1 /* $NetBSD: kvm.c,v 1.103 2018/02/07 14:03:18 maxv 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 1.103 2018/02/07 14:03:18 maxv Exp $"); 42 #endif 43 #endif /* LIBC_SCCS and not lint */ 44 45 #include <sys/param.h> 46 #include <sys/lwp.h> 47 #include <sys/proc.h> 48 #include <sys/ioctl.h> 49 #include <sys/stat.h> 50 #include <sys/sysctl.h> 51 52 #include <sys/core.h> 53 #include <sys/exec.h> 54 #include <sys/kcore.h> 55 #include <sys/ksyms.h> 56 #include <sys/types.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 off_t Lseek(kvm_t *, int, off_t, int); 83 static ssize_t Pread(kvm_t *, int, void *, size_t, off_t); 84 85 char * 86 kvm_geterr(kvm_t *kd) 87 { 88 return (kd->errbuf); 89 } 90 91 const char * 92 kvm_getkernelname(kvm_t *kd) 93 { 94 return kd->kernelname; 95 } 96 97 /* 98 * Report an error using printf style arguments. "program" is kd->program 99 * on hard errors, and 0 on soft errors, so that under sun error emulation, 100 * only hard errors are printed out (otherwise, programs like gdb will 101 * generate tons of error messages when trying to access bogus pointers). 102 */ 103 void 104 _kvm_err(kvm_t *kd, const char *program, const char *fmt, ...) 105 { 106 va_list ap; 107 108 va_start(ap, fmt); 109 if (program != NULL) { 110 (void)fprintf(stderr, "%s: ", program); 111 (void)vfprintf(stderr, fmt, ap); 112 (void)fputc('\n', stderr); 113 } else 114 (void)vsnprintf(kd->errbuf, 115 sizeof(kd->errbuf), fmt, ap); 116 117 va_end(ap); 118 } 119 120 void 121 _kvm_syserr(kvm_t *kd, const char *program, const char *fmt, ...) 122 { 123 va_list ap; 124 size_t n; 125 126 va_start(ap, fmt); 127 if (program != NULL) { 128 (void)fprintf(stderr, "%s: ", program); 129 (void)vfprintf(stderr, fmt, ap); 130 (void)fprintf(stderr, ": %s\n", strerror(errno)); 131 } else { 132 char *cp = kd->errbuf; 133 134 (void)vsnprintf(cp, sizeof(kd->errbuf), fmt, ap); 135 n = strlen(cp); 136 (void)snprintf(&cp[n], sizeof(kd->errbuf) - n, ": %s", 137 strerror(errno)); 138 } 139 va_end(ap); 140 } 141 142 void * 143 _kvm_malloc(kvm_t *kd, size_t n) 144 { 145 void *p; 146 147 if ((p = malloc(n)) == NULL) 148 _kvm_err(kd, kd->program, "%s", strerror(errno)); 149 return (p); 150 } 151 152 /* 153 * Wrapper around the lseek(2) system call; calls _kvm_syserr() for us 154 * in the event of emergency. 155 */ 156 static off_t 157 Lseek(kvm_t *kd, int fd, off_t offset, int whence) 158 { 159 off_t off; 160 161 errno = 0; 162 163 if ((off = lseek(fd, offset, whence)) == -1 && errno != 0) { 164 _kvm_syserr(kd, kd->program, "Lseek"); 165 return ((off_t)-1); 166 } 167 return (off); 168 } 169 170 ssize_t 171 _kvm_pread(kvm_t *kd, int fd, void *buf, size_t size, off_t off) 172 { 173 ptrdiff_t moff; 174 void *newbuf; 175 size_t dsize; 176 ssize_t rv; 177 off_t doff; 178 179 /* If aligned nothing to do. */ 180 if (((off % kd->fdalign) | (size % kd->fdalign)) == 0) { 181 return pread(fd, buf, size, off); 182 } 183 184 /* 185 * Otherwise must buffer. We can't tolerate short reads in this 186 * case (lazy bum). 