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![Bjoern A. Zeeb](/assets/img/avatar_default.png)
Revert parts of r353274 replacing vnet_state with a shutdown flag. Not having the state flag for the current SI_SUB_* makes it harder to debug kernel or module panics related to VNET bringup or teardown. Not having the state also does not allow us to check for other dependency levels between components, e.g. for moving interfaces. Expand the VNET structure with the new boolean flag indicating that we are doing a shutdown of a given vnet and update the vnet magic cookie for the change. Update libkvm to compile with a bool in the kernel struct. Bump __FreeBSD_version for (external) module builds to more easily detect the change. Reviewed by: hselasky MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D23097
533 lines
12 KiB
C
533 lines
12 KiB
C
/*-
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* SPDX-License-Identifier: BSD-3-Clause
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*
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* Copyright (c) 1989, 1992, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software developed by the Computer Systems
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* Engineering group at Lawrence Berkeley Laboratory under DARPA contract
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* BG 91-66 and contributed to Berkeley.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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__SCCSID("@(#)kvm.c 8.2 (Berkeley) 2/13/94");
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#include <sys/param.h>
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#include <sys/fnv_hash.h>
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#define _WANT_VNET
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#include <sys/user.h>
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#include <sys/linker.h>
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#include <sys/pcpu.h>
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#include <sys/stat.h>
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#include <sys/sysctl.h>
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#include <sys/mman.h>
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#include <stdbool.h>
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#include <net/vnet.h>
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#include <fcntl.h>
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#include <kvm.h>
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#include <limits.h>
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#include <paths.h>
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#include <stdint.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include "kvm_private.h"
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SET_DECLARE(kvm_arch, struct kvm_arch);
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static char _kd_is_null[] = "";
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char *
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kvm_geterr(kvm_t *kd)
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{
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if (kd == NULL)
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return (_kd_is_null);
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return (kd->errbuf);
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}
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static int
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_kvm_read_kernel_ehdr(kvm_t *kd)
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{
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Elf *elf;
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if (elf_version(EV_CURRENT) == EV_NONE) {
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_kvm_err(kd, kd->program, "Unsupported libelf");
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return (-1);
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}
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elf = elf_begin(kd->nlfd, ELF_C_READ, NULL);
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if (elf == NULL) {
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_kvm_err(kd, kd->program, "%s", elf_errmsg(0));
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return (-1);
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}
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if (elf_kind(elf) != ELF_K_ELF) {
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_kvm_err(kd, kd->program, "kernel is not an ELF file");
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return (-1);
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}
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if (gelf_getehdr(elf, &kd->nlehdr) == NULL) {
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_kvm_err(kd, kd->program, "%s", elf_errmsg(0));
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elf_end(elf);
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return (-1);
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}
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elf_end(elf);
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switch (kd->nlehdr.e_ident[EI_DATA]) {
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case ELFDATA2LSB:
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case ELFDATA2MSB:
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return (0);
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default:
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_kvm_err(kd, kd->program,
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"unsupported ELF data encoding for kernel");
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return (-1);
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}
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}
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static kvm_t *
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_kvm_open(kvm_t *kd, const char *uf, const char *mf, int flag, char *errout)
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{
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struct kvm_arch **parch;
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struct stat st;
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kd->vmfd = -1;
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kd->pmfd = -1;
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kd->nlfd = -1;
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kd->vmst = NULL;
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kd->procbase = NULL;
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kd->argspc = NULL;
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kd->argv = NULL;
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if (uf == NULL)
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uf = getbootfile();
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else if (strlen(uf) >= MAXPATHLEN) {
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_kvm_err(kd, kd->program, "exec file name too long");
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goto failed;
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}
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if (flag & ~O_RDWR) {
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_kvm_err(kd, kd->program, "bad flags arg");
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goto failed;
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}
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if (mf == NULL)
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mf = _PATH_MEM;
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if ((kd->pmfd = open(mf, flag | O_CLOEXEC, 0)) < 0) {
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_kvm_syserr(kd, kd->program, "%s", mf);
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goto failed;
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}
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if (fstat(kd->pmfd, &st) < 0) {
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_kvm_syserr(kd, kd->program, "%s", mf);
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goto failed;
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}
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if (S_ISREG(st.st_mode) && st.st_size <= 0) {
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errno = EINVAL;
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_kvm_syserr(kd, kd->program, "empty file");
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goto failed;
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}
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if (S_ISCHR(st.st_mode)) {
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/*
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* If this is a character special device, then check that
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* it's /dev/mem. If so, open kmem too. (Maybe we should
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* make it work for either /dev/mem or /dev/kmem -- in either
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* case you're working with a live kernel.)
