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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> |
09a913a7 | 30 | #include <linux/mm_inline.h> |
1da177e4 LT |
31 | #include <asm/pgtable.h> |
32 | #include <asm/cacheflush.h> | |
e8c24d3a | 33 | #include <asm/mmu_context.h> |
1da177e4 LT |
34 | #include <asm/tlbflush.h> |
35 | ||
36f88188 KS |
36 | #include "internal.h" |
37 | ||
4b10e7d5 | 38 | static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd, |
c1e6098b | 39 | unsigned long addr, unsigned long end, pgprot_t newprot, |
0f19c179 | 40 | int dirty_accountable, int prot_numa) |
1da177e4 | 41 | { |
4b10e7d5 | 42 | struct mm_struct *mm = vma->vm_mm; |
0697212a | 43 | pte_t *pte, oldpte; |
705e87c0 | 44 | spinlock_t *ptl; |
7da4d641 | 45 | unsigned long pages = 0; |
3e321587 | 46 | int target_node = NUMA_NO_NODE; |
1da177e4 | 47 | |
175ad4f1 AA |
48 | /* |
49 | * Can be called with only the mmap_sem for reading by | |
50 | * prot_numa so we must check the pmd isn't constantly | |
51 | * changing from under us from pmd_none to pmd_trans_huge | |
52 | * and/or the other way around. | |
53 | */ | |
54 | if (pmd_trans_unstable(pmd)) | |
55 | return 0; | |
56 | ||
57 | /* | |
58 | * The pmd points to a regular pte so the pmd can't change | |
59 | * from under us even if the mmap_sem is only hold for | |
60 | * reading. | |
61 | */ | |
62 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); | |
1ad9f620 | 63 | |
3e321587 AK |
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 | ||
3ea27719 | 69 | flush_tlb_batched_pending(vma->vm_mm); |
6606c3e0 | 70 | arch_enter_lazy_mmu_mode(); |
1da177e4 | 71 | do { |
0697212a CL |
72 | oldpte = *pte; |
73 | if (pte_present(oldpte)) { | |
1da177e4 | 74 | pte_t ptent; |
b191f9b1 | 75 | bool preserve_write = prot_numa && pte_write(oldpte); |
1da177e4 | 76 | |
e944fd67 MG |
77 | /* |
78 | * Avoid trapping faults against the zero or KSM | |
79 | * pages. See similar comment in change_huge_pmd. | |
80 | */ | |
81 | if (prot_numa) { | |
82 | struct page *page; | |
83 | ||
84 | page = vm_normal_page(vma, addr, oldpte); | |
85 | if (!page || PageKsm(page)) | |
86 | continue; | |
10c1045f | 87 | |
859d4adc HW |
88 | /* Also skip shared copy-on-write pages */ |
89 | if (is_cow_mapping(vma->vm_flags) && | |
90 | page_mapcount(page) != 1) | |
91 | continue; | |
92 | ||
09a913a7 MG |
93 | /* |
94 | * While migration can move some dirty pages, | |
95 | * it cannot move them all from MIGRATE_ASYNC | |
96 | * context. | |
97 | */ | |
98 | if (page_is_file_cache(page) && PageDirty(page)) | |
99 | continue; | |
100 | ||
10c1045f MG |
101 | /* Avoid TLB flush if possible */ |
102 | if (pte_protnone(oldpte)) | |
103 | continue; | |
3e321587 AK |
104 | |
105 | /* | |
106 | * Don't mess with PTEs if page is already on the node | |
107 | * a single-threaded process is running on. | |
108 | */ | |
109 | if (target_node == page_to_nid(page)) | |
110 | continue; | |
e944fd67 MG |
111 | } |
112 | ||
04a86453 AK |
113 | oldpte = ptep_modify_prot_start(vma, addr, pte); |
114 | ptent = pte_modify(oldpte, newprot); | |
b191f9b1 | 115 | if (preserve_write) |
