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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
2 | /* |
3 | * mm/mprotect.c | |
4 | * | |
5 | * (C) Copyright 1994 Linus Torvalds | |
6 | * (C) Copyright 2002 Christoph Hellwig | |
7 | * | |
046c6884 | 8 | * Address space accounting code <alan@lxorguk.ukuu.org.uk> |
1da177e4 LT |
9 | * (C) Copyright 2002 Red Hat Inc, All Rights Reserved |
10 | */ | |
11 | ||
12 | #include <linux/mm.h> | |
13 | #include <linux/hugetlb.h> | |
1da177e4 LT |
14 | #include <linux/shm.h> |
15 | #include <linux/mman.h> | |
16 | #include <linux/fs.h> | |
17 | #include <linux/highmem.h> | |
18 | #include <linux/security.h> | |
19 | #include <linux/mempolicy.h> | |
20 | #include <linux/personality.h> | |
21 | #include <linux/syscalls.h> | |
0697212a CL |
22 | #include <linux/swap.h> |
23 | #include <linux/swapops.h> | |
cddb8a5c | 24 | #include <linux/mmu_notifier.h> |
64cdd548 | 25 | #include <linux/migrate.h> |
cdd6c482 | 26 | #include <linux/perf_event.h> |
e8c24d3a | 27 | #include <linux/pkeys.h> |
64a9a34e | 28 | #include <linux/ksm.h> |
7c0f6ba6 | 29 | #include <linux/uaccess.h> |
1da177e4 LT |
30 | #include <asm/pgtable.h> |
31 | #include <asm/cacheflush.h> | |
e8c24d3a | 32 | #include <asm/mmu_context.h> |
1da177e4 LT |
33 | #include <asm/tlbflush.h> |
34 | ||
36f88188 KS |
35 | #include "internal.h" |
36 | ||
4b10e7d5 | 37 | static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd, |
c1e6098b | 38 | unsigned long addr, unsigned long end, pgprot_t newprot, |
0f19c179 | 39 | int dirty_accountable, int prot_numa) |
1da177e4 | 40 | { |
4b10e7d5 | 41 | struct mm_struct *mm = vma->vm_mm; |
0697212a | 42 | pte_t *pte, oldpte; |
705e87c0 | 43 | spinlock_t *ptl; |
7da4d641 | 44 | unsigned long pages = 0; |
3e321587 | 45 | int target_node = NUMA_NO_NODE; |
1da177e4 | 46 | |
175ad4f1 AA |
47 | /* |
48 | * Can be called with only the mmap_sem for reading by | |
49 | * prot_numa so we must check the pmd isn't constantly | |
50 | * changing from under us from pmd_none to pmd_trans_huge | |
51 | * and/or the other way around. | |
52 | */ | |
53 | if (pmd_trans_unstable(pmd)) | |
54 | return 0; | |
55 | ||
56 | /* | |
57 | * The pmd points to a regular pte so the pmd can't change | |
58 | * from under us even if the mmap_sem is only hold for | |
59 | * reading. | |
60 | */ | |
61 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); | |
1ad9f620 | 62 | |
3e321587 AK |
63 | /* Get target node for single threaded private VMAs */ |
64 | if (prot_numa && !(vma->vm_flags & VM_SHARED) && | |
65 | atomic_read(&vma->vm_mm->mm_users) == 1) | |
66 | target_node = numa_node_id(); | |
67 | ||
3ea27719 | 68 | flush_tlb_batched_pending(vma->vm_mm); |
6606c3e0 | 69 | arch_enter_lazy_mmu_mode(); |
1da177e4 | 70 | do { |
0697212a CL |
71 | oldpte = *pte; |
72 | if (pte_present(oldpte)) { | |
1da177e4 | 73 | pte_t ptent; |
b191f9b1 | 74 | bool preserve_write = prot_numa && pte_write(oldpte); |
