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 * Access to static (file scoped) variables in shared libraries
43 * Most of this code should work for hp300 shared libraries. Does
44 anyone care enough to weed out any SOM-isms.
46 * Do we need/want a command to load a shared library?
48 * Support for hpux8 dynamic linker.
50 * Support for tracking user calls to dld_load, dld_unload. */
52 /* The basic structure which describes a dynamically loaded object. This
53 data structure is private to the dynamic linker and isn't found in
54 any HPUX include file. */
56 struct som_solib_mapped_entry
58 /* The name of the library. */
61 /* Version of this structure (it is expected to change again in hpux10). */
62 unsigned char struct_version
;
64 /* Binding mode for this library. */
65 unsigned char bind_mode
;
67 /* Version of this library. */
68 short library_version
;
70 /* Start of text address, link-time text location, end of text address. */
72 CORE_ADDR text_link_addr
;
75 /* Start of data, start of bss and end of data. */
80 /* Value of linkage pointer (%r19). */
84 struct som_solib_mapped_entry
*next
;
86 /* There are other fields, but I don't have information as to what is
90 /* A structure to keep track of all the known shared objects. */
93 struct som_solib_mapped_entry som_solib
;
94 struct objfile
*objfile
;
96 struct section_table
*sections
;
97 struct section_table
*sections_end
;
101 static struct so_list
*so_list_head
;
103 static void som_sharedlibrary_info_command
PARAMS ((char *, int));
105 /* Add symbols from shared libraries into the symtab list. */
108 som_solib_add (arg_string
, from_tty
, target
)
111 struct target_ops
*target
;
113 struct minimal_symbol
*msymbol
;
114 struct so_list
*so_list_tail
;
116 asection
*shlib_info
;
118 unsigned int dld_flags
;
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 Skip the first entry since it's our executable. */
221 status
= target_read_memory (addr
+ 36, buf
, 4);
225 addr
= extract_unsigned_integer (buf
, 4);
227 so_list_tail
= so_list_head
;
228 /* Find the end of the list of shared objects. */
229 while (so_list_tail
&& so_list_tail
->next
)
230 so_list_tail
= so_list_tail
->next
;
234 CORE_ADDR name_addr
, text_addr
;
235 unsigned int name_len
;
237 struct so_list
*new_so
;
238 struct section_table
*p
;
243 /* Get a pointer to the name of this library. */
244 status
= target_read_memory (addr
, buf
, 4);
248 name_addr
= extract_unsigned_integer (buf
, 4);
252 target_read_memory (name_addr
+ name_len
, buf
, 1);
260 name
= alloca (name_len
);
261 status
= target_read_memory (name_addr
, name
, name_len
);
265 name
= obsavestring (name
, name_len
- 1,
266 &symfile_objfile
->symbol_obstack
);
268 status
= target_read_memory (addr
+ 8, buf
, 4);
272 text_addr
= extract_unsigned_integer (buf
, 4);
275 new_so
= (struct so_list
*) malloc (sizeof (struct so_list
));
276 memset ((char *)new_so
, 0, sizeof (struct so_list
));
277 if (so_list_head
== NULL
)
279 so_list_head
= new_so
;
280 so_list_tail
= new_so
;
284 so_list_tail
->next
= new_so
;
285 so_list_tail
= new_so
;
288 /* Fill in all the entries in GDB's shared library list. */
289 new_so
->som_solib
.name
= name
;
290 status
= target_read_memory (addr
+ 4, buf
, 4);
294 new_so
->som_solib
.struct_version
= extract_unsigned_integer (buf
+ 3, 1);
295 new_so
->som_solib
.bind_mode
= extract_unsigned_integer (buf
+ 2, 1);
296 new_so
->som_solib
.library_version
= extract_unsigned_integer (buf
, 2);
297 new_so
->som_solib
.text_addr
= text_addr
;
299 status
= target_read_memory (addr
+ 12, buf
, 4);
303 new_so
->som_solib
.text_link_addr
= extract_unsigned_integer (buf
, 4);
305 status
= target_read_memory (addr
+ 16, buf
, 4);
309 new_so
->som_solib
.text_end
= extract_unsigned_integer (buf
, 4);
311 status
= target_read_memory (addr
+ 20, buf
, 4);
315 new_so
->som_solib
.data_start
= extract_unsigned_integer (buf
, 4);
317 status
= target_read_memory (addr
+ 24, buf
, 4);
321 new_so
->som_solib
.bss_start
= extract_unsigned_integer (buf
, 4);
323 status
= target_read_memory (addr
+ 28, buf
, 4);
327 new_so
->som_solib
.data_end
= extract_unsigned_integer (buf
, 4);
329 status
= target_read_memory (addr
+ 32, buf
, 4);
333 new_so
->som_solib
.got_value
= extract_unsigned_integer (buf
, 4);
335 status
= target_read_memory (addr
+ 36, buf
, 4);
339 new_so
->som_solib
.next
= (void *)extract_unsigned_integer (buf
, 4);
340 addr
= (CORE_ADDR
)new_so
->som_solib
.next
;
342 new_so
->objfile
= symbol_file_add (name
, from_tty
, text_addr
, 0, 0, 0);
343 new_so
->abfd
= new_so
->objfile
->obfd
;
345 if (!bfd_check_format (new_so
->abfd
, bfd_object
))
347 error ("\"%s\": not in executable format: %s.",
348 name
, bfd_errmsg (bfd_get_error ()));
351 /* Now we need to build a section table for this library since
352 we might be debugging a core file from a dynamically linked
353 executable in which the libraries were not privately mapped. */
354 if (build_section_table (new_so
->abfd
,
356 &new_so
->sections_end
))
358 error ("Unable to build section table for shared library\n.");
362 /* Relocate all the sections based on where they got loaded. */
363 for (p
= new_so
->sections
; p
< new_so
->sections_end
; p
++)
365 if (p
->the_bfd_section
->flags
& SEC_CODE
)
367 p
->addr
+= text_addr
- new_so
->som_solib
.text_link_addr
;
368 p
->endaddr
+= text_addr
- new_so
->som_solib
.text_link_addr
;
370 else if (p
->the_bfd_section
->flags
& SEC_DATA
)
372 p
->addr
+= new_so
->som_solib
.data_start
;
373 p
->endaddr
+= new_so
->som_solib
.data_start
;
377 /* Now see if we need to map in the text and data for this shared
378 library (for example debugging a core file which does not use
379 private shared libraries.).
