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mtd: jedec_probe: fix NEC uPD29F064115 detection
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CommitLineData
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>
13#include <linux/slab.h>
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>
dab5855b 26#include <linux/perf_counter.h>
1da177e4
LT
27#include <asm/uaccess.h>
28#include <asm/pgtable.h>
29#include <asm/cacheflush.h>
30#include <asm/tlbflush.h>
31
1c12c4cf
VP
32#ifndef pgprot_modify
33static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot)
34{
35 return newprot;
36}
37#endif
38
1da177e4 39static void change_pte_range(struct mm_struct *mm, pmd_t *pmd,
c1e6098b
PZ
40 unsigned long addr, unsigned long end, pgprot_t newprot,
41 int dirty_accountable)
1da177e4 42{
0697212a 43 pte_t *pte, oldpte;
705e87c0 44 spinlock_t *ptl;
1da177e4 45
705e87c0 46 pte = pte_offset_map_lock(mm, pmd, addr, &ptl);
6606c3e0 47 arch_enter_lazy_mmu_mode();
1da177e4 48 do {
0697212a
CL
49 oldpte = *pte;
50 if (pte_present(oldpte)) {
1da177e4
LT
51 pte_t ptent;
52
1ea0704e 53 ptent = ptep_modify_prot_start(mm, addr, pte);
c1e6098b 54 ptent = pte_modify(ptent, newprot);
1ea0704e 55
c1e6098b
PZ
56 /*
57 * Avoid taking write faults for pages we know to be
58 * dirty.
59 */
60 if (dirty_accountable && pte_dirty(ptent))
61 ptent = pte_mkwrite(ptent);
1ea0704e
JF
62
63 ptep_modify_prot_commit(mm, addr, pte, ptent);
64cdd548 64 } else if (PAGE_MIGRATION && !pte_file(oldpte)) {
0697212a
CL
65 swp_entry_t entry = pte_to_swp_entry(oldpte);
66
67 if (is_write_migration_entry(entry)) {
68 /*
69 * A protection check is difficult so
70 * just be safe and disable write
71 */
72 make_migration_entry_read(&entry);
73 set_pte_at(mm, addr, pte,
74 swp_entry_to_pte(entry));
75 }
1da177e4
LT
76 }
77 } while (pte++, addr += PAGE_SIZE, addr != end);
6606c3e0 78 arch_leave_lazy_mmu_mode();
705e87c0 79 pte_unmap_unlock(pte - 1, ptl);
1da177e4
LT
80}
81
82static inline void change_pmd_range(struct mm_struct *mm, pud_t *pud,
c1e6098b
PZ
83 unsigned long addr, unsigned long end, pgprot_t newprot,
84 int dirty_accountable)
1da177e4
LT
85{
86 pmd_t *pmd;
87 unsigned long next;
88
89 pmd = pmd_offset(pud, addr);
90 do {
91 next = pmd_addr_end(addr, end);
92 if (pmd_none_or_clear_bad(pmd))
93 continue;
c1e6098b 94 change_pte_range(mm, pmd, addr, next, newprot, dirty_accountable);
1da177e4
LT
95 } while (pmd++, addr = next, addr != end);
96}
97
98static inline void change_pud_range(struct mm_struct *mm, pgd_t *pgd,
c1e6098b
PZ
99 unsigned long addr, unsigned long end, pgprot_t newprot,
100 int dirty_accountable)
1da177e4
LT
101{
102 pud_t *pud;
103 unsigned long next;
104
105 pud = pud_offset(pgd, addr);
