Commit | Line | Data |
---|---|---|
c4d10515 KB |
1 | /* Handle FR-V (FDPIC) shared libraries for GDB, the GNU Debugger. |
2 | Copyright 2004 | |
3 | Free Software Foundation, Inc. | |
4 | ||
5 | This file is part of GDB. | |
6 | ||
7 | This program is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 2 of the License, or | |
10 | (at your option) any later version. | |
11 | ||
12 | This program is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with this program; if not, write to the Free Software | |
19 | Foundation, Inc., 59 Temple Place - Suite 330, | |
20 | Boston, MA 02111-1307, USA. */ | |
21 | ||
22 | ||
23 | #include "defs.h" | |
24 | #include "gdb_string.h" | |
25 | #include "inferior.h" | |
26 | #include "gdbcore.h" | |
27 | #include "solist.h" | |
28 | #include "frv-tdep.h" | |
29 | #include "objfiles.h" | |
30 | #include "symtab.h" | |
31 | #include "language.h" | |
32 | #include "command.h" | |
33 | #include "gdbcmd.h" | |
34 | #include "elf/frv.h" | |
35 | ||
36 | /* Flag which indicates whether internal debug messages should be printed. */ | |
37 | static int solib_frv_debug; | |
38 | ||
39 | /* FR-V pointers are four bytes wide. */ | |
40 | enum { FRV_PTR_SIZE = 4 }; | |
41 | ||
42 | /* Representation of loadmap and related structs for the FR-V FDPIC ABI. */ | |
43 | ||
44 | /* External versions; the size and alignment of the fields should be | |
45 | the same as those on the target. When loaded, the placement of | |
46 | the bits in each field will be the same as on the target. */ | |
47 | typedef unsigned char ext_Elf32_Half[2]; | |
48 | typedef unsigned char ext_Elf32_Addr[4]; | |
49 | typedef unsigned char ext_Elf32_Word[4]; | |
50 | ||
51 | struct ext_elf32_fdpic_loadseg | |
52 | { | |
53 | /* Core address to which the segment is mapped. */ | |
54 | ext_Elf32_Addr addr; | |
55 | /* VMA recorded in the program header. */ | |
56 | ext_Elf32_Addr p_vaddr; | |
57 | /* Size of this segment in memory. */ | |
58 | ext_Elf32_Word p_memsz; | |
59 | }; | |
60 | ||
61 | struct ext_elf32_fdpic_loadmap { | |
62 | /* Protocol version number, must be zero. */ | |
63 | ext_Elf32_Half version; | |
64 | /* Number of segments in this map. */ | |
65 | ext_Elf32_Half nsegs; | |
66 | /* The actual memory map. */ | |
67 | struct ext_elf32_fdpic_loadseg segs[1 /* nsegs, actually */]; | |
68 | }; | |
69 | ||
70 | /* Internal versions; the types are GDB types and the data in each | |
71 | of the fields is (or will be) decoded from the external struct | |
72 | for ease of consumption. */ | |
73 | struct int_elf32_fdpic_loadseg | |
74 | { | |
75 | /* Core address to which the segment is mapped. */ | |
76 | CORE_ADDR addr; | |
77 | /* VMA recorded in the program header. */ | |
78 | CORE_ADDR p_vaddr; | |
79 | /* Size of this segment in memory. */ | |
80 | long p_memsz; | |
81 | }; | |
82 | ||
83 | struct int_elf32_fdpic_loadmap { | |
84 | /* Protocol version number, must be zero. */ | |
85 | int version; | |
86 | /* Number of segments in this map. */ | |
87 | int nsegs; | |
88 | /* The actual memory map. */ | |
89 | struct int_elf32_fdpic_loadseg segs[1 /* nsegs, actually */]; | |
90 | }; | |
91 | ||
92 | /* Given address LDMADDR, fetch and decode the loadmap at that address. | |
93 | Return NULL if there is a problem reading the target memory or if | |
94 | there doesn't appear to be a loadmap at the given address. The | |
95 | allocated space (representing the loadmap) returned by this | |
96 | function may be freed via a single call to xfree(). */ | |
97 | ||
98 | static struct int_elf32_fdpic_loadmap * | |
99 | fetch_loadmap (CORE_ADDR ldmaddr) | |
100 | { | |
101 | struct ext_elf32_fdpic_loadmap ext_ldmbuf_partial; | |
102 | struct ext_elf32_fdpic_loadmap *ext_ldmbuf; | |
103 | struct int_elf32_fdpic_loadmap *int_ldmbuf; | |
104 | int ext_ldmbuf_size, int_ldmbuf_size; | |
105 | int version, seg, nsegs; | |
106 | ||
107 | /* Fetch initial portion of the loadmap. */ | |
108 | if (target_read_memory (ldmaddr, (char *) &ext_ldmbuf_partial, | |
109 | sizeof ext_ldmbuf_partial)) | |
110 | { | |
111 | /* Problem reading the target's memory. */ | |
112 | return NULL; | |
113 | } | |
114 | ||
115 | /* Extract the version. */ | |
116 | version = extract_unsigned_integer (&ext_ldmbuf_partial.version, | |
117 | sizeof ext_ldmbuf_partial.version); | |
118 | if (version != 0) | |
119 | { | |
120 | /* We only handle version 0. */ | |
121 | return NULL; | |
122 | } | |
123 | ||
124 | /* Extract the number of segments. */ | |
125 | nsegs = extract_unsigned_integer (&ext_ldmbuf_partial.nsegs, | |
126 | sizeof ext_ldmbuf_partial.nsegs); | |
127 | ||
128 | /* Allocate space for the complete (external) loadmap. */ | |
129 | ext_ldmbuf_size = sizeof (struct ext_elf32_fdpic_loadmap) | |
130 | + (nsegs - 1) * sizeof (struct ext_elf32_fdpic_loadseg); | |
131 | ext_ldmbuf = xmalloc (ext_ldmbuf_size); | |
132 | ||
133 | /* Copy over the portion of the loadmap that's already been read. */ | |
134 | memcpy (ext_ldmbuf, &ext_ldmbuf_partial, sizeof ext_ldmbuf_partial); | |
135 | ||
136 | /* Read the rest of the loadmap from the target. */ | |
137 | if (target_read_memory (ldmaddr + sizeof ext_ldmbuf_partial, | |
138 | (char *) ext_ldmbuf + sizeof ext_ldmbuf_partial, | |
139 | ext_ldmbuf_size - sizeof ext_ldmbuf_partial)) | |
140 | { | |
141 | /* Couldn't read rest of the loadmap. */ | |
142 | xfree (ext_ldmbuf); | |
143 | return NULL; | |
144 | } | |
145 | ||
146 | /* Allocate space into which to put information extract from the | |
