1 /* Handle SunOS and SVR4 shared libraries for GDB, the GNU Debugger.
2 Copyright 1990, 91, 92, 93, 94, 95, 96, 98, 1999
3 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., 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
25 /* This file is only compilable if link.h is available. */
29 #include <sys/types.h>
31 #include "gdb_string.h"
32 #include <sys/param.h>
35 #ifndef SVR4_SHARED_LIBS
36 /* SunOS shared libs need the nlist structure. */
39 #include "elf/external.h"
52 #include "gnu-regex.h"
58 #define MAX_PATH_SIZE 512 /* FIXME: Should be dynamic */
60 /* On SVR4 systems, a list of symbols in the dynamic linker where
61 GDB can try to place a breakpoint to monitor shared library
64 If none of these symbols are found, or other errors occur, then
65 SVR4 systems will fall back to using a symbol as the "startup
66 mapping complete" breakpoint address. */
68 #ifdef SVR4_SHARED_LIBS
69 static char *solib_break_names
[] =
79 #define BKPT_AT_SYMBOL 1
81 #if defined (BKPT_AT_SYMBOL) && defined (SVR4_SHARED_LIBS)
82 static char *bkpt_names
[] =
84 #ifdef SOLIB_BKPT_NAME
85 SOLIB_BKPT_NAME
, /* Prefer configured name if it exists. */
93 /* Symbols which are used to locate the base of the link map structures. */
95 #ifndef SVR4_SHARED_LIBS
96 static char *debug_base_symbols
[] =
104 static char *main_name_list
[] =
110 /* local data declarations */
112 /* Macro to extract an address from a solib structure.
113 When GDB is configured for some 32-bit targets (e.g. Solaris 2.7
114 sparc), BFD is configured to handle 64-bit targets, so CORE_ADDR is
115 64 bits. We have to extract only the significant bits of addresses
116 to get the right address when accessing the core file BFD. */
118 #define SOLIB_EXTRACT_ADDRESS(member) \
119 extract_address (&member, sizeof (member))
121 #ifndef SVR4_SHARED_LIBS
123 #define LM_ADDR(so) (SOLIB_EXTRACT_ADDRESS ((so) -> lm.lm_addr))
124 #define LM_NEXT(so) (SOLIB_EXTRACT_ADDRESS ((so) -> lm.lm_next))
125 #define LM_NAME(so) (SOLIB_EXTRACT_ADDRESS ((so) -> lm.lm_name))
126 /* Test for first link map entry; first entry is a shared library. */
127 #define IGNORE_FIRST_LINK_MAP_ENTRY(so) (0)
128 static struct link_dynamic dynamic_copy
;
129 static struct link_dynamic_2 ld_2_copy
;
130 static struct ld_debug debug_copy
;
131 static CORE_ADDR debug_addr
;
132 static CORE_ADDR flag_addr
;
134 #else /* SVR4_SHARED_LIBS */
136 #define LM_ADDR(so) (SOLIB_EXTRACT_ADDRESS ((so) -> lm.l_addr))
137 #define LM_NEXT(so) (SOLIB_EXTRACT_ADDRESS ((so) -> lm.l_next))
138 #define LM_NAME(so) (SOLIB_EXTRACT_ADDRESS ((so) -> lm.l_name))
139 /* Test for first link map entry; first entry is the exec-file. */
140 #define IGNORE_FIRST_LINK_MAP_ENTRY(so) \
141 (SOLIB_EXTRACT_ADDRESS ((so) -> lm.l_prev) == 0)
142 static struct r_debug debug_copy
;
143 char shadow_contents
[BREAKPOINT_MAX
]; /* Stash old bkpt addr contents */
145 #endif /* !SVR4_SHARED_LIBS */
149 /* The following fields of the structure come directly from the
150 dynamic linker's tables in the inferior, and are initialized by
153 struct so_list
*next
; /* next structure in linked list */
154 struct link_map lm
; /* copy of link map from inferior */
155 CORE_ADDR lmaddr
; /* addr in inferior lm was read from */
157 /* Shared object file name, exactly as it appears in the
158 inferior's link map. This may be a relative path, or something
159 which needs to be looked up in LD_LIBRARY_PATH, etc. We use it
160 to tell which entries in the inferior's dynamic linker's link
161 map we've already loaded. */
162 char so_original_name
[MAX_PATH_SIZE
];
164 /* shared object file name, expanded to something GDB can open */
165 char so_name
[MAX_PATH_SIZE
];
167 /* The following fields of the structure are built from
168 information gathered from the shared object file itself, and
169 are initialized when we actually add it to our symbol tables. */
172 CORE_ADDR lmend
; /* upper addr bound of mapped object */
173 char symbols_loaded
; /* flag: symbols read in yet? */
174 char from_tty
; /* flag: print msgs? */
175 struct objfile
*objfile
; /* objfile for loaded lib */
176 struct section_table
*sections
;
177 struct section_table
*sections_end
;
178 struct section_table
*textsection
;
181 static struct so_list
*so_list_head
; /* List of known shared objects */
182 static CORE_ADDR debug_base
; /* Base of dynamic linker structures */
183 static CORE_ADDR breakpoint_addr
; /* Address where end bkpt is set */
185 static int solib_cleanup_queued
= 0; /* make_run_cleanup called */
188 fdmatch
PARAMS ((int, int)); /* In libiberty */
190 /* Local function prototypes */
193 do_clear_solib
PARAMS ((PTR
));
196 match_main
PARAMS ((char *));
199 special_symbol_handling
PARAMS ((void));
202 sharedlibrary_command
PARAMS ((char *, int));
205 enable_break
PARAMS ((void));
208 info_sharedlibrary_command
PARAMS ((char *, int));
210 static int symbol_add_stub
PARAMS ((PTR
));
213 first_link_map_member
PARAMS ((void));
216 locate_base
PARAMS ((void));
218 static int solib_map_sections
PARAMS ((PTR
));
220 #ifdef SVR4_SHARED_LIBS
223 elf_locate_base
PARAMS ((void));
227 static struct so_list
*current_sos (void);
228 static void free_so (struct so_list
*node
);
231 disable_break
PARAMS ((void));
234 allocate_rt_common_objfile
PARAMS ((void));
237 solib_add_common_symbols (CORE_ADDR
);
241 void _initialize_solib
PARAMS ((void));
243 /* If non-zero, this is a prefix that will be added to the front of the name
244 shared libraries with an absolute filename for loading. */
245 static char *solib_absolute_prefix
= NULL
;
247 /* If non-empty, this is a search path for loading non-absolute shared library
248 symbol files. This takes precedence over the environment variables PATH
249 and LD_LIBRARY_PATH. */
250 static char *solib_search_path
= NULL
;
256 solib_map_sections -- open bfd and build sections for shared lib
260 static int solib_map_sections (struct so_list *so)
264 Given a pointer to one of the shared objects in our list
265 of mapped objects, use the recorded name to open a bfd
266 descriptor for the object, build a section table, and then
267 relocate all the section addresses by the base address at
268 which the shared object was mapped.