288bc549 | 116 | ptent = pte_mk_savedwrite(ptent); |
4b10e7d5 | 117 | |
8a0516ed MG |
118 | /* Avoid taking write faults for known dirty pages */ |
119 | if (dirty_accountable && pte_dirty(ptent) && | |
120 | (pte_soft_dirty(ptent) || | |
121 | !(vma->vm_flags & VM_SOFTDIRTY))) { | |
122 | ptent = pte_mkwrite(ptent); | |
4b10e7d5 | 123 | } |
04a86453 | 124 | ptep_modify_prot_commit(vma, addr, pte, oldpte, ptent); |
8a0516ed | 125 | pages++; |
0661a336 | 126 | } else if (IS_ENABLED(CONFIG_MIGRATION)) { |
0697212a CL |
127 | swp_entry_t entry = pte_to_swp_entry(oldpte); |
128 | ||
129 | if (is_write_migration_entry(entry)) { | |
c3d16e16 | 130 | pte_t newpte; |
0697212a CL |
131 | /* |
132 | * A protection check is difficult so | |
133 | * just be safe and disable write | |
134 | */ | |
135 | make_migration_entry_read(&entry); | |
c3d16e16 CG |
136 | newpte = swp_entry_to_pte(entry); |
137 | if (pte_swp_soft_dirty(oldpte)) | |
138 | newpte = pte_swp_mksoft_dirty(newpte); | |
139 | set_pte_at(mm, addr, pte, newpte); | |
e920e14c MG |
140 | |
141 | pages++; | |
0697212a | 142 | } |
5042db43 JG |
143 | |
144 | if (is_write_device_private_entry(entry)) { | |
145 | pte_t newpte; | |
146 | ||
147 | /* | |
148 | * We do not preserve soft-dirtiness. See | |
149 | * copy_one_pte() for explanation. | |
150 | */ | |
151 | make_device_private_entry_read(&entry); | |
152 | newpte = swp_entry_to_pte(entry); | |
153 | set_pte_at(mm, addr, pte, newpte); | |
154 | ||
155 | pages++; | |
156 | } | |
1da177e4 LT |
157 | } |
158 | } while (pte++, addr += PAGE_SIZE, addr != end); | |
6606c3e0 | 159 | arch_leave_lazy_mmu_mode(); |
705e87c0 | 160 | pte_unmap_unlock(pte - 1, ptl); |
7da4d641 PZ |
161 | |
162 | return pages; | |
1da177e4 LT |
163 | } |
164 | ||
7d12efae AM |
165 | static inline unsigned long change_pmd_range(struct vm_area_struct *vma, |
166 | pud_t *pud, unsigned long addr, unsigned long end, | |
167 | pgprot_t newprot, int dirty_accountable, int prot_numa) | |
1da177e4 LT |
168 | { |
169 | pmd_t *pmd; | |
170 | unsigned long next; | |
7da4d641 | 171 | unsigned long pages = 0; |
72403b4a | 172 | unsigned long nr_huge_updates = 0; |
ac46d4f3 JG |
173 | struct mmu_notifier_range range; |
174 | ||
175 | range.start = 0; | |
1da177e4 LT |
176 | |
177 | pmd = pmd_offset(pud, addr); | |
178 | do { | |
25cbbef1 MG |
179 | unsigned long this_pages; |
180 | ||
1da177e4 | 181 | next = pmd_addr_end(addr, end); |
84c3fc4e | 182 | if (!is_swap_pmd(*pmd) && !pmd_trans_huge(*pmd) && !pmd_devmap(*pmd) |
5c7fb56e | 183 | && pmd_none_or_clear_bad(pmd)) |
4991c09c | 184 | goto next; |
a5338093 RR |
185 | |
186 | /* invoke the mmu notifier if the pmd is populated */ | |
ac46d4f3 | 187 | if (!range.start) { |
7269f999 JG |
188 | mmu_notifier_range_init(&range, |
189 | MMU_NOTIFY_PROTECTION_VMA, 0, | |
190 | vma, vma->vm_mm, addr, end); | |
ac46d4f3 | 191 | mmu_notifier_invalidate_range_start(&range); |
a5338093 RR |
192 | } |
193 | ||
84c3fc4e | 194 | if (is_swap_pmd(*pmd) || pmd_trans_huge(*pmd) || pmd_devmap(*pmd)) { |
6b9116a6 | 195 | if (next - addr != HPAGE_PMD_SIZE) { |
fd60775a | 196 | __split_huge_pmd(vma, pmd, addr, false, NULL); |
