2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 1989, 1992, 1993
5 * The Regents of the University of California. All rights reserved.
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.
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
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.
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
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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
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37 #include <sys/param.h>
38 #include <sys/fnv_hash.h>
43 #include <sys/linker.h>
46 #include <sys/sysctl.h>
62 #include "kvm_private.h"
64 SET_DECLARE(kvm_arch, struct kvm_arch);
66 static char _kd_is_null[] = "";
78 _kvm_read_kernel_ehdr(kvm_t *kd)
82 if (elf_version(EV_CURRENT) == EV_NONE) {
83 _kvm_err(kd, kd->program, "Unsupported libelf");
86 elf = elf_begin(kd->nlfd, ELF_C_READ, NULL);
88 _kvm_err(kd, kd->program, "%s", elf_errmsg(0));
91 if (elf_kind(elf) != ELF_K_ELF) {
92 _kvm_err(kd, kd->program, "kernel is not an ELF file");
95 if (gelf_getehdr(elf, &kd->nlehdr) == NULL) {
96 _kvm_err(kd, kd->program, "%s", elf_errmsg(0));
102 switch (kd->nlehdr.e_ident[EI_DATA]) {
107 _kvm_err(kd, kd->program,
108 "unsupported ELF data encoding for kernel");
114 _kvm_open(kvm_t *kd, const char *uf, const char *mf, int flag, char *errout)
116 struct kvm_arch **parch;
129 else if (strlen(uf) >= MAXPATHLEN) {
130 _kvm_err(kd, kd->program, "exec file name too long");
133 if (flag & ~O_RDWR) {
134 _kvm_err(kd, kd->program, "bad flags arg");
140 if ((kd->pmfd = open(mf, flag | O_CLOEXEC, 0)) < 0) {
141 _kvm_syserr(kd, kd->program, "%s", mf);
144 if (fstat(kd->pmfd, &st) < 0) {
145 _kvm_syserr(kd, kd->program, "%s", mf);
148 if (S_ISREG(st.st_mode) && st.st_size <= 0) {
150 _kvm_syserr(kd, kd->program, "empty file");
153 if (S_ISCHR(st.st_mode)) {
155 * If this is a character special device, then check that
156 * it's /dev/mem. If so, open kmem too. (Maybe we should
157 * make it work for either /dev/mem or /dev/kmem -- in either
158 * case you're working with a live kernel.)
160 if (strcmp(mf, _PATH_DEVNULL) == 0) {
161 kd->vmfd = open(_PATH_DEVNULL, O_RDONLY | O_CLOEXEC);
163 } else if (strcmp(mf, _PATH_MEM) == 0) {
164 if ((kd->vmfd = open(_PATH_KMEM, flag | O_CLOEXEC)) <
166 _kvm_syserr(kd, kd->program, "%s", _PATH_KMEM);
174 * This is either a crash dump or a remote live system with its physical
175 * memory fully accessible via a special device.
176 * Open the namelist fd and determine the architecture.
178 if ((kd->nlfd = open(uf, O_RDONLY | O_CLOEXEC, 0)) < 0) {
179 _kvm_syserr(kd, kd->program, "%s", uf);
182 if (_kvm_read_kernel_ehdr(kd) < 0)
184 if (strncmp(mf, _PATH_FWMEM, strlen(_PATH_FWMEM)) == 0 ||
185 strncmp(mf, _PATH_DEVVMM, strlen(_PATH_DEVVMM)) == 0) {
189 SET_FOREACH(parch, kvm_arch) {
190 if ((*parch)->ka_probe(kd)) {
195 if (kd->arch == NULL) {
196 _kvm_err(kd, kd->program, "unsupported architecture");
201 * Non-native kernels require a symbol resolver.
203 if (!kd->arch->ka_native(kd) && kd->resolve_symbol == NULL) {
204 _kvm_err(kd, kd->program,
205 "non-native kernel requires a symbol resolver");
210 * Initialize the virtual address translation machinery.
212 if (kd->arch->ka_initvtop(kd) < 0)
217 * Copy out the error if doing sane error semantics.
220 strlcpy(errout, kd->errbuf, _POSIX2_LINE_MAX);
226 kvm_openfiles(const char *uf, const char *mf, const char *sf __unused, int flag,
231 if ((kd = calloc(1, sizeof(*kd))) == NULL) {
233 (void)strlcpy(errout, strerror(errno),
237 return (_kvm_open(kd, uf, mf, flag, errout));
241 kvm_open(const char *uf, const char *mf, const char *sf __unused, int flag,
246 if ((kd = calloc(1, sizeof(*kd))) == NULL) {
248 (void)fprintf(stderr, "%s: %s\n",
249 errstr, strerror(errno));
252 kd->program = errstr;
253 return (_kvm_open(kd, uf, mf, flag, NULL));
257 kvm_open2(const char *uf, const char *mf, int flag, char *errout,
258 int (*resolver)(const char *, kvaddr_t *))
262 if ((kd = calloc(1, sizeof(*kd))) == NULL) {
264 (void)strlcpy(errout, strerror(errno),
268 kd->resolve_symbol = resolver;
269 return (_kvm_open(kd, uf, mf, flag, errout));
281 if (kd->vmst != NULL)
282 kd->arch->ka_freevtop(kd);
284 error |= close(kd->pmfd);
286 error |= close(kd->vmfd);
288 error |= close(kd->nlfd);
289 if (kd->procbase != 0)
290 free((void *)kd->procbase);
292 free((void *) kd->argbuf);
294 free((void *) kd->argspc);
296 free((void *)kd->argv);
297 if (kd->dpcpu_initialized != 0)
299 if (kd->pt_map != NULL)
301 if (kd->page_map != NULL)
303 if (kd->sparse_map != MAP_FAILED && kd->sparse_map != NULL)
304 munmap(kd->sparse_map, kd->pt_sparse_size);
311 kvm_nlist2(kvm_t *kd, struct kvm_nlist *nl)
315 * If called via the public interface, permit initialization of
316 * further virtualized modules on demand.