272 In most (all?) cases the shared object file name recorded in the
273 dynamic linkage tables will be a fully qualified pathname. For
274 cases where it isn't, do we really mimic the systems search
275 mechanism correctly in the below code (particularly the tilde
280 solib_map_sections (arg
)
283 struct so_list
*so
= (struct so_list
*) arg
; /* catch_errors bogon */
285 char *scratch_pathname
;
287 struct section_table
*p
;
288 struct cleanup
*old_chain
;
291 filename
= tilde_expand (so
->so_name
);
293 if (solib_absolute_prefix
&& ROOTED_P (filename
))
294 /* Prefix shared libraries with absolute filenames with
295 SOLIB_ABSOLUTE_PREFIX. */
300 pfx_len
= strlen (solib_absolute_prefix
);
302 /* Remove trailing slashes. */
303 while (pfx_len
> 0 && SLASH_P (solib_absolute_prefix
[pfx_len
- 1]))
306 pfxed_fn
= xmalloc (pfx_len
+ strlen (filename
) + 1);
307 strcpy (pfxed_fn
, solib_absolute_prefix
);
308 strcat (pfxed_fn
, filename
);
314 old_chain
= make_cleanup (free
, filename
);
318 if (solib_search_path
)
319 scratch_chan
= openp (solib_search_path
,
320 1, filename
, O_RDONLY
, 0, &scratch_pathname
);
321 if (scratch_chan
< 0)
322 scratch_chan
= openp (get_in_environ (inferior_environ
, "PATH"),
323 1, filename
, O_RDONLY
, 0, &scratch_pathname
);
324 if (scratch_chan
< 0)
326 scratch_chan
= openp (get_in_environ
327 (inferior_environ
, "LD_LIBRARY_PATH"),
328 1, filename
, O_RDONLY
, 0, &scratch_pathname
);
330 if (scratch_chan
< 0)
332 perror_with_name (filename
);
334 /* Leave scratch_pathname allocated. abfd->name will point to it. */
336 abfd
= bfd_fdopenr (scratch_pathname
, gnutarget
, scratch_chan
);
339 close (scratch_chan
);
340 error ("Could not open `%s' as an executable file: %s",
341 scratch_pathname
, bfd_errmsg (bfd_get_error ()));
343 /* Leave bfd open, core_xfer_memory and "info files" need it. */
345 abfd
->cacheable
= true;
347 /* copy full path name into so_name, so that later symbol_file_add can find
349 if (strlen (scratch_pathname
) >= MAX_PATH_SIZE
)
350 error ("Full path name length of shared library exceeds MAX_PATH_SIZE in so_list structure.");
351 strcpy (so
->so_name
, scratch_pathname
);
353 if (!bfd_check_format (abfd
, bfd_object
))
355 error ("\"%s\": not in executable format: %s.",
356 scratch_pathname
, bfd_errmsg (bfd_get_error ()));
358 if (build_section_table (abfd
, &so
->sections
, &so
->sections_end
))
360 error ("Can't find the file sections in `%s': %s",
361 bfd_get_filename (abfd
), bfd_errmsg (bfd_get_error ()));
364 for (p
= so
->sections
; p
< so
->sections_end
; p
++)
366 /* Relocate the section binding addresses as recorded in the shared
367 object's file by the base address to which the object was actually
369 p
->addr
+= LM_ADDR (so
);
370 p
->endaddr
+= LM_ADDR (so
);
371 so
->lmend
= max (p
->endaddr
, so
->lmend
);
372 if (STREQ (p
->the_bfd_section
->name
, ".text"))
378 /* Free the file names, close the file now. */
379 do_cleanups (old_chain
);
384 #ifndef SVR4_SHARED_LIBS
386 /* Allocate the runtime common object file. */
389 allocate_rt_common_objfile ()
391 struct objfile
*objfile
;
392 struct objfile
*last_one
;
394 objfile
= (struct objfile
*) xmalloc (sizeof (struct objfile
));
395 memset (objfile
, 0, sizeof (struct objfile
));
397 obstack_specify_allocation (&objfile
->psymbol_cache
.cache
, 0, 0,
399 obstack_specify_allocation (&objfile
->psymbol_obstack
, 0, 0, xmalloc
,
401 obstack_specify_allocation (&objfile
->symbol_obstack
, 0, 0, xmalloc
,
403 obstack_specify_allocation (&objfile
->type_obstack
, 0, 0, xmalloc
,
405 objfile
->name
= mstrsave (objfile
->md
, "rt_common");
407 /* Add this file onto the tail of the linked list of other such files. */
409 objfile
->next
= NULL
;
410 if (object_files
== NULL
)
411 object_files
= objfile
;
414 for (last_one
= object_files
;
416 last_one
= last_one
->next
);
417 last_one
->next
= objfile
;
420 rt_common_objfile
= objfile
;
423 /* Read all dynamically loaded common symbol definitions from the inferior
424 and put them into the minimal symbol table for the runtime common
428 solib_add_common_symbols (rtc_symp
)
431 struct rtc_symb inferior_rtc_symb
;
432 struct nlist inferior_rtc_nlist
;
436 /* Remove any runtime common symbols from previous runs. */
438 if (rt_common_objfile
!= NULL
&& rt_common_objfile
->minimal_symbol_count
)
440 obstack_free (&rt_common_objfile
->symbol_obstack
, 0);
441 obstack_specify_allocation (&rt_common_objfile
->symbol_obstack
, 0, 0,
443 rt_common_objfile
->minimal_symbol_count
= 0;
444 rt_common_objfile
->msymbols
= NULL
;
447 init_minimal_symbol_collection ();
448 make_cleanup ((make_cleanup_func
) discard_minimal_symbols
, 0);
452 read_memory (rtc_symp
,
453 (char *) &inferior_rtc_symb
,
454 sizeof (inferior_rtc_symb
));
455 read_memory (SOLIB_EXTRACT_ADDRESS (inferior_rtc_symb
.rtc_sp
),
456 (char *) &inferior_rtc_nlist
,
457 sizeof (inferior_rtc_nlist
));
458 if (inferior_rtc_nlist
.n_type
== N_COMM
)
460 /* FIXME: The length of the symbol name is not available, but in the
461 current implementation the common symbol is allocated immediately
462 behind the name of the symbol. */
463 len
= inferior_rtc_nlist
.n_value
- inferior_rtc_nlist
.n_un
.n_strx
;
465 name
= xmalloc (len
);
466 read_memory (SOLIB_EXTRACT_ADDRESS (inferior_rtc_nlist
.n_un
.n_name
),
469 /* Allocate the runtime common objfile if necessary. */
470 if (rt_common_objfile
== NULL
)
471 allocate_rt_common_objfile ();
473 prim_record_minimal_symbol (name
, inferior_rtc_nlist
.n_value
,
474 mst_bss
, rt_common_objfile
);
477 rtc_symp
= SOLIB_EXTRACT_ADDRESS (inferior_rtc_symb
.rtc_next
);
480 /* Install any minimal symbols that have been collected as the current
481 minimal symbols for the runtime common objfile. */
483 install_minimal_symbols (rt_common_objfile
);
486 #endif /* SVR4_SHARED_LIBS */
489 #ifdef SVR4_SHARED_LIBS
492 bfd_lookup_symbol
PARAMS ((bfd
*, char *));
498 bfd_lookup_symbol -- lookup the value for a specific symbol
502 CORE_ADDR bfd_lookup_symbol (bfd *abfd, char *symname)
506 An expensive way to lookup the value of a single symbol for
507 bfd's that are only temporary anyway. This is used by the
508 shared library support to find the address of the debugger
509 interface structures in the shared library.