147 | external loadsegs. I.e, allocate the internal loadsegs. */ | |
148 | int_ldmbuf_size = sizeof (struct int_elf32_fdpic_loadmap) | |
149 | + (nsegs - 1) * sizeof (struct int_elf32_fdpic_loadseg); | |
150 | int_ldmbuf = xmalloc (int_ldmbuf_size); | |
151 | ||
152 | /* Place extracted information in internal structs. */ | |
153 | int_ldmbuf->version = version; | |
154 | int_ldmbuf->nsegs = nsegs; | |
155 | for (seg = 0; seg < nsegs; seg++) | |
156 | { | |
157 | int_ldmbuf->segs[seg].addr | |
158 | = extract_unsigned_integer (&ext_ldmbuf->segs[seg].addr, | |
159 | sizeof (ext_ldmbuf->segs[seg].addr)); | |
160 | int_ldmbuf->segs[seg].p_vaddr | |
161 | = extract_unsigned_integer (&ext_ldmbuf->segs[seg].p_vaddr, | |
162 | sizeof (ext_ldmbuf->segs[seg].p_vaddr)); | |
163 | int_ldmbuf->segs[seg].p_memsz | |
164 | = extract_unsigned_integer (&ext_ldmbuf->segs[seg].p_memsz, | |
165 | sizeof (ext_ldmbuf->segs[seg].p_memsz)); | |
166 | } | |
167 | ||
168 | free (ext_ldmbuf); | |
169 | return int_ldmbuf; | |
170 | } | |
171 | ||
172 | /* External link_map and elf32_fdpic_loadaddr struct definitions. */ | |
173 | ||
174 | typedef unsigned char ext_ptr[4]; | |
175 | ||
176 | struct ext_elf32_fdpic_loadaddr | |
177 | { | |
178 | ext_ptr map; /* struct elf32_fdpic_loadmap *map; */ | |
179 | ext_ptr got_value; /* void *got_value; */ | |
180 | }; | |
181 | ||
182 | struct ext_link_map | |
183 | { | |
184 | struct ext_elf32_fdpic_loadaddr l_addr; | |
185 | ||
186 | /* Absolute file name object was found in. */ | |
187 | ext_ptr l_name; /* char *l_name; */ | |
188 | ||
189 | /* Dynamic section of the shared object. */ | |
190 | ext_ptr l_ld; /* ElfW(Dyn) *l_ld; */ | |
191 | ||
192 | /* Chain of loaded objects. */ | |
193 | ext_ptr l_next, l_prev; /* struct link_map *l_next, *l_prev; */ | |
194 | }; | |
195 | ||
196 | /* Link map info to include in an allocated so_list entry */ | |
197 | ||
198 | struct lm_info | |
199 | { | |
200 | /* The loadmap, digested into an easier to use form. */ | |
201 | struct int_elf32_fdpic_loadmap *map; | |
202 | /* The GOT address for this link map entry. */ | |
203 | CORE_ADDR got_value; | |
204 | ||
205 | /* Cached dynamic symbol table and dynamic relocs initialized and | |
206 | used only by find_canonical_descriptor_in_load_object(). | |
207 | ||
208 | Note: kevinb/2004-02-26: It appears that calls to | |
209 | bfd_canonicalize_dynamic_reloc() will use the same symbols as | |
210 | those supplied to the first call to this function. Therefore, | |
211 | it's important to NOT free the asymbol ** data structure | |
212 | supplied to the first call. Thus the caching of the dynamic | |
213 | symbols (dyn_syms) is critical for correct operation. The | |
214 | caching of the dynamic relocations could be dispensed with. */ | |
215 | asymbol **dyn_syms; | |
216 | arelent **dyn_relocs; | |
217 | int dyn_reloc_count; /* number of dynamic relocs. */ | |
218 | ||
219 | }; | |
220 | ||
221 | /* The load map, got value, etc. are not available from the chain | |
222 | of loaded shared objects. ``main_executable_lm_info'' provides | |
223 | a way to get at this information so that it doesn't need to be | |
224 | frequently recomputed. Initialized by frv_relocate_main_executable(). */ | |
225 | static struct lm_info *main_executable_lm_info; | |
226 | ||
227 | static void frv_relocate_main_executable (void); | |
228 | static CORE_ADDR main_got (void); | |
229 | static int enable_break2 (void); | |
230 | ||
231 | /* | |
232 | ||
233 | LOCAL FUNCTION | |
234 | ||
235 | bfd_lookup_symbol -- lookup the value for a specific symbol | |
236 | ||
237 | SYNOPSIS | |
238 | ||
239 | CORE_ADDR bfd_lookup_symbol (bfd *abfd, char *symname) | |
240 | ||
241 | DESCRIPTION | |
242 | ||
243 | An expensive way to lookup the value of a single symbol for | |
244 | bfd's that are only temporary anyway. This is used by the | |
245 | shared library support to find the address of the debugger | |
246 | interface structures in the shared library. | |
247 | ||
248 | Note that 0 is specifically allowed as an error return (no | |
249 | such symbol). | |
250 | */ | |
251 | ||
252 | static CORE_ADDR | |
253 | bfd_lookup_symbol (bfd *abfd, char *symname) | |
254 | { | |
255 | long storage_needed; | |
256 | asymbol *sym; | |
257 | asymbol **symbol_table; | |
258 | unsigned int number_of_symbols; | |
259 | unsigned int i; | |
260 | struct cleanup *back_to; | |
261 | CORE_ADDR symaddr = 0; | |
262 | ||
263 | storage_needed = bfd_get_symtab_upper_bound (abfd); | |
264 | ||
265 | if (storage_needed > 0) | |
266 | { | |
267 | symbol_table = (asymbol **) xmalloc (storage_needed); | |
268 | back_to = make_cleanup (xfree, symbol_table); | |
269 | number_of_symbols = bfd_canonicalize_symtab (abfd, symbol_table); | |
270 | ||
271 | for (i = 0; i < number_of_symbols; i++) | |
272 | { | |
273 | sym = *symbol_table++; | |
274 | if (strcmp (sym->name, symname) == 0) | |
275 | { | |
276 | /* Bfd symbols are section relative. */ | |
277 | symaddr = sym->value + sym->section->vma; | |
278 | break; | |
279 | } | |
280 | } | |
281 | do_cleanups (back_to); | |
282 | } | |
283 | ||
284 | if (symaddr) | |
285 | return symaddr; | |
286 | ||
287 | /* Look for the symbol in the dynamic string table too. */ | |
288 | ||
289 | storage_needed = bfd_get_dynamic_symtab_upper_bound (abfd); | |
290 | ||
291 | if (storage_needed > 0) | |
292 | { | |
293 | symbol_table = (asymbol **) xmalloc (storage_needed); | |
294 | back_to = make_cleanup (xfree, symbol_table); | |
