* python/py-utils.c (gdb_pymodule_addobject): Cast away const.
[deliverable/binutils-gdb.git] / gdb / solib-pa64.c
1 /* Handle PA64 shared libraries for GDB, the GNU Debugger.
2
3 Copyright (C) 2004-2013 Free Software Foundation, Inc.
4
5 This file is part of GDB.
6
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
11
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
19
20 /* HP in their infinite stupidity choose not to use standard ELF dynamic
21 linker interfaces. They also choose not to make their ELF dymamic
22 linker interfaces compatible with the SOM dynamic linker. The
23 net result is we can not use either of the existing somsolib.c or
24 solib.c. What a crock.
25
26 Even more disgusting. This file depends on functions provided only
27 in certain PA64 libraries. Thus this file is supposed to only be
28 used native. When will HP ever learn that they need to provide the
29 same functionality in all their libraries! */
30
31 #include "defs.h"
32 #include "symtab.h"
33 #include "bfd.h"
34 #include "symfile.h"
35 #include "objfiles.h"
36 #include "gdbcore.h"
37 #include "target.h"
38 #include "inferior.h"
39 #include "regcache.h"
40 #include "gdb_bfd.h"
41
42 #include "hppa-tdep.h"
43 #include "solist.h"
44 #include "solib.h"
45 #include "solib-pa64.h"
46
47 #undef SOLIB_PA64_DBG
48
49 /* We can build this file only when running natively on 64-bit HP/UX.
50 We check for that by checking for the elf_hp.h header file. */
51 #if defined(HAVE_ELF_HP_H) && defined(__LP64__)
52
53 /* FIXME: kettenis/20041213: These includes should be eliminated. */
54 #include <dlfcn.h>
55 #include <elf.h>
56 #include <elf_hp.h>
57
58 struct lm_info {
59 struct load_module_desc desc;
60 CORE_ADDR desc_addr;
61 };
62
63 /* When adding fields, be sure to clear them in _initialize_pa64_solib. */
64 typedef struct
65 {
66 CORE_ADDR dld_flags_addr;
67 LONGEST dld_flags;
68 struct bfd_section *dyninfo_sect;
69 int have_read_dld_descriptor;
70 int is_valid;
71 CORE_ADDR load_map;
72 CORE_ADDR load_map_addr;
73 struct load_module_desc dld_desc;
74 }
75 dld_cache_t;
76
77 static dld_cache_t dld_cache;
78
79 static int read_dynamic_info (asection *dyninfo_sect,
80 dld_cache_t *dld_cache_p);
81
82 static void
83 pa64_relocate_section_addresses (struct so_list *so,
84 struct target_section *sec)
85 {
86 asection *asec = sec->the_bfd_section;
87 CORE_ADDR load_offset;
88
89 /* Relocate all the sections based on where they got loaded. */
90
91 load_offset = bfd_section_vma (so->abfd, asec) - asec->filepos;
92
93 if (asec->flags & SEC_CODE)
94 {
95 sec->addr += so->lm_info->desc.text_base - load_offset;
96 sec->endaddr += so->lm_info->desc.text_base - load_offset;
97 }
98 else if (asec->flags & SEC_DATA)
99 {
100 sec->addr += so->lm_info->desc.data_base - load_offset;
101 sec->endaddr += so->lm_info->desc.data_base - load_offset;
102 }
103 }
104
105 static void
106 pa64_free_so (struct so_list *so)
107 {
108 xfree (so->lm_info);
109 }
110
111 static void
112 pa64_clear_solib (void)
113 {
114 }
115
116 /* Wrapper for target_read_memory for dlgetmodinfo. */
117
118 static void *
119 pa64_target_read_memory (void *buffer, CORE_ADDR ptr, size_t bufsiz, int ident)
120 {
121 if (target_read_memory (ptr, buffer, bufsiz) != 0)
122 return 0;
123 return buffer;
124 }
125
126 /* Read the dynamic linker's internal shared library descriptor.
