1 /*- 2 * Copyright (c) 1989, 1992, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software developed by the Computer Systems 6 * Engineering group at Lawrence Berkeley Laboratory under DARPA contract 7 * BG 91-66 and contributed to Berkeley. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. All advertising materials mentioning features or use of this software 18 * must display the following acknowledgement: 19 * This product includes software developed by the University of 20 * California, Berkeley and its contributors. 21 * 4. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 */ 37 38 #if defined(LIBC_SCCS) && !defined(lint) 39 static char sccsid[] = "@(#)kvm.c 8.2 (Berkeley) 2/13/94"; 40 #endif /* LIBC_SCCS and not lint */ 41 42 #include <sys/param.h> 43 #include <sys/user.h> 44 #include <sys/proc.h> 45 #include <sys/ioctl.h> 46 #include <sys/stat.h> 47 #include <sys/sysctl.h> 48 49 #include <vm/vm.h> 50 #include <vm/vm_param.h> 51 #include <vm/swap_pager.h> 52 53 #include <machine/vmparam.h> 54 55 #include <ctype.h> 56 #include <db.h> 57 #include <fcntl.h> 58 #include <kvm.h> 59 #include <limits.h> 60 #include <nlist.h> 61 #include <paths.h> 62 #include <stdio.h> 63 #include <stdlib.h> 64 #include <string.h> 65 #include <unistd.h> 66 67 #include "kvm_private.h" 68 69 static int kvm_dbopen __P((kvm_t *, const char *)); 70 71 char * 72 kvm_geterr(kd) 73 kvm_t *kd; 74 { 75 return (kd->errbuf); 76 } 77 78 #if __STDC__ 79 #include <stdarg.h> 80 #else 81 #include <varargs.h> 82 #endif 83 84 /* 85 * Report an error using printf style arguments. "program" is kd->program 86 * on hard errors, and 0 on soft errors, so that under sun error emulation, 87 * only hard errors are printed out (otherwise, programs like gdb will 88 * generate tons of error messages when trying to access bogus pointers). 89 */ 90 void 91 #if __STDC__ 92 _kvm_err(kvm_t *kd, const char *program, const char *fmt, ...) 93 #else 94 _kvm_err(kd, program, fmt, va_alist) 95 kvm_t *kd; 96 char *program, *fmt; 97 va_dcl 98 #endif 99 { 100 va_list ap; 101 102 #ifdef __STDC__ 103 va_start(ap, fmt); 104 #else 105 va_start(ap); 106 #endif 107 if (program != NULL) { 108 (void)fprintf(stderr, "%s: ", program); 109 (void)vfprintf(stderr, fmt, ap); 110 (void)fputc('\n', stderr); 111 } else 112 (void)vsnprintf(kd->errbuf, 113 sizeof(kd->errbuf), (char *)fmt, ap); 114 115 va_end(ap); 116 } 117 118 void 119 #if __STDC__ 120 _kvm_syserr(kvm_t *kd, const char *program, const char *fmt, ...) 121 #else 122 _kvm_syserr(kd, program, fmt, va_alist) 123 kvm_t *kd; 124 char *program, *fmt; 125 va_dcl 126 #endif 127 { 128 va_list ap; 129 register int n; 130 131 #if __STDC__ 132 va_start(ap, fmt); 133 #else 134 va_start(ap); 135 #endif 136 if (program != NULL) { 137 (void)fprintf(stderr, "%s: ", program); 138 (void)vfprintf(stderr, fmt, ap); 139 (void)fprintf(stderr, ": %s\n", strerror(errno)); 140 } else { 141 register char *cp = kd->errbuf; 142 143 (void)vsnprintf(cp, sizeof(kd->errbuf), (char *)fmt, ap); 144 n = strlen(cp); 145 (void)snprintf(&cp[n], sizeof(kd->errbuf) - n, ": %s", 146 strerror(errno)); 147 } 148 va_end(ap); 149 } 150 151 void * 152 _kvm_malloc(kd, n) 