1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2006 Peter Wemm
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD: releng/12.0/sys/amd64/amd64/minidump_machdep.c 333145 2018-05-01 17:32:43Z markj $");
31
32 #include "opt_pmap.h"
33 #include "opt_watchdog.h"
34
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/conf.h>
38 #include <sys/cons.h>
39 #include <sys/kernel.h>
40 #include <sys/kerneldump.h>
41 #include <sys/msgbuf.h>
42 #include <sys/sysctl.h>
43 #include <sys/watchdog.h>
44 #include <sys/vmmeter.h>
45 #include <vm/vm.h>
46 #include <vm/vm_param.h>
47 #include <vm/vm_page.h>
48 #include <vm/vm_phys.h>
49 #include <vm/pmap.h>
50 #include <machine/atomic.h>
51 #include <machine/elf.h>
52 #include <machine/md_var.h>
53 #include <machine/minidump.h>
54
55 CTASSERT(sizeof(struct kerneldumpheader) == 512);
56
57 uint64_t *vm_page_dump;
58 int vm_page_dump_size;
59
60 static struct kerneldumpheader kdh;
61
62 /* Handle chunked writes. */
63 static size_t fragsz;
64 static void *dump_va;
65 static size_t counter, progress, dumpsize, wdog_next;
66
67 CTASSERT(sizeof(*vm_page_dump) == 8);
68 static int dump_retry_count = 5;
69 SYSCTL_INT(_machdep, OID_AUTO, dump_retry_count, CTLFLAG_RWTUN,
70 &dump_retry_count, 0, "Number of times dump has to retry before bailing out");
71
72 static int
73 is_dumpable(vm_paddr_t pa)
74 {
75 vm_page_t m;
76 int i;
77
78 if ((m = vm_phys_paddr_to_vm_page(pa)) != NULL)
79 return ((m->flags & PG_NODUMP) == 0);
80 for (i = 0; dump_avail[i] != 0 || dump_avail[i + 1] != 0; i += 2) {
81 if (pa >= dump_avail[i] && pa < dump_avail[i + 1])
82 return (1);
83 }
84 return (0);
85 }
86
87 #define PG2MB(pgs) (((pgs) + (1 << 8) - 1) >> 8)
88
89 static int
90 blk_flush(struct dumperinfo *di)
91 {
92 int error;
93
94 if (fragsz == 0)
95 return (0);
96
97 error = dump_append(di, dump_va, 0, fragsz);
98 fragsz = 0;
99 return (error);
100 }
101
102 static struct {
103 int min_per;
104 int max_per;
105 int visited;
106 } progress_track[10] = {
107 { 0, 10, 0},
108 { 10, 20, 0},
109 { 20, 30, 0},
110 { 30, 40, 0},
111 { 40, 50, 0},
112 { 50, 60, 0},
113 { 60, 70, 0},
114 { 70, 80, 0},
115 { 80, 90, 0},
116 { 90, 100, 0}
117 };
118
119 static void
120 report_progress(size_t progress, size_t dumpsize)
121 {
122 int sofar, i;
123
124 sofar = 100 - ((progress * 100) / dumpsize);
125 for (i = 0; i < nitems(progress_track); i++) {
126 if (sofar < progress_track[i].min_per ||
127 sofar > progress_track[i].max_per)
128 continue;
129 if (progress_track[i].visited)
130 return;
131 progress_track[i].visited = 1;
132 printf("..%d%%", sofar);
133 return;
134 }
135 }
136
137 /* Pat the watchdog approximately every 128MB of the dump. */
138 #define WDOG_DUMP_INTERVAL (128 * 1024 * 1024)
139
140 static int
141 blk_write(struct dumperinfo *di, char *ptr, vm_paddr_t pa, size_t sz)