511 Note that 0 is specifically allowed as an error return (no
516 bfd_lookup_symbol (abfd
, symname
)
520 unsigned int storage_needed
;
522 asymbol
**symbol_table
;
523 unsigned int number_of_symbols
;
525 struct cleanup
*back_to
;
526 CORE_ADDR symaddr
= 0;
528 storage_needed
= bfd_get_symtab_upper_bound (abfd
);
530 if (storage_needed
> 0)
532 symbol_table
= (asymbol
**) xmalloc (storage_needed
);
533 back_to
= make_cleanup (free
, (PTR
) symbol_table
);
534 number_of_symbols
= bfd_canonicalize_symtab (abfd
, symbol_table
);
536 for (i
= 0; i
< number_of_symbols
; i
++)
538 sym
= *symbol_table
++;
539 if (STREQ (sym
->name
, symname
))
541 /* Bfd symbols are section relative. */
542 symaddr
= sym
->value
+ sym
->section
->vma
;
546 do_cleanups (back_to
);
551 #ifdef HANDLE_SVR4_EXEC_EMULATORS
554 Solaris BCP (the part of Solaris which allows it to run SunOS4
555 a.out files) throws in another wrinkle. Solaris does not fill
556 in the usual a.out link map structures when running BCP programs,
557 the only way to get at them is via groping around in the dynamic
559 The dynamic linker and it's structures are located in the shared
560 C library, which gets run as the executable's "interpreter" by
563 Note that we can assume nothing about the process state at the time
564 we need to find these structures. We may be stopped on the first
565 instruction of the interpreter (C shared library), the first
566 instruction of the executable itself, or somewhere else entirely
567 (if we attached to the process for example).
570 static char *debug_base_symbols
[] =
572 "r_debug", /* Solaris 2.3 */
573 "_r_debug", /* Solaris 2.1, 2.2 */
578 look_for_base
PARAMS ((int, CORE_ADDR
));
584 look_for_base -- examine file for each mapped address segment
588 static int look_for_base (int fd, CORE_ADDR baseaddr)
592 This function is passed to proc_iterate_over_mappings, which
593 causes it to get called once for each mapped address space, with
594 an open file descriptor for the file mapped to that space, and the
595 base address of that mapped space.
597 Our job is to find the debug base symbol in the file that this
598 fd is open on, if it exists, and if so, initialize the dynamic
599 linker structure base address debug_base.
601 Note that this is a computationally expensive proposition, since
602 we basically have to open a bfd on every call, so we specifically
603 avoid opening the exec file.
607 look_for_base (fd
, baseaddr
)
612 CORE_ADDR address
= 0;
615 /* If the fd is -1, then there is no file that corresponds to this
616 mapped memory segment, so skip it. Also, if the fd corresponds
617 to the exec file, skip it as well. */
621 && fdmatch (fileno ((FILE *) (exec_bfd
->iostream
)), fd
)))
626 /* Try to open whatever random file this fd corresponds to. Note that
627 we have no way currently to find the filename. Don't gripe about
628 any problems we might have, just fail. */
630 if ((interp_bfd
= bfd_fdopenr ("unnamed", gnutarget
, fd
)) == NULL
)
634 if (!bfd_check_format (interp_bfd
, bfd_object
))
636 /* FIXME-leak: on failure, might not free all memory associated with
638 bfd_close (interp_bfd
);
642 /* Now try to find our debug base symbol in this file, which we at
643 least know to be a valid ELF executable or shared library. */
645 for (symbolp
= debug_base_symbols
; *symbolp
!= NULL
; symbolp
++)
647 address
= bfd_lookup_symbol (interp_bfd
, *symbolp
);
655 /* FIXME-leak: on failure, might not free all memory associated with
657 bfd_close (interp_bfd
);
661 /* Eureka! We found the symbol. But now we may need to relocate it
662 by the base address. If the symbol's value is less than the base
663 address of the shared library, then it hasn't yet been relocated
664 by the dynamic linker, and we have to do it ourself. FIXME: Note
665 that we make the assumption that the first segment that corresponds
666 to the shared library has the base address to which the library
669 if (address
< baseaddr
)
673 debug_base
= address
;
674 /* FIXME-leak: on failure, might not free all memory associated with
676 bfd_close (interp_bfd
);
679 #endif /* HANDLE_SVR4_EXEC_EMULATORS */
685 elf_locate_base -- locate the base address of dynamic linker structs
686 for SVR4 elf targets.
690 CORE_ADDR elf_locate_base (void)
694 For SVR4 elf targets the address of the dynamic linker's runtime
695 structure is contained within the dynamic info section in the
696 executable file. The dynamic section is also mapped into the
697 inferior address space. Because the runtime loader fills in the
698 real address before starting the inferior, we have to read in the
699 dynamic info section from the inferior address space.
700 If there are any errors while trying to find the address, we
701 silently return 0, otherwise the found address is returned.
708 sec_ptr dyninfo_sect
;
709 int dyninfo_sect_size
;
710 CORE_ADDR dyninfo_addr
;
714 /* Find the start address of the .dynamic section. */
715 dyninfo_sect
= bfd_get_section_by_name (exec_bfd
, ".dynamic");
716 if (dyninfo_sect
== NULL
)
718 dyninfo_addr
= bfd_section_vma (exec_bfd
, dyninfo_sect
);
720 /* Read in .dynamic section, silently ignore errors. */
721 dyninfo_sect_size
= bfd_section_size (exec_bfd
, dyninfo_sect
);
722 buf
= alloca (dyninfo_sect_size
);
723 if (target_read_memory (dyninfo_addr
, buf
, dyninfo_sect_size
))
726 /* Find the DT_DEBUG entry in the the .dynamic section.
727 For mips elf we look for DT_MIPS_RLD_MAP, mips elf apparently has
728 no DT_DEBUG entries. */
730 for (bufend
= buf
+ dyninfo_sect_size
;
732 buf
+= sizeof (Elf32_External_Dyn
))
734 Elf32_External_Dyn
*x_dynp
= (Elf32_External_Dyn
*) buf
;
738 dyn_tag
= bfd_h_get_32 (exec_bfd
, (bfd_byte
*) x_dynp
->d_tag
);
739 if (dyn_tag
== DT_NULL
)
741 else if (dyn_tag
== DT_DEBUG
)
743 dyn_ptr
= bfd_h_get_32 (exec_bfd
, (bfd_byte
*) x_dynp
->d_un
.d_ptr
);
746 #ifdef DT_MIPS_RLD_MAP
747 else if (dyn_tag
== DT_MIPS_RLD_MAP
)
749 char pbuf
[TARGET_PTR_BIT
/ HOST_CHAR_BIT
];
751 /* DT_MIPS_RLD_MAP contains a pointer to the address
752 of the dynamic link structure. */
753 dyn_ptr
= bfd_h_get_32 (exec_bfd
, (bfd_byte
*) x_dynp
->d_un
.d_ptr
);
754 if (target_read_memory (dyn_ptr
, pbuf
, sizeof (pbuf
)))
756 return extract_unsigned_integer (pbuf
, sizeof (pbuf
));
761 for (bufend
= buf
+ dyninfo_sect_size
;
763 buf
+= sizeof (Elf64_External_Dyn
))
765 Elf64_External_Dyn
*x_dynp
= (Elf64_External_Dyn
*) buf
;
769 dyn_tag
= bfd_h_get_64 (exec_bfd
, (bfd_byte
*) x_dynp
->d_tag
);
770 if (dyn_tag
== DT_NULL
)
772 else if (dyn_tag
== DT_DEBUG
)
774 dyn_ptr
= bfd_h_get_64 (exec_bfd
, (bfd_byte
*) x_dynp
->d_un
.d_ptr
);
780 /* DT_DEBUG entry not found. */
784 #endif /* SVR4_SHARED_LIBS */
790 locate_base -- locate the base address of dynamic linker structs
794 CORE_ADDR locate_base (void)
798 For both the SunOS and SVR4 shared library implementations, if the
799 inferior executable has been linked dynamically, there is a single
800 address somewhere in the inferior's data space which is the key to
801 locating all of the dynamic linker's runtime structures. This
802 address is the value of the debug base symbol. The job of this
803 function is to find and return that address, or to return 0 if there
804 is no such address (the executable is statically linked for example).
