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 #include <sys/cdefs.h> 39 __FBSDID("$FreeBSD$"); 40 41 #if defined(LIBC_SCCS) && !defined(lint) 42 #if 0 43 static char sccsid[] = "@(#)kvm.c 8.2 (Berkeley) 2/13/94"; 44 #endif 45 #endif /* LIBC_SCCS and not lint */ 46 47 #include <sys/param.h> 48 #include <sys/user.h> 49 #include <sys/proc.h> 50 #include <sys/ioctl.h> 51 #include <sys/stat.h> 52 #include <sys/sysctl.h> 53 #include <sys/linker.h> 54 55 #include <vm/vm.h> 56 #include <vm/vm_param.h> 57 58 #include <machine/vmparam.h> 59 60 #include <ctype.h> 61 #include <fcntl.h> 62 #include <kvm.h> 63 #include <limits.h> 64 #include <nlist.h> 65 #include <paths.h> 66 #include <stdio.h> 67 #include <stdlib.h> 68 #include <string.h> 69 #include <unistd.h> 70 71 #include "kvm_private.h" 72 73 /* from src/lib/libc/gen/nlist.c */ 74 int __fdnlist(int, struct nlist *); 75 76 char * 77 kvm_geterr(kd) 78 kvm_t *kd; 79 { 80 return (kd->errbuf); 81 } 82 83 #include <stdarg.h> 84 85 /* 86 * Report an error using printf style arguments. "program" is kd->program 87 * on hard errors, and 0 on soft errors, so that under sun error emulation, 88 * only hard errors are printed out (otherwise, programs like gdb will 89 * generate tons of error messages when trying to access bogus pointers). 90 */ 91 void 92 _kvm_err(kvm_t *kd, const char *program, const char *fmt, ...) 93 { 94 va_list ap; 95 96 va_start(ap, fmt); 97 if (program != NULL) { 98 (void)fprintf(stderr, "%s: ", program); 99 (void)vfprintf(stderr, fmt, ap); 100 (void)fputc('\n', stderr); 101 } else 102 (void)vsnprintf(kd->errbuf, 103 sizeof(kd->errbuf), (char *)fmt, ap); 104 105 va_end(ap); 106 } 107 108 void 109 _kvm_syserr(kvm_t *kd, const char *program, const char *fmt, ...) 110 { 111 va_list ap; 112 int n; 113 114 va_start(ap, fmt); 115 if (program != NULL) { 116 (void)fprintf(stderr, "%s: ", program); 117 (void)vfprintf(stderr, fmt, ap); 118 (void)fprintf(stderr, ": %s\n", strerror(errno)); 119 } else { 120 char *cp = kd->errbuf; 121 122 (void)vsnprintf(cp, sizeof(kd->errbuf), (char *)fmt, ap); 123 n = strlen(cp); 124 (void)snprintf(&cp[n], sizeof(kd->errbuf) - n, ": %s", 125 strerror(errno)); 126 } 127 va_end(ap); 128 } 129 130 void * 131 _kvm_malloc(kd, n) 132 kvm_t *kd; 133 size_t n; 134 { 135 void *p; 136 137 if ((p = calloc(n, sizeof(char))) == NULL) 138 _kvm_err(kd, kd->program, "can't allocate %u bytes: %s", 139 n, strerror(errno)); 140 return (p); 141 } 142 143 static kvm_t * 144 _kvm_open(kd, uf, mf, flag, errout) 145 kvm_t *kd; 146 const char *uf; 147 const char *mf; 148 int flag; 149 char *errout; 150 { 151 struct stat st; 152 153 kd->vmfd = -1; 154 kd->pmfd = -1; 155 kd->nlfd = -1; 156 kd->vmst = 0; 157 kd->procbase = 0; 158 kd->argspc = 0; 159 kd->argv = 0; 160 161 if (uf == 0) 162 uf = getbootfile(); 163 else if (strlen(uf) >= MAXPATHLEN) { 164 _kvm_err(kd, kd->program, "exec file name too long"); 165 goto failed; 166 } 167 if (flag & ~O_RDWR) { 168 _kvm_err(kd, kd->program, "bad flags arg"); 169 goto failed; 170 } 171 if (mf == 0) 172 mf = _PATH_MEM; 