1 /*-
2 * Copyright (c) 2006 Peter Wemm
3 * Copyright (c) 2015 The FreeBSD Foundation
4 * All rights reserved.
5 * Copyright (c) 2019 Mitchell Horne
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 #include "opt_watchdog.h"
31
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/conf.h>
35 #include <sys/cons.h>
36 #include <sys/kernel.h>
37 #include <sys/kerneldump.h>
38 #include <sys/msgbuf.h>
39 #include <sys/watchdog.h>
40 #include <sys/vmmeter.h>
41
42 #include <vm/vm.h>
43 #include <vm/vm_param.h>
44 #include <vm/vm_page.h>
45 #include <vm/vm_phys.h>
46 #include <vm/vm_dumpset.h>
47 #include <vm/pmap.h>
48
49 #include <machine/atomic.h>
50 #include <machine/elf.h>
51 #include <machine/md_var.h>
52 #include <machine/minidump.h>
53
54 CTASSERT(sizeof(struct kerneldumpheader) == 512);
55
56 static struct kerneldumpheader kdh;
57
58 /* Handle chunked writes. */
59 static size_t fragsz;
60 static void *dump_va;
61 static size_t dumpsize;
62
63 static uint64_t tmpbuffer[PAGE_SIZE / sizeof(uint64_t)];
64
65 static int
blk_flush(struct dumperinfo * di)66 blk_flush(struct dumperinfo *di)
67 {
68 int error;
69
70 if (fragsz == 0)
71 return (0);
72
73 error = dump_append(di, dump_va, fragsz);
74 fragsz = 0;
75 return (error);
76 }
77
78 /*
79 * Write a block of data to the dump file.
80 *
81 * Caller can provide data through a pointer or by specifying its
82 * physical address.
83 *
84 * XXX writes using pa should be no larger than PAGE_SIZE.
85 */
86 static int
blk_write(struct dumperinfo * di,char * ptr,vm_paddr_t pa,size_t sz)87 blk_write(struct dumperinfo *di, char *ptr, vm_paddr_t pa, size_t sz)
88 {
89 size_t len;
90 int error, c;
91 u_int maxdumpsz;
92
93 maxdumpsz = min(di->maxiosize, MAXDUMPPGS * PAGE_SIZE);
94 if (maxdumpsz == 0) /* seatbelt */
95 maxdumpsz = PAGE_SIZE;
96 error = 0;
97 if ((sz % PAGE_SIZE) != 0) {
98 printf("size not page aligned\n");
99 return (EINVAL);
100 }
101 if (ptr != NULL && pa != 0) {
102 printf("cant have both va and pa!\n");
103 return (EINVAL);
104 }
105 if ((((uintptr_t)pa) % PAGE_SIZE) != 0) {
106 printf("address not page aligned %#lx\n", (uintptr_t)pa);
107 return (EINVAL);
108 }
109 if (ptr != NULL) {
110 /*
111 * If we're doing a virtual dump, flush any
112 * pre-existing pa pages.
113 */
114 error = blk_flush(di);
115 if (error != 0)
116 return (error);
117 }
118 while (sz) {
119 len = maxdumpsz - fragsz;
120 if (len > sz)
121 len = sz;
122
123 dumpsys_pb_progress(len);
124 wdog_kern_pat(WD_LASTVAL);
125
126 if (ptr) {
127 error = dump_append(di, ptr, len);
128 if (error != 0)
129 return (error);
130 ptr += len;
131 sz -= len;
132 } else {
133 dump_va = (void *)PHYS_TO_DMAP(pa);
134 fragsz += len;
135 pa += len;
136 sz -= len;
137 error = blk_flush(di);
138 if (error != 0)
139 return (error);
140 }
141
142 /* Check for user abort */
143 c = cncheckc();
144 if (c == 0x03)
145 return (ECANCELED);
146 if (c != -1)
147 printf(" (CTRL-C to abort) ");
148 }
149
150 return (0);
151 }
152
153 int
cpu_minidumpsys(struct dumperinfo * di,const struct minidumpstate * state)154 cpu_minidumpsys(struct dumperinfo *di, const struct minidumpstate *state)
155 {
156 pd_entry_t *l1, *l2, l2e;
157 pt_entry_t *l3, l3e;
158 struct minidumphdr mdhdr;
159 struct msgbuf *mbp;
160 uint32_t pmapsize;
161 vm_offset_t va, kva_max;
162 vm_paddr_t pa;
163 int error;
164 int i;
165 int retry_count;
166
167 retry_count = 0;
168 retry:
169 retry_count++;
170 error = 0;
171 pmapsize = 0;
172
173 /* Snapshot the KVA upper bound in case it grows. */
174 kva_max = kernel_vm_end;
175
176 /*
177 * Walk the kernel page table pages, setting the active entries in the
178 * dump bitmap.
