kvm.c revision 1.65.4.1
1 /* $NetBSD: kvm.c,v 1.65.4.1 2001/02/03 20:32:33 he 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 #include <sys/cdefs.h> 41 #if defined(LIBC_SCCS) && !defined(lint) 42 #if 0 43 static char sccsid[] = "@(#)kvm.c 8.2 (Berkeley) 2/13/94"; 44 #else 45 __RCSID("$NetBSD: kvm.c,v 1.65.4.1 2001/02/03 20:32:33 he Exp $"); 46 #endif 47 #endif /* LIBC_SCCS and not lint */ 48 49 #include <sys/param.h> 50 #include <sys/user.h> 51 #include <sys/proc.h> 52 #include <sys/ioctl.h> 53 #include <sys/stat.h> 54 #include <sys/sysctl.h> 55 56 #include <sys/core.h> 57 #include <sys/exec_aout.h> 58 #include <sys/kcore.h> 59 60 #include <vm/vm.h> 61 #include <vm/vm_param.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 Pread __P((kvm_t *, int, void *, size_t, off_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), 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 size_t 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 char *cp = kd->errbuf; 156 157 (void)vsnprintf(cp, sizeof(kd->errbuf), 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 kvm_t *kd; 168 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 * Wrapper around the lseek(2) system call; calls _kvm_syserr() for us 179 * in the event of emergency. 180 */ 181 static off_t 182 Lseek(kd, fd, offset, whence) 183 kvm_t *kd; 184 int fd; 185 off_t offset; 186 int whence; 187 { 188 off_t off; 189 190 errno = 0; 191 192 if ((off = lseek(fd, offset, whence)) == -1 && errno != 0) { 193 _kvm_syserr(kd, kd->program, "Lseek"); 194 return ((off_t)-1); 195 } 196 return (off); 197 } 198 199 /* 200 * Wrapper around the pread(2) system call; calls _kvm_syserr() for us 201 * in the event of emergency. 202 */ 203 static ssize_t 204 Pread(kd, fd, buf, nbytes, offset) 205 kvm_t *kd; 206 int fd; 207 void *buf; 208 size_t nbytes; 209 off_t offset; 210 { 211 ssize_t rv; 212 213 errno = 0; 214 215 if ((rv = pread(fd, buf, nbytes, offset)) != nbytes && 216 errno != 0) 217 _kvm_syserr(kd, kd->program, "Pread"); 218 return (rv); 219 } 220 221 static kvm_t * 222 _kvm_open(kd, uf, mf, sf, flag, errout) 223 kvm_t *kd; 224 const char *uf; 225 const char *mf; 226 const char *sf; 227 int flag; 228 char *errout; 229 { 230 struct stat st; 231 int ufgiven; 232 233 kd->db = 0; 234 kd->pmfd = -1; 235 kd->vmfd = -1; 236 kd->swfd = -1; 237 kd->nlfd = -1; 238 kd->alive = KVM_ALIVE_DEAD; 239 kd->procbase = 0; 240 kd->procbase2 = 0; 241 kd->nbpg = getpagesize(); 242 kd->swapspc = 0; 243 kd->argspc = 0; 244 kd->arglen = 0; 245 kd->argbuf = 0; 246 kd->argv = 0; 247 kd->vmst = 0; 248 kd->vm_page_buckets = 0; 249 kd->kcore_hdr = 0; 250 kd->cpu_dsize = 0; 251 kd->cpu_data = 0; 252 kd->dump_off = 0; 253 254 if (flag & KVM_NO_FILES) { 255 kd->alive = KVM_ALIVE_SYSCTL; 256 return(kd); 257 } 258 259 /* 260 * Call the MD open hook. This sets: 261 * usrstack, min_uva, max_uva 262 */ 263 if (_kvm_mdopen(kd)) { 264 _kvm_err(kd, kd->program, "md init