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("$FreeBSD$"); 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 #ifdef __amd64__ 43 #define KERNELDUMP_VERSION KERNELDUMP_AMD64_VERSION 44 #define EM_VALUE EM_X86_64 45 #else 46 #define KERNELDUMP_VERSION KERNELDUMP_I386_VERSION 47 #define EM_VALUE EM_386 48 #endif 49 50 CTASSERT(sizeof(struct kerneldumpheader) == 512); 51 52 int do_minidump = 1; 53 TUNABLE_INT("debug.minidump", &do_minidump); 54 SYSCTL_INT(_debug, OID_AUTO, minidump, CTLFLAG_RW, &do_minidump, 0, 55 "Enable mini crash dumps"); 56 57 /* 58 * Don't touch the first SIZEOF_METADATA bytes on the dump device. This 59 * is to protect us from metadata and to protect metadata from us. 60 */ 61 #define SIZEOF_METADATA (64*1024) 62 63 #define MD_ALIGN(x) (((off_t)(x) + PAGE_MASK) & ~PAGE_MASK) 64 #define DEV_ALIGN(x) (((off_t)(x) + (DEV_BSIZE-1)) & ~(DEV_BSIZE-1)) 65 66 struct md_pa { 67 vm_paddr_t md_start; 68 vm_paddr_t md_size; 69 }; 70 71 typedef int callback_t(struct md_pa *, int, void *); 72 73 static struct kerneldumpheader kdh; 74 static off_t dumplo, fileofs; 75 76 /* Handle buffered writes. */ 77 static char buffer[DEV_BSIZE]; 78 static size_t fragsz; 79 80 /* 20 phys_avail entry pairs correspond to 10 md_pa's */ 81 static struct md_pa dump_map[10]; 82 83 static void 84 md_pa_init(void) 85 { 86 int n, idx; 87 88 bzero(dump_map, sizeof(dump_map)); 89 for (n = 0; n < sizeof(dump_map) / sizeof(dump_map[0]); n++) { 90 idx = n * 2; 91 if (dump_avail[idx] == 0 && dump_avail[idx + 1] == 0) 92 break; 93 dump_map[n].md_start = dump_avail[idx]; 94 dump_map[n].md_size = dump_avail[idx + 1] - dump_avail[idx]; 95 } 96 } 97 98 static struct md_pa * 99 md_pa_first(void) 100 { 101 102 return (&dump_map[0]); 103 } 104 105 static struct md_pa * 106 md_pa_next(struct md_pa *mdp) 107 { 108 109 mdp++; 110 if (mdp->md_size == 0) 111 mdp = NULL; 112 return (mdp); 113 } 114 115 static int 116 buf_write(struct dumperinfo *di, char *ptr, size_t sz) 117 { 118 size_t len; 119 int error; 120 121 while (sz) { 122 len = DEV_BSIZE - fragsz; 123 if (len > sz) 124 len = sz; 125 bcopy(ptr, buffer + fragsz, len); 126 fragsz += len; 127 ptr += len; 128 sz -= len; 129 if (fragsz == DEV_BSIZE) { 130 error = dump_write(di, buffer, 0, dumplo, 131 DEV_BSIZE); 132 if (error) 133 return error; 134 dumplo += DEV_BSIZE; 135 fragsz = 0; 136 } 137 } 138 139 return (0); 140 } 141 142 static int 143 buf_flush(struct dumperinfo *di) 144 { 145 int error; 146 147 if (fragsz == 0) 148 return (0); 149 150 error = dump_write(di, buffer, 0, dumplo, DEV_BSIZE); 151 dumplo += DEV_BSIZE; 152 fragsz = 0; 153 return (error); 154 } 155 156 #define PG2MB(pgs) ((pgs + (1 << 8) - 1) >> 8) 157 158 static int 159 cb_dumpdata(struct md_pa *mdp, int