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 = malloc(n)) == NULL) 159 _kvm_err(kd, kd->program, strerror(errno)); 160 return (p); 161 } 162 163 static kvm_t * 164 _kvm_open(kd, uf, mf, sf, flag, errout) 165 register kvm_t *kd; 166 const char *uf; 167 const char *mf; 168 const char *sf; 169 int flag; 170 char *errout; 171 { 172 struct stat st; 173 174 kd->vmfd = -1; 175 kd->pmfd = -1; 176 kd->swfd = -1; 177 kd->nlfd = -1; 178 kd->vmst = 0; 179 kd->db = 0; 180 kd->procbase = 0; 181 kd->nbpg = getpagesize(); 182 kd->swapspc = 0; 183 kd->argspc = 0; 184 kd->argv = 0; 185 186 if (uf == 0) 187 uf = _PATH_UNIX; 188 else if (strlen(uf) >= MAXPATHLEN) { 189 _kvm_err(kd, kd->program, "exec file name too long"); 190 goto failed; 191 } 192 if (flag & ~O_RDWR) { 193 _kvm_err(kd, kd->program, "bad flags arg"); 194 goto failed; 195 } 196 if (mf == 0) 197 mf = _PATH_MEM; 198 if (sf == 0) 199 sf = _PATH_DRUM; 200 201 if ((kd->pmfd = open(mf, flag, 0)) < 0) { 202 _kvm_syserr(kd, kd->program, "%s", mf); 203 goto failed; 204 } 205 if (fstat(kd->pmfd, &st) < 0) { 206 _kvm_syserr(kd, kd->program, "%s", mf); 207 goto failed; 208 } 209 if (S_ISCHR(st.st_mode)) { 210 /* 211 * If this is a character special device, then check that 212 * it's /dev/mem. If so, open kmem too. (Maybe we should 213 * make it work for either /dev/mem or /dev/kmem -- in either 214 * case you're working with a live kernel.) 215 */ 216 if (strcmp(mf, _PATH_MEM) != 0) { /* XXX */ 217 _kvm_err(kd, kd->program, 218 "%s: not physical memory device", mf); 219 goto failed; 220 } 221 if ((kd->vmfd = open(_PATH_KMEM, flag)) < 0) { 222 _kvm_syserr(kd, kd->program, "%s", _PATH_KMEM); 223 goto failed; 224 } 225 if ((kd->swfd = open(sf, flag, 0)) < 0) { 226 _kvm_syserr(kd, kd->program, "%s", sf); 227 goto failed; 228 } 229 /* 230 * Open kvm nlist database. We go ahead and do this 231 * here so that we don't have to hold on to the vmunix 232 * path name. Since a kvm application will surely do 233 * a kvm_nlist(), this probably won't be a wasted effort. 234 * If the database cannot be opened, open the namelist 235 * argument so we revert to slow nlist() calls. 236 */ 237 if (kvm_dbopen(kd, uf) < 0 && 238 (kd->nlfd = open(uf, O_RDONLY, 0)) < 0) { 239 _kvm_syserr(kd, kd->program, "%s", uf); 240 goto failed; 241 } 242 } else { 243 /* 244 * This is a crash dump. 245 * Initalize the virtual address translation machinery, 246 * but first setup the namelist fd. 247 */ 248 if ((kd->nlfd = open(uf, O_RDONLY, 0)) < 0) { 249 _kvm_syserr(kd, kd->program, "%s", uf); 250 goto failed; 251 } 252 if (_kvm_initvtop(kd) < 0) 253 goto failed; 254 } 255 return (kd); 256 failed: 257 /* 258 * Copy out the error if doing sane error semantics. 259 */ 260 if (errout != 0) 261 strcpy(errout, kd->errbuf); 262 (void)kvm_close(kd); 263 return (0); 264 } 265 266 kvm_t * 267 kvm_openfiles(uf, mf, sf, flag, errout) 268 const char *uf; 269 const char *mf; 270 const char *sf; 271 int flag; 272 char *errout; 273 { 274 register kvm_t *kd; 275 276 if ((kd = malloc(sizeof(*kd))) == NULL) { 277 (void)strcpy(errout, strerror(errno)); 278 return (0); 279 } 280 kd->program = 0; 281 return (_kvm_open(kd, uf, mf, sf, flag, errout)); 282 } 283 284 