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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.h>
9#include <asm/pgtable.h>
10#include <asm/tlbflush.h>
11#include "as-layout.h"
12#include "mem_user.h"
13#include "os.h"
14#include "skas.h"
15
16struct host_vm_change {
17 struct host_vm_op {
18 enum { NONE, MMAP, MUNMAP, MPROTECT } type;
19 union {
20 struct {
21 unsigned long addr;
22 unsigned long len;
23 unsigned int prot;
24 int fd;
25 __u64 offset;
26 } mmap;
27 struct {
28 unsigned long addr;
29 unsigned long len;
30 } munmap;
31 struct {
32 unsigned long addr;
33 unsigned long len;
34 unsigned int prot;
35 } mprotect;
36 } u;
37 } ops[1];
38 int index;
39 struct mm_id *id;
40 void *data;
41 int force;
42};
43
44#define INIT_HVC(mm, force) \
45 ((struct host_vm_change) \
46 { .ops = { { .type = NONE } }, \
47 .id = &mm->context.id, \
48 .data = NULL, \
49 .index = 0, \
50 .force = force })
51
52static int do_ops(struct host_vm_change *hvc, int end,
53 int finished)
54{
55 struct host_vm_op *op;
56 int i, ret = 0;
57
58 for (i = 0; i < end && !ret; i++) {
59 op = &hvc->ops[i];
60 switch (op->type) {
61 case MMAP:
62 ret = map(hvc->id, op->u.mmap.addr, op->u.mmap.len,
63 op->u.mmap.prot, op->u.mmap.fd,
64 op->u.mmap.offset, finished, &hvc->data);
65 break;
66 case MUNMAP:
67 ret = unmap(hvc->id, op->u.munmap.addr,
68 op->u.munmap.len, finished, &hvc->data);
69 break;
70 case MPROTECT:
71 ret = protect(hvc->id, op->u.mprotect.addr,
72 op->u.mprotect.len, op->u.mprotect.prot,
73 finished, &hvc->data);
74 break;
75 default:
76 printk(KERN_ERR "Unknown op type %d in do_ops\n",
77 op->type);
78 BUG();
79 break;
80 }
81 }
82
83 return ret;
84}
85
86static int add_mmap(unsigned long virt, unsigned long phys, unsigned long len,
87 unsigned int prot, struct host_vm_change *hvc)
88{
89 __u64 offset;
90 struct host_vm_op *last;
91 int fd, ret = 0;
92
93 fd = phys_mapping(phys, &offset);
94 if (hvc->index != 0) {
95 last = &hvc->ops[hvc->index - 1];
96 if ((last->type == MMAP) &&
97 (last->u.mmap.addr + last->u.mmap.len == virt) &&
98 (last->u.mmap.prot == prot) && (last->u.mmap.fd == fd) &&
99 (last->u.mmap.offset + last->u.mmap.len == offset)) {
100 last->u.mmap.len += len;
101 return 0;
102 }
103 }
104
105 if (hvc->index == ARRAY_SIZE(hvc->ops)) {
106 ret = do_ops(hvc, ARRAY_SIZE(hvc->ops), 0);
107 hvc->index = 0;
108 }
109
110 hvc->ops[hvc->index++] = ((struct host_vm_op)
111 { .type = MMAP,
112 .u = { .mmap = { .addr = virt,
113 .len = len,
114 .prot = prot,
115 .fd = fd,
116 .offset = offset }
117 } });
118 return ret;
119}
120
121static int add_munmap(unsigned long addr, unsigned long len,
122 struct host_vm_change *hvc)
123{
124 struct host_vm_op *last;
125 int ret = 0;
126
127 if (hvc->index != 0) {
128 last = &hvc->ops[hvc->index - 1];
129 if ((last->type == MUNMAP) &&
130 (last->u.munmap.addr + last->u.mmap.len == addr)) {
131 last->u.munmap.len += len;
132 return 0;
133 }
134 }
135
136 if (hvc->index == ARRAY_SIZE(hvc->ops)) {
137 ret = do_ops(hvc, ARRAY_SIZE(hvc->ops), 0);
