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[bitrig.git] / sys / ddb / db_sym.c

/*      $OpenBSD: db_sym.c,v 1.32 2006/03/13 06:23:20 jsg Exp $ */
/*      $NetBSD: db_sym.c,v 1.24 2000/08/11 22:50:47 tv 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/param.h>
#include <sys/proc.h>
#include <sys/systm.h>

#include <machine/db_machdep.h>

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

/*
 * Multiple symbol tables
 */
#ifndef MAXLKMS
#define MAXLKMS 20
#endif

#ifndef MAXNOSYMTABS
#define MAXNOSYMTABS    MAXLKMS+1       /* Room for kernel + LKM's */
#endif

db_symtab_t     db_symtabs[MAXNOSYMTABS] = {{0,},};

db_symtab_t     *db_last_symtab;

static db_forall_func_t db_sift;

extern char end[];

/*
 * Put the most picky symbol table formats at the top!
 */
const db_symformat_t *db_symformats[] = {
#ifdef DB_ELF_SYMBOLS
        &db_symformat_elf,
#endif
        NULL,
};

const db_symformat_t *db_symformat;

boolean_t       X_db_sym_init(int, void *, void *, const char *);
db_sym_t        X_db_lookup(db_symtab_t *, char *);
db_sym_t        X_db_search_symbol(db_symtab_t *, db_addr_t,
                    db_strategy_t, db_expr_t *);
void            X_db_symbol_values(db_symtab_t *, db_sym_t, char **,
                    db_expr_t *);
boolean_t       X_db_line_at_pc(db_symtab_t *, db_sym_t, char **,
                    int *, db_expr_t);
int             X_db_sym_numargs(db_symtab_t *, db_sym_t, int *,
                    char **);

/*
 * Initialize the kernel debugger by initializing the master symbol
 * table.  Note that if initializing the master symbol table fails,
 * no other symbol tables can be loaded.
 */
#if 0
void
ddb_init(int symsize, void *vss, void *vse)
{
        const db_symformat_t **symf;
        const char *name = "bsd";

        if (symsize <= 0) {
                printf(" [ no symbols available ]\n");
                return;
        }

        /*
         * Do this check now for the master symbol table to avoid printing
         * the message N times.
         */
        if (ALIGNED_POINTER(vss, long) == 0) {
                printf("[ %s symbol table has bad start address %p ]\n",
                    name, vss);
                return;
        }

        for (symf = db_symformats; *symf != NULL; symf++) {
                db_symformat = *symf;
                if (X_db_sym_init(symsize, vss, vse, name) == TRUE)
                        return;
        }

        db_symformat = NULL;
        printf("[ no symbol table formats found ]\n");
}
#else
void
ddb_init(void)
{
        const db_symformat_t **symf;
        const char *name = "bsd";
        extern char *esym;
#if defined(__sparc64__) || defined(__mips__)
        extern char *ssym;
#endif
        char *xssym, *xesym;

        xesym = esym;
#if defined(__sparc64__) || defined(__mips__)
        xssym = ssym;
#else
        xssym = (char *)&end;
#endif
        /*
         * Do this check now for the master symbol table to avoid printing
         * the message N times.
         */
        if ((((vaddr_t)xssym) & (sizeof(long) - 1)) != 0) {
                printf("[ %s symbol table has bad start address %p ]\n",
                    name, xssym);
                return;
        }

        if (xesym != NULL && xesym != xssym)
                for (symf = db_symformats; *symf != NULL; symf++) {
                        db_symformat = *symf;
                        if (X_db_sym_init((vaddr_t)xesym - (vaddr_t)xssym,
                            xssym, xesym, name) == TRUE)
                        return;
                }

        db_symformat = NULL;
        printf("[ no symbol table formats found ]\n");
}
#endif