6b9116a6 | 197 | } else { |
f123d74a | 198 | int nr_ptes = change_huge_pmd(vma, pmd, addr, |
e944fd67 | 199 | newprot, prot_numa); |
f123d74a MG |
200 | |
201 | if (nr_ptes) { | |
72403b4a MG |
202 | if (nr_ptes == HPAGE_PMD_NR) { |
203 | pages += HPAGE_PMD_NR; | |
204 | nr_huge_updates++; | |
205 | } | |
1ad9f620 MG |
206 | |
207 | /* huge pmd was handled */ | |
4991c09c | 208 | goto next; |
f123d74a | 209 | } |
7da4d641 | 210 | } |
88a9ab6e | 211 | /* fall through, the trans huge pmd just split */ |
cd7548ab | 212 | } |
25cbbef1 | 213 | this_pages = change_pte_range(vma, pmd, addr, next, newprot, |
0f19c179 | 214 | dirty_accountable, prot_numa); |
25cbbef1 | 215 | pages += this_pages; |
4991c09c AK |
216 | next: |
217 | cond_resched(); | |
1da177e4 | 218 | } while (pmd++, addr = next, addr != end); |
7da4d641 | 219 | |
ac46d4f3 JG |
220 | if (range.start) |
221 | mmu_notifier_invalidate_range_end(&range); | |
a5338093 | 222 | |
72403b4a MG |
223 | if (nr_huge_updates) |
224 | count_vm_numa_events(NUMA_HUGE_PTE_UPDATES, nr_huge_updates); | |
7da4d641 | 225 | return pages; |
1da177e4 LT |
226 | } |
227 | ||
7d12efae | 228 | static inline unsigned long change_pud_range(struct vm_area_struct *vma, |
c2febafc | 229 | p4d_t *p4d, unsigned long addr, unsigned long end, |
7d12efae | 230 | pgprot_t newprot, int dirty_accountable, int prot_numa) |
1da177e4 LT |
231 | { |
232 | pud_t *pud; | |
233 | unsigned long next; | |
7da4d641 | 234 | unsigned long pages = 0; |
1da177e4 | 235 | |
c2febafc | 236 | pud = pud_offset(p4d, addr); |
1da177e4 LT |
237 | do { |
238 | next = pud_addr_end(addr, end); | |
239 | if (pud_none_or_clear_bad(pud)) | |
240 | continue; | |
7da4d641 | 241 | pages += change_pmd_range(vma, pud, addr, next, newprot, |
4b10e7d5 | 242 | dirty_accountable, prot_numa); |
1da177e4 | 243 | } while (pud++, addr = next, addr != end); |
7da4d641 PZ |
244 | |
245 | return pages; | |
1da177e4 LT |
246 | } |
247 | ||
c2febafc KS |
248 | static inline unsigned long change_p4d_range(struct vm_area_struct *vma, |
249 | pgd_t *pgd, unsigned long addr, unsigned long end, | |
250 | pgprot_t newprot, int dirty_accountable, int prot_numa) | |
251 | { | |
252 | p4d_t *p4d; | |
253 | unsigned long next; | |
254 | unsigned long pages = 0; | |
255 | ||
256 | p4d = p4d_offset(pgd, addr); | |
257 | do { | |
258 | next = p4d_addr_end(addr, end); | |
259 | if (p4d_none_or_clear_bad(p4d)) | |
260 | continue; | |
261 | pages += change_pud_range(vma, p4d, addr, next, newprot, | |
262 | dirty_accountable, prot_numa); | |
263 | } while (p4d++, addr = next, addr != end); | |
264 | ||
265 | return pages; | |
266 | } | |
267 | ||
7da4d641 | 268 | static unsigned long change_protection_range(struct vm_area_struct *vma, |
c1e6098b | 269 | unsigned long addr, unsigned long end, pgprot_t newprot, |
4b10e7d5 | 270 | int dirty_accountable, int prot_numa) |
1da177e4 LT |
271 | { |
272 | struct mm_struct *mm = vma->vm_mm; | |
273 | pgd_t *pgd; | |
274 | unsigned long next; | |
275 | unsigned long start = addr; | |
7da4d641 | 276 | unsigned long pages = 0; |
1da177e4 LT |
277 | |
278 | BUG_ON(addr >= end); | |
279 | pgd = pgd_offset(mm, addr); | |
