]>
Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * mm/mprotect.c | |
3 | * | |
4 | * (C) Copyright 1994 Linus Torvalds | |
5 | * (C) Copyright 2002 Christoph Hellwig | |
6 | * | |
046c6884 | 7 | * Address space accounting code <alan@lxorguk.ukuu.org.uk> |
1da177e4 LT |
8 | * (C) Copyright 2002 Red Hat Inc, All Rights Reserved |
9 | */ | |
10 | ||
11 | #include <linux/mm.h> | |
12 | #include <linux/hugetlb.h> | |
1da177e4 LT |
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> | |
0697212a CL |
21 | #include <linux/swap.h> |
22 | #include <linux/swapops.h> | |
cddb8a5c | 23 | #include <linux/mmu_notifier.h> |
64cdd548 | 24 | #include <linux/migrate.h> |
cdd6c482 | 25 | #include <linux/perf_event.h> |
e8c24d3a | 26 | #include <linux/pkeys.h> |
64a9a34e | 27 | #include <linux/ksm.h> |
1da177e4 LT |
28 | #include <asm/uaccess.h> |
29 | #include <asm/pgtable.h> | |
30 | #include <asm/cacheflush.h> | |
e8c24d3a | 31 | #include <asm/mmu_context.h> |
1da177e4 LT |
32 | #include <asm/tlbflush.h> |
33 | ||
36f88188 KS |
34 | #include "internal.h" |
35 | ||
1ad9f620 MG |
36 | /* |
37 | * For a prot_numa update we only hold mmap_sem for read so there is a | |
38 | * potential race with faulting where a pmd was temporarily none. This | |
39 | * function checks for a transhuge pmd under the appropriate lock. It | |
40 | * returns a pte if it was successfully locked or NULL if it raced with | |
41 | * a transhuge insertion. | |
42 | */ | |
43 | static pte_t *lock_pte_protection(struct vm_area_struct *vma, pmd_t *pmd, | |
44 | unsigned long addr, int prot_numa, spinlock_t **ptl) | |
45 | { | |
46 | pte_t *pte; | |
47 | spinlock_t *pmdl; | |
48 | ||
49 | /* !prot_numa is protected by mmap_sem held for write */ | |
50 | if (!prot_numa) | |
51 | return pte_offset_map_lock(vma->vm_mm, pmd, addr, ptl); | |
52 | ||
53 | pmdl = pmd_lock(vma->vm_mm, pmd); | |
54 | if (unlikely(pmd_trans_huge(*pmd) || pmd_none(*pmd))) { | |
55 | spin_unlock(pmdl); | |
56 | return NULL; | |
57 | } | |
58 | ||
59 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, ptl); | |
60 | spin_unlock(pmdl); | |
61 | return pte; | |
62 | } | |
63 | ||
4b10e7d5 | 64 | static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd, |
c1e6098b | 65 | unsigned long addr, unsigned long end, pgprot_t newprot, |
0f19c179 | 66 | int dirty_accountable, int prot_numa) |
1da177e4 | 67 | { |
4b10e7d5 | 68 | struct mm_struct *mm = vma->vm_mm; |
0697212a | 69 | pte_t *pte, oldpte; |
705e87c0 | 70 | spinlock_t *ptl; |
7da4d641 | 71 | unsigned long pages = 0; |
1da177e4 | 72 | |
1ad9f620 MG |
73 | pte = lock_pte_protection(vma, pmd, addr, prot_numa, &ptl); |
74 | if (!pte) | |
75 | return 0; | |
76 | ||
6606c3e0 | 77 | arch_enter_lazy_mmu_mode(); |
1da177e4 | 78 | do { |
0697212a CL |
79 | oldpte = *pte; |
80 | if (pte_present(oldpte)) { | |
1da177e4 | 81 | pte_t ptent; |
b191f9b1 | 82 | bool preserve_write = prot_numa && pte_write(oldpte); |
1da177e4 | 83 | |
e944fd67 MG |
84 | /* |
85 | * Avoid trapping faults against the zero or KSM | |
86 | * pages. See similar comment in change_huge_pmd. | |
87 | */ | |
88 | if (prot_numa) { | |
89 | struct page *page; | |
90 | ||
