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, 2008, 2009, 2010, 2011
5 Free Software Foundation, Inc.
7 This file is part of GDB.
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program. If not, see <http://www.gnu.org/licenses/>. */
24 #include "elf/external.h"
25 #include "elf/common.h"
36 #include "gdbthread.h"
39 #include "gdb_assert.h"
43 #include "solib-svr4.h"
45 #include "bfd-target.h"
49 #include "exceptions.h"
51 static struct link_map_offsets
*svr4_fetch_link_map_offsets (void);
52 static int svr4_have_link_map_offsets (void);
53 static void svr4_relocate_main_executable (void);
55 /* Link map info to include in an allocated so_list entry. */
59 /* Pointer to copy of link map from inferior. The type is char *
60 rather than void *, so that we may use byte offsets to find the
61 various fields without the need for a cast. */
64 /* Amount by which addresses in the binary should be relocated to
65 match the inferior. This could most often be taken directly
66 from lm, but when prelinking is involved and the prelink base
67 address changes, we may need a different offset, we want to
68 warn about the difference and compute it only once. */
71 /* The target location of lm. */
75 /* On SVR4 systems, a list of symbols in the dynamic linker where
76 GDB can try to place a breakpoint to monitor shared library
79 If none of these symbols are found, or other errors occur, then
80 SVR4 systems will fall back to using a symbol as the "startup
81 mapping complete" breakpoint address. */
83 static const char * const solib_break_names
[] =
89 "__dl_rtld_db_dlactivity",
95 static const char * const bkpt_names
[] =
103 static const char * const main_name_list
[] =
109 /* Return non-zero if GDB_SO_NAME and INFERIOR_SO_NAME represent
110 the same shared library. */
113 svr4_same_1 (const char *gdb_so_name
, const char *inferior_so_name
)
115 if (strcmp (gdb_so_name
, inferior_so_name
) == 0)
118 /* On Solaris, when starting inferior we think that dynamic linker is
119 /usr/lib/ld.so.1, but later on, the table of loaded shared libraries
120 contains /lib/ld.so.1. Sometimes one file is a link to another, but
121 sometimes they have identical content, but are not linked to each
122 other. We don't restrict this check for Solaris, but the chances
123 of running into this situation elsewhere are very low. */
124 if (strcmp (gdb_so_name
, "/usr/lib/ld.so.1") == 0
125 && strcmp (inferior_so_name
, "/lib/ld.so.1") == 0)
128 /* Similarly, we observed the same issue with sparc64, but with
129 different locations. */
130 if (strcmp (gdb_so_name
, "/usr/lib/sparcv9/ld.so.1") == 0
131 && strcmp (inferior_so_name
, "/lib/sparcv9/ld.so.1") == 0)
138 svr4_same (struct so_list
*gdb
, struct so_list
*inferior
)
140 return (svr4_same_1 (gdb
->so_original_name
, inferior
->so_original_name
));
143 /* link map access functions. */
146 lm_addr_from_link_map (struct so_list
*so
)
148 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
149 struct type
*ptr_type
= builtin_type (target_gdbarch
)->builtin_data_ptr
;
151 return extract_typed_address (so
->lm_info
->lm
+ lmo
->l_addr_offset
,
156 has_lm_dynamic_from_link_map (void)
158 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
160 return lmo
->l_ld_offset
>= 0;
164 lm_dynamic_from_link_map (struct so_list
*so
)
166 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
167 struct type
*ptr_type
= builtin_type (target_gdbarch
)->builtin_data_ptr
;
169 return extract_typed_address (so
->lm_info
->lm
+ lmo
->l_ld_offset
,
174 lm_addr_check (struct so_list
*so
, bfd
*abfd
)
176 if (so
->lm_info
->l_addr
== (CORE_ADDR
)-1)
178 struct bfd_section
*dyninfo_sect
;
179 CORE_ADDR l_addr
, l_dynaddr
, dynaddr
;
181 l_addr
= lm_addr_from_link_map (so
);
183 if (! abfd
|| ! has_lm_dynamic_from_link_map ())
186 l_dynaddr
= lm_dynamic_from_link_map (so
);
188 dyninfo_sect
= bfd_get_section_by_name (abfd
, ".dynamic");
189 if (dyninfo_sect
== NULL
)
192 dynaddr
= bfd_section_vma (abfd
, dyninfo_sect
);
194 if (dynaddr
+ l_addr
!= l_dynaddr
)
196 CORE_ADDR align
= 0x1000;
197 CORE_ADDR minpagesize
= align
;
199 if (bfd_get_flavour (abfd
) == bfd_target_elf_flavour
)
201 Elf_Internal_Ehdr
*ehdr
= elf_tdata (abfd
)->elf_header
;
202 Elf_Internal_Phdr
*phdr
= elf_tdata (abfd
)->phdr
;
207 for (i
= 0; i
< ehdr
->e_phnum
; i
++)
208 if (phdr
[i
].p_type
== PT_LOAD
&& phdr
[i
].p_align
> align
)
209 align
= phdr
[i
].p_align
;
211 minpagesize
= get_elf_backend_data (abfd
)->minpagesize
;
214 /* Turn it into a mask. */
217 /* If the changes match the alignment requirements, we
218 assume we're using a core file that was generated by the
219 same binary, just prelinked with a different base offset.
220 If it doesn't match, we may have a different binary, the
221 same binary with the dynamic table loaded at an unrelated
222 location, or anything, really. To avoid regressions,
223 don't adjust the base offset in the latter case, although
224 odds are that, if things really changed, debugging won't
227 One could expect more the condition
228 ((l_addr & align) == 0 && ((l_dynaddr - dynaddr) & align) == 0)
229 but the one below is relaxed for PPC. The PPC kernel supports
230 either 4k or 64k page sizes. To be prepared for 64k pages,
231 PPC ELF files are built using an alignment requirement of 64k.
232 However, when running on a kernel supporting 4k pages, the memory
233 mapping of the library may not actually happen on a 64k boundary!
235 (In the usual case where (l_addr & align) == 0, this check is
236 equivalent to the possibly expected check above.)