106 do {
107 next = pud_addr_end(addr, end);
108 if (pud_none_or_clear_bad(pud))
109 continue;
c1e6098b 110 change_pmd_range(mm, pud, addr, next, newprot, dirty_accountable);
1da177e4
LT
111 } while (pud++, addr = next, addr != end);
112}
113
114static void change_protection(struct vm_area_struct *vma,
c1e6098b
PZ
115 unsigned long addr, unsigned long end, pgprot_t newprot,
116 int dirty_accountable)
1da177e4
LT
117{
118 struct mm_struct *mm = vma->vm_mm;
119 pgd_t *pgd;
120 unsigned long next;
121 unsigned long start = addr;
122
123 BUG_ON(addr >= end);
124 pgd = pgd_offset(mm, addr);
125 flush_cache_range(vma, addr, end);
1da177e4
LT
126 do {
127 next = pgd_addr_end(addr, end);
128 if (pgd_none_or_clear_bad(pgd))
129 continue;
c1e6098b 130 change_pud_range(mm, pgd, addr, next, newprot, dirty_accountable);
1da177e4
LT
131 } while (pgd++, addr = next, addr != end);
132 flush_tlb_range(vma, start, end);
1da177e4
LT
133}
134
b6a2fea3 135int
1da177e4
LT
136mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev,
137 unsigned long start, unsigned long end, unsigned long newflags)
138{
139 struct mm_struct *mm = vma->vm_mm;
140 unsigned long oldflags = vma->vm_flags;
141 long nrpages = (end - start) >> PAGE_SHIFT;
142 unsigned long charged = 0;
1da177e4
LT
143 pgoff_t pgoff;
144 int error;
c1e6098b 145 int dirty_accountable = 0;
1da177e4
LT
146
147 if (newflags == oldflags) {
148 *pprev = vma;
149 return 0;
150 }
151
152 /*
153 * If we make a private mapping writable we increase our commit;
154 * but (without finer accounting) cannot reduce our commit if we
5a6fe125
MG
155 * make it unwritable again. hugetlb mapping were accounted for
156 * even if read-only so there is no need to account for them here
1da177e4
LT
157 */
158 if (newflags & VM_WRITE) {
5a6fe125 159 if (!(oldflags & (VM_ACCOUNT|VM_WRITE|VM_HUGETLB|
cdfd4325 160 VM_SHARED|VM_NORESERVE))) {
1da177e4
LT
161 charged = nrpages;
162 if (security_vm_enough_memory(charged))
163 return -ENOMEM;
164 newflags |= VM_ACCOUNT;
165 }
166 }
167
1da177e4
LT
168 /*
169 * First try to merge with previous and/or next vma.
170 */
171 pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
172 *pprev = vma_merge(mm, *pprev, start, end, newflags,
173 vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma));
174 if (*pprev) {
175 vma = *pprev;
176 goto success;
177 }
178
179 *pprev = vma;
180
181 if (start != vma->vm_start) {
182 error = split_vma(mm, vma, start, 1);
183 if (error)
184 goto fail;
185 }
186
187 if (end != vma->vm_end) {
188 error = split_vma(mm, vma, end, 0);
189 if (error)
190 goto fail;
191 }
192
193success:
194 /*
195 * vm_flags and vm_page_prot are protected by the mmap_sem
196 * held in write mode.
