OpenBSD-4.6/lib/libkvm/kvm.c
/* $OpenBSD: kvm.c,v 1.47 2009/06/07 03:09:34 millert Exp $ */
/* $NetBSD: kvm.c,v 1.43 1996/05/05 04:31:59 gwr Exp $ */
/*-
* Copyright (c) 1989, 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software developed by the Computer Systems
* Engineering group at Lawrence Berkeley Laboratory under DARPA contract
* BG 91-66 and contributed to Berkeley.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char sccsid[] = "@(#)kvm.c 8.2 (Berkeley) 2/13/94";
#else
static char *rcsid = "$OpenBSD: kvm.c,v 1.47 2009/06/07 03:09:34 millert Exp $";
#endif
#endif /* LIBC_SCCS and not lint */
#include <sys/param.h>
#include <sys/user.h>
#include <sys/proc.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/sysctl.h>
#include <sys/core.h>
#include <sys/exec_aout.h>
#include <sys/kcore.h>
#include <ctype.h>
#include <db.h>
#include <fcntl.h>
#include <libgen.h>
#include <limits.h>
#include <nlist.h>
#include <paths.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <kvm.h>
#include <stdarg.h>
#include "kvm_private.h"
extern int __fdnlist(int, struct nlist *);
static int kvm_dbopen(kvm_t *, const char *);
static int _kvm_get_header(kvm_t *);
static kvm_t *_kvm_open(kvm_t *, const char *, const char *, const char *,
int, char *);
static int clear_gap(kvm_t *, FILE *, int);
static int kvm_setfd(kvm_t *);
char *
kvm_geterr(kd)
kvm_t *kd;
{
return (kd->errbuf);
}
/*
* Wrapper around pread.
*/
ssize_t
_kvm_pread(kvm_t *kd, int fd, void *buf, size_t nbytes, off_t offset)
{
ssize_t rval;
errno = 0;
rval = pread(fd, buf, nbytes, offset);
if (rval == -1 || errno != 0) {
_kvm_syserr(kd, kd->program, "pread");
}
return (rval);
}
/*
* Wrapper around pwrite.
*/
ssize_t
_kvm_pwrite(kvm_t *kd, int fd, const void *buf, size_t nbytes, off_t offset)
{
ssize_t rval;
errno = 0;
rval = pwrite(fd, buf, nbytes, offset);
if (rval == -1 || errno != 0) {
_kvm_syserr(kd, kd->program, "pwrite");
}
return (rval);
}
/*
* Report an error using printf style arguments. "program" is kd->program
* on hard errors, and 0 on soft errors, so that under sun error emulation,
* only hard errors are printed out (otherwise, programs like gdb will
* generate tons of error messages when trying to access bogus pointers).
*/
void
_kvm_err(kvm_t *kd, const char *program, const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
if (program != NULL) {
(void)fprintf(stderr, "%s: ", program);
(void)vfprintf(stderr, fmt, ap);
(void)fputc('\n', stderr);
} else
(void)vsnprintf(kd->errbuf,
sizeof(kd->errbuf), fmt, ap);
va_end(ap);
}
void
_kvm_syserr(kvm_t *kd, const char *program, const char *fmt, ...)