138 hvc->index = 0;
139 }
140
141 hvc->ops[hvc->index++] = ((struct host_vm_op)
142 { .type = MUNMAP,
143 .u = { .munmap = { .addr = addr,
144 .len = len } } });
145 return ret;
146}
147
148static int add_mprotect(unsigned long addr, unsigned long len,
149 unsigned int prot, struct host_vm_change *hvc)
150{
151 struct host_vm_op *last;
152 int ret = 0;
153
154 if (hvc->index != 0) {
155 last = &hvc->ops[hvc->index - 1];
156 if ((last->type == MPROTECT) &&
157 (last->u.mprotect.addr + last->u.mprotect.len == addr) &&
158 (last->u.mprotect.prot == prot)) {
159 last->u.mprotect.len += len;
160 return 0;
161 }
162 }
163
164 if (hvc->index == ARRAY_SIZE(hvc->ops)) {
165 ret = do_ops(hvc, ARRAY_SIZE(hvc->ops), 0);
166 hvc->index = 0;
167 }
168
169 hvc->ops[hvc->index++] = ((struct host_vm_op)
170 { .type = MPROTECT,
171 .u = { .mprotect = { .addr = addr,
172 .len = len,
173 .prot = prot } } });
174 return ret;
175}
176
177#define ADD_ROUND(n, inc) (((n) + (inc)) & ~((inc) - 1))
178
179static inline int update_pte_range(pmd_t *pmd, unsigned long addr,
180 unsigned long end,
181 struct host_vm_change *hvc)
182{
183 pte_t *pte;
184 int r, w, x, prot, ret = 0;
185
186 pte = pte_offset_kernel(pmd, addr);
187 do {
188 if ((addr >= STUB_START) && (addr < STUB_END))
189 continue;
190
191 r = pte_read(*pte);
192 w = pte_write(*pte);
193 x = pte_exec(*pte);
194 if (!pte_young(*pte)) {
195 r = 0;
196 w = 0;
197 } else if (!pte_dirty(*pte))
198 w = 0;
199
200 prot = ((r ? UM_PROT_READ : 0) | (w ? UM_PROT_WRITE : 0) |
201 (x ? UM_PROT_EXEC : 0));
202 if (hvc->force || pte_newpage(*pte)) {
203 if (pte_present(*pte))
204 ret = add_mmap(addr, pte_val(*pte) & PAGE_MASK,
205 PAGE_SIZE, prot, hvc);
206 else
207 ret = add_munmap(addr, PAGE_SIZE, hvc);
208 } else if (pte_newprot(*pte))
209 ret = add_mprotect(addr, PAGE_SIZE, prot, hvc);
210 *pte = pte_mkuptodate(*pte);
211 } while (pte++, addr += PAGE_SIZE, ((addr < end) && !ret));
212 return ret;
213}
214
215static inline int update_pmd_range(pud_t *pud, unsigned long addr,
216 unsigned long end,
217 struct host_vm_change *hvc)
218{
219 pmd_t *pmd;
220 unsigned long next;
221 int ret = 0;
222
223 pmd = pmd_offset(pud, addr);
224 do {
225 next = pmd_addr_end(addr, end);
226 if (!pmd_present(*pmd)) {
227 if (hvc->force || pmd_newpage(*pmd)) {
228 ret = add_munmap(addr, next - addr, hvc);
229 pmd_mkuptodate(*pmd);
230 }
231 }
232 else ret = update_pte_range(pmd, addr, next, hvc);
233 } while (pmd++, addr = next, ((addr < end) && !ret));
234 return ret;
235}
236
237static inline int update_pud_range(pgd_t *pgd, unsigned long addr,
238 unsigned long end,
239 struct host_vm_change *hvc)
240{
241 pud_t *pud;
242 unsigned long next;
243 int ret = 0;
244
245 pud = pud_offset(pgd, addr);
246 do {
247 next = pud_addr_end(addr, end);
248 if (!pud_present(*pud)) {
249 if (hvc->force || pud_newpage(*pud)) {
250 ret = add_munmap(addr, next - addr, hvc);
251 pud_mkuptodate(*pud);
252 }
253 }
254 else ret = update_pmd_range(pud, addr, next, hvc);
