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ab31aa69 | 1 | /* Handle SunOS shared libraries for GDB, the GNU Debugger. |
8dcef9cf | 2 | |
6aba47ca | 3 | Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000, |
7b6bb8da | 4 | 2001, 2004, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc. |
ab31aa69 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 |
ab31aa69 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/>. */ |
ab31aa69 KB |
20 | |
21 | #include "defs.h" | |
22 | ||
23 | #include <sys/types.h> | |
24 | #include <signal.h> | |
25 | #include "gdb_string.h" | |
26 | #include <sys/param.h> | |
27 | #include <fcntl.h> | |
28 | ||
8dcef9cf | 29 | /* SunOS shared libs need the nlist structure. */ |
ab31aa69 KB |
30 | #include <a.out.h> |
31 | #include <link.h> | |
32 | ||
33 | #include "symtab.h" | |
34 | #include "bfd.h" | |
35 | #include "symfile.h" | |
36 | #include "objfiles.h" | |
37 | #include "gdbcore.h" | |
38 | #include "inferior.h" | |
2020b7ab | 39 | #include "gdbthread.h" |
ab31aa69 | 40 | #include "solist.h" |
03cc47f7 MK |
41 | #include "bcache.h" |
42 | #include "regcache.h" | |
ab31aa69 | 43 | |
8dcef9cf MK |
44 | /* The shared library implementation found on BSD a.out systems is |
45 | very similar to the SunOS implementation. However, the data | |
46 | structures defined in <link.h> are named very differently. Make up | |
47 | for those differences here. */ | |
48 | ||
49 | #ifdef HAVE_STRUCT_SO_MAP_WITH_SOM_MEMBERS | |
50 | ||
51 | /* FIXME: Temporary until the equivalent defines have been removed | |
52 | from all nm-*bsd*.h files. */ | |
53 | #ifndef link_dynamic | |
54 | ||
55 | /* Map `struct link_map' and its members. */ | |
56 | #define link_map so_map | |
57 | #define lm_addr som_addr | |
58 | #define lm_name som_path | |
59 | #define lm_next som_next | |
60 | ||
61 | /* Map `struct link_dynamic_2' and its members. */ | |
62 | #define link_dynamic_2 section_dispatch_table | |
63 | #define ld_loaded sdt_loaded | |
64 | ||
65 | /* Map `struct rtc_symb' and its members. */ | |
66 | #define rtc_symb rt_symbol | |
67 | #define rtc_sp rt_sp | |
68 | #define rtc_next rt_next | |
69 | ||
70 | /* Map `struct ld_debug' and its members. */ | |
71 | #define ld_debug so_debug | |
72 | #define ldd_in_debugger dd_in_debugger | |
73 | #define ldd_bp_addr dd_bpt_addr | |
74 | #define ldd_bp_inst dd_bpt_shadow | |
75 | #define ldd_cp dd_cc | |
76 | ||
77 | /* Map `struct link_dynamic' and its members. */ | |
78 | #define link_dynamic _dynamic | |
79 | #define ld_version d_version | |
80 | #define ldd d_debug | |
81 | #define ld_un d_un | |
82 | #define ld_2 d_sdt | |
83 | ||
84 | #endif | |
85 | ||
86 | #endif | |
87 | ||
c378eb4e | 88 | /* Link map info to include in an allocated so_list entry. */ |
ab31aa69 KB |
89 | |
90 | struct lm_info | |
91 | { | |
92 | /* Pointer to copy of link map from inferior. The type is char * | |
93 | rather than void *, so that we may use byte offsets to find the | |
94 | various fields without the need for a cast. */ | |
95 | char *lm; | |
96 | }; | |
97 | ||
98 | ||
c378eb4e | 99 | /* Symbols which are used to locate the base of the link map structures. */ |
ab31aa69 KB |
100 | |
101 | static char *debug_base_symbols[] = | |
102 | { | |
103 | "_DYNAMIC", | |
104 | "_DYNAMIC__MGC", | |
105 | NULL | |
106 | }; | |
107 | ||
108 | static char *main_name_list[] = | |
109 | { | |
110 | "main_$main", | |
111 | NULL | |
112 | }; | |
113 | ||
ae0167b9 AC |
114 | /* Macro to extract an address from a solib structure. When GDB is |
115 | configured for some 32-bit targets (e.g. Solaris 2.7 sparc), BFD is | |
116 | configured to handle 64-bit targets, so CORE_ADDR is 64 bits. We | |
117 | have to extract only the significant bits of addresses to get the | |
118 | right address when accessing the core file BFD. | |
119 | ||
120 | Assume that the address is unsigned. */ | |
ab31aa69 KB |
121 | |
122 | #define SOLIB_EXTRACT_ADDRESS(MEMBER) \ | |
e17a4113 UW |