1da177e4 | 75 | |
e944fd67 MG |
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; | |
10c1045f | 86 | |
859d4adc HW |
87 | /* Also skip shared copy-on-write pages */ |
88 | if (is_cow_mapping(vma->vm_flags) && | |
89 | page_mapcount(page) != 1) | |
90 | continue; | |
91 | ||
10c1045f MG |
92 | /* Avoid TLB flush if possible */ |
93 | if (pte_protnone(oldpte)) | |
94 | continue; | |
3e321587 AK |
95 | |
96 | /* | |
97 | * Don't mess with PTEs if page is already on the node | |
98 | * a single-threaded process is running on. | |
99 | */ | |
100 | if (target_node == page_to_nid(page)) | |
101 | continue; | |
e944fd67 MG |
102 | } |
103 | ||
8a0516ed MG |
104 | ptent = ptep_modify_prot_start(mm, addr, pte); |
105 | ptent = pte_modify(ptent, newprot); | |
b191f9b1 | 106 | if (preserve_write) |
288bc549 | 107 | ptent = pte_mk_savedwrite(ptent); |
4b10e7d5 | 108 | |
8a0516ed MG |
109 | /* Avoid taking write faults for known dirty pages */ |
110 | if (dirty_accountable && pte_dirty(ptent) && | |
111 | (pte_soft_dirty(ptent) || | |
112 | !(vma->vm_flags & VM_SOFTDIRTY))) { | |
113 | ptent = pte_mkwrite(ptent); | |
4b10e7d5 | 114 | } |
8a0516ed MG |
115 | ptep_modify_prot_commit(mm, addr, pte, ptent); |
116 | pages++; | |
0661a336 | 117 | } else if (IS_ENABLED(CONFIG_MIGRATION)) { |
0697212a CL |
118 | swp_entry_t entry = pte_to_swp_entry(oldpte); |
119 | ||
120 | if (is_write_migration_entry(entry)) { | |
c3d16e16 | 121 | pte_t newpte; |
0697212a CL |
122 | /* |
123 | * A protection check is difficult so | |
124 | * just be safe and disable write | |
125 | */ | |
126 | make_migration_entry_read(&entry); | |
c3d16e16 CG |
127 | newpte = swp_entry_to_pte(entry); |
128 | if (pte_swp_soft_dirty(oldpte)) | |
129 | newpte = pte_swp_mksoft_dirty(newpte); | |
130 | set_pte_at(mm, addr, pte, newpte); | |
e920e14c MG |
131 | |
132 | pages++; | |
0697212a | 133 | } |
5042db43 JG |
134 | |
135 | if (is_write_device_private_entry(entry)) { | |
136 | pte_t newpte; | |
137 | ||
138 | /* | |
139 | * We do not preserve soft-dirtiness. See | |
140 | * copy_one_pte() for explanation. | |
141 | */ | |
142 | make_device_private_entry_read(&entry); | |
143 | newpte = swp_entry_to_pte(entry); | |
144 | set_pte_at(mm, addr, pte, newpte); | |
145 | ||
146 | pages++; | |
147 | } | |
1da177e4 LT |
148 | } |
149 | } while (pte++, addr += PAGE_SIZE, addr != end); | |
6606c3e0 | 150 | arch_leave_lazy_mmu_mode(); |
705e87c0 | 151 | pte_unmap_unlock(pte - 1, ptl); |
7da4d641 PZ |
152 | |
153 | return pages; | |
1da177e4 LT |
154 | } |
155 | ||
7d12efae AM |
156 | static inline unsigned long change_pmd_range(struct vm_area_struct *vma, |
157 | pud_t *pud, unsigned long addr, unsigned long end, | |
158 | pgprot_t newprot, int dirty_accountable, int prot_numa) | |
1da177e4 LT |
159 | { |
160 | pmd_t *pmd; | |
a5338093 | 161 | struct mm_struct *mm = vma->vm_mm; |
1da177e4 | 162 | unsigned long next; |
7da4d641 | 163 | unsigned long pages = 0; |
