1 /*
2 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3 * Licensed under the GPL
4 */
5
6 #include <linux/mm.h>
7 #include <linux/module.h>
8 #include <linux/sched/signal.h>
9
10 #include <asm/pgtable.h>
11 #include <asm/tlbflush.h>
12 #include <as-layout.h>
13 #include <mem_user.h>
14 #include <os.h>
15 #include <skas.h>
16 #include <kern_util.h>
17
18 struct host_vm_change {
19 struct host_vm_op {
20 enum { NONE, MMAP, MUNMAP, MPROTECT } type;
21 union {
22 struct {
23 unsigned long addr;
24 unsigned long len;
25 unsigned int prot;
26 int fd;
27 __u64 offset;
28 } mmap;
29 struct {
30 unsigned long addr;
31 unsigned long len;
32 } munmap;
33 struct {
34 unsigned long addr;
35 unsigned long len;
36 unsigned int prot;
37 } mprotect;
38 } u;
39 } ops[1];
40 int index;
41 struct mm_id *id;
42 void *data;
43 int force;
44 };
45
46 #define INIT_HVC(mm, force) \
47 ((struct host_vm_change) \
48 { .ops = { { .type = NONE } }, \
49 .id = &mm->context.id, \
50 .data = NULL, \
51 .index = 0, \
52 .force = force })
53
report_enomem(void)54 static void report_enomem(void)
55 {
56 printk(KERN_ERR "UML ran out of memory on the host side! "
57 "This can happen due to a memory limitation or "
58 "vm.max_map_count has been reached.\n");
59 }
60
do_ops(struct host_vm_change * hvc,int end,int finished)61 static int do_ops(struct host_vm_change *hvc, int end,
62 int finished)
63 {
64 struct host_vm_op *op;
65 int i, ret = 0;
66
67 for (i = 0; i < end && !ret; i++) {
68 op = &hvc->ops[i];
69 switch (op->type) {
70 case MMAP:
71 ret = map(hvc->id, op->u.mmap.addr, op->u.mmap.len,
72 op->u.mmap.prot, op->u.mmap.fd,
73 op->u.mmap.offset, finished, &hvc->data);
74 break;
75 case MUNMAP:
76 ret = unmap(hvc->id, op->u.munmap.addr,
77 op->u.munmap.len, finished, &hvc->data);
78 break;
79 case MPROTECT:
80 ret = protect(hvc->id, op->u.mprotect.addr,
81 op->u.mprotect.len, op->u.mprotect.prot,
82 finished, &hvc->data);
83 break;
84 default:
85 printk(KERN_ERR "Unknown op type %d in do_ops\n",
86 op->type);
87 BUG();
88 break;
89 }
90 }
91
92 if (ret == -ENOMEM)
93 report_enomem();
94
95 return ret;
96 }
97
add_mmap(unsigned long virt,unsigned long phys,unsigned long len,unsigned int prot,struct host_vm_change * hvc)98 static int add_mmap(unsigned long virt, unsigned long phys, unsigned long len,
99 unsigned int prot, struct host_vm_change *hvc)
100 {
101 __u64 offset;
102 struct host_vm_op *last;
103 int fd, ret = 0;
104
105 fd = phys_mapping(phys, &offset);
106 if (hvc->index != 0) {
107 last = &hvc->ops[hvc->index - 1];
108 if ((last->type == MMAP) &&
109 (last->u.mmap.addr + last->u.mmap.len == virt) &&
110 (last->u.mmap.prot == prot) && (last->u.mmap.fd == fd) &&
111 (last->u.mmap.offset + last->u.mmap.len == offset)) {
112 last->u.mmap.len += len;
113 return 0;
114 }
115 }
116
117 if (hvc->index == ARRAY_SIZE(hvc->ops)) {
118 ret = do_ops(hvc, ARRAY_SIZE(hvc->ops), 0);
119 hvc->index = 0;
120 }
121
122 hvc->ops[hvc->index++] = ((struct host_vm_op)
123 { .type = MMAP,
