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/8.1/sys/amd64/amd64/dump_machdep.c 193066 2009-05-29 21:27:12Z jamie $");
29
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/conf.h>
33 #include <sys/cons.h>
34 #include <sys/sysctl.h>
35 #include <sys/kernel.h>
36 #include <sys/kerneldump.h>
37 #include <vm/vm.h>
38 #include <vm/pmap.h>
39 #include <machine/elf.h>
40 #include <machine/md_var.h>
41
42 CTASSERT(sizeof(struct kerneldumpheader) == 512);
43
44 int do_minidump = 1;
45 TUNABLE_INT("debug.minidump", &do_minidump);
46 SYSCTL_INT(_debug, OID_AUTO, minidump, CTLFLAG_RW, &do_minidump, 0,
47 "Enable mini crash dumps");
48
49 /*
50 * Don't touch the first SIZEOF_METADATA bytes on the dump device. This
51 * is to protect us from metadata and to protect metadata from us.
52 */
53 #define SIZEOF_METADATA (64*1024)
54
55 #define MD_ALIGN(x) (((off_t)(x) + PAGE_MASK) & ~PAGE_MASK)
56 #define DEV_ALIGN(x) (((off_t)(x) + (DEV_BSIZE-1)) & ~(DEV_BSIZE-1))
57
58 struct md_pa {
59 vm_paddr_t md_start;
60 vm_paddr_t md_size;
61 };
62
63 typedef int callback_t(struct md_pa *, int, void *);
64
65 static struct kerneldumpheader kdh;
66 static off_t dumplo, fileofs;
67
68 /* Handle buffered writes. */
69 static char buffer[DEV_BSIZE];
70 static size_t fragsz;
71
72 /* 20 phys_avail entry pairs correspond to 10 md_pa's */
73 static struct md_pa dump_map[10];
74
75 static void
76 md_pa_init(void)
77 {
78 int n, idx;
79
80 bzero(dump_map, sizeof(dump_map));
81 for (n = 0; n < sizeof(dump_map) / sizeof(dump_map[0]); n++) {
82 idx = n * 2;
83 if (dump_avail[idx] == 0 && dump_avail[idx + 1] == 0)
84 break;
85 dump_map[n].md_start = dump_avail[idx];
86 dump_map[n].md_size = dump_avail[idx + 1] - dump_avail[idx];
87 }
88 }
89
90 static struct md_pa *
91 md_pa_first(void)
92 {
93
94 return (&dump_map[0]);
95 }
96
97 static struct md_pa *
98 md_pa_next(struct md_pa *mdp)
99 {
100
101 mdp++;
102 if (mdp->md_size == 0)
103 mdp = NULL;
104 return (mdp);
105 }
106
107 static int
108 buf_write(struct dumperinfo *di, char *ptr, size_t sz)
109 {
110 size_t len;
111 int error;
112
113 while (sz) {
114 len = DEV_BSIZE - fragsz;
115 if (len > sz)
116 len = sz;
117 bcopy(ptr, buffer + fragsz, len);
118 fragsz += len;
119 ptr += len;
120 sz -= len;
121 if (fragsz == DEV_BSIZE) {
122 error = dump_write(di, buffer, 0, dumplo,
123 DEV_BSIZE);
124 if (error)
125 return error;
126 dumplo += DEV_BSIZE;
127 fragsz = 0;
128 }
129 }
130
131 return (0);
132 }
133
134 static int
135 buf_flush(struct dumperinfo *di)
136 {
137 int error;
138
139 if (fragsz == 0)
140 return (0);
141
142 error = dump_write(di, buffer, 0, dumplo, DEV_BSIZE);
143 dumplo += DEV_BSIZE;
144 fragsz = 0;
145 return (error);
146 }
147
148 #define PG2MB(pgs) ((pgs + (1 << 8) - 1) >> 8)
149
