1/*	$NetBSD: db_sym.c,v 1.63 2012/02/09 17:07:07 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 1.63 2012/02/09 17:07:07 christos Exp $");
31
32#ifdef _KERNEL_OPT
33#include "opt_ddbparam.h"
34#endif
35
36#include <sys/param.h>
37#include <sys/proc.h>
38#include <sys/systm.h>
39#include <sys/ksyms.h>
40
41#include <ddb/ddb.h>
42
43static void		db_symsplit(char *, char **, char **);
44
45
46#ifndef _KERNEL
47#define	TBLNAME	"netbsd"
48
49#define use_ksyms 0
50
51const db_symformat_t *db_symformat;
52static db_forall_func_t db_sift;
53extern db_symformat_t db_symformat_aout;
54extern db_symformat_t db_symformat_elf;
55#endif
56
57
58/*
59 * Initialize the kernel debugger by initializing the master symbol
60 * table.  Note that if initializing the master symbol table fails,
61 * no other symbol tables can be loaded.
62 */
63void
64ddb_init(int symsize, void *vss, void *vse)
65{
66#ifdef _KERNEL
67	ksyms_addsyms_elf(symsize, vss, vse);	/* Will complain if necessary */
68#else	/* _KERNEL */
69	db_symformat = &db_symformat_elf;
70	if ((*db_symformat->sym_init)(symsize, vss, vse, TBLNAME) != true)
71		printf("sym_init failed");
72#endif	/* _KERNEL */
73}
74
75bool
76db_eqname(const char *src, const char *dst, int c)
77{
78
79	if (!strcmp(src, dst))
80		return (true);
81	if (src[0] == c)
82		return (!strcmp(src+1,dst));
83	return (false);
84}
85
86bool
87db_value_of_name(const char *name, db_expr_t *valuep)
88{
89	char symbol[128];
90	char *mod, *sym;
91#ifdef _KERNEL
92	unsigned long uval;
93	long val;
94#endif
95
96#ifndef _KERNEL
97	if (!use_ksyms) {
98		db_sym_t ssym;
99
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
112	(void)strlcpy(symbol, name, sizeof(symbol));
113	db_symsplit(symbol, &mod, &sym);
114#ifdef _KERNEL
115	if (ksyms_getval_unlocked(mod, sym, &uval, KSYMS_EXTERN) == 0) {
116		val = (long) uval;
117		*valuep = (db_expr_t)val;
118		return true;
119	}
120	if (ksyms_getval_unlocked(mod, sym, &uval, KSYMS_ANY) == 0) {
121		val = (long) uval;
122		*valuep = (db_expr_t)val;
123		return true;
124	}
125#endif
126	return false;
127}
128
129#ifndef _KERNEL
130/* Private structure for passing args to db_sift() from db_sifting(). */
131struct db_sift_args {
132	char	*symstr;
133	int	mode;
134};
135
136/*
137 * Does the work of db_sifting(), called once for each
138 * symbol via db_forall(), prints out symbols matching
139 * criteria.
140 */
141static void
142db_sift(db_symtab_t *stab, db_sym_t sym, char *name,
143    char *suffix, int prefix, void *arg)
144{
145	char c, sc;
146	char *find, *p;
147	size_t len;
148	struct db_sift_args *dsa;
149
150	dsa = (struct db_sift_args*)arg;
151
152	find = dsa->symstr;	/* String we're looking for. */
153	p = name;		/* String we're searching within. */
154
155	/* Matching algorithm cribbed from strstr(), which is not
156	   in the kernel. */
157	if ((c = *find++) != 0) {
158		len = strlen(find);
159		do {
160			do {
161				if ((sc = *p++) == 0)
162					return;
163			} while (sc != c);
164		} while (strncmp(p, find, len) != 0);
165	}
166	if (dsa->mode=='F')	/* ala ls -F */
167		db_printf("%s%s ", name, suffix);
168	else
169		db_printf("%s ", name);
170}
171#endif
172
173/*
174 * "Sift" for a partial symbol.
175 * Named for the Sun OpenPROM command ("sifting").
176 * If the symbol has a qualifier (e.g., ux:vm_map),
177 * then only the specified symbol table will be searched;
178 * otherwise, all symbol tables will be searched..
179 *
180 * "mode" is how-to-display, set from modifiers.