72403b4a | 164 | unsigned long nr_huge_updates = 0; |
a5338093 | 165 | unsigned long mni_start = 0; |
1da177e4 LT |
166 | |
167 | pmd = pmd_offset(pud, addr); | |
168 | do { | |
25cbbef1 MG |
169 | unsigned long this_pages; |
170 | ||
1da177e4 | 171 | next = pmd_addr_end(addr, end); |
84c3fc4e | 172 | if (!is_swap_pmd(*pmd) && !pmd_trans_huge(*pmd) && !pmd_devmap(*pmd) |
5c7fb56e | 173 | && pmd_none_or_clear_bad(pmd)) |
4991c09c | 174 | goto next; |
a5338093 RR |
175 | |
176 | /* invoke the mmu notifier if the pmd is populated */ | |
177 | if (!mni_start) { | |
178 | mni_start = addr; | |
179 | mmu_notifier_invalidate_range_start(mm, mni_start, end); | |
180 | } | |
181 | ||
84c3fc4e | 182 | if (is_swap_pmd(*pmd) || pmd_trans_huge(*pmd) || pmd_devmap(*pmd)) { |
6b9116a6 | 183 | if (next - addr != HPAGE_PMD_SIZE) { |
fd60775a | 184 | __split_huge_pmd(vma, pmd, addr, false, NULL); |
6b9116a6 | 185 | } else { |
f123d74a | 186 | int nr_ptes = change_huge_pmd(vma, pmd, addr, |
e944fd67 | 187 | newprot, prot_numa); |
f123d74a MG |
188 | |
189 | if (nr_ptes) { | |
72403b4a MG |
190 | if (nr_ptes == HPAGE_PMD_NR) { |
191 | pages += HPAGE_PMD_NR; | |
192 | nr_huge_updates++; | |
193 | } | |
1ad9f620 MG |
194 | |
195 | /* huge pmd was handled */ | |
4991c09c | 196 | goto next; |
f123d74a | 197 | } |
7da4d641 | 198 | } |
88a9ab6e | 199 | /* fall through, the trans huge pmd just split */ |
cd7548ab | 200 | } |
25cbbef1 | 201 | this_pages = change_pte_range(vma, pmd, addr, next, newprot, |
0f19c179 | 202 | dirty_accountable, prot_numa); |
25cbbef1 | 203 | pages += this_pages; |
4991c09c AK |
204 | next: |
205 | cond_resched(); | |
1da177e4 | 206 | } while (pmd++, addr = next, addr != end); |
7da4d641 | 207 | |
a5338093 RR |
208 | if (mni_start) |
209 | mmu_notifier_invalidate_range_end(mm, mni_start, end); | |
210 | ||
72403b4a MG |
211 | if (nr_huge_updates) |
212 | count_vm_numa_events(NUMA_HUGE_PTE_UPDATES, nr_huge_updates); | |
7da4d641 | 213 | return pages; |
1da177e4 LT |
214 | } |
215 | ||
7d12efae | 216 | static inline unsigned long change_pud_range(struct vm_area_struct *vma, |
c2febafc | 217 | p4d_t *p4d, unsigned long addr, unsigned long end, |
7d12efae | 218 | pgprot_t newprot, int dirty_accountable, int prot_numa) |
1da177e4 LT |
219 | { |
220 | pud_t *pud; | |
221 | unsigned long next; | |
7da4d641 | 222 | unsigned long pages = 0; |
1da177e4 | 223 | |
c2febafc | 224 | pud = pud_offset(p4d, addr); |
1da177e4 LT |
225 | do { |
226 | next = pud_addr_end(addr, end); | |
227 | if (pud_none_or_clear_bad(pud)) | |
228 | continue; | |
7da4d641 | 229 | pages += change_pmd_range(vma, pud, addr, next, newprot, |
4b10e7d5 | 230 | dirty_accountable, prot_numa); |
1da177e4 | 231 | } while (pud++, addr = next, addr != end); |
7da4d641 PZ |
232 | |
233 | return pages; | |
1da177e4 LT |
234 | } |
235 | ||
c2febafc KS |
236 | static inline unsigned long change_p4d_range(struct vm_area_struct *vma, |
