Commit | Line | Data |
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ab31aa69 | 1 | /* Handle SVR4 shared libraries for GDB, the GNU Debugger. |
2f4950cd | 2 | |
6aba47ca DJ |
3 | Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000, |
4 | 2001, 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc. | |
13437d4b KB |
5 | |
6 | This file is part of GDB. | |
7 | ||
8 | This program is free software; you can redistribute it and/or modify | |
9 | it under the terms of the GNU General Public License as published by | |
10 | the Free Software Foundation; either version 2 of the License, or | |
11 | (at your option) any later version. | |
12 | ||
13 | This program is distributed in the hope that it will be useful, | |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | GNU General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
19 | along with this program; if not, write to the Free Software | |
197e01b6 EZ |
20 | Foundation, Inc., 51 Franklin Street, Fifth Floor, |
21 | Boston, MA 02110-1301, USA. */ | |
13437d4b | 22 | |
13437d4b KB |
23 | #include "defs.h" |
24 | ||
13437d4b | 25 | #include "elf/external.h" |
21479ded | 26 | #include "elf/common.h" |
f7856c8f | 27 | #include "elf/mips.h" |
13437d4b KB |
28 | |
29 | #include "symtab.h" | |
30 | #include "bfd.h" | |
31 | #include "symfile.h" | |
32 | #include "objfiles.h" | |
33 | #include "gdbcore.h" | |
13437d4b | 34 | #include "target.h" |
13437d4b | 35 | #include "inferior.h" |
13437d4b | 36 | |
4b188b9f MK |
37 | #include "gdb_assert.h" |
38 | ||
13437d4b | 39 | #include "solist.h" |
bba93f6c | 40 | #include "solib.h" |
13437d4b KB |
41 | #include "solib-svr4.h" |
42 | ||
2f4950cd | 43 | #include "bfd-target.h" |
cc10cae3 | 44 | #include "elf-bfd.h" |
2f4950cd AC |
45 | #include "exec.h" |
46 | ||
e5e2b9ff | 47 | static struct link_map_offsets *svr4_fetch_link_map_offsets (void); |
d5a921c9 | 48 | static int svr4_have_link_map_offsets (void); |
1c4dcb57 | 49 | |
4b188b9f MK |
50 | /* This hook is set to a function that provides native link map |
51 | offsets if the code in solib-legacy.c is linked in. */ | |
52 | struct link_map_offsets *(*legacy_svr4_fetch_link_map_offsets_hook) (void); | |
21479ded | 53 | |
13437d4b KB |
54 | /* Link map info to include in an allocated so_list entry */ |
55 | ||
56 | struct lm_info | |
57 | { | |
58 | /* Pointer to copy of link map from inferior. The type is char * | |
59 | rather than void *, so that we may use byte offsets to find the | |
60 | various fields without the need for a cast. */ | |
4066fc10 | 61 | gdb_byte *lm; |
cc10cae3 AO |
62 | |
63 | /* Amount by which addresses in the binary should be relocated to | |
64 | match the inferior. This could most often be taken directly | |
65 | from lm, but when prelinking is involved and the prelink base | |
66 | address changes, we may need a different offset, we want to | |
67 | warn about the difference and compute it only once. */ | |
68 | CORE_ADDR l_addr; | |
13437d4b KB |
69 | }; |
70 | ||
71 | /* On SVR4 systems, a list of symbols in the dynamic linker where | |
72 | GDB can try to place a breakpoint to monitor shared library | |
73 | events. | |
74 | ||
75 | If none of these symbols are found, or other errors occur, then | |
76 | SVR4 systems will fall back to using a symbol as the "startup | |
77 | mapping complete" breakpoint address. */ | |
78 | ||
13437d4b KB |
79 | static char *solib_break_names[] = |
80 | { | |
81 | "r_debug_state", | |
82 | "_r_debug_state", | |
83 | "_dl_debug_state", | |
84 | "rtld_db_dlactivity", | |
1f72e589 | 85 | "_rtld_debug_state", |
4c0122c8 | 86 | |
13437d4b KB |
87 | NULL |
88 | }; | |
13437d4b KB |
89 | |
90 | #define BKPT_AT_SYMBOL 1 | |
91 | ||
ab31aa69 | 92 | #if defined (BKPT_AT_SYMBOL) |
13437d4b KB |
93 | static char *bkpt_names[] = |
94 | { | |
95 | #ifdef SOLIB_BKPT_NAME | |
96 | SOLIB_BKPT_NAME, /* Prefer configured name if it exists. */ | |
97 | #endif | |
98 | "_start", | |
ad3dcc5c | 99 | "__start", |
13437d4b KB |
100 | "main", |
101 | NULL | |
102 | }; | |
103 | #endif | |
104 | ||
13437d4b KB |
105 | static char *main_name_list[] = |
106 | { | |
107 | "main_$main", | |
108 | NULL | |
109 | }; | |
110 | ||
13437d4b KB |
111 | /* link map access functions */ |
112 | ||
113 | static CORE_ADDR | |
cc10cae3 | 114 | LM_ADDR_FROM_LINK_MAP (struct so_list *so) |
13437d4b | 115 | { |
4b188b9f | 116 | struct link_map_offsets *lmo = svr4_fetch_link_map_offsets (); |
13437d4b | 117 | |
cfaefc65 AS |
118 | return extract_typed_address (so->lm_info->lm + lmo->l_addr_offset, |
119 | builtin_type_void_data_ptr); | |
13437d4b KB |
120 | } |
121 | ||
cc10cae3 AO |
122 | static int |
123 | HAS_LM_DYNAMIC_FROM_LINK_MAP () | |
124 | { | |
125 | struct link_map_offsets *lmo = svr4_fetch_link_map_offsets (); | |
126 | ||
cfaefc65 | 127 | return lmo->l_ld_offset >= 0; |
cc10cae3 AO |
128 | } |
129 | ||
130 | static CORE_ADDR | |
131 | LM_DYNAMIC_FROM_LINK_MAP (struct so_list *so) | |
132 | { | |
133 | struct link_map_offsets *lmo = svr4_fetch_link_map_offsets (); | |
134 | ||
cfaefc65 AS |
135 | return extract_typed_address (so->lm_info->lm + lmo->l_ld_offset, |
136 | builtin_type_void_data_ptr); | |
cc10cae3 AO |
137 | } |
138 | ||
139 | static CORE_ADDR | |
140 | LM_ADDR_CHECK (struct so_list *so, bfd *abfd) | |
141 | { | |
142 | if (so->lm_info->l_addr == (CORE_ADDR)-1) | |
143 | { | |
144 | struct bfd_section *dyninfo_sect; | |
145 | CORE_ADDR l_addr, l_dynaddr, dynaddr, align = 0x1000; | |
146 | ||
147 | l_addr = LM_ADDR_FROM_LINK_MAP (so); | |
148 | ||
149 | if (! abfd || ! HAS_LM_DYNAMIC_FROM_LINK_MAP ()) | |
150 | goto set_addr; | |
151 | ||
152 | l_dynaddr = LM_DYNAMIC_FROM_LINK_MAP (so); | |
153 | ||
154 | dyninfo_sect = bfd_get_section_by_name (abfd, ".dynamic"); | |
155 | if (dyninfo_sect == NULL) | |
156 | goto set_addr; | |
157 | ||
158 | dynaddr = bfd_section_vma (abfd, dyninfo_sect); | |
159 | ||
160 | if (dynaddr + l_addr != l_dynaddr) | |
161 | { | |
cc10cae3 AO |
162 | if (bfd_get_flavour (abfd) == bfd_target_elf_flavour) |
163 | { | |
164 | Elf_Internal_Ehdr *ehdr = elf_tdata (abfd)->elf_header; | |
165 | Elf_Internal_Phdr *phdr = elf_tdata (abfd)->phdr; | |
166 | int i; | |
167 | ||
168 | align = 1; | |
169 | ||
170 | for (i = 0; i < ehdr->e_phnum; i++) | |
171 | if (phdr[i].p_type == PT_LOAD && phdr[i].p_align > align) | |
172 | align = phdr[i].p_align; | |
173 | } | |
174 | ||
175 | /* Turn it into a mask. */ | |
176 | align--; | |
177 | ||
178 | /* If the changes match the alignment requirements, we | |
179 | assume we're using a core file that was generated by the | |
180 | same binary, just prelinked with a different base offset. | |
181 | If it doesn't match, we may have a different binary, the | |
182 | same binary with the dynamic table loaded at an unrelated | |
183 | location, or anything, really. To avoid regressions, | |
184 | don't adjust the base offset in the latter case, although | |
185 | odds are that, if things really changed, debugging won't | |
186 | quite work. */ | |
f1e55806 | 187 | if ((l_addr & align) == ((l_dynaddr - dynaddr) & align)) |
cc10cae3 AO |
188 | { |
189 | l_addr = l_dynaddr - dynaddr; | |
79d4c408 DJ |
190 | |
191 | warning (_(".dynamic section for \"%s\" " | |
192 | "is not at the expected address"), so->so_name); | |
cc10cae3 AO |
193 | warning (_("difference appears to be caused by prelink, " |
194 | "adjusting expectations")); | |
195 | } | |
79d4c408 DJ |
196 | else |
197 | warning (_(".dynamic section for \"%s\" " | |
198 | "is not at the expected address " | |
199 | "(wrong library or version mismatch?)"), so->so_name); | |
cc10cae3 AO |
200 | } |
201 | ||
202 | set_addr: | |
203 | so->lm_info->l_addr = l_addr; | |
204 | } | |
205 | ||
206 | return so->lm_info->l_addr; | |
207 | } | |
208 | ||
13437d4b KB |
209 | static CORE_ADDR |
210 | LM_NEXT (struct so_list *so) | |
211 | { | |
4b188b9f | 212 | struct link_map_offsets *lmo = svr4_fetch_link_map_offsets (); |
13437d4b | 213 | |
cfaefc65 AS |
214 | return extract_typed_address (so->lm_info->lm + lmo->l_next_offset, |
215 | builtin_type_void_data_ptr); | |
