xref: /titanic_41/usr/src/cmd/sgs/librtld/common/dynamic.c (revision 678453a8ed49104d8adad58f3ba591bdc39883e8)
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  * Update any dynamic entry offsets.  One issue with dynamic entries is that
27  * you only know whether they refer to a value or an offset if you know each
28  * type.  Thus we check for all types we know about, it a type is found that
29  * we don't know about then return and error as we have no idea what to do.
30  */
31 #pragma ident	"%Z%%M%	%I%	%E% SMI"
32 
33 #include	<libelf.h>
34 #include	<link.h>
35 #include	"libld.h"
36 #include	"msg.h"
37 #include	"rtld.h"
38 #include	"_librtld.h"
39 
40 int
41 update_dynamic(Cache *cache, Cache *_cache, Rt_map *lmp, int flags,
42     Addr addr, Off off, const char *file, Xword null, Xword data, Xword func,
43     Xword entsize, Xword checksum)
44 {
45 	Dyn		*dyn = (Dyn *)_cache->c_data->d_buf, *posdyn = 0;
46 	const char	*strs;
47 	Cache		*__cache;
48 
49 	/*
50 	 * If we're dealing with an object that might have bound to an external
51 	 * dependency establish our string table for possible NEEDED processing.
52 	 */
53 	if (flags & RTLD_REL_DEPENDS) {
54 		__cache = &cache[_cache->c_shdr->sh_link];
55 		strs = (const char *)__cache->c_data->d_buf;
56 	}
57 
58 	/*
59 	 * Loop through the dynamic table updating all offsets.
60 	 */
61 	while (dyn->d_tag != DT_NULL) {
62 		switch ((Xword)dyn->d_tag) {
63 		case DT_NEEDED:
64 			if (posdyn) {
65 				Rt_map	*dlmp;
66 
67 				/*
68 				 * Determine whether this dependency has been
69 				 * loaded (this is the most generic way to check
70 				 * any alias names), and if it has been bound
71 				 * to, undo any lazy-loading position flag.
72 				 */
73 				if (dlmp = is_so_loaded(LIST(lmp),
74 				    (strs + dyn->d_un.d_val), NULL)) {
75 					Bnd_desc	*bdp;
76 					Aliste		idx;
77 
78 					for (APLIST_TRAVERSE(DEPENDS(lmp), idx,
79 					    bdp)) {
80 						if (dlmp == bdp->b_depend) {
81 							posdyn->d_un.d_val &=
82 							    ~DF_P1_LAZYLOAD;
83 							break;
84 						}
85 					}
86 				}
87 			}
88 			break;
89 
90 		case DT_RELAENT:
91 		case DT_STRSZ:
92 		case DT_SYMENT:
93 		case DT_SONAME:
94 		case DT_RPATH:
95 		case DT_SYMBOLIC:
96 		case DT_RELENT:
97 		case DT_PLTREL:
98 		case DT_TEXTREL:
99 		case DT_VERDEFNUM:
100 		case DT_VERNEEDNUM:
101 		case DT_AUXILIARY:
102 		case DT_USED:
103 		case DT_FILTER:
104 		case DT_DEPRECATED_SPARC_REGISTER:
105 		case M_DT_REGISTER:
106 		case DT_BIND_NOW:
107 		case DT_INIT_ARRAYSZ:
108 		case DT_FINI_ARRAYSZ:
109 		case DT_RUNPATH:
110 		case DT_FLAGS:
111 		case DT_CONFIG:
112 		case DT_DEPAUDIT:
113 		case DT_AUDIT:
114 		case DT_SUNW_SYMSZ:
115 			break;
116 		case DT_PLTGOT:
117 		case DT_HASH:
118 		case DT_STRTAB:
119 		case DT_SYMTAB:
120 		case DT_SUNW_SYMTAB:
121 		case DT_INIT:
122 		case DT_FINI:
123 		case DT_VERSYM:
124 		case DT_VERDEF:
125 		case DT_VERNEED:
126 		case DT_INIT_ARRAY:
127 		case DT_FINI_ARRAY:
128 			dyn->d_un.d_ptr += addr;
129 			break;
130 
131 		/*
132 		 * If the memory image is being used, this element would have
133 		 * been initialized to the runtime linkers internal link-map
134 		 * list.  Clear it.
135 		 */
136 		case DT_DEBUG:
137 			dyn->d_un.d_val = 0;
138 			break;
139 
140 		/*
141 		 * The number of relocations may have been reduced if
142 		 * relocations have been saved in the new image.  Thus we
143 		 * compute the new relocation size and start.
