1 /* Handle PA64 shared libraries for GDB, the GNU Debugger.
3 Copyright (C) 2004 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 2 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, write to the Free Software
19 Foundation, Inc., 51 Franklin Street, Fifth Floor,
20 Boston, MA 02110-1301, USA.
22 HP in their infinite stupidity choose not to use standard ELF dynamic
23 linker interfaces. They also choose not to make their ELF dymamic
24 linker interfaces compatible with the SOM dynamic linker. The
25 net result is we can not use either of the existing somsolib.c or
26 solib.c. What a crock.
28 Even more disgusting. This file depends on functions provided only
29 in certain PA64 libraries. Thus this file is supposed to only be
30 used native. When will HP ever learn that they need to provide the
31 same functionality in all their libraries! */
42 #include "hppa-tdep.h"
44 #include "solib-pa64.h"
48 /* If we are building for a SOM-only target, then we don't need this. */
51 /* FIXME: kettenis/20041213: These includes should be eliminated. */
57 struct load_module_desc desc;
61 /* When adding fields, be sure to clear them in _initialize_pa64_solib. */
64 CORE_ADDR dld_flags_addr;
66 struct bfd_section *dyninfo_sect;
67 int have_read_dld_descriptor;
70 CORE_ADDR load_map_addr;
71 struct load_module_desc dld_desc;
75 static dld_cache_t dld_cache;
78 read_dynamic_info (asection *dyninfo_sect, dld_cache_t *dld_cache_p);
81 pa64_relocate_section_addresses (struct so_list *so,
82 struct section_table *sec)
84 asection *asec = sec->the_bfd_section;
85 CORE_ADDR load_offset;
87 /* Relocate all the sections based on where they got loaded. */
89 load_offset = bfd_section_vma (so->abfd, asec) - asec->filepos;
91 if (asec->flags & SEC_CODE)
93 sec->addr += so->lm_info->desc.text_base - load_offset;
94 sec->endaddr += so->lm_info->desc.text_base - load_offset;
96 else if (asec->flags & SEC_DATA)
98 sec->addr += so->lm_info->desc.data_base - load_offset;
99 sec->endaddr += so->lm_info->desc.data_base - load_offset;
104 pa64_free_so (struct so_list *so)
110 pa64_clear_solib (void)
114 /* Wrapper for target_read_memory for dlgetmodinfo. */
117 pa64_target_read_memory (void *buffer, CORE_ADDR ptr, size_t bufsiz, int ident)
119 if (target_read_memory (ptr, buffer, bufsiz) != 0)
124 /* Read the dynamic linker's internal shared library descriptor.
126 This must happen after dld starts running, so we can't do it in
127 read_dynamic_info. Record the fact that we have loaded the
128 descriptor. If the library is archive bound, then return zero, else
132 read_dld_descriptor (void)
135 asection *dyninfo_sect;
137 /* If necessary call read_dynamic_info to extract the contents of the
138 .dynamic section from the shared library. */
139 if (!dld_cache.is_valid)
141 if (symfile_objfile == NULL)
142 error (_("No object file symbols."));
144 dyninfo_sect = bfd_get_section_by_name (symfile_objfile->obfd,
151 if (!read_dynamic_info (dyninfo_sect, &dld_cache))
152 error (_("Unable to read in .dynamic section information."));
155 /* Read the load map pointer. */
156 if (target_read_memory (dld_cache.load_map_addr,
157 (char *) &dld_cache.load_map,
158 sizeof (dld_cache.load_map))
161 error (_("Error while reading in load map pointer."));
164 /* Read in the dld load module descriptor */
165 if (dlgetmodinfo (-1,
167 sizeof (dld_cache.dld_desc),
168 pa64_target_read_memory,
173 error (_("Error trying to get information about dynamic linker."));
176 /* Indicate that we have loaded the dld descriptor. */
177 dld_cache.have_read_dld_descriptor = 1;
183 /* Read the .dynamic section and extract the information of interest,
184 which is stored in dld_cache. The routine elf_locate_base in solib.c
185 was used as a model for this. */
188 read_dynamic_info (asection *dyninfo_sect, dld_cache_t *dld_cache_p)
192 CORE_ADDR dyninfo_addr;
193 int dyninfo_sect_size;
194 CORE_ADDR entry_addr;
196 /* Read in .dynamic section, silently ignore errors. */
197 dyninfo_addr = bfd_section_vma (symfile_objfile->obfd, dyninfo_sect);
198 dyninfo_sect_size = bfd_section_size (exec_bfd, dyninfo_sect);
199 buf = alloca (dyninfo_sect_size);
200 if (target_read_memory (dyninfo_addr, buf, dyninfo_sect_size))
203 /* Scan the .dynamic section and record the items of interest.