153 register kvm_t *kd; 154 register size_t n; 155 { 156 void *p; 157 158 if ((p = calloc(n, sizeof(char))) == NULL) 159 _kvm_err(kd, kd->program, "can't allocate %u bytes: %s", 160 n, strerror(errno)); 161 return (p); 162 } 163 164 static kvm_t * 165 _kvm_open(kd, uf, mf, sf, flag, errout) 166 register kvm_t *kd; 167 const char *uf; 168 const char *mf; 169 const char *sf; 170 int flag; 171 char *errout; 172 { 173 struct stat st; 174 175 kd->vmfd = -1; 176 kd->pmfd = -1; 177 kd->nlfd = -1; 178 kd->vmst = 0; 179 kd->db = 0; 180 kd->procbase = 0; 181 kd->argspc = 0; 182 kd->argv = 0; 183 184 if (uf == 0) 185 uf = getbootfile(); 186 else if (strlen(uf) >= MAXPATHLEN) { 187 _kvm_err(kd, kd->program, "exec file name too long"); 188 goto failed; 189 } 190 if (flag & ~O_RDWR) { 191 _kvm_err(kd, kd->program, "bad flags arg"); 192 goto failed; 193 } 194 if (mf == 0) 195 mf = _PATH_MEM; 196 if (sf == 0) 197 sf = _PATH_DRUM; 198 199 if ((kd->pmfd = open(mf, flag, 0)) < 0) { 200 _kvm_syserr(kd, kd->program, "%s", mf); 201 goto failed; 202 } 203 if (fstat(kd->pmfd, &st) < 0) { 204 _kvm_syserr(kd, kd->program, "%s", mf); 205 goto failed; 206 } 207 if (S_ISCHR(st.st_mode)) { 208 /* 209 * If this is a character special device, then check that 210 * it's /dev/mem. If so, open kmem too. (Maybe we should 211 * make it work for either /dev/mem or /dev/kmem -- in either 212 * case you're working with a live kernel.) 213 */ 214 if (strcmp(mf, _PATH_DEVNULL) == 0) { 215 kd->vmfd = open(_PATH_DEVNULL, O_RDONLY); 216 } else if (strcmp(mf, _PATH_MEM) != 0) { 217 _kvm_err(kd, kd->program, 218 "%s: not physical memory device", mf); 219 goto failed; 220 } else { 221 if ((kd->vmfd = open(_PATH_KMEM, flag)) < 0) { 222 _kvm_syserr(kd, kd->program, "%s", _PATH_KMEM); 223 goto failed; 224 } 225 } 226 /* 227 * Open kvm nlist database. We go ahead and do this 228 * here so that we don't have to hold on to the kernel 229 * path name. Since a kvm application will surely do 230 * a kvm_nlist(), this probably won't be a wasted effort. 231 * If the database cannot be opened, open the namelist 232 * argument so we revert to slow nlist() calls. 233 */ 234 if (kvm_dbopen(kd, uf) < 0 && 235 (kd->nlfd = open(uf, O_RDONLY, 0)) < 0) { 236 _kvm_syserr(kd, kd->program, "%s", uf); 237 goto failed; 238 } 239 } else { 240 /* 241 * This is a crash dump. 242 * Initialize the virtual address translation machinery, 243 * but first setup the namelist fd. 244 */ 245 if ((kd->nlfd = open(uf, O_RDONLY, 0)) < 0) { 246 _kvm_syserr(kd, kd->program, "%s", uf); 247 goto failed; 248 } 249 if (_kvm_initvtop(kd) < 0) 250 goto failed; 251 } 252 return (kd); 253 failed: 254 /* 255 * Copy out the error if doing sane error semantics. 