Doug / smarc-fsl-linux-kernel

Download as
Browse Code ยป

Commit 61469f1d51777fc3b6d8d70da8373ee77ee13349

Authored by Hugh Dickins
Committed by Linus Torvalds
1 parent 6dbf6d3bb9
Exists in master and in 7 other branches imx_3.0.35_4.1.0, imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga, smarc-l5.0.0_1.0.0-ga

memcg: when do_swap's do_wp_page fails 

Don't uncharge when do_swap_page's call to do_wp_page fails: the page which
was charged for is there in the pagetable, and will be correctly uncharged
when that area is unmapped - it was only its COWing which failed.

And while we're here, remove earlier XXX comment: yes, OR in do_wp_page's
return value (maybe VM_FAULT_WRITE) with do_swap_page's there; but if it
fails, mask out success bits, which might confuse some arches e.g.  sparc.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: David Rientjes <rientjes@google.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hirokazu Takahashi <taka@valinux.co.jp>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Showing 1 changed file with 3 additions and 6 deletions Inline Diff

1 /* 1 /*
2 * linux/mm/memory.c 2 * linux/mm/memory.c
3 * 3 *
4 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds 4 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
5 */ 5 */
6 6
7 /* 7 /*
8 * demand-loading started 01.12.91 - seems it is high on the list of 8 * demand-loading started 01.12.91 - seems it is high on the list of
9 * things wanted, and it should be easy to implement. - Linus 9 * things wanted, and it should be easy to implement. - Linus
10 */ 10 */
11 11
12 /* 12 /*
13 * Ok, demand-loading was easy, shared pages a little bit tricker. Shared 13 * Ok, demand-loading was easy, shared pages a little bit tricker. Shared
14 * pages started 02.12.91, seems to work. - Linus. 14 * pages started 02.12.91, seems to work. - Linus.
15 * 15 *
16 * Tested sharing by executing about 30 /bin/sh: under the old kernel it 16 * Tested sharing by executing about 30 /bin/sh: under the old kernel it
17 * would have taken more than the 6M I have free, but it worked well as 17 * would have taken more than the 6M I have free, but it worked well as
18 * far as I could see. 18 * far as I could see.
19 * 19 *
20 * Also corrected some "invalidate()"s - I wasn't doing enough of them. 20 * Also corrected some "invalidate()"s - I wasn't doing enough of them.
21 */ 21 */
22 22
23 /* 23 /*
24 * Real VM (paging to/from disk) started 18.12.91. Much more work and 24 * Real VM (paging to/from disk) started 18.12.91. Much more work and
25 * thought has to go into this. Oh, well.. 25 * thought has to go into this. Oh, well..
26 * 19.12.91 - works, somewhat. Sometimes I get faults, don't know why. 26 * 19.12.91 - works, somewhat. Sometimes I get faults, don't know why.
27 * Found it. Everything seems to work now. 27 * Found it. Everything seems to work now.
28 * 20.12.91 - Ok, making the swap-device changeable like the root. 28 * 20.12.91 - Ok, making the swap-device changeable like the root.
29 */ 29 */
30 30
31 /* 31 /*
32 * 05.04.94 - Multi-page memory management added for v1.1. 32 * 05.04.94 - Multi-page memory management added for v1.1.
33 * Idea by Alex Bligh (alex@cconcepts.co.uk) 33 * Idea by Alex Bligh (alex@cconcepts.co.uk)
34 * 34 *
35 * 16.07.99 - Support of BIGMEM added by Gerhard Wichert, Siemens AG 35 * 16.07.99 - Support of BIGMEM added by Gerhard Wichert, Siemens AG
36 * (Gerhard.Wichert@pdb.siemens.de) 36 * (Gerhard.Wichert@pdb.siemens.de)
37 * 37 *
38 * Aug/Sep 2004 Changed to four level page tables (Andi Kleen) 38 * Aug/Sep 2004 Changed to four level page tables (Andi Kleen)
39 */ 39 */
40 40
41 #include <linux/kernel_stat.h> 41 #include <linux/kernel_stat.h>
42 #include <linux/mm.h> 42 #include <linux/mm.h>
43 #include <linux/hugetlb.h> 43 #include <linux/hugetlb.h>
44 #include <linux/mman.h> 44 #include <linux/mman.h>
45 #include <linux/swap.h> 45 #include <linux/swap.h>
46 #include <linux/highmem.h> 46 #include <linux/highmem.h>
47 #include <linux/pagemap.h> 47 #include <linux/pagemap.h>
48 #include <linux/rmap.h> 48 #include <linux/rmap.h>
49 #include <linux/module.h> 49 #include <linux/module.h>
50 #include <linux/delayacct.h> 50 #include <linux/delayacct.h>
51 #include <linux/init.h> 51 #include <linux/init.h>
52 #include <linux/writeback.h> 52 #include <linux/writeback.h>
53 #include <linux/memcontrol.h> 53 #include <linux/memcontrol.h>
54 54
55 #include <asm/pgalloc.h> 55 #include <asm/pgalloc.h>
56 #include <asm/uaccess.h> 56 #include <asm/uaccess.h>
57 #include <asm/tlb.h> 57 #include <asm/tlb.h>
58 #include <asm/tlbflush.h> 58 #include <asm/tlbflush.h>
59 #include <asm/pgtable.h> 59 #include <asm/pgtable.h>
60 60
61 #include <linux/swapops.h> 61 #include <linux/swapops.h>
62 #include <linux/elf.h> 62 #include <linux/elf.h>
63 63
64 #ifndef CONFIG_NEED_MULTIPLE_NODES 64 #ifndef CONFIG_NEED_MULTIPLE_NODES
65 /* use the per-pgdat data instead for discontigmem - mbligh */ 65 /* use the per-pgdat data instead for discontigmem - mbligh */
66 unsigned long max_mapnr; 66 unsigned long max_mapnr;
67 struct page *mem_map; 67 struct page *mem_map;
68 68
69 EXPORT_SYMBOL(max_mapnr); 69 EXPORT_SYMBOL(max_mapnr);
70 EXPORT_SYMBOL(mem_map); 70 EXPORT_SYMBOL(mem_map);
71 #endif 71 #endif
72 72
73 unsigned long num_physpages; 73 unsigned long num_physpages;
74 /* 74 /*
75 * A number of key systems in x86 including ioremap() rely on the assumption 75 * A number of key systems in x86 including ioremap() rely on the assumption
76 * that high_memory defines the upper bound on direct map memory, then end 76 * that high_memory defines the upper bound on direct map memory, then end
77 * of ZONE_NORMAL. Under CONFIG_DISCONTIG this means that max_low_pfn and 77 * of ZONE_NORMAL. Under CONFIG_DISCONTIG this means that max_low_pfn and
78 * highstart_pfn must be the same; there must be no gap between ZONE_NORMAL 78 * highstart_pfn must be the same; there must be no gap between ZONE_NORMAL
79 * and ZONE_HIGHMEM. 79 * and ZONE_HIGHMEM.
80 */ 80 */
81 void * high_memory; 81 void * high_memory;
82 82
83 EXPORT_SYMBOL(num_physpages); 83 EXPORT_SYMBOL(num_physpages);
84 EXPORT_SYMBOL(high_memory); 84 EXPORT_SYMBOL(high_memory);
85 85
86 /* 86 /*
87 * Randomize the address space (stacks, mmaps, brk, etc.). 87 * Randomize the address space (stacks, mmaps, brk, etc.).
88 * 88 *
89 * ( When CONFIG_COMPAT_BRK=y we exclude brk from randomization, 89 * ( When CONFIG_COMPAT_BRK=y we exclude brk from randomization,
90 * as ancient (libc5 based) binaries can segfault. ) 90 * as ancient (libc5 based) binaries can segfault. )
91 */ 91 */
92 int randomize_va_space __read_mostly = 92 int randomize_va_space __read_mostly =
93 #ifdef CONFIG_COMPAT_BRK 93 #ifdef CONFIG_COMPAT_BRK
94 1; 94 1;
95 #else 95 #else
96 2; 96 2;
97 #endif 97 #endif
98 98
99 static int __init disable_randmaps(char *s) 99 static int __init disable_randmaps(char *s)
100 { 100 {
101 randomize_va_space = 0; 101 randomize_va_space = 0;
102 return 1; 102 return 1;
103 } 103 }
104 __setup("norandmaps", disable_randmaps); 104 __setup("norandmaps", disable_randmaps);
105 105
106 106
107 /* 107 /*
108 * If a p?d_bad entry is found while walking page tables, report 108 * If a p?d_bad entry is found while walking page tables, report
109 * the error, before resetting entry to p?d_none. Usually (but 109 * the error, before resetting entry to p?d_none. Usually (but
110 * very seldom) called out from the p?d_none_or_clear_bad macros. 110 * very seldom) called out from the p?d_none_or_clear_bad macros.
111 */ 111 */
112 112
113 void pgd_clear_bad(pgd_t *pgd) 113 void pgd_clear_bad(pgd_t *pgd)
114 { 114 {
115 pgd_ERROR(*pgd); 115 pgd_ERROR(*pgd);
116 pgd_clear(pgd); 116 pgd_clear(pgd);
117 } 117 }
118 118
119 void pud_clear_bad(pud_t *pud) 119 void pud_clear_bad(pud_t *pud)
120 { 120 {
121 pud_ERROR(*pud); 121 pud_ERROR(*pud);
122 pud_clear(pud); 122 pud_clear(pud);
123 } 123 }
124 124
125 void pmd_clear_bad(pmd_t *pmd) 125 void pmd_clear_bad(pmd_t *pmd)
126 { 126 {
127 pmd_ERROR(*pmd); 127 pmd_ERROR(*pmd);
128 pmd_clear(pmd); 128 pmd_clear(pmd);
129 } 129 }
130 130
131 /* 131 /*
132 * Note: this doesn't free the actual pages themselves. That 132 * Note: this doesn't free the actual pages themselves. That
133 * has been handled earlier when unmapping all the memory regions. 133 * has been handled earlier when unmapping all the memory regions.
134 */ 134 */
135 static void free_pte_range(struct mmu_gather *tlb, pmd_t *pmd) 135 static void free_pte_range(struct mmu_gather *tlb, pmd_t *pmd)
136 { 136 {
137 pgtable_t token = pmd_pgtable(*pmd); 137 pgtable_t token = pmd_pgtable(*pmd);
138 pmd_clear(pmd); 138 pmd_clear(pmd);
139 pte_free_tlb(tlb, token); 139 pte_free_tlb(tlb, token);
140 tlb->mm->nr_ptes--; 140 tlb->mm->nr_ptes--;
141 } 141 }
142 142
143 static inline void free_pmd_range(struct mmu_gather *tlb, pud_t *pud, 143 static inline void free_pmd_range(struct mmu_gather *tlb, pud_t *pud,
144 unsigned long addr, unsigned long end, 144 unsigned long addr, unsigned long end,
145 unsigned long floor, unsigned long ceiling) 145 unsigned long floor, unsigned long ceiling)
146 { 146 {
147 pmd_t *pmd; 147 pmd_t *pmd;
148 unsigned long next; 148 unsigned long next;
149 unsigned long start; 149 unsigned long start;
150 150
151 start = addr; 151 start = addr;
152 pmd = pmd_offset(pud, addr); 152 pmd = pmd_offset(pud, addr);
153 do { 153 do {
154 next = pmd_addr_end(addr, end); 154 next = pmd_addr_end(addr, end);
155 if (pmd_none_or_clear_bad(pmd)) 155 if (pmd_none_or_clear_bad(pmd))
156 continue; 156 continue;
157 free_pte_range(tlb, pmd); 157 free_pte_range(tlb, pmd);
158 } while (pmd++, addr = next, addr != end); 158 } while (pmd++, addr = next, addr != end);
159 159
160 start &= PUD_MASK; 160 start &= PUD_MASK;
161 if (start < floor) 161 if (start < floor)
162 return; 162 return;
163 if (ceiling) { 163 if (ceiling) {
164 ceiling &= PUD_MASK; 164 ceiling &= PUD_MASK;
165 if (!ceiling) 165 if (!ceiling)
166 return; 166 return;
167 } 167 }
168 if (end - 1 > ceiling - 1) 168 if (end - 1 > ceiling - 1)
169 return; 169 return;
170 170
171 pmd = pmd_offset(pud, start); 171 pmd = pmd_offset(pud, start);
172 pud_clear(pud); 172 pud_clear(pud);
173 pmd_free_tlb(tlb, pmd); 173 pmd_free_tlb(tlb, pmd);
174 } 174 }
175 175
176 static inline void free_pud_range(struct mmu_gather *tlb, pgd_t *pgd, 176 static inline void free_pud_range(struct mmu_gather *tlb, pgd_t *pgd,
177 unsigned long addr, unsigned long end, 177 unsigned long addr, unsigned long end,
178 unsigned long floor, unsigned long ceiling) 178 unsigned long floor, unsigned long ceiling)
179 { 179 {
180 pud_t *pud; 180 pud_t *pud;
181 unsigned long next; 181 unsigned long next;
182 unsigned long start; 182 unsigned long start;
183 183
184 start = addr; 184 start = addr;
185 pud = pud_offset(pgd, addr); 185 pud = pud_offset(pgd, addr);
186 do { 186 do {
187 next = pud_addr_end(addr, end); 187 next = pud_addr_end(addr, end);
188 if (pud_none_or_clear_bad(pud)) 188 if (pud_none_or_clear_bad(pud))
189 continue; 189 continue;
190 free_pmd_range(tlb, pud, addr, next, floor, ceiling); 190 free_pmd_range(tlb, pud, addr, next, floor, ceiling);
191 } while (pud++, addr = next, addr != end); 191 } while (pud++, addr = next, addr != end);
192 192
193 start &= PGDIR_MASK; 193 start &= PGDIR_MASK;
194 if (start < floor) 194 if (start < floor)
195 return; 195 return;
196 if (ceiling) { 196 if (ceiling) {
197 ceiling &= PGDIR_MASK; 197 ceiling &= PGDIR_MASK;
198 if (!ceiling) 198 if (!ceiling)
199 return; 199 return;
200 } 200 }
201 if (end - 1 > ceiling - 1) 201 if (end - 1 > ceiling - 1)
202 return; 202 return;
203 203
204 pud = pud_offset(pgd, start); 204 pud = pud_offset(pgd, start);
205 pgd_clear(pgd); 205 pgd_clear(pgd);
206 pud_free_tlb(tlb, pud); 206 pud_free_tlb(tlb, pud);
207 } 207 }
208 208
209 /* 209 /*
210 * This function frees user-level page tables of a process. 210 * This function frees user-level page tables of a process.
211 * 211 *
212 * Must be called with pagetable lock held. 212 * Must be called with pagetable lock held.
213 */ 213 */
214 void free_pgd_range(struct mmu_gather **tlb, 214 void free_pgd_range(struct mmu_gather **tlb,
215 unsigned long addr, unsigned long end, 215 unsigned long addr, unsigned long end,
216 unsigned long floor, unsigned long ceiling) 216 unsigned long floor, unsigned long ceiling)
217 { 217 {
218 pgd_t *pgd; 218 pgd_t *pgd;
219 unsigned long next; 219 unsigned long next;
220 unsigned long start; 220 unsigned long start;
221 221
222 /* 222 /*
223 * The next few lines have given us lots of grief... 223 * The next few lines have given us lots of grief...
224 * 224 *
225 * Why are we testing PMD* at this top level? Because often 225 * Why are we testing PMD* at this top level? Because often
226 * there will be no work to do at all, and we'd prefer not to 226 * there will be no work to do at all, and we'd prefer not to
227 * go all the way down to the bottom just to discover that. 227 * go all the way down to the bottom just to discover that.
228 * 228 *
229 * Why all these "- 1"s? Because 0 represents both the bottom 229 * Why all these "- 1"s? Because 0 represents both the bottom
230 * of the address space and the top of it (using -1 for the 230 * of the address space and the top of it (using -1 for the
231 * top wouldn't help much: the masks would do the wrong thing). 231 * top wouldn't help much: the masks would do the wrong thing).
232 * The rule is that addr 0 and floor 0 refer to the bottom of 232 * The rule is that addr 0 and floor 0 refer to the bottom of
233 * the address space, but end 0 and ceiling 0 refer to the top 233 * the address space, but end 0 and ceiling 0 refer to the top
234 * Comparisons need to use "end - 1" and "ceiling - 1" (though 234 * Comparisons need to use "end - 1" and "ceiling - 1" (though
235 * that end 0 case should be mythical). 235 * that end 0 case should be mythical).
236 * 236 *
237 * Wherever addr is brought up or ceiling brought down, we must 237 * Wherever addr is brought up or ceiling brought down, we must
238 * be careful to reject "the opposite 0" before it confuses the 238 * be careful to reject "the opposite 0" before it confuses the
239 * subsequent tests. But what about where end is brought down 239 * subsequent tests. But what about where end is brought down
240 * by PMD_SIZE below? no, end can't go down to 0 there. 240 * by PMD_SIZE below? no, end can't go down to 0 there.
241 * 241 *
242 * Whereas we round start (addr) and ceiling down, by different 242 * Whereas we round start (addr) and ceiling down, by different
243 * masks at different levels, in order to test whether a table 243 * masks at different levels, in order to test whether a table
244 * now has no other vmas using it, so can be freed, we don't 244 * now has no other vmas using it, so can be freed, we don't
245 * bother to round floor or end up - the tests don't need that. 245 * bother to round floor or end up - the tests don't need that.
246 */ 246 */
247 247
248 addr &= PMD_MASK; 248 addr &= PMD_MASK;
249 if (addr < floor) { 249 if (addr < floor) {
250 addr += PMD_SIZE; 250 addr += PMD_SIZE;
251 if (!addr) 251 if (!addr)
252 return; 252 return;
253 } 253 }
254 if (ceiling) { 254 if (ceiling) {
255 ceiling &= PMD_MASK; 255 ceiling &= PMD_MASK;
256 if (!ceiling) 256 if (!ceiling)
257 return; 257 return;
258 } 258 }
259 if (end - 1 > ceiling - 1) 259 if (end - 1 > ceiling - 1)
260 end -= PMD_SIZE; 260 end -= PMD_SIZE;
261 if (addr > end - 1) 261 if (addr > end - 1)
262 return; 262 return;
263 263
264 start = addr; 264 start = addr;
265 pgd = pgd_offset((*tlb)->mm, addr); 265 pgd = pgd_offset((*tlb)->mm, addr);
266 do { 266 do {
267 next = pgd_addr_end(addr, end); 267 next = pgd_addr_end(addr, end);
268 if (pgd_none_or_clear_bad(pgd)) 268 if (pgd_none_or_clear_bad(pgd))
269 continue; 269 continue;
270 free_pud_range(*tlb, pgd, addr, next, floor, ceiling); 270 free_pud_range(*tlb, pgd, addr, next, floor, ceiling);
271 } while (pgd++, addr = next, addr != end); 271 } while (pgd++, addr = next, addr != end);
272 } 272 }
273 273
274 void free_pgtables(struct mmu_gather **tlb, struct vm_area_struct *vma, 274 void free_pgtables(struct mmu_gather **tlb, struct vm_area_struct *vma,
275 unsigned long floor, unsigned long ceiling) 275 unsigned long floor, unsigned long ceiling)
276 { 276 {
277 while (vma) { 277 while (vma) {
278 struct vm_area_struct *next = vma->vm_next; 278 struct vm_area_struct *next = vma->vm_next;
279 unsigned long addr = vma->vm_start; 279 unsigned long addr = vma->vm_start;
280 280
281 /* 281 /*
282 * Hide vma from rmap and vmtruncate before freeing pgtables 282 * Hide vma from rmap and vmtruncate before freeing pgtables
283 */ 283 */
284 anon_vma_unlink(vma); 284 anon_vma_unlink(vma);
285 unlink_file_vma(vma); 285 unlink_file_vma(vma);
286 286
287 if (is_vm_hugetlb_page(vma)) { 287 if (is_vm_hugetlb_page(vma)) {
288 hugetlb_free_pgd_range(tlb, addr, vma->vm_end, 288 hugetlb_free_pgd_range(tlb, addr, vma->vm_end,
289 floor, next? next->vm_start: ceiling); 289 floor, next? next->vm_start: ceiling);
290 } else { 290 } else {
291 /* 291 /*
292 * Optimization: gather nearby vmas into one call down 292 * Optimization: gather nearby vmas into one call down
293 */ 293 */
294 while (next && next->vm_start <= vma->vm_end + PMD_SIZE 294 while (next && next->vm_start <= vma->vm_end + PMD_SIZE
295 && !is_vm_hugetlb_page(next)) { 295 && !is_vm_hugetlb_page(next)) {
296 vma = next; 296 vma = next;
297 next = vma->vm_next; 297 next = vma->vm_next;
298 anon_vma_unlink(vma); 298 anon_vma_unlink(vma);
299 unlink_file_vma(vma); 299 unlink_file_vma(vma);
300 } 300 }
301 free_pgd_range(tlb, addr, vma->vm_end, 301 free_pgd_range(tlb, addr, vma->vm_end,
302 floor, next? next->vm_start: ceiling); 302 floor, next? next->vm_start: ceiling);
303 } 303 }
304 vma = next; 304 vma = next;
305 } 305 }
306 } 306 }
307 307
308 int __pte_alloc(struct mm_struct *mm, pmd_t *pmd, unsigned long address) 308 int __pte_alloc(struct mm_struct *mm, pmd_t *pmd, unsigned long address)
309 { 309 {
310 pgtable_t new = pte_alloc_one(mm, address); 310 pgtable_t new = pte_alloc_one(mm, address);
311 if (!new) 311 if (!new)
312 return -ENOMEM; 312 return -ENOMEM;
313 313
314 spin_lock(&mm->page_table_lock); 314 spin_lock(&mm->page_table_lock);
315 if (!pmd_present(*pmd)) { /* Has another populated it ? */ 315 if (!pmd_present(*pmd)) { /* Has another populated it ? */
316 mm->nr_ptes++; 316 mm->nr_ptes++;
317 pmd_populate(mm, pmd, new); 317 pmd_populate(mm, pmd, new);
318 new = NULL; 318 new = NULL;
319 } 319 }
320 spin_unlock(&mm->page_table_lock); 320 spin_unlock(&mm->page_table_lock);
321 if (new) 321 if (new)
322 pte_free(mm, new); 322 pte_free(mm, new);
323 return 0; 323 return 0;
324 } 324 }
325 325
326 int __pte_alloc_kernel(pmd_t *pmd, unsigned long address) 326 int __pte_alloc_kernel(pmd_t *pmd, unsigned long address)
327 { 327 {
328 pte_t *new = pte_alloc_one_kernel(&init_mm, address); 328 pte_t *new = pte_alloc_one_kernel(&init_mm, address);
329 if (!new) 329 if (!new)
330 return -ENOMEM; 330 return -ENOMEM;
331 331
332 spin_lock(&init_mm.page_table_lock); 332 spin_lock(&init_mm.page_table_lock);
333 if (!pmd_present(*pmd)) { /* Has another populated it ? */ 333 if (!pmd_present(*pmd)) { /* Has another populated it ? */
334 pmd_populate_kernel(&init_mm, pmd, new); 334 pmd_populate_kernel(&init_mm, pmd, new);
335 new = NULL; 335 new = NULL;
336 } 336 }
337 spin_unlock(&init_mm.page_table_lock); 337 spin_unlock(&init_mm.page_table_lock);
338 if (new) 338 if (new)
339 pte_free_kernel(&init_mm, new); 339 pte_free_kernel(&init_mm, new);
340 return 0; 340 return 0;
341 } 341 }
342 342
343 static inline void add_mm_rss(struct mm_struct *mm, int file_rss, int anon_rss) 343 static inline void add_mm_rss(struct mm_struct *mm, int file_rss, int anon_rss)
344 { 344 {
345 if (file_rss) 345 if (file_rss)
346 add_mm_counter(mm, file_rss, file_rss); 346 add_mm_counter(mm, file_rss, file_rss);
347 if (anon_rss) 347 if (anon_rss)
348 add_mm_counter(mm, anon_rss, anon_rss); 348 add_mm_counter(mm, anon_rss, anon_rss);
349 } 349 }
350 350
351 /* 351 /*
352 * This function is called to print an error when a bad pte 352 * This function is called to print an error when a bad pte
353 * is found. For example, we might have a PFN-mapped pte in 353 * is found. For example, we might have a PFN-mapped pte in
354 * a region that doesn't allow it. 354 * a region that doesn't allow it.
355 * 355 *
356 * The calling function must still handle the error. 356 * The calling function must still handle the error.
