path: root/sys/ddb/db_aout.c

/*	$OpenBSD: db_aout.c,v 1.29 2006/03/13 06:23:20 jsg Exp $	*/
/*	$NetBSD: db_aout.c,v 1.29 2000/07/07 21:55:18 jhawk Exp $	*/

/* 
 * Mach Operating System
 * Copyright (c) 1993,1992,1991,1990 Carnegie Mellon University
 * All Rights Reserved.
 * 
 * Permission to use, copy, modify and distribute this software and its
 * documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 * 
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 * 
 * Carnegie Mellon requests users of this software to return to
 * 
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 * 
 * any improvements or extensions that they make and grant Carnegie Mellon
 * the rights to redistribute these changes.
 */

#include <sys/types.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>

#include <machine/db_machdep.h>		/* data types */

#include <ddb/db_sym.h>
#include <ddb/db_output.h>
#include <ddb/db_extern.h>

#ifdef	DB_AOUT_SYMBOLS

#include <ddb/db_aout.h>

boolean_t	db_aout_sym_init(int, void *, void *, const char *);
db_sym_t	db_aout_lookup(db_symtab_t *, char *);
db_sym_t	db_aout_search_symbol(db_symtab_t *, db_addr_t,
		    db_strategy_t, db_expr_t *);
void		db_aout_symbol_values(db_symtab_t *, db_sym_t,
		    char **, db_expr_t *);
boolean_t	db_aout_line_at_pc(db_symtab_t *, db_sym_t,
		    char **, int *, db_expr_t);
boolean_t	db_aout_sym_numargs(db_symtab_t *, db_sym_t, int *,
		    char **);
void		db_aout_forall(db_symtab_t *,
		    db_forall_func_t db_forall_func, void *);

db_symformat_t db_symformat_aout = {
	"a.out",
	db_aout_sym_init,
	db_aout_lookup,
	db_aout_search_symbol,
	db_aout_symbol_values,
	db_aout_line_at_pc,
	db_aout_sym_numargs,
	db_aout_forall
};

/*
 * An a.out symbol table as loaded into the kernel debugger:
 *
 * symtab	-> size of symbol entries, in bytes
 * sp		-> first symbol entry
 *		   ...
 * ep		-> last symbol entry + 1
 * strtab	== start of string table
 *		   size of string table in bytes,
 *		   including this word
 *		-> strings
 */
static char *strtab;
static int slen;

#define X_db_getname(t, s)	(s->n_un.n_strx ? t->end + s->n_un.n_strx : NULL)

/* XXX */
#ifndef ALIGNED_POINTER
#define ALIGNED_POINTER(p,t)        ((((u_long)(p)) & (sizeof(t)-1)) == 0)
#endif

/*
 * Find the symbol table and strings; tell ddb about them.
 *
 * symsize:	size of symbol table
 * vsymtab:	pointer to end of string table
 * vesymtab:	pointer to end of string table, for checking - rounded up to
 * 		    integer boundry
 */
boolean_t
db_aout_sym_init(int symsize, void *vsymtab, void *vesymtab, const char *name)
{
	struct nlist	*sym_start, *sym_end;
	struct nlist	*sp;
	int bad = 0;
	char *estrtab;

	/*
	 * XXX - ddb_init should take arguments.
	 *       Fixup the arguments.
	 */
	symsize = *(long *)vsymtab;
	vsymtab = (void *)((long *)vsymtab + 1);
	

	if (ALIGNED_POINTER(vsymtab, long) == 0) {
		printf("[ %s symbol table has bad start address %p ]\n",
		    name, vsymtab);
		return (FALSE);
	}

	/*
	 * Find pointers to the start and end of the symbol entries,
	 * given a pointer to the start of the symbol table.
	 */
	sym_start = (struct nlist *)vsymtab;
	sym_end   = (struct nlist *)((char *)sym_start + symsize);

	strtab = (char *)sym_end;
	if (ALIGNED_POINTER(strtab, int) == 0) {
		printf("[ %s symbol table has bad string table address %p ]\n",
		    name, strtab);
		return (FALSE);
	}
	slen = *(int *)strtab;

	estrtab = strtab + slen;

#define	round_to_size(x) \
    (((vaddr_t)(x) + sizeof(vsize_t) - 1) & ~(sizeof(vsize_t) - 1))

	if (round_to_size(estrtab) != round_to_size(vesymtab)) {
		printf("[ %s a.out symbol table not valid ]\n", name);
		return (FALSE);
        }
#undef	round_to_size
        
	for (sp = sym_start; sp < sym_end; sp++) {
		int strx;
		strx = sp->n_un.n_strx;
		if (strx != 0) {
			if (strx > slen) {
				printf("[ %s has bad a.out string table index "
				    "(0x%x) ]\n",
				    name, strx);
				bad = 1;
				continue;
			}
		}
	}

	if (bad)
		return (FALSE);

	if (db_add_symbol_table((char *)sym_start, (char *)sym_end, name,
	    NULL) !=  -1) {
                printf("[ using %ld bytes of %s a.out symbol table ]\n",
                    (long)vesymtab - (long)vsymtab, name);
		return (TRUE);
        }

	return (FALSE);
}

db_sym_t
db_aout_lookup(db_symtab_t *stab, char *symstr)
{
	struct nlist *sp, *ep;
	char *n_name;

	sp = (struct nlist *)stab->start;
	ep = (struct nlist *)stab->end;

	for (; sp < ep; sp++) {
		if ((n_name = X_db_getname(stab, sp)) == 0)
			continue;
		if ((sp->n_type & N_STAB) == 0 &&
		    db_eqname(n_name, symstr, '_'))
			return ((db_sym_t)sp);
	}
	return ((db_sym_t)0);
}

