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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
18struct 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 userspace;
41 int index;
42 struct mm_struct *mm;
43 void *data;
44 int force;
45};
46
47#define INIT_HVC(mm, force, userspace) \
48 ((struct host_vm_change) \
49 { .ops = { { .type = NONE } }, \
50 .mm = mm, \
51 .data = NULL, \
52 .userspace = userspace, \
53 .index = 0, \
54 .force = force })
55
56static void report_enomem(void)
57{
58 printk(KERN_ERR "UML ran out of memory on the host side! "
59 "This can happen due to a memory limitation or "
60 "vm.max_map_count has been reached.\n");
61}
62
63static int do_ops(struct host_vm_change *hvc, int end,
64 int finished)
65{
66 struct host_vm_op *op;
67 int i, ret = 0;
68
69 for (i = 0; i < end && !ret; i++) {
70 op = &hvc->ops[i];
71 switch (op->type) {
72 case MMAP:
73 if (hvc->userspace)
74 ret = map(&hvc->mm->context.id, op->u.mmap.addr,
75 op->u.mmap.len, op->u.mmap.prot,
76 op->u.mmap.fd,
77 op->u.mmap.offset, finished,
78 &hvc->data);
79 else
80 map_memory(op->u.mmap.addr, op->u.mmap.offset,
81 op->u.mmap.len, 1, 1, 1);
82 break;
83 case MUNMAP:
84 if (hvc->userspace)
85 ret = unmap(&hvc->mm->context.id,
86 op->u.munmap.addr,
87 op->u.munmap.len, finished,
88 &hvc->data);
89 else
90 ret = os_unmap_memory(
91 (void *) op->u.munmap.addr,
92 op->u.munmap.len);
93
94 break;
95 case MPROTECT:
96 if (hvc->userspace)
97 ret = protect(&hvc->mm->context.id,
98 op->u.mprotect.addr,
99 op->u.mprotect.len,
100 op->u.mprotect.prot,
101 finished, &hvc->data);
102 else
103 ret = os_protect_memory(
104 (void *) op->u.mprotect.addr,
105 op->u.mprotect.len,
106 1, 1, 1);
107 break;
108 default:
109 printk(KERN_ERR "Unknown op type %d in do_ops\n",
110 op->type);
111 BUG();
112 break;
113 }
114 }
115
116 if (ret == -ENOMEM)
117 report_enomem();
118
119 return ret;
120}
121
122static int add_mmap(unsigned long virt, unsigned long phys, unsigned long len,
123 unsigned int prot, struct host_vm_change *hvc)
124{
125 __u64 offset;
126 struct host_vm_op *last;
127 int fd = -1, ret = 0;
128
129 if (hvc->userspace)
130 fd = phys_mapping(phys, &offset);
131 else
132 offset = phys;
133 if (hvc->index != 0) {
134 last = &hvc->ops[hvc->index - 1];
135 if ((last->type == MMAP) &&
136 (last->u.mmap.addr + last->u.mmap.len == virt) &&
137 (last->u.mmap.prot == prot) && (last->u.mmap.fd == fd) &&
138 (last->u.mmap.offset + last->u.mmap.len == offset)) {
139 last->u.mmap.len += len;
140 return 0;
141 }
142 }
143
144 if (hvc->index == ARRAY_SIZE(hvc->ops)) {
145 ret = do_ops(hvc, ARRAY_SIZE(hvc->ops), 0);
146 hvc->index = 0;
147 }
148
149 hvc->ops[hvc->index++] = ((struct host_vm_op)
150 { .type = MMAP,
151 .u = { .mmap = { .addr = virt,
152 .len = len,
153 .prot = prot,
154 .fd = fd,
155 .offset = offset }
156 } });
157 return ret;
158}
159
160static int add_munmap(unsigned long addr, unsigned long len,
161 struct host_vm_change *hvc)
162{
163 struct host_vm_op *last;
164 int ret = 0;
165
166 if ((addr >= STUB_START) && (addr < STUB_END))
167 return -EINVAL;
168
169 if (hvc->index != 0) {
170 last = &hvc->ops[hvc->index - 1];
171 if ((last->type == MUNMAP) &&
172 (last->u.munmap.addr + last->u.mmap.len == addr)) {
173 last->u.munmap.len += len;
174 return 0;
175 }
176 }
177
178 if (hvc->index == ARRAY_SIZE(hvc->ops)) {