357 */ 357 */
358 void print_bad_pte(struct vm_area_struct *vma, pte_t pte, unsigned long vaddr) 358 void print_bad_pte(struct vm_area_struct *vma, pte_t pte, unsigned long vaddr)
359 { 359 {
360 printk(KERN_ERR "Bad pte = %08llx, process = %s, " 360 printk(KERN_ERR "Bad pte = %08llx, process = %s, "
361 "vm_flags = %lx, vaddr = %lx\n", 361 "vm_flags = %lx, vaddr = %lx\n",
362 (long long)pte_val(pte), 362 (long long)pte_val(pte),
363 (vma->vm_mm == current->mm ? current->comm : "???"), 363 (vma->vm_mm == current->mm ? current->comm : "???"),
364 vma->vm_flags, vaddr); 364 vma->vm_flags, vaddr);
365 dump_stack(); 365 dump_stack();
366 } 366 }
367 367
368 static inline int is_cow_mapping(unsigned int flags) 368 static inline int is_cow_mapping(unsigned int flags)
369 { 369 {
370 return (flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; 370 return (flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE;
371 } 371 }
372 372
373 /* 373 /*
374 * This function gets the "struct page" associated with a pte. 374 * This function gets the "struct page" associated with a pte.
375 * 375 *
376 * NOTE! Some mappings do not have "struct pages". A raw PFN mapping 376 * NOTE! Some mappings do not have "struct pages". A raw PFN mapping
377 * will have each page table entry just pointing to a raw page frame 377 * will have each page table entry just pointing to a raw page frame
378 * number, and as far as the VM layer is concerned, those do not have 378 * number, and as far as the VM layer is concerned, those do not have
379 * pages associated with them - even if the PFN might point to memory 379 * pages associated with them - even if the PFN might point to memory
380 * that otherwise is perfectly fine and has a "struct page". 380 * that otherwise is perfectly fine and has a "struct page".
381 * 381 *
382 * The way we recognize those mappings is through the rules set up 382 * The way we recognize those mappings is through the rules set up
383 * by "remap_pfn_range()": the vma will have the VM_PFNMAP bit set, 383 * by "remap_pfn_range()": the vma will have the VM_PFNMAP bit set,
384 * and the vm_pgoff will point to the first PFN mapped: thus every 384 * and the vm_pgoff will point to the first PFN mapped: thus every
385 * page that is a raw mapping will always honor the rule 385 * page that is a raw mapping will always honor the rule
386 * 386 *
387 * pfn_of_page == vma->vm_pgoff + ((addr - vma->vm_start) >> PAGE_SHIFT) 387 * pfn_of_page == vma->vm_pgoff + ((addr - vma->vm_start) >> PAGE_SHIFT)
388 * 388 *
389 * and if that isn't true, the page has been COW'ed (in which case it 389 * and if that isn't true, the page has been COW'ed (in which case it
390 * _does_ have a "struct page" associated with it even if it is in a 390 * _does_ have a "struct page" associated with it even if it is in a
391 * VM_PFNMAP range). 391 * VM_PFNMAP range).
392 */ 392 */
393 struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr, pte_t pte) 393 struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr, pte_t pte)
394 { 394 {
395 unsigned long pfn = pte_pfn(pte); 395 unsigned long pfn = pte_pfn(pte);
396 396
397 if (unlikely(vma->vm_flags & VM_PFNMAP)) { 397 if (unlikely(vma->vm_flags & VM_PFNMAP)) {
398 unsigned long off = (addr - vma->vm_start) >> PAGE_SHIFT; 398 unsigned long off = (addr - vma->vm_start) >> PAGE_SHIFT;
399 if (pfn == vma->vm_pgoff + off) 399 if (pfn == vma->vm_pgoff + off)
400 return NULL; 400 return NULL;
401 if (!is_cow_mapping(vma->vm_flags)) 401 if (!is_cow_mapping(vma->vm_flags))
402 return NULL; 402 return NULL;
403 } 403 }
404 404
405 #ifdef CONFIG_DEBUG_VM 405 #ifdef CONFIG_DEBUG_VM
406 /* 406 /*
407 * Add some anal sanity checks for now. Eventually, 407 * Add some anal sanity checks for now. Eventually,
408 * we should just do "return pfn_to_page(pfn)", but 408 * we should just do "return pfn_to_page(pfn)", but
409 * in the meantime we check that we get a valid pfn, 409 * in the meantime we check that we get a valid pfn,
410 * and that the resulting page looks ok. 410 * and that the resulting page looks ok.
411 */ 411 */
412 if (unlikely(!pfn_valid(pfn))) { 412 if (unlikely(!pfn_valid(pfn))) {
413 print_bad_pte(vma, pte, addr); 413 print_bad_pte(vma, pte, addr);
414 return NULL; 414 return NULL;
415 } 415 }
416 #endif 416 #endif
417 417
418 /* 418 /*
419 * NOTE! We still have PageReserved() pages in the page 419 * NOTE! We still have PageReserved() pages in the page
420 * tables. 420 * tables.
421 * 421 *
422 * The PAGE_ZERO() pages and various VDSO mappings can 422 * The PAGE_ZERO() pages and various VDSO mappings can
423 * cause them to exist. 423 * cause them to exist.
424 */ 424 */
425 return pfn_to_page(pfn); 425 return pfn_to_page(pfn);
426 } 426 }
427 427
428 /* 428 /*
429 * copy one vm_area from one task to the other. Assumes the page tables 429 * copy one vm_area from one task to the other. Assumes the page tables
430 * already present in the new task to be cleared in the whole range 430 * already present in the new task to be cleared in the whole range
431 * covered by this vma. 431 * covered by this vma.
432 */ 432 */
433 433
434 static inline void 434 static inline void
435 copy_one_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm, 435 copy_one_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm,
436 pte_t *dst_pte, pte_t *src_pte, struct vm_area_struct *vma, 436 pte_t *dst_pte, pte_t *src_pte, struct vm_area_struct *vma,
437 unsigned long addr, int *rss) 437 unsigned long addr, int *rss)
438 { 438 {
439 unsigned long vm_flags = vma->vm_flags; 439 unsigned long vm_flags = vma->vm_flags;
440 pte_t pte = *src_pte; 440 pte_t pte = *src_pte;
441 struct page *page; 441 struct page *page;
442 442
443 /* pte contains position in swap or file, so copy. */ 443 /* pte contains position in swap or file, so copy. */
444 if (unlikely(!pte_present(pte))) { 444 if (unlikely(!pte_present(pte))) {
445 if (!pte_file(pte)) { 445 if (!pte_file(pte)) {
446 swp_entry_t entry = pte_to_swp_entry(pte); 446 swp_entry_t entry = pte_to_swp_entry(pte);
447 447
448 swap_duplicate(entry); 448 swap_duplicate(entry);
449 /* make sure dst_mm is on swapoff's mmlist. */ 449 /* make sure dst_mm is on swapoff's mmlist. */
450 if (unlikely(list_empty(&dst_mm->mmlist))) { 450 if (unlikely(list_empty(&dst_mm->mmlist))) {
451 spin_lock(&mmlist_lock); 451 spin_lock(&mmlist_lock);
452 if (list_empty(&dst_mm->mmlist)) 452 if (list_empty(&dst_mm->mmlist))
453 list_add(&dst_mm->mmlist, 453 list_add(&dst_mm->mmlist,
454 &src_mm->mmlist); 454 &src_mm->mmlist);
455 spin_unlock(&mmlist_lock); 455 spin_unlock(&mmlist_lock);
456 } 456 }
457 if (is_write_migration_entry(entry) && 457 if (is_write_migration_entry(entry) &&
458 is_cow_mapping(vm_flags)) { 458 is_cow_mapping(vm_flags)) {
459 /* 459 /*
460 * COW mappings require pages in both parent 460 * COW mappings require pages in both parent
461 * and child to be set to read. 461 * and child to be set to read.
462 */ 462 */
463 make_migration_entry_read(&entry); 463 make_migration_entry_read(&entry);
464 pte = swp_entry_to_pte(entry); 464 pte = swp_entry_to_pte(entry);
465 set_pte_at(src_mm, addr, src_pte, pte); 465 set_pte_at(src_mm, addr, src_pte, pte);
466 } 466 }
467 } 467 }
468 goto out_set_pte; 468 goto out_set_pte;
469 } 469 }
470 470
471 /* 471 /*
472 * If it's a COW mapping, write protect it both 472 * If it's a COW mapping, write protect it both
473 * in the parent and the child 473 * in the parent and the child
474 */ 474 */
475 if (is_cow_mapping(vm_flags)) { 475 if (is_cow_mapping(vm_flags)) {
476 ptep_set_wrprotect(src_mm, addr, src_pte); 476 ptep_set_wrprotect(src_mm, addr, src_pte);
477 pte = pte_wrprotect(pte); 477 pte = pte_wrprotect(pte);
478 } 478 }
479 479
480 /* 480 /*
481 * If it's a shared mapping, mark it clean in 481 * If it's a shared mapping, mark it clean in
482 * the child 482 * the child
483 */ 483 */
484 if (vm_flags & VM_SHARED) 484 if (vm_flags & VM_SHARED)
485 pte = pte_mkclean(pte); 485 pte = pte_mkclean(pte);
486 pte = pte_mkold(pte); 486 pte = pte_mkold(pte);
487 487
488 page = vm_normal_page(vma, addr, pte); 488 page = vm_normal_page(vma, addr, pte);
489 if (page) { 489 if (page) {
490 get_page(page); 490 get_page(page);
491 page_dup_rmap(page, vma, addr); 491 page_dup_rmap(page, vma, addr);
492 rss[!!PageAnon(page)]++; 492 rss[!!PageAnon(page)]++;
493 } 493 }
494 494
495 out_set_pte: 495 out_set_pte:
496 set_pte_at(dst_mm, addr, dst_pte, pte); 496 set_pte_at(dst_mm, addr, dst_pte, pte);
497 } 497 }
498 498
499 static int copy_pte_range(struct mm_struct *dst_mm, struct mm_struct *src_mm, 499 static int copy_pte_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
500 pmd_t *dst_pmd, pmd_t *src_pmd, struct vm_area_struct *vma, 500 pmd_t *dst_pmd, pmd_t *src_pmd, struct vm_area_struct *vma,
501 unsigned long addr, unsigned long end) 501 unsigned long addr, unsigned long end)
502 { 502 {
503 pte_t *src_pte, *dst_pte; 503 pte_t *src_pte, *dst_pte;
504 spinlock_t *src_ptl, *dst_ptl; 504 spinlock_t *src_ptl, *dst_ptl;
505 int progress = 0; 505 int progress = 0;
506 int rss[2]; 506 int rss[2];
507 507
508 again: 508 again:
509 rss[1] = rss[0] = 0; 509 rss[1] = rss[0] = 0;
510 dst_pte = pte_alloc_map_lock(dst_mm, dst_pmd, addr, &dst_ptl); 510 dst_pte = pte_alloc_map_lock(dst_mm, dst_pmd, addr, &dst_ptl);
511 if (!dst_pte) 511 if (!dst_pte)
512 return -ENOMEM; 512 return -ENOMEM;
513 src_pte = pte_offset_map_nested(src_pmd, addr); 513 src_pte = pte_offset_map_nested(src_pmd, addr);
514 src_ptl = pte_lockptr(src_mm, src_pmd); 514 src_ptl = pte_lockptr(src_mm, src_pmd);
515 spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); 515 spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING);
516 arch_enter_lazy_mmu_mode(); 516 arch_enter_lazy_mmu_mode();
517 517
518 do { 518 do {
519 /* 519 /*
520 * We are holding two locks at this point - either of them 520 * We are holding two locks at this point - either of them
521 * could generate latencies in another task on another CPU. 521 * could generate latencies in another task on another CPU.
522 */ 522 */
523 if (progress >= 32) { 523 if (progress >= 32) {
524 progress = 0; 524 progress = 0;
525 if (need_resched() || 525 if (need_resched() ||
526 spin_needbreak(src_ptl) || spin_needbreak(dst_ptl)) 526 spin_needbreak(src_ptl) || spin_needbreak(dst_ptl))
527 break; 527 break;
528 } 528 }
529 if (pte_none(*src_pte)) { 529 if (pte_none(*src_pte)) {
530 progress++; 530 progress++;
531 continue; 531 continue;
532 } 532 }
533 copy_one_pte(dst_mm, src_mm, dst_pte, src_pte, vma, addr, rss); 533 copy_one_pte(dst_mm, src_mm, dst_pte, src_pte, vma, addr, rss);
534 progress += 8; 534 progress += 8;
535 } while (dst_pte++, src_pte++, addr += PAGE_SIZE, addr != end); 535 } while (dst_pte++, src_pte++, addr += PAGE_SIZE, addr != end);
536 536
537 arch_leave_lazy_mmu_mode(); 537 arch_leave_lazy_mmu_mode();
538 spin_unlock(src_ptl); 538 spin_unlock(src_ptl);
539 pte_unmap_nested(src_pte - 1); 539 pte_unmap_nested(src_pte - 1);
540 add_mm_rss(dst_mm, rss[0], rss[1]); 540 add_mm_rss(dst_mm, rss[0], rss[1]);
541 pte_unmap_unlock(dst_pte - 1, dst_ptl); 541 pte_unmap_unlock(dst_pte - 1, dst_ptl);
542 cond_resched(); 542 cond_resched();
543 if (addr != end) 543 if (addr != end)
544 goto again; 544 goto again;
545 return 0; 545 return 0;
546 } 546 }
547 547
548 static inline int copy_pmd_range(struct mm_struct *dst_mm, struct mm_struct *src_mm, 548 static inline int copy_pmd_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
549 pud_t *dst_pud, pud_t *src_pud, struct vm_area_struct *vma, 549 pud_t *dst_pud, pud_t *src_pud, struct vm_area_struct *vma,
550 unsigned long addr, unsigned long end) 550 unsigned long addr, unsigned long end)
551 { 551 {
552 pmd_t *src_pmd, *dst_pmd; 552 pmd_t *src_pmd, *dst_pmd;
553 unsigned long next; 553 unsigned long next;
554 554
555 dst_pmd = pmd_alloc(dst_mm, dst_pud, addr); 555 dst_pmd = pmd_alloc(dst_mm, dst_pud, addr);
556 if (!dst_pmd) 556 if (!dst_pmd)
557 return -ENOMEM; 557 return -ENOMEM;
558 src_pmd = pmd_offset(src_pud, addr); 558 src_pmd = pmd_offset(src_pud, addr);
559 do { 559 do {
560 next = pmd_addr_end(addr, end); 560 next = pmd_addr_end(addr, end);
561 if (pmd_none_or_clear_bad(src_pmd)) 561 if (pmd_none_or_clear_bad(src_pmd))
562 continue; 562 continue;
563 if (copy_pte_range(dst_mm, src_mm, dst_pmd, src_pmd, 563 if (copy_pte_range(dst_mm, src_mm, dst_pmd, src_pmd,
564 vma, addr, next)) 564 vma, addr, next))
565 return -ENOMEM; 565 return -ENOMEM;
566 } while (dst_pmd++, src_pmd++, addr = next, addr != end); 566 } while (dst_pmd++, src_pmd++, addr = next, addr != end);
567 return 0; 567 return 0;
568 } 568 }
569 569
570 static inline int copy_pud_range(struct mm_struct *dst_mm, struct mm_struct *src_mm, 570 static inline int copy_pud_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
571 pgd_t *dst_pgd, pgd_t *src_pgd, struct vm_area_struct *vma, 571 pgd_t *dst_pgd, pgd_t *src_pgd, struct vm_area_struct *vma,
572 unsigned long addr, unsigned long end) 572 unsigned long addr, unsigned long end)
573 { 573 {
574 pud_t *src_pud, *dst_pud; 574 pud_t *src_pud, *dst_pud;
575 unsigned long next; 575 unsigned long next;
576 576
577 dst_pud = pud_alloc(dst_mm, dst_pgd, addr); 577 dst_pud = pud_alloc(dst_mm, dst_pgd, addr);
578 if (!dst_pud) 578 if (!dst_pud)
579 return -ENOMEM; 579 return -ENOMEM;
580 src_pud = pud_offset(src_pgd, addr); 580 src_pud = pud_offset(src_pgd, addr);
581 do { 581 do {
582 next = pud_addr_end(addr, end); 582 next = pud_addr_end(addr, end);
583 if (pud_none_or_clear_bad(src_pud)) 583 if (pud_none_or_clear_bad(src_pud))
584 continue; 584 continue;
585 if (copy_pmd_range(dst_mm, src_mm, dst_pud, src_pud, 585 if (copy_pmd_range(dst_mm, src_mm, dst_pud, src_pud,
586 vma, addr, next)) 586 vma, addr, next))
587 return -ENOMEM; 587 return -ENOMEM;
588 } while (dst_pud++, src_pud++, addr = next, addr != end); 588 } while (dst_pud++, src_pud++, addr = next, addr != end);
589 return 0; 589 return 0;
590 } 590 }
591 591
592 int copy_page_range(struct mm_struct *dst_mm, struct mm_struct *src_mm, 592 int copy_page_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
593 struct vm_area_struct *vma) 593 struct vm_area_struct *vma)
594 { 594 {
595 pgd_t *src_pgd, *dst_pgd; 595 pgd_t *src_pgd, *dst_pgd;
596 unsigned long next; 596 unsigned long next;
597 unsigned long addr = vma->vm_start; 597 unsigned long addr = vma->vm_start;
598 unsigned long end = vma->vm_end; 598 unsigned long end = vma->vm_end;
599 599
600 /* 600 /*
601 * Don't copy ptes where a page fault will fill them correctly. 601 * Don't copy ptes where a page fault will fill them correctly.
602 * Fork becomes much lighter when there are big shared or private 602 * Fork becomes much lighter when there are big shared or private
603 * readonly mappings. The tradeoff is that copy_page_range is more 603 * readonly mappings. The tradeoff is that copy_page_range is more
604 * efficient than faulting. 604 * efficient than faulting.
605 */ 605 */
606 if (!(vma->vm_flags & (VM_HUGETLB|VM_NONLINEAR|VM_PFNMAP|VM_INSERTPAGE))) { 606 if (!(vma->vm_flags & (VM_HUGETLB|VM_NONLINEAR|VM_PFNMAP|VM_INSERTPAGE))) {
607 if (!vma->anon_vma) 607 if (!vma->anon_vma)
608 return 0; 608 return 0;
609 } 609 }
610 610
611 if (is_vm_hugetlb_page(vma)) 611 if (is_vm_hugetlb_page(vma))
612 return copy_hugetlb_page_range(dst_mm, src_mm, vma); 612 return copy_hugetlb_page_range(dst_mm, src_mm, vma);
613 613
614 dst_pgd = pgd_offset(dst_mm, addr); 614 dst_pgd = pgd_offset(dst_mm, addr);
615 src_pgd = pgd_offset(src_mm, addr); 615 src_pgd = pgd_offset(src_mm, addr);
616 do { 616 do {
617 next = pgd_addr_end(addr, end); 617 next = pgd_addr_end(addr, end);
618 if (pgd_none_or_clear_bad(src_pgd)) 618 if (pgd_none_or_clear_bad(src_pgd))
619 continue; 619 continue;
620 if (copy_pud_range(dst_mm, src_mm, dst_pgd, src_pgd, 620 if (copy_pud_range(dst_mm, src_mm, dst_pgd, src_pgd,
621 vma, addr, next)) 621 vma, addr, next))
622 return -ENOMEM; 622 return -ENOMEM;
623 } while (dst_pgd++, src_pgd++, addr = next, addr != end); 623 } while (dst_pgd++, src_pgd++, addr = next, addr != end);
624 return 0; 624 return 0;
625 } 625 }
626 626
627 static unsigned long zap_pte_range(struct mmu_gather *tlb, 627 static unsigned long zap_pte_range(struct mmu_gather *tlb,
628 struct vm_area_struct *vma, pmd_t *pmd, 628 struct vm_area_struct *vma, pmd_t *pmd,
629 unsigned long addr, unsigned long end, 629 unsigned long addr, unsigned long end,
630 long *zap_work, struct zap_details *details) 630 long *zap_work, struct zap_details *details)
631 { 631 {
632 struct mm_struct *mm = tlb->mm; 632 struct mm_struct *mm = tlb->mm;
633 pte_t *pte; 633 pte_t *pte;
634 spinlock_t *ptl; 634 spinlock_t *ptl;
635 int file_rss = 0; 635 int file_rss = 0;
636 int anon_rss = 0; 636 int anon_rss = 0;
637 637
638 pte = pte_offset_map_lock(mm, pmd, addr, &ptl); 638 pte = pte_offset_map_lock(mm, pmd, addr, &ptl);
639 arch_enter_lazy_mmu_mode(); 639 arch_enter_lazy_mmu_mode();
640 do { 640 do {
641 pte_t ptent = *pte; 641 pte_t ptent = *pte;
642 if (pte_none(ptent)) { 642 if (pte_none(ptent)) {
643 (*zap_work)--; 643 (*zap_work)--;
644 continue; 644 continue;
645 } 645 }
646 646
647 (*zap_work) -= PAGE_SIZE; 647 (*zap_work) -= PAGE_SIZE;
648 648
649 if (pte_present(ptent)) { 649 if (pte_present(ptent)) {
650 struct page *page; 650 struct page *page;
651 651
652 page = vm_normal_page(vma, addr, ptent); 652 page = vm_normal_page(vma, addr, ptent);
653 if (unlikely(details) && page) { 653 if (unlikely(details) && page) {
654 /* 654 /*
655 * unmap_shared_mapping_pages() wants to 655 * unmap_shared_mapping_pages() wants to
656 * invalidate cache without truncating: 656 * invalidate cache without truncating:
657 * unmap shared but keep private pages. 657 * unmap shared but keep private pages.
658 */ 658 */
659 if (details->check_mapping && 659 if (details->check_mapping &&
660 details->check_mapping != page->mapping) 660 details->check_mapping != page->mapping)
661 continue; 661 continue;
662 /* 662 /*
663 * Each page->index must be checked when 663 * Each page->index must be checked when
664 * invalidating or truncating nonlinear. 664 * invalidating or truncating nonlinear.
665 */ 665 */
666 if (details->nonlinear_vma && 666 if (details->nonlinear_vma &&
667 (page->index < details->first_index || 667 (page->index < details->first_index ||
668 page->index > details->last_index)) 668 page->index > details->last_index))
669 continue; 669 continue;
670 } 670 }
671 ptent = ptep_get_and_clear_full(mm, addr, pte, 671 ptent = ptep_get_and_clear_full(mm, addr, pte,
672 tlb->fullmm); 672 tlb->fullmm);
673 tlb_remove_tlb_entry(tlb, pte, addr); 673 tlb_remove_tlb_entry(tlb, pte, addr);
674 if (unlikely(!page)) 674 if (unlikely(!page))
675 continue; 675 continue;
676 if (unlikely(details) && details->nonlinear_vma 676 if (unlikely(details) && details->nonlinear_vma
677 && linear_page_index(details->nonlinear_vma, 677 && linear_page_index(details->nonlinear_vma,
678 addr) != page->index) 678 addr) != page->index)
679 set_pte_at(mm, addr, pte, 679 set_pte_at(mm, addr, pte,
680 pgoff_to_pte(page->index)); 680 pgoff_to_pte(page->index));
681 if (PageAnon(page)) 681 if (PageAnon(page))
682 anon_rss--; 682 anon_rss--;
683 else { 683 else {
684 if (pte_dirty(ptent)) 684 if (pte_dirty(ptent))
685 set_page_dirty(page); 685 set_page_dirty(page);
686 if (pte_young(ptent)) 686 if (pte_young(ptent))
687 SetPageReferenced(page); 687 SetPageReferenced(page);
688 file_rss--; 688 file_rss--;
689 } 689 }
690 page_remove_rmap(page, vma); 690 page_remove_rmap(page, vma);
691 tlb_remove_page(tlb, page); 691 tlb_remove_page(tlb, page);
692 continue; 692 continue;
693 } 693 }
694 /* 694 /*
695 * If details->check_mapping, we leave swap entries; 695 * If details->check_mapping, we leave swap entries;
696 * if details->nonlinear_vma, we leave file entries. 696 * if details->nonlinear_vma, we leave file entries.
