1 /* Handle SOM shared libraries.
3 Copyright (C) 2004, 2005, 2007 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. */
32 #include "hppa-tdep.h"
37 /* These ought to be defined in some public interface, but aren't. They
38 define the meaning of the various bits in the distinguished __dld_flags
39 variable that is declared in every debuggable a.out on HP-UX, and that
40 is shared between the debugger and the dynamic linker.
42 #define DLD_FLAGS_MAPPRIVATE 0x1
43 #define DLD_FLAGS_HOOKVALID 0x2
44 #define DLD_FLAGS_LISTVALID 0x4
45 #define DLD_FLAGS_BOR_ENABLE 0x8
49 /* Version of this structure (it is expected to change again in hpux10). */
50 unsigned char struct_version;
52 /* Binding mode for this library. */
53 unsigned char bind_mode;
55 /* Version of this library. */
56 short library_version;
58 /* Start of text address,
59 link-time text location (length of text area),
60 end of text address. */
62 CORE_ADDR text_link_addr;
65 /* Start of data, start of bss and end of data. */
70 /* Value of linkage pointer (%r19). */
73 /* Address in target of offset from thread-local register of
74 start of this thread's data. I.e., the first thread-local
75 variable in this shared library starts at *(tsd_start_addr)
76 from that area pointed to by cr27 (mpsfu_hi).
78 We do the indirection as soon as we read it, so from then
79 on it's the offset itself. */
80 CORE_ADDR tsd_start_addr;
82 /* Address of the link map entry in the loader. */
86 /* These addresses should be filled in by som_solib_create_inferior_hook.
87 They are also used elsewhere in this module.
92 struct unwind_table_entry *unwind;
96 /* When adding fields, be sure to clear them in _initialize_som_solib. */
100 addr_and_unwind_t hook;
101 addr_and_unwind_t hook_stub;
102 addr_and_unwind_t load;
103 addr_and_unwind_t load_stub;
104 addr_and_unwind_t unload;
105 addr_and_unwind_t unload2;
106 addr_and_unwind_t unload_stub;
111 som_relocate_section_addresses (struct so_list *so,
112 struct section_table *sec)
114 flagword aflag = bfd_get_section_flags(so->abfd, sec->the_bfd_section);
116 if (aflag & SEC_CODE)
118 sec->addr += so->lm_info->text_addr - so->lm_info->text_link_addr;
119 sec->endaddr += so->lm_info->text_addr - so->lm_info->text_link_addr;
121 else if (aflag & SEC_DATA)
123 sec->addr += so->lm_info->data_start;
124 sec->endaddr += so->lm_info->data_start;
130 /* This hook gets called just before the first instruction in the
131 inferior process is executed.
133 This is our opportunity to set magic flags in the inferior so
134 that GDB can be notified when a shared library is mapped in and
135 to tell the dynamic linker that a private copy of the library is
136 needed (so GDB can set breakpoints in the library).
138 __dld_flags is the location of the magic flags; as of this implementation
139 there are 3 flags of interest:
141 bit 0 when set indicates that private copies of the libraries are needed
142 bit 1 when set indicates that the callback hook routine is valid
143 bit 2 when set indicates that the dynamic linker should maintain the
144 __dld_list structure when loading/unloading libraries.
146 Note that shared libraries are not mapped in at this time, so we have
147 run the inferior until the libraries are mapped in. Typically this
148 means running until the "_start" is called. */
151 som_solib_create_inferior_hook (void)
153 struct minimal_symbol *msymbol;
154 unsigned int dld_flags, status, have_endo;
155 asection *shlib_info;
159 /* First, remove all the solib event breakpoints. Their addresses
160 may have changed since the last time we ran the program. */
161 remove_solib_event_breakpoints ();
163 if (symfile_objfile == NULL)
166 /* First see if the objfile was dynamically linked. */
167 shlib_info = bfd_get_section_by_name (symfile_objfile->obfd, "$SHLIB_INFO$");
171 /* It's got a $SHLIB_INFO$ section, make sure it's not empty. */
172 if (bfd_section_size (symfile_objfile->obfd, shlib_info) == 0)
176 /* Slam the pid of the process into __d_pid.
