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db_sym.c revision 1.41
      1 /*	$NetBSD: db_sym.c,v 1.41 2003/05/17 09:48:05 scw 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 (at) 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 1.41 2003/05/17 09:48:05 scw 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 	long val;
     94 
     95 #ifdef DB_AOUT_SYMBOLS
     96 	db_sym_t	ssym;
     97 
     98 	if (using_aout_symtab) {
     99 		/*
    100 		 * Cannot load symtabs in a.out kernels, so the ':'
    101 		 * style of selecting modules is irrelevant.
    102 		 */
    103 		ssym = (*db_symformat->sym_lookup)(NULL, name);
    104 		if (ssym == DB_SYM_NULL)
    105 			return (FALSE);
    106 		db_symbol_values(ssym, &name, valuep);
    107 		return (TRUE);
    108 	}
    109 #endif
    110 	db_symsplit(name, &mod, &sym);
    111 	if (ksyms_getval(mod, sym, &val, KSYMS_EXTERN) == 0) {
    112 		*valuep = (db_expr_t)val;
    113 		return TRUE;
    114 	}
    115 	if (ksyms_getval(mod, sym, &val, KSYMS_ANY) == 0) {
    116 		*valuep = (db_expr_t)val;
    117 		return TRUE;
    118 	}
    119 	return FALSE;
    120 }
    121 
    122 #ifdef DB_AOUT_SYMBOLS
    123 /* Private structure for passing args to db_sift() from db_sifting(). */
    124 struct db_sift_args {
    125 	char	*symstr;
    126 	int	mode;
    127 };
    128 
    129 /*
    130  * Does the work of db_sifting(), called once for each
    131  * symbol via db_forall(), prints out symbols matching
    132  * criteria.
    133  */
    134 static void
    135 db_sift(db_symtab_t *stab, db_sym_t sym, char *name, char *suffix, int prefix,
    136     void *arg)
    137 {
    138 	char c, sc;
    139 	char *find, *p;
    140 	size_t len;
    141 	struct db_sift_args *dsa;
    142 
    143 	dsa = (struct db_sift_args*)arg;
    144 
    145 	find = dsa->symstr;	/* String we're looking for. */
    146 	p = name;		/* String we're searching within. */
    147 
    148 	/* Matching algorithm cribbed from strstr(), which is not
    149 	   in the kernel. */
    150 	if ((c = *find++) != 0) {
    151 		len = strlen(find);
    152 		do {
    153 			do {
    154 				if ((sc = *p++) == 0)
    155 					return;
    156 			} while (sc != c);
    157 		} while (strncmp(p, find, len) != 0);
    158 	}
    159 	if (dsa->mode=='F')	/* ala ls -F */
    160 		db_printf("%s%s ", name, suffix);
    161 	else
    162 		db_printf("%s ", name);
    163 }
    164 #endif
    165 
    166 /*
    167  * "Sift" for a partial symbol.
    168  * Named for the Sun OpenPROM command ("sifting").
    169  * If the symbol has a qualifier (e.g., ux:vm_map),
    170  * then only the specified symbol table will be searched;
    171  * otherwise, all symbol tables will be searched..
    172  *
    173  * "mode" is how-to-display, set from modifiers.
    174  */
    175 void
    176 db_sifting(char *symstr, int mode)
    177 {
    178 	char *mod, *sym;
    179 
    180 #ifdef DB_AOUT_SYMBOLS
    181 	struct db_sift_args dsa;
    182 
    183 	if (using_aout_symtab) {
    184 		dsa.symstr = symstr;
    185 		dsa.mode = mode;
    186 		(*db_symformat->sym_forall)(NULL, db_sift, &dsa);
    187 		db_printf("\n");
    188 		return;
    189 	}
    190 #endif
    191 
    192 	db_symsplit(symstr, &mod, &sym);
    193 	if (ksyms_sift(mod, sym, mode) == ENODEV)
    194 		db_error("invalid symbol table name");
    195 }
    196 
    197 /*
    198  * Find the closest symbol to val, and return its name
    199  * and the difference between val and the symbol found.