seqnr, void *arg) 160 { 161 struct dumperinfo *di = (struct dumperinfo*)arg; 162 vm_paddr_t a, pa; 163 void *va; 164 uint64_t pgs; 165 size_t counter, sz, chunk; 166 int i, c, error, twiddle; 167 u_int maxdumppgs; 168 169 error = 0; /* catch case in which chunk size is 0 */ 170 counter = 0; /* Update twiddle every 16MB */ 171 twiddle = 0; 172 va = 0; 173 pgs = mdp->md_size / PAGE_SIZE; 174 pa = mdp->md_start; 175 maxdumppgs = min(di->maxiosize / PAGE_SIZE, MAXDUMPPGS); 176 if (maxdumppgs == 0) /* seatbelt */ 177 maxdumppgs = 1; 178 179 printf(" chunk %d: %juMB (%ju pages)", seqnr, (uintmax_t)PG2MB(pgs), 180 (uintmax_t)pgs); 181 182 while (pgs) { 183 chunk = pgs; 184 if (chunk > maxdumppgs) 185 chunk = maxdumppgs; 186 sz = chunk << PAGE_SHIFT; 187 counter += sz; 188 if (counter >> 24) { 189 printf(" %ju", (uintmax_t)PG2MB(pgs)); 190 counter &= (1<<24) - 1; 191 } 192 for (i = 0; i < chunk; i++) { 193 a = pa + i * PAGE_SIZE; 194 va = pmap_kenter_temporary(trunc_page(a), i); 195 } 196 error = dump_write(di, va, 0, dumplo, sz); 197 if (error) 198 break; 199 dumplo += sz; 200 pgs -= chunk; 201 pa += sz; 202 203 /* Check for user abort. */ 204 c = cncheckc(); 205 if (c == 0x03) 206 return (ECANCELED); 207 if (c != -1) 208 printf(" (CTRL-C to abort) "); 209 } 210 printf(" ... %s\n", (error) ? "fail" : "ok"); 211 return (error); 212 } 213 214 static int 215 cb_dumphdr(struct md_pa *mdp, int seqnr, void *arg) 216 { 217 struct dumperinfo *di = (struct dumperinfo*)arg; 218 Elf_Phdr phdr; 219 uint64_t size; 220 int error; 221 222 size = mdp->md_size; 223 bzero(&phdr, sizeof(phdr)); 224 phdr.p_type = PT_LOAD; 225 phdr.p_flags = PF_R; /* XXX */ 226 phdr.p_offset = fileofs; 227 phdr.p_vaddr = mdp->md_start; 228 phdr.p_paddr = mdp->md_start; 229 phdr.p_filesz = size; 230 phdr.p_memsz = size; 231 phdr.p_align = PAGE_SIZE; 232 233 error = buf_write(di, (char*)&phdr, sizeof(phdr)); 234 fileofs += phdr.p_filesz; 235 return (error); 236 } 237 238 static int 239 cb_size(struct md_pa *mdp, int seqnr, void *arg) 240 { 241 uint64_t *sz = (uint64_t*)arg; 242 243 *sz += (uint64_t)mdp->md_size; 244 return (0); 245 } 246 247 static int 248 foreach_chunk(callback_t cb, void *arg) 249 { 250 struct md_pa *mdp; 251 int error, seqnr; 252 253 seqnr = 0; 254 mdp = md_pa_first(); 255 while (mdp != NULL) { 256 error = (*cb)(mdp, seqnr++, arg); 257 if (error) 258 return (-error); 259 mdp = md_pa_next(mdp); 260 } 261 return (seqnr); 262 } 263 264 void 265 dumpsys(struct dumperinfo *di) 266 { 267 Elf_Ehdr ehdr; 268 uint64_t dumpsize; 269 off_t hdrgap; 270 size_t hdrsz; 271 int error; 272 273 if (do_minidump) { 274 minidumpsys(di); 275 return; 276 } 277 bzero(&ehdr, sizeof(ehdr)); 278 ehdr.e_ident[EI_MAG0] = ELFMAG0; 279 ehdr.e_ident[EI_MAG1] = ELFMAG1; 