178 We used to warn when this failed, but that warning is only useful
179 on very old HP systems (hpux9 and older). The warnings are an
180 annoyance to users of modern systems and foul up the testsuite as
181 well. As a result, the warnings have been disabled. */
182 msymbol = lookup_minimal_symbol ("__d_pid", NULL, symfile_objfile);
186 anaddr = SYMBOL_VALUE_ADDRESS (msymbol);
187 store_unsigned_integer (buf, 4, PIDGET (inferior_ptid));
188 status = target_write_memory (anaddr, buf, 4);
192 Unable to write __d_pid.\n\
193 Suggest linking with /opt/langtools/lib/end.o.\n\
194 GDB will be unable to track shl_load/shl_unload calls"));
198 /* Get the value of _DLD_HOOK (an export stub) and put it in __dld_hook;
199 This will force the dynamic linker to call __d_trap when significant
202 Note that the above is the pre-HP-UX 9.0 behaviour. At 9.0 and above,
203 the dld provides an export stub named "__d_trap" as well as the
204 function named "__d_trap" itself, but doesn't provide "_DLD_HOOK".
205 We'll look first for the old flavor and then the new.
207 msymbol = lookup_minimal_symbol ("_DLD_HOOK", NULL, symfile_objfile);
209 msymbol = lookup_minimal_symbol ("__d_trap", NULL, symfile_objfile);
213 Unable to find _DLD_HOOK symbol in object file.\n\
214 Suggest linking with /opt/langtools/lib/end.o.\n\
215 GDB will be unable to track shl_load/shl_unload calls"));
218 anaddr = SYMBOL_VALUE_ADDRESS (msymbol);
219 dld_cache.hook.address = anaddr;
221 /* Grrr, this might not be an export symbol! We have to find the
223 msymbol = hppa_lookup_stub_minimal_symbol (SYMBOL_LINKAGE_NAME (msymbol),
227 anaddr = SYMBOL_VALUE (msymbol);
228 dld_cache.hook_stub.address = anaddr;
230 store_unsigned_integer (buf, 4, anaddr);
232 msymbol = lookup_minimal_symbol ("__dld_hook", NULL, symfile_objfile);
236 Unable to find __dld_hook symbol in object file.\n\
237 Suggest linking with /opt/langtools/lib/end.o.\n\
238 GDB will be unable to track shl_load/shl_unload calls"));
241 anaddr = SYMBOL_VALUE_ADDRESS (msymbol);
242 status = target_write_memory (anaddr, buf, 4);
244 /* Now set a shlib_event breakpoint at __d_trap so we can track
245 significant shared library events. */
246 msymbol = lookup_minimal_symbol ("__d_trap", NULL, symfile_objfile);
250 Unable to find __dld_d_trap symbol in object file.\n\
251 Suggest linking with /opt/langtools/lib/end.o.\n\
252 GDB will be unable to track shl_load/shl_unload calls"));
255 create_solib_event_breakpoint (SYMBOL_VALUE_ADDRESS (msymbol));
257 /* We have all the support usually found in end.o, so we can track
258 shl_load and shl_unload calls. */
263 /* Get the address of __dld_flags, if no such symbol exists, then we can
264 not debug the shared code. */
265 msymbol = lookup_minimal_symbol ("__dld_flags", NULL, NULL);
268 error (_("Unable to find __dld_flags symbol in object file."));
271 anaddr = SYMBOL_VALUE_ADDRESS (msymbol);
273 /* Read the current contents. */
274 status = target_read_memory (anaddr, buf, 4);
276 error (_("Unable to read __dld_flags."));
277 dld_flags = extract_unsigned_integer (buf, 4);
279 /* Turn on the flags we care about. */
280 dld_flags |= DLD_FLAGS_MAPPRIVATE;
282 dld_flags |= DLD_FLAGS_HOOKVALID;
283 store_unsigned_integer (buf, 4, dld_flags);
284 status = target_write_memory (anaddr, buf, 4);
286 error (_("Unable to write __dld_flags."));
288 /* Now find the address of _start and set a breakpoint there.
