|
3960
|
1 /*
|
|
8750
|
2 * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.
|
|
3960
|
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
|
|
|
4 *
|
|
|
5 * This code is free software; you can redistribute it and/or modify it
|
|
|
6 * under the terms of the GNU General Public License version 2 only, as
|
|
|
7 * published by the Free Software Foundation.
|
|
|
8 *
|
|
|
9 * This code is distributed in the hope that it will be useful, but WITHOUT
|
|
|
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
|
|
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
|
|
12 * version 2 for more details (a copy is included in the LICENSE file that
|
|
|
13 * accompanied this code).
|
|
|
14 *
|
|
|
15 * You should have received a copy of the GNU General Public License version
|
|
|
16 * 2 along with this work; if not, write to the Free Software Foundation,
|
|
|
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
|
|
|
18 *
|
|
|
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
|
|
|
20 * or visit www.oracle.com if you need additional information or have any
|
|
|
21 * questions.
|
|
|
22 *
|
|
|
23 */
|
|
|
24
|
|
|
25 #include <unistd.h>
|
|
|
26 #include <search.h>
|
|
|
27 #include <stdlib.h>
|
|
|
28 #include <string.h>
|
|
|
29 #include <db.h>
|
|
|
30 #include <fcntl.h>
|
|
8750
|
31
|
|
|
32 #include "libproc_impl.h"
|
|
3960
|
33 #include "symtab.h"
|
|
8750
|
34 #ifndef __APPLE__
|
|
3960
|
35 #include "salibelf.h"
|
|
8750
|
36 #endif // __APPLE__
|
|
3960
|
37
|
|
|
38
|
|
|
39 // ----------------------------------------------------
|
|
|
40 // functions for symbol lookups
|
|
|
41 // ----------------------------------------------------
|
|
|
42
|
|
8750
|
43 typedef struct symtab_symbol {
|
|
|
44 char *name; // name like __ZThread_...
|
|
|
45 uintptr_t offset; // to loaded address
|
|
|
46 uintptr_t size; // size strlen
|
|
|
47 } symtab_symbol;
|
|
|
48
|
|
|
49 typedef struct symtab {
|
|
|
50 char *strs; // all symbols "__symbol1__'\0'__symbol2__...."
|
|
|
51 size_t num_symbols;
|
|
|
52 DB* hash_table;
|
|
|
53 symtab_symbol* symbols;
|
|
|
54 } symtab_t;
|
|
|
55
|
|
|
56 #ifdef __APPLE__
|
|
|
57
|
|
|
58 void build_search_table(symtab_t *symtab) {
|
|
|
59 int i;
|
|
|
60 for (i = 0; i < symtab->num_symbols; i++) {
|
|
|
61 DBT key, value;
|
|
|
62 key.data = symtab->symbols[i].name;
|
|
|
63 key.size = strlen(key.data) + 1;
|
|
|
64 value.data = &(symtab->symbols[i]);
|
|
|
65 value.size = sizeof(symtab_symbol);
|
|
|
66 (*symtab->hash_table->put)(symtab->hash_table, &key, &value, 0);
|
|
|
67
|
|
|
68 // check result
|
|
|
69 if (is_debug()) {
|
|
|
70 DBT rkey, rvalue;
|
|
|
71 char* tmp = (char *)malloc(strlen(symtab->symbols[i].name) + 1);
|
|
|
72 strcpy(tmp, symtab->symbols[i].name);
|
|
|
73 rkey.data = tmp;
|
|
|
74 rkey.size = strlen(tmp) + 1;
|
|
|
75 (*symtab->hash_table->get)(symtab->hash_table, &rkey, &rvalue, 0);
|
|
|
76 // we may get a copy back so compare contents
|
|
|
77 symtab_symbol *res = (symtab_symbol *)rvalue.data;
|
|
|
78 if (strcmp(res->name, symtab->symbols[i].name) ||
|
|
|
79 res->offset != symtab->symbols[i].offset ||
|
|
|
80 res->size != symtab->symbols[i].size) {
|
|
|
81 print_debug("error to get hash_table value!\n");
|
|
|
82 }
|
|
|
83 free(tmp);
|
|
|
84 }
|
|
|
85 }
|
|
|
86 }
|
|
|
87
|
|
|
88 // read symbol table from given fd.