181 */
182void
183db_sifting(char *symstr, int mode)
184{
185#ifdef _KERNEL
186	char *mod, *sym;
187#endif
188
189#ifndef _KERNEL
190	struct db_sift_args dsa;
191
192	if (!use_ksyms) {
193		dsa.symstr = symstr;
194		dsa.mode = mode;
195		(*db_symformat->sym_forall)(NULL, db_sift, &dsa);
196		db_printf("\n");
197		return;
198	}
199#endif
200
201#ifdef _KERNEL
202	db_symsplit(symstr, &mod, &sym);
203	if (ksyms_sift(mod, sym, mode) == ENODEV)
204		db_error("invalid symbol table name");
205#endif
206}
207
208/*
209 * Find the closest symbol to val, and return its name
210 * and the difference between val and the symbol found.
211 */
212db_sym_t
213db_search_symbol(db_addr_t val, db_strategy_t strategy, db_expr_t *offp)
214{
215	unsigned int diff;
216	db_sym_t ret = DB_SYM_NULL;
217#ifdef _KERNEL
218	unsigned long naddr;
219	const char *mod;
220	const char *sym;
221#endif
222
223#ifndef _KERNEL
224	if (!use_ksyms) {
225		db_expr_t newdiff;
226		db_sym_t ssym;
227
228		newdiff = diff = ~0;
229		ssym = (*db_symformat->sym_search)
230		    (NULL, val, strategy, &newdiff);
231		if ((unsigned int) newdiff < diff) {
232			diff = newdiff;
233			ret = ssym;
234		}
235		*offp = diff;
236		return ret;
237	}
238#endif
239
240#ifdef _KERNEL
241	if (ksyms_getname(&mod, &sym, (vaddr_t)val, strategy) == 0) {
242		(void)ksyms_getval_unlocked(mod, sym, &naddr, KSYMS_ANY);
243		diff = val - (db_addr_t)naddr;
244		ret = (db_sym_t)naddr;
245	} else
246#endif
247		diff = 0;
248	*offp = diff;
249	return ret;
250}
251
252/*
253 * Return name and value of a symbol
254 */
255void
256db_symbol_values(db_sym_t sym, const char **namep, db_expr_t *valuep)
257{
258#ifdef _KERNEL
259	const char *mod;
260#endif
261
262	if (sym == DB_SYM_NULL) {
263		*namep = 0;
264		return;
265	}
266
267#ifndef _KERNEL
268	if (!use_ksyms) {
269		db_expr_t value;
270
271		(*db_symformat->sym_value)(NULL, sym, namep, &value);
272		if (valuep)
273			*valuep = value;
274		return;
275	}
276#endif
277
278#ifdef _KERNEL
279	if (ksyms_getname(&mod, namep, (vaddr_t)sym,
280	    KSYMS_ANY|KSYMS_EXACT) == 0) {
281		if (valuep)
282			*valuep = sym;
283	} else
284#endif
285		*namep = NULL;
286}
287
288
289/*
290 * Print a the closest symbol to value
291 *
292 * After matching the symbol according to the given strategy
293 * we print it in the name+offset format, provided the symbol's
294 * value is close enough (eg smaller than db_maxoff).
295 * We also attempt to print [filename:linenum] when applicable
296 * (eg for procedure names).
297 *
298 * If we could not find a reasonable name+offset representation,
299 * then we just print the value in hex.  Small values might get
300 * bogus symbol associations, e.g. 3 might get some absolute
301 * value like _INCLUDE_VERSION or something, therefore we do
302 * not accept symbols whose value is zero (and use plain hex).