289 We still need this code for two reasons:
291 * Not all sites have /opt/langtools/lib/end.o, so it's not always
292 possible to track the dynamic linker's events.
294 * At this time no events are triggered for shared libraries
295 loaded at startup time (what a crock). */
297 msymbol = lookup_minimal_symbol ("_start", NULL, symfile_objfile);
299 error (_("Unable to find _start symbol in object file."));
301 anaddr = SYMBOL_VALUE_ADDRESS (msymbol);
303 /* Make the breakpoint at "_start" a shared library event breakpoint. */
304 create_solib_event_breakpoint (anaddr);
306 clear_symtab_users ();
310 som_special_symbol_handling (void)
315 som_solib_desire_dynamic_linker_symbols (void)
317 struct objfile *objfile;
318 struct unwind_table_entry *u;
319 struct minimal_symbol *dld_msymbol;
321 /* Do we already know the value of these symbols? If so, then
324 (If you add clauses to this test, be sure to likewise update the
325 test within the loop.)
327 if (dld_cache.is_valid)
330 ALL_OBJFILES (objfile)
332 dld_msymbol = lookup_minimal_symbol ("shl_load", NULL, objfile);
333 if (dld_msymbol != NULL)
335 dld_cache.load.address = SYMBOL_VALUE (dld_msymbol);
336 dld_cache.load.unwind = find_unwind_entry (dld_cache.load.address);
339 dld_msymbol = lookup_minimal_symbol_solib_trampoline ("shl_load",
341 if (dld_msymbol != NULL)
343 if (SYMBOL_TYPE (dld_msymbol) == mst_solib_trampoline)
345 u = find_unwind_entry (SYMBOL_VALUE (dld_msymbol));
346 if ((u != NULL) && (u->stub_unwind.stub_type == EXPORT))
348 dld_cache.load_stub.address = SYMBOL_VALUE (dld_msymbol);
349 dld_cache.load_stub.unwind = u;
354 dld_msymbol = lookup_minimal_symbol ("shl_unload", NULL, objfile);
355 if (dld_msymbol != NULL)
357 dld_cache.unload.address = SYMBOL_VALUE (dld_msymbol);
358 dld_cache.unload.unwind = find_unwind_entry (dld_cache.unload.address);
360 /* ??rehrauer: I'm not sure exactly what this is, but it appears
361 that on some HPUX 10.x versions, there's two unwind regions to
362 cover the body of "shl_unload", the second being 4 bytes past
363 the end of the first. This is a large hack to handle that
364 case, but since I don't seem to have any legitimate way to
365 look for this thing via the symbol table...
367 if (dld_cache.unload.unwind != NULL)
369 u = find_unwind_entry (dld_cache.unload.unwind->region_end + 4);
372 dld_cache.unload2.address = u->region_start;
373 dld_cache.unload2.unwind = u;
378 dld_msymbol = lookup_minimal_symbol_solib_trampoline ("shl_unload",
380 if (dld_msymbol != NULL)
382 if (SYMBOL_TYPE (dld_msymbol) == mst_solib_trampoline)
384 u = find_unwind_entry (SYMBOL_VALUE (dld_msymbol));
385 if ((u != NULL) && (u->stub_unwind.stub_type == EXPORT))
387 dld_cache.unload_stub.address = SYMBOL_VALUE (dld_msymbol);
388 dld_cache.unload_stub.unwind = u;
393 /* Did we find everything we were looking for? If so, stop. */
394 if ((dld_cache.load.address != 0)
395 && (dld_cache.load_stub.address != 0)
396 && (dld_cache.unload.address != 0)
397 && (dld_cache.unload_stub.address != 0))
399 dld_cache.is_valid = 1;
404 dld_cache.hook.unwind = find_unwind_entry (dld_cache.hook.address);
405 dld_cache.hook_stub.unwind = find_unwind_entry (dld_cache.hook_stub.address);
407 /* We're prepared not to find some of these symbols, which is why
408 this function is a "desire" operation, and not a "require".
