1 /* $NetBSD: kvm.c,v 1.94 2009/09/14 19:29:20 apb 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. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include <sys/cdefs.h> 37 #if defined(LIBC_SCCS) && !defined(lint) 38 #if 0 39 static char sccsid[] = "@(#)kvm.c 8.2 (Berkeley) 2/13/94"; 40 #else 41 __RCSID("$NetBSD: kvm.c,v 1.94 2009/09/14 19:29:20 apb Exp $"); 42 #endif 43 #endif /* LIBC_SCCS and not lint */ 44 45 #include <sys/param.h> 46 #include <sys/user.h> 47 #include <sys/lwp.h> 48 #include <sys/proc.h> 49 #include <sys/ioctl.h> 50 #include <sys/stat.h> 51 #include <sys/sysctl.h> 52 53 #include <sys/core.h> 54 #include <sys/exec.h> 55 #include <sys/kcore.h> 56 #include <sys/ksyms.h> 57 58 #include <uvm/uvm_extern.h> 59 60 #include <machine/cpu.h> 61 62 #include <ctype.h> 63 #include <errno.h> 64 #include <fcntl.h> 65 #include <limits.h> 66 #include <nlist.h> 67 #include <paths.h> 68 #include <stdarg.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_get_header(kvm_t *); 78 static kvm_t *_kvm_open(kvm_t *, const char *, const char *, 79 const char *, int, char *); 80 static int clear_gap(kvm_t *, bool (*)(void *, const void *, size_t), 81 void *, size_t); 82 static int open_cloexec(const char *, int, int); 83 static off_t Lseek(kvm_t *, int, off_t, int); 84 static ssize_t Pread(kvm_t *, int, void *, size_t, off_t); 85 86 char * 87 kvm_geterr(kvm_t *kd) 88 { 89 return (kd->errbuf); 90 } 91 92 /* 93 * Report an error using printf style arguments. "program" is kd->program 94 * on hard errors, and 0 on soft errors, so that under sun error emulation, 95 * only hard errors are printed out (otherwise, programs like gdb will 96 * generate tons of error messages when trying to access bogus pointers). 97 */ 98 void 99 _kvm_err(kvm_t *kd, const char *program, const char *fmt, ...) 100 { 101 va_list ap; 102 103 va_start(ap, fmt); 104 if (program != NULL) { 105 (void)fprintf(stderr, "%s: ", program); 106 (void)vfprintf(stderr, fmt, ap); 107 (void)fputc('\n', stderr); 108 } else 109 (void)vsnprintf(kd->errbuf, 110 sizeof(kd->errbuf), fmt, ap); 111 112 va_end(ap); 113 } 114 115 void 116 _kvm_syserr(kvm_t *kd, const char *program, const char *fmt, ...) 117 { 118 va_list ap; 119 size_t n; 120 121 va_start(ap, fmt); 122 if (program != NULL) { 123 (void)fprintf(stderr, "%s: ", program); 124 (void)vfprintf(stderr, fmt, ap); 125 (void)fprintf(stderr, ": %s\n", strerror(errno)); 126 } else { 127 char *cp = kd->errbuf; 128 129 (void)vsnprintf(cp, sizeof(kd->errbuf), fmt, ap); 130 n = strlen(cp); 131 (void)snprintf(&cp[n], sizeof(kd->errbuf) - n, ": %s", 132 strerror(errno)); 133 } 134 va_end(ap); 135 } 136 137 void * 138 _kvm_malloc(kvm_t *kd, size_t n) 139 { 140 void *p; 141 142 if ((p = malloc(n)) == NULL) 143 _kvm_err(kd, kd->program, "%s", strerror(errno)); 144 return (p); 145 } 146 147 /* 148 * Open a file setting the close on exec bit. 149 */ 150 static int 151 open_cloexec(const char *fname, int flags, int mode) 152 { 153 int fd; 154 155 if ((fd = open(fname, flags, mode)) == -1) 156 return fd; 157 if (fcntl(fd, F_SETFD, FD_CLOEXEC) == -1) 158 goto error; 159 160 return fd; 161 error: 162 flags = errno; 163 (void)close(fd); 164 errno = flags; 165 return -1; 166 } 167 168 /* 169 * Wrapper around the lseek(2) system call; calls _kvm_syserr() for us 170 * in the event of emergency. 171 */ 172 static off_t 173 Lseek(kvm_t *kd, int fd, off_t offset, int whence) 174 { 175 off_t off; 176 177 errno = 0; 178 179 if ((off = lseek(fd, offset, whence)) == -1 && errno != 0) { 180 _kvm_syserr(kd, kd->program, "Lseek"); 181 return ((off_t)-1); 182 } 183 return (off); 184 } 185 186 ssize_t 187 _kvm_pread(kvm_t *kd, int fd, void *buf, size_t size, off_t off) 188 { 189 ptrdiff_t moff; 190 void *newbuf; 191 size_t dsize; 192 ssize_t rv; 193 off_t doff; 194 195 /* If aligned nothing to do. */ 196 if (((off % kd->fdalign) | (size % kd->fdalign)) == 0) { 197 return pread(fd, buf, size, off); 198 } 199 200 /* 201 * Otherwise must buffer. We can't tolerate short reads in this 202 * case (lazy bum). 203 */ 204 moff = (ptrdiff_t)off % kd->fdalign; 205 doff = off - moff; 206 dsize = moff + size + kd->fdalign - 1; 207 dsize -= dsize % kd->fdalign; 208 if (kd->iobufsz < dsize) { 209 newbuf = realloc(kd->iobuf, dsize); 210 if (newbuf == NULL) { 211 _kvm_syserr(kd, 0, "cannot allocate I/O buffer"); 212 return (-1); 213 } 214 kd->iobuf = newbuf; 215 kd->iobufsz = dsize; 216 } 217 rv = pread(fd, kd->iobuf, dsize, doff); 218 if (rv < dsize) 219 return -1; 220 memcpy(buf, kd->iobuf + moff, size); 221 return size; 222 } 223 224 /* 225 * Wrapper around the pread(2) system call; calls _kvm_syserr() for us 226 * in the event of emergency. 227 */ 228 static ssize_t 229 Pread(kvm_t *kd, int fd, void *buf, size_t nbytes, off_t offset) 230 { 231 ssize_t rv; 232 233 errno = 0; 234 235 if ((rv = _kvm_pread(kd, fd, buf, nbytes, offset)) != nbytes && 236 errno != 0) 237 _kvm_syserr(kd, kd->program, "Pread"); 238 return (rv); 239 } 240 241 static kvm_t * 242 _kvm_open(kvm_t *kd, const char *uf, const char *mf, const char *sf, int flag, 243 char *errout) 244 { 245 struct stat st; 246 int ufgiven; 247 248 kd->pmfd = -1; 249 kd->vmfd = -1; 250 kd->swfd = -1; 251 kd->nlfd = -1; 252 kd->alive = KVM_ALIVE_DEAD; 253 kd->procbase = NULL; 254 kd->procbase_len = 0; 255 kd->procbase2 = NULL; 256 kd->procbase2_len = 0; 257 kd->lwpbase = NULL; 258 kd->lwpbase_len = 0; 259 kd->nbpg = getpagesize(); 260 kd->swapspc = NULL; 261 kd->argspc = NULL; 262 kd->argspc_len = 0; 263 kd->argbuf = NULL; 264 kd->argv = NULL; 265 kd->vmst = NULL; 266 kd->vm_page_buckets = NULL; 267 kd->kcore_hdr = NULL; 268 kd->cpu_dsize = 0; 269 kd->cpu_data = NULL; 270 kd->dump_off = 0; 271 kd->fdalign = 1; 272 kd->iobuf = NULL; 273 kd->iobufsz = 0; 274 275 if (flag & KVM_NO_FILES) { 276 kd->alive = KVM_ALIVE_SYSCTL; 277 return(kd); 278 } 279 280 /* 281 * Call the MD open hook. This sets: 282 * usrstack, min_uva, max_uva 283 */ 284 if (_kvm_mdopen(kd)) { 285 _kvm_err(kd, kd->program, "md init failed"); 286 goto failed; 287 } 288 289 ufgiven = (uf != NULL); 290 if (!ufgiven) { 291 #ifdef CPU_BOOTED_KERNEL 292 /* 130 is 128 + '/' + '\0' */ 293 static char booted_kernel[130]; 294 int mib[2], rc; 295 size_t len; 296 297 mib[0] = CTL_MACHDEP; 298 mib[1] = CPU_BOOTED_KERNEL; 299 booted_kernel[0] = '/'; 300 booted_kernel[1] = '\0'; 301 len = sizeof(booted_kernel) - 2; 302 rc = sysctl(&mib[0], 2, &booted_kernel[1], &len, NULL, 0); 303 booted_kernel[sizeof(booted_kernel) - 1] = '\0'; 304 uf = (booted_kernel[1] == '/') ? 305 &booted_kernel[1] : &booted_kernel[0]; 306 if (rc != -1) 307 rc = stat(uf, &st); 308 if (rc != -1 && !S_ISREG(st.st_mode)) 309 rc = -1; 310 if (rc == -1) 311 #endif /* CPU_BOOTED_KERNEL */ 312 uf = _PATH_UNIX; 313 } 314 else if (strlen(uf) >= MAXPATHLEN) { 315 _kvm_err(kd, kd->program, "exec file name too long"); 316 goto failed; 317 } 318 if (flag & ~O_RDWR) { 319 _kvm_err(kd, kd->program, "bad flags arg"); 320 goto failed; 321 } 322 if (mf == 0) 323 mf = _PATH_MEM; 324 if (sf == 0) 325 sf = _PATH_DRUM; 326 327 /* 328 * Open the kernel namelist. If /dev/ksyms doesn't 329 * exist, open the current kernel. 330 */ 331 if (ufgiven == 0) 332 kd->nlfd = open_cloexec(_PATH_KSYMS, O_RDONLY, 0); 333 if (kd->nlfd < 0) { 334 if ((kd->nlfd = open_cloexec(uf, O_RDONLY, 0)) < 0) { 335 _kvm_syserr(kd, kd->program, "%s", uf); 336 goto failed; 337 } 338 } else { 339 /* 340 * We're here because /dev/ksyms was opened 341 * successfully. However, we don't want to keep it 342 * open, so we close it now. Later, we will open 343 * it again, since it will be the only case where 344 * kd->nlfd is negative. 345 */ 346 close(kd->nlfd); 347 kd->nlfd = -1; 348 } 349 350 if ((kd->pmfd = open_cloexec(mf, flag, 0)) < 0) { 351 _kvm_syserr(kd, kd->program, "%s", mf); 352 goto failed; 353 } 354 if (fstat(kd->pmfd, &st) < 0) { 355 _kvm_syserr(kd, kd->program, "%s", mf); 356 goto failed; 357 } 358 if (S_ISCHR(st.st_mode) && strcmp(mf, _PATH_MEM) == 0) { 359 /* 360 * If this is /dev/mem, open kmem too. (Maybe we should 361 * make it work for either /dev/mem or /dev/kmem -- in either 362 * case you're working with a live kernel.) 363 */ 364 if ((kd->vmfd = open_cloexec(_PATH_KMEM, flag, 0)) < 0) { 365 _kvm_syserr(kd, kd->program, "%s", _PATH_KMEM); 366 goto failed; 367 } 368 kd->alive = KVM_ALIVE_FILES; 369 if ((kd->swfd = open_cloexec(sf, flag, 0)) < 0) { 370 if (errno != ENXIO) { 371 _kvm_syserr(kd, kd->program, "%s", sf); 372 goto failed; 373 } 374 /* swap is not configured? not fatal */ 375 } 376 } else { 377 kd->fdalign = DEV_BSIZE; /* XXX */ 378 /* 379 * This is a crash dump. 380 * Initialize the virtual address translation machinery. 