kvm.c revision 1.48
1 /* $NetBSD: kvm.c,v 1.48 1996/10/12 00:50:11 cgd Exp $ */ 2 3 /*- 4 * Copyright (c) 1989, 1992, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software developed by the Computer Systems 8 * Engineering group at Lawrence Berkeley Laboratory under DARPA contract 9 * BG 91-66 and contributed to Berkeley. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the University of 22 * California, Berkeley and its contributors. 23 * 4. Neither the name of the University nor the names of its contributors 24 * may be used to endorse or promote products derived from this software 25 * without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37 * SUCH DAMAGE. 38 */ 39 40 #if defined(LIBC_SCCS) && !defined(lint) 41 #if 0 42 static char sccsid[] = "@(#)kvm.c 8.2 (Berkeley) 2/13/94"; 43 #else 44 static char *rcsid = "$NetBSD: kvm.c,v 1.48 1996/10/12 00:50:11 cgd Exp $"; 45 #endif 46 #endif /* LIBC_SCCS and not lint */ 47 48 #include <sys/param.h> 49 #include <sys/user.h> 50 #include <sys/proc.h> 51 #include <sys/ioctl.h> 52 #include <sys/stat.h> 53 #include <sys/sysctl.h> 54 55 #include <sys/core.h> 56 #include <sys/exec_aout.h> 57 #include <sys/kcore.h> 58 59 #include <vm/vm.h> 60 #include <vm/vm_param.h> 61 #include <vm/swap_pager.h> 62 63 #include <ctype.h> 64 #include <db.h> 65 #include <fcntl.h> 66 #include <limits.h> 67 #include <nlist.h> 68 #include <paths.h> 69 #include <stdio.h> 70 #include <stdlib.h> 71 #include <string.h> 72 #include <unistd.h> 73 #include <kvm.h> 74 75 #include "kvm_private.h" 76 77 static int kvm_dbopen __P((kvm_t *)); 78 static int _kvm_get_header __P((kvm_t *)); 79 static kvm_t *_kvm_open __P((kvm_t *, const char *, const char *, 80 const char *, int, char *)); 81 static int clear_gap __P((kvm_t *, FILE *, int)); 82 static off_t Lseek __P((kvm_t *, int, off_t, int)); 83 static ssize_t Read __P(( kvm_t *, int, void *, size_t)); 84 85 char * 86 kvm_geterr(kd) 87 kvm_t *kd; 88 { 89 return (kd->errbuf); 90 } 91 92 #if __STDC__ 93 #include <stdarg.h> 94 #else 95 #include <varargs.h> 96 #endif 97 98 /* 99 * Report an error using printf style arguments. "program" is kd->program 100 * on hard errors, and 0 on soft errors, so that under sun error emulation, 101 * only hard errors are printed out (otherwise, programs like gdb will 102 * generate tons of error messages when trying to access bogus pointers). 103 */ 104 void 105 #if __STDC__ 106 _kvm_err(kvm_t *kd, const char *program, const char *fmt, ...) 107 #else 108 _kvm_err(kd, program, fmt, va_alist) 109 kvm_t *kd; 110 char *program, *fmt; 111 va_dcl 112 #endif 113 { 114 va_list ap; 115 116 #ifdef __STDC__ 117 va_start(ap, fmt); 118 #else 119 va_start(ap); 120 #endif 121 if (program != NULL) { 122 (void)fprintf(stderr, "%s: ", program); 123 (void)vfprintf(stderr, fmt, ap); 124 (void)fputc('\n', stderr); 125 } else 126 (void)vsnprintf(kd->errbuf, 127 sizeof(kd->errbuf), (char *)fmt, ap); 128 129 va_end(ap); 130 } 131 132 void 133 #if __STDC__ 134 _kvm_syserr(kvm_t *kd, const char *program, const char *fmt, ...) 