Commit | Line | Data |
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ab31aa69 | 1 | /* Handle SVR4 shared libraries for GDB, the GNU Debugger. |
2f4950cd | 2 | |
6aba47ca | 3 | Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000, |
9b254dd1 | 4 | 2001, 2003, 2004, 2005, 2006, 2007, 2008 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 | |
a9762ec7 | 10 | the Free Software Foundation; either version 3 of the License, or |
13437d4b KB |
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 | |
a9762ec7 | 19 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
13437d4b | 20 | |
13437d4b KB |
21 | #include "defs.h" |
22 | ||
13437d4b | 23 | #include "elf/external.h" |
21479ded | 24 | #include "elf/common.h" |
f7856c8f | 25 | #include "elf/mips.h" |
13437d4b KB |
26 | |
27 | #include "symtab.h" | |
28 | #include "bfd.h" | |
29 | #include "symfile.h" | |
30 | #include "objfiles.h" | |
31 | #include "gdbcore.h" | |
13437d4b | 32 | #include "target.h" |
13437d4b | 33 | #include "inferior.h" |
13437d4b | 34 | |
4b188b9f MK |
35 | #include "gdb_assert.h" |
36 | ||
13437d4b | 37 | #include "solist.h" |
bba93f6c | 38 | #include "solib.h" |
13437d4b KB |
39 | #include "solib-svr4.h" |
40 | ||
2f4950cd | 41 | #include "bfd-target.h" |
cc10cae3 | 42 | #include "elf-bfd.h" |
2f4950cd | 43 | #include "exec.h" |
8d4e36ba | 44 | #include "auxv.h" |
2f4950cd | 45 | |
e5e2b9ff | 46 | static struct link_map_offsets *svr4_fetch_link_map_offsets (void); |
d5a921c9 | 47 | static int svr4_have_link_map_offsets (void); |
1c4dcb57 | 48 | |
13437d4b KB |
49 | /* Link map info to include in an allocated so_list entry */ |
50 | ||
51 | struct lm_info | |
52 | { | |
53 | /* Pointer to copy of link map from inferior. The type is char * | |
54 | rather than void *, so that we may use byte offsets to find the | |
55 | various fields without the need for a cast. */ | |
4066fc10 | 56 | gdb_byte *lm; |
cc10cae3 AO |
57 | |
58 | /* Amount by which addresses in the binary should be relocated to | |
59 | match the inferior. This could most often be taken directly | |
60 | from lm, but when prelinking is involved and the prelink base | |
61 | address changes, we may need a different offset, we want to | |
62 | warn about the difference and compute it only once. */ | |
63 | CORE_ADDR l_addr; | |
13437d4b KB |
64 | }; |
65 | ||
66 | /* On SVR4 systems, a list of symbols in the dynamic linker where | |
67 | GDB can try to place a breakpoint to monitor shared library | |
68 | events. | |
69 | ||
70 | If none of these symbols are found, or other errors occur, then | |
71 | SVR4 systems will fall back to using a symbol as the "startup | |
72 | mapping complete" breakpoint address. */ | |
73 | ||
13437d4b KB |
74 | static char *solib_break_names[] = |
75 | { | |
76 | "r_debug_state", | |
77 | "_r_debug_state", | |
78 | "_dl_debug_state", | |
79 | "rtld_db_dlactivity", | |
1f72e589 | 80 | "_rtld_debug_state", |
4c0122c8 | 81 | |
13437d4b KB |
82 | NULL |
83 | }; | |
13437d4b KB |
84 | |
85 | #define BKPT_AT_SYMBOL 1 | |
86 | ||
ab31aa69 | 87 | #if defined (BKPT_AT_SYMBOL) |
13437d4b KB |
88 | static char *bkpt_names[] = |
89 | { | |
90 | #ifdef SOLIB_BKPT_NAME | |
91 | SOLIB_BKPT_NAME, /* Prefer configured name if it exists. */ | |
92 | #endif | |
93 | "_start", | |
ad3dcc5c | 94 | "__start", |
13437d4b KB |
95 | "main", |
96 | NULL | |
97 | }; | |
98 | #endif | |
99 | ||
13437d4b KB |
100 | static char *main_name_list[] = |
101 | { | |
102 | "main_$main", | |
103 | NULL | |
104 | }; | |
105 | ||
13437d4b KB |
106 | /* link map access functions */ |
107 | ||
108 | static CORE_ADDR | |
cc10cae3 | 109 | LM_ADDR_FROM_LINK_MAP (struct so_list *so) |
13437d4b | 110 | { |
4b188b9f | 111 | struct link_map_offsets *lmo = svr4_fetch_link_map_offsets (); |
13437d4b | 112 | |
cfaefc65 AS |
113 | return extract_typed_address (so->lm_info->lm + lmo->l_addr_offset, |
114 | builtin_type_void_data_ptr); | |
13437d4b KB |
115 | } |
116 | ||
cc10cae3 AO |
117 | static int |
118 | HAS_LM_DYNAMIC_FROM_LINK_MAP () | |
119 | { | |
120 | struct link_map_offsets *lmo = svr4_fetch_link_map_offsets (); | |
121 | ||
cfaefc65 | 122 | return lmo->l_ld_offset >= 0; |
cc10cae3 AO |
123 | } |
124 | ||
125 | static CORE_ADDR | |
126 | LM_DYNAMIC_FROM_LINK_MAP (struct so_list *so) | |
127 | { | |
128 | struct link_map_offsets *lmo = svr4_fetch_link_map_offsets (); | |
129 | ||
cfaefc65 AS |
130 | return extract_typed_address (so->lm_info->lm + lmo->l_ld_offset, |
131 | builtin_type_void_data_ptr); | |
cc10cae3 AO |
132 | } |
133 | ||
134 | static CORE_ADDR | |
135 | LM_ADDR_CHECK (struct so_list *so, bfd *abfd) | |
136 | { | |
137 | if (so->lm_info->l_addr == (CORE_ADDR)-1) | |
138 | { | |
139 | struct bfd_section *dyninfo_sect; | |
140 | CORE_ADDR l_addr, l_dynaddr, dynaddr, align = 0x1000; | |
141 | ||
142 | l_addr = LM_ADDR_FROM_LINK_MAP (so); | |
143 | ||
144 | if (! abfd || ! HAS_LM_DYNAMIC_FROM_LINK_MAP ()) | |
145 | goto set_addr; | |
146 | ||
147 | l_dynaddr = LM_DYNAMIC_FROM_LINK_MAP (so); | |
148 | ||
149 | dyninfo_sect = bfd_get_section_by_name (abfd, ".dynamic"); | |
150 | if (dyninfo_sect == NULL) | |
151 | goto set_addr; | |
152 | ||
153 | dynaddr = bfd_section_vma (abfd, dyninfo_sect); | |
154 | ||
155 | if (dynaddr + l_addr != l_dynaddr) | |
156 | { | |
cc10cae3 AO |
157 | if (bfd_get_flavour (abfd) == bfd_target_elf_flavour) |
158 | { | |
159 | Elf_Internal_Ehdr *ehdr = elf_tdata (abfd)->elf_header; | |
160 | Elf_Internal_Phdr *phdr = elf_tdata (abfd)->phdr; | |
161 | int i; | |
162 | ||
163 | align = 1; | |
164 | ||
165 | for (i = 0; i < ehdr->e_phnum; i++) | |
166 | if (phdr[i].p_type == PT_LOAD && phdr[i].p_align > align) | |
167 | align = phdr[i].p_align; | |
168 | } | |
169 | ||
170 | /* Turn it into a mask. */ | |
171 | align--; | |
172 | ||
173 | /* If the changes match the alignment requirements, we | |
174 | assume we're using a core file that was generated by the | |
175 | same binary, just prelinked with a different base offset. | |
176 | If it doesn't match, we may have a different binary, the | |
177 | same binary with the dynamic table loaded at an unrelated | |
178 | location, or anything, really. To avoid regressions, | |
179 | don't adjust the base offset in the latter case, although | |
180 | odds are that, if things really changed, debugging won't | |
181 | quite work. */ | |
f1e55806 | 182 | if ((l_addr & align) == ((l_dynaddr - dynaddr) & align)) |
cc10cae3 AO |
183 | { |
184 | l_addr = l_dynaddr - dynaddr; | |
79d4c408 DJ |
185 | |
186 | warning (_(".dynamic section for \"%s\" " | |
187 | "is not at the expected address"), so->so_name); | |
cc10cae3 AO |
188 | warning (_("difference appears to be caused by prelink, " |
189 | "adjusting expectations")); | |
190 | } | |
79d4c408 DJ |
191 | else |
192 | warning (_(".dynamic section for \"%s\" " | |
193 | "is not at the expected address " | |
194 | "(wrong library or version mismatch?)"), so->so_name); | |
cc10cae3 AO |
195 | } |
196 | ||
197 | set_addr: | |
198 | so->lm_info->l_addr = l_addr; | |
199 | } | |
200 | ||
201 | return so->lm_info->l_addr; | |
202 | } | |
203 | ||
13437d4b KB |
204 | static CORE_ADDR |
205 | LM_NEXT (struct so_list *so) | |
206 | { | |
4b188b9f | 207 | struct link_map_offsets *lmo = svr4_fetch_link_map_offsets (); |
13437d4b | 208 | |
cfaefc65 AS |
209 | return extract_typed_address (so->lm_info->lm + lmo->l_next_offset, |
210 | builtin_type_void_data_ptr); | |
13437d4b KB |
211 | } |
212 | ||
213 | static CORE_ADDR | |
214 | LM_NAME (struct so_list *so) | |
215 | { | |
4b188b9f | 216 | struct link_map_offsets *lmo = svr4_fetch_link_map_offsets (); |
13437d4b | 217 | |
cfaefc65 AS |
218 | return extract_typed_address (so->lm_info->lm + lmo->l_name_offset, |
219 | builtin_type_void_data_ptr); | |
13437d4b KB |
220 | } |
221 | ||
13437d4b KB |
222 | static int |
223 | IGNORE_FIRST_LINK_MAP_ENTRY (struct so_list *so) | |
224 | { | |
4b188b9f | 225 | struct link_map_offsets *lmo = svr4_fetch_link_map_offsets (); |
13437d4b | 226 | |
e499d0f1 DJ |
227 | /* Assume that everything is a library if the dynamic loader was loaded |
228 | late by a static executable. */ | |
229 | if (bfd_get_section_by_name (exec_bfd, ".dynamic") == NULL) | |
230 | return 0; | |
231 | ||
cfaefc65 AS |
232 | return extract_typed_address (so->lm_info->lm + lmo->l_prev_offset, |
233 | builtin_type_void_data_ptr) == 0; | |
13437d4b KB |
234 | } |
235 | ||
13437d4b | 236 | static CORE_ADDR debug_base; /* Base of dynamic linker structures */ |
13437d4b | 237 | |
34439770 DJ |
238 | /* Validity flag for debug_loader_offset. */ |