142 {
143 size_t len;
144 int error, i, c;
145 u_int maxdumpsz;
146
147 maxdumpsz = min(di->maxiosize, MAXDUMPPGS * PAGE_SIZE);
148 if (maxdumpsz == 0) /* seatbelt */
149 maxdumpsz = PAGE_SIZE;
150 error = 0;
151 if ((sz % PAGE_SIZE) != 0) {
152 printf("size not page aligned\n");
153 return (EINVAL);
154 }
155 if (ptr != NULL && pa != 0) {
156 printf("cant have both va and pa!\n");
157 return (EINVAL);
158 }
159 if ((((uintptr_t)pa) % PAGE_SIZE) != 0) {
160 printf("address not page aligned %p\n", ptr);
161 return (EINVAL);
162 }
163 if (ptr != NULL) {
164 /* If we're doing a virtual dump, flush any pre-existing pa pages */
165 error = blk_flush(di);
166 if (error)
167 return (error);
168 }
169 while (sz) {
170 len = maxdumpsz - fragsz;
171 if (len > sz)
172 len = sz;
173 counter += len;
174 progress -= len;
175 if (counter >> 24) {
176 report_progress(progress, dumpsize);
177 counter &= (1<<24) - 1;
178 }
179 if (progress <= wdog_next) {
180 wdog_kern_pat(WD_LASTVAL);
181 if (wdog_next > WDOG_DUMP_INTERVAL)
182 wdog_next -= WDOG_DUMP_INTERVAL;
183 else
184 wdog_next = 0;
185 }
186
187 if (ptr) {
188 error = dump_append(di, ptr, 0, len);
189 if (error)
190 return (error);
191 ptr += len;
192 sz -= len;
193 } else {
194 for (i = 0; i < len; i += PAGE_SIZE)
195 dump_va = pmap_kenter_temporary(pa + i, (i + fragsz) >> PAGE_SHIFT);
196 fragsz += len;
197 pa += len;
198 sz -= len;
199 if (fragsz == maxdumpsz) {
200 error = blk_flush(di);
201 if (error)
202 return (error);
203 }
204 }
205
206 /* Check for user abort. */
207 c = cncheckc();
208 if (c == 0x03)
209 return (ECANCELED);
210 if (c != -1)
211 printf(" (CTRL-C to abort) ");
212 }
213
214 return (0);
215 }
216
217 /* A fake page table page, to avoid having to handle both 4K and 2M pages */
218 static pd_entry_t fakepd[NPDEPG];
219
220 int
221 minidumpsys(struct dumperinfo *di)
222 {
223 uint32_t pmapsize;
224 vm_offset_t va;
225 int error;
226 uint64_t bits;
227 uint64_t *pml4, *pdp, *pd, *pt, pa;
228 int i, ii, j, k, n, bit;
229 int retry_count;
230 struct minidumphdr mdhdr;
231
232 retry_count = 0;
233 retry:
234 retry_count++;
235 counter = 0;
236 for (i = 0; i < nitems(progress_track); i++)
237 progress_track[i].visited = 0;
238 /* Walk page table pages, set bits in vm_page_dump */
239 pmapsize = 0;
240 for (va = VM_MIN_KERNEL_ADDRESS; va < MAX(KERNBASE + nkpt * NBPDR,
241 kernel_vm_end); ) {
242 /*
243 * We always write a page, even if it is zero. Each
244 * page written corresponds to 1GB of space
245 */
246 pmapsize += PAGE_SIZE;
247 ii = pmap_pml4e_index(va);
248 pml4 = (uint64_t *)PHYS_TO_DMAP(KPML4phys) + ii;
249 pdp = (uint64_t *)PHYS_TO_DMAP(*pml4 & PG_FRAME);
250 i = pmap_pdpe_index(va);
251 if ((pdp[i] & PG_V) == 0) {
252 va += NBPDP;
253 continue;
254 }
255
256 /*
257 * 1GB page is represented as 512 2MB pages in a dump.