135 #else 136 _kvm_syserr(kd, program, fmt, va_alist) 137 kvm_t *kd; 138 char *program, *fmt; 139 va_dcl 140 #endif 141 { 142 va_list ap; 143 register int n; 144 145 #if __STDC__ 146 va_start(ap, fmt); 147 #else 148 va_start(ap); 149 #endif 150 if (program != NULL) { 151 (void)fprintf(stderr, "%s: ", program); 152 (void)vfprintf(stderr, fmt, ap); 153 (void)fprintf(stderr, ": %s\n", strerror(errno)); 154 } else { 155 register char *cp = kd->errbuf; 156 157 (void)vsnprintf(cp, sizeof(kd->errbuf), (char *)fmt, ap); 158 n = strlen(cp); 159 (void)snprintf(&cp[n], sizeof(kd->errbuf) - n, ": %s", 160 strerror(errno)); 161 } 162 va_end(ap); 163 } 164 165 void * 166 _kvm_malloc(kd, n) 167 register kvm_t *kd; 168 register size_t n; 169 { 170 void *p; 171 172 if ((p = malloc(n)) == NULL) 173 _kvm_err(kd, kd->program, strerror(errno)); 174 return (p); 175 } 176 177 /* 178 * Wrappers for Lseek/Read system calls. They check for errors and 179 * call _kvm_syserr() if appropriate. 180 */ 181 static off_t 182 Lseek(kd, fd, offset, whence) 183 kvm_t *kd; 184 int fd, whence; 185 off_t offset; 186 { 187 off_t off; 188 189 errno = 0; 190 if ((off = lseek(fd, offset, whence)) == -1 && errno != 0) { 191 _kvm_syserr(kd, kd->program, "Lseek"); 192 return (-1); 193 } 194 return (off); 195 } 196 197 static ssize_t 198 Read(kd, fd, buf, nbytes) 199 kvm_t *kd; 200 int fd; 201 void *buf; 202 size_t nbytes; 203 { 204 ssize_t rv; 205 206 errno = 0; 207 208 if ((rv = read(fd, buf, nbytes)) != nbytes && errno != 0) 209 _kvm_syserr(kd, kd->program, "Read"); 210 return (rv); 211 } 212 213 static kvm_t * 214 _kvm_open(kd, uf, mf, sf, flag, errout) 215 register kvm_t *kd; 216 const char *uf; 217 const char *mf; 218 const char *sf; 219 int flag; 220 char *errout; 221 { 222 struct stat st; 223 int ufgiven; 224 225 kd->db = 0; 226 kd->pmfd = -1; 227 kd->vmfd = -1; 228 kd->swfd = -1; 229 kd->nlfd = -1; 230 kd->procbase = 0; 231 kd->nbpg = getpagesize(); 232 kd->swapspc = 0; 233 kd->argspc = 0; 234 kd->argbuf = 0; 235 kd->argv = 0; 236 kd->vmst = 0; 237 kd->vm_page_buckets = 0; 238 kd->kcore_hdr = 0; 239 kd->cpu_dsize = 0; 240 kd->cpu_data = 0; 241 kd->dump_off = 0; 242 243 ufgiven = (uf != NULL); 244 if (!ufgiven) 245 uf = _PATH_UNIX; 246 else if (strlen(uf) >= MAXPATHLEN) { 247 _kvm_err(kd, kd->program, "exec file name too long"); 248 goto failed; 249 } 250 if (flag & ~O_RDWR) { 251 _kvm_err(kd, kd->program, "bad flags arg"); 252 goto failed; 253 } 254 if (mf == 0) 255 mf = _PATH_MEM; 256 if (sf == 0) 257 sf = _PATH_DRUM; 258 259 if ((kd->pmfd = open(mf, flag, 0)) < 0) { 260 _kvm_syserr(kd, kd->program, "%s", mf); 261 goto failed; 262 } 263 if (fstat(kd->pmfd, &st) < 0) { 264 _kvm_syserr(kd, kd->program, "%s", mf); 265 goto failed; 266 } 267 if (S_ISCHR(st.st_mode)) { 268 /* 269 * If this is a character special device, then check that 270 * it's /dev/mem. If so, open kmem too. (Maybe we should 271 * make it work for either /dev/mem or /dev/kmem -- in either 272 * case you're working with a live kernel.) 