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 2 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, write to the Free Software
20 Foundation, Inc., 51 Franklin Street, Fifth Floor,
21 Boston, MA 02110-1301, USA. */
25 #include "elf/external.h"
26 #include "elf/common.h"
37 #include "gdb_assert.h"
41 #include "solib-svr4.h"
43 #include "bfd-target.h"
47 static struct link_map_offsets
*svr4_fetch_link_map_offsets (void);
48 static int svr4_have_link_map_offsets (void);
50 /* This hook is set to a function that provides native link map
51 offsets if the code in solib-legacy.c is linked in. */
52 struct link_map_offsets
*(*legacy_svr4_fetch_link_map_offsets_hook
) (void);
54 /* Link map info to include in an allocated so_list entry */
58 /* Pointer to copy of link map from inferior. The type is char *
59 rather than void *, so that we may use byte offsets to find the
60 various fields without the need for a cast. */
63 /* Amount by which addresses in the binary should be relocated to
64 match the inferior. This could most often be taken directly
65 from lm, but when prelinking is involved and the prelink base
66 address changes, we may need a different offset, we want to
67 warn about the difference and compute it only once. */
71 /* On SVR4 systems, a list of symbols in the dynamic linker where
72 GDB can try to place a breakpoint to monitor shared library
75 If none of these symbols are found, or other errors occur, then
76 SVR4 systems will fall back to using a symbol as the "startup
77 mapping complete" breakpoint address. */
79 static char *solib_break_names
[] =
87 /* On the 64-bit PowerPC, the linker symbol with the same name as
88 the C function points to a function descriptor, not to the entry
89 point. The linker symbol whose name is the C function name
90 prefixed with a '.' points to the function's entry point. So
91 when we look through this table, we ignore symbols that point
92 into the data section (thus skipping the descriptor's symbol),
93 and eventually try this one, giving us the real entry point
100 #define BKPT_AT_SYMBOL 1
102 #if defined (BKPT_AT_SYMBOL)
103 static char *bkpt_names
[] =
105 #ifdef SOLIB_BKPT_NAME
106 SOLIB_BKPT_NAME
, /* Prefer configured name if it exists. */
115 static char *main_name_list
[] =
121 /* link map access functions */
124 LM_ADDR_FROM_LINK_MAP (struct so_list
*so
)
126 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
128 return extract_typed_address (so
->lm_info
->lm
+ lmo
->l_addr_offset
,
129 builtin_type_void_data_ptr
);
133 HAS_LM_DYNAMIC_FROM_LINK_MAP ()
135 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
137 return lmo
->l_ld_offset
>= 0;
141 LM_DYNAMIC_FROM_LINK_MAP (struct so_list
*so
)
143 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
145 return extract_typed_address (so
->lm_info
->lm
+ lmo
->l_ld_offset
,
146 builtin_type_void_data_ptr
);
150 LM_ADDR_CHECK (struct so_list
*so
, bfd
*abfd
)
152 if (so
->lm_info
->l_addr
== (CORE_ADDR
)-1)
154 struct bfd_section
*dyninfo_sect
;
155 CORE_ADDR l_addr
, l_dynaddr
, dynaddr
, align
= 0x1000;
157 l_addr
= LM_ADDR_FROM_LINK_MAP (so
);
159 if (! abfd
|| ! HAS_LM_DYNAMIC_FROM_LINK_MAP ())
162 l_dynaddr
= LM_DYNAMIC_FROM_LINK_MAP (so
);
164 dyninfo_sect
= bfd_get_section_by_name (abfd
, ".dynamic");
165 if (dyninfo_sect
== NULL
)
168 dynaddr
= bfd_section_vma (abfd
, dyninfo_sect
);
170 if (dynaddr
+ l_addr
!= l_dynaddr
)
172 if (bfd_get_flavour (abfd
) == bfd_target_elf_flavour
)
174 Elf_Internal_Ehdr
*ehdr
= elf_tdata (abfd
)->elf_header
;
175 Elf_Internal_Phdr
*phdr
= elf_tdata (abfd
)->phdr
;
180 for (i
= 0; i
< ehdr
->e_phnum
; i
++)
181 if (phdr
[i
].p_type
== PT_LOAD
&& phdr
[i
].p_align
> align
)
182 align
= phdr
[i
].p_align
;
185 /* Turn it into a mask. */
188 /* If the changes match the alignment requirements, we
189 assume we're using a core file that was generated by the
190 same binary, just prelinked with a different base offset.
