Rev 3686 | Go to most recent revision | Only display areas with differences | Ignore whitespace | Details | Blame | Last modification | View Log | RSS feed
Rev 3686 | Rev 3689 | ||
---|---|---|---|
1 | /* |
1 | /* |
2 | * Copyright (c) 2008 Jiri Svoboda |
2 | * Copyright (c) 2008 Jiri Svoboda |
3 | * All rights reserved. |
3 | * All rights reserved. |
4 | * |
4 | * |
5 | * Redistribution and use in source and binary forms, with or without |
5 | * Redistribution and use in source and binary forms, with or without |
6 | * modification, are permitted provided that the following conditions |
6 | * modification, are permitted provided that the following conditions |
7 | * are met: |
7 | * are met: |
8 | * |
8 | * |
9 | * - Redistributions of source code must retain the above copyright |
9 | * - Redistributions of source code must retain the above copyright |
10 | * notice, this list of conditions and the following disclaimer. |
10 | * notice, this list of conditions and the following disclaimer. |
11 | * - Redistributions in binary form must reproduce the above copyright |
11 | * - Redistributions in binary form must reproduce the above copyright |
12 | * notice, this list of conditions and the following disclaimer in the |
12 | * notice, this list of conditions and the following disclaimer in the |
13 | * documentation and/or other materials provided with the distribution. |
13 | * documentation and/or other materials provided with the distribution. |
14 | * - The name of the author may not be used to endorse or promote products |
14 | * - The name of the author may not be used to endorse or promote products |
15 | * derived from this software without specific prior written permission. |
15 | * derived from this software without specific prior written permission. |
16 | * |
16 | * |
17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
27 | */ |
27 | */ |
28 | 28 | ||
29 | /** @addtogroup rtld rtld |
29 | /** @addtogroup rtld rtld |
30 | * @brief |
30 | * @brief |
31 | * @{ |
31 | * @{ |
32 | */ |
32 | */ |
33 | /** |
33 | /** |
34 | * @file |
34 | * @file |
35 | */ |
35 | */ |
36 | 36 | ||
37 | #include <stdio.h> |
37 | #include <stdio.h> |
38 | #include <stdlib.h> |
38 | #include <stdlib.h> |
39 | #include <string.h> |
39 | #include <string.h> |
40 | 40 | ||
41 | #include <rtld.h> |
41 | #include <rtld.h> |
42 | #include <symbol.h> |
42 | #include <symbol.h> |
43 | #include <elf.h> |
43 | #include <elf.h> |
44 | 44 | ||
45 | /* |
45 | /* |
46 | * Hash tables are 32-bit (elf_word) even for 64-bit ELF files. |
46 | * Hash tables are 32-bit (elf_word) even for 64-bit ELF files. |
47 | */ |
47 | */ |
48 | static elf_word elf_hash(const unsigned char *name) |
48 | static elf_word elf_hash(const unsigned char *name) |
49 | { |
49 | { |
50 | elf_word h = 0, g; |
50 | elf_word h = 0, g; |
51 | 51 | ||
52 | while (*name) { |
52 | while (*name) { |
53 | h = (h << 4) + *name++; |
53 | h = (h << 4) + *name++; |
54 | g = h & 0xf0000000; |
54 | g = h & 0xf0000000; |
55 | if (g != 0) h ^= g >> 24; |
55 | if (g != 0) h ^= g >> 24; |
56 | h &= ~g; |
56 | h &= ~g; |
57 | } |
57 | } |
58 | 58 | ||
59 | return h; |
59 | return h; |
60 | } |
60 | } |
61 | 61 | ||
