Go to most recent revision | Details | Last modification | View Log | RSS feed
Rev | Author | Line No. | Line |
---|---|---|---|
5199 | serge | 1 | /* Plugin control for the GNU linker. |
2 | Copyright 2010, 2011, 2012, 2013 Free Software Foundation, Inc. |
||
3 | |||
4 | This file is part of the GNU Binutils. |
||
5 | |||
6 | This program is free software; you can redistribute it and/or modify |
||
7 | it under the terms of the GNU General Public License as published by |
||
8 | the Free Software Foundation; either version 3 of the License, or |
||
9 | (at your option) any later version. |
||
10 | |||
11 | This program is distributed in the hope that it will be useful, |
||
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
||
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
||
14 | GNU General Public License for more details. |
||
15 | |||
16 | You should have received a copy of the GNU General Public License |
||
17 | along with this program; if not, write to the Free Software |
||
18 | Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, |
||
19 | MA 02110-1301, USA. */ |
||
20 | |||
21 | #include "sysdep.h" |
||
22 | #include "libiberty.h" |
||
23 | #include "bfd.h" |
||
24 | #include "bfdlink.h" |
||
25 | #include "bfdver.h" |
||
26 | #include "ld.h" |
||
27 | #include "ldmain.h" |
||
28 | #include "ldmisc.h" |
||
29 | #include "ldexp.h" |
||
30 | #include "ldlang.h" |
||
31 | #include "ldfile.h" |
||
32 | #include "plugin.h" |
||
33 | #include "plugin-api.h" |
||
34 | #include "elf-bfd.h" |
||
35 | #if !defined (HAVE_DLFCN_H) && defined (HAVE_WINDOWS_H) |
||
36 | #include |
||
37 | #endif |
||
38 | |||
39 | /* Report plugin symbols. */ |
||
40 | bfd_boolean report_plugin_symbols; |
||
41 | |||
42 | /* The suffix to append to the name of the real (claimed) object file |
||
43 | when generating a dummy BFD to hold the IR symbols sent from the |
||
44 | plugin. For cosmetic use only; appears in maps, crefs etc. */ |
||
45 | #define IRONLY_SUFFIX " (symbol from plugin)" |
||
46 | |||
47 | /* Stores a single argument passed to a plugin. */ |
||
48 | typedef struct plugin_arg |
||
49 | { |
||
50 | struct plugin_arg *next; |
||
51 | const char *arg; |
||
52 | } plugin_arg_t; |
||
53 | |||
54 | /* Holds all details of a single plugin. */ |
||
55 | typedef struct plugin |
||
56 | { |
||
57 | /* Next on the list of plugins, or NULL at end of chain. */ |
||
58 | struct plugin *next; |
||
59 | /* The argument string given to --plugin. */ |
||
60 | const char *name; |
||
61 | /* The shared library handle returned by dlopen. */ |
||
62 | void *dlhandle; |
||
63 | /* The list of argument string given to --plugin-opt. */ |
||
64 | plugin_arg_t *args; |
||
65 | /* Number of args in the list, for convenience. */ |
||
66 | size_t n_args; |
||
67 | /* The plugin's event handlers. */ |
||
68 | ld_plugin_claim_file_handler claim_file_handler; |
||
69 | ld_plugin_all_symbols_read_handler all_symbols_read_handler; |
||
70 | ld_plugin_cleanup_handler cleanup_handler; |
||
71 | /* TRUE if the cleanup handlers have been called. */ |
||
72 | bfd_boolean cleanup_done; |
||
73 | } plugin_t; |
||
74 | |||
75 | /* The master list of all plugins. */ |
||
76 | static plugin_t *plugins_list = NULL; |
||
77 | |||
78 | /* We keep a tail pointer for easy linking on the end. */ |
||
79 | static plugin_t **plugins_tail_chain_ptr = &plugins_list; |
||
80 | |||
81 | /* The last plugin added to the list, for receiving args. */ |
||
82 | static plugin_t *last_plugin = NULL; |
||
83 | |||
84 | /* The tail of the arg chain of the last plugin added to the list. */ |
||
85 | static plugin_arg_t **last_plugin_args_tail_chain_ptr = NULL; |
||
86 | |||
87 | /* The plugin which is currently having a callback executed. */ |
||
88 | static plugin_t *called_plugin = NULL; |
||
89 | |||
90 | /* Last plugin to cause an error, if any. */ |
||
91 | static const char *error_plugin = NULL; |
||
92 | |||
93 | /* State of linker "notice" interface before we poked at it. */ |
||
94 | static bfd_boolean orig_notice_all; |
||
95 | |||
96 | /* Original linker callbacks, and the plugin version. */ |
||
97 | static const struct bfd_link_callbacks *orig_callbacks; |
||
98 | static struct bfd_link_callbacks plugin_callbacks; |
||
99 | |||
100 | /* Set at all symbols read time, to avoid recursively offering the plugin |
||
101 | its own newly-added input files and libs to claim. */ |
||
102 | bfd_boolean no_more_claiming = FALSE; |
||
103 | |||
104 | /* List of tags to set in the constant leading part of the tv array. */ |
||
105 | static const enum ld_plugin_tag tv_header_tags[] = |
||
106 | { |
||
107 | LDPT_MESSAGE, |
||
108 | LDPT_API_VERSION, |
||
109 | LDPT_GNU_LD_VERSION, |
||
110 | LDPT_LINKER_OUTPUT, |
||
111 | LDPT_OUTPUT_NAME, |
||
112 | LDPT_REGISTER_CLAIM_FILE_HOOK, |