124 .u = { .mmap = { .addr = virt,
125 .len = len,
126 .prot = prot,
127 .fd = fd,
128 .offset = offset }
129 } });
130 return ret;
131 }
132
add_munmap(unsigned long addr,unsigned long len,struct host_vm_change * hvc)133 static int add_munmap(unsigned long addr, unsigned long len,
134 struct host_vm_change *hvc)
135 {
136 struct host_vm_op *last;
137 int ret = 0;
138
139 if ((addr >= STUB_START) && (addr < STUB_END))
140 return -EINVAL;
141
142 if (hvc->index != 0) {
143 last = &hvc->ops[hvc->index - 1];
144 if ((last->type == MUNMAP) &&
145 (last->u.munmap.addr + last->u.mmap.len == addr)) {
146 last->u.munmap.len += len;
147 return 0;
148 }
149 }
150
151 if (hvc->index == ARRAY_SIZE(hvc->ops)) {
152 ret = do_ops(hvc, ARRAY_SIZE(hvc->ops), 0);
153 hvc->index = 0;
154 }
155
156 hvc->ops[hvc->index++] = ((struct host_vm_op)
157 { .type = MUNMAP,
158 .u = { .munmap = { .addr = addr,
159 .len = len } } });
160 return ret;
161 }
162
add_mprotect(unsigned long addr,unsigned long len,unsigned int prot,struct host_vm_change * hvc)163 static int add_mprotect(unsigned long addr, unsigned long len,
164 unsigned int prot, struct host_vm_change *hvc)
165 {
166 struct host_vm_op *last;
167 int ret = 0;
168
169 if (hvc->index != 0) {
170 last = &hvc->ops[hvc->index - 1];
171 if ((last->type == MPROTECT) &&
172 (last->u.mprotect.addr + last->u.mprotect.len == addr) &&
173 (last->u.mprotect.prot == prot)) {
174 last->u.mprotect.len += len;
175 return 0;
176 }
177 }
178
179 if (hvc->index == ARRAY_SIZE(hvc->ops)) {
180 ret = do_ops(hvc, ARRAY_SIZE(hvc->ops), 0);
181 hvc->index = 0;
182 }
183
184 hvc->ops[hvc->index++] = ((struct host_vm_op)
185 { .type = MPROTECT,
186 .u = { .mprotect = { .addr = addr,
187 .len = len,
188 .prot = prot } } });
189 return ret;
190 }
191
192 #define ADD_ROUND(n, inc) (((n) + (inc)) & ~((inc) - 1))
193
update_pte_range(pmd_t * pmd,unsigned long addr,unsigned long end,struct host_vm_change * hvc)194 static inline int update_pte_range(pmd_t *pmd, unsigned long addr,
195 unsigned long end,
196 struct host_vm_change *hvc)
197 {
198 pte_t *pte;
199 int r, w, x, prot, ret = 0;
200
201 pte = pte_offset_kernel(pmd, addr);
202 do {
203 if ((addr >= STUB_START) && (addr < STUB_END))
204 continue;
205
206 r = pte_read(*pte);
207 w = pte_write(*pte);
208 x = pte_exec(*pte);
209 if (!pte_young(*pte)) {
210 r = 0;
211 w = 0;
212 } else if (!pte_dirty(*pte))
213 w = 0;
214
215 prot = ((r ? UM_PROT_READ : 0) | (w ? UM_PROT_WRITE : 0) |
216 (x ? UM_PROT_EXEC : 0));
217 if (hvc->force || pte_newpage(*pte)) {
218 if (pte_present(*pte))
219 ret = add_mmap(addr, pte_val(*pte) & PAGE_MASK,
220 PAGE_SIZE, prot, hvc);
221 else
222 ret = add_munmap(addr, PAGE_SIZE, hvc);
223 } else if (pte_newprot(*pte))
224 ret = add_mprotect(addr, PAGE_SIZE, prot, hvc);
225 *pte = pte_mkuptodate(*pte);
226 } while (pte++, addr += PAGE_SIZE, ((addr < end) && !ret));
227 return ret;
228 }
229
update_pmd_range(pud_t * pud,unsigned long addr,unsigned long end,struct host_vm_change * hvc)230 static inline int update_pmd_range(pud_t *pud, unsigned long addr,