239 | static int debug_loader_offset_p; | |
240 | ||
241 | /* Load address for the dynamic linker, inferred. */ | |
242 | static CORE_ADDR debug_loader_offset; | |
243 | ||
244 | /* Name of the dynamic linker, valid if debug_loader_offset_p. */ | |
245 | static char *debug_loader_name; | |
246 | ||
13437d4b KB |
247 | /* Local function prototypes */ |
248 | ||
249 | static int match_main (char *); | |
250 | ||
2bbe3cc1 | 251 | static CORE_ADDR bfd_lookup_symbol (bfd *, char *); |
13437d4b KB |
252 | |
253 | /* | |
254 | ||
255 | LOCAL FUNCTION | |
256 | ||
257 | bfd_lookup_symbol -- lookup the value for a specific symbol | |
258 | ||
259 | SYNOPSIS | |
260 | ||
2bbe3cc1 | 261 | CORE_ADDR bfd_lookup_symbol (bfd *abfd, char *symname) |
13437d4b KB |
262 | |
263 | DESCRIPTION | |
264 | ||
265 | An expensive way to lookup the value of a single symbol for | |
266 | bfd's that are only temporary anyway. This is used by the | |
267 | shared library support to find the address of the debugger | |
2bbe3cc1 | 268 | notification routine in the shared library. |
13437d4b | 269 | |
2bbe3cc1 DJ |
270 | The returned symbol may be in a code or data section; functions |
271 | will normally be in a code section, but may be in a data section | |
272 | if this architecture uses function descriptors. | |
87f84c9d | 273 | |
13437d4b KB |
274 | Note that 0 is specifically allowed as an error return (no |
275 | such symbol). | |
276 | */ | |
277 | ||
278 | static CORE_ADDR | |
2bbe3cc1 | 279 | bfd_lookup_symbol (bfd *abfd, char *symname) |
13437d4b | 280 | { |
435b259c | 281 | long storage_needed; |
13437d4b KB |
282 | asymbol *sym; |
283 | asymbol **symbol_table; | |
284 | unsigned int number_of_symbols; | |
285 | unsigned int i; | |
286 | struct cleanup *back_to; | |
287 | CORE_ADDR symaddr = 0; | |
288 | ||
289 | storage_needed = bfd_get_symtab_upper_bound (abfd); | |
290 | ||
291 | if (storage_needed > 0) | |
292 | { | |
293 | symbol_table = (asymbol **) xmalloc (storage_needed); | |
4efb68b1 | 294 | back_to = make_cleanup (xfree, symbol_table); |
13437d4b KB |
295 | number_of_symbols = bfd_canonicalize_symtab (abfd, symbol_table); |
296 | ||
297 | for (i = 0; i < number_of_symbols; i++) | |
298 | { | |
299 | sym = *symbol_table++; | |
6314a349 | 300 | if (strcmp (sym->name, symname) == 0 |
2bbe3cc1 | 301 | && (sym->section->flags & (SEC_CODE | SEC_DATA)) != 0) |
13437d4b | 302 | { |
2bbe3cc1 | 303 | /* BFD symbols are section relative. */ |
13437d4b KB |
304 | symaddr = sym->value + sym->section->vma; |
305 | break; | |
306 | } | |
307 | } | |
308 | do_cleanups (back_to); | |
309 | } | |
310 | ||
311 | if (symaddr) | |
312 | return symaddr; | |
313 | ||
314 | /* On FreeBSD, the dynamic linker is stripped by default. So we'll | |
315 | have to check the dynamic string table too. */ | |
316 | ||
317 | storage_needed = bfd_get_dynamic_symtab_upper_bound (abfd); | |
318 | ||
319 | if (storage_needed > 0) | |
320 | { | |
321 | symbol_table = (asymbol **) xmalloc (storage_needed); | |
4efb68b1 | 322 | back_to = make_cleanup (xfree, symbol_table); |
13437d4b KB |
323 | number_of_symbols = bfd_canonicalize_dynamic_symtab (abfd, symbol_table); |
324 | ||
325 | for (i = 0; i < number_of_symbols; i++) | |
326 | { | |
327 | sym = *symbol_table++; | |
87f84c9d | 328 | |
6314a349 | 329 | if (strcmp (sym->name, symname) == 0 |
2bbe3cc1 | 330 | && (sym->section->flags & (SEC_CODE | SEC_DATA)) != 0) |
13437d4b | 331 | { |
2bbe3cc1 | 332 | /* BFD symbols are section relative. */ |
13437d4b KB |
333 | symaddr = sym->value + sym->section->vma; |
334 | break; | |
335 | } | |
336 | } | |
337 | do_cleanups (back_to); | |
338 | } | |
339 | ||
340 | return symaddr; | |
341 | } | |
342 | ||
3a40aaa0 UW |
343 | /* Scan for DYNTAG in .dynamic section of ABFD. If DYNTAG is found 1 is |
344 | returned and the corresponding PTR is set. */ | |
345 | ||
346 | static int | |
347 | scan_dyntag (int dyntag, bfd *abfd, CORE_ADDR *ptr) | |
348 | { | |
349 | int arch_size, step, sect_size; | |
350 | long dyn_tag; | |
351 | CORE_ADDR dyn_ptr, dyn_addr; | |
65728c26 | 352 | gdb_byte *bufend, *bufstart, *buf; |
3a40aaa0 UW |
353 | Elf32_External_Dyn *x_dynp_32; |
354 | Elf64_External_Dyn *x_dynp_64; | |
355 | struct bfd_section *sect; | |
356 | ||
357 | if (abfd == NULL) | |
358 | return 0; | |
359 | arch_size = bfd_get_arch_size (abfd); | |
360 | if (arch_size == -1) | |
361 | return 0; | |
362 | ||
363 | /* Find the start address of the .dynamic section. */ | |
364 | sect = bfd_get_section_by_name (abfd, ".dynamic"); | |
365 | if (sect == NULL) | |
366 | return 0; | |
367 | dyn_addr = bfd_section_vma (abfd, sect); | |
368 | ||
65728c26 DJ |
369 | /* Read in .dynamic from the BFD. We will get the actual value |
370 | from memory later. */ | |
3a40aaa0 | 371 | sect_size = bfd_section_size (abfd, sect); |
65728c26 DJ |
372 | buf = bufstart = alloca (sect_size); |
373 | if (!bfd_get_section_contents (abfd, sect, | |
374 | buf, 0, sect_size)) | |
375 | return 0; | |
3a40aaa0 UW |
376 | |
377 | /* Iterate over BUF and scan for DYNTAG. If found, set PTR and return. */ | |
378 | step = (arch_size == 32) ? sizeof (Elf32_External_Dyn) | |
379 | : sizeof (Elf64_External_Dyn); | |
380 | for (bufend = buf + sect_size; | |
381 | buf < bufend; | |
382 | buf += step) | |
383 | { | |
384 | if (arch_size == 32) | |
385 | { | |
386 | x_dynp_32 = (Elf32_External_Dyn *) buf; | |
387 | dyn_tag = bfd_h_get_32 (abfd, (bfd_byte *) x_dynp_32->d_tag); | |
388 | dyn_ptr = bfd_h_get_32 (abfd, (bfd_byte *) x_dynp_32->d_un.d_ptr); | |
389 | } | |
65728c26 | 390 | else |
3a40aaa0 UW |
391 | { |
392 | x_dynp_64 = (Elf64_External_Dyn *) buf; | |
393 | dyn_tag = bfd_h_get_64 (abfd, (bfd_byte *) x_dynp_64->d_tag); | |
394 | dyn_ptr = bfd_h_get_64 (abfd, (bfd_byte *) x_dynp_64->d_un.d_ptr); | |
395 | } | |
396 | if (dyn_tag == DT_NULL) | |
397 | return 0; | |
398 | if (dyn_tag == dyntag) | |
399 | { | |
65728c26 DJ |
400 | /* If requested, try to read the runtime value of this .dynamic |
401 | entry. */ | |
3a40aaa0 | 402 | if (ptr) |
65728c26 DJ |
403 | { |
404 | gdb_byte ptr_buf[8]; | |
405 | CORE_ADDR ptr_addr; | |
406 | ||
407 | ptr_addr = dyn_addr + (buf - bufstart) + arch_size / 8; | |
408 | if (target_read_memory (ptr_addr, ptr_buf, arch_size / 8) == 0) | |
409 | dyn_ptr = extract_typed_address (ptr_buf, | |
410 | builtin_type_void_data_ptr); | |
411 | *ptr = dyn_ptr; | |
412 | } | |
413 | return 1; | |
3a40aaa0 UW |
414 | } |
415 | } | |
416 | ||
417 | return 0; | |
418 | } | |
419 | ||
420 | ||
13437d4b KB |
421 | /* |
422 | ||
423 | LOCAL FUNCTION | |
424 | ||
425 | elf_locate_base -- locate the base address of dynamic linker structs | |
426 | for SVR4 elf targets. | |
427 | ||
428 | SYNOPSIS | |
429 | ||
430 | CORE_ADDR elf_locate_base (void) | |
431 | ||
432 | DESCRIPTION | |
433 | ||
434 | For SVR4 elf targets the address of the dynamic linker's runtime | |
435 | structure is contained within the dynamic info section in the | |
436 | executable file. The dynamic section is also mapped into the | |
437 | inferior address space. Because the runtime loader fills in the | |
438 | real address before starting the inferior, we have to read in the | |
439 | dynamic info section from the inferior address space. | |
440 | If there are any errors while trying to find the address, we | |
441 | silently return 0, otherwise the found address is returned. | |
442 | ||
443 | */ | |
444 | ||
445 | static CORE_ADDR | |
446 | elf_locate_base (void) | |
447 | { | |
3a40aaa0 UW |
448 | struct minimal_symbol *msymbol; |
449 | CORE_ADDR dyn_ptr; | |
13437d4b | 450 | |
65728c26 DJ |
451 | /* Look for DT_MIPS_RLD_MAP first. MIPS executables use this |
452 | instead of DT_DEBUG, although they sometimes contain an unused | |
453 | DT_DEBUG. */ | |
3a40aaa0 UW |
454 | if (scan_dyntag (DT_MIPS_RLD_MAP, exec_bfd, &dyn_ptr)) |
455 | { | |
456 | gdb_byte *pbuf; | |
457 | int pbuf_size = TYPE_LENGTH (builtin_type_void_data_ptr); | |
458 | pbuf = alloca (pbuf_size); | |
459 | /* DT_MIPS_RLD_MAP contains a pointer to the address | |
460 | of the dynamic link structure. */ | |
461 | if (target_read_memory (dyn_ptr, pbuf, pbuf_size)) | |
e499d0f1 | 462 | return 0; |
3a40aaa0 | 463 | return extract_typed_address (pbuf, builtin_type_void_data_ptr); |
e499d0f1 DJ |
464 | } |
465 | ||
65728c26 DJ |
466 | /* Find DT_DEBUG. */ |
467 | if (scan_dyntag (DT_DEBUG, exec_bfd, &dyn_ptr)) | |
468 | return dyn_ptr; | |
469 | ||
3a40aaa0 UW |
470 | /* This may be a static executable. Look for the symbol |
471 | conventionally named _r_debug, as a last resort. */ | |
