NetBSD/lib/libkvm/kvm.c

904 lines
20 KiB
C

/* $NetBSD: kvm.c,v 1.82 2003/11/04 14:59:10 cube 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.
*/
#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char sccsid[] = "@(#)kvm.c 8.2 (Berkeley) 2/13/94";
#else
__RCSID("$NetBSD: kvm.c,v 1.82 2003/11/04 14:59:10 cube Exp $");
#endif
#endif /* LIBC_SCCS and not lint */
#include <sys/param.h>
#include <sys/user.h>
#include <sys/lwp.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 <sys/ksyms.h>
#include <uvm/uvm_extern.h>
#include <machine/cpu.h>
#include <ctype.h>
#include <fcntl.h>
#include <limits.h>
#include <nlist.h>
#include <paths.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <kvm.h>
#include "kvm_private.h"
static int _kvm_get_header __P((kvm_t *));
static kvm_t *_kvm_open __P((kvm_t *, const char *, const char *,
const char *, int, char *));
static int clear_gap __P((kvm_t *, FILE *, int));
static int open_cloexec __P((const char *, int, int));
static off_t Lseek __P((kvm_t *, int, off_t, int));
static ssize_t Pread __P((kvm_t *, int, void *, size_t, off_t));
char *
kvm_geterr(kd)
kvm_t *kd;
{
return (kd->errbuf);
}
/*
* 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(kd, n)
kvm_t *kd;
size_t n;
{
void *p;
if ((p = malloc(n)) == NULL)
_kvm_err(kd, kd->program, "%s", strerror(errno));
return (p);
}
/*
* Open a file setting the close on exec bit.
*/
static int
open_cloexec(fname, flags, mode)
const char *fname;
int flags, mode;
{
int fd;
if ((fd = open(fname, flags, mode)) == -1)
return fd;
if (fcntl(fd, F_SETFD, FD_CLOEXEC) == -1)
goto error;
return fd;
error:
flags = errno;
(void)close(fd);
errno = flags;
return -1;
}
/*
* Wrapper around the lseek(2) system call; calls _kvm_syserr() for us
* in the event of emergency.
*/
static off_t
Lseek(kd, fd, offset, whence)
kvm_t *kd;
int fd;
off_t offset;
int whence;
{
off_t off;
errno = 0;
if ((off = lseek(fd, offset, whence)) == -1 && errno != 0) {
_kvm_syserr(kd, kd->program, "Lseek");
return ((off_t)-1);
}
return (off);
}
/*
* Wrapper around the pread(2) system call; calls _kvm_syserr() for us
* in the event of emergency.
*/
static ssize_t
Pread(kd, fd, buf, nbytes, offset)
kvm_t *kd;
int fd;
void *buf;
size_t nbytes;
off_t offset;
{
ssize_t rv;
errno = 0;
if ((rv = pread(fd, buf, nbytes, offset)) != nbytes &&
errno != 0)
_kvm_syserr(kd, kd->program, "Pread");
return (rv);
}
static kvm_t *
_kvm_open(kd, uf, mf, sf, flag, errout)
kvm_t *kd;
const char *uf;
const char *mf;
const char *sf;
int flag;
char *errout;
{
struct stat st;
int ufgiven;
kd->pmfd = -1;
kd->vmfd = -1;
kd->swfd = -1;
kd->nlfd = -1;
kd->alive = KVM_ALIVE_DEAD;
kd->procbase = 0;
kd->procbase2 = 0;
kd->lwpbase = 0;
kd->nbpg = getpagesize();
kd->swapspc = 0;
kd->argspc = 0;
kd->arglen = 0;
kd->argbuf = 0;
kd->argv = 0;
kd->vmst = 0;
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 = KVM_ALIVE_SYSCTL;
return(kd);
}
/*
* Call the MD open hook. This sets:
* usrstack, min_uva, max_uva
*/
if (_kvm_mdopen(kd)) {
_kvm_err(kd, kd->program, "md init failed");
goto failed;
}
ufgiven = (uf != NULL);
if (!ufgiven) {
#ifdef CPU_BOOTED_KERNEL
/* 130 is 128 + '/' + '\0' */
static char booted_kernel[130];
int mib[2], rc;
size_t len;
mib[0] = CTL_MACHDEP;
mib[1] = CPU_BOOTED_KERNEL;
booted_kernel[0] = '/';
booted_kernel[1] = '\0';
len = sizeof(booted_kernel) - 2;
rc = sysctl(&mib[0], 2, &booted_kernel[1], &len, NULL, 0);
booted_kernel[sizeof(booted_kernel) - 1] = '\0';
uf = (booted_kernel[1] == '/') ?
