kmdb_dl.c revision 1219:f89f56c2d9ac 
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, Version 1.0 only
6 * (the "License").  You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22
23/*
24 * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
25 * Use is subject to license terms.
26 */
27
28#pragma ident	"%Z%%M%	%I%	%E% SMI"
29
30#include <dlfcn.h>
31#include <sys/modctl.h>
32#include <sys/kobj.h>
33
34#include <kmdb/kmdb_module.h>
35#include <mdb/mdb_debug.h>
36#include <mdb/mdb_gelf.h>
37#include <mdb/mdb_string.h>
38#include <mdb/mdb.h>
39
40/*
41 * kmdb libdl-style interface for the manipulation of dmods.
42 */
43
44static char *dl_errstr;
45
46static kmdb_modctl_t *
47dl_name2ctl(const char *pathname)
48{
49	mdb_var_t *v;
50
51	if ((v = mdb_nv_lookup(&mdb.m_dmodctl, strbasename(pathname))) ==
52	    NULL)
53		return (NULL);
54
55	return ((kmdb_modctl_t *)MDB_NV_COOKIE(v));
56}
57
58/*ARGSUSED*/
59void *
60dlmopen(Lmid_t lmid, const char *pathname, int mode)
61{
62	kmdb_modctl_t *kmc;
63
64	if ((kmc = dl_name2ctl(pathname)) == NULL) {
65		dl_errstr = "unregistered module";
66		return (NULL);
67	}
68
69	kmc->kmc_dlrefcnt++;
70
71	dl_errstr = NULL;
72
73	return (kmc);
74}
75
76int
77dlclose(void *dlp)
78{
79	kmdb_modctl_t *kmc = dlp;
80
81	dl_errstr = NULL;
82
83	ASSERT(kmc->kmc_dlrefcnt > 0);
84	if (--kmc->kmc_dlrefcnt > 0)
85		return (0);
86
87	return (0);
88}
89
90char *
91dlerror(void)
92{
93	char *str = dl_errstr;
94
95	dl_errstr = NULL;
96
97	return (str);
98}
99
100static void *
101dl_findsym(kmdb_modctl_t *kmc, const char *name)
102{
103	GElf_Sym sym;
104	uint_t symid;
105
106	if (mdb_gelf_symtab_lookup_by_name(kmc->kmc_symtab, name, &sym,
107	    &symid) < 0)
108		return (NULL);
109
110	return ((void *)(uintptr_t)sym.st_value);
111}
112
113/*ARGSUSED*/
114void *
115dlsym(void *dlp, const char *name)
116{
117	kmdb_modctl_t *kmc = dlp;
118	mdb_var_t *v;
119	void *addr;
120
121	switch ((uintptr_t)dlp) {
122	case (uintptr_t)RTLD_NEXT:
123		mdb_nv_rewind(&mdb.m_dmodctl);
124		while ((v = mdb_nv_advance(&mdb.m_dmodctl)) != NULL) {
125			if ((addr = dl_findsym(MDB_NV_COOKIE(v), name)) != NULL)
126				break;
127		}
128		break;
129
130	case (uintptr_t)RTLD_DEFAULT:
131	case (uintptr_t)RTLD_SELF:
132		dl_errstr = "invalid handle";
133		return (NULL);
134
135	default:
136		addr = dl_findsym(kmc, name);
137	}
138
139	dl_errstr = (addr == NULL) ? "symbol not found" : NULL;
140
141	return (addr);
142}
143
144#pragma weak dladdr1 = _dladdr1
145/*ARGSUSED*/
146int
147_dladdr1(void *address, Dl_info *dlip, void **info, int flags)
148{
149	/*
150	 * umem uses this for debugging information.  We'll pretend to fail.
151	 */
152
153	return (0);
154}
155