238 Even on PPC it must be zero-aligned at least for MINPAGESIZE. */
240 l_addr
= l_dynaddr
- dynaddr
;
242 if ((l_addr
& (minpagesize
- 1)) == 0
243 && (l_addr
& align
) == ((l_dynaddr
- dynaddr
) & align
))
246 printf_unfiltered (_("Using PIC (Position Independent Code) "
247 "prelink displacement %s for \"%s\".\n"),
248 paddress (target_gdbarch
, l_addr
),
253 /* There is no way to verify the library file matches. prelink
254 can during prelinking of an unprelinked file (or unprelinking
255 of a prelinked file) shift the DYNAMIC segment by arbitrary
256 offset without any page size alignment. There is no way to
257 find out the ELF header and/or Program Headers for a limited
258 verification if it they match. One could do a verification
259 of the DYNAMIC segment. Still the found address is the best
260 one GDB could find. */
262 warning (_(".dynamic section for \"%s\" "
263 "is not at the expected address "
264 "(wrong library or version mismatch?)"), so
->so_name
);
269 so
->lm_info
->l_addr
= l_addr
;
272 return so
->lm_info
->l_addr
;
276 lm_next (struct so_list
*so
)
278 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
279 struct type
*ptr_type
= builtin_type (target_gdbarch
)->builtin_data_ptr
;
281 return extract_typed_address (so
->lm_info
->lm
+ lmo
->l_next_offset
,
286 lm_prev (struct so_list
*so
)
288 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
289 struct type
*ptr_type
= builtin_type (target_gdbarch
)->builtin_data_ptr
;
291 return extract_typed_address (so
->lm_info
->lm
+ lmo
->l_prev_offset
,
296 lm_name (struct so_list
*so
)
298 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
299 struct type
*ptr_type
= builtin_type (target_gdbarch
)->builtin_data_ptr
;
301 return extract_typed_address (so
->lm_info
->lm
+ lmo
->l_name_offset
,
306 ignore_first_link_map_entry (struct so_list
*so
)
308 /* Assume that everything is a library if the dynamic loader was loaded
309 late by a static executable. */
310 if (exec_bfd
&& bfd_get_section_by_name (exec_bfd
, ".dynamic") == NULL
)
313 return lm_prev (so
) == 0;
316 /* Per pspace SVR4 specific data. */
320 CORE_ADDR debug_base
; /* Base of dynamic linker structures. */
322 /* Validity flag for debug_loader_offset. */
323 int debug_loader_offset_p
;
325 /* Load address for the dynamic linker, inferred. */
326 CORE_ADDR debug_loader_offset
;
328 /* Name of the dynamic linker, valid if debug_loader_offset_p. */
329 char *debug_loader_name
;
331 /* Load map address for the main executable. */
332 CORE_ADDR main_lm_addr
;
334 CORE_ADDR interp_text_sect_low
;
335 CORE_ADDR interp_text_sect_high
;
336 CORE_ADDR interp_plt_sect_low
;
337 CORE_ADDR interp_plt_sect_high
;
340 /* Per-program-space data key. */
341 static const struct program_space_data
*solib_svr4_pspace_data
;
344 svr4_pspace_data_cleanup (struct program_space
*pspace
, void *arg
)
346 struct svr4_info
*info
;
348 info
= program_space_data (pspace
, solib_svr4_pspace_data
);
352 /* Get the current svr4 data. If none is found yet, add it now. This
353 function always returns a valid object. */
355 static struct svr4_info
*
358 struct svr4_info
*info
;
360 info
= program_space_data (current_program_space
, solib_svr4_pspace_data
);
364 info
= XZALLOC (struct svr4_info
);
365 set_program_space_data (current_program_space
, solib_svr4_pspace_data
, info
);
369 /* Local function prototypes */
371 static int match_main (const char *);
373 /* Read program header TYPE from inferior memory. The header is found
374 by scanning the OS auxillary vector.
376 If TYPE == -1, return the program headers instead of the contents of
379 Return a pointer to allocated memory holding the program header contents,
380 or NULL on failure. If sucessful, and unless P_SECT_SIZE is NULL, the
381 size of those contents is returned to P_SECT_SIZE. Likewise, the target
382 architecture size (32-bit or 64-bit) is returned to P_ARCH_SIZE. */
385 read_program_header (int type
, int *p_sect_size
, int *p_arch_size
)
387 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch
);
388 CORE_ADDR at_phdr
, at_phent
, at_phnum
;
389 int arch_size
, sect_size
;
393 /* Get required auxv elements from target. */
394 if (target_auxv_search (¤t_target
, AT_PHDR
, &at_phdr
) <= 0)
396 if (target_auxv_search (¤t_target
, AT_PHENT
, &at_phent
) <= 0)
398 if (target_auxv_search (¤t_target
, AT_PHNUM
, &at_phnum
) <= 0)
400 if (!at_phdr
|| !at_phnum
)
403 /* Determine ELF architecture type. */
404 if (at_phent
== sizeof (Elf32_External_Phdr
))
406 else if (at_phent
== sizeof (Elf64_External_Phdr
))
411 /* Find the requested segment. */
415 sect_size
= at_phent
* at_phnum
;
417 else if (arch_size
== 32)
419 Elf32_External_Phdr phdr
;
422 /* Search for requested PHDR. */
423 for (i
= 0; i
< at_phnum
; i
++)
425 if (target_read_memory (at_phdr
+ i
* sizeof (phdr
),
426 (gdb_byte
*)&phdr
, sizeof (phdr
)))
429 if (extract_unsigned_integer ((gdb_byte
*)phdr
.p_type
,
430 4, byte_order
) == type
)
437 /* Retrieve address and size. */
438 sect_addr
= extract_unsigned_integer ((gdb_byte
*)phdr
.p_vaddr
,
440 sect_size
= extract_unsigned_integer ((gdb_byte
*)phdr
.p_memsz
,
445 Elf64_External_Phdr phdr
;
448 /* Search for requested PHDR. */
449 for (i
= 0; i
< at_phnum
; i
++)
451 if (target_read_memory (at_phdr
+ i
* sizeof (phdr
),
452 (gdb_byte
*)&phdr
, sizeof (phdr
)))
455 if (extract_unsigned_integer ((gdb_byte
*)phdr
.p_type
,
456 4, byte_order
) == type
)
463 /* Retrieve address and size. */
464 sect_addr
= extract_unsigned_integer ((gdb_byte
*)phdr
.p_vaddr
,
466 sect_size
= extract_unsigned_integer ((gdb_byte
*)phdr
.p_memsz
,
470 /* Read in requested program header. */
471 buf
= xmalloc (sect_size
);
472 if (target_read_memory (sect_addr
, buf
, sect_size
))
479 *p_arch_size
= arch_size
;
481 *p_sect_size
= sect_size
;
487 /* Return program interpreter string. */
489 find_program_interpreter (void)
491 gdb_byte
*buf
= NULL
;
493 /* If we have an exec_bfd, use its section table. */
495 && bfd_get_flavour (exec_bfd
) == bfd_target_elf_flavour
)
497 struct bfd_section
*interp_sect
;
499 interp_sect
= bfd_get_section_by_name (exec_bfd
, ".interp");
500 if (interp_sect
!= NULL
)
502 int sect_size
= bfd_section_size (exec_bfd
, interp_sect
);
504 buf
= xmalloc (sect_size
);
505 bfd_get_section_contents (exec_bfd
, interp_sect
, buf
, 0, sect_size
);
509 /* If we didn't find it, use the target auxillary vector. */
511 buf
= read_program_header (PT_INTERP
, NULL
, NULL
);
517 /* Scan for DYNTAG in .dynamic section of ABFD. If DYNTAG is found 1 is
518 returned and the corresponding PTR is set. */
521 scan_dyntag (int dyntag
, bfd
*abfd
, CORE_ADDR
*ptr
)
523 int arch_size
, step
, sect_size
;
525 CORE_ADDR dyn_ptr
, dyn_addr
;
526 gdb_byte
*bufend
, *bufstart
, *buf
;
527 Elf32_External_Dyn
*x_dynp_32
;
528 Elf64_External_Dyn
*x_dynp_64
;
529 struct bfd_section
*sect
;
530 struct target_section
*target_section
;
535 if (bfd_get_flavour (abfd