{
va_list ap;
size_t n;
va_start(ap, fmt);
if (program != NULL) {
(void)fprintf(stderr, "%s: ", program);
(void)vfprintf(stderr, fmt, ap);
(void)fprintf(stderr, ": %s\n", strerror(errno));
} else {
char *cp = kd->errbuf;
(void)vsnprintf(cp, sizeof(kd->errbuf), fmt, ap);
n = strlen(cp);
(void)snprintf(&cp[n], sizeof(kd->errbuf) - n, ": %s",
strerror(errno));
}
va_end(ap);
}
void *
_kvm_malloc(kvm_t *kd, size_t n)
{
void *p;
if ((p = malloc(n)) == NULL)
_kvm_err(kd, kd->program, "%s", strerror(errno));
return (p);
}
static kvm_t *
_kvm_open(kvm_t *kd, const char *uf, const char *mf, const char *sf,
int flag, char *errout)
{
struct stat st;
kd->db = 0;
kd->pmfd = -1;
kd->vmfd = -1;
kd->swfd = -1;
kd->nlfd = -1;
kd->alive = 0;
kd->filebase = 0;
kd->procbase = 0;
kd->procbase2 = 0;
kd->nbpg = getpagesize();
kd->swapspc = 0;
kd->argspc = 0;
kd->argbuf = 0;
kd->argv = 0;
kd->vmst = NULL;
kd->vm_page_buckets = 0;
kd->kcore_hdr = 0;
kd->cpu_dsize = 0;
kd->cpu_data = 0;
kd->dump_off = 0;
if (flag & KVM_NO_FILES) {
kd->alive = 1;
return (kd);
}
if (uf && strlen(uf) >= MAXPATHLEN) {
_kvm_err(kd, kd->program, "exec file name too long");
goto failed;
}
if (flag & ~O_ACCMODE) {
_kvm_err(kd, kd->program, "bad flags arg");
goto failed;
}
if (mf == 0)
mf = _PATH_MEM;
if ((kd->pmfd = open(mf, flag, 0)) < 0) {
_kvm_syserr(kd, kd->program, "%s", mf);
goto failed;
}
if (fstat(kd->pmfd, &st) < 0) {
_kvm_syserr(kd, kd->program, "%s", mf);
goto failed;
}
if (S_ISCHR(st.st_mode)) {
/*
* If this is a character special device, then check that
* it's /dev/mem. If so, open kmem too. (Maybe we should
* make it work for either /dev/mem or /dev/kmem -- in either
* case you're working with a live kernel.)
*/
if (strcmp(mf, _PATH_MEM) != 0) { /* XXX */
_kvm_err(kd, kd->program,
"%s: not physical memory device", mf);
goto failed;
}
if ((kd->vmfd = open(_PATH_KMEM, flag, 0)) < 0) {
_kvm_syserr(kd, kd->program, "%s", _PATH_KMEM);
goto failed;
}
kd->alive = 1;
if (sf != NULL && (kd->swfd = open(sf, flag, 0)) < 0) {
_kvm_syserr(kd, kd->program, "%s", sf);
goto failed;
}
/*
* Open kvm nlist database. We only try to use
* the pre-built database if the namelist file name
* pointer is NULL. If the database cannot or should
* not be opened, open the namelist argument so we
* revert to slow nlist() calls.
* If no file is specified, try opening _PATH_KSYMS and
* fall back to _PATH_UNIX.
*/
if (kvm_dbopen(kd, uf ? uf : _PATH_UNIX) == -1 &&
((uf && (kd->nlfd = open(uf, O_RDONLY, 0)) == -1) || (!uf &&
(kd->nlfd = open((uf = _PATH_KSYMS), O_RDONLY, 0)) == -1 &&
(kd->nlfd = open((uf = _PATH_UNIX), O_RDONLY, 0)) == -1))) {
_kvm_syserr(kd, kd->program, "%s", uf);
goto failed;
}
} else {
/*
* This is a crash dump.
* Initialize the virtual address translation machinery,
* but first setup the namelist fd.
* If no file is specified, try opening _PATH_KSYMS and
* fall back to _PATH_UNIX.
*/
if ((uf && (kd->nlfd = open(uf, O_RDONLY, 0)) == -1) || (!uf &&
(kd->nlfd = open((uf = _PATH_KSYMS), O_RDONLY, 0)) == -1 &&
(kd->nlfd = open((uf = _PATH_UNIX), O_RDONLY, 0)) == -1)) {
_kvm_syserr(kd, kd->program, "%s", uf);
goto failed;
}
/*
* If there is no valid core header, fail silently here.
* The address translations however will fail without
* header. Things can be made to run by calling
* kvm_dump_mkheader() before doing any translation.
