xref: /netbsd-src/sys/ddb/db_sym.c (revision 20e85ad185ab16980f1219a557c42e057edb42ea)
1 /*	$NetBSD: db_sym.c,v 1.50 2005/03/28 01:05:13 christos Exp $	*/
2 
3 /*
4  * Mach Operating System
5  * Copyright (c) 1991,1990 Carnegie Mellon University
6  * All Rights Reserved.
7  *
8  * Permission to use, copy, modify and distribute this software and its
9  * documentation is hereby granted, provided that both the copyright
10  * notice and this permission notice appear in all copies of the
11  * software, derivative works or modified versions, and any portions
12  * thereof, and that both notices appear in supporting documentation.
13  *
14  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
15  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
16  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
17  *
18  * Carnegie Mellon requests users of this software to return to
19  *
20  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
21  *  School of Computer Science
22  *  Carnegie Mellon University
23  *  Pittsburgh PA 15213-3890
24  *
25  * any improvements or extensions that they make and grant Carnegie the
26  * rights to redistribute these changes.
27  */
28 
29 #include <sys/cdefs.h>
30 __KERNEL_RCSID(0, "$NetBSD: db_sym.c,v 1.50 2005/03/28 01:05:13 christos Exp $");
31 
32 #include "opt_ddbparam.h"
33 
34 #include <sys/param.h>
35 #include <sys/proc.h>
36 #include <sys/systm.h>
37 #include <sys/ksyms.h>
38 
39 #include <machine/db_machdep.h>
40 
41 #include <ddb/db_lex.h>
42 #include <ddb/db_sym.h>
43 #include <ddb/db_output.h>
44 #include <ddb/db_extern.h>
45 #include <ddb/db_command.h>
46 
47 static void		db_symsplit(char *, char **, char **);
48 
49 
50 #ifdef DB_AOUT_SYMBOLS
51 #define	TBLNAME	"netbsd"
52 
53 static int using_aout_symtab;
54 const db_symformat_t *db_symformat;
55 static db_forall_func_t db_sift;
56 extern db_symformat_t db_symformat_aout;
57 #endif
58 
59 
60 /*
61  * Initialize the kernel debugger by initializing the master symbol
62  * table.  Note that if initializing the master symbol table fails,
63  * no other symbol tables can be loaded.
64  */
65 void
66 ddb_init(int symsize, void *vss, void *vse)
67 {
68 #ifdef DB_AOUT_SYMBOLS
69 	db_symformat = &db_symformat_aout;
70 	if ((*db_symformat->sym_init)(symsize, vss, vse, TBLNAME) == TRUE) {
71 		using_aout_symtab = TRUE;
72 		return;
73 	}
74 #endif
75 	ksyms_init(symsize, vss, vse);	/* Will complain if necessary */
76 }
77 
78 boolean_t
79 db_eqname(char *src, char *dst, int c)
80 {
81 
82 	if (!strcmp(src, dst))
83 		return (TRUE);
84 	if (src[0] == c)
85 		return (!strcmp(src+1,dst));
86 	return (FALSE);
87 }
88 
89 boolean_t
90 db_value_of_name(char *name, db_expr_t *valuep)
91 {
92 	char *mod, *sym;
93 	unsigned long uval;
94 	long val;
95 
96 #ifdef DB_AOUT_SYMBOLS
97 	db_sym_t	ssym;
98 
99 	if (using_aout_symtab) {
100 		/*
101 		 * Cannot load symtabs in a.out kernels, so the ':'
102 		 * style of selecting modules is irrelevant.