204 In particular, DT_HP_DLD_FLAGS */
205 for (bufend = buf + dyninfo_sect_size, entry_addr = dyninfo_addr;
207 buf += sizeof (Elf64_Dyn), entry_addr += sizeof (Elf64_Dyn))
209 Elf64_Dyn *x_dynp = (Elf64_Dyn*)buf;
210 Elf64_Sxword dyn_tag;
214 pbuf = alloca (TARGET_PTR_BIT / HOST_CHAR_BIT);
215 dyn_tag = bfd_h_get_64 (symfile_objfile->obfd,
216 (bfd_byte*) &x_dynp->d_tag);
218 /* We can't use a switch here because dyn_tag is 64 bits and HP's
219 lame comiler does not handle 64bit items in switch statements. */
220 if (dyn_tag == DT_NULL)
222 else if (dyn_tag == DT_HP_DLD_FLAGS)
224 /* Set dld_flags_addr and dld_flags in *dld_cache_p */
225 dld_cache_p->dld_flags_addr = entry_addr + offsetof(Elf64_Dyn, d_un);
226 if (target_read_memory (dld_cache_p->dld_flags_addr,
227 (char*) &dld_cache_p->dld_flags,
228 sizeof (dld_cache_p->dld_flags))
231 error (_("Error while reading in .dynamic section of the program."));
234 else if (dyn_tag == DT_HP_LOAD_MAP)
236 /* Dld will place the address of the load map at load_map_addr
237 after it starts running. */
238 if (target_read_memory (entry_addr + offsetof(Elf64_Dyn,
240 (char*) &dld_cache_p->load_map_addr,
241 sizeof (dld_cache_p->load_map_addr))
244 error (_("Error while reading in .dynamic section of the program."));
249 /* tag is not of interest */
253 /* Record other information and set is_valid to 1. */
254 dld_cache_p->dyninfo_sect = dyninfo_sect;
256 /* Verify that we read in required info. These fields are re-set to zero
257 in pa64_solib_restart. */
259 if (dld_cache_p->dld_flags_addr != 0 && dld_cache_p->load_map_addr != 0)
260 dld_cache_p->is_valid = 1;
268 bfd_lookup_symbol -- lookup the value for a specific symbol
270 An expensive way to lookup the value of a single symbol for
271 bfd's that are only temporary anyway. This is used by the
272 shared library support to find the address of the debugger
273 interface structures in the shared library.
275 Note that 0 is specifically allowed as an error return (no
280 bfd_lookup_symbol (bfd *abfd, char *symname)
282 unsigned int storage_needed;
284 asymbol **symbol_table;
285 unsigned int number_of_symbols;
287 struct cleanup *back_to;
288 CORE_ADDR symaddr = 0;
290 storage_needed = bfd_get_symtab_upper_bound (abfd);
292 if (storage_needed > 0)
294 symbol_table = (asymbol **) xmalloc (storage_needed);
295 back_to = make_cleanup (xfree, symbol_table);
296 number_of_symbols = bfd_canonicalize_symtab (abfd, symbol_table);
298 for (i = 0; i < number_of_symbols; i++)
300 sym = *symbol_table++;
301 if (strcmp (sym->name, symname) == 0)
303 /* Bfd symbols are section relative. */
304 symaddr = sym->value + sym->section->vma;
308 do_cleanups (back_to);
314 /* This hook gets called just before the first instruction in the
315 inferior process is executed.