||
113 | LDPT_REGISTER_ALL_SYMBOLS_READ_HOOK, |
||
114 | LDPT_REGISTER_CLEANUP_HOOK, |
||
115 | LDPT_ADD_SYMBOLS, |
||
116 | LDPT_GET_INPUT_FILE, |
||
117 | LDPT_RELEASE_INPUT_FILE, |
||
118 | LDPT_GET_SYMBOLS, |
||
119 | LDPT_GET_SYMBOLS_V2, |
||
120 | LDPT_ADD_INPUT_FILE, |
||
121 | LDPT_ADD_INPUT_LIBRARY, |
||
122 | LDPT_SET_EXTRA_LIBRARY_PATH |
||
123 | }; |
||
124 | |||
125 | /* How many entries in the constant leading part of the tv array. */ |
||
126 | static const size_t tv_header_size = ARRAY_SIZE (tv_header_tags); |
||
127 | |||
128 | /* Forward references. */ |
||
129 | static bfd_boolean plugin_notice (struct bfd_link_info *, |
||
130 | struct bfd_link_hash_entry *, bfd *, |
||
131 | asection *, bfd_vma, flagword, const char *); |
||
132 | |||
133 | #if !defined (HAVE_DLFCN_H) && defined (HAVE_WINDOWS_H) |
||
134 | |||
135 | #define RTLD_NOW 0 /* Dummy value. */ |
||
136 | |||
137 | static void * |
||
138 | dlopen (const char *file, int mode ATTRIBUTE_UNUSED) |
||
139 | { |
||
140 | return LoadLibrary (file); |
||
141 | } |
||
142 | |||
143 | static void * |
||
144 | dlsym (void *handle, const char *name) |
||
145 | { |
||
146 | return GetProcAddress (handle, name); |
||
147 | } |
||
148 | |||
149 | static int |
||
150 | dlclose (void *handle) |
||
151 | { |
||
152 | FreeLibrary (handle); |
||
153 | return 0; |
||
154 | } |
||
155 | |||
156 | #endif /* !defined (HAVE_DLFCN_H) && defined (HAVE_WINDOWS_H) */ |
||
157 | |||
158 | #ifndef HAVE_DLFCN_H |
||
159 | static const char * |
||
160 | dlerror (void) |
||
161 | { |
||
162 | return ""; |
||
163 | } |
||
164 | #endif |
||
165 | |||
166 | /* Helper function for exiting with error status. */ |
||
167 | static int |
||
168 | set_plugin_error (const char *plugin) |
||
169 | { |
||
170 | error_plugin = plugin; |
||
171 | return -1; |
||
172 | } |
||
173 | |||
174 | /* Test if an error occurred. */ |
||
175 | static bfd_boolean |
||
176 | plugin_error_p (void) |
||
177 | { |
||
178 | return error_plugin != NULL; |
||
179 | } |
||
180 | |||
181 | /* Return name of plugin which caused an error if any. */ |
||
182 | const char * |
||
183 | plugin_error_plugin (void) |
||
184 | { |
||
185 | return error_plugin ? error_plugin : _(" |
||
186 | } |
||
187 | |||
188 | /* Handle -plugin arg: find and load plugin, or return error. */ |
||
189 | void |
||
190 | plugin_opt_plugin (const char *plugin) |
||
191 | { |
||
192 | plugin_t *newplug; |
||
193 | |||
194 | newplug = xmalloc (sizeof *newplug); |
||
195 | memset (newplug, 0, sizeof *newplug); |
||
196 | newplug->name = plugin; |
||
197 | newplug->dlhandle = dlopen (plugin, RTLD_NOW); |
||
198 | if (!newplug->dlhandle) |
||
199 | einfo (_("%P%F: %s: error loading plugin: %s\n"), plugin, dlerror ()); |
||
200 | |||
201 | /* Chain on end, so when we run list it is in command-line order. */ |
||
202 | *plugins_tail_chain_ptr = newplug; |
||
203 | plugins_tail_chain_ptr = &newplug->next; |
||
204 | |||
205 | /* Record it as current plugin for receiving args. */ |
||
206 | last_plugin = newplug; |
||
207 | last_plugin_args_tail_chain_ptr = &newplug->args; |
||
208 | } |
||
209 | |||
210 | /* Accumulate option arguments for last-loaded plugin, or return |
||
211 | error if none. */ |
||
212 | int |
||
213 | plugin_opt_plugin_arg (const char *arg) |
||
214 | { |
||
215 | plugin_arg_t *newarg; |
||
216 | |||
217 | if (!last_plugin) |
||
218 | return set_plugin_error (_(" |
||
219 | |||
220 | newarg = xmalloc (sizeof *newarg); |
||
221 | newarg->arg = arg; |
||
222 | newarg->next = NULL; |
||
223 | |||
224 | /* Chain on end to preserve command-line order. */ |
||
225 | *last_plugin_args_tail_chain_ptr = newarg; |
||
226 | last_plugin_args_tail_chain_ptr = &newarg->next; |
||
227 | last_plugin->n_args++; |
||
228 | return 0; |
||
229 | } |
||
230 | |||
231 | /* Create a dummy BFD. */ |
||
232 | bfd * |
||
233 | plugin_get_ir_dummy_bfd (const char *name, bfd *srctemplate) |
||
234 | { |
||
235 | bfd *abfd; |
||
236 | |||
237 | bfd_use_reserved_id = 1; |
||
238 | abfd = bfd_create (concat (name, IRONLY_SUFFIX, (const char *) NULL), |
||
239 | srctemplate); |
||
240 | if (abfd != NULL) |
||
241 | { |
||
242 | abfd->flags |= BFD_LINKER_CREATED | BFD_PLUGIN; |
||
243 | bfd_set_arch_info (abfd, bfd_get_arch_info (srctemplate)); |
||
244 | bfd_set_gp_size (abfd, bfd_get_gp_size (srctemplate)); |
||
245 | if (bfd_make_writable (abfd) |
||
246 | && bfd_copy_private_bfd_data (srctemplate, abfd)) |
||
247 | { |
||
248 | flagword flags; |
||
249 | |||
250 | /* Create section to own the symbols. */ |
||
251 | flags = (SEC_CODE | SEC_HAS_CONTENTS | SEC_READONLY |
||
252 | | SEC_ALLOC | SEC_LOAD | SEC_KEEP | SEC_EXCLUDE); |
||
253 | if (bfd_make_section_anyway_with_flags (abfd, ".text", flags)) |
||
254 | return abfd; |
||
255 | } |