806 For SunOS, the job is almost trivial, since the dynamic linker and
807 all of it's structures are statically linked to the executable at
808 link time. Thus the symbol for the address we are looking for has
809 already been added to the minimal symbol table for the executable's
810 objfile at the time the symbol file's symbols were read, and all we
811 have to do is look it up there. Note that we explicitly do NOT want
812 to find the copies in the shared library.
814 The SVR4 version is a bit more complicated because the address
815 is contained somewhere in the dynamic info section. We have to go
816 to a lot more work to discover the address of the debug base symbol.
817 Because of this complexity, we cache the value we find and return that
818 value on subsequent invocations. Note there is no copy in the
819 executable symbol tables.
827 #ifndef SVR4_SHARED_LIBS
829 struct minimal_symbol
*msymbol
;
830 CORE_ADDR address
= 0;
833 /* For SunOS, we want to limit the search for the debug base symbol to the
834 executable being debugged, since there is a duplicate named symbol in the
835 shared library. We don't want the shared library versions. */
837 for (symbolp
= debug_base_symbols
; *symbolp
!= NULL
; symbolp
++)
839 msymbol
= lookup_minimal_symbol (*symbolp
, NULL
, symfile_objfile
);
840 if ((msymbol
!= NULL
) && (SYMBOL_VALUE_ADDRESS (msymbol
) != 0))
842 address
= SYMBOL_VALUE_ADDRESS (msymbol
);
848 #else /* SVR4_SHARED_LIBS */
850 /* Check to see if we have a currently valid address, and if so, avoid
851 doing all this work again and just return the cached address. If
852 we have no cached address, try to locate it in the dynamic info
853 section for ELF executables. */
858 && bfd_get_flavour (exec_bfd
) == bfd_target_elf_flavour
)
859 debug_base
= elf_locate_base ();
860 #ifdef HANDLE_SVR4_EXEC_EMULATORS
861 /* Try it the hard way for emulated executables. */
862 else if (inferior_pid
!= 0 && target_has_execution
)
863 proc_iterate_over_mappings (look_for_base
);
868 #endif /* !SVR4_SHARED_LIBS */
876 first_link_map_member -- locate first member in dynamic linker's map
880 static CORE_ADDR first_link_map_member (void)
884 Find the first element in the inferior's dynamic link map, and
885 return its address in the inferior. This function doesn't copy the
886 link map entry itself into our address space; current_sos actually
890 first_link_map_member ()
894 #ifndef SVR4_SHARED_LIBS
896 read_memory (debug_base
, (char *) &dynamic_copy
, sizeof (dynamic_copy
));
897 if (dynamic_copy
.ld_version
>= 2)
899 /* It is a version that we can deal with, so read in the secondary
900 structure and find the address of the link map list from it. */
901 read_memory (SOLIB_EXTRACT_ADDRESS (dynamic_copy
.ld_un
.ld_2
),
902 (char *) &ld_2_copy
, sizeof (struct link_dynamic_2
));
903 lm
= SOLIB_EXTRACT_ADDRESS (ld_2_copy
.ld_loaded
);
906 #else /* SVR4_SHARED_LIBS */
908 read_memory (debug_base
, (char *) &debug_copy
, sizeof (struct r_debug
));
909 /* FIXME: Perhaps we should validate the info somehow, perhaps by
910 checking r_version for a known version number, or r_state for
912 lm
= SOLIB_EXTRACT_ADDRESS (debug_copy
.r_map
);
914 #endif /* !SVR4_SHARED_LIBS */
919 #ifdef SVR4_SHARED_LIBS
924 open_symbol_file_object
928 void open_symbol_file_object (int from_tty)
932 If no open symbol file, attempt to locate and open the main symbol
933 file. On SVR4 systems, this is the first link map entry. If its
934 name is here, we can open it. Useful when attaching to a process
935 without first loading its symbol file.
940 open_symbol_file_object (from_ttyp
)
941 int *from_ttyp
; /* sneak past catch_errors */
944 struct link_map lmcopy
;
949 if (!query ("Attempt to reload symbols from process? "))
952 if ((debug_base
= locate_base ()) == 0)
953 return 0; /* failed somehow... */
955 /* First link map member should be the executable. */
956 if ((lm
= first_link_map_member ()) == 0)
957 return 0; /* failed somehow... */
959 /* Read from target memory to GDB. */
960 read_memory (lm
, (void *) &lmcopy
, sizeof (lmcopy
));
962 if (lmcopy
.l_name
== 0)
963 return 0; /* no filename. */
965 /* Now fetch the filename from target memory. */
966 target_read_string (SOLIB_EXTRACT_ADDRESS (lmcopy
.l_name
), &filename
,
967 MAX_PATH_SIZE
- 1, &errcode
);
970 warning ("failed to read exec filename from attached file: %s",
971 safe_strerror (errcode
));
975 make_cleanup ((make_cleanup_func
) free
, (void *) filename
);
976 /* Have a pathname: read the symbol file. */
977 symbol_file_command (filename
, *from_ttyp
);
981 #endif /* SVR4_SHARED_LIBS */
986 free_so --- free a `struct so_list' object
990 void free_so (struct so_list *so)
994 Free the storage associated with the `struct so_list' object SO.
995 If we have opened a BFD for SO, close it.
997 The caller is responsible for removing SO from whatever list it is
998 a member of. If we have placed SO's sections in some target's
999 section table, the caller is responsible for removing them.
1001 This function doesn't mess with objfiles at all. If there is an
1002 objfile associated with SO that needs to be removed, the caller is
1003 responsible for taking care of that. */
1006 free_so (struct so_list
*so
)
1008 char *bfd_filename
= 0;
1011 free (so
->sections
);
1015 bfd_filename
= bfd_get_filename (so
->abfd
);
1016 if (! bfd_close (so
->abfd
))
1017 warning ("cannot close \"%s\": %s",
1018 bfd_filename
, bfd_errmsg (bfd_get_error ()));
1022 free (bfd_filename
);
1028 /* On some systems, the only way to recognize the link map entry for
1029 the main executable file is by looking at its name. Return
1030 non-zero iff SONAME matches one of the known main executable names. */
1038 for (mainp
= main_name_list
; *mainp
!= NULL
; mainp
++)
1040 if (strcmp (soname
, *mainp
) == 0)
1050 current_sos -- build a list of currently loaded shared objects
1054 struct so_list *current_sos ()
1058 Build a list of `struct so_list' objects describing the shared
1059 objects currently loaded in the inferior. This list does not
1060 include an entry for the main executable file.
