1 /*-
2 * Copyright (c) 2002 Marcel Moolenaar
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD: releng/10.2/sys/x86/x86/dump_machdep.c 236503 2012-06-03 08:01:12Z avg $");
29
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/sysctl.h>
37 #include <sys/kernel.h>
38 #include <sys/kerneldump.h>
39 #include <sys/watchdog.h>
40 #include <vm/vm.h>
41 #include <vm/pmap.h>
42 #include <machine/elf.h>
43 #include <machine/md_var.h>
44
45 #ifdef __amd64__
46 #define KERNELDUMP_VERSION KERNELDUMP_AMD64_VERSION
47 #define EM_VALUE EM_X86_64
48 #else
49 #define KERNELDUMP_VERSION KERNELDUMP_I386_VERSION
50 #define EM_VALUE EM_386
51 #endif
52
53 CTASSERT(sizeof(struct kerneldumpheader) == 512);
54
55 int do_minidump = 1;
56 TUNABLE_INT("debug.minidump", &do_minidump);
57 SYSCTL_INT(_debug, OID_AUTO, minidump, CTLFLAG_RW, &do_minidump, 0,
58 "Enable mini crash dumps");
59
60 /*
61 * Don't touch the first SIZEOF_METADATA bytes on the dump device. This
62 * is to protect us from metadata and to protect metadata from us.
63 */
64 #define SIZEOF_METADATA (64*1024)
65
66 #define MD_ALIGN(x) (((off_t)(x) + PAGE_MASK) & ~PAGE_MASK)
67 #define DEV_ALIGN(x) (((off_t)(x) + (DEV_BSIZE-1)) & ~(DEV_BSIZE-1))
68
69 struct md_pa {
70 vm_paddr_t md_start;
71 vm_paddr_t md_size;
72 };
73
74 typedef int callback_t(struct md_pa *, int, void *);
75
76 static struct kerneldumpheader kdh;
77 static off_t dumplo, fileofs;
78
79 /* Handle buffered writes. */
80 static char buffer[DEV_BSIZE];
81 static size_t fragsz;
82
83 /* 20 phys_avail entry pairs correspond to 10 md_pa's */
84 static struct md_pa dump_map[10];
85
86 static void
87 md_pa_init(void)
88 {
89 int n, idx;
90
91 bzero(dump_map, sizeof(dump_map));
92 for (n = 0; n < sizeof(dump_map) / sizeof(dump_map[0]); n++) {
93 idx = n * 2;
94 if (dump_avail[idx] == 0 && dump_avail[idx + 1] == 0)
95 break;
96 dump_map[n].md_start = dump_avail[idx];
97 dump_map[n].md_size = dump_avail[idx + 1] - dump_avail[idx];
98 }
99 }
100
101 static struct md_pa *
102 md_pa_first(void)
103 {
104
105 return (&dump_map[0]);
106 }
107
108 static struct md_pa *
109 md_pa_next(struct md_pa *mdp)
110 {
111
112 mdp++;
113 if (mdp->md_size == 0)
114 mdp = NULL;
115 return (mdp);
116 }
117
118 static int
119 buf_write(struct dumperinfo *di, char *ptr, size_t sz)
120 {
121 size_t len;
122 int error;
123
124 while (sz) {
125 len = DEV_BSIZE - fragsz;
126 if (len > sz)
127 len = sz;
128 bcopy(ptr, buffer + fragsz, len);
129 fragsz += len;
130 ptr += len;
131 sz -= len;
132 if (fragsz == DEV_BSIZE) {
133 error = dump_write(di, buffer, 0, dumplo,
134 DEV_BSIZE);
135 if (error)
136 return error;
137 dumplo += DEV_BSIZE;
138 fragsz = 0;
139 }
140 }
141
142 return (0);
143 }
144
145 static int
146 buf_flush(struct dumperinfo *di)
147 {
148 int error;
149
150 if (fragsz == 0)
151 return (0);
152
153 error = dump_write(di, buffer, 0, dumplo, DEV_BSIZE);