697 */ 697 */
698 if (unlikely(details)) 698 if (unlikely(details))
699 continue; 699 continue;
700 if (!pte_file(ptent)) 700 if (!pte_file(ptent))
701 free_swap_and_cache(pte_to_swp_entry(ptent)); 701 free_swap_and_cache(pte_to_swp_entry(ptent));
702 pte_clear_not_present_full(mm, addr, pte, tlb->fullmm); 702 pte_clear_not_present_full(mm, addr, pte, tlb->fullmm);
703 } while (pte++, addr += PAGE_SIZE, (addr != end && *zap_work > 0)); 703 } while (pte++, addr += PAGE_SIZE, (addr != end && *zap_work > 0));
704 704
705 add_mm_rss(mm, file_rss, anon_rss); 705 add_mm_rss(mm, file_rss, anon_rss);
706 arch_leave_lazy_mmu_mode(); 706 arch_leave_lazy_mmu_mode();
707 pte_unmap_unlock(pte - 1, ptl); 707 pte_unmap_unlock(pte - 1, ptl);
708 708
709 return addr; 709 return addr;
710 } 710 }
711 711
712 static inline unsigned long zap_pmd_range(struct mmu_gather *tlb, 712 static inline unsigned long zap_pmd_range(struct mmu_gather *tlb,
713 struct vm_area_struct *vma, pud_t *pud, 713 struct vm_area_struct *vma, pud_t *pud,
714 unsigned long addr, unsigned long end, 714 unsigned long addr, unsigned long end,
715 long *zap_work, struct zap_details *details) 715 long *zap_work, struct zap_details *details)
716 { 716 {
717 pmd_t *pmd; 717 pmd_t *pmd;
718 unsigned long next; 718 unsigned long next;
719 719
720 pmd = pmd_offset(pud, addr); 720 pmd = pmd_offset(pud, addr);
721 do { 721 do {
722 next = pmd_addr_end(addr, end); 722 next = pmd_addr_end(addr, end);
723 if (pmd_none_or_clear_bad(pmd)) { 723 if (pmd_none_or_clear_bad(pmd)) {
724 (*zap_work)--; 724 (*zap_work)--;
725 continue; 725 continue;
726 } 726 }
727 next = zap_pte_range(tlb, vma, pmd, addr, next, 727 next = zap_pte_range(tlb, vma, pmd, addr, next,
728 zap_work, details); 728 zap_work, details);
729 } while (pmd++, addr = next, (addr != end && *zap_work > 0)); 729 } while (pmd++, addr = next, (addr != end && *zap_work > 0));
730 730
731 return addr; 731 return addr;
732 } 732 }
733 733
734 static inline unsigned long zap_pud_range(struct mmu_gather *tlb, 734 static inline unsigned long zap_pud_range(struct mmu_gather *tlb,
735 struct vm_area_struct *vma, pgd_t *pgd, 735 struct vm_area_struct *vma, pgd_t *pgd,
736 unsigned long addr, unsigned long end, 736 unsigned long addr, unsigned long end,
737 long *zap_work, struct zap_details *details) 737 long *zap_work, struct zap_details *details)
738 { 738 {
739 pud_t *pud; 739 pud_t *pud;
740 unsigned long next; 740 unsigned long next;
741 741
742 pud = pud_offset(pgd, addr); 742 pud = pud_offset(pgd, addr);
743 do { 743 do {
744 next = pud_addr_end(addr, end); 744 next = pud_addr_end(addr, end);
745 if (pud_none_or_clear_bad(pud)) { 745 if (pud_none_or_clear_bad(pud)) {
746 (*zap_work)--; 746 (*zap_work)--;
747 continue; 747 continue;
748 } 748 }
749 next = zap_pmd_range(tlb, vma, pud, addr, next, 749 next = zap_pmd_range(tlb, vma, pud, addr, next,
750 zap_work, details); 750 zap_work, details);
751 } while (pud++, addr = next, (addr != end && *zap_work > 0)); 751 } while (pud++, addr = next, (addr != end && *zap_work > 0));
752 752
753 return addr; 753 return addr;
754 } 754 }
755 755
756 static unsigned long unmap_page_range(struct mmu_gather *tlb, 756 static unsigned long unmap_page_range(struct mmu_gather *tlb,
757 struct vm_area_struct *vma, 757 struct vm_area_struct *vma,
758 unsigned long addr, unsigned long end, 758 unsigned long addr, unsigned long end,
759 long *zap_work, struct zap_details *details) 759 long *zap_work, struct zap_details *details)
760 { 760 {
761 pgd_t *pgd; 761 pgd_t *pgd;
762 unsigned long next; 762 unsigned long next;
763 763
764 if (details && !details->check_mapping && !details->nonlinear_vma) 764 if (details && !details->check_mapping && !details->nonlinear_vma)
765 details = NULL; 765 details = NULL;
766 766
767 BUG_ON(addr >= end); 767 BUG_ON(addr >= end);
768 tlb_start_vma(tlb, vma); 768 tlb_start_vma(tlb, vma);
769 pgd = pgd_offset(vma->vm_mm, addr); 769 pgd = pgd_offset(vma->vm_mm, addr);
770 do { 770 do {
771 next = pgd_addr_end(addr, end); 771 next = pgd_addr_end(addr, end);
772 if (pgd_none_or_clear_bad(pgd)) { 772 if (pgd_none_or_clear_bad(pgd)) {
773 (*zap_work)--; 773 (*zap_work)--;
774 continue; 774 continue;
775 } 775 }
776 next = zap_pud_range(tlb, vma, pgd, addr, next, 776 next = zap_pud_range(tlb, vma, pgd, addr, next,
777 zap_work, details); 777 zap_work, details);
778 } while (pgd++, addr = next, (addr != end && *zap_work > 0)); 778 } while (pgd++, addr = next, (addr != end && *zap_work > 0));
779 tlb_end_vma(tlb, vma); 779 tlb_end_vma(tlb, vma);
780 780
781 return addr; 781 return addr;
782 } 782 }
783 783
784 #ifdef CONFIG_PREEMPT 784 #ifdef CONFIG_PREEMPT
785 # define ZAP_BLOCK_SIZE (8 * PAGE_SIZE) 785 # define ZAP_BLOCK_SIZE (8 * PAGE_SIZE)
786 #else 786 #else
787 /* No preempt: go for improved straight-line efficiency */ 787 /* No preempt: go for improved straight-line efficiency */
788 # define ZAP_BLOCK_SIZE (1024 * PAGE_SIZE) 788 # define ZAP_BLOCK_SIZE (1024 * PAGE_SIZE)
789 #endif 789 #endif
790 790
791 /** 791 /**
792 * unmap_vmas - unmap a range of memory covered by a list of vma's 792 * unmap_vmas - unmap a range of memory covered by a list of vma's
793 * @tlbp: address of the caller's struct mmu_gather 793 * @tlbp: address of the caller's struct mmu_gather
794 * @vma: the starting vma 794 * @vma: the starting vma
795 * @start_addr: virtual address at which to start unmapping 795 * @start_addr: virtual address at which to start unmapping
796 * @end_addr: virtual address at which to end unmapping 796 * @end_addr: virtual address at which to end unmapping
797 * @nr_accounted: Place number of unmapped pages in vm-accountable vma's here 797 * @nr_accounted: Place number of unmapped pages in vm-accountable vma's here
798 * @details: details of nonlinear truncation or shared cache invalidation 798 * @details: details of nonlinear truncation or shared cache invalidation
799 * 799 *
800 * Returns the end address of the unmapping (restart addr if interrupted). 800 * Returns the end address of the unmapping (restart addr if interrupted).
801 * 801 *
802 * Unmap all pages in the vma list. 802 * Unmap all pages in the vma list.
803 * 803 *
804 * We aim to not hold locks for too long (for scheduling latency reasons). 804 * We aim to not hold locks for too long (for scheduling latency reasons).
805 * So zap pages in ZAP_BLOCK_SIZE bytecounts. This means we need to 805 * So zap pages in ZAP_BLOCK_SIZE bytecounts. This means we need to
806 * return the ending mmu_gather to the caller. 806 * return the ending mmu_gather to the caller.
807 * 807 *
808 * Only addresses between `start' and `end' will be unmapped. 808 * Only addresses between `start' and `end' will be unmapped.
809 * 809 *
810 * The VMA list must be sorted in ascending virtual address order. 810 * The VMA list must be sorted in ascending virtual address order.
811 * 811 *
812 * unmap_vmas() assumes that the caller will flush the whole unmapped address 812 * unmap_vmas() assumes that the caller will flush the whole unmapped address
813 * range after unmap_vmas() returns. So the only responsibility here is to 813 * range after unmap_vmas() returns. So the only responsibility here is to
814 * ensure that any thus-far unmapped pages are flushed before unmap_vmas() 814 * ensure that any thus-far unmapped pages are flushed before unmap_vmas()
815 * drops the lock and schedules. 815 * drops the lock and schedules.
816 */ 816 */
817 unsigned long unmap_vmas(struct mmu_gather **tlbp, 817 unsigned long unmap_vmas(struct mmu_gather **tlbp,
818 struct vm_area_struct *vma, unsigned long start_addr, 818 struct vm_area_struct *vma, unsigned long start_addr,
819 unsigned long end_addr, unsigned long *nr_accounted, 819 unsigned long end_addr, unsigned long *nr_accounted,
820 struct zap_details *details) 820 struct zap_details *details)
821 { 821 {
822 long zap_work = ZAP_BLOCK_SIZE; 822 long zap_work = ZAP_BLOCK_SIZE;
823 unsigned long tlb_start = 0; /* For tlb_finish_mmu */ 823 unsigned long tlb_start = 0; /* For tlb_finish_mmu */
824 int tlb_start_valid = 0; 824 int tlb_start_valid = 0;
825 unsigned long start = start_addr; 825 unsigned long start = start_addr;
826 spinlock_t *i_mmap_lock = details? details->i_mmap_lock: NULL; 826 spinlock_t *i_mmap_lock = details? details->i_mmap_lock: NULL;
827 int fullmm = (*tlbp)->fullmm; 827 int fullmm = (*tlbp)->fullmm;
828 828
829 for ( ; vma && vma->vm_start < end_addr; vma = vma->vm_next) { 829 for ( ; vma && vma->vm_start < end_addr; vma = vma->vm_next) {
830 unsigned long end; 830 unsigned long end;
831 831
832 start = max(vma->vm_start, start_addr); 832 start = max(vma->vm_start, start_addr);
833 if (start >= vma->vm_end) 833 if (start >= vma->vm_end)
834 continue; 834 continue;
835 end = min(vma->vm_end, end_addr); 835 end = min(vma->vm_end, end_addr);
836 if (end <= vma->vm_start) 836 if (end <= vma->vm_start)
837 continue; 837 continue;
838 838
839 if (vma->vm_flags & VM_ACCOUNT) 839 if (vma->vm_flags & VM_ACCOUNT)
840 *nr_accounted += (end - start) >> PAGE_SHIFT; 840 *nr_accounted += (end - start) >> PAGE_SHIFT;
841 841
842 while (start != end) { 842 while (start != end) {
843 if (!tlb_start_valid) { 843 if (!tlb_start_valid) {
844 tlb_start = start; 844 tlb_start = start;
845 tlb_start_valid = 1; 845 tlb_start_valid = 1;
846 } 846 }
847 847
848 if (unlikely(is_vm_hugetlb_page(vma))) { 848 if (unlikely(is_vm_hugetlb_page(vma))) {
849 unmap_hugepage_range(vma, start, end); 849 unmap_hugepage_range(vma, start, end);
850 zap_work -= (end - start) / 850 zap_work -= (end - start) /
851 (HPAGE_SIZE / PAGE_SIZE); 851 (HPAGE_SIZE / PAGE_SIZE);
852 start = end; 852 start = end;
853 } else 853 } else
854 start = unmap_page_range(*tlbp, vma, 854 start = unmap_page_range(*tlbp, vma,
855 start, end, &zap_work, details); 855 start, end, &zap_work, details);
856 856
857 if (zap_work > 0) { 857 if (zap_work > 0) {
858 BUG_ON(start != end); 858 BUG_ON(start != end);
859 break; 859 break;
860 } 860 }
861 861
862 tlb_finish_mmu(*tlbp, tlb_start, start); 862 tlb_finish_mmu(*tlbp, tlb_start, start);
863 863
864 if (need_resched() || 864 if (need_resched() ||
865 (i_mmap_lock && spin_needbreak(i_mmap_lock))) { 865 (i_mmap_lock && spin_needbreak(i_mmap_lock))) {
866 if (i_mmap_lock) { 866 if (i_mmap_lock) {
867 *tlbp = NULL; 867 *tlbp = NULL;
868 goto out; 868 goto out;
869 } 869 }
870 cond_resched(); 870 cond_resched();
871 } 871 }
872 872
873 *tlbp = tlb_gather_mmu(vma->vm_mm, fullmm); 873 *tlbp = tlb_gather_mmu(vma->vm_mm, fullmm);
874 tlb_start_valid = 0; 874 tlb_start_valid = 0;
875 zap_work = ZAP_BLOCK_SIZE; 875 zap_work = ZAP_BLOCK_SIZE;
876 } 876 }
877 } 877 }
878 out: 878 out:
879 return start; /* which is now the end (or restart) address */ 879 return start; /* which is now the end (or restart) address */
880 } 880 }
881 881
882 /** 882 /**
883 * zap_page_range - remove user pages in a given range 883 * zap_page_range - remove user pages in a given range
884 * @vma: vm_area_struct holding the applicable pages 884 * @vma: vm_area_struct holding the applicable pages
885 * @address: starting address of pages to zap 885 * @address: starting address of pages to zap
886 * @size: number of bytes to zap 886 * @size: number of bytes to zap
887 * @details: details of nonlinear truncation or shared cache invalidation 887 * @details: details of nonlinear truncation or shared cache invalidation
888 */ 888 */
889 unsigned long zap_page_range(struct vm_area_struct *vma, unsigned long address, 889 unsigned long zap_page_range(struct vm_area_struct *vma, unsigned long address,
890 unsigned long size, struct zap_details *details) 890 unsigned long size, struct zap_details *details)
891 { 891 {
892 struct mm_struct *mm = vma->vm_mm; 892 struct mm_struct *mm = vma->vm_mm;
893 struct mmu_gather *tlb; 893 struct mmu_gather *tlb;
894 unsigned long end = address + size; 894 unsigned long end = address + size;
895 unsigned long nr_accounted = 0; 895 unsigned long nr_accounted = 0;
896 896
897 lru_add_drain(); 897 lru_add_drain();
898 tlb = tlb_gather_mmu(mm, 0); 898 tlb = tlb_gather_mmu(mm, 0);
899 update_hiwater_rss(mm); 899 update_hiwater_rss(mm);
900 end = unmap_vmas(&tlb, vma, address, end, &nr_accounted, details); 900 end = unmap_vmas(&tlb, vma, address, end, &nr_accounted, details);
901 if (tlb) 901 if (tlb)
902 tlb_finish_mmu(tlb, address, end); 902 tlb_finish_mmu(tlb, address, end);
903 return end; 903 return end;
904 } 904 }
905 905
906 /* 906 /*
907 * Do a quick page-table lookup for a single page. 907 * Do a quick page-table lookup for a single page.
908 */ 908 */
909 struct page *follow_page(struct vm_area_struct *vma, unsigned long address, 909 struct page *follow_page(struct vm_area_struct *vma, unsigned long address,
910 unsigned int flags) 910 unsigned int flags)
911 { 911 {
912 pgd_t *pgd; 912 pgd_t *pgd;
913 pud_t *pud; 913 pud_t *pud;
914 pmd_t *pmd; 914 pmd_t *pmd;
915 pte_t *ptep, pte; 915 pte_t *ptep, pte;
916 spinlock_t *ptl; 916 spinlock_t *ptl;
917 struct page *page; 917 struct page *page;
918 struct mm_struct *mm = vma->vm_mm; 918 struct mm_struct *mm = vma->vm_mm;
919 919
920 page = follow_huge_addr(mm, address, flags & FOLL_WRITE); 920 page = follow_huge_addr(mm, address, flags & FOLL_WRITE);
921 if (!IS_ERR(page)) { 921 if (!IS_ERR(page)) {
922 BUG_ON(flags & FOLL_GET); 922 BUG_ON(flags & FOLL_GET);
923 goto out; 923 goto out;
924 } 924 }
925 925
926 page = NULL; 926 page = NULL;
927 pgd = pgd_offset(mm, address); 927 pgd = pgd_offset(mm, address);
928 if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd))) 928 if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd)))
929 goto no_page_table; 929 goto no_page_table;
930 930
931 pud = pud_offset(pgd, address); 931 pud = pud_offset(pgd, address);
932 if (pud_none(*pud) || unlikely(pud_bad(*pud))) 932 if (pud_none(*pud) || unlikely(pud_bad(*pud)))
933 goto no_page_table; 933 goto no_page_table;
934 934
935 pmd = pmd_offset(pud, address); 935 pmd = pmd_offset(pud, address);
936 if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd))) 936 if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd)))
937 goto no_page_table; 937 goto no_page_table;
938 938
939 if (pmd_huge(*pmd)) { 939 if (pmd_huge(*pmd)) {
940 BUG_ON(flags & FOLL_GET); 940 BUG_ON(flags & FOLL_GET);
941 page = follow_huge_pmd(mm, address, pmd, flags & FOLL_WRITE); 941 page = follow_huge_pmd(mm, address, pmd, flags & FOLL_WRITE);
942 goto out; 942 goto out;
943 } 943 }
944 944
945 ptep = pte_offset_map_lock(mm, pmd, address, &ptl); 945 ptep = pte_offset_map_lock(mm, pmd, address, &ptl);
946 if (!ptep) 946 if (!ptep)
947 goto out; 947 goto out;
948 948
949 pte = *ptep; 949 pte = *ptep;
950 if (!pte_present(pte)) 950 if (!pte_present(pte))
951 goto unlock; 951 goto unlock;
952 if ((flags & FOLL_WRITE) && !pte_write(pte)) 952 if ((flags & FOLL_WRITE) && !pte_write(pte))
953 goto unlock; 953 goto unlock;
954 page = vm_normal_page(vma, address, pte); 954 page = vm_normal_page(vma, address, pte);
955 if (unlikely(!page)) 955 if (unlikely(!page))
956 goto unlock; 956 goto unlock;
957 957
958 if (flags & FOLL_GET) 958 if (flags & FOLL_GET)
959 get_page(page); 959 get_page(page);
960 if (flags & FOLL_TOUCH) { 960 if (flags & FOLL_TOUCH) {
961 if ((flags & FOLL_WRITE) && 961 if ((flags & FOLL_WRITE) &&
962 !pte_dirty(pte) && !PageDirty(page)) 962 !pte_dirty(pte) && !PageDirty(page))
963 set_page_dirty(page); 963 set_page_dirty(page);
964 mark_page_accessed(page); 964 mark_page_accessed(page);
965 } 965 }
966 unlock: 966 unlock:
967 pte_unmap_unlock(ptep, ptl); 967 pte_unmap_unlock(ptep, ptl);
968 out: 968 out:
969 return page; 969 return page;
970 970
971 no_page_table: 971 no_page_table:
972 /* 972 /*
973 * When core dumping an enormous anonymous area that nobody 973 * When core dumping an enormous anonymous area that nobody
974 * has touched so far, we don't want to allocate page tables. 974 * has touched so far, we don't want to allocate page tables.
975 */ 975 */
976 if (flags & FOLL_ANON) { 976 if (flags & FOLL_ANON) {
977 page = ZERO_PAGE(0); 977 page = ZERO_PAGE(0);
978 if (flags & FOLL_GET) 978 if (flags & FOLL_GET)
979 get_page(page); 979 get_page(page);
980 BUG_ON(flags & FOLL_WRITE); 980 BUG_ON(flags & FOLL_WRITE);
981 } 981 }
982 return page; 982 return page;
983 } 983 }
984 984
985 int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, 985 int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
986 unsigned long start, int len, int write, int force, 986 unsigned long start, int len, int write, int force,
987 struct page **pages, struct vm_area_struct **vmas) 987 struct page **pages, struct vm_area_struct **vmas)
988 { 988 {
989 int i; 989 int i;
990 unsigned int vm_flags; 990 unsigned int vm_flags;
991 991
992 if (len <= 0) 992 if (len <= 0)
993 return 0; 993 return 0;
994 /* 994 /*
995 * Require read or write permissions. 995 * Require read or write permissions.
996 * If 'force' is set, we only require the "MAY" flags. 996 * If 'force' is set, we only require the "MAY" flags.
997 */ 997 */
998 vm_flags = write ? (VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD); 998 vm_flags = write ? (VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD);
999 vm_flags &= force ? (VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE); 999 vm_flags &= force ? (VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE);
1000 i = 0; 1000 i = 0;
1001 1001
1002 do { 1002 do {
1003 struct vm_area_struct *vma; 1003 struct vm_area_struct *vma;
1004 unsigned int foll_flags; 1004 unsigned int foll_flags;
1005 1005
1006 vma = find_extend_vma(mm, start); 1006 vma = find_extend_vma(mm, start);
1007 if (!vma && in_gate_area(tsk, start)) { 1007 if (!vma && in_gate_area(tsk, start)) {
1008 unsigned long pg = start & PAGE_MASK; 1008 unsigned long pg = start & PAGE_MASK;
1009 struct vm_area_struct *gate_vma = get_gate_vma(tsk); 1009 struct vm_area_struct *gate_vma = get_gate_vma(tsk);
1010 pgd_t *pgd; 1010 pgd_t *pgd;
1011 pud_t *pud; 1011 pud_t *pud;
1012 pmd_t *pmd; 1012 pmd_t *pmd;
1013 pte_t *pte; 1013 pte_t *pte;
1014 if (write) /* user gate pages are read-only */ 1014 if (write) /* user gate pages are read-only */
1015 return i ? : -EFAULT; 1015 return i ? : -EFAULT;
1016 if (pg > TASK_SIZE) 1016 if (pg > TASK_SIZE)
1017 pgd = pgd_offset_k(pg); 1017 pgd = pgd_offset_k(pg);
1018 else 1018 else
1019 pgd = pgd_offset_gate(mm, pg); 1019 pgd = pgd_offset_gate(mm, pg);
1020 BUG_ON(pgd_none(*pgd)); 1020 BUG_ON(pgd_none(*pgd));
1021 pud = pud_offset(pgd, pg); 1021 pud = pud_offset(pgd, pg);
1022 BUG_ON(pud_none(*pud)); 1022 BUG_ON(pud_none(*pud));
1023 pmd = pmd_offset(pud, pg); 1023 pmd = pmd_offset(pud, pg);
1024 if (pmd_none(*pmd)) 1024 if (pmd_none(*pmd))
1025 return i ? : -EFAULT; 1025 return i ? : -EFAULT;
1026 pte = pte_offset_map(pmd, pg); 1026 pte = pte_offset_map(pmd, pg);
1027 if (pte_none(*pte)) { 1027 if (pte_none(*pte)) {
1028 pte_unmap(pte); 1028 pte_unmap(pte);
1029 return i ? : -EFAULT; 1029 return i ? : -EFAULT;
1030 } 1030 }
1031 if (pages) { 1031 if (pages) {
1032 struct page *page = vm_normal_page(gate_vma, start, *pte); 1032 struct page *page = vm_normal_page(gate_vma, start, *pte);
1033 pages[i] = page; 1033 pages[i] = page;
1034 if (page) 1034 if (page)
1035 get_page(page); 1035 get_page(page);
1036 } 1036 }
1037 pte_unmap(pte); 1037 pte_unmap(pte);
1038 if (vmas) 1038 if (vmas)
1039 vmas[i] = gate_vma; 1039 vmas[i] = gate_vma;
1040 i++; 1040 i++;
1041 start += PAGE_SIZE; 1041 start += PAGE_SIZE;
1042 len--; 1042 len--;
1043 continue; 1043 continue;
1044 } 1044 }
1045 1045
1046 if (!vma || (vma->vm_flags & (VM_IO | VM_PFNMAP)) 1046 if (!vma || (vma->vm_flags & (VM_IO | VM_PFNMAP))
1047 || !(vm_flags & vma->vm_flags)) 1047 || !(vm_flags & vma->vm_flags))
1048 return i ? : -EFAULT; 1048 return i ? : -EFAULT;
1049 1049
1050 if (is_vm_hugetlb_page(vma)) { 1050 if (is_vm_hugetlb_page(vma)) {
1051 i = follow_hugetlb_page(mm, vma, pages, vmas, 1051 i = follow_hugetlb_page(mm, vma, pages, vmas,
1052 &start, &len, i, write); 1052 &start, &len, i, write);
1053 continue; 1053 continue;
1054 } 1054 }
1055 1055
1056 foll_flags = FOLL_TOUCH; 1056 foll_flags = FOLL_TOUCH;
1057 if (pages) 1057 if (pages)
1058 foll_flags |= FOLL_GET; 1058 foll_flags |= FOLL_GET;
1059 if (!write && !(vma->vm_flags & VM_LOCKED) && 1059 if (!write && !(vma->vm_flags & VM_LOCKED) &&
1060 (!vma->vm_ops || (!vma->vm_ops->nopage && 1060 (!vma->vm_ops || (!vma->vm_ops->nopage &&
1061 !vma->vm_ops->fault))) 1061 !vma->vm_ops->fault)))
1062 foll_flags |= FOLL_ANON; 1062 foll_flags |= FOLL_ANON;
1063 1063
1064 do { 1064 do {
1065 struct page *page; 1065 struct page *page;
1066 1066
1067 /* 1067 /*
1068 * If tsk is ooming, cut off its access to large memory 1068 * If tsk is ooming, cut off its access to large memory
1069 * allocations. It has a pending SIGKILL, but it can't 1069 * allocations. It has a pending SIGKILL, but it can't
1070 * be processed until returning to user space. 1070 * be processed until returning to user space.