||
256 | } |
||
257 | einfo (_("could not create dummy IR bfd: %F%E\n")); |
||
258 | return NULL; |
||
259 | } |
||
260 | |||
261 | /* Check if the BFD passed in is an IR dummy object file. */ |
||
262 | static bfd_boolean |
||
263 | is_ir_dummy_bfd (const bfd *abfd) |
||
264 | { |
||
265 | /* ABFD can sometimes legitimately be NULL, e.g. when called from one |
||
266 | of the linker callbacks for a symbol in the *ABS* or *UND* sections. |
||
267 | Likewise, the usrdata field may be NULL if ABFD was added by the |
||
268 | backend without a corresponding input statement, as happens e.g. |
||
269 | when processing DT_NEEDED dependencies. */ |
||
270 | return (abfd |
||
271 | && abfd->usrdata |
||
272 | && ((lang_input_statement_type *)(abfd->usrdata))->flags.claimed); |
||
273 | } |
||
274 | |||
275 | /* Helpers to convert between BFD and GOLD symbol formats. */ |
||
276 | static enum ld_plugin_status |
||
277 | asymbol_from_plugin_symbol (bfd *abfd, asymbol *asym, |
||
278 | const struct ld_plugin_symbol *ldsym) |
||
279 | { |
||
280 | flagword flags = BSF_NO_FLAGS; |
||
281 | struct bfd_section *section; |
||
282 | |||
283 | asym->the_bfd = abfd; |
||
284 | asym->name = (ldsym->version |
||
285 | ? concat (ldsym->name, "@", ldsym->version, (const char *) NULL) |
||
286 | : ldsym->name); |
||
287 | asym->value = 0; |
||
288 | switch (ldsym->def) |
||
289 | { |
||
290 | case LDPK_WEAKDEF: |
||
291 | flags = BSF_WEAK; |
||
292 | /* FALLTHRU */ |
||
293 | case LDPK_DEF: |
||
294 | flags |= BSF_GLOBAL; |
||
295 | if (ldsym->comdat_key) |
||
296 | { |
||
297 | char *name = concat (".gnu.linkonce.t.", ldsym->comdat_key, |
||
298 | (const char *) NULL); |
||
299 | section = bfd_get_section_by_name (abfd, name); |
||
300 | if (section != NULL) |
||
301 | free (name); |
||
302 | else |
||
303 | { |
||
304 | flagword sflags; |
||
305 | |||
306 | sflags = (SEC_CODE | SEC_HAS_CONTENTS | SEC_READONLY |
||
307 | | SEC_ALLOC | SEC_LOAD | SEC_KEEP | SEC_EXCLUDE |
||
308 | | SEC_LINK_ONCE | SEC_LINK_DUPLICATES_DISCARD); |
||
309 | section = bfd_make_section_anyway_with_flags (abfd, name, sflags); |
||
310 | if (section == NULL) |
||
311 | return LDPS_ERR; |
||
312 | } |
||
313 | } |
||
314 | else |
||
315 | section = bfd_get_section_by_name (abfd, ".text"); |
||
316 | break; |
||
317 | |||
318 | case LDPK_WEAKUNDEF: |
||
319 | flags = BSF_WEAK; |
||
320 | /* FALLTHRU */ |
||
321 | case LDPK_UNDEF: |
||
322 | section = bfd_und_section_ptr; |
||
323 | break; |
||
324 | |||
325 | case LDPK_COMMON: |
||
326 | flags = BSF_GLOBAL; |
||
327 | section = bfd_com_section_ptr; |
||
328 | asym->value = ldsym->size; |
||
329 | /* For ELF targets, set alignment of common symbol to 1. */ |
||
330 | if (bfd_get_flavour (abfd) == bfd_target_elf_flavour) |
||
331 | { |
||
332 | ((elf_symbol_type *) asym)->internal_elf_sym.st_shndx = SHN_COMMON; |
||
333 | ((elf_symbol_type *) asym)->internal_elf_sym.st_value = 1; |
||
334 | } |
||
335 | break; |
||
336 | |||
337 | default: |
||
338 | return LDPS_ERR; |
||
339 | } |
||
340 | asym->flags = flags; |
||
341 | asym->section = section; |
||
342 | |||
343 | /* Visibility only applies on ELF targets. */ |
||
344 | if (bfd_get_flavour (abfd) == bfd_target_elf_flavour) |
||
345 | { |
||
346 | elf_symbol_type *elfsym = elf_symbol_from (abfd, asym); |
||
347 | unsigned char visibility; |
||
348 | |||
349 | if (!elfsym) |
||
350 | einfo (_("%P%F: %s: non-ELF symbol in ELF BFD!\n"), asym->name); |
||
351 | switch (ldsym->visibility) |
||
352 | { |
||
353 | default: |
||
354 | einfo (_("%P%F: unknown ELF symbol visibility: %d!\n"), |
||
355 | ldsym->visibility); |
||
356 | case LDPV_DEFAULT: |
||
357 | visibility = STV_DEFAULT; |
||
358 | break; |
||
359 | case LDPV_PROTECTED: |
||
360 | visibility = STV_PROTECTED; |
||
361 | break; |
||
362 | case LDPV_INTERNAL: |
||
363 | visibility = STV_INTERNAL; |
||
364 | break; |
||
365 | case LDPV_HIDDEN: |
||
366 | visibility = STV_HIDDEN; |
||
367 | break; |
||
368 | } |
||
369 | elfsym->internal_elf_sym.st_other |
||
370 | = (visibility | (elfsym->internal_elf_sym.st_other |
||
371 | & ~ELF_ST_VISIBILITY (-1))); |
||
372 | } |
||
373 | |||
374 | return LDPS_OK; |
||
375 | } |
||
376 | |||
377 | /* Register a claim-file handler. */ |
||
378 | static enum ld_plugin_status |
||
379 | register_claim_file (ld_plugin_claim_file_handler handler) |
||
380 | { |
||
381 | ASSERT (called_plugin); |
||
382 | called_plugin->claim_file_handler = handler; |
||
383 | return LDPS_OK; |
||
384 | } |
||
385 | |||
386 | /* Register an all-symbols-read handler. */ |
||
387 | static enum ld_plugin_status |
||
388 | register_all_symbols_read (ld_plugin_all_symbols_read_handler handler) |
||
389 | { |
||
390 | ASSERT (called_plugin); |
||
391 | called_plugin->all_symbols_read_handler = handler; |