1062 Note that we only gather information directly available from the
1063 inferior --- we don't examine any of the shared library files
1064 themselves. The declaration of `struct so_list' says which fields
1065 we provide values for. */
1067 static struct so_list
*
1071 struct so_list
*head
= 0;
1072 struct so_list
**link_ptr
= &head
;
1074 /* Make sure we've looked up the inferior's dynamic linker's base
1078 debug_base
= locate_base ();
1080 /* If we can't find the dynamic linker's base structure, this
1081 must not be a dynamically linked executable. Hmm. */
1086 /* Walk the inferior's link map list, and build our list of
1087 `struct so_list' nodes. */
1088 lm
= first_link_map_member ();
1092 = (struct so_list
*) xmalloc (sizeof (struct so_list
));
1093 struct cleanup
*old_chain
= make_cleanup (free
, new);
1094 memset (new, 0, sizeof (*new));
1097 read_memory (lm
, (char *) &(new->lm
), sizeof (struct link_map
));
1101 /* For SVR4 versions, the first entry in the link map is for the
1102 inferior executable, so we must ignore it. For some versions of
1103 SVR4, it has no name. For others (Solaris 2.3 for example), it
1104 does have a name, so we can no longer use a missing name to
1105 decide when to ignore it. */
1106 if (IGNORE_FIRST_LINK_MAP_ENTRY (new))
1113 /* Extract this shared object's name. */
1114 target_read_string (LM_NAME (new), &buffer
,
1115 MAX_PATH_SIZE
- 1, &errcode
);
1118 warning ("current_sos: Can't read pathname for load map: %s\n",
1119 safe_strerror (errcode
));
1123 strncpy (new->so_name
, buffer
, MAX_PATH_SIZE
- 1);
1124 new->so_name
[MAX_PATH_SIZE
- 1] = '\0';
1126 strcpy (new->so_original_name
, new->so_name
);
1129 /* If this entry has no name, or its name matches the name
1130 for the main executable, don't include it in the list. */
1131 if (! new->so_name
[0]
1132 || match_main (new->so_name
))
1138 link_ptr
= &new->next
;
1142 discard_cleanups (old_chain
);
1149 /* A small stub to get us past the arg-passing pinhole of catch_errors. */
1152 symbol_add_stub (arg
)
1155 register struct so_list
*so
= (struct so_list
*) arg
; /* catch_errs bogon */
1156 CORE_ADDR text_addr
= 0;
1157 struct section_addr_info
*sap
;
1159 /* Have we already loaded this shared object? */
1160 ALL_OBJFILES (so
->objfile
)
1162 if (strcmp (so
->objfile
->name
, so
->so_name
) == 0)
1166 /* Find the shared object's text segment. */
1167 if (so
->textsection
)
1168 text_addr
= so
->textsection
->addr
;
1169 else if (so
->abfd
!= NULL
)
1171 asection
*lowest_sect
;
1173 /* If we didn't find a mapped non zero sized .text section, set up
1174 text_addr so that the relocation in symbol_file_add does no harm. */
1175 lowest_sect
= bfd_get_section_by_name (so
->abfd
, ".text");
1176 if (lowest_sect
== NULL
)
1177 bfd_map_over_sections (so
->abfd
, find_lowest_section
,
1178 (PTR
) &lowest_sect
);
1180 text_addr
= bfd_section_vma (so
->abfd
, lowest_sect
)
1184 sap
= build_section_addr_info_from_section_table (so
->sections
,
1186 sap
->text_addr
= text_addr
;
1187 so
->objfile
= symbol_file_add (so
->so_name
, so
->from_tty
,
1188 sap
, 0, OBJF_SHARED
);
1189 free_section_addr_info (sap
);
1197 solib_add -- synchronize GDB's shared object list with the inferior's
1201 void solib_add (char *pattern, int from_tty, struct target_ops *TARGET)
1205 Extract the list of currently loaded shared objects from the
1206 inferior, and compare it with the list of shared objects for which
1207 GDB has currently loaded symbolic information. If new shared
1208 objects have been loaded, or old shared objects have disappeared,
1209 make the appropriate changes to GDB's tables.
1211 If PATTERN is non-null, read symbols only for shared objects
1212 whose names match PATTERN.
1214 If FROM_TTY is non-null, feel free to print messages about what
1217 If TARGET is non-null, add the sections of all new shared objects
1218 to TARGET's section table. Note that this doesn't remove any
1219 sections for shared objects that have been unloaded, and it
1220 doesn't check to see if the new shared objects are already present in
1221 the section table. But we only use this for core files and
1222 processes we've just attached to, so that's okay. */
1225 solib_add (char *pattern
, int from_tty
, struct target_ops
*target
)
1227 struct so_list
*inferior
= current_sos ();
1228 struct so_list
*gdb
, **gdb_link
;
1230 #ifdef SVR4_SHARED_LIBS
1231 /* If we are attaching to a running process for which we
1232 have not opened a symbol file, we may be able to get its
1235 symfile_objfile
== NULL
)
1236 catch_errors (open_symbol_file_object
, (PTR
) &from_tty
,
1237 "Error reading attached process's symbol file.\n",
1240 #endif SVR4_SHARED_LIBS
1244 char *re_err
= re_comp (pattern
);
1247 error ("Invalid regexp: %s", re_err
);
1250 /* Since this function might actually add some elements to the
1251 so_list_head list, arrange for it to be cleaned up when
1253 if (!solib_cleanup_queued
)
1255 make_run_cleanup (do_clear_solib
, NULL
);
1256 solib_cleanup_queued
= 1;
1259 /* GDB and the inferior's dynamic linker each maintain their own
1260 list of currently loaded shared objects; we want to bring the
1261 former in sync with the latter. Scan both lists, seeing which
1262 shared objects appear where. There are three cases:
1264 - A shared object appears on both lists. This means that GDB
1265 knows about it already, and it's still loaded in the inferior.
1266 Nothing needs to happen.
1268 - A shared object appears only on GDB's list. This means that
1269 the inferior has unloaded it. We should remove the shared
1270 object from GDB's tables.
