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"
39 * Relocate data addresses in the shared library.
41 * Most of this code should work for hp300 shared libraries. Does
42 anyone care enough to weed out any SOM-isms.
44 * Do we need/want a command to load a shared library?
46 * Support for hpux8 dynamic linker.
48 * Support for tracking user calls to dld_load, dld_unload. */
50 /* The basic structure which describes a dynamically loaded object. This
51 data structure is private to the dynamic linker and isn't found in
52 any HPUX include file. */
54 struct som_solib_mapped_entry
56 /* The name of the library. */
59 /* Version of this structure (it is expected to change again in hpux10). */
60 unsigned char struct_version
;
62 /* Binding mode for this library. */
63 unsigned char bind_mode
;
65 /* Version of this library. */
66 short library_version
;
68 /* Start of text address, link-time text location, end of text address. */
70 CORE_ADDR text_link_addr
;
73 /* Start of data, start of bss and end of data. */
78 /* Value of linkage pointer (%r19). */
82 struct som_solib_mapped_entry
*next
;
84 /* There are other fields, but I don't have information as to what is
88 /* A structure to keep track of all the known shared objects. */
91 struct som_solib_mapped_entry som_solib
;
92 struct objfile
*objfile
;
94 struct section_table
*sections
;
95 struct section_table
*sections_end
;
99 static struct so_list
*so_list_head
;
101 static void som_sharedlibrary_info_command
PARAMS ((char *, int));
103 /* Add symbols from shared libraries into the symtab list. */
106 som_solib_add (arg_string
, from_tty
, target
)
109 struct target_ops
*target
;
111 struct minimal_symbol
*msymbol
;
112 struct so_list
*so_list_tail
;
114 asection
*shlib_info
;
116 unsigned int dld_flags
;
119 /* If we're debugging a core file, or have attached to a running
120 process, then som_solib_create_inferior_hook will not have been
123 We need to first determine if we're dealing with a dynamically
124 linked executable. If not, then return without an error or warning.
126 We also need to examine __dld_flags to determine if the shared library
127 list is valid and to determine if the libraries have been privately
129 if (symfile_objfile
== NULL
)
132 /* First see if the objfile was dynamically linked. */
133 shlib_info
= bfd_get_section_by_name (symfile_objfile
->obfd
, "$SHLIB_INFO$");
137 /* It's got a $SHLIB_INFO$ section, make sure it's not empty. */
138 if (bfd_section_size (symfile_objfile
->obfd
, shlib_info
) == 0)
141 msymbol
= lookup_minimal_symbol ("__dld_flags", NULL
, NULL
);
144 error ("Unable to find __dld_flags symbol in object file.\n");
148 addr
= SYMBOL_VALUE_ADDRESS (msymbol
);
149 /* Read the current contents. */
150 status
= target_read_memory (addr
, buf
, 4);
153 error ("Unable to read __dld_flags\n");
156 dld_flags
= extract_unsigned_integer (buf
, 4);
158 /* __dld_list may not be valid. If it's not valid tell the user. */
159 if ((dld_flags
& 4) == 0)
161 error ("__dld_list is not valid according to __dld_flags.\n");
165 /* If the libraries were not mapped private, warn the user. */
166 if ((dld_flags
& 1) == 0)
167 warning ("The shared libraries were not privately mapped; setting a\nbreakpoint in a shared library will not work until you rerun the program.\n");
169 msymbol
= lookup_minimal_symbol ("__dld_list", NULL
, NULL
);
172 /* Older crt0.o files (hpux8) don't have __dld_list as a symbol,
173 but the data is still available if you know where to look. */
174 msymbol
= lookup_minimal_symbol ("__dld_flags", NULL
, NULL
);
177 error ("Unable to find dynamic library list.\n");
180 addr
= SYMBOL_VALUE_ADDRESS (msymbol
) - 8;
183 addr
= SYMBOL_VALUE_ADDRESS (msymbol
);
185 status
= target_read_memory (addr
, buf
, 4);
188 error ("Unable to find dynamic library list.\n");
192 addr
= extract_unsigned_integer (buf
, 4);
194 /* If addr is zero, then we're using an old dynamic loader which
195 doesn't maintain __dld_list. We'll have to use a completely
196 different approach to get shared library information. */
200 /* Using the information in __dld_list is the preferred method
201 to get at shared library information. It doesn't depend on
202 any functions in /usr/lib/end.o and has a chance of working
203 with hpux10 when it is released. */
204 status
= target_read_memory (addr
, buf
, 4);
207 error ("Unable to find dynamic library list.\n");
211 /* addr now holds the address of the first entry in the dynamic
213 addr
= extract_unsigned_integer (buf
, 4);
215 /* Now that we have a pointer to the dynamic library list, walk
216 through it and add the symbols for each library.