) != bfd_target_elf_flavour
)
538 arch_size
= bfd_get_arch_size (abfd
);
542 /* Find the start address of the .dynamic section. */
543 sect
= bfd_get_section_by_name (abfd
, ".dynamic");
547 for (target_section
= current_target_sections
->sections
;
548 target_section
< current_target_sections
->sections_end
;
550 if (sect
== target_section
->the_bfd_section
)
552 if (target_section
< current_target_sections
->sections_end
)
553 dyn_addr
= target_section
->addr
;
556 /* ABFD may come from OBJFILE acting only as a symbol file without being
557 loaded into the target (see add_symbol_file_command). This case is
558 such fallback to the file VMA address without the possibility of
559 having the section relocated to its actual in-memory address. */
561 dyn_addr
= bfd_section_vma (abfd
, sect
);
564 /* Read in .dynamic from the BFD. We will get the actual value
565 from memory later. */
566 sect_size
= bfd_section_size (abfd
, sect
);
567 buf
= bufstart
= alloca (sect_size
);
568 if (!bfd_get_section_contents (abfd
, sect
,
572 /* Iterate over BUF and scan for DYNTAG. If found, set PTR and return. */
573 step
= (arch_size
== 32) ? sizeof (Elf32_External_Dyn
)
574 : sizeof (Elf64_External_Dyn
);
575 for (bufend
= buf
+ sect_size
;
581 x_dynp_32
= (Elf32_External_Dyn
*) buf
;
582 dyn_tag
= bfd_h_get_32 (abfd
, (bfd_byte
*) x_dynp_32
->d_tag
);
583 dyn_ptr
= bfd_h_get_32 (abfd
, (bfd_byte
*) x_dynp_32
->d_un
.d_ptr
);
587 x_dynp_64
= (Elf64_External_Dyn
*) buf
;
588 dyn_tag
= bfd_h_get_64 (abfd
, (bfd_byte
*) x_dynp_64
->d_tag
);
589 dyn_ptr
= bfd_h_get_64 (abfd
, (bfd_byte
*) x_dynp_64
->d_un
.d_ptr
);
591 if (dyn_tag
== DT_NULL
)
593 if (dyn_tag
== dyntag
)
595 /* If requested, try to read the runtime value of this .dynamic
599 struct type
*ptr_type
;
603 ptr_type
= builtin_type (target_gdbarch
)->builtin_data_ptr
;
604 ptr_addr
= dyn_addr
+ (buf
- bufstart
) + arch_size
/ 8;
605 if (target_read_memory (ptr_addr
, ptr_buf
, arch_size
/ 8) == 0)
606 dyn_ptr
= extract_typed_address (ptr_buf
, ptr_type
);
616 /* Scan for DYNTAG in .dynamic section of the target's main executable,
617 found by consulting the OS auxillary vector. If DYNTAG is found 1 is
618 returned and the corresponding PTR is set. */
621 scan_dyntag_auxv (int dyntag
, CORE_ADDR
*ptr
)
623 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch
);
624 int sect_size
, arch_size
, step
;
627 gdb_byte
*bufend
, *bufstart
, *buf
;
629 /* Read in .dynamic section. */
630 buf
= bufstart
= read_program_header (PT_DYNAMIC
, §_size
, &arch_size
);
634 /* Iterate over BUF and scan for DYNTAG. If found, set PTR and return. */
635 step
= (arch_size
== 32) ? sizeof (Elf32_External_Dyn
)
636 : sizeof (Elf64_External_Dyn
);
637 for (bufend
= buf
+ sect_size
;
643 Elf32_External_Dyn
*dynp
= (Elf32_External_Dyn
*) buf
;
645 dyn_tag
= extract_unsigned_integer ((gdb_byte
*) dynp
->d_tag
,
647 dyn_ptr
= extract_unsigned_integer ((gdb_byte
*) dynp
->d_un
.d_ptr
,
652 Elf64_External_Dyn
*dynp
= (Elf64_External_Dyn
*) buf
;
654 dyn_tag
= extract_unsigned_integer ((gdb_byte
*) dynp
->d_tag
,
656 dyn_ptr
= extract_unsigned_integer ((gdb_byte
*) dynp
->d_un
.d_ptr
,
659 if (dyn_tag
== DT_NULL
)
662 if (dyn_tag
== dyntag
)
676 /* Locate the base address of dynamic linker structs for SVR4 elf
679 For SVR4 elf targets the address of the dynamic linker's runtime
680 structure is contained within the dynamic info section in the
681 executable file. The dynamic section is also mapped into the
682 inferior address space. Because the runtime loader fills in the
683 real address before starting the inferior, we have to read in the
684 dynamic info section from the inferior address space.
685 If there are any errors while trying to find the address, we
686 silently return 0, otherwise the found address is returned. */
689 elf_locate_base (void)
691 struct minimal_symbol
*msymbol
;
694 /* Look for DT_MIPS_RLD_MAP first. MIPS executables use this
695 instead of DT_DEBUG, although they sometimes contain an unused
697 if (scan_dyntag (DT_MIPS_RLD_MAP
, exec_bfd
, &dyn_ptr
)
698 || scan_dyntag_auxv (DT_MIPS_RLD_MAP
, &dyn_ptr
))
700 struct type
*ptr_type
= builtin_type (target_gdbarch
)->builtin_data_ptr
;
702 int pbuf_size
= TYPE_LENGTH (ptr_type
);
704 pbuf
= alloca (pbuf_size
);
705 /* DT_MIPS_RLD_MAP contains a pointer to the address
706 of the dynamic link structure. */
707 if (target_read_memory (dyn_ptr
, pbuf
, pbuf_size
))
709 return extract_typed_address (pbuf
, ptr_type
);
713 if (scan_dyntag (DT_DEBUG
, exec_bfd
, &dyn_ptr
)
714 || scan_dyntag_auxv (DT_DEBUG
, &dyn_ptr
))
717 /* This may be a static executable. Look for the symbol
718 conventionally named _r_debug, as a last resort. */
719 msymbol
= lookup_minimal_symbol ("_r_debug", NULL
, symfile_objfile
);
721 return SYMBOL_VALUE_ADDRESS (msymbol
);
723 /* DT_DEBUG entry not found. */
727 /* Locate the base address of dynamic linker structs.
729 For both the SunOS and SVR4 shared library implementations, if the
730 inferior executable has been linked dynamically, there is a single
731 address somewhere in the inferior's data space which is the key to
732 locating all of the dynamic linker's runtime structures. This
733 address is the value of the debug base symbol. The job of this
734 function is to find and return that address, or to return 0 if there
735 is no such address (the executable is statically linked for example).
737 For SunOS, the job is almost trivial, since the dynamic linker and
738 all of it's structures are statically linked to the executable at
739 link time. Thus the symbol for the address we are looking for has
740 already been added to the minimal symbol table for the executable's
741 objfile at the time the symbol file's symbols were read, and all we
742 have to do is look it up there. Note that we explicitly do NOT want
743 to find the copies in the shared library.
745 The SVR4 version is a bit more complicated because the address
746 is contained somewhere in the dynamic info section. We have to go
747 to a lot more work to discover the address of the debug base symbol.
748 Because of this complexity, we cache the value we find and return that
749 value on subsequent invocations. Note there is no copy in the
750 executable symbol tables. */
753 locate_base (struct svr4_info
*info
)
755 /* Check to see if we have a currently valid address, and if so, avoid
756 doing all this work again and just return the cached address. If
757 we have no cached address, try to locate it in the dynamic info
758 section for ELF executables. There's no point in doing any of this
759 though if we don't have some link map offsets to work with. */
761 if (info
->debug_base
== 0 && svr4_have_link_map_offsets ())
762 info
->debug_base
= elf_locate_base ();
763 return info
->debug_base
;
766 /* Find the first element in the inferior's dynamic link map, and
767 return its address in the inferior. Return zero if the address
768 could not be determined.