91 | page = vm_normal_page(vma, addr, oldpte); | |
92 | if (!page || PageKsm(page)) | |
93 | continue; | |
10c1045f MG |
94 | |
95 | /* Avoid TLB flush if possible */ | |
96 | if (pte_protnone(oldpte)) | |
97 | continue; | |
e944fd67 MG |
98 | } |
99 | ||
8a0516ed MG |
100 | ptent = ptep_modify_prot_start(mm, addr, pte); |
101 | ptent = pte_modify(ptent, newprot); | |
b191f9b1 MG |
102 | if (preserve_write) |
103 | ptent = pte_mkwrite(ptent); | |
4b10e7d5 | 104 | |
8a0516ed MG |
105 | /* Avoid taking write faults for known dirty pages */ |
106 | if (dirty_accountable && pte_dirty(ptent) && | |
107 | (pte_soft_dirty(ptent) || | |
108 | !(vma->vm_flags & VM_SOFTDIRTY))) { | |
109 | ptent = pte_mkwrite(ptent); | |
4b10e7d5 | 110 | } |
8a0516ed MG |
111 | ptep_modify_prot_commit(mm, addr, pte, ptent); |
112 | pages++; | |
0661a336 | 113 | } else if (IS_ENABLED(CONFIG_MIGRATION)) { |
0697212a CL |
114 | swp_entry_t entry = pte_to_swp_entry(oldpte); |
115 | ||
116 | if (is_write_migration_entry(entry)) { | |
c3d16e16 | 117 | pte_t newpte; |
0697212a CL |
118 | /* |
119 | * A protection check is difficult so | |
120 | * just be safe and disable write | |
121 | */ | |
122 | make_migration_entry_read(&entry); | |
c3d16e16 CG |
123 | newpte = swp_entry_to_pte(entry); |
124 | if (pte_swp_soft_dirty(oldpte)) | |
125 | newpte = pte_swp_mksoft_dirty(newpte); | |
126 | set_pte_at(mm, addr, pte, newpte); | |
e920e14c MG |
127 | |
128 | pages++; | |
0697212a | 129 | } |
1da177e4 LT |
130 | } |
131 | } while (pte++, addr += PAGE_SIZE, addr != end); | |
6606c3e0 | 132 | arch_leave_lazy_mmu_mode(); |
705e87c0 | 133 | pte_unmap_unlock(pte - 1, ptl); |
7da4d641 PZ |
134 | |
135 | return pages; | |
1da177e4 LT |
136 | } |
137 | ||
7d12efae AM |
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) | |
1da177e4 LT |
141 | { |
142 | pmd_t *pmd; | |
a5338093 | 143 | struct mm_struct *mm = vma->vm_mm; |
1da177e4 | 144 | unsigned long next; |
7da4d641 | 145 | unsigned long pages = 0; |
72403b4a | 146 | unsigned long nr_huge_updates = 0; |
a5338093 | 147 | unsigned long mni_start = 0; |
1da177e4 LT |
148 | |
149 | pmd = pmd_offset(pud, addr); | |
150 | do { | |
25cbbef1 MG |
151 | unsigned long this_pages; |
152 | ||
1da177e4 | 153 | next = pmd_addr_end(addr, end); |
5c7fb56e DW |
154 | if (!pmd_trans_huge(*pmd) && !pmd_devmap(*pmd) |
155 | && pmd_none_or_clear_bad(pmd)) | |
88a9ab6e | 156 | continue; |
a5338093 RR |
157 | |
158 | /* invoke the mmu notifier if the pmd is populated */ | |
159 | if (!mni_start) { | |
160 | mni_start = addr; | |
161 | mmu_notifier_invalidate_range_start(mm, mni_start, end); | |
162 | } | |
163 | ||
5c7fb56e | 164 | if (pmd_trans_huge(*pmd) || pmd_devmap(*pmd)) { |
6b9116a6 | 165 | if (next - addr != HPAGE_PMD_SIZE) { |
78ddc534 | 166 | split_huge_pmd(vma, pmd, addr); |
337d9abf | 167 | if (pmd_trans_unstable(pmd)) |
6b9116a6 KS |
168 | continue; |
169 | } else { | |
f123d74a | 170 | int nr_ptes = change_huge_pmd(vma, pmd, addr, |
e944fd67 | 171 | newprot, prot_numa); |
f123d74a MG |
172 | |
173 | if (nr_ptes) { | |
72403b4a MG |
174 | if (nr_ptes == HPAGE_PMD_NR) { |
175 | pages += HPAGE_PMD_NR; | |
176 | nr_huge_updates++; | |
