Torvalds1da177e2005-04-16 15:20:36 -070076 do {
Christoph Lameter06972122006-06-23 02:03:35 -070077 oldpte = *pte;
78 if (pte_present(oldpte)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070079 pte_t ptent;
Mel Gormanb191f9b2015-03-25 15:55:40 -070080 bool preserve_write = prot_numa && pte_write(oldpte);
Linus Torvalds1da177e2005-04-16 15:20:36 -070081
Mel Gormane944fd62015-02-12 14:58:35 -080082 /*
83 * Avoid trapping faults against the zero or KSM
84 * pages. See similar comment in change_huge_pmd.
85 */
86 if (prot_numa) {
87 struct page *page;
88
89 page = vm_normal_page(vma, addr, oldpte);
90 if (!page || PageKsm(page))
91 continue;
Mel Gorman10c10452015-02-12 14:58:44 -080092
93 /* Avoid TLB flush if possible */
94 if (pte_protnone(oldpte))
95 continue;
Mel Gormane944fd62015-02-12 14:58:35 -080096 }
97
Mel Gorman8a0516e2015-02-12 14:58:22 -080098 ptent = ptep_modify_prot_start(mm, addr, pte);
99 ptent = pte_modify(ptent, newprot);
Mel Gormanb191f9b2015-03-25 15:55:40 -0700100 if (preserve_write)
101 ptent = pte_mkwrite(ptent);
Mel Gorman4b10e7d2012-10-25 14:16:32 +0200102
Mel Gorman8a0516e2015-02-12 14:58:22 -0800103 /* Avoid taking write faults for known dirty pages */
104 if (dirty_accountable && pte_dirty(ptent) &&
105 (pte_soft_dirty(ptent) ||
106 !(vma->vm_flags & VM_SOFTDIRTY))) {
107 ptent = pte_mkwrite(ptent);
Mel Gorman4b10e7d2012-10-25 14:16:32 +0200108 }
Mel Gorman8a0516e2015-02-12 14:58:22 -0800109 ptep_modify_prot_commit(mm, addr, pte, ptent);
110 pages++;
Kirill A. Shutemov0661a332015-02-10 14:10:04 -0800111 } else if (IS_ENABLED(CONFIG_MIGRATION)) {
Christoph Lameter06972122006-06-23 02:03:35 -0700112 swp_entry_t entry = pte_to_swp_entry(oldpte);
113
114 if (is_write_migration_entry(entry)) {
Cyrill Gorcunovc3d16e12013-10-16 13:46:51 -0700115 pte_t newpte;
Christoph Lameter06972122006-06-23 02:03:35 -0700116 /*
117 * A protection check is difficult so
118 * just be safe and disable write
119 */
120 make_migration_entry_read(&entry);
Cyrill Gorcunovc3d16e12013-10-16 13:46:51 -0700121 newpte = swp_entry_to_pte(entry);
122 if (pte_swp_soft_dirty(oldpte))
123 newpte = pte_swp_mksoft_dirty(newpte);
124 set_pte_at(mm, addr, pte, newpte);
Mel Gormane920e142013-10-07 11:28:48 +0100125
126 pages++;
Christoph Lameter06972122006-06-23 02:03:35 -0700127 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 }
129 } while (pte++, addr += PAGE_SIZE, addr != end);
Zachary Amsden6606c3e2006-09-30 23:29:33 -0700130 arch_leave_lazy_mmu_mode();
Hugh Dickins705e87c2005-10-29 18:16:27 -0700131 pte_unmap_unlock(pte - 1, ptl);
Peter Zijlstra7da4d642012-11-19 03:14:23 +0100132
133 return pages;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134}
135
Andrew Morton7d12efa2012-12-18 14:23:17 -0800136static inline unsigned long change_pmd_range(struct vm_area_struct *vma,
137 pud_t *pud, unsigned long addr, unsigned long end,
138 pgprot_t newprot, int dirty_accountable, int prot_numa)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139{
140 pmd_t *pmd;
Rik van Riela5338092014-04-07 15:36:57 -0700141 struct mm_struct *mm = vma->vm_mm;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142 unsigned long next;
Peter Zijlstra7da4d642012-11-19 03:14:23 +0100143 unsigned long pages = 0;
Mel Gorman72403b42013-11-12 15:08:32 -0800144 unsigned long nr_huge_updates = 0;
Rik van Riela5338092014-04-07 15:36:57 -0700145 unsigned long mni_start = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146
147 pmd = pmd_offset(pud, addr);
148 do {
Mel Gorman25cbbef2013-10-07 11:29:14 +0100149 unsigned long this_pages;
150
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151 next = pmd_addr_end(addr, end);
Rik van Riel88a9ab62014-04-07 15:36:55 -0700152 if (!pmd_trans_huge(*pmd) && pmd_none_or_clear_bad(pmd))
153 continue;
Rik van Riela5338092014-04-07 15:36:57 -0700154
155 /* invoke the mmu notifier if the pmd is populated */
156 if (!mni_start) {
157 mni_start = addr;
158 mmu_notifier_invalidate_range_start(mm, mni_start, end);
