1 /* Handle HP SOM shared libraries for GDB, the GNU Debugger.
2 Copyright 1993 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., 675 Mass Ave, Cambridge, MA 02139, 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"
40 * Most of this code should work for hp300 shared libraries. Does
41 anyone care enough to weed out any SOM-isms.
43 * Do we need/want a command to load a shared library?
45 * Support for hpux8 dynamic linker.
47 * Support for tracking user calls to dld_load, dld_unload. */
49 /* The basic structure which describes a dynamically loaded object. This
50 data structure is private to the dynamic linker and isn't found in
51 any HPUX include file. */
53 struct som_solib_mapped_entry
55 /* The name of the library. */
58 /* Version of this structure (it is expected to change again in hpux10). */
59 unsigned char struct_version;
61 /* Binding mode for this library. */
62 unsigned char bind_mode;
64 /* Version of this library. */
65 short library_version;
67 /* Start of text address, link-time text location, end of text address. */
69 CORE_ADDR text_link_addr;
72 /* Start of data, start of bss and end of data. */
77 /* Value of linkage pointer (%r19). */
81 struct som_solib_mapped_entry *next;
83 /* There are other fields, but I don't have information as to what is
87 /* A structure to keep track of all the known shared objects. */
90 struct som_solib_mapped_entry som_solib;
91 struct objfile *objfile;
93 struct section_table *sections;
94 struct section_table *sections_end;
98 static struct so_list *so_list_head;
100 static void som_sharedlibrary_info_command PARAMS ((char *, int));
102 /* Add symbols from shared libraries into the symtab list. */
105 som_solib_add (arg_string, from_tty, target)
108 struct target_ops *target;
110 struct minimal_symbol *msymbol;
111 struct so_list *so_list_tail;
113 asection *shlib_info;
115 unsigned int dld_flags;
118 /* If we're debugging a core file, or have attached to a running
119 process, then som_solib_create_inferior_hook will not have been
122 We need to first determine if we're dealing with a dynamically
123 linked executable. If not, then return without an error or warning.
125 We also need to examine __dld_flags to determine if the shared library
126 list is valid and to determine if the libraries have been privately
128 if (symfile_objfile == NULL)
131 /* First see if the objfile was dynamically linked. */
132 shlib_info = bfd_get_section_by_name (symfile_objfile->obfd, "$SHLIB_INFO$");
136 /* It's got a $SHLIB_INFO$ section, make sure it's not empty. */
137 if (bfd_section_size (symfile_objfile->obfd, shlib_info) == 0)
140 msymbol = lookup_minimal_symbol ("__dld_flags", NULL, NULL);
143 error ("Unable to find __dld_flags symbol in object file.\n");
147 addr = SYMBOL_VALUE_ADDRESS (msymbol);
148 /* Read the current contents. */
149 status = target_read_memory (addr, buf, 4);
152 error ("Unable to read __dld_flags\n");
155 dld_flags = extract_unsigned_integer (buf, 4);
157 /* __dld_list may not be valid. If it's not valid tell the user. */
158 if ((dld_flags & 4) == 0)
160 error ("__dld_list is not valid according to __dld_flags.\n");
164 /* If the libraries were not mapped private, warn the user. */
165 if ((dld_flags & 1) == 0)
166 warning ("The shared libraries were not privately mapped; setting a\nbreakpoint in a shared library will not work until you rerun the program.\n");
168 msymbol = lookup_minimal_symbol ("__dld_list", NULL, NULL);
171 /* Older crt0.o files (hpux8) don't have __dld_list as a symbol,
172 but the data is still available if you know where to look. */
173 msymbol = lookup_minimal_symbol ("__dld_flags", NULL, NULL);
176 error ("Unable to find dynamic library list.\n");
179 addr = SYMBOL_VALUE_ADDRESS (msymbol) - 8;
182 addr = SYMBOL_VALUE_ADDRESS (msymbol);
184 status = target_read_memory (addr, buf, 4);
187 error ("Unable to find dynamic library list.\n");
191 addr = extract_unsigned_integer (buf, 4);
193 /* If addr is zero, then we're using an old dynamic loader which
194 doesn't maintain __dld_list. We'll have to use a completely
195 different approach to get shared library information. */
199 /* Using the information in __dld_list is the preferred method
200 to get at shared library information. It doesn't depend on
201 any functions in /usr/lib/end.o and has a chance of working
202 with hpux10 when it is released. */
203 status = target_read_memory (addr, buf, 4);
206 error ("Unable to find dynamic library list.\n");
210 /* addr now holds the address of the first entry in the dynamic
212 addr = extract_unsigned_integer (buf, 4);
214 /* Now that we have a pointer to the dynamic library list, walk
215 through it and add the symbols for each library.