381 * 382 * If there is no valid core header, fail silently here. 383 * The address translations however will fail without 384 * header. Things can be made to run by calling 385 * kvm_dump_mkheader() before doing any translation. 386 */ 387 if (_kvm_get_header(kd) == 0) { 388 if (_kvm_initvtop(kd) < 0) 389 goto failed; 390 } 391 } 392 return (kd); 393 failed: 394 /* 395 * Copy out the error if doing sane error semantics. 396 */ 397 if (errout != 0) 398 (void)strlcpy(errout, kd->errbuf, _POSIX2_LINE_MAX); 399 (void)kvm_close(kd); 400 return (0); 401 } 402 403 /* 404 * The kernel dump file (from savecore) contains: 405 * kcore_hdr_t kcore_hdr; 406 * kcore_seg_t cpu_hdr; 407 * (opaque) cpu_data; (size is cpu_hdr.c_size) 408 * kcore_seg_t mem_hdr; 409 * (memory) mem_data; (size is mem_hdr.c_size) 410 * 411 * Note: khdr is padded to khdr.c_hdrsize; 412 * cpu_hdr and mem_hdr are padded to khdr.c_seghdrsize 413 */ 414 static int 415 _kvm_get_header(kvm_t *kd) 416 { 417 kcore_hdr_t kcore_hdr; 418 kcore_seg_t cpu_hdr; 419 kcore_seg_t mem_hdr; 420 size_t offset; 421 ssize_t sz; 422 423 /* 424 * Read the kcore_hdr_t 425 */ 426 sz = Pread(kd, kd->pmfd, &kcore_hdr, sizeof(kcore_hdr), (off_t)0); 427 if (sz != sizeof(kcore_hdr)) 428 return (-1); 429 430 /* 431 * Currently, we only support dump-files made by the current 432 * architecture... 433 */ 434 if ((CORE_GETMAGIC(kcore_hdr) != KCORE_MAGIC) || 435 (CORE_GETMID(kcore_hdr) != MID_MACHINE)) 436 return (-1); 437 438 /* 439 * Currently, we only support exactly 2 segments: cpu-segment 440 * and data-segment in exactly that order. 441 */ 442 if (kcore_hdr.c_nseg != 2) 443 return (-1); 444 445 /* 446 * Save away the kcore_hdr. All errors after this 447 * should do a to "goto fail" to deallocate things. 448 */ 449 kd->kcore_hdr = _kvm_malloc(kd, sizeof(kcore_hdr)); 450 memcpy(kd->kcore_hdr, &kcore_hdr, sizeof(kcore_hdr)); 451 offset = kcore_hdr.c_hdrsize; 452 453 /* 454 * Read the CPU segment header 455 */ 456 sz = Pread(kd, kd->pmfd, &cpu_hdr, sizeof(cpu_hdr), (off_t)offset); 457 if (sz != sizeof(cpu_hdr)) 458 goto fail; 459 if ((CORE_GETMAGIC(cpu_hdr) != KCORESEG_MAGIC) || 460 (CORE_GETFLAG(cpu_hdr) != CORE_CPU)) 461 goto fail; 462 offset += kcore_hdr.c_seghdrsize; 463 464 /* 465 * Read the CPU segment DATA. 466 */ 467 kd->cpu_dsize = cpu_hdr.c_size; 468 kd->cpu_data = _kvm_malloc(kd, cpu_hdr.c_size); 469 if (kd->cpu_data == NULL) 470 goto fail; 471 sz = Pread(kd, kd->pmfd, kd->cpu_data, cpu_hdr.c_size, (off_t)offset); 472 if (sz != cpu_hdr.c_size) 473 goto fail; 474 offset += cpu_hdr.c_size; 