*/
if (_kvm_get_header(kd) == 0) {
if (_kvm_initvtop(kd) < 0)
goto failed;
}
}
if (kvm_setfd(kd) == 0)
return (kd);
else
_kvm_syserr(kd, kd->program, "can't set close on exec flag");
failed:
/*
* Copy out the error if doing sane error semantics.
*/
if (errout != 0)
(void)strlcpy(errout, kd->errbuf, _POSIX2_LINE_MAX);
(void)kvm_close(kd);
return (0);
}
/*
* The kernel dump file (from savecore) contains:
* kcore_hdr_t kcore_hdr;
* kcore_seg_t cpu_hdr;
* (opaque) cpu_data; (size is cpu_hdr.c_size)
* kcore_seg_t mem_hdr;
* (memory) mem_data; (size is mem_hdr.c_size)
*
* Note: khdr is padded to khdr.c_hdrsize;
* cpu_hdr and mem_hdr are padded to khdr.c_seghdrsize
*/
static int
_kvm_get_header(kvm_t *kd)
{
kcore_hdr_t kcore_hdr;
kcore_seg_t cpu_hdr;
kcore_seg_t mem_hdr;
size_t offset;
ssize_t sz;
/*
* Read the kcore_hdr_t
*/
sz = _kvm_pread(kd, kd->pmfd, &kcore_hdr, sizeof(kcore_hdr), (off_t)0);
if (sz != sizeof(kcore_hdr)) {
return (-1);
}
/*
* Currently, we only support dump-files made by the current
* architecture...
*/
if ((CORE_GETMAGIC(kcore_hdr) != KCORE_MAGIC) ||
(CORE_GETMID(kcore_hdr) != MID_MACHINE))
return (-1);
/*
* Currently, we only support exactly 2 segments: cpu-segment
* and data-segment in exactly that order.
*/
if (kcore_hdr.c_nseg != 2)
return (-1);
/*
* Save away the kcore_hdr. All errors after this
* should do a to "goto fail" to deallocate things.
*/
kd->kcore_hdr = _kvm_malloc(kd, sizeof(kcore_hdr));
if (kd->kcore_hdr == NULL)
goto fail;
memcpy(kd->kcore_hdr, &kcore_hdr, sizeof(kcore_hdr));
offset = kcore_hdr.c_hdrsize;
/*
* Read the CPU segment header
*/
sz = _kvm_pread(kd, kd->pmfd, &cpu_hdr, sizeof(cpu_hdr), (off_t)offset);
if (sz != sizeof(cpu_hdr)) {
goto fail;
}
if ((CORE_GETMAGIC(cpu_hdr) != KCORESEG_MAGIC) ||
(CORE_GETFLAG(cpu_hdr) != CORE_CPU))
goto fail;
offset += kcore_hdr.c_seghdrsize;
/*
* Read the CPU segment DATA.
*/
kd->cpu_dsize = cpu_hdr.c_size;
kd->cpu_data = _kvm_malloc(kd, (size_t)cpu_hdr.c_size);
if (kd->cpu_data == NULL)
goto fail;
sz = _kvm_pread(kd, kd->pmfd, kd->cpu_data, (size_t)cpu_hdr.c_size,
(off_t)offset);
if (sz != (size_t)cpu_hdr.c_size) {
goto fail;
}
offset += cpu_hdr.c_size;
/*
* Read the next segment header: data segment
*/
sz = _kvm_pread(kd, kd->pmfd, &mem_hdr, sizeof(mem_hdr), (off_t)offset);
if (sz != sizeof(mem_hdr)) {
goto fail;
}
offset += kcore_hdr.c_seghdrsize;
if ((CORE_GETMAGIC(mem_hdr) != KCORESEG_MAGIC) ||
(CORE_GETFLAG(mem_hdr) != CORE_DATA))
goto fail;
kd->dump_off = offset;
return (0);
fail:
if (kd->kcore_hdr != NULL) {
free(kd->kcore_hdr);
