2 * SPDX-License-Identifier: BSD-2-Clause
4 * Copyright (c) 2006 Peter Wemm
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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.
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.
29 #include <sys/cdefs.h>
30 #include "opt_watchdog.h"
32 #include <sys/param.h>
33 #include <sys/systm.h>
36 #include <sys/kernel.h>
37 #include <sys/kerneldump.h>
38 #include <sys/msgbuf.h>
39 #include <sys/watchdog.h>
41 #include <vm/vm_param.h>
42 #include <vm/vm_page.h>
43 #include <vm/vm_phys.h>
44 #include <vm/vm_dumpset.h>
46 #include <machine/atomic.h>
47 #include <machine/elf.h>
48 #include <machine/md_var.h>
49 #include <machine/minidump.h>
51 CTASSERT(sizeof(struct kerneldumpheader) == 512);
53 #define MD_ALIGN(x) (((off_t)(x) + PAGE_MASK) & ~PAGE_MASK)
54 #define DEV_ALIGN(x) roundup2((off_t)(x), DEV_BSIZE)
56 static struct kerneldumpheader kdh;
58 /* Handle chunked writes. */
63 blk_flush(struct dumperinfo *di)
70 error = dump_append(di, dump_va, fragsz);
76 blk_write(struct dumperinfo *di, char *ptr, vm_paddr_t pa, size_t sz)
82 maxdumpsz = min(di->maxiosize, MAXDUMPPGS * PAGE_SIZE);
83 if (maxdumpsz == 0) /* seatbelt */
84 maxdumpsz = PAGE_SIZE;
86 if ((sz % PAGE_SIZE) != 0) {
87 printf("size not page aligned\n");
90 if (ptr != NULL && pa != 0) {
91 printf("cant have both va and pa!\n");
94 if (pa != 0 && (((uintptr_t)ptr) % PAGE_SIZE) != 0) {
95 printf("address not page aligned\n");
99 /* If we're doing a virtual dump, flush any pre-existing pa pages */
100 error = blk_flush(di);
105 len = maxdumpsz - fragsz;
109 dumpsys_pb_progress(len);
110 wdog_kern_pat(WD_LASTVAL);
113 error = dump_append(di, ptr, len);
119 for (i = 0; i < len; i += PAGE_SIZE)
120 dump_va = pmap_kenter_temporary(pa + i, (i + fragsz) >> PAGE_SHIFT);
124 if (fragsz == maxdumpsz) {
125 error = blk_flush(di);
131 /* Check for user abort. */
136 printf(" (CTRL-C to abort) ");
142 /* A fake page table page, to avoid having to handle both 4K and 2M pages */
143 static pt_entry_t fakept[NPTEPG];
146 #define cpu_minidumpsys cpu_minidumpsys_pae
147 #define IdlePTD IdlePTD_pae
149 #define cpu_minidumpsys cpu_minidumpsys_nopae
150 #define IdlePTD IdlePTD_nopae
154 cpu_minidumpsys(struct dumperinfo *di, const struct minidumpstate *state)
158 vm_offset_t va, kva_end;
164 struct minidumphdr mdhdr;
167 /* Snapshot the KVA upper bound in case it grows. */
168 kva_end = kernel_vm_end;
171 * Walk the kernel page table pages, setting the active entries in the
174 * NB: for a live dump, we may be racing with updates to the page
175 * tables, so care must be taken to read each entry only once.
