1 /* Handle PA64 shared libraries for GDB, the GNU Debugger.
3 Copyright (C) 2004, 2007, 2008, 2009 Free Software Foundation, Inc.
5 This file is part of GDB.
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.
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.
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/>.
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.
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! */
41 #include "hppa-tdep.h"
44 #include "solib-pa64.h"
48 /* We can build this file only when running natively on 64-bit HP/UX.
49 We check for that by checking for the elf_hp.h header file. */
50 #if defined(HAVE_ELF_HP_H) && defined(__LP64__)
52 /* FIXME: kettenis/20041213: These includes should be eliminated. */
58 struct load_module_desc desc;
62 /* When adding fields, be sure to clear them in _initialize_pa64_solib. */
65 CORE_ADDR dld_flags_addr;
67 struct bfd_section *dyninfo_sect;
68 int have_read_dld_descriptor;
71 CORE_ADDR load_map_addr;
72 struct load_module_desc dld_desc;
76 static dld_cache_t dld_cache;
79 read_dynamic_info (asection *dyninfo_sect, dld_cache_t *dld_cache_p);
82 pa64_relocate_section_addresses (struct so_list *so,
83 struct target_section *sec)
85 asection *asec = sec->the_bfd_section;
86 CORE_ADDR load_offset;
88 /* Relocate all the sections based on where they got loaded. */
90 load_offset = bfd_section_vma (so->abfd, asec) - asec->filepos;
92 if (asec->flags & SEC_CODE)
94 sec->addr += so->lm_info->desc.text_base - load_offset;
95 sec->endaddr += so->lm_info->desc.text_base - load_offset;
97 else if (asec->flags & SEC_DATA)
99 sec->addr += so->lm_info->desc.data_base - load_offset;
100 sec->endaddr += so->lm_info->desc.data_base - load_offset;
105 pa64_free_so (struct so_list *so)
111 pa64_clear_solib (void)
115 /* Wrapper for target_read_memory for dlgetmodinfo. */
118 pa64_target_read_memory (void *buffer, CORE_ADDR ptr, size_t bufsiz, int ident)
120 if (target_read_memory (ptr, buffer, bufsiz) != 0)
125 /* Read the dynamic linker's internal shared library descriptor.
127 This must happen after dld starts running, so we can't do it in
128 read_dynamic_info. Record the fact that we have loaded the
129 descriptor. If the library is archive bound or the load map
130 hasn't been setup, then return zero; else return nonzero. */
133 read_dld_descriptor (void)
136 asection *dyninfo_sect;
138 /* If necessary call read_dynamic_info to extract the contents of the
139 .dynamic section from the shared library. */
140 if (!dld_cache.is_valid)
142 if (symfile_objfile == NULL)
143 error (_("No object file symbols."));
145 dyninfo_sect = bfd_get_section_by_name (symfile_objfile->obfd,
152 if (!read_dynamic_info (dyninfo_sect, &dld_cache))
153 error (_("Unable to read in .dynamic section information."));
156 /* Read the load map pointer. */
157 if (target_read_memory (dld_cache.load_map_addr,
158 (char *) &dld_cache.load_map,
159 sizeof (dld_cache.load_map))
162 error (_("Error while reading in load map pointer."));
165 if (!dld_cache.load_map)
168 /* Read in the dld load module descriptor */
169 if (dlgetmodinfo (-1,
171 sizeof (dld_cache.dld_desc),
172 pa64_target_read_memory,
177 error (_("Error trying to get information about dynamic linker."));
180 /* Indicate that we have loaded the dld descriptor. */
181 dld_cache.have_read_dld_descriptor = 1;
187 /* Read the .dynamic section and extract the information of interest,
188 which is stored in dld_cache. The routine elf_locate_base in solib.c
189 was used as a model for this. */
192 read_dynamic_info (asection *dyninfo_sect, dld_cache_t *dld_cache_p)
196 CORE_ADDR dyninfo_addr;
197 int dyninfo_sect_size;
198 CORE_ADDR entry_addr;
200 /* Read in .dynamic section, silently ignore errors. */
201 dyninfo_addr = bfd_section_vma (symfile_objfile->obfd, dyninfo_sect);
202 dyninfo_sect_size = bfd_section_size (exec_bfd, dyninfo_sect);
203 buf = alloca (dyninfo_sect_size);
204 if (target_read_memory (dyninfo_addr, buf, dyninfo_sect_size))
207 /* Scan the .dynamic section and record the items of interest.
