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 } else if (strcmp(mf, _PATH_MEM) != 0) { 196 _kvm_err(kd, kd->program, 197 "%s: not physical memory device", mf); 198 goto failed; 199 } else { 200 if ((kd->vmfd = open(_PATH_KMEM, flag)) < 0) { 201 _kvm_syserr(kd, kd->program, "%s", _PATH_KMEM); 202 goto failed; 203 } 204 if (fcntl(kd->vmfd, F_SETFD, FD_CLOEXEC) < 0) { 205 _kvm_syserr(kd, kd->program, "%s", _PATH_KMEM); 206 goto failed; 207 } 208 } 209 } else { 210 /* 211 * This is a crash dump. 212 * Initialize the virtual address translation machinery, 213 * but first setup the namelist fd. 214 */ 215 if ((kd->nlfd = open(uf, O_RDONLY, 0)) < 0) { 216 _kvm_syserr(kd, kd->program, "%s", uf); 217 goto failed; 218 } 219 if (fcntl(kd->nlfd, F_SETFD, FD_CLOEXEC) < 0) { 220 _kvm_syserr(kd, kd->program, "%s", uf); 221 goto failed; 222 } 223 if (_kvm_initvtop(kd) < 0) 224 goto failed; 225 } 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->argv != 0) 294 free((void *)kd->argv); 295 free((void *)kd); 296 297 return (0); 298 } 299 300 int 301 kvm_nlist(kd, nl) 302 kvm_t *kd; 303 struct nlist *nl; 304 { 305 struct nlist *p; 306 int nvalid; 307 struct kld_sym_lookup lookup; 308 309 /* 310 * If we can't use the kld symbol lookup, revert to the 311 * slow library call. 312 */ 313 if (!ISALIVE(kd)) 314 return (__fdnlist(kd->nlfd, nl)); 315 316 /* 317 * We can use the kld lookup syscall. Go through each nlist entry 318 * and look it up with a kldsym(2) syscall. 319 */ 320 nvalid = 0; 321 for (p = nl; p->n_name && p->n_name[0]; ++p) { 322 lookup.version = sizeof(lookup); 323 lookup.symname = p->n_name; 324 lookup.symvalue = 0; 325 lookup.symsize = 0; 326 327 if (lookup.symname[0] == '_') 328 lookup.symname++; 329 330 if (kldsym(0, KLDSYM_LOOKUP, &lookup) != -1) { 331 p->n_type = N_TEXT; 332 p->n_other = 0; 333 p->n_desc = 0; 334 p->n_value = lookup.symvalue; 335 ++nvalid; 336 /* lookup.symsize */ 337 } 338 } 339 /* 340 * Return the number of entries that weren't found. 341 */ 342 return ((p - nl) - nvalid); 343 } 344 345 ssize_t 346 kvm_read(kd, kva, buf, len) 347 kvm_t *kd; 348 u_long kva; 349 void *buf; 350 size_t len; 351 { 352 int cc; 353 void *cp; 354 355 if (ISALIVE(kd)) { 356 /* 357 * We're using /dev/kmem. Just read straight from the 358 * device and let the active kernel do the address translation. 359 */ 360 errno = 0; 361 if (lseek(kd->vmfd, (off_t)kva, 0) == -1 && errno != 0) { 362 _kvm_err(kd, 0, "invalid address (%x)", kva); 363 return (-1); 364 } 365 cc = read(kd->vmfd, buf, len); 366 if (cc < 0) { 367 _kvm_syserr(kd, 0, "kvm_read"); 368 return (-1); 369 } else if (cc < len) 370 _kvm_err(kd, kd->program, "short read"); 371 return (cc); 372 } else { 373 cp = buf; 374 while (len > 0) { 375 u_long pa; 376 377 cc = _kvm_kvatop(kd, kva, &pa); 378 if (cc == 0) 379 return (-1); 380 if (cc > len) 381 cc = len; 382 errno = 0; 383 if (lseek(kd->pmfd, (off_t)pa, 0) == -1 && errno != 0) { 384 _kvm_syserr(kd, 0, _PATH_MEM); 385 break; 386 } 387 cc = read(kd->pmfd, cp, cc); 388 if (cc < 0) { 389 _kvm_syserr(kd, kd->program, "kvm_read"); 390 break; 391 } 392 /* 393 * If kvm_kvatop returns a bogus value or our core 394 * file is truncated, we might wind up seeking beyond 395 * the end of the core file in which case the read will 396 * return 0 (EOF). 397 */ 398 if (cc == 0) 399 break; 400 (char *)cp += cc; 401 kva += cc; 402 len -= cc; 403 } 404 return ((char *)cp - (char *)buf); 405 } 406 /* NOTREACHED */ 407 } 408 409 ssize_t 410 kvm_write(kd, kva, buf, len) 411 kvm_t *kd; 412 u_long kva; 413 const void *buf; 414 size_t len; 415 { 416 int cc; 417 418 if (ISALIVE(kd)) { 419 /* 420 * Just like kvm_read, only we write. 421 */ 422 errno = 0; 423 if (lseek(kd->vmfd, (off_t)kva, 0) == -1 && errno != 0) { 424 _kvm_err(kd, 0, "invalid address (%x)", kva); 425 return (-1); 426 } 427 cc = write(kd->vmfd, buf, len); 428 if (cc < 0) { 429 _kvm_syserr(kd, 0, "kvm_write"); 430 return (-1); 431 } else if (cc < len) 432 _kvm_err(kd, kd->program, "short write"); 433 return (cc); 434 } else { 435 _kvm_err(kd, kd->program, 436 "kvm_write not implemented for dead kernels"); 437 return (-1); 438 } 439 /* NOTREACHED */ 440 } 441