381 Carefully peek at the first text address in the library. If the
382 read succeeds, then the libraries were privately mapped and were
383 included in the core dump file.
385 If the peek failed, then the libraries were not privately mapped
386 and are not in the core file, we'll have to read them in ourselves. */
387 status
= target_read_memory (text_addr
, buf
, 4);
392 new = new_so
->sections_end
- new_so
->sections
;
393 /* Add sections from the shared library to the core target. */
394 if (target
->to_sections
)
396 old
= target
->to_sections_end
- target
->to_sections
;
397 target
->to_sections
= (struct section_table
*)
398 xrealloc ((char *)target
->to_sections
,
399 ((sizeof (struct section_table
)) * (old
+ new)));
404 target
->to_sections
= (struct section_table
*)
405 xmalloc ((sizeof (struct section_table
)) * new);
407 target
->to_sections_end
= (target
->to_sections
+ old
+ new);
408 memcpy ((char *)(target
->to_sections
+ old
),
410 ((sizeof (struct section_table
)) * new));
414 /* Getting new symbols may change our opinion about what is
416 reinit_frame_cache ();
420 error ("Debugging dynamic executables loaded via the hpux8 dld.sl is not supported.\n");
424 error ("Error while reading dynamic library list.\n");
429 /* This hook gets called just before the first instruction in the
430 inferior process is executed.
432 This is our opportunity to set magic flags in the inferior so
433 that GDB can be notified when a shared library is mapped in and
434 to tell the dynamic linker that a private copy of the library is
435 needed (so GDB can set breakpoints in the library).
437 __dld_flags is the location of the magic flags; as of this implementation
438 there are 3 flags of interest:
440 bit 0 when set indicates that private copies of the libraries are needed
441 bit 1 when set indicates that the callback hook routine is valid
442 bit 2 when set indicates that the dynamic linker should maintain the
443 __dld_list structure when loading/unloading libraries.
445 Note that shared libraries are not mapped in at this time, so we have
446 run the inferior until the libraries are mapped in. Typically this
447 means running until the "_start" is called. */
450 som_solib_create_inferior_hook()
452 struct minimal_symbol
*msymbol
;
453 unsigned int dld_flags
, status
;
454 asection
*shlib_info
;
455 char shadow_contents
[BREAKPOINT_MAX
], buf
[4];
458 if (symfile_objfile
== NULL
)
461 /* First see if the objfile was dynamically linked. */
462 shlib_info
= bfd_get_section_by_name (symfile_objfile
->obfd
, "$SHLIB_INFO$");
466 /* It's got a $SHLIB_INFO$ section, make sure it's not empty. */
467 if (bfd_section_size (symfile_objfile
->obfd
, shlib_info
) == 0)
470 /* Get the address of __dld_flags, if no such symbol exists, then we can
471 not debug the shared code. */
472 msymbol
= lookup_minimal_symbol ("__dld_flags", NULL
, NULL
);
475 error ("Unable to find __dld_flags symbol in object file.\n");
479 anaddr
= SYMBOL_VALUE_ADDRESS (msymbol
);
480 /* Read the current contents. */
481 status
= target_read_memory (anaddr
, buf
, 4);
484 error ("Unable to read __dld_flags\n");
487 dld_flags
= extract_unsigned_integer (buf
, 4);
489 /* Turn on the flags we care about. */
491 store_unsigned_integer (buf
, 4, dld_flags
);
492 status
= target_write_memory (anaddr
, buf
, 4);
495 error ("Unable to write __dld_flags\n");
499 /* Now find the address of _start and set a breakpoint there. */
500 msymbol
= lookup_minimal_symbol ("_start", NULL
, symfile_objfile
);
503 error ("Unable to find _start symbol in object file.\n");
507 anaddr
= SYMBOL_VALUE_ADDRESS (msymbol
);
508 if (target_insert_breakpoint (anaddr
, shadow_contents
))
510 error ("Unable to set breakpoint at _start.\n");
514 /* Wipe out all knowledge of old shared libraries since their
515 mapping can change from one exec to another! */