280 | flush_cache_range(vma, addr, end); | |
16af97dc | 281 | inc_tlb_flush_pending(mm); |
1da177e4 LT |
282 | do { |
283 | next = pgd_addr_end(addr, end); | |
284 | if (pgd_none_or_clear_bad(pgd)) | |
285 | continue; | |
c2febafc | 286 | pages += change_p4d_range(vma, pgd, addr, next, newprot, |
4b10e7d5 | 287 | dirty_accountable, prot_numa); |
1da177e4 | 288 | } while (pgd++, addr = next, addr != end); |
7da4d641 | 289 | |
1233d588 IM |
290 | /* Only flush the TLB if we actually modified any entries: */ |
291 | if (pages) | |
292 | flush_tlb_range(vma, start, end); | |
16af97dc | 293 | dec_tlb_flush_pending(mm); |
7da4d641 PZ |
294 | |
295 | return pages; | |
296 | } | |
297 | ||
298 | unsigned long change_protection(struct vm_area_struct *vma, unsigned long start, | |
299 | unsigned long end, pgprot_t newprot, | |
4b10e7d5 | 300 | int dirty_accountable, int prot_numa) |
7da4d641 | 301 | { |
7da4d641 PZ |
302 | unsigned long pages; |
303 | ||
7da4d641 PZ |
304 | if (is_vm_hugetlb_page(vma)) |
305 | pages = hugetlb_change_protection(vma, start, end, newprot); | |
306 | else | |
4b10e7d5 | 307 | pages = change_protection_range(vma, start, end, newprot, dirty_accountable, prot_numa); |
7da4d641 PZ |
308 | |
309 | return pages; | |
1da177e4 LT |
310 | } |
311 | ||
42e4089c AK |
312 | static int prot_none_pte_entry(pte_t *pte, unsigned long addr, |
313 | unsigned long next, struct mm_walk *walk) | |
314 | { | |
315 | return pfn_modify_allowed(pte_pfn(*pte), *(pgprot_t *)(walk->private)) ? | |
316 | 0 : -EACCES; | |
317 | } | |
318 | ||
319 | static int prot_none_hugetlb_entry(pte_t *pte, unsigned long hmask, | |
320 | unsigned long addr, unsigned long next, | |
321 | struct mm_walk *walk) | |
322 | { | |
323 | return pfn_modify_allowed(pte_pfn(*pte), *(pgprot_t *)(walk->private)) ? | |
324 | 0 : -EACCES; | |
325 | } | |
326 | ||
327 | static int prot_none_test(unsigned long addr, unsigned long next, | |
328 | struct mm_walk *walk) | |
329 | { | |
330 | return 0; | |
331 | } | |
332 | ||
333 | static int prot_none_walk(struct vm_area_struct *vma, unsigned long start, | |
334 | unsigned long end, unsigned long newflags) | |
335 | { | |
336 | pgprot_t new_pgprot = vm_get_page_prot(newflags); | |
337 | struct mm_walk prot_none_walk = { | |
338 | .pte_entry = prot_none_pte_entry, | |
339 | .hugetlb_entry = prot_none_hugetlb_entry, | |
340 | .test_walk = prot_none_test, | |
341 | .mm = current->mm, | |
342 | .private = &new_pgprot, | |
343 | }; | |
344 | ||
345 | return walk_page_range(start, end, &prot_none_walk); | |
346 | } | |
347 | ||
b6a2fea3 | 348 | int |
1da177e4 LT |
349 | mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev, |
350 | unsigned long start, unsigned long end, unsigned long newflags) | |
351 | { | |
352 | struct mm_struct *mm = vma->vm_mm; | |
353 | unsigned long oldflags = vma->vm_flags; | |
354 | long nrpages = (end - start) >> PAGE_SHIFT; | |
355 | unsigned long charged = 0; | |
1da177e4 LT |
356 | pgoff_t pgoff; |
357 | int error; | |
c1e6098b | 358 | int dirty_accountable = 0; |
1da177e4 LT |
359 | |
360 | if (newflags == oldflags) { | |
361 | *pprev = vma; | |
362 | return 0; | |
