1 /* Handle SVR4 shared libraries for GDB, the GNU Debugger.
3 Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000,
4 2001, 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
23 #include "elf/external.h"
24 #include "elf/common.h"
35 #include "gdb_assert.h"
39 #include "solib-svr4.h"
41 #include "bfd-target.h"
46 static struct link_map_offsets
*svr4_fetch_link_map_offsets (void);
47 static int svr4_have_link_map_offsets (void);
49 /* This hook is set to a function that provides native link map
50 offsets if the code in solib-legacy.c is linked in. */
51 struct link_map_offsets
*(*legacy_svr4_fetch_link_map_offsets_hook
) (void);
53 /* Link map info to include in an allocated so_list entry */
57 /* Pointer to copy of link map from inferior. The type is char *
58 rather than void *, so that we may use byte offsets to find the
59 various fields without the need for a cast. */
62 /* Amount by which addresses in the binary should be relocated to
63 match the inferior. This could most often be taken directly
64 from lm, but when prelinking is involved and the prelink base
65 address changes, we may need a different offset, we want to
66 warn about the difference and compute it only once. */
70 /* On SVR4 systems, a list of symbols in the dynamic linker where
71 GDB can try to place a breakpoint to monitor shared library
74 If none of these symbols are found, or other errors occur, then
75 SVR4 systems will fall back to using a symbol as the "startup
76 mapping complete" breakpoint address. */
78 static char *solib_break_names
[] =
89 #define BKPT_AT_SYMBOL 1
91 #if defined (BKPT_AT_SYMBOL)
92 static char *bkpt_names
[] =
94 #ifdef SOLIB_BKPT_NAME
95 SOLIB_BKPT_NAME
, /* Prefer configured name if it exists. */
104 static char *main_name_list
[] =
110 /* link map access functions */
113 LM_ADDR_FROM_LINK_MAP (struct so_list
*so
)
115 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
117 return extract_typed_address (so
->lm_info
->lm
+ lmo
->l_addr_offset
,
118 builtin_type_void_data_ptr
);
122 HAS_LM_DYNAMIC_FROM_LINK_MAP ()
124 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
126 return lmo
->l_ld_offset
>= 0;
130 LM_DYNAMIC_FROM_LINK_MAP (struct so_list
*so
)
132 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
134 return extract_typed_address (so
->lm_info
->lm
+ lmo
->l_ld_offset
,
135 builtin_type_void_data_ptr
);
139 LM_ADDR_CHECK (struct so_list
*so
, bfd
*abfd
)
141 if (so
->lm_info
->l_addr
== (CORE_ADDR
)-1)
143 struct bfd_section
*dyninfo_sect
;
144 CORE_ADDR l_addr
, l_dynaddr
, dynaddr
, align
= 0x1000;
146 l_addr
= LM_ADDR_FROM_LINK_MAP (so
);
148 if (! abfd
|| ! HAS_LM_DYNAMIC_FROM_LINK_MAP ())
151 l_dynaddr
= LM_DYNAMIC_FROM_LINK_MAP (so
);
153 dyninfo_sect
= bfd_get_section_by_name (abfd
, ".dynamic");
154 if (dyninfo_sect
== NULL
)
157 dynaddr
= bfd_section_vma (abfd
, dyninfo_sect
);
159 if (dynaddr
+ l_addr
!= l_dynaddr
)
161 if (bfd_get_flavour (abfd
) == bfd_target_elf_flavour
)
163 Elf_Internal_Ehdr
*ehdr
= elf_tdata (abfd
)->elf_header
;
164 Elf_Internal_Phdr
*phdr
= elf_tdata (abfd
)->phdr
;
169 for (i
= 0; i
< ehdr
->e_phnum
; i
++)
170 if (phdr
[i
].p_type
== PT_LOAD
&& phdr
[i
].p_align
> align
)
171 align
= phdr
[i
].p_align
;
174 /* Turn it into a mask. */
177 /* If the changes match the alignment requirements, we
178 assume we're using a core file that was generated by the
179 same binary, just prelinked with a different base offset.
180 If it doesn't match, we may have a different binary, the
181 same binary with the dynamic table loaded at an unrelated
182 location, or anything, really. To avoid regressions,
183 don't adjust the base offset in the latter case, although
184 odds are that, if things really changed, debugging won't
186 if ((l_addr
& align
) == ((l_dynaddr
- dynaddr
) & align
))
188 l_addr
= l_dynaddr
- dynaddr
;
190 warning (_(".dynamic section for \"%s\" "
191 "is not at the expected address"), so
->so_name
);
192 warning (_("difference appears to be caused by prelink, "
193 "adjusting expectations"));
196 warning (_(".dynamic section for \"%s\" "
197 "is not at the expected address "
198 "(wrong library or version mismatch?)"), so
->so_name
);
202 so
->lm_info
->l_addr
= l_addr
;
205 return so
->lm_info
->l_addr
;
209 LM_NEXT (struct so_list
*so
)
211 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
213 return extract_typed_address (so
->lm_info
->lm
+ lmo
->l_next_offset
,
214 builtin_type_void_data_ptr
);
218 LM_NAME (struct so_list
*so
)
220 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
222 return extract_typed_address (so
->lm_info
->lm
+ lmo
->l_name_offset
,
223 builtin_type_void_data_ptr
);
227 IGNORE_FIRST_LINK_MAP_ENTRY (struct so_list
*so
)
229 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
231 /* Assume that everything is a library if the dynamic loader was loaded
232 late by a static executable. */
233 if (bfd_get_section_by_name (exec_bfd
, ".dynamic") == NULL
)
236 return extract_typed_address (so
->lm_info
->lm
+ lmo
->l_prev_offset
,
237 builtin_type_void_data_ptr
) == 0;
240 static CORE_ADDR debug_base
; /* Base of dynamic linker structures */
242 /* Validity flag for debug_loader_offset. */
243 static int debug_loader_offset_p
;
245 /* Load address for the dynamic linker, inferred. */
246 static CORE_ADDR debug_loader_offset
;
248 /* Name of the dynamic linker, valid if debug_loader_offset_p. */
249 static char *debug_loader_name
;
251 /* Local function prototypes */
253 static int match_main (char *);
255 static CORE_ADDR
bfd_lookup_symbol (bfd
*, char *);
261 bfd_lookup_symbol -- lookup the value for a specific symbol
265 CORE_ADDR bfd_lookup_symbol (bfd *abfd, char *symname)
269 An expensive way to lookup the value of a single symbol for
270 bfd's that are only temporary anyway. This is used by the
271 shared library support to find the address of the debugger
272 notification routine in the shared library.