failed"); 265 goto failed; 266 } 267 268 ufgiven = (uf != NULL); 269 if (!ufgiven) 270 uf = _PATH_UNIX; 271 else if (strlen(uf) >= MAXPATHLEN) { 272 _kvm_err(kd, kd->program, "exec file name too long"); 273 goto failed; 274 } 275 if (flag & ~O_RDWR) { 276 _kvm_err(kd, kd->program, "bad flags arg"); 277 goto failed; 278 } 279 if (mf == 0) 280 mf = _PATH_MEM; 281 if (sf == 0) 282 sf = _PATH_DRUM; 283 284 if ((kd->pmfd = open(mf, flag, 0)) < 0) { 285 _kvm_syserr(kd, kd->program, "%s", mf); 286 goto failed; 287 } 288 if (fstat(kd->pmfd, &st) < 0) { 289 _kvm_syserr(kd, kd->program, "%s", mf); 290 goto failed; 291 } 292 if (S_ISCHR(st.st_mode)) { 293 /* 294 * If this is a character special device, then check that 295 * it's /dev/mem. If so, open kmem too. (Maybe we should 296 * make it work for either /dev/mem or /dev/kmem -- in either 297 * case you're working with a live kernel.) 298 */ 299 if (strcmp(mf, _PATH_MEM) != 0) { /* XXX */ 300 _kvm_err(kd, kd->program, 301 "%s: not physical memory device", mf); 302 goto failed; 303 } 304 if ((kd->vmfd = open(_PATH_KMEM, flag)) < 0) { 305 _kvm_syserr(kd, kd->program, "%s", _PATH_KMEM); 306 goto failed; 307 } 308 kd->alive = KVM_ALIVE_FILES; 309 if ((kd->swfd = open(sf, flag, 0)) < 0) { 310 _kvm_syserr(kd, kd->program, "%s", sf); 311 goto failed; 312 } 313 /* 314 * Open kvm nlist database. We only try to use 315 * the pre-built database if the namelist file name 316 * pointer is NULL. If the database cannot or should 317 * not be opened, open the namelist argument so we 318 * revert to slow nlist() calls. 319 */ 320 if ((ufgiven || kvm_dbopen(kd) < 0) && 321 (kd->nlfd = open(uf, O_RDONLY, 0)) < 0) { 322 _kvm_syserr(kd, kd->program, "%s", uf); 323 goto failed; 324 } 325 } else { 326 /* 327 * This is a crash dump. 328 * Initalize the virtual address translation machinery, 329 * but first setup the namelist fd. 330 */ 331 if ((kd->nlfd = open(uf, O_RDONLY, 0)) < 0) { 332 _kvm_syserr(kd, kd->program, "%s", uf); 333 goto failed; 334 } 335 336 /* 337 * If there is no valid core header, fail silently here. 338 * The address translations however will fail without 339 * header. Things can be made to run by calling 340 * kvm_dump_mkheader() before doing any translation. 341 */ 342 if (_kvm_get_header(kd) == 0) { 343 if (_kvm_initvtop(kd) < 0) 344 goto failed; 345 } 346 } 347 return (kd); 348 failed: 349 /* 350 * Copy out the error if doing sane error semantics. 351 */ 352 if (errout != 0) 353 (void)strncpy(errout, kd->errbuf, _POSIX2_LINE_MAX - 1); 354 (void)kvm_close(kd); 355 return (0); 356 } 357 358 /* 359 * The kernel dump file (from savecore) contains: 360 * kcore_hdr_t kcore_hdr; 361 * kcore_seg_t cpu_hdr; 362 * (opaque) cpu_data; (size is cpu_hdr.c_size) 363 * kcore_seg_t mem_hdr; 364 * (memory) mem_data; (size is mem_hdr.c_size) 365 * 366 * Note: khdr is padded to khdr.c_hdrsize; 367 * cpu_hdr and mem_hdr are padded to khdr.c_seghdrsize 368 */ 369 static int 370 _kvm_get_header(kd) 371 kvm_t *kd; 372 { 373 kcore_hdr_t kcore_hdr; 374 kcore_seg_t cpu_hdr; 375 kcore_seg_t mem_hdr; 376 size_t offset; 377 ssize_t sz; 378 379 /* 380 * Read the kcore_hdr_t 381 */ 382 sz = Pread(kd, kd->pmfd, &kcore_hdr, sizeof(kcore_hdr), (off_t)0); 383 if (sz != sizeof(kcore_hdr)) 384 return (-1); 385 386 /* 387 * Currently, we only support dump-files made by the current 388 * architecture... 