177 | } | |
1ad9f620 MG |
178 | |
179 | /* huge pmd was handled */ | |
f123d74a MG |
180 | continue; |
181 | } | |
7da4d641 | 182 | } |
88a9ab6e | 183 | /* fall through, the trans huge pmd just split */ |
cd7548ab | 184 | } |
25cbbef1 | 185 | this_pages = change_pte_range(vma, pmd, addr, next, newprot, |
0f19c179 | 186 | dirty_accountable, prot_numa); |
25cbbef1 | 187 | pages += this_pages; |
1da177e4 | 188 | } while (pmd++, addr = next, addr != end); |
7da4d641 | 189 | |
a5338093 RR |
190 | if (mni_start) |
191 | mmu_notifier_invalidate_range_end(mm, mni_start, end); | |
192 | ||
72403b4a MG |
193 | if (nr_huge_updates) |
194 | count_vm_numa_events(NUMA_HUGE_PTE_UPDATES, nr_huge_updates); | |
7da4d641 | 195 | return pages; |
1da177e4 LT |
196 | } |
197 | ||
7d12efae AM |
198 | static inline unsigned long change_pud_range(struct vm_area_struct *vma, |
199 | pgd_t *pgd, unsigned long addr, unsigned long end, | |
200 | pgprot_t newprot, int dirty_accountable, int prot_numa) | |
1da177e4 LT |
201 | { |
202 | pud_t *pud; | |
203 | unsigned long next; | |
7da4d641 | 204 | unsigned long pages = 0; |
1da177e4 LT |
205 | |
206 | pud = pud_offset(pgd, addr); | |
207 | do { | |
208 | next = pud_addr_end(addr, end); | |
209 | if (pud_none_or_clear_bad(pud)) | |
210 | continue; | |
7da4d641 | 211 | pages += change_pmd_range(vma, pud, addr, next, newprot, |
4b10e7d5 | 212 | dirty_accountable, prot_numa); |
1da177e4 | 213 | } while (pud++, addr = next, addr != end); |
7da4d641 PZ |
214 | |
215 | return pages; | |
1da177e4 LT |
216 | } |
217 | ||
7da4d641 | 218 | static unsigned long change_protection_range(struct vm_area_struct *vma, |
c1e6098b | 219 | unsigned long addr, unsigned long end, pgprot_t newprot, |
4b10e7d5 | 220 | int dirty_accountable, int prot_numa) |
1da177e4 LT |
221 | { |
222 | struct mm_struct *mm = vma->vm_mm; | |
223 | pgd_t *pgd; | |
224 | unsigned long next; | |
225 | unsigned long start = addr; | |
7da4d641 | 226 | unsigned long pages = 0; |
1da177e4 LT |
227 | |
228 | BUG_ON(addr >= end); | |
229 | pgd = pgd_offset(mm, addr); | |
230 | flush_cache_range(vma, addr, end); | |
20841405 | 231 | set_tlb_flush_pending(mm); |
1da177e4 LT |
232 | do { |
233 | next = pgd_addr_end(addr, end); | |
234 | if (pgd_none_or_clear_bad(pgd)) | |
235 | continue; | |
7da4d641 | 236 | pages += change_pud_range(vma, pgd, addr, next, newprot, |
4b10e7d5 | 237 | dirty_accountable, prot_numa); |
1da177e4 | 238 | } while (pgd++, addr = next, addr != end); |
7da4d641 | 239 | |
1233d588 IM |
240 | /* Only flush the TLB if we actually modified any entries: */ |
241 | if (pages) | |
242 | flush_tlb_range(vma, start, end); | |
20841405 | 243 | clear_tlb_flush_pending(mm); |
7da4d641 PZ |
244 | |
245 | return pages; | |
246 | } | |
247 | ||
248 | unsigned long change_protection(struct vm_area_struct *vma, unsigned long start, | |
249 | unsigned long end, pgprot_t newprot, | |
4b10e7d5 | 250 | int dirty_accountable, int prot_numa) |
7da4d641 | 251 | { |
7da4d641 PZ |
252 | unsigned long pages; |
253 | ||
7da4d641 PZ |
254 | if (is_vm_hugetlb_page(vma)) |
255 | pages = hugetlb_change_protection(vma, start, end, newprot); | |