274 The returned symbol may be in a code or data section; functions
275 will normally be in a code section, but may be in a data section
276 if this architecture uses function descriptors.
278 Note that 0 is specifically allowed as an error return (no
283 bfd_lookup_symbol (bfd
*abfd
, char *symname
)
287 asymbol
**symbol_table
;
288 unsigned int number_of_symbols
;
290 struct cleanup
*back_to
;
291 CORE_ADDR symaddr
= 0;
293 storage_needed
= bfd_get_symtab_upper_bound (abfd
);
295 if (storage_needed
> 0)
297 symbol_table
= (asymbol
**) xmalloc (storage_needed
);
298 back_to
= make_cleanup (xfree
, symbol_table
);
299 number_of_symbols
= bfd_canonicalize_symtab (abfd
, symbol_table
);
301 for (i
= 0; i
< number_of_symbols
; i
++)
303 sym
= *symbol_table
++;
304 if (strcmp (sym
->name
, symname
) == 0
305 && (sym
->section
->flags
& (SEC_CODE
| SEC_DATA
)) != 0)
307 /* BFD symbols are section relative. */
308 symaddr
= sym
->value
+ sym
->section
->vma
;
312 do_cleanups (back_to
);
318 /* On FreeBSD, the dynamic linker is stripped by default. So we'll
319 have to check the dynamic string table too. */
321 storage_needed
= bfd_get_dynamic_symtab_upper_bound (abfd
);
323 if (storage_needed
> 0)
325 symbol_table
= (asymbol
**) xmalloc (storage_needed
);
326 back_to
= make_cleanup (xfree
, symbol_table
);
327 number_of_symbols
= bfd_canonicalize_dynamic_symtab (abfd
, symbol_table
);
329 for (i
= 0; i
< number_of_symbols
; i
++)
331 sym
= *symbol_table
++;
333 if (strcmp (sym
->name
, symname
) == 0
334 && (sym
->section
->flags
& (SEC_CODE
| SEC_DATA
)) != 0)
336 /* BFD symbols are section relative. */
337 symaddr
= sym
->value
+ sym
->section
->vma
;
341 do_cleanups (back_to
);
347 /* Scan for DYNTAG in .dynamic section of ABFD. If DYNTAG is found 1 is
348 returned and the corresponding PTR is set. */
351 scan_dyntag (int dyntag
, bfd
*abfd
, CORE_ADDR
*ptr
)
353 int arch_size
, step
, sect_size
;
355 CORE_ADDR dyn_ptr
, dyn_addr
;
356 gdb_byte
*bufend
, *bufstart
, *buf
;
357 Elf32_External_Dyn
*x_dynp_32
;
358 Elf64_External_Dyn
*x_dynp_64
;
359 struct bfd_section
*sect
;
363 arch_size
= bfd_get_arch_size (abfd
);
367 /* Find the start address of the .dynamic section. */
368 sect
= bfd_get_section_by_name (abfd
, ".dynamic");
371 dyn_addr
= bfd_section_vma (abfd
, sect
);
373 /* Read in .dynamic from the BFD. We will get the actual value
374 from memory later. */
375 sect_size
= bfd_section_size (abfd
, sect
);
376 buf
= bufstart
= alloca (sect_size
);
377 if (!bfd_get_section_contents (abfd
, sect
,
381 /* Iterate over BUF and scan for DYNTAG. If found, set PTR and return. */
382 step
= (arch_size
== 32) ? sizeof (Elf32_External_Dyn
)
383 : sizeof (Elf64_External_Dyn
);
384 for (bufend
= buf
+ sect_size
;
390 x_dynp_32
= (Elf32_External_Dyn
*) buf
;
391 dyn_tag
= bfd_h_get_32 (abfd
, (bfd_byte
*) x_dynp_32
->d_tag
);
392 dyn_ptr
= bfd_h_get_32 (abfd
, (bfd_byte
*) x_dynp_32
->d_un
.d_ptr
);
396 x_dynp_64
= (Elf64_External_Dyn
*) buf
;
397 dyn_tag
= bfd_h_get_64 (abfd
, (bfd_byte
*) x_dynp_64
->d_tag
);
398 dyn_ptr
= bfd_h_get_64 (abfd
, (bfd_byte
*) x_dynp_64
->d_un
.d_ptr
);
400 if (dyn_tag
== DT_NULL
)
402 if (dyn_tag
== dyntag
)
404 /* If requested, try to read the runtime value of this .dynamic
411 ptr_addr
= dyn_addr
+ (buf
- bufstart
) + arch_size
/ 8;
412 if (target_read_memory (ptr_addr
, ptr_buf
, arch_size
/ 8) == 0)
413 dyn_ptr
= extract_typed_address (ptr_buf
,
414 builtin_type_void_data_ptr
);
429 elf_locate_base -- locate the base address of dynamic linker structs
430 for SVR4 elf targets.
434 CORE_ADDR elf_locate_base (void)
438 For SVR4 elf targets the address of the dynamic linker's runtime
439 structure is contained within the dynamic info section in the
440 executable file. The dynamic section is also mapped into the
441 inferior address space. Because the runtime loader fills in the
442 real address before starting the inferior, we have to read in the
443 dynamic info section from the inferior address space.
444 If there are any errors while trying to find the address, we
445 silently return 0, otherwise the found address is returned.
