asf_kvm.c revision 159720
160484Sobrien/*- 2218822Sdim * Copyright (c) 2006 The FreeBSD Project 3218822Sdim * All rights reserved. 433965Sjdp * 533965Sjdp * Redistribution and use in source and binary forms, with or without 633965Sjdp * modification, are permitted provided that the following conditions 733965Sjdp * are met: 833965Sjdp * 1. Redistributions of source code must retain the above copyright 933965Sjdp * notice, this list of conditions and the following disclaimer. 1033965Sjdp * 2. Redistributions in binary form must reproduce the above copyright 1133965Sjdp * notice, this list of conditions and the following disclaimer in the 1233965Sjdp * documentation and/or other materials provided with the distribution. 1333965Sjdp * 1433965Sjdp * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 1533965Sjdp * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 1633965Sjdp * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 1733965Sjdp * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 1833965Sjdp * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19218822Sdim * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20218822Sdim * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2133965Sjdp * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2233965Sjdp * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23130561Sobrien * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 2433965Sjdp * SUCH DAMAGE. 2533965Sjdp */ 2633965Sjdp 2733965Sjdp#include <sys/cdefs.h> 2833965Sjdp__FBSDID("$FreeBSD: head/usr.sbin/asf/asf_kvm.c 159720 2006-06-18 11:14:40Z yar $"); 2933965Sjdp 3033965Sjdp#include <sys/types.h> 3133965Sjdp#include <sys/param.h> 3233965Sjdp#include <sys/queue.h> /* for <sys/linker.h> with _KERNEL defined */ 3333965Sjdp#include <err.h> 3460484Sobrien#include <fcntl.h> 3533965Sjdp#include <kvm.h> 3633965Sjdp#include <limits.h> 3733965Sjdp#include <nlist.h> 3833965Sjdp#include <stdlib.h> 3960484Sobrien#include <string.h> 4033965Sjdp 4133965Sjdp#define _KERNEL 4233965Sjdp#include <sys/linker.h> 4333965Sjdp#undef _KERNEL 4460484Sobrien 4533965Sjdp#include "asf.h" 4633965Sjdp 4760484Sobrien/* Name of the head of the linker file list in /sys/kern/kern_linker.c */ 4833965Sjdp#define LINKER_HEAD "linker_files" 4933965Sjdp 5089857Sobrien/* 5189857Sobrien * Get the list of linker files using kvm(3). 52130561Sobrien * Can work with a live kernel as well as with a crash dump. 5333965Sjdp */ 5489857Sobrienvoid 5589857Sobrienasf_kvm(const char *kernfile, const char *corefile) 5689857Sobrien{ 5733965Sjdp char errbuf[LINE_MAX]; 5860484Sobrien char name[PATH_MAX]; 5960484Sobrien kvm_t *kd; 60218822Sdim struct nlist nl[2]; 6160484Sobrien struct linker_file lf; 6260484Sobrien linker_file_list_t linker_files; 63130561Sobrien ssize_t n; 6433965Sjdp void *kp; 6533965Sjdp 6633965Sjdp kd = kvm_openfiles(kernfile, corefile, NULL, O_RDONLY, errbuf); 6733965Sjdp if (kd == NULL) 6833965Sjdp errx(2, "open kernel memory: %s", errbuf); 6933965Sjdp 7033965Sjdp /* 7133965Sjdp * Locate the head of the linker file list using kernel symbols. 7233965Sjdp */ 7333965Sjdp strcpy(name, LINKER_HEAD); 7433965Sjdp nl[0].n_name = name; /* can't use LINKER_HEAD here because it's const */ 7533965Sjdp nl[1].n_name = NULL; /* terminate the array for kvm_nlist() */ 7633965Sjdp switch (kvm_nlist(kd, nl)) { 7733965Sjdp case 0: 7833965Sjdp break; 7933965Sjdp case -1: 8033965Sjdp warnx("%s: %s", LINKER_HEAD, kvm_geterr(kd)); 8133965Sjdp kvm_close(kd); 8233965Sjdp exit(2); 8333965Sjdp default: 8433965Sjdp kvm_close(kd); 8533965Sjdp errx(2, "%s: symbol not found", LINKER_HEAD); 8633965Sjdp } 8733965Sjdp 8860484Sobrien /* 8933965Sjdp * Read the head of the linker file list from kernel memory. 9033965Sjdp */ 9133965Sjdp n = kvm_read(kd, nl[0].n_value, &linker_files, sizeof(linker_files)); 9233965Sjdp if (n == -1) 9333965Sjdp goto read_err; 9433965Sjdp if (n != sizeof(linker_files)) { 9533965Sjdp kvm_close(kd); 9633965Sjdp errx(2, "%s: short read", LINKER_HEAD); 9733965Sjdp } 9833965Sjdp 9960484Sobrien /* 10060484Sobrien * Traverse the linker file list starting at its head. 10133965Sjdp */ 10233965Sjdp for (kp = linker_files.tqh_first; kp; kp = lf.link.tqe_next) { 10360484Sobrien /* Read a linker file structure */ 10433965Sjdp n = kvm_read(kd, (u_long)kp, &lf, sizeof(lf)); 10560484Sobrien if (n == -1) 10633965Sjdp goto read_err; 10733965Sjdp if (n != sizeof(lf)) { 10860484Sobrien kvm_close(kd); 10933965Sjdp errx(2, "kvm: short read"); 11060484Sobrien } 11133965Sjdp /* Read the name of the file stored separately */ 11233965Sjdp bzero(name, sizeof(name)); 11360484Sobrien n = kvm_read(kd, (u_long)lf.filename, name, sizeof(name) - 1); 11433965Sjdp if (n == -1) 11533965Sjdp goto read_err; 11633965Sjdp if (strcmp(name, KERNFILE) == 0) 117104834Sobrien continue; 11860484Sobrien /* Add this file to our list of linker files */ 11933965Sjdp kfile_add(name, lf.address); 12060484Sobrien } 12133965Sjdp kvm_close(kd); 12233965Sjdp return; 12360484Sobrien 12433965Sjdpread_err: /* A common error case */ 12560484Sobrien warnx("read kernel memory: %s", kvm_geterr(kd)); 12633965Sjdp kvm_close(kd); 12733965Sjdp exit(2); 12860484Sobrien} 12933965Sjdp