255 } while (pud++, addr = next, ((addr < end) && !ret));
256 return ret;
257}
258
259void fix_range_common(struct mm_struct *mm, unsigned long start_addr,
260 unsigned long end_addr, int force)
261{
262 pgd_t *pgd;
263 struct host_vm_change hvc;
264 unsigned long addr = start_addr, next;
265 int ret = 0;
266
267 hvc = INIT_HVC(mm, force);
268 pgd = pgd_offset(mm, addr);
269 do {
270 next = pgd_addr_end(addr, end_addr);
271 if (!pgd_present(*pgd)) {
272 if (force || pgd_newpage(*pgd)) {
273 ret = add_munmap(addr, next - addr, &hvc);
274 pgd_mkuptodate(*pgd);
275 }
276 }
277 else ret = update_pud_range(pgd, addr, next, &hvc);
278 } while (pgd++, addr = next, ((addr < end_addr) && !ret));
279
280 if (!ret)
281 ret = do_ops(&hvc, hvc.index, 1);
282
283 /* This is not an else because ret is modified above */
284 if (ret) {
285 printk(KERN_ERR "fix_range_common: failed, killing current "
286 "process\n");
287 force_sig(SIGKILL, current);
288 }
289}
290
291static int flush_tlb_kernel_range_common(unsigned long start, unsigned long end)
292{
293 struct mm_struct *mm;
294 pgd_t *pgd;
295 pud_t *pud;
296 pmd_t *pmd;
297 pte_t *pte;
298 unsigned long addr, last;
299 int updated = 0, err;
300
301 mm = &init_mm;
302 for (addr = start; addr < end;) {
303 pgd = pgd_offset(mm, addr);
304 if (!pgd_present(*pgd)) {
305 last = ADD_ROUND(addr, PGDIR_SIZE);
306 if (last > end)
307 last = end;
308 if (pgd_newpage(*pgd)) {
309 updated = 1;
310 err = os_unmap_memory((void *) addr,
311 last - addr);
312 if (err < 0)
313 panic("munmap failed, errno = %d\n",
314 -err);
315 }
316 addr = last;
317 continue;
318 }
319
320 pud = pud_offset(pgd, addr);
321 if (!pud_present(*pud)) {
322 last = ADD_ROUND(addr, PUD_SIZE);
323 if (last > end)
324 last = end;
325 if (pud_newpage(*pud)) {
326 updated = 1;
327 err = os_unmap_memory((void *) addr,
328 last - addr);
329 if (err < 0)
330 panic("munmap failed, errno = %d\n",
331 -err);
332 }
333 addr = last;
334 continue;
335 }
336
337 pmd = pmd_offset(pud, addr);
338 if (!pmd_present(*pmd)) {
339 last = ADD_ROUND(addr, PMD_SIZE);
340 if (last > end)
341 last = end;
342 if (pmd_newpage(*pmd)) {
343 updated = 1;
344 err = os_unmap_memory((void *) addr,
345 last - addr);
346 if (err < 0)
347 panic("munmap failed, errno = %d\n",
348 -err);
349 }
350 addr = last;
351 continue;
352 }
353
354 pte = pte_offset_kernel(pmd, addr);
355 if (!pte_present(*pte) || pte_newpage(*pte)) {
356 updated = 1;
357 err = os_unmap_memory((void *) addr,
358 PAGE_SIZE);
359 if (err < 0)
360 panic("munmap failed, errno = %d\n",
361 -err);
362 if (pte_present(*pte))
363 map_memory(addr,
364 pte_val(*pte) & PAGE_MASK,
365 PAGE_SIZE, 1, 1, 1);
366 }
367 else if (pte_newprot(*pte)) {
368 updated = 1;
369 os_protect_memory((void *) addr, PAGE_SIZE, 1, 1, 1);
370 }
371 addr += PAGE_SIZE;
372 }
373 return updated;
374}
375
376void flush_tlb_page(struct vm_area_struct *vma, unsigned long address)
377{
378 pgd_t *pgd;
379 pud_t *pud;
380 pmd_t *pmd;
381 pte_t *pte;
382 struct mm_struct *mm = vma->vm_mm;
383 void *flush = NULL;
