xref: /freebsd/sys/ddb/db_sym.c (revision 941e286383714ef25f1ffe9ba6ae5040afdd7060)
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  * 	Author: David B. Golub, Carnegie Mellon University
28  *	Date:	7/90
29  */
30 
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 
34 #include <sys/param.h>
35 #include <sys/pcpu.h>
36 #include <sys/smp.h>
37 #include <sys/systm.h>
38 
39 #include <net/vnet.h>
40 
41 #include <ddb/ddb.h>
42 #include <ddb/db_sym.h>
43 #include <ddb/db_variables.h>
44 
45 #include <opt_ddb.h>
46 
47 /*
48  * Multiple symbol tables
49  */
50 #ifndef MAXNOSYMTABS
51 #define	MAXNOSYMTABS	3	/* mach, ux, emulator */
52 #endif
53 
54 static db_symtab_t	db_symtabs[MAXNOSYMTABS] = {{0,},};
55 static int db_nsymtab = 0;
56 
57 static db_symtab_t	*db_last_symtab; /* where last symbol was found */
58 
59 static c_db_sym_t	db_lookup( const char *symstr);
60 static char		*db_qualify(c_db_sym_t sym, char *symtabname);
61 static boolean_t	db_symbol_is_ambiguous(c_db_sym_t sym);
62 static boolean_t	db_line_at_pc(c_db_sym_t, char **, int *, db_expr_t);
63 
64 static int db_cpu = -1;
65 
66 #ifdef VIMAGE
67 extern uintptr_t	*__start_set_vnet;
68 extern uintptr_t	*__stop_set_vnet;
69 
70 #define	VNET_START	(uintptr_t)&__start_set_vnet
71 #define	VNET_STOP	(uintptr_t)&__stop_set_vnet
72 
73 static void *db_vnet = NULL;
74 #endif
75 
76 /*
77  * Validate the CPU number used to interpret per-CPU variables so we can
78  * avoid later confusion if an invalid CPU is requested.
79  */
80 int
81 db_var_db_cpu(struct db_variable *vp, db_expr_t *valuep, int op)
82 {
83 
84 	switch (op) {
85 	case DB_VAR_GET:
86 		*valuep = db_cpu;
87 		return (1);
88 
89 	case DB_VAR_SET:
90 		if (*(int *)valuep < -1 && *(int *)valuep > mp_maxid) {
91 			db_printf("Invalid value: %d", *(int*)valuep);
92 			return (0);
93 		}
94 		db_cpu = *(int *)valuep;
95 		return (1);
96 
97 	default:
98 		db_printf("db_var_db_cpu: unknown operation\n");
99 		return (0);
100 	}
101 }
102 
103 /*
104  * Read-only variable reporting the current CPU, which is what we use when
105  * db_cpu is set to -1.
106  */
107 int
108 db_var_curcpu(struct db_variable *vp, db_expr_t *valuep, int op)
109 {
110 
111 	switch (op) {
112 	case DB_VAR_GET:
113 		*valuep = curcpu;
114 		return (1);
115 
116 	case DB_VAR_SET:
117 		db_printf("Read-only variable.\n");
118 		return (0);
119 
120 	default:
121 		db_printf("db_var_curcpu: unknown operation\n");
122 		return (0);
123 	}
124 }
125 
126 #ifdef VIMAGE
127 /*
128  * Validate the virtual network pointer used to interpret per-vnet global
129  * variable expansion.  Right now we don't do much here, really we should
130  * walk the global vnet list to check it's an OK pointer.
131  */
132 int
133 db_var_db_vnet(struct db_variable *vp, db_expr_t *valuep, int op)
134 {
135 
136 	switch (op) {
137 	case DB_VAR_GET:
138 		*valuep = (db_expr_t)db_vnet;
139 		return (1);
140 
141 	case DB_VAR_SET:
142 		db_vnet = *(void **)valuep;
143 		return (1);
144 
145 	default:
146 		db_printf("db_var_db_vnet: unknown operation\n");
147 		return (0);
148 	}
149 }
150 
151 /*
152  * Read-only variable reporting the current vnet, which is what we use when
153  * db_vnet is set to NULL.