413 som_in_dynsym_resolve_code (CORE_ADDR pc)
415 struct unwind_table_entry *u_pc;
417 /* Are we in the dld itself?
419 ??rehrauer: Large hack -- We'll assume that any address in a
420 shared text region is the dld's text. This would obviously
421 fall down if the user attached to a process, whose shlibs
422 weren't mapped to a (writeable) private region. However, in
423 that case the debugger probably isn't able to set the fundamental
424 breakpoint in the dld callback anyways, so this hack should be
427 if ((pc & (CORE_ADDR) 0xc0000000) == (CORE_ADDR) 0xc0000000)
430 /* Cache the address of some symbols that are part of the dynamic
431 linker, if not already known.
433 som_solib_desire_dynamic_linker_symbols ();
435 /* Are we in the dld callback? Or its export stub? */
436 u_pc = find_unwind_entry (pc);
440 if ((u_pc == dld_cache.hook.unwind) || (u_pc == dld_cache.hook_stub.unwind))
443 /* Or the interface of the dld (i.e., "shl_load" or friends)? */
444 if ((u_pc == dld_cache.load.unwind)
445 || (u_pc == dld_cache.unload.unwind)
446 || (u_pc == dld_cache.unload2.unwind)
447 || (u_pc == dld_cache.load_stub.unwind)
448 || (u_pc == dld_cache.unload_stub.unwind))
451 /* Apparently this address isn't part of the dld's text. */
456 som_clear_solib (void)
464 char text_link_addr[4];
471 char tsd_start_addr_ptr[4];
475 link_map_start (void)
477 struct minimal_symbol *sym;
480 unsigned int dld_flags;
482 sym = lookup_minimal_symbol ("__dld_flags", NULL, NULL);
484 error (_("Unable to find __dld_flags symbol in object file."));
485 addr = SYMBOL_VALUE_ADDRESS (sym);
486 read_memory (addr, buf, 4);
487 dld_flags = extract_unsigned_integer (buf, 4);
488 if ((dld_flags & DLD_FLAGS_LISTVALID) == 0)
489 error (_("__dld_list is not valid according to __dld_flags."));
491 /* If the libraries were not mapped private, warn the user. */
492 if ((dld_flags & DLD_FLAGS_MAPPRIVATE) == 0)
493 warning (_("The shared libraries were not privately mapped; setting a\n"
494 "breakpoint in a shared library will not work until you rerun the "
497 sym = lookup_minimal_symbol ("__dld_list", NULL, NULL);
500 /* Older crt0.o files (hpux8) don't have __dld_list as a symbol,
501 but the data is still available if you know where to look. */
502 sym = lookup_minimal_symbol ("__dld_flags", NULL, NULL);
505 error (_("Unable to find dynamic library list."));
508 addr = SYMBOL_VALUE_ADDRESS (sym) - 8;
511 addr = SYMBOL_VALUE_ADDRESS (sym);
513 read_memory (addr, buf, 4);
514 addr = extract_unsigned_integer (buf, 4);
518 read_memory (addr, buf, 4);
519 return extract_unsigned_integer (buf, 4);
522 /* Does this so's name match the main binary? */
524 match_main (const char *name)
526 return strcmp (name, symfile_objfile->name) == 0;
529 static struct so_list *
530 som_current_sos (void)
533 struct so_list *head = 0;
534 struct so_list **link_ptr = &head;
536 for (lm = link_map_start (); lm; )
541 struct cleanup *old_chain;
543 struct dld_list dbuf;
546 new = (struct so_list *) xmalloc (sizeof (struct so_list));
547 old_chain = make_cleanup (xfree, new);
549 memset (new, 0, sizeof (*new));
550 new->lm_info = xmalloc (sizeof (struct lm_info));
551 make_cleanup (xfree, new->lm_info);
553 read_memory (lm, (gdb_byte *)&dbuf, sizeof (struct dld_list));
555 addr = extract_unsigned_integer ((gdb_byte *)&dbuf.name,
557 target_read_string (addr, &namebuf, SO_NAME_MAX_PATH_SIZE - 1, &errcode);
559 warning (_("Can't read pathname for load map: %s."),
560 safe_strerror (errcode));
563 strncpy (new->so_name, namebuf, SO_NAME_MAX_PATH_SIZE - 1);
564 new->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