||
392 | return LDPS_OK; |
||
393 | } |
||
394 | |||
395 | /* Register a cleanup handler. */ |
||
396 | static enum ld_plugin_status |
||
397 | register_cleanup (ld_plugin_cleanup_handler handler) |
||
398 | { |
||
399 | ASSERT (called_plugin); |
||
400 | called_plugin->cleanup_handler = handler; |
||
401 | return LDPS_OK; |
||
402 | } |
||
403 | |||
404 | /* Add symbols from a plugin-claimed input file. */ |
||
405 | static enum ld_plugin_status |
||
406 | add_symbols (void *handle, int nsyms, const struct ld_plugin_symbol *syms) |
||
407 | { |
||
408 | asymbol **symptrs; |
||
409 | bfd *abfd = handle; |
||
410 | int n; |
||
411 | |||
412 | ASSERT (called_plugin); |
||
413 | symptrs = xmalloc (nsyms * sizeof *symptrs); |
||
414 | for (n = 0; n < nsyms; n++) |
||
415 | { |
||
416 | enum ld_plugin_status rv; |
||
417 | asymbol *bfdsym; |
||
418 | |||
419 | bfdsym = bfd_make_empty_symbol (abfd); |
||
420 | symptrs[n] = bfdsym; |
||
421 | rv = asymbol_from_plugin_symbol (abfd, bfdsym, syms + n); |
||
422 | if (rv != LDPS_OK) |
||
423 | return rv; |
||
424 | } |
||
425 | bfd_set_symtab (abfd, symptrs, nsyms); |
||
426 | return LDPS_OK; |
||
427 | } |
||
428 | |||
429 | /* Get the input file information with an open (possibly re-opened) |
||
430 | file descriptor. */ |
||
431 | static enum ld_plugin_status |
||
432 | get_input_file (const void *handle ATTRIBUTE_UNUSED, |
||
433 | struct ld_plugin_input_file *file ATTRIBUTE_UNUSED) |
||
434 | { |
||
435 | ASSERT (called_plugin); |
||
436 | return LDPS_ERR; |
||
437 | } |
||
438 | |||
439 | /* Release the input file. */ |
||
440 | static enum ld_plugin_status |
||
441 | release_input_file (const void *handle ATTRIBUTE_UNUSED) |
||
442 | { |
||
443 | ASSERT (called_plugin); |
||
444 | return LDPS_ERR; |
||
445 | } |
||
446 | |||
447 | /* Return TRUE if a defined symbol might be reachable from outside the |
||
448 | universe of claimed objects. */ |
||
449 | static inline bfd_boolean |
||
450 | is_visible_from_outside (struct ld_plugin_symbol *lsym, |
||
451 | struct bfd_link_hash_entry *blhe) |
||
452 | { |
||
453 | struct bfd_sym_chain *sym; |
||
454 | |||
455 | if (link_info.relocatable) |
||
456 | return TRUE; |
||
457 | if (link_info.export_dynamic || !link_info.executable) |
||
458 | { |
||
459 | /* Check if symbol is hidden by version script. */ |
||
460 | if (bfd_hide_sym_by_version (link_info.version_info, |
||
461 | blhe->root.string)) |
||
462 | return FALSE; |
||
463 | /* Only ELF symbols really have visibility. */ |
||
464 | if (bfd_get_flavour (link_info.output_bfd) == bfd_target_elf_flavour) |
||
465 | { |
||
466 | struct elf_link_hash_entry *el = (struct elf_link_hash_entry *)blhe; |
||
467 | int vis = ELF_ST_VISIBILITY (el->other); |
||
468 | return vis == STV_DEFAULT || vis == STV_PROTECTED; |
||
469 | } |
||
470 | /* On non-ELF targets, we can safely make inferences by considering |
||
471 | what visibility the plugin would have liked to apply when it first |
||
472 | sent us the symbol. During ELF symbol processing, visibility only |
||
473 | ever becomes more restrictive, not less, when symbols are merged, |
||
474 | so this is a conservative estimate; it may give false positives, |
||
475 | declaring something visible from outside when it in fact would |
||
476 | not have been, but this will only lead to missed optimisation |
||
477 | opportunities during LTRANS at worst; it will not give false |
||
478 | negatives, which can lead to the disastrous conclusion that the |
||
479 | related symbol is IRONLY. (See GCC PR46319 for an example.) */ |
||
480 | return (lsym->visibility == LDPV_DEFAULT |
||
481 | || lsym->visibility == LDPV_PROTECTED); |
||
482 | } |
||
483 | |||
484 | for (sym = &entry_symbol; sym != NULL; sym = sym->next) |
||
485 | if (sym->name |
||
486 | && strcmp (sym->name, blhe->root.string) == 0) |
||
487 | return TRUE; |
||
488 | |||
489 | return FALSE; |
||
490 | } |
||
491 | |||
492 | /* Get the symbol resolution info for a plugin-claimed input file. */ |
||
493 | static enum ld_plugin_status |
||
494 | get_symbols (const void *handle, int nsyms, struct ld_plugin_symbol *syms, |
||
495 | int def_ironly_exp) |
||
496 | { |
||
497 | const bfd *abfd = handle; |
||
498 | int n; |
||
499 | |||
500 | ASSERT (called_plugin); |
||
501 | for (n = 0; n < nsyms; n++) |
||
502 | { |
||
503 | struct bfd_link_hash_entry *blhe; |
||
504 | asection *owner_sec; |
||
505 | int res; |
||
506 | |||
507 | if (syms[n].def != LDPK_UNDEF) |
||
508 | blhe = bfd_link_hash_lookup (link_info.hash, syms[n].name, |
||
509 | FALSE, FALSE, TRUE); |
||
510 | else |
||
511 | blhe = bfd_wrapped_link_hash_lookup (link_info.output_bfd, &link_info, |
||
512 | syms[n].name, FALSE, FALSE, TRUE); |
||
513 | if (!blhe) |
||
514 | { |
||
515 | res = LDPR_UNKNOWN; |
||