159 }
160
Johannes Weinercd7548a2011-01-13 15:47:04 -0800161 if (pmd_trans_huge(*pmd)) {
162 if (next - addr != HPAGE_PMD_SIZE)
Kirill A. Shutemove1803772012-12-12 13:50:59 -0800163 split_huge_page_pmd(vma, addr, pmd);
Mel Gormanf123d742013-10-07 11:28:49 +0100164 else {
165 int nr_ptes = change_huge_pmd(vma, pmd, addr,
Mel Gormane944fd62015-02-12 14:58:35 -0800166 newprot, prot_numa);
Mel Gormanf123d742013-10-07 11:28:49 +0100167
168 if (nr_ptes) {
Mel Gorman72403b42013-11-12 15:08:32 -0800169 if (nr_ptes == HPAGE_PMD_NR) {
170 pages += HPAGE_PMD_NR;
171 nr_huge_updates++;
172 }
Mel Gorman1ad9f622014-04-07 15:36:56 -0700173
174 /* huge pmd was handled */
Mel Gormanf123d742013-10-07 11:28:49 +0100175 continue;
176 }
Peter Zijlstra7da4d642012-11-19 03:14:23 +0100177 }
Rik van Riel88a9ab62014-04-07 15:36:55 -0700178 /* fall through, the trans huge pmd just split */
Johannes Weinercd7548a2011-01-13 15:47:04 -0800179 }
Mel Gorman25cbbef2013-10-07 11:29:14 +0100180 this_pages = change_pte_range(vma, pmd, addr, next, newprot,
Mel Gorman0f19c172013-10-07 11:29:25 +0100181 dirty_accountable, prot_numa);
Mel Gorman25cbbef2013-10-07 11:29:14 +0100182 pages += this_pages;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183 } while (pmd++, addr = next, addr != end);
Peter Zijlstra7da4d642012-11-19 03:14:23 +0100184
Rik van Riela5338092014-04-07 15:36:57 -0700185 if (mni_start)
186 mmu_notifier_invalidate_range_end(mm, mni_start, end);
187
Mel Gorman72403b42013-11-12 15:08:32 -0800188 if (nr_huge_updates)
189 count_vm_numa_events(NUMA_HUGE_PTE_UPDATES, nr_huge_updates);
Peter Zijlstra7da4d642012-11-19 03:14:23 +0100190 return pages;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191}
192
Andrew Morton7d12efa2012-12-18 14:23:17 -0800193static inline unsigned long change_pud_range(struct vm_area_struct *vma,
194 pgd_t *pgd, unsigned long addr, unsigned long end,
195 pgprot_t newprot, int dirty_accountable, int prot_numa)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196{
197 pud_t *pud;
198 unsigned long next;
Peter Zijlstra7da4d642012-11-19 03:14:23 +0100199 unsigned long pages = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200
201 pud = pud_offset(pgd, addr);
202 do {
203 next = pud_addr_end(addr, end);
204 if (pud_none_or_clear_bad(pud))
205 continue;
Peter Zijlstra7da4d642012-11-19 03:14:23 +0100206 pages += change_pmd_range(vma, pud, addr, next, newprot,
Mel Gorman4b10e7d2012-10-25 14:16:32 +0200207 dirty_accountable, prot_numa);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208 } while (pud++, addr = next, addr != end);
Peter Zijlstra7da4d642012-11-19 03:14:23 +0100209
210 return pages;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211}
212
Peter Zijlstra7da4d642012-11-19 03:14:23 +0100213static unsigned long change_protection_range(struct vm_area_struct *vma,
Peter Zijlstrac1e60982006-09-25 23:30:59 -0700214 unsigned long addr, unsigned long end, pgprot_t newprot,
Mel Gorman4b10e7d2012-10-25 14:16:32 +0200215 int dirty_accountable, int prot_numa)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216{
217 struct mm_struct *mm = vma->vm_mm;
218 pgd_t *pgd;
219 unsigned long next;
220 unsigned long start = addr;
Peter Zijlstra7da4d642012-11-19 03:14:23 +0100221 unsigned long pages = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222
223 BUG_ON(addr >= end);
224 pgd = pgd_offset(mm, addr);
225 flush_cache_range(vma, addr, end);
Rik van Riel20841402013-12-18 17:08:44 -0800226 set_tlb_flush_pending(mm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227 do {
228 next = pgd_addr_end(addr, end);
229 if (pgd_none_or_clear_bad(pgd))
230 continue;
Peter Zijlstra7da4d642012-11-19 03:14:23 +0100231 pages += change_pud_range(vma, pgd, addr, next, newprot,
Mel Gorman4b10e7d2012-10-25 14:16:32 +0200232 dirty_accountable, prot_numa);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233 } while (pgd++, addr = next, addr != end);
Peter Zijlstra7da4d642012-11-19 03:14:23 +0100234