384 int r, w, x, prot, err = 0;
385 struct mm_id *mm_id;
386
387 address &= PAGE_MASK;
388 pgd = pgd_offset(mm, address);
389 if (!pgd_present(*pgd))
390 goto kill;
391
392 pud = pud_offset(pgd, address);
393 if (!pud_present(*pud))
394 goto kill;
395
396 pmd = pmd_offset(pud, address);
397 if (!pmd_present(*pmd))
398 goto kill;
399
400 pte = pte_offset_kernel(pmd, address);
401
402 r = pte_read(*pte);
403 w = pte_write(*pte);
404 x = pte_exec(*pte);
405 if (!pte_young(*pte)) {
406 r = 0;
407 w = 0;
408 } else if (!pte_dirty(*pte)) {
409 w = 0;
410 }
411
412 mm_id = &mm->context.id;
413 prot = ((r ? UM_PROT_READ : 0) | (w ? UM_PROT_WRITE : 0) |
414 (x ? UM_PROT_EXEC : 0));
415 if (pte_newpage(*pte)) {
416 if (pte_present(*pte)) {
417 unsigned long long offset;
418 int fd;
419
420 fd = phys_mapping(pte_val(*pte) & PAGE_MASK, &offset);
421 err = map(mm_id, address, PAGE_SIZE, prot, fd, offset,
422 1, &flush);
423 }
424 else err = unmap(mm_id, address, PAGE_SIZE, 1, &flush);
425 }
426 else if (pte_newprot(*pte))
427 err = protect(mm_id, address, PAGE_SIZE, prot, 1, &flush);
428
429 if (err)
430 goto kill;
431
432 *pte = pte_mkuptodate(*pte);
433
434 return;
435
436kill:
437 printk(KERN_ERR "Failed to flush page for address 0x%lx\n", address);
438 force_sig(SIGKILL, current);
439}
440
441pgd_t *pgd_offset_proc(struct mm_struct *mm, unsigned long address)
442{
443 return pgd_offset(mm, address);
444}
445
446pud_t *pud_offset_proc(pgd_t *pgd, unsigned long address)
447{
448 return pud_offset(pgd, address);
449}
450
451pmd_t *pmd_offset_proc(pud_t *pud, unsigned long address)
452{
453 return pmd_offset(pud, address);
454}
455
456pte_t *pte_offset_proc(pmd_t *pmd, unsigned long address)
457{
458 return pte_offset_kernel(pmd, address);
459}
460
461pte_t *addr_pte(struct task_struct *task, unsigned long addr)
462{
463 pgd_t *pgd = pgd_offset(task->mm, addr);
464 pud_t *pud = pud_offset(pgd, addr);
465 pmd_t *pmd = pmd_offset(pud, addr);
466
467 return pte_offset_map(pmd, addr);
468}
469
470void flush_tlb_all(void)
471{
472 flush_tlb_mm(current->mm);
473}
474
475void flush_tlb_kernel_range(unsigned long start, unsigned long end)
476{
477 flush_tlb_kernel_range_common(start, end);
478}
479
480void flush_tlb_kernel_vm(void)
481{
482 flush_tlb_kernel_range_common(start_vm, end_vm);
483}
484
485void __flush_tlb_one(unsigned long addr)
486{
487 flush_tlb_kernel_range_common(addr, addr + PAGE_SIZE);
488}
489
490static void fix_range(struct mm_struct *mm, unsigned long start_addr,
491 unsigned long end_addr, int force)
492{
493 fix_range_common(mm, start_addr, end_addr, force);
494}
495
496void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
497 unsigned long end)
498{
499 if (vma->vm_mm == NULL)
500 flush_tlb_kernel_range_common(start, end);
501 else fix_range(vma->vm_mm, start, end, 0);
502}
503EXPORT_SYMBOL(flush_tlb_range);
504
505void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
506 unsigned long end)
507{
508 /*
509 * Don't bother flushing if this address space is about to be
510 * destroyed.