363 | } | |
364 | ||
42e4089c AK |
365 | /* |
366 | * Do PROT_NONE PFN permission checks here when we can still | |
367 | * bail out without undoing a lot of state. This is a rather | |
368 | * uncommon case, so doesn't need to be very optimized. | |
369 | */ | |
370 | if (arch_has_pfn_modify_check() && | |
371 | (vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) && | |
372 | (newflags & (VM_READ|VM_WRITE|VM_EXEC)) == 0) { | |
373 | error = prot_none_walk(vma, start, end, newflags); | |
374 | if (error) | |
375 | return error; | |
376 | } | |
377 | ||
1da177e4 LT |
378 | /* |
379 | * If we make a private mapping writable we increase our commit; | |
380 | * but (without finer accounting) cannot reduce our commit if we | |
5a6fe125 MG |
381 | * make it unwritable again. hugetlb mapping were accounted for |
382 | * even if read-only so there is no need to account for them here | |
1da177e4 LT |
383 | */ |
384 | if (newflags & VM_WRITE) { | |
84638335 KK |
385 | /* Check space limits when area turns into data. */ |
386 | if (!may_expand_vm(mm, newflags, nrpages) && | |
387 | may_expand_vm(mm, oldflags, nrpages)) | |
388 | return -ENOMEM; | |
5a6fe125 | 389 | if (!(oldflags & (VM_ACCOUNT|VM_WRITE|VM_HUGETLB| |
cdfd4325 | 390 | VM_SHARED|VM_NORESERVE))) { |
1da177e4 | 391 | charged = nrpages; |
191c5424 | 392 | if (security_vm_enough_memory_mm(mm, charged)) |
1da177e4 LT |
393 | return -ENOMEM; |
394 | newflags |= VM_ACCOUNT; | |
395 | } | |
396 | } | |
397 | ||
1da177e4 LT |
398 | /* |
399 | * First try to merge with previous and/or next vma. | |
400 | */ | |
401 | pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT); | |
402 | *pprev = vma_merge(mm, *pprev, start, end, newflags, | |
19a809af AA |
403 | vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma), |
404 | vma->vm_userfaultfd_ctx); | |
1da177e4 LT |
405 | if (*pprev) { |
406 | vma = *pprev; | |
e86f15ee | 407 | VM_WARN_ON((vma->vm_flags ^ newflags) & ~VM_SOFTDIRTY); |
1da177e4 LT |
408 | goto success; |
409 | } | |
410 | ||
411 | *pprev = vma; | |
412 | ||
413 | if (start != vma->vm_start) { | |
414 | error = split_vma(mm, vma, start, 1); | |
415 | if (error) | |
416 | goto fail; | |
417 | } | |
418 | ||
419 | if (end != vma->vm_end) { | |
420 | error = split_vma(mm, vma, end, 0); | |
421 | if (error) | |
422 | goto fail; | |
423 | } | |
424 | ||
425 | success: | |
426 | /* | |
427 | * vm_flags and vm_page_prot are protected by the mmap_sem | |
428 | * held in write mode. | |
429 | */ | |
430 | vma->vm_flags = newflags; | |
6d2329f8 | 431 | dirty_accountable = vma_wants_writenotify(vma, vma->vm_page_prot); |
64e45507 | 432 | vma_set_page_prot(vma); |
d08b3851 | 433 | |
7d12efae AM |
434 | change_protection(vma, start, end, vma->vm_page_prot, |
435 | dirty_accountable, 0); | |
7da4d641 | 436 | |
36f88188 KS |
437 | /* |
438 | * Private VM_LOCKED VMA becoming writable: trigger COW to avoid major | |
439 | * fault on access. | |
440 | */ | |
441 | if ((oldflags & (VM_WRITE | VM_SHARED | VM_LOCKED)) == VM_LOCKED && | |
442 | (newflags & VM_WRITE)) { | |
443 | populate_vma_page_range(vma, start, end, NULL); | |
444 | } | |
445 | ||