208 In particular, DT_HP_DLD_FLAGS */
209 for (bufend = buf + dyninfo_sect_size, entry_addr = dyninfo_addr;
211 buf += sizeof (Elf64_Dyn), entry_addr += sizeof (Elf64_Dyn))
213 Elf64_Dyn *x_dynp = (Elf64_Dyn*)buf;
214 Elf64_Sxword dyn_tag;
217 dyn_tag = bfd_h_get_64 (symfile_objfile->obfd,
218 (bfd_byte*) &x_dynp->d_tag);
220 /* We can't use a switch here because dyn_tag is 64 bits and HP's
221 lame comiler does not handle 64bit items in switch statements. */
222 if (dyn_tag == DT_NULL)
224 else if (dyn_tag == DT_HP_DLD_FLAGS)
226 /* Set dld_flags_addr and dld_flags in *dld_cache_p */
227 dld_cache_p->dld_flags_addr = entry_addr + offsetof(Elf64_Dyn, d_un);
228 if (target_read_memory (dld_cache_p->dld_flags_addr,
229 (char*) &dld_cache_p->dld_flags,
230 sizeof (dld_cache_p->dld_flags))
233 error (_("Error while reading in .dynamic section of the program."));
236 else if (dyn_tag == DT_HP_LOAD_MAP)
238 /* Dld will place the address of the load map at load_map_addr
239 after it starts running. */
240 if (target_read_memory (entry_addr + offsetof(Elf64_Dyn,
242 (char*) &dld_cache_p->load_map_addr,
243 sizeof (dld_cache_p->load_map_addr))
246 error (_("Error while reading in .dynamic section of the program."));
251 /* tag is not of interest */
255 /* Record other information and set is_valid to 1. */
256 dld_cache_p->dyninfo_sect = dyninfo_sect;
258 /* Verify that we read in required info. These fields are re-set to zero
259 in pa64_solib_restart. */
261 if (dld_cache_p->dld_flags_addr != 0 && dld_cache_p->load_map_addr != 0)
262 dld_cache_p->is_valid = 1;
270 bfd_lookup_symbol -- lookup the value for a specific symbol
272 An expensive way to lookup the value of a single symbol for
273 bfd's that are only temporary anyway. This is used by the
274 shared library support to find the address of the debugger
275 interface structures in the shared library.
277 Note that 0 is specifically allowed as an error return (no
282 bfd_lookup_symbol (bfd *abfd, char *symname)
284 unsigned int storage_needed;
286 asymbol **symbol_table;
287 unsigned int number_of_symbols;
289 struct cleanup *back_to;
290 CORE_ADDR symaddr = 0;
292 storage_needed = bfd_get_symtab_upper_bound (abfd);
294 if (storage_needed > 0)
296 symbol_table = (asymbol **) xmalloc (storage_needed);
297 back_to = make_cleanup (xfree, symbol_table);
298 number_of_symbols = bfd_canonicalize_symtab (abfd, symbol_table);
300 for (i = 0; i < number_of_symbols; i++)
302 sym = *symbol_table++;
303 if (strcmp (sym->name, symname) == 0)
305 /* Bfd symbols are section relative. */
306 symaddr = sym->value + sym->section->vma;
310 do_cleanups (back_to);
316 /* This hook gets called just before the first instruction in the
317 inferior process is executed.
319 This is our opportunity to set magic flags in the inferior so
320 that GDB can be notified when a shared library is mapped in and
321 to tell the dynamic linker that a private copy of the library is
322 needed (so GDB can set breakpoints in the library).
