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db_sym.c revision 1.49
      1 /*	$NetBSD: db_sym.c,v 1.49 2005/02/26 23:04:17 perry 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 1.49 2005/02/26 23:04:17 perry 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 /*###207 [cc] warning: `diff' might be used uninitialized in this function%%%*/
    208 	unsigned int diff;
    209 	unsigned long naddr;
    210 	db_sym_t ret = DB_SYM_NULL;
    211 	const char *mod;
    212 	char *sym;
    213 
    214 #ifdef DB_AOUT_SYMBOLS
    215 	db_expr_t newdiff;
    216 	db_sym_t ssym;
    217 
    218 	if (using_aout_symtab) {
    219 		newdiff = diff = ~0;
    220 		ssym = (*db_symformat->sym_search)
    221 		    (NULL, val, strategy, &newdiff);
    222 		if ((unsigned int) newdiff < diff) {
    223 			diff = newdiff;
    224 			ret = ssym;
    225 		}
    226 		*offp = diff;
    227 		return ret;
    228 	}
    229 #endif
    230 
    231 	if (ksyms_getname(&mod, &sym, (vaddr_t)val, strategy) == 0) {
    232 		(void)ksyms_getval(mod, sym, &naddr, KSYMS_ANY);
    233 		diff = val - (db_addr_t)naddr;
    234 		ret = (db_sym_t)naddr;
    235 	} else
    236 		diff = 0;
    237 	*offp = diff;
    238 	return ret;
    239 }
    240 
    241 /*
    242  * Return name and value of a symbol
    243  */
    244 void
    245 db_symbol_values(db_sym_t sym, char **namep, db_expr_t *valuep)
    246 {
    247 	const char *mod;
    248 
    249 	if (sym == DB_SYM_NULL) {
    250 		*namep = 0;
    251 		return;
    252 	}
    253 
    254 #ifdef DB_AOUT_SYMBOLS
    255 	if (using_aout_symtab) {
    256 		db_expr_t value;
    257 		(*db_symformat->sym_value)(NULL, sym, namep, &value);
    258 		if (valuep)
    259 			*valuep = value;
    260 		return;
    261 	}
    262 #endif
    263 
    264 	if (ksyms_getname(&mod, namep, (vaddr_t)sym,
    265 	    KSYMS_ANY|KSYMS_EXACT) == 0) {
    266 		if (valuep)
    267 			*valuep = sym;
    268 	} else
    269 		*namep = NULL;
    270 }
    271 
    272 
    273 /*
    274  * Print a the closest symbol to value
    275  *
    276  * After matching the symbol according to the given strategy
    277  * we print it in the name+offset format, provided the symbol's
    278  * value is close enough (eg smaller than db_maxoff).
    279  * We also attempt to print [filename:linenum] when applicable
    280  * (eg for procedure names).
    281  *
    282  * If we could not find a reasonable name+offset representation,
    283  * then we just print the value in hex.  Small values might get
    284  * bogus symbol associations, e.g. 3 might get some absolute
    285  * value like _INCLUDE_VERSION or something, therefore we do
    286  * not accept symbols whose value is zero (and use plain hex).
    287  * Also, avoid printing as "end+0x????" which is useless.
    288  * The variable db_lastsym is used instead of "end" in case we
    289  * add support for symbols in loadable driver modules.
    290  */
    291 extern char end[];
    292 unsigned long	db_lastsym = (unsigned long)end;
    293 unsigned int	db_maxoff = 0x100000;
    294 
    295 void
    296 db_symstr(char *buf, size_t buflen, db_expr_t off, db_strategy_t strategy)
    297 {
    298 	char  *name;
    299 	const char *mod;
    300 	unsigned long val;
    301 
    302 #ifdef DB_AOUT_SYMBOLS
    303 	if (using_aout_symtab) {
    304 		db_expr_t	d;
    305 		char 		*filename;
    306 		char		*name;
    307 		db_expr_t	value;
    308 		int 		linenum;
    309 		db_sym_t	cursym;
    310 
    311 		if ((unsigned long) off <= db_lastsym) {
    312 			cursym = db_search_symbol(off, strategy, &d);
    313 			db_symbol_values(cursym, &name, &value);
    314 			if (name != NULL &&
    315 			    ((unsigned int) d < db_maxoff) &&
    316 			    value != 0) {
    317 				strlcpy(buf, name, buflen);
    318 				if (d) {
    319 					strlcat(buf, "+", buflen);
    320 					db_format_radix(buf+strlen(buf),
    321 					    24, d, TRUE);
    322 				}
    323 				if (strategy == DB_STGY_PROC) {
    324 					if ((*db_symformat->sym_line_at_pc)
    325 					    (NULL, cursym, &filename,
    326 					    &linenum, off))
    327 						snprintf(buf + strlen(buf),
    328 						    buflen - strlen(buf),
    329 						    " [%s:%d]",
    330 						    filename, linenum);
    331 				}
    332 				return;
    333 			}
    334 		}
    335 		strlcpy(buf, db_num_to_str(off), buflen);
    336 		return;
    337 	}
    338 #endif
    339 	if (ksyms_getname(&mod, &name, (vaddr_t)off,
    340 	    strategy|KSYMS_CLOSEST) == 0) {
    341 		(void)ksyms_getval(mod, name, &val, KSYMS_ANY);
    342 		if (((off - val) < db_maxoff) && val) {
    343 			snprintf(buf, buflen, "%s:%s", mod, name);
    344 			if (off - val) {
    345 				strlcat(buf, "+", buflen);
    346 				db_format_radix(buf+strlen(buf),
    347 				    24, off - val, TRUE);
    348 			}
    349 #ifdef notyet
    350 			if (strategy & KSYMS_PROC) {
    351 				if (ksyms_fmaddr(off, &filename, &linenum) == 0)
    352 					snprintf(buf + strlen(buf),
    353 					    buflen - strlen(buf),
    354 					    " [%s:%d]", filename, linenum);
    355 			}
    356 #endif
    357 			return;
    358 		}
    359 	}
    360 	strlcpy(buf, db_num_to_str(off), buflen);
    361 }
    362 
    363 void
    364 db_printsym(db_expr_t off, db_strategy_t strategy,
    365     void (*pr)(const char *, ...))
