xref: /openbsd/sys/ddb/db_trap.c (revision 73471bf0)
1 /*	$OpenBSD: db_trap.c,v 1.30 2019/11/06 07:30:08 mpi Exp $	*/
2 /*	$NetBSD: db_trap.c,v 1.9 1996/02/05 01:57:18 christos Exp $	*/
3 
4 /*
5  * Mach Operating System
6  * Copyright (c) 1993,1992,1991,1990 Carnegie Mellon University
7  * All Rights Reserved.
8  *
9  * Permission to use, copy, modify and distribute this software and its
10  * documentation is hereby granted, provided that both the copyright
11  * notice and this permission notice appear in all copies of the
12  * software, derivative works or modified versions, and any portions
13  * thereof, and that both notices appear in supporting documentation.
14  *
15  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
16  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
17  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
18  *
19  * Carnegie Mellon requests users of this software to return to
20  *
21  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
22  *  School of Computer Science
23  *  Carnegie Mellon University
24  *  Pittsburgh PA 15213-3890
25  *
26  * any improvements or extensions that they make and grant Carnegie Mellon
27  * the rights to redistribute these changes.
28  *
29  * 	Author: David B. Golub, Carnegie Mellon University
30  *	Date:	7/90
31  */
32 
33 /*
34  * Trap entry point to kernel debugger.
35  */
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 
39 #include <machine/db_machdep.h>
40 
41 #include <ddb/db_run.h>
42 #include <ddb/db_command.h>
43 #include <ddb/db_output.h>
44 #include <ddb/db_sym.h>
45 #include <ddb/db_extern.h>
46 #include <ddb/db_interface.h>
47 #include <ddb/db_var.h>
48 
49 void
50 db_trap(int type, int code)
51 {
52 	int	bkpt;
53 	int	watchpt;
54 
55 	bkpt = IS_BREAKPOINT_TRAP(type, code);
56 	watchpt = IS_WATCHPOINT_TRAP(type, code);
57 
58 	if (db_stop_at_pc(&ddb_regs, &bkpt)) {
59 		if (db_inst_count) {
60 			db_printf("After %d instructions\n", db_inst_count);
61 		}
62 		if (bkpt)
63 			db_printf("Breakpoint at\t");
64 		else if (watchpt)
65 			db_printf("Watchpoint at\t");
66 		else
67 			db_printf("Stopped at\t");
68 		db_dot = PC_REGS(&ddb_regs);
69 		db_print_loc_and_inst(db_dot);
70 
71 		if (panicstr != NULL) {
72 			static int ddb_msg_shown;
73 
74 			if (! ddb_msg_shown) {
75 				/* show on-proc threads */
76 				db_show_all_procs(0, 0, 0, "o");
77 			}
78 			/* then the backtrace */
79 			db_stack_trace_print(db_dot, 0, 14 /* arbitrary */, "",
80 			    db_printf);
81 
82 			if (db_print_position() != 0)
83 				db_printf("\n");
84 			if (! ddb_msg_shown) {
85 				db_printf(
86 "https://www.openbsd.org/ddb.html describes the minimum info required in bug\n"
87 "reports.  Insufficient info makes it difficult to find and fix bugs.\n");
88 				ddb_msg_shown = 1;
89 			}
90 		}
91 
92 		db_command_loop();
93 	}
94 
95 	db_restart_at_pc(&ddb_regs, watchpt);
96 }
97