2 * Copyright (c) 1989, 1992, 1993
3 * The Regents of the University of California. All rights reserved.
5 * This code is derived from software developed by the Computer Systems
6 * Engineering group at Lawrence Berkeley Laboratory under DARPA contract
7 * BG 91-66 and contributed to Berkeley.
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
37 #if defined(LIBC_SCCS) && !defined(lint)
39 static char sccsid[] = "@(#)kvm.c 8.2 (Berkeley) 2/13/94";
41 #endif /* LIBC_SCCS and not lint */
43 #include <sys/param.h>
44 #include <sys/fnv_hash.h>
49 #include <sys/linker.h>
65 #include "kvm_private.h"
67 SET_DECLARE(kvm_arch, struct kvm_arch);
76 _kvm_read_kernel_ehdr(kvm_t *kd)
80 if (elf_version(EV_CURRENT) == EV_NONE) {
81 _kvm_err(kd, kd->program, "Unsupported libelf");
84 elf = elf_begin(kd->nlfd, ELF_C_READ, NULL);
86 _kvm_err(kd, kd->program, "%s", elf_errmsg(0));
89 if (elf_kind(elf) != ELF_K_ELF) {
90 _kvm_err(kd, kd->program, "kernel is not an ELF file");
93 if (gelf_getehdr(elf, &kd->nlehdr) == NULL) {
94 _kvm_err(kd, kd->program, "%s", elf_errmsg(0));
100 switch (kd->nlehdr.e_ident[EI_DATA]) {
105 _kvm_err(kd, kd->program,
106 "unsupported ELF data encoding for kernel");
112 _kvm_open(kvm_t *kd, const char *uf, const char *mf, int flag, char *errout)
114 struct kvm_arch **parch;
127 else if (strlen(uf) >= MAXPATHLEN) {
128 _kvm_err(kd, kd->program, "exec file name too long");
131 if (flag & ~O_RDWR) {
132 _kvm_err(kd, kd->program, "bad flags arg");
138 if ((kd->pmfd = open(mf, flag | O_CLOEXEC, 0)) < 0) {
139 _kvm_syserr(kd, kd->program, "%s", mf);
142 if (fstat(kd->pmfd, &st) < 0) {
143 _kvm_syserr(kd, kd->program, "%s", mf);
146 if (S_ISREG(st.st_mode) && st.st_size <= 0) {
148 _kvm_syserr(kd, kd->program, "empty file");
151 if (S_ISCHR(st.st_mode)) {
153 * If this is a character special device, then check that
154 * it's /dev/mem. If so, open kmem too. (Maybe we should
155 * make it work for either /dev/mem or /dev/kmem -- in either
156 * case you're working with a live kernel.)
158 if (strcmp(mf, _PATH_DEVNULL) == 0) {
159 kd->vmfd = open(_PATH_DEVNULL, O_RDONLY | O_CLOEXEC);
161 } else if (strcmp(mf, _PATH_MEM) == 0) {
162 if ((kd->vmfd = open(_PATH_KMEM, flag | O_CLOEXEC)) <
164 _kvm_syserr(kd, kd->program, "%s", _PATH_KMEM);
172 * This is either a crash dump or a remote live system with its physical
173 * memory fully accessible via a special device.
174 * Open the namelist fd and determine the architecture.
176 if ((kd->nlfd = open(uf, O_RDONLY | O_CLOEXEC, 0)) < 0) {
177 _kvm_syserr(kd, kd->program, "%s", uf);
180 if (_kvm_read_kernel_ehdr(kd) < 0)
182 if (strncmp(mf, _PATH_FWMEM, strlen(_PATH_FWMEM)) == 0 ||
183 strncmp(mf, _PATH_DEVVMM, strlen(_PATH_DEVVMM)) == 0) {
187 SET_FOREACH(parch, kvm_arch) {
188 if ((*parch)->ka_probe(kd)) {
193 if (kd->arch == NULL) {
194 _kvm_err(kd, kd->program, "unsupported architecture");
199 * Non-native kernels require a symbol resolver.
201 if (!kd->arch->ka_native(kd) && kd->resolve_symbol == NULL) {
202 _kvm_err(kd, kd->program,
203 "non-native kernel requires a symbol resolver");
208 * Initialize the virtual address translation machinery.
210 if (kd->arch->ka_initvtop(kd) < 0)
215 * Copy out the error if doing sane error semantics.