295 | number_of_symbols = bfd_canonicalize_dynamic_symtab (abfd, symbol_table); | |
296 | ||
297 | for (i = 0; i < number_of_symbols; i++) | |
298 | { | |
299 | sym = *symbol_table++; | |
300 | if (strcmp (sym->name, symname) == 0) | |
301 | { | |
302 | /* Bfd symbols are section relative. */ | |
303 | symaddr = sym->value + sym->section->vma; | |
304 | break; | |
305 | } | |
306 | } | |
307 | do_cleanups (back_to); | |
308 | } | |
309 | ||
310 | return symaddr; | |
311 | } | |
312 | ||
313 | ||
314 | /* | |
315 | ||
316 | LOCAL FUNCTION | |
317 | ||
318 | open_symbol_file_object | |
319 | ||
320 | SYNOPSIS | |
321 | ||
322 | void open_symbol_file_object (void *from_tty) | |
323 | ||
324 | DESCRIPTION | |
325 | ||
326 | If no open symbol file, attempt to locate and open the main symbol | |
327 | file. | |
328 | ||
329 | If FROM_TTYP dereferences to a non-zero integer, allow messages to | |
330 | be printed. This parameter is a pointer rather than an int because | |
331 | open_symbol_file_object() is called via catch_errors() and | |
332 | catch_errors() requires a pointer argument. */ | |
333 | ||
334 | static int | |
335 | open_symbol_file_object (void *from_ttyp) | |
336 | { | |
337 | /* Unimplemented. */ | |
338 | return 0; | |
339 | } | |
340 | ||
341 | /* Cached value for lm_base(), below. */ | |
342 | static CORE_ADDR lm_base_cache = 0; | |
343 | ||
344 | /* Return the address from which the link map chain may be found. On | |
345 | the FR-V, this may be found in a number of ways. Assuming that the | |
346 | main executable has already been relocated, the easiest way to find | |
347 | this value is to look up the address of _GLOBAL_OFFSET_TABLE_. A | |
348 | pointer to the start of the link map will be located at the word found | |
349 | at _GLOBAL_OFFSET_TABLE_ + 8. (This is part of the dynamic linker | |
350 | reserve area mandated by the ABI.) */ | |
351 | ||
352 | static CORE_ADDR | |
353 | lm_base (void) | |
354 | { | |
355 | struct minimal_symbol *got_sym; | |
356 | CORE_ADDR addr; | |
357 | char buf[FRV_PTR_SIZE]; | |
358 | ||
359 | /* If we already have a cached value, return it. */ | |
360 | if (lm_base_cache) | |
361 | return lm_base_cache; | |
362 | ||
363 | got_sym = lookup_minimal_symbol ("_GLOBAL_OFFSET_TABLE_", NULL, | |
364 | symfile_objfile); | |
365 | if (got_sym == 0) | |
366 | { | |
367 | if (solib_frv_debug) | |
368 | fprintf_unfiltered (gdb_stdlog, | |
369 | "lm_base: _GLOBAL_OFFSET_TABLE_ not found.\n"); | |
370 | return 0; | |
371 | } | |
372 | ||
373 | addr = SYMBOL_VALUE_ADDRESS (got_sym) + 8; | |
374 | ||
375 | if (solib_frv_debug) | |
376 | fprintf_unfiltered (gdb_stdlog, | |
377 | "lm_base: _GLOBAL_OFFSET_TABLE_ + 8 = %s\n", | |
378 | local_hex_string_custom (addr, "08l")); | |
379 | ||
380 | if (target_read_memory (addr, buf, sizeof buf) != 0) | |
381 | return 0; | |
382 | lm_base_cache = extract_unsigned_integer (buf, sizeof buf); | |
383 | ||
384 | if (solib_frv_debug) | |
385 | fprintf_unfiltered (gdb_stdlog, | |
386 | "lm_base: lm_base_cache = %s\n", | |
387 | local_hex_string_custom (lm_base_cache, "08l")); | |
388 | ||
389 | return lm_base_cache; | |
390 | } | |
391 | ||
392 | ||
393 | /* LOCAL FUNCTION | |
394 | ||
395 | frv_current_sos -- build a list of currently loaded shared objects | |
396 | ||
397 | SYNOPSIS | |
398 | ||
399 | struct so_list *frv_current_sos () | |
400 | ||
401 | DESCRIPTION | |
402 | ||
403 | Build a list of `struct so_list' objects describing the shared | |
404 | objects currently loaded in the inferior. This list does not | |
405 | include an entry for the main executable file. | |
406 | ||
407 | Note that we only gather information directly available from the | |
408 | inferior --- we don't examine any of the shared library files | |
409 | themselves. The declaration of `struct so_list' says which fields | |
410 | we provide values for. */ | |
411 | ||
412 | static struct so_list * | |
413 | frv_current_sos (void) | |
414 | { | |
415 | CORE_ADDR lm_addr, mgot; | |
416 | struct so_list *sos_head = NULL; | |
417 | struct so_list **sos_next_ptr = &sos_head; | |
418 | ||
419 | mgot = main_got (); | |
420 | ||
421 | /* Locate the address of the first link map struct. */ | |
422 | lm_addr = lm_base (); | |
423 | ||
424 | /* We have at least one link map entry. Fetch the the lot of them, | |
425 | building the solist chain. */ | |
426 | while (lm_addr) | |
427 | { | |
428 | struct ext_link_map lm_buf; | |
429 | CORE_ADDR got_addr; | |
430 | ||
431 | if (solib_frv_debug) | |
432 | fprintf_unfiltered (gdb_stdlog, | |
433 | "current_sos: reading link_map entry at %s\n", | |
434 | local_hex_string_custom (lm_addr, "08l")); | |
435 | ||
436 | if (target_read_memory (lm_addr, (char *) &lm_buf, sizeof (lm_buf)) != 0) | |
437 | { | |
438 | warning ("frv_current_sos: Unable to read link map entry. Shared object chain may be incomplete."); | |
439 | break; | |
440 | } | |
441 | ||
442 | got_addr | |
443 | = extract_unsigned_integer (&lm_buf.l_addr.got_value, | |
444 | sizeof (lm_buf.l_addr.got_value)); | |
445 | /* If the got_addr is the same as mgotr, then we're looking at the | |
446 | entry for the main executable. By convention, we don't include | |
447 | this in the list of shared objects. */ | |
448 | if (got_addr != mgot) | |
449 | { | |
450 | int errcode; | |
451 | char *name_buf; | |
452 | struct int_elf32_fdpic_loadmap *loadmap; | |
453 | struct so_list *sop; | |
454 | CORE_ADDR addr; | |
455 | ||
456 | /* Fetch the load map address. */ | |