273 */ 274 if (strcmp(mf, _PATH_MEM) != 0) { /* XXX */ 275 _kvm_err(kd, kd->program, 276 "%s: not physical memory device", mf); 277 goto failed; 278 } 279 if ((kd->vmfd = open(_PATH_KMEM, flag)) < 0) { 280 _kvm_syserr(kd, kd->program, "%s", _PATH_KMEM); 281 goto failed; 282 } 283 if ((kd->swfd = open(sf, flag, 0)) < 0) { 284 _kvm_syserr(kd, kd->program, "%s", sf); 285 goto failed; 286 } 287 /* 288 * Open kvm nlist database. We only try to use 289 * the pre-built database if the namelist file name 290 * pointer is NULL. If the database cannot or should 291 * not be opened, open the namelist argument so we 292 * revert to slow nlist() calls. 293 */ 294 if ((ufgiven || kvm_dbopen(kd) < 0) && 295 (kd->nlfd = open(uf, O_RDONLY, 0)) < 0) { 296 _kvm_syserr(kd, kd->program, "%s", uf); 297 goto failed; 298 } 299 } else { 300 /* 301 * This is a crash dump. 302 * Initalize the virtual address translation machinery, 303 * but first setup the namelist fd. 304 */ 305 if ((kd->nlfd = open(uf, O_RDONLY, 0)) < 0) { 306 _kvm_syserr(kd, kd->program, "%s", uf); 307 goto failed; 308 } 309 310 /* 311 * If there is no valid core header, fail silently here. 312 * The address translations however will fail without 313 * header. Things can be made to run by calling 314 * kvm_dump_mkheader() before doing any translation. 315 */ 316 if (_kvm_get_header(kd) == 0) { 317 if (_kvm_initvtop(kd) < 0) 318 goto failed; 319 } 320 } 321 return (kd); 322 failed: 323 /* 324 * Copy out the error if doing sane error semantics. 325 */ 326 if (errout != 0) 327 strcpy(errout, kd->errbuf); 328 (void)kvm_close(kd); 329 return (0); 330 } 331 332 /* 333 * The kernel dump file (from savecore) contains: 334 * kcore_hdr_t kcore_hdr; 335 * kcore_seg_t cpu_hdr; 336 * (opaque) cpu_data; (size is cpu_hdr.c_size) 337 * kcore_seg_t mem_hdr; 338 * (memory) mem_data; (size is mem_hdr.c_size) 339 * 340 * Note: khdr is padded to khdr.c_hdrsize; 341 * cpu_hdr and mem_hdr are padded to khdr.c_seghdrsize 342 */ 343 static int 344 _kvm_get_header(kd) 345 kvm_t *kd; 346 { 347 kcore_hdr_t kcore_hdr; 348 kcore_seg_t cpu_hdr; 349 kcore_seg_t mem_hdr; 350 size_t offset; 351 ssize_t sz; 352 353 /* 354 * Read the kcore_hdr_t 355 */ 356 if (Lseek(kd, kd->pmfd, (off_t)0, SEEK_SET) == -1) 357 return (-1); 358 sz = Read(kd, kd->pmfd, &kcore_hdr, sizeof(kcore_hdr)); 359 if (sz != sizeof(kcore_hdr)) 360 return (-1); 361 362 /* 363 * Currently, we only support dump-files made by the current 364 * architecture... 365 */ 366 if ((CORE_GETMAGIC(kcore_hdr) != KCORE_MAGIC) || 367 (CORE_GETMID(kcore_hdr) != MID_MACHINE)) 368 return (-1); 369 370 /* 371 * Currently, we only support exactly 2 segments: cpu-segment 372 * and data-segment in exactly that order. 