kd->kcore_hdr = NULL;
}
if (kd->cpu_data != NULL) {
free(kd->cpu_data);
kd->cpu_data = NULL;
kd->cpu_dsize = 0;
}
return (-1);
}
/*
* The format while on the dump device is: (new format)
* kcore_seg_t cpu_hdr;
* (opaque) cpu_data; (size is cpu_hdr.c_size)
* kcore_seg_t mem_hdr;
* (memory) mem_data; (size is mem_hdr.c_size)
*/
int
kvm_dump_mkheader(kvm_t *kd, off_t dump_off)
{
kcore_seg_t cpu_hdr;
int hdr_size;
ssize_t sz;
if (kd->kcore_hdr != NULL) {
_kvm_err(kd, kd->program, "already has a dump header");
return (-1);
}
if (ISALIVE(kd)) {
_kvm_err(kd, kd->program, "don't use on live kernel");
return (-1);
}
/*
* Validate new format crash dump
*/
sz = _kvm_pread(kd, kd->pmfd, &cpu_hdr, sizeof(cpu_hdr), (off_t)dump_off);
if (sz != sizeof(cpu_hdr)) {
return (-1);
}
if ((CORE_GETMAGIC(cpu_hdr) != KCORE_MAGIC)
|| (CORE_GETMID(cpu_hdr) != MID_MACHINE)) {
_kvm_err(kd, 0, "invalid magic in cpu_hdr");
return (-1);
}
hdr_size = ALIGN(sizeof(cpu_hdr));
/*
* Read the CPU segment.
*/
kd->cpu_dsize = cpu_hdr.c_size;
kd->cpu_data = _kvm_malloc(kd, kd->cpu_dsize);
if (kd->cpu_data == NULL)
goto fail;
sz = _kvm_pread(kd, kd->pmfd, kd->cpu_data, (size_t)cpu_hdr.c_size,
(off_t)dump_off+hdr_size);
if (sz != (ssize_t)cpu_hdr.c_size) {
_kvm_err(kd, 0, "invalid size in cpu_hdr");
goto fail;
}
hdr_size += kd->cpu_dsize;
/*
* Leave phys mem pointer at beginning of memory data
*/
kd->dump_off = dump_off + hdr_size;
errno = 0;
if (lseek(kd->pmfd, kd->dump_off, SEEK_SET) != kd->dump_off && errno != 0) {
_kvm_err(kd, 0, "invalid dump offset - lseek");
goto fail;
}
/*
* Create a kcore_hdr.
*/
kd->kcore_hdr = _kvm_malloc(kd, sizeof(kcore_hdr_t));
if (kd->kcore_hdr == NULL)
goto fail;
kd->kcore_hdr->c_hdrsize = ALIGN(sizeof(kcore_hdr_t));
kd->kcore_hdr->c_seghdrsize = ALIGN(sizeof(kcore_seg_t));
kd->kcore_hdr->c_nseg = 2;
CORE_SETMAGIC(*(kd->kcore_hdr), KCORE_MAGIC, MID_MACHINE,0);
/*
* Now that we have a valid header, enable translations.
*/
if (_kvm_initvtop(kd) == 0)
/* Success */
return (hdr_size);
fail:
if (kd->kcore_hdr != NULL) {
free(kd->kcore_hdr);
kd->kcore_hdr = NULL;
}
if (kd->cpu_data != NULL) {
free(kd->cpu_data);
kd->cpu_data = NULL;
kd->cpu_dsize = 0;
}
return (-1);
}
static int
clear_gap(kvm_t *kd, FILE *fp, int size)
{
if (size <= 0) /* XXX - < 0 should never happen */
return (0);
while (size-- > 0) {
if (fputc(0, fp) == EOF) {
_kvm_syserr(kd, kd->program, "clear_gap");
return (-1);
}
}
return (0);
}
/*
* Write the dump header info to 'fp'. Note that we can't use fseek(3) here
* because 'fp' might be a file pointer obtained by zopen().