317 This is our opportunity to set magic flags in the inferior so
318 that GDB can be notified when a shared library is mapped in and
319 to tell the dynamic linker that a private copy of the library is
320 needed (so GDB can set breakpoints in the library).
322 We need to set two flag bits in this routine.
324 DT_HP_DEBUG_PRIVATE to indicate that shared libraries should be
327 DT_HP_DEBUG_CALLBACK to indicate that we want the dynamic linker to
328 call the breakpoint routine for significant events. */
331 pa64_solib_create_inferior_hook (void)
333 struct minimal_symbol *msymbol;
334 unsigned int dld_flags, status;
335 asection *shlib_info, *interp_sect;
337 struct objfile *objfile;
340 /* First, remove all the solib event breakpoints. Their addresses
341 may have changed since the last time we ran the program. */
342 remove_solib_event_breakpoints ();
344 if (symfile_objfile == NULL)
347 /* First see if the objfile was dynamically linked. */
348 shlib_info = bfd_get_section_by_name (symfile_objfile->obfd, ".dynamic");
352 /* It's got a .dynamic section, make sure it's not empty. */
353 if (bfd_section_size (symfile_objfile->obfd, shlib_info) == 0)
356 /* Read in the .dynamic section. */
357 if (! read_dynamic_info (shlib_info, &dld_cache))
358 error (_("Unable to read the .dynamic section."));
360 /* Turn on the flags we care about. */
361 dld_cache.dld_flags |= DT_HP_DEBUG_PRIVATE;
362 dld_cache.dld_flags |= DT_HP_DEBUG_CALLBACK;
363 status = target_write_memory (dld_cache.dld_flags_addr,
364 (char *) &dld_cache.dld_flags,
365 sizeof (dld_cache.dld_flags));
367 error (_("Unable to modify dynamic linker flags."));
369 /* Now we have to create a shared library breakpoint in the dynamic
370 linker. This can be somewhat tricky since the symbol is inside
371 the dynamic linker (for which we do not have symbols or a base
372 load address! Luckily I wrote this code for solib.c years ago. */
373 interp_sect = bfd_get_section_by_name (exec_bfd, ".interp");
376 unsigned int interp_sect_size;
380 CORE_ADDR sym_addr = 0;
382 /* Read the contents of the .interp section into a local buffer;
383 the contents specify the dynamic linker this program uses. */
384 interp_sect_size = bfd_section_size (exec_bfd, interp_sect);
385 buf = alloca (interp_sect_size);
386 bfd_get_section_contents (exec_bfd, interp_sect,
387 buf, 0, interp_sect_size);
389 /* Now we need to figure out where the dynamic linker was
390 loaded so that we can load its symbols and place a breakpoint
391 in the dynamic linker itself.
393 This address is stored on the stack. However, I've been unable
394 to find any magic formula to find it for Solaris (appears to
395 be trivial on GNU/Linux). Therefore, we have to try an alternate
396 mechanism to find the dynamic linker's base address. */
397 tmp_bfd = bfd_openr (buf, gnutarget);
401 /* Make sure the dynamic linker's really a useful object. */
402 if (!bfd_check_format (tmp_bfd, bfd_object))
404 warning (_("Unable to grok dynamic linker %s as an object file"), buf);
409 /* We find the dynamic linker's base address by examining the
410 current pc (which point at the entry point for the dynamic
411 linker) and subtracting the offset of the entry point.