389 */ 390 if ((CORE_GETMAGIC(kcore_hdr) != KCORE_MAGIC) || 391 (CORE_GETMID(kcore_hdr) != MID_MACHINE)) 392 return (-1); 393 394 /* 395 * Currently, we only support exactly 2 segments: cpu-segment 396 * and data-segment in exactly that order. 397 */ 398 if (kcore_hdr.c_nseg != 2) 399 return (-1); 400 401 /* 402 * Save away the kcore_hdr. All errors after this 403 * should do a to "goto fail" to deallocate things. 404 */ 405 kd->kcore_hdr = _kvm_malloc(kd, sizeof(kcore_hdr)); 406 memcpy(kd->kcore_hdr, &kcore_hdr, sizeof(kcore_hdr)); 407 offset = kcore_hdr.c_hdrsize; 408 409 /* 410 * Read the CPU segment header 411 */ 412 sz = Pread(kd, kd->pmfd, &cpu_hdr, sizeof(cpu_hdr), (off_t)offset); 413 if (sz != sizeof(cpu_hdr)) 414 goto fail; 415 if ((CORE_GETMAGIC(cpu_hdr) != KCORESEG_MAGIC) || 416 (CORE_GETFLAG(cpu_hdr) != CORE_CPU)) 417 goto fail; 418 offset += kcore_hdr.c_seghdrsize; 419 420 /* 421 * Read the CPU segment DATA. 422 */ 423 kd->cpu_dsize = cpu_hdr.c_size; 424 kd->cpu_data = _kvm_malloc(kd, cpu_hdr.c_size); 425 if (kd->cpu_data == NULL) 426 goto fail; 427 sz = Pread(kd, kd->pmfd, kd->cpu_data, cpu_hdr.c_size, (off_t)offset); 428 if (sz != cpu_hdr.c_size) 429 goto fail; 430 offset += cpu_hdr.c_size; 431 432 /* 433 * Read the next segment header: data segment 434 */ 435 sz = Pread(kd, kd->pmfd, &mem_hdr, sizeof(mem_hdr), (off_t)offset); 436 if (sz != sizeof(mem_hdr)) 437 goto fail; 438 offset += kcore_hdr.c_seghdrsize; 439 440 if ((CORE_GETMAGIC(mem_hdr) != KCORESEG_MAGIC) || 441 (CORE_GETFLAG(mem_hdr) != CORE_DATA)) 442 goto fail; 443 444 kd->dump_off = offset; 445 return (0); 446 447 fail: 448 if (kd->kcore_hdr != NULL) { 449 free(kd->kcore_hdr); 450 kd->kcore_hdr = NULL; 451 } 452 if (kd->cpu_data != NULL) { 453 free(kd->cpu_data); 454 kd->cpu_data = NULL; 455 kd->cpu_dsize = 0; 456 } 457 return (-1); 458 } 459 460 /* 461 * The format while on the dump device is: (new format) 462 * kcore_seg_t cpu_hdr; 463 * (opaque) cpu_data; (size is cpu_hdr.c_size) 464 * kcore_seg_t mem_hdr; 465 * (memory) mem_data; (size is mem_hdr.c_size) 466 */ 467 int 468 kvm_dump_mkheader(kd, dump_off) 469 kvm_t *kd; 470 off_t dump_off; 471 { 472 kcore_seg_t cpu_hdr; 473 size_t hdr_size; 474 ssize_t sz; 475 476 if (kd->kcore_hdr != NULL) { 477 _kvm_err(kd, kd->program, "already has a dump header"); 478 return (-1); 479 } 480 if (ISALIVE(kd)) { 481 _kvm_err(kd, kd->program, "don't use on live kernel"); 482 return (-1); 483 } 484 485 /* 486 * Validate new format crash dump 487 */ 488 sz = Pread(kd, kd->pmfd, &cpu_hdr, sizeof(cpu_hdr), dump_off); 489 if (sz != sizeof(cpu_hdr)) 490 return (-1); 491 if ((CORE_GETMAGIC(cpu_hdr) != KCORE_MAGIC) 492 || (CORE_GETMID(cpu_hdr) != MID_MACHINE)) { 493 _kvm_err(kd, 0, "invalid magic in cpu_hdr"); 494 return (0); 495 } 496 hdr_size = ALIGN(sizeof(cpu_hdr)); 497 498 /* 499 * Read the CPU segment. 