Ingo Molnar1233d582012-11-19 03:14:24 +0100235 /* Only flush the TLB if we actually modified any entries: */
236 if (pages)
237 flush_tlb_range(vma, start, end);
Rik van Riel20841402013-12-18 17:08:44 -0800238 clear_tlb_flush_pending(mm);
Peter Zijlstra7da4d642012-11-19 03:14:23 +0100239
240 return pages;
241}
242
243unsigned long change_protection(struct vm_area_struct *vma, unsigned long start,
244 unsigned long end, pgprot_t newprot,
Mel Gorman4b10e7d2012-10-25 14:16:32 +0200245 int dirty_accountable, int prot_numa)
Peter Zijlstra7da4d642012-11-19 03:14:23 +0100246{
Peter Zijlstra7da4d642012-11-19 03:14:23 +0100247 unsigned long pages;
248
Peter Zijlstra7da4d642012-11-19 03:14:23 +0100249 if (is_vm_hugetlb_page(vma))
250 pages = hugetlb_change_protection(vma, start, end, newprot);
251 else
Mel Gorman4b10e7d2012-10-25 14:16:32 +0200252 pages = change_protection_range(vma, start, end, newprot, dirty_accountable, prot_numa);
Peter Zijlstra7da4d642012-11-19 03:14:23 +0100253
254 return pages;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255}
256
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700257int
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev,
259 unsigned long start, unsigned long end, unsigned long newflags)
260{
261 struct mm_struct *mm = vma->vm_mm;
262 unsigned long oldflags = vma->vm_flags;
263 long nrpages = (end - start) >> PAGE_SHIFT;
264 unsigned long charged = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265 pgoff_t pgoff;
266 int error;
Peter Zijlstrac1e60982006-09-25 23:30:59 -0700267 int dirty_accountable = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268
269 if (newflags == oldflags) {
270 *pprev = vma;
271 return 0;
272 }
273
274 /*
275 * If we make a private mapping writable we increase our commit;
276 * but (without finer accounting) cannot reduce our commit if we
Mel Gorman5a6fe122009-02-10 14:02:27 +0000277 * make it unwritable again. hugetlb mapping were accounted for
278 * even if read-only so there is no need to account for them here
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279 */
280 if (newflags & VM_WRITE) {
Mel Gorman5a6fe122009-02-10 14:02:27 +0000281 if (!(oldflags & (VM_ACCOUNT|VM_WRITE|VM_HUGETLB|
Andy Whitcroftcdfd4322008-07-23 21:27:28 -0700282 VM_SHARED|VM_NORESERVE))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283 charged = nrpages;
Al Viro191c5422012-02-13 03:58:52 +0000284 if (security_vm_enough_memory_mm(mm, charged))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285 return -ENOMEM;
286 newflags |= VM_ACCOUNT;
287 }
288 }
289
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290 /*
291 * First try to merge with previous and/or next vma.
292 */
293 pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
294 *pprev = vma_merge(mm, *pprev, start, end, newflags,
Andrea Arcangeli19a809a2015-09-04 15:46:24 -0700295 vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma),
296 vma->vm_userfaultfd_ctx);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297 if (*pprev) {
298 vma = *pprev;
299 goto success;
300 }
301
302 *pprev = vma;
303
304 if (start != vma->vm_start) {
305 error = split_vma(mm, vma, start, 1);
306 if (error)
307 goto fail;
308 }
309
310 if (end != vma->vm_end) {
311 error = split_vma(mm, vma, end, 0);
312 if (error)
313 goto fail;
314 }
315
316success:
317 /*
318 * vm_flags and vm_page_prot are protected by the mmap_sem
319 * held in write mode.
320 */
321 vma->vm_flags = newflags;
Peter Feiner64e45502014-10-13 15:55:46 -0700322 dirty_accountable = vma_wants_writenotify(vma);
323 vma_set_page_prot(vma);
Peter Zijlstrad08b3852006-09-25 23:30:57 -0700324
Andrew Morton7d12efa2012-12-18 14:23:17 -0800325 change_protection(vma, start, end, vma->vm_page_prot,
326 dirty_accountable, 0);
Peter Zijlstra7da4d642012-11-19 03:14:23 +0100327
Kirill A. Shutemov36f88182015-06-24 16:56:10 -0700328 /*
329 * Private VM_LOCKED VMA becoming writable: trigger COW to avoid major
330 * fault on access.