154  */
155 int
156 db_var_curvnet(struct db_variable *vp, db_expr_t *valuep, int op)
157 {
158 
159 	switch (op) {
160 	case DB_VAR_GET:
161 		*valuep = (db_expr_t)curvnet;
162 		return (1);
163 
164 	case DB_VAR_SET:
165 		db_printf("Read-only variable.\n");
166 		return (0);
167 
168 	default:
169 		db_printf("db_var_curcpu: unknown operation\n");
170 		return (0);
171 	}
172 }
173 #endif
174 
175 /*
176  * Add symbol table, with given name, to list of symbol tables.
177  */
178 void
179 db_add_symbol_table(start, end, name, ref)
180 	char *start;
181 	char *end;
182 	char *name;
183 	char *ref;
184 {
185 	if (db_nsymtab >= MAXNOSYMTABS) {
186 		printf ("No slots left for %s symbol table", name);
187 		panic ("db_sym.c: db_add_symbol_table");
188 	}
189 
190 	db_symtabs[db_nsymtab].start = start;
191 	db_symtabs[db_nsymtab].end = end;
192 	db_symtabs[db_nsymtab].name = name;
193 	db_symtabs[db_nsymtab].private = ref;
194 	db_nsymtab++;
195 }
196 
197 /*
198  *  db_qualify("vm_map", "ux") returns "unix:vm_map".
199  *
200  *  Note: return value points to static data whose content is
201  *  overwritten by each call... but in practice this seems okay.
202  */
203 static char *
204 db_qualify(sym, symtabname)
205 	c_db_sym_t	sym;
206 	register char	*symtabname;
207 {
208 	const char	*symname;
209 	static char     tmp[256];
210 
211 	db_symbol_values(sym, &symname, 0);
212 	snprintf(tmp, sizeof(tmp), "%s:%s", symtabname, symname);
213 	return tmp;
214 }
215 
216 
217 boolean_t
218 db_eqname(src, dst, c)
219 	const char *src;
220 	const char *dst;
221 	int c;
222 {
223 	if (!strcmp(src, dst))
224 	    return (TRUE);
225 	if (src[0] == c)
226 	    return (!strcmp(src+1,dst));
227 	return (FALSE);
228 }
229 
230 boolean_t
231 db_value_of_name(name, valuep)
232 	const char	*name;
233 	db_expr_t	*valuep;
234 {
235 	c_db_sym_t	sym;
236 
237 	sym = db_lookup(name);
238 	if (sym == C_DB_SYM_NULL)
239 	    return (FALSE);
240 	db_symbol_values(sym, &name, valuep);
241 	return (TRUE);
242 }
243 
244 boolean_t
245 db_value_of_name_pcpu(name, valuep)
246 	const char	*name;
247 	db_expr_t	*valuep;
248 {
249 	static char     tmp[256];
250 	db_expr_t	value;
251 	c_db_sym_t	sym;
252 	int		cpu;
253 
254 	if (db_cpu != -1)
255 		cpu = db_cpu;
256 	else
257 		cpu = curcpu;
258 	snprintf(tmp, sizeof(tmp), "pcpu_entry_%s", name);
259 	sym = db_lookup(tmp);
260 	if (sym == C_DB_SYM_NULL)
261 		return (FALSE);
262 	db_symbol_values(sym, &name, &value);
263 	if (value < DPCPU_START || value >= DPCPU_STOP)
264 		return (FALSE);
265 	*valuep = (db_expr_t)((uintptr_t)value + dpcpu_off[cpu]);
266 	return (TRUE);
267 }
268 
269 boolean_t
270 db_value_of_name_vnet(name, valuep)
271 	const char	*name;
272 	db_expr_t	*valuep;
273 {
274 #ifdef VIMAGE
275 	static char     tmp[256];
276 	db_expr_t	value;
277 	c_db_sym_t	sym;
278 	struct vnet	*vnet;
279 
280 	if (db_vnet != NULL)
281 		vnet = db_vnet;
282 	else
283 		vnet = curvnet;
284 	snprintf(tmp, sizeof(tmp), "vnet_entry_%s", name);
285 	sym = db_lookup(tmp);
286 	if (sym == C_DB_SYM_NULL)
287 		return (FALSE);
288 	db_symbol_values(sym, &name, &value);
289 	if (value < VNET_START || value >= VNET_STOP)
290 		return (FALSE);
291 	*valuep = (db_expr_t)((uintptr_t)value + vnet->vnet_data_base);
292 	return (TRUE);
293 #else
294 	return (FALSE);
295 #endif
296 }
297 
298 /*
299  * Lookup a symbol.