123 | extract_unsigned_integer (&(MEMBER), sizeof (MEMBER), \ |
124 | gdbarch_byte_order (target_gdbarch)) | |
ab31aa69 KB |
125 | |
126 | /* local data declarations */ | |
127 | ||
128 | static struct link_dynamic dynamic_copy; | |
129 | static struct link_dynamic_2 ld_2_copy; | |
130 | static struct ld_debug debug_copy; | |
131 | static CORE_ADDR debug_addr; | |
132 | static CORE_ADDR flag_addr; | |
133 | ||
134 | #ifndef offsetof | |
135 | #define offsetof(TYPE, MEMBER) ((unsigned long) &((TYPE *)0)->MEMBER) | |
136 | #endif | |
137 | #define fieldsize(TYPE, MEMBER) (sizeof (((TYPE *)0)->MEMBER)) | |
138 | ||
139 | /* link map access functions */ | |
140 | ||
141 | static CORE_ADDR | |
142 | LM_ADDR (struct so_list *so) | |
143 | { | |
e17a4113 | 144 | enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch); |
ab31aa69 KB |
145 | int lm_addr_offset = offsetof (struct link_map, lm_addr); |
146 | int lm_addr_size = fieldsize (struct link_map, lm_addr); | |
147 | ||
148 | return (CORE_ADDR) extract_signed_integer (so->lm_info->lm + lm_addr_offset, | |
e17a4113 | 149 | lm_addr_size, byte_order); |
ab31aa69 KB |
150 | } |
151 | ||
152 | static CORE_ADDR | |
153 | LM_NEXT (struct so_list *so) | |
154 | { | |
e17a4113 | 155 | enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch); |
ab31aa69 KB |
156 | int lm_next_offset = offsetof (struct link_map, lm_next); |
157 | int lm_next_size = fieldsize (struct link_map, lm_next); | |
158 | ||
ae0167b9 AC |
159 | /* Assume that the address is unsigned. */ |
160 | return extract_unsigned_integer (so->lm_info->lm + lm_next_offset, | |
e17a4113 | 161 | lm_next_size, byte_order); |
ab31aa69 KB |
162 | } |
163 | ||
164 | static CORE_ADDR | |
165 | LM_NAME (struct so_list *so) | |
166 | { | |
e17a4113 | 167 | enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch); |
ab31aa69 KB |
168 | int lm_name_offset = offsetof (struct link_map, lm_name); |
169 | int lm_name_size = fieldsize (struct link_map, lm_name); | |
170 | ||
ae0167b9 AC |
171 | /* Assume that the address is unsigned. */ |
172 | return extract_unsigned_integer (so->lm_info->lm + lm_name_offset, | |
e17a4113 | 173 | lm_name_size, byte_order); |
ab31aa69 KB |
174 | } |
175 | ||
c378eb4e | 176 | static CORE_ADDR debug_base; /* Base of dynamic linker structures. */ |
ab31aa69 KB |
177 | |
178 | /* Local function prototypes */ | |
179 | ||
180 | static int match_main (char *); | |
181 | ||
182 | /* Allocate the runtime common object file. */ | |
183 | ||
184 | static void | |
185 | allocate_rt_common_objfile (void) | |
186 | { | |
187 | struct objfile *objfile; | |
188 | struct objfile *last_one; | |
189 | ||
190 | objfile = (struct objfile *) xmalloc (sizeof (struct objfile)); | |
191 | memset (objfile, 0, sizeof (struct objfile)); | |
ce1ed485 MK |
192 | objfile->psymbol_cache = bcache_xmalloc (); |
193 | objfile->macro_cache = bcache_xmalloc (); | |
10abe6bf | 194 | objfile->filename_cache = bcache_xmalloc (); |
1ab21617 | 195 | obstack_init (&objfile->objfile_obstack); |
982526a1 | 196 | objfile->name = xstrdup ("rt_common"); |
ab31aa69 | 197 | |
c378eb4e | 198 | /* Add this file onto the tail of the linked list of other such files. */ |
ab31aa69 KB |
199 | |
200 | objfile->next = NULL; | |
201 | if (object_files == NULL) | |
202 | object_files = objfile; | |
203 | else | |
204 | { | |
205 | for (last_one = object_files; | |
206 | last_one->next; | |
207 | last_one = last_one->next); | |
208 | last_one->next = objfile; | |
209 | } | |
210 | ||
211 | rt_common_objfile = objfile; | |
212 | } | |
213 | ||
214 | /* Read all dynamically loaded common symbol definitions from the inferior | |
215 | and put them into the minimal symbol table for the runtime common | |
216 | objfile. */ | |
217 | ||
218 | static void | |
219 | solib_add_common_symbols (CORE_ADDR rtc_symp) | |
220 | { | |
221 | struct rtc_symb inferior_rtc_symb; | |
222 | struct nlist inferior_rtc_nlist; | |
223 | int len; | |
224 | char *name; | |
225 | ||