500 */ 501 kd->cpu_dsize = cpu_hdr.c_size; 502 kd->cpu_data = _kvm_malloc(kd, kd->cpu_dsize); 503 if (kd->cpu_data == NULL) 504 goto fail; 505 sz = Pread(kd, kd->pmfd, kd->cpu_data, cpu_hdr.c_size, 506 dump_off + hdr_size); 507 if (sz != cpu_hdr.c_size) 508 goto fail; 509 hdr_size += kd->cpu_dsize; 510 511 /* 512 * Leave phys mem pointer at beginning of memory data 513 */ 514 kd->dump_off = dump_off + hdr_size; 515 if (Lseek(kd, kd->pmfd, kd->dump_off, SEEK_SET) == -1) 516 goto fail; 517 518 /* 519 * Create a kcore_hdr. 520 */ 521 kd->kcore_hdr = _kvm_malloc(kd, sizeof(kcore_hdr_t)); 522 if (kd->kcore_hdr == NULL) 523 goto fail; 524 525 kd->kcore_hdr->c_hdrsize = ALIGN(sizeof(kcore_hdr_t)); 526 kd->kcore_hdr->c_seghdrsize = ALIGN(sizeof(kcore_seg_t)); 527 kd->kcore_hdr->c_nseg = 2; 528 CORE_SETMAGIC(*(kd->kcore_hdr), KCORE_MAGIC, MID_MACHINE,0); 529 530 /* 531 * Now that we have a valid header, enable translations. 532 */ 533 if (_kvm_initvtop(kd) == 0) 534 /* Success */ 535 return (hdr_size); 536 537 fail: 538 if (kd->kcore_hdr != NULL) { 539 free(kd->kcore_hdr); 540 kd->kcore_hdr = NULL; 541 } 542 if (kd->cpu_data != NULL) { 543 free(kd->cpu_data); 544 kd->cpu_data = NULL; 545 kd->cpu_dsize = 0; 546 } 547 return (-1); 548 } 549 550 static int 551 clear_gap(kd, fp, size) 552 kvm_t *kd; 553 FILE *fp; 554 int size; 555 { 556 if (size <= 0) /* XXX - < 0 should never happen */ 557 return (0); 558 while (size-- > 0) { 559 if (fputc(0, fp) == EOF) { 560 _kvm_syserr(kd, kd->program, "clear_gap"); 561 return (-1); 562 } 563 } 564 return (0); 565 } 566 567 /* 568 * Write the dump header info to 'fp'. Note that we can't use fseek(3) here 569 * because 'fp' might be a file pointer obtained by zopen(). 570 */ 571 int 572 kvm_dump_wrtheader(kd, fp, dumpsize) 573 kvm_t *kd; 574 FILE *fp; 575 int dumpsize; 576 { 577 kcore_seg_t seghdr; 578 long offset; 579 int gap; 580 581 if (kd->kcore_hdr == NULL || kd->cpu_data == NULL) { 582 _kvm_err(kd, kd->program, "no valid dump header(s)"); 583 return (-1); 584 } 585 586 /* 587 * Write the generic header 588 */ 589 offset = 0; 590 if (fwrite((void*)kd->kcore_hdr, sizeof(kcore_hdr_t), 1, fp) == 0) { 591 _kvm_syserr(kd, kd->program, "kvm_dump_wrtheader"); 592 return (-1); 593 } 594 offset += kd->kcore_hdr->c_hdrsize; 595 gap = kd->kcore_hdr->c_hdrsize - sizeof(kcore_hdr_t); 596 if (clear_gap(kd, fp, gap) == -1) 597 return (-1); 598 599 /* 600 * Write the cpu header 601 */ 602 CORE_SETMAGIC(seghdr, KCORESEG_MAGIC, 0, CORE_CPU); 603 seghdr.c_size = ALIGN(kd->cpu_dsize); 604 if (fwrite((void*)&seghdr, sizeof(seghdr), 1, fp) == 0) { 605 _kvm_syserr(kd, kd->program, "kvm_dump_wrtheader"); 606 return (-1); 607 } 608 offset += kd->kcore_hdr->c_seghdrsize; 609 gap = kd->kcore_hdr->c_seghdrsize - sizeof(seghdr); 610 if (clear_gap(kd, fp, gap) == -1) 611 return (-1); 612 613 if (fwrite((void*)kd->cpu_data, kd->cpu_dsize, 1, fp) == 0) { 614 _kvm_syserr(kd, kd->program, "kvm_dump_wrtheader"); 615 return (-1); 616 } 617 offset += seghdr.c_size; 618 gap = seghdr.c_size - kd->cpu_dsize; 619 if (clear_gap(kd, fp, gap) == -1) 620 return (-1); 621 622 /* 623 * Write the actual dump data segment header 624 */ 625 CORE_SETMAGIC(seghdr, KCORESEG_MAGIC, 0, CORE_DATA); 626 seghdr.c_size = dumpsize; 627 if (fwrite((void*)&seghdr, sizeof(seghdr), 1, fp) == 0) { 628 _kvm_syserr(kd, kd->program, "kvm_dump_wrtheader"); 629 return (-1); 630 } 631 offset += kd->kcore_hdr->c_seghdrsize; 632 gap = kd->kcore_hdr->c_seghdrsize - sizeof(seghdr); 633 if (clear_gap(kd, fp, gap) == -1) 634 return (-1); 635 636 return (int)offset; 637 } 638 639 kvm_t * 640 kvm_openfiles(uf, mf, sf, flag, errout) 641 const char *uf; 642 const char *mf; 643 const char *sf; 644 int flag; 645 char *errout; 646 { 647 kvm_t *kd; 648 649 if ((kd = malloc(sizeof(*kd))) == NULL) { 650 (void)strncpy(errout, strerror(errno), _POSIX2_LINE_MAX - 1); 651 return (0); 652 } 653 kd->program = 0; 654 return (_kvm_open(kd, uf, mf, sf, flag, errout)); 655 } 656 657 kvm_t * 658 kvm_open(uf, mf, sf, flag, program) 659 const char *uf; 660 const char *mf; 661 const char *sf; 662 int flag; 663 const char *program; 664 { 665 kvm_t *kd; 666 667 if ((kd = malloc(sizeof(*kd))) == NULL && program != NULL) { 668 (void)fprintf(stderr, "%s: %s\n", program, strerror(errno)); 669 return (0); 670 } 671 kd->program = program; 672 return (_kvm_open(kd, uf, mf, sf, flag, NULL)); 673 } 674 675 int 676 kvm_close(kd) 677 kvm_t *kd; 678 { 679 int error = 0; 680 681 if (kd->pmfd >= 0) 682 error |= close(kd->pmfd); 683 if (kd->vmfd >= 0) 684 error |= close(kd->vmfd); 685 if (kd->nlfd >= 0) 686 error |= close(kd->nlfd); 687 if (kd->swfd >= 0) 688 error |= close(kd->swfd); 689 if (kd->db != 0) 690 error |= (kd->db->close)(kd->db); 691 if (kd->vmst) 692 _kvm_freevtop(kd); 693 kd->cpu_dsize = 0; 694 if (kd->cpu_data != NULL) 695 free((void *)kd->cpu_data); 696 if (kd->kcore_hdr != NULL) 697 free((void *)kd->kcore_hdr); 698 if (kd->procbase != 0) 699 free((void *)kd->procbase); 700 if (kd->procbase2 != 0) 701 free((void *)kd->procbase2); 702 if (kd->swapspc != 0) 703 free((void *)kd->swapspc); 704 if (kd->argspc != 0) 705 free((void *)kd->argspc); 706 if (kd->argbuf != 0) 707 free((void *)kd->argbuf); 708 if (kd->argv != 0) 709 free((void *)kd->argv); 710 free((void *)kd); 711 712 return (0); 713 } 714 715 /* 716 * Set up state necessary to do queries on the kernel namelist 717 * data base. If the data base is out-of-data/incompatible with 718 * given executable, set up things so we revert to standard nlist call. 719 * Only called for live kernels. Return 0 on success, -1 on failure. 