373 */ 374 if (kcore_hdr.c_nseg != 2) 375 return (-1); 376 377 /* 378 * Save away the kcore_hdr. All errors after this 379 * should do a to "goto fail" to deallocate things. 380 */ 381 kd->kcore_hdr = _kvm_malloc(kd, sizeof(kcore_hdr)); 382 memcpy(kd->kcore_hdr, &kcore_hdr, sizeof(kcore_hdr)); 383 offset = kcore_hdr.c_hdrsize; 384 385 /* 386 * Read the CPU segment header 387 */ 388 if (Lseek(kd, kd->pmfd, (off_t)offset, SEEK_SET) == -1) 389 goto fail; 390 sz = Read(kd, kd->pmfd, &cpu_hdr, sizeof(cpu_hdr)); 391 if (sz != sizeof(cpu_hdr)) 392 goto fail; 393 if ((CORE_GETMAGIC(cpu_hdr) != KCORESEG_MAGIC) || 394 (CORE_GETFLAG(cpu_hdr) != CORE_CPU)) 395 goto fail; 396 offset += kcore_hdr.c_seghdrsize; 397 398 /* 399 * Read the CPU segment DATA. 400 */ 401 kd->cpu_dsize = cpu_hdr.c_size; 402 kd->cpu_data = _kvm_malloc(kd, cpu_hdr.c_size); 403 if (kd->cpu_data == NULL) 404 goto fail; 405 if (Lseek(kd, kd->pmfd, (off_t)offset, SEEK_SET) == -1) 406 goto fail; 407 sz = Read(kd, kd->pmfd, kd->cpu_data, cpu_hdr.c_size); 408 if (sz != cpu_hdr.c_size) 409 goto fail; 410 offset += cpu_hdr.c_size; 411 412 /* 413 * Read the next segment header: data segment 414 */ 415 if (Lseek(kd, kd->pmfd, (off_t)offset, SEEK_SET) == -1) 416 goto fail; 417 sz = Read(kd, kd->pmfd, &mem_hdr, sizeof(mem_hdr)); 418 if (sz != sizeof(mem_hdr)) 419 goto fail; 420 offset += kcore_hdr.c_seghdrsize; 421 422 if ((CORE_GETMAGIC(mem_hdr) != KCORESEG_MAGIC) || 423 (CORE_GETFLAG(mem_hdr) != CORE_DATA)) 424 goto fail; 425 426 kd->dump_off = offset; 427 return (0); 428 429 fail: 430 if (kd->kcore_hdr != NULL) { 431 free(kd->kcore_hdr); 432 kd->kcore_hdr = NULL; 433 } 434 if (kd->cpu_data != NULL) { 435 free(kd->cpu_data); 436 kd->cpu_data = NULL; 437 kd->cpu_dsize = 0; 438 } 439 440 } 441 442 /* 443 * The format while on the dump device is: (new format) 444 * kcore_seg_t cpu_hdr; 445 * (opaque) cpu_data; (size is cpu_hdr.c_size) 446 * kcore_seg_t mem_hdr; 447 * (memory) mem_data; (size is mem_hdr.c_size) 448 */ 449 int 450 kvm_dump_mkheader(kd, dump_off) 451 kvm_t *kd; 452 off_t dump_off; 453 { 454 kcore_seg_t cpu_hdr; 455 int hdr_size, sz; 456 457 if (kd->kcore_hdr != NULL) { 458 _kvm_err(kd, kd->program, "already has a dump header"); 459 return (-1); 460 } 461 if (ISALIVE(kd)) { 462 _kvm_err(kd, kd->program, "don't use on live kernel"); 463 return (-1); 464 } 465 466 /* 467 * Validate new format crash dump 468 */ 469 if (Lseek(kd, kd->pmfd, dump_off, SEEK_SET) == -1) 470 return (-1); 471 sz = Read(kd, kd->pmfd, &cpu_hdr, sizeof(cpu_hdr)); 472 if (sz != sizeof(cpu_hdr)) 473 return (-1); 474 if ((CORE_GETMAGIC(cpu_hdr) != KCORE_MAGIC) 475 || (CORE_GETMID(cpu_hdr) != MID_MACHINE)) { 476 _kvm_err(kd, 0, "invalid magic in cpu_hdr"); 477 return (0); 478 } 479 hdr_size = ALIGN(sizeof(cpu_hdr)); 480 481 /* 482 * Read the CPU segment. 