258 */
259 if ((pdp[i] & PG_PS) != 0) {
260 va += NBPDP;
261 pa = pdp[i] & PG_PS_FRAME;
262 for (n = 0; n < NPDEPG * NPTEPG; n++) {
263 if (is_dumpable(pa))
264 dump_add_page(pa);
265 pa += PAGE_SIZE;
266 }
267 continue;
268 }
269
270 pd = (uint64_t *)PHYS_TO_DMAP(pdp[i] & PG_FRAME);
271 for (n = 0; n < NPDEPG; n++, va += NBPDR) {
272 j = pmap_pde_index(va);
273
274 if ((pd[j] & PG_V) == 0)
275 continue;
276
277 if ((pd[j] & PG_PS) != 0) {
278 /* This is an entire 2M page. */
279 pa = pd[j] & PG_PS_FRAME;
280 for (k = 0; k < NPTEPG; k++) {
281 if (is_dumpable(pa))
282 dump_add_page(pa);
283 pa += PAGE_SIZE;
284 }
285 continue;
286 }
287
288 pa = pd[j] & PG_FRAME;
289 /* set bit for this PTE page */
290 if (is_dumpable(pa))
291 dump_add_page(pa);
292 /* and for each valid page in this 2MB block */
293 pt = (uint64_t *)PHYS_TO_DMAP(pd[j] & PG_FRAME);
294 for (k = 0; k < NPTEPG; k++) {
295 if ((pt[k] & PG_V) == 0)
296 continue;
297 pa = pt[k] & PG_FRAME;
298 if (is_dumpable(pa))
299 dump_add_page(pa);
300 }
301 }
302 }
303
304 /* Calculate dump size. */
305 dumpsize = pmapsize;
306 dumpsize += round_page(msgbufp->msg_size);
307 dumpsize += round_page(vm_page_dump_size);
308 for (i = 0; i < vm_page_dump_size / sizeof(*vm_page_dump); i++) {
309 bits = vm_page_dump[i];
310 while (bits) {
311 bit = bsfq(bits);
312 pa = (((uint64_t)i * sizeof(*vm_page_dump) * NBBY) + bit) * PAGE_SIZE;
313 /* Clear out undumpable pages now if needed */
314 if (is_dumpable(pa)) {
315 dumpsize += PAGE_SIZE;
316 } else {
317 dump_drop_page(pa);
318 }
319 bits &= ~(1ul << bit);
320 }
321 }
322 dumpsize += PAGE_SIZE;
323
324 wdog_next = progress = dumpsize;
325
326 /* Initialize mdhdr */
327 bzero(&mdhdr, sizeof(mdhdr));
328 strcpy(mdhdr.magic, MINIDUMP_MAGIC);
329 mdhdr.version = MINIDUMP_VERSION;
330 mdhdr.msgbufsize = msgbufp->msg_size;
331 mdhdr.bitmapsize = vm_page_dump_size;
332 mdhdr.pmapsize = pmapsize;
333 mdhdr.kernbase = VM_MIN_KERNEL_ADDRESS;
334 mdhdr.dmapbase = DMAP_MIN_ADDRESS;
335 mdhdr.dmapend = DMAP_MAX_ADDRESS;
336
337 dump_init_header(di, &kdh, KERNELDUMPMAGIC, KERNELDUMP_AMD64_VERSION,
338 dumpsize);
339
340 error = dump_start(di, &kdh);
341 if (error != 0)
342 goto fail;
343
344 printf("Dumping %llu out of %ju MB:", (long long)dumpsize >> 20,
345 ptoa((uintmax_t)physmem) / 1048576);
346
347 /* Dump my header */
348 bzero(&fakepd, sizeof(fakepd));
349 bcopy(&mdhdr, &fakepd, sizeof(mdhdr));
350 error = blk_write(di, (char *)&fakepd, 0, PAGE_SIZE);
351 if (error)
352 goto fail;
353
354 /* Dump msgbuf up front */
355 error = blk_write(di, (char *)msgbufp->msg_ptr, 0, round_page(msgbufp->msg_size));
356 if (error)
357 goto fail;
358
359 /* Dump bitmap */
360 error = blk_write(di, (char *)vm_page_dump, 0, round_page(vm_page_dump_size));
361 if (error)
362 goto fail;
363
364 /* Dump kernel page directory pages */
365 bzero(fakepd, sizeof(fakepd));