144 		 */
145 		case DT_RELASZ:
146 		case DT_RELSZ:
147 			dyn->d_un.d_val = ((data + func) * entsize);
148 			break;
149 
150 		case DT_RELA:
151 		case DT_REL:
152 			dyn->d_un.d_ptr = (addr + off + (null * entsize));
153 			break;
154 
155 		/*
156 		 * If relative relocations have been processed clear the count.
157 		 */
158 		case DT_RELACOUNT:
159 		case DT_RELCOUNT:
160 			if (flags & RTLD_REL_RELATIVE)
161 				dyn->d_un.d_val = 0;
162 			break;
163 
164 		case DT_PLTRELSZ:
165 			dyn->d_un.d_val = (func * entsize);
166 			break;
167 
168 		case DT_JMPREL:
169 			dyn->d_un.d_ptr = (addr + off +
170 			    ((null + data) * entsize));
171 			break;
172 
173 		/*
174 		 * Recompute the images elf checksum.
175 		 */
176 		case DT_CHECKSUM:
177 			dyn->d_un.d_val = checksum;
178 			break;
179 
180 		/*
181 		 * If a flag entry is available, indicate if this image has
182 		 * been generated via the configuration process (crle(1)).
183 		 * Because we only started depositing DT_FLAGS_1 entries in all
184 		 * objects starting with Solaris 8, set a feature flag if it
185 		 * is present (these got added in Solaris 7).
186 		 * The runtime linker may use this flag to search for a local
187 		 * configuration file - this is only meaningful in executables
188 		 * but the flag has value for identifying images regardless.
189 		 *
190 		 * If this file is acting as a filter, and dependency
191 		 * relocations have been processed (a filter is thought of as a
192 		 * dependency in terms of symbol binding), we may have bound to
193 		 * the filtee, and hence carried out the relocation.  Indicate
194 		 * that the filtee must be preloaded, as the .plt won't get
195 		 * exercised to cause its normal loading.
196 		 */
197 		case DT_FLAGS_1:
198 			if (flags & RTLD_CONFSET)
199 				dyn->d_un.d_val |= DF_1_CONFALT;
200 			if ((flags & RTLD_REL_DEPENDS) &&
201 			    (FLAGS1(lmp)) & MSK_RT_FILTER)
202 				dyn->d_un.d_val |= DF_1_LOADFLTR;
203 			break;
204 
205 		case DT_FEATURE_1:
206 			if (flags & RTLD_CONFSET)
207 				dyn->d_un.d_val |= DTF_1_CONFEXP;
208 			break;
209 
210 		/*
211 		 * If a position flag is available save it for possible update
212 		 * when processing the next NEEDED tag.
213 		 */
214 		case DT_POSFLAG_1:
215 			if (flags & RTLD_REL_DEPENDS) {
216 				posdyn = dyn++;
217 				continue;
218 			}
219 			break;
220 
221 		/*
222 		 * Collect the defaults.
223 		 */
224 		default:
225 			/*
226 			 * If d_val is used, don't touch.
227 			 */
228 			if ((dyn->d_tag >= DT_VALRNGLO) &&
229 			    (dyn->d_tag <= DT_VALRNGHI))
230 				break;
231 
232 			/*
233 			 * If d_ptr is used, adjust.  Note, some entries that
234 			 * fell into this range are offsets into the dynamic
235 			 * string table.  Although these would need modifying
236 			 * if the section itself were resized, there is no
237 			 * resizing with dldump().  Entries that correspond to
238 			 * offsets are picked off in the initial DT_ loop
239 			 * above.
240 			 */
241 			if ((dyn->d_tag >= DT_ADDRRNGLO) &&
242 			    (dyn->d_tag <= DT_ADDRRNGHI)) {
243 				dyn->d_un.d_ptr += addr;
244 				break;
245 			}
246 
247 			/*
248 			 * Check to see if this DT_ entry conforms
249 			 * to the DT_ENCODING rules.
250 			 */
251 			if ((dyn->d_tag >= DT_ENCODING) &&
252 			    (dyn->d_tag <= DT_HIOS)) {
253 				/*
254 				 * Even tag values are ADDRESS encodings
255 				 */
256 				if ((dyn->d_tag % 2) == 0) {
257 					dyn->d_un.d_ptr += addr;
258 				}
259 				break;
260 			}
261 			eprintf(LIST(lmp), ERR_WARNING,
262 			    MSG_INTL(MSG_DT_UNKNOWN), file,
263 			    EC_XWORD(dyn->d_tag));
264 			return (1);
265 		}
266 		posdyn = 0;
267 		dyn++;
268 	}
269 	return (0);
270 }
271