187 */ 188 moff = (ptrdiff_t)off % kd->fdalign; 189 doff = off - moff; 190 dsize = moff + size + kd->fdalign - 1; 191 dsize -= dsize % kd->fdalign; 192 if (kd->iobufsz < dsize) { 193 newbuf = realloc(kd->iobuf, dsize); 194 if (newbuf == NULL) { 195 _kvm_syserr(kd, 0, "cannot allocate I/O buffer"); 196 return (-1); 197 } 198 kd->iobuf = newbuf; 199 kd->iobufsz = dsize; 200 } 201 rv = pread(fd, kd->iobuf, dsize, doff); 202 if (rv < size + moff) 203 return -1; 204 memcpy(buf, kd->iobuf + moff, size); 205 return size; 206 } 207 208 /* 209 * Wrapper around the pread(2) system call; calls _kvm_syserr() for us 210 * in the event of emergency. 211 */ 212 static ssize_t 213 Pread(kvm_t *kd, int fd, void *buf, size_t nbytes, off_t offset) 214 { 215 ssize_t rv; 216 217 errno = 0; 218 219 if ((rv = _kvm_pread(kd, fd, buf, nbytes, offset)) != nbytes && 220 errno != 0) 221 _kvm_syserr(kd, kd->program, "Pread"); 222 return (rv); 223 } 224 225 static kvm_t * 226 _kvm_open(kvm_t *kd, const char *uf, const char *mf, const char *sf, int flag, 227 char *errout) 228 { 229 struct stat st; 230 int ufgiven; 231 232 kd->pmfd = -1; 233 kd->vmfd = -1; 234 kd->swfd = -1; 235 kd->nlfd = -1; 236 kd->alive = KVM_ALIVE_DEAD; 237 kd->procbase = NULL; 238 kd->procbase_len = 0; 239 kd->procbase2 = NULL; 240 kd->procbase2_len = 0; 241 kd->lwpbase = NULL; 242 kd->lwpbase_len = 0; 243 kd->nbpg = getpagesize(); 244 kd->swapspc = NULL; 245 kd->argspc = NULL; 246 kd->argspc_len = 0; 247 kd->argbuf = NULL; 248 kd->argv = NULL; 249 kd->vmst = NULL; 250 kd->vm_page_buckets = NULL; 251 kd->kcore_hdr = NULL; 252 kd->cpu_dsize = 0; 253 kd->cpu_data = NULL; 254 kd->dump_off = 0; 255 kd->fdalign = 1; 256 kd->iobuf = NULL; 257 kd->iobufsz = 0; 258 259 if (flag & KVM_NO_FILES) { 260 kd->alive = KVM_ALIVE_SYSCTL; 261 return(kd); 262 } 263 264 /* 265 * Call the MD open hook. This sets: 266 * usrstack, min_uva, max_uva 267 */ 268 if (_kvm_mdopen(kd)) { 269 _kvm_err(kd, kd->program, "md init failed"); 270 goto failed; 271 } 272 273 ufgiven = (uf != NULL); 274 if (!ufgiven) { 275 #ifdef CPU_BOOTED_KERNEL 276 /* 130 is 128 + '/' + '\0' */ 277 static char booted_kernel[130]; 278 int mib[2], rc; 279 size_t len; 280 281 mib[0] = CTL_MACHDEP; 282 mib[1] = CPU_BOOTED_KERNEL; 283 booted_kernel[0] = '/'; 284 booted_kernel[1] = '\0'; 285 len = sizeof(booted_kernel) - 2; 286 rc = sysctl(&mib[0], 2, &booted_kernel[1], &len, NULL, 0); 287 booted_kernel[sizeof(booted_kernel) - 1] = '\0'; 288 uf = (booted_kernel[1] == '/') ? 