103 		 */
104 		ssym = (*db_symformat->sym_lookup)(NULL, name);
105 		if (ssym == DB_SYM_NULL)
106 			return (FALSE);
107 		db_symbol_values(ssym, &name, valuep);
108 		return (TRUE);
109 	}
110 #endif
111 	db_symsplit(name, &mod, &sym);
112 	if (ksyms_getval(mod, sym, &uval, KSYMS_EXTERN) == 0) {
113 		val = (long) uval;
114 		*valuep = (db_expr_t)val;
115 		return TRUE;
116 	}
117 	if (ksyms_getval(mod, sym, &uval, KSYMS_ANY) == 0) {
118 		val = (long) uval;
119 		*valuep = (db_expr_t)val;
120 		return TRUE;
121 	}
122 	return FALSE;
123 }
124 
125 #ifdef DB_AOUT_SYMBOLS
126 /* Private structure for passing args to db_sift() from db_sifting(). */
127 struct db_sift_args {
128 	char	*symstr;
129 	int	mode;
130 };
131 
132 /*
133  * Does the work of db_sifting(), called once for each
134  * symbol via db_forall(), prints out symbols matching
135  * criteria.
136  */
137 static void
138 db_sift(db_symtab_t *stab, db_sym_t sym, char *name, char *suffix, int prefix,
139     void *arg)
140 {
141 	char c, sc;
142 	char *find, *p;
143 	size_t len;
144 	struct db_sift_args *dsa;
145 
146 	dsa = (struct db_sift_args*)arg;
147 
148 	find = dsa->symstr;	/* String we're looking for. */
149 	p = name;		/* String we're searching within. */
150 
151 	/* Matching algorithm cribbed from strstr(), which is not
152 	   in the kernel. */
153 	if ((c = *find++) != 0) {
154 		len = strlen(find);
155 		do {
156 			do {
157 				if ((sc = *p++) == 0)
158 					return;
159 			} while (sc != c);
160 		} while (strncmp(p, find, len) != 0);
161 	}
162 	if (dsa->mode=='F')	/* ala ls -F */
163 		db_printf("%s%s ", name, suffix);
164 	else
165 		db_printf("%s ", name);
166 }
167 #endif
168 
169 /*
170  * "Sift" for a partial symbol.
171  * Named for the Sun OpenPROM command ("sifting").
172  * If the symbol has a qualifier (e.g., ux:vm_map),
173  * then only the specified symbol table will be searched;
174  * otherwise, all symbol tables will be searched..
175  *
176  * "mode" is how-to-display, set from modifiers.
177  */
178 void
179 db_sifting(char *symstr, int mode)
180 {
181 	char *mod, *sym;
182 
183 #ifdef DB_AOUT_SYMBOLS
184 	struct db_sift_args dsa;
185 
186 	if (using_aout_symtab) {
187 		dsa.symstr = symstr;
188 		dsa.mode = mode;
189 		(*db_symformat->sym_forall)(NULL, db_sift, &dsa);
190 		db_printf("\n");
191 		return;
192 	}
193 #endif
194 
195 	db_symsplit(symstr, &mod, &sym);
196 	if (ksyms_sift(mod, sym, mode) == ENODEV)
197 		db_error("invalid symbol table name");
198 }
199 
200 /*
201  * Find the closest symbol to val, and return its name
202  * and the difference between val and the symbol found.
