xref: /freebsd/sys/ddb/db_sym.c (revision 0e97acdf58fe27b09c4824a474b0344daf997c5f)
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 static void *db_vnet = NULL;
68 #endif
69 
70 /*
71  * Validate the CPU number used to interpret per-CPU variables so we can
72  * avoid later confusion if an invalid CPU is requested.
73  */
74 int
75 db_var_db_cpu(struct db_variable *vp, db_expr_t *valuep, int op)
76 {
77 
78 	switch (op) {
79 	case DB_VAR_GET:
80 		*valuep = db_cpu;
81 		return (1);
82 
83 	case DB_VAR_SET:
84 		if (*(int *)valuep < -1 && *(int *)valuep > mp_maxid) {
85 			db_printf("Invalid value: %d", *(int*)valuep);
86 			return (0);
87 		}
88 		db_cpu = *(int *)valuep;
89 		return (1);
90 
91 	default:
92 		db_printf("db_var_db_cpu: unknown operation\n");
93 		return (0);
94 	}
95 }
96 
97 /*
98  * Read-only variable reporting the current CPU, which is what we use when
99  * db_cpu is set to -1.
100  */
101 int
102 db_var_curcpu(struct db_variable *vp, db_expr_t *valuep, int op)
103 {
104 
105 	switch (op) {
106 	case DB_VAR_GET:
107 		*valuep = curcpu;
108 		return (1);
109 
110 	case DB_VAR_SET:
111 		db_printf("Read-only variable.\n");
112 		return (0);
113 
114 	default:
115 		db_printf("db_var_curcpu: unknown operation\n");
116 		return (0);
117 	}
118 }
119 
120 #ifdef VIMAGE
121 /*
122  * Validate the virtual network pointer used to interpret per-vnet global
123  * variable expansion.  Right now we don't do much here, really we should
124  * walk the global vnet list to check it's an OK pointer.
125  */
126 int
127 db_var_db_vnet(struct db_variable *vp, db_expr_t *valuep, int op)
128 {
129 
130 	switch (op) {
131 	case DB_VAR_GET:
132 		*valuep = (db_expr_t)db_vnet;
133 		return (1);
134 
135 	case DB_VAR_SET:
136 		db_vnet = *(void **)valuep;
137 		return (1);
138 
139 	default:
140 		db_printf("db_var_db_vnet: unknown operation\n");
141 		return (0);
142 	}
143 }
144 
145 /*
146  * Read-only variable reporting the current vnet, which is what we use when
147  * db_vnet is set to NULL.
148  */
149 int
150 db_var_curvnet(struct db_variable *vp, db_expr_t *valuep, int op)
151 {
152 
153 	switch (op) {
154 	case DB_VAR_GET:
155 		*valuep = (db_expr_t)curvnet;
156 		return (1);
157 
158 	case DB_VAR_SET:
159 		db_printf("Read-only variable.\n");
160 		return (0);
161 
162 	default:
163 		db_printf("db_var_curcpu: unknown operation\n");
164 		return (0);
165 	}
166 }
167 #endif
168 
169 /*
170  * Add symbol table, with given name, to list of symbol tables.
171  */
172 void
173 db_add_symbol_table(char *start, char *end, char *name, char *ref)
174 {
175 	if (db_nsymtab >= MAXNOSYMTABS) {
176 		printf ("No slots left for %s symbol table", name);
177 		panic ("db_sym.c: db_add_symbol_table");
178 	}
179 
180 	db_symtabs[db_nsymtab].start = start;
181 	db_symtabs[db_nsymtab].end = end;
182 	db_symtabs[db_nsymtab].name = name;
183 	db_symtabs[db_nsymtab].private = ref;
184 	db_nsymtab++;
185 }
186 
187 /*
188  *  db_qualify("vm_map", "ux") returns "unix:vm_map".
189  *
190  *  Note: return value points to static data whose content is
191  *  overwritten by each call... but in practice this seems okay.