289 &booted_kernel[1] : &booted_kernel[0]; 290 if (rc != -1) 291 rc = stat(uf, &st); 292 if (rc != -1 && !S_ISREG(st.st_mode)) 293 rc = -1; 294 if (rc == -1) 295 #endif /* CPU_BOOTED_KERNEL */ 296 uf = _PATH_UNIX; 297 } 298 else if (strlen(uf) >= MAXPATHLEN) { 299 _kvm_err(kd, kd->program, "exec file name too long"); 300 goto failed; 301 } 302 if (flag & ~O_RDWR) { 303 _kvm_err(kd, kd->program, "bad flags arg"); 304 goto failed; 305 } 306 if (mf == 0) 307 mf = _PATH_MEM; 308 if (sf == 0) 309 sf = _PATH_DRUM; 310 311 /* 312 * Open the kernel namelist. If /dev/ksyms doesn't 313 * exist, open the current kernel. 314 */ 315 if (ufgiven == 0) 316 kd->nlfd = open(_PATH_KSYMS, O_RDONLY | O_CLOEXEC, 0); 317 if (kd->nlfd < 0) { 318 if ((kd->nlfd = open(uf, O_RDONLY | O_CLOEXEC, 0)) < 0) { 319 _kvm_syserr(kd, kd->program, "%s", uf); 320 goto failed; 321 } 322 strlcpy(kd->kernelname, uf, sizeof(kd->kernelname)); 323 } else { 324 strlcpy(kd->kernelname, _PATH_KSYMS, sizeof(kd->kernelname)); 325 } 326 327 if ((kd->pmfd = open(mf, flag | O_CLOEXEC, 0)) < 0) { 328 _kvm_syserr(kd, kd->program, "%s", mf); 329 goto failed; 330 } 331 if (fstat(kd->pmfd, &st) < 0) { 332 _kvm_syserr(kd, kd->program, "%s", mf); 333 goto failed; 334 } 335 if (S_ISCHR(st.st_mode) && strcmp(mf, _PATH_MEM) == 0) { 336 /* 337 * If this is /dev/mem, open kmem too. (Maybe we should 338 * make it work for either /dev/mem or /dev/kmem -- in either 339 * case you're working with a live kernel.) 340 */ 341 if ((kd->vmfd = open(_PATH_KMEM, flag | O_CLOEXEC, 0)) < 0) { 342 _kvm_syserr(kd, kd->program, "%s", _PATH_KMEM); 343 goto failed; 344 } 345 kd->alive = KVM_ALIVE_FILES; 346 if ((kd->swfd = open(sf, flag | O_CLOEXEC, 0)) < 0) { 347 if (errno != ENXIO) { 348 _kvm_syserr(kd, kd->program, "%s", sf); 349 goto failed; 350 } 351 /* swap is not configured? not fatal */ 352 } 353 } else { 354 kd->fdalign = DEV_BSIZE; /* XXX */ 355 /* 356 * This is a crash dump. 357 * Initialize the virtual address translation machinery. 358 * 359 * If there is no valid core header, fail silently here. 360 * The address translations however will fail without 361 * header. Things can be made to run by calling 362 * kvm_dump_mkheader() before doing any translation. 363 */ 364 if (_kvm_get_header(kd) == 0) { 365 if (_kvm_initvtop(kd) < 0) 366 goto failed; 367 } 368 } 369 return (kd); 370 failed: 371 /* 372 * Copy out the error if doing sane error semantics. 