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