770 FIXME: Perhaps we should validate the info somehow, perhaps by
771 checking r_version for a known version number, or r_state for
775 solib_svr4_r_map (struct svr4_info
*info
)
777 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
778 struct type
*ptr_type
= builtin_type (target_gdbarch
)->builtin_data_ptr
;
780 volatile struct gdb_exception ex
;
782 TRY_CATCH (ex
, RETURN_MASK_ERROR
)
784 addr
= read_memory_typed_address (info
->debug_base
+ lmo
->r_map_offset
,
787 exception_print (gdb_stderr
, ex
);
791 /* Find r_brk from the inferior's debug base. */
794 solib_svr4_r_brk (struct svr4_info
*info
)
796 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
797 struct type
*ptr_type
= builtin_type (target_gdbarch
)->builtin_data_ptr
;
799 return read_memory_typed_address (info
->debug_base
+ lmo
->r_brk_offset
,
803 /* Find the link map for the dynamic linker (if it is not in the
804 normal list of loaded shared objects). */
807 solib_svr4_r_ldsomap (struct svr4_info
*info
)
809 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
810 struct type
*ptr_type
= builtin_type (target_gdbarch
)->builtin_data_ptr
;
811 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch
);
814 /* Check version, and return zero if `struct r_debug' doesn't have
815 the r_ldsomap member. */
817 = read_memory_unsigned_integer (info
->debug_base
+ lmo
->r_version_offset
,
818 lmo
->r_version_size
, byte_order
);
819 if (version
< 2 || lmo
->r_ldsomap_offset
== -1)
822 return read_memory_typed_address (info
->debug_base
+ lmo
->r_ldsomap_offset
,
826 /* On Solaris systems with some versions of the dynamic linker,
827 ld.so's l_name pointer points to the SONAME in the string table
828 rather than into writable memory. So that GDB can find shared
829 libraries when loading a core file generated by gcore, ensure that
830 memory areas containing the l_name string are saved in the core
834 svr4_keep_data_in_core (CORE_ADDR vaddr
, unsigned long size
)
836 struct svr4_info
*info
;
839 struct cleanup
*old_chain
;
840 struct link_map_offsets
*lmo
;
843 info
= get_svr4_info ();
845 info
->debug_base
= 0;
847 if (!info
->debug_base
)
850 ldsomap
= solib_svr4_r_ldsomap (info
);
854 lmo
= svr4_fetch_link_map_offsets ();
855 new = XZALLOC (struct so_list
);
856 old_chain
= make_cleanup (xfree
, new);
857 new->lm_info
= xmalloc (sizeof (struct lm_info
));
858 make_cleanup (xfree
, new->lm_info
);
859 new->lm_info
->l_addr
= (CORE_ADDR
)-1;
860 new->lm_info
->lm_addr
= ldsomap
;
861 new->lm_info
->lm
= xzalloc (lmo
->link_map_size
);
862 make_cleanup (xfree
, new->lm_info
->lm
);
863 read_memory (ldsomap
, new->lm_info
->lm
, lmo
->link_map_size
);
864 name_lm
= lm_name (new);
865 do_cleanups (old_chain
);
867 return (name_lm
>= vaddr
&& name_lm
< vaddr
+ size
);
870 /* Implement the "open_symbol_file_object" target_so_ops method.
872 If no open symbol file, attempt to locate and open the main symbol
873 file. On SVR4 systems, this is the first link map entry. If its
874 name is here, we can open it. Useful when attaching to a process
875 without first loading its symbol file. */
878 open_symbol_file_object (void *from_ttyp
)
880 CORE_ADDR lm
, l_name
;
883 int from_tty
= *(int *)from_ttyp
;
884 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
885 struct type
*ptr_type
= builtin_type (target_gdbarch
)->builtin_data_ptr
;
886 int l_name_size
= TYPE_LENGTH (ptr_type
);
887 gdb_byte
*l_name_buf
= xmalloc (l_name_size
);
888 struct cleanup
*cleanups
= make_cleanup (xfree
, l_name_buf
);
889 struct svr4_info
*info
= get_svr4_info ();
892 if (!query (_("Attempt to reload symbols from process? ")))
894 do_cleanups (cleanups
);
898 /* Always locate the debug struct, in case it has moved. */
899 info
->debug_base
= 0;
900 if (locate_base (info
) == 0)
902 do_cleanups (cleanups
);
903 return 0; /* failed somehow... */
906 /* First link map member should be the executable. */
907 lm
= solib_svr4_r_map (info
);
910 do_cleanups (cleanups
);
911 return 0; /* failed somehow... */
914 /* Read address of name from target memory to GDB. */
915 read_memory (lm
+ lmo
->l_name_offset
, l_name_buf
, l_name_size
);
917 /* Convert the address to host format. */
918 l_name
= extract_typed_address (l_name_buf
, ptr_type
);
922 do_cleanups (cleanups
);
923 return 0; /* No filename. */
926 /* Now fetch the filename from target memory. */
927 target_read_string (l_name
, &filename
, SO_NAME_MAX_PATH_SIZE
- 1, &errcode
);
928 make_cleanup (xfree
, filename
);
932 warning (_("failed to read exec filename from attached file: %s"),
933 safe_strerror (errcode
));
934 do_cleanups (cleanups
);
938 /* Have a pathname: read the symbol file. */
939 symbol_file_add_main (filename
, from_tty
);
941 do_cleanups (cleanups
);
945 /* If no shared library information is available from the dynamic
946 linker, build a fallback list from other sources. */
948 static struct so_list
*
949 svr4_default_sos (void)
951 struct svr4_info
*info
= get_svr4_info ();
954 if (!info
->debug_loader_offset_p
)
957 new = XZALLOC (struct so_list
);
959 new->lm_info
= xmalloc (sizeof (struct lm_info
));
961 /* Nothing will ever check the cached copy of the link
962 map if we set l_addr. */
963 new->lm_info
->l_addr
= info
->debug_loader_offset
;
964 new->lm_info
->lm_addr
= 0;
965 new->lm_info
->lm
= NULL
;
967 strncpy (new->so_name
, info
->debug_loader_name
, SO_NAME_MAX_PATH_SIZE
- 1);
968 new->so_name
[SO_NAME_MAX_PATH_SIZE
- 1] = '\0';
969 strcpy (new->so_original_name
, new->so_name
);
974 /* Implement the "current_sos" target_so_ops method. */
976 static struct so_list
*
977 svr4_current_sos (void)
979 CORE_ADDR lm
, prev_lm
;
980 struct so_list
*head
= 0;
981 struct so_list
**link_ptr
= &head
;
982 CORE_ADDR ldsomap
= 0;
983 struct svr4_info
*info
;
985 info
= get_svr4_info ();
987 /* Always locate the debug struct, in case it has moved. */
988 info
->debug_base
= 0;
991 /* If we can't find the dynamic linker's base structure, this
992 must not be a dynamically linked executable. Hmm. */
993 if (! info
->debug_base
)
994 return svr4_default_sos ();
996 /* Walk the inferior's link map list, and build our list of
997 `struct so_list' nodes. */
999 lm
= solib_svr4_r_map (info
);
1003 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
1004 struct so_list
*new = XZALLOC (struct so_list
);
1005 struct cleanup
*old_chain
= make_cleanup (xfree
, new);
1008 new->lm_info
= xmalloc (sizeof (struct lm_info
));
1009 make_cleanup (xfree
, new->lm_info
);
1011 new->lm_info
->l_addr
= (CORE_ADDR
)-1;
1012 new->lm_info
->lm_addr
= lm
;
1013 new->lm_info
->lm
= xzalloc (lmo
->link_map_size
);
1014 make_cleanup (xfree
, new->lm_info
->lm
);
1016 read_memory (lm
, new->lm_info
->lm
, lmo
->link_map_size
);
1018 next_lm
= lm_next (new);
1020 if (lm_prev (new) != prev_lm
)
1022 warning (_("Corrupted shared library list"));
1027 /* For SVR4 versions, the first entry in the link map is for the