179 *
180 * NB: for a live dump, we may be racing with updates to the page
181 * tables, so care must be taken to read each entry only once.
182 */
183 for (va = VM_MIN_KERNEL_ADDRESS; va < kva_max; va += L2_SIZE) {
184 pmapsize += PAGE_SIZE;
185 if (!pmap_get_tables(pmap_kernel(), va, &l1, &l2, &l3))
186 continue;
187
188 /* We should always be using the l2 table for kvm */
189 if (l2 == NULL)
190 continue;
191
192 /* l2 may be a superpage */
193 l2e = atomic_load_64(l2);
194 if ((l2e & PTE_RWX) != 0) {
195 pa = (l2e >> PTE_PPN1_S) << L2_SHIFT;
196 for (i = 0; i < Ln_ENTRIES; i++, pa += PAGE_SIZE) {
197 if (vm_phys_is_dumpable(pa))
198 vm_page_dump_add(state->dump_bitset,
199 pa);
200 }
201 } else {
202 for (i = 0; i < Ln_ENTRIES; i++) {
203 l3e = atomic_load_64(&l3[i]);
204 if ((l3e & PTE_V) == 0)
205 continue;
206 pa = (l3e >> PTE_PPN0_S) * PAGE_SIZE;
207 if (PHYS_IN_DMAP(pa) && vm_phys_is_dumpable(pa))
208 vm_page_dump_add(state->dump_bitset,
209 pa);
210 }
211 }
212 }
213
214 /* Calculate dump size */
215 mbp = state->msgbufp;
216 dumpsize = pmapsize;
217 dumpsize += round_page(mbp->msg_size);
218 dumpsize += round_page(sizeof(dump_avail));
219 dumpsize += round_page(BITSET_SIZE(vm_page_dump_pages));
220 VM_PAGE_DUMP_FOREACH(state->dump_bitset, pa) {
221 /* Clear out undumpable pages now if needed */
222 if (PHYS_IN_DMAP(pa) && vm_phys_is_dumpable(pa))
223 dumpsize += PAGE_SIZE;
224 else
225 vm_page_dump_drop(state->dump_bitset, pa);
226 }
227 dumpsize += PAGE_SIZE;
228
229 dumpsys_pb_init(dumpsize);
230
231 /* Initialize mdhdr */
232 bzero(&mdhdr, sizeof(mdhdr));
233 strcpy(mdhdr.magic, MINIDUMP_MAGIC);
234 mdhdr.version = MINIDUMP_VERSION;
235 mdhdr.msgbufsize = mbp->msg_size;
236 mdhdr.bitmapsize = round_page(BITSET_SIZE(vm_page_dump_pages));
237 mdhdr.pmapsize = pmapsize;
238 mdhdr.kernbase = KERNBASE;
239 mdhdr.dmapphys = DMAP_MIN_PHYSADDR;
240 mdhdr.dmapbase = DMAP_MIN_ADDRESS;
241 mdhdr.dmapend = DMAP_MAX_ADDRESS;
242 mdhdr.dumpavailsize = round_page(sizeof(dump_avail));
243
244 dump_init_header(di, &kdh, KERNELDUMPMAGIC, KERNELDUMP_RISCV_VERSION,
245 dumpsize);
246
247 error = dump_start(di, &kdh);
248 if (error != 0)
249 goto fail;
250
251 printf("Dumping %llu out of %ju MB:", (long long)dumpsize >> 20,
252 ptoa((uintmax_t)physmem) / 1048576);
253
254 /* Dump minidump header */
255 bzero(&tmpbuffer, sizeof(tmpbuffer));
256 bcopy(&mdhdr, &tmpbuffer, sizeof(mdhdr));
257 error = blk_write(di, (char *)&tmpbuffer, 0, PAGE_SIZE);
258 if (error)
259 goto fail;
260
261 /* Dump msgbuf up front */
262 error = blk_write(di, mbp->msg_ptr, 0, round_page(mbp->msg_size));
263 if (error)
264 goto fail;
265
266 /* Dump dump_avail */
267 _Static_assert(sizeof(dump_avail) <= sizeof(tmpbuffer),