1071 */ 1071 */
1072 if (unlikely(test_tsk_thread_flag(tsk, TIF_MEMDIE))) 1072 if (unlikely(test_tsk_thread_flag(tsk, TIF_MEMDIE)))
1073 return -ENOMEM; 1073 return -ENOMEM;
1074 1074
1075 if (write) 1075 if (write)
1076 foll_flags |= FOLL_WRITE; 1076 foll_flags |= FOLL_WRITE;
1077 1077
1078 cond_resched(); 1078 cond_resched();
1079 while (!(page = follow_page(vma, start, foll_flags))) { 1079 while (!(page = follow_page(vma, start, foll_flags))) {
1080 int ret; 1080 int ret;
1081 ret = handle_mm_fault(mm, vma, start, 1081 ret = handle_mm_fault(mm, vma, start,
1082 foll_flags & FOLL_WRITE); 1082 foll_flags & FOLL_WRITE);
1083 if (ret & VM_FAULT_ERROR) { 1083 if (ret & VM_FAULT_ERROR) {
1084 if (ret & VM_FAULT_OOM) 1084 if (ret & VM_FAULT_OOM)
1085 return i ? i : -ENOMEM; 1085 return i ? i : -ENOMEM;
1086 else if (ret & VM_FAULT_SIGBUS) 1086 else if (ret & VM_FAULT_SIGBUS)
1087 return i ? i : -EFAULT; 1087 return i ? i : -EFAULT;
1088 BUG(); 1088 BUG();
1089 } 1089 }
1090 if (ret & VM_FAULT_MAJOR) 1090 if (ret & VM_FAULT_MAJOR)
1091 tsk->maj_flt++; 1091 tsk->maj_flt++;
1092 else 1092 else
1093 tsk->min_flt++; 1093 tsk->min_flt++;
1094 1094
1095 /* 1095 /*
1096 * The VM_FAULT_WRITE bit tells us that 1096 * The VM_FAULT_WRITE bit tells us that
1097 * do_wp_page has broken COW when necessary, 1097 * do_wp_page has broken COW when necessary,
1098 * even if maybe_mkwrite decided not to set 1098 * even if maybe_mkwrite decided not to set
1099 * pte_write. We can thus safely do subsequent 1099 * pte_write. We can thus safely do subsequent
1100 * page lookups as if they were reads. 1100 * page lookups as if they were reads.
1101 */ 1101 */
1102 if (ret & VM_FAULT_WRITE) 1102 if (ret & VM_FAULT_WRITE)
1103 foll_flags &= ~FOLL_WRITE; 1103 foll_flags &= ~FOLL_WRITE;
1104 1104
1105 cond_resched(); 1105 cond_resched();
1106 } 1106 }
1107 if (pages) { 1107 if (pages) {
1108 pages[i] = page; 1108 pages[i] = page;
1109 1109
1110 flush_anon_page(vma, page, start); 1110 flush_anon_page(vma, page, start);
1111 flush_dcache_page(page); 1111 flush_dcache_page(page);
1112 } 1112 }
1113 if (vmas) 1113 if (vmas)
1114 vmas[i] = vma; 1114 vmas[i] = vma;
1115 i++; 1115 i++;
1116 start += PAGE_SIZE; 1116 start += PAGE_SIZE;
1117 len--; 1117 len--;
1118 } while (len && start < vma->vm_end); 1118 } while (len && start < vma->vm_end);
1119 } while (len); 1119 } while (len);
1120 return i; 1120 return i;
1121 } 1121 }
1122 EXPORT_SYMBOL(get_user_pages); 1122 EXPORT_SYMBOL(get_user_pages);
1123 1123
1124 pte_t *get_locked_pte(struct mm_struct *mm, unsigned long addr, 1124 pte_t *get_locked_pte(struct mm_struct *mm, unsigned long addr,
1125 spinlock_t **ptl) 1125 spinlock_t **ptl)
1126 { 1126 {
1127 pgd_t * pgd = pgd_offset(mm, addr); 1127 pgd_t * pgd = pgd_offset(mm, addr);
1128 pud_t * pud = pud_alloc(mm, pgd, addr); 1128 pud_t * pud = pud_alloc(mm, pgd, addr);
1129 if (pud) { 1129 if (pud) {
1130 pmd_t * pmd = pmd_alloc(mm, pud, addr); 1130 pmd_t * pmd = pmd_alloc(mm, pud, addr);
1131 if (pmd) 1131 if (pmd)
1132 return pte_alloc_map_lock(mm, pmd, addr, ptl); 1132 return pte_alloc_map_lock(mm, pmd, addr, ptl);
1133 } 1133 }
1134 return NULL; 1134 return NULL;
1135 } 1135 }
1136 1136
1137 /* 1137 /*
1138 * This is the old fallback for page remapping. 1138 * This is the old fallback for page remapping.
1139 * 1139 *
1140 * For historical reasons, it only allows reserved pages. Only 1140 * For historical reasons, it only allows reserved pages. Only
1141 * old drivers should use this, and they needed to mark their 1141 * old drivers should use this, and they needed to mark their
1142 * pages reserved for the old functions anyway. 1142 * pages reserved for the old functions anyway.
1143 */ 1143 */
1144 static int insert_page(struct mm_struct *mm, unsigned long addr, struct page *page, pgprot_t prot) 1144 static int insert_page(struct mm_struct *mm, unsigned long addr, struct page *page, pgprot_t prot)
1145 { 1145 {
1146 int retval; 1146 int retval;
1147 pte_t *pte; 1147 pte_t *pte;
1148 spinlock_t *ptl; 1148 spinlock_t *ptl;
1149 1149
1150 retval = mem_cgroup_charge(page, mm, GFP_KERNEL); 1150 retval = mem_cgroup_charge(page, mm, GFP_KERNEL);
1151 if (retval) 1151 if (retval)
1152 goto out; 1152 goto out;
1153 1153
1154 retval = -EINVAL; 1154 retval = -EINVAL;
1155 if (PageAnon(page)) 1155 if (PageAnon(page))
1156 goto out_uncharge; 1156 goto out_uncharge;
1157 retval = -ENOMEM; 1157 retval = -ENOMEM;
1158 flush_dcache_page(page); 1158 flush_dcache_page(page);
1159 pte = get_locked_pte(mm, addr, &ptl); 1159 pte = get_locked_pte(mm, addr, &ptl);
1160 if (!pte) 1160 if (!pte)
1161 goto out_uncharge; 1161 goto out_uncharge;
1162 retval = -EBUSY; 1162 retval = -EBUSY;
1163 if (!pte_none(*pte)) 1163 if (!pte_none(*pte))
1164 goto out_unlock; 1164 goto out_unlock;
1165 1165
1166 /* Ok, finally just insert the thing.. */ 1166 /* Ok, finally just insert the thing.. */
1167 get_page(page); 1167 get_page(page);
1168 inc_mm_counter(mm, file_rss); 1168 inc_mm_counter(mm, file_rss);
1169 page_add_file_rmap(page); 1169 page_add_file_rmap(page);
1170 set_pte_at(mm, addr, pte, mk_pte(page, prot)); 1170 set_pte_at(mm, addr, pte, mk_pte(page, prot));
1171 1171
1172 retval = 0; 1172 retval = 0;
1173 pte_unmap_unlock(pte, ptl); 1173 pte_unmap_unlock(pte, ptl);
1174 return retval; 1174 return retval;
1175 out_unlock: 1175 out_unlock:
1176 pte_unmap_unlock(pte, ptl); 1176 pte_unmap_unlock(pte, ptl);
1177 out_uncharge: 1177 out_uncharge:
1178 mem_cgroup_uncharge_page(page); 1178 mem_cgroup_uncharge_page(page);
1179 out: 1179 out:
1180 return retval; 1180 return retval;
1181 } 1181 }
1182 1182
1183 /** 1183 /**
1184 * vm_insert_page - insert single page into user vma 1184 * vm_insert_page - insert single page into user vma
1185 * @vma: user vma to map to 1185 * @vma: user vma to map to
1186 * @addr: target user address of this page 1186 * @addr: target user address of this page
1187 * @page: source kernel page 1187 * @page: source kernel page
1188 * 1188 *
1189 * This allows drivers to insert individual pages they've allocated 1189 * This allows drivers to insert individual pages they've allocated
1190 * into a user vma. 1190 * into a user vma.
1191 * 1191 *
1192 * The page has to be a nice clean _individual_ kernel allocation. 1192 * The page has to be a nice clean _individual_ kernel allocation.
1193 * If you allocate a compound page, you need to have marked it as 1193 * If you allocate a compound page, you need to have marked it as
1194 * such (__GFP_COMP), or manually just split the page up yourself 1194 * such (__GFP_COMP), or manually just split the page up yourself
1195 * (see split_page()). 1195 * (see split_page()).
1196 * 1196 *
1197 * NOTE! Traditionally this was done with "remap_pfn_range()" which 1197 * NOTE! Traditionally this was done with "remap_pfn_range()" which
1198 * took an arbitrary page protection parameter. This doesn't allow 1198 * took an arbitrary page protection parameter. This doesn't allow
1199 * that. Your vma protection will have to be set up correctly, which 1199 * that. Your vma protection will have to be set up correctly, which
1200 * means that if you want a shared writable mapping, you'd better 1200 * means that if you want a shared writable mapping, you'd better
1201 * ask for a shared writable mapping! 1201 * ask for a shared writable mapping!
1202 * 1202 *
1203 * The page does not need to be reserved. 1203 * The page does not need to be reserved.
1204 */ 1204 */
1205 int vm_insert_page(struct vm_area_struct *vma, unsigned long addr, struct page *page) 1205 int vm_insert_page(struct vm_area_struct *vma, unsigned long addr, struct page *page)
1206 { 1206 {
1207 if (addr < vma->vm_start || addr >= vma->vm_end) 1207 if (addr < vma->vm_start || addr >= vma->vm_end)
1208 return -EFAULT; 1208 return -EFAULT;
1209 if (!page_count(page)) 1209 if (!page_count(page))
1210 return -EINVAL; 1210 return -EINVAL;
1211 vma->vm_flags |= VM_INSERTPAGE; 1211 vma->vm_flags |= VM_INSERTPAGE;
1212 return insert_page(vma->vm_mm, addr, page, vma->vm_page_prot); 1212 return insert_page(vma->vm_mm, addr, page, vma->vm_page_prot);
1213 } 1213 }
1214 EXPORT_SYMBOL(vm_insert_page); 1214 EXPORT_SYMBOL(vm_insert_page);
1215 1215
1216 /** 1216 /**
1217 * vm_insert_pfn - insert single pfn into user vma 1217 * vm_insert_pfn - insert single pfn into user vma
1218 * @vma: user vma to map to 1218 * @vma: user vma to map to
1219 * @addr: target user address of this page 1219 * @addr: target user address of this page
1220 * @pfn: source kernel pfn 1220 * @pfn: source kernel pfn
1221 * 1221 *
1222 * Similar to vm_inert_page, this allows drivers to insert individual pages 1222 * Similar to vm_inert_page, this allows drivers to insert individual pages
1223 * they've allocated into a user vma. Same comments apply. 1223 * they've allocated into a user vma. Same comments apply.
1224 * 1224 *
1225 * This function should only be called from a vm_ops->fault handler, and 1225 * This function should only be called from a vm_ops->fault handler, and
1226 * in that case the handler should return NULL. 1226 * in that case the handler should return NULL.
1227 */ 1227 */
1228 int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr, 1228 int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
1229 unsigned long pfn) 1229 unsigned long pfn)
1230 { 1230 {
1231 struct mm_struct *mm = vma->vm_mm; 1231 struct mm_struct *mm = vma->vm_mm;
1232 int retval; 1232 int retval;
1233 pte_t *pte, entry; 1233 pte_t *pte, entry;
1234 spinlock_t *ptl; 1234 spinlock_t *ptl;
1235 1235
1236 BUG_ON(!(vma->vm_flags & VM_PFNMAP)); 1236 BUG_ON(!(vma->vm_flags & VM_PFNMAP));
1237 BUG_ON(is_cow_mapping(vma->vm_flags)); 1237 BUG_ON(is_cow_mapping(vma->vm_flags));
1238 1238
1239 retval = -ENOMEM; 1239 retval = -ENOMEM;
1240 pte = get_locked_pte(mm, addr, &ptl); 1240 pte = get_locked_pte(mm, addr, &ptl);
1241 if (!pte) 1241 if (!pte)
1242 goto out; 1242 goto out;
1243 retval = -EBUSY; 1243 retval = -EBUSY;
1244 if (!pte_none(*pte)) 1244 if (!pte_none(*pte))
1245 goto out_unlock; 1245 goto out_unlock;
1246 1246
1247 /* Ok, finally just insert the thing.. */ 1247 /* Ok, finally just insert the thing.. */
1248 entry = pfn_pte(pfn, vma->vm_page_prot); 1248 entry = pfn_pte(pfn, vma->vm_page_prot);
1249 set_pte_at(mm, addr, pte, entry); 1249 set_pte_at(mm, addr, pte, entry);
1250 update_mmu_cache(vma, addr, entry); 1250 update_mmu_cache(vma, addr, entry);
1251 1251
1252 retval = 0; 1252 retval = 0;
1253 out_unlock: 1253 out_unlock:
1254 pte_unmap_unlock(pte, ptl); 1254 pte_unmap_unlock(pte, ptl);
1255 1255
1256 out: 1256 out:
1257 return retval; 1257 return retval;
1258 } 1258 }
1259 EXPORT_SYMBOL(vm_insert_pfn); 1259 EXPORT_SYMBOL(vm_insert_pfn);
1260 1260
1261 /* 1261 /*
1262 * maps a range of physical memory into the requested pages. the old 1262 * maps a range of physical memory into the requested pages. the old
1263 * mappings are removed. any references to nonexistent pages results 1263 * mappings are removed. any references to nonexistent pages results
1264 * in null mappings (currently treated as "copy-on-access") 1264 * in null mappings (currently treated as "copy-on-access")
1265 */ 1265 */
1266 static int remap_pte_range(struct mm_struct *mm, pmd_t *pmd, 1266 static int remap_pte_range(struct mm_struct *mm, pmd_t *pmd,
1267 unsigned long addr, unsigned long end, 1267 unsigned long addr, unsigned long end,
1268 unsigned long pfn, pgprot_t prot) 1268 unsigned long pfn, pgprot_t prot)
1269 { 1269 {
1270 pte_t *pte; 1270 pte_t *pte;
1271 spinlock_t *ptl; 1271 spinlock_t *ptl;
1272 1272
1273 pte = pte_alloc_map_lock(mm, pmd, addr, &ptl); 1273 pte = pte_alloc_map_lock(mm, pmd, addr, &ptl);
1274 if (!pte) 1274 if (!pte)
1275 return -ENOMEM; 1275 return -ENOMEM;
1276 arch_enter_lazy_mmu_mode(); 1276 arch_enter_lazy_mmu_mode();
1277 do { 1277 do {
1278 BUG_ON(!pte_none(*pte)); 1278 BUG_ON(!pte_none(*pte));
1279 set_pte_at(mm, addr, pte, pfn_pte(pfn, prot)); 1279 set_pte_at(mm, addr, pte, pfn_pte(pfn, prot));
1280 pfn++; 1280 pfn++;
1281 } while (pte++, addr += PAGE_SIZE, addr != end); 1281 } while (pte++, addr += PAGE_SIZE, addr != end);
1282 arch_leave_lazy_mmu_mode(); 1282 arch_leave_lazy_mmu_mode();
1283 pte_unmap_unlock(pte - 1, ptl); 1283 pte_unmap_unlock(pte - 1, ptl);
1284 return 0; 1284 return 0;
1285 } 1285 }
1286 1286
1287 static inline int remap_pmd_range(struct mm_struct *mm, pud_t *pud, 1287 static inline int remap_pmd_range(struct mm_struct *mm, pud_t *pud,
1288 unsigned long addr, unsigned long end, 1288 unsigned long addr, unsigned long end,
1289 unsigned long pfn, pgprot_t prot) 1289 unsigned long pfn, pgprot_t prot)
1290 { 1290 {
1291 pmd_t *pmd; 1291 pmd_t *pmd;
1292 unsigned long next; 1292 unsigned long next;
1293 1293
1294 pfn -= addr >> PAGE_SHIFT; 1294 pfn -= addr >> PAGE_SHIFT;
1295 pmd = pmd_alloc(mm, pud, addr); 1295 pmd = pmd_alloc(mm, pud, addr);
1296 if (!pmd) 1296 if (!pmd)
1297 return -ENOMEM; 1297 return -ENOMEM;
1298 do { 1298 do {
1299 next = pmd_addr_end(addr, end); 1299 next = pmd_addr_end(addr, end);
1300 if (remap_pte_range(mm, pmd, addr, next, 1300 if (remap_pte_range(mm, pmd, addr, next,
1301 pfn + (addr >> PAGE_SHIFT), prot)) 1301 pfn + (addr >> PAGE_SHIFT), prot))
1302 return -ENOMEM; 1302 return -ENOMEM;
1303 } while (pmd++, addr = next, addr != end); 1303 } while (pmd++, addr = next, addr != end);
1304 return 0; 1304 return 0;
1305 } 1305 }
1306 1306
1307 static inline int remap_pud_range(struct mm_struct *mm, pgd_t *pgd, 1307 static inline int remap_pud_range(struct mm_struct *mm, pgd_t *pgd,
1308 unsigned long addr, unsigned long end, 1308 unsigned long addr, unsigned long end,
1309 unsigned long pfn, pgprot_t prot) 1309 unsigned long pfn, pgprot_t prot)
1310 { 1310 {
1311 pud_t *pud; 1311 pud_t *pud;
1312 unsigned long next; 1312 unsigned long next;
1313 1313
1314 pfn -= addr >> PAGE_SHIFT; 1314 pfn -= addr >> PAGE_SHIFT;
1315 pud = pud_alloc(mm, pgd, addr); 1315 pud = pud_alloc(mm, pgd, addr);
1316 if (!pud) 1316 if (!pud)
1317 return -ENOMEM; 1317 return -ENOMEM;
1318 do { 1318 do {
1319 next = pud_addr_end(addr, end); 1319 next = pud_addr_end(addr, end);
1320 if (remap_pmd_range(mm, pud, addr, next, 1320 if (remap_pmd_range(mm, pud, addr, next,
1321 pfn + (addr >> PAGE_SHIFT), prot)) 1321 pfn + (addr >> PAGE_SHIFT), prot))
1322 return -ENOMEM; 1322 return -ENOMEM;
1323 } while (pud++, addr = next, addr != end); 1323 } while (pud++, addr = next, addr != end);
1324 return 0; 1324 return 0;
1325 } 1325 }
1326 1326
1327 /** 1327 /**
1328 * remap_pfn_range - remap kernel memory to userspace 1328 * remap_pfn_range - remap kernel memory to userspace
1329 * @vma: user vma to map to 1329 * @vma: user vma to map to
1330 * @addr: target user address to start at 1330 * @addr: target user address to start at
1331 * @pfn: physical address of kernel memory 1331 * @pfn: physical address of kernel memory
1332 * @size: size of map area 1332 * @size: size of map area
1333 * @prot: page protection flags for this mapping 1333 * @prot: page protection flags for this mapping
1334 * 1334 *
1335 * Note: this is only safe if the mm semaphore is held when called. 1335 * Note: this is only safe if the mm semaphore is held when called.
1336 */ 1336 */
1337 int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr, 1337 int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr,
1338 unsigned long pfn, unsigned long size, pgprot_t prot) 1338 unsigned long pfn, unsigned long size, pgprot_t prot)
1339 { 1339 {
1340 pgd_t *pgd; 1340 pgd_t *pgd;
1341 unsigned long next; 1341 unsigned long next;
1342 unsigned long end = addr + PAGE_ALIGN(size); 1342 unsigned long end = addr + PAGE_ALIGN(size);
1343 struct mm_struct *mm = vma->vm_mm; 1343 struct mm_struct *mm = vma->vm_mm;
1344 int err; 1344 int err;
1345 1345
1346 /* 1346 /*
1347 * Physically remapped pages are special. Tell the 1347 * Physically remapped pages are special. Tell the
1348 * rest of the world about it: 1348 * rest of the world about it:
1349 * VM_IO tells people not to look at these pages 1349 * VM_IO tells people not to look at these pages
1350 * (accesses can have side effects). 1350 * (accesses can have side effects).
1351 * VM_RESERVED is specified all over the place, because 1351 * VM_RESERVED is specified all over the place, because
1352 * in 2.4 it kept swapout's vma scan off this vma; but 1352 * in 2.4 it kept swapout's vma scan off this vma; but
1353 * in 2.6 the LRU scan won't even find its pages, so this 1353 * in 2.6 the LRU scan won't even find its pages, so this
1354 * flag means no more than count its pages in reserved_vm, 1354 * flag means no more than count its pages in reserved_vm,
1355 * and omit it from core dump, even when VM_IO turned off. 1355 * and omit it from core dump, even when VM_IO turned off.
1356 * VM_PFNMAP tells the core MM that the base pages are just 1356 * VM_PFNMAP tells the core MM that the base pages are just
1357 * raw PFN mappings, and do not have a "struct page" associated 1357 * raw PFN mappings, and do not have a "struct page" associated
1358 * with them. 1358 * with them.
1359 * 1359 *
1360 * There's a horrible special case to handle copy-on-write 1360 * There's a horrible special case to handle copy-on-write
1361 * behaviour that some programs depend on. We mark the "original" 1361 * behaviour that some programs depend on. We mark the "original"
1362 * un-COW'ed pages by matching them up with "vma->vm_pgoff". 1362 * un-COW'ed pages by matching them up with "vma->vm_pgoff".
1363 */ 1363 */
1364 if (is_cow_mapping(vma->vm_flags)) { 1364 if (is_cow_mapping(vma->vm_flags)) {
1365 if (addr != vma->vm_start || end != vma->vm_end) 1365 if (addr != vma->vm_start || end != vma->vm_end)
1366 return -EINVAL; 1366 return -EINVAL;
1367 vma->vm_pgoff = pfn; 1367 vma->vm_pgoff = pfn;
1368 } 1368 }
1369 1369
1370 vma->vm_flags |= VM_IO | VM_RESERVED | VM_PFNMAP; 1370 vma->vm_flags |= VM_IO | VM_RESERVED | VM_PFNMAP;
1371 1371
1372 BUG_ON(addr >= end); 1372 BUG_ON(addr >= end);
1373 pfn -= addr >> PAGE_SHIFT; 1373 pfn -= addr >> PAGE_SHIFT;
1374 pgd = pgd_offset(mm, addr); 1374 pgd = pgd_offset(mm, addr);
1375 flush_cache_range(vma, addr, end); 1375 flush_cache_range(vma, addr, end);
1376 do { 1376 do {
1377 next = pgd_addr_end(addr, end); 1377 next = pgd_addr_end(addr, end);
1378 err = remap_pud_range(mm, pgd, addr, next, 1378 err = remap_pud_range(mm, pgd, addr, next,
1379 pfn + (addr >> PAGE_SHIFT), prot); 1379 pfn + (addr >> PAGE_SHIFT), prot);
1380 if (err) 1380 if (err)
1381 break; 1381 break;
1382 } while (pgd++, addr = next, addr != end); 1382 } while (pgd++, addr = next, addr != end);
1383 return err; 1383 return err;
1384 } 1384 }
1385 EXPORT_SYMBOL(remap_pfn_range); 1385 EXPORT_SYMBOL(remap_pfn_range);
1386 1386
1387 static int apply_to_pte_range(struct mm_struct *mm, pmd_t *pmd, 1387 static int apply_to_pte_range(struct mm_struct *mm, pmd_t *pmd,
1388 unsigned long addr, unsigned long end, 1388 unsigned long addr, unsigned long end,
1389 pte_fn_t fn, void *data) 1389 pte_fn_t fn, void *data)
1390 { 1390 {
1391 pte_t *pte; 1391 pte_t *pte;
1392 int err; 1392 int err;
1393 pgtable_t token; 1393 pgtable_t token;
1394 spinlock_t *uninitialized_var(ptl); 1394 spinlock_t *uninitialized_var(ptl);
1395 1395
1396 pte = (mm == &init_mm) ? 1396 pte = (mm == &init_mm) ?