|
|
|
89 struct symtab* build_symtab(int fd) {
|
|
|
90 symtab_t* symtab = NULL;
|
|
|
91 int i;
|
|
|
92 mach_header_64 header;
|
|
|
93 off_t image_start;
|
|
|
94
|
|
|
95 if (!get_arch_off(fd, CPU_TYPE_X86_64, &image_start)) {
|
|
|
96 print_debug("failed in get fat header\n");
|
|
|
97 return NULL;
|
|
|
98 }
|
|
|
99 lseek(fd, image_start, SEEK_SET);
|
|
|
100 if (read(fd, (void *)&header, sizeof(mach_header_64)) != sizeof(mach_header_64)) {
|
|
|
101 print_debug("reading header failed!\n");
|
|
|
102 return NULL;
|
|
|
103 }
|
|
|
104 // header
|
|
|
105 if (header.magic != MH_MAGIC_64) {
|
|
|
106 print_debug("not a valid .dylib file\n");
|
|
|
107 return NULL;
|
|
|
108 }
|
|
|
109
|
|
|
110 load_command lcmd;
|
|
|
111 symtab_command symtabcmd;
|
|
|
112 nlist_64 lentry;
|
|
|
113
|
|
|
114 bool lcsymtab_exist = false;
|
|
|
115
|
|
|
116 long filepos = ltell(fd);
|
|
|
117 for (i = 0; i < header.ncmds; i++) {
|
|
|
118 lseek(fd, filepos, SEEK_SET);
|
|
|
119 if (read(fd, (void *)&lcmd, sizeof(load_command)) != sizeof(load_command)) {
|
|
|
120 print_debug("read load_command failed for file\n");
|
|
|
121 return NULL;
|
|
|
122 }
|
|
|
123 filepos += lcmd.cmdsize; // next command position
|
|
|
124 if (lcmd.cmd == LC_SYMTAB) {
|
|
|
125 lseek(fd, -sizeof(load_command), SEEK_CUR);
|
|
|
126 lcsymtab_exist = true;
|
|
|
127 break;
|
|
|
128 }
|
|
|
129 }
|
|
|
130 if (!lcsymtab_exist) {
|
|
|
131 print_debug("No symtab command found!\n");
|
|
|
132 return NULL;
|
|
|
133 }
|
|
|
134 if (read(fd, (void *)&symtabcmd, sizeof(symtab_command)) != sizeof(symtab_command)) {
|
|
|
135 print_debug("read symtab_command failed for file");
|
|
|
136 return NULL;
|
|
|
137 }
|
|
|
138 symtab = (symtab_t *)malloc(sizeof(symtab_t));
|
|
|
139 if (symtab == NULL) {
|
|
|
140 print_debug("out of memory: allocating symtab\n");
|
|
|
141 return NULL;
|
|
|
142 }
|
|
|
143
|
|
|
144 // create hash table, we use berkeley db to
|
|
|
145 // manipulate the hash table.