373 */ 374 if (errout != 0) 375 (void)strlcpy(errout, kd->errbuf, _POSIX2_LINE_MAX); 376 (void)kvm_close(kd); 377 return (0); 378 } 379 380 /* 381 * The kernel dump file (from savecore) contains: 382 * kcore_hdr_t kcore_hdr; 383 * kcore_seg_t cpu_hdr; 384 * (opaque) cpu_data; (size is cpu_hdr.c_size) 385 * kcore_seg_t mem_hdr; 386 * (memory) mem_data; (size is mem_hdr.c_size) 387 * 388 * Note: khdr is padded to khdr.c_hdrsize; 389 * cpu_hdr and mem_hdr are padded to khdr.c_seghdrsize 390 */ 391 static int 392 _kvm_get_header(kvm_t *kd) 393 { 394 kcore_hdr_t kcore_hdr; 395 kcore_seg_t cpu_hdr; 396 kcore_seg_t mem_hdr; 397 size_t offset; 398 ssize_t sz; 399 400 /* 401 * Read the kcore_hdr_t 402 */ 403 sz = Pread(kd, kd->pmfd, &kcore_hdr, sizeof(kcore_hdr), (off_t)0); 404 if (sz != sizeof(kcore_hdr)) 405 return (-1); 406 407 /* 408 * Currently, we only support dump-files made by the current 409 * architecture... 410 */ 411 if ((CORE_GETMAGIC(kcore_hdr) != KCORE_MAGIC) || 412 (CORE_GETMID(kcore_hdr) != MID_MACHINE)) 413 return (-1); 414 415 /* 416 * Currently, we only support exactly 2 segments: cpu-segment 417 * and data-segment in exactly that order. 418 */ 419 if (kcore_hdr.c_nseg != 2) 420 return (-1); 421 422 /* 423 * Save away the kcore_hdr. All errors after this 424 * should do a to "goto fail" to deallocate things. 425 */ 426 kd->kcore_hdr = _kvm_malloc(kd, sizeof(kcore_hdr)); 427 memcpy(kd->kcore_hdr, &kcore_hdr, sizeof(kcore_hdr)); 428 offset = kcore_hdr.c_hdrsize; 429 430 /* 431 * Read the CPU segment header 432 */ 433 sz = Pread(kd, kd->pmfd, &cpu_hdr, sizeof(cpu_hdr), (off_t)offset); 434 if (sz != sizeof(cpu_hdr)) 435 goto fail; 436 if ((CORE_GETMAGIC(cpu_hdr) != KCORESEG_MAGIC) || 437 (CORE_GETFLAG(cpu_hdr) != CORE_CPU)) 438 goto fail; 439 offset += kcore_hdr.c_seghdrsize; 440 441 /* 442 * Read the CPU segment DATA. 443 */ 444 kd->cpu_dsize = cpu_hdr.c_size; 445 kd->cpu_data = _kvm_malloc(kd, cpu_hdr.c_size); 446 if (kd->cpu_data == NULL) 447 goto fail; 448 sz = Pread(kd, kd->pmfd, kd->cpu_data, cpu_hdr.c_size, (off_t)offset); 449 if (sz != cpu_hdr.c_size) 450 goto fail; 451 offset += cpu_hdr.c_size; 452 453 /* 454 * Read the next segment header: data segment 455 */ 456 sz = Pread(kd, kd->pmfd, &mem_hdr, sizeof(mem_hdr), (off_t)offset); 457 if (sz != sizeof(mem_hdr)) 458 goto fail; 459 offset += kcore_hdr.c_seghdrsize; 460 461 if ((CORE_GETMAGIC(mem_hdr) != KCORESEG_MAGIC) || 462 (CORE_GETFLAG(mem_hdr) != CORE_DATA)) 463 goto fail; 464 465 kd->dump_off = offset; 466 return (0); 467 468 fail: 469 if (kd->kcore_hdr != NULL) { 470 free(kd->kcore_hdr); 471 kd->kcore_hdr = NULL; 472 } 473 if (kd->cpu_data != NULL) { 474 free(kd->cpu_data); 475 kd->cpu_data = NULL; 476 kd->cpu_dsize = 0; 477 } 478 return (-1); 479 } 480 481 /* 482 * The format while on the dump