Add command-line tool ddb(8), which allows DDB(4) scripts to be

managed from userspace.  It is largely a wrapper for sysctl()
calls, but because the sysctls for adding and removing scripts
are awkward to use directly, this provides an easier-to-use
interface.

MFC after:	3 months
This commit is contained in:
Robert Watson 2007-12-26 09:38:22 +00:00
parent c9b0cc3b96
commit a1f25b0daa
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/head/; revision=174915
6 changed files with 379 additions and 0 deletions

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@ -15,6 +15,7 @@ SUBDIR= adjkerntz \
clri \ clri \
comcontrol \ comcontrol \
conscontrol \ conscontrol \
ddb \
${_devd} \ ${_devd} \
devfs \ devfs \
dhclient \ dhclient \

8
sbin/ddb/Makefile Normal file
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@ -0,0 +1,8 @@
# $FreeBSD$
PROG= ddb
SRCS= ddb.c ddb_script.c
MAN= ddb.8
WARNS= 3
.include <bsd.prog.mk>

106
sbin/ddb/ddb.8 Normal file
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@ -0,0 +1,106 @@
.\"-
.\" Copyright (c) 2007 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.
.\"
.\" $FreeBSD$
.\"
.Dd 25 December, 2007
.Dt DDB 8
.Os
.Sh NAME
.Nm ddb
.Nd Configure DDB kernel debugger properties
.Sh SYNOPSIS
.Nm
.Cm script
.Ar scriptname
.Nm
.Cm script
.Ar scriptname=script
.Nm
.Cm scripts
.Nm
.Cm unscript
.Ar scriptname
.Sh DESCRIPTION
.Nm
configures certain aspects of the
.Xr DDB 4
kernel debugger from user space that are not configured at compile-time or
easily via
.Xr sysctl 8
MIB entries.
.Sh SCRIPTING
.Nm
can be used to configure aspects of
.Xr DDB 4
scripting from user space; scripting support is described in more detail in
.Xr DDB 4 .
Each of the debugger commands is available from the command line:
.Bl -tag -width indent
.It Cm script Ar scriptname
Print the script named
.Ar scriptname .
.It Cm script Ar scriptname=scriptvalue
Define a script named
.Ar scriptname ;
as many scripts contain characters interpreted in special ways by the shell,
it is advisable to enclose
.Ar scriptvalue
in quotes.
.It Cm scripts
List currently defined scripts.
.It Cm unset Ar scriptname
Delete the script named
.Ar scriptname .
.El
.Sh EXAMPLES
The following example defines a script that will execute when the kernel
debugger is entered as a result of a break signal:
.Bd -literal -offset indent
ddb script kdb.enter.break="show pcpu;bt"
.Ed
.Pp
The following example will delete the script:
.Bd -literal -offset indent
ddb unscript kdb.enter.break
.Ed
.Sh EXIT STATUS
.Ex -std
.Sh SEE ALSO
.Xr DDB 4 ,
.Xr sysctl 8
.Sh HISTORY
.Nm
first appeared in
.Fx 8.0 .
.Sh AUTHORS
.An Robert N M Watson
.Sh BUGS
Ideally,
.Nm
would not exist, as all pertinent aspects of
.Xr DDB 4
could be configured directly via
.Xr sysctl 8 .

67
sbin/ddb/ddb.c Normal file
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/*-
* Copyright (c) 2007 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 <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
#include "ddb.h"
void
usage(void)
{
fprintf(stderr, "usage:\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");
exit(EX_USAGE);
}
int
main(int argc, char *argv[])
{
if (argc < 2)
usage();
argc -= 1;
argv += 1;
if (strcmp(argv[0], "script") == 0)
ddb_script(argc, argv);
else if (strcmp(argv[0], "scripts") == 0)
ddb_scripts(argc, argv);
else if (strcmp(argv[0], "unscript") == 0)
ddb_unscript(argc, argv);
else
usage();
exit(EX_OK);
}