13437d4b KB |
216 | } |
217 | ||
218 | static CORE_ADDR | |
219 | LM_NAME (struct so_list *so) | |
220 | { | |
4b188b9f | 221 | struct link_map_offsets *lmo = svr4_fetch_link_map_offsets (); |
13437d4b | 222 | |
cfaefc65 AS |
223 | return extract_typed_address (so->lm_info->lm + lmo->l_name_offset, |
224 | builtin_type_void_data_ptr); | |
13437d4b KB |
225 | } |
226 | ||
13437d4b KB |
227 | static int |
228 | IGNORE_FIRST_LINK_MAP_ENTRY (struct so_list *so) | |
229 | { | |
4b188b9f | 230 | struct link_map_offsets *lmo = svr4_fetch_link_map_offsets (); |
13437d4b | 231 | |
e499d0f1 DJ |
232 | /* Assume that everything is a library if the dynamic loader was loaded |
233 | late by a static executable. */ | |
234 | if (bfd_get_section_by_name (exec_bfd, ".dynamic") == NULL) | |
235 | return 0; | |
236 | ||
cfaefc65 AS |
237 | return extract_typed_address (so->lm_info->lm + lmo->l_prev_offset, |
238 | builtin_type_void_data_ptr) == 0; | |
13437d4b KB |
239 | } |
240 | ||
13437d4b | 241 | static CORE_ADDR debug_base; /* Base of dynamic linker structures */ |
13437d4b | 242 | |
34439770 DJ |
243 | /* Validity flag for debug_loader_offset. */ |
244 | static int debug_loader_offset_p; | |
245 | ||
246 | /* Load address for the dynamic linker, inferred. */ | |
247 | static CORE_ADDR debug_loader_offset; | |
248 | ||
249 | /* Name of the dynamic linker, valid if debug_loader_offset_p. */ | |
250 | static char *debug_loader_name; | |
251 | ||
13437d4b KB |
252 | /* Local function prototypes */ |
253 | ||
254 | static int match_main (char *); | |
255 | ||
2bbe3cc1 | 256 | static CORE_ADDR bfd_lookup_symbol (bfd *, char *); |
13437d4b KB |
257 | |
258 | /* | |
259 | ||
260 | LOCAL FUNCTION | |
261 | ||
262 | bfd_lookup_symbol -- lookup the value for a specific symbol | |
263 | ||
264 | SYNOPSIS | |
265 | ||
2bbe3cc1 | 266 | CORE_ADDR bfd_lookup_symbol (bfd *abfd, char *symname) |
13437d4b KB |
267 | |
268 | DESCRIPTION | |
269 | ||
270 | An expensive way to lookup the value of a single symbol for | |
271 | bfd's that are only temporary anyway. This is used by the | |
272 | shared library support to find the address of the debugger | |
2bbe3cc1 | 273 | notification routine in the shared library. |
13437d4b | 274 | |
2bbe3cc1 DJ |
275 | The returned symbol may be in a code or data section; functions |
276 | will normally be in a code section, but may be in a data section | |
277 | if this architecture uses function descriptors. | |
87f84c9d | 278 | |
13437d4b KB |
279 | Note that 0 is specifically allowed as an error return (no |
280 | such symbol). | |
281 | */ | |
282 | ||
283 | static CORE_ADDR | |
2bbe3cc1 | 284 | bfd_lookup_symbol (bfd *abfd, char *symname) |
13437d4b | 285 | { |
435b259c | 286 | long storage_needed; |
13437d4b KB |
287 | asymbol *sym; |
288 | asymbol **symbol_table; | |
289 | unsigned int number_of_symbols; | |
290 | unsigned int i; | |
291 | struct cleanup *back_to; | |
292 | CORE_ADDR symaddr = 0; | |
293 | ||
294 | storage_needed = bfd_get_symtab_upper_bound (abfd); | |
295 | ||
296 | if (storage_needed > 0) | |
297 | { | |
298 | symbol_table = (asymbol **) xmalloc (storage_needed); | |
4efb68b1 | 299 | back_to = make_cleanup (xfree, symbol_table); |
13437d4b KB |
300 | number_of_symbols = bfd_canonicalize_symtab (abfd, symbol_table); |
301 | ||
302 | for (i = 0; i < number_of_symbols; i++) | |
303 | { | |
304 | sym = *symbol_table++; | |
6314a349 | 305 | if (strcmp (sym->name, symname) == 0 |
2bbe3cc1 | 306 | && (sym->section->flags & (SEC_CODE | SEC_DATA)) != 0) |
13437d4b | 307 | { |
2bbe3cc1 | 308 | /* BFD symbols are section relative. */ |
13437d4b KB |
309 | symaddr = sym->value + sym->section->vma; |
310 | break; | |
311 | } | |
312 | } | |
313 | do_cleanups (back_to); | |
314 | } | |
315 | ||
316 | if (symaddr) | |
317 | return symaddr; | |
318 | ||
319 | /* On FreeBSD, the dynamic linker is stripped by default. So we'll | |
320 | have to check the dynamic string table too. */ | |
321 | ||
322 | storage_needed = bfd_get_dynamic_symtab_upper_bound (abfd); | |
323 | ||
324 | if (storage_needed > 0) | |
325 | { | |
326 | symbol_table = (asymbol **) xmalloc (storage_needed); | |
4efb68b1 | 327 | back_to = make_cleanup (xfree, symbol_table); |
13437d4b KB |
328 | number_of_symbols = bfd_canonicalize_dynamic_symtab (abfd, symbol_table); |
329 | ||
330 | for (i = 0; i < number_of_symbols; i++) | |
331 | { | |
332 | sym = *symbol_table++; | |
87f84c9d | 333 | |
6314a349 | 334 | if (strcmp (sym->name, symname) == 0 |
2bbe3cc1 | 335 | && (sym->section->flags & (SEC_CODE | SEC_DATA)) != 0) |
13437d4b | 336 | { |
2bbe3cc1 | 337 | /* BFD symbols are section relative. */ |
13437d4b KB |
338 | symaddr = sym->value + sym->section->vma; |
339 | break; | |
340 | } | |
341 | } | |
342 | do_cleanups (back_to); | |
343 | } | |
344 | ||
345 | return symaddr; | |
346 | } | |
347 | ||
3a40aaa0 UW |
348 | /* Scan for DYNTAG in .dynamic section of ABFD. If DYNTAG is found 1 is |
349 | returned and the corresponding PTR is set. */ | |
350 | ||
351 | static int | |
352 | scan_dyntag (int dyntag, bfd *abfd, CORE_ADDR *ptr) | |
353 | { | |
354 | int arch_size, step, sect_size; | |
355 | long dyn_tag; | |
356 | CORE_ADDR dyn_ptr, dyn_addr; | |
357 | gdb_byte *bufend, *buf; | |
358 | Elf32_External_Dyn *x_dynp_32; | |
359 | Elf64_External_Dyn *x_dynp_64; | |
360 | struct bfd_section *sect; | |
361 | ||
362 | if (abfd == NULL) | |
363 | return 0; | |
364 | arch_size = bfd_get_arch_size (abfd); | |
365 | if (arch_size == -1) | |
366 | return 0; | |
367 | ||
368 | /* Find the start address of the .dynamic section. */ | |
369 | sect = bfd_get_section_by_name (abfd, ".dynamic"); | |
370 | if (sect == NULL) | |
371 | return 0; | |
372 | dyn_addr = bfd_section_vma (abfd, sect); | |
373 | ||
374 | /* Read in .dynamic section, silently ignore errors. */ | |
375 | sect_size = bfd_section_size (abfd, sect); | |
376 | buf = alloca (sect_size); | |
377 | if (target_read_memory (dyn_addr, buf, sect_size)) | |
378 | { | |
379 | /* If target_read_memory fails, try reading the BFD file. */ | |
380 | if (!bfd_get_section_contents (abfd, sect, | |
381 | buf, 0, sect_size)) | |
382 | return 0; | |
383 | } | |
384 | ||
385 | /* Iterate over BUF and scan for DYNTAG. If found, set PTR and return. */ | |
386 | step = (arch_size == 32) ? sizeof (Elf32_External_Dyn) | |
387 | : sizeof (Elf64_External_Dyn); | |
388 | for (bufend = buf + sect_size; | |
389 | buf < bufend; | |
390 | buf += step) | |
391 | { | |
392 | if (arch_size == 32) | |
393 | { | |
394 | x_dynp_32 = (Elf32_External_Dyn *) buf; | |
395 | dyn_tag = bfd_h_get_32 (abfd, (bfd_byte *) x_dynp_32->d_tag); | |
396 | dyn_ptr = bfd_h_get_32 (abfd, (bfd_byte *) x_dynp_32->d_un.d_ptr); | |
397 | } | |
398 | else | |
399 | { | |
400 | x_dynp_64 = (Elf64_External_Dyn *) buf; | |
401 | dyn_tag = bfd_h_get_64 (abfd, (bfd_byte *) x_dynp_64->d_tag); | |
402 | dyn_ptr = bfd_h_get_64 (abfd, (bfd_byte *) x_dynp_64->d_un.d_ptr); | |
403 | } | |
404 | if (dyn_tag == DT_NULL) | |
405 | return 0; | |
406 | if (dyn_tag == dyntag) | |
407 | { | |
408 | if (ptr) | |
409 | *ptr = dyn_ptr; | |
410 | return 1; | |
411 | } | |
412 | } | |
413 | ||
414 | return 0; | |
415 | } | |
416 | ||
417 | ||
13437d4b KB |
418 | /* |
419 | ||
420 | LOCAL FUNCTION | |
421 | ||
422 | elf_locate_base -- locate the base address of dynamic linker structs | |
423 | for SVR4 elf targets. | |
424 | ||
425 | SYNOPSIS | |
426 | ||
427 | CORE_ADDR elf_locate_base (void) | |
428 | ||
429 | DESCRIPTION | |
430 | ||
431 | For SVR4 elf targets the address of the dynamic linker's runtime | |
432 | structure is contained within the dynamic info section in the | |
433 | executable file. The dynamic section is also mapped into the | |
434 | inferior address space. Because the runtime loader fills in the | |
435 | real address before starting the inferior, we have to read in the | |
436 | dynamic info section from the inferior address space. | |
437 | If there are any errors while trying to find the address, we | |
438 | silently return 0, otherwise the found address is returned. | |
