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 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #include <sys/cdefs.h> 35 __FBSDID("$FreeBSD$"); 36 37 #if defined(LIBC_SCCS) && !defined(lint) 38 #if 0 39 static char sccsid[] = "@(#)kvm.c 8.2 (Berkeley) 2/13/94"; 40 #endif 41 #endif /* LIBC_SCCS and not lint */ 42 43 #include <sys/param.h> 44 #include <sys/user.h> 45 #include <sys/proc.h> 46 #include <sys/ioctl.h> 47 #include <sys/stat.h> 48 #include <sys/sysctl.h> 49 #include <sys/linker.h> 50 51 #include <vm/vm.h> 52 #include <vm/vm_param.h> 53 54 #include <machine/vmparam.h> 55 56 #include <ctype.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 /* from src/lib/libc/gen/nlist.c */ 70 int __fdnlist(int, struct nlist *); 71 72 char * 73 kvm_geterr(kd) 74 kvm_t *kd; 75 { 76 return (kd->errbuf); 77 } 78 79 #include <stdarg.h> 80 81 /* 82 * Report an error using printf style arguments. "program" is kd->program 83 * on hard errors, and 0 on soft errors, so that under sun error emulation, 84 * only hard errors are printed out (otherwise, programs like gdb will 85 * generate tons of error messages when trying to access bogus pointers). 86 */ 87 void 88 _kvm_err(kvm_t *kd, const char *program, const char *fmt, ...) 89 { 90 va_list ap; 91 92 va_start(ap, fmt); 93 if (program != NULL) { 94 (void)fprintf(stderr, "%s: ", program); 95 (void)vfprintf(stderr, fmt, ap); 96 (void)fputc('\n', stderr); 97 } else 98 (void)vsnprintf(kd->errbuf, 99 sizeof(kd->errbuf), (char *)fmt, ap); 100 101 va_end(ap); 102 } 103 104 void 105 _kvm_syserr(kvm_t *kd, const char *program, const char *fmt, ...) 106 { 107 va_list ap; 108 int n; 109 110 va_start(ap, fmt); 111 if (program != NULL) { 112 (void)fprintf(stderr, "%s: ", program); 113 (void)vfprintf(stderr, fmt, ap); 114 (void)fprintf(stderr, ": %s\n", strerror(errno)); 115 } else { 116 char *cp = kd->errbuf; 117 118 (void)vsnprintf(cp, sizeof(kd->errbuf), (char *)fmt, ap); 119 n = strlen(cp); 120 (void)snprintf(&cp[n], sizeof(kd->errbuf) - n, ": %s", 121 strerror(errno)); 122 } 123 va_end(ap); 124 } 125 126 void * 127 _kvm_malloc(kd, n) 128 kvm_t *kd; 129 size_t n; 130 { 131 void *p; 132 133 if ((p = calloc(n, sizeof(char))) == NULL) 134 _kvm_err(kd, kd->program, "can't allocate %u bytes: %s", 135 n, strerror(errno)); 136 return (p); 137 } 138 139 static kvm_t * 140 _kvm_open(kd, uf, mf, flag, errout) 141 kvm_t *kd; 142 const char *uf; 143 const char *mf; 144 int flag; 145 char *errout; 146 { 147 struct stat st; 148 149 kd->vmfd = -1; 150 kd->pmfd = -1; 151 kd->nlfd = -1; 152 kd->vmst = 0; 153 kd->procbase = 0; 154 kd->argspc = 0; 155 kd->argv = 0; 156 157 if (uf == 0) 158 uf = getbootfile(); 159 else if (strlen(uf) >= MAXPATHLEN) { 160 _kvm_err(kd, kd->program, "exec file name too long"); 161 goto failed; 162 } 163 if (flag & ~O_RDWR) { 164 _kvm_err(kd, kd->program, "bad flags arg"); 165 goto failed; 166 } 167 if (mf == 0) 168 mf = _PATH_MEM; 169 170 if ((kd->pmfd = open(mf, flag, 0)) < 0) { 171 _kvm_syserr(kd, kd->program, "%s", mf); 172 goto failed; 173 } 174 if (fstat(kd->pmfd, &st) < 0) { 175 _kvm_syserr(kd, kd->program, "%s", mf); 176 goto failed; 177 } 178 if (S_ISREG(st.st_mode) && st.st_size <= 0) { 179 errno = EINVAL; 180 _kvm_syserr(kd, kd->program, "empty file"); 181 goto failed; 182 } 183 if (fcntl(kd->pmfd, F_SETFD, FD_CLOEXEC) < 0) { 184 _kvm_syserr(kd, kd->program, "%s", mf); 185 goto failed; 186 } 187 if (S_ISCHR(st.st_mode)) { 188 /* 189 * If this is a character special device, then check that 190 * it's /dev/mem. If so, open kmem too. (Maybe we should 191 * make it work for either /dev/mem or /dev/kmem -- in either 192 * case you're working with a live kernel.) 193 */ 194 if (strcmp(mf, _PATH_DEVNULL) == 0) { 195 kd->vmfd = open(_PATH_DEVNULL, O_RDONLY); 196 return (kd); 197 } else if (strcmp(mf, _PATH_MEM) == 0) { 198 if ((kd->vmfd = open(_PATH_KMEM, flag)) < 0) { 199 _kvm_syserr(kd, kd->program, "%s", _PATH_KMEM); 200 goto failed; 201 } 202 if (fcntl(kd->vmfd, F_SETFD, FD_CLOEXEC) < 0) { 203 _kvm_syserr(kd, kd->program, "%s", _PATH_KMEM); 204 goto failed; 205 } 206 return (kd); 207 } 208 } 209 /* 210 * This is a crash dump. 211 * Initialize the virtual address translation machinery, 212 * but first setup the namelist fd. 213 */ 214 if ((kd->nlfd = open(uf, O_RDONLY, 0)) < 0) { 215 _kvm_syserr(kd, kd->program, "%s", uf); 216 goto failed; 217 } 218 if (fcntl(kd->nlfd, F_SETFD, FD_CLOEXEC) < 0) { 219 _kvm_syserr(kd, kd->program, "%s", uf); 220 goto failed; 221 } 222 if (strncmp(mf, _PATH_FWMEM, strlen(_PATH_FWMEM)) == 0) 223 kd->rawdump = 1; 224 if (_kvm_initvtop(kd) < 0) 225 goto failed; 226 return (kd); 227 failed: 228 /* 229 * Copy out the error if doing sane error semantics. 230 */ 231 if (errout != 0) 232 strlcpy(errout, kd->errbuf, _POSIX2_LINE_MAX); 233 (void)kvm_close(kd); 234 return (0); 235 } 236 237 kvm_t * 238 kvm_openfiles(uf, mf, sf, flag, errout) 239 const char *uf; 240 const char *mf; 241 const char *sf __unused; 242 int flag; 243 char *errout; 244 { 245 kvm_t *kd; 246 247 if ((kd = malloc(sizeof(*kd))) == NULL) { 248 (void)strlcpy(errout, strerror(errno), _POSIX2_LINE_MAX); 249 return (0); 250 } 251 memset(kd, 0, sizeof(*kd)); 252 kd->program = 0; 253 return (_kvm_open(kd, uf, mf, flag, errout)); 254 } 255 256 kvm_t * 257 kvm_open(uf, mf, sf, flag, errstr) 258 const char *uf; 259 const char *mf; 260 const char *sf __unused; 261 int flag; 262 const char *errstr; 263 { 264 kvm_t *kd; 265 266 if ((kd = malloc(sizeof(*kd))) == NULL) { 267 if (errstr != NULL) 268 (void)fprintf(stderr, "%s: %s\n", 269 errstr, strerror(errno)); 270 return (0); 271 } 272 memset(kd, 0, sizeof(*kd)); 273 kd->program = errstr; 274 return (_kvm_open(kd, uf, mf, flag, NULL)); 275 } 276 277 int 278 kvm_close(kd) 279 kvm_t *kd; 280 { 281 int error = 0; 282 283 if (kd->pmfd >= 0) 284 error |= close(kd->pmfd); 285 if (kd->vmfd >= 0) 286 error |= close(kd->vmfd); 287 if (kd->nlfd >= 0) 288 error |= close(kd->nlfd); 289 if (kd->vmst) 290 _kvm_freevtop(kd); 291 if (kd->procbase != 0) 292 free((void *)kd->procbase); 293 if (kd->argbuf != 0) 294 free((void *) kd->argbuf); 295 if (kd->argspc != 0) 296 free((void *) kd->argspc); 297 if (kd->argv != 0) 298 free((void *)kd->argv); 299 free((void *)kd); 300 301 return (0); 302 } 303 304 int 305 kvm_nlist(kd, nl) 306 kvm_t *kd; 307 struct nlist *nl; 308 { 309 struct nlist *p; 310 int nvalid; 311 struct kld_sym_lookup lookup; 312 int error; 313 314 /* 315 * If we can't use the kld symbol lookup, revert to the 316 * slow library call. 317 */ 318 if (!ISALIVE(kd)) 319 return (__fdnlist(kd->nlfd, nl)); 320 321 /* 322 * We can use the kld lookup syscall. Go through each nlist entry 323 * and look it up with a kldsym(2) syscall. 