1 /* $NetBSD: kvm.c,v 1.101 2014/02/19 20:21:22 dsl 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 1.101 2014/02/19 20:21:22 dsl 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 * We're here because /dev/ksyms was opened 327 * successfully. However, we don't want to keep it 328 * open, so we close it now. Later, we will open 329 * it again, since it will be the only case where 330 * kd->nlfd is negative. 331 */ 332 close(kd->nlfd); 333 kd->nlfd = -1; 334 } 335 336 if ((kd->pmfd = open(mf, flag | O_CLOEXEC, 0)) < 0) { 337 _kvm_syserr(kd, kd->program, "%s", mf); 338 goto failed; 339 } 340 if (fstat(kd->pmfd, &st) < 0) { 341 _kvm_syserr(kd, kd->program, "%s", mf); 342 goto failed; 343 } 344 if (S_ISCHR(st.st_mode) && strcmp(mf, _PATH_MEM) == 0) { 345 /* 346 * If this is /dev/mem, open kmem too. (Maybe we should 347 * make it work for either /dev/mem or /dev/kmem -- in either 348 * case you're working with a live kernel.) 349 */ 350 if ((kd->vmfd = open(_PATH_KMEM, flag | O_CLOEXEC, 0)) < 0) { 351 _kvm_syserr(kd, kd->program, "%s", _PATH_KMEM); 352 goto failed; 353 } 354 kd->alive = KVM_ALIVE_FILES; 355 if ((kd->swfd = open(sf, flag | O_CLOEXEC, 0)) < 0) { 356 if (errno != ENXIO) { 357 _kvm_syserr(kd, kd->program, "%s", sf); 358 goto failed; 359 } 360 /* swap is not configured? not fatal */ 361 } 362 } else { 363 kd->fdalign = DEV_BSIZE; /* XXX */ 364 /* 365 * This is a crash dump. 366 * Initialize the virtual address translation machinery. 367 * 368 * If there is no valid core header, fail silently here. 369 * The address translations however will fail without 370 * header. Things can be made to run by calling 371 * kvm_dump_mkheader() before doing any translation. 372 */ 373 if (_kvm_get_header(kd) == 0) { 374 if (_kvm_initvtop(kd) < 0) 375 goto failed; 376 } 377 } 378 return (kd); 379 failed: 380 /* 381 * Copy out the error if doing sane error semantics. 382 */ 383 if (errout != 0) 384 (void)strlcpy(errout, kd->errbuf, _POSIX2_LINE_MAX); 385 (void)kvm_close(kd); 386 return (0); 387 } 388 389 /* 390 * The kernel dump file (from savecore) contains: 391 * kcore_hdr_t kcore_hdr; 392 * kcore_seg_t cpu_hdr; 393 * (opaque) cpu_data; (size is cpu_hdr.c_size) 394 * kcore_seg_t mem_hdr; 395 * (memory) mem_data; (size is mem_hdr.c_size) 396 * 397 * Note: khdr is padded to khdr.c_hdrsize; 398 * cpu_hdr and mem_hdr are padded to khdr.c_seghdrsize 399 */ 400 static int 401 _kvm_get_header(kvm_t *kd) 402 { 403 kcore_hdr_t kcore_hdr; 404 kcore_seg_t cpu_hdr; 405 kcore_seg_t mem_hdr; 406 size_t offset; 407 ssize_t sz; 408 409 /* 410 * Read the kcore_hdr_t 411 */ 412 sz = Pread(kd, kd->pmfd, &kcore_hdr, sizeof(kcore_hdr), (off_t)0); 413 if (sz != sizeof(kcore_hdr)) 414 return (-1); 415 416 /* 417 * Currently, we only support dump-files made by the current 418 * architecture... 419 */ 420 if ((CORE_GETMAGIC(kcore_hdr) != KCORE_MAGIC) || 421 (CORE_GETMID(kcore_hdr) != MID_MACHINE)) 422 return (-1); 423 424 /* 425 * Currently, we only support exactly 2 segments: cpu-segment 426 * and data-segment in exactly that order. 427 */ 428 if (kcore_hdr.c_nseg != 2) 429 return (-1); 430 431 /* 432 * Save away the kcore_hdr. All errors after this 433 * should do a to "goto fail" to deallocate things. 