84638335 KK |
446 | vm_stat_account(mm, oldflags, -nrpages); |
447 | vm_stat_account(mm, newflags, nrpages); | |
63bfd738 | 448 | perf_event_mmap(vma); |
1da177e4 LT |
449 | return 0; |
450 | ||
451 | fail: | |
452 | vm_unacct_memory(charged); | |
453 | return error; | |
454 | } | |
455 | ||
7d06d9c9 DH |
456 | /* |
457 | * pkey==-1 when doing a legacy mprotect() | |
458 | */ | |
459 | static int do_mprotect_pkey(unsigned long start, size_t len, | |
460 | unsigned long prot, int pkey) | |
1da177e4 | 461 | { |
62b5f7d0 | 462 | unsigned long nstart, end, tmp, reqprot; |
1da177e4 LT |
463 | struct vm_area_struct *vma, *prev; |
464 | int error = -EINVAL; | |
465 | const int grows = prot & (PROT_GROWSDOWN|PROT_GROWSUP); | |
f138556d PK |
466 | const bool rier = (current->personality & READ_IMPLIES_EXEC) && |
467 | (prot & PROT_READ); | |
468 | ||
1da177e4 LT |
469 | prot &= ~(PROT_GROWSDOWN|PROT_GROWSUP); |
470 | if (grows == (PROT_GROWSDOWN|PROT_GROWSUP)) /* can't be both */ | |
471 | return -EINVAL; | |
472 | ||
473 | if (start & ~PAGE_MASK) | |
474 | return -EINVAL; | |
475 | if (!len) | |
476 | return 0; | |
477 | len = PAGE_ALIGN(len); | |
478 | end = start + len; | |
479 | if (end <= start) | |
480 | return -ENOMEM; | |
9035cf9a | 481 | if (!arch_validate_prot(prot, start)) |
1da177e4 LT |
482 | return -EINVAL; |
483 | ||
484 | reqprot = prot; | |
1da177e4 | 485 | |
dc0ef0df MH |
486 | if (down_write_killable(¤t->mm->mmap_sem)) |
487 | return -EINTR; | |
1da177e4 | 488 | |
e8c24d3a DH |
489 | /* |
490 | * If userspace did not allocate the pkey, do not let | |
491 | * them use it here. | |
492 | */ | |
493 | error = -EINVAL; | |
494 | if ((pkey != -1) && !mm_pkey_is_allocated(current->mm, pkey)) | |
495 | goto out; | |
496 | ||
097d5910 | 497 | vma = find_vma(current->mm, start); |
1da177e4 LT |
498 | error = -ENOMEM; |
499 | if (!vma) | |
500 | goto out; | |
097d5910 | 501 | prev = vma->vm_prev; |
1da177e4 LT |
502 | if (unlikely(grows & PROT_GROWSDOWN)) { |
503 | if (vma->vm_start >= end) | |
504 | goto out; | |
505 | start = vma->vm_start; | |
506 | error = -EINVAL; | |
507 | if (!(vma->vm_flags & VM_GROWSDOWN)) | |
508 | goto out; | |
7d12efae | 509 | } else { |
1da177e4 LT |
510 | if (vma->vm_start > start) |
511 | goto out; | |
512 | if (unlikely(grows & PROT_GROWSUP)) { | |
513 | end = vma->vm_end; | |
514 | error = -EINVAL; | |
515 | if (!(vma->vm_flags & VM_GROWSUP)) | |
516 | goto out; | |
517 | } | |
518 | } | |
519 | if (start > vma->vm_start) | |
520 | prev = vma; | |
521 | ||
522 | for (nstart = start ; ; ) { | |
a8502b67 | 523 | unsigned long mask_off_old_flags; |
1da177e4 | 524 | unsigned long newflags; |
7d06d9c9 | 525 | int new_vma_pkey; |
1da177e4 | 526 | |
7d12efae | 527 | /* Here we know that vma->vm_start <= nstart < vma->vm_end. */ |
1da177e4 | 528 | |
f138556d PK |
529 | /* Does the application expect PROT_READ to imply PROT_EXEC */ |
530 | if (rier && (vma->vm_flags & VM_MAYEXEC)) | |
531 | prot |= PROT_EXEC; | |
532 | ||
a8502b67 DH |
533 | /* |
534 | * Each mprotect() call explicitly passes r/w/x permissions. | |
535 | * If a permission is not passed to mprotect(), it must be | |