439 | ||
440 | */ | |
441 | ||
442 | static CORE_ADDR | |
443 | elf_locate_base (void) | |
444 | { | |
3a40aaa0 UW |
445 | struct minimal_symbol *msymbol; |
446 | CORE_ADDR dyn_ptr; | |
13437d4b | 447 | |
3a40aaa0 UW |
448 | /* Find DT_DEBUG. */ |
449 | if (scan_dyntag (DT_DEBUG, exec_bfd, &dyn_ptr)) | |
450 | return dyn_ptr; | |
e499d0f1 | 451 | |
3a40aaa0 UW |
452 | /* Find DT_MIPS_RLD_MAP. */ |
453 | if (scan_dyntag (DT_MIPS_RLD_MAP, exec_bfd, &dyn_ptr)) | |
454 | { | |
455 | gdb_byte *pbuf; | |
456 | int pbuf_size = TYPE_LENGTH (builtin_type_void_data_ptr); | |
457 | pbuf = alloca (pbuf_size); | |
458 | /* DT_MIPS_RLD_MAP contains a pointer to the address | |
459 | of the dynamic link structure. */ | |
460 | if (target_read_memory (dyn_ptr, pbuf, pbuf_size)) | |
e499d0f1 | 461 | return 0; |
3a40aaa0 | 462 | return extract_typed_address (pbuf, builtin_type_void_data_ptr); |
e499d0f1 DJ |
463 | } |
464 | ||
3a40aaa0 UW |
465 | /* This may be a static executable. Look for the symbol |
466 | conventionally named _r_debug, as a last resort. */ | |
467 | msymbol = lookup_minimal_symbol ("_r_debug", NULL, symfile_objfile); | |
468 | if (msymbol != NULL) | |
469 | return SYMBOL_VALUE_ADDRESS (msymbol); | |
13437d4b KB |
470 | |
471 | /* DT_DEBUG entry not found. */ | |
472 | return 0; | |
473 | } | |
474 | ||
13437d4b KB |
475 | /* |
476 | ||
477 | LOCAL FUNCTION | |
478 | ||
479 | locate_base -- locate the base address of dynamic linker structs | |
480 | ||
481 | SYNOPSIS | |
482 | ||
483 | CORE_ADDR locate_base (void) | |
484 | ||
485 | DESCRIPTION | |
486 | ||
487 | For both the SunOS and SVR4 shared library implementations, if the | |
488 | inferior executable has been linked dynamically, there is a single | |
489 | address somewhere in the inferior's data space which is the key to | |
490 | locating all of the dynamic linker's runtime structures. This | |
491 | address is the value of the debug base symbol. The job of this | |
492 | function is to find and return that address, or to return 0 if there | |
493 | is no such address (the executable is statically linked for example). | |
494 | ||
495 | For SunOS, the job is almost trivial, since the dynamic linker and | |
496 | all of it's structures are statically linked to the executable at | |
497 | link time. Thus the symbol for the address we are looking for has | |
498 | already been added to the minimal symbol table for the executable's | |
499 | objfile at the time the symbol file's symbols were read, and all we | |
500 | have to do is look it up there. Note that we explicitly do NOT want | |
501 | to find the copies in the shared library. | |
502 | ||
503 | The SVR4 version is a bit more complicated because the address | |
504 | is contained somewhere in the dynamic info section. We have to go | |
505 | to a lot more work to discover the address of the debug base symbol. | |
506 | Because of this complexity, we cache the value we find and return that | |
507 | value on subsequent invocations. Note there is no copy in the | |
508 | executable symbol tables. | |
509 | ||
510 | */ | |
511 | ||
512 | static CORE_ADDR | |
513 | locate_base (void) | |
514 | { | |
13437d4b KB |
515 | /* Check to see if we have a currently valid address, and if so, avoid |
516 | doing all this work again and just return the cached address. If | |
517 | we have no cached address, try to locate it in the dynamic info | |
d5a921c9 KB |
518 | section for ELF executables. There's no point in doing any of this |
519 | though if we don't have some link map offsets to work with. */ | |
13437d4b | 520 | |
d5a921c9 | 521 | if (debug_base == 0 && svr4_have_link_map_offsets ()) |
13437d4b KB |
522 | { |
523 | if (exec_bfd != NULL | |
524 | && bfd_get_flavour (exec_bfd) == bfd_target_elf_flavour) | |
525 | debug_base = elf_locate_base (); | |
13437d4b KB |
526 | } |
527 | return (debug_base); | |
13437d4b KB |
528 | } |
529 | ||
e4cd0d6a MK |
530 | /* Find the first element in the inferior's dynamic link map, and |
531 | return its address in the inferior. | |
13437d4b | 532 | |
e4cd0d6a MK |
533 | FIXME: Perhaps we should validate the info somehow, perhaps by |
534 | checking r_version for a known version number, or r_state for | |
535 | RT_CONSISTENT. */ | |
13437d4b KB |
536 | |
537 | static CORE_ADDR | |
e4cd0d6a | 538 | solib_svr4_r_map (void) |
13437d4b | 539 | { |
4b188b9f | 540 | struct link_map_offsets *lmo = svr4_fetch_link_map_offsets (); |
13437d4b | 541 | |
e4cd0d6a MK |
542 | return read_memory_typed_address (debug_base + lmo->r_map_offset, |
543 | builtin_type_void_data_ptr); | |
544 | } | |
13437d4b | 545 | |
e4cd0d6a MK |
546 | /* Find the link map for the dynamic linker (if it is not in the |
547 | normal list of loaded shared objects). */ | |
13437d4b | 548 | |
e4cd0d6a MK |
549 | static CORE_ADDR |
550 | solib_svr4_r_ldsomap (void) | |
551 | { | |
552 | struct link_map_offsets *lmo = svr4_fetch_link_map_offsets (); | |
553 | ULONGEST version; | |
13437d4b | 554 | |
e4cd0d6a MK |
555 | /* Check version, and return zero if `struct r_debug' doesn't have |
556 | the r_ldsomap member. */ | |
557 | version = read_memory_unsigned_integer (debug_base + lmo->r_version_offset, | |
558 | lmo->r_version_size); | |
559 | if (version < 2 || lmo->r_ldsomap_offset == -1) | |
560 | return 0; | |
13437d4b | 561 | |
e4cd0d6a MK |
562 | return read_memory_typed_address (debug_base + lmo->r_ldsomap_offset, |
563 | builtin_type_void_data_ptr); | |
13437d4b KB |
564 | } |
565 | ||
13437d4b KB |
566 | /* |
567 | ||
568 | LOCAL FUNCTION | |
569 | ||
570 | open_symbol_file_object | |
571 | ||
572 | SYNOPSIS | |
573 | ||
574 | void open_symbol_file_object (void *from_tty) | |
575 | ||
576 | DESCRIPTION | |
577 | ||
578 | If no open symbol file, attempt to locate and open the main symbol | |
579 | file. On SVR4 systems, this is the first link map entry. If its | |
580 | name is here, we can open it. Useful when attaching to a process | |
581 | without first loading its symbol file. | |
582 | ||
583 | If FROM_TTYP dereferences to a non-zero integer, allow messages to | |
584 | be printed. This parameter is a pointer rather than an int because | |
585 | open_symbol_file_object() is called via catch_errors() and | |
586 | catch_errors() requires a pointer argument. */ | |
587 | ||
588 | static int | |
589 | open_symbol_file_object (void *from_ttyp) | |
590 | { | |
591 | CORE_ADDR lm, l_name; | |
592 | char *filename; | |
593 | int errcode; | |
594 | int from_tty = *(int *)from_ttyp; | |
4b188b9f | 595 | struct link_map_offsets *lmo = svr4_fetch_link_map_offsets (); |
cfaefc65 AS |
596 | int l_name_size = TYPE_LENGTH (builtin_type_void_data_ptr); |
597 | gdb_byte *l_name_buf = xmalloc (l_name_size); | |
b8c9b27d | 598 | struct cleanup *cleanups = make_cleanup (xfree, l_name_buf); |
13437d4b KB |
599 | |
600 | if (symfile_objfile) | |
601 | if (!query ("Attempt to reload symbols from process? ")) | |
602 | return 0; | |
603 | ||
604 | if ((debug_base = locate_base ()) == 0) | |
605 | return 0; /* failed somehow... */ | |
606 | ||
607 | /* First link map member should be the executable. */ | |
e4cd0d6a MK |
608 | lm = solib_svr4_r_map (); |
609 | if (lm == 0) | |
13437d4b KB |
610 | return 0; /* failed somehow... */ |
611 | ||
612 | /* Read address of name from target memory to GDB. */ | |
cfaefc65 | 613 | read_memory (lm + lmo->l_name_offset, l_name_buf, l_name_size); |
13437d4b | 614 | |
cfaefc65 AS |
615 | /* Convert the address to host format. */ |
616 | l_name = extract_typed_address (l_name_buf, builtin_type_void_data_ptr); | |
13437d4b KB |
617 | |
618 | /* Free l_name_buf. */ | |
619 | do_cleanups (cleanups); | |
620 | ||
621 | if (l_name == 0) | |
622 | return 0; /* No filename. */ | |
623 | ||
624 | /* Now fetch the filename from target memory. */ | |
625 | target_read_string (l_name, &filename, SO_NAME_MAX_PATH_SIZE - 1, &errcode); | |
626 | ||
627 | if (errcode) | |
628 | { | |
8a3fe4f8 | 629 | warning (_("failed to read exec filename from attached file: %s"), |
13437d4b KB |
630 | safe_strerror (errcode)); |
631 | return 0; | |