203  */
204 db_sym_t
205 db_search_symbol(db_addr_t val, db_strategy_t strategy, db_expr_t *offp)
206 {
207 	unsigned int diff;
208 	unsigned long naddr;
209 	db_sym_t ret = DB_SYM_NULL;
210 	const char *mod;
211 	char *sym;
212 
213 #ifdef DB_AOUT_SYMBOLS
214 	db_expr_t newdiff;
215 	db_sym_t ssym;
216 
217 	if (using_aout_symtab) {
218 		newdiff = diff = ~0;
219 		ssym = (*db_symformat->sym_search)
220 		    (NULL, val, strategy, &newdiff);
221 		if ((unsigned int) newdiff < diff) {
222 			diff = newdiff;
223 			ret = ssym;
224 		}
225 		*offp = diff;
226 		return ret;
227 	}
228 #endif
229 
230 	if (ksyms_getname(&mod, &sym, (vaddr_t)val, strategy) == 0) {
231 		(void)ksyms_getval(mod, sym, &naddr, KSYMS_ANY);
232 		diff = val - (db_addr_t)naddr;
233 		ret = (db_sym_t)naddr;
234 	} else
235 		diff = 0;
236 	*offp = diff;
237 	return ret;
238 }
239 
240 /*
241  * Return name and value of a symbol
242  */
243 void
244 db_symbol_values(db_sym_t sym, char **namep, db_expr_t *valuep)
245 {
246 	const char *mod;
247 
248 	if (sym == DB_SYM_NULL) {
249 		*namep = 0;
250 		return;
251 	}
252 
253 #ifdef DB_AOUT_SYMBOLS
254 	if (using_aout_symtab) {
255 		db_expr_t value;
256 		(*db_symformat->sym_value)(NULL, sym, namep, &value);
257 		if (valuep)
258 			*valuep = value;
259 		return;
260 	}
261 #endif
262 
263 	if (ksyms_getname(&mod, namep, (vaddr_t)sym,
264 	    KSYMS_ANY|KSYMS_EXACT) == 0) {
265 		if (valuep)
266 			*valuep = sym;
267 	} else
268 		*namep = NULL;
269 }
270 
271 
272 /*
273  * Print a the closest symbol to value
274  *
275  * After matching the symbol according to the given strategy
276  * we print it in the name+offset format, provided the symbol's
277  * value is close enough (eg smaller than db_maxoff).
278  * We also attempt to print [filename:linenum] when applicable
279  * (eg for procedure names).
280  *
281  * If we could not find a reasonable name+offset representation,
282  * then we just print the value in hex.  Small values might get
283  * bogus symbol associations, e.g. 3 might get some absolute
284  * value like _INCLUDE_VERSION or something, therefore we do
285  * not accept symbols whose value is zero (and use plain hex).
286  * Also, avoid printing as "end+0x????" which is useless.
287  * The variable db_lastsym is used instead of "end" in case we
288  * add support for symbols in loadable driver modules.
289  */
290 extern char end[];
291 unsigned long	db_lastsym = (unsigned long)end;
292 unsigned int	db_maxoff = 0x100000;
293 
294 void
295 db_symstr(char *buf, size_t buflen, db_expr_t off, db_strategy_t strategy)
296 {
297 	char  *name;
298 	const char *mod;
299 	unsigned long val;
300 
301 #ifdef DB_AOUT_SYMBOLS
302 	if (using_aout_symtab) {
303 		db_expr_t	d;
304 		char 		*filename;
305 		char		*name;
306 		db_expr_t	value;
307 		int 		linenum;
308 		db_sym_t	cursym;
309 
310 		if ((unsigned long) off <= db_lastsym) {
311 			cursym = db_search_symbol(off, strategy, &d);
312 			db_symbol_values(cursym, &name, &value);
313 			if (name != NULL &&
314 			    ((unsigned int) d < db_maxoff) &&
315 			    value != 0) {
316 				strlcpy(buf, name, buflen);
317 				if (d) {
318 					strlcat(buf, "+", buflen);
319 					db_format_radix(buf+strlen(buf),
320 					    24, d, TRUE);
321 				}
322 				if (strategy == DB_STGY_PROC) {
323 					if ((*db_symformat->sym_line_at_pc)
324 					    (NULL, cursym, &filename,
325 					    &linenum, off))
326 						snprintf(buf + strlen(buf),
327 						    buflen - strlen(buf),
328 						    " [%s:%d]",
329 						    filename, linenum);
330 				}
331 				return;
332 			}
333 		}
334 		strlcpy(buf, db_num_to_str(off), buflen);
335 		return;
336 	}
337 #endif
338 	if (ksyms_getname(&mod, &name, (vaddr_t)off,
339 	    strategy|KSYMS_CLOSEST) == 0) {
340 		(void)ksyms_getval(mod, name, &val, KSYMS_ANY);
341 		if (((off - val) < db_maxoff) && val) {
342 			snprintf(buf, buflen, "%s:%s", mod, name);
343 			if (off - val) {
344 				strlcat(buf, "+", buflen);
345 				db_format_radix(buf+strlen(buf),
346 				    24, off - val, TRUE);
347 			}
348 #ifdef notyet
349 			if (strategy & KSYMS_PROC) {
350 				if (ksyms_fmaddr(off, &filename, &linenum) == 0)
351 					snprintf(buf + strlen(buf),
352 					    buflen - strlen(buf),
353 					    " [%s:%d]", filename, linenum);
354 			}
355 #endif
356 			return;
357 		}
358 	}
359 	strlcpy(buf, db_num_to_str(off), buflen);
360 }
361 
362 void
363 db_printsym(db_expr_t off, db_strategy_t strategy,
364     void (*pr)(const char *, ...))