450 elf_locate_base (void)
452 struct minimal_symbol
*msymbol
;
455 /* Look for DT_MIPS_RLD_MAP first. MIPS executables use this
456 instead of DT_DEBUG, although they sometimes contain an unused
458 if (scan_dyntag (DT_MIPS_RLD_MAP
, exec_bfd
, &dyn_ptr
))
461 int pbuf_size
= TYPE_LENGTH (builtin_type_void_data_ptr
);
462 pbuf
= alloca (pbuf_size
);
463 /* DT_MIPS_RLD_MAP contains a pointer to the address
464 of the dynamic link structure. */
465 if (target_read_memory (dyn_ptr
, pbuf
, pbuf_size
))
467 return extract_typed_address (pbuf
, builtin_type_void_data_ptr
);
471 if (scan_dyntag (DT_DEBUG
, exec_bfd
, &dyn_ptr
))
474 /* This may be a static executable. Look for the symbol
475 conventionally named _r_debug, as a last resort. */
476 msymbol
= lookup_minimal_symbol ("_r_debug", NULL
, symfile_objfile
);
478 return SYMBOL_VALUE_ADDRESS (msymbol
);
480 /* DT_DEBUG entry not found. */
488 locate_base -- locate the base address of dynamic linker structs
492 CORE_ADDR locate_base (void)
496 For both the SunOS and SVR4 shared library implementations, if the
497 inferior executable has been linked dynamically, there is a single
498 address somewhere in the inferior's data space which is the key to
499 locating all of the dynamic linker's runtime structures. This
500 address is the value of the debug base symbol. The job of this
501 function is to find and return that address, or to return 0 if there
502 is no such address (the executable is statically linked for example).
504 For SunOS, the job is almost trivial, since the dynamic linker and
505 all of it's structures are statically linked to the executable at
506 link time. Thus the symbol for the address we are looking for has
507 already been added to the minimal symbol table for the executable's
508 objfile at the time the symbol file's symbols were read, and all we
509 have to do is look it up there. Note that we explicitly do NOT want
510 to find the copies in the shared library.
512 The SVR4 version is a bit more complicated because the address
513 is contained somewhere in the dynamic info section. We have to go
514 to a lot more work to discover the address of the debug base symbol.
515 Because of this complexity, we cache the value we find and return that
516 value on subsequent invocations. Note there is no copy in the
517 executable symbol tables.
524 /* Check to see if we have a currently valid address, and if so, avoid
525 doing all this work again and just return the cached address. If
526 we have no cached address, try to locate it in the dynamic info
527 section for ELF executables. There's no point in doing any of this
528 though if we don't have some link map offsets to work with. */
530 if (debug_base
== 0 && svr4_have_link_map_offsets ())
533 && bfd_get_flavour (exec_bfd
) == bfd_target_elf_flavour
)
534 debug_base
= elf_locate_base ();
539 /* Find the first element in the inferior's dynamic link map, and
540 return its address in the inferior.
542 FIXME: Perhaps we should validate the info somehow, perhaps by
543 checking r_version for a known version number, or r_state for
547 solib_svr4_r_map (void)
549 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
551 return read_memory_typed_address (debug_base
+ lmo
->r_map_offset
,
552 builtin_type_void_data_ptr
);
555 /* Find the link map for the dynamic linker (if it is not in the
556 normal list of loaded shared objects). */
559 solib_svr4_r_ldsomap (void)
561 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
564 /* Check version, and return zero if `struct r_debug' doesn't have
565 the r_ldsomap member. */
566 version
= read_memory_unsigned_integer (debug_base
+ lmo
->r_version_offset
,
567 lmo
->r_version_size
);
568 if (version
< 2 || lmo
->r_ldsomap_offset
== -1)
571 return read_memory_typed_address (debug_base
+ lmo
->r_ldsomap_offset
,
572 builtin_type_void_data_ptr
);
579 open_symbol_file_object
583 void open_symbol_file_object (void *from_tty)
587 If no open symbol file, attempt to locate and open the main symbol
588 file. On SVR4 systems, this is the first link map entry. If its
589 name is here, we can open it. Useful when attaching to a process
590 without first loading its symbol file.
592 If FROM_TTYP dereferences to a non-zero integer, allow messages to
593 be printed. This parameter is a pointer rather than an int because
594 open_symbol_file_object() is called via catch_errors() and
595 catch_errors() requires a pointer argument. */
598 open_symbol_file_object (void *from_ttyp
)
600 CORE_ADDR lm
, l_name
;
603 int from_tty
= *(int *)from_ttyp
;
604 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
605 int l_name_size
= TYPE_LENGTH (builtin_type_void_data_ptr
);
606 gdb_byte
*l_name_buf
= xmalloc (l_name_size
);
607 struct cleanup
*cleanups
= make_cleanup (xfree
, l_name_buf
);
610 if (!query ("Attempt to reload symbols from process? "))
613 if ((debug_base
= locate_base ()) == 0)
614 return 0; /* failed somehow... */
616 /* First link map member should be the executable. */
617 lm
= solib_svr4_r_map ();
619 return 0; /* failed somehow... */
621 /* Read address of name from target memory to GDB. */
622 read_memory (lm
+ lmo
->l_name_offset
, l_name_buf
, l_name_size
);
624 /* Convert the address to host format. */
625 l_name
= extract_typed_address (l_name_buf
, builtin_type_void_data_ptr
);
627 /* Free l_name_buf. */
628 do_cleanups (cleanups
);
631 return 0; /* No filename. */
633 /* Now fetch the filename from target memory. */
634 target_read_string (l_name
, &filename
, SO_NAME_MAX_PATH_SIZE
- 1, &errcode
);
635 make_cleanup (xfree
, filename
);
639 warning (_("failed to read exec filename from attached file: %s"),
640 safe_strerror (errcode
));
644 /* Have a pathname: read the symbol file. */
645 symbol_file_add_main (filename
, from_tty
);
650 /* If no shared library information is available from the dynamic
651 linker, build a fallback list from other sources. */
653 static struct so_list
*
654 svr4_default_sos (void)
656 struct so_list
*head
= NULL
;
657 struct so_list
**link_ptr
= &head
;
659 if (debug_loader_offset_p
)
661 struct so_list
*new = XZALLOC (struct so_list
);
663 new->lm_info
= xmalloc (sizeof (struct lm_info
));
665 /* Nothing will ever check the cached copy of the link
666 map if we set l_addr. */
667 new->lm_info
->l_addr
= debug_loader_offset
;
668 new->lm_info
->lm
= NULL
;
670 strncpy (new->so_name
, debug_loader_name
, SO_NAME_MAX_PATH_SIZE
- 1);
671 new->so_name
[SO_NAME_MAX_PATH_SIZE
- 1] = '\0';
672 strcpy (new->so_original_name
, new->so_name
);
675 link_ptr
= &new->next
;
683 current_sos -- build a list of currently loaded shared objects
687 struct so_list *current_sos ()
691 Build a list of `struct so_list' objects describing the shared
692 objects currently loaded in the inferior. This list does not
693 include an entry for the main executable file.