127
128 This must happen after dld starts running, so we can't do it in
129 read_dynamic_info. Record the fact that we have loaded the
130 descriptor. If the library is archive bound or the load map
131 hasn't been setup, then return zero; else return nonzero. */
132
133 static int
134 read_dld_descriptor (void)
135 {
136 char *dll_path;
137 asection *dyninfo_sect;
138
139 /* If necessary call read_dynamic_info to extract the contents of the
140 .dynamic section from the shared library. */
141 if (!dld_cache.is_valid)
142 {
143 if (symfile_objfile == NULL)
144 error (_("No object file symbols."));
145
146 dyninfo_sect = bfd_get_section_by_name (symfile_objfile->obfd,
147 ".dynamic");
148 if (!dyninfo_sect)
149 {
150 return 0;
151 }
152
153 if (!read_dynamic_info (dyninfo_sect, &dld_cache))
154 error (_("Unable to read in .dynamic section information."));
155 }
156
157 /* Read the load map pointer. */
158 if (target_read_memory (dld_cache.load_map_addr,
159 (char *) &dld_cache.load_map,
160 sizeof (dld_cache.load_map))
161 != 0)
162 {
163 error (_("Error while reading in load map pointer."));
164 }
165
166 if (!dld_cache.load_map)
167 return 0;
168
169 /* Read in the dld load module descriptor. */
170 if (dlgetmodinfo (-1,
171 &dld_cache.dld_desc,
172 sizeof (dld_cache.dld_desc),
173 pa64_target_read_memory,
174 0,
175 dld_cache.load_map)
176 == 0)
177 {
178 error (_("Error trying to get information about dynamic linker."));
179 }
180
181 /* Indicate that we have loaded the dld descriptor. */
182 dld_cache.have_read_dld_descriptor = 1;
183
184 return 1;
185 }
186
187
188 /* Read the .dynamic section and extract the information of interest,
189 which is stored in dld_cache. The routine elf_locate_base in solib.c
190 was used as a model for this. */
191
192 static int
193 read_dynamic_info (asection *dyninfo_sect, dld_cache_t *dld_cache_p)
194 {
195 char *buf;
196 char *bufend;
197 CORE_ADDR dyninfo_addr;
198 int dyninfo_sect_size;
199 CORE_ADDR entry_addr;
200
201 /* Read in .dynamic section, silently ignore errors. */
202 dyninfo_addr = bfd_section_vma (symfile_objfile->obfd, dyninfo_sect);
203 dyninfo_sect_size = bfd_section_size (exec_bfd, dyninfo_sect);
204 buf = alloca (dyninfo_sect_size);
205 if (target_read_memory (dyninfo_addr, buf, dyninfo_sect_size))
206 return 0;
207
208 /* Scan the .dynamic section and record the items of interest.
209 In particular, DT_HP_DLD_FLAGS. */
210 for (bufend = buf + dyninfo_sect_size, entry_addr = dyninfo_addr;
211 buf < bufend;
212 buf += sizeof (Elf64_Dyn), entry_addr += sizeof (Elf64_Dyn))
213 {
214 Elf64_Dyn *x_dynp = (Elf64_Dyn*)buf;
215 Elf64_Sxword dyn_tag;
216 CORE_ADDR dyn_ptr;
217
218 dyn_tag = bfd_h_get_64 (symfile_objfile->obfd,
219 (bfd_byte*) &x_dynp->d_tag);
220
221 /* We can't use a switch here because dyn_tag is 64 bits and HP's
222 lame comiler does not handle 64bit items in switch statements. */
223 if (dyn_tag == DT_NULL)
224 break;
225 else if (dyn_tag == DT_HP_DLD_FLAGS)
226 {
227 /* Set dld_flags_addr and dld_flags in *dld_cache_p. */
228 dld_cache_p->dld_flags_addr = entry_addr + offsetof(Elf64_Dyn, d_un);
229 if (target_read_memory (dld_cache_p->dld_flags_addr,
230 (char*) &dld_cache_p->dld_flags,
231 sizeof (dld_cache_p->dld_flags))
232 != 0)
233 {
234 error (_("Error while reading in "
235 ".dynamic section of the program."));
236 }
237 }
238 else if (dyn_tag == DT_HP_LOAD_MAP)
239 {
240 /* Dld will place the address of the load map at load_map_addr
241 after it starts running. */
242 if (target_read_memory (entry_addr + offsetof(Elf64_Dyn,
243 d_un.d_ptr),
244 (char*) &dld_cache_p->load_map_addr,
245 sizeof (dld_cache_p->load_map_addr))
246 != 0)
247 {
248 error (_("Error while reading in "
249 ".dynamic section of the program."));
250 }
251 }
252 else
253 {
254 /* Tag is not of interest. */
255 }
256 }