483 */ 484 kd->cpu_dsize = cpu_hdr.c_size; 485 kd->cpu_data = _kvm_malloc(kd, kd->cpu_dsize); 486 if (kd->cpu_data == NULL) 487 goto fail; 488 if (Lseek(kd, kd->pmfd, dump_off+hdr_size, SEEK_SET) == -1) 489 goto fail; 490 sz = Read(kd, kd->pmfd, kd->cpu_data, cpu_hdr.c_size); 491 if (sz != cpu_hdr.c_size) 492 goto fail; 493 hdr_size += kd->cpu_dsize; 494 495 /* 496 * Leave phys mem pointer at beginning of memory data 497 */ 498 kd->dump_off = dump_off + hdr_size; 499 if (Lseek(kd, kd->pmfd, kd->dump_off, SEEK_SET) == -1) 500 goto fail; 501 502 /* 503 * Create a kcore_hdr. 504 */ 505 kd->kcore_hdr = _kvm_malloc(kd, sizeof(kcore_hdr_t)); 506 if (kd->kcore_hdr == NULL) 507 goto fail; 508 509 kd->kcore_hdr->c_hdrsize = ALIGN(sizeof(kcore_hdr_t)); 510 kd->kcore_hdr->c_seghdrsize = ALIGN(sizeof(kcore_seg_t)); 511 kd->kcore_hdr->c_nseg = 2; 512 CORE_SETMAGIC(*(kd->kcore_hdr), KCORE_MAGIC, MID_MACHINE,0); 513 514 /* 515 * Now that we have a valid header, enable translations. 516 */ 517 _kvm_initvtop(kd); 518 519 return(hdr_size); 520 521 fail: 522 if (kd->kcore_hdr != NULL) { 523 free(kd->kcore_hdr); 524 kd->kcore_hdr = NULL; 525 } 526 if (kd->cpu_data != NULL) { 527 free(kd->cpu_data); 528 kd->cpu_data = NULL; 529 kd->cpu_dsize = 0; 530 } 531 return (-1); 532 } 533 534 static int 535 clear_gap(kd, fp, size) 536 kvm_t *kd; 537 FILE *fp; 538 int size; 539 { 540 if (size <= 0) /* XXX - < 0 should never happen */ 541 return (0); 542 while (size-- > 0) { 543 if (fputc(0, fp) == EOF) { 544 _kvm_syserr(kd, kd->program, "clear_gap"); 545 return (-1); 546 } 547 } 548 return (0); 549 } 550 551 /* 552 * Write the dump header info to 'fp'. Note that we can't use fseek(3) here 553 * because 'fp' might be a file pointer obtained by zopen(). 554 */ 555 int 556 kvm_dump_wrtheader(kd, fp, dumpsize) 557 kvm_t *kd; 558 FILE *fp; 559 int dumpsize; 560 { 561 kcore_seg_t seghdr; 562 long offset; 563 int gap; 564 565 if (kd->kcore_hdr == NULL || kd->cpu_data == NULL) { 566 _kvm_err(kd, kd->program, "no valid dump header(s)"); 567 return (-1); 568 } 569 570 /* 571 * Write the generic header 572 */ 573 offset = 0; 574 if (fwrite((void*)kd->kcore_hdr, sizeof(kcore_hdr_t), 1, fp) <= 0) { 575 _kvm_syserr(kd, kd->program, "kvm_dump_wrtheader"); 576 return (-1); 577 } 578 offset += kd->kcore_hdr->c_hdrsize; 579 gap = kd->kcore_hdr->c_hdrsize - sizeof(kcore_hdr_t); 580 if (clear_gap(kd, fp, gap) == -1) 581 return (-1); 582 583 /* 584 * Write the cpu header 585 */ 586 CORE_SETMAGIC(seghdr, KCORESEG_MAGIC, 0, CORE_CPU); 587 seghdr.c_size = ALIGN(kd->cpu_dsize); 588 if (fwrite((void*)&seghdr, sizeof(seghdr), 1, fp) <= 0) { 589 _kvm_syserr(kd, kd->program, "kvm_dump_wrtheader"); 590 return (-1); 591 } 592 offset += kd->kcore_hdr->c_seghdrsize; 593 gap = kd->kcore_hdr->c_seghdrsize - sizeof(seghdr); 594 if (clear_gap(kd, fp, gap) == -1) 595 return (-1); 596 597 if (fwrite((void*)kd->cpu_data, kd->cpu_dsize, 1, fp) <= 0) { 