365 {
366 	char  *name;
367 	const char *mod;
368 	unsigned long uval;
369 	long val;
370 #ifdef notyet
371 	char *filename;
372 	int  linenum;
373 #endif
374 
375 #ifdef DB_AOUT_SYMBOLS
376 	if (using_aout_symtab) {
377 		db_expr_t	d;
378 		char 		*filename;
379 		char		*name;
380 		db_expr_t	value;
381 		int 		linenum;
382 		db_sym_t	cursym;
383 		if ((unsigned long) off <= db_lastsym) {
384 			cursym = db_search_symbol(off, strategy, &d);
385 			db_symbol_values(cursym, &name, &value);
386 			if (name != NULL &&
387 			    ((unsigned int) d < db_maxoff) &&
388 			    value != 0) {
389 				(*pr)("%s", name);
390 				if (d) {
391 					char tbuf[24];
392 
393 					db_format_radix(tbuf, 24, d, TRUE);
394 					(*pr)("+%s", tbuf);
395 				}
396 				if (strategy == DB_STGY_PROC) {
397 					if ((*db_symformat->sym_line_at_pc)
398 					    (NULL, cursym, &filename,
399 					    &linenum, off))
400 						(*pr)(" [%s:%d]",
401 						    filename, linenum);
402 				}
403 				return;
404 			}
405 		}
406 		(*pr)(db_num_to_str(off));
407 		return;
408 	}
409 #endif
410 	if (ksyms_getname(&mod, &name, (vaddr_t)off,
411 	    strategy|KSYMS_CLOSEST) == 0) {
412 		(void)ksyms_getval(mod, name, &uval, KSYMS_ANY);
413 		val = (long) uval;
414 		if (((off - val) < db_maxoff) && val) {
415 			(*pr)("%s:%s", mod, name);
416 			if (off - val) {
417 				char tbuf[24];
418 
419 				db_format_radix(tbuf, 24, off - val, TRUE);
420 				(*pr)("+%s", tbuf);
421 			}
422 #ifdef notyet
423 			if (strategy & KSYMS_PROC) {
424 				if (ksyms_fmaddr(off, &filename, &linenum) == 0)
425 					(*pr)(" [%s:%d]", filename, linenum);
426 			}
427 #endif
428 			return;
429 		}
430 	}
431 	(*pr)(db_num_to_str(off));
432 	return;
433 }
434 
435 /*
436  * Splits a string in the form "mod:sym" to two strings.
437  */
438 static void
439 db_symsplit(char *str, char **mod, char **sym)
440 {
441 	char *cp;
442 
443 	if ((cp = strchr(str, ':')) != NULL) {
444 		*cp++ = '\0';
445 		*mod = str;
446 		*sym = cp;
447 	} else {
448 		*mod = NULL;
449 		*sym = str;
450 	}
451 }
452 
453 boolean_t
454 db_sym_numargs(db_sym_t cursym, int *nargp, char **argnamep)
455 {
456 #ifdef DB_AOUT_SYMBOLS
457 	if (using_aout_symtab)
458 		return ((*db_symformat->sym_numargs)(NULL, cursym, nargp,
459 		    argnamep));
460 #endif
461 	return (FALSE);
462 }
463 
464