154 dumplo += DEV_BSIZE;
155 fragsz = 0;
156 return (error);
157 }
158
159 #define PG2MB(pgs) ((pgs + (1 << 8) - 1) >> 8)
160
161 static int
162 cb_dumpdata(struct md_pa *mdp, int seqnr, void *arg)
163 {
164 struct dumperinfo *di = (struct dumperinfo*)arg;
165 vm_paddr_t a, pa;
166 void *va;
167 uint64_t pgs;
168 size_t counter, sz, chunk;
169 int i, c, error, twiddle;
170 u_int maxdumppgs;
171
172 error = 0; /* catch case in which chunk size is 0 */
173 counter = 0; /* Update twiddle every 16MB */
174 twiddle = 0;
175 va = 0;
176 pgs = mdp->md_size / PAGE_SIZE;
177 pa = mdp->md_start;
178 maxdumppgs = min(di->maxiosize / PAGE_SIZE, MAXDUMPPGS);
179 if (maxdumppgs == 0) /* seatbelt */
180 maxdumppgs = 1;
181
182 printf(" chunk %d: %juMB (%ju pages)", seqnr, (uintmax_t)PG2MB(pgs),
183 (uintmax_t)pgs);
184
185 while (pgs) {
186 chunk = pgs;
187 if (chunk > maxdumppgs)
188 chunk = maxdumppgs;
189 sz = chunk << PAGE_SHIFT;
190 counter += sz;
191 if (counter >> 24) {
192 printf(" %ju", (uintmax_t)PG2MB(pgs));
193 counter &= (1<<24) - 1;
194 }
195 for (i = 0; i < chunk; i++) {
196 a = pa + i * PAGE_SIZE;
197 va = pmap_kenter_temporary(trunc_page(a), i);
198 }
199
200 wdog_kern_pat(WD_LASTVAL);
201
202 error = dump_write(di, va, 0, dumplo, sz);
203 if (error)
204 break;
205 dumplo += sz;
206 pgs -= chunk;
207 pa += sz;
208
209 /* Check for user abort. */
210 c = cncheckc();
211 if (c == 0x03)
212 return (ECANCELED);
213 if (c != -1)
214 printf(" (CTRL-C to abort) ");
215 }
216 printf(" ... %s\n", (error) ? "fail" : "ok");
217 return (error);
218 }
219
220 static int
221 cb_dumphdr(struct md_pa *mdp, int seqnr, void *arg)
222 {
223 struct dumperinfo *di = (struct dumperinfo*)arg;
224 Elf_Phdr phdr;
225 uint64_t size;
226 int error;
227
228 size = mdp->md_size;
229 bzero(&phdr, sizeof(phdr));
230 phdr.p_type = PT_LOAD;
231 phdr.p_flags = PF_R; /* XXX */
232 phdr.p_offset = fileofs;
233 phdr.p_vaddr = mdp->md_start;
234 phdr.p_paddr = mdp->md_start;
235 phdr.p_filesz = size;
236 phdr.p_memsz = size;
237 phdr.p_align = PAGE_SIZE;
238
239 error = buf_write(di, (char*)&phdr, sizeof(phdr));
240 fileofs += phdr.p_filesz;
241 return (error);
242 }
243
244 static int
245 cb_size(struct md_pa *mdp, int seqnr, void *arg)
246 {
247 uint64_t *sz = (uint64_t*)arg;
248
249 *sz += (uint64_t)mdp->md_size;
250 return (0);
251 }
252
253 static int
254 foreach_chunk(callback_t cb, void *arg)
255 {
256 struct md_pa *mdp;
257 int error, seqnr;
258
259 seqnr = 0;
260 mdp = md_pa_first();
261 while (mdp != NULL) {
262 error = (*cb)(mdp, seqnr++, arg);
263 if (error)
264 return (-error);
265 mdp = md_pa_next(mdp);
266 }
267 return (seqnr);
268 }
269
270 void
271 dumpsys(struct dumperinfo *di)
272 {
273 Elf_Ehdr ehdr;
274 uint64_t dumpsize;
275 off_t hdrgap;
276 size_t hdrsz;
277 int error;
278
279 if (do_minidump) {
280 minidumpsys(di);
281 return;
282 }
283 bzero(&ehdr, sizeof(ehdr));