413 Also note the breakpoint is the second instruction in the
415 load_addr = read_pc () - tmp_bfd->start_address;
416 sym_addr = bfd_lookup_symbol (tmp_bfd, "__dld_break");
417 sym_addr = load_addr + sym_addr + 4;
419 /* Create the shared library breakpoint. */
422 = create_solib_event_breakpoint (sym_addr);
424 /* The breakpoint is actually hard-coded into the dynamic linker,
425 so we don't need to actually insert a breakpoint instruction
426 there. In fact, the dynamic linker's code is immutable, even to
427 ttrace, so we shouldn't even try to do that. For cases like
428 this, we have "permanent" breakpoints. */
429 make_breakpoint_permanent (b);
432 /* We're done with the temporary bfd. */
438 pa64_special_symbol_handling (void)
442 static struct so_list *
443 pa64_current_sos (void)
445 struct so_list *head = 0;
446 struct so_list **link_ptr = &head;
449 /* Read in the load map pointer if we have not done so already. */
450 if (! dld_cache.have_read_dld_descriptor)
451 if (! read_dld_descriptor ())
454 /* If the libraries were not mapped private, warn the user. */
455 if ((dld_cache.dld_flags & DT_HP_DEBUG_PRIVATE) == 0)
456 warning (_("The shared libraries were not privately mapped; setting a\n"
457 "breakpoint in a shared library will not work until you rerun "
460 for (dll_index = -1; ; dll_index++)
462 struct load_module_desc dll_desc;
465 struct cleanup *old_chain;
470 /* Read in the load module descriptor. */
471 if (dlgetmodinfo (dll_index, &dll_desc, sizeof (dll_desc),
472 pa64_target_read_memory, 0, dld_cache.load_map)
476 /* Get the name of the shared library. */
477 dll_path = (char *)dlgetname (&dll_desc, sizeof (dll_desc),
478 pa64_target_read_memory,
479 0, dld_cache.load_map);
481 new = (struct so_list *) xmalloc (sizeof (struct so_list));
482 memset (new, 0, sizeof (struct so_list));
483 new->lm_info = (struct lm_info *) xmalloc (sizeof (struct lm_info));
484 memset (new->lm_info, 0, sizeof (struct lm_info));
486 strncpy (new->so_name, dll_path, SO_NAME_MAX_PATH_SIZE - 1);
487 new->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
488 strcpy (new->so_original_name, new->so_name);
490 memcpy (&new->lm_info->desc, &dll_desc, sizeof (dll_desc));
492 #ifdef SOLIB_PA64_DBG
494 struct load_module_desc *d = &new->lm_info->desc;
495 printf ("\n+ library \"%s\" is described at index %d\n", new->so_name,
497 printf (" text_base = 0x%llx\n", d->text_base);
498 printf (" text_size = 0x%llx\n", d->text_size);
499 printf (" data_base = 0x%llx\n", d->data_base);
500 printf (" data_size = 0x%llx\n", d->data_size);
501 printf (" unwind_base = 0x%llx\n", d->unwind_base);
502 printf (" linkage_ptr = 0x%llx\n", d->linkage_ptr);
503 printf (" phdr_base = 0x%llx\n", d->phdr_base);
504 printf (" tls_size = 0x%llx\n", d->tls_size);
505 printf (" tls_start_addr = 0x%llx\n", d->tls_start_addr);
506 printf (" unwind_size = 0x%llx\n", d->unwind_size);
507 printf (" tls_index = 0x%llx\n", d->tls_index);
511 /* Link the new object onto the list. */
514 link_ptr = &new->next;
521 pa64_open_symbol_file_object (void *from_ttyp)
523 int from_tty = *(int *)from_ttyp;
525 struct load_module_desc dll_desc;
529 if (!query ("Attempt to reload symbols from process? "))
532 /* Read in the load map pointer if we have not done so already. */
533 if (! dld_cache.have_read_dld_descriptor)
534 if (! read_dld_descriptor ())
537 /* Read in the load module descriptor. */
538 if (dlgetmodinfo (0, &dll_desc, sizeof (dll_desc),
539 pa64_target_read_memory, 0, dld_cache.load_map) == 0)
542 /* Get the name of the shared library. */