191 If it doesn't match, we may have a different binary, the
192 same binary with the dynamic table loaded at an unrelated
193 location, or anything, really. To avoid regressions,
194 don't adjust the base offset in the latter case, although
195 odds are that, if things really changed, debugging won't
197 if ((l_addr
& align
) == 0 && ((dynaddr
- l_dynaddr
) & align
) == 0)
199 l_addr
= l_dynaddr
- dynaddr
;
201 warning (_(".dynamic section for \"%s\" "
202 "is not at the expected address"), so
->so_name
);
203 warning (_("difference appears to be caused by prelink, "
204 "adjusting expectations"));
207 warning (_(".dynamic section for \"%s\" "
208 "is not at the expected address "
209 "(wrong library or version mismatch?)"), so
->so_name
);
213 so
->lm_info
->l_addr
= l_addr
;
216 return so
->lm_info
->l_addr
;
220 LM_NEXT (struct so_list
*so
)
222 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
224 return extract_typed_address (so
->lm_info
->lm
+ lmo
->l_next_offset
,
225 builtin_type_void_data_ptr
);
229 LM_NAME (struct so_list
*so
)
231 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
233 return extract_typed_address (so
->lm_info
->lm
+ lmo
->l_name_offset
,
234 builtin_type_void_data_ptr
);
238 IGNORE_FIRST_LINK_MAP_ENTRY (struct so_list
*so
)
240 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
242 /* Assume that everything is a library if the dynamic loader was loaded
243 late by a static executable. */
244 if (bfd_get_section_by_name (exec_bfd
, ".dynamic") == NULL
)
247 return extract_typed_address (so
->lm_info
->lm
+ lmo
->l_prev_offset
,
248 builtin_type_void_data_ptr
) == 0;
251 static CORE_ADDR debug_base
; /* Base of dynamic linker structures */
253 /* Validity flag for debug_loader_offset. */
254 static int debug_loader_offset_p
;
256 /* Load address for the dynamic linker, inferred. */
257 static CORE_ADDR debug_loader_offset
;
259 /* Name of the dynamic linker, valid if debug_loader_offset_p. */
260 static char *debug_loader_name
;
262 /* Local function prototypes */
264 static int match_main (char *);
266 static CORE_ADDR
bfd_lookup_symbol (bfd
*, char *, flagword
);
272 bfd_lookup_symbol -- lookup the value for a specific symbol
276 CORE_ADDR bfd_lookup_symbol (bfd *abfd, char *symname, flagword sect_flags)
280 An expensive way to lookup the value of a single symbol for
281 bfd's that are only temporary anyway. This is used by the
282 shared library support to find the address of the debugger
283 interface structures in the shared library.
285 If SECT_FLAGS is non-zero, only match symbols in sections whose
286 flags include all those in SECT_FLAGS.
288 Note that 0 is specifically allowed as an error return (no
293 bfd_lookup_symbol (bfd
*abfd
, char *symname
, flagword sect_flags
)
297 asymbol
**symbol_table
;
298 unsigned int number_of_symbols
;
300 struct cleanup
*back_to
;
301 CORE_ADDR symaddr
= 0;
303 storage_needed
= bfd_get_symtab_upper_bound (abfd
);
305 if (storage_needed
> 0)
307 symbol_table
= (asymbol
**) xmalloc (storage_needed
);
308 back_to
= make_cleanup (xfree
, symbol_table
);
309 number_of_symbols
= bfd_canonicalize_symtab (abfd
, symbol_table
);
311 for (i
= 0; i
< number_of_symbols
; i
++)
313 sym
= *symbol_table
++;
314 if (strcmp (sym
->name
, symname
) == 0
315 && (sym
->section
->flags
& sect_flags
) == sect_flags
)
317 /* Bfd symbols are section relative. */
318 symaddr
= sym
->value
+ sym
->section
->vma
;
322 do_cleanups (back_to
);
328 /* On FreeBSD, the dynamic linker is stripped by default. So we'll
329 have to check the dynamic string table too. */
331 storage_needed
= bfd_get_dynamic_symtab_upper_bound (abfd
);
333 if (storage_needed
> 0)
335 symbol_table
= (asymbol
**) xmalloc (storage_needed
);
336 back_to
= make_cleanup (xfree
, symbol_table
);
337 number_of_symbols
= bfd_canonicalize_dynamic_symtab (abfd
, symbol_table
);
339 for (i
= 0; i
< number_of_symbols
; i
++)
341 sym
= *symbol_table
++;
343 if (strcmp (sym
->name
, symname
) == 0
344 && (sym
->section
->flags
& sect_flags
) == sect_flags
)
346 /* Bfd symbols are section relative. */
347 symaddr
= sym
->value
+ sym
->section
->vma
;
351 do_cleanups (back_to
);
357 /* Scan for DYNTAG in .dynamic section of ABFD. If DYNTAG is found 1 is
358 returned and the corresponding PTR is set. */
361 scan_dyntag (int dyntag
, bfd
*abfd
, CORE_ADDR
*ptr
)
363 int arch_size
, step
, sect_size
;
365 CORE_ADDR dyn_ptr
, dyn_addr
;
366 gdb_byte
*bufend
, *buf
;
367 Elf32_External_Dyn
*x_dynp_32
;
368 Elf64_External_Dyn
*x_dynp_64
;
369 struct bfd_section
*sect
;
373 arch_size
= bfd_get_arch_size (abfd
);
377 /* Find the start address of the .dynamic section. */
378 sect
= bfd_get_section_by_name (abfd
, ".dynamic");
381 dyn_addr
= bfd_section_vma (abfd