1397 pte_alloc_kernel(pmd, addr) : 1397 pte_alloc_kernel(pmd, addr) :
1398 pte_alloc_map_lock(mm, pmd, addr, &ptl); 1398 pte_alloc_map_lock(mm, pmd, addr, &ptl);
1399 if (!pte) 1399 if (!pte)
1400 return -ENOMEM; 1400 return -ENOMEM;
1401 1401
1402 BUG_ON(pmd_huge(*pmd)); 1402 BUG_ON(pmd_huge(*pmd));
1403 1403
1404 token = pmd_pgtable(*pmd); 1404 token = pmd_pgtable(*pmd);
1405 1405
1406 do { 1406 do {
1407 err = fn(pte, token, addr, data); 1407 err = fn(pte, token, addr, data);
1408 if (err) 1408 if (err)
1409 break; 1409 break;
1410 } while (pte++, addr += PAGE_SIZE, addr != end); 1410 } while (pte++, addr += PAGE_SIZE, addr != end);
1411 1411
1412 if (mm != &init_mm) 1412 if (mm != &init_mm)
1413 pte_unmap_unlock(pte-1, ptl); 1413 pte_unmap_unlock(pte-1, ptl);
1414 return err; 1414 return err;
1415 } 1415 }
1416 1416
1417 static int apply_to_pmd_range(struct mm_struct *mm, pud_t *pud, 1417 static int apply_to_pmd_range(struct mm_struct *mm, pud_t *pud,
1418 unsigned long addr, unsigned long end, 1418 unsigned long addr, unsigned long end,
1419 pte_fn_t fn, void *data) 1419 pte_fn_t fn, void *data)
1420 { 1420 {
1421 pmd_t *pmd; 1421 pmd_t *pmd;
1422 unsigned long next; 1422 unsigned long next;
1423 int err; 1423 int err;
1424 1424
1425 pmd = pmd_alloc(mm, pud, addr); 1425 pmd = pmd_alloc(mm, pud, addr);
1426 if (!pmd) 1426 if (!pmd)
1427 return -ENOMEM; 1427 return -ENOMEM;
1428 do { 1428 do {
1429 next = pmd_addr_end(addr, end); 1429 next = pmd_addr_end(addr, end);
1430 err = apply_to_pte_range(mm, pmd, addr, next, fn, data); 1430 err = apply_to_pte_range(mm, pmd, addr, next, fn, data);
1431 if (err) 1431 if (err)
1432 break; 1432 break;
1433 } while (pmd++, addr = next, addr != end); 1433 } while (pmd++, addr = next, addr != end);
1434 return err; 1434 return err;
1435 } 1435 }
1436 1436
1437 static int apply_to_pud_range(struct mm_struct *mm, pgd_t *pgd, 1437 static int apply_to_pud_range(struct mm_struct *mm, pgd_t *pgd,
1438 unsigned long addr, unsigned long end, 1438 unsigned long addr, unsigned long end,
1439 pte_fn_t fn, void *data) 1439 pte_fn_t fn, void *data)
1440 { 1440 {
1441 pud_t *pud; 1441 pud_t *pud;
1442 unsigned long next; 1442 unsigned long next;
1443 int err; 1443 int err;
1444 1444
1445 pud = pud_alloc(mm, pgd, addr); 1445 pud = pud_alloc(mm, pgd, addr);
1446 if (!pud) 1446 if (!pud)
1447 return -ENOMEM; 1447 return -ENOMEM;
1448 do { 1448 do {
1449 next = pud_addr_end(addr, end); 1449 next = pud_addr_end(addr, end);
1450 err = apply_to_pmd_range(mm, pud, addr, next, fn, data); 1450 err = apply_to_pmd_range(mm, pud, addr, next, fn, data);
1451 if (err) 1451 if (err)
1452 break; 1452 break;
1453 } while (pud++, addr = next, addr != end); 1453 } while (pud++, addr = next, addr != end);
1454 return err; 1454 return err;
1455 } 1455 }
1456 1456
1457 /* 1457 /*
1458 * Scan a region of virtual memory, filling in page tables as necessary 1458 * Scan a region of virtual memory, filling in page tables as necessary
1459 * and calling a provided function on each leaf page table. 1459 * and calling a provided function on each leaf page table.
1460 */ 1460 */
1461 int apply_to_page_range(struct mm_struct *mm, unsigned long addr, 1461 int apply_to_page_range(struct mm_struct *mm, unsigned long addr,
1462 unsigned long size, pte_fn_t fn, void *data) 1462 unsigned long size, pte_fn_t fn, void *data)
1463 { 1463 {
1464 pgd_t *pgd; 1464 pgd_t *pgd;
1465 unsigned long next; 1465 unsigned long next;
1466 unsigned long end = addr + size; 1466 unsigned long end = addr + size;
1467 int err; 1467 int err;
1468 1468
1469 BUG_ON(addr >= end); 1469 BUG_ON(addr >= end);
1470 pgd = pgd_offset(mm, addr); 1470 pgd = pgd_offset(mm, addr);
1471 do { 1471 do {
1472 next = pgd_addr_end(addr, end); 1472 next = pgd_addr_end(addr, end);
1473 err = apply_to_pud_range(mm, pgd, addr, next, fn, data); 1473 err = apply_to_pud_range(mm, pgd, addr, next, fn, data);
1474 if (err) 1474 if (err)
1475 break; 1475 break;
1476 } while (pgd++, addr = next, addr != end); 1476 } while (pgd++, addr = next, addr != end);
1477 return err; 1477 return err;
1478 } 1478 }
1479 EXPORT_SYMBOL_GPL(apply_to_page_range); 1479 EXPORT_SYMBOL_GPL(apply_to_page_range);
1480 1480
1481 /* 1481 /*
1482 * handle_pte_fault chooses page fault handler according to an entry 1482 * handle_pte_fault chooses page fault handler according to an entry
1483 * which was read non-atomically. Before making any commitment, on 1483 * which was read non-atomically. Before making any commitment, on
1484 * those architectures or configurations (e.g. i386 with PAE) which 1484 * those architectures or configurations (e.g. i386 with PAE) which
1485 * might give a mix of unmatched parts, do_swap_page and do_file_page 1485 * might give a mix of unmatched parts, do_swap_page and do_file_page
1486 * must check under lock before unmapping the pte and proceeding 1486 * must check under lock before unmapping the pte and proceeding
1487 * (but do_wp_page is only called after already making such a check; 1487 * (but do_wp_page is only called after already making such a check;
1488 * and do_anonymous_page and do_no_page can safely check later on). 1488 * and do_anonymous_page and do_no_page can safely check later on).
1489 */ 1489 */
1490 static inline int pte_unmap_same(struct mm_struct *mm, pmd_t *pmd, 1490 static inline int pte_unmap_same(struct mm_struct *mm, pmd_t *pmd,
1491 pte_t *page_table, pte_t orig_pte) 1491 pte_t *page_table, pte_t orig_pte)
1492 { 1492 {
1493 int same = 1; 1493 int same = 1;
1494 #if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT) 1494 #if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT)
1495 if (sizeof(pte_t) > sizeof(unsigned long)) { 1495 if (sizeof(pte_t) > sizeof(unsigned long)) {
1496 spinlock_t *ptl = pte_lockptr(mm, pmd); 1496 spinlock_t *ptl = pte_lockptr(mm, pmd);
1497 spin_lock(ptl); 1497 spin_lock(ptl);
1498 same = pte_same(*page_table, orig_pte); 1498 same = pte_same(*page_table, orig_pte);
1499 spin_unlock(ptl); 1499 spin_unlock(ptl);
1500 } 1500 }
1501 #endif 1501 #endif
1502 pte_unmap(page_table); 1502 pte_unmap(page_table);
1503 return same; 1503 return same;
1504 } 1504 }
1505 1505
1506 /* 1506 /*
1507 * Do pte_mkwrite, but only if the vma says VM_WRITE. We do this when 1507 * Do pte_mkwrite, but only if the vma says VM_WRITE. We do this when
1508 * servicing faults for write access. In the normal case, do always want 1508 * servicing faults for write access. In the normal case, do always want
1509 * pte_mkwrite. But get_user_pages can cause write faults for mappings 1509 * pte_mkwrite. But get_user_pages can cause write faults for mappings
1510 * that do not have writing enabled, when used by access_process_vm. 1510 * that do not have writing enabled, when used by access_process_vm.
1511 */ 1511 */
1512 static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma) 1512 static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma)
1513 { 1513 {
1514 if (likely(vma->vm_flags & VM_WRITE)) 1514 if (likely(vma->vm_flags & VM_WRITE))
1515 pte = pte_mkwrite(pte); 1515 pte = pte_mkwrite(pte);
1516 return pte; 1516 return pte;
1517 } 1517 }
1518 1518
1519 static inline void cow_user_page(struct page *dst, struct page *src, unsigned long va, struct vm_area_struct *vma) 1519 static inline void cow_user_page(struct page *dst, struct page *src, unsigned long va, struct vm_area_struct *vma)
1520 { 1520 {
1521 /* 1521 /*
1522 * If the source page was a PFN mapping, we don't have 1522 * If the source page was a PFN mapping, we don't have
1523 * a "struct page" for it. We do a best-effort copy by 1523 * a "struct page" for it. We do a best-effort copy by
1524 * just copying from the original user address. If that 1524 * just copying from the original user address. If that
1525 * fails, we just zero-fill it. Live with it. 1525 * fails, we just zero-fill it. Live with it.
1526 */ 1526 */
1527 if (unlikely(!src)) { 1527 if (unlikely(!src)) {
1528 void *kaddr = kmap_atomic(dst, KM_USER0); 1528 void *kaddr = kmap_atomic(dst, KM_USER0);
1529 void __user *uaddr = (void __user *)(va & PAGE_MASK); 1529 void __user *uaddr = (void __user *)(va & PAGE_MASK);
1530 1530
1531 /* 1531 /*
1532 * This really shouldn't fail, because the page is there 1532 * This really shouldn't fail, because the page is there
1533 * in the page tables. But it might just be unreadable, 1533 * in the page tables. But it might just be unreadable,
1534 * in which case we just give up and fill the result with 1534 * in which case we just give up and fill the result with
1535 * zeroes. 1535 * zeroes.
1536 */ 1536 */
1537 if (__copy_from_user_inatomic(kaddr, uaddr, PAGE_SIZE)) 1537 if (__copy_from_user_inatomic(kaddr, uaddr, PAGE_SIZE))
1538 memset(kaddr, 0, PAGE_SIZE); 1538 memset(kaddr, 0, PAGE_SIZE);
1539 kunmap_atomic(kaddr, KM_USER0); 1539 kunmap_atomic(kaddr, KM_USER0);
1540 flush_dcache_page(dst); 1540 flush_dcache_page(dst);
1541 } else 1541 } else
1542 copy_user_highpage(dst, src, va, vma); 1542 copy_user_highpage(dst, src, va, vma);
1543 } 1543 }
1544 1544
1545 /* 1545 /*
1546 * This routine handles present pages, when users try to write 1546 * This routine handles present pages, when users try to write
1547 * to a shared page. It is done by copying the page to a new address 1547 * to a shared page. It is done by copying the page to a new address
1548 * and decrementing the shared-page counter for the old page. 1548 * and decrementing the shared-page counter for the old page.
1549 * 1549 *
1550 * Note that this routine assumes that the protection checks have been 1550 * Note that this routine assumes that the protection checks have been
1551 * done by the caller (the low-level page fault routine in most cases). 1551 * done by the caller (the low-level page fault routine in most cases).
1552 * Thus we can safely just mark it writable once we've done any necessary 1552 * Thus we can safely just mark it writable once we've done any necessary
1553 * COW. 1553 * COW.
1554 * 1554 *
1555 * We also mark the page dirty at this point even though the page will 1555 * We also mark the page dirty at this point even though the page will
1556 * change only once the write actually happens. This avoids a few races, 1556 * change only once the write actually happens. This avoids a few races,
1557 * and potentially makes it more efficient. 1557 * and potentially makes it more efficient.
1558 * 1558 *
1559 * We enter with non-exclusive mmap_sem (to exclude vma changes, 1559 * We enter with non-exclusive mmap_sem (to exclude vma changes,
1560 * but allow concurrent faults), with pte both mapped and locked. 1560 * but allow concurrent faults), with pte both mapped and locked.
1561 * We return with mmap_sem still held, but pte unmapped and unlocked. 1561 * We return with mmap_sem still held, but pte unmapped and unlocked.
1562 */ 1562 */
1563 static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma, 1563 static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
1564 unsigned long address, pte_t *page_table, pmd_t *pmd, 1564 unsigned long address, pte_t *page_table, pmd_t *pmd,
1565 spinlock_t *ptl, pte_t orig_pte) 1565 spinlock_t *ptl, pte_t orig_pte)
1566 { 1566 {
1567 struct page *old_page, *new_page; 1567 struct page *old_page, *new_page;
1568 pte_t entry; 1568 pte_t entry;
1569 int reuse = 0, ret = 0; 1569 int reuse = 0, ret = 0;
1570 int page_mkwrite = 0; 1570 int page_mkwrite = 0;
1571 struct page *dirty_page = NULL; 1571 struct page *dirty_page = NULL;
1572 1572
1573 old_page = vm_normal_page(vma, address, orig_pte); 1573 old_page = vm_normal_page(vma, address, orig_pte);
1574 if (!old_page) 1574 if (!old_page)
1575 goto gotten; 1575 goto gotten;
1576 1576
1577 /* 1577 /*
1578 * Take out anonymous pages first, anonymous shared vmas are 1578 * Take out anonymous pages first, anonymous shared vmas are
1579 * not dirty accountable. 1579 * not dirty accountable.
1580 */ 1580 */
1581 if (PageAnon(old_page)) { 1581 if (PageAnon(old_page)) {
1582 if (!TestSetPageLocked(old_page)) { 1582 if (!TestSetPageLocked(old_page)) {
1583 reuse = can_share_swap_page(old_page); 1583 reuse = can_share_swap_page(old_page);
1584 unlock_page(old_page); 1584 unlock_page(old_page);
1585 } 1585 }
1586 } else if (unlikely((vma->vm_flags & (VM_WRITE|VM_SHARED)) == 1586 } else if (unlikely((vma->vm_flags & (VM_WRITE|VM_SHARED)) ==
1587 (VM_WRITE|VM_SHARED))) { 1587 (VM_WRITE|VM_SHARED))) {
1588 /* 1588 /*
1589 * Only catch write-faults on shared writable pages, 1589 * Only catch write-faults on shared writable pages,
1590 * read-only shared pages can get COWed by 1590 * read-only shared pages can get COWed by
1591 * get_user_pages(.write=1, .force=1). 1591 * get_user_pages(.write=1, .force=1).
1592 */ 1592 */
1593 if (vma->vm_ops && vma->vm_ops->page_mkwrite) { 1593 if (vma->vm_ops && vma->vm_ops->page_mkwrite) {
1594 /* 1594 /*
1595 * Notify the address space that the page is about to 1595 * Notify the address space that the page is about to
1596 * become writable so that it can prohibit this or wait 1596 * become writable so that it can prohibit this or wait
1597 * for the page to get into an appropriate state. 1597 * for the page to get into an appropriate state.
1598 * 1598 *
1599 * We do this without the lock held, so that it can 1599 * We do this without the lock held, so that it can
1600 * sleep if it needs to. 1600 * sleep if it needs to.
1601 */ 1601 */
1602 page_cache_get(old_page); 1602 page_cache_get(old_page);
1603 pte_unmap_unlock(page_table, ptl); 1603 pte_unmap_unlock(page_table, ptl);
1604 1604
1605 if (vma->vm_ops->page_mkwrite(vma, old_page) < 0) 1605 if (vma->vm_ops->page_mkwrite(vma, old_page) < 0)
1606 goto unwritable_page; 1606 goto unwritable_page;
1607 1607
1608 /* 1608 /*
1609 * Since we dropped the lock we need to revalidate 1609 * Since we dropped the lock we need to revalidate
1610 * the PTE as someone else may have changed it. If 1610 * the PTE as someone else may have changed it. If
1611 * they did, we just return, as we can count on the 1611 * they did, we just return, as we can count on the
1612 * MMU to tell us if they didn't also make it writable. 1612 * MMU to tell us if they didn't also make it writable.
1613 */ 1613 */
1614 page_table = pte_offset_map_lock(mm, pmd, address, 1614 page_table = pte_offset_map_lock(mm, pmd, address,
1615 &ptl); 1615 &ptl);
1616 page_cache_release(old_page); 1616 page_cache_release(old_page);
1617 if (!pte_same(*page_table, orig_pte)) 1617 if (!pte_same(*page_table, orig_pte))
1618 goto unlock; 1618 goto unlock;
1619 1619
1620 page_mkwrite = 1; 1620 page_mkwrite = 1;
1621 } 1621 }
1622 dirty_page = old_page; 1622 dirty_page = old_page;
1623 get_page(dirty_page); 1623 get_page(dirty_page);
1624 reuse = 1; 1624 reuse = 1;
1625 } 1625 }
1626 1626
1627 if (reuse) { 1627 if (reuse) {
1628 flush_cache_page(vma, address, pte_pfn(orig_pte)); 1628 flush_cache_page(vma, address, pte_pfn(orig_pte));
1629 entry = pte_mkyoung(orig_pte); 1629 entry = pte_mkyoung(orig_pte);
1630 entry = maybe_mkwrite(pte_mkdirty(entry), vma); 1630 entry = maybe_mkwrite(pte_mkdirty(entry), vma);
1631 if (ptep_set_access_flags(vma, address, page_table, entry,1)) 1631 if (ptep_set_access_flags(vma, address, page_table, entry,1))
1632 update_mmu_cache(vma, address, entry); 1632 update_mmu_cache(vma, address, entry);
1633 ret |= VM_FAULT_WRITE; 1633 ret |= VM_FAULT_WRITE;
1634 goto unlock; 1634 goto unlock;
1635 } 1635 }
1636 1636
1637 /* 1637 /*
1638 * Ok, we need to copy. Oh, well.. 1638 * Ok, we need to copy. Oh, well..
1639 */ 1639 */
1640 page_cache_get(old_page); 1640 page_cache_get(old_page);
1641 gotten: 1641 gotten:
1642 pte_unmap_unlock(page_table, ptl); 1642 pte_unmap_unlock(page_table, ptl);
1643 1643
1644 if (unlikely(anon_vma_prepare(vma))) 1644 if (unlikely(anon_vma_prepare(vma)))
1645 goto oom; 1645 goto oom;
1646 VM_BUG_ON(old_page == ZERO_PAGE(0)); 1646 VM_BUG_ON(old_page == ZERO_PAGE(0));
1647 new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address); 1647 new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address);
1648 if (!new_page) 1648 if (!new_page)
1649 goto oom; 1649 goto oom;
1650 cow_user_page(new_page, old_page, address, vma); 1650 cow_user_page(new_page, old_page, address, vma);
1651 __SetPageUptodate(new_page); 1651 __SetPageUptodate(new_page);
1652 1652
1653 if (mem_cgroup_charge(new_page, mm, GFP_KERNEL)) 1653 if (mem_cgroup_charge(new_page, mm, GFP_KERNEL))
1654 goto oom_free_new; 1654 goto oom_free_new;
1655 1655
1656 /* 1656 /*
1657 * Re-check the pte - we dropped the lock 1657 * Re-check the pte - we dropped the lock
1658 */ 1658 */
1659 page_table = pte_offset_map_lock(mm, pmd, address, &ptl); 1659 page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
1660 if (likely(pte_same(*page_table, orig_pte))) { 1660 if (likely(pte_same(*page_table, orig_pte))) {
1661 if (old_page) { 1661 if (old_page) {
1662 page_remove_rmap(old_page, vma); 1662 page_remove_rmap(old_page, vma);
1663 if (!PageAnon(old_page)) { 1663 if (!PageAnon(old_page)) {
1664 dec_mm_counter(mm, file_rss); 1664 dec_mm_counter(mm, file_rss);
1665 inc_mm_counter(mm, anon_rss); 1665 inc_mm_counter(mm, anon_rss);
1666 } 1666 }
1667 } else 1667 } else
1668 inc_mm_counter(mm, anon_rss); 1668 inc_mm_counter(mm, anon_rss);
1669 flush_cache_page(vma, address, pte_pfn(orig_pte)); 1669 flush_cache_page(vma, address, pte_pfn(orig_pte));
1670 entry = mk_pte(new_page, vma->vm_page_prot); 1670 entry = mk_pte(new_page, vma->vm_page_prot);
1671 entry = maybe_mkwrite(pte_mkdirty(entry), vma); 1671 entry = maybe_mkwrite(pte_mkdirty(entry), vma);
1672 /* 1672 /*
1673 * Clear the pte entry and flush it first, before updating the 1673 * Clear the pte entry and flush it first, before updating the
1674 * pte with the new entry. This will avoid a race condition 1674 * pte with the new entry. This will avoid a race condition
1675 * seen in the presence of one thread doing SMC and another 1675 * seen in the presence of one thread doing SMC and another
1676 * thread doing COW. 1676 * thread doing COW.
1677 */ 1677 */
1678 ptep_clear_flush(vma, address, page_table); 1678 ptep_clear_flush(vma, address, page_table);
1679 set_pte_at(mm, address, page_table, entry); 1679 set_pte_at(mm, address, page_table, entry);
1680 update_mmu_cache(vma, address, entry); 1680 update_mmu_cache(vma, address, entry);
1681 lru_cache_add_active(new_page); 1681 lru_cache_add_active(new_page);
1682 page_add_new_anon_rmap(new_page, vma, address); 1682 page_add_new_anon_rmap(new_page, vma, address);
1683 1683
1684 /* Free the old page.. */ 1684 /* Free the old page.. */
1685 new_page = old_page; 1685 new_page = old_page;
1686 ret |= VM_FAULT_WRITE; 1686 ret |= VM_FAULT_WRITE;
1687 } else 1687 } else
1688 mem_cgroup_uncharge_page(new_page); 1688 mem_cgroup_uncharge_page(new_page);
1689 1689
1690 if (new_page) 1690 if (new_page)
1691 page_cache_release(new_page); 1691 page_cache_release(new_page);
1692 if (old_page) 1692 if (old_page)
1693 page_cache_release(old_page); 1693 page_cache_release(old_page);
1694 unlock: 1694 unlock:
1695 pte_unmap_unlock(page_table, ptl); 1695 pte_unmap_unlock(page_table, ptl);
1696 if (dirty_page) { 1696 if (dirty_page) {
1697 if (vma->vm_file) 1697 if (vma->vm_file)
1698 file_update_time(vma->vm_file); 1698 file_update_time(vma->vm_file);
1699 1699
1700 /* 1700 /*
1701 * Yes, Virginia, this is actually required to prevent a race 1701 * Yes, Virginia, this is actually required to prevent a race
1702 * with clear_page_dirty_for_io() from clearing the page dirty 1702 * with clear_page_dirty_for_io() from clearing the page dirty
1703 * bit after it clear all dirty ptes, but before a racing 1703 * bit after it clear all dirty ptes, but before a racing
1704 * do_wp_page installs a dirty pte. 1704 * do_wp_page installs a dirty pte.
1705 * 1705 *
1706 * do_no_page is protected similarly. 1706 * do_no_page is protected similarly.
1707 */ 1707 */
1708 wait_on_page_locked(dirty_page); 1708 wait_on_page_locked(dirty_page);
1709 set_page_dirty_balance(dirty_page, page_mkwrite); 1709 set_page_dirty_balance(dirty_page, page_mkwrite);
1710 put_page(dirty_page); 1710 put_page(dirty_page);
1711 } 1711 }
1712 return ret; 1712 return ret;
1713 oom_free_new: 1713 oom_free_new:
1714 page_cache_release(new_page); 1714 page_cache_release(new_page);
1715 oom: 1715 oom:
1716 if (old_page) 1716 if (old_page)
1717 page_cache_release(old_page); 1717 page_cache_release(old_page);
1718 return VM_FAULT_OOM; 1718 return VM_FAULT_OOM;
1719 1719
1720 unwritable_page: 1720 unwritable_page:
1721 page_cache_release(old_page); 1721 page_cache_release(old_page);
1722 return VM_FAULT_SIGBUS; 1722 return VM_FAULT_SIGBUS;
1723 } 1723 }
1724 1724
1725 /* 1725 /*
1726 * Helper functions for unmap_mapping_range(). 1726 * Helper functions for unmap_mapping_range().
1727 * 1727 *
1728 * __ Notes on dropping i_mmap_lock to reduce latency while unmapping __ 1728 * __ Notes on dropping i_mmap_lock to reduce latency while unmapping __
1729 * 1729 *
1730 * We have to restart searching the prio_tree whenever we drop the lock, 1730 * We have to restart searching the prio_tree whenever we drop the lock,
1731 * since the iterator is only valid while the lock is held, and anyway 1731 * since the iterator is only valid while the lock is held, and anyway
1732 * a later vma might be split and reinserted earlier while lock dropped. 1732 * a later vma might be split and reinserted earlier while lock dropped.
1733 * 1733 *
1734 * The list of nonlinear vmas could be handled more efficiently, using 1734 * The list of nonlinear vmas could be handled more efficiently, using
1735 * a placeholder, but handle it in the same way until a need is shown. 1735 * a placeholder, but handle it in the same way until a need is shown.
1736 * It is important to search the prio_tree before nonlinear list: a vma 1736 * It is important to search the prio_tree before nonlinear list: a vma
1737 * may become nonlinear and be shifted from prio_tree to nonlinear list 1737 * may become nonlinear and be shifted from prio_tree to nonlinear list
1738 * while the lock is dropped; but never shifted from list to prio_tree. 1738 * while the lock is dropped; but never shifted from list to prio_tree.
1739 * 1739 *
1740 * In order to make forward progress despite restarting the search, 1740 * In order to make forward progress despite restarting the search,
1741 * vm_truncate_count is used to mark a vma as now dealt with, so we can 1741 * vm_truncate_count is used to mark a vma as now dealt with, so we can
1742 * quickly skip it next time around. Since the prio_tree search only 1742 * quickly skip it next time around. Since the prio_tree search only
1743 * shows us those vmas affected by unmapping the range in question, we 1743 * shows us those vmas affected by unmapping the range in question, we
1744 * can't efficiently keep all vmas in step with mapping->truncate_count: 1744 * can't efficiently keep all vmas in step with mapping->truncate_count:
1745 * so instead reset them all whenever it wraps back to 0 (then go to 1). 1745 * so instead reset them all whenever it wraps back to 0 (then go to 1).
