db_trace.c revision 174195 
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 174195 2007-12-02 20:40:35Z rwatson $");
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#include <machine/armreg.h>
42#include <machine/asm.h>
43#include <machine/cpufunc.h>
44#include <machine/db_machdep.h>
45#include <machine/pcb.h>
46#include <machine/stack.h>
47#include <machine/vmparam.h>
48#include <ddb/ddb.h>
49#include <ddb/db_access.h>
50#include <ddb/db_sym.h>
51#include <ddb/db_output.h>
52
53/*
54 * APCS stack frames are awkward beasts, so I don't think even trying to use
55 * a structure to represent them is a good idea.
56 *
57 * Here's the diagram from the APCS.  Increasing address is _up_ the page.
58 *
59 *          save code pointer       [fp]        <- fp points to here
60 *          return link value       [fp, #-4]
61 *          return sp value         [fp, #-8]
62 *          return fp value         [fp, #-12]
63 *          [saved v7 value]
64 *          [saved v6 value]
65 *          [saved v5 value]
66 *          [saved v4 value]
67 *          [saved v3 value]
68 *          [saved v2 value]
69 *          [saved v1 value]
70 *          [saved a4 value]
71 *          [saved a3 value]
72 *          [saved a2 value]
73 *          [saved a1 value]
74 *
75 * The save code pointer points twelve bytes beyond the start of the
76 * code sequence (usually a single STM) that created the stack frame.
77 * We have to disassemble it if we want to know which of the optional
78 * fields are actually present.
79 */
80
81static void
82db_stack_trace_cmd(db_expr_t addr, db_expr_t count)
83{
84	u_int32_t	*frame, *lastframe;
85	c_db_sym_t sym;
86	const char *name;
87	db_expr_t value;
88	db_expr_t offset;
89	boolean_t	kernel_only = TRUE;
90	int	scp_offset;
91
92	frame = (u_int32_t *)addr;
93	lastframe = NULL;
94	scp_offset = -(get_pc_str_offset() >> 2);
95
96	while (count-- && frame != NULL && !db_pager_quit) {
97		db_addr_t	scp;
98		u_int32_t	savecode;
99		int		r;
100		u_int32_t	*rp;
101		const char	*sep;
102
103		/*
104		 * In theory, the SCP isn't guaranteed to be in the function
105		 * that generated the stack frame.  We hope for the best.
106		 */
107		scp = frame[FR_SCP];
108
109		sym = db_search_symbol(scp, DB_STGY_ANY, &offset);
110		if (sym == C_DB_SYM_NULL) {
111			value = 0;
112			name = "(null)";
113		} else
114			db_symbol_values(sym, &name, &value);
115		db_printf("%s() at ", name);
116		db_printsym(scp, DB_STGY_PROC);
117		db_printf("\n");
118#ifdef __PROG26
119		db_printf("scp=0x%08x rlv=0x%08x (", scp, frame[FR_RLV] & R15_PC);
120		db_printsym(frame[FR_RLV] & R15_PC, DB_STGY_PROC);
121		db_printf(")\n");
122#else
123		db_printf("scp=0x%08x rlv=0x%08x (", scp, frame[FR_RLV]);
124		db_printsym(frame[FR_RLV], DB_STGY_PROC);
125		db_printf(")\n");
126#endif
127		db_printf("\trsp=0x%08x rfp=0x%08x", frame[FR_RSP], frame[FR_RFP]);
128
129		savecode = ((u_int32_t *)scp)[scp_offset];
130		if ((savecode & 0x0e100000) == 0x08000000) {
131			/* Looks like an STM */
132			rp = frame - 4;
133			sep = "\n\t";
134			for (r = 10; r >= 0; r--) {
135				if (savecode & (1 << r)) {
136					db_printf("%sr%d=0x%08x",
137					    sep, r, *rp--);
138					sep = (frame - rp) % 4 == 2 ?
139					    "\n\t" : " ";
140				}
141			}
142		}
143
144		db_printf("\n");
145
146		/*
147		 * Switch to next frame up
148		 */
149		if (frame[FR_RFP] == 0)
150			break; /* Top of stack */
151
152		lastframe = frame;
153		frame = (u_int32_t *)(frame[FR_RFP]);
154
155		if (INKERNEL((int)frame)) {
156			/* staying in kernel */
157			if (frame <= lastframe) {
158				db_printf("Bad frame pointer: %p\n", frame);
159				break;
160			}
161		} else if (INKERNEL((int)lastframe)) {
162			/* switch from user to kernel */
163			if (kernel_only)
164				break;	/* kernel stack only */
165		} else {
166			/* in user */
167			if (frame <= lastframe) {
168				db_printf("Bad user frame pointer: %p\n",
169					  frame);
170				break;
171			}
172		}
173	}
174}
175
176/* XXX stubs */
177void
178db_md_list_watchpoints()
179{
180}
181
182int
183db_md_clr_watchpoint(db_expr_t addr, db_expr_t size)
184{
185	return (0);
186}
187
188int
189db_md_set_watchpoint(db_expr_t addr, db_expr_t size)
190{
191	return (0);
192}
193
194int
195db_trace_thread(struct thread *thr, int count)
196{
197	uint32_t addr;
198
199	if (thr == curthread)
200		addr = (uint32_t)__builtin_frame_address(0);
201	else
202		addr = thr->td_pcb->un_32.pcb32_r11;
203	db_stack_trace_cmd(addr, -1);
204	return (0);
205}
206
207void
208db_trace_self(void)
209{
210	db_trace_thread(curthread, -1);
211}
212