, sect
);
383 /* Read in .dynamic section, silently ignore errors. */
384 sect_size
= bfd_section_size (abfd
, sect
);
385 buf
= alloca (sect_size
);
386 if (target_read_memory (dyn_addr
, buf
, sect_size
))
388 /* If target_read_memory fails, try reading the BFD file. */
389 if (!bfd_get_section_contents (abfd
, sect
,
394 /* Iterate over BUF and scan for DYNTAG. If found, set PTR and return. */
395 step
= (arch_size
== 32) ? sizeof (Elf32_External_Dyn
)
396 : sizeof (Elf64_External_Dyn
);
397 for (bufend
= buf
+ sect_size
;
403 x_dynp_32
= (Elf32_External_Dyn
*) buf
;
404 dyn_tag
= bfd_h_get_32 (abfd
, (bfd_byte
*) x_dynp_32
->d_tag
);
405 dyn_ptr
= bfd_h_get_32 (abfd
, (bfd_byte
*) x_dynp_32
->d_un
.d_ptr
);
409 x_dynp_64
= (Elf64_External_Dyn
*) buf
;
410 dyn_tag
= bfd_h_get_64 (abfd
, (bfd_byte
*) x_dynp_64
->d_tag
);
411 dyn_ptr
= bfd_h_get_64 (abfd
, (bfd_byte
*) x_dynp_64
->d_un
.d_ptr
);
413 if (dyn_tag
== DT_NULL
)
415 if (dyn_tag
== dyntag
)
431 elf_locate_base -- locate the base address of dynamic linker structs
432 for SVR4 elf targets.
436 CORE_ADDR elf_locate_base (void)
440 For SVR4 elf targets the address of the dynamic linker's runtime
441 structure is contained within the dynamic info section in the
442 executable file. The dynamic section is also mapped into the
443 inferior address space. Because the runtime loader fills in the
444 real address before starting the inferior, we have to read in the
445 dynamic info section from the inferior address space.
446 If there are any errors while trying to find the address, we
447 silently return 0, otherwise the found address is returned.
452 elf_locate_base (void)
454 struct minimal_symbol
*msymbol
;
458 if (scan_dyntag (DT_DEBUG
, exec_bfd
, &dyn_ptr
))
461 /* Find DT_MIPS_RLD_MAP. */
462 if (scan_dyntag (DT_MIPS_RLD_MAP
, exec_bfd
, &dyn_ptr
))
465 int pbuf_size
= TYPE_LENGTH (builtin_type_void_data_ptr
);
466 pbuf
= alloca (pbuf_size
);
467 /* DT_MIPS_RLD_MAP contains a pointer to the address
468 of the dynamic link structure. */
469 if (target_read_memory (dyn_ptr
, pbuf
, pbuf_size
))
471 return extract_typed_address (pbuf
, builtin_type_void_data_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
);
638 warning (_("failed to read exec filename from attached file: %s"),
639 safe_strerror (errcode
));
643 make_cleanup (xfree
, filename
);
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';
764 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. */
851 if ((buffer
&& strcmp (buffer
, objfile
->name
) == 0)
852 || (!(objfile
->flags
& OBJF_SHARED
) && (strcmp (buffer
, "") == 0)))
854 do_cleanups (old_chain
);
858 /* Not the file we wanted, continue checking. */
859 lm
= extract_typed_address (objfile_lm_info
.lm
+ lmo
->l_next_offset
,
860 builtin_type_void_data_ptr
);
861 do_cleanups (old_chain
);
866 /* On some systems, the only way to recognize the link map entry for
867 the main executable file is by looking at its name. Return
868 non-zero iff SONAME matches one of the known main executable names. */
871 match_main (char *soname
)
875 for (mainp
= main_name_list
; *mainp
!= NULL
; mainp
++)
877 if (strcmp (soname
, *mainp
) == 0)
884 /* Return 1 if PC lies in the dynamic symbol resolution code of the
885 SVR4 run time loader. */
886 static CORE_ADDR interp_text_sect_low
;
887 static CORE_ADDR interp_text_sect_high
;
888 static CORE_ADDR interp_plt_sect_low
;
889 static CORE_ADDR interp_plt_sect_high
;
892 svr4_in_dynsym_resolve_code (CORE_ADDR pc
)
894 return ((pc
>= interp_text_sect_low
&& pc
< interp_text_sect_high
)
895 || (pc
>= interp_plt_sect_low
&& pc
< interp_plt_sect_high
)
896 || in_plt_section (pc
, NULL
));
899 /* Given an executable's ABFD and target, compute the entry-point
903 exec_entry_point (struct bfd
*abfd
, struct target_ops
*targ
)
905 /* KevinB wrote ... for most targets, the address returned by
906 bfd_get_start_address() is the entry point for the start
907 function. But, for some targets, bfd_get_start_address() returns
908 the address of a function descriptor from which the entry point
909 address may be extracted. This address is extracted by
910 gdbarch_convert_from_func_ptr_addr(). The method
911 gdbarch_convert_from_func_ptr_addr() is the merely the identify
912 function for targets which don't use function descriptors. */
913 return gdbarch_convert_from_func_ptr_addr (current_gdbarch
,
914 bfd_get_start_address (abfd
),
922 enable_break -- arrange for dynamic linker to hit breakpoint
926 int enable_break (void)
930 Both the SunOS and the SVR4 dynamic linkers have, as part of their
931 debugger interface, support for arranging for the inferior to hit
932 a breakpoint after mapping in the shared libraries. This function
933 enables that breakpoint.