150 static int
151 cb_dumpdata(struct md_pa *mdp, int seqnr, void *arg)
152 {
153 struct dumperinfo *di = (struct dumperinfo*)arg;
154 vm_paddr_t a, pa;
155 void *va;
156 uint64_t pgs;
157 size_t counter, sz, chunk;
158 int i, c, error, twiddle;
159 u_int maxdumppgs;
160
161 error = 0; /* catch case in which chunk size is 0 */
162 counter = 0; /* Update twiddle every 16MB */
163 twiddle = 0;
164 va = 0;
165 pgs = mdp->md_size / PAGE_SIZE;
166 pa = mdp->md_start;
167 maxdumppgs = min(di->maxiosize / PAGE_SIZE, MAXDUMPPGS);
168 if (maxdumppgs == 0) /* seatbelt */
169 maxdumppgs = 1;
170
171 printf(" chunk %d: %ldMB (%ld pages)", seqnr, PG2MB(pgs), pgs);
172
173 while (pgs) {
174 chunk = pgs;
175 if (chunk > maxdumppgs)
176 chunk = maxdumppgs;
177 sz = chunk << PAGE_SHIFT;
178 counter += sz;
179 if (counter >> 24) {
180 printf(" %ld", PG2MB(pgs));
181 counter &= (1<<24) - 1;
182 }
183 for (i = 0; i < chunk; i++) {
184 a = pa + i * PAGE_SIZE;
185 va = pmap_kenter_temporary(trunc_page(a), i);
186 }
187 error = dump_write(di, va, 0, dumplo, sz);
188 if (error)
189 break;
190 dumplo += sz;
191 pgs -= chunk;
192 pa += sz;
193
194 /* Check for user abort. */
195 c = cncheckc();
196 if (c == 0x03)
197 return (ECANCELED);
198 if (c != -1)
199 printf(" (CTRL-C to abort) ");
200 }
201 printf(" ... %s\n", (error) ? "fail" : "ok");
202 return (error);
203 }
204
205 static int
206 cb_dumphdr(struct md_pa *mdp, int seqnr, void *arg)
207 {
208 struct dumperinfo *di = (struct dumperinfo*)arg;
209 Elf_Phdr phdr;
210 uint64_t size;
211 int error;
212
213 size = mdp->md_size;
214 bzero(&phdr, sizeof(phdr));
215 phdr.p_type = PT_LOAD;
216 phdr.p_flags = PF_R; /* XXX */
217 phdr.p_offset = fileofs;
218 phdr.p_vaddr = mdp->md_start;
219 phdr.p_paddr = mdp->md_start;
220 phdr.p_filesz = size;
221 phdr.p_memsz = size;
222 phdr.p_align = PAGE_SIZE;
223
224 error = buf_write(di, (char*)&phdr, sizeof(phdr));
225 fileofs += phdr.p_filesz;
226 return (error);
227 }
228
229 static int
230 cb_size(struct md_pa *mdp, int seqnr, void *arg)
231 {
232 uint64_t *sz = (uint64_t*)arg;
233
234 *sz += (uint64_t)mdp->md_size;
235 return (0);
236 }
237
238 static int
239 foreach_chunk(callback_t cb, void *arg)
240 {
241 struct md_pa *mdp;
242 int error, seqnr;
243
244 seqnr = 0;
245 mdp = md_pa_first();
246 while (mdp != NULL) {
247 error = (*cb)(mdp, seqnr++, arg);
248 if (error)
249 return (-error);
250 mdp = md_pa_next(mdp);
251 }
252 return (seqnr);
253 }
254
255 void
256 dumpsys(struct dumperinfo *di)
257 {
258 Elf_Ehdr ehdr;
259 uint64_t dumpsize;
260 off_t hdrgap;
261 size_t hdrsz;
262 int error;
263
264 if (do_minidump) {
265 minidumpsys(di);
266 return;
267 }
268 bzero(&ehdr, sizeof(ehdr));
269 ehdr.e_ident[EI_MAG0] = ELFMAG0;
270 ehdr.e_ident[EI_MAG1] = ELFMAG1;