226 | /* Remove any runtime common symbols from previous runs. */ | |
227 | ||
228 | if (rt_common_objfile != NULL && rt_common_objfile->minimal_symbol_count) | |
229 | { | |
4a146b47 | 230 | obstack_free (&rt_common_objfile->objfile_obstack, 0); |
1ab21617 | 231 | obstack_init (&rt_common_objfile->objfile_obstack); |
ab31aa69 KB |
232 | rt_common_objfile->minimal_symbol_count = 0; |
233 | rt_common_objfile->msymbols = NULL; | |
15831452 | 234 | terminate_minimal_symbol_table (rt_common_objfile); |
ab31aa69 KB |
235 | } |
236 | ||
237 | init_minimal_symbol_collection (); | |
238 | make_cleanup_discard_minimal_symbols (); | |
239 | ||
240 | while (rtc_symp) | |
241 | { | |
242 | read_memory (rtc_symp, | |
243 | (char *) &inferior_rtc_symb, | |
244 | sizeof (inferior_rtc_symb)); | |
245 | read_memory (SOLIB_EXTRACT_ADDRESS (inferior_rtc_symb.rtc_sp), | |
246 | (char *) &inferior_rtc_nlist, | |
247 | sizeof (inferior_rtc_nlist)); | |
248 | if (inferior_rtc_nlist.n_type == N_COMM) | |
249 | { | |
250 | /* FIXME: The length of the symbol name is not available, but in the | |
251 | current implementation the common symbol is allocated immediately | |
c378eb4e | 252 | behind the name of the symbol. */ |
ab31aa69 KB |
253 | len = inferior_rtc_nlist.n_value - inferior_rtc_nlist.n_un.n_strx; |
254 | ||
255 | name = xmalloc (len); | |
256 | read_memory (SOLIB_EXTRACT_ADDRESS (inferior_rtc_nlist.n_un.n_name), | |
257 | name, len); | |
258 | ||
c378eb4e | 259 | /* Allocate the runtime common objfile if necessary. */ |
ab31aa69 KB |
260 | if (rt_common_objfile == NULL) |
261 | allocate_rt_common_objfile (); | |
262 | ||
263 | prim_record_minimal_symbol (name, inferior_rtc_nlist.n_value, | |
264 | mst_bss, rt_common_objfile); | |
265 | xfree (name); | |
266 | } | |
267 | rtc_symp = SOLIB_EXTRACT_ADDRESS (inferior_rtc_symb.rtc_next); | |
268 | } | |
269 | ||
270 | /* Install any minimal symbols that have been collected as the current | |
271 | minimal symbols for the runtime common objfile. */ | |
272 | ||
273 | install_minimal_symbols (rt_common_objfile); | |
274 | } | |
275 | ||
276 | ||
277 | /* | |
278 | ||
279 | LOCAL FUNCTION | |
280 | ||
281 | locate_base -- locate the base address of dynamic linker structs | |
282 | ||
283 | SYNOPSIS | |
284 | ||
285 | CORE_ADDR locate_base (void) | |
286 | ||
287 | DESCRIPTION | |
288 | ||
289 | For both the SunOS and SVR4 shared library implementations, if the | |
290 | inferior executable has been linked dynamically, there is a single | |
291 | address somewhere in the inferior's data space which is the key to | |
292 | locating all of the dynamic linker's runtime structures. This | |
293 | address is the value of the debug base symbol. The job of this | |
294 | function is to find and return that address, or to return 0 if there | |
295 | is no such address (the executable is statically linked for example). | |
296 | ||
297 | For SunOS, the job is almost trivial, since the dynamic linker and | |
298 | all of it's structures are statically linked to the executable at | |
299 | link time. Thus the symbol for the address we are looking for has | |
300 | already been added to the minimal symbol table for the executable's | |
301 | objfile at the time the symbol file's symbols were read, and all we | |
302 | have to do is look it up there. Note that we explicitly do NOT want | |
303 | to find the copies in the shared library. | |
304 | ||
305 | The SVR4 version is a bit more complicated because the address | |
306 | is contained somewhere in the dynamic info section. We have to go | |
307 | to a lot more work to discover the address of the debug base symbol. | |
308 | Because of this complexity, we cache the value we find and return that | |
309 | value on subsequent invocations. Note there is no copy in the | |
310 | executable symbol tables. | |
311 | ||
312 | */ | |
313 | ||
314 | static CORE_ADDR | |
315 | locate_base (void) | |
316 | { | |
317 | struct minimal_symbol *msymbol; | |
318 | CORE_ADDR address = 0; | |