935 For SunOS, there is a special flag location (in_debugger) which we
936 set to 1. When the dynamic linker sees this flag set, it will set
937 a breakpoint at a location known only to itself, after saving the
938 original contents of that place and the breakpoint address itself,
939 in it's own internal structures. When we resume the inferior, it
940 will eventually take a SIGTRAP when it runs into the breakpoint.
941 We handle this (in a different place) by restoring the contents of
942 the breakpointed location (which is only known after it stops),
943 chasing around to locate the shared libraries that have been
944 loaded, then resuming.
946 For SVR4, the debugger interface structure contains a member (r_brk)
947 which is statically initialized at the time the shared library is
948 built, to the offset of a function (_r_debug_state) which is guaran-
949 teed to be called once before mapping in a library, and again when
950 the mapping is complete. At the time we are examining this member,
951 it contains only the unrelocated offset of the function, so we have
952 to do our own relocation. Later, when the dynamic linker actually
953 runs, it relocates r_brk to be the actual address of _r_debug_state().
955 The debugger interface structure also contains an enumeration which
956 is set to either RT_ADD or RT_DELETE prior to changing the mapping,
957 depending upon whether or not the library is being mapped or unmapped,
958 and then set to RT_CONSISTENT after the library is mapped/unmapped.
964 #ifdef BKPT_AT_SYMBOL
966 struct minimal_symbol
*msymbol
;
968 asection
*interp_sect
;
970 /* First, remove all the solib event breakpoints. Their addresses
971 may have changed since the last time we ran the program. */
972 remove_solib_event_breakpoints ();
974 interp_text_sect_low
= interp_text_sect_high
= 0;
975 interp_plt_sect_low
= interp_plt_sect_high
= 0;
977 /* Find the .interp section; if not found, warn the user and drop
978 into the old breakpoint at symbol code. */
979 interp_sect
= bfd_get_section_by_name (exec_bfd
, ".interp");
982 unsigned int interp_sect_size
;
984 CORE_ADDR load_addr
= 0;
985 int load_addr_found
= 0;
988 struct target_ops
*tmp_bfd_target
;
990 char *tmp_pathname
= NULL
;
991 CORE_ADDR sym_addr
= 0;
993 /* Read the contents of the .interp section into a local buffer;
994 the contents specify the dynamic linker this program uses. */
995 interp_sect_size
= bfd_section_size (exec_bfd
, interp_sect
);
996 buf
= alloca (interp_sect_size
);
997 bfd_get_section_contents (exec_bfd
, interp_sect
,
998 buf
, 0, interp_sect_size
);
1000 /* Now we need to figure out where the dynamic linker was
1001 loaded so that we can load its symbols and place a breakpoint
1002 in the dynamic linker itself.
