db_trace.c revision 279667 
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: head/sys/arm/arm/db_trace.c 279667 2015-03-05 17:55:31Z andrew $");
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
55static void
56db_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 */
131void
132db_md_list_watchpoints()
133{
134}
135
136int
137db_md_clr_watchpoint(db_expr_t addr, db_expr_t size)
138{
139	return (0);
140}
141
142int
143db_md_set_watchpoint(db_expr_t addr, db_expr_t size)
144{
145	return (0);
146}
147
148int
149db_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
168void
169db_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