&booted_kernel[1] : &booted_kernel[0];
if (rc != -1)
rc = stat(uf, &st);
if (rc != -1 && !S_ISREG(st.st_mode))
rc = -1;
if (rc == -1)
#endif /* CPU_BOOTED_KERNEL */
uf = _PATH_UNIX;
}
else if (strlen(uf) >= MAXPATHLEN) {
_kvm_err(kd, kd->program, "exec file name too long");
goto failed;
}
if (flag & ~O_RDWR) {
_kvm_err(kd, kd->program, "bad flags arg");
goto failed;
}
if (mf == 0)
mf = _PATH_MEM;
if (sf == 0)
sf = _PATH_DRUM;
if ((kd->pmfd = open_cloexec(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_cloexec(_PATH_KMEM, flag, 0)) < 0) {
_kvm_syserr(kd, kd->program, "%s", _PATH_KMEM);
goto failed;
}
kd->alive = KVM_ALIVE_FILES;
if ((kd->swfd = open_cloexec(sf, flag, 0)) < 0) {
_kvm_syserr(kd, kd->program, "%s", sf);
goto failed;
}
/*
* Open the kernel namelist. If /dev/ksyms doesn't
* exist, open the current kernel.
*/
if (ufgiven == 0)
kd->nlfd = open_cloexec(_PATH_KSYMS, O_RDONLY, 0);
if (kd->nlfd < 0) {
if ((kd->nlfd = open_cloexec(uf, O_RDONLY, 0)) < 0) {
_kvm_syserr(kd, kd->program, "%s", uf);
goto failed;
}
} else {
/*
* We're here because /dev/ksyms was opened
* successfully. However, we don't want to keep it
* open, so we close it now. Later, we will open
* it again, since it will be the only case where
* kd->nlfd is negative.
*/
close(kd->nlfd);
kd->nlfd = -1;
}
} else {
/*
* This is a crash dump.
* Initialize the virtual address translation machinery,
* but first setup the namelist fd.
*/
if ((kd->nlfd = open_cloexec(uf, O_RDONLY, 0)) < 0) {
_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;
}
}
return (kd);
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(kd)
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 = 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));
memcpy(kd->kcore_hdr, &kcore_hdr, sizeof(kcore_hdr));
offset = kcore_hdr.c_hdrsize;
/*
* Read the CPU segment header
*/
sz = 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, cpu_hdr.c_size);
if (kd->cpu_data == NULL)
goto fail;
sz = Pread(kd, kd->pmfd, kd->cpu_data, cpu_hdr.c_size, (off_t)offset);
if (sz != cpu_hdr.c_size)
goto fail;
offset += cpu_hdr.c_size;
/*
* Read the next segment header: data segment
*/
sz = 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(kd, dump_off)
kvm_t *kd;
off_t dump_off;
{
kcore_seg_t cpu_hdr;
size_t 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 = Pread(kd, kd->pmfd, &cpu_hdr, sizeof(cpu_hdr), 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 (0);
}
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 = Pread(kd, kd->pmfd, kd->cpu_data, cpu_hdr.c_size,
dump_off + hdr_size);
if (sz != cpu_hdr.c_size)
goto fail;
hdr_size += kd->cpu_dsize;
/*
* Leave phys mem pointer at beginning of memory data
*/
kd->dump_off = dump_off + hdr_size;
if (Lseek(kd, kd->pmfd, kd->dump_off, SEEK_SET) == -1)
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(kd, fp, size)
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(kd, fp, dumpsize)
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((void*)kd->kcore_hdr, sizeof(kcore_hdr_t), 1, fp) == 0) {
_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 = ALIGN(kd->cpu_dsize);
if (fwrite((void*)&seghdr, sizeof(seghdr), 1, fp) == 0) {
_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((void*)kd->cpu_data, kd->cpu_dsize, 1, fp) == 0) {
_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((void*)&seghdr, sizeof(seghdr), 1, fp) == 0) {
_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 (int)offset;
}
kvm_t *
kvm_openfiles(uf, mf, sf, flag, errout)
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(uf, mf, sf, flag, program)
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(kd)
kvm_t *kd;
{
int error = 0;
if (kd->pmfd >= 0)
error |= close(kd->pmfd);
if (kd->vmfd >= 0)
error |= close(kd->vmfd);
if (kd->nlfd >= 0)
error |= close(kd->nlfd);
if (kd->swfd >= 0)
error |= close(kd->swfd);
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->procbase != 0)
free((void *)kd->procbase);
if (kd->procbase2 != 0)
free((void *)kd->procbase2);
if (kd->lwpbase != 0)
free((void *)kd->lwpbase);
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 (0);
}
int
kvm_nlist(kd, nl)
kvm_t *kd;
struct nlist *nl;
{
int rv, nlfd;
/*
* kd->nlfd might be negative when we get here, and in that
* case that means that we're using /dev/ksyms.