632 | } | |
633 | ||
b8c9b27d | 634 | make_cleanup (xfree, filename); |
13437d4b | 635 | /* Have a pathname: read the symbol file. */ |
1adeb98a | 636 | symbol_file_add_main (filename, from_tty); |
13437d4b KB |
637 | |
638 | return 1; | |
639 | } | |
13437d4b | 640 | |
34439770 DJ |
641 | /* If no shared library information is available from the dynamic |
642 | linker, build a fallback list from other sources. */ | |
643 | ||
644 | static struct so_list * | |
645 | svr4_default_sos (void) | |
646 | { | |
647 | struct so_list *head = NULL; | |
648 | struct so_list **link_ptr = &head; | |
649 | ||
650 | if (debug_loader_offset_p) | |
651 | { | |
652 | struct so_list *new = XZALLOC (struct so_list); | |
653 | ||
654 | new->lm_info = xmalloc (sizeof (struct lm_info)); | |
655 | ||
656 | /* Nothing will ever check the cached copy of the link | |
657 | map if we set l_addr. */ | |
658 | new->lm_info->l_addr = debug_loader_offset; | |
659 | new->lm_info->lm = NULL; | |
660 | ||
661 | strncpy (new->so_name, debug_loader_name, SO_NAME_MAX_PATH_SIZE - 1); | |
662 | new->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0'; | |
663 | strcpy (new->so_original_name, new->so_name); | |
664 | ||
665 | *link_ptr = new; | |
666 | link_ptr = &new->next; | |
667 | } | |
668 | ||
669 | return head; | |
670 | } | |
671 | ||
13437d4b KB |
672 | /* LOCAL FUNCTION |
673 | ||
674 | current_sos -- build a list of currently loaded shared objects | |
675 | ||
676 | SYNOPSIS | |
677 | ||
678 | struct so_list *current_sos () | |
679 | ||
680 | DESCRIPTION | |
681 | ||
682 | Build a list of `struct so_list' objects describing the shared | |
683 | objects currently loaded in the inferior. This list does not | |
684 | include an entry for the main executable file. | |
685 | ||
686 | Note that we only gather information directly available from the | |
687 | inferior --- we don't examine any of the shared library files | |
688 | themselves. The declaration of `struct so_list' says which fields | |
689 | we provide values for. */ | |
690 | ||
691 | static struct so_list * | |
692 | svr4_current_sos (void) | |
693 | { | |
694 | CORE_ADDR lm; | |
695 | struct so_list *head = 0; | |
696 | struct so_list **link_ptr = &head; | |
e4cd0d6a | 697 | CORE_ADDR ldsomap = 0; |
13437d4b KB |
698 | |
699 | /* Make sure we've looked up the inferior's dynamic linker's base | |
700 | structure. */ | |
701 | if (! debug_base) | |
702 | { | |
703 | debug_base = locate_base (); | |
704 | ||
705 | /* If we can't find the dynamic linker's base structure, this | |
706 | must not be a dynamically linked executable. Hmm. */ | |
707 | if (! debug_base) | |
34439770 | 708 | return svr4_default_sos (); |
13437d4b KB |
709 | } |
710 | ||
711 | /* Walk the inferior's link map list, and build our list of | |
712 | `struct so_list' nodes. */ | |
e4cd0d6a | 713 | lm = solib_svr4_r_map (); |
34439770 | 714 | |
13437d4b KB |
715 | while (lm) |
716 | { | |
4b188b9f | 717 | struct link_map_offsets *lmo = svr4_fetch_link_map_offsets (); |
f4456994 | 718 | struct so_list *new = XZALLOC (struct so_list); |
b8c9b27d | 719 | struct cleanup *old_chain = make_cleanup (xfree, new); |
13437d4b | 720 | |
13437d4b | 721 | new->lm_info = xmalloc (sizeof (struct lm_info)); |
b8c9b27d | 722 | make_cleanup (xfree, new->lm_info); |
13437d4b | 723 | |
831004b7 | 724 | new->lm_info->l_addr = (CORE_ADDR)-1; |
f4456994 | 725 | new->lm_info->lm = xzalloc (lmo->link_map_size); |
b8c9b27d | 726 | make_cleanup (xfree, new->lm_info->lm); |
13437d4b KB |
727 | |
728 | read_memory (lm, new->lm_info->lm, lmo->link_map_size); | |
729 | ||
730 | lm = LM_NEXT (new); | |
731 | ||
732 | /* For SVR4 versions, the first entry in the link map is for the | |
733 | inferior executable, so we must ignore it. For some versions of | |
734 | SVR4, it has no name. For others (Solaris 2.3 for example), it | |
735 | does have a name, so we can no longer use a missing name to | |
736 | decide when to ignore it. */ | |
e4cd0d6a | 737 | if (IGNORE_FIRST_LINK_MAP_ENTRY (new) && ldsomap == 0) |
13437d4b KB |
738 | free_so (new); |
739 | else | |
740 | { | |
741 | int errcode; | |
742 | char *buffer; | |
743 | ||
744 | /* Extract this shared object's name. */ | |
745 | target_read_string (LM_NAME (new), &buffer, | |
746 | SO_NAME_MAX_PATH_SIZE - 1, &errcode); | |
747 | if (errcode != 0) | |
8a3fe4f8 AC |
748 | warning (_("Can't read pathname for load map: %s."), |
749 | safe_strerror (errcode)); | |
13437d4b KB |
750 | else |
751 | { | |
752 | strncpy (new->so_name, buffer, SO_NAME_MAX_PATH_SIZE - 1); | |
753 | new->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0'; | |
b8c9b27d | 754 | xfree (buffer); |
13437d4b KB |
755 | strcpy (new->so_original_name, new->so_name); |
756 | } | |
757 | ||
758 | /* If this entry has no name, or its name matches the name | |
759 | for the main executable, don't include it in the list. */ | |
760 | if (! new->so_name[0] | |
761 | || match_main (new->so_name)) | |
762 | free_so (new); | |
763 | else | |
764 | { | |
765 | new->next = 0; | |
766 | *link_ptr = new; | |
767 | link_ptr = &new->next; | |
768 | } | |
769 | } | |
770 | ||
e4cd0d6a MK |
771 | /* On Solaris, the dynamic linker is not in the normal list of |
772 | shared objects, so make sure we pick it up too. Having | |
773 | symbol information for the dynamic linker is quite crucial | |
774 | for skipping dynamic linker resolver code. */ | |
775 | if (lm == 0 && ldsomap == 0) | |
776 | lm = ldsomap = solib_svr4_r_ldsomap (); | |
777 | ||
13437d4b KB |
778 | discard_cleanups (old_chain); |
779 | } | |
780 | ||
34439770 DJ |
781 | if (head == NULL) |
782 | return svr4_default_sos (); | |
783 | ||
13437d4b KB |
784 | return head; |
785 | } | |
786 | ||
bc4a16ae EZ |
787 | /* Get the address of the link_map for a given OBJFILE. Loop through |
788 | the link maps, and return the address of the one corresponding to | |
789 | the given objfile. Note that this function takes into account that | |
790 | objfile can be the main executable, not just a shared library. The | |
791 | main executable has always an empty name field in the linkmap. */ | |
792 | ||
793 | CORE_ADDR | |
794 | svr4_fetch_objfile_link_map (struct objfile *objfile) | |
795 | { | |
796 | CORE_ADDR lm; | |
797 | ||
798 | if ((debug_base = locate_base ()) == 0) | |
799 | return 0; /* failed somehow... */ | |
800 | ||
801 | /* Position ourselves on the first link map. */ | |
e4cd0d6a | 802 | lm = solib_svr4_r_map (); |
bc4a16ae EZ |
803 | while (lm) |
804 | { | |
805 | /* Get info on the layout of the r_debug and link_map structures. */ | |
4b188b9f | 806 | struct link_map_offsets *lmo = svr4_fetch_link_map_offsets (); |
bc4a16ae EZ |
807 | int errcode; |
808 | char *buffer; | |
809 | struct lm_info objfile_lm_info; | |
810 | struct cleanup *old_chain; | |
811 | CORE_ADDR name_address; | |
cfaefc65 AS |
812 | int l_name_size = TYPE_LENGTH (builtin_type_void_data_ptr); |
813 | gdb_byte *l_name_buf = xmalloc (l_name_size); | |
bc4a16ae EZ |
814 | old_chain = make_cleanup (xfree, l_name_buf); |
815 | ||
816 | /* Set up the buffer to contain the portion of the link_map | |
817 | structure that gdb cares about. Note that this is not the | |
818 | whole link_map structure. */ | |
f4456994 | 819 | objfile_lm_info.lm = xzalloc (lmo->link_map_size); |
bc4a16ae | 820 | make_cleanup (xfree, objfile_lm_info.lm); |
bc4a16ae EZ |
821 | |
822 | /* Read the link map into our internal structure. */ | |
823 | read_memory (lm, objfile_lm_info.lm, lmo->link_map_size); | |
824 | ||
825 | /* Read address of name from target memory to GDB. */ | |
cfaefc65 | 826 | read_memory (lm + lmo->l_name_offset, l_name_buf, l_name_size); |
bc4a16ae | 827 | |
cfaefc65 AS |
828 | /* Extract this object's name. */ |
829 | name_address = extract_typed_address (l_name_buf, | |
830 | builtin_type_void_data_ptr); | |
bc4a16ae EZ |
831 | target_read_string (name_address, &buffer, |
832 | SO_NAME_MAX_PATH_SIZE - 1, &errcode); | |
833 | make_cleanup (xfree, buffer); | |
834 | if (errcode != 0) | |
8a3fe4f8 AC |
835 | warning (_("Can't read pathname for load map: %s."), |