695 Note that we only gather information directly available from the
696 inferior --- we don't examine any of the shared library files
697 themselves. The declaration of `struct so_list' says which fields
698 we provide values for. */
700 static struct so_list
*
701 svr4_current_sos (void)
704 struct so_list
*head
= 0;
705 struct so_list
**link_ptr
= &head
;
706 CORE_ADDR ldsomap
= 0;
708 /* Make sure we've looked up the inferior's dynamic linker's base
712 debug_base
= locate_base ();
714 /* If we can't find the dynamic linker's base structure, this
715 must not be a dynamically linked executable. Hmm. */
717 return svr4_default_sos ();
720 /* Walk the inferior's link map list, and build our list of
721 `struct so_list' nodes. */
722 lm
= solib_svr4_r_map ();
726 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
727 struct so_list
*new = XZALLOC (struct so_list
);
728 struct cleanup
*old_chain
= make_cleanup (xfree
, new);
730 new->lm_info
= xmalloc (sizeof (struct lm_info
));
731 make_cleanup (xfree
, new->lm_info
);
733 new->lm_info
->l_addr
= (CORE_ADDR
)-1;
734 new->lm_info
->lm
= xzalloc (lmo
->link_map_size
);
735 make_cleanup (xfree
, new->lm_info
->lm
);
737 read_memory (lm
, new->lm_info
->lm
, lmo
->link_map_size
);
741 /* For SVR4 versions, the first entry in the link map is for the
742 inferior executable, so we must ignore it. For some versions of
743 SVR4, it has no name. For others (Solaris 2.3 for example), it
744 does have a name, so we can no longer use a missing name to
745 decide when to ignore it. */
746 if (IGNORE_FIRST_LINK_MAP_ENTRY (new) && ldsomap
== 0)
753 /* Extract this shared object's name. */
754 target_read_string (LM_NAME (new), &buffer
,
755 SO_NAME_MAX_PATH_SIZE
- 1, &errcode
);
757 warning (_("Can't read pathname for load map: %s."),
758 safe_strerror (errcode
));
761 strncpy (new->so_name
, buffer
, SO_NAME_MAX_PATH_SIZE
- 1);
762 new->so_name
[SO_NAME_MAX_PATH_SIZE
- 1] = '\0';
763 strcpy (new->so_original_name
, new->so_name
);
767 /* If this entry has no name, or its name matches the name
768 for the main executable, don't include it in the list. */
769 if (! new->so_name
[0]
770 || match_main (new->so_name
))
776 link_ptr
= &new->next
;
780 /* On Solaris, the dynamic linker is not in the normal list of
781 shared objects, so make sure we pick it up too. Having
782 symbol information for the dynamic linker is quite crucial
783 for skipping dynamic linker resolver code. */
784 if (lm
== 0 && ldsomap
== 0)
785 lm
= ldsomap
= solib_svr4_r_ldsomap ();
787 discard_cleanups (old_chain
);
791 return svr4_default_sos ();
796 /* Get the address of the link_map for a given OBJFILE. Loop through
797 the link maps, and return the address of the one corresponding to
798 the given objfile. Note that this function takes into account that
799 objfile can be the main executable, not just a shared library. The
800 main executable has always an empty name field in the linkmap. */
803 svr4_fetch_objfile_link_map (struct objfile
*objfile
)
807 if ((debug_base
= locate_base ()) == 0)
808 return 0; /* failed somehow... */
810 /* Position ourselves on the first link map. */
811 lm
= solib_svr4_r_map ();
814 /* Get info on the layout of the r_debug and link_map structures. */
815 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
818 struct lm_info objfile_lm_info
;
819 struct cleanup
*old_chain
;
820 CORE_ADDR name_address
;
821 int l_name_size
= TYPE_LENGTH (builtin_type_void_data_ptr
);
822 gdb_byte
*l_name_buf
= xmalloc (l_name_size
);
823 old_chain
= make_cleanup (xfree
, l_name_buf
);
825 /* Set up the buffer to contain the portion of the link_map
826 structure that gdb cares about. Note that this is not the
827 whole link_map structure. */
828 objfile_lm_info
.lm
= xzalloc (lmo
->link_map_size
);
829 make_cleanup (xfree
, objfile_lm_info
.lm
);
831 /* Read the link map into our internal structure. */
832 read_memory (lm
, objfile_lm_info
.lm
, lmo
->link_map_size
);
834 /* Read address of name from target memory to GDB. */
835 read_memory (lm
+ lmo
->l_name_offset
, l_name_buf
, l_name_size
);
837 /* Extract this object's name. */
838 name_address
= extract_typed_address (l_name_buf
,
839 builtin_type_void_data_ptr
);
840 target_read_string (name_address
, &buffer
,
841 SO_NAME_MAX_PATH_SIZE
- 1, &errcode
);
842 make_cleanup (xfree
, buffer
);
844 warning (_("Can't read pathname for load map: %s."),
845 safe_strerror (errcode
));
848 /* Is this the linkmap for the file we want? */
849 /* If the file is not a shared library and has no name,
850 we are sure it is the main executable, so we return that. */
853 && ((strcmp (buffer
, objfile
->name
) == 0)
854 || (!(objfile
->flags
& OBJF_SHARED
)
855 && (strcmp (buffer
, "") == 0))))
857 do_cleanups (old_chain
);
861 /* Not the file we wanted, continue checking. */
862 lm
= extract_typed_address (objfile_lm_info
.lm
+ lmo
->l_next_offset
,
863 builtin_type_void_data_ptr
);
864 do_cleanups (old_chain
);
869 /* On some systems, the only way to recognize the link map entry for
870 the main executable file is by looking at its name. Return
871 non-zero iff SONAME matches one of the known main executable names. */
874 match_main (char *soname
)
878 for (mainp
= main_name_list
; *mainp
!= NULL
; mainp
++)
880 if (strcmp (soname
, *mainp
) == 0)
887 /* Return 1 if PC lies in the dynamic symbol resolution code of the
888 SVR4 run time loader. */
889 static CORE_ADDR interp_text_sect_low
;
890 static CORE_ADDR interp_text_sect_high
;
891 static CORE_ADDR interp_plt_sect_low
;
892 static CORE_ADDR interp_plt_sect_high
;
895 svr4_in_dynsym_resolve_code (CORE_ADDR pc
)
897 return ((pc
>= interp_text_sect_low
&& pc
< interp_text_sect_high
)
898 || (pc
>= interp_plt_sect_low
&& pc
< interp_plt_sect_high
)
899 || in_plt_section (pc
, NULL
));
902 /* Given an executable's ABFD and target, compute the entry-point
906 exec_entry_point (struct bfd
*abfd
, struct target_ops
*targ
)
908 /* KevinB wrote ... for most targets, the address returned by
909 bfd_get_start_address() is the entry point for the start
910 function. But, for some targets, bfd_get_start_address() returns
911 the address of a function descriptor from which the entry point
912 address may be extracted. This address is extracted by
913 gdbarch_convert_from_func_ptr_addr(). The method
914 gdbarch_convert_from_func_ptr_addr() is the merely the identify
915 function for targets which don't use function descriptors. */
916 return gdbarch_convert_from_func_ptr_addr (current_gdbarch
,
917 bfd_get_start_address (abfd
),
925 enable_break -- arrange for dynamic linker to hit breakpoint
929 int enable_break (void)
933 Both the SunOS and the SVR4 dynamic linkers have, as part of their
934 debugger interface, support for arranging for the inferior to hit
935 a breakpoint after mapping in the shared libraries. This function
936 enables that breakpoint.
