xref: /freebsd/sys/arm/arm/db_trace.c (revision fdafd315ad0d0f28a11b9fb4476a9ab059c62b92)
1 /*	$NetBSD: db_trace.c,v 1.8 2003/01/17 22:28:48 thorpej Exp $	*/
2 
3 /*-
4  * Copyright (c) 2000, 2001 Ben Harris
5  * Copyright (c) 1996 Scott K. Stevens
6  *
7  * Mach Operating System
8  * Copyright (c) 1991,1990 Carnegie Mellon University
9  * All Rights Reserved.
10  *
11  * Permission to use, copy, modify and distribute this software and its
12  * documentation is hereby granted, provided that both the copyright
13  * notice and this permission notice appear in all copies of the
14  * software, derivative works or modified versions, and any portions
15  * thereof, and that both notices appear in supporting documentation.
16  *
17  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
18  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
19  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
20  *
21  * Carnegie Mellon requests users of this software to return to
22  *
23  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
24  *  School of Computer Science
25  *  Carnegie Mellon University
26  *  Pittsburgh PA 15213-3890
27  *
28  * any improvements or extensions that they make and grant Carnegie the
29  * rights to redistribute these changes.
30  */
31 #include "opt_ddb.h"
32 
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 
36 #include <sys/proc.h>
37 #include <sys/kdb.h>
38 #include <sys/stack.h>
39 
40 #include <machine/armreg.h>
41 #include <machine/asm.h>
42 #include <machine/cpufunc.h>
43 #include <machine/db_machdep.h>
44 #include <machine/debug_monitor.h>
45 #include <machine/pcb.h>
46 #include <machine/stack.h>
47 #include <machine/vmparam.h>
48 
49 #include <ddb/ddb.h>
50 #include <ddb/db_access.h>
51 #include <ddb/db_sym.h>
52 #include <ddb/db_output.h>
53 
54 static void
db_stack_trace_cmd(struct unwind_state * state)55 db_stack_trace_cmd(struct unwind_state *state)
56 {
57 	const char *name;
58 	db_expr_t value;
59 	db_expr_t offset;
60 	c_db_sym_t sym;
61 	u_int reg, i;
62 	char *sep;
63 	uint16_t upd_mask;
64 	bool finished;
65 
66 	finished = false;
67 	while (!finished) {
68 		finished = unwind_stack_one(state, 1);
69 
70 		/* Print the frame details */
71 		sym = db_search_symbol(state->start_pc, DB_STGY_ANY, &offset);
72 		if (sym == C_DB_SYM_NULL) {
73 			value = 0;
74 			name = "(null)";
75 		} else
76 			db_symbol_values(sym, &name, &value);
77 		db_printf("%s() at ", name);
78 		db_printsym(state->start_pc, DB_STGY_PROC);
79 		db_printf("\n");
80 		db_printf("\t pc = 0x%08x  lr = 0x%08x (", state->start_pc,
81 		    state->registers[LR]);
82 		db_printsym(state->registers[LR], DB_STGY_PROC);
83 		db_printf(")\n");
84 		db_printf("\t sp = 0x%08x  fp = 0x%08x",
85 		    state->registers[SP], state->registers[FP]);
86 
87 		/* Don't print the registers we have already printed */
88 		upd_mask = state->update_mask &
89 		    ~((1 << SP) | (1 << FP) | (1 << LR) | (1 << PC));
90 		sep = "\n\t";
91 		for (i = 0, reg = 0; upd_mask != 0; upd_mask >>= 1, reg++) {
92 			if ((upd_mask & 1) != 0) {
93 				db_printf("%s%sr%d = 0x%08x", sep,
94 				    (reg < 10) ? " " : "", reg,
95 				    state->registers[reg]);
96 				i++;
97 				if (i == 2) {
98 					sep = "\n\t";
99 					i = 0;
100 				} else
101 					sep = " ";
102 			}
103 		}
104 		db_printf("\n");
105 
106 		if (finished)
107 			break;
108 
109 		/*
110 		 * Stop if directed to do so, or if we've unwound back to the
111 		 * kernel entry point, or if the unwind function didn't change
112 		 * anything (to avoid getting stuck in this loop forever).
113 		 * If the latter happens, it's an indication that the unwind
114 		 * information is incorrect somehow for the function named in
115 		 * the last frame printed before you see the unwind failure
116 		 * message (maybe it needs a STOP_UNWINDING).
117 		 */
118 		if (state->registers[PC] < VM_MIN_KERNEL_ADDRESS) {
119 			db_printf("Unable to unwind into user mode\n");
120 			finished = true;
121 		} else if (state->update_mask == 0) {
122 			db_printf("Unwind failure (no registers changed)\n");
123 			finished = true;
124 		}
125 	}
126 }
127 
128 void
db_md_list_watchpoints(void)129 db_md_list_watchpoints(void)
130 {
131 
132 	dbg_show_watchpoint();
133 }
134 
135 int
db_trace_thread(struct thread * thr,int count)136 db_trace_thread(struct thread *thr, int count)
137 {
138 	struct unwind_state state;
139 	struct pcb *ctx;
140 
141 	if (thr != curthread) {
142 		ctx = kdb_thr_ctx(thr);
143 
144 		state.registers[FP] = ctx->pcb_regs.sf_r11;
145 		state.registers[SP] = ctx->pcb_regs.sf_sp;
146 		state.registers[LR] = ctx->pcb_regs.sf_lr;
147 		state.registers[PC] = ctx->pcb_regs.sf_pc;
148 
149 		db_stack_trace_cmd(&state);
150 	} else
151 		db_trace_self();
152 	return (0);
153 }
154 
155 void
db_trace_self(void)156 db_trace_self(void)
157 {
158 	struct unwind_state state;
159 	uint32_t sp;
160 
161 	/* Read the stack pointer */
162 	__asm __volatile("mov %0, sp" : "=&r" (sp));
163 
164 	state.registers[FP] = (uint32_t)__builtin_frame_address(0);
165 	state.registers[SP] = sp;
166 	state.registers[LR] = (uint32_t)__builtin_return_address(0);
167 	state.registers[PC] = (uint32_t)db_trace_self;
168 
169 	db_stack_trace_cmd(&state);
170 }
171