457 | addr = extract_unsigned_integer (&lm_buf.l_addr.map, | |
458 | sizeof lm_buf.l_addr.map); | |
459 | loadmap = fetch_loadmap (addr); | |
460 | if (loadmap == NULL) | |
461 | { | |
462 | warning ("frv_current_sos: Unable to fetch load map. Shared object chain may be incomplete."); | |
463 | break; | |
464 | } | |
465 | ||
466 | sop = xcalloc (1, sizeof (struct so_list)); | |
467 | sop->lm_info = xcalloc (1, sizeof (struct lm_info)); | |
468 | sop->lm_info->map = loadmap; | |
469 | sop->lm_info->got_value = got_addr; | |
470 | /* Fetch the name. */ | |
471 | addr = extract_unsigned_integer (&lm_buf.l_name, | |
472 | sizeof (lm_buf.l_name)); | |
473 | target_read_string (addr, &name_buf, SO_NAME_MAX_PATH_SIZE - 1, | |
474 | &errcode); | |
475 | ||
476 | if (solib_frv_debug) | |
477 | fprintf_unfiltered (gdb_stdlog, "current_sos: name = %s\n", | |
478 | name_buf); | |
479 | ||
480 | if (errcode != 0) | |
481 | { | |
482 | warning ("frv_current_sos: Can't read pathname for link map entry: %s\n", | |
483 | safe_strerror (errcode)); | |
484 | } | |
485 | else | |
486 | { | |
487 | strncpy (sop->so_name, name_buf, SO_NAME_MAX_PATH_SIZE - 1); | |
488 | sop->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0'; | |
489 | xfree (name_buf); | |
490 | strcpy (sop->so_original_name, sop->so_name); | |
491 | } | |
492 | ||
493 | *sos_next_ptr = sop; | |
494 | sos_next_ptr = &sop->next; | |
495 | } | |
496 | ||
497 | lm_addr = extract_unsigned_integer (&lm_buf.l_next, sizeof (lm_buf.l_next)); | |
498 | } | |
499 | ||
500 | enable_break2 (); | |
501 | ||
502 | return sos_head; | |
503 | } | |
504 | ||
505 | ||
506 | /* Return 1 if PC lies in the dynamic symbol resolution code of the | |
507 | run time loader. */ | |
508 | ||
509 | static CORE_ADDR interp_text_sect_low; | |
510 | static CORE_ADDR interp_text_sect_high; | |
511 | static CORE_ADDR interp_plt_sect_low; | |
512 | static CORE_ADDR interp_plt_sect_high; | |
513 | ||
514 | static int | |
515 | frv_in_dynsym_resolve_code (CORE_ADDR pc) | |
516 | { | |
517 | return ((pc >= interp_text_sect_low && pc < interp_text_sect_high) | |
518 | || (pc >= interp_plt_sect_low && pc < interp_plt_sect_high) | |
519 | || in_plt_section (pc, NULL)); | |
520 | } | |
521 | ||
522 | /* Given a loadmap and an address, return the displacement needed | |
523 | to relocate the address. */ | |
524 | ||
525 | CORE_ADDR | |
526 | displacement_from_map (struct int_elf32_fdpic_loadmap *map, | |
527 | CORE_ADDR addr) | |
528 | { | |
529 | int seg; | |
530 | ||
531 | for (seg = 0; seg < map->nsegs; seg++) | |
532 | { | |
533 | if (map->segs[seg].p_vaddr <= addr | |
534 | && addr < map->segs[seg].p_vaddr + map->segs[seg].p_memsz) | |
535 | { | |
536 | return map->segs[seg].addr - map->segs[seg].p_vaddr; | |
537 | } | |
538 | } | |
539 | ||
540 | return 0; | |
541 | } | |
542 | ||
543 | /* Print a warning about being unable to set the dynamic linker | |
544 | breakpoint. */ | |
545 | ||
546 | static void | |
547 | enable_break_failure_warning (void) | |
548 | { | |
549 | warning ("Unable to find dynamic linker breakpoint function.\n" | |
550 | "GDB will be unable to debug shared library initializers\n" | |
551 | "and track explicitly loaded dynamic code."); | |
552 | } | |
553 | ||
554 | /* | |
555 | ||
556 | LOCAL FUNCTION | |
557 | ||
558 | enable_break -- arrange for dynamic linker to hit breakpoint | |
559 | ||
560 | SYNOPSIS | |
561 | ||
562 | int enable_break (void) | |
563 | ||
564 | DESCRIPTION | |
565 | ||
566 | The dynamic linkers has, as part of its debugger interface, support | |
567 | for arranging for the inferior to hit a breakpoint after mapping in | |
568 | the shared libraries. This function enables that breakpoint. | |
569 | ||
570 | On the FR-V, using the shared library (FDPIC) ABI, the symbol | |
571 | _dl_debug_addr points to the r_debug struct which contains | |
572 | a field called r_brk. r_brk is the address of the function | |
573 | descriptor upon which a breakpoint must be placed. Being a | |
574 | function descriptor, we must extract the entry point in order | |
575 | to set the breakpoint. | |
576 | ||
577 | Our strategy will be to get the .interp section from the | |
578 | executable. This section will provide us with the name of the | |
579 | interpreter. We'll open the interpreter and then look up | |
580 | the address of _dl_debug_addr. We then relocate this address | |
581 | using the interpreter's loadmap. Once the relocated address | |
582 | is known, we fetch the value (address) corresponding to r_brk | |
583 | and then use that value to fetch the entry point of the function | |
584 | we're interested in. | |
585 | ||
586 | */ | |
587 | ||
588 | static int enable_break1_done = 0; | |
589 | static int enable_break2_done = 0; | |
590 | ||
591 | static int | |
592 | enable_break2 (void) | |
593 | { | |
594 | int success = 0; | |
595 | char **bkpt_namep; | |
596 | asection *interp_sect; | |
597 | ||
598 | if (!enable_break1_done || enable_break2_done) | |
599 | return 1; | |
600 | ||
601 | enable_break2_done = 1; | |
602 | ||
603 | /* First, remove all the solib event breakpoints. Their addresses | |
604 | may have changed since the last time we ran the program. */ | |
605 | remove_solib_event_breakpoints (); | |
606 | ||
607 | interp_text_sect_low = interp_text_sect_high = 0; | |
608 | interp_plt_sect_low = interp_plt_sect_high = 0; | |
609 | ||
610 | /* Find the .interp section; if not found, warn the user and drop | |