598 _kvm_syserr(kd, kd->program, "kvm_dump_wrtheader"); 599 return (-1); 600 } 601 offset += seghdr.c_size; 602 gap = seghdr.c_size - kd->cpu_dsize; 603 if (clear_gap(kd, fp, gap) == -1) 604 return (-1); 605 606 /* 607 * Write the actual dump data segment header 608 */ 609 CORE_SETMAGIC(seghdr, KCORESEG_MAGIC, 0, CORE_DATA); 610 seghdr.c_size = dumpsize; 611 if (fwrite((void*)&seghdr, sizeof(seghdr), 1, fp) <= 0) { 612 _kvm_syserr(kd, kd->program, "kvm_dump_wrtheader"); 613 return (-1); 614 } 615 offset += kd->kcore_hdr->c_seghdrsize; 616 gap = kd->kcore_hdr->c_seghdrsize - sizeof(seghdr); 617 if (clear_gap(kd, fp, gap) == -1) 618 return (-1); 619 620 return (offset); 621 } 622 623 kvm_t * 624 kvm_openfiles(uf, mf, sf, flag, errout) 625 const char *uf; 626 const char *mf; 627 const char *sf; 628 int flag; 629 char *errout; 630 { 631 register kvm_t *kd; 632 633 if ((kd = malloc(sizeof(*kd))) == NULL) { 634 (void)strcpy(errout, strerror(errno)); 635 return (0); 636 } 637 kd->program = 0; 638 return (_kvm_open(kd, uf, mf, sf, flag, errout)); 639 } 640 641 kvm_t * 642 kvm_open(uf, mf, sf, flag, program) 643 const char *uf; 644 const char *mf; 645 const char *sf; 646 int flag; 647 const char *program; 648 { 649 register kvm_t *kd; 650 651 if ((kd = malloc(sizeof(*kd))) == NULL && program != NULL) { 652 (void)fprintf(stderr, "%s: %s\n", strerror(errno)); 653 return (0); 654 } 655 kd->program = program; 656 return (_kvm_open(kd, uf, mf, sf, flag, NULL)); 657 } 658 659 int 660 kvm_close(kd) 661 kvm_t *kd; 662 { 663 register int error = 0; 664 665 if (kd->pmfd >= 0) 666 error |= close(kd->pmfd); 667 if (kd->vmfd >= 0) 668 error |= close(kd->vmfd); 669 if (kd->nlfd >= 0) 670 error |= close(kd->nlfd); 671 if (kd->swfd >= 0) 672 error |= close(kd->swfd); 673 if (kd->db != 0) 674 error |= (kd->db->close)(kd->db); 675 if (kd->vmst) 676 _kvm_freevtop(kd); 677 kd->cpu_dsize = 0; 678 if (kd->cpu_data != NULL) 679 free((void *)kd->cpu_data); 680 if (kd->kcore_hdr != NULL) 681 free((void *)kd->kcore_hdr); 682 if (kd->procbase != 0) 683 free((void *)kd->procbase); 684 if (kd->swapspc != 0) 685 free((void *)kd->swapspc); 686 if (kd->argspc != 0) 687 free((void *)kd->argspc); 688 if (kd->argbuf != 0) 689 free((void *)kd->argbuf); 690 if (kd->argv != 0) 691 free((void *)kd->argv); 692 free((void *)kd); 693 694 return (0); 695 } 696 697 /* 698 * Set up state necessary to do queries on the kernel namelist 699 * data base. If the data base is out-of-data/incompatible with 700 * given executable, set up things so we revert to standard nlist call. 701 * Only called for live kernels. Return 0 on success, -1 on failure. 