217 Skip the first entry since it's our executable. */
218 status = target_read_memory (addr + 36, buf, 4);
222 addr = extract_unsigned_integer (buf, 4);
224 so_list_tail = so_list_head;
225 /* Find the end of the list of shared objects. */
226 while (so_list_tail && so_list_tail->next)
227 so_list_tail = so_list_tail->next;
231 CORE_ADDR name_addr, text_addr;
232 unsigned int name_len;
234 struct so_list *new_so;
235 struct section_table *p;
240 /* Get a pointer to the name of this library. */
241 status = target_read_memory (addr, buf, 4);
245 name_addr = extract_unsigned_integer (buf, 4);
249 target_read_memory (name_addr + name_len, buf, 1);
257 name = alloca (name_len);
258 status = target_read_memory (name_addr, name, name_len);
262 name = obsavestring (name, name_len - 1,
263 &symfile_objfile->symbol_obstack);
265 status = target_read_memory (addr + 8, buf, 4);
269 text_addr = extract_unsigned_integer (buf, 4);
272 new_so = (struct so_list *) malloc (sizeof (struct so_list));
273 memset ((char *)new_so, 0, sizeof (struct so_list));
274 if (so_list_head == NULL)
276 so_list_head = new_so;
277 so_list_tail = new_so;
281 so_list_tail->next = new_so;
282 so_list_tail = new_so;
285 /* Fill in all the entries in GDB's shared library list. */
286 new_so->som_solib.name = name;
287 status = target_read_memory (addr + 4, buf, 4);
291 new_so->som_solib.struct_version = extract_unsigned_integer (buf + 3, 1);
292 new_so->som_solib.bind_mode = extract_unsigned_integer (buf + 2, 1);
293 new_so->som_solib.library_version = extract_unsigned_integer (buf, 2);
294 new_so->som_solib.text_addr = text_addr;
296 status = target_read_memory (addr + 12, buf, 4);
300 new_so->som_solib.text_link_addr = extract_unsigned_integer (buf, 4);
302 status = target_read_memory (addr + 16, buf, 4);
306 new_so->som_solib.text_end = extract_unsigned_integer (buf, 4);
308 status = target_read_memory (addr + 20, buf, 4);
312 new_so->som_solib.data_start = extract_unsigned_integer (buf, 4);
314 status = target_read_memory (addr + 24, buf, 4);
318 new_so->som_solib.bss_start = extract_unsigned_integer (buf, 4);
320 status = target_read_memory (addr + 28, buf, 4);
324 new_so->som_solib.data_end = extract_unsigned_integer (buf, 4);
326 status = target_read_memory (addr + 32, buf, 4);
330 new_so->som_solib.got_value = extract_unsigned_integer (buf, 4);
332 status = target_read_memory (addr + 36, buf, 4);
336 new_so->som_solib.next = (void *)extract_unsigned_integer (buf, 4);
337 addr = (CORE_ADDR)new_so->som_solib.next;
339 new_so->objfile = symbol_file_add (name, from_tty, text_addr, 0, 0, 0);
340 new_so->abfd = new_so->objfile->obfd;
342 if (!bfd_check_format (new_so->abfd, bfd_object))
344 error ("\"%s\": not in executable format: %s.",
345 name, bfd_errmsg (bfd_get_error ()));
348 /* Now we need to build a section table for this library since
349 we might be debugging a core file from a dynamically linked
350 executable in which the libraries were not privately mapped. */
351 if (build_section_table (new_so->abfd,
353 &new_so->sections_end))
355 error ("Unable to build section table for shared library\n.");
359 /* Relocate all the sections based on where they got loaded. */
360 for (p = new_so->sections; p < new_so->sections_end; p++)
362 if (p->the_bfd_section->flags & SEC_CODE)
364 p->addr += text_addr - new_so->som_solib.text_link_addr;
365 p->endaddr += text_addr - new_so->som_solib.text_link_addr;
367 else if (p->the_bfd_section->flags & SEC_DATA)
369 p->addr += new_so->som_solib.data_start;
370 p->endaddr += new_so->som_solib.data_start;
374 /* Now see if we need to map in the text and data for this shared
375 library (for example debugging a core file which does not use
376 private shared libraries.).