516 | goto report_symbol; |
||
517 | } |
||
518 | |||
519 | /* Determine resolution from blhe type and symbol's original type. */ |
||
520 | if (blhe->type == bfd_link_hash_undefined |
||
521 | || blhe->type == bfd_link_hash_undefweak) |
||
522 | { |
||
523 | res = LDPR_UNDEF; |
||
524 | goto report_symbol; |
||
525 | } |
||
526 | if (blhe->type != bfd_link_hash_defined |
||
527 | && blhe->type != bfd_link_hash_defweak |
||
528 | && blhe->type != bfd_link_hash_common) |
||
529 | { |
||
530 | /* We should not have a new, indirect or warning symbol here. */ |
||
531 | einfo ("%P%F: %s: plugin symbol table corrupt (sym type %d)\n", |
||
532 | called_plugin->name, blhe->type); |
||
533 | } |
||
534 | |||
535 | /* Find out which section owns the symbol. Since it's not undef, |
||
536 | it must have an owner; if it's not a common symbol, both defs |
||
537 | and weakdefs keep it in the same place. */ |
||
538 | owner_sec = (blhe->type == bfd_link_hash_common |
||
539 | ? blhe->u.c.p->section |
||
540 | : blhe->u.def.section); |
||
541 | |||
542 | |||
543 | /* If it was originally undefined or common, then it has been |
||
544 | resolved; determine how. */ |
||
545 | if (syms[n].def == LDPK_UNDEF |
||
546 | || syms[n].def == LDPK_WEAKUNDEF |
||
547 | || syms[n].def == LDPK_COMMON) |
||
548 | { |
||
549 | if (owner_sec->owner == link_info.output_bfd) |
||
550 | res = LDPR_RESOLVED_EXEC; |
||
551 | else if (owner_sec->owner == abfd) |
||
552 | res = LDPR_PREVAILING_DEF_IRONLY; |
||
553 | else if (is_ir_dummy_bfd (owner_sec->owner)) |
||
554 | res = LDPR_RESOLVED_IR; |
||
555 | else if (owner_sec->owner != NULL |
||
556 | && (owner_sec->owner->flags & DYNAMIC) != 0) |
||
557 | res = LDPR_RESOLVED_DYN; |
||
558 | else |
||
559 | res = LDPR_RESOLVED_EXEC; |
||
560 | } |
||
561 | |||
562 | /* Was originally def, or weakdef. Does it prevail? If the |
||
563 | owner is the original dummy bfd that supplied it, then this |
||
564 | is the definition that has prevailed. */ |
||
565 | else if (owner_sec->owner == link_info.output_bfd) |
||
566 | res = LDPR_PREEMPTED_REG; |
||
567 | else if (owner_sec->owner == abfd) |
||
568 | res = LDPR_PREVAILING_DEF_IRONLY; |
||
569 | |||
570 | /* Was originally def, weakdef, or common, but has been pre-empted. */ |
||
571 | else if (is_ir_dummy_bfd (owner_sec->owner)) |
||
572 | res = LDPR_PREEMPTED_IR; |
||
573 | else |
||
574 | res = LDPR_PREEMPTED_REG; |
||
575 | |||
576 | if (res == LDPR_PREVAILING_DEF_IRONLY) |
||
577 | { |
||
578 | /* We need to know if the sym is referenced from non-IR files. Or |
||
579 | even potentially-referenced, perhaps in a future final link if |
||
580 | this is a partial one, perhaps dynamically at load-time if the |
||
581 | symbol is externally visible. */ |
||
582 | if (blhe->non_ir_ref) |
||
583 | res = LDPR_PREVAILING_DEF; |
||
584 | else if (is_visible_from_outside (&syms[n], blhe)) |
||
585 | res = def_ironly_exp; |
||
586 | } |
||
587 | |||
588 | report_symbol: |
||
589 | syms[n].resolution = res; |
||
590 | if (report_plugin_symbols) |
||
591 | einfo (_("%P: %B: symbol `%s' " |
||
592 | "definition: %d, visibility: %d, resolution: %d\n"), |
||
593 | abfd, syms[n].name, |
||
594 | syms[n].def, syms[n].visibility, res); |
||
595 | } |
||
596 | return LDPS_OK; |
||
597 | } |
||
598 | |||
599 | static enum ld_plugin_status |
||
600 | get_symbols_v1 (const void *handle, int nsyms, struct ld_plugin_symbol *syms) |
||
601 | { |
||
602 | return get_symbols (handle, nsyms, syms, LDPR_PREVAILING_DEF); |
||
603 | } |
||
604 | |||
605 | static enum ld_plugin_status |
||
606 | get_symbols_v2 (const void *handle, int nsyms, struct ld_plugin_symbol *syms) |
||
607 | { |
||
608 | return get_symbols (handle, nsyms, syms, LDPR_PREVAILING_DEF_IRONLY_EXP); |
||
609 | } |
||
610 | |||
611 | /* Add a new (real) input file generated by a plugin. */ |
||
612 | static enum ld_plugin_status |
||
613 | add_input_file (const char *pathname) |
||
614 | { |
||
615 | ASSERT (called_plugin); |
||
616 | if (!lang_add_input_file (xstrdup (pathname), lang_input_file_is_file_enum, |
||
617 | NULL)) |
||
618 | return LDPS_ERR; |
||
619 | return LDPS_OK; |
||
620 | } |
||
621 | |||
622 | /* Add a new (real) library required by a plugin. */ |
||
623 | static enum ld_plugin_status |
||
624 | add_input_library (const char *pathname) |
||
625 | { |
||
626 | ASSERT (called_plugin); |
||
627 | if (!lang_add_input_file (xstrdup (pathname), lang_input_file_is_l_enum, |
||
628 | NULL)) |
||
629 | return LDPS_ERR; |
||
630 | return LDPS_OK; |
||
631 | } |
||
632 | |||
633 | /* Set the extra library path to be used by libraries added via |
||
634 | add_input_library. */ |
||
635 | static enum ld_plugin_status |
||
636 | set_extra_library_path (const char *path) |
||
637 | { |
||
638 | ASSERT (called_plugin); |
