summaryrefslogtreecommitdiffstats
path: root/sys/ddb/db_main.c
blob: 0a2cd56d9b13d0f3e454fec8edffddc76b206702 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
/*
 * Mach Operating System
 * Copyright (c) 1991,1990 Carnegie Mellon University
 * All Rights Reserved.
 *
 * Permission to use, copy, modify and distribute this software and its
 * documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 *
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 *
 * Carnegie Mellon requests users of this software to return to
 *
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 *
 * any improvements or extensions that they make and grant Carnegie the
 * rights to redistribute these changes.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/cons.h>
#include <sys/linker.h>
#include <sys/kdb.h>
#include <sys/kernel.h>
#include <sys/pcpu.h>
#include <sys/proc.h>
#include <sys/reboot.h>

#include <machine/kdb.h>
#include <machine/pcb.h>
#include <machine/setjmp.h>

#include <ddb/ddb.h>
#include <ddb/db_command.h>
#include <ddb/db_sym.h>

static dbbe_init_f db_init;
static dbbe_trap_f db_trap;

KDB_BACKEND(ddb, db_init, db_trace_self, db_trap);

vm_offset_t ksym_start, ksym_end;

boolean_t
X_db_line_at_pc(db_symtab_t *symtab, c_db_sym_t sym, char **file, int *line,
    db_expr_t off)
{
	return (FALSE);
}

c_db_sym_t
X_db_lookup(db_symtab_t *symtab, const char *symbol)
{
	c_linker_sym_t lsym;
	Elf_Sym *sym;

	if (symtab->private == NULL) {
		return ((c_db_sym_t)((!linker_ddb_lookup(symbol, &lsym))
			? lsym : NULL));
	} else {
		sym = (Elf_Sym *)symtab->start;
		while ((char *)sym < symtab->end) {
			if (sym->st_name != 0 &&
			    !strcmp(symtab->private + sym->st_name, symbol))
				return ((c_db_sym_t)sym);
			sym++;
		}
	}
	return (NULL);
}

c_db_sym_t
X_db_search_symbol(db_symtab_t *symtab, db_addr_t off, db_strategy_t strat,
    db_expr_t *diffp)
{
	c_linker_sym_t lsym;
	Elf_Sym *sym, *match;
	unsigned long diff;

	if (symtab->private == NULL) {
		if (!linker_ddb_search_symbol((caddr_t)off, &lsym, &diff)) {
			*diffp = (db_expr_t)diff;
			return ((c_db_sym_t)lsym);
		}
		return (NULL);
	}

	diff = ~0UL;
	match = NULL;
	for (sym = (Elf_Sym*)symtab->start; (char*)sym < symtab->end; sym++) {
		if (sym->st_name == 0)
			continue;
		if (off < sym->st_value)
			continue;
		if (ELF_ST_TYPE(sym->st_info) != STT_OBJECT &&
		    ELF_ST_TYPE(sym->st_info) != STT_FUNC &&
		    ELF_ST_TYPE(sym->st_info) != STT_NOTYPE)
			continue;
		if ((off - sym->st_value) > diff)
			continue;
		if ((off - sym->st_value) < diff) {
			diff = off - sym->st_value;
			match = sym;
		} else {
			if (match == NULL)
				match = sym;
			else if (ELF_ST_BIND(match->st_info) == STB_LOCAL &&
			    ELF_ST_BIND(sym->st_info) != STB_LOCAL)
				match = sym;
		}
		if (diff == 0) {
			if (strat == DB_STGY_PROC &&
			    ELF_ST_TYPE(sym->st_info) == STT_FUNC &&
			    ELF_ST_BIND(sym->st_info) != STB_LOCAL)
				break;
			if (strat == DB_STGY_ANY &&
			    ELF_ST_BIND(sym->st_info) != STB_LOCAL)
				break;
		}
	}

	*diffp = (match == NULL) ? off : diff;
	return ((c_db_sym_t)match);
}

boolean_t
X_db_sym_numargs(db_symtab_t *symtab, c_db_sym_t sym, int *nargp,
    char **argp)
{
	return (FALSE);
}

void
X_db_symbol_values(db_symtab_t *symtab, c_db_sym_t sym, const char **namep,
    db_expr_t *valp)
{
	linker_symval_t lval;

	if (symtab->private == NULL) {
		linker_ddb_symbol_values((c_linker_sym_t)sym, &lval);
		if (namep != NULL)
			*namep = (const char*)lval.name;
		if (valp != NULL)
			*valp = (db_expr_t)lval.value;
	} else {
		if (namep != NULL)
			*namep = (const char *)symtab->private +
			    ((const Elf_Sym *)sym)->st_name;
		if (valp != NULL)
			*valp = (db_expr_t)((const Elf_Sym *)sym)->st_value;
	}
}

static int
db_init(void)
{
	uintptr_t symtab, strtab;
	Elf_Size tabsz, strsz;

	if (ksym_end > ksym_start && ksym_start != 0) {
		symtab = ksym_start;
		tabsz = *((Elf_Size*)symtab);
		tabsz += sizeof(Elf_Size);
		strtab = symtab + tabsz;
		strsz = *((Elf_Size*)strtab);
		strsz += sizeof(Elf_Size);
		if (strtab + strsz <= ksym_end) {
			db_add_symbol_table((char *)symtab,
			    (char *)(symtab + tabsz), "elf", (char *)strtab);
		}
	}
	db_add_symbol_table(NULL, NULL, "kld", NULL);
	return (1);	/* We're the default debugger. */
}

static int
db_trap(int type, int code)
{
	jmp_buf jb;
	void *prev_jb;
	boolean_t bkpt, watchpt;

	/*
	 * Don't handle the trap if the console is unavailable (i.e. it
	 * is in graphics mode).
	 */
	if (cnunavailable())
		return (0);

	bkpt = IS_BREAKPOINT_TRAP(type, code);
	watchpt = IS_WATCHPOINT_TRAP(type, code);

	if (db_stop_at_pc(&bkpt)) {
		if (db_inst_count) {
			db_printf("After %d instructions (%d loads, %d stores),\n",
			    db_inst_count, db_load_count, db_store_count);
		}
		prev_jb = kdb_jmpbuf(jb);
		if (setjmp(jb) == 0) {
			db_dot = PC_REGS();
			db_print_thread();
			if (bkpt)
				db_printf("Breakpoint at\t");
			else if (watchpt)
				db_printf("Watchpoint at\t");
			else
				db_printf("Stopped at\t");
			db_print_loc_and_inst(db_dot);
		}
		db_command_loop();
		(void)kdb_jmpbuf(prev_jb);
	}

	db_restart_at_pc(watchpt);

	return (1);
}
OpenPOWER on IntegriCloud