472 | msymbol = lookup_minimal_symbol ("_r_debug", NULL, symfile_objfile); | |
473 | if (msymbol != NULL) | |
474 | return SYMBOL_VALUE_ADDRESS (msymbol); | |
13437d4b KB |
475 | |
476 | /* DT_DEBUG entry not found. */ | |
477 | return 0; | |
478 | } | |
479 | ||
13437d4b KB |
480 | /* |
481 | ||
482 | LOCAL FUNCTION | |
483 | ||
484 | locate_base -- locate the base address of dynamic linker structs | |
485 | ||
486 | SYNOPSIS | |
487 | ||
488 | CORE_ADDR locate_base (void) | |
489 | ||
490 | DESCRIPTION | |
491 | ||
492 | For both the SunOS and SVR4 shared library implementations, if the | |
493 | inferior executable has been linked dynamically, there is a single | |
494 | address somewhere in the inferior's data space which is the key to | |
495 | locating all of the dynamic linker's runtime structures. This | |
496 | address is the value of the debug base symbol. The job of this | |
497 | function is to find and return that address, or to return 0 if there | |
498 | is no such address (the executable is statically linked for example). | |
499 | ||
500 | For SunOS, the job is almost trivial, since the dynamic linker and | |
501 | all of it's structures are statically linked to the executable at | |
502 | link time. Thus the symbol for the address we are looking for has | |
503 | already been added to the minimal symbol table for the executable's | |
504 | objfile at the time the symbol file's symbols were read, and all we | |
505 | have to do is look it up there. Note that we explicitly do NOT want | |
506 | to find the copies in the shared library. | |
507 | ||
508 | The SVR4 version is a bit more complicated because the address | |
509 | is contained somewhere in the dynamic info section. We have to go | |
510 | to a lot more work to discover the address of the debug base symbol. | |
511 | Because of this complexity, we cache the value we find and return that | |
512 | value on subsequent invocations. Note there is no copy in the | |
513 | executable symbol tables. | |
514 | ||
515 | */ | |
516 | ||
517 | static CORE_ADDR | |
518 | locate_base (void) | |
519 | { | |
13437d4b KB |
520 | /* Check to see if we have a currently valid address, and if so, avoid |
521 | doing all this work again and just return the cached address. If | |
522 | we have no cached address, try to locate it in the dynamic info | |
d5a921c9 KB |
523 | section for ELF executables. There's no point in doing any of this |
524 | though if we don't have some link map offsets to work with. */ | |
13437d4b | 525 | |
d5a921c9 | 526 | if (debug_base == 0 && svr4_have_link_map_offsets ()) |
13437d4b KB |
527 | { |
528 | if (exec_bfd != NULL | |
529 | && bfd_get_flavour (exec_bfd) == bfd_target_elf_flavour) | |
530 | debug_base = elf_locate_base (); | |
13437d4b KB |
531 | } |
532 | return (debug_base); | |
13437d4b KB |
533 | } |
534 | ||
e4cd0d6a MK |
535 | /* Find the first element in the inferior's dynamic link map, and |
536 | return its address in the inferior. | |
13437d4b | 537 | |
e4cd0d6a MK |
538 | FIXME: Perhaps we should validate the info somehow, perhaps by |
539 | checking r_version for a known version number, or r_state for | |
540 | RT_CONSISTENT. */ | |
13437d4b KB |
541 | |
542 | static CORE_ADDR | |
e4cd0d6a | 543 | solib_svr4_r_map (void) |
13437d4b | 544 | { |
4b188b9f | 545 | struct link_map_offsets *lmo = svr4_fetch_link_map_offsets (); |
13437d4b | 546 | |
e4cd0d6a MK |
547 | return read_memory_typed_address (debug_base + lmo->r_map_offset, |
548 | builtin_type_void_data_ptr); | |
549 | } | |
13437d4b | 550 | |
7cd25cfc DJ |
551 | /* Find r_brk from the inferior's debug base. */ |
552 | ||
553 | static CORE_ADDR | |
554 | solib_svr4_r_brk (void) | |
555 | { | |
556 | struct link_map_offsets *lmo = svr4_fetch_link_map_offsets (); | |
557 | ||
558 | return read_memory_typed_address (debug_base + lmo->r_brk_offset, | |
559 | builtin_type_void_data_ptr); | |
560 | } | |
561 | ||
e4cd0d6a MK |
562 | /* Find the link map for the dynamic linker (if it is not in the |
563 | normal list of loaded shared objects). */ | |
13437d4b | 564 | |
e4cd0d6a MK |
565 | static CORE_ADDR |
566 | solib_svr4_r_ldsomap (void) | |
567 | { | |
568 | struct link_map_offsets *lmo = svr4_fetch_link_map_offsets (); | |
569 | ULONGEST version; | |
13437d4b | 570 | |
e4cd0d6a MK |
571 | /* Check version, and return zero if `struct r_debug' doesn't have |
572 | the r_ldsomap member. */ | |
573 | version = read_memory_unsigned_integer (debug_base + lmo->r_version_offset, | |
574 | lmo->r_version_size); | |
575 | if (version < 2 || lmo->r_ldsomap_offset == -1) | |
576 | return 0; | |
13437d4b | 577 | |
e4cd0d6a MK |
578 | return read_memory_typed_address (debug_base + lmo->r_ldsomap_offset, |
579 | builtin_type_void_data_ptr); | |
13437d4b KB |
580 | } |
581 | ||
13437d4b KB |
582 | /* |
583 | ||
584 | LOCAL FUNCTION | |
585 | ||
586 | open_symbol_file_object | |
587 | ||
588 | SYNOPSIS | |
589 | ||
590 | void open_symbol_file_object (void *from_tty) | |
591 | ||
592 | DESCRIPTION | |
593 | ||
594 | If no open symbol file, attempt to locate and open the main symbol | |
595 | file. On SVR4 systems, this is the first link map entry. If its | |
596 | name is here, we can open it. Useful when attaching to a process | |
597 | without first loading its symbol file. | |
598 | ||
599 | If FROM_TTYP dereferences to a non-zero integer, allow messages to | |
600 | be printed. This parameter is a pointer rather than an int because | |
601 | open_symbol_file_object() is called via catch_errors() and | |
602 | catch_errors() requires a pointer argument. */ | |
603 | ||
604 | static int | |
605 | open_symbol_file_object (void *from_ttyp) | |
606 | { | |
607 | CORE_ADDR lm, l_name; | |
608 | char *filename; | |
609 | int errcode; | |
610 | int from_tty = *(int *)from_ttyp; | |
4b188b9f | 611 | struct link_map_offsets *lmo = svr4_fetch_link_map_offsets (); |
cfaefc65 AS |
612 | int l_name_size = TYPE_LENGTH (builtin_type_void_data_ptr); |
613 | gdb_byte *l_name_buf = xmalloc (l_name_size); | |
b8c9b27d | 614 | struct cleanup *cleanups = make_cleanup (xfree, l_name_buf); |
13437d4b KB |
615 | |
616 | if (symfile_objfile) | |
617 | if (!query ("Attempt to reload symbols from process? ")) | |
618 | return 0; | |
619 | ||
7cd25cfc DJ |
620 | /* Always locate the debug struct, in case it has moved. */ |
621 | debug_base = 0; | |
622 | if (locate_base () == 0) | |
13437d4b KB |
623 | return 0; /* failed somehow... */ |
624 | ||
625 | /* First link map member should be the executable. */ | |
e4cd0d6a MK |
626 | lm = solib_svr4_r_map (); |
627 | if (lm == 0) | |
13437d4b KB |
628 | return 0; /* failed somehow... */ |
629 | ||
630 | /* Read address of name from target memory to GDB. */ | |
cfaefc65 | 631 | read_memory (lm + lmo->l_name_offset, l_name_buf, l_name_size); |
13437d4b | 632 | |
cfaefc65 AS |
633 | /* Convert the address to host format. */ |
634 | l_name = extract_typed_address (l_name_buf, builtin_type_void_data_ptr); | |
13437d4b KB |
635 | |
636 | /* Free l_name_buf. */ | |
637 | do_cleanups (cleanups); | |
638 | ||
639 | if (l_name == 0) | |
640 | return 0; /* No filename. */ | |
641 | ||
642 | /* Now fetch the filename from target memory. */ | |
643 | target_read_string (l_name, &filename, SO_NAME_MAX_PATH_SIZE - 1, &errcode); | |
ea5bf0a1 | 644 | make_cleanup (xfree, filename); |
13437d4b KB |
645 | |
646 | if (errcode) | |
647 | { | |
8a3fe4f8 | 648 | warning (_("failed to read exec filename from attached file: %s"), |
13437d4b KB |
649 | safe_strerror (errcode)); |
650 | return 0; | |
651 | } | |
652 | ||
13437d4b | 653 | /* Have a pathname: read the symbol file. */ |
1adeb98a | 654 | symbol_file_add_main (filename, from_tty); |
13437d4b KB |
655 | |
656 | return 1; | |
657 | } | |
13437d4b | 658 | |
34439770 DJ |
659 | /* If no shared library information is available from the dynamic |
660 | linker, build a fallback list from other sources. */ | |
661 | ||
662 | static struct so_list * | |
663 | svr4_default_sos (void) | |
664 | { | |
665 | struct so_list *head = NULL; | |
666 | struct so_list **link_ptr = &head; | |
667 | ||
668 | if (debug_loader_offset_p) | |
669 | { | |
670 | struct so_list *new = XZALLOC (struct so_list); | |
671 | ||
672 | new->lm_info = xmalloc (sizeof (struct lm_info)); | |
673 | ||
674 | /* Nothing will ever check the cached copy of the link | |
675 | map if we set l_addr. */ | |
676 | new->lm_info->l_addr = debug_loader_offset; | |
677 | new->lm_info->lm = NULL; | |
678 | ||
679 | strncpy (new->so_name, debug_loader_name, SO_NAME_MAX_PATH_SIZE - 1); | |
