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NetBSD/lib/libkvm/kvm.c

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/* $NetBSD: kvm.c,v 1.104 2018/11/05 00:43:30 mrg 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 1.104 2018/11/05 00:43:30 mrg Exp $");
#endif
#endif /* LIBC_SCCS and not lint */
#include <sys/param.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.h>
#include <sys/kcore.h>
#include <sys/ksyms.h>
#include <sys/types.h>
#include <uvm/uvm_extern.h>
#include <machine/cpu.h>
#include <ctype.h>
#include <errno.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(kvm_t *);
static kvm_t *_kvm_open(kvm_t *, const char *, const char *,
const char *, int, char *);
static int clear_gap(kvm_t *, bool (*)(void *, const void *, size_t),
void *, size_t);
static off_t Lseek(kvm_t *, int, off_t, int);
static ssize_t Pread(kvm_t *, int, void *, size_t, off_t);
char *
kvm_geterr(kvm_t *kd)
{
return (kd->errbuf);
}
const char *
kvm_getkernelname(kvm_t *kd)
{
return kd->kernelname;
}
/*
* 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);
}
/*
* Wrapper around the lseek(2) system call; calls _kvm_syserr() for us
* in the event of emergency.
*/
static off_t
Lseek(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);
}
ssize_t
_kvm_pread(kvm_t *kd, int fd, void *buf, size_t size, off_t off)
{
ptrdiff_t moff;
void *newbuf;
size_t dsize;
ssize_t rv;
off_t doff;
/* If aligned nothing to do. */
if (((off % kd->fdalign) | (size % kd->fdalign)) == 0) {
return pread(fd, buf, size, off);
}
/*
* Otherwise must buffer. We can't tolerate short reads in this
* case (lazy bum).
*/
moff = (ptrdiff_t)off % kd->fdalign;
doff = off - moff;
dsize = moff + size + kd->fdalign - 1;
dsize -= dsize % kd->fdalign;
if (kd->iobufsz < dsize) {
newbuf = realloc(kd->iobuf, dsize);
if (newbuf == NULL) {
_kvm_syserr(kd, 0, "cannot allocate I/O buffer");
return (-1);
}
kd->iobuf = newbuf;
kd->iobufsz = dsize;
}
rv = pread(fd, kd->iobuf, dsize, doff);
if (rv < size + moff)
return -1;
memcpy(buf, kd->iobuf + moff, size);
return size;
}
/*
* Wrapper around the pread(2) system call; calls _kvm_syserr() for us
* in the event of emergency.
*/
static ssize_t
Pread(kvm_t *kd, int fd, void *buf, size_t nbytes, off_t offset)
{
ssize_t rv;
errno = 0;
if ((rv = _kvm_pread(kd, fd, buf, nbytes, offset)) != nbytes &&
errno != 0)
_kvm_syserr(kd, kd->program, "Pread");
return (rv);
}
static kvm_t *
_kvm_open(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 = NULL;
kd->procbase_len = 0;
kd->procbase2 = NULL;
kd->procbase2_len = 0;
kd->lwpbase = NULL;
kd->lwpbase_len = 0;
kd->nbpg = getpagesize();
kd->swapspc = NULL;
kd->argspc = NULL;
kd->argspc_len = 0;
kd->argbuf = NULL;
kd->argv = NULL;
kd->vmst = NULL;
kd->vm_page_buckets = NULL;
kd->kcore_hdr = NULL;
kd->cpu_dsize = 0;
kd->cpu_data = NULL;
kd->dump_off = 0;
kd->fdalign = 1;
kd->iobuf = NULL;
kd->iobufsz = 0;
kd->errbuf[0] = '\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;
/*
* Open the kernel namelist. If /dev/ksyms doesn't
* exist, open the current kernel.