237 | pgd_t *pgd, unsigned long addr, unsigned long end, | |
238 | pgprot_t newprot, int dirty_accountable, int prot_numa) | |
239 | { | |
240 | p4d_t *p4d; | |
241 | unsigned long next; | |
242 | unsigned long pages = 0; | |
243 | ||
244 | p4d = p4d_offset(pgd, addr); | |
245 | do { | |
246 | next = p4d_addr_end(addr, end); | |
247 | if (p4d_none_or_clear_bad(p4d)) | |
248 | continue; | |
249 | pages += change_pud_range(vma, p4d, addr, next, newprot, | |
250 | dirty_accountable, prot_numa); | |
251 | } while (p4d++, addr = next, addr != end); | |
252 | ||
253 | return pages; | |
254 | } | |
255 | ||
7da4d641 | 256 | static unsigned long change_protection_range(struct vm_area_struct *vma, |
c1e6098b | 257 | unsigned long addr, unsigned long end, pgprot_t newprot, |
4b10e7d5 | 258 | int dirty_accountable, int prot_numa) |
1da177e4 LT |
259 | { |
260 | struct mm_struct *mm = vma->vm_mm; | |
261 | pgd_t *pgd; | |
262 | unsigned long next; | |
263 | unsigned long start = addr; | |
7da4d641 | 264 | unsigned long pages = 0; |
1da177e4 LT |
265 | |
266 | BUG_ON(addr >= end); | |
267 | pgd = pgd_offset(mm, addr); | |
268 | flush_cache_range(vma, addr, end); | |
16af97dc | 269 | inc_tlb_flush_pending(mm); |
1da177e4 LT |
270 | do { |
271 | next = pgd_addr_end(addr, end); | |
272 | if (pgd_none_or_clear_bad(pgd)) | |
273 | continue; | |
c2febafc | 274 | pages += change_p4d_range(vma, pgd, addr, next, newprot, |
4b10e7d5 | 275 | dirty_accountable, prot_numa); |
1da177e4 | 276 | } while (pgd++, addr = next, addr != end); |
7da4d641 | 277 | |
1233d588 IM |
278 | /* Only flush the TLB if we actually modified any entries: */ |
279 | if (pages) | |
280 | flush_tlb_range(vma, start, end); | |
16af97dc | 281 | dec_tlb_flush_pending(mm); |
7da4d641 PZ |
282 | |
283 | return pages; | |
284 | } | |
285 | ||
286 | unsigned long change_protection(struct vm_area_struct *vma, unsigned long start, | |
287 | unsigned long end, pgprot_t newprot, | |
4b10e7d5 | 288 | int dirty_accountable, int prot_numa) |
7da4d641 | 289 | { |
7da4d641 PZ |
290 | unsigned long pages; |
291 | ||
7da4d641 PZ |
292 | if (is_vm_hugetlb_page(vma)) |
293 | pages = hugetlb_change_protection(vma, start, end, newprot); | |
294 | else | |
4b10e7d5 | 295 | pages = change_protection_range(vma, start, end, newprot, dirty_accountable, prot_numa); |
7da4d641 PZ |
296 | |
297 | return pages; | |
1da177e4 LT |
298 | } |
299 | ||
b6a2fea3 | 300 | int |
1da177e4 LT |
301 | mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev, |
302 | unsigned long start, unsigned long end, unsigned long newflags) | |
303 | { | |
304 | struct mm_struct *mm = vma->vm_mm; | |
305 | unsigned long oldflags = vma->vm_flags; | |
306 | long nrpages = (end - start) >> PAGE_SHIFT; | |
307 | unsigned long charged = 0; | |
1da177e4 LT |
308 | pgoff_t pgoff; |
309 | int error; | |
c1e6098b | 310 | int dirty_accountable = 0; |
1da177e4 LT |
311 | |
312 | if (newflags == oldflags) { | |
313 | *pprev = vma; | |
314 | return 0; | |