836 | safe_strerror (errcode)); | |
bc4a16ae EZ |
837 | else |
838 | { | |
839 | /* Is this the linkmap for the file we want? */ | |
840 | /* If the file is not a shared library and has no name, | |
841 | we are sure it is the main executable, so we return that. */ | |
f52df7d9 MS |
842 | |
843 | if (buffer | |
844 | && ((strcmp (buffer, objfile->name) == 0) | |
845 | || (!(objfile->flags & OBJF_SHARED) | |
846 | && (strcmp (buffer, "") == 0)))) | |
bc4a16ae EZ |
847 | { |
848 | do_cleanups (old_chain); | |
849 | return lm; | |
850 | } | |
851 | } | |
cfaefc65 AS |
852 | /* Not the file we wanted, continue checking. */ |
853 | lm = extract_typed_address (objfile_lm_info.lm + lmo->l_next_offset, | |
854 | builtin_type_void_data_ptr); | |
bc4a16ae EZ |
855 | do_cleanups (old_chain); |
856 | } | |
857 | return 0; | |
858 | } | |
13437d4b KB |
859 | |
860 | /* On some systems, the only way to recognize the link map entry for | |
861 | the main executable file is by looking at its name. Return | |
862 | non-zero iff SONAME matches one of the known main executable names. */ | |
863 | ||
864 | static int | |
865 | match_main (char *soname) | |
866 | { | |
867 | char **mainp; | |
868 | ||
869 | for (mainp = main_name_list; *mainp != NULL; mainp++) | |
870 | { | |
871 | if (strcmp (soname, *mainp) == 0) | |
872 | return (1); | |
873 | } | |
874 | ||
875 | return (0); | |
876 | } | |
877 | ||
13437d4b KB |
878 | /* Return 1 if PC lies in the dynamic symbol resolution code of the |
879 | SVR4 run time loader. */ | |
13437d4b KB |
880 | static CORE_ADDR interp_text_sect_low; |
881 | static CORE_ADDR interp_text_sect_high; | |
882 | static CORE_ADDR interp_plt_sect_low; | |
883 | static CORE_ADDR interp_plt_sect_high; | |
884 | ||
7d522c90 | 885 | int |
d7fa2ae2 | 886 | svr4_in_dynsym_resolve_code (CORE_ADDR pc) |
13437d4b KB |
887 | { |
888 | return ((pc >= interp_text_sect_low && pc < interp_text_sect_high) | |
889 | || (pc >= interp_plt_sect_low && pc < interp_plt_sect_high) | |
890 | || in_plt_section (pc, NULL)); | |
891 | } | |
13437d4b | 892 | |
2f4950cd AC |
893 | /* Given an executable's ABFD and target, compute the entry-point |
894 | address. */ | |
895 | ||
896 | static CORE_ADDR | |
897 | exec_entry_point (struct bfd *abfd, struct target_ops *targ) | |
898 | { | |
899 | /* KevinB wrote ... for most targets, the address returned by | |
900 | bfd_get_start_address() is the entry point for the start | |
901 | function. But, for some targets, bfd_get_start_address() returns | |
902 | the address of a function descriptor from which the entry point | |
903 | address may be extracted. This address is extracted by | |
904 | gdbarch_convert_from_func_ptr_addr(). The method | |
905 | gdbarch_convert_from_func_ptr_addr() is the merely the identify | |
906 | function for targets which don't use function descriptors. */ | |
907 | return gdbarch_convert_from_func_ptr_addr (current_gdbarch, | |
908 | bfd_get_start_address (abfd), | |
909 | targ); | |
910 | } | |
13437d4b KB |
911 | |
912 | /* | |
913 | ||
914 | LOCAL FUNCTION | |
915 | ||
916 | enable_break -- arrange for dynamic linker to hit breakpoint | |
917 | ||
918 | SYNOPSIS | |
919 | ||
920 | int enable_break (void) | |
921 | ||
922 | DESCRIPTION | |
923 | ||
924 | Both the SunOS and the SVR4 dynamic linkers have, as part of their | |
925 | debugger interface, support for arranging for the inferior to hit | |
926 | a breakpoint after mapping in the shared libraries. This function | |
927 | enables that breakpoint. | |
928 | ||
929 | For SunOS, there is a special flag location (in_debugger) which we | |
930 | set to 1. When the dynamic linker sees this flag set, it will set | |
931 | a breakpoint at a location known only to itself, after saving the | |
932 | original contents of that place and the breakpoint address itself, | |
933 | in it's own internal structures. When we resume the inferior, it | |
934 | will eventually take a SIGTRAP when it runs into the breakpoint. | |
935 | We handle this (in a different place) by restoring the contents of | |
936 | the breakpointed location (which is only known after it stops), | |
937 | chasing around to locate the shared libraries that have been | |
938 | loaded, then resuming. | |
939 | ||
940 | For SVR4, the debugger interface structure contains a member (r_brk) | |
941 | which is statically initialized at the time the shared library is | |
942 | built, to the offset of a function (_r_debug_state) which is guaran- | |
943 | teed to be called once before mapping in a library, and again when | |
944 | the mapping is complete. At the time we are examining this member, | |
945 | it contains only the unrelocated offset of the function, so we have | |
946 | to do our own relocation. Later, when the dynamic linker actually | |
947 | runs, it relocates r_brk to be the actual address of _r_debug_state(). | |
948 | ||
949 | The debugger interface structure also contains an enumeration which | |
950 | is set to either RT_ADD or RT_DELETE prior to changing the mapping, | |
951 | depending upon whether or not the library is being mapped or unmapped, | |
952 | and then set to RT_CONSISTENT after the library is mapped/unmapped. | |
953 | */ | |
954 | ||
955 | static int | |
956 | enable_break (void) | |
957 | { | |
13437d4b KB |
958 | #ifdef BKPT_AT_SYMBOL |
959 | ||
960 | struct minimal_symbol *msymbol; | |
961 | char **bkpt_namep; | |
962 | asection *interp_sect; | |
963 | ||
964 | /* First, remove all the solib event breakpoints. Their addresses | |
965 | may have changed since the last time we ran the program. */ | |
966 | remove_solib_event_breakpoints (); | |
967 | ||
13437d4b KB |
968 | interp_text_sect_low = interp_text_sect_high = 0; |
969 | interp_plt_sect_low = interp_plt_sect_high = 0; | |
970 | ||
971 | /* Find the .interp section; if not found, warn the user and drop | |
972 | into the old breakpoint at symbol code. */ | |
973 | interp_sect = bfd_get_section_by_name (exec_bfd, ".interp"); | |
974 | if (interp_sect) | |
975 | { | |
976 | unsigned int interp_sect_size; | |
977 | char *buf; | |
8ad2fcde KB |
978 | CORE_ADDR load_addr = 0; |
979 | int load_addr_found = 0; | |
f8766ec1 | 980 | struct so_list *so; |
e4f7b8c8 | 981 | bfd *tmp_bfd = NULL; |
2f4950cd | 982 | struct target_ops *tmp_bfd_target; |
e4f7b8c8 MS |
983 | int tmp_fd = -1; |
984 | char *tmp_pathname = NULL; | |
13437d4b KB |
985 | CORE_ADDR sym_addr = 0; |
986 | ||
987 | /* Read the contents of the .interp section into a local buffer; | |
988 | the contents specify the dynamic linker this program uses. */ | |
989 | interp_sect_size = bfd_section_size (exec_bfd, interp_sect); | |
990 | buf = alloca (interp_sect_size); | |
991 | bfd_get_section_contents (exec_bfd, interp_sect, | |
992 | buf, 0, interp_sect_size); | |
993 | ||
994 | /* Now we need to figure out where the dynamic linker was | |
995 | loaded so that we can load its symbols and place a breakpoint | |
996 | in the dynamic linker itself. | |
997 | ||
998 | This address is stored on the stack. However, I've been unable | |
999 | to find any magic formula to find it for Solaris (appears to | |
1000 | be trivial on GNU/Linux). Therefore, we have to try an alternate | |
1001 | mechanism to find the dynamic linker's base address. */ | |
e4f7b8c8 | 1002 | |
34439770 DJ |
1003 | /* TODO drow/2006-09-12: This is somewhat fragile, because it |
1004 | relies on read_pc. On both Solaris and GNU/Linux we can use | |
1005 | the AT_BASE auxilliary entry, which GDB now knows how to | |
1006 | access, to find the base address. */ | |
1007 | ||
1008 | tmp_fd = solib_open (buf, &tmp_pathname); | |
e4f7b8c8 | 1009 | if (tmp_fd >= 0) |
9f76c2cd | 1010 | tmp_bfd = bfd_fopen (tmp_pathname, gnutarget, FOPEN_RB, tmp_fd); |
e4f7b8c8 | 1011 | |
13437d4b KB |
1012 | if (tmp_bfd == NULL) |
1013 | goto bkpt_at_symbol; | |
1014 | ||
1015 | /* Make sure the dynamic linker's really a useful object. */ | |
1016 | if (!bfd_check_format (tmp_bfd, bfd_object)) | |
1017 | { | |
8a3fe4f8 | 1018 | warning (_("Unable to grok dynamic linker %s as an object file"), buf); |