319 | char **symbolp; | |
320 | ||
321 | /* For SunOS, we want to limit the search for the debug base symbol to the | |
322 | executable being debugged, since there is a duplicate named symbol in the | |
c378eb4e | 323 | shared library. We don't want the shared library versions. */ |
ab31aa69 KB |
324 | |
325 | for (symbolp = debug_base_symbols; *symbolp != NULL; symbolp++) | |
326 | { | |
327 | msymbol = lookup_minimal_symbol (*symbolp, NULL, symfile_objfile); | |
328 | if ((msymbol != NULL) && (SYMBOL_VALUE_ADDRESS (msymbol) != 0)) | |
329 | { | |
330 | address = SYMBOL_VALUE_ADDRESS (msymbol); | |
331 | return (address); | |
332 | } | |
333 | } | |
334 | return (0); | |
335 | } | |
336 | ||
337 | /* | |
338 | ||
339 | LOCAL FUNCTION | |
340 | ||
341 | first_link_map_member -- locate first member in dynamic linker's map | |
342 | ||
343 | SYNOPSIS | |
344 | ||
345 | static CORE_ADDR first_link_map_member (void) | |
346 | ||
347 | DESCRIPTION | |
348 | ||
349 | Find the first element in the inferior's dynamic link map, and | |
350 | return its address in the inferior. This function doesn't copy the | |
351 | link map entry itself into our address space; current_sos actually | |
352 | does the reading. */ | |
353 | ||
354 | static CORE_ADDR | |
355 | first_link_map_member (void) | |
356 | { | |
357 | CORE_ADDR lm = 0; | |
358 | ||
359 | read_memory (debug_base, (char *) &dynamic_copy, sizeof (dynamic_copy)); | |
360 | if (dynamic_copy.ld_version >= 2) | |
361 | { | |
362 | /* It is a version that we can deal with, so read in the secondary | |
c378eb4e | 363 | structure and find the address of the link map list from it. */ |
ab31aa69 KB |
364 | read_memory (SOLIB_EXTRACT_ADDRESS (dynamic_copy.ld_un.ld_2), |
365 | (char *) &ld_2_copy, sizeof (struct link_dynamic_2)); | |
366 | lm = SOLIB_EXTRACT_ADDRESS (ld_2_copy.ld_loaded); | |
367 | } | |
368 | return (lm); | |
369 | } | |
370 | ||
371 | static int | |
372 | open_symbol_file_object (void *from_ttyp) | |
373 | { | |
374 | return 1; | |
375 | } | |
376 | ||
377 | ||
378 | /* LOCAL FUNCTION | |
379 | ||
380 | current_sos -- build a list of currently loaded shared objects | |
381 | ||
382 | SYNOPSIS | |
383 | ||
384 | struct so_list *current_sos () | |
385 | ||
386 | DESCRIPTION | |
387 | ||
388 | Build a list of `struct so_list' objects describing the shared | |
389 | objects currently loaded in the inferior. This list does not | |
390 | include an entry for the main executable file. | |
391 | ||
392 | Note that we only gather information directly available from the | |
393 | inferior --- we don't examine any of the shared library files | |
394 | themselves. The declaration of `struct so_list' says which fields | |
395 | we provide values for. */ | |
396 | ||
397 | static struct so_list * | |
398 | sunos_current_sos (void) | |
399 | { | |
400 | CORE_ADDR lm; | |
401 | struct so_list *head = 0; | |
402 | struct so_list **link_ptr = &head; | |
403 | int errcode; | |
404 | char *buffer; | |
405 | ||
406 | /* Make sure we've looked up the inferior's dynamic linker's base | |
407 | structure. */ | |
408 | if (! debug_base) | |
409 | { | |
410 | debug_base = locate_base (); | |
411 | ||
412 | /* If we can't find the dynamic linker's base structure, this | |
413 | must not be a dynamically linked executable. Hmm. */ | |
414 | if (! debug_base) | |
415 | return 0; | |
416 | } | |
417 | ||
418 | /* Walk the inferior's link map list, and build our list of | |
419 | `struct so_list' nodes. */ | |
420 | lm = first_link_map_member (); | |
421 | while (lm) | |
422 | { | |
423 | struct so_list *new | |
424 | = (struct so_list *) xmalloc (sizeof (struct so_list)); | |
425 | struct cleanup *old_chain = make_cleanup (xfree, new); | |
426 | ||
427 | memset (new, 0, sizeof (*new)); | |
428 | ||
429 | new->lm_info = xmalloc (sizeof (struct lm_info)); | |
430 | make_cleanup (xfree, new->lm_info); | |
431 | ||
432 | new->lm_info->lm = xmalloc (sizeof (struct link_map)); | |
