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