566 strcpy (new->so_original_name, new->so_name);
569 if (new->so_name[0] && !match_main (new->so_name))
571 struct lm_info *lmi = new->lm_info;
576 #define EXTRACT(_fld) \
577 extract_unsigned_integer ((gdb_byte *)&dbuf._fld, sizeof (dbuf._fld));
579 lmi->text_addr = EXTRACT (text_addr);
580 tmp = EXTRACT (info);
581 lmi->library_version = (tmp >> 16) & 0xffff;
582 lmi->bind_mode = (tmp >> 8) & 0xff;
583 lmi->struct_version = tmp & 0xff;
584 lmi->text_link_addr = EXTRACT (text_link_addr);
585 lmi->text_end = EXTRACT (text_end);
586 lmi->data_start = EXTRACT (data_start);
587 lmi->bss_start = EXTRACT (bss_start);
588 lmi->data_end = EXTRACT (data_end);
589 lmi->got_value = EXTRACT (got_value);
590 tmp = EXTRACT (tsd_start_addr_ptr);
591 read_memory (tmp, tsdbuf, 4);
592 lmi->tsd_start_addr = extract_unsigned_integer (tsdbuf, 4);
595 printf ("\n+ library \"%s\" is described at 0x%s\n", new->so_name,
597 printf (" 'version' is %d\n", new->lm_info->struct_version);
598 printf (" 'bind_mode' is %d\n", new->lm_info->bind_mode);
599 printf (" 'library_version' is %d\n",
600 new->lm_info->library_version);
601 printf (" 'text_addr' is 0x%s\n",
602 paddr_nz (new->lm_info->text_addr));
603 printf (" 'text_link_addr' is 0x%s\n",
604 paddr_nz (new->lm_info->text_link_addr));
605 printf (" 'text_end' is 0x%s\n",
606 paddr_nz (new->lm_info->text_end));
607 printf (" 'data_start' is 0x%s\n",
608 paddr_nz (new->lm_info->data_start));
609 printf (" 'bss_start' is 0x%s\n",
610 paddr_nz (new->lm_info->bss_start));
611 printf (" 'data_end' is 0x%s\n",
612 paddr_nz (new->lm_info->data_end));
613 printf (" 'got_value' is %s\n",
614 paddr_nz (new->lm_info->got_value));
615 printf (" 'tsd_start_addr' is 0x%s\n",
616 paddr_nz (new->lm_info->tsd_start_addr));
619 new->addr_low = lmi->text_addr;
620 new->addr_high = lmi->text_end;
622 /* Link the new object onto the list. */
625 link_ptr = &new->next;
633 discard_cleanups (old_chain);
637 /* TODO: The original somsolib code has logic to detect and eliminate
638 duplicate entries. Do we need that? */
644 som_open_symbol_file_object (void *from_ttyp)
646 CORE_ADDR lm, l_name;
649 int from_tty = *(int *)from_ttyp;
653 if (!query ("Attempt to reload symbols from process? "))
656 /* First link map member should be the executable. */
657 if ((lm = link_map_start ()) == 0)
658 return 0; /* failed somehow... */
660 /* Read address of name from target memory to GDB. */
661 read_memory (lm + offsetof (struct dld_list, name), buf, 4);
663 /* Convert the address to host format. Assume that the address is
665 l_name = extract_unsigned_integer (buf, 4);
668 return 0; /* No filename. */
670 /* Now fetch the filename from target memory. */
671 target_read_string (l_name, &filename, SO_NAME_MAX_PATH_SIZE - 1, &errcode);
675 warning (_("failed to read exec filename from attached file: %s"),
676 safe_strerror (errcode));
680 make_cleanup (xfree, filename);
681 /* Have a pathname: read the symbol file. */
682 symbol_file_add_main (filename, from_tty);
688 som_free_so (struct so_list *so)
694 som_solib_thread_start_addr (struct so_list *so)
696 return so->lm_info->tsd_start_addr;
699 /* Return the GOT value for the shared library in which ADDR belongs. If
700 ADDR isn't in any known shared library, return zero. */
703 som_solib_get_got_by_pc (CORE_ADDR addr)
705 struct so_list *so_list = master_so_list ();
706 CORE_ADDR got_value = 0;
710 if (so_list->lm_info->text_addr <= addr
711 && so_list->lm_info->text_end > addr)
713 got_value = so_list->lm_info->got_value;
716 so_list = so_list->next;
721 /* Return the address of the handle of the shared library in which ADDR belongs.
