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authorRobert Watson <rwatson@FreeBSD.org>2008-04-25 17:34:09 +0000
committerRobert Watson <rwatson@FreeBSD.org>2008-04-25 17:34:09 +0000
commit06934245766b7f6666faba1986d8f1c47c8f8102 (patch)
treee99ccd79b541b051bd09429988773c054aa6b02d /sbin/ddb
parentedbb029388dbf6767b29eb7b03ca6e5278a328cc (diff)
downloadsrc-06934245766b7f6666faba1986d8f1c47c8f8102.tar.gz
src-06934245766b7f6666faba1986d8f1c47c8f8102.zip
Add "ddb capture print" and "ddb capture status" commands do ddb(8),
alowing the DDB output capture buffer to be easily extracted from user space. Both of these commands include -M/-N arguments, allowing them to be used with kernel crash dumps (or /dev/mem). This makes it easier to use DDB scripting and output capture with minidumps or full dumps rather than with text dumps, allowing DDB output (scripted or otherwise) to be easily extracted from a crash dump. MFC after: 1 week Discussed with: brooks, jhb
Notes
Notes: svn path=/head/; revision=178515
Diffstat (limited to 'sbin/ddb')
-rw-r--r--sbin/ddb/Makefile5
-rw-r--r--sbin/ddb/ddb.841
-rw-r--r--sbin/ddb/ddb.c8
-rw-r--r--sbin/ddb/ddb.h1
-rw-r--r--sbin/ddb/ddb_capture.c247
5 files changed, 297 insertions, 5 deletions
diff --git a/sbin/ddb/Makefile b/sbin/ddb/Makefile
index 1ae724b55ee3..b9189c1c0d9e 100644
--- a/sbin/ddb/Makefile
+++ b/sbin/ddb/Makefile
@@ -1,8 +1,11 @@
# $FreeBSD$
PROG= ddb
-SRCS= ddb.c ddb_script.c
+SRCS= ddb.c ddb_capture.c ddb_script.c
MAN= ddb.8
WARNS= 3
+DPADD= ${LIBKVM}
+LDADD= -lkvm
+
.include <bsd.prog.mk>
diff --git a/sbin/ddb/ddb.8 b/sbin/ddb/ddb.8
index 0165f56fbefd..90ceb6300c3d 100644
--- a/sbin/ddb/ddb.8
+++ b/sbin/ddb/ddb.8
@@ -1,5 +1,5 @@
.\"-
-.\" Copyright (c) 2007 Robert N. M. Watson
+.\" Copyright (c) 2007-2008 Robert N. M. Watson
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
@@ -25,7 +25,7 @@
.\"
.\" $FreeBSD$
.\"
-.Dd April 4, 2008
+.Dd April 24, 2008
.Dt DDB 8
.Os
.Sh NAME
@@ -33,6 +33,16 @@
.Nd "configure DDB kernel debugger properties"
.Sh SYNOPSIS
.Nm
+.Cm capture
+.Op Fl M core
+.Op Fl N system
+.Cm print
+.Nm
+.Cm capture
+.Op Fl M core
+.Op Fl N system
+.Cm status
+.Nm
.Cm script
.Ar scriptname
.Nm
@@ -67,6 +77,33 @@ utility.
Whitespace at the beginning of lines will be ignored as will lines where the
first non-whitespace character is
.Ql # .
+.Sh OUTPUT CAPTURE
+The
+.Nm
+utility can be used to extract the contents of the
+.Xr ddb 4
+output capture buffer of the current live kernel, or from the crash dump of a
+kernel on disk.
+The following debugger commands are available from the command line:
+.Bl -tag -width indent
+.It Xo
+.Ic Cm capture
+.Op Fl M Ar core
+.Op Fl N Ar system
+.Cm print
+.Xc
+Print the current contents of the
+.Xr ddb 4
+output capture buffer.
+.It Xo
+.Ic Cm capture
+.Op Fl M Ar core
+.Op Fl N Ar system
+.Cm status
+.Xc
+Print the current status of the
+.Xr ddb 4
+output capture buffer.