324 We need to set DT_HP_DEBUG_CALLBACK to indicate that we want the
325 dynamic linker to call the breakpoint routine for significant events.
326 We used to set DT_HP_DEBUG_PRIVATE to indicate that shared libraries
327 should be mapped private. However, this flag can be set using
328 "chatr +dbg enable". Not setting DT_HP_DEBUG_PRIVATE allows debugging
329 with shared libraries mapped shareable. */
332 pa64_solib_create_inferior_hook (void)
334 struct minimal_symbol *msymbol;
335 unsigned int dld_flags, status;
336 asection *shlib_info, *interp_sect;
338 struct objfile *objfile;
341 /* First, remove all the solib event breakpoints. Their addresses
342 may have changed since the last time we ran the program. */
343 remove_solib_event_breakpoints ();
345 if (symfile_objfile == NULL)
348 /* First see if the objfile was dynamically linked. */
349 shlib_info = bfd_get_section_by_name (symfile_objfile->obfd, ".dynamic");
353 /* It's got a .dynamic section, make sure it's not empty. */
354 if (bfd_section_size (symfile_objfile->obfd, shlib_info) == 0)
357 /* Read in the .dynamic section. */
358 if (! read_dynamic_info (shlib_info, &dld_cache))
359 error (_("Unable to read the .dynamic section."));
361 /* If the libraries were not mapped private, warn the user. */
362 if ((dld_cache.dld_flags & DT_HP_DEBUG_PRIVATE) == 0)
364 (_("Private mapping of shared library text was not specified\n"
365 "by the executable; setting a breakpoint in a shared library which\n"
366 "is not privately mapped will not work. See the HP-UX 11i v3 chatr\n"
367 "manpage for methods to privately map shared library text."));
369 /* Turn on the flags we care about. */
370 dld_cache.dld_flags |= DT_HP_DEBUG_CALLBACK;
371 status = target_write_memory (dld_cache.dld_flags_addr,
372 (char *) &dld_cache.dld_flags,
373 sizeof (dld_cache.dld_flags));
375 error (_("Unable to modify dynamic linker flags."));
377 /* Now we have to create a shared library breakpoint in the dynamic
378 linker. This can be somewhat tricky since the symbol is inside
379 the dynamic linker (for which we do not have symbols or a base
380 load address! Luckily I wrote this code for solib.c years ago. */
381 interp_sect = bfd_get_section_by_name (exec_bfd, ".interp");
384 unsigned int interp_sect_size;
388 CORE_ADDR sym_addr = 0;
390 /* Read the contents of the .interp section into a local buffer;
391 the contents specify the dynamic linker this program uses. */
392 interp_sect_size = bfd_section_size (exec_bfd, interp_sect);
393 buf = alloca (interp_sect_size);
394 bfd_get_section_contents (exec_bfd, interp_sect,
395 buf, 0, interp_sect_size);
397 /* Now we need to figure out where the dynamic linker was
398 loaded so that we can load its symbols and place a breakpoint
399 in the dynamic linker itself.
401 This address is stored on the stack. However, I've been unable
402 to find any magic formula to find it for Solaris (appears to
403 be trivial on GNU/Linux). Therefore, we have to try an alternate
404 mechanism to find the dynamic linker's base address. */
405 tmp_bfd = bfd_openr (buf, gnutarget);
409 /* Make sure the dynamic linker's really a useful object. */
410 if (!bfd_check_format (tmp_bfd, bfd_object))
412 warning (_("Unable to grok dynamic linker %s as an object file"), buf);
417 /* We find the dynamic linker's base address by examining the
418 current pc (which point at the entry point for the dynamic
419 linker) and subtracting the offset of the entry point.