680 | new->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0'; | |
681 | strcpy (new->so_original_name, new->so_name); | |
682 | ||
683 | *link_ptr = new; | |
684 | link_ptr = &new->next; | |
685 | } | |
686 | ||
687 | return head; | |
688 | } | |
689 | ||
13437d4b KB |
690 | /* LOCAL FUNCTION |
691 | ||
692 | current_sos -- build a list of currently loaded shared objects | |
693 | ||
694 | SYNOPSIS | |
695 | ||
696 | struct so_list *current_sos () | |
697 | ||
698 | DESCRIPTION | |
699 | ||
700 | Build a list of `struct so_list' objects describing the shared | |
701 | objects currently loaded in the inferior. This list does not | |
702 | include an entry for the main executable file. | |
703 | ||
704 | Note that we only gather information directly available from the | |
705 | inferior --- we don't examine any of the shared library files | |
706 | themselves. The declaration of `struct so_list' says which fields | |
707 | we provide values for. */ | |
708 | ||
709 | static struct so_list * | |
710 | svr4_current_sos (void) | |
711 | { | |
712 | CORE_ADDR lm; | |
713 | struct so_list *head = 0; | |
714 | struct so_list **link_ptr = &head; | |
e4cd0d6a | 715 | CORE_ADDR ldsomap = 0; |
13437d4b | 716 | |
7cd25cfc DJ |
717 | /* Always locate the debug struct, in case it has moved. */ |
718 | debug_base = 0; | |
719 | locate_base (); | |
13437d4b | 720 | |
7cd25cfc DJ |
721 | /* If we can't find the dynamic linker's base structure, this |
722 | must not be a dynamically linked executable. Hmm. */ | |
723 | if (! debug_base) | |
724 | return svr4_default_sos (); | |
13437d4b KB |
725 | |
726 | /* Walk the inferior's link map list, and build our list of | |
727 | `struct so_list' nodes. */ | |
e4cd0d6a | 728 | lm = solib_svr4_r_map (); |
34439770 | 729 | |
13437d4b KB |
730 | while (lm) |
731 | { | |
4b188b9f | 732 | struct link_map_offsets *lmo = svr4_fetch_link_map_offsets (); |
f4456994 | 733 | struct so_list *new = XZALLOC (struct so_list); |
b8c9b27d | 734 | struct cleanup *old_chain = make_cleanup (xfree, new); |
13437d4b | 735 | |
13437d4b | 736 | new->lm_info = xmalloc (sizeof (struct lm_info)); |
b8c9b27d | 737 | make_cleanup (xfree, new->lm_info); |
13437d4b | 738 | |
831004b7 | 739 | new->lm_info->l_addr = (CORE_ADDR)-1; |
f4456994 | 740 | new->lm_info->lm = xzalloc (lmo->link_map_size); |
b8c9b27d | 741 | make_cleanup (xfree, new->lm_info->lm); |
13437d4b KB |
742 | |
743 | read_memory (lm, new->lm_info->lm, lmo->link_map_size); | |
744 | ||
745 | lm = LM_NEXT (new); | |
746 | ||
747 | /* For SVR4 versions, the first entry in the link map is for the | |
748 | inferior executable, so we must ignore it. For some versions of | |
749 | SVR4, it has no name. For others (Solaris 2.3 for example), it | |
750 | does have a name, so we can no longer use a missing name to | |
751 | decide when to ignore it. */ | |
e4cd0d6a | 752 | if (IGNORE_FIRST_LINK_MAP_ENTRY (new) && ldsomap == 0) |
13437d4b KB |
753 | free_so (new); |
754 | else | |
755 | { | |
756 | int errcode; | |
757 | char *buffer; | |
758 | ||
759 | /* Extract this shared object's name. */ | |
760 | target_read_string (LM_NAME (new), &buffer, | |
761 | SO_NAME_MAX_PATH_SIZE - 1, &errcode); | |
762 | if (errcode != 0) | |
8a3fe4f8 AC |
763 | warning (_("Can't read pathname for load map: %s."), |
764 | safe_strerror (errcode)); | |
13437d4b KB |
765 | else |
766 | { | |
767 | strncpy (new->so_name, buffer, SO_NAME_MAX_PATH_SIZE - 1); | |
768 | new->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0'; | |
13437d4b KB |
769 | strcpy (new->so_original_name, new->so_name); |
770 | } | |
ea5bf0a1 | 771 | xfree (buffer); |
13437d4b KB |
772 | |
773 | /* If this entry has no name, or its name matches the name | |
774 | for the main executable, don't include it in the list. */ | |
775 | if (! new->so_name[0] | |
776 | || match_main (new->so_name)) | |
777 | free_so (new); | |
778 | else | |
779 | { | |
780 | new->next = 0; | |
781 | *link_ptr = new; | |
782 | link_ptr = &new->next; | |
783 | } | |
784 | } | |
785 | ||
e4cd0d6a MK |
786 | /* On Solaris, the dynamic linker is not in the normal list of |
787 | shared objects, so make sure we pick it up too. Having | |
788 | symbol information for the dynamic linker is quite crucial | |
789 | for skipping dynamic linker resolver code. */ | |
790 | if (lm == 0 && ldsomap == 0) | |
791 | lm = ldsomap = solib_svr4_r_ldsomap (); | |
792 | ||
13437d4b KB |
793 | discard_cleanups (old_chain); |
794 | } | |
795 | ||
34439770 DJ |
796 | if (head == NULL) |
797 | return svr4_default_sos (); | |
798 | ||
13437d4b KB |
799 | return head; |
800 | } | |
801 | ||
bc4a16ae EZ |
802 | /* Get the address of the link_map for a given OBJFILE. Loop through |
803 | the link maps, and return the address of the one corresponding to | |
804 | the given objfile. Note that this function takes into account that | |
805 | objfile can be the main executable, not just a shared library. The | |
806 | main executable has always an empty name field in the linkmap. */ | |
807 | ||
808 | CORE_ADDR | |
809 | svr4_fetch_objfile_link_map (struct objfile *objfile) | |
810 | { | |
811 | CORE_ADDR lm; | |
812 | ||
7cd25cfc | 813 | if (locate_base () == 0) |
bc4a16ae EZ |
814 | return 0; /* failed somehow... */ |
815 | ||
816 | /* Position ourselves on the first link map. */ | |
e4cd0d6a | 817 | lm = solib_svr4_r_map (); |
bc4a16ae EZ |
818 | while (lm) |
819 | { | |
820 | /* Get info on the layout of the r_debug and link_map structures. */ | |
4b188b9f | 821 | struct link_map_offsets *lmo = svr4_fetch_link_map_offsets (); |
bc4a16ae EZ |
822 | int errcode; |
823 | char *buffer; | |
824 | struct lm_info objfile_lm_info; | |
825 | struct cleanup *old_chain; | |
826 | CORE_ADDR name_address; | |
cfaefc65 AS |
827 | int l_name_size = TYPE_LENGTH (builtin_type_void_data_ptr); |
828 | gdb_byte *l_name_buf = xmalloc (l_name_size); | |
bc4a16ae EZ |
829 | old_chain = make_cleanup (xfree, l_name_buf); |
830 | ||
831 | /* Set up the buffer to contain the portion of the link_map | |
832 | structure that gdb cares about. Note that this is not the | |
833 | whole link_map structure. */ | |
f4456994 | 834 | objfile_lm_info.lm = xzalloc (lmo->link_map_size); |
bc4a16ae | 835 | make_cleanup (xfree, objfile_lm_info.lm); |
bc4a16ae EZ |
836 | |
837 | /* Read the link map into our internal structure. */ | |
838 | read_memory (lm, objfile_lm_info.lm, lmo->link_map_size); | |
839 | ||
840 | /* Read address of name from target memory to GDB. */ | |
cfaefc65 | 841 | read_memory (lm + lmo->l_name_offset, l_name_buf, l_name_size); |
bc4a16ae | 842 | |
cfaefc65 AS |
843 | /* Extract this object's name. */ |
844 | name_address = extract_typed_address (l_name_buf, | |
845 | builtin_type_void_data_ptr); | |
bc4a16ae EZ |
846 | target_read_string (name_address, &buffer, |
847 | SO_NAME_MAX_PATH_SIZE - 1, &errcode); | |
848 | make_cleanup (xfree, buffer); | |
849 | if (errcode != 0) | |
8a3fe4f8 AC |
850 | warning (_("Can't read pathname for load map: %s."), |
851 | safe_strerror (errcode)); | |
bc4a16ae EZ |
852 | else |
853 | { | |
854 | /* Is this the linkmap for the file we want? */ | |
855 | /* If the file is not a shared library and has no name, | |
856 | we are sure it is the main executable, so we return that. */ | |
f52df7d9 MS |
857 | |
858 | if (buffer | |
859 | && ((strcmp (buffer, objfile->name) == 0) | |
860 | || (!(objfile->flags & OBJF_SHARED) | |
861 | && (strcmp (buffer, "") == 0)))) | |
bc4a16ae EZ |
862 | { |
863 | do_cleanups (old_chain); | |
864 | return lm; | |
865 | } | |
866 | } | |
cfaefc65 AS |
867 | /* Not the file we wanted, continue checking. */ |
868 | lm = extract_typed_address (objfile_lm_info.lm + lmo->l_next_offset, | |
869 | builtin_type_void_data_ptr); | |
bc4a16ae EZ |
870 | do_cleanups (old_chain); |
871 | } | |
872 | return 0; | |
873 | } | |
13437d4b KB |
874 | |
875 | /* On some systems, the only way to recognize the link map entry for | |
876 | the main executable file is by looking at its name. Return | |
877 | non-zero iff SONAME matches one of the known main executable names. */ | |
878 | ||
879 | static int | |
880 | match_main (char *soname) | |
881 | { | |
882 | char **mainp; | |
883 | ||
884 | for (mainp = main_name_list; *mainp != NULL; mainp++) | |
885 | { | |
886 | if (strcmp (soname, *mainp) == 0) | |
887 | return (1); | |
888 | } | |
889 | ||
890 | return (0); | |
891 | } | |
892 | ||
13437d4b KB |
893 | /* Return 1 if PC lies in the dynamic symbol resolution code of the |
894 | SVR4 run time loader. */ | |
13437d4b KB |
