Introduce the KDB debugger frontend. The frontend provides a framework

in which multiple (presumably different) debugger backends can be
configured and which provides basic services to those backends.
Besides providing services to backends, it also serves as the single
point of contact for any and all code that wants to make use of the
debugger functions, such as entering the debugger or handling of the
alternate break sequence. For this purpose, the frontend has been
made non-optional.
All debugger requests are forwarded or handed over to the current
backend, if applicable. Selection of the current backend is done by
the debug.kdb.current sysctl. A list of configured backends can be
obtained with the debug.kdb.available sysctl. One can enter the
debugger by writing to the debug.kdb.enter sysctl.

1 files changed, 78 insertions, 0 deletions

diff --git a/sys/sys/kdb.h b/sys/sys/kdb.h
new file mode 100644
index 0000000..f7c0988
--- /dev/null
+++ b/sys/sys/kdb.h
@@ -0,0 +1,78 @@
+/*
+ * 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.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef _SYS_KDB_H_
+#define	_SYS_KDB_H_
+
+#include <machine/setjmp.h>
+
+typedef int dbbe_init_f(void);
+typedef void dbbe_trace_f(void);
+typedef int dbbe_trap_f(int, int);
+
+struct kdb_dbbe {
+	const char	*dbbe_name;
+	dbbe_init_f	*dbbe_init;
+	dbbe_trace_f	*dbbe_trace;
+	dbbe_trap_f	*dbbe_trap;
+	int		dbbe_active;
+};
+
+#define	KDB_BACKEND(name, init, trace, trap)		\
+	static struct kdb_dbbe name##_dbbe = {		\
+		.dbbe_name = #name,			\
+		.dbbe_init = init,			\
+		.dbbe_trace = trace,			\
+		.dbbe_trap = trap			\
+	};						\
+	DATA_SET(kdb_dbbe_set, name##_dbbe)
+
+struct pcb;
+struct thread;
+struct trapframe;
+
+extern int kdb_active;			/* Non-zero while in debugger. */
+extern struct kdb_dbbe *kdb_dbbe;	/* Default debugger backend or NULL. */
+extern struct trapframe *kdb_frame;	/* Frame to kdb_trap(). */
+extern struct pcb *kdb_thrctx;		/* Current context. */
+extern struct thread *kdb_thread;	/* Current thread. */
+
+int	kdb_alt_break(int, int *);
+void	kdb_backtrace(void);
+void	kdb_enter(const char *);
+void	kdb_init(void);
+void *	kdb_jmpbuf(jmp_buf);
+void	kdb_reenter(void);
+struct pcb *kdb_thr_ctx(struct thread *);
+struct thread *kdb_thr_first(void);
+struct thread *kdb_thr_lookup(pid_t);
+struct thread *kdb_thr_next(struct thread *);
+int	kdb_thr_select(struct thread *);
+int	kdb_trap(int, int, struct trapframe *);
+
+#endif /* !_SYS_KDB_H_ */