|
|
|
146 symtab->hash_table = dbopen(NULL, O_CREAT | O_RDWR, 0600, DB_HASH, NULL);
|
|
|
147 if (symtab->hash_table == NULL)
|
|
|
148 goto quit;
|
|
|
149
|
|
|
150 symtab->num_symbols = symtabcmd.nsyms;
|
|
|
151 symtab->symbols = (symtab_symbol *)malloc(sizeof(symtab_symbol) * symtab->num_symbols);
|
|
|
152 symtab->strs = (char *)malloc(sizeof(char) * symtabcmd.strsize);
|
|
|
153 if (symtab->symbols == NULL || symtab->strs == NULL) {
|
|
|
154 print_debug("out of memory: allocating symtab.symbol or symtab.strs\n");
|
|
|
155 goto quit;
|
|
|
156 }
|
|
|
157 lseek(fd, image_start + symtabcmd.symoff, SEEK_SET);
|
|
|
158 for (i = 0; i < symtab->num_symbols; i++) {
|
|
|
159 if (read(fd, (void *)&lentry, sizeof(nlist_64)) != sizeof(nlist_64)) {
|
|
|
160 print_debug("read nlist_64 failed at %i\n", i);
|
|
|
161 goto quit;
|
|
|
162 }
|
|
|
163 symtab->symbols[i].offset = lentry.n_value;
|
|
|
164 symtab->symbols[i].size = lentry.n_un.n_strx; // index
|
|
|
165 }
|
|
|
166
|
|
|
167 // string table
|
|
|
168 lseek(fd, image_start + symtabcmd.stroff, SEEK_SET);
|
|
|
169 int size = read(fd, (void *)(symtab->strs), symtabcmd.strsize * sizeof(char));
|
|
|
170 if (size != symtabcmd.strsize * sizeof(char)) {
|
|
|
171 print_debug("reading string table failed\n");
|
|
|
172 goto quit;
|
|
|
173 }
|
|
|
174
|
|
|
175 for (i = 0; i < symtab->num_symbols; i++) {
|
|
|
176 symtab->symbols[i].name = symtab->strs + symtab->symbols[i].size;
|
|
|
177 if (i > 0) {
|
|
|
178 // fix size
|
|
|
179 symtab->symbols[i - 1].size = symtab->symbols[i].size - symtab->symbols[i - 1].size;
|
|
|
180 print_debug("%s size = %d\n", symtab->symbols[i - 1].name, symtab->symbols[i - 1].size);
|
|
|
181
|
|
|
182 }
|
|
|
183
|
|
|
184 if (i == symtab->num_symbols - 1) {
|
|
|
185 // last index
|
|
|
186 symtab->symbols[i].size =
|
|
|
187 symtabcmd.strsize - symtab->symbols[i].size;
|
|
|
188 print_debug("%s size = %d\n", symtab->symbols[i].name, symtab->symbols[i].size);
|
|
|
189 }
|
|
|
190 }
|
|
|
191
|
|
|
192 // build a hashtable for fast query
|
|
|
193 build_search_table(symtab);
|
|
|
194 return symtab;
|
|
|
195 quit:
|
|
|
196 if (symtab) destroy_symtab(symtab);
|
|
|
197 return NULL;
|
|
|
198 }
|
|
|
199
|
|
|
200 #else // __APPLE__
|
|
|
201
|
|
3960
|
202 struct elf_section {
|
|
|
203 ELF_SHDR *c_shdr;
|
|
|
204 void *c_data;
|
|
|
205 };
|
|
|
206
|
|
|
207 // read symbol table from given fd.
|
|
|
208 struct symtab* build_symtab(int fd) {
|
|
|
209 ELF_EHDR ehdr;
|
|
|
210 struct symtab* symtab = NULL;
|
|
|
211
|
|
|
212 // Reading of elf header
|
|
|
213 struct elf_section *scn_cache = NULL;
|
|
|
214 int cnt = 0;
|
|
|
215 ELF_SHDR* shbuf = NULL;
|
|
|
216 ELF_SHDR* cursct = NULL;
|
|
|
217 ELF_PHDR* phbuf = NULL;
|
|
|
