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