179 ret = do_ops(hvc, ARRAY_SIZE(hvc->ops), 0);
180 hvc->index = 0;
181 }
182
183 hvc->ops[hvc->index++] = ((struct host_vm_op)
184 { .type = MUNMAP,
185 .u = { .munmap = { .addr = addr,
186 .len = len } } });
187 return ret;
188}
189
190static int add_mprotect(unsigned long addr, unsigned long len,
191 unsigned int prot, struct host_vm_change *hvc)
192{
193 struct host_vm_op *last;
194 int ret = 0;
195
196 if (hvc->index != 0) {
197 last = &hvc->ops[hvc->index - 1];
198 if ((last->type == MPROTECT) &&
199 (last->u.mprotect.addr + last->u.mprotect.len == addr) &&
200 (last->u.mprotect.prot == prot)) {
201 last->u.mprotect.len += len;
202 return 0;
203 }
204 }
205
206 if (hvc->index == ARRAY_SIZE(hvc->ops)) {
207 ret = do_ops(hvc, ARRAY_SIZE(hvc->ops), 0);
208 hvc->index = 0;
209 }
210
211 hvc->ops[hvc->index++] = ((struct host_vm_op)
212 { .type = MPROTECT,
213 .u = { .mprotect = { .addr = addr,
214 .len = len,
215 .prot = prot } } });
216 return ret;
217}
218
219#define ADD_ROUND(n, inc) (((n) + (inc)) & ~((inc) - 1))
220
221static inline int update_pte_range(pmd_t *pmd, unsigned long addr,
222 unsigned long end,
223 struct host_vm_change *hvc)
224{
225 pte_t *pte;
226 int r, w, x, prot, ret = 0;
227
228 pte = pte_offset_kernel(pmd, addr);
229 do {
230 if ((addr >= STUB_START) && (addr < STUB_END))
231 continue;
232
233 r = pte_read(*pte);
234 w = pte_write(*pte);
235 x = pte_exec(*pte);
236 if (!pte_young(*pte)) {
237 r = 0;
238 w = 0;
239 } else if (!pte_dirty(*pte))
240 w = 0;
241
242 prot = ((r ? UM_PROT_READ : 0) | (w ? UM_PROT_WRITE : 0) |
243 (x ? UM_PROT_EXEC : 0));
244 if (hvc->force || pte_newpage(*pte)) {
245 if (pte_present(*pte)) {
246 if (pte_newpage(*pte))
247 ret = add_mmap(addr, pte_val(*pte) & PAGE_MASK,
248 PAGE_SIZE, prot, hvc);
249 } else
250 ret = add_munmap(addr, PAGE_SIZE, hvc);
251 } else if (pte_newprot(*pte))
252 ret = add_mprotect(addr, PAGE_SIZE, prot, hvc);
253 *pte = pte_mkuptodate(*pte);
254 } while (pte++, addr += PAGE_SIZE, ((addr < end) && !ret));
255 return ret;
256}
257
258static inline int update_pmd_range(pud_t *pud, unsigned long addr,
259 unsigned long end,
260 struct host_vm_change *hvc)
261{
262 pmd_t *pmd;
263 unsigned long next;
264 int ret = 0;
265
266 pmd = pmd_offset(pud, addr);
267 do {
268 next = pmd_addr_end(addr, end);
269 if (!pmd_present(*pmd)) {
270 if (hvc->force || pmd_newpage(*pmd)) {
271 ret = add_munmap(addr, next - addr, hvc);
272 pmd_mkuptodate(*pmd);
273 }
274 }
275 else ret = update_pte_range(pmd, addr, next, hvc);
276 } while (pmd++, addr = next, ((addr < end) && !ret));
277 return ret;
278}
279
280static inline int update_pud_range(pgd_t *pgd, unsigned long addr,
281 unsigned long end,
282 struct host_vm_change *hvc)
283{
284 pud_t *pud;
285 unsigned long next;
286 int ret = 0;
287
288 pud = pud_offset(pgd, addr);
289 do {
290 next = pud_addr_end(addr, end);
291 if (!pud_present(*pud)) {
292 if (hvc->force || pud_newpage(*pud)) {
293 ret = add_munmap(addr, next - addr, hvc);
294 pud_mkuptodate(*pud);
295 }
296 }
297 else ret = update_pmd_range(pud, addr, next, hvc);
298 } while (pud++, addr = next, ((addr < end) && !ret));
299 return ret;
300}
301
302void fix_range_common(struct mm_struct *mm, unsigned long start_addr,
303 unsigned long end_addr, int force)
304{
305 pgd_t *pgd;
306 struct host_vm_change hvc;