62 | static elf_symbol_t *def_find_in_module(char *name, module_t *m) |
62 | static elf_symbol_t *def_find_in_module(char *name, module_t *m) |
63 | { |
63 | { |
64 | elf_symbol_t *sym_table; |
64 | elf_symbol_t *sym_table; |
65 | elf_symbol_t *s, *sym; |
65 | elf_symbol_t *s, *sym; |
66 | elf_word nbucket; |
66 | elf_word nbucket; |
67 | elf_word nchain; |
67 | elf_word nchain; |
68 | elf_word i; |
68 | elf_word i; |
69 | char *s_name; |
69 | char *s_name; |
70 | elf_word bucket; |
70 | elf_word bucket; |
71 | 71 | ||
72 | // module_name = m->dyn.soname; |
72 | // module_name = m->dyn.soname; |
73 | // DPRINTF("def_find_in_module('%s', %s)\n", name, module_name); |
73 | DPRINTF("def_find_in_module('%s', %s)\n", name, module_name); |
74 | 74 | ||
75 | sym_table = m->dyn.sym_tab; |
75 | sym_table = m->dyn.sym_tab; |
76 | nbucket = m->dyn.hash[0]; |
76 | nbucket = m->dyn.hash[0]; |
77 | nchain = m->dyn.hash[1]; |
77 | nchain = m->dyn.hash[1]; |
78 | 78 | ||
79 | bucket = elf_hash((unsigned char *)name) % nbucket; |
79 | bucket = elf_hash((unsigned char *)name) % nbucket; |
80 | i = m->dyn.hash[2 + bucket]; |
80 | i = m->dyn.hash[2 + bucket]; |
81 | 81 | ||
82 | sym = NULL; |
82 | sym = NULL; |
83 | while (i != STN_UNDEF) { |
83 | while (i != STN_UNDEF) { |
84 | s = &sym_table[i]; |
84 | s = &sym_table[i]; |
85 | s_name = m->dyn.str_tab + s->st_name; |
85 | s_name = m->dyn.str_tab + s->st_name; |
86 | 86 | ||
87 | if (strcmp(name, s_name) == 0) { |
87 | if (strcmp(name, s_name) == 0) { |
88 | sym = s; |
88 | sym = s; |
89 | break; |
89 | break; |
90 | } |
90 | } |
91 | 91 | ||
92 | i = m->dyn.hash[2 + nbucket + i]; |
92 | i = m->dyn.hash[2 + nbucket + i]; |
93 | } |
93 | } |
94 | 94 | ||
95 | if (!sym) |
95 | if (!sym) |
96 | return NULL; /* Not found */ |
96 | return NULL; /* Not found */ |
97 | 97 | ||
98 | if (sym->st_shndx == SHN_UNDEF) { |
98 | if (sym->st_shndx == SHN_UNDEF) { |
99 | /* Not a definition */ |
99 | /* Not a definition */ |
100 | return NULL; |
100 | return NULL; |
101 | } |
101 | } |
102 | 102 | ||
103 | return sym; /* Found */ |
103 | return sym; /* Found */ |
104 | } |
104 | } |
105 | 105 | ||
106 | /** Find the definition of a symbol. |
106 | /** Find the definition of a symbol in a module and its deps. |
107 | * |
107 | * |
108 | * By definition in System V ABI, if module origin has the flag DT_SYMBOLIC, |
- | |
109 | * origin is searched first. Otherwise, or if the symbol hasn't been found, |
108 | * Search the module dependency graph is breadth-first, beginning |
110 | * the module dependency graph is searched breadth-first, beginning |
109 | * from the module @a start. Thus, @start and all its dependencies |
111 | * from the executable program. |
110 | * get searched. |
112 | * |
111 | * |
113 | * @param name Name of the symbol to search for. |
112 | * @param name Name of the symbol to search for. |
114 | * @param origin Module in which the dependency originates. |
113 | * @param start Module in which to start the search.. |
115 | * @param mod (output) Will be filled with a pointer to the module |
114 | * @param mod (output) Will be filled with a pointer to the module |
116 | * that contains the symbol. |
115 | * that contains the symbol. |
117 | */ |
116 | */ |