device is: (new format) 483 * kcore_seg_t cpu_hdr; 484 * (opaque) cpu_data; (size is cpu_hdr.c_size) 485 * kcore_seg_t mem_hdr; 486 * (memory) mem_data; (size is mem_hdr.c_size) 487 */ 488 int 489 kvm_dump_mkheader(kvm_t *kd, off_t dump_off) 490 { 491 kcore_seg_t cpu_hdr; 492 size_t hdr_size; 493 ssize_t sz; 494 495 if (kd->kcore_hdr != NULL) { 496 _kvm_err(kd, kd->program, "already has a dump header"); 497 return (-1); 498 } 499 if (ISALIVE(kd)) { 500 _kvm_err(kd, kd->program, "don't use on live kernel"); 501 return (-1); 502 } 503 504 /* 505 * Validate new format crash dump 506 */ 507 sz = Pread(kd, kd->pmfd, &cpu_hdr, sizeof(cpu_hdr), dump_off); 508 if (sz != sizeof(cpu_hdr)) { 509 if (sz == -1) 510 _kvm_err(kd, 0, "read %zx bytes at offset %"PRIx64 511 " for cpu_hdr failed: %s", sizeof(cpu_hdr), 512 dump_off, strerror(errno)); 513 else 514 _kvm_err(kd, 0, "read %zx bytes at offset %"PRIx64 515 " for cpu_hdr instead of requested %zu", 516 sz, dump_off, sizeof(cpu_hdr)); 517 return (-1); 518 } 519 if ((CORE_GETMAGIC(cpu_hdr) != KCORE_MAGIC) 520 || (CORE_GETMID(cpu_hdr) != MID_MACHINE)) { 521 _kvm_err(kd, 0, "invalid magic in cpu_hdr"); 522 return (0); 523 } 524 hdr_size = ALIGN(sizeof(cpu_hdr)); 525 526 /* 527 * Read the CPU segment. 528 */ 529 kd->cpu_dsize = cpu_hdr.c_size; 530 kd->cpu_data = _kvm_malloc(kd, kd->cpu_dsize); 531 if (kd->cpu_data == NULL) { 532 _kvm_err(kd, kd->program, "no cpu_data"); 533 goto fail; 534 } 535 sz = Pread(kd, kd->pmfd, kd->cpu_data, cpu_hdr.c_size, 536 dump_off + hdr_size); 537 if (sz != cpu_hdr.c_size) { 538 _kvm_err(kd, kd->program, "size %zu != cpu_hdr.csize %"PRIu32, 539 sz, cpu_hdr.c_size); 540 goto fail; 541 } 542 hdr_size += kd->cpu_dsize; 543 544 /* 545 * Leave phys mem pointer at beginning of memory data 546 */ 547 kd->dump_off = dump_off + hdr_size; 548 if (Lseek(kd, kd->pmfd, kd->dump_off, SEEK_SET) == -1) { 549 _kvm_err(kd, kd->program, "failed to seek to %" PRId64, 550 (int64_t)kd->dump_off); 551 goto fail; 552 } 553 554 /* 555 * Create a kcore_hdr. 556 */ 557 kd->kcore_hdr = _kvm_malloc(kd, sizeof(kcore_hdr_t)); 558 if (kd->kcore_hdr == NULL) { 559 _kvm_err(kd, kd->program, "failed to allocate header"); 560 goto fail; 561 } 562 563 kd->kcore_hdr->c_hdrsize = ALIGN(sizeof(kcore_hdr_t)); 564 kd->kcore_hdr->c_seghdrsize = ALIGN(sizeof(kcore_seg_t)); 565 kd->kcore_hdr->c_nseg = 2; 566 CORE_SETMAGIC(*(kd->kcore_hdr), KCORE_MAGIC, MID_MACHINE,0); 567 568 /* 569 * Now that we have a valid header, enable translations. 