511 */
512 if (atomic_read(&mm->mm_users) == 0)
513 return;
514
515 fix_range(mm, start, end, 0);
516}
517
518void flush_tlb_mm(struct mm_struct *mm)
519{
520 struct vm_area_struct *vma = mm->mmap;
521
522 while (vma != NULL) {
523 fix_range(mm, vma->vm_start, vma->vm_end, 0);
524 vma = vma->vm_next;
525 }
526}
527
528void force_flush_all(void)
529{
530 struct mm_struct *mm = current->mm;
531 struct vm_area_struct *vma = mm->mmap;
532
533 while (vma != NULL) {
534 fix_range(mm, vma->vm_start, vma->vm_end, 1);
535 vma = vma->vm_next;
536 }
537}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
4 */
5
6#include <linux/mm.h>
7#include <linux/module.h>
8#include <linux/sched/signal.h>
9
10#include <asm/tlbflush.h>
11#include <asm/mmu_context.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 vm_ops {
19 struct mm_id *mm_idp;
20
21 int (*mmap)(struct mm_id *mm_idp,
22 unsigned long virt, unsigned long len, int prot,
23 int phys_fd, unsigned long long offset);
24 int (*unmap)(struct mm_id *mm_idp,
25 unsigned long virt, unsigned long len);
26};
27
28static int kern_map(struct mm_id *mm_idp,
29 unsigned long virt, unsigned long len, int prot,
30 int phys_fd, unsigned long long offset)
31{
32 /* TODO: Why is executable needed to be always set in the kernel? */
33 return os_map_memory((void *)virt, phys_fd, offset, len,
34 prot & UM_PROT_READ, prot & UM_PROT_WRITE,
35 1);
36}
37
38static int kern_unmap(struct mm_id *mm_idp,
39 unsigned long virt, unsigned long len)
40{
41 return os_unmap_memory((void *)virt, len);
42}
43
44void report_enomem(void)
45{
46 printk(KERN_ERR "UML ran out of memory on the host side! "
47 "This can happen due to a memory limitation or "
48 "vm.max_map_count has been reached.\n");
49}
50
51static inline int update_pte_range(pmd_t *pmd, unsigned long addr,
52 unsigned long end,
53 struct vm_ops *ops)
54{
55 pte_t *pte;
56 int ret = 0;
57
58 pte = pte_offset_kernel(pmd, addr);
59 do {
60 if (!pte_needsync(*pte))
61 continue;
62
63 if (pte_present(*pte)) {
64 __u64 offset;
65 unsigned long phys = pte_val(*pte) & PAGE_MASK;
66 int fd = phys_mapping(phys, &offset);
67 int r, w, x, prot;
68
69 r = pte_read(*pte);
70 w = pte_write(*pte);
71 x = pte_exec(*pte);
72 if (!pte_young(*pte)) {
73 r = 0;
74 w = 0;
75 } else if (!pte_dirty(*pte))
76 w = 0;
77
78 prot = (r ? UM_PROT_READ : 0) |
79 (w ? UM_PROT_WRITE : 0) |
80 (x ? UM_PROT_EXEC : 0);
81
82 ret = ops->mmap(ops->mm_idp, addr, PAGE_SIZE,
83 prot, fd, offset);
84 } else
85 ret = ops->unmap(ops->mm_idp, addr, PAGE_SIZE);
86
87 *pte = pte_mkuptodate(*pte);
88 } while (pte++, addr += PAGE_SIZE, ((addr < end) && !ret));
89 return ret;
90}
91
92static inline int update_pmd_range(pud_t *pud, unsigned long addr,
93 unsigned long end,
94 struct vm_ops *ops)
95{
96 pmd_t *pmd;
97 unsigned long next;
98 int ret = 0;
99
100 pmd = pmd_offset(pud, addr);
