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 (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
24  * Copyright (c) 2012 by Delphix. All rights reserved.
25  * Copyright 2019 Joyent, Inc.
26  * Copyright 2021 Oxide Computer Company
27  */
28 
29 #include <sys/param.h>
30 #include <unistd.h>
31 #include <strings.h>
32 #include <dlfcn.h>
33 #include <ctype.h>
34 #include <link.h>
35 
36 #include <mdb/mdb_module.h>
37 #include <mdb/mdb_modapi.h>
38 #include <mdb/mdb_debug.h>
39 #include <mdb/mdb_string.h>
40 #include <mdb/mdb_err.h>
41 #include <mdb/mdb_io.h>
42 #include <mdb/mdb_frame.h>
43 #include <mdb/mdb.h>
44 
45 int
mdb_module_load(const char * name,int mode)46 mdb_module_load(const char *name, int mode)
47 {
48 	const char *wformat = "no module '%s' could be found\n";
49 	const char *fullname = NULL;
50 	char buf[MAXPATHLEN], *p, *q;
51 	int i;
52 
53 	ASSERT(!(mode & MDB_MOD_DEFER));
54 
55 	if (strchr(name, '/') != NULL) {
56 		ASSERT(!(mode & MDB_MOD_BUILTIN));
57 
58 		(void) mdb_iob_snprintf(buf, sizeof (buf), "%s",
59 		    strbasename(name));
60 
61 		/*
62 		 * Remove any .so(.[0-9]+)? suffix
63 		 */
64 		if ((p = strrchr(buf, '.')) != NULL) {
65 			for (q = p + 1; isdigit(*q); q++)
66 				;
67 
68 			if (*q == '\0') {
69 				if (q > p + 1) {
70 
71 					/* found digits to remove */
72 					*p = '\0';
73 				}
74 			}
75 			if ((p = strrchr(buf, '.')) != NULL) {
76 				if (strcmp(p, ".so") == 0) {
77 					*p = '\0';
78 				}
79 			}
80 		}
81 		fullname = name;
82 		name = buf;
83 	}
84 
85 	if (!mdb_module_validate_name(name, &wformat))
86 		goto err;
87 
88 	if (fullname != NULL) {
89 		if (access(fullname, F_OK) != 0) {
90 			name = fullname; /* for warn() below */
91 			goto err;
92 		}
93 		return (mdb_module_create(name, fullname, mode, NULL));
94 	}
95 
96 	/*
97 	 * If a simple name is specified, search for it in the module path.
98 	 * The module path is searched in order, and for each element we
99 	 * look for the following files:
100 	 *
101 	 * 1. If the module name ends in ".so(.[0-9]+)?", search for the literal
102 	 *    name and then search for the name without the [0-9]+ suffix.
103 	 * 2. If the module name ends in ".so", search for the literal name.
104 	 * 3. Search for the module name with ".so" appended.
105 	 *
106 	 * Once a matching file is detected, we attempt to load that module
107 	 * and do not resume our search in the case of an error.