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*/
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if (strcmp(mf, _PATH_DEVNULL) == 0) {
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kd->vmfd = open(_PATH_DEVNULL, O_RDONLY | O_CLOEXEC);
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return (kd);
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} else if (strcmp(mf, _PATH_MEM) == 0) {
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if ((kd->vmfd = open(_PATH_KMEM, flag | O_CLOEXEC)) <
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0) {
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_kvm_syserr(kd, kd->program, "%s", _PATH_KMEM);
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goto failed;
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}
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return (kd);
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}
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}
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/*
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* This is either a crash dump or a remote live system with its physical
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* memory fully accessible via a special device.
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* Open the namelist fd and determine the architecture.
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*/
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if ((kd->nlfd = open(uf, O_RDONLY | O_CLOEXEC, 0)) < 0) {
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_kvm_syserr(kd, kd->program, "%s", uf);
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goto failed;
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}
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if (_kvm_read_kernel_ehdr(kd) < 0)
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goto failed;
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if (strncmp(mf, _PATH_FWMEM, strlen(_PATH_FWMEM)) == 0 ||
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strncmp(mf, _PATH_DEVVMM, strlen(_PATH_DEVVMM)) == 0) {
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kd->rawdump = 1;
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kd->writable = 1;
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}
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SET_FOREACH(parch, kvm_arch) {
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if ((*parch)->ka_probe(kd)) {
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kd->arch = *parch;
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break;
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}
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}
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if (kd->arch == NULL) {
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_kvm_err(kd, kd->program, "unsupported architecture");
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goto failed;
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}
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/*
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* Non-native kernels require a symbol resolver.
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*/
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if (!kd->arch->ka_native(kd) && kd->resolve_symbol == NULL) {
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_kvm_err(kd, kd->program,
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"non-native kernel requires a symbol resolver");
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goto failed;
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}
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/*
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* Initialize the virtual address translation machinery.
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*/
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if (kd->arch->ka_initvtop(kd) < 0)
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goto failed;
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return (kd);
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failed:
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/*
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* Copy out the error if doing sane error semantics.
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*/
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if (errout != NULL)
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strlcpy(errout, kd->errbuf, _POSIX2_LINE_MAX);
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(void)kvm_close(kd);
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return (NULL);
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}
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kvm_t *
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kvm_openfiles(const char *uf, const char *mf, const char *sf __unused, int flag,
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char *errout)
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{
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kvm_t *kd;
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if ((kd = calloc(1, sizeof(*kd))) == NULL) {
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if (errout != NULL)
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(void)strlcpy(errout, strerror(errno),
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_POSIX2_LINE_MAX);
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return (NULL);
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}
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return (_kvm_open(kd, uf, mf, flag, errout));
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}
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kvm_t *
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kvm_open(const char *uf, const char *mf, const char *sf __unused, int flag,
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const char *errstr)
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{
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kvm_t *kd;
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if ((kd = calloc(1, sizeof(*kd))) == NULL) {
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if (errstr != NULL)
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(void)fprintf(stderr, "%s: %s\n",
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errstr, strerror(errno));
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return (NULL);
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}
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kd->program = errstr;
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return (_kvm_open(kd, uf, mf, flag, NULL));
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}
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kvm_t *
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kvm_open2(const char *uf, const char *mf, int flag, char *errout,
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int (*resolver)(const char *, kvaddr_t *))
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{
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kvm_t *kd;
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if ((kd = calloc(1, sizeof(*kd))) == NULL) {
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if (errout != NULL)
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(void)strlcpy(errout, strerror(errno),
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_POSIX2_LINE_MAX);
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return (NULL);
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}
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kd->resolve_symbol = resolver;
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return (_kvm_open(kd, uf, mf, flag, errout));
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}
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int
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kvm_close(kvm_t *kd)
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{
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int error = 0;
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if (kd == NULL) {
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errno = EINVAL;
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return (-1);
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}
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if (kd->vmst != NULL)
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kd->arch->ka_freevtop(kd);