938 For SunOS, there is a special flag location (in_debugger) which we
939 set to 1. When the dynamic linker sees this flag set, it will set
940 a breakpoint at a location known only to itself, after saving the
941 original contents of that place and the breakpoint address itself,
942 in it's own internal structures. When we resume the inferior, it
943 will eventually take a SIGTRAP when it runs into the breakpoint.
944 We handle this (in a different place) by restoring the contents of
945 the breakpointed location (which is only known after it stops),
946 chasing around to locate the shared libraries that have been
947 loaded, then resuming.
949 For SVR4, the debugger interface structure contains a member (r_brk)
950 which is statically initialized at the time the shared library is
951 built, to the offset of a function (_r_debug_state) which is guaran-
952 teed to be called once before mapping in a library, and again when
953 the mapping is complete. At the time we are examining this member,
954 it contains only the unrelocated offset of the function, so we have
955 to do our own relocation. Later, when the dynamic linker actually
956 runs, it relocates r_brk to be the actual address of _r_debug_state().
958 The debugger interface structure also contains an enumeration which
959 is set to either RT_ADD or RT_DELETE prior to changing the mapping,
960 depending upon whether or not the library is being mapped or unmapped,
961 and then set to RT_CONSISTENT after the library is mapped/unmapped.
967 #ifdef BKPT_AT_SYMBOL
969 struct minimal_symbol
*msymbol
;
971 asection
*interp_sect
;
973 /* First, remove all the solib event breakpoints. Their addresses
974 may have changed since the last time we ran the program. */
975 remove_solib_event_breakpoints ();
977 interp_text_sect_low
= interp_text_sect_high
= 0;
978 interp_plt_sect_low
= interp_plt_sect_high
= 0;
980 /* Find the .interp section; if not found, warn the user and drop
981 into the old breakpoint at symbol code. */
982 interp_sect
= bfd_get_section_by_name (exec_bfd
, ".interp");
985 unsigned int interp_sect_size
;
987 CORE_ADDR load_addr
= 0;
988 int load_addr_found
= 0;
991 struct target_ops
*tmp_bfd_target
;
993 char *tmp_pathname
= NULL
;
994 CORE_ADDR sym_addr
= 0;
996 /* Read the contents of the .interp section into a local buffer;
997 the contents specify the dynamic linker this program uses. */
998 interp_sect_size
= bfd_section_size (exec_bfd
, interp_sect
);
999 buf
= alloca (interp_sect_size
);
1000 bfd_get_section_contents (exec_bfd
, interp_sect
,
1001 buf
, 0, interp_sect_size
);
1003 /* Now we need to figure out where the dynamic linker was
1004 loaded so that we can load its symbols and place a breakpoint
1005 in the dynamic linker itself.
1007 This address is stored on the stack. However, I've been unable
1008 to find any magic formula to find it for Solaris (appears to
1009 be trivial on GNU/Linux). Therefore, we have to try an alternate
1010 mechanism to find the dynamic linker's base address. */
1012 tmp_fd
= solib_open (buf
, &tmp_pathname
);
1014 tmp_bfd
= bfd_fopen (tmp_pathname
, gnutarget
, FOPEN_RB
, tmp_fd
);
1016 if (tmp_bfd
== NULL
)
1017 goto bkpt_at_symbol
;
1019 /* Make sure the dynamic linker's really a useful object. */
1020 if (!bfd_check_format (tmp_bfd
, bfd_object
))
1022 warning (_("Unable to grok dynamic linker %s as an object file"), buf
);
1023 bfd_close (tmp_bfd
);
1024 goto bkpt_at_symbol
;
1027 /* Now convert the TMP_BFD into a target. That way target, as
1028 well as BFD operations can be used. Note that closing the
1029 target will also close the underlying bfd. */
1030 tmp_bfd_target
= target_bfd_reopen (tmp_bfd
);
1032 /* On a running target, we can get the dynamic linker's base
1033 address from the shared library table. */
1034 solib_add (NULL
, 0, ¤t_target
, auto_solib_add
);
1035 so
= master_so_list ();
1038 if (strcmp (buf
, so
->so_original_name
) == 0)
1040 load_addr_found
= 1;
1041 load_addr
= LM_ADDR_CHECK (so
, tmp_bfd
);
1047 /* If we were not able to find the base address of the loader
1048 from our so_list, then try using the AT_BASE auxilliary entry. */
1049 if (!load_addr_found
)
1050 if (target_auxv_search (¤t_target
, AT_BASE
, &load_addr
) > 0)
1051 load_addr_found
= 1;
1053 /* Otherwise we find the dynamic linker's base address by examining
1054 the current pc (which should point at the entry point for the
1055 dynamic linker) and subtracting the offset of the entry point.