218 Skip the first entry since it's our executable. */
219 status
= target_read_memory (addr
+ 36, buf
, 4);
223 addr
= extract_unsigned_integer (buf
, 4);
225 so_list_tail
= so_list_head
;
226 /* Find the end of the list of shared objects. */
227 while (so_list_tail
&& so_list_tail
->next
)
228 so_list_tail
= so_list_tail
->next
;
232 CORE_ADDR name_addr
, text_addr
;
233 unsigned int name_len
;
235 struct so_list
*new_so
;
236 struct section_table
*p
;
241 /* Get a pointer to the name of this library. */
242 status
= target_read_memory (addr
, buf
, 4);
246 name_addr
= extract_unsigned_integer (buf
, 4);
250 target_read_memory (name_addr
+ name_len
, buf
, 1);
258 name
= alloca (name_len
);
259 status
= target_read_memory (name_addr
, name
, name_len
);
263 name
= obsavestring (name
, name_len
- 1,
264 &symfile_objfile
->symbol_obstack
);
266 status
= target_read_memory (addr
+ 8, buf
, 4);
270 text_addr
= extract_unsigned_integer (buf
, 4);
273 new_so
= (struct so_list
*) malloc (sizeof (struct so_list
));
274 memset ((char *)new_so
, 0, sizeof (struct so_list
));
275 if (so_list_head
== NULL
)
277 so_list_head
= new_so
;
278 so_list_tail
= new_so
;
282 so_list_tail
->next
= new_so
;
283 so_list_tail
= new_so
;
286 /* Fill in all the entries in GDB's shared library list. */
287 new_so
->som_solib
.name
= name
;
288 status
= target_read_memory (addr
+ 4, buf
, 4);
292 new_so
->som_solib
.struct_version
= extract_unsigned_integer (buf
+ 3, 1);
293 new_so
->som_solib
.bind_mode
= extract_unsigned_integer (buf
+ 2, 1);
294 new_so
->som_solib
.library_version
= extract_unsigned_integer (buf
, 2);
295 new_so
->som_solib
.text_addr
= text_addr
;
297 status
= target_read_memory (addr
+ 12, buf
, 4);
301 new_so
->som_solib
.text_link_addr
= extract_unsigned_integer (buf
, 4);
303 status
= target_read_memory (addr
+ 16, buf
, 4);
307 new_so
->som_solib
.text_end
= extract_unsigned_integer (buf
, 4);
309 status
= target_read_memory (addr
+ 20, buf
, 4);
313 new_so
->som_solib
.data_start
= extract_unsigned_integer (buf
, 4);
315 status
= target_read_memory (addr
+ 24, buf
, 4);
319 new_so
->som_solib
.bss_start
= extract_unsigned_integer (buf
, 4);
321 status
= target_read_memory (addr
+ 28, buf
, 4);
325 new_so
->som_solib
.data_end
= extract_unsigned_integer (buf
, 4);
327 status
= target_read_memory (addr
+ 32, buf
, 4);
331 new_so
->som_solib
.got_value
= extract_unsigned_integer (buf
, 4);
333 status
= target_read_memory (addr
+ 36, buf
, 4);
337 new_so
->som_solib
.next
= (void *)extract_unsigned_integer (buf
, 4);
338 addr
= (CORE_ADDR
)new_so
->som_solib
.next
;
340 new_so
->objfile
= symbol_file_add (name
, from_tty
, text_addr
, 0, 0, 0);
341 new_so
->abfd
= new_so
->objfile
->obfd
;
343 if (!bfd_check_format (new_so
->abfd
, bfd_object
))
345 error ("\"%s\": not in executable format: %s.",
346 name
, bfd_errmsg (bfd_get_error ()));
349 /* Now we need to build a section table for this library since
350 we might be debugging a core file from a dynamically linked
351 executable in which the libraries were not privately mapped. */
352 if (build_section_table (new_so
->abfd
,
354 &new_so
->sections_end
))
356 error ("Unable to build section table for shared library\n.");
360 /* Relocate all the sections based on where they got loaded. */
361 for (p
= new_so
->sections
; p
< new_so
->sections_end
; p
++)
363 if (p
->the_bfd_section
->flags
& SEC_CODE
)
365 p
->addr
+= text_addr
- new_so
->som_solib
.text_link_addr
;
366 p
->endaddr
+= text_addr
- new_so
->som_solib
.text_link_addr
;
368 else if (p
->the_bfd_section
->flags
& SEC_DATA
)
370 p
->addr
+= new_so
->som_solib
.data_start
;
371 p
->endaddr
+= new_so
->som_solib
.data_start
;
375 /* Now see if we need to map in the text and data for this shared
376 library (for example debugging a core file which does not use
377 private shared libraries.).