kvm_t * 285 kvm_open(uf, mf, sf, flag, program) 286 const char *uf; 287 const char *mf; 288 const char *sf; 289 int flag; 290 const char *program; 291 { 292 register kvm_t *kd; 293 294 if ((kd = malloc(sizeof(*kd))) == NULL && program != NULL) { 295 (void)fprintf(stderr, "%s: %s\n", strerror(errno)); 296 return (0); 297 } 298 kd->program = program; 299 return (_kvm_open(kd, uf, mf, sf, flag, NULL)); 300 } 301 302 int 303 kvm_close(kd) 304 kvm_t *kd; 305 { 306 register int error = 0; 307 308 if (kd->pmfd >= 0) 309 error |= close(kd->pmfd); 310 if (kd->vmfd >= 0) 311 error |= close(kd->vmfd); 312 if (kd->nlfd >= 0) 313 error |= close(kd->nlfd); 314 if (kd->swfd >= 0) 315 error |= close(kd->swfd); 316 if (kd->db != 0) 317 error |= (kd->db->close)(kd->db); 318 if (kd->vmst) 319 _kvm_freevtop(kd); 320 if (kd->procbase != 0) 321 free((void *)kd->procbase); 322 if (kd->swapspc != 0) 323 free((void *)kd->swapspc); 324 if (kd->argspc != 0) 325 free((void *)kd->argspc); 326 if (kd->argv != 0) 327 free((void *)kd->argv); 328 free((void *)kd); 329 330 return (0); 331 } 332 333 /* 334 * Set up state necessary to do queries on the kernel namelist 335 * data base. If the data base is out-of-data/incompatible with 336 * given executable, set up things so we revert to standard nlist call. 337 * Only called for live kernels. Return 0 on success, -1 on failure. 338 */ 339 static int 340 kvm_dbopen(kd, uf) 341 kvm_t *kd; 342 const char *uf; 343 { 344 char *cp; 345 DBT rec; 346 int dbversionlen; 347 struct nlist nitem; 348 char dbversion[_POSIX2_LINE_MAX]; 349 char kversion[_POSIX2_LINE_MAX]; 350 char dbname[MAXPATHLEN]; 351 352 if ((cp = rindex(uf, '/')) != 0) 353 uf = cp + 1; 354 355 (void)snprintf(dbname, sizeof(dbname), "%skvm_%s.db", _PATH_VARDB, uf); 356 kd->db = dbopen(dbname, O_RDONLY, 0, DB_HASH, NULL); 357 if (kd->db == 0) 358 return (-1); 359 /* 360 * read version out of database 361 */ 362 rec.data = VRS_KEY; 363 rec.size = sizeof(VRS_KEY) - 1; 364 if ((kd->db->get)(kd->db, (DBT *)&rec, (DBT *)&rec, 0)) 365 goto close; 366 if (rec.data == 0 || rec.size > sizeof(dbversion)) 367 goto close; 368 369 bcopy(rec.data, dbversion, rec.size); 370 dbversionlen = rec.size; 371 /* 372 * Read version string from kernel memory. 373 * Since we are dealing with a live kernel, we can call kvm_read() 374 * at this point. 375 */ 376 rec.data = VRS_SYM; 377 rec.size = sizeof(VRS_SYM) - 1; 378 if ((kd->db->get)(kd->db, (DBT *)&rec, (DBT *)&rec, 0)) 379 goto close; 380 if (rec.data == 0 || rec.size != sizeof(struct nlist)) 381 goto close; 382 bcopy((char *)rec.data, (char *)&nitem, sizeof(nitem)); 383 if (kvm_read(kd, (u_long)nitem.n_value, kversion, dbversionlen) != 384 dbversionlen) 385 goto close; 386 /* 387 * If they match, we win - otherwise clear out kd->db so 388 * we revert to slow nlist(). 389 */ 390 if (bcmp(dbversion, kversion, dbversionlen) == 0) 391 return (0); 392 close: 393 (void)(kd->db->close)(kd->db); 394 kd->db = 0; 395 396 return (-1); 397 } 398 399 int 400 kvm_nlist(kd, nl) 401 kvm_t *kd; 402 struct nlist *nl; 403 { 404 register struct nlist *p; 405 register int nvalid; 406 407 /* 408 * If we can't use the data base, revert to the 409 * slow library call. 410 */ 411 if (kd->db == 0) 412 return (__fdnlist(kd->nlfd, nl)); 413 414 /* 415 * We can use the kvm data base. Go through each nlist entry 416 * and look it up with a db query. 