218 int symtab_found = 0;
|
|
|
219 int dynsym_found = 0;
|
|
|
220 uint32_t symsection = SHT_SYMTAB;
|
|
|
221
|
|
|
222 uintptr_t baseaddr = (uintptr_t)-1;
|
|
|
223
|
|
|
224 lseek(fd, (off_t)0L, SEEK_SET);
|
|
|
225 if (! read_elf_header(fd, &ehdr)) {
|
|
|
226 // not an elf
|
|
|
227 return NULL;
|
|
|
228 }
|
|
|
229
|
|
|
230 // read ELF header
|
|
|
231 if ((shbuf = read_section_header_table(fd, &ehdr)) == NULL) {
|
|
|
232 goto quit;
|
|
|
233 }
|
|
|
234
|
|
|
235 baseaddr = find_base_address(fd, &ehdr);
|
|
|
236
|
|
|
237 scn_cache = calloc(ehdr.e_shnum, sizeof(*scn_cache));
|
|
|
238 if (scn_cache == NULL) {
|
|
|
239 goto quit;
|
|
|
240 }
|
|
|
241
|
|
|
242 for (cursct = shbuf, cnt = 0; cnt < ehdr.e_shnum; cnt++) {
|
|
|
243 scn_cache[cnt].c_shdr = cursct;
|
|
|
244 if (cursct->sh_type == SHT_SYMTAB ||
|
|
|
245 cursct->sh_type == SHT_STRTAB ||
|
|
|
246 cursct->sh_type == SHT_DYNSYM) {
|
|
|
247 if ( (scn_cache[cnt].c_data = read_section_data(fd, &ehdr, cursct)) == NULL) {
|
|
|
248 goto quit;
|
|
|
249 }
|
|
|
250 }
|
|
|
251
|
|
|
252 if (cursct->sh_type == SHT_SYMTAB)
|
|
|
253 symtab_found++;
|
|
|
254
|
|
|
255 if (cursct->sh_type == SHT_DYNSYM)
|
|
|
256 dynsym_found++;
|
|
|
257
|
|
|
258 cursct++;
|
|
|
259 }
|
|
|
260
|
|
|
261 if (!symtab_found && dynsym_found)
|
|
|
262 symsection = SHT_DYNSYM;
|
|
|
263
|
|
|
264 for (cnt = 1; cnt < ehdr.e_shnum; cnt++) {
|
|
|
265 ELF_SHDR *shdr = scn_cache[cnt].c_shdr;
|
|
|
266
|
|
|
267 if (shdr->sh_type == symsection) {
|
|
|
268 ELF_SYM *syms;
|
|
4006
|
269 int j, n;
|
|
3960
|
270 size_t size;
|
|
|
271
|
|
|
272 // FIXME: there could be multiple data buffers associated with the
|
|
|
273 // same ELF section. Here we can handle only one buffer. See man page
|
|
|
274 // for elf_getdata on Solaris.
|
|
|
275
|
|
|
276 // guarantee(symtab == NULL, "multiple symtab");
|
|
|
277 symtab = calloc(1, sizeof(*symtab));
|
|
|
278 if (symtab == NULL) {
|
|
|
279 goto quit;
|
|
|
280 }
|
|
|
281 // the symbol table
|
|
|
282 syms = (ELF_SYM *)scn_cache[cnt].c_data;
|
|
|
283
|
|
|
284 // number of symbols
|
|
|
285 n = shdr->sh_size / shdr->sh_entsize;
|
|
|
286
|
|
|
287 // create hash table, we use berkeley db to
|
|
|
288 // manipulate the hash table.
|
|
|
289 symtab->hash_table = dbopen(NULL, O_CREAT | O_RDWR, 0600, DB_HASH, NULL);
|
|
|
290 // guarantee(symtab->hash_table, "unexpected failure: dbopen");
|
|
4006
|
291 if (symtab->hash_table == NULL)
|
|
|
292 goto bad;
|
|
3960
|
293
|
|
|
294 // shdr->sh_link points to the section that contains the actual strings
|
|
|
295 // for symbol names. the st_name field in ELF_SYM is just the
|
|
|
296 // string table index. we make a copy of the string table so the
|
|
|
297 // strings will not be destroyed by elf_end.