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if (kd->pmfd >= 0)
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error |= close(kd->pmfd);
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if (kd->vmfd >= 0)
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error |= close(kd->vmfd);
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if (kd->nlfd >= 0)
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error |= close(kd->nlfd);
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if (kd->procbase != 0)
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free((void *)kd->procbase);
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if (kd->argbuf != 0)
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free((void *) kd->argbuf);
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if (kd->argspc != 0)
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free((void *) kd->argspc);
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if (kd->argv != 0)
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free((void *)kd->argv);
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if (kd->pt_map != NULL)
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free(kd->pt_map);
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if (kd->page_map != NULL)
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free(kd->page_map);
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if (kd->sparse_map != MAP_FAILED)
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munmap(kd->sparse_map, kd->pt_sparse_size);
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free((void *)kd);
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return (error);
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}
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int
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kvm_nlist2(kvm_t *kd, struct kvm_nlist *nl)
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{
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/*
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* If called via the public interface, permit initialization of
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* further virtualized modules on demand.
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*/
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return (_kvm_nlist(kd, nl, 1));
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}
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int
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kvm_nlist(kvm_t *kd, struct nlist *nl)
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{
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struct kvm_nlist *kl;
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int count, i, nfail;
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/*
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* Avoid reporting truncated addresses by failing for non-native
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* cores.
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*/
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if (!kvm_native(kd)) {
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_kvm_err(kd, kd->program, "kvm_nlist of non-native vmcore");
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return (-1);
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}
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for (count = 0; nl[count].n_name != NULL && nl[count].n_name[0] != '\0';
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count++)
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;
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if (count == 0)
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return (0);
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kl = calloc(count + 1, sizeof(*kl));
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for (i = 0; i < count; i++)
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kl[i].n_name = nl[i].n_name;
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nfail = kvm_nlist2(kd, kl);
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for (i = 0; i < count; i++) {
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nl[i].n_type = kl[i].n_type;
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nl[i].n_other = 0;
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nl[i].n_desc = 0;
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nl[i].n_value = kl[i].n_value;
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}
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return (nfail);
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}
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ssize_t
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kvm_read(kvm_t *kd, u_long kva, void *buf, size_t len)
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{
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return (kvm_read2(kd, kva, buf, len));
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}
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ssize_t
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kvm_read2(kvm_t *kd, kvaddr_t kva, void *buf, size_t len)
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{
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int cc;
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ssize_t cr;
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off_t pa;
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char *cp;
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if (ISALIVE(kd)) {
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/*
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* We're using /dev/kmem. Just read straight from the
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* device and let the active kernel do the address translation.
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*/
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errno = 0;
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if (lseek(kd->vmfd, (off_t)kva, 0) == -1 && errno != 0) {
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_kvm_err(kd, 0, "invalid address (0x%jx)",
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(uintmax_t)kva);
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return (-1);
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}
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cr = read(kd->vmfd, buf, len);
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if (cr < 0) {
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_kvm_syserr(kd, 0, "kvm_read");
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return (-1);
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} else if (cr < (ssize_t)len)
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_kvm_err(kd, kd->program, "short read");
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return (cr);
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}
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cp = buf;
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while (len > 0) {
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cc = kd->arch->ka_kvatop(kd, kva, &pa);
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if (cc == 0)
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return (-1);
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if (cc > (ssize_t)len)
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cc = len;
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errno = 0;
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if (lseek(kd->pmfd, pa, 0) == -1 && errno != 0) {
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_kvm_syserr(kd, 0, _PATH_MEM);
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break;
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}
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cr = read(kd->pmfd, cp, cc);
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if (cr < 0) {
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_kvm_syserr(kd, kd->program, "kvm_read");
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break;
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}
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/*
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* If ka_kvatop returns a bogus value or our core file is
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* truncated, we might wind up seeking beyond the end of the
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* core file in which case the read will return 0 (EOF).