434 */ 435 kd->kcore_hdr = _kvm_malloc(kd, sizeof(kcore_hdr)); 436 memcpy(kd->kcore_hdr, &kcore_hdr, sizeof(kcore_hdr)); 437 offset = kcore_hdr.c_hdrsize; 438 439 /* 440 * Read the CPU segment header 441 */ 442 sz = Pread(kd, kd->pmfd, &cpu_hdr, sizeof(cpu_hdr), (off_t)offset); 443 if (sz != sizeof(cpu_hdr)) 444 goto fail; 445 if ((CORE_GETMAGIC(cpu_hdr) != KCORESEG_MAGIC) || 446 (CORE_GETFLAG(cpu_hdr) != CORE_CPU)) 447 goto fail; 448 offset += kcore_hdr.c_seghdrsize; 449 450 /* 451 * Read the CPU segment DATA. 452 */ 453 kd->cpu_dsize = cpu_hdr.c_size; 454 kd->cpu_data = _kvm_malloc(kd, cpu_hdr.c_size); 455 if (kd->cpu_data == NULL) 456 goto fail; 457 sz = Pread(kd, kd->pmfd, kd->cpu_data, cpu_hdr.c_size, (off_t)offset); 458 if (sz != cpu_hdr.c_size) 459 goto fail; 460 offset += cpu_hdr.c_size; 461 462 /* 463 * Read the next segment header: data segment 464 */ 465 sz = Pread(kd, kd->pmfd, &mem_hdr, sizeof(mem_hdr), (off_t)offset); 466 if (sz != sizeof(mem_hdr)) 467 goto fail; 468 offset += kcore_hdr.c_seghdrsize; 469 470 if ((CORE_GETMAGIC(mem_hdr) != KCORESEG_MAGIC) || 471 (CORE_GETFLAG(mem_hdr) != CORE_DATA)) 472 goto fail; 473 474 kd->dump_off = offset; 475 return (0); 476 477 fail: 478 if (kd->kcore_hdr != NULL) { 479 free(kd->kcore_hdr); 480 kd->kcore_hdr = NULL; 481 } 482 if (kd->cpu_data != NULL) { 483 free(kd->cpu_data); 484 kd->cpu_data = NULL; 485 kd->cpu_dsize = 0; 486 } 487 return (-1); 488 } 489 490 /* 491 * The format while on the dump device is: (new format) 492 * kcore_seg_t cpu_hdr; 493 * (opaque) cpu_data; (size is cpu_hdr.c_size) 494 * kcore_seg_t mem_hdr; 495 * (memory) mem_data; (size is mem_hdr.c_size) 496 */ 497 int 498 kvm_dump_mkheader(kvm_t *kd, off_t dump_off) 499 { 500 kcore_seg_t cpu_hdr; 501 size_t hdr_size; 502 ssize_t sz; 503 504 if (kd->kcore_hdr != NULL) { 505 _kvm_err(kd, kd->program, "already has a dump header"); 506 return (-1); 507 } 508 if (ISALIVE(kd)) { 509 _kvm_err(kd, kd->program, "don't use on live kernel"); 510 return (-1); 511 } 512 513 /* 514 * Validate new format crash dump 515 */ 516 sz = Pread(kd, kd->pmfd, &cpu_hdr, sizeof(cpu_hdr), dump_off); 517 if (sz != sizeof(cpu_hdr)) { 518 _kvm_err(kd, 0, "read %zx bytes at offset %"PRIx64 519 " for cpu_hdr instead of requested %zu", 520 sz, dump_off, sizeof(cpu_hdr)); 521 return (-1); 522 } 523 if ((CORE_GETMAGIC(cpu_hdr) != KCORE_MAGIC) 524 || (CORE_GETMID(cpu_hdr) != MID_MACHINE)) { 525 _kvm_err(kd, 0, "invalid magic in cpu_hdr"); 526 return (0); 527 } 528 hdr_size = ALIGN(sizeof(cpu_hdr)); 529 530 /* 531 * Read the CPU segment. 532 */ 533 kd->cpu_dsize = cpu_hdr.c_size; 534 kd->cpu_data = _kvm_malloc(kd, kd->cpu_dsize); 535 if (kd->cpu_data == NULL) { 536 _kvm_err(kd, kd->program, "no cpu_data"); 537 goto fail; 538 } 539 sz = Pread(kd, kd->pmfd, kd->cpu_data, cpu_hdr.c_size, 540 dump_off + hdr_size); 541 if (sz != cpu_hdr.c_size) { 542 _kvm_err(kd, kd->program, "size %zu != cpu_hdr.csize %"PRIu32, 543 sz, cpu_hdr.c_size); 544 goto fail; 545 } 546 hdr_size += kd->cpu_dsize; 547 548 /* 549 * Leave phys mem pointer at beginning of memory data 550 */ 551 kd->dump_off = dump_off + hdr_size; 552 if (Lseek(kd, kd->pmfd, kd->dump_off, SEEK_SET) == -1) { 553 _kvm_err(kd, kd->program, "failed to seek to %" PRId64, 554 (int64_t)kd->dump_off); 555 goto fail; 556 } 557 558 /* 559 * Create a kcore_hdr. 560 */ 561 kd->kcore_hdr = _kvm_malloc(kd, sizeof(kcore_hdr_t)); 562 if (kd->kcore_hdr == NULL) { 563 _kvm_err(kd, kd->program, "failed to allocate header"); 564 goto fail; 565 } 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 (error); 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(_PATH_KSYMS, O_RDONLY | O_CLOEXEC, 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 paddr_t 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, (vaddr_t)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 paddr_t pa; 872 off_t foff; 873 874 cc = _kvm_kvatop(kd, (vaddr_t)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