231 unsigned long end,
232 struct host_vm_change *hvc)
233 {
234 pmd_t *pmd;
235 unsigned long next;
236 int ret = 0;
237
238 pmd = pmd_offset(pud, addr);
239 do {
240 next = pmd_addr_end(addr, end);
241 if (!pmd_present(*pmd)) {
242 if (hvc->force || pmd_newpage(*pmd)) {
243 ret = add_munmap(addr, next - addr, hvc);
244 pmd_mkuptodate(*pmd);
245 }
246 }
247 else ret = update_pte_range(pmd, addr, next, hvc);
248 } while (pmd++, addr = next, ((addr < end) && !ret));
249 return ret;
250 }
251
update_pud_range(pgd_t * pgd,unsigned long addr,unsigned long end,struct host_vm_change * hvc)252 static inline int update_pud_range(pgd_t *pgd, unsigned long addr,
253 unsigned long end,
254 struct host_vm_change *hvc)
255 {
256 pud_t *pud;
257 unsigned long next;
258 int ret = 0;
259
260 pud = pud_offset(pgd, addr);
261 do {
262 next = pud_addr_end(addr, end);
263 if (!pud_present(*pud)) {
264 if (hvc->force || pud_newpage(*pud)) {
265 ret = add_munmap(addr, next - addr, hvc);
266 pud_mkuptodate(*pud);
267 }
268 }
269 else ret = update_pmd_range(pud, addr, next, hvc);
270 } while (pud++, addr = next, ((addr < end) && !ret));
271 return ret;
272 }
273
fix_range_common(struct mm_struct * mm,unsigned long start_addr,unsigned long end_addr,int force)274 void fix_range_common(struct mm_struct *mm, unsigned long start_addr,
275 unsigned long end_addr, int force)
276 {
277 pgd_t *pgd;
278 struct host_vm_change hvc;
279 unsigned long addr = start_addr, next;
280 int ret = 0;
281
282 hvc = INIT_HVC(mm, force);
283 pgd = pgd_offset(mm, addr);
284 do {
285 next = pgd_addr_end(addr, end_addr);
286 if (!pgd_present(*pgd)) {
287 if (force || pgd_newpage(*pgd)) {
288 ret = add_munmap(addr, next - addr, &hvc);
289 pgd_mkuptodate(*pgd);
290 }
291 }
292 else ret = update_pud_range(pgd, addr, next, &hvc);
293 } while (pgd++, addr = next, ((addr < end_addr) && !ret));
294
295 if (!ret)
296 ret = do_ops(&hvc, hvc.index, 1);
297
298 /* This is not an else because ret is modified above */
299 if (ret) {
300 printk(KERN_ERR "fix_range_common: failed, killing current "
301 "process: %d\n", task_tgid_vnr(current));
302 /* We are under mmap_sem, release it such that current can terminate */
303 up_write(¤t->mm->mmap_sem);
304 force_sig(SIGKILL, current);
305 do_signal(¤t->thread.regs);
306 }
307 }
308
flush_tlb_kernel_range_common(unsigned long start,unsigned long end)309 static int flush_tlb_kernel_range_common(unsigned long start, unsigned long end)
310 {
311 struct mm_struct *mm;
312 pgd_t *pgd;
313 pud_t *pud;
314 pmd_t *pmd;
315 pte_t *pte;
316 unsigned long addr, last;
317 int updated = 0, err;
318
319 mm = &init_mm;
320 for (addr = start; addr < end;) {
321 pgd = pgd_offset(mm, addr);
322 if (!pgd_present(*pgd)) {
323 last = ADD_ROUND(addr, PGDIR_SIZE);
324 if (last > end)
325 last = end;
326 if (pgd_newpage(*pgd)) {
327 updated = 1;
328 err = os_unmap_memory((void *) addr,
329 last - addr);
330 if (err < 0)