1057 This is more fragile than the previous approaches, but is a good
1058 fallback method because it has actually been working well in
1060 if (!load_addr_found
)
1062 load_addr
= (read_pc ()
1063 - exec_entry_point (tmp_bfd
, tmp_bfd_target
));
1064 debug_loader_name
= xstrdup (buf
);
1065 debug_loader_offset_p
= 1;
1066 debug_loader_offset
= load_addr
;
1067 solib_add (NULL
, 0, ¤t_target
, auto_solib_add
);
1070 /* Record the relocated start and end address of the dynamic linker
1071 text and plt section for svr4_in_dynsym_resolve_code. */
1072 interp_sect
= bfd_get_section_by_name (tmp_bfd
, ".text");
1075 interp_text_sect_low
=
1076 bfd_section_vma (tmp_bfd
, interp_sect
) + load_addr
;
1077 interp_text_sect_high
=
1078 interp_text_sect_low
+ bfd_section_size (tmp_bfd
, interp_sect
);
1080 interp_sect
= bfd_get_section_by_name (tmp_bfd
, ".plt");
1083 interp_plt_sect_low
=
1084 bfd_section_vma (tmp_bfd
, interp_sect
) + load_addr
;
1085 interp_plt_sect_high
=
1086 interp_plt_sect_low
+ bfd_section_size (tmp_bfd
, interp_sect
);
1089 /* Now try to set a breakpoint in the dynamic linker. */
1090 for (bkpt_namep
= solib_break_names
; *bkpt_namep
!= NULL
; bkpt_namep
++)
1092 sym_addr
= bfd_lookup_symbol (tmp_bfd
, *bkpt_namep
);
1098 /* Convert 'sym_addr' from a function pointer to an address.
1099 Because we pass tmp_bfd_target instead of the current
1100 target, this will always produce an unrelocated value. */
1101 sym_addr
= gdbarch_convert_from_func_ptr_addr (current_gdbarch
,
1105 /* We're done with both the temporary bfd and target. Remember,
1106 closing the target closes the underlying bfd. */
1107 target_close (tmp_bfd_target
, 0);
1111 create_solib_event_breakpoint (load_addr
+ sym_addr
);
1115 /* For whatever reason we couldn't set a breakpoint in the dynamic
1116 linker. Warn and drop into the old code. */
1118 xfree (tmp_pathname
);
1119 warning (_("Unable to find dynamic linker breakpoint function.\n"
1120 "GDB will be unable to debug shared library initializers\n"
1121 "and track explicitly loaded dynamic code."));
1124 /* Scan through the lists of symbols, trying to look up the symbol and
1125 set a breakpoint there. Terminate loop when we/if we succeed. */
1127 for (bkpt_namep
= solib_break_names
; *bkpt_namep
!= NULL
; bkpt_namep
++)
1129 msymbol
= lookup_minimal_symbol (*bkpt_namep
, NULL
, symfile_objfile
);
1130 if ((msymbol
!= NULL
) && (SYMBOL_VALUE_ADDRESS (msymbol
) != 0))
1132 create_solib_event_breakpoint (SYMBOL_VALUE_ADDRESS (msymbol
));
1137 for (bkpt_namep
= bkpt_names
; *bkpt_namep
!= NULL
; bkpt_namep
++)
1139 msymbol
= lookup_minimal_symbol (*bkpt_namep
, NULL
, symfile_objfile
);
1140 if ((msymbol
!= NULL
) && (SYMBOL_VALUE_ADDRESS (msymbol
) != 0))
1142 create_solib_event_breakpoint (SYMBOL_VALUE_ADDRESS (msymbol
));
1146 #endif /* BKPT_AT_SYMBOL */
1155 special_symbol_handling -- additional shared library symbol handling
1159 void special_symbol_handling ()
1163 Once the symbols from a shared object have been loaded in the usual
1164 way, we are called to do any system specific symbol handling that
1167 For SunOS4, this consisted of grunging around in the dynamic
1168 linkers structures to find symbol definitions for "common" symbols
1169 and adding them to the minimal symbol table for the runtime common
1172 However, for SVR4, there's nothing to do.
1177 svr4_special_symbol_handling (void)
1181 /* Relocate the main executable. This function should be called upon
1182 stopping the inferior process at the entry point to the program.
1183 The entry point from BFD is compared to the PC and if they are
1184 different, the main executable is relocated by the proper amount.
1186 As written it will only attempt to relocate executables which
1187 lack interpreter sections. It seems likely that only dynamic
1188 linker executables will get relocated, though it should work
1189 properly for a position-independent static executable as well. */
1192 svr4_relocate_main_executable (void)
1194 asection
*interp_sect
;
1195 CORE_ADDR pc
= read_pc ();
1197 /* Decide if the objfile needs to be relocated. As indicated above,
1198 we will only be here when execution is stopped at the beginning
1199 of the program. Relocation is necessary if the address at which
1200 we are presently stopped differs from the start address stored in
1201 the executable AND there's no interpreter section. The condition
1202 regarding the interpreter section is very important because if
1203 there *is* an interpreter section, execution will begin there
1204 instead. When there is an interpreter section, the start address
1205 is (presumably) used by the interpreter at some point to start
1206 execution of the program.
1208 If there is an interpreter, it is normal for it to be set to an
1209 arbitrary address at the outset. The job of finding it is
1210 handled in enable_break().
1212 So, to summarize, relocations are necessary when there is no
1213 interpreter section and the start address obtained from the
1214 executable is different from the address at which GDB is
1217 [ The astute reader will note that we also test to make sure that
1218 the executable in question has the DYNAMIC flag set. It is my
1219 opinion that this test is unnecessary (undesirable even). It
1220 was added to avoid inadvertent relocation of an executable
1221 whose e_type member in the ELF header is not ET_DYN. There may
1222 be a time in the future when it is desirable to do relocations
1223 on other types of files as well in which case this condition
1224 should either be removed or modified to accomodate the new file
1225 type. (E.g, an ET_EXEC executable which has been built to be
1226 position-independent could safely be relocated by the OS if
1227 desired. It is true that this violates the ABI, but the ABI
1228 has been known to be bent from time to time.) - Kevin, Nov 2000. ]
1231 interp_sect
= bfd_get_section_by_name (exec_bfd
, ".interp");
1232 if (interp_sect
== NULL
1233 && (bfd_get_file_flags (exec_bfd
) & DYNAMIC
) != 0
1234 && (exec_entry_point (exec_bfd
, &exec_ops
) != pc
))
1236 struct cleanup
*old_chain
;
1237 struct section_offsets
*new_offsets
;
1239 CORE_ADDR displacement
;
1241 /* It is necessary to relocate the objfile. The amount to
1242 relocate by is simply the address at which we are stopped
1243 minus the starting address from the executable.