/*
 * Add symbol table, with given name, to list of symbol tables.
 */
int
db_add_symbol_table(char *start, char *end, const char *name, char *ref)
{
        int slot;

        for (slot = 0; slot < MAXNOSYMTABS; slot++) {
                if (db_symtabs[slot].name == NULL)
                        break;
        }
        if (slot >= MAXNOSYMTABS) {
                db_printf("No slots left for %s symbol table", name);
                return(-1);
        }

        db_symtabs[slot].start = start;
        db_symtabs[slot].end = end;
        db_symtabs[slot].name = name;
        db_symtabs[slot].private = ref;

        return(slot);
}

/*
 * Delete a symbol table. Caller is responsible for freeing storage.
 */
void
db_del_symbol_table(char *name)
{
        int slot;

        for (slot = 0; slot < MAXNOSYMTABS; slot++) {
                if (db_symtabs[slot].name &&
                    ! strcmp(db_symtabs[slot].name, name))
                        break;
        }
        if (slot >= MAXNOSYMTABS) {
                db_printf("Unable to find symbol table slot for %s.", name);
                return;
        }

        db_symtabs[slot].start = 0;
        db_symtabs[slot].end = 0;
        db_symtabs[slot].name = 0;
        db_symtabs[slot].private = 0;
}

/*
 *  db_qualify("vm_map", "bsd") returns "bsd:vm_map".
 *
 *  Note: return value points to static data whose content is
 *  overwritten by each call... but in practice this seems okay.
 */
char *
db_qualify(db_sym_t sym, const char *symtabname)
{
        char            *symname;
        static char     tmp[256];
        char    *s;

        db_symbol_values(sym, &symname, 0);
        s = tmp;
        while ((*s++ = *symtabname++) != '\0')
                ;
        s[-1] = ':';
        while ((*s++ = *symname++) != '\0')
                ;
        return tmp;
}


boolean_t
db_eqname(char *src, char *dst, int c)
{
        if (!strcmp(src, dst))
            return (TRUE);
        if (src[0] == c)
            return (!strcmp(src+1,dst));
        return (FALSE);
}

boolean_t
db_value_of_name(char *name, db_expr_t *valuep)
{
        db_sym_t        sym;

        sym = db_lookup(name);
        if (sym == DB_SYM_NULL)
            return (FALSE);
        db_symbol_values(sym, &name, valuep);
        return (TRUE);
}


/*
 * Lookup a symbol.
 * If the symbol has a qualifier (e.g., ux:vm_map),
 * then only the specified symbol table will be searched;
 * otherwise, all symbol tables will be searched.
 */
db_sym_t
db_lookup(char *symstr)
{
        db_sym_t sp;
        int i;
        int symtab_start = 0;
        int symtab_end = MAXNOSYMTABS;
        char *cp;

        /*
         * Look for, remove, and remember any symbol table specifier.
         */
        for (cp = symstr; *cp; cp++) {
                if (*cp == ':') {
                        *cp = '\0';
                        for (i = 0; i < MAXNOSYMTABS; i++) {
                                if (db_symtabs[i].name &&
                                    ! strcmp(symstr, db_symtabs[i].name)) {
                                        symtab_start = i;
                                        symtab_end = i + 1;
                                        break;
                                }
                        }
                        *cp = ':';
                        if (i == MAXNOSYMTABS) {
                                db_error("invalid symbol table name");
                                /*NOTREACHED*/
                        }
                        symstr = cp+1;
                }
        }

        /*
         * Look in the specified set of symbol tables.
         * Return on first match.
         */
        for (i = symtab_start; i < symtab_end; i++) {
                if (db_symtabs[i].name && 
                    (sp = X_db_lookup(&db_symtabs[i], symstr))) {
                        db_last_symtab = &db_symtabs[i];
                        return sp;
                }
        }
        return 0;
}

/* Private structure for passing args to db_sift() from db_sifting(). */
struct db_sift_args {
        char    *symstr;
        int     mode;
};

/*
 * Does the work of db_sifting(), called once for each
 * symbol via X_db_forall(), prints out symbols matching
 * criteria.
 */
static void
db_sift(db_symtab_t *stab, db_sym_t sym, char *name, char *suffix, int prefix,
    void *arg)
{
        char c, sc;
        char *find, *p;
        size_t len;
        struct db_sift_args *dsa;

        dsa = (struct db_sift_args*)arg;

        find = dsa->symstr;     /* String we're looking for. */
        p = name;               /* String we're searching within. */
        