256 */ 257 if (errout != 0) 258 strcpy(errout, kd->errbuf); 259 (void)kvm_close(kd); 260 return (0); 261 } 262 263 kvm_t * 264 kvm_openfiles(uf, mf, sf, flag, errout) 265 const char *uf; 266 const char *mf; 267 const char *sf; 268 int flag; 269 char *errout; 270 { 271 register kvm_t *kd; 272 273 if ((kd = malloc(sizeof(*kd))) == NULL) { 274 (void)strcpy(errout, strerror(errno)); 275 return (0); 276 } 277 memset(kd, 0, sizeof(*kd)); 278 kd->program = 0; 279 return (_kvm_open(kd, uf, mf, sf, flag, errout)); 280 } 281 282 kvm_t * 283 kvm_open(uf, mf, sf, flag, errstr) 284 const char *uf; 285 const char *mf; 286 const char *sf; 287 int flag; 288 const char *errstr; 289 { 290 register kvm_t *kd; 291 292 if ((kd = malloc(sizeof(*kd))) == NULL) { 293 if (errstr != NULL) 294 (void)fprintf(stderr, "%s: %s\n", 295 errstr, strerror(errno)); 296 return (0); 297 } 298 memset(kd, 0, sizeof(*kd)); 299 kd->program = errstr; 300 return (_kvm_open(kd, uf, mf, sf, flag, NULL)); 301 } 302 303 int 304 kvm_close(kd) 305 kvm_t *kd; 306 { 307 register int error = 0; 308 309 if (kd->pmfd >= 0) 310 error |= close(kd->pmfd); 311 if (kd->vmfd >= 0) 312 error |= close(kd->vmfd); 313 if (kd->nlfd >= 0) 314 error |= close(kd->nlfd); 315 if (kd->db != 0) 316 error |= (kd->db->close)(kd->db); 317 if (kd->vmst) 318 _kvm_freevtop(kd); 319 if (kd->procbase != 0) 320 free((void *)kd->procbase); 321 if (kd->argv != 0) 322 free((void *)kd->argv); 323 free((void *)kd); 324 325 return (0); 326 } 327 328 /* 329 * Set up state necessary to do queries on the kernel namelist 330 * data base. If the data base is out-of-data/incompatible with 331 * given executable, set up things so we revert to standard nlist call. 332 * Only called for live kernels. Return 0 on success, -1 on failure. 333 */ 334 static int 335 kvm_dbopen(kd, uf) 336 kvm_t *kd; 337 const char *uf; 338 { 339 char *cp; 340 DBT rec; 341 int dbversionlen; 342 struct nlist nitem; 343 char dbversion[_POSIX2_LINE_MAX]; 344 char kversion[_POSIX2_LINE_MAX]; 345 char dbname[MAXPATHLEN]; 346 347 if ((cp = rindex(uf, '/')) != 0) 348 uf = cp + 1; 349 350 (void)snprintf(dbname, sizeof(dbname), "%skvm_%s.db", _PATH_VARDB, uf); 351 kd->db = dbopen(dbname, O_RDONLY, 0, DB_HASH, NULL); 352 if (kd->db == 0) 353 return (-1); 354 /* 355 * read version out of database 356 */ 357 rec.data = VRS_KEY; 358 rec.size = sizeof(VRS_KEY) - 1; 359 if ((kd->db->get)(kd->db, (DBT *)&rec, (DBT *)&rec, 0)) 360 goto close; 361 if (rec.data == 0 || rec.size > sizeof(dbversion)) 362 goto close; 363 364 bcopy(rec.data, dbversion, rec.size); 365 dbversionlen = rec.size; 366 /* 367 * Read version string from kernel memory. 368 * Since we are dealing with a live kernel, we can call kvm_read() 369 * at this point. 370 */ 371 rec.data = VRS_SYM; 372 rec.size = sizeof(VRS_SYM) - 1; 373 if ((kd->db->get)(kd->db, (DBT *)&rec, (DBT *)&rec, 0)) 374 goto close; 375 if (rec.data == 0 || rec.size != sizeof(struct nlist)) 376 goto close; 377 bcopy((char *)rec.data, (char *)&nitem, sizeof(nitem)); 378 if (kvm_read(kd, (u_long)nitem.n_value, kversion, dbversionlen) != 379 dbversionlen) 380 goto close; 381 /* 382 * If they match, we win - otherwise clear out kd->db so 383 * we revert to slow nlist(). 384 */ 385 if (bcmp(dbversion, kversion, dbversionlen) == 0) 386 return (0); 387 close: 388 (void)(kd->db->close)(kd->db); 389 kd->db = 0; 390 391 return (-1); 392 } 393 394 int 395 kvm_nlist(kd, nl) 396 kvm_t *kd; 397 struct nlist *nl; 398 { 399 register struct nlist *p; 400 register int nvalid; 401 402 /* 403 * If we can't use the data base, revert to the 404 * slow library call. 405 */ 406 if (kd->db == 0) 407 return (__fdnlist(kd->nlfd, nl)); 408 409 /* 410 * We can use the kvm data base. Go through each nlist entry 411 * and look it up with a db query. 