db_sym_t
db_aout_search_symbol(db_symtab_t *symtab, db_addr_t off,
    db_strategy_t strategy, db_expr_t *diffp)
{
	unsigned int	diff = *diffp;
	struct nlist	*symp = 0;
	struct nlist	*sp, *ep;

	sp = (struct nlist *)symtab->start;
	ep = (struct nlist *)symtab->end;

	for (; sp < ep; sp++) {
		if ((sp->n_type & N_STAB) != 0 ||
		    (sp->n_type & N_TYPE) == N_FN)
			continue;
		if (X_db_getname(symtab, sp) == 0)
			continue;
		if (off >= sp->n_value) {
			if (off - sp->n_value < diff) {
				diff = off - sp->n_value;
				symp = sp;
				if (diff == 0 && ((strategy == DB_STGY_PROC &&
				    sp->n_type == (N_TEXT|N_EXT)) ||
				    (strategy == DB_STGY_ANY &&
				    (sp->n_type & N_EXT))))
					break;
			} else if (off - sp->n_value == diff) {
				if (symp == 0)
					symp = sp;
				else if ((symp->n_type & N_EXT) == 0 &&
				    (sp->n_type & N_EXT) != 0)
					symp = sp;	/* pick the ext. sym */
			}
		}
	}
	if (symp == 0) {
		*diffp = off;
	} else {
		*diffp = diff;
	}
	return ((db_sym_t)symp);
}

/*
 * Return the name and value for a symbol.
 */
void
db_aout_symbol_values(db_symtab_t *symtab, db_sym_t sym, char **namep,
    db_expr_t *valuep)
{
	struct nlist *sp;

	sp = (struct nlist *)sym;
	if (namep)
		*namep = X_db_getname(symtab, sp);
	if (valuep)
		*valuep = sp->n_value;
}


boolean_t
db_aout_line_at_pc(db_symtab_t *symtab, db_sym_t cursym, char **filename,
    int *linenum, db_expr_t off)
{
	struct nlist	*sp, *ep;
	unsigned long	sodiff = -1UL, lndiff = -1UL, ln = 0;
	char		*fname = NULL;

	sp = (struct nlist *)symtab->start;
	ep = (struct nlist *)symtab->end;

/* XXX - gcc specific */
#define NEWSRC(str)	((str) != NULL && \
    (str)[0] == 'g' && strcmp((str), "gcc_compiled.") == 0)

	for (; sp < ep; sp++) {

		/*
		 * Prevent bogus linenumbers in case module not compiled
		 * with debugging options
		 */
#if 0
		if (sp->n_value <= off && (off - sp->n_value) <= sodiff &&
		    NEWSRC(X_db_getname(symtab, sp))) {
#endif
		if ((sp->n_type & N_TYPE) == N_FN ||
		    NEWSRC(X_db_getname(symtab, sp))) {
			sodiff = lndiff = -1UL;
			ln = 0;
			fname = NULL;
		}

		if (sp->n_type == N_SO) {
			if (sp->n_value <= off &&
			    (off - sp->n_value) < sodiff) {
				sodiff = off - sp->n_value;
				fname = X_db_getname(symtab, sp);
			}
			continue;
		}

		if (sp->n_type != N_SLINE)
			continue;

		if (sp->n_value > off)
			break;

		if (off - sp->n_value < lndiff) {
			lndiff = off - sp->n_value;
			ln = sp->n_desc;
		}
	}

	if (fname != NULL && ln != 0) {
		*filename = fname;
		*linenum = ln;
		return (TRUE);
	}

	return (FALSE);
}

boolean_t
db_aout_sym_numargs(db_symtab_t *symtab, db_sym_t cursym, int *nargp,
    char **argnamep)
{
	struct nlist	*sp, *ep;
	u_long		addr;
	int		maxnarg = *nargp, nargs = 0;
	char		*n_name;

	if (cursym == NULL)
		return (FALSE);

	addr = ((struct nlist *)cursym)->n_value;
	sp = (struct nlist *)symtab->start;
	ep = (struct nlist *)symtab->end;

	for (; sp < ep; sp++) {
		if (sp->n_type == N_FUN && sp->n_value == addr) {
			while (++sp < ep && sp->n_type == N_PSYM) {
				if (nargs >= maxnarg)
					break;
				nargs++;
				n_name = X_db_getname(symtab, sp);
				*argnamep++ = n_name ? n_name : "???";
				{
					/* XXX - remove trailers */
					char *cp = *(argnamep - 1);

					while (*cp != '\0' && *cp != ':')
						cp++;
					if (*cp == ':') *cp = '\0';
				}
			}
			*nargp = nargs;
			return (TRUE);
		}
	}
	return (FALSE);
}

void
db_aout_forall(db_symtab_t *stab, db_forall_func_t db_forall_func, void *arg)
{
	static char suffix[2];
	struct nlist *sp, *ep;

	sp = (struct nlist *)stab->start;
	ep = (struct nlist *)stab->end;

	for (; sp < ep; sp++) {
		if (X_db_getname(stab, sp) == 0)
			continue;
		if ((sp->n_type & N_STAB) == 0) {
			suffix[1] = '\0';
			switch(sp->n_type & N_TYPE) {
			case N_ABS:
				suffix[0] = '@';
				break;
			case N_TEXT:
				suffix[0] = '*';
				break;
			case N_DATA:
				suffix[0] = '+';
				break;
			case N_BSS:
				suffix[0] = '-';
				break;
			case N_FN:
				suffix[0] = '/';
				break;
			default:
				suffix[0] = '\0';
			}
			(*db_forall_func)(stab, (db_sym_t)sp,
			    X_db_getname(stab, sp), suffix, '_', arg);
		}
	}
	return;
}

	
#endif	/* DB_AOUT_SYMBOLS */