    200  */
    201 db_sym_t
    202 db_search_symbol(db_addr_t val, db_strategy_t strategy, db_expr_t *offp)
    203 {
    204 	unsigned int diff;
    205 	unsigned long naddr;
    206 	db_sym_t ret = DB_SYM_NULL;
    207 	const char *mod;
    208 	char *sym;
    209 
    210 #ifdef DB_AOUT_SYMBOLS
    211 	db_expr_t newdiff;
    212 	db_sym_t ssym;
    213 
    214 	if (using_aout_symtab) {
    215 		newdiff = diff = ~0;
    216 		ssym = (*db_symformat->sym_search)
    217 		    (NULL, val, strategy, &newdiff);
    218 		if ((unsigned int) newdiff < diff) {
    219 			diff = newdiff;
    220 			ret = ssym;
    221 		}
    222 		*offp = diff;
    223 		return ret;
    224 	}
    225 #endif
    226 
    227 	if (ksyms_getname(&mod, &sym, (vaddr_t)val, strategy) == 0) {
    228 		(void)ksyms_getval(mod, sym, &naddr, KSYMS_ANY);
    229 		diff = val - (db_addr_t)naddr;
    230 		ret = (db_sym_t)naddr;
    231 	}
    232 	*offp = diff;
    233 	return ret;
    234 }
    235 
    236 /*
    237  * Return name and value of a symbol
    238  */
    239 void
    240 db_symbol_values(db_sym_t sym, char **namep, db_expr_t *valuep)
    241 {
    242 	const char *mod;
    243 
    244 	if (sym == DB_SYM_NULL) {
    245 		*namep = 0;
    246 		return;
    247 	}
    248 
    249 #ifdef DB_AOUT_SYMBOLS
    250 	if (using_aout_symtab) {
    251 		db_expr_t value;
    252 		(*db_symformat->sym_value)(NULL, sym, namep, &value);
    253 		if (valuep)
    254 			*valuep = value;
    255 		return;
    256 	}
    257 #endif
    258 
    259 	if (ksyms_getname(&mod, namep, (vaddr_t)sym,
    260 	    KSYMS_ANY|KSYMS_EXACT) == 0) {
    261 		if (valuep)
    262 			*valuep = sym;
    263 	} else
    264 		*namep = NULL;
    265 }
    266 
    267 
    268 /*
    269  * Print a the closest symbol to value
    270  *
    271  * After matching the symbol according to the given strategy
    272  * we print it in the name+offset format, provided the symbol's
    273  * value is close enough (eg smaller than db_maxoff).
    274  * We also attempt to print [filename:linenum] when applicable
    275  * (eg for procedure names).
    276  *
    277  * If we could not find a reasonable name+offset representation,
    278  * then we just print the value in hex.  Small values might get
    279  * bogus symbol associations, e.g. 3 might get some absolute
    280  * value like _INCLUDE_VERSION or something, therefore we do
    281  * not accept symbols whose value is zero (and use plain hex).
    282  * Also, avoid printing as "end+0x????" which is useless.
    283  * The variable db_lastsym is used instead of "end" in case we
    284  * add support for symbols in loadable driver modules.
    285  */
    286 extern char end[];
    287 unsigned long	db_lastsym = (unsigned long)end;
    288 unsigned int	db_maxoff = 0x10000000;
    289 
    290 void
    291 db_symstr(char *buf, size_t buflen, db_expr_t off, db_strategy_t strategy)
    292 {
    293 	char  *name;
    294 	const char *mod;
    295 	long val;
    296 
    297 #ifdef DB_AOUT_SYMBOLS
    298 	if (using_aout_symtab) {
    299 		db_expr_t	d;
    300 		char 		*filename;
    301 		char		*name;
    302 		db_expr_t	value;
    303 		int 		linenum;
    304 		db_sym_t	cursym;
    305 
    306 		if ((unsigned long) off <= db_lastsym) {
    307 			cursym = db_search_symbol(off, strategy, &d);
    308 			db_symbol_values(cursym, &name, &value);
    309 			if (name != NULL &&
    310 			    ((unsigned int) d < db_maxoff) &&
    311 			    value != 0) {
    312 				strlcpy(buf, name, buflen);
    313 				if (d) {
    314 					strlcat(buf, "+", buflen);
    315 					db_format_radix(buf+strlen(buf),
    316 					    24, d, TRUE);
    317 				}
    318 				if (strategy == DB_STGY_PROC) {
    319 					if ((*db_symformat->sym_line_at_pc)
    320 					    (NULL, cursym, &filename,
    321 					    &linenum, off))
    322 						sprintf(buf+strlen(buf),
    323 						    " [%s:%d]",
    324 						    filename, linenum);
    325 				}
    326 				return;
    327 			}
    328 		}
    329 		strlcpy(buf, db_num_to_str(off), buflen);
    330 		return;
    331 	}
    332 #endif
    333 	if (ksyms_getname(&mod, &name, (vaddr_t)off,
    334 	    strategy|KSYMS_CLOSEST) == 0) {
    335 		(void)ksyms_getval(mod, name, &val, KSYMS_ANY);
    336 		if (((off - val) < db_maxoff) && val) {
    337 			sprintf(buf, "%s:%s", mod, name);
    338 			if (off - val) {
    339 				strlcat(buf, "+", buflen);
    340 				db_format_radix(buf+strlen(buf),
    341 				    24, off - val, TRUE);
    342 			}
    343 #ifdef notyet
    344 			if (strategy & KSYMS_PROC) {
    345 				if (ksyms_fmaddr(off, &filename, &linenum) == 0)					sprintf(buf+strlen(buf),
    346 					    " [%s:%d]", filename, linenum);
    347 			}
    348 #endif
    349 			return;
    350 		}
    351 	}
    352 	strlcpy(buf, db_num_to_str(off), buflen);
    353 }
    354 
    355 void
    356 db_printsym(db_expr_t off, db_strategy_t strategy,
    357     void (*pr)(const char *, ...))