1028 inferior executable, so we must ignore it. For some versions of
1029 SVR4, it has no name. For others (Solaris 2.3 for example), it
1030 does have a name, so we can no longer use a missing name to
1031 decide when to ignore it. */
1032 else if (ignore_first_link_map_entry (new) && ldsomap
== 0)
1034 info
->main_lm_addr
= new->lm_info
->lm_addr
;
1042 /* Extract this shared object's name. */
1043 target_read_string (lm_name (new), &buffer
,
1044 SO_NAME_MAX_PATH_SIZE
- 1, &errcode
);
1046 warning (_("Can't read pathname for load map: %s."),
1047 safe_strerror (errcode
));
1050 strncpy (new->so_name
, buffer
, SO_NAME_MAX_PATH_SIZE
- 1);
1051 new->so_name
[SO_NAME_MAX_PATH_SIZE
- 1] = '\0';
1052 strcpy (new->so_original_name
, new->so_name
);
1056 /* If this entry has no name, or its name matches the name
1057 for the main executable, don't include it in the list. */
1058 if (! new->so_name
[0]
1059 || match_main (new->so_name
))
1065 link_ptr
= &new->next
;
1072 /* On Solaris, the dynamic linker is not in the normal list of
1073 shared objects, so make sure we pick it up too. Having
1074 symbol information for the dynamic linker is quite crucial
1075 for skipping dynamic linker resolver code. */
1076 if (lm
== 0 && ldsomap
== 0)
1078 lm
= ldsomap
= solib_svr4_r_ldsomap (info
);
1082 discard_cleanups (old_chain
);
1086 return svr4_default_sos ();
1091 /* Get the address of the link_map for a given OBJFILE. */
1094 svr4_fetch_objfile_link_map (struct objfile
*objfile
)
1097 struct svr4_info
*info
= get_svr4_info ();
1099 /* Cause svr4_current_sos() to be run if it hasn't been already. */
1100 if (info
->main_lm_addr
== 0)
1101 solib_add (NULL
, 0, ¤t_target
, auto_solib_add
);
1103 /* svr4_current_sos() will set main_lm_addr for the main executable. */
1104 if (objfile
== symfile_objfile
)
1105 return info
->main_lm_addr
;
1107 /* The other link map addresses may be found by examining the list
1108 of shared libraries. */
1109 for (so
= master_so_list (); so
; so
= so
->next
)
1110 if (so
->objfile
== objfile
)
1111 return so
->lm_info
->lm_addr
;
1117 /* On some systems, the only way to recognize the link map entry for
1118 the main executable file is by looking at its name. Return
1119 non-zero iff SONAME matches one of the known main executable names. */
1122 match_main (const char *soname
)
1124 const char * const *mainp
;
1126 for (mainp
= main_name_list
; *mainp
!= NULL
; mainp
++)
1128 if (strcmp (soname
, *mainp
) == 0)
1135 /* Return 1 if PC lies in the dynamic symbol resolution code of the
1136 SVR4 run time loader. */
1139 svr4_in_dynsym_resolve_code (CORE_ADDR pc
)
1141 struct svr4_info
*info
= get_svr4_info ();
1143 return ((pc
>= info
->interp_text_sect_low
1144 && pc
< info
->interp_text_sect_high
)
1145 || (pc
>= info
->interp_plt_sect_low
1146 && pc
< info
->interp_plt_sect_high
)
1147 || in_plt_section (pc
, NULL
)
1148 || in_gnu_ifunc_stub (pc
));
1151 /* Given an executable's ABFD and target, compute the entry-point
1155 exec_entry_point (struct bfd
*abfd
, struct target_ops
*targ
)
1157 /* KevinB wrote ... for most targets, the address returned by
1158 bfd_get_start_address() is the entry point for the start
1159 function. But, for some targets, bfd_get_start_address() returns
1160 the address of a function descriptor from which the entry point
1161 address may be extracted. This address is extracted by
1162 gdbarch_convert_from_func_ptr_addr(). The method
1163 gdbarch_convert_from_func_ptr_addr() is the merely the identify
1164 function for targets which don't use function descriptors. */
1165 return gdbarch_convert_from_func_ptr_addr (target_gdbarch
,
1166 bfd_get_start_address (abfd
),
1170 /* Helper function for gdb_bfd_lookup_symbol. */
1173 cmp_name_and_sec_flags (asymbol
*sym
, void *data
)
1175 return (strcmp (sym
->name
, (const char *) data
) == 0
1176 && (sym
->section
->flags
& (SEC_CODE
| SEC_DATA
)) != 0);
1178 /* Arrange for dynamic linker to hit breakpoint.
1180 Both the SunOS and the SVR4 dynamic linkers have, as part of their
1181 debugger interface, support for arranging for the inferior to hit
1182 a breakpoint after mapping in the shared libraries. This function
1183 enables that breakpoint.
1185 For SunOS, there is a special flag location (in_debugger) which we
1186 set to 1. When the dynamic linker sees this flag set, it will set
1187 a breakpoint at a location known only to itself, after saving the
1188 original contents of that place and the breakpoint address itself,
1189 in it's own internal structures. When we resume the inferior, it
1190 will eventually take a SIGTRAP when it runs into the breakpoint.
1191 We handle this (in a different place) by restoring the contents of
1192 the breakpointed location (which is only known after it stops),
1193 chasing around to locate the shared libraries that have been
1194 loaded, then resuming.
1196 For SVR4, the debugger interface structure contains a member (r_brk)
1197 which is statically initialized at the time the shared library is
1198 built, to the offset of a function (_r_debug_state) which is guaran-
1199 teed to be called once before mapping in a library, and again when
1200 the mapping is complete. At the time we are examining this member,
1201 it contains only the unrelocated offset of the function, so we have
1202 to do our own relocation. Later, when the dynamic linker actually
1203 runs, it relocates r_brk to be the actual address of _r_debug_state().
1205 The debugger interface structure also contains an enumeration which
1206 is set to either RT_ADD or RT_DELETE prior to changing the mapping,
1207 depending upon whether or not the library is being mapped or unmapped,
1208 and then set to RT_CONSISTENT after the library is mapped/unmapped. */
1211 enable_break (struct svr4_info
*info
, int from_tty
)
1213 struct minimal_symbol
*msymbol
;
1214 const char * const *bkpt_namep
;
1215 asection
*interp_sect
;
1216 gdb_byte
*interp_name
;
1219 info
->interp_text_sect_low
= info
->interp_text_sect_high
= 0;
1220 info
->interp_plt_sect_low
= info
->interp_plt_sect_high
= 0;
1222 /* If we already have a shared library list in the target, and
1223 r_debug contains r_brk, set the breakpoint there - this should
1224 mean r_brk has already been relocated. Assume the dynamic linker
1225 is the object containing r_brk. */
1227 solib_add (NULL
, from_tty
, ¤t_target
, auto_solib_add
);
1229 if (info
->debug_base
&& solib_svr4_r_map (info
) != 0)
1230 sym_addr
= solib_svr4_r_brk (info
);
1234 struct obj_section
*os
;
1236 sym_addr
= gdbarch_addr_bits_remove
1237 (target_gdbarch
, gdbarch_convert_from_func_ptr_addr (target_gdbarch
,
1241 /* On at least some versions of Solaris there's a dynamic relocation
1242 on _r_debug.r_brk and SYM_ADDR may not be relocated yet, e.g., if
1243 we get control before the dynamic linker has self-relocated.