518 struct so_list
*temp
;
520 free_objfile (so_list_head
->objfile
);
523 so_list_head
= temp
->next
;
526 /* Start the process again and wait for it to hit our breakpoint. */
527 clear_proceed_status ();
528 stop_soon_quietly
= 1;
529 stop_signal
= TARGET_SIGNAL_0
;
532 target_resume (-1, 0, stop_signal
);
533 wait_for_inferior ();
535 while (stop_signal
!= TARGET_SIGNAL_TRAP
);
536 stop_soon_quietly
= 0;
538 /* All the libraries should be mapped in now. Remove our breakpoint and
539 read in the symbol tables from the shared libraries. */
540 if (target_remove_breakpoint (anaddr
, shadow_contents
))
542 error ("Unable to remove breakpoint at _start.\n");
546 som_solib_add ((char *) 0, 0, (struct target_ops
*) 0);
549 /* Return the GOT value for the shared library in which ADDR belongs. If
550 ADDR isn't in any known shared library, return zero. */
553 som_solib_get_got_by_pc (addr
)
556 struct so_list
*so_list
= so_list_head
;
557 CORE_ADDR got_value
= 0;
561 if (so_list
->som_solib
.text_addr
<= addr
562 && so_list
->som_solib
.text_end
> addr
)
564 got_value
= so_list
->som_solib
.got_value
;
567 so_list
= so_list
->next
;
573 som_solib_section_offsets (objfile
, offsets
)
574 struct objfile
*objfile
;
575 struct section_offsets
*offsets
;
577 struct so_list
*so_list
= so_list_head
;
581 /* Oh what a pain! We need the offsets before so_list->objfile
582 is valid. The BFDs will never match. Make a best guess. */
583 if (strstr (objfile
->name
, so_list
->som_solib
.name
))
585 asection
*private_section
;
587 /* The text offset is easy. */
588 ANOFFSET (offsets
, SECT_OFF_TEXT
)
589 = (so_list
->som_solib
.text_addr
590 - so_list
->som_solib
.text_link_addr
);
591 ANOFFSET (offsets
, SECT_OFF_RODATA
)
592 = ANOFFSET (offsets
, SECT_OFF_TEXT
);
594 /* We should look at presumed_dp in the SOM header, but
595 that's not easily available. This should be OK though. */
596 private_section
= bfd_get_section_by_name (objfile
->obfd
,
598 if (!private_section
)
600 warning ("Unable to find $PRIVATE$ in shared library!");
601 ANOFFSET (offsets
, SECT_OFF_DATA
) = 0;
602 ANOFFSET (offsets
, SECT_OFF_BSS
) = 0;
605 ANOFFSET (offsets
, SECT_OFF_DATA
)
606 = (so_list
->som_solib
.data_start
- private_section
->vma
);
607 ANOFFSET (offsets
, SECT_OFF_BSS
)
608 = ANOFFSET (offsets
, SECT_OFF_DATA
);
611 so_list
= so_list
->next
;
616 /* Dump information about all the currently loaded shared libraries. */
619 som_sharedlibrary_info_command (ignore
, from_tty
)
623 struct so_list
*so_list
= so_list_head
;
625 if (exec_bfd
== NULL
)
627 printf_unfiltered ("no exec file.\n");
633 printf_unfiltered ("No shared libraries loaded at this time.\n");
637 printf_unfiltered ("Shared Object Libraries\n");
638 printf_unfiltered (" %-12s%-12s%-12s%-12s%-12s%-12s\n",
639 " flags", " tstart", " tend", " dstart", " dend", " dlt");
644 flags
= so_list
->som_solib
.struct_version
<< 24;
645 flags
|= so_list
->som_solib
.bind_mode
<< 16;
646 flags
|= so_list
->som_solib
.library_version
;
647 printf_unfiltered ("%s\n", so_list
->som_solib
.name
);
648 printf_unfiltered (" %-12s", local_hex_string_custom (flags
, "08l"));
649 printf_unfiltered ("%-12s",
650 local_hex_string_custom (so_list
->som_solib
.text_addr
, "08l"));
651 printf_unfiltered ("%-12s",
652 local_hex_string_custom (so_list
->som_solib
.text_end
, "08l"));
653 printf_unfiltered ("%-12s",
654 local_hex_string_custom (so_list
->som_solib
.data_start
, "08l"));
655 printf_unfiltered ("%-12s",
656 local_hex_string_custom (so_list
->som_solib
.data_end
, "08l"));
657 printf_unfiltered ("%-12s\n",
658 local_hex_string_custom (so_list
->som_solib
.got_value
, "08l"));
659 so_list
= so_list
->next
;
664 _initialize_som_solib ()
666 add_info ("sharedlibrary", som_sharedlibrary_info_command
,
667 "Status of loaded shared object libraries.");