722 If ADDR isn't in any known shared library, return zero. */
723 /* this function is used in initialize_hp_cxx_exception_support in
727 som_solib_get_solib_by_pc (CORE_ADDR addr)
729 struct so_list *so_list = master_so_list ();
733 if (so_list->lm_info->text_addr <= addr
734 && so_list->lm_info->text_end > addr)
738 so_list = so_list->next;
741 return so_list->lm_info->lm_addr;
747 static struct target_so_ops som_so_ops;
749 extern initialize_file_ftype _initialize_som_solib; /* -Wmissing-prototypes */
752 _initialize_som_solib (void)
754 som_so_ops.relocate_section_addresses = som_relocate_section_addresses;
755 som_so_ops.free_so = som_free_so;
756 som_so_ops.clear_solib = som_clear_solib;
757 som_so_ops.solib_create_inferior_hook = som_solib_create_inferior_hook;
758 som_so_ops.special_symbol_handling = som_special_symbol_handling;
759 som_so_ops.current_sos = som_current_sos;
760 som_so_ops.open_symbol_file_object = som_open_symbol_file_object;
761 som_so_ops.in_dynsym_resolve_code = som_in_dynsym_resolve_code;
764 void som_solib_select (struct gdbarch_tdep *tdep)
766 current_target_so_ops = &som_so_ops;
768 tdep->solib_thread_start_addr = som_solib_thread_start_addr;
769 tdep->solib_get_got_by_pc = som_solib_get_got_by_pc;
770 tdep->solib_get_solib_by_pc = som_solib_get_solib_by_pc;
773 /* The rest of these functions are not part of the solib interface; they
774 are used by somread.c or hppa-hpux-tdep.c */
777 som_solib_section_offsets (struct objfile *objfile,
778 struct section_offsets *offsets)
780 struct so_list *so_list = master_so_list ();
784 /* Oh what a pain! We need the offsets before so_list->objfile
785 is valid. The BFDs will never match. Make a best guess. */
786 if (strstr (objfile->name, so_list->so_name))
788 asection *private_section;
790 /* The text offset is easy. */
791 offsets->offsets[SECT_OFF_TEXT (objfile)]
792 = (so_list->lm_info->text_addr
793 - so_list->lm_info->text_link_addr);
794 offsets->offsets[SECT_OFF_RODATA (objfile)]
795 = ANOFFSET (offsets, SECT_OFF_TEXT (objfile));
797 /* We should look at presumed_dp in the SOM header, but
798 that's not easily available. This should be OK though. */
799 private_section = bfd_get_section_by_name (objfile->obfd,
801 if (!private_section)
803 warning (_("Unable to find $PRIVATE$ in shared library!"));
804 offsets->offsets[SECT_OFF_DATA (objfile)] = 0;
805 offsets->offsets[SECT_OFF_BSS (objfile)] = 0;
808 offsets->offsets[SECT_OFF_DATA (objfile)]
809 = (so_list->lm_info->data_start - private_section->vma);
810 offsets->offsets[SECT_OFF_BSS (objfile)]
811 = ANOFFSET (offsets, SECT_OFF_DATA (objfile));
814 so_list = so_list->next;