1004 This address is stored on the stack. However, I've been unable
1005 to find any magic formula to find it for Solaris (appears to
1006 be trivial on GNU/Linux). Therefore, we have to try an alternate
1007 mechanism to find the dynamic linker's base address. */
1009 /* TODO drow/2006-09-12: This is somewhat fragile, because it
1010 relies on read_pc. On both Solaris and GNU/Linux we can use
1011 the AT_BASE auxilliary entry, which GDB now knows how to
1012 access, to find the base address. */
1014 tmp_fd
= solib_open (buf
, &tmp_pathname
);
1016 tmp_bfd
= bfd_fopen (tmp_pathname
, gnutarget
, FOPEN_RB
, tmp_fd
);
1018 if (tmp_bfd
== NULL
)
1019 goto bkpt_at_symbol
;
1021 /* Make sure the dynamic linker's really a useful object. */
1022 if (!bfd_check_format (tmp_bfd
, bfd_object
))
1024 warning (_("Unable to grok dynamic linker %s as an object file"), buf
);
1025 bfd_close (tmp_bfd
);
1026 goto bkpt_at_symbol
;
1029 /* Now convert the TMP_BFD into a target. That way target, as
1030 well as BFD operations can be used. Note that closing the
1031 target will also close the underlying bfd. */
1032 tmp_bfd_target
= target_bfd_reopen (tmp_bfd
);
1034 /* On a running target, we can get the dynamic linker's base
1035 address from the shared library table. */
1036 solib_add (NULL
, 0, NULL
, auto_solib_add
);
1037 so
= master_so_list ();
1040 if (strcmp (buf
, so
->so_original_name
) == 0)
1042 load_addr_found
= 1;
1043 load_addr
= LM_ADDR_CHECK (so
, tmp_bfd
);
1049 /* Otherwise we find the dynamic linker's base address by examining
1050 the current pc (which should point at the entry point for the
1051 dynamic linker) and subtracting the offset of the entry point. */
1052 if (!load_addr_found
)
1054 load_addr
= (read_pc ()
1055 - exec_entry_point (tmp_bfd
, tmp_bfd_target
));
1056 debug_loader_name
= xstrdup (buf
);
1057 debug_loader_offset_p
= 1;
1058 debug_loader_offset
= load_addr
;
1059 solib_add (NULL
, 0, NULL
, auto_solib_add
);
1062 /* Record the relocated start and end address of the dynamic linker
1063 text and plt section for svr4_in_dynsym_resolve_code. */
1064 interp_sect
= bfd_get_section_by_name (tmp_bfd
, ".text");
1067 interp_text_sect_low
=
1068 bfd_section_vma (tmp_bfd
, interp_sect
) + load_addr
;
1069 interp_text_sect_high
=
1070 interp_text_sect_low
+ bfd_section_size (tmp_bfd
, interp_sect
);
1072 interp_sect
= bfd_get_section_by_name (tmp_bfd
, ".plt");
1075 interp_plt_sect_low
=
1076 bfd_section_vma (tmp_bfd
, interp_sect
) + load_addr
;
1077 interp_plt_sect_high
=
1078 interp_plt_sect_low
+ bfd_section_size (tmp_bfd
, interp_sect
);
1081 /* Now try to set a breakpoint in the dynamic linker. */
1082 for (bkpt_namep
= solib_break_names
; *bkpt_namep
!= NULL
; bkpt_namep
++)
1084 /* On ABI's that use function descriptors, there are usually
1085 two linker symbols associated with each C function: one
1086 pointing at the actual entry point of the machine code,
1087 and one pointing at the function's descriptor. The
1088 latter symbol has the same name as the C function.
1090 What we're looking for here is the machine code entry
1091 point, so we are only interested in symbols in code
1093 sym_addr
= bfd_lookup_symbol (tmp_bfd
, *bkpt_namep
, SEC_CODE
);
1098 /* We're done with both the temporary bfd and target. Remember,
1099 closing the target closes the underlying bfd. */
1100 target_close (tmp_bfd_target
, 0);
1104 create_solib_event_breakpoint (load_addr
+ sym_addr
);
1108 /* For whatever reason we couldn't set a breakpoint in the dynamic
1109 linker. Warn and drop into the old code. */
1111 warning (_("Unable to find dynamic linker breakpoint function.\n"
1112 "GDB will be unable to debug shared library initializers\n"
1113 "and track explicitly loaded dynamic code."));
1116 /* Scan through the lists of symbols, trying to look up the symbol and
1117 set a breakpoint there. Terminate loop when we/if we succeed. */
1119 for (bkpt_namep
= solib_break_names
; *bkpt_namep
!= NULL
; bkpt_namep
++)
1121 msymbol
= lookup_minimal_symbol (*bkpt_namep
, NULL
, symfile_objfile
);
1122 if ((msymbol
!= NULL
) && (SYMBOL_VALUE_ADDRESS (msymbol
) != 0))
1124 create_solib_event_breakpoint (SYMBOL_VALUE_ADDRESS (msymbol
));
1129 for (bkpt_namep
= bkpt_names
; *bkpt_namep
!= NULL
; bkpt_namep
++)
1131 msymbol
= lookup_minimal_symbol (*bkpt_namep
, NULL
, symfile_objfile
);
1132 if ((msymbol
!= NULL
) && (SYMBOL_VALUE_ADDRESS (msymbol
) != 0))
1134 create_solib_event_breakpoint (SYMBOL_VALUE_ADDRESS (msymbol
));
1138 #endif /* BKPT_AT_SYMBOL */
1147 special_symbol_handling -- additional shared library symbol handling
1151 void special_symbol_handling ()
1155 Once the symbols from a shared object have been loaded in the usual
1156 way, we are called to do any system specific symbol handling that
1159 For SunOS4, this consisted of grunging around in the dynamic
1160 linkers structures to find symbol definitions for "common" symbols
1161 and adding them to the minimal symbol table for the runtime common
1164 However, for SVR4, there's nothing to do.
1169 svr4_special_symbol_handling (void)
1173 /* Relocate the main executable. This function should be called upon
1174 stopping the inferior process at the entry point to the program.
1175 The entry point from BFD is compared to the PC and if they are
1176 different, the main executable is relocated by the proper amount.