895 | static CORE_ADDR interp_text_sect_low; |
896 | static CORE_ADDR interp_text_sect_high; | |
897 | static CORE_ADDR interp_plt_sect_low; | |
898 | static CORE_ADDR interp_plt_sect_high; | |
899 | ||
7d522c90 | 900 | int |
d7fa2ae2 | 901 | svr4_in_dynsym_resolve_code (CORE_ADDR pc) |
13437d4b KB |
902 | { |
903 | return ((pc >= interp_text_sect_low && pc < interp_text_sect_high) | |
904 | || (pc >= interp_plt_sect_low && pc < interp_plt_sect_high) | |
905 | || in_plt_section (pc, NULL)); | |
906 | } | |
13437d4b | 907 | |
2f4950cd AC |
908 | /* Given an executable's ABFD and target, compute the entry-point |
909 | address. */ | |
910 | ||
911 | static CORE_ADDR | |
912 | exec_entry_point (struct bfd *abfd, struct target_ops *targ) | |
913 | { | |
914 | /* KevinB wrote ... for most targets, the address returned by | |
915 | bfd_get_start_address() is the entry point for the start | |
916 | function. But, for some targets, bfd_get_start_address() returns | |
917 | the address of a function descriptor from which the entry point | |
918 | address may be extracted. This address is extracted by | |
919 | gdbarch_convert_from_func_ptr_addr(). The method | |
920 | gdbarch_convert_from_func_ptr_addr() is the merely the identify | |
921 | function for targets which don't use function descriptors. */ | |
922 | return gdbarch_convert_from_func_ptr_addr (current_gdbarch, | |
923 | bfd_get_start_address (abfd), | |
924 | targ); | |
925 | } | |
13437d4b KB |
926 | |
927 | /* | |
928 | ||
929 | LOCAL FUNCTION | |
930 | ||
931 | enable_break -- arrange for dynamic linker to hit breakpoint | |
932 | ||
933 | SYNOPSIS | |
934 | ||
935 | int enable_break (void) | |
936 | ||
937 | DESCRIPTION | |
938 | ||
939 | Both the SunOS and the SVR4 dynamic linkers have, as part of their | |
940 | debugger interface, support for arranging for the inferior to hit | |
941 | a breakpoint after mapping in the shared libraries. This function | |
942 | enables that breakpoint. | |
943 | ||
944 | For SunOS, there is a special flag location (in_debugger) which we | |
945 | set to 1. When the dynamic linker sees this flag set, it will set | |
946 | a breakpoint at a location known only to itself, after saving the | |
947 | original contents of that place and the breakpoint address itself, | |
948 | in it's own internal structures. When we resume the inferior, it | |
949 | will eventually take a SIGTRAP when it runs into the breakpoint. | |
950 | We handle this (in a different place) by restoring the contents of | |
951 | the breakpointed location (which is only known after it stops), | |
952 | chasing around to locate the shared libraries that have been | |
953 | loaded, then resuming. | |
954 | ||
955 | For SVR4, the debugger interface structure contains a member (r_brk) | |
956 | which is statically initialized at the time the shared library is | |
957 | built, to the offset of a function (_r_debug_state) which is guaran- | |
958 | teed to be called once before mapping in a library, and again when | |
959 | the mapping is complete. At the time we are examining this member, | |
960 | it contains only the unrelocated offset of the function, so we have | |
961 | to do our own relocation. Later, when the dynamic linker actually | |
962 | runs, it relocates r_brk to be the actual address of _r_debug_state(). | |
963 | ||
964 | The debugger interface structure also contains an enumeration which | |
965 | is set to either RT_ADD or RT_DELETE prior to changing the mapping, | |
966 | depending upon whether or not the library is being mapped or unmapped, | |
967 | and then set to RT_CONSISTENT after the library is mapped/unmapped. | |
968 | */ | |
969 | ||
970 | static int | |
971 | enable_break (void) | |
972 | { | |
13437d4b KB |
973 | #ifdef BKPT_AT_SYMBOL |
974 | ||
975 | struct minimal_symbol *msymbol; | |
976 | char **bkpt_namep; | |
977 | asection *interp_sect; | |
7cd25cfc | 978 | CORE_ADDR sym_addr; |
13437d4b KB |
979 | |
980 | /* First, remove all the solib event breakpoints. Their addresses | |
981 | may have changed since the last time we ran the program. */ | |
982 | remove_solib_event_breakpoints (); | |
983 | ||
13437d4b KB |
984 | interp_text_sect_low = interp_text_sect_high = 0; |
985 | interp_plt_sect_low = interp_plt_sect_high = 0; | |
986 | ||
7cd25cfc DJ |
987 | /* If we already have a shared library list in the target, and |
988 | r_debug contains r_brk, set the breakpoint there - this should | |
989 | mean r_brk has already been relocated. Assume the dynamic linker | |
990 | is the object containing r_brk. */ | |
991 | ||
992 | solib_add (NULL, 0, ¤t_target, auto_solib_add); | |
993 | sym_addr = 0; | |
994 | if (debug_base && solib_svr4_r_map () != 0) | |
995 | sym_addr = solib_svr4_r_brk (); | |
996 | ||
997 | if (sym_addr != 0) | |
998 | { | |
999 | struct obj_section *os; | |
1000 | ||
b36ec657 DJ |
1001 | sym_addr = gdbarch_addr_bits_remove |
1002 | (current_gdbarch, gdbarch_convert_from_func_ptr_addr (current_gdbarch, | |
1003 | sym_addr, | |
1004 | ¤t_target)); | |
1005 | ||
7cd25cfc DJ |
1006 | os = find_pc_section (sym_addr); |
1007 | if (os != NULL) | |
1008 | { | |
1009 | /* Record the relocated start and end address of the dynamic linker | |
1010 | text and plt section for svr4_in_dynsym_resolve_code. */ | |
1011 | bfd *tmp_bfd; | |
1012 | CORE_ADDR load_addr; | |
1013 | ||
1014 | tmp_bfd = os->objfile->obfd; | |
1015 | load_addr = ANOFFSET (os->objfile->section_offsets, | |
1016 | os->objfile->sect_index_text); | |
1017 | ||
1018 | interp_sect = bfd_get_section_by_name (tmp_bfd, ".text"); | |
1019 | if (interp_sect) | |
1020 | { | |
1021 | interp_text_sect_low = | |
1022 | bfd_section_vma (tmp_bfd, interp_sect) + load_addr; | |
1023 | interp_text_sect_high = | |
1024 | interp_text_sect_low + bfd_section_size (tmp_bfd, interp_sect); | |
1025 | } | |
1026 | interp_sect = bfd_get_section_by_name (tmp_bfd, ".plt"); | |
1027 | if (interp_sect) | |
1028 | { | |
1029 | interp_plt_sect_low = | |
1030 | bfd_section_vma (tmp_bfd, interp_sect) + load_addr; | |
1031 | interp_plt_sect_high = | |
1032 | interp_plt_sect_low + bfd_section_size (tmp_bfd, interp_sect); | |
1033 | } | |
1034 | ||
1035 | create_solib_event_breakpoint (sym_addr); | |
1036 | return 1; | |
1037 | } | |
1038 | } | |
1039 | ||
13437d4b KB |
1040 | /* Find the .interp section; if not found, warn the user and drop |
1041 | into the old breakpoint at symbol code. */ | |
1042 | interp_sect = bfd_get_section_by_name (exec_bfd, ".interp"); | |
1043 | if (interp_sect) | |
1044 | { | |
1045 | unsigned int interp_sect_size; | |
1046 | char *buf; | |
8ad2fcde KB |
1047 | CORE_ADDR load_addr = 0; |
1048 | int load_addr_found = 0; | |
2ec9a4f8 | 1049 | int loader_found_in_list = 0; |
f8766ec1 | 1050 | struct so_list *so; |
e4f7b8c8 | 1051 | bfd *tmp_bfd = NULL; |
2f4950cd | 1052 | struct target_ops *tmp_bfd_target; |
e4f7b8c8 MS |
1053 | int tmp_fd = -1; |
1054 | char *tmp_pathname = NULL; | |
13437d4b KB |
1055 | |
1056 | /* Read the contents of the .interp section into a local buffer; | |
1057 | the contents specify the dynamic linker this program uses. */ | |
7cd25cfc | 1058 | sym_addr = 0; |
13437d4b KB |
1059 | interp_sect_size = bfd_section_size (exec_bfd, interp_sect); |
1060 | buf = alloca (interp_sect_size); | |
1061 | bfd_get_section_contents (exec_bfd, interp_sect, | |
1062 | buf, 0, interp_sect_size); | |
1063 | ||
1064 | /* Now we need to figure out where the dynamic linker was | |
1065 | loaded so that we can load its symbols and place a breakpoint | |
1066 | in the dynamic linker itself. | |
1067 | ||
1068 | This address is stored on the stack. However, I've been unable | |
1069 | to find any magic formula to find it for Solaris (appears to | |
1070 | be trivial on GNU/Linux). Therefore, we have to try an alternate | |
1071 | mechanism to find the dynamic linker's base address. */ | |
e4f7b8c8 | 1072 | |
34439770 | 1073 | tmp_fd = solib_open (buf, &tmp_pathname); |
e4f7b8c8 | 1074 | if (tmp_fd >= 0) |
9f76c2cd | 1075 | tmp_bfd = bfd_fopen (tmp_pathname, gnutarget, FOPEN_RB, tmp_fd); |
e4f7b8c8 | 1076 | |
13437d4b KB |
1077 | if (tmp_bfd == NULL) |
1078 | goto bkpt_at_symbol; | |
1079 | ||
1080 | /* Make sure the dynamic linker's really a useful object. */ | |
1081 | if (!bfd_check_format (tmp_bfd, bfd_object)) | |
1082 | { | |
8a3fe4f8 | 1083 | warning (_("Unable to grok dynamic linker %s as an object file"), buf); |
13437d4b KB |
1084 | bfd_close (tmp_bfd); |
1085 | goto bkpt_at_symbol; | |
1086 | } | |
1087 | ||
2f4950cd AC |
1088 | /* Now convert the TMP_BFD into a target. That way target, as |