307 unsigned long addr = start_addr, next;
308 int ret = 0, userspace = 1;
309
310 hvc = INIT_HVC(mm, force, userspace);
311 pgd = pgd_offset(mm, addr);
312 do {
313 next = pgd_addr_end(addr, end_addr);
314 if (!pgd_present(*pgd)) {
315 if (force || pgd_newpage(*pgd)) {
316 ret = add_munmap(addr, next - addr, &hvc);
317 pgd_mkuptodate(*pgd);
318 }
319 }
320 else ret = update_pud_range(pgd, addr, next, &hvc);
321 } while (pgd++, addr = next, ((addr < end_addr) && !ret));
322
323 if (!ret)
324 ret = do_ops(&hvc, hvc.index, 1);
325
326
327 if (ret) {
328 printk(KERN_ERR "fix_range_common: failed, killing current "
329 "process: %d\n", task_tgid_vnr(current));
330
331 up_write(¤t->mm->mmap_sem);
332 force_sig(SIGKILL);
333 do_signal(¤t->thread.regs);
334 }
335}
336
337static int flush_tlb_kernel_range_common(unsigned long start, unsigned long end)
338{
339 struct mm_struct *mm;
340 pgd_t *pgd;
341 pud_t *pud;
342 pmd_t *pmd;
343 pte_t *pte;
344 unsigned long addr, last;
345 int updated = 0, err = 0, force = 0, userspace = 0;
346 struct host_vm_change hvc;
347
348 mm = &init_mm;
349 hvc = INIT_HVC(mm, force, userspace);
350 for (addr = start; addr < end;) {
351 pgd = pgd_offset(mm, addr);
352 if (!pgd_present(*pgd)) {
353 last = ADD_ROUND(addr, PGDIR_SIZE);
354 if (last > end)
355 last = end;
356 if (pgd_newpage(*pgd)) {
357 updated = 1;
358 err = add_munmap(addr, last - addr, &hvc);
359 if (err < 0)
360 panic("munmap failed, errno = %d\n",
361 -err);
362 }
363 addr = last;
364 continue;
365 }
366
367 pud = pud_offset(pgd, addr);
368 if (!pud_present(*pud)) {
369 last = ADD_ROUND(addr, PUD_SIZE);
370 if (last > end)
371 last = end;
372 if (pud_newpage(*pud)) {
373 updated = 1;
374 err = add_munmap(addr, last - addr, &hvc);
375 if (err < 0)
376 panic("munmap failed, errno = %d\n",
377 -err);
378 }
379 addr = last;
380 continue;
381 }
382
383 pmd = pmd_offset(pud, addr);
384 if (!pmd_present(*pmd)) {
385 last = ADD_ROUND(addr, PMD_SIZE);
386 if (last > end)
387 last = end;
388 if (pmd_newpage(*pmd)) {
389 updated = 1;
390 err = add_munmap(addr, last - addr, &hvc);
391 if (err < 0)
392 panic("munmap failed, errno = %d\n",
393 -err);
394 }
395 addr = last;
396 continue;
397 }
398
399 pte = pte_offset_kernel(pmd, addr);
400 if (!pte_present(*pte) || pte_newpage(*pte)) {
401 updated = 1;
402 err = add_munmap(addr, PAGE_SIZE, &hvc);
403 if (err < 0)
404 panic("munmap failed, errno = %d\n",
405 -err);
406 if (pte_present(*pte))
407 err = add_mmap(addr, pte_val(*pte) & PAGE_MASK,
408 PAGE_SIZE, 0, &hvc);
409 }
410 else if (pte_newprot(*pte)) {
411 updated = 1;
412 err = add_mprotect(addr, PAGE_SIZE, 0, &hvc);
413 }
414 addr += PAGE_SIZE;
415 }
416 if (!err)
417 err = do_ops(&hvc, hvc.index, 1);
418
419 if (err < 0)
420 panic("flush_tlb_kernel failed, errno = %d\n", err);
421 return updated;
422}
423
424void flush_tlb_page(struct vm_area_struct *vma, unsigned long address)
425{
426 pgd_t *pgd;
427 pud_t *pud;
428 pmd_t *pmd;
429 pte_t *pte;
430 struct mm_struct *mm = vma->vm_mm;
431 void *flush = NULL;
432 int r, w, x, prot, err = 0;
433 struct mm_id *mm_id;
434
435 address &= PAGE_MASK;
436 pgd = pgd_offset(mm, address);
437 if (!pgd_present(*pgd))
438 goto kill;
439
440 pud = pud_offset(pgd, address);
441 if (!pud_present(*pud))
442 goto kill;
443
444 pmd = pmd_offset(pud, address);