1244 Check if SYM_ADDR is in a known section, if it is assume we can
1245 trust its value. This is just a heuristic though, it could go away
1246 or be replaced if it's getting in the way.
1248 On ARM we need to know whether the ISA of rtld_db_dlactivity (or
1249 however it's spelled in your particular system) is ARM or Thumb.
1250 That knowledge is encoded in the address, if it's Thumb the low bit
1251 is 1. However, we've stripped that info above and it's not clear
1252 what all the consequences are of passing a non-addr_bits_remove'd
1253 address to create_solib_event_breakpoint. The call to
1254 find_pc_section verifies we know about the address and have some
1255 hope of computing the right kind of breakpoint to use (via
1256 symbol info). It does mean that GDB needs to be pointed at a
1257 non-stripped version of the dynamic linker in order to obtain
1258 information it already knows about. Sigh. */
1260 os
= find_pc_section (sym_addr
);
1263 /* Record the relocated start and end address of the dynamic linker
1264 text and plt section for svr4_in_dynsym_resolve_code. */
1266 CORE_ADDR load_addr
;
1268 tmp_bfd
= os
->objfile
->obfd
;
1269 load_addr
= ANOFFSET (os
->objfile
->section_offsets
,
1270 os
->objfile
->sect_index_text
);
1272 interp_sect
= bfd_get_section_by_name (tmp_bfd
, ".text");
1275 info
->interp_text_sect_low
=
1276 bfd_section_vma (tmp_bfd
, interp_sect
) + load_addr
;
1277 info
->interp_text_sect_high
=
1278 info
->interp_text_sect_low
1279 + bfd_section_size (tmp_bfd
, interp_sect
);
1281 interp_sect
= bfd_get_section_by_name (tmp_bfd
, ".plt");
1284 info
->interp_plt_sect_low
=
1285 bfd_section_vma (tmp_bfd
, interp_sect
) + load_addr
;
1286 info
->interp_plt_sect_high
=
1287 info
->interp_plt_sect_low
1288 + bfd_section_size (tmp_bfd
, interp_sect
);
1291 create_solib_event_breakpoint (target_gdbarch
, sym_addr
);
1296 /* Find the program interpreter; if not found, warn the user and drop
1297 into the old breakpoint at symbol code. */
1298 interp_name
= find_program_interpreter ();
1301 CORE_ADDR load_addr
= 0;
1302 int load_addr_found
= 0;
1303 int loader_found_in_list
= 0;
1305 bfd
*tmp_bfd
= NULL
;
1306 struct target_ops
*tmp_bfd_target
;
1307 volatile struct gdb_exception ex
;
1311 /* Now we need to figure out where the dynamic linker was
1312 loaded so that we can load its symbols and place a breakpoint
1313 in the dynamic linker itself.
1315 This address is stored on the stack. However, I've been unable
1316 to find any magic formula to find it for Solaris (appears to
1317 be trivial on GNU/Linux). Therefore, we have to try an alternate
1318 mechanism to find the dynamic linker's base address. */
1320 TRY_CATCH (ex
, RETURN_MASK_ALL
)
1322 tmp_bfd
= solib_bfd_open (interp_name
);
1324 if (tmp_bfd
== NULL
)
1325 goto bkpt_at_symbol
;
1327 /* Now convert the TMP_BFD into a target. That way target, as
1328 well as BFD operations can be used. Note that closing the
1329 target will also close the underlying bfd. */
1330 tmp_bfd_target
= target_bfd_reopen (tmp_bfd
);
1332 /* On a running target, we can get the dynamic linker's base
1333 address from the shared library table. */
1334 so
= master_so_list ();
1337 if (svr4_same_1 (interp_name
, so
->so_original_name
))
1339 load_addr_found
= 1;
1340 loader_found_in_list
= 1;
1341 load_addr
= lm_addr_check (so
, tmp_bfd
);
1347 /* If we were not able to find the base address of the loader
1348 from our so_list, then try using the AT_BASE auxilliary entry. */
1349 if (!load_addr_found
)
1350 if (target_auxv_search (¤t_target
, AT_BASE
, &load_addr
) > 0)
1352 int addr_bit
= gdbarch_addr_bit (target_gdbarch
);
1354 /* Ensure LOAD_ADDR has proper sign in its possible upper bits so
1355 that `+ load_addr' will overflow CORE_ADDR width not creating
1356 invalid addresses like 0x101234567 for 32bit inferiors on 64bit
1359 if (addr_bit
< (sizeof (CORE_ADDR
) * HOST_CHAR_BIT
))
1361 CORE_ADDR space_size
= (CORE_ADDR
) 1 << addr_bit
;
1362 CORE_ADDR tmp_entry_point
= exec_entry_point (tmp_bfd
,
1365 gdb_assert (load_addr
< space_size
);
1367 /* TMP_ENTRY_POINT exceeding SPACE_SIZE would be for prelinked
1368 64bit ld.so with 32bit executable, it should not happen. */
1370 if (tmp_entry_point
< space_size
1371 && tmp_entry_point
+ load_addr
>= space_size
)
1372 load_addr
-= space_size
;
1375 load_addr_found
= 1;
1378 /* Otherwise we find the dynamic linker's base address by examining
1379 the current pc (which should point at the entry point for the
1380 dynamic linker) and subtracting the offset of the entry point.
1382 This is more fragile than the previous approaches, but is a good
1383 fallback method because it has actually been working well in
1385 if (!load_addr_found
)
1387 struct regcache
*regcache
1388 = get_thread_arch_regcache (inferior_ptid
, target_gdbarch
);
1390 load_addr
= (regcache_read_pc (regcache
)
1391 - exec_entry_point (tmp_bfd
, tmp_bfd_target
));
1394 if (!loader_found_in_list
)
1396 info
->debug_loader_name
= xstrdup (interp_name
);
1397 info
->debug_loader_offset_p
= 1;
1398 info
->debug_loader_offset
= load_addr
;
1399 solib_add (NULL
, from_tty
, ¤t_target
, auto_solib_add
);
1402 /* Record the relocated start and end address of the dynamic linker
1403 text and plt section for svr4_in_dynsym_resolve_code. */
1404 interp_sect
= bfd_get_section_by_name (tmp_bfd
, ".text");
1407 info
->interp_text_sect_low
=
1408 bfd_section_vma (tmp_bfd
, interp_sect
) + load_addr
;
1409 info
->interp_text_sect_high
=
1410 info
->interp_text_sect_low
1411 + bfd_section_size (tmp_bfd
, interp_sect
);
1413 interp_sect
= bfd_get_section_by_name (tmp_bfd
, ".plt");
1416 info
->interp_plt_sect_low
=
1417 bfd_section_vma (tmp_bfd
, interp_sect
) + load_addr
;
1418 info
->interp_plt_sect_high
=
1419 info
->interp_plt_sect_low
1420 + bfd_section_size (tmp_bfd
, interp_sect
);
1423 /* Now try to set a breakpoint in the dynamic linker. */
1424 for (bkpt_namep
= solib_break_names
; *bkpt_namep
!= NULL
; bkpt_namep
++)
1426 sym_addr
= gdb_bfd_lookup_symbol (tmp_bfd
, cmp_name_and_sec_flags
,
1427 (void *) *bkpt_namep
);
1433 /* Convert 'sym_addr' from a function pointer to an address.