*/
if (ufgiven == 0)
kd->nlfd = open(_PATH_KSYMS, O_RDONLY | O_CLOEXEC, 0);
if (kd->nlfd < 0) {
if ((kd->nlfd = open(uf, O_RDONLY | O_CLOEXEC, 0)) < 0) {
_kvm_syserr(kd, kd->program, "%s", uf);
goto failed;
}
strlcpy(kd->kernelname, uf, sizeof(kd->kernelname));
} else {
strlcpy(kd->kernelname, _PATH_KSYMS, sizeof(kd->kernelname));
}
if ((kd->pmfd = open(mf, flag | O_CLOEXEC, 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) && strcmp(mf, _PATH_MEM) == 0) {
/*
* If this is /dev/mem, 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 ((kd->vmfd = open(_PATH_KMEM, flag | O_CLOEXEC, 0)) < 0) {
_kvm_syserr(kd, kd->program, "%s", _PATH_KMEM);
goto failed;
}
kd->alive = KVM_ALIVE_FILES;
if ((kd->swfd = open(sf, flag | O_CLOEXEC, 0)) < 0) {
if (errno != ENXIO) {
_kvm_syserr(kd, kd->program, "%s", sf);
goto failed;
}
/* swap is not configured? not fatal */
}
} else {
kd->fdalign = DEV_BSIZE; /* XXX */
/*
* This is a crash dump.
* Initialize the virtual address translation machinery.
*
* 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(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(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)) {
if (sz == -1)
_kvm_err(kd, 0, "read %zx bytes at offset %"PRIx64
" for cpu_hdr failed: %s", sizeof(cpu_hdr),
dump_off, strerror(errno));
else
_kvm_err(kd, 0, "read %zx bytes at offset %"PRIx64
" for cpu_hdr instead of requested %zu",
sz, dump_off, 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) {
_kvm_err(kd, kd->program, "no cpu_data");
goto fail;
}
sz = Pread(kd, kd->pmfd, kd->cpu_data, cpu_hdr.c_size,
dump_off + hdr_size);
if (sz != cpu_hdr.c_size) {
_kvm_err(kd, kd->program, "size %zu != cpu_hdr.csize %"PRIu32,
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) {
_kvm_err(kd, kd->program, "failed to seek to %" PRId64,
(int64_t)kd->dump_off);
goto fail;
}
/*
* Create a kcore_hdr.
*/
kd->kcore_hdr = _kvm_malloc(kd, sizeof(kcore_hdr_t));
if (kd->kcore_hdr == NULL) {
_kvm_err(kd, kd->program, "failed to allocate header");
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, bool (*write_buf)(void *, const void *, size_t),
void *cookie, size_t size)
{
char buf[1024];
size_t len;
(void)memset(buf, 0, size > sizeof(buf) ? sizeof(buf) : size);
while (size > 0) {
len = size > sizeof(buf) ? sizeof(buf) : size;
if (!(*write_buf)(cookie, buf, len)) {
_kvm_syserr(kd, kd->program, "clear_gap");
return -1;
}
size -= len;
}
return 0;
}
/*
* Write the dump header by calling write_buf with cookie as first argument.