315 | } | |
316 | ||
317 | /* | |
318 | * If we make a private mapping writable we increase our commit; | |
319 | * but (without finer accounting) cannot reduce our commit if we | |
5a6fe125 MG |
320 | * make it unwritable again. hugetlb mapping were accounted for |
321 | * even if read-only so there is no need to account for them here | |
1da177e4 LT |
322 | */ |
323 | if (newflags & VM_WRITE) { | |
84638335 KK |
324 | /* Check space limits when area turns into data. */ |
325 | if (!may_expand_vm(mm, newflags, nrpages) && | |
326 | may_expand_vm(mm, oldflags, nrpages)) | |
327 | return -ENOMEM; | |
5a6fe125 | 328 | if (!(oldflags & (VM_ACCOUNT|VM_WRITE|VM_HUGETLB| |
cdfd4325 | 329 | VM_SHARED|VM_NORESERVE))) { |
1da177e4 | 330 | charged = nrpages; |
191c5424 | 331 | if (security_vm_enough_memory_mm(mm, charged)) |
1da177e4 LT |
332 | return -ENOMEM; |
333 | newflags |= VM_ACCOUNT; | |
334 | } | |
335 | } | |
336 | ||
1da177e4 LT |
337 | /* |
338 | * First try to merge with previous and/or next vma. | |
339 | */ | |
340 | pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT); | |
341 | *pprev = vma_merge(mm, *pprev, start, end, newflags, | |
19a809af AA |
342 | vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma), |
343 | vma->vm_userfaultfd_ctx); | |
1da177e4 LT |
344 | if (*pprev) { |
345 | vma = *pprev; | |
e86f15ee | 346 | VM_WARN_ON((vma->vm_flags ^ newflags) & ~VM_SOFTDIRTY); |
1da177e4 LT |
347 | goto success; |
348 | } | |
349 | ||
350 | *pprev = vma; | |
351 | ||
352 | if (start != vma->vm_start) { | |
353 | error = split_vma(mm, vma, start, 1); | |
354 | if (error) | |
355 | goto fail; | |
356 | } | |
357 | ||
358 | if (end != vma->vm_end) { | |
359 | error = split_vma(mm, vma, end, 0); | |
360 | if (error) | |
361 | goto fail; | |
362 | } | |
363 | ||
364 | success: | |
365 | /* | |
366 | * vm_flags and vm_page_prot are protected by the mmap_sem | |
367 | * held in write mode. | |
368 | */ | |
369 | vma->vm_flags = newflags; | |
6d2329f8 | 370 | dirty_accountable = vma_wants_writenotify(vma, vma->vm_page_prot); |
64e45507 | 371 | vma_set_page_prot(vma); |
d08b3851 | 372 | |
7d12efae AM |
373 | change_protection(vma, start, end, vma->vm_page_prot, |
374 | dirty_accountable, 0); | |
7da4d641 | 375 | |
36f88188 KS |
376 | /* |
377 | * Private VM_LOCKED VMA becoming writable: trigger COW to avoid major | |
378 | * fault on access. | |
379 | */ | |
380 | if ((oldflags & (VM_WRITE | VM_SHARED | VM_LOCKED)) == VM_LOCKED && | |
381 | (newflags & VM_WRITE)) { | |
382 | populate_vma_page_range(vma, start, end, NULL); | |
383 | } | |
384 | ||
84638335 KK |
385 | vm_stat_account(mm, oldflags, -nrpages); |
386 | vm_stat_account(mm, newflags, nrpages); | |
63bfd738 | 387 | perf_event_mmap(vma); |
1da177e4 LT |
388 | return 0; |
389 | ||
390 | fail: | |
391 | vm_unacct_memory(charged); | |
392 | return error; | |
393 | } | |
394 | ||
7d06d9c9 DH |
395 | /* |
396 | * pkey==-1 when doing a legacy mprotect() | |