475 476 /* 477 * Read the next segment header: data segment 478 */ 479 sz = Pread(kd, kd->pmfd, &mem_hdr, sizeof(mem_hdr), (off_t)offset); 480 if (sz != sizeof(mem_hdr)) 481 goto fail; 482 offset += kcore_hdr.c_seghdrsize; 483 484 if ((CORE_GETMAGIC(mem_hdr) != KCORESEG_MAGIC) || 485 (CORE_GETFLAG(mem_hdr) != CORE_DATA)) 486 goto fail; 487 488 kd->dump_off = offset; 489 return (0); 490 491 fail: 492 if (kd->kcore_hdr != NULL) { 493 free(kd->kcore_hdr); 494 kd->kcore_hdr = NULL; 495 } 496 if (kd->cpu_data != NULL) { 497 free(kd->cpu_data); 498 kd->cpu_data = NULL; 499 kd->cpu_dsize = 0; 500 } 501 return (-1); 502 } 503 504 /* 505 * The format while on the dump device is: (new format) 506 * kcore_seg_t cpu_hdr; 507 * (opaque) cpu_data; (size is cpu_hdr.c_size) 508 * kcore_seg_t mem_hdr; 509 * (memory) mem_data; (size is mem_hdr.c_size) 510 */ 511 int 512 kvm_dump_mkheader(kvm_t *kd, off_t dump_off) 513 { 514 kcore_seg_t cpu_hdr; 515 size_t hdr_size; 516 ssize_t sz; 517 518 if (kd->kcore_hdr != NULL) { 519 _kvm_err(kd, kd->program, "already has a dump header"); 520 return (-1); 521 } 522 if (ISALIVE(kd)) { 523 _kvm_err(kd, kd->program, "don't use on live kernel"); 524 return (-1); 525 } 526 527 /* 528 * Validate new format crash dump 529 */ 530 sz = Pread(kd, kd->pmfd, &cpu_hdr, sizeof(cpu_hdr), dump_off); 531 if (sz != sizeof(cpu_hdr)) 532 return (-1); 533 if ((CORE_GETMAGIC(cpu_hdr) != KCORE_MAGIC) 534 || (CORE_GETMID(cpu_hdr) != MID_MACHINE)) { 535 _kvm_err(kd, 0, "invalid magic in cpu_hdr"); 536 return (0); 537 } 538 hdr_size = ALIGN(sizeof(cpu_hdr)); 539 540 /* 541 * Read the CPU segment. 542 */ 543 kd->cpu_dsize = cpu_hdr.c_size; 544 kd->cpu_data = _kvm_malloc(kd, kd->cpu_dsize); 545 if (kd->cpu_data == NULL) 546 goto fail; 547 sz = Pread(kd, kd->pmfd, kd->cpu_data, cpu_hdr.c_size, 548 dump_off + hdr_size); 549 if (sz != cpu_hdr.c_size) 550 goto fail; 551 hdr_size += kd->cpu_dsize; 552 553 /* 554 * Leave phys mem pointer at beginning of memory data 555 */ 556 kd->dump_off = dump_off + hdr_size; 557 if (Lseek(kd, kd->pmfd, kd->dump_off, SEEK_SET) == -1) 558 goto fail; 559 560 /* 561 * Create a kcore_hdr. 562 */ 563 kd->kcore_hdr = _kvm_malloc(kd, sizeof(kcore_hdr_t)); 564 if (kd->kcore_hdr == NULL) 565 goto fail; 566 567 kd->kcore_hdr->c_hdrsize = ALIGN(sizeof(kcore_hdr_t)); 568 kd->kcore_hdr->c_seghdrsize = ALIGN(sizeof(kcore_seg_t)); 569 kd->kcore_hdr->c_nseg = 2; 570 CORE_SETMAGIC(*(kd->kcore_hdr), KCORE_MAGIC, MID_MACHINE,0); 571 572 /* 573 * Now that we have a valid header, enable translations. 