        /* Matching algorithm cribbed from strstr(), which is not
           in the kernel. */
        if ((c = *find++) != 0) {
                len = strlen(find);
                do {
                        do {
                                if ((sc = *p++) == 0)
                                        return;
                        } while (sc != c);
                } while (strncmp(p, find, len) != 0);
        }
        if (dsa->mode=='F')     /* ala ls -F */
                db_printf("%s%s ", name, suffix);
        else
                db_printf("%s ", name);
}

/*
 * "Sift" for a partial symbol.
 * Named for the Sun OpenPROM command ("sifting").
 * If the symbol has a qualifier (e.g., ux:vm_map),
 * then only the specified symbol table will be searched;
 * otherwise, all symbol tables will be searched..
 *
 * "mode" is how-to-display, set from modifiers.
 */
void
db_sifting(char *symstr, int mode)
{
        char *cp;
        int i;
        int symtab_start = 0;
        int symtab_end = MAXNOSYMTABS;
        struct db_sift_args dsa;

        /*
         * Look for, remove, and remember any symbol table specifier.
         */
        for (cp = symstr; *cp; cp++) {
                if (*cp == ':') {
                        *cp = '\0';
                        for (i = 0; i < MAXNOSYMTABS; i++) {
                                if (db_symtabs[i].name &&
                                    ! strcmp(symstr, db_symtabs[i].name)) {
                                        symtab_start = i;
                                        symtab_end = i + 1;
                                        break;
                                }
                        }
                        *cp = ':';
                        if (i == MAXNOSYMTABS) {
                                db_error("invalid symbol table name");
                                /*NOTREACHED*/
                        }
                        symstr = cp+1;
                }
        }

        /* Pass args to db_sift(). */
        dsa.symstr = symstr;
        dsa.mode = mode;

        /*
         * Look in the specified set of symbol tables.
         */
        for (i = symtab_start; i < symtab_end; i++)
                if (db_symtabs[i].name) {
                        db_printf("Sifting table %s:\n", db_symtabs[i].name);
                        X_db_forall(&db_symtabs[i], db_sift, &dsa);
                }

        return;
}


/*
 * Does this symbol name appear in more than one symbol table?
 * Used by db_symbol_values to decide whether to qualify a symbol.
 */
boolean_t db_qualify_ambiguous_names = FALSE;

boolean_t
db_symbol_is_ambiguous(db_sym_t sym)
{
        char            *sym_name;
        int     i;
        boolean_t       found_once = FALSE;

        if (!db_qualify_ambiguous_names)
                return FALSE;

        db_symbol_values(sym, &sym_name, 0);
        for (i = 0; i < MAXNOSYMTABS; i++) {
                if (db_symtabs[i].name &&
                    X_db_lookup(&db_symtabs[i], sym_name)) {
                        if (found_once)
                                return TRUE;
                        found_once = TRUE;
                }
        }
        return FALSE;
}

/*
 * Find the closest symbol to val, and return its name
 * and the difference between val and the symbol found.
 */
db_sym_t
db_search_symbol(db_addr_t val, db_strategy_t strategy, db_expr_t *offp)
{
        unsigned int    diff;
        db_expr_t       newdiff;
        int             i;
        db_sym_t        ret = DB_SYM_NULL, sym;

        newdiff = diff = ~0;
        db_last_symtab = 0;
        for (i = 0; i < MAXNOSYMTABS; i++) {
            if (!db_symtabs[i].name)
                continue;
            sym = X_db_search_symbol(&db_symtabs[i], val, strategy, &newdiff);
            if (newdiff < diff) {
                db_last_symtab = &db_symtabs[i];
                diff = newdiff;
                ret = sym;
            }
        }
        *offp = diff;
        return ret;
}

/*
 * Return name and value of a symbol
 */
void
db_symbol_values(db_sym_t sym, char **namep, db_expr_t *valuep)
{
        db_expr_t       value;

        if (sym == DB_SYM_NULL) {
                *namep = 0;
                return;
        }

        X_db_symbol_values(db_last_symtab, sym, namep, &value);

        if (db_symbol_is_ambiguous(sym))
                *namep = db_qualify(sym, db_last_symtab->name);
        if (valuep)
                *valuep = value;
}