433 | make_cleanup (xfree, new->lm_info->lm); | |
434 | memset (new->lm_info->lm, 0, sizeof (struct link_map)); | |
435 | ||
436 | read_memory (lm, new->lm_info->lm, sizeof (struct link_map)); | |
437 | ||
438 | lm = LM_NEXT (new); | |
439 | ||
440 | /* Extract this shared object's name. */ | |
441 | target_read_string (LM_NAME (new), &buffer, | |
442 | SO_NAME_MAX_PATH_SIZE - 1, &errcode); | |
443 | if (errcode != 0) | |
8a3fe4f8 AC |
444 | warning (_("Can't read pathname for load map: %s."), |
445 | safe_strerror (errcode)); | |
ab31aa69 KB |
446 | else |
447 | { | |
448 | strncpy (new->so_name, buffer, SO_NAME_MAX_PATH_SIZE - 1); | |
449 | new->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0'; | |
450 | xfree (buffer); | |
451 | strcpy (new->so_original_name, new->so_name); | |
452 | } | |
453 | ||
454 | /* If this entry has no name, or its name matches the name | |
455 | for the main executable, don't include it in the list. */ | |
456 | if (! new->so_name[0] | |
457 | || match_main (new->so_name)) | |
458 | free_so (new); | |
459 | else | |
460 | { | |
461 | new->next = 0; | |
462 | *link_ptr = new; | |
463 | link_ptr = &new->next; | |
464 | } | |
465 | ||
466 | discard_cleanups (old_chain); | |
467 | } | |
468 | ||
469 | return head; | |
470 | } | |
471 | ||
472 | ||
473 | /* On some systems, the only way to recognize the link map entry for | |
474 | the main executable file is by looking at its name. Return | |
475 | non-zero iff SONAME matches one of the known main executable names. */ | |
476 | ||
477 | static int | |
478 | match_main (char *soname) | |
479 | { | |
480 | char **mainp; | |
481 | ||
482 | for (mainp = main_name_list; *mainp != NULL; mainp++) | |
483 | { | |
484 | if (strcmp (soname, *mainp) == 0) | |
485 | return (1); | |
486 | } | |
487 | ||
488 | return (0); | |
489 | } | |
490 | ||
491 | ||
492 | static int | |
493 | sunos_in_dynsym_resolve_code (CORE_ADDR pc) | |
494 | { | |
495 | return 0; | |
496 | } | |
497 | ||
498 | /* | |
499 | ||
500 | LOCAL FUNCTION | |
501 | ||
502 | disable_break -- remove the "mapping changed" breakpoint | |
503 | ||
504 | SYNOPSIS | |
505 | ||
506 | static int disable_break () | |
507 | ||
508 | DESCRIPTION | |
509 | ||
510 | Removes the breakpoint that gets hit when the dynamic linker | |
511 | completes a mapping change. | |
512 | ||
513 | */ | |
514 | ||
515 | static int | |
516 | disable_break (void) | |
517 | { | |
c378eb4e | 518 | CORE_ADDR breakpoint_addr; /* Address where end bkpt is set. */ |
ab31aa69 KB |
519 | |
520 | int in_debugger = 0; | |
521 | ||
522 | /* Read the debugger structure from the inferior to retrieve the | |
523 | address of the breakpoint and the original contents of the | |
524 | breakpoint address. Remove the breakpoint by writing the original | |
c378eb4e | 525 | contents back. */ |
ab31aa69 KB |
526 | |
527 | read_memory (debug_addr, (char *) &debug_copy, sizeof (debug_copy)); | |
528 | ||
c378eb4e | 529 | /* Set `in_debugger' to zero now. */ |
ab31aa69 KB |
530 | |
531 | write_memory (flag_addr, (char *) &in_debugger, sizeof (in_debugger)); | |
532 | ||
533 | breakpoint_addr = SOLIB_EXTRACT_ADDRESS (debug_copy.ldd_bp_addr); | |
534 | write_memory (breakpoint_addr, (char *) &debug_copy.ldd_bp_inst, | |
535 | sizeof (debug_copy.ldd_bp_inst)); | |
536 | ||
537 | /* For the SVR4 version, we always know the breakpoint address. For the | |
538 | SunOS version we don't know it until the above code is executed. | |
c378eb4e | 539 | Grumble if we are stopped anywhere besides the breakpoint address. */ |
ab31aa69 KB |
540 | |
541 | if (stop_pc != breakpoint_addr) | |
542 | { | |
3e43a32a MS |
543 | warning (_("stopped at unknown breakpoint " |
544 | "while handling shared libraries")); | |
ab31aa69 KB |
545 | } |
546 | ||
547 | return 1; | |
548 | } | |
549 | ||
550 | ||
551 | /* | |
552 | ||
553 | LOCAL FUNCTION | |
554 | ||
555 | enable_break -- arrange for dynamic linker to hit breakpoint | |
556 | ||
557 | SYNOPSIS | |
558 | ||
