FreeBSD/Linux Kernel Cross Reference
sys/ddb/db_sym.c
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: releng/8.0/sys/ddb/db_sym.c 196019 2009-08-01 19:26:27Z rwatson $");
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 }
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