1 /* Handle HP SOM shared libraries for GDB, the GNU Debugger.
2 Copyright 1993, 1996 Free Software Foundation, Inc.
4 This file is part of GDB.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
20 Written by the Center for Software Science at the Univerity of Utah
21 and by Cygnus Support. */
32 #include "breakpoint.h"
36 #include "gdb-stabs.h"
41 * Most of this code should work for hp300 shared libraries. Does
42 anyone care enough to weed out any SOM-isms.
44 * Support for hpux8 dynamic linker. */
46 /* The basic structure which describes a dynamically loaded object. This
47 data structure is private to the dynamic linker and isn't found in
48 any HPUX include file. */
50 struct som_solib_mapped_entry
52 /* The name of the library. */
55 /* Version of this structure (it is expected to change again in hpux10). */
56 unsigned char struct_version;
58 /* Binding mode for this library. */
59 unsigned char bind_mode;
61 /* Version of this library. */
62 short library_version;
64 /* Start of text address, link-time text location, end of text address. */
66 CORE_ADDR text_link_addr;
69 /* Start of data, start of bss and end of data. */
74 /* Value of linkage pointer (%r19). */
78 struct som_solib_mapped_entry *next;
80 /* There are other fields, but I don't have information as to what is
84 /* A structure to keep track of all the known shared objects. */
87 struct som_solib_mapped_entry som_solib;
88 struct objfile *objfile;
90 struct section_table *sections;
91 struct section_table *sections_end;
95 static struct so_list *so_list_head;
97 static void som_sharedlibrary_info_command PARAMS ((char *, int));
99 /* Add symbols from shared libraries into the symtab list. */
102 som_solib_add (arg_string, from_tty, target)
105 struct target_ops *target;
107 struct minimal_symbol *msymbol;
108 struct so_list *so_list_tail;
110 asection *shlib_info;
112 unsigned int dld_flags;
113 char buf[4], *re_err;
115 /* First validate our arguments. */
116 if ((re_err = re_comp (arg_string ? arg_string : ".")) != NULL)
118 error ("Invalid regexp: %s", re_err);
121 /* If we're debugging a core file, or have attached to a running
122 process, then som_solib_create_inferior_hook will not have been
125 We need to first determine if we're dealing with a dynamically
126 linked executable. If not, then return without an error or warning.
128 We also need to examine __dld_flags to determine if the shared library
129 list is valid and to determine if the libraries have been privately
131 if (symfile_objfile == NULL)
134 /* First see if the objfile was dynamically linked. */
135 shlib_info = bfd_get_section_by_name (symfile_objfile->obfd, "$SHLIB_INFO$");
139 /* It's got a $SHLIB_INFO$ section, make sure it's not empty. */
140 if (bfd_section_size (symfile_objfile->obfd, shlib_info) == 0)
143 msymbol = lookup_minimal_symbol ("__dld_flags", NULL, NULL);
146 error ("Unable to find __dld_flags symbol in object file.\n");
150 addr = SYMBOL_VALUE_ADDRESS (msymbol);
151 /* Read the current contents. */
152 status = target_read_memory (addr, buf, 4);
155 error ("Unable to read __dld_flags\n");
158 dld_flags = extract_unsigned_integer (buf, 4);
160 /* __dld_list may not be valid. If it's not valid tell the user. */
161 if ((dld_flags & 4) == 0)
163 error ("__dld_list is not valid according to __dld_flags.\n");
167 /* If the libraries were not mapped private, warn the user. */
168 if ((dld_flags & 1) == 0)
169 warning ("The shared libraries were not privately mapped; setting a\nbreakpoint in a shared library will not work until you rerun the program.\n");
171 msymbol = lookup_minimal_symbol ("__dld_list", NULL, NULL);
174 /* Older crt0.o files (hpux8) don't have __dld_list as a symbol,
175 but the data is still available if you know where to look. */
176 msymbol = lookup_minimal_symbol ("__dld_flags", NULL, NULL);
179 error ("Unable to find dynamic library list.\n");
182 addr = SYMBOL_VALUE_ADDRESS (msymbol) - 8;
185 addr = SYMBOL_VALUE_ADDRESS (msymbol);
187 status = target_read_memory (addr, buf, 4);
190 error ("Unable to find dynamic library list.\n");
194 addr = extract_unsigned_integer (buf, 4);
196 /* If addr is zero, then we're using an old dynamic loader which
197 doesn't maintain __dld_list. We'll have to use a completely
198 different approach to get shared library information. */
202 /* Using the information in __dld_list is the preferred method
203 to get at shared library information. It doesn't depend on
204 any functions in /usr/lib/end.o and has a chance of working
205 with hpux10 when it is released. */
206 status = target_read_memory (addr, buf, 4);