559 | int enable_break (void) | |
560 | ||
561 | DESCRIPTION | |
562 | ||
563 | Both the SunOS and the SVR4 dynamic linkers have, as part of their | |
564 | debugger interface, support for arranging for the inferior to hit | |
565 | a breakpoint after mapping in the shared libraries. This function | |
566 | enables that breakpoint. | |
567 | ||
568 | For SunOS, there is a special flag location (in_debugger) which we | |
569 | set to 1. When the dynamic linker sees this flag set, it will set | |
570 | a breakpoint at a location known only to itself, after saving the | |
571 | original contents of that place and the breakpoint address itself, | |
572 | in it's own internal structures. When we resume the inferior, it | |
573 | will eventually take a SIGTRAP when it runs into the breakpoint. | |
574 | We handle this (in a different place) by restoring the contents of | |
575 | the breakpointed location (which is only known after it stops), | |
576 | chasing around to locate the shared libraries that have been | |
577 | loaded, then resuming. | |
578 | ||
579 | For SVR4, the debugger interface structure contains a member (r_brk) | |
580 | which is statically initialized at the time the shared library is | |
581 | built, to the offset of a function (_r_debug_state) which is guaran- | |
582 | teed to be called once before mapping in a library, and again when | |
583 | the mapping is complete. At the time we are examining this member, | |
584 | it contains only the unrelocated offset of the function, so we have | |
585 | to do our own relocation. Later, when the dynamic linker actually | |
586 | runs, it relocates r_brk to be the actual address of _r_debug_state(). | |
587 | ||
588 | The debugger interface structure also contains an enumeration which | |
589 | is set to either RT_ADD or RT_DELETE prior to changing the mapping, | |
590 | depending upon whether or not the library is being mapped or unmapped, | |
591 | and then set to RT_CONSISTENT after the library is mapped/unmapped. | |
592 | */ | |
593 | ||
594 | static int | |
595 | enable_break (void) | |
596 | { | |
597 | int success = 0; | |
598 | int j; | |
599 | int in_debugger; | |
600 | ||
c378eb4e | 601 | /* Get link_dynamic structure. */ |
ab31aa69 KB |
602 | |
603 | j = target_read_memory (debug_base, (char *) &dynamic_copy, | |
604 | sizeof (dynamic_copy)); | |
605 | if (j) | |
606 | { | |
607 | /* unreadable */ | |
608 | return (0); | |
609 | } | |
610 | ||
c378eb4e | 611 | /* Calc address of debugger interface structure. */ |
ab31aa69 KB |
612 | |
613 | debug_addr = SOLIB_EXTRACT_ADDRESS (dynamic_copy.ldd); | |
614 | ||
c378eb4e | 615 | /* Calc address of `in_debugger' member of debugger interface structure. */ |
ab31aa69 KB |
616 | |
617 | flag_addr = debug_addr + (CORE_ADDR) ((char *) &debug_copy.ldd_in_debugger - | |
618 | (char *) &debug_copy); | |
619 | ||
620 | /* Write a value of 1 to this member. */ | |
621 | ||
622 | in_debugger = 1; | |
623 | write_memory (flag_addr, (char *) &in_debugger, sizeof (in_debugger)); | |
624 | success = 1; | |
625 | ||
626 | return (success); | |
627 | } | |
628 | ||
629 | /* | |
630 | ||
631 | LOCAL FUNCTION | |
632 | ||
633 | special_symbol_handling -- additional shared library symbol handling | |
634 | ||
635 | SYNOPSIS | |
636 | ||
637 | void special_symbol_handling () | |
638 | ||
639 | DESCRIPTION | |
640 | ||
641 | Once the symbols from a shared object have been loaded in the usual | |
642 | way, we are called to do any system specific symbol handling that | |
643 | is needed. | |
644 | ||
645 | For SunOS4, this consists of grunging around in the dynamic | |
646 | linkers structures to find symbol definitions for "common" symbols | |
647 | and adding them to the minimal symbol table for the runtime common | |
648 | objfile. | |
649 | ||
650 | */ | |
651 | ||
652 | static void | |
653 | sunos_special_symbol_handling (void) | |
654 | { | |
655 | int j; | |
656 | ||
657 | if (debug_addr == 0) | |
658 | { | |