574 */ 575 if (_kvm_initvtop(kd) == 0) 576 /* Success */ 577 return (hdr_size); 578 579 fail: 580 if (kd->kcore_hdr != NULL) { 581 free(kd->kcore_hdr); 582 kd->kcore_hdr = NULL; 583 } 584 if (kd->cpu_data != NULL) { 585 free(kd->cpu_data); 586 kd->cpu_data = NULL; 587 kd->cpu_dsize = 0; 588 } 589 return (-1); 590 } 591 592 static int 593 clear_gap(kvm_t *kd, bool (*write_buf)(void *, const void *, size_t), 594 void *cookie, size_t size) 595 { 596 char buf[1024]; 597 size_t len; 598 599 (void)memset(buf, 0, size > sizeof(buf) ? sizeof(buf) : size); 600 601 while (size > 0) { 602 len = size > sizeof(buf) ? sizeof(buf) : size; 603 if (!(*write_buf)(cookie, buf, len)) { 604 _kvm_syserr(kd, kd->program, "clear_gap"); 605 return -1; 606 } 607 size -= len; 608 } 609 610 return 0; 611 } 612 613 /* 614 * Write the dump header by calling write_buf with cookie as first argument. 615 */ 616 int 617 kvm_dump_header(kvm_t *kd, bool (*write_buf)(void *, const void *, size_t), 618 void *cookie, int dumpsize) 619 { 620 kcore_seg_t seghdr; 621 long offset; 622 size_t gap; 623 624 if (kd->kcore_hdr == NULL || kd->cpu_data == NULL) { 625 _kvm_err(kd, kd->program, "no valid dump header(s)"); 626 return (-1); 627 } 628 629 /* 630 * Write the generic header 631 */ 632 offset = 0; 633 if (!(*write_buf)(cookie, kd->kcore_hdr, sizeof(kcore_hdr_t))) { 634 _kvm_syserr(kd, kd->program, "kvm_dump_header"); 635 return (-1); 636 } 637 offset += kd->kcore_hdr->c_hdrsize; 638 gap = kd->kcore_hdr->c_hdrsize - sizeof(kcore_hdr_t); 639 if (clear_gap(kd, write_buf, cookie, gap) == -1) 640 return (-1); 641 642 /* 643 * Write the CPU header 644 */ 645 CORE_SETMAGIC(seghdr, KCORESEG_MAGIC, 0, CORE_CPU); 646 seghdr.c_size = ALIGN(kd->cpu_dsize); 647 if (!(*write_buf)(cookie, &seghdr, sizeof(seghdr))) { 648 _kvm_syserr(kd, kd->program, "kvm_dump_header"); 649 return (-1); 650 } 651 offset += kd->kcore_hdr->c_seghdrsize; 652 gap = kd->kcore_hdr->c_seghdrsize - sizeof(seghdr); 653 if (clear_gap(kd, write_buf, cookie, gap) == -1) 654 return (-1); 655 656 if (!(*write_buf)(cookie, kd->cpu_data, kd->cpu_dsize)) { 657 _kvm_syserr(kd, kd->program, "kvm_dump_header"); 658 return (-1); 659 } 660 offset += seghdr.c_size; 661 gap = seghdr.c_size - kd->cpu_dsize; 662 if (clear_gap(kd, write_buf, cookie, gap) == -1) 663 return (-1); 664 665 /* 666 * Write the actual dump data segment header 667 */ 668 CORE_SETMAGIC(seghdr, KCORESEG_MAGIC, 0, CORE_DATA); 669 seghdr.c_size = dumpsize; 670 if (!(*write_buf)(cookie, &seghdr, sizeof(seghdr))) { 671 _kvm_syserr(kd, kd->program, "kvm_dump_header"); 672 return (-1); 673 } 674 offset += kd->kcore_hdr->c_seghdrsize; 675 gap = kd->kcore_hdr->c_seghdrsize - sizeof(seghdr); 676 if (clear_gap(kd, write_buf, cookie, gap) == -1) 677 return (-1); 678 679 return (int)offset; 680 } 681 682 static bool 683 kvm_dump_header_stdio(void *cookie, const void *buf, size_t len) 684 { 685 return fwrite(buf, len, 1, (FILE *)cookie) == 1; 686 } 687 688 int 689 kvm_dump_wrtheader(kvm_t *kd, FILE *fp, int dumpsize) 690 { 691 return