611 | into the old breakpoint at symbol code. */ | |
612 | interp_sect = bfd_get_section_by_name (exec_bfd, ".interp"); | |
613 | if (interp_sect) | |
614 | { | |
615 | unsigned int interp_sect_size; | |
616 | char *buf; | |
617 | bfd *tmp_bfd = NULL; | |
618 | int tmp_fd = -1; | |
619 | char *tmp_pathname = NULL; | |
620 | int status; | |
621 | CORE_ADDR addr, interp_loadmap_addr; | |
622 | char addr_buf[FRV_PTR_SIZE]; | |
623 | struct int_elf32_fdpic_loadmap *ldm; | |
624 | ||
625 | /* Read the contents of the .interp section into a local buffer; | |
626 | the contents specify the dynamic linker this program uses. */ | |
627 | interp_sect_size = bfd_section_size (exec_bfd, interp_sect); | |
628 | buf = alloca (interp_sect_size); | |
629 | bfd_get_section_contents (exec_bfd, interp_sect, | |
630 | buf, 0, interp_sect_size); | |
631 | ||
632 | /* Now we need to figure out where the dynamic linker was | |
633 | loaded so that we can load its symbols and place a breakpoint | |
634 | in the dynamic linker itself. | |
635 | ||
636 | This address is stored on the stack. However, I've been unable | |
637 | to find any magic formula to find it for Solaris (appears to | |
638 | be trivial on GNU/Linux). Therefore, we have to try an alternate | |
639 | mechanism to find the dynamic linker's base address. */ | |
640 | ||
641 | tmp_fd = solib_open (buf, &tmp_pathname); | |
642 | if (tmp_fd >= 0) | |
643 | tmp_bfd = bfd_fdopenr (tmp_pathname, gnutarget, tmp_fd); | |
644 | ||
645 | if (tmp_bfd == NULL) | |
646 | { | |
647 | enable_break_failure_warning (); | |
648 | return 0; | |
649 | } | |
650 | ||
651 | /* Make sure the dynamic linker is really a useful object. */ | |
652 | if (!bfd_check_format (tmp_bfd, bfd_object)) | |
653 | { | |
654 | warning ("Unable to grok dynamic linker %s as an object file", buf); | |
655 | enable_break_failure_warning (); | |
656 | bfd_close (tmp_bfd); | |
657 | return 0; | |
658 | } | |
659 | ||
660 | status = frv_fdpic_loadmap_addresses (current_gdbarch, | |
661 | &interp_loadmap_addr, 0); | |
662 | if (status < 0) | |
663 | { | |
664 | warning ("Unable to determine dynamic linker loadmap address\n"); | |
665 | enable_break_failure_warning (); | |
666 | bfd_close (tmp_bfd); | |
667 | return 0; | |
668 | } | |
669 | ||
670 | if (solib_frv_debug) | |
671 | fprintf_unfiltered (gdb_stdlog, | |
672 | "enable_break: interp_loadmap_addr = %s\n", | |
673 | local_hex_string_custom (interp_loadmap_addr, | |
674 | "08l")); | |
675 | ||
676 | ldm = fetch_loadmap (interp_loadmap_addr); | |
677 | if (ldm == NULL) | |
678 | { | |
679 | warning ("Unable to load dynamic linker loadmap at address %s\n", | |
680 | local_hex_string_custom (interp_loadmap_addr, "08l")); | |
681 | enable_break_failure_warning (); | |
682 | bfd_close (tmp_bfd); | |
683 | return 0; | |
684 | } | |
685 | ||
686 | /* Record the relocated start and end address of the dynamic linker | |
687 | text and plt section for svr4_in_dynsym_resolve_code. */ | |
688 | interp_sect = bfd_get_section_by_name (tmp_bfd, ".text"); | |
689 | if (interp_sect) | |
690 | { | |
691 | interp_text_sect_low | |
692 | = bfd_section_vma (tmp_bfd, interp_sect); | |
693 | interp_text_sect_low | |
694 | += displacement_from_map (ldm, interp_text_sect_low); | |
695 | interp_text_sect_high | |
696 | = interp_text_sect_low + bfd_section_size (tmp_bfd, interp_sect); | |
697 | } | |
698 | interp_sect = bfd_get_section_by_name (tmp_bfd, ".plt"); | |
699 | if (interp_sect) | |
700 | { | |
701 | interp_plt_sect_low = | |
702 | bfd_section_vma (tmp_bfd, interp_sect); | |
703 | interp_plt_sect_low | |
704 | += displacement_from_map (ldm, interp_plt_sect_low); | |
705 | interp_plt_sect_high = | |
706 | interp_plt_sect_low + bfd_section_size (tmp_bfd, interp_sect); | |
707 | } | |
708 | ||
709 | addr = bfd_lookup_symbol (tmp_bfd, "_dl_debug_addr"); | |
710 | if (addr == 0) | |
711 | { | |
712 | warning ("Could not find symbol _dl_debug_addr in dynamic linker"); | |
713 | enable_break_failure_warning (); | |
714 | bfd_close (tmp_bfd); | |
715 | return 0; | |
716 | } | |
717 | ||
718 | if (solib_frv_debug) | |
719 | fprintf_unfiltered (gdb_stdlog, | |
720 | "enable_break: _dl_debug_addr (prior to relocation) = %s\n", | |
721 | local_hex_string_custom (addr, "08l")); | |
722 | ||
723 | addr += displacement_from_map (ldm, addr); | |
724 | ||
725 | if (solib_frv_debug) | |
726 | fprintf_unfiltered (gdb_stdlog, | |
727 | "enable_break: _dl_debug_addr (after relocation) = %s\n", | |
728 | local_hex_string_custom (addr, "08l")); | |
729 | ||
730 | /* Fetch the address of the r_debug struct. */ | |
731 | if (target_read_memory (addr, addr_buf, sizeof addr_buf) != 0) | |
732 | { | |
733 | warning ("Unable to fetch contents of _dl_debug_addr (at address %s) from dynamic linker", | |
734 | local_hex_string_custom (addr, "08l")); | |
735 | } | |
736 | addr = extract_unsigned_integer (addr_buf, sizeof addr_buf); | |
737 | ||
738 | /* Fetch the r_brk field. It's 8 bytes from the start of | |
739 | _dl_debug_addr. */ | |
740 | if (target_read_memory (addr + 8, addr_buf, sizeof addr_buf) != 0) | |
741 | { | |
742 | warning ("Unable to fetch _dl_debug_addr->r_brk (at address %s) from dynamic linker", | |
743 | local_hex_string_custom (addr + 8, "08l")); | |
744 | enable_break_failure_warning (); | |
745 | bfd_close (tmp_bfd); | |
746 | return 0; | |
747 | } | |
748 | addr = extract_unsigned_integer (addr_buf, sizeof addr_buf); | |
749 | ||
750 | /* Now fetch the function entry point. */ | |