397 | */ | |
398 | static int do_mprotect_pkey(unsigned long start, size_t len, | |
399 | unsigned long prot, int pkey) | |
1da177e4 | 400 | { |
62b5f7d0 | 401 | unsigned long nstart, end, tmp, reqprot; |
1da177e4 LT |
402 | struct vm_area_struct *vma, *prev; |
403 | int error = -EINVAL; | |
404 | const int grows = prot & (PROT_GROWSDOWN|PROT_GROWSUP); | |
f138556d PK |
405 | const bool rier = (current->personality & READ_IMPLIES_EXEC) && |
406 | (prot & PROT_READ); | |
407 | ||
1da177e4 LT |
408 | prot &= ~(PROT_GROWSDOWN|PROT_GROWSUP); |
409 | if (grows == (PROT_GROWSDOWN|PROT_GROWSUP)) /* can't be both */ | |
410 | return -EINVAL; | |
411 | ||
412 | if (start & ~PAGE_MASK) | |
413 | return -EINVAL; | |
414 | if (!len) | |
415 | return 0; | |
416 | len = PAGE_ALIGN(len); | |
417 | end = start + len; | |
418 | if (end <= start) | |
419 | return -ENOMEM; | |
b845f313 | 420 | if (!arch_validate_prot(prot)) |
1da177e4 LT |
421 | return -EINVAL; |
422 | ||
423 | reqprot = prot; | |
1da177e4 | 424 | |
dc0ef0df MH |
425 | if (down_write_killable(¤t->mm->mmap_sem)) |
426 | return -EINTR; | |
1da177e4 | 427 | |
e8c24d3a DH |
428 | /* |
429 | * If userspace did not allocate the pkey, do not let | |
430 | * them use it here. | |
431 | */ | |
432 | error = -EINVAL; | |
433 | if ((pkey != -1) && !mm_pkey_is_allocated(current->mm, pkey)) | |
434 | goto out; | |
435 | ||
097d5910 | 436 | vma = find_vma(current->mm, start); |
1da177e4 LT |
437 | error = -ENOMEM; |
438 | if (!vma) | |
439 | goto out; | |
097d5910 | 440 | prev = vma->vm_prev; |
1da177e4 LT |
441 | if (unlikely(grows & PROT_GROWSDOWN)) { |
442 | if (vma->vm_start >= end) | |
443 | goto out; | |
444 | start = vma->vm_start; | |
445 | error = -EINVAL; | |
446 | if (!(vma->vm_flags & VM_GROWSDOWN)) | |
447 | goto out; | |
7d12efae | 448 | } else { |
1da177e4 LT |
449 | if (vma->vm_start > start) |
450 | goto out; | |
451 | if (unlikely(grows & PROT_GROWSUP)) { | |
452 | end = vma->vm_end; | |
453 | error = -EINVAL; | |
454 | if (!(vma->vm_flags & VM_GROWSUP)) | |
455 | goto out; | |
456 | } | |
457 | } | |
458 | if (start > vma->vm_start) | |
459 | prev = vma; | |
460 | ||
461 | for (nstart = start ; ; ) { | |
a8502b67 | 462 | unsigned long mask_off_old_flags; |
1da177e4 | 463 | unsigned long newflags; |
7d06d9c9 | 464 | int new_vma_pkey; |
1da177e4 | 465 | |
7d12efae | 466 | /* Here we know that vma->vm_start <= nstart < vma->vm_end. */ |
1da177e4 | 467 | |
f138556d PK |
468 | /* Does the application expect PROT_READ to imply PROT_EXEC */ |
469 | if (rier && (vma->vm_flags & VM_MAYEXEC)) | |
470 | prot |= PROT_EXEC; | |
471 | ||
a8502b67 DH |
472 | /* |
473 | * Each mprotect() call explicitly passes r/w/x permissions. | |
474 | * If a permission is not passed to mprotect(), it must be | |
475 | * cleared from the VMA. | |
476 | */ | |
477 | mask_off_old_flags = VM_READ | VM_WRITE | VM_EXEC | | |
478 | ARCH_VM_PKEY_FLAGS; | |
479 | ||
7d06d9c9 DH |
