1/*-
2 * Mach Operating System
3 * Copyright (c) 1991,1990 Carnegie Mellon University
4 * All Rights Reserved.
5 *
6 * Permission to use, copy, modify and distribute this software and its
7 * documentation is hereby granted, provided that both the copyright
8 * notice and this permission notice appear in all copies of the
9 * software, derivative works or modified versions, and any portions
10 * thereof, and that both notices appear in supporting documentation.
11 *
12 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS
13 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
14 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
15 *
16 * Carnegie Mellon requests users of this software to return to
17 *
18 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
19 *  School of Computer Science
20 *  Carnegie Mellon University
21 *  Pittsburgh PA 15213-3890
22 *
23 * any improvements or extensions that they make and grant Carnegie the
24 * rights to redistribute these changes.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD$");
29
30#include <sys/param.h>
31#include <sys/systm.h>
32#include <sys/cons.h>
33#include <sys/linker.h>
34#include <sys/kdb.h>
35#include <sys/kernel.h>
36#include <sys/pcpu.h>
37#include <sys/proc.h>
38#include <sys/reboot.h>
39#include <sys/sysctl.h>
40
41#include <machine/kdb.h>
42#include <machine/pcb.h>
43#include <machine/setjmp.h>
44
45#include <ddb/ddb.h>
46#include <ddb/db_command.h>
47#include <ddb/db_sym.h>
48
49SYSCTL_NODE(_debug, OID_AUTO, ddb, CTLFLAG_RW, 0, "DDB settings");
50
51static dbbe_init_f db_init;
52static dbbe_trap_f db_trap;
53static dbbe_trace_f db_trace_self_wrapper;
54static dbbe_trace_thread_f db_trace_thread_wrapper;
55
56KDB_BACKEND(ddb, db_init, db_trace_self_wrapper, db_trace_thread_wrapper,
57    db_trap);
58
59vm_offset_t ksym_start, ksym_end;
60
61boolean_t
62X_db_line_at_pc(db_symtab_t *symtab, c_db_sym_t sym, char **file, int *line,
63    db_expr_t off)
64{
65	return (FALSE);
66}
67
68c_db_sym_t
69X_db_lookup(db_symtab_t *symtab, const char *symbol)
70{
71	c_linker_sym_t lsym;
72	Elf_Sym *sym;
73
74	if (symtab->private == NULL) {
75		return ((c_db_sym_t)((!linker_ddb_lookup(symbol, &lsym))
76			? lsym : NULL));
77	} else {
78		sym = (Elf_Sym *)symtab->start;
79		while ((char *)sym < symtab->end) {
80			if (sym->st_name != 0 &&
81			    !strcmp(symtab->private + sym->st_name, symbol))
82				return ((c_db_sym_t)sym);
83			sym++;
84		}
85	}
86	return (NULL);
87}
88
89c_db_sym_t
90X_db_search_symbol(db_symtab_t *symtab, db_addr_t off, db_strategy_t strat,
91    db_expr_t *diffp)
92{
93	c_linker_sym_t lsym;
94	Elf_Sym *sym, *match;
95	unsigned long diff;
96
97	if (symtab->private == NULL) {
98		if (!linker_ddb_search_symbol((caddr_t)off, &lsym, &diff)) {
99			*diffp = (db_expr_t)diff;
100			return ((c_db_sym_t)lsym);
101		}
102		return (NULL);
103	}
104
105	diff = ~0UL;
106	match = NULL;
107	for (sym = (Elf_Sym*)symtab->start; (char*)sym < symtab->end; sym++) {
108		if (sym->st_name == 0)
109			continue;
110		if (off < sym->st_value)
111			continue;
112		if (ELF_ST_TYPE(sym->st_info) != STT_OBJECT &&
113		    ELF_ST_TYPE(sym->st_info) != STT_FUNC &&
114		    ELF_ST_TYPE(sym->st_info) != STT_NOTYPE)
115			continue;
116		if ((off - sym->st_value) > diff)
117			continue;
118		if ((off - sym->st_value) < diff) {
119			diff = off - sym->st_value;
120			match = sym;
121		} else {
122			if (match == NULL)