751 | if (target_read_memory (addr, addr_buf, sizeof addr_buf) != 0) | |
752 | { | |
753 | warning ("Unable to fetch _dl_debug_addr->.r_brk entry point (at address %s) from dynamic linker", | |
754 | local_hex_string_custom (addr, "08l")); | |
755 | enable_break_failure_warning (); | |
756 | bfd_close (tmp_bfd); | |
757 | return 0; | |
758 | } | |
759 | addr = extract_unsigned_integer (addr_buf, sizeof addr_buf); | |
760 | ||
761 | /* We're done with the temporary bfd. */ | |
762 | bfd_close (tmp_bfd); | |
763 | ||
764 | /* We're also done with the loadmap. */ | |
765 | xfree (ldm); | |
766 | ||
767 | /* Now (finally!) create the solib breakpoint. */ | |
768 | create_solib_event_breakpoint (addr); | |
769 | ||
770 | return 1; | |
771 | } | |
772 | ||
773 | /* Tell the user we couldn't set a dynamic linker breakpoint. */ | |
774 | enable_break_failure_warning (); | |
775 | ||
776 | /* Failure return. */ | |
777 | return 0; | |
778 | } | |
779 | ||
780 | static int | |
781 | enable_break (void) | |
782 | { | |
783 | asection *interp_sect; | |
784 | ||
785 | /* Remove all the solib event breakpoints. Their addresses | |
786 | may have changed since the last time we ran the program. */ | |
787 | remove_solib_event_breakpoints (); | |
788 | ||
789 | /* Check for the presence of a .interp section. If there is no | |
790 | such section, the executable is statically linked. */ | |
791 | ||
792 | interp_sect = bfd_get_section_by_name (exec_bfd, ".interp"); | |
793 | ||
794 | if (interp_sect) | |
795 | { | |
796 | enable_break1_done = 1; | |
797 | create_solib_event_breakpoint (symfile_objfile->ei.entry_point); | |
798 | ||
799 | if (solib_frv_debug) | |
800 | fprintf_unfiltered (gdb_stdlog, | |
801 | "enable_break: solib event breakpoint placed at entry point: %s\n", | |
802 | local_hex_string_custom | |
803 | (symfile_objfile->ei.entry_point, "08l")); | |
804 | } | |
805 | else | |
806 | { | |
807 | if (solib_frv_debug) | |
808 | fprintf_unfiltered (gdb_stdlog, | |
809 | "enable_break: No .interp section found.\n"); | |
810 | } | |
811 | ||
812 | return 1; | |
813 | } | |
814 | ||
815 | /* | |
816 | ||
817 | LOCAL FUNCTION | |
818 | ||
819 | special_symbol_handling -- additional shared library symbol handling | |
820 | ||
821 | SYNOPSIS | |
822 | ||
823 | void special_symbol_handling () | |
824 | ||
825 | DESCRIPTION | |
826 | ||
827 | Once the symbols from a shared object have been loaded in the usual | |
828 | way, we are called to do any system specific symbol handling that | |
829 | is needed. | |
830 | ||
831 | */ | |
832 | ||
833 | static void | |
834 | frv_special_symbol_handling (void) | |
835 | { | |
836 | /* Nothing needed (yet) for FRV. */ | |
837 | } | |
838 | ||
839 | static void | |
840 | frv_relocate_main_executable (void) | |
841 | { | |
842 | int status; | |
843 | CORE_ADDR exec_addr; | |
844 | struct int_elf32_fdpic_loadmap *ldm; | |
845 | struct cleanup *old_chain; | |
846 | struct section_offsets *new_offsets; | |
847 | int changed; | |
848 | struct obj_section *osect; | |
849 | ||
850 | status = frv_fdpic_loadmap_addresses (current_gdbarch, 0, &exec_addr); | |
851 | ||
852 | if (status < 0) | |
853 | { | |
854 | /* Not using FDPIC ABI, so do nothing. */ | |
855 | return; | |
856 | } | |
857 | ||
858 | /* Fetch the loadmap located at ``exec_addr''. */ | |
859 | ldm = fetch_loadmap (exec_addr); | |
860 | if (ldm == NULL) | |
861 | error ("Unable to load the executable's loadmap."); | |
862 | ||
863 | if (main_executable_lm_info) | |
864 | xfree (main_executable_lm_info); | |
865 | main_executable_lm_info = xcalloc (1, sizeof (struct lm_info)); | |
866 | main_executable_lm_info->map = ldm; | |
867 | ||
868 | new_offsets = xcalloc (symfile_objfile->num_sections, | |
869 | sizeof (struct section_offsets)); | |
870 | old_chain = make_cleanup (xfree, new_offsets); | |
871 | changed = 0; | |
872 | ||
873 | ALL_OBJFILE_OSECTIONS (symfile_objfile, osect) | |
874 | { | |
875 | CORE_ADDR orig_addr, addr, offset; | |
876 | int osect_idx; | |
877 | int seg; | |
878 | ||
879 | osect_idx = osect->the_bfd_section->index; | |
880 | ||
881 | /* Current address of section. */ | |
882 | addr = osect->addr; | |
883 | /* Offset from where this section started. */ | |
884 | offset = ANOFFSET (symfile_objfile->section_offsets, osect_idx); | |
885 | /* Original address prior to any past relocations. */ | |
886 | orig_addr = addr - offset; | |
887 | ||
888 | for (seg = 0; seg < ldm->nsegs; seg++) | |
889 | { | |
890 | if (ldm->segs[seg].p_vaddr <= orig_addr | |
891 | && orig_addr < ldm->segs[seg].p_vaddr + ldm->segs[seg].p_memsz) | |
892 | { | |
893 | new_offsets->offsets[osect_idx] | |
894 | = ldm->segs[seg].addr - ldm->segs[seg].p_vaddr; | |
895 | ||
896 | if (new_offsets->offsets[osect_idx] != offset) | |
897 | changed = 1; | |
898 | break; | |
899 | } | |
900 | } | |
901 | } | |
902 | ||
903 | if (changed) | |
904 | objfile_relocate (symfile_objfile, new_offsets); | |
905 | ||
906 | do_cleanups (old_chain); | |
907 | ||
908 | /* Now that symfile_objfile has been relocated, we can compute the | |
909 | GOT value and stash it away. */ | |
910 | main_executable_lm_info->got_value = main_got (); | |
911 | } | |
912 | ||
913 | /* | |
914 | ||
915 | GLOBAL FUNCTION | |
916 | ||
917 | frv_solib_create_inferior_hook -- shared library startup support | |
918 | ||
919 | SYNOPSIS | |
920 | ||
921 | void frv_solib_create_inferior_hook() | |
922 | ||
923 | DESCRIPTION | |
924 | ||
925 | When gdb starts up the inferior, it nurses it along (through the | |