417 */ 418 nvalid = 0; 419 for (p = nl; p->n_name && p->n_name[0]; ++p) { 420 register int len; 421 DBT rec; 422 423 if ((len = strlen(p->n_name)) > 4096) { 424 /* sanity */ 425 _kvm_err(kd, kd->program, "symbol too large"); 426 return (-1); 427 } 428 rec.data = p->n_name; 429 rec.size = len; 430 if ((kd->db->get)(kd->db, (DBT *)&rec, (DBT *)&rec, 0)) 431 continue; 432 if (rec.data == 0 || rec.size != sizeof(struct nlist)) 433 continue; 434 ++nvalid; 435 /* 436 * Avoid alignment issues. 437 */ 438 bcopy((char *)&((struct nlist *)rec.data)->n_type, 439 (char *)&p->n_type, 440 sizeof(p->n_type)); 441 bcopy((char *)&((struct nlist *)rec.data)->n_value, 442 (char *)&p->n_value, 443 sizeof(p->n_value)); 444 } 445 /* 446 * Return the number of entries that weren't found. 447 */ 448 return ((p - nl) - nvalid); 449 } 450 451 ssize_t 452 kvm_read(kd, kva, buf, len) 453 kvm_t *kd; 454 register u_long kva; 455 register void *buf; 456 register size_t len; 457 { 458 register int cc; 459 register void *cp; 460 461 if (ISALIVE(kd)) { 462 /* 463 * We're using /dev/kmem. Just read straight from the 464 * device and let the active kernel do the address translation. 465 */ 466 errno = 0; 467 if (lseek(kd->vmfd, (off_t)kva, 0) == -1 && errno != 0) { 468 _kvm_err(kd, 0, "invalid address (%x)", kva); 469 return (0); 470 } 471 cc = read(kd->vmfd, buf, len); 472 if (cc < 0) { 473 _kvm_syserr(kd, 0, "kvm_read"); 474 return (0); 475 } else if (cc < len) 476 _kvm_err(kd, kd->program, "short read"); 477 return (cc); 478 } else { 479 cp = buf; 480 while (len > 0) { 481 u_long pa; 482 483 cc = _kvm_kvatop(kd, kva, &pa); 484 if (cc == 0) 485 return (0); 486 if (cc > len) 487 cc = len; 488 errno = 0; 489 if (lseek(kd->pmfd, (off_t)pa, 0) == -1 && errno != 0) { 490 _kvm_syserr(kd, 0, _PATH_MEM); 491 break; 492 } 493 cc = read(kd->pmfd, cp, cc); 494 if (cc < 0) { 495 _kvm_syserr(kd, kd->program, "kvm_read"); 496 break; 497 } 498 /* 499 * If kvm_kvatop returns a bogus value or our core 500 * file is truncated, we might wind up seeking beyond 501 * the end of the core file in which case the read will 502 * return 0 (EOF). 503 */ 504 if (cc == 0) 505 break; 506 (char *)cp += cc; 507 kva += cc; 508 len -= cc; 509 } 510 return ((char *)cp - (char *)buf); 511 } 512 /* NOTREACHED */ 513 } 514 515 ssize_t 516 kvm_write(kd, kva, buf, len) 517 kvm_t *kd; 518 register u_long kva; 519 register const void *buf; 520 register size_t len; 521 { 522 register int cc; 523 524 if (ISALIVE(kd)) { 525 /* 526 * Just like kvm_read, only we write. 527 */ 528 errno = 0; 529 if (lseek(kd->vmfd, (off_t)kva, 0) == -1 && errno != 0) { 530 _kvm_err(kd, 0, "invalid address (%x)", kva); 531 return (0); 532 } 533 cc = write(kd->vmfd, buf, len); 534 if (cc < 0) { 535 _kvm_syserr(kd, 0, "kvm_write"); 536 return (0); 537 } else if (cc < len) 538 _kvm_err(kd, kd->program, "short write"); 539 return (cc); 540 } else { 541 _kvm_err(kd, kd->program, 542 "kvm_write not implemented for dead kernels"); 543 return (0); 544 } 545 /* NOTREACHED */ 546 } 547