1089 | well as BFD operations can be used. Note that closing the | |
1090 | target will also close the underlying bfd. */ | |
1091 | tmp_bfd_target = target_bfd_reopen (tmp_bfd); | |
1092 | ||
f8766ec1 KB |
1093 | /* On a running target, we can get the dynamic linker's base |
1094 | address from the shared library table. */ | |
f8766ec1 KB |
1095 | so = master_so_list (); |
1096 | while (so) | |
8ad2fcde | 1097 | { |
f8766ec1 | 1098 | if (strcmp (buf, so->so_original_name) == 0) |
8ad2fcde KB |
1099 | { |
1100 | load_addr_found = 1; | |
2ec9a4f8 | 1101 | loader_found_in_list = 1; |
cc10cae3 | 1102 | load_addr = LM_ADDR_CHECK (so, tmp_bfd); |
8ad2fcde KB |
1103 | break; |
1104 | } | |
f8766ec1 | 1105 | so = so->next; |
8ad2fcde KB |
1106 | } |
1107 | ||
8d4e36ba JB |
1108 | /* If we were not able to find the base address of the loader |
1109 | from our so_list, then try using the AT_BASE auxilliary entry. */ | |
1110 | if (!load_addr_found) | |
1111 | if (target_auxv_search (¤t_target, AT_BASE, &load_addr) > 0) | |
1112 | load_addr_found = 1; | |
1113 | ||
8ad2fcde KB |
1114 | /* Otherwise we find the dynamic linker's base address by examining |
1115 | the current pc (which should point at the entry point for the | |
8d4e36ba JB |
1116 | dynamic linker) and subtracting the offset of the entry point. |
1117 | ||
1118 | This is more fragile than the previous approaches, but is a good | |
1119 | fallback method because it has actually been working well in | |
1120 | most cases. */ | |
8ad2fcde | 1121 | if (!load_addr_found) |
2ec9a4f8 DJ |
1122 | load_addr = (read_pc () |
1123 | - exec_entry_point (tmp_bfd, tmp_bfd_target)); | |
1124 | ||
1125 | if (!loader_found_in_list) | |
34439770 | 1126 | { |
34439770 DJ |
1127 | debug_loader_name = xstrdup (buf); |
1128 | debug_loader_offset_p = 1; | |
1129 | debug_loader_offset = load_addr; | |
2bbe3cc1 | 1130 | solib_add (NULL, 0, ¤t_target, auto_solib_add); |
34439770 | 1131 | } |
13437d4b KB |
1132 | |
1133 | /* Record the relocated start and end address of the dynamic linker | |
d7fa2ae2 | 1134 | text and plt section for svr4_in_dynsym_resolve_code. */ |
13437d4b KB |
1135 | interp_sect = bfd_get_section_by_name (tmp_bfd, ".text"); |
1136 | if (interp_sect) | |
1137 | { | |
1138 | interp_text_sect_low = | |
1139 | bfd_section_vma (tmp_bfd, interp_sect) + load_addr; | |
1140 | interp_text_sect_high = | |
1141 | interp_text_sect_low + bfd_section_size (tmp_bfd, interp_sect); | |
1142 | } | |
1143 | interp_sect = bfd_get_section_by_name (tmp_bfd, ".plt"); | |
1144 | if (interp_sect) | |
1145 | { | |
1146 | interp_plt_sect_low = | |
1147 | bfd_section_vma (tmp_bfd, interp_sect) + load_addr; | |
1148 | interp_plt_sect_high = | |
1149 | interp_plt_sect_low + bfd_section_size (tmp_bfd, interp_sect); | |
1150 | } | |
1151 | ||
1152 | /* Now try to set a breakpoint in the dynamic linker. */ | |
1153 | for (bkpt_namep = solib_break_names; *bkpt_namep != NULL; bkpt_namep++) | |
1154 | { | |
2bbe3cc1 | 1155 | sym_addr = bfd_lookup_symbol (tmp_bfd, *bkpt_namep); |
13437d4b KB |
1156 | if (sym_addr != 0) |
1157 | break; | |
1158 | } | |
1159 | ||
2bbe3cc1 DJ |
1160 | if (sym_addr != 0) |
1161 | /* Convert 'sym_addr' from a function pointer to an address. | |
1162 | Because we pass tmp_bfd_target instead of the current | |
1163 | target, this will always produce an unrelocated value. */ | |
1164 | sym_addr = gdbarch_convert_from_func_ptr_addr (current_gdbarch, | |
1165 | sym_addr, | |
1166 | tmp_bfd_target); | |
1167 | ||
2f4950cd AC |
1168 | /* We're done with both the temporary bfd and target. Remember, |
1169 | closing the target closes the underlying bfd. */ | |
1170 | target_close (tmp_bfd_target, 0); | |
13437d4b KB |
1171 | |
1172 | if (sym_addr != 0) | |
1173 | { | |
1174 | create_solib_event_breakpoint (load_addr + sym_addr); | |
1175 | return 1; | |
1176 | } | |
1177 | ||
1178 | /* For whatever reason we couldn't set a breakpoint in the dynamic | |
1179 | linker. Warn and drop into the old code. */ | |
1180 | bkpt_at_symbol: | |
518f9d3c | 1181 | xfree (tmp_pathname); |
82d03102 PG |
1182 | warning (_("Unable to find dynamic linker breakpoint function.\n" |
1183 | "GDB will be unable to debug shared library initializers\n" | |
1184 | "and track explicitly loaded dynamic code.")); | |
13437d4b | 1185 | } |
13437d4b | 1186 | |
e499d0f1 DJ |
1187 | /* Scan through the lists of symbols, trying to look up the symbol and |
1188 | set a breakpoint there. Terminate loop when we/if we succeed. */ | |
1189 | ||
1190 | for (bkpt_namep = solib_break_names; *bkpt_namep != NULL; bkpt_namep++) | |
1191 | { | |
1192 | msymbol = lookup_minimal_symbol (*bkpt_namep, NULL, symfile_objfile); | |
1193 | if ((msymbol != NULL) && (SYMBOL_VALUE_ADDRESS (msymbol) != 0)) | |
1194 | { | |
1195 | create_solib_event_breakpoint (SYMBOL_VALUE_ADDRESS (msymbol)); | |
1196 | return 1; | |
1197 | } | |
1198 | } | |
13437d4b | 1199 | |
13437d4b KB |
1200 | for (bkpt_namep = bkpt_names; *bkpt_namep != NULL; bkpt_namep++) |
1201 | { | |
1202 | msymbol = lookup_minimal_symbol (*bkpt_namep, NULL, symfile_objfile); | |
1203 | if ((msymbol != NULL) && (SYMBOL_VALUE_ADDRESS (msymbol) != 0)) | |
1204 | { | |
1205 | create_solib_event_breakpoint (SYMBOL_VALUE_ADDRESS (msymbol)); | |
1206 | return 1; | |
1207 | } | |
1208 | } | |
13437d4b KB |
1209 | #endif /* BKPT_AT_SYMBOL */ |
1210 | ||
542c95c2 | 1211 | return 0; |
13437d4b KB |
1212 | } |
1213 | ||
1214 | /* | |
1215 | ||
1216 | LOCAL FUNCTION | |
1217 | ||
1218 | special_symbol_handling -- additional shared library symbol handling | |
1219 | ||
1220 | SYNOPSIS | |
1221 | ||
1222 | void special_symbol_handling () | |
1223 | ||
1224 | DESCRIPTION | |
1225 | ||
1226 | Once the symbols from a shared object have been loaded in the usual | |
1227 | way, we are called to do any system specific symbol handling that | |
1228 | is needed. | |
1229 | ||
ab31aa69 | 1230 | For SunOS4, this consisted of grunging around in the dynamic |
13437d4b KB |
1231 | linkers structures to find symbol definitions for "common" symbols |
1232 | and adding them to the minimal symbol table for the runtime common | |
1233 | objfile. | |
1234 | ||
ab31aa69 KB |
1235 | However, for SVR4, there's nothing to do. |
1236 | ||
13437d4b KB |
1237 | */ |
1238 | ||
1239 | static void | |
1240 | svr4_special_symbol_handling (void) | |
1241 | { | |
13437d4b KB |
1242 | } |
1243 | ||
e2a44558 KB |
1244 | /* Relocate the main executable. This function should be called upon |
1245 | stopping the inferior process at the entry point to the program. | |
1246 | The entry point from BFD is compared to the PC and if they are | |
1247 | different, the main executable is relocated by the proper amount. | |
1248 | ||
1249 | As written it will only attempt to relocate executables which | |
1250 | lack interpreter sections. It seems likely that only dynamic | |
1251 | linker executables will get relocated, though it should work | |
1252 | properly for a position-independent static executable as well. */ | |
1253 | ||
1254 | static void | |
1255 | svr4_relocate_main_executable (void) | |
1256 | { | |
1257 | asection *interp_sect; | |
1258 | CORE_ADDR pc = read_pc (); | |
1259 | ||
1260 | /* Decide if the objfile needs to be relocated. As indicated above, | |
1261 | we will only be here when execution is stopped at the beginning | |
1262 | of the program. Relocation is necessary if the address at which | |
1263 | we are presently stopped differs from the start address stored in | |
1264 | the executable AND there's no interpreter section. The condition | |
1265 | regarding the interpreter section is very important because if | |
1266 | there *is* an interpreter section, execution will begin there | |
1267 | instead. When there is an interpreter section, the start address | |
1268 | is (presumably) used by the interpreter at some point to start | |
1269 | execution of the program. | |
1270 | ||
1271 | If there is an interpreter, it is normal for it to be set to an | |
1272 | arbitrary address at the outset. The job of finding it is | |
1273 | handled in enable_break(). | |
1274 | ||
1275 | So, to summarize, relocations are necessary when there is no | |
1276 | interpreter section and the start address obtained from the | |
1277 | executable is different from the address at which GDB is | |
1278 | currently stopped. | |
1279 | ||
1280 | [ The astute reader will note that we also test to make sure that | |
1281 | the executable in question has the DYNAMIC flag set. It is my | |
1282 | opinion that this test is unnecessary (undesirable even). It | |