256 | else | |
4b10e7d5 | 257 | pages = change_protection_range(vma, start, end, newprot, dirty_accountable, prot_numa); |
7da4d641 PZ |
258 | |
259 | return pages; | |
1da177e4 LT |
260 | } |
261 | ||
b6a2fea3 | 262 | int |
1da177e4 LT |
263 | mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev, |
264 | unsigned long start, unsigned long end, unsigned long newflags) | |
265 | { | |
266 | struct mm_struct *mm = vma->vm_mm; | |
267 | unsigned long oldflags = vma->vm_flags; | |
268 | long nrpages = (end - start) >> PAGE_SHIFT; | |
269 | unsigned long charged = 0; | |
1da177e4 LT |
270 | pgoff_t pgoff; |
271 | int error; | |
c1e6098b | 272 | int dirty_accountable = 0; |
1da177e4 LT |
273 | |
274 | if (newflags == oldflags) { | |
275 | *pprev = vma; | |
276 | return 0; | |
277 | } | |
278 | ||
279 | /* | |
280 | * If we make a private mapping writable we increase our commit; | |
281 | * but (without finer accounting) cannot reduce our commit if we | |
5a6fe125 MG |
282 | * make it unwritable again. hugetlb mapping were accounted for |
283 | * even if read-only so there is no need to account for them here | |
1da177e4 LT |
284 | */ |
285 | if (newflags & VM_WRITE) { | |
84638335 KK |
286 | /* Check space limits when area turns into data. */ |
287 | if (!may_expand_vm(mm, newflags, nrpages) && | |
288 | may_expand_vm(mm, oldflags, nrpages)) | |
289 | return -ENOMEM; | |
5a6fe125 | 290 | if (!(oldflags & (VM_ACCOUNT|VM_WRITE|VM_HUGETLB| |
cdfd4325 | 291 | VM_SHARED|VM_NORESERVE))) { |
1da177e4 | 292 | charged = nrpages; |
191c5424 | 293 | if (security_vm_enough_memory_mm(mm, charged)) |
1da177e4 LT |
294 | return -ENOMEM; |
295 | newflags |= VM_ACCOUNT; | |
296 | } | |
297 | } | |
298 | ||
1da177e4 LT |
299 | /* |
300 | * First try to merge with previous and/or next vma. | |
301 | */ | |
302 | pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT); | |
303 | *pprev = vma_merge(mm, *pprev, start, end, newflags, | |
19a809af AA |
304 | vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma), |
305 | vma->vm_userfaultfd_ctx); | |
1da177e4 LT |
306 | if (*pprev) { |
307 | vma = *pprev; | |
e86f15ee | 308 | VM_WARN_ON((vma->vm_flags ^ newflags) & ~VM_SOFTDIRTY); |
1da177e4 LT |
309 | goto success; |
310 | } | |
311 | ||
312 | *pprev = vma; | |
313 | ||
314 | if (start != vma->vm_start) { | |
315 | error = split_vma(mm, vma, start, 1); | |
316 | if (error) | |
317 | goto fail; | |
318 | } | |
319 | ||
320 | if (end != vma->vm_end) { | |
321 | error = split_vma(mm, vma, end, 0); | |
322 | if (error) | |
323 | goto fail; | |
324 | } | |
325 | ||
326 | success: | |
327 | /* | |
328 | * vm_flags and vm_page_prot are protected by the mmap_sem | |
329 | * held in write mode. | |
330 | */ | |
331 | vma->vm_flags = newflags; | |
6d2329f8 | 332 | dirty_accountable = vma_wants_writenotify(vma, vma->vm_page_prot); |
64e45507 | 333 | vma_set_page_prot(vma); |
d08b3851 | 334 | |
7d12efae AM |
335 | change_protection(vma, start, end, vma->vm_page_prot, |
336 | dirty_accountable, 0); | |
7da4d641 | 337 | |
36f88188 KS |
338 | /* |
339 | * Private VM_LOCKED VMA becoming writable: trigger COW to avoid major | |
340 | * fault on access. | |