570 */ 571 if (_kvm_initvtop(kd) == 0) 572 /* Success */ 573 return (hdr_size); 574 575 fail: 576 if (kd->kcore_hdr != NULL) { 577 free(kd->kcore_hdr); 578 kd->kcore_hdr = NULL; 579 } 580 if (kd->cpu_data != NULL) { 581 free(kd->cpu_data); 582 kd->cpu_data = NULL; 583 kd->cpu_dsize = 0; 584 } 585 return (-1); 586 } 587 588 static int 589 clear_gap(kvm_t *kd, bool (*write_buf)(void *, const void *, size_t), 590 void *cookie, size_t size) 591 { 592 char buf[1024]; 593 size_t len; 594 595 (void)memset(buf, 0, size > sizeof(buf) ? sizeof(buf) : size); 596 597 while (size > 0) { 598 len = size > sizeof(buf) ? sizeof(buf) : size; 599 if (!(*write_buf)(cookie, buf, len)) { 600 _kvm_syserr(kd, kd->program, "clear_gap"); 601 return -1; 602 } 603 size -= len; 604 } 605 606 return 0; 607 } 608 609 /* 610 * Write the dump header by calling write_buf with cookie as first argument. 611 */ 612 int 613 kvm_dump_header(kvm_t *kd, bool (*write_buf)(void *, const void *, size_t), 614 void *cookie, int dumpsize) 615 { 616 kcore_seg_t seghdr; 617 long offset; 618 size_t gap; 619 620 if (kd->kcore_hdr == NULL || kd->cpu_data == NULL) { 621 _kvm_err(kd, kd->program, "no valid dump header(s)"); 622 return (-1); 623 } 624 625 /* 626 * Write the generic header 627 */ 628 offset = 0; 629 if (!(*write_buf)(cookie, kd->kcore_hdr, sizeof(kcore_hdr_t))) { 630 _kvm_syserr(kd, kd->program, "kvm_dump_header"); 631 return (-1); 632 } 633 offset += kd->kcore_hdr->c_hdrsize; 634 gap = kd->kcore_hdr->c_hdrsize - sizeof(kcore_hdr_t); 635 if (clear_gap(kd, write_buf, cookie, gap) == -1) 636 return (-1); 637 638 /* 639 * Write the CPU header 640 */ 641 CORE_SETMAGIC(seghdr, KCORESEG_MAGIC, 0, CORE_CPU); 642 seghdr.c_size = ALIGN(kd->cpu_dsize); 643 if (!(*write_buf)(cookie, &seghdr, sizeof(seghdr))) { 644 _kvm_syserr(kd, kd->program, "kvm_dump_header"); 645 return (-1); 646 } 647 offset += kd->kcore_hdr->c_seghdrsize; 648 gap = kd->kcore_hdr->c_seghdrsize - sizeof(seghdr); 649 if (clear_gap(kd, write_buf, cookie, gap) == -1) 650 return (-1); 651 652 if (!(*write_buf)(cookie, kd->cpu_data, kd->cpu_dsize)) { 653 _kvm_syserr(kd, kd->program, "kvm_dump_header"); 654 return (-1); 655 } 656 offset += seghdr.c_size; 657 gap = seghdr.c_size - kd->cpu_dsize; 658 if (clear_gap(kd, write_buf, cookie, gap) == -1) 659 return (-1); 660 661 /* 662 * Write the actual dump data segment header 663 */ 664 CORE_SETMAGIC(seghdr, KCORESEG_MAGIC, 0, CORE_DATA); 665 seghdr.c_size = dumpsize; 666 if (!