268 "Large dump_avail not handled");
269 bzero(tmpbuffer, sizeof(tmpbuffer));
270 memcpy(tmpbuffer, dump_avail, sizeof(dump_avail));
271 error = blk_write(di, (char *)&tmpbuffer, 0, PAGE_SIZE);
272 if (error)
273 goto fail;
274
275 /* Dump bitmap */
276 error = blk_write(di, (char *)vm_page_dump, 0,
277 round_page(BITSET_SIZE(vm_page_dump_pages)));
278 if (error)
279 goto fail;
280
281 /* Dump kernel page directory pages */
282 bzero(&tmpbuffer, sizeof(tmpbuffer));
283 for (va = VM_MIN_KERNEL_ADDRESS; va < kva_max; va += L2_SIZE) {
284 if (!pmap_get_tables(pmap_kernel(), va, &l1, &l2, &l3)) {
285 /* We always write a page, even if it is zero */
286 error = blk_write(di, (char *)&tmpbuffer, 0, PAGE_SIZE);
287 if (error)
288 goto fail;
289 /* Flush, in case we reuse tmpbuffer in the same block */
290 error = blk_flush(di);
291 if (error)
292 goto fail;
293 continue;
294 }
295
296 l2e = atomic_load_64(l2);
297 if ((l2e & PTE_RWX) != 0) {
298 /* Generate fake l3 entries based on the l2 superpage */
299 for (i = 0; i < Ln_ENTRIES; i++) {
300 tmpbuffer[i] = (l2e | (i << PTE_PPN0_S));
301 }
302 /* We always write a page, even if it is zero */
303 error = blk_write(di, (char *)&tmpbuffer, 0, PAGE_SIZE);
304 if (error)
305 goto fail;
306 /* Flush, in case we reuse tmpbuffer in the same block */
307 error = blk_flush(di);
308 if (error)
309 goto fail;
310 bzero(&tmpbuffer, sizeof(tmpbuffer));
311 } else {
312 pa = (l2e >> PTE_PPN0_S) * PAGE_SIZE;
313
314 /*
315 * We always write a page, even if it is zero. If pa
316 * is malformed, write the zeroed tmpbuffer.
317 */
318 if (PHYS_IN_DMAP(pa) && vm_phys_is_dumpable(pa))
319 error = blk_write(di, NULL, pa, PAGE_SIZE);
320 else
321 error = blk_write(di, (char *)&tmpbuffer, 0,
322 PAGE_SIZE);
323 if (error)
324 goto fail;
325 }
326 }
327
328 /* Dump memory chunks */
329 /* XXX cluster it up and use blk_dump() */
330 VM_PAGE_DUMP_FOREACH(state->dump_bitset, pa) {
331 error = blk_write(di, 0, pa, PAGE_SIZE);
332 if (error)
333 goto fail;
334 }
335
336 error = blk_flush(di);
337 if (error)
338 goto fail;
339
340 error = dump_finish(di, &kdh);
341 if (error != 0)
342 goto fail;
343
344 printf("\nDump complete\n");
345 return (0);
346
347 fail:
348 if (error < 0)
349 error = -error;
350
351 printf("\n");
352 if (error == ENOSPC) {
353 printf("Dump map grown while dumping. ");
354 if (retry_count < 5) {
355 printf("Retrying...\n");
356 goto retry;
357 }
358 printf("Dump failed.\n");
359 }
360 else if (error == ECANCELED)
361 printf("Dump aborted\n");
362 else if (error == E2BIG) {
363 printf("Dump failed. Partition too small (about %lluMB were "
364 "needed this time).\n", (long long)dumpsize >> 20);
365 } else
366 printf("** DUMP FAILED (ERROR %d) **\n", error);
367 return (error);
368 }
369