1178 As written it will only attempt to relocate executables which
1179 lack interpreter sections. It seems likely that only dynamic
1180 linker executables will get relocated, though it should work
1181 properly for a position-independent static executable as well. */
1184 svr4_relocate_main_executable (void)
1186 asection
*interp_sect
;
1187 CORE_ADDR pc
= read_pc ();
1189 /* Decide if the objfile needs to be relocated. As indicated above,
1190 we will only be here when execution is stopped at the beginning
1191 of the program. Relocation is necessary if the address at which
1192 we are presently stopped differs from the start address stored in
1193 the executable AND there's no interpreter section. The condition
1194 regarding the interpreter section is very important because if
1195 there *is* an interpreter section, execution will begin there
1196 instead. When there is an interpreter section, the start address
1197 is (presumably) used by the interpreter at some point to start
1198 execution of the program.
1200 If there is an interpreter, it is normal for it to be set to an
1201 arbitrary address at the outset. The job of finding it is
1202 handled in enable_break().
1204 So, to summarize, relocations are necessary when there is no
1205 interpreter section and the start address obtained from the
1206 executable is different from the address at which GDB is
1209 [ The astute reader will note that we also test to make sure that
1210 the executable in question has the DYNAMIC flag set. It is my
1211 opinion that this test is unnecessary (undesirable even). It
1212 was added to avoid inadvertent relocation of an executable
1213 whose e_type member in the ELF header is not ET_DYN. There may
1214 be a time in the future when it is desirable to do relocations
1215 on other types of files as well in which case this condition
1216 should either be removed or modified to accomodate the new file
1217 type. (E.g, an ET_EXEC executable which has been built to be
1218 position-independent could safely be relocated by the OS if
1219 desired. It is true that this violates the ABI, but the ABI
1220 has been known to be bent from time to time.) - Kevin, Nov 2000. ]
1223 interp_sect
= bfd_get_section_by_name (exec_bfd
, ".interp");
1224 if (interp_sect
== NULL
1225 && (bfd_get_file_flags (exec_bfd
) & DYNAMIC
) != 0
1226 && (exec_entry_point (exec_bfd
, &exec_ops
) != pc
))
1228 struct cleanup
*old_chain
;
1229 struct section_offsets
*new_offsets
;
1231 CORE_ADDR displacement
;
1233 /* It is necessary to relocate the objfile. The amount to
1234 relocate by is simply the address at which we are stopped
1235 minus the starting address from the executable.
1237 We relocate all of the sections by the same amount. This
1238 behavior is mandated by recent editions of the System V ABI.
1239 According to the System V Application Binary Interface,
1240 Edition 4.1, page 5-5:
1242 ... Though the system chooses virtual addresses for
1243 individual processes, it maintains the segments' relative
1244 positions. Because position-independent code uses relative
1245 addressesing between segments, the difference between
1246 virtual addresses in memory must match the difference
1247 between virtual addresses in the file. The difference
1248 between the virtual address of any segment in memory and
1249 the corresponding virtual address in the file is thus a
1250 single constant value for any one executable or shared
1251 object in a given process. This difference is the base
1252 address. One use of the base address is to relocate the
1253 memory image of the program during dynamic linking.
1255 The same language also appears in Edition 4.0 of the System V
1256 ABI and is left unspecified in some of the earlier editions. */
1258 displacement
= pc
- exec_entry_point (exec_bfd
, &exec_ops
);
1261 new_offsets
= xcalloc (symfile_objfile
->num_sections
,
1262 sizeof (struct section_offsets
));
1263 old_chain
= make_cleanup (xfree
, new_offsets
);
1265 for (i
= 0; i
< symfile_objfile
->num_sections
; i
++)
1267 if (displacement
!= ANOFFSET (symfile_objfile
->section_offsets
, i
))
1269 new_offsets
->offsets
[i
] = displacement
;
1273 objfile_relocate (symfile_objfile
, new_offsets
);
1275 do_cleanups (old_chain
);
1283 svr4_solib_create_inferior_hook -- shared library startup support
1287 void svr4_solib_create_inferior_hook ()
1291 When gdb starts up the inferior, it nurses it along (through the
1292 shell) until it is ready to execute it's first instruction. At this
1293 point, this function gets called via expansion of the macro
1294 SOLIB_CREATE_INFERIOR_HOOK.
1296 For SunOS executables, this first instruction is typically the
1297 one at "_start", or a similar text label, regardless of whether
1298 the executable is statically or dynamically linked. The runtime
1299 startup code takes care of dynamically linking in any shared
1300 libraries, once gdb allows the inferior to continue.
1302 For SVR4 executables, this first instruction is either the first
1303 instruction in the dynamic linker (for dynamically linked
1304 executables) or the instruction at "start" for statically linked
1305 executables. For dynamically linked executables, the system
1306 first exec's /lib/libc.so.N, which contains the dynamic linker,
1307 and starts it running. The dynamic linker maps in any needed
1308 shared libraries, maps in the actual user executable, and then
1309 jumps to "start" in the user executable.