118 | elf_symbol_t *symbol_def_find(char *name, module_t *origin, module_t **mod) |
117 | elf_symbol_t *symbol_bfs_find(char *name, module_t *start, module_t **mod) |
119 | { |
118 | { |
120 | module_t *m, *dm; |
119 | module_t *m, *dm; |
121 | elf_symbol_t *sym, *s; |
120 | elf_symbol_t *sym, *s; |
122 | link_t queue_head; |
121 | link_t queue_head; |
123 | size_t i; |
122 | size_t i; |
124 | 123 | ||
125 | if (origin->dyn.symbolic) { |
- | |
126 | /* |
- | |
127 | * Origin module has a DT_SYMBOLIC flag. |
- | |
128 | * Try this module first |
- | |
129 | */ |
- | |
130 | s = def_find_in_module(name, origin); |
- | |
131 | if (s != NULL) { |
- | |
132 | /* Found */ |
- | |
133 | *mod = origin; |
- | |
134 | return s; |
- | |
135 | } |
- | |
136 | } |
- | |
137 | - | ||
138 | /* Otherwise start in the executable program */ |
- | |
139 | - | ||
140 | /* |
124 | /* |
141 | * Do a BFS using the queue_link and bfs_tag fields. |
125 | * Do a BFS using the queue_link and bfs_tag fields. |
142 | * Vertices (modules) are tagged the moment they are inserted |
126 | * Vertices (modules) are tagged the moment they are inserted |
143 | * into the queue. This prevents from visiting the same vertex |
127 | * into the queue. This prevents from visiting the same vertex |
144 | * more times in case of circular dependencies. |
128 | * more times in case of circular dependencies. |
145 | */ |
129 | */ |
146 | 130 | ||
147 | /* Mark all vertices (modules) as unvisited */ |
131 | /* Mark all vertices (modules) as unvisited */ |
148 | modules_untag(); |
132 | modules_untag(); |
149 | 133 | ||
150 | /* Insert root (the program) into the queue and tag it */ |
134 | /* Insert root (the program) into the queue and tag it */ |
151 | list_initialize(&queue_head); |
135 | list_initialize(&queue_head); |
152 | runtime_env->program->bfs_tag = true; |
136 | start->bfs_tag = true; |
153 | list_append(&runtime_env->program->queue_link, &queue_head); |
137 | list_append(&start->queue_link, &queue_head); |
154 | 138 | ||
155 | /* If the symbol is found, it will be stored in 'sym' */ |
139 | /* If the symbol is found, it will be stored in 'sym' */ |
156 | sym = NULL; |
140 | sym = NULL; |
157 | 141 | ||
158 | /* While queue is not empty */ |
142 | /* While queue is not empty */ |
159 | while (!list_empty(&queue_head)) { |
143 | while (!list_empty(&queue_head)) { |
160 | /* Pop first element from the queue */ |
144 | /* Pop first element from the queue */ |
161 | m = list_get_instance(queue_head.next, module_t, queue_link); |
145 | m = list_get_instance(queue_head.next, module_t, queue_link); |
162 | list_remove(&m->queue_link); |
146 | list_remove(&m->queue_link); |
163 | 147 | ||
164 | s = def_find_in_module(name, m); |
148 | s = def_find_in_module(name, m); |
165 | if (s != NULL) { |
149 | if (s != NULL) { |
166 | /* Symbol found */ |
150 | /* Symbol found */ |
167 | sym = s; |
151 | sym = s; |
168 | *mod = m; |
152 | *mod = m; |
169 | break; |
153 | break; |
170 | } |
154 | } |
171 | 155 | ||
172 | /* |
156 | /* |
173 | * Insert m's untagged dependencies into the queue |
157 | * Insert m's untagged dependencies into the queue |
174 | * and tag them. |
158 | * and tag them. |
175 | */ |
159 | */ |
176 | for (i = 0; i < m->n_deps; ++i) { |