257
258 /* Record other information and set is_valid to 1. */
259 dld_cache_p->dyninfo_sect = dyninfo_sect;
260
261 /* Verify that we read in required info. These fields are re-set to zero
262 in pa64_solib_restart. */
263
264 if (dld_cache_p->dld_flags_addr != 0 && dld_cache_p->load_map_addr != 0)
265 dld_cache_p->is_valid = 1;
266 else
267 return 0;
268
269 return 1;
270 }
271
272 /* Helper function for gdb_bfd_lookup_symbol_from_symtab. */
273
274 static int
275 cmp_name (asymbol *sym, void *data)
276 {
277 return (strcmp (sym->name, (const char *) data) == 0);
278 }
279
280 /* This hook gets called just before the first instruction in the
281 inferior process is executed.
282
283 This is our opportunity to set magic flags in the inferior so
284 that GDB can be notified when a shared library is mapped in and
285 to tell the dynamic linker that a private copy of the library is
286 needed (so GDB can set breakpoints in the library).
287
288 We need to set DT_HP_DEBUG_CALLBACK to indicate that we want the
289 dynamic linker to call the breakpoint routine for significant events.
290 We used to set DT_HP_DEBUG_PRIVATE to indicate that shared libraries
291 should be mapped private. However, this flag can be set using
292 "chatr +dbg enable". Not setting DT_HP_DEBUG_PRIVATE allows debugging
293 with shared libraries mapped shareable. */
294
295 static void
296 pa64_solib_create_inferior_hook (int from_tty)
297 {
298 struct minimal_symbol *msymbol;
299 unsigned int dld_flags, status;
300 asection *shlib_info, *interp_sect;
301 struct objfile *objfile;
302 CORE_ADDR anaddr;
303
304 if (symfile_objfile == NULL)
305 return;
306
307 /* First see if the objfile was dynamically linked. */
308 shlib_info = bfd_get_section_by_name (symfile_objfile->obfd, ".dynamic");
309 if (!shlib_info)
310 return;
311
312 /* It's got a .dynamic section, make sure it's not empty. */
313 if (bfd_section_size (symfile_objfile->obfd, shlib_info) == 0)
314 return;
315
316 /* Read in the .dynamic section. */
317 if (! read_dynamic_info (shlib_info, &dld_cache))
318 error (_("Unable to read the .dynamic section."));
319
320 /* If the libraries were not mapped private, warn the user. */
321 if ((dld_cache.dld_flags & DT_HP_DEBUG_PRIVATE) == 0)
322 warning
323 (_("\
324 Private mapping of shared library text was not specified\n\
325 by the executable; setting a breakpoint in a shared library which\n\
326 is not privately mapped will not work. See the HP-UX 11i v3 chatr\n\
327 manpage for methods to privately map shared library text."));
328
329 /* Turn on the flags we care about. */
330 dld_cache.dld_flags |= DT_HP_DEBUG_CALLBACK;
331 status = target_write_memory (dld_cache.dld_flags_addr,
332 (char *) &dld_cache.dld_flags,
333 sizeof (dld_cache.dld_flags));
334 if (status != 0)
335 error (_("Unable to modify dynamic linker flags."));
336
337 /* Now we have to create a shared library breakpoint in the dynamic
338 linker. This can be somewhat tricky since the symbol is inside
339 the dynamic linker (for which we do not have symbols or a base
340 load address! Luckily I wrote this code for solib.c years ago. */
341 interp_sect = bfd_get_section_by_name (exec_bfd, ".interp");
342 if (interp_sect)
343 {
344 unsigned int interp_sect_size;
345 char *buf;
346 CORE_ADDR load_addr;
347 bfd *tmp_bfd;
348 CORE_ADDR sym_addr = 0;
349
350 /* Read the contents of the .interp section into a local buffer;
351 the contents specify the dynamic linker this program uses. */
352 interp_sect_size = bfd_section_size (exec_bfd, interp_sect);
353 buf = alloca (interp_sect_size);
354 bfd_get_section_contents (exec_bfd, interp_sect,
355 buf, 0, interp_sect_size);
356
357 /* Now we need to figure out where the dynamic linker was
358 loaded so that we can load its symbols and place a breakpoint
359 in the dynamic linker itself.