||
639 | ldfile_add_library_path (xstrdup (path), FALSE); |
||
640 | return LDPS_OK; |
||
641 | } |
||
642 | |||
643 | /* Issue a diagnostic message from a plugin. */ |
||
644 | static enum ld_plugin_status |
||
645 | message (int level, const char *format, ...) |
||
646 | { |
||
647 | va_list args; |
||
648 | va_start (args, format); |
||
649 | |||
650 | switch (level) |
||
651 | { |
||
652 | case LDPL_INFO: |
||
653 | vfinfo (stdout, format, args, FALSE); |
||
654 | putchar ('\n'); |
||
655 | break; |
||
656 | case LDPL_WARNING: |
||
657 | vfinfo (stdout, format, args, TRUE); |
||
658 | putchar ('\n'); |
||
659 | break; |
||
660 | case LDPL_FATAL: |
||
661 | case LDPL_ERROR: |
||
662 | default: |
||
663 | { |
||
664 | char *newfmt = ACONCAT ((level == LDPL_FATAL ? "%P%F: " : "%P%X: ", |
||
665 | format, "\n", (const char *) NULL)); |
||
666 | fflush (stdout); |
||
667 | vfinfo (stderr, newfmt, args, TRUE); |
||
668 | fflush (stderr); |
||
669 | } |
||
670 | break; |
||
671 | } |
||
672 | |||
673 | va_end (args); |
||
674 | return LDPS_OK; |
||
675 | } |
||
676 | |||
677 | /* Helper to size leading part of tv array and set it up. */ |
||
678 | static void |
||
679 | set_tv_header (struct ld_plugin_tv *tv) |
||
680 | { |
||
681 | size_t i; |
||
682 | |||
683 | /* Version info. */ |
||
684 | static const unsigned int major = (unsigned)(BFD_VERSION / 100000000UL); |
||
685 | static const unsigned int minor = (unsigned)(BFD_VERSION / 1000000UL) % 100; |
||
686 | |||
687 | for (i = 0; i < tv_header_size; i++) |
||
688 | { |
||
689 | tv[i].tv_tag = tv_header_tags[i]; |
||
690 | #define TVU(x) tv[i].tv_u.tv_ ## x |
||
691 | switch (tv[i].tv_tag) |
||
692 | { |
||
693 | case LDPT_MESSAGE: |
||
694 | TVU(message) = message; |
||
695 | break; |
||
696 | case LDPT_API_VERSION: |
||
697 | TVU(val) = LD_PLUGIN_API_VERSION; |
||
698 | break; |
||
699 | case LDPT_GNU_LD_VERSION: |
||
700 | TVU(val) = major * 100 + minor; |
||
701 | break; |
||
702 | case LDPT_LINKER_OUTPUT: |
||
703 | TVU(val) = (link_info.relocatable |
||
704 | ? LDPO_REL |
||
705 | : (link_info.executable |
||
706 | ? (link_info.pie ? LDPO_PIE : LDPO_EXEC) |
||
707 | : LDPO_DYN)); |
||
708 | break; |
||
709 | case LDPT_OUTPUT_NAME: |
||
710 | TVU(string) = output_filename; |
||
711 | break; |
||
712 | case LDPT_REGISTER_CLAIM_FILE_HOOK: |
||
713 | TVU(register_claim_file) = register_claim_file; |
||
714 | break; |
||
715 | case LDPT_REGISTER_ALL_SYMBOLS_READ_HOOK: |
||
716 | TVU(register_all_symbols_read) = register_all_symbols_read; |
||
717 | break; |
||
718 | case LDPT_REGISTER_CLEANUP_HOOK: |
||
719 | TVU(register_cleanup) = register_cleanup; |
||
720 | break; |
||
721 | case LDPT_ADD_SYMBOLS: |
||
722 | TVU(add_symbols) = add_symbols; |
||
723 | break; |
||
724 | case LDPT_GET_INPUT_FILE: |
||
725 | TVU(get_input_file) = get_input_file; |
||
726 | break; |
||
727 | case LDPT_RELEASE_INPUT_FILE: |
||
728 | TVU(release_input_file) = release_input_file; |
||
729 | break; |
||
730 | case LDPT_GET_SYMBOLS: |
||
731 | TVU(get_symbols) = get_symbols_v1; |
||
732 | break; |
||
733 | case LDPT_GET_SYMBOLS_V2: |
||
734 | TVU(get_symbols) = get_symbols_v2; |
||
735 | break; |
||
736 | case LDPT_ADD_INPUT_FILE: |
||
737 | TVU(add_input_file) = add_input_file; |
||
738 | break; |
||
739 | case LDPT_ADD_INPUT_LIBRARY: |
||
740 | TVU(add_input_library) = add_input_library; |
||
741 | break; |
||
742 | case LDPT_SET_EXTRA_LIBRARY_PATH: |
||
743 | TVU(set_extra_library_path) = set_extra_library_path; |
||
744 | break; |
||
745 | default: |
||
746 | /* Added a new entry to the array without adding |
||
747 | a new case to set up its value is a bug. */ |
||
748 | FAIL (); |
||
749 | } |
||
750 | #undef TVU |
||
751 | } |
||
752 | } |
||
753 | |||
754 | /* Append the per-plugin args list and trailing LDPT_NULL to tv. */ |
||
755 | static void |
||
756 | set_tv_plugin_args (plugin_t *plugin, struct ld_plugin_tv *tv) |
||
757 | { |
||
758 | plugin_arg_t *arg = plugin->args; |
||
759 | while (arg) |
||
760 | { |
||
761 | tv->tv_tag = LDPT_OPTION; |
||
762 | tv->tv_u.tv_string = arg->arg; |
||
763 | arg = arg->next; |
||
764 | tv++; |
||
765 | } |
||
766 | tv->tv_tag = LDPT_NULL; |
||
767 | tv->tv_u.tv_val = 0; |
||
768 | } |
||
769 | |||
770 | /* Return true if any plugins are active this run. Only valid |
||
771 | after options have been processed. */ |
||
772 | bfd_boolean |
||
773 | plugin_active_plugins_p (void) |
||
774 | { |
||
775 | return plugins_list != NULL; |
||
776 | } |
||
777 | |||
778 | /* Load up and initialise all plugins after argument parsing. */ |
||
779 | void |
||
780 | plugin_load_plugins (void) |
||
781 | { |
||
782 | struct ld_plugin_tv *my_tv; |
||
783 | unsigned int max_args = 0; |
||
784 | plugin_t *curplug = plugins_list; |
||
785 | |||