108 	 */
109 	for (i = 0; mdb.m_lpath[i] != NULL; i++) {
110 		if ((p = strrchr(name, '.')) != NULL && *++p != '\0') {
111 			if (strisnum(p) || strcmp(p, "so") == 0) {
112 				(void) mdb_iob_snprintf(buf, sizeof (buf),
113 				    "%s/%s", mdb.m_lpath[i], name);
114 				mdb_dprintf(MDB_DBG_MODULE,
115 				    "checking for %s\n", buf);
116 				if (access(buf, F_OK) == 0) {
117 					return (mdb_module_create(name, buf,
118 					    mode, NULL));
119 				}
120 			}
121 
122 			while (strisnum(p) && (p = strrchr(buf, '.')) != NULL) {
123 				*p = '\0'; /* strip trailing digits */
124 				mdb_dprintf(MDB_DBG_MODULE,
125 				    "checking for %s\n", buf);
126 				if (access(buf, F_OK) == 0) {
127 					return (mdb_module_create(name, buf,
128 					    mode, NULL));
129 				}
130 			}
131 		}
132 
133 		(void) mdb_iob_snprintf(buf, sizeof (buf), "%s/%s.so",
134 		    mdb.m_lpath[i], name);
135 
136 		mdb_dprintf(MDB_DBG_MODULE, "checking for %s\n", buf);
137 
138 		if (access(buf, F_OK) == 0)
139 			return (mdb_module_create(name, buf, mode, NULL));
140 	}
141 err:
142 	if (!(mode & MDB_MOD_SILENT))
143 		warn(wformat, name);
144 
145 	return (-1);
146 }
147 
148 typedef struct mdb_modload_data {
149 	int mld_first;
150 	int mld_mode;
151 } mdb_modload_data_t;
152 
153 /*ARGSUSED*/
154 static int
module_load(void * fp,const mdb_map_t * map,const char * fullname)155 module_load(void *fp, const mdb_map_t *map, const char *fullname)
156 {
157 	mdb_modload_data_t *mld = fp;
158 	const char *name = strbasename(fullname);
159 
160 	if (mdb_module_load(name, mld->mld_mode) == 0 && mdb.m_term != NULL) {
161 		if (mld->mld_first == TRUE) {
162 			mdb_iob_puts(mdb.m_out, "Loading modules: [");
163 			mld->mld_first = FALSE;
164 		}
165 		mdb_iob_printf(mdb.m_out, " %s", name);
166 		mdb_iob_flush(mdb.m_out);
167 	}
168 
169 	if (strstr(fullname, "/libc/") != NULL) {
170 		/*
171 		 * A bit of a kludge:  because we manage alternately capable
172 		 * libc instances by mounting the appropriately capable
173 		 * instance over /lib/libc.so.1, we may find that our object
174 		 * list does not contain libc.so.1, but rather one of its
175 		 * hwcap variants.  Unfortunately, there is not a way of
176 		 * getting from this shared object to the object that it is
177 		 * effectively interposing on -- which means that without
178 		 * special processing, we will not load any libc.so dmod.  So
179 		 * if we see that we have a shared object coming out of the
180 		 * "libc" directory, we assume that we have a "libc-like"
181 		 * object, and explicitly load the "libc.so" dmod.
182 		 */
183 		return (module_load(fp, map, "libc.so.1"));
184 	}
185 
186 	if (strstr(fullname, "ld.so") != NULL) {
187 		/*
188 		 * This is even more of a kludge. But if we find something has
189 		 * basically tried to load ld, we will always implicitly load
190 		 * the list dmod because several binaries and libraries just
191 		 * build it as a .o and include it in their ELF object.
192 		 */
193 		(void) mdb_module_load("list", mld->mld_mode);
194 	}
195 
196 	return (0);
197 }
198 
199 void
mdb_module_load_all(int mode)200 mdb_module_load_all(int mode)
201 {
202 	uint_t oflag = mdb_iob_getflags(mdb.m_out) & MDB_IOB_PGENABLE;
203 	mdb_modload_data_t mld;
204 
205 	mld.mld_first = TRUE;
206 	mld.mld_mode = mode | MDB_MOD_LOCAL | MDB_MOD_SILENT;
207 
208 	mdb_iob_clrflags(mdb.m_out, oflag);
209 
210 	(void) mdb_tgt_object_iter(mdb.m_target, module_load, &mld);
211 
212 	if (mdb.m_term != NULL && mld.mld_first == FALSE)
213 		mdb_iob_puts(mdb.m_out, " ]\n");
214 
215 	mdb_iob_setflags(mdb.m_out, oflag);
216 }
217 
218 /*ARGSUSED*/
219 int
mdb_module_unload(const char * name,int mode)220 mdb_module_unload(const char *name, int mode)
221 {
222 	ASSERT((mode & ~MDB_MOD_SILENT) == 0);
223 
224 	return (mdb_module_unload_common(name));
225 }
226