1283 | was added to avoid inadvertent relocation of an executable | |
1284 | whose e_type member in the ELF header is not ET_DYN. There may | |
1285 | be a time in the future when it is desirable to do relocations | |
1286 | on other types of files as well in which case this condition | |
1287 | should either be removed or modified to accomodate the new file | |
1288 | type. (E.g, an ET_EXEC executable which has been built to be | |
1289 | position-independent could safely be relocated by the OS if | |
1290 | desired. It is true that this violates the ABI, but the ABI | |
1291 | has been known to be bent from time to time.) - Kevin, Nov 2000. ] | |
1292 | */ | |
1293 | ||
1294 | interp_sect = bfd_get_section_by_name (exec_bfd, ".interp"); | |
1295 | if (interp_sect == NULL | |
1296 | && (bfd_get_file_flags (exec_bfd) & DYNAMIC) != 0 | |
2f4950cd | 1297 | && (exec_entry_point (exec_bfd, &exec_ops) != pc)) |
e2a44558 KB |
1298 | { |
1299 | struct cleanup *old_chain; | |
1300 | struct section_offsets *new_offsets; | |
1301 | int i, changed; | |
1302 | CORE_ADDR displacement; | |
1303 | ||
1304 | /* It is necessary to relocate the objfile. The amount to | |
1305 | relocate by is simply the address at which we are stopped | |
1306 | minus the starting address from the executable. | |
1307 | ||
1308 | We relocate all of the sections by the same amount. This | |
1309 | behavior is mandated by recent editions of the System V ABI. | |
1310 | According to the System V Application Binary Interface, | |
1311 | Edition 4.1, page 5-5: | |
1312 | ||
1313 | ... Though the system chooses virtual addresses for | |
1314 | individual processes, it maintains the segments' relative | |
1315 | positions. Because position-independent code uses relative | |
1316 | addressesing between segments, the difference between | |
1317 | virtual addresses in memory must match the difference | |
1318 | between virtual addresses in the file. The difference | |
1319 | between the virtual address of any segment in memory and | |
1320 | the corresponding virtual address in the file is thus a | |
1321 | single constant value for any one executable or shared | |
1322 | object in a given process. This difference is the base | |
1323 | address. One use of the base address is to relocate the | |
1324 | memory image of the program during dynamic linking. | |
1325 | ||
1326 | The same language also appears in Edition 4.0 of the System V | |
1327 | ABI and is left unspecified in some of the earlier editions. */ | |
1328 | ||
2f4950cd | 1329 | displacement = pc - exec_entry_point (exec_bfd, &exec_ops); |
e2a44558 KB |
1330 | changed = 0; |
1331 | ||
13fc0c2f KB |
1332 | new_offsets = xcalloc (symfile_objfile->num_sections, |
1333 | sizeof (struct section_offsets)); | |
b8c9b27d | 1334 | old_chain = make_cleanup (xfree, new_offsets); |
e2a44558 KB |
1335 | |
1336 | for (i = 0; i < symfile_objfile->num_sections; i++) | |
1337 | { | |
1338 | if (displacement != ANOFFSET (symfile_objfile->section_offsets, i)) | |
1339 | changed = 1; | |
1340 | new_offsets->offsets[i] = displacement; | |
1341 | } | |
1342 | ||
1343 | if (changed) | |
1344 | objfile_relocate (symfile_objfile, new_offsets); | |
1345 | ||
1346 | do_cleanups (old_chain); | |
1347 | } | |
1348 | } | |
1349 | ||
13437d4b KB |
1350 | /* |
1351 | ||
1352 | GLOBAL FUNCTION | |
1353 | ||
1354 | svr4_solib_create_inferior_hook -- shared library startup support | |
1355 | ||
1356 | SYNOPSIS | |
1357 | ||
7095b863 | 1358 | void svr4_solib_create_inferior_hook () |
13437d4b KB |
1359 | |
1360 | DESCRIPTION | |
1361 | ||
1362 | When gdb starts up the inferior, it nurses it along (through the | |
1363 | shell) until it is ready to execute it's first instruction. At this | |
1364 | point, this function gets called via expansion of the macro | |
1365 | SOLIB_CREATE_INFERIOR_HOOK. | |
1366 | ||
1367 | For SunOS executables, this first instruction is typically the | |
1368 | one at "_start", or a similar text label, regardless of whether | |
1369 | the executable is statically or dynamically linked. The runtime | |
1370 | startup code takes care of dynamically linking in any shared | |
1371 | libraries, once gdb allows the inferior to continue. | |
1372 | ||
1373 | For SVR4 executables, this first instruction is either the first | |
1374 | instruction in the dynamic linker (for dynamically linked | |
1375 | executables) or the instruction at "start" for statically linked | |
1376 | executables. For dynamically linked executables, the system | |
1377 | first exec's /lib/libc.so.N, which contains the dynamic linker, | |
1378 | and starts it running. The dynamic linker maps in any needed | |
1379 | shared libraries, maps in the actual user executable, and then | |
1380 | jumps to "start" in the user executable. | |
1381 | ||
1382 | For both SunOS shared libraries, and SVR4 shared libraries, we | |
1383 | can arrange to cooperate with the dynamic linker to discover the | |
1384 | names of shared libraries that are dynamically linked, and the | |
1385 | base addresses to which they are linked. | |
1386 | ||
1387 | This function is responsible for discovering those names and | |
1388 | addresses, and saving sufficient information about them to allow | |
1389 | their symbols to be read at a later time. | |
1390 | ||
1391 | FIXME | |
1392 | ||
1393 | Between enable_break() and disable_break(), this code does not | |
1394 | properly handle hitting breakpoints which the user might have | |
1395 | set in the startup code or in the dynamic linker itself. Proper | |
1396 | handling will probably have to wait until the implementation is | |
1397 | changed to use the "breakpoint handler function" method. | |
1398 | ||
1399 | Also, what if child has exit()ed? Must exit loop somehow. | |
1400 | */ | |
1401 | ||
e2a44558 | 1402 | static void |
13437d4b KB |
1403 | svr4_solib_create_inferior_hook (void) |
1404 | { | |
e2a44558 KB |
1405 | /* Relocate the main executable if necessary. */ |
1406 | svr4_relocate_main_executable (); | |
1407 | ||
d5a921c9 | 1408 | if (!svr4_have_link_map_offsets ()) |
513f5903 | 1409 | return; |
d5a921c9 | 1410 | |
13437d4b | 1411 | if (!enable_break ()) |
542c95c2 | 1412 | return; |
13437d4b | 1413 | |
ab31aa69 KB |
1414 | #if defined(_SCO_DS) |
1415 | /* SCO needs the loop below, other systems should be using the | |
13437d4b KB |
1416 | special shared library breakpoints and the shared library breakpoint |
1417 | service routine. | |
1418 | ||
1419 | Now run the target. It will eventually hit the breakpoint, at | |
1420 | which point all of the libraries will have been mapped in and we | |
1421 | can go groveling around in the dynamic linker structures to find | |
1422 | out what we need to know about them. */ | |
1423 | ||
1424 | clear_proceed_status (); | |
c0236d92 | 1425 | stop_soon = STOP_QUIETLY; |
13437d4b KB |
1426 | stop_signal = TARGET_SIGNAL_0; |
1427 | do | |
1428 | { | |
39f77062 | 1429 | target_resume (pid_to_ptid (-1), 0, stop_signal); |
ae123ec6 | 1430 | wait_for_inferior (0); |
13437d4b KB |
1431 | } |
1432 | while (stop_signal != TARGET_SIGNAL_TRAP); | |
c0236d92 | 1433 | stop_soon = NO_STOP_QUIETLY; |
ab31aa69 | 1434 | #endif /* defined(_SCO_DS) */ |
13437d4b KB |
1435 | } |
1436 | ||
1437 | static void | |
1438 | svr4_clear_solib (void) | |
1439 | { | |
1440 | debug_base = 0; | |
34439770 DJ |
1441 | debug_loader_offset_p = 0; |
1442 | debug_loader_offset = 0; | |
1443 | xfree (debug_loader_name); | |
1444 | debug_loader_name = NULL; | |
13437d4b KB |
1445 | } |
1446 | ||
1447 | static void | |
1448 | svr4_free_so (struct so_list *so) | |
1449 | { | |
b8c9b27d KB |
1450 | xfree (so->lm_info->lm); |
1451 | xfree (so->lm_info); | |
13437d4b KB |
1452 | } |
1453 | ||
6bb7be43 JB |
1454 | |
1455 | /* Clear any bits of ADDR that wouldn't fit in a target-format | |
1456 | data pointer. "Data pointer" here refers to whatever sort of | |
1457 | address the dynamic linker uses to manage its sections. At the | |
1458 | moment, we don't support shared libraries on any processors where | |
1459 | code and data pointers are different sizes. | |
1460 | ||
1461 | This isn't really the right solution. What we really need here is | |
1462 | a way to do arithmetic on CORE_ADDR values that respects the | |
1463 | natural pointer/address correspondence. (For example, on the MIPS, | |
1464 | converting a 32-bit pointer to a 64-bit CORE_ADDR requires you to | |
1465 | sign-extend the value. There, simply truncating the bits above | |
819844ad | 1466 | gdbarch_ptr_bit, as we do below, is no good.) This should probably |