378 Carefully peek at the first text address in the library. If the
379 read succeeds, then the libraries were privately mapped and were
380 included in the core dump file.
382 If the peek failed, then the libraries were not privately mapped
383 and are not in the core file, we'll have to read them in ourselves. */
384 status = target_read_memory (text_addr, buf, 4);
389 new = new_so->sections_end - new_so->sections;
390 /* Add sections from the shared library to the core target. */
391 if (target->to_sections)
393 old = target->to_sections_end - target->to_sections;
394 target->to_sections = (struct section_table *)
395 xrealloc ((char *)target->to_sections,
396 ((sizeof (struct section_table)) * (old + new)));
401 target->to_sections = (struct section_table *)
402 xmalloc ((sizeof (struct section_table)) * new);
404 target->to_sections_end = (target->to_sections + old + new);
405 memcpy ((char *)(target->to_sections + old),
407 ((sizeof (struct section_table)) * new));
411 /* Getting new symbols may change our opinion about what is
413 reinit_frame_cache ();
417 error ("Debugging dynamic executables loaded via the hpux8 dld.sl is not supported.\n");
421 error ("Error while reading dynamic library list.\n");
426 /* This hook gets called just before the first instruction in the
427 inferior process is executed.
429 This is our opportunity to set magic flags in the inferior so
430 that GDB can be notified when a shared library is mapped in and
431 to tell the dynamic linker that a private copy of the library is
432 needed (so GDB can set breakpoints in the library).
434 __dld_flags is the location of the magic flags; as of this implementation
435 there are 3 flags of interest:
437 bit 0 when set indicates that private copies of the libraries are needed
438 bit 1 when set indicates that the callback hook routine is valid
439 bit 2 when set indicates that the dynamic linker should maintain the
440 __dld_list structure when loading/unloading libraries.
442 Note that shared libraries are not mapped in at this time, so we have
443 run the inferior until the libraries are mapped in. Typically this
444 means running until the "_start" is called. */
447 som_solib_create_inferior_hook()
449 struct minimal_symbol *msymbol;
450 unsigned int dld_flags, status;
451 asection *shlib_info;
452 char shadow_contents[BREAKPOINT_MAX], buf[4];
455 if (symfile_objfile == NULL)
458 /* First see if the objfile was dynamically linked. */
459 shlib_info = bfd_get_section_by_name (symfile_objfile->obfd, "$SHLIB_INFO$");
463 /* It's got a $SHLIB_INFO$ section, make sure it's not empty. */
464 if (bfd_section_size (symfile_objfile->obfd, shlib_info) == 0)
467 /* Get the address of __dld_flags, if no such symbol exists, then we can
468 not debug the shared code. */
469 msymbol = lookup_minimal_symbol ("__dld_flags", NULL, NULL);
472 error ("Unable to find __dld_flags symbol in object file.\n");
476 anaddr = SYMBOL_VALUE_ADDRESS (msymbol);
477 /* Read the current contents. */
478 status = target_read_memory (anaddr, buf, 4);
481 error ("Unable to read __dld_flags\n");
484 dld_flags = extract_unsigned_integer (buf, 4);
486 /* Turn on the flags we care about. */
488 store_unsigned_integer (buf, 4, dld_flags);
489 status = target_write_memory (anaddr, buf, 4);
492 error ("Unable to write __dld_flags\n");
496 /* Now find the address of _start and set a breakpoint there. */
497 msymbol = lookup_minimal_symbol ("_start", NULL, symfile_objfile);
500 error ("Unable to find _start symbol in object file.\n");
504 anaddr = SYMBOL_VALUE_ADDRESS (msymbol);
505 if (target_insert_breakpoint (anaddr, shadow_contents))
507 error ("Unable to set breakpoint at _start.\n");
511 /* Wipe out all knowledge of old shared libraries since their