1434 Because we pass tmp_bfd_target instead of the current
1435 target, this will always produce an unrelocated value. */
1436 sym_addr
= gdbarch_convert_from_func_ptr_addr (target_gdbarch
,
1440 /* We're done with both the temporary bfd and target. Remember,
1441 closing the target closes the underlying bfd. */
1442 target_close (tmp_bfd_target
, 0);
1446 create_solib_event_breakpoint (target_gdbarch
, load_addr
+ sym_addr
);
1447 xfree (interp_name
);
1451 /* For whatever reason we couldn't set a breakpoint in the dynamic
1452 linker. Warn and drop into the old code. */
1454 xfree (interp_name
);
1455 warning (_("Unable to find dynamic linker breakpoint function.\n"
1456 "GDB will be unable to debug shared library initializers\n"
1457 "and track explicitly loaded dynamic code."));
1460 /* Scan through the lists of symbols, trying to look up the symbol and
1461 set a breakpoint there. Terminate loop when we/if we succeed. */
1463 for (bkpt_namep
= solib_break_names
; *bkpt_namep
!= NULL
; bkpt_namep
++)
1465 msymbol
= lookup_minimal_symbol (*bkpt_namep
, NULL
, symfile_objfile
);
1466 if ((msymbol
!= NULL
) && (SYMBOL_VALUE_ADDRESS (msymbol
) != 0))
1468 sym_addr
= SYMBOL_VALUE_ADDRESS (msymbol
);
1469 sym_addr
= gdbarch_convert_from_func_ptr_addr (target_gdbarch
,
1472 create_solib_event_breakpoint (target_gdbarch
, sym_addr
);
1477 if (!current_inferior ()->attach_flag
)
1479 for (bkpt_namep
= bkpt_names
; *bkpt_namep
!= NULL
; bkpt_namep
++)
1481 msymbol
= lookup_minimal_symbol (*bkpt_namep
, NULL
, symfile_objfile
);
1482 if ((msymbol
!= NULL
) && (SYMBOL_VALUE_ADDRESS (msymbol
) != 0))
1484 sym_addr
= SYMBOL_VALUE_ADDRESS (msymbol
);
1485 sym_addr
= gdbarch_convert_from_func_ptr_addr (target_gdbarch
,
1488 create_solib_event_breakpoint (target_gdbarch
, sym_addr
);
1496 /* Implement the "special_symbol_handling" target_so_ops method. */
1499 svr4_special_symbol_handling (void)
1501 /* Nothing to do. */
1504 /* Read the ELF program headers from ABFD. Return the contents and
1505 set *PHDRS_SIZE to the size of the program headers. */
1508 read_program_headers_from_bfd (bfd
*abfd
, int *phdrs_size
)
1510 Elf_Internal_Ehdr
*ehdr
;
1513 ehdr
= elf_elfheader (abfd
);
1515 *phdrs_size
= ehdr
->e_phnum
* ehdr
->e_phentsize
;
1516 if (*phdrs_size
== 0)
1519 buf
= xmalloc (*phdrs_size
);
1520 if (bfd_seek (abfd
, ehdr
->e_phoff
, SEEK_SET
) != 0
1521 || bfd_bread (buf
, *phdrs_size
, abfd
) != *phdrs_size
)
1530 /* Return 1 and fill *DISPLACEMENTP with detected PIE offset of inferior
1531 exec_bfd. Otherwise return 0.
1533 We relocate all of the sections by the same amount. This
1534 behavior is mandated by recent editions of the System V ABI.
1535 According to the System V Application Binary Interface,
1536 Edition 4.1, page 5-5:
1538 ... Though the system chooses virtual addresses for
1539 individual processes, it maintains the segments' relative
1540 positions. Because position-independent code uses relative
1541 addressesing between segments, the difference between
1542 virtual addresses in memory must match the difference
1543 between virtual addresses in the file. The difference
1544 between the virtual address of any segment in memory and
1545 the corresponding virtual address in the file is thus a
1546 single constant value for any one executable or shared
1547 object in a given process. This difference is the base
1548 address. One use of the base address is to relocate the
1549 memory image of the program during dynamic linking.
1551 The same language also appears in Edition 4.0 of the System V
1552 ABI and is left unspecified in some of the earlier editions.
1554 Decide if the objfile needs to be relocated. As indicated above, we will
1555 only be here when execution is stopped. But during attachment PC can be at
1556 arbitrary address therefore regcache_read_pc can be misleading (contrary to
1557 the auxv AT_ENTRY value). Moreover for executable with interpreter section
1558 regcache_read_pc would point to the interpreter and not the main executable.
1560 So, to summarize, relocations are necessary when the start address obtained
1561 from the executable is different from the address in auxv AT_ENTRY entry.
1563 [ The astute reader will note that we also test to make sure that
1564 the executable in question has the DYNAMIC flag set. It is my
1565 opinion that this test is unnecessary (undesirable even). It
1566 was added to avoid inadvertent relocation of an executable
1567 whose e_type member in the ELF header is not ET_DYN. There may
1568 be a time in the future when it is desirable to do relocations
1569 on other types of files as well in which case this condition
1570 should either be removed or modified to accomodate the new file
1571 type. - Kevin, Nov 2000. ] */
1574 svr4_exec_displacement (CORE_ADDR
*displacementp
)
1576 /* ENTRY_POINT is a possible function descriptor - before
1577 a call to gdbarch_convert_from_func_ptr_addr. */
1578 CORE_ADDR entry_point
, displacement
;
1580 if (exec_bfd
== NULL
)
1583 /* Therefore for ELF it is ET_EXEC and not ET_DYN. Both shared libraries
1584 being executed themselves and PIE (Position Independent Executable)
1585 executables are ET_DYN. */
1587 if ((bfd_get_file_flags (exec_bfd
) & DYNAMIC
) == 0)
1590 if (target_auxv_search (¤t_target
, AT_ENTRY
, &entry_point
) <= 0)
1593 displacement
= entry_point
- bfd_get_start_address (exec_bfd
);
1595 /* Verify the DISPLACEMENT candidate complies with the required page
1596 alignment. It is cheaper than the program headers comparison below. */
1598 if (bfd_get_flavour (exec_bfd
) == bfd_target_elf_flavour
)
1600 const struct elf_backend_data
*elf
= get_elf_backend_data (exec_bfd
);
1602 /* p_align of PT_LOAD segments does not specify any alignment but
1603 only congruency of addresses:
1604 p_offset % p_align == p_vaddr % p_align
1605 Kernel is free to load the executable with lower alignment. */
1607 if ((displacement
& (elf
->minpagesize
- 1)) != 0)
1611 /* Verify that the auxilliary vector describes the same file as exec_bfd, by
1612 comparing their program headers. If the program headers in the auxilliary
1613 vector do not match the program headers in the executable, then we are
1614 looking at a different file than the one used by the kernel - for
1615 instance, "gdb program" connected to "gdbserver :PORT ld.so program". */
1617 if (bfd_get_flavour (exec_bfd
) == bfd_target_elf_flavour
)
1619 /* Be optimistic and clear OK only if GDB was able to verify the headers
1620 really do not match. */
1621 int phdrs_size
, phdrs2_size
, ok
= 1;
1622 gdb_byte
*buf
, *buf2
;
1625 buf
= read_program_header (-1, &phdrs_size
, &arch_size
);
1626 buf2
= read_program_headers_from_bfd (exec_bfd
, &phdrs2_size
);
1627 if (buf
!= NULL
&& buf2
!= NULL
)
1629 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch
);
1631 /* We are dealing with three different addresses. EXEC_BFD
1632 represents current address in on-disk file. target memory content
1633 may be different from EXEC_BFD as the file may have been prelinked
1634 to a different address after the executable has been loaded.