*/
int
kvm_dump_wrtheader(kvm_t *kd, FILE *fp, int dumpsize)
{
kcore_seg_t seghdr;
long offset;
int gap;
if (kd->kcore_hdr == NULL || kd->cpu_data == NULL) {
_kvm_err(kd, kd->program, "no valid dump header(s)");
return (-1);
}
/*
* Write the generic header
*/
offset = 0;
if (fwrite(kd->kcore_hdr, sizeof(kcore_hdr_t), 1, fp) < 1) {
_kvm_syserr(kd, kd->program, "kvm_dump_wrtheader");
return (-1);
}
offset += kd->kcore_hdr->c_hdrsize;
gap = kd->kcore_hdr->c_hdrsize - sizeof(kcore_hdr_t);
if (clear_gap(kd, fp, gap) == -1)
return (-1);
/*
* Write the cpu header
*/
CORE_SETMAGIC(seghdr, KCORESEG_MAGIC, 0, CORE_CPU);
seghdr.c_size = (u_long)ALIGN(kd->cpu_dsize);
if (fwrite(&seghdr, sizeof(seghdr), 1, fp) < 1) {
_kvm_syserr(kd, kd->program, "kvm_dump_wrtheader");
return (-1);
}
offset += kd->kcore_hdr->c_seghdrsize;
gap = kd->kcore_hdr->c_seghdrsize - sizeof(seghdr);
if (clear_gap(kd, fp, gap) == -1)
return (-1);
if (fwrite(kd->cpu_data, kd->cpu_dsize, 1, fp) < 1) {
_kvm_syserr(kd, kd->program, "kvm_dump_wrtheader");
return (-1);
}
offset += seghdr.c_size;
gap = seghdr.c_size - kd->cpu_dsize;
if (clear_gap(kd, fp, gap) == -1)
return (-1);
/*
* Write the actual dump data segment header
*/
CORE_SETMAGIC(seghdr, KCORESEG_MAGIC, 0, CORE_DATA);
seghdr.c_size = dumpsize;
if (fwrite(&seghdr, sizeof(seghdr), 1, fp) < 1) {
_kvm_syserr(kd, kd->program, "kvm_dump_wrtheader");
return (-1);
}
offset += kd->kcore_hdr->c_seghdrsize;
gap = kd->kcore_hdr->c_seghdrsize - sizeof(seghdr);
if (clear_gap(kd, fp, gap) == -1)
return (-1);
return (offset);
}
kvm_t *
kvm_openfiles(const char *uf, const char *mf, const char *sf,
int flag, char *errout)
{
kvm_t *kd;
if ((kd = malloc(sizeof(*kd))) == NULL) {
(void)strlcpy(errout, strerror(errno), _POSIX2_LINE_MAX);
return (0);
}
kd->program = 0;
return (_kvm_open(kd, uf, mf, sf, flag, errout));
}
kvm_t *
kvm_open(const char *uf, const char *mf, const char *sf, int flag,
const char *program)
{
kvm_t *kd;
if ((kd = malloc(sizeof(*kd))) == NULL && program != NULL) {
(void)fprintf(stderr, "%s: %s\n", program, strerror(errno));
return (0);
}
kd->program = program;
return (_kvm_open(kd, uf, mf, sf, flag, NULL));
}
int
kvm_close(kvm_t *kd)
{
int error = 0;
if (kd->pmfd >= 0)
error |= close(kd->pmfd);
if (kd->vmfd >= 0)
error |= close(kd->vmfd);
kd->alive = 0;
if (kd->nlfd >= 0)
error |= close(kd->nlfd);
if (kd->swfd >= 0)
error |= close(kd->swfd);
if (kd->db != 0)
error |= (kd->db->close)(kd->db);
if (kd->vmst)
_kvm_freevtop(kd);
kd->cpu_dsize = 0;
if (kd->cpu_data != NULL)
free((void *)kd->cpu_data);
if (kd->kcore_hdr != NULL)
free((void *)kd->kcore_hdr);
if (kd->filebase != 0)
free((void *)kd->filebase);
if (kd->procbase != 0)
free((void *)kd->procbase);
if (kd->procbase2 != 0)
free(kd->procbase2);
if (kd->swapspc != 0)
free((void *)kd->swapspc);
if (kd->argspc != 0)
free((void *)kd->argspc);
if (kd->argbuf != 0)
free((void *)kd->argbuf);
if (kd->argv != 0)
free((void *)kd->argv);
free((void *)kd);
return (error);
}
/*
* Set up state necessary to do queries on the kernel namelist
* data base. If the data base is out-of-data/incompatible with
* given executable, set up things so we revert to standard nlist call.