360
361 This address is stored on the stack. However, I've been unable
362 to find any magic formula to find it for Solaris (appears to
363 be trivial on GNU/Linux). Therefore, we have to try an alternate
364 mechanism to find the dynamic linker's base address. */
365 tmp_bfd = gdb_bfd_open (buf, gnutarget, -1);
366 if (tmp_bfd == NULL)
367 return;
368
369 /* Make sure the dynamic linker's really a useful object. */
370 if (!bfd_check_format (tmp_bfd, bfd_object))
371 {
372 warning (_("Unable to grok dynamic linker %s as an object file"),
373 buf);
374 gdb_bfd_unref (tmp_bfd);
375 return;
376 }
377
378 /* We find the dynamic linker's base address by examining the
379 current pc (which point at the entry point for the dynamic
380 linker) and subtracting the offset of the entry point.
381
382 Also note the breakpoint is the second instruction in the
383 routine. */
384 load_addr = regcache_read_pc (get_current_regcache ())
385 - tmp_bfd->start_address;
386 sym_addr = gdb_bfd_lookup_symbol_from_symtab (tmp_bfd, cmp_name,
387 "__dld_break");
388 sym_addr = load_addr + sym_addr + 4;
389
390 /* Create the shared library breakpoint. */
391 {
392 struct breakpoint *b
393 = create_solib_event_breakpoint (target_gdbarch (), sym_addr);
394
395 /* The breakpoint is actually hard-coded into the dynamic linker,
396 so we don't need to actually insert a breakpoint instruction
397 there. In fact, the dynamic linker's code is immutable, even to
398 ttrace, so we shouldn't even try to do that. For cases like
399 this, we have "permanent" breakpoints. */
400 make_breakpoint_permanent (b);
401 }
402
403 /* We're done with the temporary bfd. */
404 gdb_bfd_unref (tmp_bfd);
405 }
406 }
407
408 static void
409 pa64_special_symbol_handling (void)
410 {
411 }
412
413 static struct so_list *
414 pa64_current_sos (void)
415 {
416 struct so_list *head = 0;
417 struct so_list **link_ptr = &head;
418 int dll_index;
419
420 /* Read in the load map pointer if we have not done so already. */
421 if (! dld_cache.have_read_dld_descriptor)
422 if (! read_dld_descriptor ())
423 return NULL;
424
425 for (dll_index = -1; ; dll_index++)
426 {
427 struct load_module_desc dll_desc;
428 char *dll_path;
429 struct so_list *new;
430 struct cleanup *old_chain;
431
432 if (dll_index == 0)
433 continue;
434
435 /* Read in the load module descriptor. */
436 if (dlgetmodinfo (dll_index, &dll_desc, sizeof (dll_desc),
437 pa64_target_read_memory, 0, dld_cache.load_map)
438 == 0)
439 break;
440
441 /* Get the name of the shared library. */
442 dll_path = (char *)dlgetname (&dll_desc, sizeof (dll_desc),
443 pa64_target_read_memory,
444 0, dld_cache.load_map);
445
446 new = (struct so_list *) xmalloc (sizeof (struct so_list));
447 memset (new, 0, sizeof (struct so_list));
448 new->lm_info = (struct lm_info *) xmalloc (sizeof (struct lm_info));
449 memset (new->lm_info, 0, sizeof (struct lm_info));
450
451 strncpy (new->so_name, dll_path, SO_NAME_MAX_PATH_SIZE - 1);
452 new->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
453 strcpy (new->so_original_name, new->so_name);
454