331 panic("munmap failed, errno = %d\n",
332 -err);
333 }
334 addr = last;
335 continue;
336 }
337
338 pud = pud_offset(pgd, addr);
339 if (!pud_present(*pud)) {
340 last = ADD_ROUND(addr, PUD_SIZE);
341 if (last > end)
342 last = end;
343 if (pud_newpage(*pud)) {
344 updated = 1;
345 err = os_unmap_memory((void *) addr,
346 last - addr);
347 if (err < 0)
348 panic("munmap failed, errno = %d\n",
349 -err);
350 }
351 addr = last;
352 continue;
353 }
354
355 pmd = pmd_offset(pud, addr);
356 if (!pmd_present(*pmd)) {
357 last = ADD_ROUND(addr, PMD_SIZE);
358 if (last > end)
359 last = end;
360 if (pmd_newpage(*pmd)) {
361 updated = 1;
362 err = os_unmap_memory((void *) addr,
363 last - addr);
364 if (err < 0)
365 panic("munmap failed, errno = %d\n",
366 -err);
367 }
368 addr = last;
369 continue;
370 }
371
372 pte = pte_offset_kernel(pmd, addr);
373 if (!pte_present(*pte) || pte_newpage(*pte)) {
374 updated = 1;
375 err = os_unmap_memory((void *) addr,
376 PAGE_SIZE);
377 if (err < 0)
378 panic("munmap failed, errno = %d\n",
379 -err);
380 if (pte_present(*pte))
381 map_memory(addr,
382 pte_val(*pte) & PAGE_MASK,
383 PAGE_SIZE, 1, 1, 1);
384 }
385 else if (pte_newprot(*pte)) {
386 updated = 1;
387 os_protect_memory((void *) addr, PAGE_SIZE, 1, 1, 1);
388 }
389 addr += PAGE_SIZE;
390 }
391 return updated;
392 }
393
flush_tlb_page(struct vm_area_struct * vma,unsigned long address)394 void flush_tlb_page(struct vm_area_struct *vma, unsigned long address)
395 {
396 pgd_t *pgd;
397 pud_t *pud;
398 pmd_t *pmd;
399 pte_t *pte;
400 struct mm_struct *mm = vma->vm_mm;
401 void *flush = NULL;
402 int r, w, x, prot, err = 0;
403 struct mm_id *mm_id;
404
405 address &= PAGE_MASK;
406 pgd = pgd_offset(mm, address);
407 if (!pgd_present(*pgd))
408 goto kill;
409
410 pud = pud_offset(pgd, address);
411 if (!pud_present(*pud))
412 goto kill;
413
414 pmd = pmd_offset(pud, address);
415 if (!pmd_present(*pmd))
416 goto kill;
417
418 pte = pte_offset_kernel(pmd, address);
419
420 r = pte_read(*pte);
421 w = pte_write(*pte);
422 x = pte_exec(*pte);
423 if (!pte_young(*pte)) {
424 r = 0;
425 w = 0;
426 } else if (!pte_dirty(*pte)) {
427 w = 0;
428 }
429
430 mm_id = &mm->context.id;
431 prot = ((r ? UM_PROT_READ : 0) | (w ? UM_PROT_WRITE : 0) |
432 (x ? UM_PROT_EXEC : 0));
433 if (pte_newpage(*pte)) {
434 if (pte_present(*pte)) {
435 unsigned long long offset;
436 int fd;
437
438 fd = phys_mapping(pte_val(*pte) & PAGE_MASK, &offset);
439 err = map(mm_id, address, PAGE_SIZE, prot, fd, offset,
440 1, &flush);
441 }
442 else err = unmap(mm_id, address, PAGE_SIZE, 1, &flush);
443 }
444 else if (pte_newprot(*pte))
445 err = protect(mm_id, address, PAGE_SIZE, prot, 1, &flush);
446
447 if (err) {
448 if (err == -ENOMEM)
449 report_enomem();
450
451 goto kill;
452 }
453
454 *pte = pte_mkuptodate(*pte);
455
456 return;
457
458 kill:
459 printk(KERN_ERR "Failed to flush page for address 0x%lx\n", address);
460 force_sig(SIGKILL, current);
461 }
462