1272 - A shared object appears only on the inferior's list. This
1273 means that it's just been loaded. We should add it to GDB's
1276 So we walk GDB's list, checking each entry to see if it appears
1277 in the inferior's list too. If it does, no action is needed, and
1278 we remove it from the inferior's list. If it doesn't, the
1279 inferior has unloaded it, and we remove it from GDB's list. By
1280 the time we're done walking GDB's list, the inferior's list
1281 contains only the new shared objects, which we then add. */
1284 gdb_link
= &so_list_head
;
1287 struct so_list
*i
= inferior
;
1288 struct so_list
**i_link
= &inferior
;
1290 /* Check to see whether the shared object *gdb also appears in
1291 the inferior's current list. */
1294 if (! strcmp (gdb
->so_original_name
, i
->so_original_name
))
1301 /* If the shared object appears on the inferior's list too, then
1302 it's still loaded, so we don't need to do anything. Delete
1303 it from the inferior's list, and leave it on GDB's list. */
1308 gdb_link
= &gdb
->next
;
1312 /* If it's not on the inferior's list, remove it from GDB's tables. */
1315 *gdb_link
= gdb
->next
;
1317 /* Unless the user loaded it explicitly, free SO's objfile. */
1318 if (gdb
->objfile
&& ! (gdb
->objfile
->flags
& OBJF_USERLOADED
))
1319 free_objfile (gdb
->objfile
);
1321 /* Some targets' section tables might be referring to
1322 sections from so->abfd; remove them. */
1323 remove_target_sections (gdb
->abfd
);
1330 /* Now the inferior's list contains only shared objects that don't
1331 appear in GDB's list --- those that are newly loaded. Add them
1332 to GDB's shared object list. */
1337 /* Add the new shared objects to GDB's list. */
1338 *gdb_link
= inferior
;
1340 /* Fill in the rest of each of the `struct so_list' nodes. */
1341 for (i
= inferior
; i
; i
= i
->next
)
1343 i
->from_tty
= from_tty
;
1345 /* Fill in the rest of the `struct so_list' node. */
1346 catch_errors (solib_map_sections
, i
,
1347 "Error while mapping shared library sections:\n",
1351 /* If requested, add the shared objects' sections to the the
1352 TARGET's section table. */
1357 /* Figure out how many sections we'll need to add in total. */
1359 for (i
= inferior
; i
; i
= i
->next
)
1360 new_sections
+= (i
->sections_end
- i
->sections
);
1362 if (new_sections
> 0)
1364 int space
= target_resize_to_sections (target
, new_sections
);
1366 for (i
= inferior
; i
; i
= i
->next
)
1368 int count
= (i
->sections_end
- i
->sections
);
1369 memcpy (target
->to_sections
+ space
,
1371 count
* sizeof (i
->sections
[0]));
1378 /* Finally, read the symbols as requested. Walk the list of
1379 currently loaded shared libraries, and read symbols for any that
1380 match the pattern --- or any whose symbols aren't already loaded,
1381 if no pattern was given. */
1383 int any_matches
= 0;
1384 int loaded_any_symbols
= 0;
1386 for (gdb
= so_list_head
; gdb
; gdb
= gdb
->next
)
1387 if (! pattern
|| re_exec (gdb
->so_name
))
1391 if (gdb
->symbols_loaded
)
1394 printf_unfiltered ("Symbols already loaded for %s\n",
1400 (symbol_add_stub
, gdb
,
1401 "Error while reading shared library symbols:\n",
1405 printf_unfiltered ("Loaded symbols for %s\n",
1407 gdb
->symbols_loaded
= 1;
1408 loaded_any_symbols
= 1;
1413 if (from_tty
&& pattern
&& ! any_matches
)
1415 ("No loaded shared libraries match the pattern `%s'.\n", pattern
);
1417 if (loaded_any_symbols
)
1419 /* Getting new symbols may change our opinion about what is
1421 reinit_frame_cache ();
1423 special_symbol_handling ();
1433 info_sharedlibrary_command -- code for "info sharedlibrary"
1437 static void info_sharedlibrary_command ()
1441 Walk through the shared library list and print information
1442 about each attached library.
1446 info_sharedlibrary_command (ignore
, from_tty
)
1450 register struct so_list
*so
= NULL
; /* link map state variable */
1451 int header_done
= 0;
1455 if (exec_bfd
== NULL
)
1457 printf_unfiltered ("No executable file.\n");
1461 #ifndef TARGET_ELF64
1465 addr_width
= 16 + 4;
1469 solib_add (0, 0, 0);
1471 for (so
= so_list_head
; so
; so
= so
->next
)
1477 printf_unfiltered ("%-*s%-*s%-12s%s\n", addr_width
, "From",
1478 addr_width
, "To", "Syms Read",
1479 "Shared Object Library");
1483 printf_unfiltered ("%-*s", addr_width
,
1484 local_hex_string_custom ((unsigned long) LM_ADDR (so
),
1486 printf_unfiltered ("%-*s", addr_width
,
1487 local_hex_string_custom ((unsigned long) so
->lmend
,
1489 printf_unfiltered ("%-12s", so
->symbols_loaded
? "Yes" : "No");
1490 printf_unfiltered ("%s\n", so
->so_name
);
1493 if (so_list_head
== NULL
)
1495 printf_unfiltered ("No shared libraries loaded at this time.\n");
1503 solib_address -- check to see if an address is in a shared lib
1507 char * solib_address (CORE_ADDR address)
1511 Provides a hook for other gdb routines to discover whether or
1512 not a particular address is within the mapped address space of
1513 a shared library. Any address between the base mapping address
1514 and the first address beyond the end of the last mapping, is
1515 considered to be within the shared library address space, for
1518 For example, this routine is called at one point to disable
1519 breakpoints which are in shared libraries that are not currently
1524 solib_address (address
)
1527 register struct so_list
*so
= 0; /* link map state variable */
1529 for (so
= so_list_head
; so
; so
= so
->next
)
1531 if (LM_ADDR (so
) <= address
&& address
< so
->lmend
)
1532 return (so
->so_name
);
1538 /* Called by free_all_symtabs */
1543 /* This function is expected to handle ELF shared libraries. It is
1544 also used on Solaris, which can run either ELF or a.out binaries
1545 (for compatibility with SunOS 4), both of which can use shared
1546 libraries. So we don't know whether we have an ELF executable or
1547 an a.out executable until the user chooses an executable file.
1549 ELF shared libraries don't get mapped into the address space
1550 until after the program starts, so we'd better not try to insert
1551 breakpoints in them immediately. We have to wait until the
1552 dynamic linker has loaded them; we'll hit a bp_shlib_event
1553 breakpoint (look for calls to create_solib_event_breakpoint) when
1556 SunOS shared libraries seem to be different --- they're present
1557 as soon as the process begins execution, so there's no need to
1558 put off inserting breakpoints. There's also nowhere to put a
1559 bp_shlib_event breakpoint, so if we put it off, we'll never get
1562 So: disable breakpoints only if we're using ELF shared libs. */
1563 if (exec_bfd
!= NULL
1564 && bfd_get_flavour (exec_bfd
) != bfd_target_aout_flavour
)
1565 disable_breakpoints_in_shlibs (1);
1567 while (so_list_head
)
1569 struct so_list
*so
= so_list_head
;
1570 so_list_head
= so
->next
;
1578 do_clear_solib (dummy
)
1581 solib_cleanup_queued
= 0;
1585 #ifdef SVR4_SHARED_LIBS
1587 /* Return 1 if PC lies in the dynamic symbol resolution code of the
1588 SVR4 run time loader. */
1590 static CORE_ADDR interp_text_sect_low
;
1591 static CORE_ADDR interp_text_sect_high
;
1592 static CORE_ADDR interp_plt_sect_low
;
1593 static CORE_ADDR interp_plt_sect_high
;
1596 in_svr4_dynsym_resolve_code (pc
)
1599 return ((pc
>= interp_text_sect_low
&& pc
< interp_text_sect_high
)
1600 || (pc
>= interp_plt_sect_low
&& pc
< interp_plt_sect_high
)
1601 || in_plt_section (pc
, NULL
));
1609 disable_break -- remove the "mapping changed" breakpoint
1613 static int disable_break ()
1617 Removes the breakpoint that gets hit when the dynamic linker
1618 completes a mapping change.