1746 * mapping->truncate_count and vma->vm_truncate_count are protected by 1746 * mapping->truncate_count and vma->vm_truncate_count are protected by
1747 * i_mmap_lock. 1747 * i_mmap_lock.
1748 * 1748 *
1749 * In order to make forward progress despite repeatedly restarting some 1749 * In order to make forward progress despite repeatedly restarting some
1750 * large vma, note the restart_addr from unmap_vmas when it breaks out: 1750 * large vma, note the restart_addr from unmap_vmas when it breaks out:
1751 * and restart from that address when we reach that vma again. It might 1751 * and restart from that address when we reach that vma again. It might
1752 * have been split or merged, shrunk or extended, but never shifted: so 1752 * have been split or merged, shrunk or extended, but never shifted: so
1753 * restart_addr remains valid so long as it remains in the vma's range. 1753 * restart_addr remains valid so long as it remains in the vma's range.
1754 * unmap_mapping_range forces truncate_count to leap over page-aligned 1754 * unmap_mapping_range forces truncate_count to leap over page-aligned
1755 * values so we can save vma's restart_addr in its truncate_count field. 1755 * values so we can save vma's restart_addr in its truncate_count field.
1756 */ 1756 */
1757 #define is_restart_addr(truncate_count) (!((truncate_count) & ~PAGE_MASK)) 1757 #define is_restart_addr(truncate_count) (!((truncate_count) & ~PAGE_MASK))
1758 1758
1759 static void reset_vma_truncate_counts(struct address_space *mapping) 1759 static void reset_vma_truncate_counts(struct address_space *mapping)
1760 { 1760 {
1761 struct vm_area_struct *vma; 1761 struct vm_area_struct *vma;
1762 struct prio_tree_iter iter; 1762 struct prio_tree_iter iter;
1763 1763
1764 vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, 0, ULONG_MAX) 1764 vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, 0, ULONG_MAX)
1765 vma->vm_truncate_count = 0; 1765 vma->vm_truncate_count = 0;
1766 list_for_each_entry(vma, &mapping->i_mmap_nonlinear, shared.vm_set.list) 1766 list_for_each_entry(vma, &mapping->i_mmap_nonlinear, shared.vm_set.list)
1767 vma->vm_truncate_count = 0; 1767 vma->vm_truncate_count = 0;
1768 } 1768 }
1769 1769
1770 static int unmap_mapping_range_vma(struct vm_area_struct *vma, 1770 static int unmap_mapping_range_vma(struct vm_area_struct *vma,
1771 unsigned long start_addr, unsigned long end_addr, 1771 unsigned long start_addr, unsigned long end_addr,
1772 struct zap_details *details) 1772 struct zap_details *details)
1773 { 1773 {
1774 unsigned long restart_addr; 1774 unsigned long restart_addr;
1775 int need_break; 1775 int need_break;
1776 1776
1777 /* 1777 /*
1778 * files that support invalidating or truncating portions of the 1778 * files that support invalidating or truncating portions of the
1779 * file from under mmaped areas must have their ->fault function 1779 * file from under mmaped areas must have their ->fault function
1780 * return a locked page (and set VM_FAULT_LOCKED in the return). 1780 * return a locked page (and set VM_FAULT_LOCKED in the return).
1781 * This provides synchronisation against concurrent unmapping here. 1781 * This provides synchronisation against concurrent unmapping here.
1782 */ 1782 */
1783 1783
1784 again: 1784 again:
1785 restart_addr = vma->vm_truncate_count; 1785 restart_addr = vma->vm_truncate_count;
1786 if (is_restart_addr(restart_addr) && start_addr < restart_addr) { 1786 if (is_restart_addr(restart_addr) && start_addr < restart_addr) {
1787 start_addr = restart_addr; 1787 start_addr = restart_addr;
1788 if (start_addr >= end_addr) { 1788 if (start_addr >= end_addr) {
1789 /* Top of vma has been split off since last time */ 1789 /* Top of vma has been split off since last time */
1790 vma->vm_truncate_count = details->truncate_count; 1790 vma->vm_truncate_count = details->truncate_count;
1791 return 0; 1791 return 0;
1792 } 1792 }
1793 } 1793 }
1794 1794
1795 restart_addr = zap_page_range(vma, start_addr, 1795 restart_addr = zap_page_range(vma, start_addr,
1796 end_addr - start_addr, details); 1796 end_addr - start_addr, details);
1797 need_break = need_resched() || spin_needbreak(details->i_mmap_lock); 1797 need_break = need_resched() || spin_needbreak(details->i_mmap_lock);
1798 1798
1799 if (restart_addr >= end_addr) { 1799 if (restart_addr >= end_addr) {
1800 /* We have now completed this vma: mark it so */ 1800 /* We have now completed this vma: mark it so */
1801 vma->vm_truncate_count = details->truncate_count; 1801 vma->vm_truncate_count = details->truncate_count;
1802 if (!need_break) 1802 if (!need_break)
1803 return 0; 1803 return 0;
1804 } else { 1804 } else {
1805 /* Note restart_addr in vma's truncate_count field */ 1805 /* Note restart_addr in vma's truncate_count field */
1806 vma->vm_truncate_count = restart_addr; 1806 vma->vm_truncate_count = restart_addr;
1807 if (!need_break) 1807 if (!need_break)
1808 goto again; 1808 goto again;
1809 } 1809 }
1810 1810
1811 spin_unlock(details->i_mmap_lock); 1811 spin_unlock(details->i_mmap_lock);
1812 cond_resched(); 1812 cond_resched();
1813 spin_lock(details->i_mmap_lock); 1813 spin_lock(details->i_mmap_lock);
1814 return -EINTR; 1814 return -EINTR;
1815 } 1815 }
1816 1816
1817 static inline void unmap_mapping_range_tree(struct prio_tree_root *root, 1817 static inline void unmap_mapping_range_tree(struct prio_tree_root *root,
1818 struct zap_details *details) 1818 struct zap_details *details)
1819 { 1819 {
1820 struct vm_area_struct *vma; 1820 struct vm_area_struct *vma;
1821 struct prio_tree_iter iter; 1821 struct prio_tree_iter iter;
1822 pgoff_t vba, vea, zba, zea; 1822 pgoff_t vba, vea, zba, zea;
1823 1823
1824 restart: 1824 restart:
1825 vma_prio_tree_foreach(vma, &iter, root, 1825 vma_prio_tree_foreach(vma, &iter, root,
1826 details->first_index, details->last_index) { 1826 details->first_index, details->last_index) {
1827 /* Skip quickly over those we have already dealt with */ 1827 /* Skip quickly over those we have already dealt with */
1828 if (vma->vm_truncate_count == details->truncate_count) 1828 if (vma->vm_truncate_count == details->truncate_count)
1829 continue; 1829 continue;
1830 1830
1831 vba = vma->vm_pgoff; 1831 vba = vma->vm_pgoff;
1832 vea = vba + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) - 1; 1832 vea = vba + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) - 1;
1833 /* Assume for now that PAGE_CACHE_SHIFT == PAGE_SHIFT */ 1833 /* Assume for now that PAGE_CACHE_SHIFT == PAGE_SHIFT */
1834 zba = details->first_index; 1834 zba = details->first_index;
1835 if (zba < vba) 1835 if (zba < vba)
1836 zba = vba; 1836 zba = vba;
1837 zea = details->last_index; 1837 zea = details->last_index;
1838 if (zea > vea) 1838 if (zea > vea)
1839 zea = vea; 1839 zea = vea;
1840 1840
1841 if (unmap_mapping_range_vma(vma, 1841 if (unmap_mapping_range_vma(vma,
1842 ((zba - vba) << PAGE_SHIFT) + vma->vm_start, 1842 ((zba - vba) << PAGE_SHIFT) + vma->vm_start,
1843 ((zea - vba + 1) << PAGE_SHIFT) + vma->vm_start, 1843 ((zea - vba + 1) << PAGE_SHIFT) + vma->vm_start,
1844 details) < 0) 1844 details) < 0)
1845 goto restart; 1845 goto restart;
1846 } 1846 }
1847 } 1847 }
1848 1848
1849 static inline void unmap_mapping_range_list(struct list_head *head, 1849 static inline void unmap_mapping_range_list(struct list_head *head,
1850 struct zap_details *details) 1850 struct zap_details *details)
1851 { 1851 {
1852 struct vm_area_struct *vma; 1852 struct vm_area_struct *vma;
1853 1853
1854 /* 1854 /*
1855 * In nonlinear VMAs there is no correspondence between virtual address 1855 * In nonlinear VMAs there is no correspondence between virtual address
1856 * offset and file offset. So we must perform an exhaustive search 1856 * offset and file offset. So we must perform an exhaustive search
1857 * across *all* the pages in each nonlinear VMA, not just the pages 1857 * across *all* the pages in each nonlinear VMA, not just the pages
1858 * whose virtual address lies outside the file truncation point. 1858 * whose virtual address lies outside the file truncation point.
1859 */ 1859 */
1860 restart: 1860 restart:
1861 list_for_each_entry(vma, head, shared.vm_set.list) { 1861 list_for_each_entry(vma, head, shared.vm_set.list) {
1862 /* Skip quickly over those we have already dealt with */ 1862 /* Skip quickly over those we have already dealt with */
1863 if (vma->vm_truncate_count == details->truncate_count) 1863 if (vma->vm_truncate_count == details->truncate_count)
1864 continue; 1864 continue;
1865 details->nonlinear_vma = vma; 1865 details->nonlinear_vma = vma;
1866 if (unmap_mapping_range_vma(vma, vma->vm_start, 1866 if (unmap_mapping_range_vma(vma, vma->vm_start,
1867 vma->vm_end, details) < 0) 1867 vma->vm_end, details) < 0)
1868 goto restart; 1868 goto restart;
1869 } 1869 }
1870 } 1870 }
1871 1871
1872 /** 1872 /**
1873 * unmap_mapping_range - unmap the portion of all mmaps in the specified address_space corresponding to the specified page range in the underlying file. 1873 * unmap_mapping_range - unmap the portion of all mmaps in the specified address_space corresponding to the specified page range in the underlying file.
1874 * @mapping: the address space containing mmaps to be unmapped. 1874 * @mapping: the address space containing mmaps to be unmapped.
1875 * @holebegin: byte in first page to unmap, relative to the start of 1875 * @holebegin: byte in first page to unmap, relative to the start of
1876 * the underlying file. This will be rounded down to a PAGE_SIZE 1876 * the underlying file. This will be rounded down to a PAGE_SIZE
1877 * boundary. Note that this is different from vmtruncate(), which 1877 * boundary. Note that this is different from vmtruncate(), which
1878 * must keep the partial page. In contrast, we must get rid of 1878 * must keep the partial page. In contrast, we must get rid of
1879 * partial pages. 1879 * partial pages.
1880 * @holelen: size of prospective hole in bytes. This will be rounded 1880 * @holelen: size of prospective hole in bytes. This will be rounded
1881 * up to a PAGE_SIZE boundary. A holelen of zero truncates to the 1881 * up to a PAGE_SIZE boundary. A holelen of zero truncates to the
1882 * end of the file. 1882 * end of the file.
1883 * @even_cows: 1 when truncating a file, unmap even private COWed pages; 1883 * @even_cows: 1 when truncating a file, unmap even private COWed pages;
1884 * but 0 when invalidating pagecache, don't throw away private data. 1884 * but 0 when invalidating pagecache, don't throw away private data.
1885 */ 1885 */
1886 void unmap_mapping_range(struct address_space *mapping, 1886 void unmap_mapping_range(struct address_space *mapping,
1887 loff_t const holebegin, loff_t const holelen, int even_cows) 1887 loff_t const holebegin, loff_t const holelen, int even_cows)
1888 { 1888 {
1889 struct zap_details details; 1889 struct zap_details details;
1890 pgoff_t hba = holebegin >> PAGE_SHIFT; 1890 pgoff_t hba = holebegin >> PAGE_SHIFT;
1891 pgoff_t hlen = (holelen + PAGE_SIZE - 1) >> PAGE_SHIFT; 1891 pgoff_t hlen = (holelen + PAGE_SIZE - 1) >> PAGE_SHIFT;
1892 1892
1893 /* Check for overflow. */ 1893 /* Check for overflow. */
1894 if (sizeof(holelen) > sizeof(hlen)) { 1894 if (sizeof(holelen) > sizeof(hlen)) {
1895 long long holeend = 1895 long long holeend =
1896 (holebegin + holelen + PAGE_SIZE - 1) >> PAGE_SHIFT; 1896 (holebegin + holelen + PAGE_SIZE - 1) >> PAGE_SHIFT;
1897 if (holeend & ~(long long)ULONG_MAX) 1897 if (holeend & ~(long long)ULONG_MAX)
1898 hlen = ULONG_MAX - hba + 1; 1898 hlen = ULONG_MAX - hba + 1;
1899 } 1899 }
1900 1900
1901 details.check_mapping = even_cows? NULL: mapping; 1901 details.check_mapping = even_cows? NULL: mapping;
1902 details.nonlinear_vma = NULL; 1902 details.nonlinear_vma = NULL;
1903 details.first_index = hba; 1903 details.first_index = hba;
1904 details.last_index = hba + hlen - 1; 1904 details.last_index = hba + hlen - 1;
1905 if (details.last_index < details.first_index) 1905 if (details.last_index < details.first_index)
1906 details.last_index = ULONG_MAX; 1906 details.last_index = ULONG_MAX;
1907 details.i_mmap_lock = &mapping->i_mmap_lock; 1907 details.i_mmap_lock = &mapping->i_mmap_lock;
1908 1908
1909 spin_lock(&mapping->i_mmap_lock); 1909 spin_lock(&mapping->i_mmap_lock);
1910 1910
1911 /* Protect against endless unmapping loops */ 1911 /* Protect against endless unmapping loops */
1912 mapping->truncate_count++; 1912 mapping->truncate_count++;
1913 if (unlikely(is_restart_addr(mapping->truncate_count))) { 1913 if (unlikely(is_restart_addr(mapping->truncate_count))) {
1914 if (mapping->truncate_count == 0) 1914 if (mapping->truncate_count == 0)
1915 reset_vma_truncate_counts(mapping); 1915 reset_vma_truncate_counts(mapping);
1916 mapping->truncate_count++; 1916 mapping->truncate_count++;
1917 } 1917 }
1918 details.truncate_count = mapping->truncate_count; 1918 details.truncate_count = mapping->truncate_count;
1919 1919
1920 if (unlikely(!prio_tree_empty(&mapping->i_mmap))) 1920 if (unlikely(!prio_tree_empty(&mapping->i_mmap)))
1921 unmap_mapping_range_tree(&mapping->i_mmap, &details); 1921 unmap_mapping_range_tree(&mapping->i_mmap, &details);
1922 if (unlikely(!list_empty(&mapping->i_mmap_nonlinear))) 1922 if (unlikely(!list_empty(&mapping->i_mmap_nonlinear)))
1923 unmap_mapping_range_list(&mapping->i_mmap_nonlinear, &details); 1923 unmap_mapping_range_list(&mapping->i_mmap_nonlinear, &details);
1924 spin_unlock(&mapping->i_mmap_lock); 1924 spin_unlock(&mapping->i_mmap_lock);
1925 } 1925 }
1926 EXPORT_SYMBOL(unmap_mapping_range); 1926 EXPORT_SYMBOL(unmap_mapping_range);
1927 1927
1928 /** 1928 /**
1929 * vmtruncate - unmap mappings "freed" by truncate() syscall 1929 * vmtruncate - unmap mappings "freed" by truncate() syscall
1930 * @inode: inode of the file used 1930 * @inode: inode of the file used
1931 * @offset: file offset to start truncating 1931 * @offset: file offset to start truncating
1932 * 1932 *
1933 * NOTE! We have to be ready to update the memory sharing 1933 * NOTE! We have to be ready to update the memory sharing
1934 * between the file and the memory map for a potential last 1934 * between the file and the memory map for a potential last
1935 * incomplete page. Ugly, but necessary. 1935 * incomplete page. Ugly, but necessary.
1936 */ 1936 */
1937 int vmtruncate(struct inode * inode, loff_t offset) 1937 int vmtruncate(struct inode * inode, loff_t offset)
1938 { 1938 {
1939 if (inode->i_size < offset) { 1939 if (inode->i_size < offset) {
1940 unsigned long limit; 1940 unsigned long limit;
1941 1941
1942 limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur; 1942 limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur;
1943 if (limit != RLIM_INFINITY && offset > limit) 1943 if (limit != RLIM_INFINITY && offset > limit)
1944 goto out_sig; 1944 goto out_sig;
1945 if (offset > inode->i_sb->s_maxbytes) 1945 if (offset > inode->i_sb->s_maxbytes)
1946 goto out_big; 1946 goto out_big;
1947 i_size_write(inode, offset); 1947 i_size_write(inode, offset);
1948 } else { 1948 } else {
1949 struct address_space *mapping = inode->i_mapping; 1949 struct address_space *mapping = inode->i_mapping;
1950 1950
1951 /* 1951 /*
1952 * truncation of in-use swapfiles is disallowed - it would 1952 * truncation of in-use swapfiles is disallowed - it would
1953 * cause subsequent swapout to scribble on the now-freed 1953 * cause subsequent swapout to scribble on the now-freed
1954 * blocks. 1954 * blocks.
1955 */ 1955 */
1956 if (IS_SWAPFILE(inode)) 1956 if (IS_SWAPFILE(inode))
1957 return -ETXTBSY; 1957 return -ETXTBSY;
1958 i_size_write(inode, offset); 1958 i_size_write(inode, offset);
1959 1959
1960 /* 1960 /*
1961 * unmap_mapping_range is called twice, first simply for 1961 * unmap_mapping_range is called twice, first simply for
1962 * efficiency so that truncate_inode_pages does fewer 1962 * efficiency so that truncate_inode_pages does fewer
1963 * single-page unmaps. However after this first call, and 1963 * single-page unmaps. However after this first call, and
1964 * before truncate_inode_pages finishes, it is possible for 1964 * before truncate_inode_pages finishes, it is possible for
1965 * private pages to be COWed, which remain after 1965 * private pages to be COWed, which remain after
1966 * truncate_inode_pages finishes, hence the second 1966 * truncate_inode_pages finishes, hence the second
1967 * unmap_mapping_range call must be made for correctness. 1967 * unmap_mapping_range call must be made for correctness.
1968 */ 1968 */
1969 unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1); 1969 unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
1970 truncate_inode_pages(mapping, offset); 1970 truncate_inode_pages(mapping, offset);
1971 unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1); 1971 unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
1972 } 1972 }
1973 1973
1974 if (inode->i_op && inode->i_op->truncate) 1974 if (inode->i_op && inode->i_op->truncate)
1975 inode->i_op->truncate(inode); 1975 inode->i_op->truncate(inode);
1976 return 0; 1976 return 0;
1977 1977
1978 out_sig: 1978 out_sig:
1979 send_sig(SIGXFSZ, current, 0); 1979 send_sig(SIGXFSZ, current, 0);
1980 out_big: 1980 out_big:
1981 return -EFBIG; 1981 return -EFBIG;
1982 } 1982 }
1983 EXPORT_SYMBOL(vmtruncate); 1983 EXPORT_SYMBOL(vmtruncate);
1984 1984
1985 int vmtruncate_range(struct inode *inode, loff_t offset, loff_t end) 1985 int vmtruncate_range(struct inode *inode, loff_t offset, loff_t end)
1986 { 1986 {
1987 struct address_space *mapping = inode->i_mapping; 1987 struct address_space *mapping = inode->i_mapping;
1988 1988
1989 /* 1989 /*
1990 * If the underlying filesystem is not going to provide 1990 * If the underlying filesystem is not going to provide
1991 * a way to truncate a range of blocks (punch a hole) - 1991 * a way to truncate a range of blocks (punch a hole) -
1992 * we should return failure right now. 1992 * we should return failure right now.
1993 */ 1993 */
1994 if (!inode->i_op || !inode->i_op->truncate_range) 1994 if (!inode->i_op || !inode->i_op->truncate_range)
1995 return -ENOSYS; 1995 return -ENOSYS;
1996 1996
1997 mutex_lock(&inode->i_mutex); 1997 mutex_lock(&inode->i_mutex);
1998 down_write(&inode->i_alloc_sem); 1998 down_write(&inode->i_alloc_sem);
1999 unmap_mapping_range(mapping, offset, (end - offset), 1); 1999 unmap_mapping_range(mapping, offset, (end - offset), 1);
2000 truncate_inode_pages_range(mapping, offset, end); 2000 truncate_inode_pages_range(mapping, offset, end);
2001 unmap_mapping_range(mapping, offset, (end - offset), 1); 2001 unmap_mapping_range(mapping, offset, (end - offset), 1);
2002 inode->i_op->truncate_range(inode, offset, end); 2002 inode->i_op->truncate_range(inode, offset, end);
2003 up_write(&inode->i_alloc_sem); 2003 up_write(&inode->i_alloc_sem);
2004 mutex_unlock(&inode->i_mutex); 2004 mutex_unlock(&inode->i_mutex);
2005 2005
2006 return 0; 2006 return 0;
2007 } 2007 }
2008 2008
2009 /* 2009 /*
2010 * We enter with non-exclusive mmap_sem (to exclude vma changes, 2010 * We enter with non-exclusive mmap_sem (to exclude vma changes,
2011 * but allow concurrent faults), and pte mapped but not yet locked. 2011 * but allow concurrent faults), and pte mapped but not yet locked.
2012 * We return with mmap_sem still held, but pte unmapped and unlocked. 2012 * We return with mmap_sem still held, but pte unmapped and unlocked.
2013 */ 2013 */
2014 static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma, 2014 static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma,
2015 unsigned long address, pte_t *page_table, pmd_t *pmd, 2015 unsigned long address, pte_t *page_table, pmd_t *pmd,
2016 int write_access, pte_t orig_pte) 2016 int write_access, pte_t orig_pte)
2017 { 2017 {
2018 spinlock_t *ptl; 2018 spinlock_t *ptl;
2019 struct page *page; 2019 struct page *page;
2020 swp_entry_t entry; 2020 swp_entry_t entry;
2021 pte_t pte; 2021 pte_t pte;
2022 int ret = 0; 2022 int ret = 0;
2023 2023
2024 if (!pte_unmap_same(mm, pmd, page_table, orig_pte)) 2024 if (!pte_unmap_same(mm, pmd, page_table, orig_pte))
2025 goto out; 2025 goto out;
2026 2026
2027 entry = pte_to_swp_entry(orig_pte); 2027 entry = pte_to_swp_entry(orig_pte);
2028 if (is_migration_entry(entry)) { 2028 if (is_migration_entry(entry)) {
2029 migration_entry_wait(mm, pmd, address); 2029 migration_entry_wait(mm, pmd, address);
2030 goto out; 2030 goto out;
2031 } 2031 }
2032 delayacct_set_flag(DELAYACCT_PF_SWAPIN); 2032 delayacct_set_flag(DELAYACCT_PF_SWAPIN);
2033 page = lookup_swap_cache(entry); 2033 page = lookup_swap_cache(entry);
2034 if (!page) { 2034 if (!page) {
2035 grab_swap_token(); /* Contend for token _before_ read-in */ 2035 grab_swap_token(); /* Contend for token _before_ read-in */
2036 page = swapin_readahead(entry, 2036 page = swapin_readahead(entry,
2037 GFP_HIGHUSER_MOVABLE, vma, address); 2037 GFP_HIGHUSER_MOVABLE, vma, address);
2038 if (!page) { 2038 if (!page) {
2039 /* 2039 /*
2040 * Back out if somebody else faulted in this pte 2040 * Back out if somebody else faulted in this pte
2041 * while we released the pte lock. 2041 * while we released the pte lock.
2042 */ 2042 */
2043 page_table = pte_offset_map_lock(mm, pmd, address, &ptl); 2043 page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
2044 if (likely(pte_same(*page_table, orig_pte))) 2044 if (likely(pte_same(*page_table, orig_pte)))
2045 ret = VM_FAULT_OOM; 2045 ret = VM_FAULT_OOM;
2046 delayacct_clear_flag(DELAYACCT_PF_SWAPIN); 2046 delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
2047 goto unlock; 2047 goto unlock;
2048 } 2048 }
2049 2049
2050 /* Had to read the page from swap area: Major fault */ 2050 /* Had to read the page from swap area: Major fault */
2051 ret = VM_FAULT_MAJOR; 2051 ret = VM_FAULT_MAJOR;
2052 count_vm_event(PGMAJFAULT); 2052 count_vm_event(PGMAJFAULT);
2053 } 2053 }
2054 2054
2055 if (mem_cgroup_charge(page, mm, GFP_KERNEL)) { 2055 if (mem_cgroup_charge(page, mm, GFP_KERNEL)) {
2056 delayacct_clear_flag(DELAYACCT_PF_SWAPIN); 2056 delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
2057 ret = VM_FAULT_OOM; 2057 ret = VM_FAULT_OOM;
2058 goto out; 2058 goto out;
2059 } 2059 }
2060 2060
2061 mark_page_accessed(page); 2061 mark_page_accessed(page);
2062 lock_page(page); 2062 lock_page(page);
2063 delayacct_clear_flag(DELAYACCT_PF_SWAPIN); 2063 delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
2064 2064
2065 /* 2065 /*
2066 * Back out if somebody else already faulted in this pte. 2066 * Back out if somebody else already faulted in this pte.