280 ehdr.e_ident[EI_MAG2] = ELFMAG2; 281 ehdr.e_ident[EI_MAG3] = ELFMAG3; 282 ehdr.e_ident[EI_CLASS] = ELF_CLASS; 283 #if BYTE_ORDER == LITTLE_ENDIAN 284 ehdr.e_ident[EI_DATA] = ELFDATA2LSB; 285 #else 286 ehdr.e_ident[EI_DATA] = ELFDATA2MSB; 287 #endif 288 ehdr.e_ident[EI_VERSION] = EV_CURRENT; 289 ehdr.e_ident[EI_OSABI] = ELFOSABI_STANDALONE; /* XXX big picture? */ 290 ehdr.e_type = ET_CORE; 291 ehdr.e_machine = EM_VALUE; 292 ehdr.e_phoff = sizeof(ehdr); 293 ehdr.e_flags = 0; 294 ehdr.e_ehsize = sizeof(ehdr); 295 ehdr.e_phentsize = sizeof(Elf_Phdr); 296 ehdr.e_shentsize = sizeof(Elf_Shdr); 297 298 md_pa_init(); 299 300 /* Calculate dump size. */ 301 dumpsize = 0L; 302 ehdr.e_phnum = foreach_chunk(cb_size, &dumpsize); 303 hdrsz = ehdr.e_phoff + ehdr.e_phnum * ehdr.e_phentsize; 304 fileofs = MD_ALIGN(hdrsz); 305 dumpsize += fileofs; 306 hdrgap = fileofs - DEV_ALIGN(hdrsz); 307 308 /* Determine dump offset on device. */ 309 if (di->mediasize < SIZEOF_METADATA + dumpsize + sizeof(kdh) * 2) { 310 error = ENOSPC; 311 goto fail; 312 } 313 dumplo = di->mediaoffset + di->mediasize - dumpsize; 314 dumplo -= sizeof(kdh) * 2; 315 316 mkdumpheader(&kdh, KERNELDUMPMAGIC, KERNELDUMP_VERSION, dumpsize, 317 di->blocksize); 318 319 printf("Dumping %llu MB (%d chunks)\n", (long long)dumpsize >> 20, 320 ehdr.e_phnum); 321 322 /* Dump leader */ 323 error = dump_write(di, &kdh, 0, dumplo, sizeof(kdh)); 324 if (error) 325 goto fail; 326 dumplo += sizeof(kdh); 327 328 /* Dump ELF header */ 329 error = buf_write(di, (char*)&ehdr, sizeof(ehdr)); 330 if (error) 331 goto fail; 332 333 /* Dump program headers */ 334 error = foreach_chunk(cb_dumphdr, di); 335 if (error < 0) 336 goto fail; 337 buf_flush(di); 338 339 /* 340 * All headers are written using blocked I/O, so we know the 341 * current offset is (still) block aligned. Skip the alignement 342 * in the file to have the segment contents aligned at page 343 * boundary. We cannot use MD_ALIGN on dumplo, because we don't 344 * care and may very well be unaligned within the dump device. 345 */ 346 dumplo += hdrgap; 347 348 /* Dump memory chunks (updates dumplo) */ 349 error = foreach_chunk(cb_dumpdata, di); 350 if (error < 0) 351 goto fail; 352 353 /* Dump trailer */ 354 error = dump_write(di, &kdh, 0, dumplo, sizeof(kdh)); 355 if (error) 356 goto fail; 357 358 /* Signal completion, signoff and exit stage left. */ 359 dump_write(di, NULL, 0, 0, 0); 360 printf("\nDump complete\n"); 361 return; 362 363 fail: 364 if (error < 0) 365 error = -error; 366 367 if (error == ECANCELED) 368 printf("\nDump aborted\n"); 369 else if (error == ENOSPC) 370 printf("\nDump failed. Partition too small.\n"); 371 else 372 printf("\n** DUMP FAILED (ERROR %d) **\n", error); 373 } 374