|
|
|
298 size = scn_cache[shdr->sh_link].c_shdr->sh_size;
|
|
|
299 symtab->strs = malloc(size);
|
|
4006
|
300 if (symtab->strs == NULL)
|
|
|
301 goto bad;
|
|
3960
|
302 memcpy(symtab->strs, scn_cache[shdr->sh_link].c_data, size);
|
|
|
303
|
|
|
304 // allocate memory for storing symbol offset and size;
|
|
|
305 symtab->num_symbols = n;
|
|
|
306 symtab->symbols = calloc(n , sizeof(*symtab->symbols));
|
|
4006
|
307 if (symtab->symbols == NULL)
|
|
|
308 goto bad;
|
|
3960
|
309
|
|
|
310 // copy symbols info our symtab and enter them info the hash table
|
|
|
311 for (j = 0; j < n; j++, syms++) {
|
|
|
312 DBT key, value;
|
|
|
313 char *sym_name = symtab->strs + syms->st_name;
|
|
|
314
|
|
|
315 // skip non-object and non-function symbols
|
|
|
316 int st_type = ELF_ST_TYPE(syms->st_info);
|
|
|
317 if ( st_type != STT_FUNC && st_type != STT_OBJECT)
|
|
|
318 continue;
|
|
|
319 // skip empty strings and undefined symbols
|
|
|
320 if (*sym_name == '\0' || syms->st_shndx == SHN_UNDEF) continue;
|
|
|
321
|
|
|
322 symtab->symbols[j].name = sym_name;
|
|
|
323 symtab->symbols[j].offset = syms->st_value - baseaddr;
|
|
|
324 symtab->symbols[j].size = syms->st_size;
|
|
|
325
|
|
|
326 key.data = sym_name;
|
|
|
327 key.size = strlen(sym_name) + 1;
|
|
|
328 value.data = &(symtab->symbols[j]);
|
|
8750
|
329 value.size = sizeof(symtab_symbol);
|
|
3960
|
330 (*symtab->hash_table->put)(symtab->hash_table, &key, &value, 0);
|
|
|
331 }
|
|
|
332 }
|
|
|
333 }
|
|
4006
|
334 goto quit;
|
|
|
335
|
|
|
336 bad:
|
|
|
337 destroy_symtab(symtab);
|
|
|
338 symtab = NULL;
|
|
3960
|
339
|
|
|
340 quit:
|
|
|
341 if (shbuf) free(shbuf);
|
|
|
342 if (phbuf) free(phbuf);
|
|
|
343 if (scn_cache) {
|
|
|
344 for (cnt = 0; cnt < ehdr.e_shnum; cnt++) {
|
|
|
345 if (scn_cache[cnt].c_data != NULL) {
|
|
|
346 free(scn_cache[cnt].c_data);
|
|
|
347 }
|
|
|
348 }
|
|
|
349 free(scn_cache);
|
|
|
350 }
|
|
|
351 return symtab;
|
|
|
352 }
|
|
|
353
|
|
8750
|
354 #endif // __APPLE__
|
|
|
355
|
|
|
356 void destroy_symtab(symtab_t* symtab) {
|
|
3960
|
357 if (!symtab) return;
|
|
8750
|
358 free(symtab->strs);
|
|
|
359 free(symtab->symbols);
|
|
3960
|
360 free(symtab);
|
|
|
361 }
|
|
|
362
|
|
8750
|
363 uintptr_t search_symbol(struct symtab* symtab, uintptr_t base, const char *sym_name, int *sym_size) {
|
|
3960
|
364 DBT key, value;
|
|
|
365 int ret;
|
|
|
366
|
|
|
367 // library does not have symbol table
|
|
8750
|
368 if (!symtab || !symtab->hash_table) {
|
|
3960
|
369 return 0;
|
|
8750
|
370 }
|
|
3960
|
371
|
|
|
372 key.data = (char*)(uintptr_t)sym_name;
|
|
|
373 key.size = strlen(sym_name) + 1;
|
|
|
374 ret = (*symtab->hash_table->get)(symtab->hash_table, &key, &value, 0);
|
|
|
375 if (ret == 0) {
|
|
8750
|
376 symtab_symbol *sym = value.data;
|
|
3960
|
377 uintptr_t rslt = (uintptr_t) ((char*)base + sym->offset);
|
|
|
378 if (sym_size) *sym_size = sym->size;
|
|
|
379 return rslt;
|
|
|
380 }
|
|
|
381
|
|
|
382 return 0;
|
|
|
383 }
|
|
|
384
|
|
|
385 const char* nearest_symbol(struct symtab* symtab, uintptr_t offset,
|
|
|
386 uintptr_t* poffset) {
|
|
|
387 int n = 0;
|
|
|
388 if (!symtab) return NULL;
|
|
|
389 for (; n < symtab->num_symbols; n++) {
|
|
8750
|
390 symtab_symbol* sym = &(symtab->symbols[n]);
|
|
4006
|
391 if (sym->name != NULL &&
|
|
|
392 offset >= sym->offset && offset < sym->offset + sym->size) {
|
|
|
393 if (poffset) *poffset = (offset - sym->offset);
|
|
|
394 return sym->name;
|
|
|
395 }
|
|
3960
|
396 }
|
|
|
397 return NULL;
|
|
|
398 }
|