192  */
193 static char *
194 db_qualify(c_db_sym_t sym, char *symtabname)
195 {
196 	const char	*symname;
197 	static char     tmp[256];
198 
199 	db_symbol_values(sym, &symname, 0);
200 	snprintf(tmp, sizeof(tmp), "%s:%s", symtabname, symname);
201 	return tmp;
202 }
203 
204 
205 boolean_t
206 db_eqname(const char *src, const char *dst, int c)
207 {
208 	if (!strcmp(src, dst))
209 	    return (TRUE);
210 	if (src[0] == c)
211 	    return (!strcmp(src+1,dst));
212 	return (FALSE);
213 }
214 
215 boolean_t
216 db_value_of_name(const char *name, db_expr_t *valuep)
217 {
218 	c_db_sym_t	sym;
219 
220 	sym = db_lookup(name);
221 	if (sym == C_DB_SYM_NULL)
222 	    return (FALSE);
223 	db_symbol_values(sym, &name, valuep);
224 	return (TRUE);
225 }
226 
227 boolean_t
228 db_value_of_name_pcpu(const char *name, db_expr_t *valuep)
229 {
230 	static char     tmp[256];
231 	db_expr_t	value;
232 	c_db_sym_t	sym;
233 	int		cpu;
234 
235 	if (db_cpu != -1)
236 		cpu = db_cpu;
237 	else
238 		cpu = curcpu;
239 	snprintf(tmp, sizeof(tmp), "pcpu_entry_%s", name);
240 	sym = db_lookup(tmp);
241 	if (sym == C_DB_SYM_NULL)
242 		return (FALSE);
243 	db_symbol_values(sym, &name, &value);
244 	if (value < DPCPU_START || value >= DPCPU_STOP)
245 		return (FALSE);
246 	*valuep = (db_expr_t)((uintptr_t)value + dpcpu_off[cpu]);
247 	return (TRUE);
248 }
249 
250 boolean_t
251 db_value_of_name_vnet(const char *name, db_expr_t *valuep)
252 {
253 #ifdef VIMAGE
254 	static char     tmp[256];
255 	db_expr_t	value;
256 	c_db_sym_t	sym;
257 	struct vnet	*vnet;
258 
259 	if (db_vnet != NULL)
260 		vnet = db_vnet;
261 	else
262 		vnet = curvnet;
263 	snprintf(tmp, sizeof(tmp), "vnet_entry_%s", name);
264 	sym = db_lookup(tmp);
265 	if (sym == C_DB_SYM_NULL)
266 		return (FALSE);
267 	db_symbol_values(sym, &name, &value);
268 	if (value < VNET_START || value >= VNET_STOP)
269 		return (FALSE);
270 	*valuep = (db_expr_t)((uintptr_t)value + vnet->vnet_data_base);
271 	return (TRUE);
272 #else
273 	return (FALSE);
274 #endif
275 }
276 
277 /*
278  * Lookup a symbol.
279  * If the symbol has a qualifier (e.g., ux:vm_map),
280  * then only the specified symbol table will be searched;
281  * otherwise, all symbol tables will be searched.
282  */
283 static c_db_sym_t
284 db_lookup(const char *symstr)
285 {
286 	c_db_sym_t sp;
287 	register int i;
288 	int symtab_start = 0;
289 	int symtab_end = db_nsymtab;
290 	register const char *cp;
291 
292 	/*
293 	 * Look for, remove, and remember any symbol table specifier.
294 	 */
295 	for (cp = symstr; *cp; cp++) {
296 		if (*cp == ':') {
297 			for (i = 0; i < db_nsymtab; i++) {
298 				int n = strlen(db_symtabs[i].name);
299 
300 				if (
301 				    n == (cp - symstr) &&
302 				    strncmp(symstr, db_symtabs[i].name, n) == 0
303 				) {
304 					symtab_start = i;
305 					symtab_end = i + 1;
306 					break;
307 				}
308 			}
309 			if (i == db_nsymtab) {
310 				db_error("invalid symbol table name");
311 			}
312 			symstr = cp+1;
313 		}
314 	}
315 
316 	/*
317 	 * Look in the specified set of symbol tables.
318 	 * Return on first match.
319 	 */
320 	for (i = symtab_start; i < symtab_end; i++) {
321 		sp = X_db_lookup(&db_symtabs[i], symstr);
322 		if (sp) {
323 			db_last_symtab = &db_symtabs[i];
324 			return sp;
325 		}
326 	}
327 	return 0;
328 }
329 
330 /*
331  * If TRUE, check across symbol tables for multiple occurrences
332  * of a name.  Might slow things down quite a bit.
333  */
334 static volatile boolean_t db_qualify_ambiguous_names = FALSE;
335 
336 /*
337  * Does this symbol name appear in more than one symbol table?
338  * Used by db_symbol_values to decide whether to qualify a symbol.