160 | for (i = 0; i < m->n_deps; ++i) { |
177 | dm = m->deps[i]; |
161 | dm = m->deps[i]; |
178 | 162 | ||
179 | if (dm->bfs_tag == false) { |
163 | if (dm->bfs_tag == false) { |
180 | dm->bfs_tag = true; |
164 | dm->bfs_tag = true; |
181 | list_append(&dm->queue_link, &queue_head); |
165 | list_append(&dm->queue_link, &queue_head); |
182 | } |
166 | } |
183 | } |
167 | } |
184 | } |
168 | } |
185 | 169 | ||
186 | /* Empty the queue so that we leave it in a clean state */ |
170 | /* Empty the queue so that we leave it in a clean state */ |
187 | while (!list_empty(&queue_head)) |
171 | while (!list_empty(&queue_head)) |
188 | list_remove(queue_head.next); |
172 | list_remove(queue_head.next); |
189 | 173 | ||
190 | if (!sym) { |
174 | if (!sym) { |
191 | printf("Error, symbol '%s' not found anywhere\n", name); |
175 | printf("Error, symbol '%s' not found anywhere\n", name); |
192 | exit(1); |
176 | exit(1); |
193 | return NULL; /* Not found */ |
177 | return NULL; /* Not found */ |
194 | } |
178 | } |
195 | 179 | ||
196 | return sym; /* Symbol found */ |
180 | return sym; /* Symbol found */ |
197 | } |
181 | } |
- | 182 | ||
- | 183 | ||
- | 184 | /** Find the definition of a symbol.. |
|
- | 185 | * |
|
- | 186 | * By definition in System V ABI, if module origin has the flag DT_SYMBOLIC, |
|
- | 187 | * origin is searched first. Otherwise, or if the symbol hasn't been found, |
|
- | 188 | * the module dependency graph is searched breadth-first, beginning |
|
- | 189 | * from the executable program. |
|
- | 190 | * |
|
- | 191 | * @param name Name of the symbol to search for. |
|
- | 192 | * @param origin Module in which the dependency originates. |
|
- | 193 | * @param mod (output) Will be filled with a pointer to the module |
|
- | 194 | * that contains the symbol. |
|
- | 195 | */ |
|
- | 196 | elf_symbol_t *symbol_def_find(char *name, module_t *origin, module_t **mod) |
|
- | 197 | { |
|
- | 198 | module_t *m, *dm; |
|
- | 199 | elf_symbol_t *sym, *s; |
|
- | 200 | link_t queue_head; |
|
- | 201 | size_t i; |
|
- | 202 | ||
- | 203 | if (origin->dyn.symbolic) { |
|
- | 204 | /* |
|
- | 205 | * Origin module has a DT_SYMBOLIC flag. |
|
- | 206 | * Try this module first |
|
- | 207 | */ |
|
- | 208 | s = def_find_in_module(name, origin); |
|
- | 209 | if (s != NULL) { |
|
- | 210 | /* Found */ |
|
- | 211 | *mod = origin; |
|
- | 212 | return s; |
|
- | 213 | } |
|
- | 214 | } |
|
- | 215 | ||
- | 216 | /* Otherwise start in the executable program */ |
|
- | 217 | return symbol_bfs_find(name, runtime_env->program, mod); |
|
- | 218 | } |
|
198 | 219 | ||
199 | uintptr_t symbol_get_addr(elf_symbol_t *sym, module_t *m) |
220 | uintptr_t symbol_get_addr(elf_symbol_t *sym, module_t *m) |
200 | { |
221 | { |
201 | if (sym->st_shndx == SHN_ABS) { |
222 | if (sym->st_shndx == SHN_ABS) { |
202 | /* Do not add bias to absolute symbols */ |
223 | /* Do not add bias to absolute symbols */ |
203 | return sym->st_value; |
224 | return sym->st_value; |
204 | } else { |
225 | } else { |
205 | return sym->st_value + m->bias; |
226 | return sym->st_value + m->bias; |
206 | } |
227 | } |
207 | } |
228 | } |
208 | 229 | ||
209 | /** @} |
230 | /** @} |
210 | */ |
231 | */ |
211 | 232 |