/*
 * Print a the closest symbol to value
 *
 * After matching the symbol according to the given strategy
 * we print it in the name+offset format, provided the symbol's
 * value is close enough (eg smaller than db_maxoff).
 * We also attempt to print [filename:linenum] when applicable
 * (eg for procedure names).
 *
 * If we could not find a reasonable name+offset representation,
 * then we just print the value in hex.  Small values might get
 * bogus symbol associations, e.g. 3 might get some absolute
 * value like _INCLUDE_VERSION or something, therefore we do
 * not accept symbols whose value is zero (and use plain hex).
 * Also, avoid printing as "end+0x????" which is useless.
 * The variable db_lastsym is used instead of "end" in case we
 * add support for symbols in loadable driver modules.
 */
unsigned long   db_lastsym = (unsigned long)end;
unsigned int    db_maxoff = 0x10000000;


void
db_printsym(db_expr_t off, db_strategy_t strategy,
    int (*pr)(const char *, ...))
{
        db_expr_t       d;
        char            *filename;
        char            *name;
        db_expr_t       value;
        int             linenum;
        db_sym_t        cursym;
        char            buf[DB_FORMAT_BUF_SIZE];

        if (off <= db_lastsym) {
                cursym = db_search_symbol(off, strategy, &d);
                db_symbol_values(cursym, &name, &value);
                if (name && (d < db_maxoff) && value) {
                        (*pr)("%s", name);
                        if (d) {
                                (*pr)("+%s", db_format(buf, sizeof(buf),
                                    d, DB_FORMAT_R, 1, 0));
                        }
                        if (strategy == DB_STGY_PROC) {
                                if (db_line_at_pc(cursym, &filename, &linenum, off))
                                        (*pr)(" [%s:%d]", filename, linenum);
                        }
                        return;
                }
        }

        (*pr)("%s", db_format(buf, sizeof(buf), off, DB_FORMAT_N, 1, 0));
        return;
}


boolean_t
db_line_at_pc(db_sym_t sym, char **filename, int *linenum, db_expr_t pc)
{
        return X_db_line_at_pc(db_last_symtab, sym, filename, linenum, pc);
}

int
db_sym_numargs(db_sym_t sym, int *nargp, char **argnames)
{
        return X_db_sym_numargs(db_last_symtab, sym, nargp, argnames);
}

boolean_t
X_db_sym_init(int symsize, void *vss, void *vse, const char *name)
{

        if (db_symformat != NULL)
                return ((*db_symformat->sym_init)(symsize, vss, vse, name));
        return (FALSE);
}

db_sym_t
X_db_lookup(db_symtab_t *stab, char *symstr)
{

        if (db_symformat != NULL)
                return ((*db_symformat->sym_lookup)(stab, symstr));
        return ((db_sym_t)0);
}

db_sym_t
X_db_search_symbol(db_symtab_t *stab, db_addr_t off, db_strategy_t strategy,
    db_expr_t *diffp)
{

        if (db_symformat != NULL)
                return ((*db_symformat->sym_search)(stab, off, strategy,
                    diffp));
        return ((db_sym_t)0);
}

void
X_db_symbol_values(db_symtab_t *stab, db_sym_t sym, char **namep,
    db_expr_t *valuep)
{

        if (db_symformat != NULL) 
                (*db_symformat->sym_value)(stab, sym, namep, valuep);
}

boolean_t
X_db_line_at_pc(db_symtab_t *stab, db_sym_t cursym, char **filename,
    int *linenum, db_expr_t off)
{

        if (db_symformat != NULL)
                return ((*db_symformat->sym_line_at_pc)(stab, cursym,
                    filename, linenum, off));
        return (FALSE);
}

boolean_t
X_db_sym_numargs(db_symtab_t *stab, db_sym_t cursym, int *nargp,
    char **argnamep)
{

        if (db_symformat != NULL)
                return ((*db_symformat->sym_numargs)(stab, cursym, nargp,
                    argnamep));
        return (FALSE);
}

void
X_db_forall(db_symtab_t *stab, db_forall_func_t db_forall_func, void *arg)
{
        if (db_symformat != NULL)
                (*db_symformat->sym_forall)(stab, db_forall_func, arg);
}