    358 {
    359 	char  *name;
    360 	const char *mod;
    361 	long val;
    362 #ifdef notyet
    363 	char *filename;
    364 	int  linenum;
    365 #endif
    366 
    367 #ifdef DB_AOUT_SYMBOLS
    368 	if (using_aout_symtab) {
    369 		db_expr_t	d;
    370 		char 		*filename;
    371 		char		*name;
    372 		db_expr_t	value;
    373 		int 		linenum;
    374 		db_sym_t	cursym;
    375 		if ((unsigned long) off <= db_lastsym) {
    376 			cursym = db_search_symbol(off, strategy, &d);
    377 			db_symbol_values(cursym, &name, &value);
    378 			if (name != NULL &&
    379 			    ((unsigned int) d < db_maxoff) &&
    380 			    value != 0) {
    381 				(*pr)("%s", name);
    382 				if (d) {
    383 					char tbuf[24];
    384 
    385 					db_format_radix(tbuf, 24, d, TRUE);
    386 					(*pr)("+%s", tbuf);
    387 				}
    388 				if (strategy == DB_STGY_PROC) {
    389 					if ((*db_symformat->sym_line_at_pc)
    390 					    (NULL, cursym, &filename,
    391 					    &linenum, off))
    392 						(*pr)(" [%s:%d]",
    393 						    filename, linenum);
    394 				}
    395 				return;
    396 			}
    397 		}
    398 		(*pr)(db_num_to_str(off));
    399 		return;
    400 	}
    401 #endif
    402 	if (ksyms_getname(&mod, &name, (vaddr_t)off,
    403 	    strategy|KSYMS_CLOSEST) == 0) {
    404 		(void)ksyms_getval(mod, name, &val, KSYMS_ANY);
    405 		if (((off - val) < db_maxoff) && val) {
    406 			(*pr)("%s:%s", mod, name);
    407 			if (off - val) {
    408 				char tbuf[24];
    409 
    410 				db_format_radix(tbuf, 24, off - val, TRUE);
    411 				(*pr)("+%s", tbuf);
    412 			}
    413 #ifdef notyet
    414 			if (strategy & KSYMS_PROC) {
    415 				if (ksyms_fmaddr(off, &filename, &linenum) == 0)
    416 					(*pr)(" [%s:%d]", filename, linenum);
    417 			}
    418 #endif
    419 			return;
    420 		}
    421 	}
    422 	(*pr)(db_num_to_str(off));
    423 	return;
    424 }
    425 
    426 /*
    427  * Splits a string in the form "mod:sym" to two strings.
    428  */
    429 static void
    430 db_symsplit(char *str, char **mod, char **sym)
    431 {
    432 	char *cp;
    433 
    434 	if ((cp = strchr(str, ':')) != NULL) {
    435 		*cp++ = '\0';
    436 		*mod = str;
    437 		*sym = cp;
    438 	} else {
    439 		*mod = NULL;
    440 		*sym = str;
    441 	}
    442 }
    443 
    444 boolean_t
    445 db_sym_numargs(db_sym_t cursym, int *nargp, char **argnamep)
    446 {
    447 #ifdef DB_AOUT_SYMBOLS
    448 	if (using_aout_symtab)
    449 		return ((*db_symformat->sym_numargs)(NULL, cursym, nargp,
    450 		    argnamep));
    451 #endif
    452 	return (FALSE);
    453 }
    454 
    455