786 | /* If there are no plugins, we need do nothing this run. */ |
||
787 | if (!curplug) |
||
788 | return; |
||
789 | |||
790 | /* First pass over plugins to find max # args needed so that we |
||
791 | can size and allocate the tv array. */ |
||
792 | while (curplug) |
||
793 | { |
||
794 | if (curplug->n_args > max_args) |
||
795 | max_args = curplug->n_args; |
||
796 | curplug = curplug->next; |
||
797 | } |
||
798 | |||
799 | /* Allocate tv array and initialise constant part. */ |
||
800 | my_tv = xmalloc ((max_args + 1 + tv_header_size) * sizeof *my_tv); |
||
801 | set_tv_header (my_tv); |
||
802 | |||
803 | /* Pass over plugins again, activating them. */ |
||
804 | curplug = plugins_list; |
||
805 | while (curplug) |
||
806 | { |
||
807 | enum ld_plugin_status rv; |
||
808 | ld_plugin_onload onloadfn; |
||
809 | |||
810 | onloadfn = (ld_plugin_onload) dlsym (curplug->dlhandle, "onload"); |
||
811 | if (!onloadfn) |
||
812 | onloadfn = (ld_plugin_onload) dlsym (curplug->dlhandle, "_onload"); |
||
813 | if (!onloadfn) |
||
814 | einfo (_("%P%F: %s: error loading plugin: %s\n"), |
||
815 | curplug->name, dlerror ()); |
||
816 | set_tv_plugin_args (curplug, &my_tv[tv_header_size]); |
||
817 | called_plugin = curplug; |
||
818 | rv = (*onloadfn) (my_tv); |
||
819 | called_plugin = NULL; |
||
820 | if (rv != LDPS_OK) |
||
821 | einfo (_("%P%F: %s: plugin error: %d\n"), curplug->name, rv); |
||
822 | curplug = curplug->next; |
||
823 | } |
||
824 | |||
825 | /* Since plugin(s) inited ok, assume they're going to want symbol |
||
826 | resolutions, which needs us to track which symbols are referenced |
||
827 | by non-IR files using the linker's notice callback. */ |
||
828 | orig_notice_all = link_info.notice_all; |
||
829 | orig_callbacks = link_info.callbacks; |
||
830 | plugin_callbacks = *orig_callbacks; |
||
831 | plugin_callbacks.notice = &plugin_notice; |
||
832 | link_info.notice_all = TRUE; |
||
833 | link_info.callbacks = &plugin_callbacks; |
||
834 | } |
||
835 | |||
836 | /* Call 'claim file' hook for all plugins. */ |
||
837 | static int |
||
838 | plugin_call_claim_file (const struct ld_plugin_input_file *file, int *claimed) |
||
839 | { |
||
840 | plugin_t *curplug = plugins_list; |
||
841 | *claimed = FALSE; |
||
842 | if (no_more_claiming) |
||
843 | return 0; |
||
844 | while (curplug && !*claimed) |
||
845 | { |
||
846 | if (curplug->claim_file_handler) |
||
847 | { |
||
848 | enum ld_plugin_status rv; |
||
849 | called_plugin = curplug; |
||
850 | rv = (*curplug->claim_file_handler) (file, claimed); |
||
851 | called_plugin = NULL; |
||
852 | if (rv != LDPS_OK) |
||
853 | set_plugin_error (curplug->name); |
||
854 | } |
||
855 | curplug = curplug->next; |
||
856 | } |
||
857 | return plugin_error_p () ? -1 : 0; |
||
858 | } |
||
859 | |||
860 | void |
||
861 | plugin_maybe_claim (struct ld_plugin_input_file *file, |
||
862 | lang_input_statement_type *entry) |
||
863 | { |
||
864 | int claimed = 0; |
||
865 | |||
866 | /* We create a dummy BFD, initially empty, to house whatever symbols |
||
867 | the plugin may want to add. */ |
||
868 | file->handle = plugin_get_ir_dummy_bfd (entry->the_bfd->filename, |
||
869 | entry->the_bfd); |
||
870 | if (plugin_call_claim_file (file, &claimed)) |
||
871 | einfo (_("%P%F: %s: plugin reported error claiming file\n"), |
||
872 | plugin_error_plugin ()); |
||
873 | /* fd belongs to us, not the plugin; but we don't need it. */ |
||
874 | close (file->fd); |
||
875 | if (claimed) |
||
876 | { |
||
877 | /* Discard the real file's BFD and substitute the dummy one. */ |
||
878 | |||
879 | /* BFD archive handling caches elements so we can't call |
||
880 | bfd_close for archives. */ |
||
881 | if (entry->the_bfd->my_archive == NULL) |
||
882 | bfd_close (entry->the_bfd); |
||
883 | entry->the_bfd = file->handle; |
||
884 | entry->flags.claimed = TRUE; |
||
885 | bfd_make_readable (entry->the_bfd); |
||
886 | } |
||
887 | else |
||
888 | { |
||
889 | /* If plugin didn't claim the file, we don't need the dummy bfd. |
||
890 | Can't avoid speculatively creating it, alas. */ |
||
891 | bfd_close_all_done (file->handle); |
||
892 | entry->flags.claimed = FALSE; |
||
893 | } |
||
894 | } |
||
895 | |||
896 | /* Call 'all symbols read' hook for all plugins. */ |
||
897 | int |
||
898 | plugin_call_all_symbols_read (void) |
||
899 | { |
||
900 | plugin_t *curplug = plugins_list; |
||
901 | |||
902 | /* Disable any further file-claiming. */ |
||
903 | no_more_claiming = TRUE; |
||
904 | |||
905 | while (curplug) |
||
906 | { |
||
907 | if (curplug->all_symbols_read_handler) |
||
908 | { |
||
909 | enum ld_plugin_status rv; |
||
910 | called_plugin = curplug; |
||
911 | rv = (*curplug->all_symbols_read_handler) (); |
||
912 | called_plugin = NULL; |
||
913 | if (rv != LDPS_OK) |
||