339  */
340 static boolean_t
341 db_symbol_is_ambiguous(c_db_sym_t sym)
342 {
343 	const char	*sym_name;
344 	register int	i;
345 	register
346 	boolean_t	found_once = FALSE;
347 
348 	if (!db_qualify_ambiguous_names)
349 		return FALSE;
350 
351 	db_symbol_values(sym, &sym_name, 0);
352 	for (i = 0; i < db_nsymtab; i++) {
353 		if (X_db_lookup(&db_symtabs[i], sym_name)) {
354 			if (found_once)
355 				return TRUE;
356 			found_once = TRUE;
357 		}
358 	}
359 	return FALSE;
360 }
361 
362 /*
363  * Find the closest symbol to val, and return its name
364  * and the difference between val and the symbol found.
365  */
366 c_db_sym_t
367 db_search_symbol(db_addr_t val, db_strategy_t strategy, db_expr_t *offp)
368 {
369 	register
370 	unsigned int	diff;
371 	size_t		newdiff;
372 	register int	i;
373 	c_db_sym_t	ret = C_DB_SYM_NULL, sym;
374 
375 	newdiff = diff = ~0;
376 	for (i = 0; i < db_nsymtab; i++) {
377 	    sym = X_db_search_symbol(&db_symtabs[i], val, strategy, &newdiff);
378 	    if (newdiff < diff) {
379 		db_last_symtab = &db_symtabs[i];
380 		diff = newdiff;
381 		ret = sym;
382 	    }
383 	}
384 	*offp = diff;
385 	return ret;
386 }
387 
388 /*
389  * Return name and value of a symbol
390  */
391 void
392 db_symbol_values(c_db_sym_t sym, const char **namep, db_expr_t *valuep)
393 {
394 	db_expr_t	value;
395 
396 	if (sym == DB_SYM_NULL) {
397 		*namep = 0;
398 		return;
399 	}
400 
401 	X_db_symbol_values(db_last_symtab, sym, namep, &value);
402 
403 	if (db_symbol_is_ambiguous(sym))
404 		*namep = db_qualify(sym, db_last_symtab->name);
405 	if (valuep)
406 		*valuep = value;
407 }
408 
409 
410 /*
411  * Print a the closest symbol to value
412  *
413  * After matching the symbol according to the given strategy
414  * we print it in the name+offset format, provided the symbol's
415  * value is close enough (eg smaller than db_maxoff).
416  * We also attempt to print [filename:linenum] when applicable
417  * (eg for procedure names).
418  *
419  * If we could not find a reasonable name+offset representation,
420  * then we just print the value in hex.  Small values might get
421  * bogus symbol associations, e.g. 3 might get some absolute
422  * value like _INCLUDE_VERSION or something, therefore we do
423  * not accept symbols whose value is "small" (and use plain hex).
424  */
425 
426 db_expr_t	db_maxoff = 0x10000;
427 
428 void
429 db_printsym(db_expr_t off, db_strategy_t strategy)
430 {
431 	db_expr_t	d;
432 	char 		*filename;
433 	const char	*name;
434 	db_expr_t	value;
435 	int 		linenum;
436 	c_db_sym_t	cursym;
437 
438 	cursym = db_search_symbol(off, strategy, &d);
439 	db_symbol_values(cursym, &name, &value);
440 	if (name == 0)
441 		value = off;
442 	if (value >= DB_SMALL_VALUE_MIN && value <= DB_SMALL_VALUE_MAX) {
443 		db_printf("%+#lr", (long)off);
444 		return;
445 	}
446 	if (name == 0 || d >= (unsigned long)db_maxoff) {
447 		db_printf("%#lr", (unsigned long)off);
448 		return;
449 	}
450 #ifdef DDB_NUMSYM
451 	db_printf("%#lr = %s", (unsigned long)off, name);
452 #else
453 	db_printf("%s", name);
454 #endif
455 	if (d)
456 		db_printf("+%+#lr", (long)d);
457 	if (strategy == DB_STGY_PROC) {
458 		if (db_line_at_pc(cursym, &filename, &linenum, off))
459 			db_printf(" [%s:%d]", filename, linenum);
460 	}
461 }
462 
463 static boolean_t
464 db_line_at_pc(c_db_sym_t sym, char **filename, int *linenum, db_expr_t pc)
465 {
466 	return X_db_line_at_pc( db_last_symtab, sym, filename, linenum, pc);
467 }
468 
469 int
470 db_sym_numargs(c_db_sym_t sym, int *nargp, char **argnames)
471 {
472 	return X_db_sym_numargs(db_last_symtab, sym, nargp, argnames);
473 }
474