197 */
198 vma->vm_flags = newflags;
1c12c4cf
VP
199 vma->vm_page_prot = pgprot_modify(vma->vm_page_prot,
200 vm_get_page_prot(newflags));
201
c1e6098b 202 if (vma_wants_writenotify(vma)) {
1ddd439e 203 vma->vm_page_prot = vm_get_page_prot(newflags & ~VM_SHARED);
c1e6098b
PZ
204 dirty_accountable = 1;
205 }
d08b3851 206
cddb8a5c 207 mmu_notifier_invalidate_range_start(mm, start, end);
8f860591 208 if (is_vm_hugetlb_page(vma))
d08b3851 209 hugetlb_change_protection(vma, start, end, vma->vm_page_prot);
8f860591 210 else
c1e6098b 211 change_protection(vma, start, end, vma->vm_page_prot, dirty_accountable);
cddb8a5c 212 mmu_notifier_invalidate_range_end(mm, start, end);
ab50b8ed
HD
213 vm_stat_account(mm, oldflags, vma->vm_file, -nrpages);
214 vm_stat_account(mm, newflags, vma->vm_file, nrpages);
1da177e4
LT
215 return 0;
216
217fail:
218 vm_unacct_memory(charged);
219 return error;
220}
221
6a6160a7
HC
222SYSCALL_DEFINE3(mprotect, unsigned long, start, size_t, len,
223 unsigned long, prot)
1da177e4
LT
224{
225 unsigned long vm_flags, nstart, end, tmp, reqprot;
226 struct vm_area_struct *vma, *prev;
227 int error = -EINVAL;
228 const int grows = prot & (PROT_GROWSDOWN|PROT_GROWSUP);
229 prot &= ~(PROT_GROWSDOWN|PROT_GROWSUP);
230 if (grows == (PROT_GROWSDOWN|PROT_GROWSUP)) /* can't be both */
231 return -EINVAL;
232
233 if (start & ~PAGE_MASK)
234 return -EINVAL;
235 if (!len)
236 return 0;
237 len = PAGE_ALIGN(len);
238 end = start + len;
239 if (end <= start)
240 return -ENOMEM;
b845f313 241 if (!arch_validate_prot(prot))
1da177e4
LT
242 return -EINVAL;
243
244 reqprot = prot;
245 /*
246 * Does the application expect PROT_READ to imply PROT_EXEC:
247 */
b344e05c 248 if ((prot & PROT_READ) && (current->personality & READ_IMPLIES_EXEC))
1da177e4
LT
249 prot |= PROT_EXEC;
250
251 vm_flags = calc_vm_prot_bits(prot);
252
253 down_write(&current->mm->mmap_sem);
254
255 vma = find_vma_prev(current->mm, start, &prev);
256 error = -ENOMEM;
257 if (!vma)
258 goto out;
259 if (unlikely(grows & PROT_GROWSDOWN)) {
260 if (vma->vm_start >= end)
261 goto out;
262 start = vma->vm_start;
263 error = -EINVAL;
264 if (!(vma->vm_flags & VM_GROWSDOWN))
265 goto out;
266 }
267 else {
268 if (vma->vm_start > start)
269 goto out;
270 if (unlikely(grows & PROT_GROWSUP)) {
271 end = vma->vm_end;
272 error = -EINVAL;
273 if (!(vma->vm_flags & VM_GROWSUP))
274 goto out;
275 }
276 }
277 if (start > vma->vm_start)
278 prev = vma;
279
280 for (nstart = start ; ; ) {
281 unsigned long newflags;
282
283 /* Here we know that vma->vm_start <= nstart < vma->vm_end. */
284
1da177e4
LT
285 newflags = vm_flags | (vma->vm_flags & ~(VM_READ | VM_WRITE | VM_EXEC));
286
7e2cff42
PBG
287 /* newflags >> 4 shift VM_MAY% in place of VM_% */
288 if ((newflags & ~(newflags >> 4)) & (VM_READ | VM_WRITE | VM_EXEC)) {
1da177e4
LT
289 error = -EACCES;
290 goto out;
291 }
292
293 error = security_file_mprotect(vma, reqprot, prot);
294 if (error)
295 goto out;
296
297 tmp = vma->vm_end;
298 if (tmp > end)
299 tmp = end;
300 error = mprotect_fixup(vma, &prev, nstart, tmp, newflags);
301 if (error)
302 goto out;
dab5855b 303 perf_counter_mmap(vma);
1da177e4
LT
304 nstart = tmp;
305
306 if (nstart < prev->vm_end)
307 nstart = prev->vm_end;
308 if (nstart >= end)
309 goto out;
310
311 vma = prev->vm_next;
312 if (!vma || vma->vm_start != nstart) {
313 error = -ENOMEM;
314 goto out;
315 }
316 }
317out:
318 up_write(&current->mm->mmap_sem);
319 return error;
320}