173 174 if ((kd->pmfd = open(mf, flag, 0)) < 0) { 175 _kvm_syserr(kd, kd->program, "%s", mf); 176 goto failed; 177 } 178 if (fstat(kd->pmfd, &st) < 0) { 179 _kvm_syserr(kd, kd->program, "%s", mf); 180 goto failed; 181 } 182 if (fcntl(kd->pmfd, F_SETFD, FD_CLOEXEC) < 0) { 183 _kvm_syserr(kd, kd->program, "%s", mf); 184 goto failed; 185 } 186 if (S_ISCHR(st.st_mode)) { 187 /* 188 * If this is a character special device, then check that 189 * it's /dev/mem. If so, open kmem too. (Maybe we should 190 * make it work for either /dev/mem or /dev/kmem -- in either 191 * case you're working with a live kernel.) 192 */ 193 if (strcmp(mf, _PATH_DEVNULL) == 0) { 194 kd->vmfd = open(_PATH_DEVNULL, O_RDONLY); 195 return (kd); 196 } else if (strcmp(mf, _PATH_MEM) == 0) { 197 if ((kd->vmfd = open(_PATH_KMEM, flag)) < 0) { 198 _kvm_syserr(kd, kd->program, "%s", _PATH_KMEM); 199 goto failed; 200 } 201 if (fcntl(kd->vmfd, F_SETFD, FD_CLOEXEC) < 0) { 202 _kvm_syserr(kd, kd->program, "%s", _PATH_KMEM); 203 goto failed; 204 } 205 return (kd); 206 } 207 } 208 /* 209 * This is a crash dump. 210 * Initialize the virtual address translation machinery, 211 * but first setup the namelist fd. 212 */ 213 if ((kd->nlfd = open(uf, O_RDONLY, 0)) < 0) { 214 _kvm_syserr(kd, kd->program, "%s", uf); 215 goto failed; 216 } 217 if (fcntl(kd->nlfd, F_SETFD, FD_CLOEXEC) < 0) { 218 _kvm_syserr(kd, kd->program, "%s", uf); 219 goto failed; 220 } 221 if (_kvm_initvtop(kd) < 0) 222 goto failed; 223 return (kd); 224 failed: 225 /* 226 * Copy out the error if doing sane error semantics. 227 */ 228 if (errout != 0) 229 strlcpy(errout, kd->errbuf, _POSIX2_LINE_MAX); 230 (void)kvm_close(kd); 231 return (0); 232 } 233 234 kvm_t * 235 kvm_openfiles(uf, mf, sf, flag, errout) 236 const char *uf; 237 const char *mf; 238 const char *sf __unused; 239 int flag; 240 char *errout; 241 { 242 kvm_t *kd; 243 244 if ((kd = malloc(sizeof(*kd))) == NULL) { 245 (void)strlcpy(errout, strerror(errno), _POSIX2_LINE_MAX); 246 return (0); 247 } 248 memset(kd, 0, sizeof(*kd)); 249 kd->program = 0; 250 return (_kvm_open(kd, uf, mf, flag, errout)); 251 } 252 253 kvm_t * 254 kvm_open(uf, mf, sf, flag, errstr) 255 const char *uf; 256 const char *mf; 257 const char *sf __unused; 258 int flag; 259 const char *errstr; 260 { 261 kvm_t *kd; 262 263 if ((kd = malloc(sizeof(*kd))) == NULL) { 264 if (errstr != NULL) 265 (void)fprintf(stderr, "%s: %s\n", 266 errstr, strerror(errno)); 267 return (0); 268 } 269 memset(kd, 0, sizeof(*kd)); 270 kd->program = errstr; 271 return (_kvm_open(kd, uf, mf, flag, NULL)); 272 } 273 274 int 275 kvm_close(kd) 276 kvm_t *kd; 277 { 278 int error = 0; 279 280 if (kd->pmfd >= 0) 281 error |= close(kd->pmfd); 282 if (kd->vmfd >= 0) 283 error |= close(kd->vmfd); 284 if (kd->nlfd >= 0) 285 error |= close(kd->nlfd); 286 if (kd->vmst) 287 _kvm_freevtop(kd); 288 if (kd->procbase != 0) 289 free((void *)kd->procbase); 290 if (kd->argv != 0) 291 free((void *)kd->argv); 292 free((void *)kd); 293 294 return (0); 295 } 296 297 int 298 kvm_nlist(kd, nl) 299 kvm_t *kd; 300 struct nlist *nl; 301 { 302 struct nlist *p; 303 int nvalid; 304 struct kld_sym_lookup lookup; 305 306 /* 307 * If we can't use the kld symbol lookup, revert to the 308 * slow library call. 309 */ 310 if (!ISALIVE(kd)) 311 return (__fdnlist(kd->nlfd, nl)); 312 313 /* 314 * We can use the kld lookup syscall. Go through each nlist entry 315 * and look it up with a kldsym(2) syscall. 