37
sbin/ddb/ddb.h Normal file
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/*-
* Copyright (c) 2007 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.
*
* $FreeBSD$
*/
#ifndef DDB_H
#define DDB_H
void ddb_script(int argc, char *argv[]);
void ddb_scripts(int argc, char *argv[]);
void ddb_unscript(int argc, char *argv[]);
void usage(void);
#endif /* DDB_H */

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sbin/ddb/ddb_script.c Normal file
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/*-
* Copyright (c) 2007 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 <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
#include "ddb.h"
/*
* These commands manage DDB(4) scripts from user space. For better or worse,
* the setting and unsetting of scripts is only poorly represented using
* sysctl(8), and this interface provides a more user-friendly way to
* accomplish this management, wrapped around lower-level sysctls. For
* completeness, listing of scripts is also included.
*/
#define SYSCTL_SCRIPT "debug.ddb.scripting.script"
#define SYSCTL_SCRIPTS "debug.ddb.scripting.scripts"
#define SYSCTL_UNSCRIPT "debug.ddb.scripting.unscript"
/*
* Print all scripts (scriptname==NULL) or a specific script.
*/
static void
ddb_list_scripts(const char *scriptname)
{
char *buffer, *line, *nextline;
char *line_script, *line_scriptname;
size_t buflen, len;
int ret;
repeat:
if (sysctlbyname(SYSCTL_SCRIPTS, NULL, &buflen, NULL, 0) < 0)
err(EX_OSERR, "sysctl: %s", SYSCTL_SCRIPTS);
if (buflen == 0)
return;
buffer = malloc(buflen);
if (buffer == NULL)
err(EX_OSERR, "malloc");
bzero(buffer, buflen);
len = buflen;
ret = sysctlbyname(SYSCTL_SCRIPTS, buffer, &len, NULL, 0);
if (ret < 0 && errno != ENOMEM)
err(EX_OSERR, "sysctl: %s", SYSCTL_SCRIPTS);
if (ret < 0) {
free(buffer);
goto repeat;
}
/*
* We nul'd the buffer before calling sysctl(), so at worst empty.
*
* If a specific script hasn't been requested, print it all.
*/
if (scriptname == NULL) {
printf("%s", buffer);
free(buffer);
return;
}
/*
* If a specific script has been requested, we have to parse the
* string to find it.
*/
nextline = buffer;
while ((line = strsep(&nextline, "\n")) != NULL) {
line_script = line;
line_scriptname = strsep(&line_script, "=");
if (line_script == NULL)
continue;
if (strcmp(scriptname, line_scriptname) != 0)
continue;
printf("%s\n", line_script);
break;
}
if (line == NULL) {
errno = ENOENT;
err(EX_DATAERR, "%s", scriptname);
}
free(buffer);
}
/*
* "ddb script" can be used to either print or set a script.
*/
void
ddb_script(int argc, char *argv[])
{
if (argc != 2)
usage();
argv++;
argc--;
if (strchr(argv[0], '=') != 0) {
if (sysctlbyname(SYSCTL_SCRIPT, NULL, NULL, argv[0],
strlen(argv[0]) + 1) < 0)
err(EX_OSERR, "sysctl: %s", SYSCTL_SCRIPTS);
} else
ddb_list_scripts(argv[0]);
}
void
ddb_scripts(int argc, char *argv[])
{
if (argc != 1)
usage();
ddb_list_scripts(NULL);
}
void
ddb_unscript(int argc, char *argv[])
{
int ret;
if (argc != 2)
usage();
argv++;
argc--;
ret = sysctlbyname(SYSCTL_UNSCRIPT, NULL, NULL, argv[0],
strlen(argv[0]) + 1);
if (ret < 0 && errno == EINVAL) {
errno = ENOENT;
err(EX_DATAERR, "sysctl: %s", argv[0]);
} else if (ret < 0)
err(EX_OSERR, "sysctl: %s", SYSCTL_UNSCRIPT);
}