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. All advertising materials mentioning features or use of this software
18 * must display the following acknowledgement:
19 * This product includes software developed by the University of
20 * California, Berkeley and its contributors.
21 * 4. Neither the name of the University nor the names of its contributors
22 * may be used to endorse or promote products derived from this software
23 * without specific prior written permission.
25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 * @(#)kvm.c 8.2 (Berkeley) 2/13/94
38 * $FreeBSD: src/lib/libkvm/kvm.c,v 1.12.2.3 2002/09/13 14:53:43 nectar Exp $
39 * $DragonFly: src/lib/libkvm/kvm.c,v 1.12 2008/02/13 00:12:46 corecode Exp $
42 #include <sys/user.h> /* MUST BE FIRST */
43 #include <sys/param.h>
45 #include <sys/ioctl.h>
47 #include <sys/sysctl.h>
48 #include <sys/linker.h>
51 #include <vm/vm_param.h>
52 #include <vm/swap_pager.h>
54 #include <machine/vmparam.h>
68 #include "kvm_private.h"
70 /* from src/lib/libc/gen/nlist.c */
71 int __fdnlist (int, struct nlist
*);
80 * Report an error using printf style arguments. "program" is kd->program
81 * on hard errors, and 0 on soft errors, so that under sun error emulation,
82 * only hard errors are printed out (otherwise, programs like gdb will
83 * generate tons of error messages when trying to access bogus pointers).
86 _kvm_err(kvm_t
*kd
, const char *program
, const char *fmt
, ...)
91 if (program
!= NULL
) {
92 (void)fprintf(stderr
, "%s: ", program
);
93 (void)vfprintf(stderr
, fmt
, ap
);
94 (void)fputc('\n', stderr
);
96 (void)vsnprintf(kd
->errbuf
,
97 sizeof(kd
->errbuf
), (char *)fmt
, ap
);
103 _kvm_syserr(kvm_t
*kd
, const char *program
, const char *fmt
, ...)
109 if (program
!= NULL
) {
110 (void)fprintf(stderr
, "%s: ", program
);
111 (void)vfprintf(stderr
, fmt
, ap
);
112 (void)fprintf(stderr
, ": %s\n", strerror(errno
));
114 char *cp
= kd
->errbuf
;
116 (void)vsnprintf(cp
, sizeof(kd
->errbuf
), (char *)fmt
, ap
);
118 (void)snprintf(&cp
[n
], sizeof(kd
->errbuf
) - n
, ": %s",
125 _kvm_malloc(kvm_t
*kd
, size_t n
)
129 if ((p
= calloc(n
, sizeof(char))) == NULL
)
130 _kvm_err(kd
, kd
->program
, "can't allocate %u bytes: %s",
136 is_proc_mem(const char *p
)
138 static char proc
[] = "/proc/";
139 static char mem
[] = "/mem";
140 if (strncmp(proc
, p
, sizeof(proc
) - 1))
142 p
+= sizeof(proc
) - 1;
143 for (; p
!= '\0'; ++p
)
146 if (!isdigit(*(p
- 1)))
148 return !strncmp(p
, mem
, sizeof(mem
) - 1);
152 _kvm_open(kvm_t
*kd
, const char *uf
, const char *mf
, int flag
, char *errout
)
168 else if (strlen(uf
) >= MAXPATHLEN
) {
169 _kvm_err(kd
, kd
->program
, "exec file name too long");
172 if (flag
& ~O_RDWR
) {
173 _kvm_err(kd
, kd
->program
, "bad flags arg");
179 if ((kd
->pmfd
= open(mf
, flag
, 0)) < 0) {
180 _kvm_syserr(kd
, kd
->program
, "%s", mf
);
183 if (fstat(kd
->pmfd
, &st
) < 0) {
184 _kvm_syserr(kd
, kd
->program
, "%s", mf
);
187 if (fcntl(kd
->pmfd
, F_SETFD
, FD_CLOEXEC
) < 0) {
188 _kvm_syserr(kd
, kd
->program
, "%s", mf
);
191 if (S_ISCHR(st
.st_mode
)) {
193 * If this is a character special device, then check that
194 * it's /dev/mem. If so, open kmem too. (Maybe we should
195 * make it work for either /dev/mem or /dev/kmem -- in either
196 * case you're working with a live kernel.)