455 memcpy (&new->lm_info->desc, &dll_desc, sizeof (dll_desc));
456
457 #ifdef SOLIB_PA64_DBG
458 {
459 struct load_module_desc *d = &new->lm_info->desc;
460
461 printf ("\n+ library \"%s\" is described at index %d\n", new->so_name,
462 dll_index);
463 printf (" text_base = %s\n", hex_string (d->text_base));
464 printf (" text_size = %s\n", hex_string (d->text_size));
465 printf (" data_base = %s\n", hex_string (d->data_base));
466 printf (" data_size = %s\n", hex_string (d->data_size));
467 printf (" unwind_base = %s\n", hex_string (d->unwind_base));
468 printf (" linkage_ptr = %s\n", hex_string (d->linkage_ptr));
469 printf (" phdr_base = %s\n", hex_string (d->phdr_base));
470 printf (" tls_size = %s\n", hex_string (d->tls_size));
471 printf (" tls_start_addr = %s\n", hex_string (d->tls_start_addr));
472 printf (" unwind_size = %s\n", hex_string (d->unwind_size));
473 printf (" tls_index = %s\n", hex_string (d->tls_index));
474 }
475 #endif
476
477 /* Link the new object onto the list. */
478 new->next = NULL;
479 *link_ptr = new;
480 link_ptr = &new->next;
481 }
482
483 return head;
484 }
485
486 static int
487 pa64_open_symbol_file_object (void *from_ttyp)
488 {
489 int from_tty = *(int *)from_ttyp;
490 struct load_module_desc dll_desc;
491 char *dll_path;
492
493 if (symfile_objfile)
494 if (!query (_("Attempt to reload symbols from process? ")))
495 return 0;
496
497 /* Read in the load map pointer if we have not done so already. */
498 if (! dld_cache.have_read_dld_descriptor)
499 if (! read_dld_descriptor ())
500 return 0;
501
502 /* Read in the load module descriptor. */
503 if (dlgetmodinfo (0, &dll_desc, sizeof (dll_desc),
504 pa64_target_read_memory, 0, dld_cache.load_map) == 0)
505 return 0;
506
507 /* Get the name of the shared library. */
508 dll_path = (char *)dlgetname (&dll_desc, sizeof (dll_desc),
509 pa64_target_read_memory,
510 0, dld_cache.load_map);
511
512 /* Have a pathname: read the symbol file. */
513 symbol_file_add_main (dll_path, from_tty);
514
515 return 1;
516 }
517
518 /* Return nonzero if PC is an address inside the dynamic linker. */
519 static int
520 pa64_in_dynsym_resolve_code (CORE_ADDR pc)
521 {
522 asection *shlib_info;
523
524 if (symfile_objfile == NULL)
525 return 0;
526
527 if (!dld_cache.have_read_dld_descriptor)
528 if (!read_dld_descriptor ())
529 return 0;
530
531 return (pc >= dld_cache.dld_desc.text_base
532 && pc < dld_cache.dld_desc.text_base + dld_cache.dld_desc.text_size);
533 }
534
535
536 /* Return the GOT value for the shared library in which ADDR belongs. If
537 ADDR isn't in any known shared library, return zero. */
538
539 static CORE_ADDR
540 pa64_solib_get_got_by_pc (CORE_ADDR addr)
541 {
542 struct so_list *so_list = master_so_list ();
543 CORE_ADDR got_value = 0;
544
545 while (so_list)
546 {
547 if (so_list->lm_info->desc.text_base <= addr
548 && ((so_list->lm_info->desc.text_base
549 + so_list->lm_info->desc.text_size)
550 > addr))
551 {
552 got_value = so_list->lm_info->desc.linkage_ptr;
553 break;
554 }
555 so_list = so_list->next;
556 }
557 return got_value;
558 }
559