pgd_offset_proc(struct mm_struct * mm,unsigned long address)463 pgd_t *pgd_offset_proc(struct mm_struct *mm, unsigned long address)
464 {
465 return pgd_offset(mm, address);
466 }
467
pud_offset_proc(pgd_t * pgd,unsigned long address)468 pud_t *pud_offset_proc(pgd_t *pgd, unsigned long address)
469 {
470 return pud_offset(pgd, address);
471 }
472
pmd_offset_proc(pud_t * pud,unsigned long address)473 pmd_t *pmd_offset_proc(pud_t *pud, unsigned long address)
474 {
475 return pmd_offset(pud, address);
476 }
477
pte_offset_proc(pmd_t * pmd,unsigned long address)478 pte_t *pte_offset_proc(pmd_t *pmd, unsigned long address)
479 {
480 return pte_offset_kernel(pmd, address);
481 }
482
addr_pte(struct task_struct * task,unsigned long addr)483 pte_t *addr_pte(struct task_struct *task, unsigned long addr)
484 {
485 pgd_t *pgd = pgd_offset(task->mm, addr);
486 pud_t *pud = pud_offset(pgd, addr);
487 pmd_t *pmd = pmd_offset(pud, addr);
488
489 return pte_offset_map(pmd, addr);
490 }
491
flush_tlb_all(void)492 void flush_tlb_all(void)
493 {
494 flush_tlb_mm(current->mm);
495 }
496
flush_tlb_kernel_range(unsigned long start,unsigned long end)497 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
498 {
499 flush_tlb_kernel_range_common(start, end);
500 }
501
flush_tlb_kernel_vm(void)502 void flush_tlb_kernel_vm(void)
503 {
504 flush_tlb_kernel_range_common(start_vm, end_vm);
505 }
506
__flush_tlb_one(unsigned long addr)507 void __flush_tlb_one(unsigned long addr)
508 {
509 flush_tlb_kernel_range_common(addr, addr + PAGE_SIZE);
510 }
511
fix_range(struct mm_struct * mm,unsigned long start_addr,unsigned long end_addr,int force)512 static void fix_range(struct mm_struct *mm, unsigned long start_addr,
513 unsigned long end_addr, int force)
514 {
515 fix_range_common(mm, start_addr, end_addr, force);
516 }
517
flush_tlb_range(struct vm_area_struct * vma,unsigned long start,unsigned long end)518 void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
519 unsigned long end)
520 {
521 if (vma->vm_mm == NULL)
522 flush_tlb_kernel_range_common(start, end);
523 else fix_range(vma->vm_mm, start, end, 0);
524 }
525 EXPORT_SYMBOL(flush_tlb_range);
526
flush_tlb_mm_range(struct mm_struct * mm,unsigned long start,unsigned long end)527 void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
528 unsigned long end)
529 {
530 /*
531 * Don't bother flushing if this address space is about to be
532 * destroyed.
533 */
534 if (atomic_read(&mm->mm_users) == 0)
535 return;
536
537 fix_range(mm, start, end, 0);
538 }
539
flush_tlb_mm(struct mm_struct * mm)540 void flush_tlb_mm(struct mm_struct *mm)
541 {
542 struct vm_area_struct *vma = mm->mmap;
543
544 while (vma != NULL) {
545 fix_range(mm, vma->vm_start, vma->vm_end, 0);
546 vma = vma->vm_next;
547 }
548 }
549
force_flush_all(void)550 void force_flush_all(void)
551 {
552 struct mm_struct *mm = current->mm;
553 struct vm_area_struct *vma = mm->mmap;
554
555 while (vma != NULL) {
556 fix_range(mm, vma->vm_start, vma->vm_end, 1);
557 vma = vma->vm_next;
558 }
559 }
560