331 */
332 if ((oldflags & (VM_WRITE | VM_SHARED | VM_LOCKED)) == VM_LOCKED &&
333 (newflags & VM_WRITE)) {
334 populate_vma_page_range(vma, start, end, NULL);
335 }
336
Hugh Dickinsab50b8e2005-10-29 18:15:56 -0700337 vm_stat_account(mm, oldflags, vma->vm_file, -nrpages);
338 vm_stat_account(mm, newflags, vma->vm_file, nrpages);
Pekka Enberg63bfd732010-11-08 21:29:07 +0200339 perf_event_mmap(vma);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340 return 0;
341
342fail:
343 vm_unacct_memory(charged);
344 return error;
345}
346
Heiko Carstens6a6160a2009-01-14 14:14:15 +0100347SYSCALL_DEFINE3(mprotect, unsigned long, start, size_t, len,
348 unsigned long, prot)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349{
350 unsigned long vm_flags, nstart, end, tmp, reqprot;
351 struct vm_area_struct *vma, *prev;
352 int error = -EINVAL;
353 const int grows = prot & (PROT_GROWSDOWN|PROT_GROWSUP);
354 prot &= ~(PROT_GROWSDOWN|PROT_GROWSUP);
355 if (grows == (PROT_GROWSDOWN|PROT_GROWSUP)) /* can't be both */
356 return -EINVAL;
357
358 if (start & ~PAGE_MASK)
359 return -EINVAL;
360 if (!len)
361 return 0;
362 len = PAGE_ALIGN(len);
363 end = start + len;
364 if (end <= start)
365 return -ENOMEM;
Dave Kleikampb845f312008-07-08 00:28:51 +1000366 if (!arch_validate_prot(prot))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367 return -EINVAL;
368
369 reqprot = prot;
370 /*
371 * Does the application expect PROT_READ to imply PROT_EXEC:
372 */
Hua Zhongb344e052006-06-23 02:03:23 -0700373 if ((prot & PROT_READ) && (current->personality & READ_IMPLIES_EXEC))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374 prot |= PROT_EXEC;
375
376 vm_flags = calc_vm_prot_bits(prot);
377
378 down_write(&current->mm->mmap_sem);
379
Linus Torvalds097d5912012-03-06 18:23:36 -0800380 vma = find_vma(current->mm, start);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381 error = -ENOMEM;
382 if (!vma)
383 goto out;
Linus Torvalds097d5912012-03-06 18:23:36 -0800384 prev = vma->vm_prev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385 if (unlikely(grows & PROT_GROWSDOWN)) {
386 if (vma->vm_start >= end)
387 goto out;
388 start = vma->vm_start;
389 error = -EINVAL;
390 if (!(vma->vm_flags & VM_GROWSDOWN))
391 goto out;
Andrew Morton7d12efa2012-12-18 14:23:17 -0800392 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393 if (vma->vm_start > start)
394 goto out;
395 if (unlikely(grows & PROT_GROWSUP)) {
396 end = vma->vm_end;
397 error = -EINVAL;
398 if (!(vma->vm_flags & VM_GROWSUP))
399 goto out;
400 }
401 }
402 if (start > vma->vm_start)
403 prev = vma;
404
405 for (nstart = start ; ; ) {
406 unsigned long newflags;
407
Andrew Morton7d12efa2012-12-18 14:23:17 -0800408 /* Here we know that vma->vm_start <= nstart < vma->vm_end. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409
Andrew Morton7d12efa2012-12-18 14:23:17 -0800410 newflags = vm_flags;
411 newflags |= (vma->vm_flags & ~(VM_READ | VM_WRITE | VM_EXEC));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412
Paolo 'Blaisorblade' Giarrusso7e2cff42005-09-21 09:55:39 -0700413 /* newflags >> 4 shift VM_MAY% in place of VM_% */
414 if ((newflags & ~(newflags >> 4)) & (VM_READ | VM_WRITE | VM_EXEC)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415 error = -EACCES;
416 goto out;
417 }
418
419 error = security_file_mprotect(vma, reqprot, prot);
420 if (error)
421 goto out;
422
423 tmp = vma->vm_end;
424 if (tmp > end)
425 tmp = end;
426 error = mprotect_fixup(vma, &prev, nstart, tmp, newflags);
427 if (error)
428 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429 nstart = tmp;
430
431 if (nstart < prev->vm_end)
432 nstart = prev->vm_end;
433 if (nstart >= end)
434 goto out;
435
436 vma = prev->vm_next;
437 if (!vma || vma->vm_start != nstart) {
438 error = -ENOMEM;
439 goto out;
440 }
441 }
442out:
443 up_write(&current->mm->mmap_sem);
444 return error;
445}