13437d4b KB |
1019 | bfd_close (tmp_bfd); |
1020 | goto bkpt_at_symbol; | |
1021 | } | |
1022 | ||
2f4950cd AC |
1023 | /* Now convert the TMP_BFD into a target. That way target, as |
1024 | well as BFD operations can be used. Note that closing the | |
1025 | target will also close the underlying bfd. */ | |
1026 | tmp_bfd_target = target_bfd_reopen (tmp_bfd); | |
1027 | ||
f8766ec1 KB |
1028 | /* On a running target, we can get the dynamic linker's base |
1029 | address from the shared library table. */ | |
2bbe3cc1 | 1030 | solib_add (NULL, 0, ¤t_target, auto_solib_add); |
f8766ec1 KB |
1031 | so = master_so_list (); |
1032 | while (so) | |
8ad2fcde | 1033 | { |
f8766ec1 | 1034 | if (strcmp (buf, so->so_original_name) == 0) |
8ad2fcde KB |
1035 | { |
1036 | load_addr_found = 1; | |
cc10cae3 | 1037 | load_addr = LM_ADDR_CHECK (so, tmp_bfd); |
8ad2fcde KB |
1038 | break; |
1039 | } | |
f8766ec1 | 1040 | so = so->next; |
8ad2fcde KB |
1041 | } |
1042 | ||
1043 | /* Otherwise we find the dynamic linker's base address by examining | |
1044 | the current pc (which should point at the entry point for the | |
1045 | dynamic linker) and subtracting the offset of the entry point. */ | |
1046 | if (!load_addr_found) | |
34439770 DJ |
1047 | { |
1048 | load_addr = (read_pc () | |
1049 | - exec_entry_point (tmp_bfd, tmp_bfd_target)); | |
1050 | debug_loader_name = xstrdup (buf); | |
1051 | debug_loader_offset_p = 1; | |
1052 | debug_loader_offset = load_addr; | |
2bbe3cc1 | 1053 | solib_add (NULL, 0, ¤t_target, auto_solib_add); |
34439770 | 1054 | } |
13437d4b KB |
1055 | |
1056 | /* Record the relocated start and end address of the dynamic linker | |
d7fa2ae2 | 1057 | text and plt section for svr4_in_dynsym_resolve_code. */ |
13437d4b KB |
1058 | interp_sect = bfd_get_section_by_name (tmp_bfd, ".text"); |
1059 | if (interp_sect) | |
1060 | { | |
1061 | interp_text_sect_low = | |
1062 | bfd_section_vma (tmp_bfd, interp_sect) + load_addr; | |
1063 | interp_text_sect_high = | |
1064 | interp_text_sect_low + bfd_section_size (tmp_bfd, interp_sect); | |
1065 | } | |
1066 | interp_sect = bfd_get_section_by_name (tmp_bfd, ".plt"); | |
1067 | if (interp_sect) | |
1068 | { | |
1069 | interp_plt_sect_low = | |
1070 | bfd_section_vma (tmp_bfd, interp_sect) + load_addr; | |
1071 | interp_plt_sect_high = | |
1072 | interp_plt_sect_low + bfd_section_size (tmp_bfd, interp_sect); | |
1073 | } | |
1074 | ||
1075 | /* Now try to set a breakpoint in the dynamic linker. */ | |
1076 | for (bkpt_namep = solib_break_names; *bkpt_namep != NULL; bkpt_namep++) | |
1077 | { | |
2bbe3cc1 | 1078 | sym_addr = bfd_lookup_symbol (tmp_bfd, *bkpt_namep); |
13437d4b KB |
1079 | if (sym_addr != 0) |
1080 | break; | |
1081 | } | |
1082 | ||
2bbe3cc1 DJ |
1083 | if (sym_addr != 0) |
1084 | /* Convert 'sym_addr' from a function pointer to an address. | |
1085 | Because we pass tmp_bfd_target instead of the current | |
1086 | target, this will always produce an unrelocated value. */ | |
1087 | sym_addr = gdbarch_convert_from_func_ptr_addr (current_gdbarch, | |
1088 | sym_addr, | |
1089 | tmp_bfd_target); | |
1090 | ||
2f4950cd AC |
1091 | /* We're done with both the temporary bfd and target. Remember, |
1092 | closing the target closes the underlying bfd. */ | |
1093 | target_close (tmp_bfd_target, 0); | |
13437d4b KB |
1094 | |
1095 | if (sym_addr != 0) | |
1096 | { | |
1097 | create_solib_event_breakpoint (load_addr + sym_addr); | |
1098 | return 1; | |
1099 | } | |
1100 | ||
1101 | /* For whatever reason we couldn't set a breakpoint in the dynamic | |
1102 | linker. Warn and drop into the old code. */ | |
1103 | bkpt_at_symbol: | |
82d03102 PG |
1104 | warning (_("Unable to find dynamic linker breakpoint function.\n" |
1105 | "GDB will be unable to debug shared library initializers\n" | |
1106 | "and track explicitly loaded dynamic code.")); | |
13437d4b | 1107 | } |
13437d4b | 1108 | |
e499d0f1 DJ |
1109 | /* Scan through the lists of symbols, trying to look up the symbol and |
1110 | set a breakpoint there. Terminate loop when we/if we succeed. */ | |
1111 | ||
1112 | for (bkpt_namep = solib_break_names; *bkpt_namep != NULL; bkpt_namep++) | |
1113 | { | |
1114 | msymbol = lookup_minimal_symbol (*bkpt_namep, NULL, symfile_objfile); | |
1115 | if ((msymbol != NULL) && (SYMBOL_VALUE_ADDRESS (msymbol) != 0)) | |
1116 | { | |
1117 | create_solib_event_breakpoint (SYMBOL_VALUE_ADDRESS (msymbol)); | |
1118 | return 1; | |
1119 | } | |
1120 | } | |
13437d4b | 1121 | |
13437d4b KB |
1122 | for (bkpt_namep = bkpt_names; *bkpt_namep != NULL; bkpt_namep++) |
1123 | { | |
1124 | msymbol = lookup_minimal_symbol (*bkpt_namep, NULL, symfile_objfile); | |
1125 | if ((msymbol != NULL) && (SYMBOL_VALUE_ADDRESS (msymbol) != 0)) | |
1126 | { | |
1127 | create_solib_event_breakpoint (SYMBOL_VALUE_ADDRESS (msymbol)); | |
1128 | return 1; | |
1129 | } | |
1130 | } | |
13437d4b KB |
1131 | #endif /* BKPT_AT_SYMBOL */ |
1132 | ||
542c95c2 | 1133 | return 0; |
13437d4b KB |
1134 | } |
1135 | ||
1136 | /* | |
1137 | ||
1138 | LOCAL FUNCTION | |
1139 | ||
1140 | special_symbol_handling -- additional shared library symbol handling | |
1141 | ||
1142 | SYNOPSIS | |
1143 | ||
1144 | void special_symbol_handling () | |
1145 | ||
1146 | DESCRIPTION | |
1147 | ||
1148 | Once the symbols from a shared object have been loaded in the usual | |
1149 | way, we are called to do any system specific symbol handling that | |
1150 | is needed. | |
1151 | ||
ab31aa69 | 1152 | For SunOS4, this consisted of grunging around in the dynamic |
13437d4b KB |
1153 | linkers structures to find symbol definitions for "common" symbols |
1154 | and adding them to the minimal symbol table for the runtime common | |
1155 | objfile. | |
1156 | ||
ab31aa69 KB |
1157 | However, for SVR4, there's nothing to do. |
1158 | ||
13437d4b KB |
1159 | */ |
1160 | ||
1161 | static void | |
1162 | svr4_special_symbol_handling (void) | |
1163 | { | |
13437d4b KB |
1164 | } |
1165 | ||
e2a44558 KB |
1166 | /* Relocate the main executable. This function should be called upon |
1167 | stopping the inferior process at the entry point to the program. | |
1168 | The entry point from BFD is compared to the PC and if they are | |
1169 | different, the main executable is relocated by the proper amount. | |
1170 | ||
1171 | As written it will only attempt to relocate executables which | |
1172 | lack interpreter sections. It seems likely that only dynamic | |
1173 | linker executables will get relocated, though it should work | |
1174 | properly for a position-independent static executable as well. */ | |
1175 | ||
1176 | static void | |
1177 | svr4_relocate_main_executable (void) | |
1178 | { | |
1179 | asection *interp_sect; | |
1180 | CORE_ADDR pc = read_pc (); | |
1181 | ||
1182 | /* Decide if the objfile needs to be relocated. As indicated above, | |
1183 | we will only be here when execution is stopped at the beginning | |
1184 | of the program. Relocation is necessary if the address at which | |
1185 | we are presently stopped differs from the start address stored in | |
1186 | the executable AND there's no interpreter section. The condition | |
1187 | regarding the interpreter section is very important because if | |
1188 | there *is* an interpreter section, execution will begin there | |
1189 | instead. When there is an interpreter section, the start address | |
1190 | is (presumably) used by the interpreter at some point to start | |
1191 | execution of the program. | |
1192 | ||
1193 | If there is an interpreter, it is normal for it to be set to an | |
1194 | arbitrary address at the outset. The job of finding it is | |
1195 | handled in enable_break(). | |
1196 | ||
1197 | So, to summarize, relocations are necessary when there is no | |
1198 | interpreter section and the start address obtained from the | |
1199 | executable is different from the address at which GDB is | |
1200 | currently stopped. | |
1201 | ||
1202 | [ The astute reader will note that we also test to make sure that | |
1203 | the executable in question has the DYNAMIC flag set. It is my | |