560 /* Get some HPUX-specific data from a shared lib. */
561 static CORE_ADDR
562 pa64_solib_thread_start_addr (struct so_list *so)
563 {
564 return so->lm_info->desc.tls_start_addr;
565 }
566
567
568 /* Return the address of the handle of the shared library in which ADDR
569 belongs. If ADDR isn't in any known shared library, return zero. */
570
571 static CORE_ADDR
572 pa64_solib_get_solib_by_pc (CORE_ADDR addr)
573 {
574 struct so_list *so_list = master_so_list ();
575 CORE_ADDR retval = 0;
576
577 while (so_list)
578 {
579 if (so_list->lm_info->desc.text_base <= addr
580 && ((so_list->lm_info->desc.text_base
581 + so_list->lm_info->desc.text_size)
582 > addr))
583 {
584 retval = so_list->lm_info->desc_addr;
585 break;
586 }
587 so_list = so_list->next;
588 }
589 return retval;
590 }
591
592 /* pa64 libraries do not seem to set the section offsets in a standard (i.e.
593 SVr4) way; the text section offset stored in the file doesn't correspond
594 to the place where the library is actually loaded into memory. Instead,
595 we rely on the dll descriptor to tell us where things were loaded. */
596 static CORE_ADDR
597 pa64_solib_get_text_base (struct objfile *objfile)
598 {
599 struct so_list *so;
600
601 for (so = master_so_list (); so; so = so->next)
602 if (so->objfile == objfile)
603 return so->lm_info->desc.text_base;
604
605 return 0;
606 }
607
608 static struct target_so_ops pa64_so_ops;
609
610 extern initialize_file_ftype _initialize_pa64_solib; /* -Wmissing-prototypes */
611
612 void
613 _initialize_pa64_solib (void)
614 {
615 pa64_so_ops.relocate_section_addresses = pa64_relocate_section_addresses;
616 pa64_so_ops.free_so = pa64_free_so;
617 pa64_so_ops.clear_solib = pa64_clear_solib;
618 pa64_so_ops.solib_create_inferior_hook = pa64_solib_create_inferior_hook;
619 pa64_so_ops.special_symbol_handling = pa64_special_symbol_handling;
620 pa64_so_ops.current_sos = pa64_current_sos;
621 pa64_so_ops.open_symbol_file_object = pa64_open_symbol_file_object;
622 pa64_so_ops.in_dynsym_resolve_code = pa64_in_dynsym_resolve_code;
623 pa64_so_ops.bfd_open = solib_bfd_open;
624
625 memset (&dld_cache, 0, sizeof (dld_cache));
626 }
627
628 void pa64_solib_select (struct gdbarch *gdbarch)
629 {
630 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
631
632 set_solib_ops (gdbarch, &pa64_so_ops);
633 tdep->solib_thread_start_addr = pa64_solib_thread_start_addr;
634 tdep->solib_get_got_by_pc = pa64_solib_get_got_by_pc;
635 tdep->solib_get_solib_by_pc = pa64_solib_get_solib_by_pc;
636 tdep->solib_get_text_base = pa64_solib_get_text_base;
637 }
638
639 #else /* HAVE_ELF_HP_H */
640
641 extern initialize_file_ftype _initialize_pa64_solib; /* -Wmissing-prototypes */
642
643 void
644 _initialize_pa64_solib (void)
645 {
646 }
647
648 void pa64_solib_select (struct gdbarch *gdbarch)
649 {
650 /* For a SOM-only target, there is no pa64 solib support. This is needed
651 for hppa-hpux-tdep.c to build. */
652 error (_("Cannot select pa64 solib support for this configuration."));
653 }
654 #endif
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