xref: /freebsd/sys/arm/arm/db_trace.c (revision b2d48be1bc7df45ddd13b143a160d0acb5a383c5)
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 
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 
37 
38 #include <sys/proc.h>
39 #include <sys/kdb.h>
40 #include <sys/stack.h>
41 
42 #include <machine/armreg.h>
43 #include <machine/asm.h>
44 #include <machine/cpufunc.h>
45 #include <machine/db_machdep.h>
46 #include <machine/pcb.h>
47 #include <machine/stack.h>
48 #include <machine/vmparam.h>
49 
50 #include <ddb/ddb.h>
51 #include <ddb/db_access.h>
52 #include <ddb/db_sym.h>
53 #include <ddb/db_output.h>
54 
55 static void
56 db_stack_trace_cmd(struct unwind_state *state)
57 {
58 	const char *name;
59 	db_expr_t value;
60 	db_expr_t offset;
61 	c_db_sym_t sym;
62 	u_int reg, i;
63 	char *sep;
64 	uint16_t upd_mask;
65 	bool finished;
66 
67 	finished = false;
68 	while (!finished) {
69 		finished = unwind_stack_one(state, 1);
70 
71 		/* Print the frame details */
72 		sym = db_search_symbol(state->start_pc, DB_STGY_ANY, &offset);
73 		if (sym == C_DB_SYM_NULL) {
74 			value = 0;
75 			name = "(null)";
76 		} else
77 			db_symbol_values(sym, &name, &value);
78 		db_printf("%s() at ", name);
79 		db_printsym(state->start_pc, DB_STGY_PROC);
80 		db_printf("\n");
81 		db_printf("\t pc = 0x%08x  lr = 0x%08x (", state->start_pc,
82 		    state->registers[LR]);
83 		db_printsym(state->registers[LR], DB_STGY_PROC);
84 		db_printf(")\n");
85 		db_printf("\t sp = 0x%08x  fp = 0x%08x",
86 		    state->registers[SP], state->registers[FP]);
87 
88 		/* Don't print the registers we have already printed */
89 		upd_mask = state->update_mask &
90 		    ~((1 << SP) | (1 << FP) | (1 << LR) | (1 << PC));
91 		sep = "\n\t";
92 		for (i = 0, reg = 0; upd_mask != 0; upd_mask >>= 1, reg++) {
93 			if ((upd_mask & 1) != 0) {
94 				db_printf("%s%sr%d = 0x%08x", sep,
95 				    (reg < 10) ? " " : "", reg,
96 				    state->registers[reg]);
97 				i++;
98 				if (i == 2) {
99 					sep = "\n\t";
100 					i = 0;
101 				} else
102 					sep = " ";
103 
104 			}
105 		}
106 		db_printf("\n");
107 
108 		if (finished)
109 			break;
110 
111 		/*
112 		 * Stop if directed to do so, or if we've unwound back to the
113 		 * kernel entry point, or if the unwind function didn't change
114 		 * anything (to avoid getting stuck in this loop forever).
115 		 * If the latter happens, it's an indication that the unwind
116 		 * information is incorrect somehow for the function named in
117 		 * the last frame printed before you see the unwind failure
118 		 * message (maybe it needs a STOP_UNWINDING).
119 		 */
120 		if (state->registers[PC] < VM_MIN_KERNEL_ADDRESS) {
121 			db_printf("Unable to unwind into user mode\n");
122 			finished = true;
123 		} else if (state->update_mask == 0) {
124 			db_printf("Unwind failure (no registers changed)\n");
125 			finished = true;
126 		}
127 	}
128 }
129 
130 /* XXX stubs */
131 void
132 db_md_list_watchpoints()
133 {
134 }
135 
136 int
137 db_md_clr_watchpoint(db_expr_t addr, db_expr_t size)
138 {
139 	return (0);
140 }
141 
142 int
143 db_md_set_watchpoint(db_expr_t addr, db_expr_t size)
144 {
145 	return (0);
146 }
147 
148 int
149 db_trace_thread(struct thread *thr, int count)
150 {
151 	struct unwind_state state;
152 	struct pcb *ctx;
153 
154 	if (thr != curthread) {
155 		ctx = kdb_thr_ctx(thr);
156 
157 		state.registers[FP] = ctx->pcb_regs.sf_r11;
158 		state.registers[SP] = ctx->pcb_regs.sf_sp;
159 		state.registers[LR] = ctx->pcb_regs.sf_lr;
160 		state.registers[PC] = ctx->pcb_regs.sf_pc;
161 
162 		db_stack_trace_cmd(&state);
163 	} else
164 		db_trace_self();
165 	return (0);
166 }
167 
168 void
169 db_trace_self(void)
170 {
171 	struct unwind_state state;
172 	uint32_t sp;
173 
174 	/* Read the stack pointer */
175 	__asm __volatile("mov %0, sp" : "=&r" (sp));
176 
177 	state.registers[FP] = (uint32_t)__builtin_frame_address(0);
178 	state.registers[SP] = sp;
179 	state.registers[LR] = (uint32_t)__builtin_return_address(0);
180 	state.registers[PC] = (uint32_t)db_trace_self;
181 
182 	db_stack_trace_cmd(&state);
183 }
184