kvm_dump_header(kd, kvm_dump_header_stdio, fp, dumpsize); 692 } 693 694 kvm_t * 695 kvm_openfiles(const char *uf, const char *mf, const char *sf, 696 int flag, char *errout) 697 { 698 kvm_t *kd; 699 700 if ((kd = malloc(sizeof(*kd))) == NULL) { 701 (void)strlcpy(errout, strerror(errno), _POSIX2_LINE_MAX); 702 return (0); 703 } 704 kd->program = 0; 705 return (_kvm_open(kd, uf, mf, sf, flag, errout)); 706 } 707 708 kvm_t * 709 kvm_open(const char *uf, const char *mf, const char *sf, int flag, 710 const char *program) 711 { 712 kvm_t *kd; 713 714 if ((kd = malloc(sizeof(*kd))) == NULL) { 715 (void)fprintf(stderr, "%s: %s\n", 716 program ? program : getprogname(), strerror(errno)); 717 return (0); 718 } 719 kd->program = program; 720 return (_kvm_open(kd, uf, mf, sf, flag, NULL)); 721 } 722 723 int 724 kvm_close(kvm_t *kd) 725 { 726 int error = 0; 727 728 if (kd->pmfd >= 0) 729 error |= close(kd->pmfd); 730 if (kd->vmfd >= 0) 731 error |= close(kd->vmfd); 732 if (kd->nlfd >= 0) 733 error |= close(kd->nlfd); 734 if (kd->swfd >= 0) 735 error |= close(kd->swfd); 736 if (kd->vmst) 737 _kvm_freevtop(kd); 738 kd->cpu_dsize = 0; 739 if (kd->cpu_data != NULL) 740 free(kd->cpu_data); 741 if (kd->kcore_hdr != NULL) 742 free(kd->kcore_hdr); 743 if (kd->procbase != 0) 744 free(kd->procbase); 745 if (kd->procbase2 != 0) 746 free(kd->procbase2); 747 if (kd->lwpbase != 0) 748 free(kd->lwpbase); 749 if (kd->swapspc != 0) 750 free(kd->swapspc); 751 if (kd->argspc != 0) 752 free(kd->argspc); 753 if (kd->argbuf != 0) 754 free(kd->argbuf); 755 if (kd->argv != 0) 756 free(kd->argv); 757 if (kd->iobuf != 0) 758 free(kd->iobuf); 759 free(kd); 760 761 return (0); 762 } 763 764 int 765 kvm_nlist(kvm_t *kd, struct nlist *nl) 766 { 767 int rv, nlfd; 768 769 /* 770 * kd->nlfd might be negative when we get here, and in that 771 * case that means that we're using /dev/ksyms. 772 * So open it again, just for the time we retrieve the list. 773 */ 774 if (kd->nlfd < 0) { 775 nlfd = open_cloexec(_PATH_KSYMS, O_RDONLY, 0); 776 if (nlfd < 0) { 777 _kvm_err(kd, 0, "failed to open %s", _PATH_KSYMS); 778 return (nlfd); 779 } 780 } else 781 nlfd = kd->nlfd; 782 783 /* 784 * Call the nlist(3) routines to retrieve the given namelist. 785 */ 786 rv = __fdnlist(nlfd, nl); 787 788 if (rv == -1) 789 _kvm_err(kd, 0, "bad namelist"); 790 791 if (kd->nlfd < 0) 792 close(nlfd); 793 794 return (rv); 795 } 796 797 int 798 kvm_dump_inval(kvm_t *kd) 799 { 800 struct nlist nl[2]; 801 u_long pa; 802 size_t dsize; 803 off_t doff; 804 void *newbuf; 805 806 if (ISALIVE(kd)) { 807 _kvm_err(kd, kd->program, "clearing dump on live kernel"); 808 return (-1); 809 } 810 nl[0].n_name = "_dumpmag"; 811 nl[1].n_name = NULL; 812 813 if (kvm_nlist(kd, nl) == -1) { 814 _kvm_err(kd, 0, "bad namelist"); 815 return (-1); 816 } 817 if (_kvm_kvatop(kd, (u_long)nl[0].n_value, &pa) == 