209 error ("Unable to find dynamic library list.\n");
213 /* addr now holds the address of the first entry in the dynamic
215 addr = extract_unsigned_integer (buf, 4);
217 /* Now that we have a pointer to the dynamic library list, walk
218 through it and add the symbols for each library. */
220 so_list_tail = so_list_head;
221 /* Find the end of the list of shared objects. */
222 while (so_list_tail && so_list_tail->next)
223 so_list_tail = so_list_tail->next;
227 CORE_ADDR name_addr, text_addr;
228 unsigned int name_len;
230 struct so_list *new_so;
231 struct so_list *so_list = so_list_head;
232 struct section_table *p;
238 /* Get a pointer to the name of this library. */
239 status = target_read_memory (addr, buf, 4);
243 name_addr = extract_unsigned_integer (buf, 4);
247 target_read_memory (name_addr + name_len, buf, 1);
255 name = alloca (name_len);
256 status = target_read_memory (name_addr, name, name_len);
260 /* See if we've already loaded something with this name. */
263 if (!strcmp (so_list->som_solib.name, name))
265 so_list = so_list->next;
268 /* See if the file exists. If not, give a warning, but don't
270 status = stat (name, &statbuf);
273 warning ("Can't find file %s referenced in dld_list.", name);
275 status = target_read_memory (addr + 36, buf, 4);
279 addr = (CORE_ADDR) extract_unsigned_integer (buf, 4);
283 /* If we've already loaded this one or it's the main program, skip it. */
284 if (so_list || !strcmp (name, symfile_objfile->name))
286 status = target_read_memory (addr + 36, buf, 4);
290 addr = (CORE_ADDR) extract_unsigned_integer (buf, 4);
294 name = obsavestring (name, name_len - 1,
295 &symfile_objfile->symbol_obstack);
297 status = target_read_memory (addr + 8, buf, 4);
301 text_addr = extract_unsigned_integer (buf, 4);
304 new_so = (struct so_list *) xmalloc (sizeof (struct so_list));
305 memset ((char *)new_so, 0, sizeof (struct so_list));
306 if (so_list_head == NULL)
308 so_list_head = new_so;
309 so_list_tail = new_so;
313 so_list_tail->next = new_so;
314 so_list_tail = new_so;
317 /* Fill in all the entries in GDB's shared library list. */
318 new_so->som_solib.name = name;
319 status = target_read_memory (addr + 4, buf, 4);
323 new_so->som_solib.struct_version = extract_unsigned_integer (buf + 3, 1);
324 new_so->som_solib.bind_mode = extract_unsigned_integer (buf + 2, 1);
325 new_so->som_solib.library_version = extract_unsigned_integer (buf, 2);
326 new_so->som_solib.text_addr = text_addr;
328 status = target_read_memory (addr + 12, buf, 4);
332 new_so->som_solib.text_link_addr = extract_unsigned_integer (buf, 4);
334 status = target_read_memory (addr + 16, buf, 4);
338 new_so->som_solib.text_end = extract_unsigned_integer (buf, 4);
340 status = target_read_memory (addr + 20, buf, 4);
344 new_so->som_solib.data_start = extract_unsigned_integer (buf, 4);
346 status = target_read_memory (addr + 24, buf, 4);
350 new_so->som_solib.bss_start = extract_unsigned_integer (buf, 4);
352 status = target_read_memory (addr + 28, buf, 4);
356 new_so->som_solib.data_end = extract_unsigned_integer (buf, 4);
358 status = target_read_memory (addr + 32, buf, 4);
362 new_so->som_solib.got_value = extract_unsigned_integer (buf, 4);
364 status = target_read_memory (addr + 36, buf, 4);
368 new_so->som_solib.next = (void *)extract_unsigned_integer (buf, 4);
369 addr = (CORE_ADDR)new_so->som_solib.next;
371 new_so->objfile = symbol_file_add (name, from_tty, text_addr, 0, 0, 0);
372 new_so->abfd = new_so->objfile->obfd;
374 if (!bfd_check_format (new_so->abfd, bfd_object))
376 error ("\"%s\": not in executable format: %s.",
377 name, bfd_errmsg (bfd_get_error ()));
380 /* Now we need to build a section table for this library since
381 we might be debugging a core file from a dynamically linked
382 executable in which the libraries were not privately mapped. */
383 if (build_section_table (new_so->abfd,
385 &new_so->sections_end))
387 error ("Unable to build section table for shared library\n.");
391 /* Relocate all the sections based on where they got loaded. */
392 for (p = new_so->sections; p < new_so->sections_end; p++)
394 if (p->the_bfd_section->flags & SEC_CODE)
396 p->addr += text_addr - new_so->som_solib.text_link_addr;
397 p->endaddr += text_addr - new_so->som_solib.text_link_addr;
399 else if (p->the_bfd_section->flags & SEC_DATA)
401 p->addr += new_so->som_solib.data_start;
402 p->endaddr += new_so->som_solib.data_start;
406 /* Now see if we need to map in the text and data for this shared
407 library (for example debugging a core file which does not use
408 private shared libraries.).