512 mapping can change from one exec to another! */
515 struct so_list *temp;
517 free_objfile (so_list_head->objfile);
520 so_list_head = temp->next;
523 /* Start the process again and wait for it to hit our breakpoint. */
524 clear_proceed_status ();
525 stop_soon_quietly = 1;
526 stop_signal = TARGET_SIGNAL_0;
529 target_resume (-1, 0, stop_signal);
530 wait_for_inferior ();
532 while (stop_signal != TARGET_SIGNAL_TRAP);
533 stop_soon_quietly = 0;
535 /* All the libraries should be mapped in now. Remove our breakpoint and
536 read in the symbol tables from the shared libraries. */
537 if (target_remove_breakpoint (anaddr, shadow_contents))
539 error ("Unable to remove breakpoint at _start.\n");
543 som_solib_add ((char *) 0, 0, (struct target_ops *) 0);
546 /* Return the GOT value for the shared library in which ADDR belongs. If
547 ADDR isn't in any known shared library, return zero. */
550 som_solib_get_got_by_pc (addr)
553 struct so_list *so_list = so_list_head;
554 CORE_ADDR got_value = 0;
558 if (so_list->som_solib.text_addr <= addr
559 && so_list->som_solib.text_end > addr)
561 got_value = so_list->som_solib.got_value;
564 so_list = so_list->next;
570 som_solib_section_offsets (objfile, offsets)
571 struct objfile *objfile;
572 struct section_offsets *offsets;
574 struct so_list *so_list = so_list_head;
578 /* Oh what a pain! We need the offsets before so_list->objfile
579 is valid. The BFDs will never match. Make a best guess. */
580 if (strstr (objfile->name, so_list->som_solib.name))
582 asection *private_section;
584 /* The text offset is easy. */
585 ANOFFSET (offsets, SECT_OFF_TEXT)
586 = (so_list->som_solib.text_addr
587 - so_list->som_solib.text_link_addr);
588 ANOFFSET (offsets, SECT_OFF_RODATA)
589 = ANOFFSET (offsets, SECT_OFF_TEXT);
591 /* We should look at presumed_dp in the SOM header, but
592 that's not easily available. This should be OK though. */
593 private_section = bfd_get_section_by_name (objfile->obfd,
595 if (!private_section)
597 warning ("Unable to find $PRIVATE$ in shared library!");
598 ANOFFSET (offsets, SECT_OFF_DATA) = 0;
599 ANOFFSET (offsets, SECT_OFF_BSS) = 0;
602 ANOFFSET (offsets, SECT_OFF_DATA)
603 = (so_list->som_solib.data_start - private_section->vma);
604 ANOFFSET (offsets, SECT_OFF_BSS)
605 = ANOFFSET (offsets, SECT_OFF_DATA);
608 so_list = so_list->next;
613 /* Dump information about all the currently loaded shared libraries. */
616 som_sharedlibrary_info_command (ignore, from_tty)
620 struct so_list *so_list = so_list_head;
622 if (exec_bfd == NULL)
624 printf_unfiltered ("no exec file.\n");
630 printf_unfiltered ("No shared libraries loaded at this time.\n");
634 printf_unfiltered ("Shared Object Libraries\n");
635 printf_unfiltered (" %-12s%-12s%-12s%-12s%-12s%-12s\n",
636 " flags", " tstart", " tend", " dstart", " dend", " dlt");
641 flags = so_list->som_solib.struct_version << 24;
642 flags |= so_list->som_solib.bind_mode << 16;
643 flags |= so_list->som_solib.library_version;
644 printf_unfiltered ("%s\n", so_list->som_solib.name);
645 printf_unfiltered (" %-12s", local_hex_string_custom (flags, "08l"));
646 printf_unfiltered ("%-12s",
647 local_hex_string_custom (so_list->som_solib.text_addr, "08l"));
648 printf_unfiltered ("%-12s",
649 local_hex_string_custom (so_list->som_solib.text_end, "08l"));
650 printf_unfiltered ("%-12s",
651 local_hex_string_custom (so_list->som_solib.data_start, "08l"));
652 printf_unfiltered ("%-12s",
653 local_hex_string_custom (so_list->som_solib.data_end, "08l"));
654 printf_unfiltered ("%-12s\n",
655 local_hex_string_custom (so_list->som_solib.got_value, "08l"));
656 so_list = so_list->next;
661 _initialize_som_solib ()
663 add_info ("sharedlibrary", som_sharedlibrary_info_command,
664 "Status of loaded shared object libraries.");