1245 We relocate all of the sections by the same amount. This
1246 behavior is mandated by recent editions of the System V ABI.
1247 According to the System V Application Binary Interface,
1248 Edition 4.1, page 5-5:
1250 ... Though the system chooses virtual addresses for
1251 individual processes, it maintains the segments' relative
1252 positions. Because position-independent code uses relative
1253 addressesing between segments, the difference between
1254 virtual addresses in memory must match the difference
1255 between virtual addresses in the file. The difference
1256 between the virtual address of any segment in memory and
1257 the corresponding virtual address in the file is thus a
1258 single constant value for any one executable or shared
1259 object in a given process. This difference is the base
1260 address. One use of the base address is to relocate the
1261 memory image of the program during dynamic linking.
1263 The same language also appears in Edition 4.0 of the System V
1264 ABI and is left unspecified in some of the earlier editions. */
1266 displacement
= pc
- exec_entry_point (exec_bfd
, &exec_ops
);
1269 new_offsets
= xcalloc (symfile_objfile
->num_sections
,
1270 sizeof (struct section_offsets
));
1271 old_chain
= make_cleanup (xfree
, new_offsets
);
1273 for (i
= 0; i
< symfile_objfile
->num_sections
; i
++)
1275 if (displacement
!= ANOFFSET (symfile_objfile
->section_offsets
, i
))
1277 new_offsets
->offsets
[i
] = displacement
;
1281 objfile_relocate (symfile_objfile
, new_offsets
);
1283 do_cleanups (old_chain
);
1291 svr4_solib_create_inferior_hook -- shared library startup support
1295 void svr4_solib_create_inferior_hook ()
1299 When gdb starts up the inferior, it nurses it along (through the
1300 shell) until it is ready to execute it's first instruction. At this
1301 point, this function gets called via expansion of the macro
1302 SOLIB_CREATE_INFERIOR_HOOK.
1304 For SunOS executables, this first instruction is typically the
1305 one at "_start", or a similar text label, regardless of whether
1306 the executable is statically or dynamically linked. The runtime
1307 startup code takes care of dynamically linking in any shared
1308 libraries, once gdb allows the inferior to continue.
1310 For SVR4 executables, this first instruction is either the first
1311 instruction in the dynamic linker (for dynamically linked
1312 executables) or the instruction at "start" for statically linked
1313 executables. For dynamically linked executables, the system
1314 first exec's /lib/libc.so.N, which contains the dynamic linker,
1315 and starts it running. The dynamic linker maps in any needed
1316 shared libraries, maps in the actual user executable, and then
1317 jumps to "start" in the user executable.
1319 For both SunOS shared libraries, and SVR4 shared libraries, we
1320 can arrange to cooperate with the dynamic linker to discover the
1321 names of shared libraries that are dynamically linked, and the
1322 base addresses to which they are linked.
1324 This function is responsible for discovering those names and
1325 addresses, and saving sufficient information about them to allow
1326 their symbols to be read at a later time.
1330 Between enable_break() and disable_break(), this code does not
1331 properly handle hitting breakpoints which the user might have
1332 set in the startup code or in the dynamic linker itself. Proper
1333 handling will probably have to wait until the implementation is
1334 changed to use the "breakpoint handler function" method.
1336 Also, what if child has exit()ed? Must exit loop somehow.
1340 svr4_solib_create_inferior_hook (void)
1342 /* Relocate the main executable if necessary. */
1343 svr4_relocate_main_executable ();
1345 if (!svr4_have_link_map_offsets ())
1348 if (!enable_break ())
1351 #if defined(_SCO_DS)
1352 /* SCO needs the loop below, other systems should be using the
1353 special shared library breakpoints and the shared library breakpoint
1356 Now run the target. It will eventually hit the breakpoint, at
1357 which point all of the libraries will have been mapped in and we
1358 can go groveling around in the dynamic linker structures to find
1359 out what we need to know about them. */
1361 clear_proceed_status ();
1362 stop_soon
= STOP_QUIETLY
;
1363 stop_signal
= TARGET_SIGNAL_0
;
1366 target_resume (pid_to_ptid (-1), 0, stop_signal
);
1367 wait_for_inferior ();
1369 while (stop_signal
!= TARGET_SIGNAL_TRAP
);
1370 stop_soon
= NO_STOP_QUIETLY
;
1371 #endif /* defined(_SCO_DS) */
1375 svr4_clear_solib (void)
1378 debug_loader_offset_p
= 0;
1379 debug_loader_offset
= 0;
1380 xfree (debug_loader_name
);
1381 debug_loader_name
= NULL
;
1385 svr4_free_so (struct so_list
*so
)
1387 xfree (so
->lm_info
->lm
);
1388 xfree (so
->lm_info
);
1392 /* Clear any bits of ADDR that wouldn't fit in a target-format
1393 data pointer. "Data pointer" here refers to whatever sort of
1394 address the dynamic linker uses to manage its sections. At the
1395 moment, we don't support shared libraries on any processors where
1396 code and data pointers are different sizes.
