xref: /illumos-gate/usr/src/uts/sparc/os/obpsym.c (revision b01c3b58f7eb7fb570f606f96f130fb9b2018b49)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 /*
30  * This module supports callbacks from the firmware
31  * such that address and name lookups can work and use kernel symbol names.
32  * For example "ctrace" will provide symbolic names, if they are available.
33  * Also, normal firmware name to address lookups should work, though be
34  * careful with clashing kernel names, such as "startup" and "reset" which
35  * may be the firmware names and *not* the kernel names.
36  *
37  * The module locks the symbol tables in memory, when it's installed,
38  * and unlocks them when it is removed.  The module is loaded automatically
39  * on cobp systems and is replaced by forthdebug on all other systems.
40  *
41  * This file contains the actual code the does the lookups, and interfaces
42  * with the kernel kobj stuff.  The transfer of data and control to/from
43  * the firmware is handled in prom-dependent code.
44  */
45 
46 #include <sys/types.h>
47 #include <sys/param.h>
48 #include <sys/systm.h>
49 #include <sys/debug.h>
50 #include <sys/errno.h>
51 #include <sys/modctl.h>
52 #include <sys/kobj.h>
53 #include <sys/promif.h>
54 #include <sys/ddi.h>
55 #include <sys/sunddi.h>
56 #include <sys/reboot.h>
57 #include <sys/callb.h>
58 
59 int obpsym_debug = 0;
60 #define	DPRINTF(str)		if (obpsym_debug) prom_printf(str)
61 #define	DPRINTF1(str, a)	if (obpsym_debug) prom_printf(str, a);
62 #define	DPRINTF2(str, a, b)	if (obpsym_debug) prom_printf(str, a, b);
63 #define	DXPRINTF		if (obpsym_debug > 1) prom_printf
64 
65 int obpheld = 1;		/* Prevents unloading when set */
66 
67 /*
68  * name_to_value - translate a string into an address
69  *
70  * The string may be one of two forms - 'symname' or 'modname:symname'.
71  * (We also accept 'unix:symname' as a synonymn for 'symname'.)
72  * The latter form causes a kobj_lookup() to occur only in the given module,
73  * the former causes a kobj_getsymvalue() on the entire kernel symbol table.
74  *
75  * mod_lock locking is not needed for the &modules list because
76  * modctl structures are never unlinked from the &modules list.
77  */
78 int
79 name_to_value(char *name, uintptr_t *value)
80 {
81 	register char *symname = name;
82 	register char *modname = "";
83 	char *p;
84 	int retval = 0;
85 	uintptr_t symvalue = 0;
86 	char c = (char)0;
87 
88 	/*
89 	 * we take names of the form: "modname:symbol", "unix:symbol", "symbol"
90 	 */
91 	if ((p = strchr(name, ':')) != NULL && p[1] != (char)0) {
92 		symname = p + 1;
93 		modname = name;
94 		c = *p;
95 		*p = (char)0;
96 	}
97 
98 	if (*modname == (char)0) {
99 		symvalue = kobj_getsymvalue(symname, 0);
100 	} else  {
101 		struct modctl *mp = &modules;
102 
103 		do {
104 			if (strcmp(modname, mp->mod_modname) == 0) {
105 				symvalue = kobj_lookup(mp->mod_mp, symname);
106 				break;
107 			}
108 		} while ((mp = mp->mod_next) != &modules);
109 	}
110 
111 	if (symvalue == 0)
112 		retval = -1;
113 	if (c != (char)0)		/* Restore incoming cstr */
114 		*p = c;
115 
116 	*value = symvalue;
117 	return (retval);
118 }
119 
120 /*
121  * value_to_name - translate an address into a string + offset
122  *
123  * mod_lock locking is not needed fro the modules list because
124  * modctl structures are never unlinked from the &modules list.
125  */
126 ulong_t
127 value_to_name(uintptr_t value, char *symbol)
128 {
129 	struct modctl *modp = &modules;
130 	ulong_t offset;
131 	char *name;
132 
133 	DPRINTF1("value_to_name: Looking for %p\n", (void *)value);
134 
135 	do {
136 		if (modp->mod_mp &&
137 		    (name = kobj_searchsym(modp->mod_mp, value, &offset))) {
138 			(void) strcpy(symbol, modp->mod_modname);
139 			(void) strcat(symbol, ":");
140 			(void) strcat(symbol, name);
141 			return (offset);
142 		}
143 	} while ((modp = modp->mod_next) != &modules);
144 
145 	*symbol = (char)0;
146 	return ((ulong_t)-1l);
147 }
148 
149 /*
150  * loadable module wrapper
151  */
152 static struct modlmisc modlmisc = {
153 	&mod_miscops, "OBP symbol callbacks %I%"
154 };
155 
156 static struct modlinkage modlinkage = {
157 	MODREV_1, (void *)&modlmisc, NULL
158 };
159 
160 /*ARGSUSED*/
161 static boolean_t
162 reset_callbacks(void *arg, int code)
163 {
164 	extern void set_sym_callbacks();
165 
166 	if (code == CB_CODE_CPR_RESUME)
167 		set_sym_callbacks();
168 	return (B_TRUE);
169 }
170 
171 int
172 _init(void)
173 {
174 	int retval;
175 	extern int install_callbacks(void);
176 	extern void remove_callbacks(void);
177 
178 	if (install_callbacks() != 0)
179 		return (ENXIO);
180 
181 	if (boothowto & RB_HALT)
182 		debug_enter("obpsym: halt flag (-h) is set.\n");
183 
184 	retval = mod_install(&modlinkage);
185 
186 	/*
187 	 * if load fails remove callback and unlock symbols
188 	 */
189 	if (retval) {
190 		printf("obpsym: Error %d installing OBP syms module\n", retval);
191 		remove_callbacks();
192 	}
193 	else
194 		(void) callb_add(reset_callbacks, 0, CB_CL_CPR_OBP, "obpsym");
195 
196 	return (retval);
197 }
198 
199 int
200 _fini(void)
201 {
202 	int retval;
203 	extern void remove_callbacks(void);
204 
205 	if (obpheld != 0)
206 		return (EBUSY);
207 
208 	retval = mod_remove(&modlinkage);
209 
210 	/*
211 	 * if unload succeeds remove callback and unlock symbols
212 	 */
213 	if (retval == 0) {
214 		remove_callbacks();
215 	}
216 	return (retval);
217 }
218 
219 int
220 _info(struct modinfo *modinfop)
221 {
222 	return (mod_info(&modlinkage, modinfop));
223 }
224