366 for (va = VM_MIN_KERNEL_ADDRESS; va < MAX(KERNBASE + nkpt * NBPDR,
367 kernel_vm_end); va += NBPDP) {
368 ii = pmap_pml4e_index(va);
369 pml4 = (uint64_t *)PHYS_TO_DMAP(KPML4phys) + ii;
370 pdp = (uint64_t *)PHYS_TO_DMAP(*pml4 & PG_FRAME);
371 i = pmap_pdpe_index(va);
372
373 /* We always write a page, even if it is zero */
374 if ((pdp[i] & PG_V) == 0) {
375 error = blk_write(di, (char *)&fakepd, 0, PAGE_SIZE);
376 if (error)
377 goto fail;
378 /* flush, in case we reuse fakepd in the same block */
379 error = blk_flush(di);
380 if (error)
381 goto fail;
382 continue;
383 }
384
385 /* 1GB page is represented as 512 2MB pages in a dump */
386 if ((pdp[i] & PG_PS) != 0) {
387 /* PDPE and PDP have identical layout in this case */
388 fakepd[0] = pdp[i];
389 for (j = 1; j < NPDEPG; j++)
390 fakepd[j] = fakepd[j - 1] + NBPDR;
391 error = blk_write(di, (char *)&fakepd, 0, PAGE_SIZE);
392 if (error)
393 goto fail;
394 /* flush, in case we reuse fakepd in the same block */
395 error = blk_flush(di);
396 if (error)
397 goto fail;
398 bzero(fakepd, sizeof(fakepd));
399 continue;
400 }
401
402 pd = (uint64_t *)PHYS_TO_DMAP(pdp[i] & PG_FRAME);
403 error = blk_write(di, (char *)pd, 0, PAGE_SIZE);
404 if (error)
405 goto fail;
406 error = blk_flush(di);
407 if (error)
408 goto fail;
409 }
410
411 /* Dump memory chunks */
412 /* XXX cluster it up and use blk_dump() */
413 for (i = 0; i < vm_page_dump_size / sizeof(*vm_page_dump); i++) {
414 bits = vm_page_dump[i];
415 while (bits) {
416 bit = bsfq(bits);
417 pa = (((uint64_t)i * sizeof(*vm_page_dump) * NBBY) + bit) * PAGE_SIZE;
418 error = blk_write(di, 0, pa, PAGE_SIZE);
419 if (error)
420 goto fail;
421 bits &= ~(1ul << bit);
422 }
423 }
424
425 error = blk_flush(di);
426 if (error)
427 goto fail;
428
429 error = dump_finish(di, &kdh);
430 if (error != 0)
431 goto fail;
432
433 printf("\nDump complete\n");
434 return (0);
435
436 fail:
437 if (error < 0)
438 error = -error;
439
440 printf("\n");
441 if (error == ENOSPC) {
442 printf("Dump map grown while dumping. ");
443 if (retry_count < dump_retry_count) {
444 printf("Retrying...\n");
445 goto retry;
446 }
447 printf("Dump failed.\n");
448 }
449 else if (error == ECANCELED)
450 printf("Dump aborted\n");
451 else if (error == E2BIG)
452 printf("Dump failed. Partition too small.\n");
453 else
454 printf("** DUMP FAILED (ERROR %d) **\n", error);
455 return (error);
456 }
457
458 void
459 dump_add_page(vm_paddr_t pa)
460 {
461 int idx, bit;
462
463 pa >>= PAGE_SHIFT;
464 idx = pa >> 6; /* 2^6 = 64 */
465 bit = pa & 63;
466 atomic_set_long(&vm_page_dump[idx], 1ul << bit);
467 }
468
469 void
470 dump_drop_page(vm_paddr_t pa)
471 {
472 int idx, bit;
473
474 pa >>= PAGE_SHIFT;
475 idx = pa >> 6; /* 2^6 = 64 */
476 bit = pa & 63;
477 atomic_clear_long(&vm_page_dump[idx], 1ul << bit);
478 }
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