1204 | opinion that this test is unnecessary (undesirable even). It | |
1205 | was added to avoid inadvertent relocation of an executable | |
1206 | whose e_type member in the ELF header is not ET_DYN. There may | |
1207 | be a time in the future when it is desirable to do relocations | |
1208 | on other types of files as well in which case this condition | |
1209 | should either be removed or modified to accomodate the new file | |
1210 | type. (E.g, an ET_EXEC executable which has been built to be | |
1211 | position-independent could safely be relocated by the OS if | |
1212 | desired. It is true that this violates the ABI, but the ABI | |
1213 | has been known to be bent from time to time.) - Kevin, Nov 2000. ] | |
1214 | */ | |
1215 | ||
1216 | interp_sect = bfd_get_section_by_name (exec_bfd, ".interp"); | |
1217 | if (interp_sect == NULL | |
1218 | && (bfd_get_file_flags (exec_bfd) & DYNAMIC) != 0 | |
2f4950cd | 1219 | && (exec_entry_point (exec_bfd, &exec_ops) != pc)) |
e2a44558 KB |
1220 | { |
1221 | struct cleanup *old_chain; | |
1222 | struct section_offsets *new_offsets; | |
1223 | int i, changed; | |
1224 | CORE_ADDR displacement; | |
1225 | ||
1226 | /* It is necessary to relocate the objfile. The amount to | |
1227 | relocate by is simply the address at which we are stopped | |
1228 | minus the starting address from the executable. | |
1229 | ||
1230 | We relocate all of the sections by the same amount. This | |
1231 | behavior is mandated by recent editions of the System V ABI. | |
1232 | According to the System V Application Binary Interface, | |
1233 | Edition 4.1, page 5-5: | |
1234 | ||
1235 | ... Though the system chooses virtual addresses for | |
1236 | individual processes, it maintains the segments' relative | |
1237 | positions. Because position-independent code uses relative | |
1238 | addressesing between segments, the difference between | |
1239 | virtual addresses in memory must match the difference | |
1240 | between virtual addresses in the file. The difference | |
1241 | between the virtual address of any segment in memory and | |
1242 | the corresponding virtual address in the file is thus a | |
1243 | single constant value for any one executable or shared | |
1244 | object in a given process. This difference is the base | |
1245 | address. One use of the base address is to relocate the | |
1246 | memory image of the program during dynamic linking. | |
1247 | ||
1248 | The same language also appears in Edition 4.0 of the System V | |
1249 | ABI and is left unspecified in some of the earlier editions. */ | |
1250 | ||
2f4950cd | 1251 | displacement = pc - exec_entry_point (exec_bfd, &exec_ops); |
e2a44558 KB |
1252 | changed = 0; |
1253 | ||
13fc0c2f KB |
1254 | new_offsets = xcalloc (symfile_objfile->num_sections, |
1255 | sizeof (struct section_offsets)); | |
b8c9b27d | 1256 | old_chain = make_cleanup (xfree, new_offsets); |
e2a44558 KB |
1257 | |
1258 | for (i = 0; i < symfile_objfile->num_sections; i++) | |
1259 | { | |
1260 | if (displacement != ANOFFSET (symfile_objfile->section_offsets, i)) | |
1261 | changed = 1; | |
1262 | new_offsets->offsets[i] = displacement; | |
1263 | } | |
1264 | ||
1265 | if (changed) | |
1266 | objfile_relocate (symfile_objfile, new_offsets); | |
1267 | ||
1268 | do_cleanups (old_chain); | |
1269 | } | |
1270 | } | |
1271 | ||
13437d4b KB |
1272 | /* |
1273 | ||
1274 | GLOBAL FUNCTION | |
1275 | ||
1276 | svr4_solib_create_inferior_hook -- shared library startup support | |
1277 | ||
1278 | SYNOPSIS | |
1279 | ||
7095b863 | 1280 | void svr4_solib_create_inferior_hook () |
13437d4b KB |
1281 | |
1282 | DESCRIPTION | |
1283 | ||
1284 | When gdb starts up the inferior, it nurses it along (through the | |
1285 | shell) until it is ready to execute it's first instruction. At this | |
1286 | point, this function gets called via expansion of the macro | |
1287 | SOLIB_CREATE_INFERIOR_HOOK. | |
1288 | ||
1289 | For SunOS executables, this first instruction is typically the | |
1290 | one at "_start", or a similar text label, regardless of whether | |
1291 | the executable is statically or dynamically linked. The runtime | |
1292 | startup code takes care of dynamically linking in any shared | |
1293 | libraries, once gdb allows the inferior to continue. | |
1294 | ||
1295 | For SVR4 executables, this first instruction is either the first | |
1296 | instruction in the dynamic linker (for dynamically linked | |
1297 | executables) or the instruction at "start" for statically linked | |
1298 | executables. For dynamically linked executables, the system | |
1299 | first exec's /lib/libc.so.N, which contains the dynamic linker, | |
1300 | and starts it running. The dynamic linker maps in any needed | |
1301 | shared libraries, maps in the actual user executable, and then | |
1302 | jumps to "start" in the user executable. | |
1303 | ||
1304 | For both SunOS shared libraries, and SVR4 shared libraries, we | |
1305 | can arrange to cooperate with the dynamic linker to discover the | |
1306 | names of shared libraries that are dynamically linked, and the | |
1307 | base addresses to which they are linked. | |
1308 | ||
1309 | This function is responsible for discovering those names and | |
1310 | addresses, and saving sufficient information about them to allow | |
1311 | their symbols to be read at a later time. | |
1312 | ||
1313 | FIXME | |
1314 | ||
1315 | Between enable_break() and disable_break(), this code does not | |
1316 | properly handle hitting breakpoints which the user might have | |
1317 | set in the startup code or in the dynamic linker itself. Proper | |
1318 | handling will probably have to wait until the implementation is | |
1319 | changed to use the "breakpoint handler function" method. | |
1320 | ||
1321 | Also, what if child has exit()ed? Must exit loop somehow. | |
1322 | */ | |
1323 | ||
e2a44558 | 1324 | static void |
13437d4b KB |
1325 | svr4_solib_create_inferior_hook (void) |
1326 | { | |
e2a44558 KB |
1327 | /* Relocate the main executable if necessary. */ |
1328 | svr4_relocate_main_executable (); | |
1329 | ||
d5a921c9 | 1330 | if (!svr4_have_link_map_offsets ()) |
513f5903 | 1331 | return; |
d5a921c9 | 1332 | |
13437d4b | 1333 | if (!enable_break ()) |
542c95c2 | 1334 | return; |
13437d4b | 1335 | |
ab31aa69 KB |
1336 | #if defined(_SCO_DS) |
1337 | /* SCO needs the loop below, other systems should be using the | |
13437d4b KB |
1338 | special shared library breakpoints and the shared library breakpoint |
1339 | service routine. | |
1340 | ||
1341 | Now run the target. It will eventually hit the breakpoint, at | |
1342 | which point all of the libraries will have been mapped in and we | |
1343 | can go groveling around in the dynamic linker structures to find | |
1344 | out what we need to know about them. */ | |
1345 | ||
1346 | clear_proceed_status (); | |
c0236d92 | 1347 | stop_soon = STOP_QUIETLY; |
13437d4b KB |
1348 | stop_signal = TARGET_SIGNAL_0; |
1349 | do | |
1350 | { | |
39f77062 | 1351 | target_resume (pid_to_ptid (-1), 0, stop_signal); |
13437d4b KB |
1352 | wait_for_inferior (); |
1353 | } | |
1354 | while (stop_signal != TARGET_SIGNAL_TRAP); | |
c0236d92 | 1355 | stop_soon = NO_STOP_QUIETLY; |
ab31aa69 | 1356 | #endif /* defined(_SCO_DS) */ |
13437d4b KB |
1357 | } |
1358 | ||
1359 | static void | |
1360 | svr4_clear_solib (void) | |
1361 | { | |
1362 | debug_base = 0; | |
34439770 DJ |
1363 | debug_loader_offset_p = 0; |
1364 | debug_loader_offset = 0; | |
1365 | xfree (debug_loader_name); | |
1366 | debug_loader_name = NULL; | |
13437d4b KB |
1367 | } |
1368 | ||
1369 | static void | |
1370 | svr4_free_so (struct so_list *so) | |
1371 | { | |
b8c9b27d KB |
1372 | xfree (so->lm_info->lm); |
1373 | xfree (so->lm_info); | |
13437d4b KB |
1374 | } |
1375 | ||
6bb7be43 JB |
1376 | |
1377 | /* Clear any bits of ADDR that wouldn't fit in a target-format | |
1378 | data pointer. "Data pointer" here refers to whatever sort of | |
1379 | address the dynamic linker uses to manage its sections. At the | |
1380 | moment, we don't support shared libraries on any processors where | |