926 | shell) until it is ready to execute it's first instruction. At this | |
927 | point, this function gets called via expansion of the macro | |
928 | SOLIB_CREATE_INFERIOR_HOOK. | |
929 | ||
930 | For the FR-V shared library ABI (FDPIC), the main executable | |
931 | needs to be relocated. The shared library breakpoints also need | |
932 | to be enabled. | |
933 | */ | |
934 | ||
935 | static void | |
936 | frv_solib_create_inferior_hook (void) | |
937 | { | |
938 | /* Relocate main executable. */ | |
939 | frv_relocate_main_executable (); | |
940 | ||
941 | /* Enable shared library breakpoints. */ | |
942 | if (!enable_break ()) | |
943 | { | |
944 | warning ("shared library handler failed to enable breakpoint"); | |
945 | return; | |
946 | } | |
947 | } | |
948 | ||
949 | static void | |
950 | frv_clear_solib (void) | |
951 | { | |
952 | lm_base_cache = 0; | |
953 | enable_break1_done = 0; | |
954 | enable_break2_done = 0; | |
955 | } | |
956 | ||
957 | static void | |
958 | frv_free_so (struct so_list *so) | |
959 | { | |
960 | xfree (so->lm_info->map); | |
961 | xfree (so->lm_info->dyn_syms); | |
962 | xfree (so->lm_info->dyn_relocs); | |
963 | xfree (so->lm_info); | |
964 | } | |
965 | ||
966 | static void | |
967 | frv_relocate_section_addresses (struct so_list *so, | |
968 | struct section_table *sec) | |
969 | { | |
970 | int seg; | |
971 | struct int_elf32_fdpic_loadmap *map; | |
972 | ||
973 | map = so->lm_info->map; | |
974 | ||
975 | for (seg = 0; seg < map->nsegs; seg++) | |
976 | { | |
977 | if (map->segs[seg].p_vaddr <= sec->addr | |
978 | && sec->addr < map->segs[seg].p_vaddr + map->segs[seg].p_memsz) | |
979 | { | |
980 | CORE_ADDR displ = map->segs[seg].addr - map->segs[seg].p_vaddr; | |
981 | sec->addr += displ; | |
982 | sec->endaddr += displ; | |
983 | break; | |
984 | } | |
985 | } | |
986 | } | |
987 | ||
988 | /* Return the GOT address associated with the main executable. Return | |
989 | 0 if it can't be found. */ | |
990 | ||
991 | static CORE_ADDR | |
992 | main_got (void) | |
993 | { | |
994 | struct minimal_symbol *got_sym; | |
995 | ||
996 | got_sym = lookup_minimal_symbol ("_GLOBAL_OFFSET_TABLE_", NULL, symfile_objfile); | |
997 | if (got_sym == 0) | |
998 | return 0; | |
999 | ||
1000 | return SYMBOL_VALUE_ADDRESS (got_sym); | |
1001 | } | |
1002 | ||
1003 | /* Find the global pointer for the given function address ADDR. */ | |
1004 | ||
1005 | CORE_ADDR | |
1006 | frv_fdpic_find_global_pointer (CORE_ADDR addr) | |
1007 | { | |
1008 | struct so_list *so; | |
1009 | ||
1010 | so = master_so_list (); | |
1011 | while (so) | |
1012 | { | |
1013 | int seg; | |
1014 | struct int_elf32_fdpic_loadmap *map; | |
1015 | ||
1016 | map = so->lm_info->map; | |
1017 | ||
1018 | for (seg = 0; seg < map->nsegs; seg++) | |
1019 | { | |
1020 | if (map->segs[seg].addr <= addr | |
1021 | && addr < map->segs[seg].addr + map->segs[seg].p_memsz) | |
1022 | return so->lm_info->got_value; | |
1023 | } | |
1024 | ||
1025 | so = so->next; | |
1026 | } | |
1027 | ||
1028 | /* Didn't find it it any of the shared objects. So assume it's in the | |
1029 | main executable. */ | |
1030 | return main_got (); | |
1031 | } | |
1032 | ||
1033 | /* Forward declarations for frv_fdpic_find_canonical_descriptor(). */ | |
1034 | static CORE_ADDR find_canonical_descriptor_in_load_object | |
1035 | (CORE_ADDR, CORE_ADDR, char *, bfd *, struct lm_info *); | |
1036 | ||
1037 | /* Given a function entry point, attempt to find the canonical descriptor | |
1038 | associated with that entry point. Return 0 if no canonical descriptor | |
1039 | could be found. */ | |
1040 | ||
1041 | CORE_ADDR | |
1042 | frv_fdpic_find_canonical_descriptor (CORE_ADDR entry_point) | |
1043 | { | |
1044 | char *name; | |
1045 | CORE_ADDR addr; | |
1046 | CORE_ADDR got_value; | |
1047 | struct int_elf32_fdpic_loadmap *ldm = 0; | |
1048 | struct symbol *sym; | |
1049 | int status; | |
1050 | CORE_ADDR exec_loadmap_addr; | |
1051 | ||
1052 | /* Fetch the corresponding global pointer for the entry point. */ | |
1053 | got_value = frv_fdpic_find_global_pointer (entry_point); | |
1054 | ||
1055 | /* Attempt to find the name of the function. If the name is available, | |
1056 | it'll be used as an aid in finding matching functions in the dynamic | |
1057 | symbol table. */ | |
1058 | sym = find_pc_function (entry_point); | |
1059 | if (sym == 0) | |
1060 | name = 0; | |
1061 | else | |
1062 | name = SYMBOL_LINKAGE_NAME (sym); | |
1063 | ||
1064 | /* Check the main executable. */ | |
1065 | addr = find_canonical_descriptor_in_load_object | |
1066 | (entry_point, got_value, name, symfile_objfile->obfd, | |
1067 | main_executable_lm_info); | |
1068 | ||
1069 | /* If descriptor not found via main executable, check each load object | |
1070 | in list of shared objects. */ | |
1071 | if (addr == 0) | |
1072 | { | |
1073 | struct so_list *so; | |
1074 | ||
1075 | so = master_so_list (); | |
1076 | while (so) | |
1077 | { | |
1078 | addr = find_canonical_descriptor_in_load_object | |
1079 | (entry_point, got_value, name, so->abfd, so->lm_info); | |
1080 | ||
1081 | if (addr != 0) | |
1082 | break; | |
1083 | ||
1084 | so = so->next; | |
1085 | } | |
1086 | } | |
1087 | ||
1088 | return addr; | |
1089 | } | |
1090 | ||
1091 | static CORE_ADDR | |
1092 | find_canonical_descriptor_in_load_object | |
1093 | (CORE_ADDR entry_point, CORE_ADDR got_value, char *name, bfd *abfd, | |
1094 | struct lm_info *lm) | |
1095 | { | |
1096 | arelent *rel; | |