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*/
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if (cr == 0)
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break;
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cp += cr;
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kva += cr;
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len -= cr;
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}
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return (cp - (char *)buf);
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}
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ssize_t
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kvm_write(kvm_t *kd, u_long kva, const void *buf, size_t len)
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{
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int cc;
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ssize_t cw;
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off_t pa;
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const char *cp;
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if (!ISALIVE(kd) && !kd->writable) {
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_kvm_err(kd, kd->program,
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"kvm_write not implemented for dead kernels");
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return (-1);
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}
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if (ISALIVE(kd)) {
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/*
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* Just like kvm_read, only we write.
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*/
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errno = 0;
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if (lseek(kd->vmfd, (off_t)kva, 0) == -1 && errno != 0) {
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_kvm_err(kd, 0, "invalid address (%lx)", kva);
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return (-1);
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}
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cc = write(kd->vmfd, buf, len);
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if (cc < 0) {
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_kvm_syserr(kd, 0, "kvm_write");
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return (-1);
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} else if ((size_t)cc < len)
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_kvm_err(kd, kd->program, "short write");
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return (cc);
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}
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cp = buf;
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while (len > 0) {
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cc = kd->arch->ka_kvatop(kd, kva, &pa);
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if (cc == 0)
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return (-1);
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if (cc > (ssize_t)len)
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cc = len;
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errno = 0;
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if (lseek(kd->pmfd, pa, 0) == -1 && errno != 0) {
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_kvm_syserr(kd, 0, _PATH_MEM);
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break;
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}
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cw = write(kd->pmfd, cp, cc);
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if (cw < 0) {
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_kvm_syserr(kd, kd->program, "kvm_write");
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break;
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}
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/*
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* If ka_kvatop returns a bogus value or our core file is
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* truncated, we might wind up seeking beyond the end of the
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* core file in which case the read will return 0 (EOF).
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*/
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if (cw == 0)
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break;
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cp += cw;
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kva += cw;
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len -= cw;
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}
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return (cp - (const char *)buf);
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}
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int
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kvm_native(kvm_t *kd)
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{
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if (ISALIVE(kd))
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return (1);
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return (kd->arch->ka_native(kd));
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}
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int
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kvm_walk_pages(kvm_t *kd, kvm_walk_pages_cb_t *cb, void *closure)
|
|
{
|
|
|
|
if (kd->arch->ka_walk_pages == NULL)
|
|
return (0);
|
|
|
|
return (kd->arch->ka_walk_pages(kd, cb, closure));
|
|
}
|
|
|
|
kssize_t
|
|
kvm_kerndisp(kvm_t *kd)
|
|
{
|
|
unsigned long kernbase, rel_kernbase;
|
|
size_t kernbase_len = sizeof(kernbase);
|
|
size_t rel_kernbase_len = sizeof(rel_kernbase);
|
|
|
|
if (ISALIVE(kd)) {
|
|
if (sysctlbyname("kern.base_address", &kernbase,
|
|
&kernbase_len, NULL, 0) == -1) {
|
|
_kvm_syserr(kd, kd->program,
|
|
"failed to get kernel base address");
|
|
return (0);
|
|
}
|
|
if (sysctlbyname("kern.relbase_address", &rel_kernbase,
|
|
&rel_kernbase_len, NULL, 0) == -1) {
|
|
_kvm_syserr(kd, kd->program,
|
|
"failed to get relocated kernel base address");
|
|
return (0);
|
|
}
|
|
return (rel_kernbase - kernbase);
|
|
}
|
|
|
|
if (kd->arch->ka_kerndisp == NULL)
|
|
return (0);
|
|
|
|
return (kd->arch->ka_kerndisp(kd));
|
|
}
|