341 | */ | |
342 | if ((oldflags & (VM_WRITE | VM_SHARED | VM_LOCKED)) == VM_LOCKED && | |
343 | (newflags & VM_WRITE)) { | |
344 | populate_vma_page_range(vma, start, end, NULL); | |
345 | } | |
346 | ||
84638335 KK |
347 | vm_stat_account(mm, oldflags, -nrpages); |
348 | vm_stat_account(mm, newflags, nrpages); | |
63bfd738 | 349 | perf_event_mmap(vma); |
1da177e4 LT |
350 | return 0; |
351 | ||
352 | fail: | |
353 | vm_unacct_memory(charged); | |
354 | return error; | |
355 | } | |
356 | ||
7d06d9c9 DH |
357 | /* |
358 | * pkey==-1 when doing a legacy mprotect() | |
359 | */ | |
360 | static int do_mprotect_pkey(unsigned long start, size_t len, | |
361 | unsigned long prot, int pkey) | |
1da177e4 | 362 | { |
62b5f7d0 | 363 | unsigned long nstart, end, tmp, reqprot; |
1da177e4 LT |
364 | struct vm_area_struct *vma, *prev; |
365 | int error = -EINVAL; | |
366 | const int grows = prot & (PROT_GROWSDOWN|PROT_GROWSUP); | |
f138556d PK |
367 | const bool rier = (current->personality & READ_IMPLIES_EXEC) && |
368 | (prot & PROT_READ); | |
369 | ||
1da177e4 LT |
370 | prot &= ~(PROT_GROWSDOWN|PROT_GROWSUP); |
371 | if (grows == (PROT_GROWSDOWN|PROT_GROWSUP)) /* can't be both */ | |
372 | return -EINVAL; | |
373 | ||
374 | if (start & ~PAGE_MASK) | |
375 | return -EINVAL; | |
376 | if (!len) | |
377 | return 0; | |
378 | len = PAGE_ALIGN(len); | |
379 | end = start + len; | |
380 | if (end <= start) | |
381 | return -ENOMEM; | |
b845f313 | 382 | if (!arch_validate_prot(prot)) |
1da177e4 LT |
383 | return -EINVAL; |
384 | ||
385 | reqprot = prot; | |
1da177e4 | 386 | |
dc0ef0df MH |
387 | if (down_write_killable(¤t->mm->mmap_sem)) |
388 | return -EINTR; | |
1da177e4 | 389 | |
e8c24d3a DH |
390 | /* |
391 | * If userspace did not allocate the pkey, do not let | |
392 | * them use it here. | |
393 | */ | |
394 | error = -EINVAL; | |
395 | if ((pkey != -1) && !mm_pkey_is_allocated(current->mm, pkey)) | |
396 | goto out; | |
397 | ||
097d5910 | 398 | vma = find_vma(current->mm, start); |
1da177e4 LT |
399 | error = -ENOMEM; |
400 | if (!vma) | |
401 | goto out; | |
097d5910 | 402 | prev = vma->vm_prev; |
1da177e4 LT |
403 | if (unlikely(grows & PROT_GROWSDOWN)) { |
404 | if (vma->vm_start >= end) | |
405 | goto out; | |
406 | start = vma->vm_start; | |
407 | error = -EINVAL; | |
408 | if (!(vma->vm_flags & VM_GROWSDOWN)) | |
409 | goto out; | |
7d12efae | 410 | } else { |
1da177e4 LT |
411 | if (vma->vm_start > start) |
412 | goto out; | |
413 | if (unlikely(grows & PROT_GROWSUP)) { | |
414 | end = vma->vm_end; | |
415 | error = -EINVAL; | |
416 | if (!(vma->vm_flags & VM_GROWSUP)) | |
417 | goto out; | |
418 | } | |
419 | } | |
420 | if (start > vma->vm_start) | |
421 | prev = vma; | |
422 | ||
423 | for (nstart = start ; ; ) { | |
a8502b67 | 424 | unsigned long mask_off_old_flags; |
1da177e4 | 425 | unsigned long newflags; |
7d06d9c9 | 426 | int new_vma_pkey; |
1da177e4 | 427 | |
7d12efae | 428 | /* Here we know that vma->vm_start <= nstart < vma->vm_end. */ |
1da177e4 | 429 | |
f138556d PK |
430 | /* Does the application expect PROT_READ to imply PROT_EXEC */ |
431 | if (rier && (vma->vm_flags & VM_MAYEXEC)) | |
432 | prot |= PROT_EXEC; | |