.Sh SCRIPTING
The
.Nm
diff --git a/sbin/ddb/ddb.c b/sbin/ddb/ddb.c
index 5e86efc1e47b..f5c5dd026451 100644
--- a/sbin/ddb/ddb.c
+++ b/sbin/ddb/ddb.c
@@ -43,7 +43,9 @@ void
usage(void)
{
- fprintf(stderr, "usage: ddb script scriptname\n");
+ fprintf(stderr, "usage: ddb capture [-M core] [-N system] print\n");
+ fprintf(stderr, " ddb capture [-M core] [-N system] status\n");
+ fprintf(stderr, " ddb script scriptname\n");
fprintf(stderr, " ddb script scriptname=script\n");
fprintf(stderr, " ddb scripts\n");
fprintf(stderr, " ddb unscript scriptname\n");
@@ -103,7 +105,9 @@ ddb_main(int argc, char *argv[])
if (argc < 1)
usage();
- if (strcmp(argv[0], "script") == 0)
+ if (strcmp(argv[0], "capture") == 0)
+ ddb_capture(argc, argv);
+ else if (strcmp(argv[0], "script") == 0)
ddb_script(argc, argv);
else if (strcmp(argv[0], "scripts") == 0)
ddb_scripts(argc, argv);
diff --git a/sbin/ddb/ddb.h b/sbin/ddb/ddb.h
index 50128bd43c61..8363bccfd889 100644
--- a/sbin/ddb/ddb.h
+++ b/sbin/ddb/ddb.h
@@ -29,6 +29,7 @@
#ifndef DDB_H
#define DDB_H
+void ddb_capture(int argc, char *argv[]);
void ddb_script(int argc, char *argv[]);
void ddb_scripts(int argc, char *argv[]);
void ddb_unscript(int argc, char *argv[]);
diff --git a/sbin/ddb/ddb_capture.c b/sbin/ddb/ddb_capture.c
new file mode 100644
index 000000000000..9f83acbb03a5
--- /dev/null
+++ b/sbin/ddb/ddb_capture.c
@@ -0,0 +1,247 @@
+/*-
+ * Copyright (c) 2008 Robert N. M. Watson
+ * 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/sysctl.h>
+
+#include <err.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <kvm.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sysexits.h>
+#include <unistd.h>
+
+#include "ddb.h"
+
+/*
+ * Interface with the ddb(4) capture buffer of a live kernel using sysctl, or
+ * for a crash dump using libkvm.
+ */
+#define SYSCTL_DDB_CAPTURE_BUFOFF "debug.ddb.capture.bufoff"
+#define SYSCTL_DDB_CAPTURE_BUFSIZE "debug.ddb.capture.bufsize"
+#define SYSCTL_DDB_CAPTURE_MAXBUFSIZE "debug.ddb.capture.maxbufsize"
+#define SYSCTL_DDB_CAPTURE_DATA "debug.ddb.capture.data"
+#define SYSCTL_DDB_CAPTURE_INPROGRESS "debug.ddb.capture.inprogress"
+
+static struct nlist namelist[] = {
+#define X_DB_CAPTURE_BUF 0
+ { .n_name = "_db_capture_buf" },
+#define X_DB_CAPTURE_BUFSIZE 1
+ { .n_name = "_db_capture_bufsize" },
+#define X_DB_CAPTURE_MAXBUFSIZE 2
+ { .n_name = "_db_capture_maxbufsize" },
+#define X_DB_CAPTURE_BUFOFF 3
+ { .n_name = "_db_capture_bufoff" },
+#define X_DB_CAPTURE_INPROGRESS 4
+ { .n_name = "_db_capture_inprogress" },
+ { .n_name = "" },
+};
+
+static int
+kread(kvm_t *kvm, void *kvm_pointer, void *address, size_t size,
+ size_t offset)
+{
+ ssize_t ret;
+
+ ret = kvm_read(kvm, (unsigned long)kvm_pointer + offset, address,
+ size);
+ if (ret < 0 || (size_t)ret != size)
+ return (-1);
+ return (0);
+}
+
+static int
+kread_symbol(kvm_t *kvm, int index, void *address, size_t size,
+ size_t offset)
+{
+ ssize_t ret;
+
+ ret = kvm_read(kvm, namelist[index].n_value + offset, address, size);
+ if (ret < 0 || (size_t)ret != size)
+ return (-1);
+ return (0);
+}
+
+static void
+ddb_capture_print_kvm(kvm_t *kvm)
+{
+ u_int db_capture_bufsize;
+ char *buffer, *db_capture_buf;
+
+ if (kread_symbol(kvm, X_DB_CAPTURE_BUF, &db_capture_buf,
+ sizeof(db_capture_buf), 0) < 0)
+ errx(-1, "kvm: unable to read db_capture_buf");
+
+ if (kread_symbol(kvm, X_DB_CAPTURE_BUFSIZE, &db_capture_bufsize,
+ sizeof(db_capture_bufsize), 0) < 0)
+ errx(-1, "kvm: unable to read db_capture_bufsize");
+
+ buffer = malloc(db_capture_bufsize + 1);