271 ehdr.e_ident[EI_MAG2] = ELFMAG2;
272 ehdr.e_ident[EI_MAG3] = ELFMAG3;
273 ehdr.e_ident[EI_CLASS] = ELF_CLASS;
274 #if BYTE_ORDER == LITTLE_ENDIAN
275 ehdr.e_ident[EI_DATA] = ELFDATA2LSB;
276 #else
277 ehdr.e_ident[EI_DATA] = ELFDATA2MSB;
278 #endif
279 ehdr.e_ident[EI_VERSION] = EV_CURRENT;
280 ehdr.e_ident[EI_OSABI] = ELFOSABI_STANDALONE; /* XXX big picture? */
281 ehdr.e_type = ET_CORE;
282 ehdr.e_machine = EM_X86_64;
283 ehdr.e_phoff = sizeof(ehdr);
284 ehdr.e_flags = 0;
285 ehdr.e_ehsize = sizeof(ehdr);
286 ehdr.e_phentsize = sizeof(Elf_Phdr);
287 ehdr.e_shentsize = sizeof(Elf_Shdr);
288
289 md_pa_init();
290
291 /* Calculate dump size. */
292 dumpsize = 0L;
293 ehdr.e_phnum = foreach_chunk(cb_size, &dumpsize);
294 hdrsz = ehdr.e_phoff + ehdr.e_phnum * ehdr.e_phentsize;
295 fileofs = MD_ALIGN(hdrsz);
296 dumpsize += fileofs;
297 hdrgap = fileofs - DEV_ALIGN(hdrsz);
298
299 /* Determine dump offset on device. */
300 if (di->mediasize < SIZEOF_METADATA + dumpsize + sizeof(kdh) * 2) {
301 error = ENOSPC;
302 goto fail;
303 }
304 dumplo = di->mediaoffset + di->mediasize - dumpsize;
305 dumplo -= sizeof(kdh) * 2;
306
307 mkdumpheader(&kdh, KERNELDUMPMAGIC, KERNELDUMP_AMD64_VERSION, dumpsize, di->blocksize);
308
309 printf("Dumping %llu MB (%d chunks)\n", (long long)dumpsize >> 20,
310 ehdr.e_phnum);
311
312 /* Dump leader */
313 error = dump_write(di, &kdh, 0, dumplo, sizeof(kdh));
314 if (error)
315 goto fail;
316 dumplo += sizeof(kdh);
317
318 /* Dump ELF header */
319 error = buf_write(di, (char*)&ehdr, sizeof(ehdr));
320 if (error)
321 goto fail;
322
323 /* Dump program headers */
324 error = foreach_chunk(cb_dumphdr, di);
325 if (error < 0)
326 goto fail;
327 buf_flush(di);
328
329 /*
330 * All headers are written using blocked I/O, so we know the
331 * current offset is (still) block aligned. Skip the alignement
332 * in the file to have the segment contents aligned at page
333 * boundary. We cannot use MD_ALIGN on dumplo, because we don't
334 * care and may very well be unaligned within the dump device.
335 */
336 dumplo += hdrgap;
337
338 /* Dump memory chunks (updates dumplo) */
339 error = foreach_chunk(cb_dumpdata, di);
340 if (error < 0)
341 goto fail;
342
343 /* Dump trailer */
344 error = dump_write(di, &kdh, 0, dumplo, sizeof(kdh));
345 if (error)
346 goto fail;
347
348 /* Signal completion, signoff and exit stage left. */
349 dump_write(di, NULL, 0, 0, 0);
350 printf("\nDump complete\n");
351 return;
352
353 fail:
354 if (error < 0)
355 error = -error;
356
357 if (error == ECANCELED)
358 printf("\nDump aborted\n");
359 else if (error == ENOSPC)
360 printf("\nDump failed. Partition too small.\n");
361 else
362 printf("\n** DUMP FAILED (ERROR %d) **\n", error);
363 }
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