303 */
304unsigned int	db_maxoff = 0x100000;
305
306void
307db_symstr(char *buf, size_t buflen, db_expr_t off, db_strategy_t strategy)
308{
309	const char  *name;
310#ifdef _KERNEL
311	const char *mod;
312	unsigned long val;
313#endif
314
315#ifndef _KERNEL
316	if (!use_ksyms) {
317		db_expr_t	d;
318		char 		*filename;
319		db_expr_t	value;
320		int 		linenum;
321		db_sym_t	cursym;
322
323		cursym = db_search_symbol(off, strategy, &d);
324		db_symbol_values(cursym, &name, &value);
325		if (name != NULL && ((unsigned int)d < db_maxoff) &&
326		    value != 0) {
327			strlcpy(buf, name, buflen);
328			if (d) {
329				strlcat(buf, "+", buflen);
330				db_format_radix(buf + strlen(buf), 24, d, true);
331			}
332			if (strategy == DB_STGY_PROC) {
333				if ((*db_symformat->sym_line_at_pc)
334				    (NULL, cursym, &filename, &linenum, off)) {
335					size_t len = strlen(buf);
336					snprintf(buf + len, buflen - len,
337					    " [%s:%d]", filename, linenum);
338				}
339			}
340			return;
341		}
342		strlcpy(buf, db_num_to_str(off), buflen);
343		return;
344	}
345#endif
346#ifdef _KERNEL
347	if (ksyms_getname(&mod, &name, (vaddr_t)off,
348	    strategy|KSYMS_CLOSEST) == 0) {
349		(void)ksyms_getval_unlocked(mod, name, &val, KSYMS_ANY);
350		if (((off - val) < db_maxoff) && val) {
351			snprintf(buf, buflen, "%s:%s", mod, name);
352			if (off - val) {
353				strlcat(buf, "+", buflen);
354				db_format_radix(buf+strlen(buf),
355				    24, off - val, true);
356			}
357#ifdef notyet
358			if (strategy & KSYMS_PROC) {
359				if (ksyms_fmaddr(off, &filename, &linenum) == 0)
360					snprintf(buf + strlen(buf),
361					    buflen - strlen(buf),
362					    " [%s:%d]", filename, linenum);
363			}
364#endif
365			return;
366		}
367	}
368	strlcpy(buf, db_num_to_str(off), buflen);
369#endif
370}
371
372void
373db_printsym(db_expr_t off, db_strategy_t strategy,
374    void (*pr)(const char *, ...))
375{
376	const char  *name;
377#ifdef _KERNEL
378	const char *mod;
379	unsigned long uval;
380	long val;
381#endif
382#ifdef notyet
383	char *filename;
384	int  linenum;
385#endif
386
387#ifndef _KERNEL
388	if (!use_ksyms) {
389		db_expr_t	d;
390		char 		*filename;
391		db_expr_t	value;
392		int 		linenum;
393		db_sym_t	cursym;
394
395		cursym = db_search_symbol(off, strategy, &d);
396		db_symbol_values(cursym, &name, &value);
397		if (name != NULL && ((unsigned int)d < db_maxoff) &&
398		    value != 0) {
399			(*pr)("%s", name);
400			if (d) {
401				char tbuf[24];
402
403				db_format_radix(tbuf, 24, d, true);
404				(*pr)("+%s", tbuf);
405			}
406			if (strategy == DB_STGY_PROC) {
407				if ((*db_symformat->sym_line_at_pc)
408				    (NULL, cursym, &filename, &linenum, off))
409					(*pr)(" [%s:%d]", filename, linenum);
410			}
411			return;
412		}
413		(*pr)("%s", db_num_to_str(off));
414		return;
415	}
416#endif
417#ifdef _KERNEL
418	if (ksyms_getname(&mod, &name, (vaddr_t)off,
419	    strategy|KSYMS_CLOSEST) == 0) {
420		(void)ksyms_getval_unlocked(mod, name, &uval, KSYMS_ANY);
421		val = (long) uval;
422		if (((off - val) < db_maxoff) && val) {
423			(*pr)("%s:%s", mod, name);
424			if (off - val) {
425				char tbuf[24];
426
427				db_format_radix(tbuf, 24, off - val, true);
428				(*pr)("+%s", tbuf);
429			}
430#ifdef notyet
431			if (strategy & KSYMS_PROC) {
432				if (ksyms_fmaddr(off, &filename, &linenum) == 0)
433					(*pr)(" [%s:%d]", filename, linenum);
434			}
435#endif
436			return;
437		}
438	}
439#endif
440	(*pr)("%s", db_num_to_str(off));
441	return;
442}
443
444/*
445 * Splits a string in the form "mod:sym" to two strings.
446 */
447static void
448db_symsplit(char *str, char **mod, char **sym)
449{
450	char *cp;
451
452	if ((cp = strchr(str, ':')) != NULL) {
453		*cp++ = '\0';
454		*mod = str;
455		*sym = cp;
456	} else {
457		*mod = NULL;
458		*sym = str;
459	}
460}
461
462bool
463db_sym_numargs(db_sym_t cursym, int *nargp, char **argnamep)
464{
465#ifndef _KERNEL
466	if (!use_ksyms)
467		return ((*db_symformat->sym_numargs)(NULL, cursym, nargp,
468		    argnamep));
469#endif
470	return (false);
471}
472
473