1622 #ifndef SVR4_SHARED_LIBS
1629 #ifndef SVR4_SHARED_LIBS
1631 int in_debugger
= 0;
1633 /* Read the debugger structure from the inferior to retrieve the
1634 address of the breakpoint and the original contents of the
1635 breakpoint address. Remove the breakpoint by writing the original
1638 read_memory (debug_addr
, (char *) &debug_copy
, sizeof (debug_copy
));
1640 /* Set `in_debugger' to zero now. */
1642 write_memory (flag_addr
, (char *) &in_debugger
, sizeof (in_debugger
));
1644 breakpoint_addr
= SOLIB_EXTRACT_ADDRESS (debug_copy
.ldd_bp_addr
);
1645 write_memory (breakpoint_addr
, (char *) &debug_copy
.ldd_bp_inst
,
1646 sizeof (debug_copy
.ldd_bp_inst
));
1648 #else /* SVR4_SHARED_LIBS */
1650 /* Note that breakpoint address and original contents are in our address
1651 space, so we just need to write the original contents back. */
1653 if (memory_remove_breakpoint (breakpoint_addr
, shadow_contents
) != 0)
1658 #endif /* !SVR4_SHARED_LIBS */
1660 /* For the SVR4 version, we always know the breakpoint address. For the
1661 SunOS version we don't know it until the above code is executed.
1662 Grumble if we are stopped anywhere besides the breakpoint address. */
1664 if (stop_pc
!= breakpoint_addr
)
1666 warning ("stopped at unknown breakpoint while handling shared libraries");
1672 #endif /* #ifdef SVR4_SHARED_LIBS */
1678 enable_break -- arrange for dynamic linker to hit breakpoint
1682 int enable_break (void)
1686 Both the SunOS and the SVR4 dynamic linkers have, as part of their
1687 debugger interface, support for arranging for the inferior to hit
1688 a breakpoint after mapping in the shared libraries. This function
1689 enables that breakpoint.
1691 For SunOS, there is a special flag location (in_debugger) which we
1692 set to 1. When the dynamic linker sees this flag set, it will set
1693 a breakpoint at a location known only to itself, after saving the
1694 original contents of that place and the breakpoint address itself,
1695 in it's own internal structures. When we resume the inferior, it
1696 will eventually take a SIGTRAP when it runs into the breakpoint.
1697 We handle this (in a different place) by restoring the contents of
1698 the breakpointed location (which is only known after it stops),
1699 chasing around to locate the shared libraries that have been
1700 loaded, then resuming.
1702 For SVR4, the debugger interface structure contains a member (r_brk)
1703 which is statically initialized at the time the shared library is
1704 built, to the offset of a function (_r_debug_state) which is guaran-
1705 teed to be called once before mapping in a library, and again when
1706 the mapping is complete. At the time we are examining this member,
1707 it contains only the unrelocated offset of the function, so we have
1708 to do our own relocation. Later, when the dynamic linker actually
1709 runs, it relocates r_brk to be the actual address of _r_debug_state().
1711 The debugger interface structure also contains an enumeration which
1712 is set to either RT_ADD or RT_DELETE prior to changing the mapping,
1713 depending upon whether or not the library is being mapped or unmapped,
1714 and then set to RT_CONSISTENT after the library is mapped/unmapped.
1722 #ifndef SVR4_SHARED_LIBS
1727 /* Get link_dynamic structure */
1729 j
= target_read_memory (debug_base
, (char *) &dynamic_copy
,
1730 sizeof (dynamic_copy
));
1737 /* Calc address of debugger interface structure */
1739 debug_addr
= SOLIB_EXTRACT_ADDRESS (dynamic_copy
.ldd
);
1741 /* Calc address of `in_debugger' member of debugger interface structure */
1743 flag_addr
= debug_addr
+ (CORE_ADDR
) ((char *) &debug_copy
.ldd_in_debugger
-
1744 (char *) &debug_copy
);
1746 /* Write a value of 1 to this member. */
1749 write_memory (flag_addr
, (char *) &in_debugger
, sizeof (in_debugger
));
1752 #else /* SVR4_SHARED_LIBS */
1754 #ifdef BKPT_AT_SYMBOL
1756 struct minimal_symbol
*msymbol
;
1758 asection
*interp_sect
;
1760 /* First, remove all the solib event breakpoints. Their addresses
1761 may have changed since the last time we ran the program. */
1762 remove_solib_event_breakpoints ();
1764 #ifdef SVR4_SHARED_LIBS
1765 interp_text_sect_low
= interp_text_sect_high
= 0;
1766 interp_plt_sect_low
= interp_plt_sect_high
= 0;
1768 /* Find the .interp section; if not found, warn the user and drop
1769 into the old breakpoint at symbol code. */
1770 interp_sect
= bfd_get_section_by_name (exec_bfd
, ".interp");
1773 unsigned int interp_sect_size
;
1775 CORE_ADDR load_addr
;
1777 CORE_ADDR sym_addr
= 0;
1779 /* Read the contents of the .interp section into a local buffer;
1780 the contents specify the dynamic linker this program uses. */
1781 interp_sect_size
= bfd_section_size (exec_bfd
, interp_sect
);
1782 buf
= alloca (interp_sect_size
);
1783 bfd_get_section_contents (exec_bfd
, interp_sect
,
1784 buf
, 0, interp_sect_size
);
1786 /* Now we need to figure out where the dynamic linker was
1787 loaded so that we can load its symbols and place a breakpoint
1788 in the dynamic linker itself.
1790 This address is stored on the stack. However, I've been unable
1791 to find any magic formula to find it for Solaris (appears to
1792 be trivial on GNU/Linux). Therefore, we have to try an alternate
1793 mechanism to find the dynamic linker's base address. */
1794 tmp_bfd
= bfd_openr (buf
, gnutarget
);
1795 if (tmp_bfd
== NULL
)
1796 goto bkpt_at_symbol
;
1798 /* Make sure the dynamic linker's really a useful object. */
1799 if (!bfd_check_format (tmp_bfd
, bfd_object
))
1801 warning ("Unable to grok dynamic linker %s as an object file", buf
);
1802 bfd_close (tmp_bfd
);
1803 goto bkpt_at_symbol
;
1806 /* We find the dynamic linker's base address by examining the
1807 current pc (which point at the entry point for the dynamic
1808 linker) and subtracting the offset of the entry point. */
1809 load_addr
= read_pc () - tmp_bfd
->start_address
;
1811 /* Record the relocated start and end address of the dynamic linker
1812 text and plt section for in_svr4_dynsym_resolve_code. */
1813 interp_sect
= bfd_get_section_by_name (tmp_bfd
, ".text");
1816 interp_text_sect_low
=
1817 bfd_section_vma (tmp_bfd
, interp_sect
) + load_addr
;
1818 interp_text_sect_high
=
1819 interp_text_sect_low
+ bfd_section_size (tmp_bfd
, interp_sect
);
1821 interp_sect
= bfd_get_section_by_name (tmp_bfd
, ".plt");
1824 interp_plt_sect_low
=
1825 bfd_section_vma (tmp_bfd
, interp_sect
) + load_addr
;
1826 interp_plt_sect_high
=
1827 interp_plt_sect_low
+ bfd_section_size (tmp_bfd
, interp_sect
);
1830 /* Now try to set a breakpoint in the dynamic linker. */
1831 for (bkpt_namep
= solib_break_names
; *bkpt_namep
!= NULL
; bkpt_namep
++)
1833 sym_addr
= bfd_lookup_symbol (tmp_bfd
, *bkpt_namep
);
1838 /* We're done with the temporary bfd. */
1839 bfd_close (tmp_bfd
);
1843 create_solib_event_breakpoint (load_addr
+ sym_addr
);
1847 /* For whatever reason we couldn't set a breakpoint in the dynamic
1848 linker. Warn and drop into the old code. */
1850 warning ("Unable to find dynamic linker breakpoint function.\nGDB will be unable to debug shared library initializers\nand track explicitly loaded dynamic code.");
1854 /* Scan through the list of symbols, trying to look up the symbol and
1855 set a breakpoint there. Terminate loop when we/if we succeed. */
1857 breakpoint_addr
= 0;
1858 for (bkpt_namep
= bkpt_names
; *bkpt_namep
!= NULL
; bkpt_namep
++)
1860 msymbol
= lookup_minimal_symbol (*bkpt_namep
, NULL
, symfile_objfile
);
1861 if ((msymbol
!= NULL
) && (SYMBOL_VALUE_ADDRESS (msymbol
) != 0))
1863 create_solib_event_breakpoint (SYMBOL_VALUE_ADDRESS (msymbol
));
1868 /* Nothing good happened. */
1871 #endif /* BKPT_AT_SYMBOL */
1873 #endif /* !SVR4_SHARED_LIBS */
1882 solib_create_inferior_hook -- shared library startup support
1886 void solib_create_inferior_hook()
1890 When gdb starts up the inferior, it nurses it along (through the
1891 shell) until it is ready to execute it's first instruction. At this
1892 point, this function gets called via expansion of the macro
1893 SOLIB_CREATE_INFERIOR_HOOK.
1895 For SunOS executables, this first instruction is typically the
1896 one at "_start", or a similar text label, regardless of whether
1897 the executable is statically or dynamically linked. The runtime
1898 startup code takes care of dynamically linking in any shared
1899 libraries, once gdb allows the inferior to continue.