433 | ||
a8502b67 DH |
434 | /* |
435 | * Each mprotect() call explicitly passes r/w/x permissions. | |
436 | * If a permission is not passed to mprotect(), it must be | |
437 | * cleared from the VMA. | |
438 | */ | |
439 | mask_off_old_flags = VM_READ | VM_WRITE | VM_EXEC | | |
440 | ARCH_VM_PKEY_FLAGS; | |
441 | ||
7d06d9c9 DH |
442 | new_vma_pkey = arch_override_mprotect_pkey(vma, prot, pkey); |
443 | newflags = calc_vm_prot_bits(prot, new_vma_pkey); | |
a8502b67 | 444 | newflags |= (vma->vm_flags & ~mask_off_old_flags); |
1da177e4 | 445 | |
7e2cff42 PBG |
446 | /* newflags >> 4 shift VM_MAY% in place of VM_% */ |
447 | if ((newflags & ~(newflags >> 4)) & (VM_READ | VM_WRITE | VM_EXEC)) { | |
1da177e4 LT |
448 | error = -EACCES; |
449 | goto out; | |
450 | } | |
451 | ||
452 | error = security_file_mprotect(vma, reqprot, prot); | |
453 | if (error) | |
454 | goto out; | |
455 | ||
456 | tmp = vma->vm_end; | |
457 | if (tmp > end) | |
458 | tmp = end; | |
459 | error = mprotect_fixup(vma, &prev, nstart, tmp, newflags); | |
460 | if (error) | |
461 | goto out; | |
462 | nstart = tmp; | |
463 | ||
464 | if (nstart < prev->vm_end) | |
465 | nstart = prev->vm_end; | |
466 | if (nstart >= end) | |
467 | goto out; | |
468 | ||
469 | vma = prev->vm_next; | |
470 | if (!vma || vma->vm_start != nstart) { | |
471 | error = -ENOMEM; | |
472 | goto out; | |
473 | } | |
f138556d | 474 | prot = reqprot; |
1da177e4 LT |
475 | } |
476 | out: | |
477 | up_write(¤t->mm->mmap_sem); | |
478 | return error; | |
479 | } | |
7d06d9c9 DH |
480 | |
481 | SYSCALL_DEFINE3(mprotect, unsigned long, start, size_t, len, | |
482 | unsigned long, prot) | |
483 | { | |
484 | return do_mprotect_pkey(start, len, prot, -1); | |
485 | } | |
486 | ||
487 | SYSCALL_DEFINE4(pkey_mprotect, unsigned long, start, size_t, len, | |
488 | unsigned long, prot, int, pkey) | |
489 | { | |
490 | return do_mprotect_pkey(start, len, prot, pkey); | |
491 | } | |
e8c24d3a DH |
492 | |
493 | SYSCALL_DEFINE2(pkey_alloc, unsigned long, flags, unsigned long, init_val) | |
494 | { | |
495 | int pkey; | |
496 | int ret; | |
497 | ||
498 | /* No flags supported yet. */ | |
499 | if (flags) | |
500 | return -EINVAL; | |
501 | /* check for unsupported init values */ | |
502 | if (init_val & ~PKEY_ACCESS_MASK) | |
503 | return -EINVAL; | |
504 | ||
505 | down_write(¤t->mm->mmap_sem); | |
506 | pkey = mm_pkey_alloc(current->mm); | |
507 | ||
508 | ret = -ENOSPC; | |
509 | if (pkey == -1) | |
510 | goto out; | |
511 | ||
512 | ret = arch_set_user_pkey_access(current, pkey, init_val); | |
513 | if (ret) { | |
514 | mm_pkey_free(current->mm, pkey); | |
515 | goto out; | |
516 | } | |
517 | ret = pkey; | |
518 | out: | |
519 | up_write(¤t->mm->mmap_sem); | |
520 | return ret; | |
521 | } | |
522 | ||
523 | SYSCALL_DEFINE1(pkey_free, int, pkey) | |
524 | { | |
525 | int ret; | |
526 | ||
527 | down_write(¤t->mm->mmap_sem); | |
528 | ret = mm_pkey_free(current->mm, pkey); | |
529 | up_write(¤t->mm->mmap_sem); | |
530 | ||
531 | /* | |
532 | * We could provie warnings or errors if any VMA still | |
533 | * has the pkey set here. | |
534 | */ | |
535 | return ret; | |
536 | } |