178 for (va = KERNBASE; va < kva_end; va += NBPDR) {
180 * We always write a page, even if it is zero. Each
181 * page written corresponds to 2MB of space
183 ptesize += PAGE_SIZE;
184 pd = IdlePTD; /* always mapped! */
185 pde = pte_load(&pd[va >> PDRSHIFT]);
186 if ((pde & (PG_PS | PG_V)) == (PG_PS | PG_V)) {
187 /* This is an entire 2M page. */
188 pa = pde & PG_PS_FRAME;
189 for (k = 0; k < NPTEPG; k++) {
190 if (vm_phys_is_dumpable(pa))
191 vm_page_dump_add(state->dump_bitset,
197 if ((pde & PG_V) == PG_V) {
198 /* set bit for each valid page in this 2MB block */
199 pt = pmap_kenter_temporary(pde & PG_FRAME, 0);
200 for (k = 0; k < NPTEPG; k++) {
201 pte = pte_load(&pt[k]);
202 if ((pte & PG_V) == PG_V) {
204 if (vm_phys_is_dumpable(pa))
206 state->dump_bitset, pa);
210 /* nothing, we're going to dump a null page */
214 /* Calculate dump size. */
215 mbp = state->msgbufp;
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 (vm_phys_is_dumpable(pa)) {
223 dumpsize += PAGE_SIZE;
225 vm_page_dump_drop(state->dump_bitset, pa);
228 dumpsize += PAGE_SIZE;
230 dumpsys_pb_init(dumpsize);
232 /* Initialize mdhdr */
233 bzero(&mdhdr, sizeof(mdhdr));
234 strcpy(mdhdr.magic, MINIDUMP_MAGIC);
235 mdhdr.version = MINIDUMP_VERSION;
236 mdhdr.msgbufsize = mbp->msg_size;
237 mdhdr.bitmapsize = round_page(BITSET_SIZE(vm_page_dump_pages));
238 mdhdr.ptesize = ptesize;
239 mdhdr.kernbase = KERNBASE;
240 mdhdr.paemode = pae_mode;
241 mdhdr.dumpavailsize = round_page(sizeof(dump_avail));
243 dump_init_header(di, &kdh, KERNELDUMPMAGIC, KERNELDUMP_I386_VERSION,
246 error = dump_start(di, &kdh);
250 printf("Physical memory: %ju MB\n", ptoa((uintmax_t)physmem) / 1048576);
251 printf("Dumping %llu MB:", (long long)dumpsize >> 20);
254 bzero(&fakept, sizeof(fakept));
255 bcopy(&mdhdr, &fakept, sizeof(mdhdr));
256 error = blk_write(di, (char *)&fakept, 0, PAGE_SIZE);
260 /* Dump msgbuf up front */
261 error = blk_write(di, (char *)mbp->msg_ptr, 0,
262 round_page(mbp->msg_size));
266 /* Dump dump_avail */
267 _Static_assert(sizeof(dump_avail) <= sizeof(fakept),
268 "Large dump_avail not handled");
269 bzero(fakept, sizeof(fakept));
270 memcpy(fakept, dump_avail, sizeof(dump_avail));
271 error = blk_write(di, (char *)&fakept, 0, PAGE_SIZE);
276 error = blk_write(di, (char *)vm_page_dump, 0,
277 round_page(BITSET_SIZE(vm_page_dump_pages)));
281 /* Dump kernel page table pages */
282 for (va = KERNBASE; va < kva_end; va += NBPDR) {
283 /* We always write a page, even if it is zero */
284 pd = IdlePTD; /* always mapped! */
285 pde = pte_load(&pd[va >> PDRSHIFT]);
286 if ((pde & (PG_PS | PG_V)) == (PG_PS | PG_V)) {
287 /* This is a single 2M block. Generate a fake PTP */
288 pa = pde & PG_PS_FRAME;
289 for (k = 0; k < NPTEPG; k++) {
290 fakept[k] = (pa + (k * PAGE_SIZE)) | PG_V | PG_RW | PG_A | PG_M;
292 error = blk_write(di, (char *)&fakept, 0, PAGE_SIZE);
295 /* flush, in case we reuse fakept in the same block */
296 error = blk_flush(di);
301 if ((pde & PG_V) == PG_V) {
303 error = blk_write(di, 0, pa, PAGE_SIZE);
307 bzero(fakept, sizeof(fakept));
308 error = blk_write(di, (char *)&fakept, 0, PAGE_SIZE);
311 /* flush, in case we reuse fakept in the same block */
312 error = blk_flush(di);
318 /* Dump memory chunks */
319 VM_PAGE_DUMP_FOREACH(state->dump_bitset, pa) {
320 error = blk_write(di, 0, pa, PAGE_SIZE);
325 error = blk_flush(di);
329 error = dump_finish(di, &kdh);
333 printf("\nDump complete\n");
340 if (error == ECANCELED)
341 printf("\nDump aborted\n");
342 else if (error == E2BIG || error == ENOSPC) {
343 printf("\nDump failed. Partition too small (about %lluMB were "
344 "needed this time).\n", (long long)dumpsize >> 20);
346 printf("\n** DUMP FAILED (ERROR %d) **\n", error);