1311 For both SunOS shared libraries, and SVR4 shared libraries, we
1312 can arrange to cooperate with the dynamic linker to discover the
1313 names of shared libraries that are dynamically linked, and the
1314 base addresses to which they are linked.
1316 This function is responsible for discovering those names and
1317 addresses, and saving sufficient information about them to allow
1318 their symbols to be read at a later time.
1322 Between enable_break() and disable_break(), this code does not
1323 properly handle hitting breakpoints which the user might have
1324 set in the startup code or in the dynamic linker itself. Proper
1325 handling will probably have to wait until the implementation is
1326 changed to use the "breakpoint handler function" method.
1328 Also, what if child has exit()ed? Must exit loop somehow.
1332 svr4_solib_create_inferior_hook (void)
1334 /* Relocate the main executable if necessary. */
1335 svr4_relocate_main_executable ();
1337 if (!svr4_have_link_map_offsets ())
1340 if (!enable_break ())
1343 #if defined(_SCO_DS)
1344 /* SCO needs the loop below, other systems should be using the
1345 special shared library breakpoints and the shared library breakpoint
1348 Now run the target. It will eventually hit the breakpoint, at
1349 which point all of the libraries will have been mapped in and we
1350 can go groveling around in the dynamic linker structures to find
1351 out what we need to know about them. */
1353 clear_proceed_status ();
1354 stop_soon
= STOP_QUIETLY
;
1355 stop_signal
= TARGET_SIGNAL_0
;
1358 target_resume (pid_to_ptid (-1), 0, stop_signal
);
1359 wait_for_inferior ();
1361 while (stop_signal
!= TARGET_SIGNAL_TRAP
);
1362 stop_soon
= NO_STOP_QUIETLY
;
1363 #endif /* defined(_SCO_DS) */
1367 svr4_clear_solib (void)
1370 debug_loader_offset_p
= 0;
1371 debug_loader_offset
= 0;
1372 xfree (debug_loader_name
);
1373 debug_loader_name
= NULL
;
1377 svr4_free_so (struct so_list
*so
)
1379 xfree (so
->lm_info
->lm
);
1380 xfree (so
->lm_info
);
1384 /* Clear any bits of ADDR that wouldn't fit in a target-format
1385 data pointer. "Data pointer" here refers to whatever sort of
1386 address the dynamic linker uses to manage its sections. At the
1387 moment, we don't support shared libraries on any processors where
1388 code and data pointers are different sizes.
1390 This isn't really the right solution. What we really need here is
1391 a way to do arithmetic on CORE_ADDR values that respects the
1392 natural pointer/address correspondence. (For example, on the MIPS,
1393 converting a 32-bit pointer to a 64-bit CORE_ADDR requires you to
1394 sign-extend the value. There, simply truncating the bits above
1395 gdbarch_ptr_bit, as we do below, is no good.) This should probably
1396 be a new gdbarch method or something. */
1398 svr4_truncate_ptr (CORE_ADDR addr
)
1400 if (gdbarch_ptr_bit (current_gdbarch
) == sizeof (CORE_ADDR
) * 8)
1401 /* We don't need to truncate anything, and the bit twiddling below
1402 will fail due to overflow problems. */
1405 return addr
& (((CORE_ADDR
) 1 << gdbarch_ptr_bit (current_gdbarch
)) - 1);
1410 svr4_relocate_section_addresses (struct so_list
*so
,
1411 struct section_table
*sec
)
1413 sec
->addr
= svr4_truncate_ptr (sec
->addr
+ LM_ADDR_CHECK (so
,
1415 sec
->endaddr
= svr4_truncate_ptr (sec
->endaddr
+ LM_ADDR_CHECK (so
,
1420 /* Architecture-specific operations. */
1422 /* Per-architecture data key. */
1423 static struct gdbarch_data
*solib_svr4_data
;
1425 struct solib_svr4_ops
1427 /* Return a description of the layout of `struct link_map'. */
1428 struct link_map_offsets
*(*fetch_link_map_offsets
)(void);
1431 /* Return a default for the architecture-specific operations. */
1434 solib_svr4_init (struct obstack
*obstack
)
1436 struct solib_svr4_ops
*ops
;
1438 ops
= OBSTACK_ZALLOC (obstack
, struct solib_svr4_ops
);
1439 ops
->fetch_link_map_offsets
= legacy_svr4_fetch_link_map_offsets_hook