421 Also note the breakpoint is the second instruction in the
423 load_addr = regcache_read_pc (get_current_regcache ())
424 - tmp_bfd->start_address;
425 sym_addr = bfd_lookup_symbol (tmp_bfd, "__dld_break");
426 sym_addr = load_addr + sym_addr + 4;
428 /* Create the shared library breakpoint. */
431 = create_solib_event_breakpoint (target_gdbarch, sym_addr);
433 /* The breakpoint is actually hard-coded into the dynamic linker,
434 so we don't need to actually insert a breakpoint instruction
435 there. In fact, the dynamic linker's code is immutable, even to
436 ttrace, so we shouldn't even try to do that. For cases like
437 this, we have "permanent" breakpoints. */
438 make_breakpoint_permanent (b);
441 /* We're done with the temporary bfd. */
447 pa64_special_symbol_handling (void)
451 static struct so_list *
452 pa64_current_sos (void)
454 struct so_list *head = 0;
455 struct so_list **link_ptr = &head;
458 /* Read in the load map pointer if we have not done so already. */
459 if (! dld_cache.have_read_dld_descriptor)
460 if (! read_dld_descriptor ())
463 for (dll_index = -1; ; dll_index++)
465 struct load_module_desc dll_desc;
468 struct cleanup *old_chain;
473 /* Read in the load module descriptor. */
474 if (dlgetmodinfo (dll_index, &dll_desc, sizeof (dll_desc),
475 pa64_target_read_memory, 0, dld_cache.load_map)
479 /* Get the name of the shared library. */
480 dll_path = (char *)dlgetname (&dll_desc, sizeof (dll_desc),
481 pa64_target_read_memory,
482 0, dld_cache.load_map);
484 new = (struct so_list *) xmalloc (sizeof (struct so_list));
485 memset (new, 0, sizeof (struct so_list));
486 new->lm_info = (struct lm_info *) xmalloc (sizeof (struct lm_info));
487 memset (new->lm_info, 0, sizeof (struct lm_info));
489 strncpy (new->so_name, dll_path, SO_NAME_MAX_PATH_SIZE - 1);
490 new->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
491 strcpy (new->so_original_name, new->so_name);
493 memcpy (&new->lm_info->desc, &dll_desc, sizeof (dll_desc));
495 #ifdef SOLIB_PA64_DBG
497 struct load_module_desc *d = &new->lm_info->desc;
498 printf ("\n+ library \"%s\" is described at index %d\n", new->so_name,
500 printf (" text_base = 0x%llx\n", d->text_base);
501 printf (" text_size = 0x%llx\n", d->text_size);
502 printf (" data_base = 0x%llx\n", d->data_base);
503 printf (" data_size = 0x%llx\n", d->data_size);
504 printf (" unwind_base = 0x%llx\n", d->unwind_base);
505 printf (" linkage_ptr = 0x%llx\n", d->linkage_ptr);
506 printf (" phdr_base = 0x%llx\n", d->phdr_base);
507 printf (" tls_size = 0x%llx\n", d->tls_size);
508 printf (" tls_start_addr = 0x%llx\n", d->tls_start_addr);
509 printf (" unwind_size = 0x%llx\n", d->unwind_size);
510 printf (" tls_index = 0x%llx\n", d->tls_index);
514 /* Link the new object onto the list. */
517 link_ptr = &new->next;
524 pa64_open_symbol_file_object (void *from_ttyp)
526 int from_tty = *(int *)from_ttyp;
528 struct load_module_desc dll_desc;
532 if (!query (_("Attempt to reload symbols from process? ")))
535 /* Read in the load map pointer if we have not done so already. */
536 if (! dld_cache.have_read_dld_descriptor)
537 if (! read_dld_descriptor ())
540 /* Read in the load module descriptor. */
541 if (dlgetmodinfo (0, &dll_desc, sizeof (dll_desc),
542 pa64_target_read_memory, 0, dld_cache.load_map) == 0)
545 /* Get the name of the shared library. */
546 dll_path = (char *)dlgetname (&dll_desc, sizeof (dll_desc),
547 pa64_target_read_memory,
548 0, dld_cache.load_map);
550 /* Have a pathname: read the symbol file. */