101 do {
102 next = pmd_addr_end(addr, end);
103 if (!pmd_present(*pmd)) {
104 if (pmd_needsync(*pmd)) {
105 ret = ops->unmap(ops->mm_idp, addr,
106 next - addr);
107 pmd_mkuptodate(*pmd);
108 }
109 }
110 else ret = update_pte_range(pmd, addr, next, ops);
111 } while (pmd++, addr = next, ((addr < end) && !ret));
112 return ret;
113}
114
115static inline int update_pud_range(p4d_t *p4d, unsigned long addr,
116 unsigned long end,
117 struct vm_ops *ops)
118{
119 pud_t *pud;
120 unsigned long next;
121 int ret = 0;
122
123 pud = pud_offset(p4d, addr);
124 do {
125 next = pud_addr_end(addr, end);
126 if (!pud_present(*pud)) {
127 if (pud_needsync(*pud)) {
128 ret = ops->unmap(ops->mm_idp, addr,
129 next - addr);
130 pud_mkuptodate(*pud);
131 }
132 }
133 else ret = update_pmd_range(pud, addr, next, ops);
134 } while (pud++, addr = next, ((addr < end) && !ret));
135 return ret;
136}
137
138static inline int update_p4d_range(pgd_t *pgd, unsigned long addr,
139 unsigned long end,
140 struct vm_ops *ops)
141{
142 p4d_t *p4d;
143 unsigned long next;
144 int ret = 0;
145
146 p4d = p4d_offset(pgd, addr);
147 do {
148 next = p4d_addr_end(addr, end);
149 if (!p4d_present(*p4d)) {
150 if (p4d_needsync(*p4d)) {
151 ret = ops->unmap(ops->mm_idp, addr,
152 next - addr);
153 p4d_mkuptodate(*p4d);
154 }
155 } else
156 ret = update_pud_range(p4d, addr, next, ops);
157 } while (p4d++, addr = next, ((addr < end) && !ret));
158 return ret;
159}
160
161int um_tlb_sync(struct mm_struct *mm)
162{
163 pgd_t *pgd;
164 struct vm_ops ops;
165 unsigned long addr = mm->context.sync_tlb_range_from, next;
166 int ret = 0;
167
168 if (mm->context.sync_tlb_range_to == 0)
169 return 0;
170
171 ops.mm_idp = &mm->context.id;
172 if (mm == &init_mm) {
173 ops.mmap = kern_map;
174 ops.unmap = kern_unmap;
175 } else {
176 ops.mmap = map;
177 ops.unmap = unmap;
178 }
179
180 pgd = pgd_offset(mm, addr);
181 do {
182 next = pgd_addr_end(addr, mm->context.sync_tlb_range_to);
183 if (!pgd_present(*pgd)) {
184 if (pgd_needsync(*pgd)) {
185 ret = ops.unmap(ops.mm_idp, addr,
186 next - addr);
187 pgd_mkuptodate(*pgd);
188 }
189 } else
190 ret = update_p4d_range(pgd, addr, next, &ops);
191 } while (pgd++, addr = next,
192 ((addr < mm->context.sync_tlb_range_to) && !ret));
193
194 if (ret == -ENOMEM)
195 report_enomem();
196
197 mm->context.sync_tlb_range_from = 0;
198 mm->context.sync_tlb_range_to = 0;
199
200 return ret;
201}
202
203void flush_tlb_all(void)
204{
205 /*
206 * Don't bother flushing if this address space is about to be
207 * destroyed.
208 */
209 if (atomic_read(¤t->mm->mm_users) == 0)
210 return;
211
212 flush_tlb_mm(current->mm);
213}
214
215void flush_tlb_mm(struct mm_struct *mm)
216{
217 struct vm_area_struct *vma;
218 VMA_ITERATOR(vmi, mm, 0);
219
220 for_each_vma(vmi, vma)
221 um_tlb_mark_sync(mm, vma->vm_start, vma->vm_end);
222}