914 | set_plugin_error (curplug->name); |
||
915 | } |
||
916 | curplug = curplug->next; |
||
917 | } |
||
918 | return plugin_error_p () ? -1 : 0; |
||
919 | } |
||
920 | |||
921 | /* Call 'cleanup' hook for all plugins at exit. */ |
||
922 | void |
||
923 | plugin_call_cleanup (void) |
||
924 | { |
||
925 | plugin_t *curplug = plugins_list; |
||
926 | while (curplug) |
||
927 | { |
||
928 | if (curplug->cleanup_handler && !curplug->cleanup_done) |
||
929 | { |
||
930 | enum ld_plugin_status rv; |
||
931 | curplug->cleanup_done = TRUE; |
||
932 | called_plugin = curplug; |
||
933 | rv = (*curplug->cleanup_handler) (); |
||
934 | called_plugin = NULL; |
||
935 | if (rv != LDPS_OK) |
||
936 | info_msg (_("%P: %s: error in plugin cleanup: %d (ignored)\n"), |
||
937 | curplug->name, rv); |
||
938 | dlclose (curplug->dlhandle); |
||
939 | } |
||
940 | curplug = curplug->next; |
||
941 | } |
||
942 | } |
||
943 | |||
944 | /* To determine which symbols should be resolved LDPR_PREVAILING_DEF |
||
945 | and which LDPR_PREVAILING_DEF_IRONLY, we notice all the symbols as |
||
946 | the linker adds them to the linker hash table. Mark those |
||
947 | referenced from a non-IR file with non_ir_ref. We have to |
||
948 | notice_all symbols, because we won't necessarily know until later |
||
949 | which ones will be contributed by IR files. */ |
||
950 | static bfd_boolean |
||
951 | plugin_notice (struct bfd_link_info *info, |
||
952 | struct bfd_link_hash_entry *h, |
||
953 | bfd *abfd, |
||
954 | asection *section, |
||
955 | bfd_vma value, |
||
956 | flagword flags, |
||
957 | const char *string) |
||
958 | { |
||
959 | if (h != NULL) |
||
960 | { |
||
961 | bfd *sym_bfd; |
||
962 | |||
963 | /* Nothing to do here if this def/ref is from an IR dummy BFD. */ |
||
964 | if (is_ir_dummy_bfd (abfd)) |
||
965 | ; |
||
966 | |||
967 | /* Making an indirect symbol counts as a reference unless this |
||
968 | is a brand new symbol. */ |
||
969 | else if (bfd_is_ind_section (section) |
||
970 | || (flags & BSF_INDIRECT) != 0) |
||
971 | { |
||
972 | if (h->type != bfd_link_hash_new) |
||
973 | { |
||
974 | struct bfd_link_hash_entry *inh; |
||
975 | |||
976 | h->non_ir_ref = TRUE; |
||
977 | inh = bfd_wrapped_link_hash_lookup (abfd, info, string, FALSE, |
||
978 | FALSE, FALSE); |
||
979 | if (inh != NULL) |
||
980 | inh->non_ir_ref = TRUE; |
||
981 | } |
||
982 | } |
||
983 | |||
984 | /* Nothing to do here for warning symbols. */ |
||
985 | else if ((flags & BSF_WARNING) != 0) |
||
986 | ; |
||
987 | |||
988 | /* Nothing to do here for constructor symbols. */ |
||
989 | else if ((flags & BSF_CONSTRUCTOR) != 0) |
||
990 | ; |
||
991 | |||
992 | /* If this is a ref, set non_ir_ref. */ |
||
993 | else if (bfd_is_und_section (section)) |
||
994 | { |
||
995 | /* Replace the undefined dummy bfd with the real one. */ |
||
996 | if ((h->type == bfd_link_hash_undefined |
||
997 | || h->type == bfd_link_hash_undefweak) |
||
998 | && (h->u.undef.abfd == NULL |
||
999 | || (h->u.undef.abfd->flags & BFD_PLUGIN) != 0)) |
||
1000 | h->u.undef.abfd = abfd; |
||
1001 | h->non_ir_ref = TRUE; |
||
1002 | } |
||
1003 | |||
1004 | /* Otherwise, it must be a new def. Ensure any symbol defined |
||
1005 | in an IR dummy BFD takes on a new value from a real BFD. |
||
1006 | Weak symbols are not normally overridden by a new weak |
||
1007 | definition, and strong symbols will normally cause multiple |
||
1008 | definition errors. Avoid this by making the symbol appear |
||
1009 | to be undefined. */ |
||
1010 | else if (((h->type == bfd_link_hash_defweak |
||
1011 | || h->type == bfd_link_hash_defined) |
||
1012 | && is_ir_dummy_bfd (sym_bfd = h->u.def.section->owner)) |
||
1013 | || (h->type == bfd_link_hash_common |
||
1014 | && is_ir_dummy_bfd (sym_bfd = h->u.c.p->section->owner))) |
||
1015 | { |
||
1016 | h->type = bfd_link_hash_undefweak; |
||
1017 | h->u.undef.abfd = sym_bfd; |
||
1018 | } |
||
1019 | } |
||
1020 | |||
1021 | /* Continue with cref/nocrossref/trace-sym processing. */ |
||
1022 | if (h == NULL |
||
1023 | || orig_notice_all |
||
1024 | || (info->notice_hash != NULL |
||
1025 | && bfd_hash_lookup (info->notice_hash, h->root.string, |
||
1026 | FALSE, FALSE) != NULL)) |
||
1027 | return (*orig_callbacks->notice) (info, h, |
||
1028 | abfd, section, value, flags, string); |
||
1029 | return TRUE; |
||
1030 | } |
||
1031 | |||
1032 | /* Return true if bfd is a dynamic library that should be reloaded. */ |
||
1033 | |||
1034 | bfd_boolean |
||
1035 | plugin_should_reload (bfd *abfd) |
||
1036 | { |
||
1037 | return ((abfd->flags & DYNAMIC) != 0 |
||
1038 | && bfd_get_flavour (abfd) == bfd_target_elf_flavour |
||
1039 | && bfd_get_format (abfd) == bfd_object |
||
1040 | && (elf_dyn_lib_class (abfd) & DYN_AS_NEEDED) != 0); |
||
1041 | }>>> |