480 | new_vma_pkey = arch_override_mprotect_pkey(vma, prot, pkey); |
481 | newflags = calc_vm_prot_bits(prot, new_vma_pkey); | |
a8502b67 | 482 | newflags |= (vma->vm_flags & ~mask_off_old_flags); |
1da177e4 | 483 | |
7e2cff42 PBG |
484 | /* newflags >> 4 shift VM_MAY% in place of VM_% */ |
485 | if ((newflags & ~(newflags >> 4)) & (VM_READ | VM_WRITE | VM_EXEC)) { | |
1da177e4 LT |
486 | error = -EACCES; |
487 | goto out; | |
488 | } | |
489 | ||
490 | error = security_file_mprotect(vma, reqprot, prot); | |
491 | if (error) | |
492 | goto out; | |
493 | ||
494 | tmp = vma->vm_end; | |
495 | if (tmp > end) | |
496 | tmp = end; | |
497 | error = mprotect_fixup(vma, &prev, nstart, tmp, newflags); | |
498 | if (error) | |
499 | goto out; | |
500 | nstart = tmp; | |
501 | ||
502 | if (nstart < prev->vm_end) | |
503 | nstart = prev->vm_end; | |
504 | if (nstart >= end) | |
505 | goto out; | |
506 | ||
507 | vma = prev->vm_next; | |
508 | if (!vma || vma->vm_start != nstart) { | |
509 | error = -ENOMEM; | |
510 | goto out; | |
511 | } | |
f138556d | 512 | prot = reqprot; |
1da177e4 LT |
513 | } |
514 | out: | |
515 | up_write(¤t->mm->mmap_sem); | |
516 | return error; | |
517 | } | |
7d06d9c9 DH |
518 | |
519 | SYSCALL_DEFINE3(mprotect, unsigned long, start, size_t, len, | |
520 | unsigned long, prot) | |
521 | { | |
522 | return do_mprotect_pkey(start, len, prot, -1); | |
523 | } | |
524 | ||
c7142aea HC |
525 | #ifdef CONFIG_ARCH_HAS_PKEYS |
526 | ||
7d06d9c9 DH |
527 | SYSCALL_DEFINE4(pkey_mprotect, unsigned long, start, size_t, len, |
528 | unsigned long, prot, int, pkey) | |
529 | { | |
530 | return do_mprotect_pkey(start, len, prot, pkey); | |
531 | } | |
e8c24d3a DH |
532 | |
533 | SYSCALL_DEFINE2(pkey_alloc, unsigned long, flags, unsigned long, init_val) | |
534 | { | |
535 | int pkey; | |
536 | int ret; | |
537 | ||
538 | /* No flags supported yet. */ | |
539 | if (flags) | |
540 | return -EINVAL; | |
541 | /* check for unsupported init values */ | |
542 | if (init_val & ~PKEY_ACCESS_MASK) | |
543 | return -EINVAL; | |
544 | ||
545 | down_write(¤t->mm->mmap_sem); | |
546 | pkey = mm_pkey_alloc(current->mm); | |
547 | ||
548 | ret = -ENOSPC; | |
549 | if (pkey == -1) | |
550 | goto out; | |
551 | ||
552 | ret = arch_set_user_pkey_access(current, pkey, init_val); | |
553 | if (ret) { | |
554 | mm_pkey_free(current->mm, pkey); | |
555 | goto out; | |
556 | } | |
557 | ret = pkey; | |
558 | out: | |
559 | up_write(¤t->mm->mmap_sem); | |
560 | return ret; | |
561 | } | |
562 | ||
563 | SYSCALL_DEFINE1(pkey_free, int, pkey) | |
564 | { | |
565 | int ret; | |
566 | ||
567 | down_write(¤t->mm->mmap_sem); | |
568 | ret = mm_pkey_free(current->mm, pkey); | |
569 | up_write(¤t->mm->mmap_sem); | |
570 | ||
571 | /* | |
572 | * We could provie warnings or errors if any VMA still | |
573 | * has the pkey set here. | |
574 | */ | |
575 | return ret; | |
576 | } | |
c7142aea HC |
577 | |
578 | #endif /* CONFIG_ARCH_HAS_PKEYS */ |