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