freebsd-nq/gnu/usr.bin/gdb/kgdb/trgt.c
Marcel Moolenaar 60b992ff2f Add the beginnings of kernel debugging support. the kgdb(1) tool
is basicly a shell on top of libgdb that knows about kernel threads,
kernel modules and kvm(3). As the word "beginnings" implies, not
all of the features have been implemented yet. The tool is useful
and I'd like feedback on the taken route.

The simplest way to debug a kernel core file is:
	kgdb -n 0

This opens /var/crash/vmcore.0 with the corresponding kernel in
the object directory (kernel.debug is used if it exists).

Typical things that need to be added are:
o  Auto loading of kernel modules,
o  Handling of trapframes so that backtraces can be taken across
   them,
o  Some fancy commands to extract useful information out of a core
   file,
o  Various (probably many) other things.
2004-07-25 05:29:15 +00:00

113 lines
3.2 KiB
C

/*
* Copyright (c) 2004 Marcel Moolenaar
* 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 ``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 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 <kvm.h>
#include "kgdb.h"
#include <defs.h>
#include <gdbthread.h>
#include <inferior.h>
#include <target.h>
static struct target_ops kgdb_trgt_ops;
static char *
kgdb_trgt_extra_thread_info(struct thread_info *ti __unused)
{
return (NULL);
}
static void
kgdb_trgt_find_new_threads(void)
{
}
static char *
kgdb_trgt_pid_to_str(ptid_t ptid)
{
static char buf[16];
snprintf(buf, sizeof(buf), "TID %d", ptid_get_pid(ptid));
return (buf);
}
static int
kgdb_trgt_thread_alive(ptid_t ptid)
{
return (kgdb_thr_lookup(ptid_get_pid(ptid)) != NULL);
}
static int
kgdb_trgt_xfer_memory(CORE_ADDR memaddr, char *myaddr, int len, int write,
struct mem_attrib *attrib __unused, struct target_ops *target __unused)
{
if (len == 0)
return (0);
if (!write)
return (kvm_read(kvm, memaddr, myaddr, len));
else
return (kvm_write(kvm, memaddr, myaddr, len));
}
void
kgdb_target(void)
{
struct kthr *kt;
struct thread_info *ti;
kgdb_trgt_ops.to_magic = OPS_MAGIC;
kgdb_trgt_ops.to_shortname = "kernel";
kgdb_trgt_ops.to_longname = "kernel core files.";
kgdb_trgt_ops.to_doc = "Kernel core files.";
kgdb_trgt_ops.to_stratum = thread_stratum;
kgdb_trgt_ops.to_has_memory = 1;
kgdb_trgt_ops.to_has_registers = 1;
kgdb_trgt_ops.to_has_stack = 1;
kgdb_trgt_ops.to_extra_thread_info = kgdb_trgt_extra_thread_info;
kgdb_trgt_ops.to_fetch_registers = kgdb_trgt_fetch_registers;
kgdb_trgt_ops.to_find_new_threads = kgdb_trgt_find_new_threads;
kgdb_trgt_ops.to_pid_to_str = kgdb_trgt_pid_to_str;
kgdb_trgt_ops.to_store_registers = kgdb_trgt_store_registers;
kgdb_trgt_ops.to_thread_alive = kgdb_trgt_thread_alive;
kgdb_trgt_ops.to_xfer_memory = kgdb_trgt_xfer_memory;
add_target(&kgdb_trgt_ops);
push_target(&kgdb_trgt_ops);
kt = kgdb_thr_first();
while (kt != NULL) {
ti = add_thread(ptid_build(kt->tid, 0, 0));
kt = kgdb_thr_next(kt);
}
inferior_ptid = ptid_build(curkthr->tid, 0, 0);
}