300  * If the symbol has a qualifier (e.g., ux:vm_map),
301  * then only the specified symbol table will be searched;
302  * otherwise, all symbol tables will be searched.
303  */
304 static c_db_sym_t
305 db_lookup(symstr)
306 	const char *symstr;
307 {
308 	c_db_sym_t sp;
309 	register int i;
310 	int symtab_start = 0;
311 	int symtab_end = db_nsymtab;
312 	register const char *cp;
313 
314 	/*
315 	 * Look for, remove, and remember any symbol table specifier.
316 	 */
317 	for (cp = symstr; *cp; cp++) {
318 		if (*cp == ':') {
319 			for (i = 0; i < db_nsymtab; i++) {
320 				int n = strlen(db_symtabs[i].name);
321 
322 				if (
323 				    n == (cp - symstr) &&
324 				    strncmp(symstr, db_symtabs[i].name, n) == 0
325 				) {
326 					symtab_start = i;
327 					symtab_end = i + 1;
328 					break;
329 				}
330 			}
331 			if (i == db_nsymtab) {
332 				db_error("invalid symbol table name");
333 			}
334 			symstr = cp+1;
335 		}
336 	}
337 
338 	/*
339 	 * Look in the specified set of symbol tables.
340 	 * Return on first match.
341 	 */
342 	for (i = symtab_start; i < symtab_end; i++) {
343 		sp = X_db_lookup(&db_symtabs[i], symstr);
344 		if (sp) {
345 			db_last_symtab = &db_symtabs[i];
346 			return sp;
347 		}
348 	}
349 	return 0;
350 }
351 
352 /*
353  * If TRUE, check across symbol tables for multiple occurrences
354  * of a name.  Might slow things down quite a bit.
355  */
356 static volatile boolean_t db_qualify_ambiguous_names = FALSE;
357 
358 /*
359  * Does this symbol name appear in more than one symbol table?
360  * Used by db_symbol_values to decide whether to qualify a symbol.
361  */
362 static boolean_t
363 db_symbol_is_ambiguous(sym)
364 	c_db_sym_t	sym;
365 {
366 	const char	*sym_name;
367 	register int	i;
368 	register
369 	boolean_t	found_once = FALSE;
370 
371 	if (!db_qualify_ambiguous_names)
372 		return FALSE;
373 
374 	db_symbol_values(sym, &sym_name, 0);
375 	for (i = 0; i < db_nsymtab; i++) {
376 		if (X_db_lookup(&db_symtabs[i], sym_name)) {
377 			if (found_once)
378 				return TRUE;
379 			found_once = TRUE;
380 		}
381 	}
382 	return FALSE;
383 }
384 
385 /*
386  * Find the closest symbol to val, and return its name
387  * and the difference between val and the symbol found.