;
1443 /* Set the architecture-specific `struct link_map_offsets' fetcher for
1447 set_solib_svr4_fetch_link_map_offsets (struct gdbarch
*gdbarch
,
1448 struct link_map_offsets
*(*flmo
) (void))
1450 struct solib_svr4_ops
*ops
= gdbarch_data (gdbarch
, solib_svr4_data
);
1452 ops
->fetch_link_map_offsets
= flmo
;
1455 /* Fetch a link_map_offsets structure using the architecture-specific
1456 `struct link_map_offsets' fetcher. */
1458 static struct link_map_offsets
*
1459 svr4_fetch_link_map_offsets (void)
1461 struct solib_svr4_ops
*ops
= gdbarch_data (current_gdbarch
, solib_svr4_data
);
1463 gdb_assert (ops
->fetch_link_map_offsets
);
1464 return ops
->fetch_link_map_offsets ();
1467 /* Return 1 if a link map offset fetcher has been defined, 0 otherwise. */
1470 svr4_have_link_map_offsets (void)
1472 struct solib_svr4_ops
*ops
= gdbarch_data (current_gdbarch
, solib_svr4_data
);
1473 return (ops
->fetch_link_map_offsets
!= NULL
);
1477 /* Most OS'es that have SVR4-style ELF dynamic libraries define a
1478 `struct r_debug' and a `struct link_map' that are binary compatible
1479 with the origional SVR4 implementation. */
1481 /* Fetch (and possibly build) an appropriate `struct link_map_offsets'
1482 for an ILP32 SVR4 system. */
1484 struct link_map_offsets
*
1485 svr4_ilp32_fetch_link_map_offsets (void)
1487 static struct link_map_offsets lmo
;
1488 static struct link_map_offsets
*lmp
= NULL
;
1494 lmo
.r_version_offset
= 0;
1495 lmo
.r_version_size
= 4;
1496 lmo
.r_map_offset
= 4;
1497 lmo
.r_ldsomap_offset
= 20;
1499 /* Everything we need is in the first 20 bytes. */
1500 lmo
.link_map_size
= 20;
1501 lmo
.l_addr_offset
= 0;
1502 lmo
.l_name_offset
= 4;
1503 lmo
.l_ld_offset
= 8;
1504 lmo
.l_next_offset
= 12;
1505 lmo
.l_prev_offset
= 16;
1511 /* Fetch (and possibly build) an appropriate `struct link_map_offsets'
1512 for an LP64 SVR4 system. */
1514 struct link_map_offsets
*
1515 svr4_lp64_fetch_link_map_offsets (void)
1517 static struct link_map_offsets lmo
;
1518 static struct link_map_offsets
*lmp
= NULL
;
1524 lmo
.r_version_offset
= 0;
1525 lmo
.r_version_size
= 4;
1526 lmo
.r_map_offset
= 8;
1527 lmo
.r_ldsomap_offset
= 40;
1529 /* Everything we need is in the first 40 bytes. */
1530 lmo
.link_map_size
= 40;
1531 lmo
.l_addr_offset
= 0;
1532 lmo
.l_name_offset
= 8;
1533 lmo
.l_ld_offset
= 16;
1534 lmo
.l_next_offset
= 24;
1535 lmo
.l_prev_offset
= 32;
1542 struct target_so_ops svr4_so_ops
;
1544 /* Lookup global symbol for ELF DSOs linked with -Bsymbolic. Those DSOs have a
1545 different rule for symbol lookup. The lookup begins here in the DSO, not in
1546 the main executable. */
1548 static struct symbol
*
1549 elf_lookup_lib_symbol (const struct objfile
*objfile
,
1551 const char *linkage_name
,
1552 const domain_enum domain
, struct symtab
**symtab
)
1554 if (objfile
->obfd
== NULL
1555 || scan_dyntag (DT_SYMBOLIC
, objfile
->obfd
, NULL
) != 1)
1558 return lookup_global_symbol_from_objfile
1559 (objfile
, name
, linkage_name
, domain
, symtab
);
1562 extern initialize_file_ftype _initialize_svr4_solib
; /* -Wmissing-prototypes */
1565 _initialize_svr4_solib (void)
1567 solib_svr4_data
= gdbarch_data_register_pre_init (solib_svr4_init
);
1569 svr4_so_ops
.relocate_section_addresses
= svr4_relocate_section_addresses
;
1570 svr4_so_ops
.free_so
= svr4_free_so
;
1571 svr4_so_ops
.clear_solib
= svr4_clear_solib
;
1572 svr4_so_ops
.solib_create_inferior_hook
= svr4_solib_create_inferior_hook
;
1573 svr4_so_ops
.special_symbol_handling
= svr4_special_symbol_handling
;
1574 svr4_so_ops
.current_sos
= svr4_current_sos
;
1575 svr4_so_ops
.open_symbol_file_object
= open_symbol_file_object
;
1576 svr4_so_ops
.in_dynsym_resolve_code
= svr4_in_dynsym_resolve_code
;
1577 svr4_so_ops
.lookup_lib_global_symbol
= elf_lookup_lib_symbol
;
1579 /* FIXME: Don't do this here. *_gdbarch_init() should set so_ops. */
1580 current_target_so_ops
= &svr4_so_ops
;