702 */ 703 static int 704 kvm_dbopen(kd) 705 kvm_t *kd; 706 { 707 DBT rec; 708 int dbversionlen; 709 struct nlist nitem; 710 char dbversion[_POSIX2_LINE_MAX]; 711 char kversion[_POSIX2_LINE_MAX]; 712 713 kd->db = dbopen(_PATH_KVMDB, O_RDONLY, 0, DB_HASH, NULL); 714 if (kd->db == 0) 715 return (-1); 716 /* 717 * read version out of database 718 */ 719 rec.data = VRS_KEY; 720 rec.size = sizeof(VRS_KEY) - 1; 721 if ((kd->db->get)(kd->db, (DBT *)&rec, (DBT *)&rec, 0)) 722 goto close; 723 if (rec.data == 0 || rec.size > sizeof(dbversion)) 724 goto close; 725 726 bcopy(rec.data, dbversion, rec.size); 727 dbversionlen = rec.size; 728 /* 729 * Read version string from kernel memory. 730 * Since we are dealing with a live kernel, we can call kvm_read() 731 * at this point. 732 */ 733 rec.data = VRS_SYM; 734 rec.size = sizeof(VRS_SYM) - 1; 735 if ((kd->db->get)(kd->db, (DBT *)&rec, (DBT *)&rec, 0)) 736 goto close; 737 if (rec.data == 0 || rec.size != sizeof(struct nlist)) 738 goto close; 739 bcopy((char *)rec.data, (char *)&nitem, sizeof(nitem)); 740 if (kvm_read(kd, (u_long)nitem.n_value, kversion, dbversionlen) != 741 dbversionlen) 742 goto close; 743 /* 744 * If they match, we win - otherwise clear out kd->db so 745 * we revert to slow nlist(). 746 */ 747 if (bcmp(dbversion, kversion, dbversionlen) == 0) 748 return (0); 749 close: 750 (void)(kd->db->close)(kd->db); 751 kd->db = 0; 752 753 return (-1); 754 } 755 756 int 757 kvm_nlist(kd, nl) 758 kvm_t *kd; 759 struct nlist *nl; 760 { 761 register struct nlist *p; 762 register int nvalid, rv; 763 764 /* 765 * If we can't use the data base, revert to the 766 * slow library call. 767 */ 768 if (kd->db == 0) { 769 rv = __fdnlist(kd->nlfd, nl); 770 if (rv == -1) 771 _kvm_err(kd, 0, "bad namelist"); 772 return (rv); 773 } 774 775 /* 776 * We can use the kvm data base. Go through each nlist entry 777 * and look it up with a db query. 778 */ 779 nvalid = 0; 780 for (p = nl; p->n_name && p->n_name[0]; ++p) { 781 register int len; 782 DBT rec; 783 784 if ((len = strlen(p->n_name)) > 4096) { 785 /* sanity */ 786 _kvm_err(kd, kd->program, "symbol too large"); 787 return (-1); 788 } 789 rec.data = p->n_name; 790 rec.size = len; 791 792 /* 793 * Make sure that n_value = 0 when the symbol isn't found 794 */ 795 p->n_value = 0; 796 797 if ((kd->db->get)(kd->db, (DBT *)&rec, (DBT *)&rec, 0)) 798 continue; 799 if (rec.data == 0 || rec.size != sizeof(struct nlist)) 800 continue; 801 ++nvalid; 802 /* 803 * Avoid alignment issues. 804 */ 805 bcopy((char *)&((struct nlist *)rec.data)->n_type, 806 (char *)&p->n_type, 807 sizeof(p->n_type)); 808 bcopy((char *)&((struct nlist *)rec.data)->n_value, 809 (char *)&p->n_value, 810 sizeof(p->n_value)); 811 } 812 /* 813 * Return the number of entries that weren't found. 