388  */
389 c_db_sym_t
390 db_search_symbol( val, strategy, offp)
391 	register db_addr_t	val;
392 	db_strategy_t		strategy;
393 	db_expr_t		*offp;
394 {
395 	register
396 	unsigned int	diff;
397 	size_t		newdiff;
398 	register int	i;
399 	c_db_sym_t	ret = C_DB_SYM_NULL, sym;
400 
401 	newdiff = diff = ~0;
402 	for (i = 0; i < db_nsymtab; i++) {
403 	    sym = X_db_search_symbol(&db_symtabs[i], val, strategy, &newdiff);
404 	    if (newdiff < diff) {
405 		db_last_symtab = &db_symtabs[i];
406 		diff = newdiff;
407 		ret = sym;
408 	    }
409 	}
410 	*offp = diff;
411 	return ret;
412 }
413 
414 /*
415  * Return name and value of a symbol
416  */
417 void
418 db_symbol_values(sym, namep, valuep)
419 	c_db_sym_t	sym;
420 	const char	**namep;
421 	db_expr_t	*valuep;
422 {
423 	db_expr_t	value;
424 
425 	if (sym == DB_SYM_NULL) {
426 		*namep = 0;
427 		return;
428 	}
429 
430 	X_db_symbol_values(db_last_symtab, sym, namep, &value);
431 
432 	if (db_symbol_is_ambiguous(sym))
433 		*namep = db_qualify(sym, db_last_symtab->name);
434 	if (valuep)
435 		*valuep = value;
436 }
437 
438 
439 /*
440  * Print a the closest symbol to value
441  *
442  * After matching the symbol according to the given strategy
443  * we print it in the name+offset format, provided the symbol's
444  * value is close enough (eg smaller than db_maxoff).
445  * We also attempt to print [filename:linenum] when applicable
446  * (eg for procedure names).
447  *
448  * If we could not find a reasonable name+offset representation,
449  * then we just print the value in hex.  Small values might get
450  * bogus symbol associations, e.g. 3 might get some absolute
451  * value like _INCLUDE_VERSION or something, therefore we do
452  * not accept symbols whose value is "small" (and use plain hex).
453  */
454 
455 db_expr_t	db_maxoff = 0x10000;
456 
457 void
458 db_printsym(off, strategy)
459 	db_expr_t	off;
460 	db_strategy_t	strategy;
461 {
462 	db_expr_t	d;
463 	char 		*filename;
464 	const char	*name;
465 	db_expr_t	value;
466 	int 		linenum;
467 	c_db_sym_t	cursym;
468 
469 	cursym = db_search_symbol(off, strategy, &d);
470 	db_symbol_values(cursym, &name, &value);
471 	if (name == 0)
472 		value = off;
473 	if (value >= DB_SMALL_VALUE_MIN && value <= DB_SMALL_VALUE_MAX) {
474 		db_printf("%+#lr", (long)off);
475 		return;
476 	}
477 	if (name == 0 || d >= (unsigned long)db_maxoff) {
478 		db_printf("%#lr", (unsigned long)off);
479 		return;
480 	}
481 #ifdef DDB_NUMSYM
482 	db_printf("%#lr = %s", (unsigned long)off, name);
483 #else
484 	db_printf("%s", name);
485 #endif
486 	if (d)
487 		db_printf("+%+#lr", (long)d);
488 	if (strategy == DB_STGY_PROC) {
489 		if (db_line_at_pc(cursym, &filename, &linenum, off))
490 			db_printf(" [%s:%d]", filename, linenum);
491 	}
492 }
493 
494 static boolean_t
495 db_line_at_pc( sym, filename, linenum, pc)
496 	c_db_sym_t	sym;
497 	char		**filename;
498 	int		*linenum;
499 	db_expr_t	pc;
500 {
501 	return X_db_line_at_pc( db_last_symtab, sym, filename, linenum, pc);
502 }
503 
504 int
505 db_sym_numargs(sym, nargp, argnames)
506 	c_db_sym_t	sym;
507 	int		*nargp;
508 	char		**argnames;
509 {
510 	return X_db_sym_numargs(db_last_symtab, sym, nargp, argnames);
511 }
512