xref: /illumos-gate/usr/src/uts/sun4/os/forthdebug.c (revision 986fd29a0dc13f7608ef7f508f6e700bd7bc2720)
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  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #pragma ident	"%Z%%M%	%I%	%E% SMI"
27 
28 #include <sys/types.h>
29 #include <sys/cmn_err.h>
30 #include <sys/modctl.h>
31 #include <sys/kobj.h>
32 #include <sys/kobj_impl.h>
33 #include <sys/promif.h>
34 #include <sys/promimpl.h>
35 #include <sys/reboot.h>
36 #include <sys/bootconf.h>
37 #include <sys/systm.h>		/* strstr */
38 #include <sys/machsystm.h>	/* obpdebug */
39 
40 #define	FDEBUGFILE	"misc/forthdebug"
41 #define	INSTALL_DBP	"kdbg-words dbp-install previous"
42 #define	SYMBOL_END	"END OF SYMBOL"
43 
44 #ifdef DEBUG
45 static int forthdebug	= 1;
46 #else
47 static int forthdebug	= 0;
48 #endif /* DEBUG */
49 
50 static int forthdebug_dbp = 0;
51 int forthdebug_supported = 1;
52 int modreloc_flag = KOBJ_RELOCATED;
53 
54 /*
55  * basic_sym[] holds all essential symbols the symbol lookup
56  * service requires. Forthdebug stub names appears in forthdebug
57  * as place holders. They are replaced with the value of corresponding
58  * kernel variables. For example, "modules-val-here" in forthdebug
59  * is replaced with the address of "modules" variable.
60  *
61  * To improve performance, we mandate the records be in the same
62  * sequence they appear in forthdebug, i.e "modules-val-here" is
63  * ahead of "primaries-v-here" in misc/forthdebug.
64  *
65  * The last record must be all 0 to indicate end of the array.
66  */
67 static char *basic_sym[] = {
68 	/* kernel variable */	/* forthdebug stub name - must be 16 chars */
69 	"modules",		"modules-val-here",
70 	"primaries",		"primaries-v-here",
71 	"modreloc_flag",	"modreloc-flagval",
72 	0,			0
73 };
74 
fdbp_hook()75 static void fdbp_hook() {} /* null function for defer breakpoint operation */
76 
77 /*ARGSUSED*/
fdbp_snoop(unsigned int i,struct modctl * modctl_p)78 static void fdbp_snoop(unsigned int i, struct modctl *modctl_p)
79 {
80 	promif_preprom();
81 	fdbp_hook();
82 	promif_postprom();
83 }
84 
85 static kobj_notify_list_t knl_load = {
86 	fdbp_snoop, KOBJ_NOTIFY_MODLOADED, 0, 0
87 };
88 
89 static kobj_notify_list_t knl_unload = {
90 	fdbp_snoop, KOBJ_NOTIFY_MODUNLOADING, 0, 0
91 };
92 
93 void
forthdebug_init(void)94 forthdebug_init(void)
95 {
96 	char *fth_buf, *buf_p;
97 	ulong_t modsym;
98 	int i, sz;
99 	uint64_t fsz;
100 	struct _buf *file;
101 
102 	if (!forthdebug_supported) {
103 		(void) modload("misc", "obpsym");
104 		return;
105 	}
106 
107 	forthdebug_dbp |= boothowto & RB_FORTHDEBUGDBP;
108 	forthdebug |= (boothowto & RB_FORTHDEBUG) | forthdebug_dbp;
109 
110 	file = kobj_open_path(FDEBUGFILE, 1, 1);
111 	if (file == (struct _buf *)-1) {
112 		cmn_err(CE_CONT, "Can't open %s\n", FDEBUGFILE);
113 		return;
114 	}
115 
116 	i = kobj_get_filesize(file, &fsz);
117 	if (i || !fsz) {
118 		cmn_err(CE_CONT, "Can't stat %s stat=%x sz=%llx\n",
119 		    FDEBUGFILE, i, (long long)fsz);
120 		goto err_stat;
121 	}
122 
123 	fth_buf = (char *)kobj_zalloc(fsz + 1, KM_SLEEP);
124 	sz = kobj_read_file(file, fth_buf, fsz, 0); /* entire file */
125 	if (sz < 0) {
126 		cmn_err(CE_CONT, "Error(%d) reading %s\n", sz, FDEBUGFILE);
127 		goto done;
128 	}
129 	ASSERT(fsz == sz);
130 	fth_buf[sz] = 0;
131 
132 	/* resolve all essential symbols in basic_sym[] */
133 	for (i = 0; basic_sym[i]; i += 2) {
134 		buf_p = strstr(fth_buf, basic_sym[i + 1]);
135 		modsym = kobj_getsymvalue(basic_sym[i], 0);
136 		if (buf_p && modsym) {
137 			(void) sprintf(buf_p, "%16p", (void *)modsym);
138 			buf_p += 16;
139 			*buf_p++ = ' ';	/* erase null char by sprintf */
140 		} else {
141 			cmn_err(CE_CONT,
142 			    "forthdebug_init: No %s symbol(%p,%p), aborted\n",
143 			    basic_sym[i], (void *)buf_p, (void *)modsym);
144 			goto done;
145 		}
146 	}
147 	if (!forthdebug) {	/* symbol lookup services only */
148 		if (!(buf_p = strstr(fth_buf, SYMBOL_END))) {
149 			cmn_err(CE_CONT, "No %s in forthdebug\n", SYMBOL_END);
150 			goto done;
151 		}
152 		*buf_p = '\0';
153 #ifdef DEBUG
154 		cmn_err(CE_CONT, "symbol lookup service (%ld bytes)\n",
155 		    (long)(buf_p - fth_buf));
156 #endif /* DEBUG */
157 		prom_interpret(fth_buf, 0, 0, 0, 0, 0);
158 		goto done;
159 	}
160 
161 	cmn_err(CE_CONT, "%s (%d bytes) ", FDEBUGFILE, sz);
162 	prom_interpret(fth_buf, 0, 0, 0, 0, 0);
163 	cmn_err(CE_CONT, "loaded\n");
164 	obpdebug = 1;	/* backward compatibility */
165 
166 	if (forthdebug_dbp) {
167 #ifdef NO_KOBJ_NOTIFY
168 		modsym = kobj_getsymvalue("kobj_notify_add", 0);
169 		(void) ((int (*)(kobj_notify_list_t *))modsym)(&knl_load);
170 		(void) ((int (*)(kobj_notify_list_t *))modsym)(&knl_unload);
171 #else
172 		(void) kobj_notify_add(&knl_load);
173 		(void) kobj_notify_add(&knl_unload);
174 #endif	/* NO_KOBJ_NOTIFY */
175 		prom_interpret(INSTALL_DBP, 0, 0, 0, 0, 0);
176 		debug_enter("Defer breakpoint enabled. Add breakpoints, then");
177 	}
178 done:
179 	kobj_free(fth_buf, fsz + 1);
180 err_stat:
181 	kobj_close_file(file);
182 
183 	if (boothowto & RB_HALT)
184 		debug_enter("forthdebug: halt flag (-h) is set.\n");
185 }
186