0) 818 return (-1); 819 820 errno = 0; 821 dsize = MAX(kd->fdalign, sizeof(u_long)); 822 if (kd->iobufsz < dsize) { 823 newbuf = realloc(kd->iobuf, dsize); 824 if (newbuf == NULL) { 825 _kvm_syserr(kd, 0, "cannot allocate I/O buffer"); 826 return (-1); 827 } 828 kd->iobuf = newbuf; 829 kd->iobufsz = dsize; 830 } 831 memset(kd->iobuf, 0, dsize); 832 doff = _kvm_pa2off(kd, pa); 833 doff -= doff % kd->fdalign; 834 if (pwrite(kd->pmfd, kd->iobuf, dsize, doff) == -1) { 835 _kvm_syserr(kd, 0, "cannot invalidate dump - pwrite"); 836 return (-1); 837 } 838 return (0); 839 } 840 841 ssize_t 842 kvm_read(kvm_t *kd, u_long kva, void *buf, size_t len) 843 { 844 int cc; 845 void *cp; 846 847 if (ISKMEM(kd)) { 848 /* 849 * We're using /dev/kmem. Just read straight from the 850 * device and let the active kernel do the address translation. 851 */ 852 errno = 0; 853 cc = _kvm_pread(kd, kd->vmfd, buf, len, (off_t)kva); 854 if (cc < 0) { 855 _kvm_syserr(kd, 0, "kvm_read"); 856 return (-1); 857 } else if (cc < len) 858 _kvm_err(kd, kd->program, "short read"); 859 return (cc); 860 } else if (ISSYSCTL(kd)) { 861 _kvm_err(kd, kd->program, "kvm_open called with KVM_NO_FILES, " 862 "can't use kvm_read"); 863 return (-1); 864 } else { 865 if ((kd->kcore_hdr == NULL) || (kd->cpu_data == NULL)) { 866 _kvm_err(kd, kd->program, "no valid dump header"); 867 return (-1); 868 } 869 cp = buf; 870 while (len > 0) { 871 u_long pa; 872 off_t foff; 873 874 cc = _kvm_kvatop(kd, kva, &pa); 875 if (cc == 0) 876 return (-1); 877 if (cc > len) 878 cc = len; 879 foff = _kvm_pa2off(kd, pa); 880 errno = 0; 881 cc = _kvm_pread(kd, kd->pmfd, cp, (size_t)cc, foff); 882 if (cc < 0) { 883 _kvm_syserr(kd, kd->program, "kvm_read"); 884 break; 885 } 886 /* 887 * If kvm_kvatop returns a bogus value or our core 888 * file is truncated, we might wind up seeking beyond 889 * the end of the core file in which case the read will 890 * return 0 (EOF). 891 */ 892 if (cc == 0) 893 break; 894 cp = (char *)cp + cc; 895 kva += cc; 896 len -= cc; 897 } 898 return ((char *)cp - (char *)buf); 899 } 900 /* NOTREACHED */ 901 } 902 903 ssize_t 904 kvm_write(kvm_t *kd, u_long kva, const void *buf, size_t len) 905 { 906 int cc; 907 908 if (ISKMEM(kd)) { 909 /* 910 * Just like kvm_read, only we write. 911 */ 912 errno = 0; 913 cc = pwrite(kd->vmfd, buf, len, (off_t)kva); 914 if (cc < 0) { 915 _kvm_syserr(kd, 0, "kvm_write"); 916 return (-1); 917 } else if (cc < len) 918 _kvm_err(kd, kd->program, "short write"); 919 return (cc); 920 } else if (ISSYSCTL(kd)) { 921 _kvm_err(kd, kd->program, "kvm_open called with KVM_NO_FILES, " 922 "can't use kvm_write"); 923 return (-1); 924 } else { 925 _kvm_err(kd, kd->program, 926 "kvm_write not implemented for dead kernels"); 927 return (-1); 928 } 929 /* NOTREACHED */ 930 } 931