412 */ 413 nvalid = 0; 414 for (p = nl; p->n_name && p->n_name[0]; ++p) { 415 register int len; 416 DBT rec; 417 418 if ((len = strlen(p->n_name)) > 4096) { 419 /* sanity */ 420 _kvm_err(kd, kd->program, "symbol too large"); 421 return (-1); 422 } 423 rec.data = p->n_name; 424 rec.size = len; 425 if ((kd->db->get)(kd->db, (DBT *)&rec, (DBT *)&rec, 0)) 426 continue; 427 if (rec.data == 0 || rec.size != sizeof(struct nlist)) 428 continue; 429 ++nvalid; 430 /* 431 * Avoid alignment issues. 432 */ 433 bcopy((char *)&((struct nlist *)rec.data)->n_type, 434 (char *)&p->n_type, 435 sizeof(p->n_type)); 436 bcopy((char *)&((struct nlist *)rec.data)->n_value, 437 (char *)&p->n_value, 438 sizeof(p->n_value)); 439 } 440 /* 441 * Return the number of entries that weren't found. 442 */ 443 return ((p - nl) - nvalid); 444 } 445 446 ssize_t 447 kvm_read(kd, kva, buf, len) 448 kvm_t *kd; 449 register u_long kva; 450 register void *buf; 451 register size_t len; 452 { 453 register int cc; 454 register void *cp; 455 456 if (ISALIVE(kd)) { 457 /* 458 * We're using /dev/kmem. Just read straight from the 459 * device and let the active kernel do the address translation. 460 */ 461 errno = 0; 462 if (lseek(kd->vmfd, (off_t)kva, 0) == -1 && errno != 0) { 463 _kvm_err(kd, 0, "invalid address (%x)", kva); 464 return (0); 465 } 466 cc = read(kd->vmfd, buf, len); 467 if (cc < 0) { 468 _kvm_syserr(kd, 0, "kvm_read"); 469 return (0); 470 } else if (cc < len) 471 _kvm_err(kd, kd->program, "short read"); 472 return (cc); 473 } else { 474 cp = buf; 475 while (len > 0) { 476 u_long pa; 477 478 cc = _kvm_kvatop(kd, kva, &pa); 479 if (cc == 0) 480 return (0); 481 if (cc > len) 482 cc = len; 483 errno = 0; 484 if (lseek(kd->pmfd, (off_t)pa, 0) == -1 && errno != 0) { 485 _kvm_syserr(kd, 0, _PATH_MEM); 486 break; 487 } 488 cc = read(kd->pmfd, cp, cc); 489 if (cc < 0) { 490 _kvm_syserr(kd, kd->program, "kvm_read"); 491 break; 492 } 493 /* 494 * If kvm_kvatop returns a bogus value or our core 495 * file is truncated, we might wind up seeking beyond 496 * the end of the core file in which case the read will 497 * return 0 (EOF). 498 */ 499 if (cc == 0) 500 break; 501 (char *)cp += cc; 502 kva += cc; 503 len -= cc; 504 } 505 return ((char *)cp - (char *)buf); 506 } 507 /* NOTREACHED */ 508 } 509 510 ssize_t 511 kvm_write(kd, kva, buf, len) 512 kvm_t *kd; 513 register u_long kva; 514 register const void *buf; 515 register size_t len; 516 { 517 register int cc; 518 519 if (ISALIVE(kd)) { 520 /* 521 * Just like kvm_read, only we write. 522 */ 523 errno = 0; 524 if (lseek(kd->vmfd, (off_t)kva, 0) == -1 && errno != 0) { 525 _kvm_err(kd, 0, "invalid address (%x)", kva); 526 return (0); 527 } 528 cc = write(kd->vmfd, buf, len); 529 if (cc < 0) { 530 _kvm_syserr(kd, 0, "kvm_write"); 531 return (0); 532 } else if (cc < len) 533 _kvm_err(kd, kd->program, "short write"); 534 return (cc); 535 } else { 536 _kvm_err(kd, kd->program, 537 "kvm_write not implemented for dead kernels"); 538 return (0); 539 } 540 /* NOTREACHED */ 541 } 542