6bb7be43 JB |
1467 | be a new gdbarch method or something. */ |
1468 | static CORE_ADDR | |
1469 | svr4_truncate_ptr (CORE_ADDR addr) | |
1470 | { | |
819844ad | 1471 | if (gdbarch_ptr_bit (current_gdbarch) == sizeof (CORE_ADDR) * 8) |
6bb7be43 JB |
1472 | /* We don't need to truncate anything, and the bit twiddling below |
1473 | will fail due to overflow problems. */ | |
1474 | return addr; | |
1475 | else | |
819844ad | 1476 | return addr & (((CORE_ADDR) 1 << gdbarch_ptr_bit (current_gdbarch)) - 1); |
6bb7be43 JB |
1477 | } |
1478 | ||
1479 | ||
749499cb KB |
1480 | static void |
1481 | svr4_relocate_section_addresses (struct so_list *so, | |
1482 | struct section_table *sec) | |
1483 | { | |
cc10cae3 AO |
1484 | sec->addr = svr4_truncate_ptr (sec->addr + LM_ADDR_CHECK (so, |
1485 | sec->bfd)); | |
1486 | sec->endaddr = svr4_truncate_ptr (sec->endaddr + LM_ADDR_CHECK (so, | |
1487 | sec->bfd)); | |
749499cb | 1488 | } |
4b188b9f | 1489 | \f |
749499cb | 1490 | |
4b188b9f | 1491 | /* Architecture-specific operations. */ |
6bb7be43 | 1492 | |
4b188b9f MK |
1493 | /* Per-architecture data key. */ |
1494 | static struct gdbarch_data *solib_svr4_data; | |
e5e2b9ff | 1495 | |
4b188b9f | 1496 | struct solib_svr4_ops |
e5e2b9ff | 1497 | { |
4b188b9f MK |
1498 | /* Return a description of the layout of `struct link_map'. */ |
1499 | struct link_map_offsets *(*fetch_link_map_offsets)(void); | |
1500 | }; | |
e5e2b9ff | 1501 | |
4b188b9f | 1502 | /* Return a default for the architecture-specific operations. */ |
e5e2b9ff | 1503 | |
4b188b9f MK |
1504 | static void * |
1505 | solib_svr4_init (struct obstack *obstack) | |
e5e2b9ff | 1506 | { |
4b188b9f | 1507 | struct solib_svr4_ops *ops; |
e5e2b9ff | 1508 | |
4b188b9f | 1509 | ops = OBSTACK_ZALLOC (obstack, struct solib_svr4_ops); |
8d005789 | 1510 | ops->fetch_link_map_offsets = NULL; |
4b188b9f | 1511 | return ops; |
e5e2b9ff KB |
1512 | } |
1513 | ||
4b188b9f | 1514 | /* Set the architecture-specific `struct link_map_offsets' fetcher for |
7e3cb44c | 1515 | GDBARCH to FLMO. Also, install SVR4 solib_ops into GDBARCH. */ |
1c4dcb57 | 1516 | |
21479ded | 1517 | void |
e5e2b9ff KB |
1518 | set_solib_svr4_fetch_link_map_offsets (struct gdbarch *gdbarch, |
1519 | struct link_map_offsets *(*flmo) (void)) | |
21479ded | 1520 | { |
4b188b9f MK |
1521 | struct solib_svr4_ops *ops = gdbarch_data (gdbarch, solib_svr4_data); |
1522 | ||
1523 | ops->fetch_link_map_offsets = flmo; | |
7e3cb44c UW |
1524 | |
1525 | set_solib_ops (gdbarch, &svr4_so_ops); | |
21479ded KB |
1526 | } |
1527 | ||
4b188b9f MK |
1528 | /* Fetch a link_map_offsets structure using the architecture-specific |
1529 | `struct link_map_offsets' fetcher. */ | |
1c4dcb57 | 1530 | |
4b188b9f MK |
1531 | static struct link_map_offsets * |
1532 | svr4_fetch_link_map_offsets (void) | |
21479ded | 1533 | { |
4b188b9f MK |
1534 | struct solib_svr4_ops *ops = gdbarch_data (current_gdbarch, solib_svr4_data); |
1535 | ||
1536 | gdb_assert (ops->fetch_link_map_offsets); | |
1537 | return ops->fetch_link_map_offsets (); | |
21479ded KB |
1538 | } |
1539 | ||
4b188b9f MK |
1540 | /* Return 1 if a link map offset fetcher has been defined, 0 otherwise. */ |
1541 | ||
1542 | static int | |
1543 | svr4_have_link_map_offsets (void) | |
1544 | { | |
1545 | struct solib_svr4_ops *ops = gdbarch_data (current_gdbarch, solib_svr4_data); | |
1546 | return (ops->fetch_link_map_offsets != NULL); | |
1547 | } | |
1548 | \f | |
1549 | ||
e4bbbda8 MK |
1550 | /* Most OS'es that have SVR4-style ELF dynamic libraries define a |
1551 | `struct r_debug' and a `struct link_map' that are binary compatible | |
1552 | with the origional SVR4 implementation. */ | |
1553 | ||
1554 | /* Fetch (and possibly build) an appropriate `struct link_map_offsets' | |
1555 | for an ILP32 SVR4 system. */ | |
1556 | ||
1557 | struct link_map_offsets * | |
1558 | svr4_ilp32_fetch_link_map_offsets (void) | |
1559 | { | |
1560 | static struct link_map_offsets lmo; | |
1561 | static struct link_map_offsets *lmp = NULL; | |
1562 | ||
1563 | if (lmp == NULL) | |
1564 | { | |
1565 | lmp = &lmo; | |
1566 | ||
e4cd0d6a MK |
1567 | lmo.r_version_offset = 0; |
1568 | lmo.r_version_size = 4; | |
e4bbbda8 | 1569 | lmo.r_map_offset = 4; |
7cd25cfc | 1570 | lmo.r_brk_offset = 8; |
e4cd0d6a | 1571 | lmo.r_ldsomap_offset = 20; |
e4bbbda8 MK |
1572 | |
1573 | /* Everything we need is in the first 20 bytes. */ | |
1574 | lmo.link_map_size = 20; | |
1575 | lmo.l_addr_offset = 0; | |
e4bbbda8 | 1576 | lmo.l_name_offset = 4; |
cc10cae3 | 1577 | lmo.l_ld_offset = 8; |
e4bbbda8 | 1578 | lmo.l_next_offset = 12; |
e4bbbda8 | 1579 | lmo.l_prev_offset = 16; |
e4bbbda8 MK |
1580 | } |
1581 | ||
1582 | return lmp; | |
1583 | } | |
1584 | ||
1585 | /* Fetch (and possibly build) an appropriate `struct link_map_offsets' | |
1586 | for an LP64 SVR4 system. */ | |
1587 | ||
1588 | struct link_map_offsets * | |
1589 | svr4_lp64_fetch_link_map_offsets (void) | |
1590 | { | |
1591 | static struct link_map_offsets lmo; | |
1592 | static struct link_map_offsets *lmp = NULL; | |
1593 | ||
1594 | if (lmp == NULL) | |
1595 | { | |
1596 | lmp = &lmo; | |
1597 | ||
e4cd0d6a MK |
1598 | lmo.r_version_offset = 0; |
1599 | lmo.r_version_size = 4; | |
e4bbbda8 | 1600 | lmo.r_map_offset = 8; |
7cd25cfc | 1601 | lmo.r_brk_offset = 16; |
e4cd0d6a | 1602 | lmo.r_ldsomap_offset = 40; |
e4bbbda8 MK |
1603 | |
1604 | /* Everything we need is in the first 40 bytes. */ | |
1605 | lmo.link_map_size = 40; | |
1606 | lmo.l_addr_offset = 0; | |
e4bbbda8 | 1607 | lmo.l_name_offset = 8; |
cc10cae3 | 1608 | lmo.l_ld_offset = 16; |
e4bbbda8 | 1609 | lmo.l_next_offset = 24; |
e4bbbda8 | 1610 | lmo.l_prev_offset = 32; |
e4bbbda8 MK |
1611 | } |
1612 | ||
1613 | return lmp; | |
1614 | } | |
1615 | \f | |
1616 | ||
7d522c90 | 1617 | struct target_so_ops svr4_so_ops; |
13437d4b | 1618 | |
3a40aaa0 UW |
1619 | /* Lookup global symbol for ELF DSOs linked with -Bsymbolic. Those DSOs have a |
1620 | different rule for symbol lookup. The lookup begins here in the DSO, not in | |
1621 | the main executable. */ | |
1622 | ||
1623 | static struct symbol * | |
1624 | elf_lookup_lib_symbol (const struct objfile *objfile, | |
1625 | const char *name, | |
1626 | const char *linkage_name, | |
1627 | const domain_enum domain, struct symtab **symtab) | |
1628 | { | |
1629 | if (objfile->obfd == NULL | |
1630 | || scan_dyntag (DT_SYMBOLIC, objfile->obfd, NULL) != 1) | |
1631 | return NULL; | |
1632 | ||
65728c26 | 1633 | return lookup_global_symbol_from_objfile |
3a40aaa0 UW |
1634 | (objfile, name, linkage_name, domain, symtab); |
1635 | } | |
1636 | ||
a7c02bc8 VP |
1637 | static int |
1638 | svr4_same (struct so_list *gdb, struct so_list *inferior) | |
1639 | { | |
1640 | if (! strcmp (gdb->so_original_name, inferior->so_original_name)) | |
1641 | return 1; | |
1642 | ||
1643 | /* On Solaris, when starting inferior we think that dynamic linker is | |
1644 | /usr/lib/ld.so.1, but later on, the table of loaded shared libraries | |
1645 | contains /lib/ld.so.1. Sometimes one file is a link to another, but | |
1646 | sometimes they have identical content, but are not linked to each | |
1647 | other. We don't restrict this check for Solaris, but the chances | |
1648 | of running into this situation elsewhere are very low. */ | |
1649 | if (strcmp (gdb->so_original_name, "/usr/lib/ld.so.1") == 0 | |
1650 | && strcmp (inferior->so_original_name, "/lib/ld.so.1") == 0) | |
1651 | return 1; | |
1652 | ||
1653 | return 0; | |
1654 | } | |
1655 | ||
a78f21af AC |
1656 | extern initialize_file_ftype _initialize_svr4_solib; /* -Wmissing-prototypes */ |
1657 | ||
13437d4b KB |
1658 | void |
1659 | _initialize_svr4_solib (void) | |
1660 | { | |
4b188b9f MK |
1661 | solib_svr4_data = gdbarch_data_register_pre_init (solib_svr4_init); |
1662 | ||
749499cb | 1663 | svr4_so_ops.relocate_section_addresses = svr4_relocate_section_addresses; |
13437d4b KB |
1664 | svr4_so_ops.free_so = svr4_free_so; |
1665 | svr4_so_ops.clear_solib = svr4_clear_solib; | |
1666 | svr4_so_ops.solib_create_inferior_hook = svr4_solib_create_inferior_hook; | |
1667 | svr4_so_ops.special_symbol_handling = svr4_special_symbol_handling; | |
1668 | svr4_so_ops.current_sos = svr4_current_sos; | |
1669 | svr4_so_ops.open_symbol_file_object = open_symbol_file_object; | |
d7fa2ae2 | 1670 | svr4_so_ops.in_dynsym_resolve_code = svr4_in_dynsym_resolve_code; |
3a40aaa0 | 1671 | svr4_so_ops.lookup_lib_global_symbol = elf_lookup_lib_symbol; |
a7c02bc8 | 1672 | svr4_so_ops.same = svr4_same; |
13437d4b | 1673 | } |