410 Carefully peek at the first text address in the library. If the
411 read succeeds, then the libraries were privately mapped and were
412 included in the core dump file.
414 If the peek failed, then the libraries were not privately mapped
415 and are not in the core file, we'll have to read them in ourselves. */
416 status = target_read_memory (text_addr, buf, 4);
422 /* We must update the to_sections field in the core_ops structure
423 here, otherwise we dereference a potential dangling pointer
424 for each call to target_read/write_memory within this routine. */
425 update_coreops = core_ops.to_sections == target->to_sections;
427 new = new_so->sections_end - new_so->sections;
428 /* Add sections from the shared library to the core target. */
429 if (target->to_sections)
431 old = target->to_sections_end - target->to_sections;
432 target->to_sections = (struct section_table *)
433 xrealloc ((char *)target->to_sections,
434 ((sizeof (struct section_table)) * (old + new)));
439 target->to_sections = (struct section_table *)
440 xmalloc ((sizeof (struct section_table)) * new);
442 target->to_sections_end = (target->to_sections + old + new);
444 /* Update the to_sections field in the core_ops structure
448 core_ops.to_sections = target->to_sections;
449 core_ops.to_sections_end = target->to_sections_end;
452 /* Copy over the old data before it gets clobbered. */
453 memcpy ((char *)(target->to_sections + old),
455 ((sizeof (struct section_table)) * new));
459 /* Getting new symbols may change our opinion about what is
461 reinit_frame_cache ();
465 error ("Debugging dynamic executables loaded via the hpux8 dld.sl is not supported.\n");
469 error ("Error while reading dynamic library list.\n");
474 /* This hook gets called just before the first instruction in the
475 inferior process is executed.
477 This is our opportunity to set magic flags in the inferior so
478 that GDB can be notified when a shared library is mapped in and
479 to tell the dynamic linker that a private copy of the library is
480 needed (so GDB can set breakpoints in the library).
482 __dld_flags is the location of the magic flags; as of this implementation
483 there are 3 flags of interest:
485 bit 0 when set indicates that private copies of the libraries are needed
486 bit 1 when set indicates that the callback hook routine is valid
487 bit 2 when set indicates that the dynamic linker should maintain the
488 __dld_list structure when loading/unloading libraries.
490 Note that shared libraries are not mapped in at this time, so we have
491 run the inferior until the libraries are mapped in. Typically this
492 means running until the "_start" is called. */
495 som_solib_create_inferior_hook()
497 struct minimal_symbol *msymbol;
498 unsigned int dld_flags, status, have_endo;
499 asection *shlib_info;
500 char shadow_contents[BREAKPOINT_MAX], buf[4];
501 struct objfile *objfile;
504 /* First, remove all the solib event breakpoints. Their addresses
505 may have changed since the last time we ran the program. */
506 remove_solib_event_breakpoints ();
508 if (symfile_objfile == NULL)
511 /* First see if the objfile was dynamically linked. */
512 shlib_info = bfd_get_section_by_name (symfile_objfile->obfd, "$SHLIB_INFO$");
516 /* It's got a $SHLIB_INFO$ section, make sure it's not empty. */
517 if (bfd_section_size (symfile_objfile->obfd, shlib_info) == 0)
521 /* Slam the pid of the process into __d_pid; failing is only a warning! */
522 msymbol = lookup_minimal_symbol ("__d_pid", NULL, symfile_objfile);
