diff options
Diffstat (limited to 'usr.sbin/asf/asf_kvm.c')
| -rw-r--r-- | usr.sbin/asf/asf_kvm.c | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/usr.sbin/asf/asf_kvm.c b/usr.sbin/asf/asf_kvm.c new file mode 100644 index 0000000..aa4effe --- /dev/null +++ b/usr.sbin/asf/asf_kvm.c @@ -0,0 +1,128 @@ +/*- + * Copyright (c) 2006 The FreeBSD Project + * All rights reserved. + * + * 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. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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> +__FBSDID("$FreeBSD$"); + +#include <sys/types.h> +#include <sys/param.h> +#include <sys/queue.h> /* for <sys/linker.h> with _KERNEL defined */ +#include <err.h> +#include <fcntl.h> +#include <kvm.h> +#include <limits.h> +#include <nlist.h> +#include <stdlib.h> +#include <string.h> + +#define _KERNEL +#include <sys/linker.h> +#undef _KERNEL + +#include "asf.h" + +/* Name of the head of the linker file list in /sys/kern/kern_linker.c */ +#define LINKER_HEAD "linker_files" + +/* + * Get the list of linker files using kvm(3). + * Can work with a live kernel as well as with a crash dump. + */ +void +asf_kvm(const char *kernfile, const char *corefile) +{ + char errbuf[LINE_MAX]; + char name[PATH_MAX]; + kvm_t *kd; + struct nlist nl[2]; + struct linker_file lf; + linker_file_list_t linker_files; + ssize_t n; + void *kp; + + kd = kvm_openfiles(kernfile, corefile, NULL, O_RDONLY, errbuf); + if (kd == NULL) + errx(2, "open kernel memory: %s", errbuf); + + /* + * Locate the head of the linker file list using kernel symbols. + */ + strcpy(name, LINKER_HEAD); + nl[0].n_name = name; /* can't use LINKER_HEAD here because it's const */ + nl[1].n_name = NULL; /* terminate the array for kvm_nlist() */ + switch (kvm_nlist(kd, nl)) { + case 0: + break; + case -1: + warnx("%s: %s", LINKER_HEAD, kvm_geterr(kd)); + kvm_close(kd); + exit(2); + default: + kvm_close(kd); + errx(2, "%s: symbol not found", LINKER_HEAD); + } + + /* + * Read the head of the linker file list from kernel memory. + */ + n = kvm_read(kd, nl[0].n_value, &linker_files, sizeof(linker_files)); + if (n == -1) + goto read_err; + if (n != sizeof(linker_files)) { + kvm_close(kd); + errx(2, "%s: short read", LINKER_HEAD); + } + + /* + * Traverse the linker file list starting at its head. + */ + for (kp = linker_files.tqh_first; kp; kp = lf.link.tqe_next) { + /* Read a linker file structure */ + n = kvm_read(kd, (u_long)kp, &lf, sizeof(lf)); + if (n == -1) + goto read_err; + if (n != sizeof(lf)) { + kvm_close(kd); + errx(2, "kvm: short read"); + } + /* Read the name of the file stored separately */ + bzero(name, sizeof(name)); + n = kvm_read(kd, (u_long)lf.filename, name, sizeof(name) - 1); + if (n == -1) + goto read_err; + if (strcmp(name, KERNFILE) == 0) + continue; + /* Add this file to our list of linker files */ + kfile_add(name, lf.address); + } + kvm_close(kd); + return; + +read_err: /* A common error case */ + warnx("read kernel memory: %s", kvm_geterr(kd)); + kvm_close(kd); + exit(2); +} |
