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 (_kvm_initvtop(kd) < 0) 223 goto failed; 224 return (kd); 225 failed: 226 /* 227 * Copy out the error if doing sane error semantics. 228 */ 229 if (errout != 0) 230 strlcpy(errout, kd->errbuf, _POSIX2_LINE_MAX); 231 (void)kvm_close(kd); 232 return (0); 233 } 234 235 kvm_t * 236 kvm_openfiles(uf, mf, sf, flag, errout) 237 const char *uf; 238 const char *mf; 239 const char *sf __unused; 240 int flag; 241 char *errout; 242 { 243 kvm_t *kd; 244 245 if ((kd = malloc(sizeof(*kd))) == NULL) { 246 (void)strlcpy(errout, strerror(errno), _POSIX2_LINE_MAX); 247 return (0); 248 } 249 memset(kd, 0, sizeof(*kd)); 250 kd->program = 0; 251 return (_kvm_open(kd, uf, mf, flag, errout)); 252 } 253 254 kvm_t * 255 kvm_open(uf, mf, sf, flag, errstr) 256 const char *uf; 257 const char *mf; 258 const char *sf __unused; 259 int flag; 260 const char *errstr; 261 { 262 kvm_t *kd; 263 264 if ((kd = malloc(sizeof(*kd))) == NULL) { 265 if (errstr != NULL) 266 (void)fprintf(stderr, "%s: %s\n", 267 errstr, strerror(errno)); 268 return (0); 269 } 270 memset(kd, 0, sizeof(*kd)); 271 kd->program = errstr; 272 return (_kvm_open(kd, uf, mf, flag, NULL)); 273 } 274 275 int 276 kvm_close(kd) 277 kvm_t *kd; 278 { 279 int error = 0; 280 281 if (kd->pmfd >= 0) 282 error |= close(kd->pmfd); 283 if (kd->vmfd >= 0) 284 error |= close(kd->vmfd); 285 if (kd->nlfd >= 0) 286 error |= close(kd->nlfd); 287 if (kd->vmst) 288 _kvm_freevtop(kd); 289 if (kd->procbase != 0) 290 free((void *)kd->procbase); 291 if (kd->argv != 0) 292 free((void *)kd->argv); 293 free((void *)kd); 294 295 return (0); 296 } 297 298 int 299 kvm_nlist(kd, nl) 300 kvm_t *kd; 301 struct nlist *nl; 302 { 303 struct nlist *p; 304 int nvalid; 305 struct kld_sym_lookup lookup; 306 int error; 307 308 /* 309 * If we can't use the kld symbol lookup, revert to the 310 * slow library call. 311 */ 312 if (!ISALIVE(kd)) 313 return (__fdnlist(kd->nlfd, nl)); 314 315 /* 316 * We can use the kld lookup syscall. Go through each nlist entry 317 * and look it up with a kldsym(2) syscall. 318 */ 319 nvalid = 0; 320 for (p = nl; p->n_name && p->n_name[0]; ++p) { 321 lookup.version = sizeof(lookup); 322 lookup.symname = p->n_name; 323 lookup.symvalue = 0; 324 lookup.symsize = 0; 325 326 if (lookup.symname[0] == '_') 327 lookup.symname++; 328 329 if (kldsym(0, KLDSYM_LOOKUP, &lookup) != -1) { 330 p->n_type = N_TEXT; 331 p->n_other = 0; 332 p->n_desc = 0; 333 p->n_value = lookup.symvalue; 334 ++nvalid; 335 /* lookup.symsize */ 336 } 337 } 338 /* 339 * Return the number of entries that weren't found. If they exist, 340 * also fill internal error buffer. 341 */ 342 error = ((p - nl) - nvalid); 343 if (error) 344 _kvm_syserr(kd, kd->program, "kvm_nlist"); 345 return (error); 346 } 347 348 ssize_t 349 kvm_read(kd, kva, buf, len) 350 kvm_t *kd; 351 u_long kva; 352 void *buf; 353 size_t len; 354 { 355 int cc; 356 char *cp; 357 358 if (ISALIVE(kd)) { 359 /* 360 * We're using /dev/kmem. Just read straight from the 361 * device and let the active kernel do the address translation. 362 */ 363 errno = 0; 364 if (lseek(kd->vmfd, (off_t)kva, 0) == -1 && errno != 0) { 365 _kvm_err(kd, 0, "invalid address (%x)", kva); 366 return (-1); 367 } 368 cc = read(kd->vmfd, buf, len); 369 if (cc < 0) { 370 _kvm_syserr(kd, 0, "kvm_read"); 371 return (-1); 372 } else if (cc < len) 373 _kvm_err(kd, kd->program, "short read"); 374 return (cc); 375 } else { 376 cp = buf; 377 while (len > 0) { 378 off_t pa; 379 380 cc = _kvm_kvatop(kd, kva, &pa); 381 if (cc == 0) 382 return (-1); 383 if (cc > len) 384 cc = len; 385 errno = 0; 386 if (lseek(kd->pmfd, pa, 0) == -1 && errno != 0) { 387 _kvm_syserr(kd, 0, _PATH_MEM); 388 break; 389 } 390 cc = read(kd->pmfd, cp, cc); 391 if (cc < 0) { 392 _kvm_syserr(kd, kd->program, "kvm_read"); 393 break; 394 } 395 /* 396 * If kvm_kvatop returns a bogus value or our core 397 * file is truncated, we might wind up seeking beyond 398 * the end of the core file in which case the read will 399 * return 0 (EOF). 400 */ 401 if (cc == 0) 402 break; 403 cp += cc; 404 kva += cc; 405 len -= cc; 406 } 407 return (cp - (char *)buf); 408 } 409 /* NOTREACHED */ 410 } 411 412 ssize_t 413 kvm_write(kd, kva, buf, len) 414 kvm_t *kd; 415 u_long kva; 416 const void *buf; 417 size_t len; 418 { 419 int cc; 420 421 if (ISALIVE(kd)) { 422 /* 423 * Just like kvm_read, only we write. 424 */ 425 errno = 0; 426 if (lseek(kd->vmfd, (off_t)kva, 0) == -1 && errno != 0) { 427 _kvm_err(kd, 0, "invalid address (%x)", kva); 428 return (-1); 429 } 430 cc = write(kd->vmfd, buf, len); 431 if (cc < 0) { 432 _kvm_syserr(kd, 0, "kvm_write"); 433 return (-1); 434 } else if (cc < len) 435 _kvm_err(kd, kd->program, "short write"); 436 return (cc); 437 } else { 438 _kvm_err(kd, kd->program, 439 "kvm_write not implemented for dead kernels"); 440 return (-1); 441 } 442 /* NOTREACHED */ 443 } 444