2067 */ 2067 */
2068 page_table = pte_offset_map_lock(mm, pmd, address, &ptl); 2068 page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
2069 if (unlikely(!pte_same(*page_table, orig_pte))) 2069 if (unlikely(!pte_same(*page_table, orig_pte)))
2070 goto out_nomap; 2070 goto out_nomap;
2071 2071
2072 if (unlikely(!PageUptodate(page))) { 2072 if (unlikely(!PageUptodate(page))) {
2073 ret = VM_FAULT_SIGBUS; 2073 ret = VM_FAULT_SIGBUS;
2074 goto out_nomap; 2074 goto out_nomap;
2075 } 2075 }
2076 2076
2077 /* The page isn't present yet, go ahead with the fault. */ 2077 /* The page isn't present yet, go ahead with the fault. */
2078 2078
2079 inc_mm_counter(mm, anon_rss); 2079 inc_mm_counter(mm, anon_rss);
2080 pte = mk_pte(page, vma->vm_page_prot); 2080 pte = mk_pte(page, vma->vm_page_prot);
2081 if (write_access && can_share_swap_page(page)) { 2081 if (write_access && can_share_swap_page(page)) {
2082 pte = maybe_mkwrite(pte_mkdirty(pte), vma); 2082 pte = maybe_mkwrite(pte_mkdirty(pte), vma);
2083 write_access = 0; 2083 write_access = 0;
2084 } 2084 }
2085 2085
2086 flush_icache_page(vma, page); 2086 flush_icache_page(vma, page);
2087 set_pte_at(mm, address, page_table, pte); 2087 set_pte_at(mm, address, page_table, pte);
2088 page_add_anon_rmap(page, vma, address); 2088 page_add_anon_rmap(page, vma, address);
2089 2089
2090 swap_free(entry); 2090 swap_free(entry);
2091 if (vm_swap_full()) 2091 if (vm_swap_full())
2092 remove_exclusive_swap_page(page); 2092 remove_exclusive_swap_page(page);
2093 unlock_page(page); 2093 unlock_page(page);
2094 2094
2095 if (write_access) { 2095 if (write_access) {
2096 /* XXX: We could OR the do_wp_page code with this one? */ 2096 ret |= do_wp_page(mm, vma, address, page_table, pmd, ptl, pte);
2097 if (do_wp_page(mm, vma, address, 2097 if (ret & VM_FAULT_ERROR)
2098 page_table, pmd, ptl, pte) & VM_FAULT_OOM) { 2098 ret &= VM_FAULT_ERROR;
2099 mem_cgroup_uncharge_page(page);
2100 ret = VM_FAULT_OOM;
2101 }
2102 goto out; 2099 goto out;
2103 } 2100 }
2104 2101
2105 /* No need to invalidate - it was non-present before */ 2102 /* No need to invalidate - it was non-present before */
2106 update_mmu_cache(vma, address, pte); 2103 update_mmu_cache(vma, address, pte);
2107 unlock: 2104 unlock:
2108 pte_unmap_unlock(page_table, ptl); 2105 pte_unmap_unlock(page_table, ptl);
2109 out: 2106 out:
2110 return ret; 2107 return ret;
2111 out_nomap: 2108 out_nomap:
2112 mem_cgroup_uncharge_page(page); 2109 mem_cgroup_uncharge_page(page);
2113 pte_unmap_unlock(page_table, ptl); 2110 pte_unmap_unlock(page_table, ptl);
2114 unlock_page(page); 2111 unlock_page(page);
2115 page_cache_release(page); 2112 page_cache_release(page);
2116 return ret; 2113 return ret;
2117 } 2114 }
2118 2115
2119 /* 2116 /*
2120 * We enter with non-exclusive mmap_sem (to exclude vma changes, 2117 * We enter with non-exclusive mmap_sem (to exclude vma changes,
2121 * but allow concurrent faults), and pte mapped but not yet locked. 2118 * but allow concurrent faults), and pte mapped but not yet locked.
2122 * We return with mmap_sem still held, but pte unmapped and unlocked. 2119 * We return with mmap_sem still held, but pte unmapped and unlocked.
2123 */ 2120 */
2124 static int do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, 2121 static int do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
2125 unsigned long address, pte_t *page_table, pmd_t *pmd, 2122 unsigned long address, pte_t *page_table, pmd_t *pmd,
2126 int write_access) 2123 int write_access)
2127 { 2124 {
2128 struct page *page; 2125 struct page *page;
2129 spinlock_t *ptl; 2126 spinlock_t *ptl;
2130 pte_t entry; 2127 pte_t entry;
2131 2128
2132 /* Allocate our own private page. */ 2129 /* Allocate our own private page. */
2133 pte_unmap(page_table); 2130 pte_unmap(page_table);
2134 2131
2135 if (unlikely(anon_vma_prepare(vma))) 2132 if (unlikely(anon_vma_prepare(vma)))
2136 goto oom; 2133 goto oom;
2137 page = alloc_zeroed_user_highpage_movable(vma, address); 2134 page = alloc_zeroed_user_highpage_movable(vma, address);
2138 if (!page) 2135 if (!page)
2139 goto oom; 2136 goto oom;
2140 __SetPageUptodate(page); 2137 __SetPageUptodate(page);
2141 2138
2142 if (mem_cgroup_charge(page, mm, GFP_KERNEL)) 2139 if (mem_cgroup_charge(page, mm, GFP_KERNEL))
2143 goto oom_free_page; 2140 goto oom_free_page;
2144 2141
2145 entry = mk_pte(page, vma->vm_page_prot); 2142 entry = mk_pte(page, vma->vm_page_prot);
2146 entry = maybe_mkwrite(pte_mkdirty(entry), vma); 2143 entry = maybe_mkwrite(pte_mkdirty(entry), vma);
2147 2144
2148 page_table = pte_offset_map_lock(mm, pmd, address, &ptl); 2145 page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
2149 if (!pte_none(*page_table)) 2146 if (!pte_none(*page_table))
2150 goto release; 2147 goto release;
2151 inc_mm_counter(mm, anon_rss); 2148 inc_mm_counter(mm, anon_rss);
2152 lru_cache_add_active(page); 2149 lru_cache_add_active(page);
2153 page_add_new_anon_rmap(page, vma, address); 2150 page_add_new_anon_rmap(page, vma, address);
2154 set_pte_at(mm, address, page_table, entry); 2151 set_pte_at(mm, address, page_table, entry);
2155 2152
2156 /* No need to invalidate - it was non-present before */ 2153 /* No need to invalidate - it was non-present before */
2157 update_mmu_cache(vma, address, entry); 2154 update_mmu_cache(vma, address, entry);
2158 unlock: 2155 unlock:
2159 pte_unmap_unlock(page_table, ptl); 2156 pte_unmap_unlock(page_table, ptl);
2160 return 0; 2157 return 0;
2161 release: 2158 release:
2162 mem_cgroup_uncharge_page(page); 2159 mem_cgroup_uncharge_page(page);
2163 page_cache_release(page); 2160 page_cache_release(page);
2164 goto unlock; 2161 goto unlock;
2165 oom_free_page: 2162 oom_free_page:
2166 page_cache_release(page); 2163 page_cache_release(page);
2167 oom: 2164 oom:
2168 return VM_FAULT_OOM; 2165 return VM_FAULT_OOM;
2169 } 2166 }
2170 2167
2171 /* 2168 /*
2172 * __do_fault() tries to create a new page mapping. It aggressively 2169 * __do_fault() tries to create a new page mapping. It aggressively
2173 * tries to share with existing pages, but makes a separate copy if 2170 * tries to share with existing pages, but makes a separate copy if
2174 * the FAULT_FLAG_WRITE is set in the flags parameter in order to avoid 2171 * the FAULT_FLAG_WRITE is set in the flags parameter in order to avoid
2175 * the next page fault. 2172 * the next page fault.
2176 * 2173 *
2177 * As this is called only for pages that do not currently exist, we 2174 * As this is called only for pages that do not currently exist, we
2178 * do not need to flush old virtual caches or the TLB. 2175 * do not need to flush old virtual caches or the TLB.
2179 * 2176 *
2180 * We enter with non-exclusive mmap_sem (to exclude vma changes, 2177 * We enter with non-exclusive mmap_sem (to exclude vma changes,
2181 * but allow concurrent faults), and pte neither mapped nor locked. 2178 * but allow concurrent faults), and pte neither mapped nor locked.
2182 * We return with mmap_sem still held, but pte unmapped and unlocked. 2179 * We return with mmap_sem still held, but pte unmapped and unlocked.
2183 */ 2180 */
2184 static int __do_fault(struct mm_struct *mm, struct vm_area_struct *vma, 2181 static int __do_fault(struct mm_struct *mm, struct vm_area_struct *vma,
2185 unsigned long address, pmd_t *pmd, 2182 unsigned long address, pmd_t *pmd,
2186 pgoff_t pgoff, unsigned int flags, pte_t orig_pte) 2183 pgoff_t pgoff, unsigned int flags, pte_t orig_pte)
2187 { 2184 {
2188 pte_t *page_table; 2185 pte_t *page_table;
2189 spinlock_t *ptl; 2186 spinlock_t *ptl;
2190 struct page *page; 2187 struct page *page;
2191 pte_t entry; 2188 pte_t entry;
2192 int anon = 0; 2189 int anon = 0;
2193 struct page *dirty_page = NULL; 2190 struct page *dirty_page = NULL;
2194 struct vm_fault vmf; 2191 struct vm_fault vmf;
2195 int ret; 2192 int ret;
2196 int page_mkwrite = 0; 2193 int page_mkwrite = 0;
2197 2194
2198 vmf.virtual_address = (void __user *)(address & PAGE_MASK); 2195 vmf.virtual_address = (void __user *)(address & PAGE_MASK);
2199 vmf.pgoff = pgoff; 2196 vmf.pgoff = pgoff;
2200 vmf.flags = flags; 2197 vmf.flags = flags;
2201 vmf.page = NULL; 2198 vmf.page = NULL;
2202 2199
2203 BUG_ON(vma->vm_flags & VM_PFNMAP); 2200 BUG_ON(vma->vm_flags & VM_PFNMAP);
2204 2201
2205 if (likely(vma->vm_ops->fault)) { 2202 if (likely(vma->vm_ops->fault)) {
2206 ret = vma->vm_ops->fault(vma, &vmf); 2203 ret = vma->vm_ops->fault(vma, &vmf);
2207 if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE))) 2204 if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE)))
2208 return ret; 2205 return ret;
2209 } else { 2206 } else {
2210 /* Legacy ->nopage path */ 2207 /* Legacy ->nopage path */
2211 ret = 0; 2208 ret = 0;
2212 vmf.page = vma->vm_ops->nopage(vma, address & PAGE_MASK, &ret); 2209 vmf.page = vma->vm_ops->nopage(vma, address & PAGE_MASK, &ret);
2213 /* no page was available -- either SIGBUS or OOM */ 2210 /* no page was available -- either SIGBUS or OOM */
2214 if (unlikely(vmf.page == NOPAGE_SIGBUS)) 2211 if (unlikely(vmf.page == NOPAGE_SIGBUS))
2215 return VM_FAULT_SIGBUS; 2212 return VM_FAULT_SIGBUS;
2216 else if (unlikely(vmf.page == NOPAGE_OOM)) 2213 else if (unlikely(vmf.page == NOPAGE_OOM))
2217 return VM_FAULT_OOM; 2214 return VM_FAULT_OOM;
2218 } 2215 }
2219 2216
2220 /* 2217 /*
2221 * For consistency in subsequent calls, make the faulted page always 2218 * For consistency in subsequent calls, make the faulted page always
2222 * locked. 2219 * locked.
2223 */ 2220 */
2224 if (unlikely(!(ret & VM_FAULT_LOCKED))) 2221 if (unlikely(!(ret & VM_FAULT_LOCKED)))
2225 lock_page(vmf.page); 2222 lock_page(vmf.page);
2226 else 2223 else
2227 VM_BUG_ON(!PageLocked(vmf.page)); 2224 VM_BUG_ON(!PageLocked(vmf.page));
2228 2225
2229 /* 2226 /*
2230 * Should we do an early C-O-W break? 2227 * Should we do an early C-O-W break?
2231 */ 2228 */
2232 page = vmf.page; 2229 page = vmf.page;
2233 if (flags & FAULT_FLAG_WRITE) { 2230 if (flags & FAULT_FLAG_WRITE) {
2234 if (!(vma->vm_flags & VM_SHARED)) { 2231 if (!(vma->vm_flags & VM_SHARED)) {
2235 anon = 1; 2232 anon = 1;
2236 if (unlikely(anon_vma_prepare(vma))) { 2233 if (unlikely(anon_vma_prepare(vma))) {
2237 ret = VM_FAULT_OOM; 2234 ret = VM_FAULT_OOM;
2238 goto out; 2235 goto out;
2239 } 2236 }
2240 page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, 2237 page = alloc_page_vma(GFP_HIGHUSER_MOVABLE,
2241 vma, address); 2238 vma, address);
2242 if (!page) { 2239 if (!page) {
2243 ret = VM_FAULT_OOM; 2240 ret = VM_FAULT_OOM;
2244 goto out; 2241 goto out;
2245 } 2242 }
2246 copy_user_highpage(page, vmf.page, address, vma); 2243 copy_user_highpage(page, vmf.page, address, vma);
2247 __SetPageUptodate(page); 2244 __SetPageUptodate(page);
2248 } else { 2245 } else {
2249 /* 2246 /*
2250 * If the page will be shareable, see if the backing 2247 * If the page will be shareable, see if the backing
2251 * address space wants to know that the page is about 2248 * address space wants to know that the page is about
2252 * to become writable 2249 * to become writable
2253 */ 2250 */
2254 if (vma->vm_ops->page_mkwrite) { 2251 if (vma->vm_ops->page_mkwrite) {
2255 unlock_page(page); 2252 unlock_page(page);
2256 if (vma->vm_ops->page_mkwrite(vma, page) < 0) { 2253 if (vma->vm_ops->page_mkwrite(vma, page) < 0) {
2257 ret = VM_FAULT_SIGBUS; 2254 ret = VM_FAULT_SIGBUS;
2258 anon = 1; /* no anon but release vmf.page */ 2255 anon = 1; /* no anon but release vmf.page */
2259 goto out_unlocked; 2256 goto out_unlocked;
2260 } 2257 }
2261 lock_page(page); 2258 lock_page(page);
2262 /* 2259 /*
2263 * XXX: this is not quite right (racy vs 2260 * XXX: this is not quite right (racy vs
2264 * invalidate) to unlock and relock the page 2261 * invalidate) to unlock and relock the page
2265 * like this, however a better fix requires 2262 * like this, however a better fix requires
2266 * reworking page_mkwrite locking API, which 2263 * reworking page_mkwrite locking API, which
2267 * is better done later. 2264 * is better done later.
2268 */ 2265 */
2269 if (!page->mapping) { 2266 if (!page->mapping) {
2270 ret = 0; 2267 ret = 0;
2271 anon = 1; /* no anon but release vmf.page */ 2268 anon = 1; /* no anon but release vmf.page */
2272 goto out; 2269 goto out;
2273 } 2270 }
2274 page_mkwrite = 1; 2271 page_mkwrite = 1;
2275 } 2272 }
2276 } 2273 }
2277 2274
2278 } 2275 }
2279 2276
2280 if (mem_cgroup_charge(page, mm, GFP_KERNEL)) { 2277 if (mem_cgroup_charge(page, mm, GFP_KERNEL)) {
2281 ret = VM_FAULT_OOM; 2278 ret = VM_FAULT_OOM;
2282 goto out; 2279 goto out;
2283 } 2280 }
2284 2281
2285 page_table = pte_offset_map_lock(mm, pmd, address, &ptl); 2282 page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
2286 2283
2287 /* 2284 /*
2288 * This silly early PAGE_DIRTY setting removes a race 2285 * This silly early PAGE_DIRTY setting removes a race
2289 * due to the bad i386 page protection. But it's valid 2286 * due to the bad i386 page protection. But it's valid
2290 * for other architectures too. 2287 * for other architectures too.
2291 * 2288 *
2292 * Note that if write_access is true, we either now have 2289 * Note that if write_access is true, we either now have
2293 * an exclusive copy of the page, or this is a shared mapping, 2290 * an exclusive copy of the page, or this is a shared mapping,
2294 * so we can make it writable and dirty to avoid having to 2291 * so we can make it writable and dirty to avoid having to
2295 * handle that later. 2292 * handle that later.
2296 */ 2293 */
2297 /* Only go through if we didn't race with anybody else... */ 2294 /* Only go through if we didn't race with anybody else... */
2298 if (likely(pte_same(*page_table, orig_pte))) { 2295 if (likely(pte_same(*page_table, orig_pte))) {
2299 flush_icache_page(vma, page); 2296 flush_icache_page(vma, page);
2300 entry = mk_pte(page, vma->vm_page_prot); 2297 entry = mk_pte(page, vma->vm_page_prot);
2301 if (flags & FAULT_FLAG_WRITE) 2298 if (flags & FAULT_FLAG_WRITE)
2302 entry = maybe_mkwrite(pte_mkdirty(entry), vma); 2299 entry = maybe_mkwrite(pte_mkdirty(entry), vma);
2303 set_pte_at(mm, address, page_table, entry); 2300 set_pte_at(mm, address, page_table, entry);
2304 if (anon) { 2301 if (anon) {
2305 inc_mm_counter(mm, anon_rss); 2302 inc_mm_counter(mm, anon_rss);
2306 lru_cache_add_active(page); 2303 lru_cache_add_active(page);
2307 page_add_new_anon_rmap(page, vma, address); 2304 page_add_new_anon_rmap(page, vma, address);
2308 } else { 2305 } else {
2309 inc_mm_counter(mm, file_rss); 2306 inc_mm_counter(mm, file_rss);
2310 page_add_file_rmap(page); 2307 page_add_file_rmap(page);
2311 if (flags & FAULT_FLAG_WRITE) { 2308 if (flags & FAULT_FLAG_WRITE) {
2312 dirty_page = page; 2309 dirty_page = page;
2313 get_page(dirty_page); 2310 get_page(dirty_page);
2314 } 2311 }
2315 } 2312 }
2316 2313
2317 /* no need to invalidate: a not-present page won't be cached */ 2314 /* no need to invalidate: a not-present page won't be cached */
2318 update_mmu_cache(vma, address, entry); 2315 update_mmu_cache(vma, address, entry);
2319 } else { 2316 } else {
2320 mem_cgroup_uncharge_page(page); 2317 mem_cgroup_uncharge_page(page);
2321 if (anon) 2318 if (anon)
2322 page_cache_release(page); 2319 page_cache_release(page);
2323 else 2320 else
2324 anon = 1; /* no anon but release faulted_page */ 2321 anon = 1; /* no anon but release faulted_page */
2325 } 2322 }
2326 2323
2327 pte_unmap_unlock(page_table, ptl); 2324 pte_unmap_unlock(page_table, ptl);
2328 2325
2329 out: 2326 out:
2330 unlock_page(vmf.page); 2327 unlock_page(vmf.page);
2331 out_unlocked: 2328 out_unlocked:
2332 if (anon) 2329 if (anon)
2333 page_cache_release(vmf.page); 2330 page_cache_release(vmf.page);
2334 else if (dirty_page) { 2331 else if (dirty_page) {
2335 if (vma->vm_file) 2332 if (vma->vm_file)
2336 file_update_time(vma->vm_file); 2333 file_update_time(vma->vm_file);
2337 2334
2338 set_page_dirty_balance(dirty_page, page_mkwrite); 2335 set_page_dirty_balance(dirty_page, page_mkwrite);
2339 put_page(dirty_page); 2336 put_page(dirty_page);
2340 } 2337 }
2341 2338
2342 return ret; 2339 return ret;
2343 } 2340 }
2344 2341
2345 static int do_linear_fault(struct mm_struct *mm, struct vm_area_struct *vma, 2342 static int do_linear_fault(struct mm_struct *mm, struct vm_area_struct *vma,
2346 unsigned long address, pte_t *page_table, pmd_t *pmd, 2343 unsigned long address, pte_t *page_table, pmd_t *pmd,
2347 int write_access, pte_t orig_pte) 2344 int write_access, pte_t orig_pte)
2348 { 2345 {
2349 pgoff_t pgoff = (((address & PAGE_MASK) 2346 pgoff_t pgoff = (((address & PAGE_MASK)
2350 - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff; 2347 - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
2351 unsigned int flags = (write_access ? FAULT_FLAG_WRITE : 0); 2348 unsigned int flags = (write_access ? FAULT_FLAG_WRITE : 0);
2352 2349
2353 pte_unmap(page_table); 2350 pte_unmap(page_table);
2354 return __do_fault(mm, vma, address, pmd, pgoff, flags, orig_pte); 2351 return __do_fault(mm, vma, address, pmd, pgoff, flags, orig_pte);
2355 } 2352 }
2356 2353
2357 2354
2358 /* 2355 /*
2359 * do_no_pfn() tries to create a new page mapping for a page without 2356 * do_no_pfn() tries to create a new page mapping for a page without
2360 * a struct_page backing it 2357 * a struct_page backing it
2361 * 2358 *
2362 * As this is called only for pages that do not currently exist, we 2359 * As this is called only for pages that do not currently exist, we
2363 * do not need to flush old virtual caches or the TLB. 2360 * do not need to flush old virtual caches or the TLB.
2364 * 2361 *
2365 * We enter with non-exclusive mmap_sem (to exclude vma changes, 2362 * We enter with non-exclusive mmap_sem (to exclude vma changes,
2366 * but allow concurrent faults), and pte mapped but not yet locked. 2363 * but allow concurrent faults), and pte mapped but not yet locked.
2367 * We return with mmap_sem still held, but pte unmapped and unlocked. 2364 * We return with mmap_sem still held, but pte unmapped and unlocked.
2368 * 2365 *
2369 * It is expected that the ->nopfn handler always returns the same pfn 2366 * It is expected that the ->nopfn handler always returns the same pfn
2370 * for a given virtual mapping. 2367 * for a given virtual mapping.
2371 * 2368 *
2372 * Mark this `noinline' to prevent it from bloating the main pagefault code. 2369 * Mark this `noinline' to prevent it from bloating the main pagefault code.
2373 */ 2370 */
2374 static noinline int do_no_pfn(struct mm_struct *mm, struct vm_area_struct *vma, 2371 static noinline int do_no_pfn(struct mm_struct *mm, struct vm_area_struct *vma,
2375 unsigned long address, pte_t *page_table, pmd_t *pmd, 2372 unsigned long address, pte_t *page_table, pmd_t *pmd,
2376 int write_access) 2373 int write_access)
2377 { 2374 {
2378 spinlock_t *ptl; 2375 spinlock_t *ptl;
2379 pte_t entry; 2376 pte_t entry;
2380 unsigned long pfn; 2377 unsigned long pfn;
2381 2378
2382 pte_unmap(page_table); 2379 pte_unmap(page_table);
2383 BUG_ON(!(vma->vm_flags & VM_PFNMAP)); 2380 BUG_ON(!(vma->vm_flags & VM_PFNMAP));
2384 BUG_ON(is_cow_mapping(vma->vm_flags)); 2381 BUG_ON(is_cow_mapping(vma->vm_flags));
2385 2382
2386 pfn = vma->vm_ops->nopfn(vma, address & PAGE_MASK); 2383 pfn = vma->vm_ops->nopfn(vma, address & PAGE_MASK);
2387 if (unlikely(pfn == NOPFN_OOM)) 2384 if (unlikely(pfn == NOPFN_OOM))
2388 return VM_FAULT_OOM; 2385 return VM_FAULT_OOM;
2389 else if (unlikely(pfn == NOPFN_SIGBUS)) 2386 else if (unlikely(pfn == NOPFN_SIGBUS))
2390 return VM_FAULT_SIGBUS; 2387 return VM_FAULT_SIGBUS;
2391 else if (unlikely(pfn == NOPFN_REFAULT)) 2388 else if (unlikely(pfn == NOPFN_REFAULT))
2392 return 0; 2389 return 0;
2393 2390
2394 page_table = pte_offset_map_lock(mm, pmd, address, &ptl); 2391 page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
2395 2392
2396 /* Only go through if we didn't race with anybody else... */ 2393 /* Only go through if we didn't race with anybody else... */
2397 if (pte_none(*page_table)) { 2394 if (pte_none(*page_table)) {
2398 entry = pfn_pte(pfn, vma->vm_page_prot); 2395 entry = pfn_pte(pfn, vma->vm_page_prot);
2399 if (write_access) 2396 if (write_access)
2400 entry = maybe_mkwrite(pte_mkdirty(entry), vma); 2397 entry = maybe_mkwrite(pte_mkdirty(entry), vma);
2401 set_pte_at(mm, address, page_table, entry); 2398 set_pte_at(mm, address, page_table, entry);
2402 } 2399 }
2403 pte_unmap_unlock(page_table, ptl); 2400 pte_unmap_unlock(page_table, ptl);
2404 return 0; 2401 return 0;
2405 } 2402 }
2406 2403
2407 /* 2404 /*
2408 * Fault of a previously existing named mapping. Repopulate the pte 2405 * Fault of a previously existing named mapping. Repopulate the pte
2409 * from the encoded file_pte if possible. This enables swappable 2406 * from the encoded file_pte if possible. This enables swappable
2410 * nonlinear vmas. 2407 * nonlinear vmas.