c378eb4e | 659 | /* Get link_dynamic structure. */ |
ab31aa69 KB |
660 | |
661 | j = target_read_memory (debug_base, (char *) &dynamic_copy, | |
662 | sizeof (dynamic_copy)); | |
663 | if (j) | |
664 | { | |
665 | /* unreadable */ | |
666 | return; | |
667 | } | |
668 | ||
c378eb4e | 669 | /* Calc address of debugger interface structure. */ |
ab31aa69 KB |
670 | /* FIXME, this needs work for cross-debugging of core files |
671 | (byteorder, size, alignment, etc). */ | |
672 | ||
673 | debug_addr = SOLIB_EXTRACT_ADDRESS (dynamic_copy.ldd); | |
674 | } | |
675 | ||
676 | /* Read the debugger structure from the inferior, just to make sure | |
c378eb4e | 677 | we have a current copy. */ |
ab31aa69 KB |
678 | |
679 | j = target_read_memory (debug_addr, (char *) &debug_copy, | |
680 | sizeof (debug_copy)); | |
681 | if (j) | |
682 | return; /* unreadable */ | |
683 | ||
c378eb4e | 684 | /* Get common symbol definitions for the loaded object. */ |
ab31aa69 KB |
685 | |
686 | if (debug_copy.ldd_cp) | |
687 | { | |
688 | solib_add_common_symbols (SOLIB_EXTRACT_ADDRESS (debug_copy.ldd_cp)); | |
689 | } | |
690 | } | |
691 | ||
ab31aa69 KB |
692 | /* |
693 | ||
694 | GLOBAL FUNCTION | |
695 | ||
696 | sunos_solib_create_inferior_hook -- shared library startup support | |
697 | ||
698 | SYNOPSIS | |
699 | ||
7095b863 | 700 | void sunos_solib_create_inferior_hook () |
ab31aa69 KB |
701 | |
702 | DESCRIPTION | |
703 | ||
704 | When gdb starts up the inferior, it nurses it along (through the | |
705 | shell) until it is ready to execute it's first instruction. At this | |
706 | point, this function gets called via expansion of the macro | |
707 | SOLIB_CREATE_INFERIOR_HOOK. | |
708 | ||
709 | For SunOS executables, this first instruction is typically the | |
710 | one at "_start", or a similar text label, regardless of whether | |
711 | the executable is statically or dynamically linked. The runtime | |
712 | startup code takes care of dynamically linking in any shared | |
713 | libraries, once gdb allows the inferior to continue. | |
714 | ||
715 | For SVR4 executables, this first instruction is either the first | |
716 | instruction in the dynamic linker (for dynamically linked | |
717 | executables) or the instruction at "start" for statically linked | |
718 | executables. For dynamically linked executables, the system | |
719 | first exec's /lib/libc.so.N, which contains the dynamic linker, | |
720 | and starts it running. The dynamic linker maps in any needed | |
721 | shared libraries, maps in the actual user executable, and then | |
722 | jumps to "start" in the user executable. | |
723 | ||
724 | For both SunOS shared libraries, and SVR4 shared libraries, we | |
725 | can arrange to cooperate with the dynamic linker to discover the | |
726 | names of shared libraries that are dynamically linked, and the | |
727 | base addresses to which they are linked. | |
728 | ||
729 | This function is responsible for discovering those names and | |
730 | addresses, and saving sufficient information about them to allow | |
731 | their symbols to be read at a later time. | |
732 | ||
733 | FIXME | |
734 | ||
735 | Between enable_break() and disable_break(), this code does not | |
736 | properly handle hitting breakpoints which the user might have | |
737 | set in the startup code or in the dynamic linker itself. Proper | |
738 | handling will probably have to wait until the implementation is | |
739 | changed to use the "breakpoint handler function" method. | |
740 | ||
741 | Also, what if child has exit()ed? Must exit loop somehow. | |
742 | */ | |
743 | ||
744 | static void | |
268a4a75 | 745 | sunos_solib_create_inferior_hook (int from_tty) |
ab31aa69 | 746 | { |
2020b7ab | 747 | struct thread_info *tp; |
d6b48e9c | 748 | struct inferior *inf; |
2020b7ab | 749 | |
ab31aa69 KB |
750 | if ((debug_base = locate_base ()) == 0) |
751 | { | |
c378eb4e | 752 | /* Can't find the symbol or the executable is statically linked. */ |
ab31aa69 KB |
753 | return; |