551 symbol_file_add_main (dll_path, from_tty);
556 /* Return nonzero if PC is an address inside the dynamic linker. */
558 pa64_in_dynsym_resolve_code (CORE_ADDR pc)
560 asection *shlib_info;
562 if (symfile_objfile == NULL)
565 if (!dld_cache.have_read_dld_descriptor)
566 if (!read_dld_descriptor ())
569 return (pc >= dld_cache.dld_desc.text_base
570 && pc < dld_cache.dld_desc.text_base + dld_cache.dld_desc.text_size);
574 /* Return the GOT value for the shared library in which ADDR belongs. If
575 ADDR isn't in any known shared library, return zero. */
578 pa64_solib_get_got_by_pc (CORE_ADDR addr)
580 struct so_list *so_list = master_so_list ();
581 CORE_ADDR got_value = 0;
585 if (so_list->lm_info->desc.text_base <= addr
586 && ((so_list->lm_info->desc.text_base
587 + so_list->lm_info->desc.text_size)
590 got_value = so_list->lm_info->desc.linkage_ptr;
593 so_list = so_list->next;
598 /* Get some HPUX-specific data from a shared lib. */
600 pa64_solib_thread_start_addr (struct so_list *so)
602 return so->lm_info->desc.tls_start_addr;
606 /* Return the address of the handle of the shared library in which ADDR
607 belongs. If ADDR isn't in any known shared library, return zero. */
610 pa64_solib_get_solib_by_pc (CORE_ADDR addr)
612 struct so_list *so_list = master_so_list ();
613 CORE_ADDR retval = 0;
617 if (so_list->lm_info->desc.text_base <= addr
618 && ((so_list->lm_info->desc.text_base
619 + so_list->lm_info->desc.text_size)
622 retval = so_list->lm_info->desc_addr;
625 so_list = so_list->next;
630 /* pa64 libraries do not seem to set the section offsets in a standard (i.e.
631 SVr4) way; the text section offset stored in the file doesn't correspond
632 to the place where the library is actually loaded into memory. Instead,
633 we rely on the dll descriptor to tell us where things were loaded. */
635 pa64_solib_get_text_base (struct objfile *objfile)
639 for (so = master_so_list (); so; so = so->next)
640 if (so->objfile == objfile)
641 return so->lm_info->desc.text_base;
646 static struct target_so_ops pa64_so_ops;
648 extern initialize_file_ftype _initialize_pa64_solib; /* -Wmissing-prototypes */
651 _initialize_pa64_solib (void)
653 pa64_so_ops.relocate_section_addresses = pa64_relocate_section_addresses;
654 pa64_so_ops.free_so = pa64_free_so;
655 pa64_so_ops.clear_solib = pa64_clear_solib;
656 pa64_so_ops.solib_create_inferior_hook = pa64_solib_create_inferior_hook;
657 pa64_so_ops.special_symbol_handling = pa64_special_symbol_handling;
658 pa64_so_ops.current_sos = pa64_current_sos;
659 pa64_so_ops.open_symbol_file_object = pa64_open_symbol_file_object;
660 pa64_so_ops.in_dynsym_resolve_code = pa64_in_dynsym_resolve_code;
661 pa64_so_ops.bfd_open = solib_bfd_open;
663 memset (&dld_cache, 0, sizeof (dld_cache));
666 void pa64_solib_select (struct gdbarch *gdbarch)
668 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
669 set_solib_ops (gdbarch, &pa64_so_ops);
671 tdep->solib_thread_start_addr = pa64_solib_thread_start_addr;
672 tdep->solib_get_got_by_pc = pa64_solib_get_got_by_pc;
673 tdep->solib_get_solib_by_pc = pa64_solib_get_solib_by_pc;
674 tdep->solib_get_text_base = pa64_solib_get_text_base;
677 #else /* HAVE_ELF_HP_H */
679 extern initialize_file_ftype _initialize_pa64_solib; /* -Wmissing-prototypes */
682 _initialize_pa64_solib (void)
686 void pa64_solib_select (struct gdbarch *gdbarch)
688 /* For a SOM-only target, there is no pa64 solib support. This is needed
689 for hppa-hpux-tdep.c to build. */
690 error (_("Cannot select pa64 solib support for this configuration."));