284 ehdr.e_ident[EI_MAG0] = ELFMAG0;
285 ehdr.e_ident[EI_MAG1] = ELFMAG1;
286 ehdr.e_ident[EI_MAG2] = ELFMAG2;
287 ehdr.e_ident[EI_MAG3] = ELFMAG3;
288 ehdr.e_ident[EI_CLASS] = ELF_CLASS;
289 #if BYTE_ORDER == LITTLE_ENDIAN
290 ehdr.e_ident[EI_DATA] = ELFDATA2LSB;
291 #else
292 ehdr.e_ident[EI_DATA] = ELFDATA2MSB;
293 #endif
294 ehdr.e_ident[EI_VERSION] = EV_CURRENT;
295 ehdr.e_ident[EI_OSABI] = ELFOSABI_STANDALONE; /* XXX big picture? */
296 ehdr.e_type = ET_CORE;
297 ehdr.e_machine = EM_VALUE;
298 ehdr.e_phoff = sizeof(ehdr);
299 ehdr.e_flags = 0;
300 ehdr.e_ehsize = sizeof(ehdr);
301 ehdr.e_phentsize = sizeof(Elf_Phdr);
302 ehdr.e_shentsize = sizeof(Elf_Shdr);
303
304 md_pa_init();
305
306 /* Calculate dump size. */
307 dumpsize = 0L;
308 ehdr.e_phnum = foreach_chunk(cb_size, &dumpsize);
309 hdrsz = ehdr.e_phoff + ehdr.e_phnum * ehdr.e_phentsize;
310 fileofs = MD_ALIGN(hdrsz);
311 dumpsize += fileofs;
312 hdrgap = fileofs - DEV_ALIGN(hdrsz);
313
314 /* Determine dump offset on device. */
315 if (di->mediasize < SIZEOF_METADATA + dumpsize + sizeof(kdh) * 2) {
316 error = ENOSPC;
317 goto fail;
318 }
319 dumplo = di->mediaoffset + di->mediasize - dumpsize;
320 dumplo -= sizeof(kdh) * 2;
321
322 mkdumpheader(&kdh, KERNELDUMPMAGIC, KERNELDUMP_VERSION, dumpsize,
323 di->blocksize);
324
325 printf("Dumping %llu MB (%d chunks)\n", (long long)dumpsize >> 20,
326 ehdr.e_phnum);
327
328 /* Dump leader */
329 error = dump_write(di, &kdh, 0, dumplo, sizeof(kdh));
330 if (error)
331 goto fail;
332 dumplo += sizeof(kdh);
333
334 /* Dump ELF header */
335 error = buf_write(di, (char*)&ehdr, sizeof(ehdr));
336 if (error)
337 goto fail;
338
339 /* Dump program headers */
340 error = foreach_chunk(cb_dumphdr, di);
341 if (error < 0)
342 goto fail;
343 buf_flush(di);
344
345 /*
346 * All headers are written using blocked I/O, so we know the
347 * current offset is (still) block aligned. Skip the alignement
348 * in the file to have the segment contents aligned at page
349 * boundary. We cannot use MD_ALIGN on dumplo, because we don't
350 * care and may very well be unaligned within the dump device.
351 */
352 dumplo += hdrgap;
353
354 /* Dump memory chunks (updates dumplo) */
355 error = foreach_chunk(cb_dumpdata, di);
356 if (error < 0)
357 goto fail;
358
359 /* Dump trailer */
360 error = dump_write(di, &kdh, 0, dumplo, sizeof(kdh));
361 if (error)
362 goto fail;
363
364 /* Signal completion, signoff and exit stage left. */
365 dump_write(di, NULL, 0, 0, 0);
366 printf("\nDump complete\n");
367 return;
368
369 fail:
370 if (error < 0)
371 error = -error;
372
373 if (error == ECANCELED)
374 printf("\nDump aborted\n");
375 else if (error == ENOSPC)
376 printf("\nDump failed. Partition too small.\n");
377 else
378 printf("\n** DUMP FAILED (ERROR %d) **\n", error);
379 }
Cache object: f85fb833042f5db25f53f590381a4dd3
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