2411 * 2408 *
2412 * We enter with non-exclusive mmap_sem (to exclude vma changes, 2409 * We enter with non-exclusive mmap_sem (to exclude vma changes,
2413 * but allow concurrent faults), and pte mapped but not yet locked. 2410 * but allow concurrent faults), and pte mapped but not yet locked.
2414 * We return with mmap_sem still held, but pte unmapped and unlocked. 2411 * We return with mmap_sem still held, but pte unmapped and unlocked.
2415 */ 2412 */
2416 static int do_nonlinear_fault(struct mm_struct *mm, struct vm_area_struct *vma, 2413 static int do_nonlinear_fault(struct mm_struct *mm, struct vm_area_struct *vma,
2417 unsigned long address, pte_t *page_table, pmd_t *pmd, 2414 unsigned long address, pte_t *page_table, pmd_t *pmd,
2418 int write_access, pte_t orig_pte) 2415 int write_access, pte_t orig_pte)
2419 { 2416 {
2420 unsigned int flags = FAULT_FLAG_NONLINEAR | 2417 unsigned int flags = FAULT_FLAG_NONLINEAR |
2421 (write_access ? FAULT_FLAG_WRITE : 0); 2418 (write_access ? FAULT_FLAG_WRITE : 0);
2422 pgoff_t pgoff; 2419 pgoff_t pgoff;
2423 2420
2424 if (!pte_unmap_same(mm, pmd, page_table, orig_pte)) 2421 if (!pte_unmap_same(mm, pmd, page_table, orig_pte))
2425 return 0; 2422 return 0;
2426 2423
2427 if (unlikely(!(vma->vm_flags & VM_NONLINEAR) || 2424 if (unlikely(!(vma->vm_flags & VM_NONLINEAR) ||
2428 !(vma->vm_flags & VM_CAN_NONLINEAR))) { 2425 !(vma->vm_flags & VM_CAN_NONLINEAR))) {
2429 /* 2426 /*
2430 * Page table corrupted: show pte and kill process. 2427 * Page table corrupted: show pte and kill process.
2431 */ 2428 */
2432 print_bad_pte(vma, orig_pte, address); 2429 print_bad_pte(vma, orig_pte, address);
2433 return VM_FAULT_OOM; 2430 return VM_FAULT_OOM;
2434 } 2431 }
2435 2432
2436 pgoff = pte_to_pgoff(orig_pte); 2433 pgoff = pte_to_pgoff(orig_pte);
2437 return __do_fault(mm, vma, address, pmd, pgoff, flags, orig_pte); 2434 return __do_fault(mm, vma, address, pmd, pgoff, flags, orig_pte);
2438 } 2435 }
2439 2436
2440 /* 2437 /*
2441 * These routines also need to handle stuff like marking pages dirty 2438 * These routines also need to handle stuff like marking pages dirty
2442 * and/or accessed for architectures that don't do it in hardware (most 2439 * and/or accessed for architectures that don't do it in hardware (most
2443 * RISC architectures). The early dirtying is also good on the i386. 2440 * RISC architectures). The early dirtying is also good on the i386.
2444 * 2441 *
2445 * There is also a hook called "update_mmu_cache()" that architectures 2442 * There is also a hook called "update_mmu_cache()" that architectures
2446 * with external mmu caches can use to update those (ie the Sparc or 2443 * with external mmu caches can use to update those (ie the Sparc or
2447 * PowerPC hashed page tables that act as extended TLBs). 2444 * PowerPC hashed page tables that act as extended TLBs).
2448 * 2445 *
2449 * We enter with non-exclusive mmap_sem (to exclude vma changes, 2446 * We enter with non-exclusive mmap_sem (to exclude vma changes,
2450 * but allow concurrent faults), and pte mapped but not yet locked. 2447 * but allow concurrent faults), and pte mapped but not yet locked.
2451 * We return with mmap_sem still held, but pte unmapped and unlocked. 2448 * We return with mmap_sem still held, but pte unmapped and unlocked.
2452 */ 2449 */
2453 static inline int handle_pte_fault(struct mm_struct *mm, 2450 static inline int handle_pte_fault(struct mm_struct *mm,
2454 struct vm_area_struct *vma, unsigned long address, 2451 struct vm_area_struct *vma, unsigned long address,
2455 pte_t *pte, pmd_t *pmd, int write_access) 2452 pte_t *pte, pmd_t *pmd, int write_access)
2456 { 2453 {
2457 pte_t entry; 2454 pte_t entry;
2458 spinlock_t *ptl; 2455 spinlock_t *ptl;
2459 2456
2460 entry = *pte; 2457 entry = *pte;
2461 if (!pte_present(entry)) { 2458 if (!pte_present(entry)) {
2462 if (pte_none(entry)) { 2459 if (pte_none(entry)) {
2463 if (vma->vm_ops) { 2460 if (vma->vm_ops) {
2464 if (vma->vm_ops->fault || vma->vm_ops->nopage) 2461 if (vma->vm_ops->fault || vma->vm_ops->nopage)
2465 return do_linear_fault(mm, vma, address, 2462 return do_linear_fault(mm, vma, address,
2466 pte, pmd, write_access, entry); 2463 pte, pmd, write_access, entry);
2467 if (unlikely(vma->vm_ops->nopfn)) 2464 if (unlikely(vma->vm_ops->nopfn))
2468 return do_no_pfn(mm, vma, address, pte, 2465 return do_no_pfn(mm, vma, address, pte,
2469 pmd, write_access); 2466 pmd, write_access);
2470 } 2467 }
2471 return do_anonymous_page(mm, vma, address, 2468 return do_anonymous_page(mm, vma, address,
2472 pte, pmd, write_access); 2469 pte, pmd, write_access);
2473 } 2470 }
2474 if (pte_file(entry)) 2471 if (pte_file(entry))
2475 return do_nonlinear_fault(mm, vma, address, 2472 return do_nonlinear_fault(mm, vma, address,
2476 pte, pmd, write_access, entry); 2473 pte, pmd, write_access, entry);
2477 return do_swap_page(mm, vma, address, 2474 return do_swap_page(mm, vma, address,
2478 pte, pmd, write_access, entry); 2475 pte, pmd, write_access, entry);
2479 } 2476 }
2480 2477
2481 ptl = pte_lockptr(mm, pmd); 2478 ptl = pte_lockptr(mm, pmd);
2482 spin_lock(ptl); 2479 spin_lock(ptl);
2483 if (unlikely(!pte_same(*pte, entry))) 2480 if (unlikely(!pte_same(*pte, entry)))
2484 goto unlock; 2481 goto unlock;
2485 if (write_access) { 2482 if (write_access) {
2486 if (!pte_write(entry)) 2483 if (!pte_write(entry))
2487 return do_wp_page(mm, vma, address, 2484 return do_wp_page(mm, vma, address,
2488 pte, pmd, ptl, entry); 2485 pte, pmd, ptl, entry);
2489 entry = pte_mkdirty(entry); 2486 entry = pte_mkdirty(entry);
2490 } 2487 }
2491 entry = pte_mkyoung(entry); 2488 entry = pte_mkyoung(entry);
2492 if (ptep_set_access_flags(vma, address, pte, entry, write_access)) { 2489 if (ptep_set_access_flags(vma, address, pte, entry, write_access)) {
2493 update_mmu_cache(vma, address, entry); 2490 update_mmu_cache(vma, address, entry);
2494 } else { 2491 } else {
2495 /* 2492 /*
2496 * This is needed only for protection faults but the arch code 2493 * This is needed only for protection faults but the arch code
2497 * is not yet telling us if this is a protection fault or not. 2494 * is not yet telling us if this is a protection fault or not.
2498 * This still avoids useless tlb flushes for .text page faults 2495 * This still avoids useless tlb flushes for .text page faults
2499 * with threads. 2496 * with threads.
2500 */ 2497 */
2501 if (write_access) 2498 if (write_access)
2502 flush_tlb_page(vma, address); 2499 flush_tlb_page(vma, address);
2503 } 2500 }
2504 unlock: 2501 unlock:
2505 pte_unmap_unlock(pte, ptl); 2502 pte_unmap_unlock(pte, ptl);
2506 return 0; 2503 return 0;
2507 } 2504 }
2508 2505
2509 /* 2506 /*
2510 * By the time we get here, we already hold the mm semaphore 2507 * By the time we get here, we already hold the mm semaphore
2511 */ 2508 */
2512 int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma, 2509 int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
2513 unsigned long address, int write_access) 2510 unsigned long address, int write_access)
2514 { 2511 {
2515 pgd_t *pgd; 2512 pgd_t *pgd;
2516 pud_t *pud; 2513 pud_t *pud;
2517 pmd_t *pmd; 2514 pmd_t *pmd;
2518 pte_t *pte; 2515 pte_t *pte;
2519 2516
2520 __set_current_state(TASK_RUNNING); 2517 __set_current_state(TASK_RUNNING);
2521 2518
2522 count_vm_event(PGFAULT); 2519 count_vm_event(PGFAULT);
2523 2520
2524 if (unlikely(is_vm_hugetlb_page(vma))) 2521 if (unlikely(is_vm_hugetlb_page(vma)))
2525 return hugetlb_fault(mm, vma, address, write_access); 2522 return hugetlb_fault(mm, vma, address, write_access);
2526 2523
2527 pgd = pgd_offset(mm, address); 2524 pgd = pgd_offset(mm, address);
2528 pud = pud_alloc(mm, pgd, address); 2525 pud = pud_alloc(mm, pgd, address);
2529 if (!pud) 2526 if (!pud)
2530 return VM_FAULT_OOM; 2527 return VM_FAULT_OOM;
2531 pmd = pmd_alloc(mm, pud, address); 2528 pmd = pmd_alloc(mm, pud, address);
2532 if (!pmd) 2529 if (!pmd)
2533 return VM_FAULT_OOM; 2530 return VM_FAULT_OOM;
2534 pte = pte_alloc_map(mm, pmd, address); 2531 pte = pte_alloc_map(mm, pmd, address);
2535 if (!pte) 2532 if (!pte)
2536 return VM_FAULT_OOM; 2533 return VM_FAULT_OOM;
2537 2534
2538 return handle_pte_fault(mm, vma, address, pte, pmd, write_access); 2535 return handle_pte_fault(mm, vma, address, pte, pmd, write_access);
2539 } 2536 }
2540 2537
2541 #ifndef __PAGETABLE_PUD_FOLDED 2538 #ifndef __PAGETABLE_PUD_FOLDED
2542 /* 2539 /*
2543 * Allocate page upper directory. 2540 * Allocate page upper directory.
2544 * We've already handled the fast-path in-line. 2541 * We've already handled the fast-path in-line.
2545 */ 2542 */
2546 int __pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address) 2543 int __pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address)
2547 { 2544 {
2548 pud_t *new = pud_alloc_one(mm, address); 2545 pud_t *new = pud_alloc_one(mm, address);
2549 if (!new) 2546 if (!new)
2550 return -ENOMEM; 2547 return -ENOMEM;
2551 2548
2552 spin_lock(&mm->page_table_lock); 2549 spin_lock(&mm->page_table_lock);
2553 if (pgd_present(*pgd)) /* Another has populated it */ 2550 if (pgd_present(*pgd)) /* Another has populated it */
2554 pud_free(mm, new); 2551 pud_free(mm, new);
2555 else 2552 else
2556 pgd_populate(mm, pgd, new); 2553 pgd_populate(mm, pgd, new);
2557 spin_unlock(&mm->page_table_lock); 2554 spin_unlock(&mm->page_table_lock);
2558 return 0; 2555 return 0;
2559 } 2556 }
2560 #endif /* __PAGETABLE_PUD_FOLDED */ 2557 #endif /* __PAGETABLE_PUD_FOLDED */
2561 2558
2562 #ifndef __PAGETABLE_PMD_FOLDED 2559 #ifndef __PAGETABLE_PMD_FOLDED
2563 /* 2560 /*
2564 * Allocate page middle directory. 2561 * Allocate page middle directory.
2565 * We've already handled the fast-path in-line. 2562 * We've already handled the fast-path in-line.
2566 */ 2563 */
2567 int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address) 2564 int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
2568 { 2565 {
2569 pmd_t *new = pmd_alloc_one(mm, address); 2566 pmd_t *new = pmd_alloc_one(mm, address);
2570 if (!new) 2567 if (!new)
2571 return -ENOMEM; 2568 return -ENOMEM;
2572 2569
2573 spin_lock(&mm->page_table_lock); 2570 spin_lock(&mm->page_table_lock);
2574 #ifndef __ARCH_HAS_4LEVEL_HACK 2571 #ifndef __ARCH_HAS_4LEVEL_HACK
2575 if (pud_present(*pud)) /* Another has populated it */ 2572 if (pud_present(*pud)) /* Another has populated it */
2576 pmd_free(mm, new); 2573 pmd_free(mm, new);
2577 else 2574 else
2578 pud_populate(mm, pud, new); 2575 pud_populate(mm, pud, new);
2579 #else 2576 #else
2580 if (pgd_present(*pud)) /* Another has populated it */ 2577 if (pgd_present(*pud)) /* Another has populated it */
2581 pmd_free(mm, new); 2578 pmd_free(mm, new);
2582 else 2579 else
2583 pgd_populate(mm, pud, new); 2580 pgd_populate(mm, pud, new);
2584 #endif /* __ARCH_HAS_4LEVEL_HACK */ 2581 #endif /* __ARCH_HAS_4LEVEL_HACK */
2585 spin_unlock(&mm->page_table_lock); 2582 spin_unlock(&mm->page_table_lock);
2586 return 0; 2583 return 0;
2587 } 2584 }
2588 #endif /* __PAGETABLE_PMD_FOLDED */ 2585 #endif /* __PAGETABLE_PMD_FOLDED */
2589 2586
2590 int make_pages_present(unsigned long addr, unsigned long end) 2587 int make_pages_present(unsigned long addr, unsigned long end)
2591 { 2588 {
2592 int ret, len, write; 2589 int ret, len, write;
2593 struct vm_area_struct * vma; 2590 struct vm_area_struct * vma;
2594 2591
2595 vma = find_vma(current->mm, addr); 2592 vma = find_vma(current->mm, addr);
2596 if (!vma) 2593 if (!vma)
2597 return -1; 2594 return -1;
2598 write = (vma->vm_flags & VM_WRITE) != 0; 2595 write = (vma->vm_flags & VM_WRITE) != 0;
2599 BUG_ON(addr >= end); 2596 BUG_ON(addr >= end);
2600 BUG_ON(end > vma->vm_end); 2597 BUG_ON(end > vma->vm_end);
2601 len = DIV_ROUND_UP(end, PAGE_SIZE) - addr/PAGE_SIZE; 2598 len = DIV_ROUND_UP(end, PAGE_SIZE) - addr/PAGE_SIZE;
2602 ret = get_user_pages(current, current->mm, addr, 2599 ret = get_user_pages(current, current->mm, addr,
2603 len, write, 0, NULL, NULL); 2600 len, write, 0, NULL, NULL);
2604 if (ret < 0) 2601 if (ret < 0)
2605 return ret; 2602 return ret;
2606 return ret == len ? 0 : -1; 2603 return ret == len ? 0 : -1;
2607 } 2604 }
2608 2605
2609 #if !defined(__HAVE_ARCH_GATE_AREA) 2606 #if !defined(__HAVE_ARCH_GATE_AREA)
2610 2607
2611 #if defined(AT_SYSINFO_EHDR) 2608 #if defined(AT_SYSINFO_EHDR)
2612 static struct vm_area_struct gate_vma; 2609 static struct vm_area_struct gate_vma;
2613 2610
2614 static int __init gate_vma_init(void) 2611 static int __init gate_vma_init(void)
2615 { 2612 {
2616 gate_vma.vm_mm = NULL; 2613 gate_vma.vm_mm = NULL;
2617 gate_vma.vm_start = FIXADDR_USER_START; 2614 gate_vma.vm_start = FIXADDR_USER_START;
2618 gate_vma.vm_end = FIXADDR_USER_END; 2615 gate_vma.vm_end = FIXADDR_USER_END;
2619 gate_vma.vm_flags = VM_READ | VM_MAYREAD | VM_EXEC | VM_MAYEXEC; 2616 gate_vma.vm_flags = VM_READ | VM_MAYREAD | VM_EXEC | VM_MAYEXEC;
2620 gate_vma.vm_page_prot = __P101; 2617 gate_vma.vm_page_prot = __P101;
2621 /* 2618 /*
2622 * Make sure the vDSO gets into every core dump. 2619 * Make sure the vDSO gets into every core dump.
2623 * Dumping its contents makes post-mortem fully interpretable later 2620 * Dumping its contents makes post-mortem fully interpretable later
2624 * without matching up the same kernel and hardware config to see 2621 * without matching up the same kernel and hardware config to see
2625 * what PC values meant. 2622 * what PC values meant.
2626 */ 2623 */
2627 gate_vma.vm_flags |= VM_ALWAYSDUMP; 2624 gate_vma.vm_flags |= VM_ALWAYSDUMP;
2628 return 0; 2625 return 0;
2629 } 2626 }
2630 __initcall(gate_vma_init); 2627 __initcall(gate_vma_init);
2631 #endif 2628 #endif
2632 2629
2633 struct vm_area_struct *get_gate_vma(struct task_struct *tsk) 2630 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
2634 { 2631 {
2635 #ifdef AT_SYSINFO_EHDR 2632 #ifdef AT_SYSINFO_EHDR
2636 return &gate_vma; 2633 return &gate_vma;
2637 #else 2634 #else
2638 return NULL; 2635 return NULL;
2639 #endif 2636 #endif
2640 } 2637 }
2641 2638
2642 int in_gate_area_no_task(unsigned long addr) 2639 int in_gate_area_no_task(unsigned long addr)
2643 { 2640 {
2644 #ifdef AT_SYSINFO_EHDR 2641 #ifdef AT_SYSINFO_EHDR
2645 if ((addr >= FIXADDR_USER_START) && (addr < FIXADDR_USER_END)) 2642 if ((addr >= FIXADDR_USER_START) && (addr < FIXADDR_USER_END))
2646 return 1; 2643 return 1;
2647 #endif 2644 #endif
2648 return 0; 2645 return 0;
2649 } 2646 }
2650 2647
2651 #endif /* __HAVE_ARCH_GATE_AREA */ 2648 #endif /* __HAVE_ARCH_GATE_AREA */
2652 2649
2653 /* 2650 /*
2654 * Access another process' address space. 2651 * Access another process' address space.
2655 * Source/target buffer must be kernel space, 2652 * Source/target buffer must be kernel space,
2656 * Do not walk the page table directly, use get_user_pages 2653 * Do not walk the page table directly, use get_user_pages
2657 */ 2654 */
2658 int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write) 2655 int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write)
2659 { 2656 {
2660 struct mm_struct *mm; 2657 struct mm_struct *mm;
2661 struct vm_area_struct *vma; 2658 struct vm_area_struct *vma;
2662 struct page *page; 2659 struct page *page;
2663 void *old_buf = buf; 2660 void *old_buf = buf;
2664 2661
2665 mm = get_task_mm(tsk); 2662 mm = get_task_mm(tsk);
2666 if (!mm) 2663 if (!mm)
2667 return 0; 2664 return 0;
2668 2665
2669 down_read(&mm->mmap_sem); 2666 down_read(&mm->mmap_sem);
2670 /* ignore errors, just check how much was successfully transferred */ 2667 /* ignore errors, just check how much was successfully transferred */
2671 while (len) { 2668 while (len) {
2672 int bytes, ret, offset; 2669 int bytes, ret, offset;
2673 void *maddr; 2670 void *maddr;
2674 2671
2675 ret = get_user_pages(tsk, mm, addr, 1, 2672 ret = get_user_pages(tsk, mm, addr, 1,
2676 write, 1, &page, &vma); 2673 write, 1, &page, &vma);
2677 if (ret <= 0) 2674 if (ret <= 0)
2678 break; 2675 break;
2679 2676
2680 bytes = len; 2677 bytes = len;
2681 offset = addr & (PAGE_SIZE-1); 2678 offset = addr & (PAGE_SIZE-1);
2682 if (bytes > PAGE_SIZE-offset) 2679 if (bytes > PAGE_SIZE-offset)
2683 bytes = PAGE_SIZE-offset; 2680 bytes = PAGE_SIZE-offset;
2684 2681
2685 maddr = kmap(page); 2682 maddr = kmap(page);
2686 if (write) { 2683 if (write) {
2687 copy_to_user_page(vma, page, addr, 2684 copy_to_user_page(vma, page, addr,
2688 maddr + offset, buf, bytes); 2685 maddr + offset, buf, bytes);
2689 set_page_dirty_lock(page); 2686 set_page_dirty_lock(page);
2690 } else { 2687 } else {
2691 copy_from_user_page(vma, page, addr, 2688 copy_from_user_page(vma, page, addr,
2692 buf, maddr + offset, bytes); 2689 buf, maddr + offset, bytes);
2693 } 2690 }
2694 kunmap(page); 2691 kunmap(page);
2695 page_cache_release(page); 2692 page_cache_release(page);
2696 len -= bytes; 2693 len -= bytes;
2697 buf += bytes; 2694 buf += bytes;
2698 addr += bytes; 2695 addr += bytes;
2699 } 2696 }
2700 up_read(&mm->mmap_sem); 2697 up_read(&mm->mmap_sem);
2701 mmput(mm); 2698 mmput(mm);
2702 2699
2703 return buf - old_buf; 2700 return buf - old_buf;
2704 } 2701 }
2705 2702
2706 /* 2703 /*
2707 * Print the name of a VMA. 2704 * Print the name of a VMA.
2708 */ 2705 */
2709 void print_vma_addr(char *prefix, unsigned long ip) 2706 void print_vma_addr(char *prefix, unsigned long ip)
2710 { 2707 {
2711 struct mm_struct *mm = current->mm; 2708 struct mm_struct *mm = current->mm;
2712 struct vm_area_struct *vma; 2709 struct vm_area_struct *vma;
2713 2710
2714 /* 2711 /*
2715 * Do not print if we are in atomic 2712 * Do not print if we are in atomic
2716 * contexts (in exception stacks, etc.): 2713 * contexts (in exception stacks, etc.):
2717 */ 2714 */
2718 if (preempt_count()) 2715 if (preempt_count())
2719 return; 2716 return;
2720 2717
2721 down_read(&mm->mmap_sem); 2718 down_read(&mm->mmap_sem);
2722 vma = find_vma(mm, ip); 2719 vma = find_vma(mm, ip);
2723 if (vma && vma->vm_file) { 2720 if (vma && vma->vm_file) {
2724 struct file *f = vma->vm_file; 2721 struct file *f = vma->vm_file;
2725 char *buf = (char *)__get_free_page(GFP_KERNEL); 2722 char *buf = (char *)__get_free_page(GFP_KERNEL);
2726 if (buf) { 2723 if (buf) {
2727 char *p, *s; 2724 char *p, *s;
2728 2725
2729 p = d_path(&f->f_path, buf, PAGE_SIZE); 2726 p = d_path(&f->f_path, buf, PAGE_SIZE);
2730 if (IS_ERR(p)) 2727 if (IS_ERR(p))
2731 p = "?"; 2728 p = "?";
2732 s = strrchr(p, '/'); 2729 s = strrchr(p, '/');
2733 if (s) 2730 if (s)
2734 p = s+1; 2731 p = s+1;
2735 printk("%s%s[%lx+%lx]", prefix, p, 2732 printk("%s%s[%lx+%lx]", prefix, p,
2736 vma->vm_start, 2733 vma->vm_start,
2737 vma->vm_end - vma->vm_start); 2734 vma->vm_end - vma->vm_start);
2738 free_page((unsigned long)buf); 2735 free_page((unsigned long)buf);
2739 } 2736 }
2740 } 2737 }
2741 up_read(&current->mm->mmap_sem); 2738 up_read(&current->mm->mmap_sem);
2742 } 2739 }
2743 2740