*/
int
kvm_dump_header(kvm_t *kd, bool (*write_buf)(void *, const void *, size_t),
void *cookie, int dumpsize)
{
kcore_seg_t seghdr;
long offset;
size_t 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 (!(*write_buf)(cookie, kd->kcore_hdr, sizeof(kcore_hdr_t))) {
_kvm_syserr(kd, kd->program, "kvm_dump_header");
return (-1);
}
offset += kd->kcore_hdr->c_hdrsize;
gap = kd->kcore_hdr->c_hdrsize - sizeof(kcore_hdr_t);
if (clear_gap(kd, write_buf, cookie, gap) == -1)
return (-1);
/*
* Write the CPU header
*/
CORE_SETMAGIC(seghdr, KCORESEG_MAGIC, 0, CORE_CPU);
seghdr.c_size = ALIGN(kd->cpu_dsize);
if (!(*write_buf)(cookie, &seghdr, sizeof(seghdr))) {
_kvm_syserr(kd, kd->program, "kvm_dump_header");
return (-1);
}
offset += kd->kcore_hdr->c_seghdrsize;
gap = kd->kcore_hdr->c_seghdrsize - sizeof(seghdr);
if (clear_gap(kd, write_buf, cookie, gap) == -1)
return (-1);
if (!(*write_buf)(cookie, kd->cpu_data, kd->cpu_dsize)) {
_kvm_syserr(kd, kd->program, "kvm_dump_header");
return (-1);
}
offset += seghdr.c_size;
gap = seghdr.c_size - kd->cpu_dsize;
if (clear_gap(kd, write_buf, cookie, gap) == -1)
return (-1);
/*
* Write the actual dump data segment header
*/
CORE_SETMAGIC(seghdr, KCORESEG_MAGIC, 0, CORE_DATA);
seghdr.c_size = dumpsize;
if (!(*write_buf)(cookie, &seghdr, sizeof(seghdr))) {
_kvm_syserr(kd, kd->program, "kvm_dump_header");
return (-1);
}
offset += kd->kcore_hdr->c_seghdrsize;
gap = kd->kcore_hdr->c_seghdrsize - sizeof(seghdr);
if (clear_gap(kd, write_buf, cookie, gap) == -1)
return (-1);
return (int)offset;
}
static bool
kvm_dump_header_stdio(void *cookie, const void *buf, size_t len)
{
return fwrite(buf, len, 1, (FILE *)cookie) == 1;
}
int
kvm_dump_wrtheader(kvm_t *kd, FILE *fp, int dumpsize)
{
return kvm_dump_header(kd, kvm_dump_header_stdio, fp, dumpsize);
}
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) {
(void)fprintf(stderr, "%s: %s\n",
program ? program : getprogname(), 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);
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(kd->cpu_data);
if (kd->kcore_hdr != NULL)
free(kd->kcore_hdr);
if (kd->procbase != 0)
free(kd->procbase);
if (kd->procbase2 != 0)
free(kd->procbase2);
if (kd->lwpbase != 0)
free(kd->lwpbase);
if (kd->swapspc != 0)
free(kd->swapspc);
if (kd->argspc != 0)
free(kd->argspc);
if (kd->argbuf != 0)
free(kd->argbuf);
if (kd->argv != 0)
free(kd->argv);
if (kd->iobuf != 0)
free(kd->iobuf);
free(kd);
return (error);
}
int
kvm_nlist(kvm_t *kd, struct nlist *nl)
{
int rv;
/*
* Call the nlist(3) routines to retrieve the given namelist.
*/
rv = __fdnlist(kd->nlfd, nl);
if (rv == -1)
_kvm_err(kd, 0, "bad namelist");
return (rv);
}
int
kvm_dump_inval(kvm_t *kd)
{
struct nlist nl[2];
paddr_t pa;
size_t dsize;
off_t doff;
void *newbuf;
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, (vaddr_t)nl[0].n_value, &pa) == 0)
return (-1);
errno = 0;
dsize = MAX(kd->fdalign, sizeof(u_long));
if (kd->iobufsz < dsize) {
newbuf = realloc(kd->iobuf, dsize);
if (newbuf == NULL) {
_kvm_syserr(kd, 0, "cannot allocate I/O buffer");
return (-1);
}
kd->iobuf = newbuf;
kd->iobufsz = dsize;
}
memset(kd->iobuf, 0, dsize);
doff = _kvm_pa2off(kd, pa);
doff -= doff % kd->fdalign;
if (pwrite(kd->pmfd, kd->iobuf, dsize, doff) == -1) {
_kvm_syserr(kd, 0, "cannot invalidate dump - pwrite");
return (-1);
}
return (0);
}
ssize_t
kvm_read(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 = _kvm_pread(kd, 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) {
paddr_t pa;
off_t foff;
cc = _kvm_kvatop(kd, (vaddr_t)kva, &pa);
if (cc == 0) {
_kvm_err(kd, kd->program, "_kvm_kvatop(%lx)", kva);
return (-1);
}
if (cc > len)
cc = len;
foff = _kvm_pa2off(kd, pa);
errno = 0;
cc = _kvm_pread(kd, 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(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 */
}
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