316 */ 317 nvalid = 0; 318 for (p = nl; p->n_name && p->n_name[0]; ++p) { 319 lookup.version = sizeof(lookup); 320 lookup.symname = p->n_name; 321 lookup.symvalue = 0; 322 lookup.symsize = 0; 323 324 if (lookup.symname[0] == '_') 325 lookup.symname++; 326 327 if (kldsym(0, KLDSYM_LOOKUP, &lookup) != -1) { 328 p->n_type = N_TEXT; 329 p->n_other = 0; 330 p->n_desc = 0; 331 p->n_value = lookup.symvalue; 332 ++nvalid; 333 /* lookup.symsize */ 334 } 335 } 336 /* 337 * Return the number of entries that weren't found. 338 */ 339 return ((p - nl) - nvalid); 340 } 341 342 ssize_t 343 kvm_read(kd, kva, buf, len) 344 kvm_t *kd; 345 u_long kva; 346 void *buf; 347 size_t len; 348 { 349 int cc; 350 char *cp; 351 352 if (ISALIVE(kd)) { 353 /* 354 * We're using /dev/kmem. Just read straight from the 355 * device and let the active kernel do the address translation. 356 */ 357 errno = 0; 358 if (lseek(kd->vmfd, (off_t)kva, 0) == -1 && errno != 0) { 359 _kvm_err(kd, 0, "invalid address (%x)", kva); 360 return (-1); 361 } 362 cc = read(kd->vmfd, buf, len); 363 if (cc < 0) { 364 _kvm_syserr(kd, 0, "kvm_read"); 365 return (-1); 366 } else if (cc < len) 367 _kvm_err(kd, kd->program, "short read"); 368 return (cc); 369 } else { 370 cp = buf; 371 while (len > 0) { 372 off_t pa; 373 374 cc = _kvm_kvatop(kd, kva, &pa); 375 if (cc == 0) 376 return (-1); 377 if (cc > len) 378 cc = len; 379 errno = 0; 380 if (lseek(kd->pmfd, pa, 0) == -1 && errno != 0) { 381 _kvm_syserr(kd, 0, _PATH_MEM); 382 break; 383 } 384 cc = read(kd->pmfd, cp, cc); 385 if (cc < 0) { 386 _kvm_syserr(kd, kd->program, "kvm_read"); 387 break; 388 } 389 /* 390 * If kvm_kvatop returns a bogus value or our core 391 * file is truncated, we might wind up seeking beyond 392 * the end of the core file in which case the read will 393 * return 0 (EOF). 394 */ 395 if (cc == 0) 396 break; 397 cp += cc; 398 kva += cc; 399 len -= cc; 400 } 401 return (cp - (char *)buf); 402 } 403 /* NOTREACHED */ 404 } 405 406 ssize_t 407 kvm_write(kd, kva, buf, len) 408 kvm_t *kd; 409 u_long kva; 410 const void *buf; 411 size_t len; 412 { 413 int cc; 414 415 if (ISALIVE(kd)) { 416 /* 417 * Just like kvm_read, only we write. 418 */ 419 errno = 0; 420 if (lseek(kd->vmfd, (off_t)kva, 0) == -1 && errno != 0) { 421 _kvm_err(kd, 0, "invalid address (%x)", kva); 422 return (-1); 423 } 424 cc = write(kd->vmfd, buf, len); 425 if (cc < 0) { 426 _kvm_syserr(kd, 0, "kvm_write"); 427 return (-1); 428 } else if (cc < len) 429 _kvm_err(kd, kd->program, "short write"); 430 return (cc); 431 } else { 432 _kvm_err(kd, kd->program, 433 "kvm_write not implemented for dead kernels"); 434 return (-1); 435 } 436 /* NOTREACHED */ 437 } 438