1097 | unsigned int i; | |
1098 | CORE_ADDR addr = 0; | |
1099 | ||
1100 | /* Nothing to do if no bfd. */ | |
1101 | if (abfd == 0) | |
1102 | return 0; | |
1103 | ||
1104 | /* We want to scan the dynamic relocs for R_FRV_FUNCDESC relocations. | |
1105 | (More about this later.) But in order to fetch the relocs, we | |
1106 | need to first fetch the dynamic symbols. These symbols need to | |
1107 | be cached due to the way that bfd_canonicalize_dynamic_reloc() | |
1108 | works. (See the comments in the declaration of struct lm_info | |
1109 | for more information.) */ | |
1110 | if (lm->dyn_syms == NULL) | |
1111 | { | |
1112 | long storage_needed; | |
1113 | unsigned int number_of_symbols; | |
1114 | ||
1115 | /* Determine amount of space needed to hold the dynamic symbol table. */ | |
1116 | storage_needed = bfd_get_dynamic_symtab_upper_bound (abfd); | |
1117 | ||
1118 | /* If there are no dynamic symbols, there's nothing to do. */ | |
1119 | if (storage_needed <= 0) | |
1120 | return 0; | |
1121 | ||
1122 | /* Allocate space for the dynamic symbol table. */ | |
1123 | lm->dyn_syms = (asymbol **) xmalloc (storage_needed); | |
1124 | ||
1125 | /* Fetch the dynamic symbol table. */ | |
1126 | number_of_symbols = bfd_canonicalize_dynamic_symtab (abfd, lm->dyn_syms); | |
1127 | ||
1128 | if (number_of_symbols == 0) | |
1129 | return 0; | |
1130 | } | |
1131 | ||
1132 | /* Fetch the dynamic relocations if not already cached. */ | |
1133 | if (lm->dyn_relocs == NULL) | |
1134 | { | |
1135 | long storage_needed; | |
1136 | ||
1137 | /* Determine amount of space needed to hold the dynamic relocs. */ | |
1138 | storage_needed = bfd_get_dynamic_reloc_upper_bound (abfd); | |
1139 | ||
1140 | /* Bail out if there are no dynamic relocs. */ | |
1141 | if (storage_needed <= 0) | |
1142 | return 0; | |
1143 | ||
1144 | /* Allocate space for the relocs. */ | |
1145 | lm->dyn_relocs = (arelent **) xmalloc (storage_needed); | |
1146 | ||
1147 | /* Fetch the dynamic relocs. */ | |
1148 | lm->dyn_reloc_count | |
1149 | = bfd_canonicalize_dynamic_reloc (abfd, lm->dyn_relocs, lm->dyn_syms); | |
1150 | } | |
1151 | ||
1152 | /* Search the dynamic relocs. */ | |
1153 | for (i = 0; i < lm->dyn_reloc_count; i++) | |
1154 | { | |
1155 | rel = lm->dyn_relocs[i]; | |
1156 | ||
1157 | /* Relocs of interest are those which meet the following | |
1158 | criteria: | |
1159 | ||
1160 | - the names match (assuming the caller could provide | |
1161 | a name which matches ``entry_point''). | |
1162 | - the relocation type must be R_FRV_FUNCDESC. Relocs | |
1163 | of this type are used (by the dynamic linker) to | |
1164 | look up the address of a canonical descriptor (allocating | |
1165 | it if need be) and initializing the GOT entry referred | |
1166 | to by the offset to the address of the descriptor. | |
1167 | ||
1168 | These relocs of interest may be used to obtain a | |
1169 | candidate descriptor by first adjusting the reloc's | |
1170 | address according to the link map and then dereferencing | |
1171 | this address (which is a GOT entry) to obtain a descriptor | |
1172 | address. */ | |
1173 | if ((name == 0 || strcmp (name, (*rel->sym_ptr_ptr)->name) == 0) | |
1174 | && rel->howto->type == R_FRV_FUNCDESC) | |
1175 | { | |
1176 | char buf[FRV_PTR_SIZE]; | |
1177 | ||
1178 | /* Compute address of address of candidate descriptor. */ | |
1179 | addr = rel->address + displacement_from_map (lm->map, rel->address); | |
1180 | ||
1181 | /* Fetch address of candidate descriptor. */ | |
1182 | if (target_read_memory (addr, buf, sizeof buf) != 0) | |
1183 | continue; | |
1184 | addr = extract_unsigned_integer (buf, sizeof buf); | |
1185 | ||
1186 | /* Check for matching entry point. */ | |
1187 | if (target_read_memory (addr, buf, sizeof buf) != 0) | |
1188 | continue; | |
1189 | if (extract_unsigned_integer (buf, sizeof buf) != entry_point) | |
1190 | continue; | |
1191 | ||
1192 | /* Check for matching got value. */ | |
1193 | if (target_read_memory (addr + 4, buf, sizeof buf) != 0) | |
1194 | continue; | |
1195 | if (extract_unsigned_integer (buf, sizeof buf) != got_value) | |
1196 | continue; | |
1197 | ||
1198 | /* Match was successful! Exit loop. */ | |
1199 | break; | |
1200 | } | |
1201 | } | |
1202 | ||
1203 | return addr; | |
1204 | } | |
1205 | ||
1206 | static struct target_so_ops frv_so_ops; | |
1207 | ||
1208 | void | |
1209 | _initialize_frv_solib (void) | |
1210 | { | |
1211 | frv_so_ops.relocate_section_addresses = frv_relocate_section_addresses; | |
1212 | frv_so_ops.free_so = frv_free_so; | |
1213 | frv_so_ops.clear_solib = frv_clear_solib; | |
1214 | frv_so_ops.solib_create_inferior_hook = frv_solib_create_inferior_hook; | |
1215 | frv_so_ops.special_symbol_handling = frv_special_symbol_handling; | |
1216 | frv_so_ops.current_sos = frv_current_sos; | |
1217 | frv_so_ops.open_symbol_file_object = open_symbol_file_object; | |
1218 | frv_so_ops.in_dynsym_resolve_code = frv_in_dynsym_resolve_code; | |
1219 | ||
1220 | /* FIXME: Don't do this here. *_gdbarch_init() should set so_ops. */ | |
1221 | current_target_so_ops = &frv_so_ops; | |
1222 | ||
1223 | /* Debug this file's internals. */ | |
1224 | add_show_from_set (add_set_cmd ("solib-frv", class_maintenance, var_zinteger, | |
1225 | &solib_frv_debug, | |
1226 | "Set internal debugging of shared library code for FR-V.\n" | |
1227 | "When non-zero, FR-V solib specific internal debugging is enabled.", | |
1228 | &setdebuglist), | |
1229 | &showdebuglist); | |
1230 | } |