324 */ 325 nvalid = 0; 326 for (p = nl; p->n_name && p->n_name[0]; ++p) { 327 lookup.version = sizeof(lookup); 328 lookup.symname = p->n_name; 329 lookup.symvalue = 0; 330 lookup.symsize = 0; 331 332 if (lookup.symname[0] == '_') 333 lookup.symname++; 334 335 if (kldsym(0, KLDSYM_LOOKUP, &lookup) != -1) { 336 p->n_type = N_TEXT; 337 p->n_other = 0; 338 p->n_desc = 0; 339 p->n_value = lookup.symvalue; 340 ++nvalid; 341 /* lookup.symsize */ 342 } 343 } 344 /* 345 * Return the number of entries that weren't found. If they exist, 346 * also fill internal error buffer. 347 */ 348 error = ((p - nl) - nvalid); 349 if (error) 350 _kvm_syserr(kd, kd->program, "kvm_nlist"); 351 return (error); 352 } 353 354 ssize_t 355 kvm_read(kd, kva, buf, len) 356 kvm_t *kd; 357 u_long kva; 358 void *buf; 359 size_t len; 360 { 361 int cc; 362 char *cp; 363 364 if (ISALIVE(kd)) { 365 /* 366 * We're using /dev/kmem. Just read straight from the 367 * device and let the active kernel do the address translation. 368 */ 369 errno = 0; 370 if (lseek(kd->vmfd, (off_t)kva, 0) == -1 && errno != 0) { 371 _kvm_err(kd, 0, "invalid address (%x)", kva); 372 return (-1); 373 } 374 cc = read(kd->vmfd, buf, len); 375 if (cc < 0) { 376 _kvm_syserr(kd, 0, "kvm_read"); 377 return (-1); 378 } else if (cc < len) 379 _kvm_err(kd, kd->program, "short read"); 380 return (cc); 381 } else { 382 cp = buf; 383 while (len > 0) { 384 off_t pa; 385 386 cc = _kvm_kvatop(kd, kva, &pa); 387 if (cc == 0) 388 return (-1); 389 if (cc > len) 390 cc = len; 391 errno = 0; 392 if (lseek(kd->pmfd, pa, 0) == -1 && errno != 0) { 393 _kvm_syserr(kd, 0, _PATH_MEM); 394 break; 395 } 396 cc = read(kd->pmfd, cp, cc); 397 if (cc < 0) { 398 _kvm_syserr(kd, kd->program, "kvm_read"); 399 break; 400 } 401 /* 402 * If kvm_kvatop returns a bogus value or our core 403 * file is truncated, we might wind up seeking beyond 404 * the end of the core file in which case the read will 405 * return 0 (EOF). 406 */ 407 if (cc == 0) 408 break; 409 cp += cc; 410 kva += cc; 411 len -= cc; 412 } 413 return (cp - (char *)buf); 414 } 415 /* NOTREACHED */ 416 } 417 418 ssize_t 419 kvm_write(kd, kva, buf, len) 420 kvm_t *kd; 421 u_long kva; 422 const void *buf; 423 size_t len; 424 { 425 int cc; 426 427 if (ISALIVE(kd)) { 428 /* 429 * Just like kvm_read, only we write. 430 */ 431 errno = 0; 432 if (lseek(kd->vmfd, (off_t)kva, 0) == -1 && errno != 0) { 433 _kvm_err(kd, 0, "invalid address (%x)", kva); 434 return (-1); 435 } 436 cc = write(kd->vmfd, buf, len); 437 if (cc < 0) { 438 _kvm_syserr(kd, 0, "kvm_write"); 439 return (-1); 440 } else if (cc < len) 441 _kvm_err(kd, kd->program, "short write"); 442 return (cc); 443 } else { 444 _kvm_err(kd, kd->program, 445 "kvm_write not implemented for dead kernels"); 446 return (-1); 447 } 448 /* NOTREACHED */ 449 } 450