525 warning ("Unable to find __d_pid symbol in object file.");
526 warning ("Suggest linking with /usr/lib/end.o.");
527 warning ("GDB will be unable to track shl_load/shl_unload calls");
531 anaddr = SYMBOL_VALUE_ADDRESS (msymbol);
532 store_unsigned_integer (buf, 4, inferior_pid);
533 status = target_write_memory (anaddr, buf, 4);
536 warning ("Unable to write __d_pid");
537 warning ("Suggest linking with /usr/lib/end.o.");
538 warning ("GDB will be unable to track shl_load/shl_unload calls");
542 /* Get the value of _DLD_HOOK (an export stub) and put it in __dld_hook;
543 This will force the dynamic linker to call __d_trap when significant
545 msymbol = lookup_minimal_symbol ("_DLD_HOOK", NULL, symfile_objfile);
548 warning ("Unable to find _DLD_HOOK symbol in object file.");
549 warning ("Suggest linking with /usr/lib/end.o.");
550 warning ("GDB will be unable to track shl_load/shl_unload calls");
553 anaddr = SYMBOL_VALUE_ADDRESS (msymbol);
555 /* Grrr, this might not be an export symbol! We have to find the
557 ALL_OBJFILES (objfile)
559 struct unwind_table_entry *u;
560 extern struct unwind_table_entry *find_unwind_entry PARAMS ((CORE_ADDR pc));
563 msymbol = lookup_minimal_symbol_solib_trampoline (SYMBOL_NAME (msymbol),
565 /* Found a symbol with the right name. */
568 struct unwind_table_entry *u;
569 /* It must be a shared library trampoline. */
570 if (SYMBOL_TYPE (msymbol) != mst_solib_trampoline)
573 /* It must also be an export stub. */
574 u = find_unwind_entry (SYMBOL_VALUE (msymbol));
575 if (!u || u->stub_type != EXPORT)
578 /* OK. Looks like the correct import stub. */
579 anaddr = SYMBOL_VALUE (msymbol);
583 store_unsigned_integer (buf, 4, anaddr);
585 msymbol = lookup_minimal_symbol ("__dld_hook", NULL, symfile_objfile);
588 warning ("Unable to find __dld_hook symbol in object file.");
589 warning ("Suggest linking with /usr/lib/end.o.");
590 warning ("GDB will be unable to track shl_load/shl_unload calls");
593 anaddr = SYMBOL_VALUE_ADDRESS (msymbol);
594 status = target_write_memory (anaddr, buf, 4);
596 /* Now set a shlib_event breakpoint at __d_trap so we can track
597 significant shared library events. */
598 msymbol = lookup_minimal_symbol ("__d_trap", NULL, symfile_objfile);
601 warning ("Unable to find __dld_d_trap symbol in object file.");
602 warning ("Suggest linking with /usr/lib/end.o.");
603 warning ("GDB will be unable to track shl_load/shl_unload calls");
606 create_solib_event_breakpoint (SYMBOL_VALUE_ADDRESS (msymbol));
608 /* We have all the support usually found in end.o, so we can track
609 shl_load and shl_unload calls. */
614 /* Get the address of __dld_flags, if no such symbol exists, then we can
615 not debug the shared code. */
616 msymbol = lookup_minimal_symbol ("__dld_flags", NULL, NULL);
619 error ("Unable to find __dld_flags symbol in object file.\n");
624 anaddr = SYMBOL_VALUE_ADDRESS (msymbol);
625 /* Read the current contents. */
626 status = target_read_memory (anaddr, buf, 4);
629 error ("Unable to read __dld_flags\n");
632 dld_flags = extract_unsigned_integer (buf, 4);
634 /* Turn on the flags we care about. */
635 dld_flags |= (0x5 | (have_endo << 1));
636 store_unsigned_integer (buf, 4, dld_flags);
637 status = target_write_memory (anaddr, buf, 4);
640 error ("Unable to write __dld_flags\n");
644 /* Now find the address of _start and set a breakpoint there.
645 We still need this code for two reasons:
647 * Not all sites have /usr/lib/end.o, so it's not always
648 possible to track the dynamic linker's events.