814 */ 815 return ((p - nl) - nvalid); 816 } 817 818 int kvm_dump_inval(kd) 819 kvm_t *kd; 820 { 821 struct nlist nlist[2]; 822 u_long pa; 823 824 if (ISALIVE(kd)) { 825 _kvm_err(kd, kd->program, "clearing dump on live kernel"); 826 return (-1); 827 } 828 nlist[0].n_name = "_dumpmag"; 829 nlist[1].n_name = NULL; 830 831 if (kvm_nlist(kd, nlist) == -1) { 832 _kvm_err(kd, 0, "bad namelist"); 833 return (-1); 834 } 835 if (_kvm_kvatop(kd, (u_long)nlist[0].n_value, &pa) == 0) 836 return (-1); 837 838 errno = 0; 839 if (lseek(kd->pmfd, _kvm_pa2off(kd, pa), SEEK_SET) == -1 840 && errno != 0) { 841 _kvm_err(kd, 0, "cannot invalidate dump - lseek"); 842 return (-1); 843 } 844 pa = 0; 845 if (write(kd->pmfd, &pa, sizeof(pa)) != sizeof(pa)) { 846 _kvm_err(kd, 0, "cannot invalidate dump - write"); 847 return (-1); 848 } 849 return (0); 850 } 851 852 ssize_t 853 kvm_read(kd, kva, buf, len) 854 kvm_t *kd; 855 register u_long kva; 856 register void *buf; 857 register size_t len; 858 { 859 register int cc; 860 register void *cp; 861 862 if (ISALIVE(kd)) { 863 /* 864 * We're using /dev/kmem. Just read straight from the 865 * device and let the active kernel do the address translation. 866 */ 867 errno = 0; 868 if (lseek(kd->vmfd, (off_t)kva, SEEK_SET) == -1 869 && errno != 0) { 870 _kvm_err(kd, 0, "invalid address (%x)", kva); 871 return (0); 872 } 873 cc = read(kd->vmfd, buf, len); 874 if (cc < 0) { 875 _kvm_syserr(kd, 0, "kvm_read"); 876 return (0); 877 } else if (cc < len) 878 _kvm_err(kd, kd->program, "short read"); 879 return (cc); 880 } else { 881 if ((kd->kcore_hdr == NULL) || (kd->cpu_data == NULL)) { 882 _kvm_err(kd, kd->program, "no valid dump header"); 883 return (0); 884 } 885 cp = buf; 886 while (len > 0) { 887 u_long pa; 888 off_t foff; 889 890 cc = _kvm_kvatop(kd, kva, &pa); 891 if (cc == 0) 892 return (0); 893 if (cc > len) 894 cc = len; 895 foff = _kvm_pa2off(kd, pa); 896 errno = 0; 897 if (lseek(kd->pmfd, foff, SEEK_SET) == -1 898 && errno != 0) { 899 _kvm_syserr(kd, 0, _PATH_MEM); 900 break; 901 } 902 cc = read(kd->pmfd, cp, cc); 903 if (cc < 0) { 904 _kvm_syserr(kd, kd->program, "kvm_read"); 905 break; 906 } 907 /* 908 * If kvm_kvatop returns a bogus value or our core 909 * file is truncated, we might wind up seeking beyond 910 * the end of the core file in which case the read will 911 * return 0 (EOF). 912 */ 913 if (cc == 0) 914 break; 915 cp = (char *)cp + cc; 916 kva += cc; 917 len -= cc; 918 } 919 return ((char *)cp - (char *)buf); 920 } 921 /* NOTREACHED */ 922 } 923 924 ssize_t 925 kvm_write(kd, kva, buf, len) 926 kvm_t *kd; 927 register u_long kva; 928 register const void *buf; 929 register size_t len; 930 { 931 register int cc; 932 933 if (ISALIVE(kd)) { 934 /* 935 * Just like kvm_read, only we write. 936 */ 937 errno = 0; 938 if (lseek(kd->vmfd, (off_t)kva, SEEK_SET) == -1 939 && errno != 0) { 940 _kvm_err(kd, 0, "invalid address (%x)", kva); 941 return (0); 942 } 943 cc = write(kd->vmfd, buf, len); 944 if (cc < 0) { 945 _kvm_syserr(kd, 0, "kvm_write"); 946 return (0); 947 } else if (cc < len) 948 _kvm_err(kd, kd->program, "short write"); 949 return (cc); 950 } else { 951 _kvm_err(kd, kd->program, 952 "kvm_write not implemented for dead kernels"); 953 return (0); 954 } 955 /* NOTREACHED */ 956 } 957
Indexes created Sun Sep 21 20:09:37 GMT 2025