* Only called for live kernels. Return 0 on success, -1 on failure.
*/
static int
kvm_dbopen(kvm_t *kd, const char *uf)
{
char dbversion[_POSIX2_LINE_MAX], kversion[_POSIX2_LINE_MAX];
char dbname[MAXPATHLEN];
struct nlist nitem;
size_t dbversionlen;
DBT rec;
uf = basename(uf);
(void)snprintf(dbname, sizeof(dbname), "%skvm_%s.db", _PATH_VARDB, uf);
kd->db = dbopen(dbname, O_RDONLY, 0, DB_HASH, NULL);
if (kd->db == NULL) {
switch (errno) {
case ENOENT:
/* No kvm_bsd.db, fall back to /bsd silently */
break;
case EFTYPE:
_kvm_err(kd, kd->program,
"file %s is incorrectly formatted", dbname);
break;
case EINVAL:
_kvm_err(kd, kd->program,
"invalid argument to dbopen()");
break;
default:
_kvm_err(kd, kd->program, "unknown dbopen() error");
break;
}
return (-1);
}
/*
* read version out of database
*/
rec.data = VRS_KEY;
rec.size = sizeof(VRS_KEY) - 1;
if ((kd->db->get)(kd->db, (DBT *)&rec, (DBT *)&rec, 0))
goto close;
if (rec.data == 0 || rec.size > sizeof(dbversion))
goto close;
bcopy(rec.data, dbversion, rec.size);
dbversionlen = rec.size;
/*
* Read version string from kernel memory.
* Since we are dealing with a live kernel, we can call kvm_read()
* at this point.
*/
rec.data = VRS_SYM;
rec.size = sizeof(VRS_SYM) - 1;
if ((kd->db->get)(kd->db, (DBT *)&rec, (DBT *)&rec, 0))
goto close;
if (rec.data == 0 || rec.size != sizeof(struct nlist))
goto close;
bcopy(rec.data, &nitem, sizeof(nitem));
if (kvm_read(kd, (u_long)nitem.n_value, kversion, dbversionlen) !=
dbversionlen)
goto close;
/*
* If they match, we win - otherwise clear out kd->db so
* we revert to slow nlist().
*/
if (bcmp(dbversion, kversion, dbversionlen) == 0)
return (0);
close:
(void)(kd->db->close)(kd->db);
kd->db = 0;
return (-1);
}
int
kvm_nlist(kvm_t *kd, struct nlist *nl)
{
struct nlist *p;
int nvalid, rv;
/*
* If we can't use the data base, revert to the
* slow library call.
*/
if (kd->db == 0) {
rv = __fdnlist(kd->nlfd, nl);
if (rv == -1)
_kvm_err(kd, 0, "bad namelist");
return (rv);
}
/*
* We can use the kvm data base. Go through each nlist entry
* and look it up with a db query.
*/
nvalid = 0;
for (p = nl; p->n_name && p->n_name[0]; ++p) {
size_t len;
DBT rec;
if ((len = strlen(p->n_name)) > 4096) {
/* sanity */
_kvm_err(kd, kd->program, "symbol too large");
return (-1);
}
rec.data = p->n_name;
rec.size = len;
/*
* Make sure that n_value = 0 when the symbol isn't found
*/
p->n_value = 0;
if ((kd->db->get)(kd->db, (DBT *)&rec, (DBT *)&rec, 0))
continue;
if (rec.data == 0 || rec.size != sizeof(struct nlist))
continue;
++nvalid;
/*
* Avoid alignment issues.
*/
bcopy(&((struct nlist *)rec.data)->n_type,
&p->n_type, sizeof(p->n_type));
bcopy(&((struct nlist *)rec.data)->n_value,
&p->n_value, sizeof(p->n_value));
}
/*
* Return the number of entries that weren't found.