379 Carefully peek at the first text address in the library. If the
380 read succeeds, then the libraries were privately mapped and were
381 included in the core dump file.
383 If the peek failed, then the libraries were not privately mapped
384 and are not in the core file, we'll have to read them in ourselves. */
385 status
= target_read_memory (text_addr
, buf
, 4);
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
))
397 * (old
+ bfd_count_sections (new_so
->abfd
))));
402 target
->to_sections
= (struct section_table
*)
403 xmalloc ((sizeof (struct section_table
))
404 * bfd_count_sections (new_so
->abfd
));
406 target
->to_sections_end
= (target
->to_sections
407 + old
+ bfd_count_sections (new_so
->abfd
));
408 memcpy ((char *)(target
->to_sections
+ old
),
410 ((sizeof (struct section_table
))
411 * bfd_count_sections (new_so
->abfd
)));
415 /* Getting new symbols may change our opinion about what is
417 reinit_frame_cache ();
421 error ("Debugging dynamic executables loaded via the hpux8 dld.sl is not supported.\n");
425 error ("Error while reading dynamic library list.\n");
430 /* This hook gets called just before the first instruction in the
431 inferior process is executed.
433 This is our opportunity to set magic flags in the inferior so
434 that GDB can be notified when a shared library is mapped in and
435 to tell the dynamic linker that a private copy of the library is
436 needed (so GDB can set breakpoints in the library).
438 __dld_flags is the location of the magic flags; as of this implementation
439 there are 3 flags of interest:
441 bit 0 when set indicates that private copies of the libraries are needed
442 bit 1 when set indicates that the callback hook routine is valid
443 bit 2 when set indicates that the dynamic linker should maintain the
444 __dld_list structure when loading/unloading libraries.
446 Note that shared libraries are not mapped in at this time, so we have
447 run the inferior until the libraries are mapped in. Typically this
448 means running until the "_start" is called. */
451 som_solib_create_inferior_hook()
453 struct minimal_symbol
*msymbol
;
454 unsigned int dld_flags
, status
;
455 asection
*shlib_info
;
456 char shadow_contents
[BREAKPOINT_MAX
], buf
[4];
459 if (symfile_objfile
== NULL
)
462 /* First see if the objfile was dynamically linked. */
463 shlib_info
= bfd_get_section_by_name (symfile_objfile
->obfd
, "$SHLIB_INFO$");
467 /* It's got a $SHLIB_INFO$ section, make sure it's not empty. */
468 if (bfd_section_size (symfile_objfile
->obfd
, shlib_info
) == 0)
471 /* Get the address of __dld_flags, if no such symbol exists, then we can
472 not debug the shared code. */
473 msymbol
= lookup_minimal_symbol ("__dld_flags", NULL
, NULL
);
476 error ("Unable to find __dld_flags symbol in object file.\n");
480 anaddr
= SYMBOL_VALUE_ADDRESS (msymbol
);
481 /* Read the current contents. */
482 status
= target_read_memory (anaddr
, buf
, 4);
485 error ("Unable to read __dld_flags\n");
488 dld_flags
= extract_unsigned_integer (buf
, 4);
490 /* Turn on the flags we care about. */
492 store_unsigned_integer (buf
, 4, dld_flags
);
493 status
= target_write_memory (anaddr
, buf
, 4);
496 error ("Unable to write __dld_flags\n");
500 /* Now find the address of _start and set a breakpoint there. */
501 msymbol
= lookup_minimal_symbol ("_start", NULL
, symfile_objfile
);
504 error ("Unable to find _start symbol in object file.\n");
508 anaddr
= SYMBOL_VALUE_ADDRESS (msymbol
);
509 if (target_insert_breakpoint (anaddr