720 */ 721 static int 722 kvm_dbopen(kd) 723 kvm_t *kd; 724 { 725 DBT rec; 726 size_t dbversionlen; 727 struct nlist nitem; 728 char dbversion[_POSIX2_LINE_MAX]; 729 char kversion[_POSIX2_LINE_MAX]; 730 731 kd->db = dbopen(_PATH_KVMDB, O_RDONLY, 0, DB_HASH, NULL); 732 if (kd->db == 0) 733 return (-1); 734 /* 735 * read version out of database 736 */ 737 rec.data = VRS_KEY; 738 rec.size = sizeof(VRS_KEY) - 1; 739 if ((kd->db->get)(kd->db, (DBT *)&rec, (DBT *)&rec, 0)) 740 goto close; 741 if (rec.data == 0 || rec.size > sizeof(dbversion)) 742 goto close; 743 744 memcpy(dbversion, rec.data, rec.size); 745 dbversionlen = rec.size; 746 /* 747 * Read version string from kernel memory. 748 * Since we are dealing with a live kernel, we can call kvm_read() 749 * at this point. 750 */ 751 rec.data = VRS_SYM; 752 rec.size = sizeof(VRS_SYM) - 1; 753 if ((kd->db->get)(kd->db, (DBT *)&rec, (DBT *)&rec, 0)) 754 goto close; 755 if (rec.data == 0 || rec.size != sizeof(struct nlist)) 756 goto close; 757 memcpy(&nitem, rec.data, sizeof(nitem)); 758 if (kvm_read(kd, (u_long)nitem.n_value, kversion, dbversionlen) != 759 dbversionlen) 760 goto close; 761 /* 762 * If they match, we win - otherwise clear out kd->db so 763 * we revert to slow nlist(). 764 */ 765 if (memcmp(dbversion, kversion, dbversionlen) == 0) 766 return (0); 767 close: 768 (void)(kd->db->close)(kd->db); 769 kd->db = 0; 770 771 return (-1); 772 } 773 774 int 775 kvm_nlist(kd, nl) 776 kvm_t *kd; 777 struct nlist *nl; 778 { 779 struct nlist *p; 780 int nvalid, rv; 781 782 /* 783 * If we can't use the data base, revert to the 784 * slow library call. 785 */ 786 if (kd->db == 0) { 787 rv = __fdnlist(kd->nlfd, nl); 788 if (rv == -1) 789 _kvm_err(kd, 0, "bad namelist"); 790 return (rv); 791 } 792 793 /* 794 * We can use the kvm data base. Go through each nlist entry 795 * and look it up with a db query. 796 */ 797 nvalid = 0; 798 for (p = nl; p->n_name && p->n_name[0]; ++p) { 799 int len; 800 DBT rec; 801 802 if ((len = strlen(p->n_name)) > 4096) { 803 /* sanity */ 804 _kvm_err(kd, kd->program, "symbol too large"); 805 return (-1); 806 } 807 rec.data = (char *)p->n_name; 808 rec.size = len; 809 810 /* 811 * Make sure that n_value = 0 when the symbol isn't found 812 */ 813 p->n_value = 0; 814 815 if ((kd->db->get)(kd->db, (DBT *)&rec, (DBT *)&rec, 0)) 816 continue; 817 if (rec.data == 0 || rec.size != sizeof(struct nlist)) 818 continue; 819 ++nvalid; 820 /* 821 * Avoid alignment issues. 822 */ 823 (void)memcpy(&p->n_type, &((struct nlist *)rec.data)->n_type, 824 sizeof(p->n_type)); 825 (void)memcpy(&p->n_value, &((struct nlist *)rec.data)->n_value, 826 sizeof(p->n_value)); 827 } 828 /* 829 * Return the number of entries that weren't found. 