    366 {
    367 	char  *name;
    368 	const char *mod;
    369 	unsigned long uval;
    370 	long val;
    371 #ifdef notyet
    372 	char *filename;
    373 	int  linenum;
    374 #endif
    375 
    376 #ifdef DB_AOUT_SYMBOLS
    377 	if (using_aout_symtab) {
    378 		db_expr_t	d;
    379 		char 		*filename;
    380 		char		*name;
    381 		db_expr_t	value;
    382 		int 		linenum;
    383 		db_sym_t	cursym;
    384 		if ((unsigned long) off <= db_lastsym) {
    385 			cursym = db_search_symbol(off, strategy, &d);
    386 			db_symbol_values(cursym, &name, &value);
    387 			if (name != NULL &&
    388 			    ((unsigned int) d < db_maxoff) &&
    389 			    value != 0) {
    390 				(*pr)("%s", name);
    391 				if (d) {
    392 					char tbuf[24];
    393 
    394 					db_format_radix(tbuf, 24, d, TRUE);
    395 					(*pr)("+%s", tbuf);
    396 				}
    397 				if (strategy == DB_STGY_PROC) {
    398 					if ((*db_symformat->sym_line_at_pc)
    399 					    (NULL, cursym, &filename,
    400 					    &linenum, off))
    401 						(*pr)(" [%s:%d]",
    402 						    filename, linenum);
    403 				}
    404 				return;
    405 			}
    406 		}
    407 		(*pr)(db_num_to_str(off));
    408 		return;
    409 	}
    410 #endif
    411 	if (ksyms_getname(&mod, &name, (vaddr_t)off,
    412 	    strategy|KSYMS_CLOSEST) == 0) {
    413 		(void)ksyms_getval(mod, name, &uval, KSYMS_ANY);
    414 		val = (long) uval;
    415 		if (((off - val) < db_maxoff) && val) {
    416 			(*pr)("%s:%s", mod, name);
    417 			if (off - val) {
    418 				char tbuf[24];
    419 
    420 				db_format_radix(tbuf, 24, off - val, TRUE);
    421 				(*pr)("+%s", tbuf);
    422 			}
    423 #ifdef notyet
    424 			if (strategy & KSYMS_PROC) {
    425 				if (ksyms_fmaddr(off, &filename, &linenum) == 0)
    426 					(*pr)(" [%s:%d]", filename, linenum);
    427 			}
    428 #endif
    429 			return;
    430 		}
    431 	}
    432 	(*pr)(db_num_to_str(off));
    433 	return;
    434 }
    435 
    436 /*
    437  * Splits a string in the form "mod:sym" to two strings.
    438  */
    439 static void
    440 db_symsplit(char *str, char **mod, char **sym)
    441 {
    442 	char *cp;
    443 
    444 	if ((cp = strchr(str, ':')) != NULL) {
    445 		*cp++ = '\0';
    446 		*mod = str;
    447 		*sym = cp;
    448 	} else {
    449 		*mod = NULL;
    450 		*sym = str;
    451 	}
    452 }
    453 
    454 boolean_t
    455 db_sym_numargs(db_sym_t cursym, int *nargp, char **argnamep)
    456 {
    457 #ifdef DB_AOUT_SYMBOLS
    458 	if (using_aout_symtab)
    459 		return ((*db_symformat->sym_numargs)(NULL, cursym, nargp,
    460 		    argnamep));
    461 #endif
    462 	return (FALSE);
    463 }
    464 
    465