536 | * cleared from the VMA. | |
537 | */ | |
538 | mask_off_old_flags = VM_READ | VM_WRITE | VM_EXEC | | |
2c2d57b5 | 539 | VM_FLAGS_CLEAR; |
a8502b67 | 540 | |
7d06d9c9 DH |
541 | new_vma_pkey = arch_override_mprotect_pkey(vma, prot, pkey); |
542 | newflags = calc_vm_prot_bits(prot, new_vma_pkey); | |
a8502b67 | 543 | newflags |= (vma->vm_flags & ~mask_off_old_flags); |
1da177e4 | 544 | |
7e2cff42 PBG |
545 | /* newflags >> 4 shift VM_MAY% in place of VM_% */ |
546 | if ((newflags & ~(newflags >> 4)) & (VM_READ | VM_WRITE | VM_EXEC)) { | |
1da177e4 LT |
547 | error = -EACCES; |
548 | goto out; | |
549 | } | |
550 | ||
551 | error = security_file_mprotect(vma, reqprot, prot); | |
552 | if (error) | |
553 | goto out; | |
554 | ||
555 | tmp = vma->vm_end; | |
556 | if (tmp > end) | |
557 | tmp = end; | |
558 | error = mprotect_fixup(vma, &prev, nstart, tmp, newflags); | |
559 | if (error) | |
560 | goto out; | |
561 | nstart = tmp; | |
562 | ||
563 | if (nstart < prev->vm_end) | |
564 | nstart = prev->vm_end; | |
565 | if (nstart >= end) | |
566 | goto out; | |
567 | ||
568 | vma = prev->vm_next; | |
569 | if (!vma || vma->vm_start != nstart) { | |
570 | error = -ENOMEM; | |
571 | goto out; | |
572 | } | |
f138556d | 573 | prot = reqprot; |
1da177e4 LT |
574 | } |
575 | out: | |
576 | up_write(¤t->mm->mmap_sem); | |
577 | return error; | |
578 | } | |
7d06d9c9 DH |
579 | |
580 | SYSCALL_DEFINE3(mprotect, unsigned long, start, size_t, len, | |
581 | unsigned long, prot) | |
582 | { | |
583 | return do_mprotect_pkey(start, len, prot, -1); | |
584 | } | |
585 | ||
c7142aea HC |
586 | #ifdef CONFIG_ARCH_HAS_PKEYS |
587 | ||
7d06d9c9 DH |
588 | SYSCALL_DEFINE4(pkey_mprotect, unsigned long, start, size_t, len, |
589 | unsigned long, prot, int, pkey) | |
590 | { | |
591 | return do_mprotect_pkey(start, len, prot, pkey); | |
592 | } | |
e8c24d3a DH |
593 | |
594 | SYSCALL_DEFINE2(pkey_alloc, unsigned long, flags, unsigned long, init_val) | |
595 | { | |
596 | int pkey; | |
597 | int ret; | |
598 | ||
599 | /* No flags supported yet. */ | |
600 | if (flags) | |
601 | return -EINVAL; | |
602 | /* check for unsupported init values */ | |
603 | if (init_val & ~PKEY_ACCESS_MASK) | |
604 | return -EINVAL; | |
605 | ||
606 | down_write(¤t->mm->mmap_sem); | |
607 | pkey = mm_pkey_alloc(current->mm); | |
608 | ||
609 | ret = -ENOSPC; | |
610 | if (pkey == -1) | |
611 | goto out; | |
612 | ||
613 | ret = arch_set_user_pkey_access(current, pkey, init_val); | |
614 | if (ret) { | |
615 | mm_pkey_free(current->mm, pkey); | |
616 | goto out; | |
617 | } | |
618 | ret = pkey; | |
619 | out: | |
620 | up_write(¤t->mm->mmap_sem); | |
621 | return ret; | |
622 | } | |
623 | ||
624 | SYSCALL_DEFINE1(pkey_free, int, pkey) | |
625 | { | |
626 | int ret; | |
627 | ||
628 | down_write(¤t->mm->mmap_sem); | |
629 | ret = mm_pkey_free(current->mm, pkey); | |
630 | up_write(¤t->mm->mmap_sem); | |
631 | ||
632 | /* | |
633 | * We could provie warnings or errors if any VMA still | |
634 | * has the pkey set here. | |
635 | */ | |
636 | return ret; | |
637 | } | |
c7142aea HC |
638 | |
639 | #endif /* CONFIG_ARCH_HAS_PKEYS */ |