218 strlcpy(errout, kd->errbuf, _POSIX2_LINE_MAX);
224 kvm_openfiles(const char *uf, const char *mf, const char *sf __unused, int flag,
229 if ((kd = calloc(1, sizeof(*kd))) == NULL) {
231 (void)strlcpy(errout, strerror(errno),
235 return (_kvm_open(kd, uf, mf, flag, errout));
239 kvm_open(const char *uf, const char *mf, const char *sf __unused, int flag,
244 if ((kd = calloc(1, sizeof(*kd))) == NULL) {
246 (void)fprintf(stderr, "%s: %s\n",
247 errstr, strerror(errno));
250 kd->program = errstr;
251 return (_kvm_open(kd, uf, mf, flag, NULL));
255 kvm_open2(const char *uf, const char *mf, int flag, char *errout,
256 int (*resolver)(const char *, kvaddr_t *))
260 if ((kd = calloc(1, sizeof(*kd))) == NULL) {
262 (void)strlcpy(errout, strerror(errno),
266 kd->resolve_symbol = resolver;
267 return (_kvm_open(kd, uf, mf, flag, errout));
275 if (kd->vmst != NULL)
276 kd->arch->ka_freevtop(kd);
278 error |= close(kd->pmfd);
280 error |= close(kd->vmfd);
282 error |= close(kd->nlfd);
283 if (kd->procbase != 0)
284 free((void *)kd->procbase);
286 free((void *) kd->argbuf);
288 free((void *) kd->argspc);
290 free((void *)kd->argv);
291 if (kd->pt_map != NULL)
299 kvm_nlist2(kvm_t *kd, struct kvm_nlist *nl)
303 * If called via the public interface, permit initialization of
304 * further virtualized modules on demand.
306 return (_kvm_nlist(kd, nl, 1));
310 kvm_nlist(kvm_t *kd, struct nlist *nl)
312 struct kvm_nlist *kl;
316 * Avoid reporting truncated addresses by failing for non-native
319 if (!kvm_native(kd)) {
320 _kvm_err(kd, kd->program, "kvm_nlist of non-native vmcore");
324 for (count = 0; nl[count].n_name != NULL && nl[count].n_name[0] != '\0';
329 kl = calloc(count + 1, sizeof(*kl));
330 for (i = 0; i < count; i++)
331 kl[i].n_name = nl[i].n_name;
332 nfail = kvm_nlist2(kd, kl);
333 for (i = 0; i < count; i++) {
334 nl[i].n_type = kl[i].n_type;
337 nl[i].n_value = kl[i].n_value;
343 kvm_read(kvm_t *kd, u_long kva, void *buf, size_t len)
346 return (kvm_read2(kd, kva, buf, len));
350 kvm_read2(kvm_t *kd, kvaddr_t kva, void *buf, size_t len)
359 * We're using /dev/kmem. Just read straight from the
360 * device and let the active kernel do the address translation.
363 if (lseek(kd->vmfd, (off_t)kva, 0) == -1 && errno != 0) {
364 _kvm_err(kd, 0, "invalid address (0x%jx)",
368 cr = read(kd->vmfd, buf, len);
370 _kvm_syserr(kd, 0, "kvm_read");
372 } else if (cr < (ssize_t)len)
373 _kvm_err(kd, kd->program, "short read");
379 cc = kd->arch->ka_kvatop(kd, kva, &pa);
382 if (cc > (ssize_t)len)
385 if (lseek(kd->pmfd, pa, 0) == -1 && errno != 0) {
386 _kvm_syserr(kd, 0, _PATH_MEM);
389 cr = read(kd->pmfd, cp, cc);
391 _kvm_syserr(kd, kd->program, "kvm_read");
395 * If ka_kvatop returns a bogus value or our core file is
396 * truncated, we might wind up seeking beyond the end of the
397 * core file in which case the read will return 0 (EOF).
406 return (cp - (char *)buf);
410 kvm_write(kvm_t *kd, u_long kva, const void *buf, size_t len)
417 if (!ISALIVE(kd) && !kd->writable) {
418 _kvm_err(kd, kd->program,
419 "kvm_write not implemented for dead kernels");
425 * Just like kvm_read, only we write.
428 if (lseek(kd->vmfd, (off_t)kva, 0) == -1 && errno != 0) {
429 _kvm_err(kd, 0, "invalid address (%lx)", kva);
432 cc = write(kd->vmfd, buf, len);
434 _kvm_syserr(kd, 0, "kvm_write");
436 } else if ((size_t)cc < len)
437 _kvm_err(kd, kd->program, "short write");
443 cc = kd->arch->ka_kvatop(kd, kva, &pa);
446 if (cc > (ssize_t)len)
449 if (lseek(kd->pmfd, pa, 0) == -1 && errno != 0) {
450 _kvm_syserr(kd, 0, _PATH_MEM);
453 cw = write(kd->pmfd, cp, cc);
455 _kvm_syserr(kd, kd->program, "kvm_write");
459 * If ka_kvatop returns a bogus value or our core file is
460 * truncated, we might wind up seeking beyond the end of the
461 * core file in which case the read will return 0 (EOF).
470 return (cp - (char *)buf);
474 kvm_native(kvm_t *kd)
479 return (kd->arch->ka_native(kd));