543 dll_path = (char *)dlgetname (&dll_desc, sizeof (dll_desc),
544 pa64_target_read_memory,
545 0, dld_cache.load_map);
547 /* Have a pathname: read the symbol file. */
548 symbol_file_add_main (dll_path, from_tty);
553 /* Return nonzero if PC is an address inside the dynamic linker. */
555 pa64_in_dynsym_resolve_code (CORE_ADDR pc)
557 asection *shlib_info;
559 if (symfile_objfile == NULL)
562 if (!dld_cache.have_read_dld_descriptor)
563 if (!read_dld_descriptor ())
566 return (pc >= dld_cache.dld_desc.text_base
567 && pc < dld_cache.dld_desc.text_base + dld_cache.dld_desc.text_size);
571 /* Return the GOT value for the shared library in which ADDR belongs. If
572 ADDR isn't in any known shared library, return zero. */
575 pa64_solib_get_got_by_pc (CORE_ADDR addr)
577 struct so_list *so_list = master_so_list ();
578 CORE_ADDR got_value = 0;
582 if (so_list->lm_info->desc.text_base <= addr
583 && ((so_list->lm_info->desc.text_base
584 + so_list->lm_info->desc.text_size)
587 got_value = so_list->lm_info->desc.linkage_ptr;
590 so_list = so_list->next;
595 /* Get some HPUX-specific data from a shared lib. */
597 pa64_solib_thread_start_addr (struct so_list *so)
599 return so->lm_info->desc.tls_start_addr;
603 /* Return the address of the handle of the shared library in which ADDR
604 belongs. If ADDR isn't in any known shared library, return zero. */
607 pa64_solib_get_solib_by_pc (CORE_ADDR addr)
609 struct so_list *so_list = master_so_list ();
610 CORE_ADDR retval = 0;
614 if (so_list->lm_info->desc.text_base <= addr
615 && ((so_list->lm_info->desc.text_base
616 + so_list->lm_info->desc.text_size)
619 retval = so_list->lm_info->desc_addr;
622 so_list = so_list->next;
627 /* pa64 libraries do not seem to set the section offsets in a standard (i.e.
628 SVr4) way; the text section offset stored in the file doesn't correspond
629 to the place where the library is actually loaded into memory. Instead,
630 we rely on the dll descriptor to tell us where things were loaded. */
632 pa64_solib_get_text_base (struct objfile *objfile)
636 for (so = master_so_list (); so; so = so->next)
637 if (so->objfile == objfile)
638 return so->lm_info->desc.text_base;
643 static struct target_so_ops pa64_so_ops;
645 extern initialize_file_ftype _initialize_pa64_solib; /* -Wmissing-prototypes */
648 _initialize_pa64_solib (void)
650 pa64_so_ops.relocate_section_addresses = pa64_relocate_section_addresses;
651 pa64_so_ops.free_so = pa64_free_so;
652 pa64_so_ops.clear_solib = pa64_clear_solib;
653 pa64_so_ops.solib_create_inferior_hook = pa64_solib_create_inferior_hook;
654 pa64_so_ops.special_symbol_handling = pa64_special_symbol_handling;
655 pa64_so_ops.current_sos = pa64_current_sos;
656 pa64_so_ops.open_symbol_file_object = pa64_open_symbol_file_object;
657 pa64_so_ops.in_dynsym_resolve_code = pa64_in_dynsym_resolve_code;
659 memset (&dld_cache, 0, sizeof (dld_cache));
662 void pa64_solib_select (struct gdbarch_tdep *tdep)
664 current_target_so_ops = &pa64_so_ops;
666 tdep->solib_thread_start_addr = pa64_solib_thread_start_addr;
667 tdep->solib_get_got_by_pc = pa64_solib_get_got_by_pc;
668 tdep->solib_get_solib_by_pc = pa64_solib_get_solib_by_pc;
669 tdep->solib_get_text_base = pa64_solib_get_text_base;
672 #else /* PA_SOM_ONLY */
674 extern initialize_file_ftype _initialize_pa64_solib; /* -Wmissing-prototypes */
677 _initialize_pa64_solib (void)
681 void pa64_solib_select (struct gdbarch_tdep *tdep)
683 /* For a SOM-only target, there is no pa64 solib support. This is needed
684 for hppa-hpux-tdep.c to build. */
685 error (_("Cannot select pa64 solib support for this configuration."));