obpsym.c revision 75521904d7c3dbe11337904d9bead2518c94cc50
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2005 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
/*
* This module supports callbacks from the firmware
* such that address and name lookups can work and use kernel symbol names.
* For example "ctrace" will provide symbolic names, if they are available.
* Also, normal firmware name to address lookups should work, though be
* careful with clashing kernel names, such as "startup" and "reset" which
* may be the firmware names and *not* the kernel names.
*
* The module locks the symbol tables in memory, when it's installed,
* and unlocks them when it is removed. To install the module, you
* may either add "set obpdebug=1" to /etc/system or just modload it.
*
* This file contains the actual code the does the lookups, and interfaces
* with the kernel kobj stuff. The transfer of data and control to/from
* the firmware is handled in prom-dependent code.
*/
#include <sys/types.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/debug.h>
#include <sys/errno.h>
#include <sys/modctl.h>
#include <sys/kobj.h>
#include <sys/promif.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
#include <sys/reboot.h>
#include <sys/callb.h>
int obpsym_debug = 0;
#define DPRINTF(str) if (obpsym_debug) prom_printf(str)
#define DPRINTF1(str, a) if (obpsym_debug) prom_printf(str, a);
#define DPRINTF2(str, a, b) if (obpsym_debug) prom_printf(str, a, b);
#define DXPRINTF if (obpsym_debug > 1) prom_printf
int obpheld = 1; /* Prevents unloading when set */
extern int obpdebug;
/*
* name_to_value - translate a string into an address
*
* The string may be one of two forms - 'symname' or 'modname:symname'.
* (We also accept 'unix:symname' as a synonymn for 'symname'.)
* The latter form causes a kobj_lookup() to occur only in the given module,
* the former causes a kobj_getsymvalue() on the entire kernel symbol table.
*
* mod_lock locking is not needed for the &modules list because
* modctl structures are never unlinked from the &modules list.
*/
int
name_to_value(char *name, uintptr_t *value)
{
register char *symname = name;
register char *modname = "";
char *p;
int retval = 0;
uintptr_t symvalue = 0;
char c = (char)0;
/*
* we take names of the form: "modname:symbol", "unix:symbol", "symbol"
*/
if ((p = strchr(name, ':')) != NULL && p[1] != (char)0) {
symname = p + 1;
modname = name;
c = *p;
*p = (char)0;
}
if (*modname == (char)0) {
symvalue = kobj_getsymvalue(symname, 0);
} else {
struct modctl *mp = &modules;
do {
if (strcmp(modname, mp->mod_modname) == 0) {
symvalue = kobj_lookup(mp->mod_mp, symname);
break;
}
} while ((mp = mp->mod_next) != &modules);
}
if (symvalue == 0)
retval = -1;
if (c != (char)0) /* Restore incoming cstr */
*p = c;
*value = symvalue;
return (retval);
}
/*
* value_to_name - translate an address into a string + offset
*
* mod_lock locking is not needed fro the modules list because
* modctl structures are never unlinked from the &modules list.
*/
ulong_t
value_to_name(uintptr_t value, char *symbol)
{
struct modctl *modp = &modules;
ulong_t offset;
char *name;
DPRINTF1("value_to_name: Looking for %p\n", (void *)value);
do {
if (modp->mod_mp &&
(name = kobj_searchsym(modp->mod_mp, value, &offset))) {
(void) strcpy(symbol, modp->mod_modname);
(void) strcat(symbol, ":");
(void) strcat(symbol, name);
return (offset);
}
} while ((modp = modp->mod_next) != &modules);
*symbol = (char)0;
return ((ulong_t)-1l);
}
/*
* loadable module wrapper
*/
static struct modlmisc modlmisc = {
&mod_miscops, "OBP symbol callbacks %I%"
};
static struct modlinkage modlinkage = {
MODREV_1, (void *)&modlmisc, NULL
};
/*ARGSUSED*/
static boolean_t
reset_callbacks(void *arg, int code)
{
extern void set_sym_callbacks();
if (code == CB_CODE_CPR_RESUME)
set_sym_callbacks();
return (B_TRUE);
}
int
_init(void)
{
int retval;
extern int install_callbacks(void);
extern void remove_callbacks(void);
if (install_callbacks() != 0)
return (ENXIO);
obpdebug = 1;
if (boothowto & RB_HALT)
debug_enter("obpsym: halt flag (-h) is set.\n");
retval = mod_install(&modlinkage);
/*
* if load fails remove callback and unlock symbols
*/
if (retval) {
printf("obpsym: Error %d installing OBP syms module\n", retval);
remove_callbacks();
obpdebug = 0;
}
else
(void) callb_add(reset_callbacks, 0, CB_CL_CPR_OBP, "obpsym");
return (retval);
}
int
_fini(void)
{
int retval;
extern void remove_callbacks(void);
if (obpheld != 0)
return (EBUSY);
retval = mod_remove(&modlinkage);
/*
* if unload succeeds remove callback and unlock symbols
*/
if (retval == 0) {
remove_callbacks();
obpdebug = 0;
}
return (retval);
}
int
_info(struct modinfo *modinfop)
{
return (mod_info(&modlinkage, modinfop));
}