123				match = sym;
124			else if (ELF_ST_BIND(match->st_info) == STB_LOCAL &&
125			    ELF_ST_BIND(sym->st_info) != STB_LOCAL)
126				match = sym;
127		}
128		if (diff == 0) {
129			if (strat == DB_STGY_PROC &&
130			    ELF_ST_TYPE(sym->st_info) == STT_FUNC &&
131			    ELF_ST_BIND(sym->st_info) != STB_LOCAL)
132				break;
133			if (strat == DB_STGY_ANY &&
134			    ELF_ST_BIND(sym->st_info) != STB_LOCAL)
135				break;
136		}
137	}
138
139	*diffp = (match == NULL) ? off : diff;
140	return ((c_db_sym_t)match);
141}
142
143boolean_t
144X_db_sym_numargs(db_symtab_t *symtab, c_db_sym_t sym, int *nargp,
145    char **argp)
146{
147	return (FALSE);
148}
149
150void
151X_db_symbol_values(db_symtab_t *symtab, c_db_sym_t sym, const char **namep,
152    db_expr_t *valp)
153{
154	linker_symval_t lval;
155
156	if (symtab->private == NULL) {
157		linker_ddb_symbol_values((c_linker_sym_t)sym, &lval);
158		if (namep != NULL)
159			*namep = (const char*)lval.name;
160		if (valp != NULL)
161			*valp = (db_expr_t)lval.value;
162	} else {
163		if (namep != NULL)
164			*namep = (const char *)symtab->private +
165			    ((const Elf_Sym *)sym)->st_name;
166		if (valp != NULL)
167			*valp = (db_expr_t)((const Elf_Sym *)sym)->st_value;
168	}
169}
170
171static int
172db_init(void)
173{
174	uintptr_t symtab, strtab;
175	Elf_Size tabsz, strsz;
176
177	db_command_init();
178	if (ksym_end > ksym_start && ksym_start != 0) {
179		symtab = ksym_start;
180		tabsz = *((Elf_Size*)symtab);
181		symtab += sizeof(Elf_Size);
182		strtab = symtab + tabsz;
183		strsz = *((Elf_Size*)strtab);
184		strtab += sizeof(Elf_Size);
185		if (strtab + strsz <= ksym_end) {
186			db_add_symbol_table((char *)symtab,
187			    (char *)(symtab + tabsz), "elf", (char *)strtab);
188		}
189	}
190	db_add_symbol_table(NULL, NULL, "kld", NULL);
191	return (1);	/* We're the default debugger. */
192}
193
194static int
195db_trap(int type, int code)
196{
197	jmp_buf jb;
198	void *prev_jb;
199	boolean_t bkpt, watchpt;
200	const char *why;
201
202	/*
203	 * Don't handle the trap if the console is unavailable (i.e. it
204	 * is in graphics mode).
205	 */
206	if (cnunavailable())
207		return (0);
208
209	bkpt = IS_BREAKPOINT_TRAP(type, code);
210	watchpt = IS_WATCHPOINT_TRAP(type, code);
211
212	if (db_stop_at_pc(&bkpt)) {
213		if (db_inst_count) {
214			db_printf("After %d instructions (%d loads, %d stores),\n",
215			    db_inst_count, db_load_count, db_store_count);
216		}
217		prev_jb = kdb_jmpbuf(jb);
218		if (setjmp(jb) == 0) {
219			db_dot = PC_REGS();
220			db_print_thread();
221			if (bkpt)
222				db_printf("Breakpoint at\t");
223			else if (watchpt)
224				db_printf("Watchpoint at\t");
225			else
226				db_printf("Stopped at\t");
227			db_print_loc_and_inst(db_dot);
228		}
229		why = kdb_why;
230		db_script_kdbenter(why != KDB_WHY_UNSET ? why : "unknown");
231		db_command_loop();
232		(void)kdb_jmpbuf(prev_jb);
233	}
234
235	db_restart_at_pc(watchpt);
236
237	return (1);
238}
239
240static void
241db_trace_self_wrapper(void)
242{
243	jmp_buf jb;
244	void *prev_jb;
245
246	prev_jb = kdb_jmpbuf(jb);
247	if (setjmp(jb) == 0)
248		db_trace_self();
249	(void)kdb_jmpbuf(prev_jb);
250}
251
252static void
253db_trace_thread_wrapper(struct thread *td)
254{
255	jmp_buf jb;
256	void *prev_jb;
257
258	prev_jb = kdb_jmpbuf(jb);
259	if (setjmp(jb) == 0)
260		db_trace_thread(td, -1);
261	(void)kdb_jmpbuf(prev_jb);
262}
263