*/
return ((p - nl) - nvalid);
}
int
kvm_dump_inval(kvm_t *kd)
{
struct nlist nl[2];
u_long x;
paddr_t pa;
if (ISALIVE(kd)) {
_kvm_err(kd, kd->program, "clearing dump on live kernel");
return (-1);
}
nl[0].n_name = "_dumpmag";
nl[1].n_name = NULL;
if (kvm_nlist(kd, nl) == -1) {
_kvm_err(kd, 0, "bad namelist");
return (-1);
}
if (nl[0].n_value == 0) {
_kvm_err(kd, nl[0].n_name, "not in name list");
return (-1);
}
if (_kvm_kvatop(kd, (u_long)nl[0].n_value, &pa) == 0)
return (-1);
x = 0;
if (_kvm_pwrite(kd, kd->pmfd, &x, sizeof(x),
(off_t)_kvm_pa2off(kd, pa)) != sizeof(x)) {
_kvm_err(kd, 0, "cannot invalidate dump");
return (-1);
}
return (0);
}
ssize_t
kvm_read(kvm_t *kd, u_long kva, void *buf, size_t len)
{
ssize_t cc;
void *cp;
if (ISALIVE(kd)) {
/*
* We're using /dev/kmem. Just read straight from the
* device and let the active kernel do the address translation.
*/
cc = _kvm_pread(kd, kd->vmfd, buf, len, (off_t)kva);
if (cc == -1) {
_kvm_err(kd, 0, "invalid address (%lx)", kva);
return (-1);
} else if (cc < len)
_kvm_err(kd, kd->program, "short read");
return (cc);
} else {
if ((kd->kcore_hdr == NULL) || (kd->cpu_data == NULL)) {
_kvm_err(kd, kd->program, "no valid dump header");
return (-1);
}
cp = buf;
while (len > 0) {
paddr_t pa;
/* In case of error, _kvm_kvatop sets the err string */
cc = _kvm_kvatop(kd, kva, &pa);
if (cc == 0)
return (-1);
if (cc > len)
cc = len;
cc = _kvm_pread(kd, kd->pmfd, cp, (size_t)cc,
(off_t)_kvm_pa2off(kd, pa));
if (cc == -1) {
_kvm_syserr(kd, 0, _PATH_MEM);
break;
}
/*
* If kvm_kvatop returns a bogus value or our core
* file is truncated, we might wind up seeking beyond
* the end of the core file in which case the read will
* return 0 (EOF).
*/
if (cc == 0)
break;
cp = (char *)cp + cc;
kva += cc;
len -= cc;
}
return ((char *)cp - (char *)buf);
}
/* NOTREACHED */
}
ssize_t
kvm_write(kvm_t *kd, u_long kva, const void *buf, size_t len)
{
int cc;
if (ISALIVE(kd)) {
/*
* Just like kvm_read, only we write.
*/
cc = _kvm_pwrite(kd, kd->vmfd, buf, len, (off_t)kva);
if (cc == -1) {
_kvm_err(kd, 0, "invalid address (%lx)", kva);
return (-1);
} else if (cc < len)
_kvm_err(kd, kd->program, "short write");
return (cc);
} else {
_kvm_err(kd, kd->program,
"kvm_write not implemented for dead kernels");
return (-1);
}
/* NOTREACHED */
}
static int
kvm_setfd(kvm_t *kd)
{
if (kd->pmfd >= 0 && fcntl(kd->pmfd, F_SETFD, FD_CLOEXEC) < 0)
return (-1);
if (kd->vmfd >= 0 && fcntl(kd->vmfd, F_SETFD, FD_CLOEXEC) < 0)
return (-1);
if (kd->nlfd >= 0 && fcntl(kd->nlfd, F_SETFD, FD_CLOEXEC) < 0)
return (-1);
if (kd->swfd >= 0 && fcntl(kd->swfd, F_SETFD, FD_CLOEXEC) < 0)
return (-1);
return (0);
}