1381 | code and data pointers are different sizes. | |
1382 | ||
1383 | This isn't really the right solution. What we really need here is | |
1384 | a way to do arithmetic on CORE_ADDR values that respects the | |
1385 | natural pointer/address correspondence. (For example, on the MIPS, | |
1386 | converting a 32-bit pointer to a 64-bit CORE_ADDR requires you to | |
1387 | sign-extend the value. There, simply truncating the bits above | |
819844ad | 1388 | gdbarch_ptr_bit, as we do below, is no good.) This should probably |
6bb7be43 JB |
1389 | be a new gdbarch method or something. */ |
1390 | static CORE_ADDR | |
1391 | svr4_truncate_ptr (CORE_ADDR addr) | |
1392 | { | |
819844ad | 1393 | if (gdbarch_ptr_bit (current_gdbarch) == sizeof (CORE_ADDR) * 8) |
6bb7be43 JB |
1394 | /* We don't need to truncate anything, and the bit twiddling below |
1395 | will fail due to overflow problems. */ | |
1396 | return addr; | |
1397 | else | |
819844ad | 1398 | return addr & (((CORE_ADDR) 1 << gdbarch_ptr_bit (current_gdbarch)) - 1); |
6bb7be43 JB |
1399 | } |
1400 | ||
1401 | ||
749499cb KB |
1402 | static void |
1403 | svr4_relocate_section_addresses (struct so_list *so, | |
1404 | struct section_table *sec) | |
1405 | { | |
cc10cae3 AO |
1406 | sec->addr = svr4_truncate_ptr (sec->addr + LM_ADDR_CHECK (so, |
1407 | sec->bfd)); | |
1408 | sec->endaddr = svr4_truncate_ptr (sec->endaddr + LM_ADDR_CHECK (so, | |
1409 | sec->bfd)); | |
749499cb | 1410 | } |
4b188b9f | 1411 | \f |
749499cb | 1412 | |
4b188b9f | 1413 | /* Architecture-specific operations. */ |
6bb7be43 | 1414 | |
4b188b9f MK |
1415 | /* Per-architecture data key. */ |
1416 | static struct gdbarch_data *solib_svr4_data; | |
e5e2b9ff | 1417 | |
4b188b9f | 1418 | struct solib_svr4_ops |
e5e2b9ff | 1419 | { |
4b188b9f MK |
1420 | /* Return a description of the layout of `struct link_map'. */ |
1421 | struct link_map_offsets *(*fetch_link_map_offsets)(void); | |
1422 | }; | |
e5e2b9ff | 1423 | |
4b188b9f | 1424 | /* Return a default for the architecture-specific operations. */ |
e5e2b9ff | 1425 | |
4b188b9f MK |
1426 | static void * |
1427 | solib_svr4_init (struct obstack *obstack) | |
e5e2b9ff | 1428 | { |
4b188b9f | 1429 | struct solib_svr4_ops *ops; |
e5e2b9ff | 1430 | |
4b188b9f MK |
1431 | ops = OBSTACK_ZALLOC (obstack, struct solib_svr4_ops); |
1432 | ops->fetch_link_map_offsets = legacy_svr4_fetch_link_map_offsets_hook; | |
1433 | return ops; | |
e5e2b9ff KB |
1434 | } |
1435 | ||
4b188b9f MK |
1436 | /* Set the architecture-specific `struct link_map_offsets' fetcher for |
1437 | GDBARCH to FLMO. */ | |
1c4dcb57 | 1438 | |
21479ded | 1439 | void |
e5e2b9ff KB |
1440 | set_solib_svr4_fetch_link_map_offsets (struct gdbarch *gdbarch, |
1441 | struct link_map_offsets *(*flmo) (void)) | |
21479ded | 1442 | { |
4b188b9f MK |
1443 | struct solib_svr4_ops *ops = gdbarch_data (gdbarch, solib_svr4_data); |
1444 | ||
1445 | ops->fetch_link_map_offsets = flmo; | |
21479ded KB |
1446 | } |
1447 | ||
4b188b9f MK |
1448 | /* Fetch a link_map_offsets structure using the architecture-specific |
1449 | `struct link_map_offsets' fetcher. */ | |
1c4dcb57 | 1450 | |
4b188b9f MK |
1451 | static struct link_map_offsets * |
1452 | svr4_fetch_link_map_offsets (void) | |
21479ded | 1453 | { |
4b188b9f MK |
1454 | struct solib_svr4_ops *ops = gdbarch_data (current_gdbarch, solib_svr4_data); |
1455 | ||
1456 | gdb_assert (ops->fetch_link_map_offsets); | |
1457 | return ops->fetch_link_map_offsets (); | |
21479ded KB |
1458 | } |
1459 | ||
4b188b9f MK |
1460 | /* Return 1 if a link map offset fetcher has been defined, 0 otherwise. */ |
1461 | ||
1462 | static int | |
1463 | svr4_have_link_map_offsets (void) | |
1464 | { | |
1465 | struct solib_svr4_ops *ops = gdbarch_data (current_gdbarch, solib_svr4_data); | |
1466 | return (ops->fetch_link_map_offsets != NULL); | |
1467 | } | |
1468 | \f | |
1469 | ||
e4bbbda8 MK |
1470 | /* Most OS'es that have SVR4-style ELF dynamic libraries define a |
1471 | `struct r_debug' and a `struct link_map' that are binary compatible | |
1472 | with the origional SVR4 implementation. */ | |
1473 | ||
1474 | /* Fetch (and possibly build) an appropriate `struct link_map_offsets' | |
1475 | for an ILP32 SVR4 system. */ | |
1476 | ||
1477 | struct link_map_offsets * | |
1478 | svr4_ilp32_fetch_link_map_offsets (void) | |
1479 | { | |
1480 | static struct link_map_offsets lmo; | |
1481 | static struct link_map_offsets *lmp = NULL; | |
1482 | ||
1483 | if (lmp == NULL) | |
1484 | { | |
1485 | lmp = &lmo; | |
1486 | ||
e4cd0d6a MK |
1487 | lmo.r_version_offset = 0; |
1488 | lmo.r_version_size = 4; | |
e4bbbda8 | 1489 | lmo.r_map_offset = 4; |
e4cd0d6a | 1490 | lmo.r_ldsomap_offset = 20; |
e4bbbda8 MK |
1491 | |
1492 | /* Everything we need is in the first 20 bytes. */ | |
1493 | lmo.link_map_size = 20; | |
1494 | lmo.l_addr_offset = 0; | |
e4bbbda8 | 1495 | lmo.l_name_offset = 4; |
cc10cae3 | 1496 | lmo.l_ld_offset = 8; |
e4bbbda8 | 1497 | lmo.l_next_offset = 12; |
e4bbbda8 | 1498 | lmo.l_prev_offset = 16; |
e4bbbda8 MK |
1499 | } |
1500 | ||
1501 | return lmp; | |
1502 | } | |
1503 | ||
1504 | /* Fetch (and possibly build) an appropriate `struct link_map_offsets' | |
1505 | for an LP64 SVR4 system. */ | |
1506 | ||
1507 | struct link_map_offsets * | |
1508 | svr4_lp64_fetch_link_map_offsets (void) | |
1509 | { | |
1510 | static struct link_map_offsets lmo; | |
1511 | static struct link_map_offsets *lmp = NULL; | |
1512 | ||
1513 | if (lmp == NULL) | |
1514 | { | |
1515 | lmp = &lmo; | |
1516 | ||
e4cd0d6a MK |
1517 | lmo.r_version_offset = 0; |
1518 | lmo.r_version_size = 4; | |
e4bbbda8 | 1519 | lmo.r_map_offset = 8; |
e4cd0d6a | 1520 | lmo.r_ldsomap_offset = 40; |
e4bbbda8 MK |
1521 | |
1522 | /* Everything we need is in the first 40 bytes. */ | |
1523 | lmo.link_map_size = 40; | |
1524 | lmo.l_addr_offset = 0; | |
e4bbbda8 | 1525 | lmo.l_name_offset = 8; |
cc10cae3 | 1526 | lmo.l_ld_offset = 16; |
e4bbbda8 | 1527 | lmo.l_next_offset = 24; |
e4bbbda8 | 1528 | lmo.l_prev_offset = 32; |
e4bbbda8 MK |
1529 | } |
1530 | ||
1531 | return lmp; | |
1532 | } | |
1533 | \f | |
1534 | ||
7d522c90 | 1535 | struct target_so_ops svr4_so_ops; |
13437d4b | 1536 | |
3a40aaa0 UW |
1537 | /* Lookup global symbol for ELF DSOs linked with -Bsymbolic. Those DSOs have a |
1538 | different rule for symbol lookup. The lookup begins here in the DSO, not in | |
1539 | the main executable. */ | |
1540 | ||
1541 | static struct symbol * | |
1542 | elf_lookup_lib_symbol (const struct objfile *objfile, | |
1543 | const char *name, | |
1544 | const char *linkage_name, | |
1545 | const domain_enum domain, struct symtab **symtab) | |
1546 | { | |
1547 | if (objfile->obfd == NULL | |
1548 | || scan_dyntag (DT_SYMBOLIC, objfile->obfd, NULL) != 1) | |
1549 | return NULL; | |
1550 | ||
1551 | return lookup_global_symbol_from_objfile | |
1552 | (objfile, name, linkage_name, domain, symtab); | |
1553 | } | |
1554 | ||
a78f21af AC |
1555 | extern initialize_file_ftype _initialize_svr4_solib; /* -Wmissing-prototypes */ |
1556 | ||
13437d4b KB |
1557 | void |
1558 | _initialize_svr4_solib (void) | |
1559 | { | |
4b188b9f MK |
1560 | solib_svr4_data = gdbarch_data_register_pre_init (solib_svr4_init); |
1561 | ||
749499cb | 1562 | svr4_so_ops.relocate_section_addresses = svr4_relocate_section_addresses; |
13437d4b KB |
1563 | svr4_so_ops.free_so = svr4_free_so; |
1564 | svr4_so_ops.clear_solib = svr4_clear_solib; | |
1565 | svr4_so_ops.solib_create_inferior_hook = svr4_solib_create_inferior_hook; | |
1566 | svr4_so_ops.special_symbol_handling = svr4_special_symbol_handling; | |
1567 | svr4_so_ops.current_sos = svr4_current_sos; | |
1568 | svr4_so_ops.open_symbol_file_object = open_symbol_file_object; | |
d7fa2ae2 | 1569 | svr4_so_ops.in_dynsym_resolve_code = svr4_in_dynsym_resolve_code; |
3a40aaa0 | 1570 | svr4_so_ops.lookup_lib_global_symbol = elf_lookup_lib_symbol; |
13437d4b KB |
1571 | |
1572 | /* FIXME: Don't do this here. *_gdbarch_init() should set so_ops. */ | |
1573 | current_target_so_ops = &svr4_so_ops; | |
1574 | } |