xref: /titanic_41/usr/src/cmd/mdb/common/kmdb/kmdb_dl.c (revision 7257d1b4d25bfac0c802847390e98a464fd787ac)
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 2008 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 #include <dlfcn.h>
30 #include <sys/modctl.h>
31 #include <sys/kobj.h>
32 
33 #include <kmdb/kmdb_module.h>
34 #include <mdb/mdb_debug.h>
35 #include <mdb/mdb_gelf.h>
36 #include <mdb/mdb_string.h>
37 #include <mdb/mdb.h>
38 
39 /*
40  * kmdb libdl-style interface for the manipulation of dmods.
41  */
42 
43 static char *dl_errstr;
44 
45 static kmdb_modctl_t *
dl_name2ctl(const char * pathname)46 dl_name2ctl(const char *pathname)
47 {
48 	mdb_var_t *v;
49 
50 	if ((v = mdb_nv_lookup(&mdb.m_dmodctl, strbasename(pathname))) ==
51 	    NULL)
52 		return (NULL);
53 
54 	return ((kmdb_modctl_t *)MDB_NV_COOKIE(v));
55 }
56 
57 /*ARGSUSED*/
58 void *
dlmopen(Lmid_t lmid,const char * pathname,int mode)59 dlmopen(Lmid_t lmid, const char *pathname, int mode)
60 {
61 	kmdb_modctl_t *kmc;
62 
63 	if ((kmc = dl_name2ctl(pathname)) == NULL) {
64 		dl_errstr = "unregistered module";
65 		return (NULL);
66 	}
67 
68 	kmc->kmc_dlrefcnt++;
69 
70 	dl_errstr = NULL;
71 
72 	return (kmc);
73 }
74 
75 int
dlclose(void * dlp)76 dlclose(void *dlp)
77 {
78 	kmdb_modctl_t *kmc = dlp;
79 
80 	dl_errstr = NULL;
81 
82 	ASSERT(kmc->kmc_dlrefcnt > 0);
83 	if (--kmc->kmc_dlrefcnt > 0)
84 		return (0);
85 
86 	return (0);
87 }
88 
89 char *
dlerror(void)90 dlerror(void)
91 {
92 	char *str = dl_errstr;
93 
94 	dl_errstr = NULL;
95 
96 	return (str);
97 }
98 
99 static void *
dl_findsym(kmdb_modctl_t * kmc,const char * name)100 dl_findsym(kmdb_modctl_t *kmc, const char *name)
101 {
102 	GElf_Sym sym;
103 	uint_t symid;
104 
105 	if (mdb_gelf_symtab_lookup_by_name(kmc->kmc_symtab, name, &sym,
106 	    &symid) < 0)
107 		return (NULL);
108 
109 	return ((void *)(uintptr_t)sym.st_value);
110 }
111 
112 /*ARGSUSED*/
113 void *
dlsym(void * dlp,const char * name)114 dlsym(void *dlp, const char *name)
115 {
116 	kmdb_modctl_t *kmc = dlp;
117 	mdb_var_t *v;
118 	void *addr;
119 
120 	switch ((uintptr_t)dlp) {
121 	case (uintptr_t)RTLD_NEXT:
122 		mdb_nv_rewind(&mdb.m_dmodctl);
123 		while ((v = mdb_nv_advance(&mdb.m_dmodctl)) != NULL) {
124 			if ((addr = dl_findsym(MDB_NV_COOKIE(v), name)) != NULL)
125 				break;
126 		}
127 		break;
128 
129 	case (uintptr_t)RTLD_DEFAULT:
130 	case (uintptr_t)RTLD_SELF:
131 		dl_errstr = "invalid handle";
132 		return (NULL);
133 
134 	default:
135 		addr = dl_findsym(kmc, name);
136 	}
137 
138 	dl_errstr = (addr == NULL) ? "symbol not found" : NULL;
139 
140 	return (addr);
141 }
142 
143 #pragma weak _dladdr1 = dladdr1
144 /*ARGSUSED*/
145 int
dladdr1(void * address,Dl_info * dlip,void ** info,int flags)146 dladdr1(void *address, Dl_info *dlip, void **info, int flags)
147 {
148 	/*
149 	 * umem uses this for debugging information.  We'll pretend to fail.
150 	 */
151 
152 	return (0);
153 }
154