445 if (!pmd_present(*pmd))
446 goto kill;
447
448 pte = pte_offset_kernel(pmd, address);
449
450 r = pte_read(*pte);
451 w = pte_write(*pte);
452 x = pte_exec(*pte);
453 if (!pte_young(*pte)) {
454 r = 0;
455 w = 0;
456 } else if (!pte_dirty(*pte)) {
457 w = 0;
458 }
459
460 mm_id = &mm->context.id;
461 prot = ((r ? UM_PROT_READ : 0) | (w ? UM_PROT_WRITE : 0) |
462 (x ? UM_PROT_EXEC : 0));
463 if (pte_newpage(*pte)) {
464 if (pte_present(*pte)) {
465 unsigned long long offset;
466 int fd;
467
468 fd = phys_mapping(pte_val(*pte) & PAGE_MASK, &offset);
469 err = map(mm_id, address, PAGE_SIZE, prot, fd, offset,
470 1, &flush);
471 }
472 else err = unmap(mm_id, address, PAGE_SIZE, 1, &flush);
473 }
474 else if (pte_newprot(*pte))
475 err = protect(mm_id, address, PAGE_SIZE, prot, 1, &flush);
476
477 if (err) {
478 if (err == -ENOMEM)
479 report_enomem();
480
481 goto kill;
482 }
483
484 *pte = pte_mkuptodate(*pte);
485
486 return;
487
488kill:
489 printk(KERN_ERR "Failed to flush page for address 0x%lx\n", address);
490 force_sig(SIGKILL);
491}
492
493pgd_t *pgd_offset_proc(struct mm_struct *mm, unsigned long address)
494{
495 return pgd_offset(mm, address);
496}
497
498pud_t *pud_offset_proc(pgd_t *pgd, unsigned long address)
499{
500 return pud_offset(pgd, address);
501}
502
503pmd_t *pmd_offset_proc(pud_t *pud, unsigned long address)
504{
505 return pmd_offset(pud, address);
506}
507
508pte_t *pte_offset_proc(pmd_t *pmd, unsigned long address)
509{
510 return pte_offset_kernel(pmd, address);
511}
512
513pte_t *addr_pte(struct task_struct *task, unsigned long addr)
514{
515 pgd_t *pgd = pgd_offset(task->mm, addr);
516 pud_t *pud = pud_offset(pgd, addr);
517 pmd_t *pmd = pmd_offset(pud, addr);
518
519 return pte_offset_map(pmd, addr);
520}
521
522void flush_tlb_all(void)
523{
524
525
526
527
528 if (atomic_read(¤t->mm->mm_users) == 0)
529 return;
530
531 flush_tlb_mm(current->mm);
532}
533
534void flush_tlb_kernel_range(unsigned long start, unsigned long end)
535{
536 flush_tlb_kernel_range_common(start, end);
537}
538
539void flush_tlb_kernel_vm(void)
540{
541 flush_tlb_kernel_range_common(start_vm, end_vm);
542}
543
544void __flush_tlb_one(unsigned long addr)
545{
546 flush_tlb_kernel_range_common(addr, addr + PAGE_SIZE);
547}
548
549static void fix_range(struct mm_struct *mm, unsigned long start_addr,
550 unsigned long end_addr, int force)
551{
552
553
554
555
556 if (atomic_read(&mm->mm_users) == 0)
557 return;
558
559 fix_range_common(mm, start_addr, end_addr, force);
560}
561
562void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
563 unsigned long end)
564{
565 if (vma->vm_mm == NULL)
566 flush_tlb_kernel_range_common(start, end);
567 else fix_range(vma->vm_mm, start, end, 0);
568}
569EXPORT_SYMBOL(flush_tlb_range);
570
571void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
572 unsigned long end)
573{
574 fix_range(mm, start, end, 0);
575}
576
577void flush_tlb_mm(struct mm_struct *mm)
578{
579 struct vm_area_struct *vma = mm->mmap;
580
581 while (vma != NULL) {
582 fix_range(mm, vma->vm_start, vma->vm_end, 0);
583 vma = vma->vm_next;
584 }
585}
586
587void force_flush_all(void)
588{
589 struct mm_struct *mm = current->mm;
590 struct vm_area_struct *vma = mm->mmap;
591
592 while (vma != NULL) {
593 fix_range(mm, vma->vm_start, vma->vm_end, 1);
594 vma = vma->vm_next;
595 }
596}
597