1901 For SVR4 executables, this first instruction is either the first
1902 instruction in the dynamic linker (for dynamically linked
1903 executables) or the instruction at "start" for statically linked
1904 executables. For dynamically linked executables, the system
1905 first exec's /lib/libc.so.N, which contains the dynamic linker,
1906 and starts it running. The dynamic linker maps in any needed
1907 shared libraries, maps in the actual user executable, and then
1908 jumps to "start" in the user executable.
1910 For both SunOS shared libraries, and SVR4 shared libraries, we
1911 can arrange to cooperate with the dynamic linker to discover the
1912 names of shared libraries that are dynamically linked, and the
1913 base addresses to which they are linked.
1915 This function is responsible for discovering those names and
1916 addresses, and saving sufficient information about them to allow
1917 their symbols to be read at a later time.
1921 Between enable_break() and disable_break(), this code does not
1922 properly handle hitting breakpoints which the user might have
1923 set in the startup code or in the dynamic linker itself. Proper
1924 handling will probably have to wait until the implementation is
1925 changed to use the "breakpoint handler function" method.
1927 Also, what if child has exit()ed? Must exit loop somehow.
1931 solib_create_inferior_hook ()
1933 /* If we are using the BKPT_AT_SYMBOL code, then we don't need the base
1934 yet. In fact, in the case of a SunOS4 executable being run on
1935 Solaris, we can't get it yet. current_sos will get it when it needs
1937 #if !(defined (SVR4_SHARED_LIBS) && defined (BKPT_AT_SYMBOL))
1938 if ((debug_base
= locate_base ()) == 0)
1940 /* Can't find the symbol or the executable is statically linked. */
1945 if (!enable_break ())
1947 warning ("shared library handler failed to enable breakpoint");
1951 #if !defined(SVR4_SHARED_LIBS) || defined(_SCO_DS)
1952 /* SCO and SunOS need the loop below, other systems should be using the
1953 special shared library breakpoints and the shared library breakpoint
1956 Now run the target. It will eventually hit the breakpoint, at
1957 which point all of the libraries will have been mapped in and we
1958 can go groveling around in the dynamic linker structures to find
1959 out what we need to know about them. */
1961 clear_proceed_status ();
1962 stop_soon_quietly
= 1;
1963 stop_signal
= TARGET_SIGNAL_0
;
1966 target_resume (-1, 0, stop_signal
);
1967 wait_for_inferior ();
1969 while (stop_signal
!= TARGET_SIGNAL_TRAP
);
1970 stop_soon_quietly
= 0;
1972 #if !defined(_SCO_DS)
1973 /* We are now either at the "mapping complete" breakpoint (or somewhere
1974 else, a condition we aren't prepared to deal with anyway), so adjust
1975 the PC as necessary after a breakpoint, disable the breakpoint, and
1976 add any shared libraries that were mapped in. */
1978 if (DECR_PC_AFTER_BREAK
)
1980 stop_pc
-= DECR_PC_AFTER_BREAK
;
1981 write_register (PC_REGNUM
, stop_pc
);
1984 if (!disable_break ())
1986 warning ("shared library handler failed to disable breakpoint");
1990 solib_add ((char *) 0, 0, (struct target_ops
*) 0);
1991 #endif /* ! _SCO_DS */
1999 special_symbol_handling -- additional shared library symbol handling
2003 void special_symbol_handling ()
2007 Once the symbols from a shared object have been loaded in the usual
2008 way, we are called to do any system specific symbol handling that
2011 For SunOS4, this consists of grunging around in the dynamic
2012 linkers structures to find symbol definitions for "common" symbols
2013 and adding them to the minimal symbol table for the runtime common
2019 special_symbol_handling ()
2021 #ifndef SVR4_SHARED_LIBS
2024 if (debug_addr
== 0)
2026 /* Get link_dynamic structure */
2028 j
= target_read_memory (debug_base
, (char *) &dynamic_copy
,
2029 sizeof (dynamic_copy
));
2036 /* Calc address of debugger interface structure */
2037 /* FIXME, this needs work for cross-debugging of core files
2038 (byteorder, size, alignment, etc). */
2040 debug_addr
= SOLIB_EXTRACT_ADDRESS (dynamic_copy
.ldd
);
2043 /* Read the debugger structure from the inferior, just to make sure
2044 we have a current copy. */
2046 j
= target_read_memory (debug_addr
, (char *) &debug_copy
,
2047 sizeof (debug_copy
));
2049 return; /* unreadable */
2051 /* Get common symbol definitions for the loaded object. */
2053 if (debug_copy
.ldd_cp
)
2055 solib_add_common_symbols (SOLIB_EXTRACT_ADDRESS (debug_copy
.ldd_cp
));
2058 #endif /* !SVR4_SHARED_LIBS */
2066 sharedlibrary_command -- handle command to explicitly add library
2070 static void sharedlibrary_command (char *args, int from_tty)
2077 sharedlibrary_command (args
, from_tty
)
2082 solib_add (args
, from_tty
, (struct target_ops
*) 0);
2085 #endif /* HAVE_LINK_H */
2088 _initialize_solib ()
2092 add_com ("sharedlibrary", class_files
, sharedlibrary_command
,
2093 "Load shared object library symbols for files matching REGEXP.");
2094 add_info ("sharedlibrary", info_sharedlibrary_command
,
2095 "Status of loaded shared object libraries.");
2098 (add_set_cmd ("auto-solib-add", class_support
, var_zinteger
,
2099 (char *) &auto_solib_add
,
2100 "Set autoloading of shared library symbols.\n\
2101 If nonzero, symbols from all shared object libraries will be loaded\n\
2102 automatically when the inferior begins execution or when the dynamic linker\n\
2103 informs gdb that a new library has been loaded. Otherwise, symbols\n\
2104 must be loaded manually, using `sharedlibrary'.",
2109 (add_set_cmd ("solib-absolute-prefix", class_support
, var_filename
,
2110 (char *) &solib_absolute_prefix
,
2111 "Set prefix for loading absolute shared library symbol files.\n\
2112 For other (relative) files, you can add values using `set solib-search-path'.",
2116 (add_set_cmd ("solib-search-path", class_support
, var_string
,
2117 (char *) &solib_search_path
,
2118 "Set the search path for loading non-absolute shared library symbol files.\n\
2119 This takes precedence over the environment variables PATH and LD_LIBRARY_PATH.",
2123 #endif /* HAVE_LINK_H */