1398 This isn't really the right solution. What we really need here is
1399 a way to do arithmetic on CORE_ADDR values that respects the
1400 natural pointer/address correspondence. (For example, on the MIPS,
1401 converting a 32-bit pointer to a 64-bit CORE_ADDR requires you to
1402 sign-extend the value. There, simply truncating the bits above
1403 gdbarch_ptr_bit, as we do below, is no good.) This should probably
1404 be a new gdbarch method or something. */
1406 svr4_truncate_ptr (CORE_ADDR addr
)
1408 if (gdbarch_ptr_bit (current_gdbarch
) == sizeof (CORE_ADDR
) * 8)
1409 /* We don't need to truncate anything, and the bit twiddling below
1410 will fail due to overflow problems. */
1413 return addr
& (((CORE_ADDR
) 1 << gdbarch_ptr_bit (current_gdbarch
)) - 1);
1418 svr4_relocate_section_addresses (struct so_list
*so
,
1419 struct section_table
*sec
)
1421 sec
->addr
= svr4_truncate_ptr (sec
->addr
+ LM_ADDR_CHECK (so
,
1423 sec
->endaddr
= svr4_truncate_ptr (sec
->endaddr
+ LM_ADDR_CHECK (so
,
1428 /* Architecture-specific operations. */
1430 /* Per-architecture data key. */
1431 static struct gdbarch_data
*solib_svr4_data
;
1433 struct solib_svr4_ops
1435 /* Return a description of the layout of `struct link_map'. */
1436 struct link_map_offsets
*(*fetch_link_map_offsets
)(void);
1439 /* Return a default for the architecture-specific operations. */
1442 solib_svr4_init (struct obstack
*obstack
)
1444 struct solib_svr4_ops
*ops
;
1446 ops
= OBSTACK_ZALLOC (obstack
, struct solib_svr4_ops
);
1447 ops
->fetch_link_map_offsets
= legacy_svr4_fetch_link_map_offsets_hook
;
1451 /* Set the architecture-specific `struct link_map_offsets' fetcher for
1455 set_solib_svr4_fetch_link_map_offsets (struct gdbarch
*gdbarch
,
1456 struct link_map_offsets
*(*flmo
) (void))
1458 struct solib_svr4_ops
*ops
= gdbarch_data (gdbarch
, solib_svr4_data
);
1460 ops
->fetch_link_map_offsets
= flmo
;
1463 /* Fetch a link_map_offsets structure using the architecture-specific
1464 `struct link_map_offsets' fetcher. */
1466 static struct link_map_offsets
*
1467 svr4_fetch_link_map_offsets (void)
1469 struct solib_svr4_ops
*ops
= gdbarch_data (current_gdbarch
, solib_svr4_data
);
1471 gdb_assert (ops
->fetch_link_map_offsets
);
1472 return ops
->fetch_link_map_offsets ();
1475 /* Return 1 if a link map offset fetcher has been defined, 0 otherwise. */
1478 svr4_have_link_map_offsets (void)
1480 struct solib_svr4_ops
*ops
= gdbarch_data (current_gdbarch
, solib_svr4_data
);
1481 return (ops
->fetch_link_map_offsets
!= NULL
);
1485 /* Most OS'es that have SVR4-style ELF dynamic libraries define a
1486 `struct r_debug' and a `struct link_map' that are binary compatible
1487 with the origional SVR4 implementation. */
1489 /* Fetch (and possibly build) an appropriate `struct link_map_offsets'
1490 for an ILP32 SVR4 system. */
1492 struct link_map_offsets
*
1493 svr4_ilp32_fetch_link_map_offsets (void)
1495 static struct link_map_offsets lmo
;
1496 static struct link_map_offsets
*lmp
= NULL
;
1502 lmo
.r_version_offset
= 0;
1503 lmo
.r_version_size
= 4;
1504 lmo
.r_map_offset
= 4;
1505 lmo
.r_ldsomap_offset
= 20;
1507 /* Everything we need is in the first 20 bytes. */
1508 lmo
.link_map_size
= 20;
1509 lmo
.l_addr_offset
= 0;
1510 lmo
.l_name_offset
= 4;
1511 lmo
.l_ld_offset
= 8;
1512 lmo
.l_next_offset
= 12;
1513 lmo
.l_prev_offset
= 16;
1519 /* Fetch (and possibly build) an appropriate `struct link_map_offsets'
1520 for an LP64 SVR4 system. */
1522 struct link_map_offsets
*
1523 svr4_lp64_fetch_link_map_offsets (void)
1525 static struct link_map_offsets lmo
;
1526 static struct link_map_offsets
*lmp
= NULL
;
1532 lmo
.r_version_offset
= 0;
1533 lmo
.r_version_size
= 4;
1534 lmo
.r_map_offset
= 8;
1535 lmo
.r_ldsomap_offset
= 40;
1537 /* Everything we need is in the first 40 bytes. */
1538 lmo
.link_map_size
= 40;
1539 lmo
.l_addr_offset
= 0;
1540 lmo
.l_name_offset
= 8;
1541 lmo
.l_ld_offset
= 16;
1542 lmo
.l_next_offset
= 24;
1543 lmo
.l_prev_offset
= 32;
1550 struct target_so_ops svr4_so_ops
;
1552 /* Lookup global symbol for ELF DSOs linked with -Bsymbolic. Those DSOs have a
1553 different rule for symbol lookup. The lookup begins here in the DSO, not in
1554 the main executable. */
1556 static struct symbol
*
1557 elf_lookup_lib_symbol (const struct objfile
*objfile
,
1559 const char *linkage_name
,
1560 const domain_enum domain
, struct symtab
**symtab
)
1562 if (objfile
->obfd
== NULL
1563 || scan_dyntag (DT_SYMBOLIC
, objfile
->obfd
, NULL
) != 1)
1566 return lookup_global_symbol_from_objfile
1567 (objfile
, name
, linkage_name
, domain
, symtab
);
1570 extern initialize_file_ftype _initialize_svr4_solib
; /* -Wmissing-prototypes */
1573 _initialize_svr4_solib (void)
1575 solib_svr4_data
= gdbarch_data_register_pre_init (solib_svr4_init
);
1577 svr4_so_ops
.relocate_section_addresses
= svr4_relocate_section_addresses
;
1578 svr4_so_ops
.free_so
= svr4_free_so
;
1579 svr4_so_ops
.clear_solib
= svr4_clear_solib
;
1580 svr4_so_ops
.solib_create_inferior_hook
= svr4_solib_create_inferior_hook
;
1581 svr4_so_ops
.special_symbol_handling
= svr4_special_symbol_handling
;
1582 svr4_so_ops
.current_sos
= svr4_current_sos
;
1583 svr4_so_ops
.open_symbol_file_object
= open_symbol_file_object
;
1584 svr4_so_ops
.in_dynsym_resolve_code
= svr4_in_dynsym_resolve_code
;
1585 svr4_so_ops
.lookup_lib_global_symbol
= elf_lookup_lib_symbol
;
1587 /* FIXME: Don't do this here. *_gdbarch_init() should set so_ops. */
1588 current_target_so_ops
= &svr4_so_ops
;