+ if (buffer == NULL)
+ err(-1, "malloc: db_capture_bufsize (%u)",
+ db_capture_bufsize);
+ bzero(buffer, db_capture_bufsize + 1);
+
+ if (kread(kvm, db_capture_buf, buffer, db_capture_bufsize, 0) < 0)
+ errx(-1, "kvm: unable to read buffer");
+
+ printf("%s\n", buffer);
+ free(buffer);
+}
+
+static void
+ddb_capture_print_sysctl(void)
+{
+ size_t buflen, len;
+ char *buffer;
+ int ret;
+
+repeat:
+ if (sysctlbyname(SYSCTL_DDB_CAPTURE_DATA, NULL, &buflen, NULL, 0) < 0)
+ err(EX_OSERR, "sysctl: %s", SYSCTL_DDB_CAPTURE_DATA);
+ if (buflen == 0)
+ return;
+ buffer = malloc(buflen);
+ if (buffer == NULL)
+ err(EX_OSERR, "malloc");
+ bzero(buffer, buflen);
+ len = buflen;
+ ret = sysctlbyname(SYSCTL_DDB_CAPTURE_DATA, buffer, &len, NULL, 0);
+ if (ret < 0 && errno != ENOMEM)
+ err(EX_OSERR, "sysctl: %s", SYSCTL_DDB_CAPTURE_DATA);
+ if (ret < 0) {
+ free(buffer);
+ goto repeat;
+ }
+
+ printf("%s\n", buffer);
+ free(buffer);
+}
+
+static void
+ddb_capture_status_kvm(kvm_t *kvm)
+{
+ u_int db_capture_bufoff, db_capture_bufsize, db_capture_inprogress;
+
+ if (kread_symbol(kvm, X_DB_CAPTURE_BUFOFF, &db_capture_bufoff,
+ sizeof(db_capture_bufoff), 0) < 0)
+ errx(-1, "kvm: unable to read db_capture_bufoff");
+ if (kread_symbol(kvm, X_DB_CAPTURE_BUFSIZE, &db_capture_bufsize,
+ sizeof(db_capture_bufsize), 0) < 0)
+ errx(-1, "kvm: unable to read db_capture_bufsize");
+ if (kread_symbol(kvm, X_DB_CAPTURE_INPROGRESS,
+ &db_capture_inprogress, sizeof(db_capture_inprogress), 0) < 0)
+ err(-1, "kvm: unable to read db_capture_inpgoress");
+ printf("%u/%u bytes used\n", db_capture_bufoff, db_capture_bufsize);
+ if (db_capture_inprogress)
+ printf("capture is on\n");
+ else
+ printf("capture is off\n");
+
+}
+
+static void
+ddb_capture_status_sysctl(void)
+{
+ u_int db_capture_bufoff, db_capture_bufsize, db_capture_inprogress;
+ size_t len;
+
+ len = sizeof(db_capture_bufoff);
+ if (sysctlbyname(SYSCTL_DDB_CAPTURE_BUFOFF, &db_capture_bufoff, &len,
+ NULL, 0) < 0)
+ err(EX_OSERR, "sysctl: %s", SYSCTL_DDB_CAPTURE_BUFOFF);
+ len = sizeof(db_capture_bufoff);
+ if (sysctlbyname(SYSCTL_DDB_CAPTURE_BUFSIZE, &db_capture_bufsize,
+ &len, NULL, 0) < 0)
+ err(EX_OSERR, "sysctl: %s", SYSCTL_DDB_CAPTURE_BUFSIZE);
+ len = sizeof(db_capture_inprogress);
+ if (sysctlbyname(SYSCTL_DDB_CAPTURE_INPROGRESS,
+ &db_capture_inprogress, &len, NULL, 0) < 0)
+ err(EX_OSERR, "sysctl: %s", SYSCTL_DDB_CAPTURE_INPROGRESS);
+ printf("%u/%u bytes used\n", db_capture_bufoff, db_capture_bufsize);
+ if (db_capture_inprogress)
+ printf("capture is on\n");
+ else
+ printf("capture is off\n");
+}
+
+void
+ddb_capture(int argc, char *argv[])
+{
+ char *mflag, *nflag, errbuf[_POSIX2_LINE_MAX];
+ kvm_t *kvm;
+ int ch;
+
+ mflag = NULL;
+ nflag = NULL;
+ while ((ch = getopt(argc, argv, "M:N:")) != -1) {
+ switch (ch) {
+ case 'M':
+ mflag = optarg;
+ break;
+
+ case 'N':
+ nflag = optarg;
+ break;
+
+ default:
+ usage();
+ }
+ }
+ argc -= optind;
+ argv += optind;
+
+ if (argc != 1)
+ usage();
+
+ if (mflag != NULL) {
+ kvm = kvm_openfiles(nflag, mflag, NULL, O_RDONLY, errbuf);
+ if (kvm == NULL)
+ errx(-1, "ddb_capture: kvm_openfiles: %s", errbuf);
+ if (kvm_nlist(kvm, namelist) != 0)
+ errx(-1, "ddb_capture: kvm_nlist");
+ } else if (nflag != NULL)
+ usage();
+ if (strcmp(argv[0], "print") == 0) {
+ if (kvm != NULL)
+ ddb_capture_print_kvm(kvm);
+ else
+ ddb_capture_print_sysctl();
+ } else if (strcmp(argv[0], "status") == 0) {
+ if (kvm != NULL)
+ ddb_capture_status_kvm(kvm);
+ else
+ ddb_capture_status_sysctl();
+ } else
+ usage();
+}