830 */ 831 return ((p - nl) - nvalid); 832 } 833 834 int kvm_dump_inval(kd) 835 kvm_t *kd; 836 { 837 struct nlist nl[2]; 838 u_long pa, val; 839 840 if (ISALIVE(kd)) { 841 _kvm_err(kd, kd->program, "clearing dump on live kernel"); 842 return (-1); 843 } 844 nl[0].n_name = "_dumpmag"; 845 nl[1].n_name = NULL; 846 847 if (kvm_nlist(kd, nl) == -1) { 848 _kvm_err(kd, 0, "bad namelist"); 849 return (-1); 850 } 851 if (_kvm_kvatop(kd, (u_long)nl[0].n_value, &pa) == 0) 852 return (-1); 853 854 errno = 0; 855 val = 0; 856 if (pwrite(kd->pmfd, (void *) &val, sizeof(val), 857 _kvm_pa2off(kd, pa)) == -1) { 858 _kvm_syserr(kd, 0, "cannot invalidate dump - pwrite"); 859 return (-1); 860 } 861 return (0); 862 } 863 864 ssize_t 865 kvm_read(kd, kva, buf, len) 866 kvm_t *kd; 867 u_long kva; 868 void *buf; 869 size_t len; 870 { 871 int cc; 872 void *cp; 873 874 if (ISKMEM(kd)) { 875 /* 876 * We're using /dev/kmem. Just read straight from the 877 * device and let the active kernel do the address translation. 878 */ 879 errno = 0; 880 cc = pread(kd->vmfd, buf, len, (off_t)kva); 881 if (cc < 0) { 882 _kvm_syserr(kd, 0, "kvm_read"); 883 return (-1); 884 } else if (cc < len) 885 _kvm_err(kd, kd->program, "short read"); 886 return (cc); 887 } else if (ISSYSCTL(kd)) { 888 _kvm_err(kd, kd->program, "kvm_open called with KVM_NO_FILES, " 889 "can't use kvm_read"); 890 return (-1); 891 } else { 892 if ((kd->kcore_hdr == NULL) || (kd->cpu_data == NULL)) { 893 _kvm_err(kd, kd->program, "no valid dump header"); 894 return (-1); 895 } 896 cp = buf; 897 while (len > 0) { 898 u_long pa; 899 off_t foff; 900 901 cc = _kvm_kvatop(kd, kva, &pa); 902 if (cc == 0) 903 return (-1); 904 if (cc > len) 905 cc = len; 906 foff = _kvm_pa2off(kd, pa); 907 errno = 0; 908 cc = pread(kd->pmfd, cp, (size_t)cc, foff); 909 if (cc < 0) { 910 _kvm_syserr(kd, kd->program, "kvm_read"); 911 break; 912 } 913 /* 914 * If kvm_kvatop returns a bogus value or our core 915 * file is truncated, we might wind up seeking beyond 916 * the end of the core file in which case the read will 917 * return 0 (EOF). 918 */ 919 if (cc == 0) 920 break; 921 cp = (char *)cp + cc; 922 kva += cc; 923 len -= cc; 924 } 925 return ((char *)cp - (char *)buf); 926 } 927 /* NOTREACHED */ 928 } 929 930 ssize_t 931 kvm_write(kd, kva, buf, len) 932 kvm_t *kd; 933 u_long kva; 934 const void *buf; 935 size_t len; 936 { 937 int cc; 938 939 if (ISKMEM(kd)) { 940 /* 941 * Just like kvm_read, only we write. 942 */ 943 errno = 0; 944 cc = pwrite(kd->vmfd, buf, len, (off_t)kva); 945 if (cc < 0) { 946 _kvm_syserr(kd, 0, "kvm_write"); 947 return (-1); 948 } else if (cc < len) 949 _kvm_err(kd, kd->program, "short write"); 950 return (cc); 951 } else if (ISSYSCTL(kd)) { 952 _kvm_err(kd, kd->program, "kvm_open called with KVM_NO_FILES, " 953 "can't use kvm_write"); 954 return (-1); 955 } else { 956 _kvm_err(kd, kd->program, 957 "kvm_write not implemented for dead kernels"); 958 return (-1); 959 } 960 /* NOTREACHED */ 961 } 962
Indexes created Mon Sep 29 18:09:42 GMT 2025