1/*- 2 * Copyright (c) 2006 The FreeBSD Project 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27#include <sys/cdefs.h> 28__FBSDID("$FreeBSD: releng/10.2/usr.sbin/asf/asf_kvm.c 159720 2006-06-18 11:14:40Z yar $"); 29 30#include <sys/types.h> 31#include <sys/param.h> 32#include <sys/queue.h> /* for <sys/linker.h> with _KERNEL defined */ 33#include <err.h> 34#include <fcntl.h> 35#include <kvm.h> 36#include <limits.h> 37#include <nlist.h> 38#include <stdlib.h> 39#include <string.h> 40 41#define _KERNEL 42#include <sys/linker.h> 43#undef _KERNEL 44 45#include "asf.h" 46 47/* Name of the head of the linker file list in /sys/kern/kern_linker.c */ 48#define LINKER_HEAD "linker_files" 49 50/* 51 * Get the list of linker files using kvm(3). 52 * Can work with a live kernel as well as with a crash dump. 53 */ 54void 55asf_kvm(const char *kernfile, const char *corefile) 56{ 57 char errbuf[LINE_MAX]; 58 char name[PATH_MAX]; 59 kvm_t *kd; 60 struct nlist nl[2]; 61 struct linker_file lf; 62 linker_file_list_t linker_files; 63 ssize_t n; 64 void *kp; 65 66 kd = kvm_openfiles(kernfile, corefile, NULL, O_RDONLY, errbuf); 67 if (kd == NULL) 68 errx(2, "open kernel memory: %s", errbuf); 69 70 /* 71 * Locate the head of the linker file list using kernel symbols. 72 */ 73 strcpy(name, LINKER_HEAD); 74 nl[0].n_name = name; /* can't use LINKER_HEAD here because it's const */ 75 nl[1].n_name = NULL; /* terminate the array for kvm_nlist() */ 76 switch (kvm_nlist(kd, nl)) { 77 case 0: 78 break; 79 case -1: 80 warnx("%s: %s", LINKER_HEAD, kvm_geterr(kd)); 81 kvm_close(kd); 82 exit(2); 83 default: 84 kvm_close(kd); 85 errx(2, "%s: symbol not found", LINKER_HEAD); 86 } 87 88 /* 89 * Read the head of the linker file list from kernel memory. 90 */ 91 n = kvm_read(kd, nl[0].n_value, &linker_files, sizeof(linker_files)); 92 if (n == -1) 93 goto read_err; 94 if (n != sizeof(linker_files)) { 95 kvm_close(kd); 96 errx(2, "%s: short read", LINKER_HEAD); 97 } 98 99 /* 100 * Traverse the linker file list starting at its head. 101 */ 102 for (kp = linker_files.tqh_first; kp; kp = lf.link.tqe_next) { 103 /* Read a linker file structure */ 104 n = kvm_read(kd, (u_long)kp, &lf, sizeof(lf)); 105 if (n == -1) 106 goto read_err; 107 if (n != sizeof(lf)) { 108 kvm_close(kd); 109 errx(2, "kvm: short read"); 110 } 111 /* Read the name of the file stored separately */ 112 bzero(name, sizeof(name)); 113 n = kvm_read(kd, (u_long)lf.filename, name, sizeof(name) - 1); 114 if (n == -1) 115 goto read_err; 116 if (strcmp(name, KERNFILE) == 0) 117 continue; 118 /* Add this file to our list of linker files */ 119 kfile_add(name, lf.address); 120 } 121 kvm_close(kd); 122 return; 123 124read_err: /* A common error case */ 125 warnx("read kernel memory: %s", kvm_geterr(kd)); 126 kvm_close(kd); 127 exit(2); 128} 129