198 if (strcmp(mf
, _PATH_DEVNULL
) == 0) {
199 kd
->vmfd
= open(_PATH_DEVNULL
, O_RDONLY
);
201 if ((kd
->vmfd
= open(_PATH_KMEM
, flag
)) < 0) {
202 _kvm_syserr(kd
, kd
->program
, "%s", _PATH_KMEM
);
205 if (fcntl(kd
->vmfd
, F_SETFD
, FD_CLOEXEC
) < 0) {
206 _kvm_syserr(kd
, kd
->program
, "%s", _PATH_KMEM
);
210 kd
->flags
|= KVMF_HOST
;
213 * Crash dump or vkernel /proc/$pid/mem file:
214 * can't use kldsym, we are going to need ->nlfd
216 if ((kd
->nlfd
= open(uf
, O_RDONLY
, 0)) < 0) {
217 _kvm_syserr(kd
, kd
->program
, "%s", uf
);
220 if (fcntl(kd
->nlfd
, F_SETFD
, FD_CLOEXEC
) < 0) {
221 _kvm_syserr(kd
, kd
->program
, "%s", uf
);
224 if(is_proc_mem(mf
)) {
226 * It's /proc/$pid/mem, so we rely on the host
227 * kernel to do address translation for us.
231 kd
->flags
|= KVMF_VKERN
;
233 if (st
.st_size
<= 0) {
235 _kvm_syserr(kd
, kd
->program
, "empty file");
240 * This is a crash dump.
241 * Initialize the virtual address translation machinery,
242 * but first setup the namelist fd.
244 if (_kvm_initvtop(kd
) < 0)
251 * Copy out the error if doing sane error semantics.
254 strlcpy(errout
, kd
->errbuf
, _POSIX2_LINE_MAX
);
260 kvm_openfiles(const char *uf
, const char *mf
, const char *sf
, int flag
,
265 if ((kd
= malloc(sizeof(*kd
))) == NULL
) {
266 (void)strlcpy(errout
, strerror(errno
), _POSIX2_LINE_MAX
);
269 memset(kd
, 0, sizeof(*kd
));
271 return (_kvm_open(kd
, uf
, mf
, flag
, errout
));
275 kvm_open(const char *uf
, const char *mf
, const char *sf
, int flag
,
280 if ((kd
= malloc(sizeof(*kd
))) == NULL
) {
282 (void)fprintf(stderr
, "%s: %s\n",
283 errstr
, strerror(errno
));
286 memset(kd
, 0, sizeof(*kd
));
287 kd
->program
= errstr
;
288 return (_kvm_open(kd
, uf
, mf
, flag
, NULL
));
297 error
|= close(kd
->pmfd
);
299 error
|= close(kd
->vmfd
);
301 error
|= close(kd
->nlfd
);
304 if (kd
->procbase
!= NULL
)
307 free((void *)kd
->argv
);
314 kvm_nlist(kvm_t
*kd
, struct nlist
*nl
)
318 struct kld_sym_lookup lookup
;
322 * If we can't use the kld symbol lookup, revert to the
326 return (__fdnlist(kd
->nlfd
, nl
));
329 * We can use the kld lookup syscall. Go through each nlist entry
330 * and look it up with a kldsym(2) syscall.
333 for (p
= nl
; p
->n_name
&& p
->n_name
[0]; ++p
) {
334 lookup
.version
= sizeof(lookup
);
335 lookup
.symname
= p
->n_name
;
339 if (lookup
.symname
[0] == '_')
342 if (kldsym(0, KLDSYM_LOOKUP
, &lookup
) != -1) {
346 p
->n_value
= lookup
.symvalue
;
352 * Return the number of entries that weren't found. If they exist,
353 * also fill internal error buffer.