650 * At this time no events are triggered for shared libraries
651 loaded at startup time (what a crock). */
653 msymbol = lookup_minimal_symbol ("_start", NULL, symfile_objfile);
656 error ("Unable to find _start symbol in object file.\n");
660 anaddr = SYMBOL_VALUE_ADDRESS (msymbol);
662 /* Make the breakpoint at "_start" a shared library event breakpoint. */
663 create_solib_event_breakpoint (anaddr);
665 /* Wipe out all knowledge of old shared libraries since their
666 mapping can change from one exec to another! */
669 struct so_list *temp;
671 free_objfile (so_list_head->objfile);
674 so_list_head = temp->next;
676 clear_symtab_users ();
679 /* Return the GOT value for the shared library in which ADDR belongs. If
680 ADDR isn't in any known shared library, return zero. */
683 som_solib_get_got_by_pc (addr)
686 struct so_list *so_list = so_list_head;
687 CORE_ADDR got_value = 0;
691 if (so_list->som_solib.text_addr <= addr
692 && so_list->som_solib.text_end > addr)
694 got_value = so_list->som_solib.got_value;
697 so_list = so_list->next;
703 som_solib_section_offsets (objfile, offsets)
704 struct objfile *objfile;
705 struct section_offsets *offsets;
707 struct so_list *so_list = so_list_head;
711 /* Oh what a pain! We need the offsets before so_list->objfile
712 is valid. The BFDs will never match. Make a best guess. */
713 if (strstr (objfile->name, so_list->som_solib.name))
715 asection *private_section;
717 /* The text offset is easy. */
718 ANOFFSET (offsets, SECT_OFF_TEXT)
719 = (so_list->som_solib.text_addr
720 - so_list->som_solib.text_link_addr);
721 ANOFFSET (offsets, SECT_OFF_RODATA)
722 = ANOFFSET (offsets, SECT_OFF_TEXT);
724 /* We should look at presumed_dp in the SOM header, but
725 that's not easily available. This should be OK though. */
726 private_section = bfd_get_section_by_name (objfile->obfd,
728 if (!private_section)
730 warning ("Unable to find $PRIVATE$ in shared library!");
731 ANOFFSET (offsets, SECT_OFF_DATA) = 0;
732 ANOFFSET (offsets, SECT_OFF_BSS) = 0;
735 ANOFFSET (offsets, SECT_OFF_DATA)
736 = (so_list->som_solib.data_start - private_section->vma);
737 ANOFFSET (offsets, SECT_OFF_BSS)
738 = ANOFFSET (offsets, SECT_OFF_DATA);
741 so_list = so_list->next;
746 /* Dump information about all the currently loaded shared libraries. */
749 som_sharedlibrary_info_command (ignore, from_tty)
753 struct so_list *so_list = so_list_head;
755 if (exec_bfd == NULL)
757 printf_unfiltered ("no exec file.\n");
763 printf_unfiltered ("No shared libraries loaded at this time.\n");
767 printf_unfiltered ("Shared Object Libraries\n");
768 printf_unfiltered (" %-12s%-12s%-12s%-12s%-12s%-12s\n",
769 " flags", " tstart", " tend", " dstart", " dend", " dlt");
774 flags = so_list->som_solib.struct_version << 24;
775 flags |= so_list->som_solib.bind_mode << 16;
776 flags |= so_list->som_solib.library_version;
777 printf_unfiltered ("%s\n", so_list->som_solib.name);
778 printf_unfiltered (" %-12s", local_hex_string_custom (flags, "08l"));
779 printf_unfiltered ("%-12s",
780 local_hex_string_custom (so_list->som_solib.text_addr, "08l"));
781 printf_unfiltered ("%-12s",
782 local_hex_string_custom (so_list->som_solib.text_end, "08l"));
783 printf_unfiltered ("%-12s",
784 local_hex_string_custom (so_list->som_solib.data_start, "08l"));
785 printf_unfiltered ("%-12s",
786 local_hex_string_custom (so_list->som_solib.data_end, "08l"));
787 printf_unfiltered ("%-12s\n",
788 local_hex_string_custom (so_list->som_solib.got_value, "08l"));
789 so_list = so_list->next;
794 som_solib_sharedlibrary_command (args, from_tty)
799 som_solib_add (args, from_tty, (struct target_ops *) 0);
803 _initialize_som_solib ()
805 add_com ("sharedlibrary", class_files, som_solib_sharedlibrary_command,
806 "Load shared object library symbols for files matching REGEXP.");
807 add_info ("sharedlibrary", som_sharedlibrary_info_command,
808 "Status of loaded shared object libraries.");
810 (add_set_cmd ("auto-solib-add", class_support, var_zinteger,
811 (char *) &auto_solib_add,
812 "Set autoloading of shared library symbols at startup.\n\
813 If nonzero, symbols from all shared object libraries will be loaded\n\
814 automatically when the inferior begins execution or when the dynamic linker\n\
815 informs gdb that a new library has been loaded. Otherwise, symbols\n\
816 must be loaded manually, using `sharedlibrary'.",