754 | } | |
755 | ||
756 | if (!enable_break ()) | |
757 | { | |
8a3fe4f8 | 758 | warning (_("shared library handler failed to enable breakpoint")); |
ab31aa69 KB |
759 | return; |
760 | } | |
761 | ||
762 | /* SCO and SunOS need the loop below, other systems should be using the | |
763 | special shared library breakpoints and the shared library breakpoint | |
764 | service routine. | |
765 | ||
766 | Now run the target. It will eventually hit the breakpoint, at | |
767 | which point all of the libraries will have been mapped in and we | |
768 | can go groveling around in the dynamic linker structures to find | |
c378eb4e | 769 | out what we need to know about them. */ |
ab31aa69 | 770 | |
d6b48e9c | 771 | inf = current_inferior (); |
2020b7ab | 772 | tp = inferior_thread (); |
d6b48e9c | 773 | |
ab31aa69 | 774 | clear_proceed_status (); |
d6b48e9c | 775 | |
16c381f0 JK |
776 | inf->control.stop_soon = STOP_QUIETLY; |
777 | tp->suspend.stop_signal = TARGET_SIGNAL_0; | |
ab31aa69 KB |
778 | do |
779 | { | |
16c381f0 | 780 | target_resume (pid_to_ptid (-1), 0, tp->suspend.stop_signal); |
ae123ec6 | 781 | wait_for_inferior (0); |
ab31aa69 | 782 | } |
16c381f0 JK |
783 | while (tp->suspend.stop_signal != TARGET_SIGNAL_TRAP); |
784 | inf->control.stop_soon = NO_STOP_QUIETLY; | |
ab31aa69 KB |
785 | |
786 | /* We are now either at the "mapping complete" breakpoint (or somewhere | |
787 | else, a condition we aren't prepared to deal with anyway), so adjust | |
788 | the PC as necessary after a breakpoint, disable the breakpoint, and | |
b4397864 UW |
789 | add any shared libraries that were mapped in. |
790 | ||
791 | Note that adjust_pc_after_break did not perform any PC adjustment, | |
792 | as the breakpoint the inferior just hit was not inserted by GDB, | |
793 | but by the dynamic loader itself, and is therefore not found on | |
794 | the GDB software break point list. Thus we have to adjust the | |
795 | PC here. */ | |
ab31aa69 | 796 | |
1cf3db46 | 797 | if (gdbarch_decr_pc_after_break (target_gdbarch)) |
ab31aa69 | 798 | { |
1cf3db46 | 799 | stop_pc -= gdbarch_decr_pc_after_break (target_gdbarch); |
fb14de7b | 800 | regcache_write_pc (get_current_regcache (), stop_pc); |
ab31aa69 KB |
801 | } |
802 | ||
803 | if (!disable_break ()) | |
804 | { | |
8a3fe4f8 | 805 | warning (_("shared library handler failed to disable breakpoint")); |
ab31aa69 KB |
806 | } |
807 | ||
990f9fe3 | 808 | solib_add ((char *) 0, 0, (struct target_ops *) 0, auto_solib_add); |
ab31aa69 KB |
809 | } |
810 | ||
811 | static void | |
812 | sunos_clear_solib (void) | |
813 | { | |
814 | debug_base = 0; | |
815 | } | |
816 | ||
817 | static void | |
818 | sunos_free_so (struct so_list *so) | |
819 | { | |
820 | xfree (so->lm_info->lm); | |
821 | xfree (so->lm_info); | |
822 | } | |
823 | ||
824 | static void | |
825 | sunos_relocate_section_addresses (struct so_list *so, | |
0542c86d | 826 | struct target_section *sec) |
ab31aa69 KB |
827 | { |
828 | sec->addr += LM_ADDR (so); | |
829 | sec->endaddr += LM_ADDR (so); | |
830 | } | |
831 | ||
832 | static struct target_so_ops sunos_so_ops; | |
833 | ||
834 | void | |
835 | _initialize_sunos_solib (void) | |
836 | { | |
837 | sunos_so_ops.relocate_section_addresses = sunos_relocate_section_addresses; | |
838 | sunos_so_ops.free_so = sunos_free_so; | |
839 | sunos_so_ops.clear_solib = sunos_clear_solib; | |
840 | sunos_so_ops.solib_create_inferior_hook = sunos_solib_create_inferior_hook; | |
841 | sunos_so_ops.special_symbol_handling = sunos_special_symbol_handling; | |
842 | sunos_so_ops.current_sos = sunos_current_sos; | |
843 | sunos_so_ops.open_symbol_file_object = open_symbol_file_object; | |
844 | sunos_so_ops.in_dynsym_resolve_code = sunos_in_dynsym_resolve_code; | |
831a0c44 | 845 | sunos_so_ops.bfd_open = solib_bfd_open; |
ab31aa69 | 846 | |
c378eb4e | 847 | /* FIXME: Don't do this here. *_gdbarch_init() should set so_ops. */ |
ab31aa69 KB |
848 | current_target_so_ops = &sunos_so_ops; |
849 | } |