355 error
= ((p
- nl
) - nvalid
);
357 _kvm_syserr(kd
, kd
->program
, "kvm_nlist");
362 kvm_read(kvm_t
*kd
, u_long kva
, void *buf
, size_t len
)
367 if (kvm_notrans(kd
)) {
369 * We're using /dev/kmem. Just read straight from the
370 * device and let the active kernel do the address translation.
373 if (lseek(kd
->vmfd
, (off_t
)kva
, 0) == -1 && errno
!= 0) {
374 _kvm_err(kd
, 0, "invalid address (%x)", kva
);
379 * Try to pre-fault the user memory to reduce instances of
380 * races within the kernel. XXX workaround for kernel bug
381 * where kernel does a sanity check, but user faults during
382 * the copy can block and race against another kernel entity
383 * unmapping the memory in question.
386 cc
= read(kd
->vmfd
, buf
, len
);
388 _kvm_syserr(kd
, 0, "kvm_read");
391 _kvm_err(kd
, kd
->program
, "short read");
398 cc
= _kvm_kvatop(kd
, kva
, &pa
);
404 if (lseek(kd
->pmfd
, (off_t
)pa
, 0) == -1 && errno
!= 0) {
405 _kvm_syserr(kd
, 0, _PATH_MEM
);
409 cc
= read(kd
->pmfd
, cp
, cc
);
411 _kvm_syserr(kd
, kd
->program
, "kvm_read");
415 * If kvm_kvatop returns a bogus value or our core
416 * file is truncated, we might wind up seeking beyond
417 * the end of the core file in which case the read will
422 cp
= (char *)cp
+ cc
;
426 return ((char *)cp
- (char *)buf
);
432 kvm_readstr(kvm_t
*kd
, u_long kva
, char *buf
, size_t *lenp
)
442 _kvm_syserr(kd
, kd
->program
, "kvm_readstr");
449 if (kvm_notrans(kd
)) {
451 * We're using /dev/kmem. Just read straight from the
452 * device and let the active kernel do the address translation.
455 if (lseek(kd
->vmfd
, (off_t
)kva
, 0) == -1 && errno
!= 0) {
456 _kvm_err(kd
, 0, "invalid address (%x)", kva
);
460 for (pos
= 0, ch
= -1; ch
!= 0; pos
++) {
461 cc
= read(kd
->vmfd
, &ch
, 1);
462 if ((ssize_t
)cc
< 0) {
463 _kvm_syserr(kd
, 0, "kvm_readstr");
466 _kvm_err(kd
, kd
->program
, "short read");
468 buf
= realloc(buf
, asize
*= 2);
470 _kvm_syserr(kd
, kd
->program
, "kvm_readstr");
487 for (pos
= 0, ch
= -1; ch
!= 0; pos
++, left
--, kva
++) {
491 left
= _kvm_kvatop(kd
, kva
, &pa
);
495 if (lseek(kd
->pmfd
, (off_t
)pa
, 0) == -1 && errno
!= 0) {
496 _kvm_syserr(kd
, 0, _PATH_MEM
);
500 cc
= read(kd
->pmfd
, &ch
, 1);
501 if ((ssize_t
)cc
< 0) {
502 _kvm_syserr(kd
, 0, "kvm_readstr");
505 _kvm_err(kd
, kd
->program
, "short read");
507 buf
= realloc(buf
, asize
*= 2);
509 _kvm_syserr(kd
, kd
->program
, "kvm_readstr");
529 kvm_write(kvm_t
*kd
, u_long kva
, const void *buf
, size_t len
)
533 if (kvm_notrans(kd
)) {
535 * Just like kvm_read, only we write.
538 if (lseek(kd
->vmfd
, (off_t
)kva
, 0) == -1 && errno
!= 0) {
539 _kvm_err(kd
, 0, "invalid address (%x)", kva
);
542 cc
= write(kd
->vmfd
, buf
, len
);
544 _kvm_syserr(kd
, 0, "kvm_write");
547 _kvm_err(kd
, kd
->program
, "short write");
550 _kvm_err(kd
, kd
->program
,
551 "kvm_write not implemented for dead kernels");