, shadow_contents
))
511 error ("Unable to set breakpoint at _start.\n");
515 /* Wipe out all knowledge of old shared libraries since their
516 mapping can change from one exec to another! */
519 struct so_list
*temp
;
521 free_objfile (so_list_head
->objfile
);
524 so_list_head
= temp
->next
;
527 /* Start the process again and wait for it to hit our breakpoint. */
528 clear_proceed_status ();
529 stop_soon_quietly
= 1;
530 stop_signal
= TARGET_SIGNAL_0
;
533 target_resume (-1, 0, stop_signal
);
534 wait_for_inferior ();
536 while (stop_signal
!= TARGET_SIGNAL_TRAP
);
537 stop_soon_quietly
= 0;
539 /* All the libraries should be mapped in now. Remove our breakpoint and
540 read in the symbol tables from the shared libraries. */
541 if (target_remove_breakpoint (anaddr
, shadow_contents
))
543 error ("Unable to remove breakpoint at _start.\n");
547 som_solib_add ((char *) 0, 0, (struct target_ops
*) 0);
550 /* Return the GOT value for the shared library in which ADDR belongs. If
551 ADDR isn't in any known shared library, return zero. */
554 som_solib_get_got_by_pc (addr
)
557 struct so_list
*so_list
= so_list_head
;
558 CORE_ADDR got_value
= 0;
562 if (so_list
->som_solib
.text_addr
<= addr
563 && so_list
->som_solib
.text_end
> addr
)
565 got_value
= so_list
->som_solib
.got_value
;
568 so_list
= so_list
->next
;
574 som_solib_section_offsets (objfile
, offsets
)
575 struct objfile
*objfile
;
576 struct section_offsets
*offsets
;
578 struct so_list
*so_list
= so_list_head
;
582 /* Oh what a pain! We need the offsets before so_list->objfile
583 is valid. The BFDs will never match. Make a best guess. */
584 if (!strcmp (so_list
->som_solib
.name
, objfile
->name
))
586 asection
*private_section
;
588 /* The text offset is easy. */
589 ANOFFSET (offsets
, 0) = so_list
->som_solib
.text_addr
;
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
, 1) = 0;
601 ANOFFSET (offsets
, 1) = (so_list
->som_solib
.data_start
602 - private_section
->vma
);
605 so_list
= so_list
->next
;
610 /* Dump information about all the currently loaded shared libraries. */
613 som_sharedlibrary_info_command (ignore
, from_tty
)
617 struct so_list
*so_list
= so_list_head
;
619 if (exec_bfd
== NULL
)
621 printf_unfiltered ("no exec file.\n");
627 printf_unfiltered ("No shared libraries loaded at this time.\n");
631 printf_unfiltered ("Shared Object Libraries\n");
632 printf_unfiltered (" %-12s%-12s%-12s%-12s%-12s%-12s\n",
633 " flags", " tstart", " tend", " dstart", " dend", " dlt");
638 flags
= so_list
->som_solib
.struct_version
<< 24;
639 flags
|= so_list
->som_solib
.bind_mode
<< 16;
640 flags
|= so_list
->som_solib
.library_version
;
641 printf_unfiltered ("%s\n", so_list
->som_solib
.name
);
642 printf_unfiltered (" %-12s", local_hex_string_custom (flags
, "08l"));
643 printf_unfiltered ("%-12s",
644 local_hex_string_custom (so_list
->som_solib
.text_addr
, "08l"));
645 printf_unfiltered ("%-12s",
646 local_hex_string_custom (so_list
->som_solib
.text_end
, "08l"));
647 printf_unfiltered ("%-12s",
648 local_hex_string_custom (so_list
->som_solib
.data_start
, "08l"));
649 printf_unfiltered ("%-12s",
650 local_hex_string_custom (so_list
->som_solib
.data_end
, "08l"));
651 printf_unfiltered ("%-12s\n",
652 local_hex_string_custom (so_list
->som_solib
.got_value
, "08l"));
653 so_list
= so_list
->next
;
658 _initialize_som_solib ()
660 add_info ("sharedlibrary", som_sharedlibrary_info_command
,
661 "Status of loaded shared object libraries.");