* So open it again, just for the time we retrieve the list.
*/
if (kd->nlfd < 0) {
nlfd = open_cloexec(_PATH_KSYMS, O_RDONLY, 0);
if (nlfd < 0) {
_kvm_err(kd, 0, "failed to open %s", _PATH_KSYMS);
return (nlfd);
}
} else
nlfd = kd->nlfd;
/*
* Call the nlist(3) routines to retrieve the given namelist.
*/
rv = __fdnlist(nlfd, nl);
if (rv == -1)
_kvm_err(kd, 0, "bad namelist");
if (kd->nlfd < 0)
close(nlfd);
return (rv);
}
int kvm_dump_inval(kd)
kvm_t *kd;
{
struct nlist nl[2];
u_long pa, val;
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 (_kvm_kvatop(kd, (u_long)nl[0].n_value, &pa) == 0)
return (-1);
errno = 0;
val = 0;
if (pwrite(kd->pmfd, (void *)&val, sizeof(val),
_kvm_pa2off(kd, pa)) == -1) {
_kvm_syserr(kd, 0, "cannot invalidate dump - pwrite");
return (-1);
}
return (0);
}
ssize_t
kvm_read(kd, kva, buf, len)
kvm_t *kd;
u_long kva;
void *buf;
size_t len;
{
int cc;
void *cp;
if (ISKMEM(kd)) {
/*
* We're using /dev/kmem. Just read straight from the
* device and let the active kernel do the address translation.
*/
errno = 0;
cc = pread(kd->vmfd, buf, len, (off_t)kva);
if (cc < 0) {
_kvm_syserr(kd, 0, "kvm_read");
return (-1);
} else if (cc < len)
_kvm_err(kd, kd->program, "short read");
return (cc);
} else if (ISSYSCTL(kd)) {
_kvm_err(kd, kd->program, "kvm_open called with KVM_NO_FILES, "
"can't use kvm_read");
return (-1);
} 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) {
u_long pa;
off_t foff;
cc = _kvm_kvatop(kd, kva, &pa);
if (cc == 0)
return (-1);
if (cc > len)
cc = len;
foff = _kvm_pa2off(kd, pa);
errno = 0;
cc = pread(kd->pmfd, cp, (size_t)cc, foff);
if (cc < 0) {
_kvm_syserr(kd, kd->program, "kvm_read");
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(kd, kva, buf, len)
kvm_t *kd;
u_long kva;
const void *buf;
size_t len;
{
int cc;
if (ISKMEM(kd)) {
/*
* Just like kvm_read, only we write.
*/
errno = 0;
cc = pwrite(kd->vmfd, buf, len, (off_t)kva);
if (cc < 0) {
_kvm_syserr(kd, 0, "kvm_write");
return (-1);
} else if (cc < len)
_kvm_err(kd, kd->program, "short write");
return (cc);
} else if (ISSYSCTL(kd)) {
_kvm_err(kd, kd->program, "kvm_open called with KVM_NO_FILES, "
"can't use kvm_write");
return (-1);
} else {
_kvm_err(kd, kd->program,
"kvm_write not implemented for dead kernels");
return (-1);
}
/* NOTREACHED */
}