(*write_buf)(cookie, &seghdr, sizeof(seghdr))) { 667 _kvm_syserr(kd, kd->program, "kvm_dump_header"); 668 return (-1); 669 } 670 offset += kd->kcore_hdr->c_seghdrsize; 671 gap = kd->kcore_hdr->c_seghdrsize - sizeof(seghdr); 672 if (clear_gap(kd, write_buf, cookie, gap) == -1) 673 return (-1); 674 675 return (int)offset; 676 } 677 678 static bool 679 kvm_dump_header_stdio(void *cookie, const void *buf, size_t len) 680 { 681 return fwrite(buf, len, 1, (FILE *)cookie) == 1; 682 } 683 684 int 685 kvm_dump_wrtheader(kvm_t *kd, FILE *fp, int dumpsize) 686 { 687 return kvm_dump_header(kd, kvm_dump_header_stdio, fp, dumpsize); 688 } 689 690 kvm_t * 691 kvm_openfiles(const char *uf, const char *mf, const char *sf, 692 int flag, char *errout) 693 { 694 kvm_t *kd; 695 696 if ((kd = malloc(sizeof(*kd))) == NULL) { 697 (void)strlcpy(errout, strerror(errno), _POSIX2_LINE_MAX); 698 return (0); 699 } 700 kd->program = 0; 701 return (_kvm_open(kd, uf, mf, sf, flag, errout)); 702 } 703 704 kvm_t * 705 kvm_open(const char *uf, const char *mf, const char *sf, int flag, 706 const char *program) 707 { 708 kvm_t *kd; 709 710 if ((kd = malloc(sizeof(*kd))) == NULL) { 711 (void)fprintf(stderr, "%s: %s\n", 712 program ? program : getprogname(), strerror(errno)); 713 return (0); 714 } 715 kd->program = program; 716 return (_kvm_open(kd, uf, mf, sf, flag, NULL)); 717 } 718 719 int 720 kvm_close(kvm_t *kd) 721 { 722 int error = 0; 723 724 if (kd->pmfd >= 0) 725 error |= close(kd->pmfd); 726 if (kd->vmfd >= 0) 727 error |= close(kd->vmfd); 728 if (kd->nlfd >= 0) 729 error |= close(kd->nlfd); 730 if (kd->swfd >= 0) 731 error |= close(kd->swfd); 732 if (kd->vmst) 733 _kvm_freevtop(kd); 734 kd->cpu_dsize = 0; 735 if (kd->cpu_data != NULL) 736 free(kd->cpu_data); 737 if (kd->kcore_hdr != NULL) 738 free(kd->kcore_hdr); 739 if (kd->procbase != 0) 740 free(kd->procbase); 741 if (kd->procbase2 != 0) 742 free(kd->procbase2); 743 if (kd->lwpbase != 0) 744 free(kd->lwpbase); 745 if (kd->swapspc != 0) 746 free(kd->swapspc); 747 if (kd->argspc != 0) 748 free(kd->argspc); 749 if (kd->argbuf != 0) 750 free(kd->argbuf); 751 if (kd->argv != 0) 752 free(kd->argv); 753 if (kd->iobuf != 0) 754 free(kd->iobuf); 755 free(kd); 756 757 return (error); 758 } 759 760 int 761 kvm_nlist(kvm_t *kd, struct nlist *nl) 762 { 763 int rv; 764 765 /* 766 * Call the nlist(3) routines to retrieve the given namelist. 767 */ 768 rv = __fdnlist(kd->nlfd, nl); 769 770 if (rv == -1) 771 _kvm_err(kd, 0, "bad namelist"); 772 773 return (rv); 774 } 775 776 int 777 kvm_dump_inval(kvm_t *kd) 778 { 779 struct nlist nl[2]; 780 paddr_t pa; 781 size_t dsize; 782 off_t doff; 783 void *newbuf; 784 785 if (ISALIVE(kd)) { 786 _kvm_err(kd, kd->program, "clearing dump on live kernel"); 787 return (-1); 788 } 789 nl[0].n_name = "_dumpmag"; 790 nl[1].n_name = NULL; 791 792 if (kvm_nlist(kd, nl) == -1) { 793 _kvm_err(kd, 0, "bad namelist"); 794 return (-1); 795 } 796 if (_kvm_kvatop(kd, (vaddr_t)nl[0].n_value, &pa) == 0) 797 return (-1); 798 799 errno = 0; 800 dsize = MAX(kd->fdalign, sizeof(u_long)); 801 if (kd->iobufsz < dsize) { 802 newbuf = realloc(kd->iobuf, dsize); 803 if (newbuf == NULL) { 804 _kvm_syserr(kd, 0, "cannot allocate I/O buffer"); 805 return (-1); 806 } 807 kd->iobuf = newbuf; 808 kd->iobufsz = dsize; 809 } 810 memset(kd->iobuf, 0, dsize); 811 doff = _kvm_pa2off(kd, pa); 812 doff -= doff % kd->fdalign; 813 if (pwrite(kd->pmfd, kd->iobuf, dsize, doff) == -1) { 814 _kvm_syserr(kd, 0, "cannot invalidate dump - pwrite"); 815 return (-1); 816 } 817 return (0); 818 } 819 820 ssize_t 821 kvm_read(kvm_t *kd, u_long kva, void *buf, size_t len) 822 { 823 int cc; 824 void *cp; 825 826 if (ISKMEM(kd)) { 827 /* 828 * We're using /dev/kmem. Just read straight from the 829 * device and let the active kernel do the address translation. 830 */ 831 errno = 0; 832 cc = _kvm_pread(kd, kd->vmfd, buf, len, (off_t)kva); 833 if (cc < 0) { 834 _kvm_syserr(kd, 0, "kvm_read"); 835 return (-1); 836 } else if (cc < len) 837 _kvm_err(kd, kd->program, "short read"); 838 return (cc); 839 } else if (ISSYSCTL(kd)) { 840 _kvm_err(kd, kd->program, "kvm_open called with KVM_NO_FILES, " 841 "can't use kvm_read"); 842 return (-1); 843 } else { 844 if ((kd->kcore_hdr == NULL) || (kd->cpu_data == NULL)) { 845 _kvm_err(kd, kd->program, "no valid dump header"); 846 return (-1); 847 } 848 cp = buf; 849 while (len > 0) { 850 paddr_t pa; 851 off_t foff; 852 853 cc = _kvm_kvatop(kd, (vaddr_t)kva, &pa); 854 if (cc == 0) 855 return (-1); 856 if (cc > len) 857 cc = len; 858 foff = _kvm_pa2off(kd, pa); 859 errno = 0; 860 cc = _kvm_pread(kd, kd->pmfd, cp, (size_t)cc, foff); 861 if (cc < 0) { 862 _kvm_syserr(kd, kd->program, "kvm_read"); 863 break; 864 } 865 /* 866 * If kvm_kvatop returns a bogus value or our core 867 * file is truncated, we might wind up seeking beyond 868 * the end of the core file in which case the read will 869 * return 0 (EOF). 870 */ 871 if (cc == 0) 872 break; 873 cp = (char *)cp + cc; 874 kva += cc; 875 len -= cc; 876 } 877 return ((char *)cp - (char *)buf); 878 } 879 /* NOTREACHED */ 880 } 881 882 ssize_t 883 kvm_write(kvm_t *kd, u_long kva, const void *buf, size_t len) 884 { 885 int cc; 886 887 if (ISKMEM(kd)) { 888 /* 889 * Just like kvm_read, only we write. 890 */ 891 errno = 0; 892 cc = pwrite(kd->vmfd, buf, len, (off_t)kva); 893 if (cc < 0) { 894 _kvm_syserr(kd, 0, "kvm_write"); 895 return (-1); 896 } else if (cc < len) 897 _kvm_err(kd, kd->program, "short write"); 898 return (cc); 899 } else if (ISSYSCTL(kd)) { 900 _kvm_err(kd, kd->program, "kvm_open called with KVM_NO_FILES, " 901 "can't use kvm_write"); 902 return (-1); 903 } else { 904 _kvm_err(kd, kd->program, 905 "kvm_write not implemented for dead kernels"); 906 return (-1); 907 } 908 /* NOTREACHED */ 909 } 910