318 return (_kvm_nlist(kd, nl, 1));
322 kvm_nlist(kvm_t *kd, struct nlist *nl)
324 struct kvm_nlist *kl;
328 * Avoid reporting truncated addresses by failing for non-native
331 if (!kvm_native(kd)) {
332 _kvm_err(kd, kd->program, "kvm_nlist of non-native vmcore");
336 for (count = 0; nl[count].n_name != NULL && nl[count].n_name[0] != '\0';
341 kl = calloc(count + 1, sizeof(*kl));
343 _kvm_err(kd, kd->program, "cannot allocate memory");
346 for (i = 0; i < count; i++)
347 kl[i].n_name = nl[i].n_name;
348 nfail = kvm_nlist2(kd, kl);
349 for (i = 0; i < count; i++) {
350 nl[i].n_type = kl[i].n_type;
353 nl[i].n_value = kl[i].n_value;
360 kvm_read(kvm_t *kd, u_long kva, void *buf, size_t len)
363 return (kvm_read2(kd, kva, buf, len));
367 kvm_read2(kvm_t *kd, kvaddr_t kva, void *buf, size_t len)
376 * We're using /dev/kmem. Just read straight from the
377 * device and let the active kernel do the address translation.
380 if (lseek(kd->vmfd, (off_t)kva, 0) == -1 && errno != 0) {
381 _kvm_err(kd, 0, "invalid address (0x%jx)",
385 cr = read(kd->vmfd, buf, len);
387 _kvm_syserr(kd, 0, "kvm_read");
389 } else if (cr < (ssize_t)len)
390 _kvm_err(kd, kd->program, "short read");
396 cc = kd->arch->ka_kvatop(kd, kva, &pa);
399 if (cc > (ssize_t)len)
402 if (lseek(kd->pmfd, pa, 0) == -1 && errno != 0) {
403 _kvm_syserr(kd, 0, _PATH_MEM);
406 cr = read(kd->pmfd, cp, cc);
408 _kvm_syserr(kd, kd->program, "kvm_read");
412 * If ka_kvatop returns a bogus value or our core file is
413 * truncated, we might wind up seeking beyond the end of the
414 * core file in which case the read will return 0 (EOF).
423 return (cp - (char *)buf);
427 kvm_write(kvm_t *kd, u_long kva, const void *buf, size_t len)
434 if (!ISALIVE(kd) && !kd->writable) {
435 _kvm_err(kd, kd->program,
436 "kvm_write not implemented for dead kernels");
442 * Just like kvm_read, only we write.
445 if (lseek(kd->vmfd, (off_t)kva, 0) == -1 && errno != 0) {
446 _kvm_err(kd, 0, "invalid address (%lx)", kva);
449 cc = write(kd->vmfd, buf, len);
451 _kvm_syserr(kd, 0, "kvm_write");
453 } else if ((size_t)cc < len)
454 _kvm_err(kd, kd->program, "short write");
460 cc = kd->arch->ka_kvatop(kd, kva, &pa);
463 if (cc > (ssize_t)len)
466 if (lseek(kd->pmfd, pa, 0) == -1 && errno != 0) {
467 _kvm_syserr(kd, 0, _PATH_MEM);
470 cw = write(kd->pmfd, cp, cc);
472 _kvm_syserr(kd, kd->program, "kvm_write");
476 * If ka_kvatop returns a bogus value or our core file is
477 * truncated, we might wind up seeking beyond the end of the
478 * core file in which case the read will return 0 (EOF).
487 return (cp - (const char *)buf);
491 kvm_native(kvm_t *kd)
496 return (kd->arch->ka_native(kd));
500 kvm_walk_pages(kvm_t *kd, kvm_walk_pages_cb_t *cb, void *closure)
503 if (kd->arch->ka_walk_pages == NULL)
506 return (kd->arch->ka_walk_pages(kd, cb, closure));
510 kvm_kerndisp(kvm_t *kd)
512 unsigned long kernbase, rel_kernbase;
513 size_t kernbase_len = sizeof(kernbase);
514 size_t rel_kernbase_len = sizeof(rel_kernbase);
517 if (sysctlbyname("kern.base_address", &kernbase,
518 &kernbase_len, NULL, 0) == -1) {
519 _kvm_syserr(kd, kd->program,
520 "failed to get kernel base address");
523 if (sysctlbyname("kern.relbase_address", &rel_kernbase,
524 &rel_kernbase_len, NULL, 0) == -1) {
525 _kvm_syserr(kd, kd->program,
526 "failed to get relocated kernel base address");
529 return (rel_kernbase - kernbase);
532 if (kd->arch->ka_kerndisp == NULL)
535 return (kd->arch->ka_kerndisp(kd));