1635 Moreover the address of placement in target memory can be
1636 different from what the program headers in target memory say -
1637 this is the goal of PIE.
1639 Detected DISPLACEMENT covers both the offsets of PIE placement and
1640 possible new prelink performed after start of the program. Here
1641 relocate BUF and BUF2 just by the EXEC_BFD vs. target memory
1642 content offset for the verification purpose. */
1644 if (phdrs_size
!= phdrs2_size
1645 || bfd_get_arch_size (exec_bfd
) != arch_size
)
1647 else if (arch_size
== 32
1648 && phdrs_size
>= sizeof (Elf32_External_Phdr
)
1649 && phdrs_size
% sizeof (Elf32_External_Phdr
) == 0)
1651 Elf_Internal_Ehdr
*ehdr2
= elf_tdata (exec_bfd
)->elf_header
;
1652 Elf_Internal_Phdr
*phdr2
= elf_tdata (exec_bfd
)->phdr
;
1653 CORE_ADDR displacement
= 0;
1656 /* DISPLACEMENT could be found more easily by the difference of
1657 ehdr2->e_entry. But we haven't read the ehdr yet, and we
1658 already have enough information to compute that displacement
1659 with what we've read. */
1661 for (i
= 0; i
< ehdr2
->e_phnum
; i
++)
1662 if (phdr2
[i
].p_type
== PT_LOAD
)
1664 Elf32_External_Phdr
*phdrp
;
1665 gdb_byte
*buf_vaddr_p
, *buf_paddr_p
;
1666 CORE_ADDR vaddr
, paddr
;
1667 CORE_ADDR displacement_vaddr
= 0;
1668 CORE_ADDR displacement_paddr
= 0;
1670 phdrp
= &((Elf32_External_Phdr
*) buf
)[i
];
1671 buf_vaddr_p
= (gdb_byte
*) &phdrp
->p_vaddr
;
1672 buf_paddr_p
= (gdb_byte
*) &phdrp
->p_paddr
;
1674 vaddr
= extract_unsigned_integer (buf_vaddr_p
, 4,
1676 displacement_vaddr
= vaddr
- phdr2
[i
].p_vaddr
;
1678 paddr
= extract_unsigned_integer (buf_paddr_p
, 4,
1680 displacement_paddr
= paddr
- phdr2
[i
].p_paddr
;
1682 if (displacement_vaddr
== displacement_paddr
)
1683 displacement
= displacement_vaddr
;
1688 /* Now compare BUF and BUF2 with optional DISPLACEMENT. */
1690 for (i
= 0; i
< phdrs_size
/ sizeof (Elf32_External_Phdr
); i
++)
1692 Elf32_External_Phdr
*phdrp
;
1693 Elf32_External_Phdr
*phdr2p
;
1694 gdb_byte
*buf_vaddr_p
, *buf_paddr_p
;
1695 CORE_ADDR vaddr
, paddr
;
1696 asection
*plt2_asect
;
1698 phdrp
= &((Elf32_External_Phdr
*) buf
)[i
];
1699 buf_vaddr_p
= (gdb_byte
*) &phdrp
->p_vaddr
;
1700 buf_paddr_p
= (gdb_byte
*) &phdrp
->p_paddr
;
1701 phdr2p
= &((Elf32_External_Phdr
*) buf2
)[i
];
1703 /* PT_GNU_STACK is an exception by being never relocated by
1704 prelink as its addresses are always zero. */
1706 if (memcmp (phdrp
, phdr2p
, sizeof (*phdrp
)) == 0)
1709 /* Check also other adjustment combinations - PR 11786. */
1711 vaddr
= extract_unsigned_integer (buf_vaddr_p
, 4,
1713 vaddr
-= displacement
;
1714 store_unsigned_integer (buf_vaddr_p
, 4, byte_order
, vaddr
);
1716 paddr
= extract_unsigned_integer (buf_paddr_p
, 4,
1718 paddr
-= displacement
;
1719 store_unsigned_integer (buf_paddr_p
, 4, byte_order
, paddr
);
1721 if (memcmp (phdrp
, phdr2p
, sizeof (*phdrp
)) == 0)
1724 /* prelink can convert .plt SHT_NOBITS to SHT_PROGBITS. */
1725 plt2_asect
= bfd_get_section_by_name (exec_bfd
, ".plt");
1729 gdb_byte
*buf_filesz_p
= (gdb_byte
*) &phdrp
->p_filesz
;
1732 content2
= (bfd_get_section_flags (exec_bfd
, plt2_asect
)
1733 & SEC_HAS_CONTENTS
) != 0;
1735 filesz
= extract_unsigned_integer (buf_filesz_p
, 4,
1738 /* PLT2_ASECT is from on-disk file (exec_bfd) while
1739 FILESZ is from the in-memory image. */
1741 filesz
+= bfd_get_section_size (plt2_asect
);
1743 filesz
-= bfd_get_section_size (plt2_asect
);
1745 store_unsigned_integer (buf_filesz_p
, 4, byte_order
,
1748 if (memcmp (phdrp
, phdr2p
, sizeof (*phdrp
)) == 0)
1756 else if (arch_size
== 64
1757 && phdrs_size
>= sizeof (Elf64_External_Phdr
)
1758 && phdrs_size
% sizeof (Elf64_External_Phdr
) == 0)
1760 Elf_Internal_Ehdr
*ehdr2
= elf_tdata (exec_bfd
)->elf_header
;
1761 Elf_Internal_Phdr
*phdr2
= elf_tdata (exec_bfd
)->phdr
;
1762 CORE_ADDR displacement
= 0;
1765 /* DISPLACEMENT could be found more easily by the difference of
1766 ehdr2->e_entry. But we haven't read the ehdr yet, and we
1767 already have enough information to compute that displacement
1768 with what we've read. */
1770 for (i
= 0; i
< ehdr2
->e_phnum
; i
++)
1771 if (phdr2
[i
].p_type
== PT_LOAD
)
1773 Elf64_External_Phdr
*phdrp
;
1774 gdb_byte
*buf_vaddr_p
, *buf_paddr_p
;
1775 CORE_ADDR vaddr
, paddr
;
1776 CORE_ADDR displacement_vaddr
= 0;
1777 CORE_ADDR displacement_paddr
= 0;
1779 phdrp
= &((Elf64_External_Phdr
*) buf
)[i
];
1780 buf_vaddr_p
= (gdb_byte
*) &phdrp
->p_vaddr
;
1781 buf_paddr_p
= (gdb_byte
*) &phdrp
->p_paddr
;
1783 vaddr
= extract_unsigned_integer (buf_vaddr_p
, 8,
1785 displacement_vaddr
= vaddr
- phdr2
[i
].p_vaddr
;
1787 paddr
= extract_unsigned_integer (buf_paddr_p
, 8,
1789 displacement_paddr
= paddr
- phdr2
[i
].p_paddr
;
1791 if (displacement_vaddr
== displacement_paddr
)
1792 displacement
= displacement_vaddr
;
1797 /* Now compare BUF and BUF2 with optional DISPLACEMENT. */
1799 for (i
= 0; i
< phdrs_size
/ sizeof (Elf64_External_Phdr
); i
++)
1801 Elf64_External_Phdr
*phdrp
;
1802 Elf64_External_Phdr
*phdr2p
;
1803 gdb_byte
*buf_vaddr_p
, *buf_paddr_p
;
1804 CORE_ADDR vaddr
, paddr
;
1805 asection
*plt2_asect
;
1807 phdrp
= &((Elf64_External_Phdr
*) buf
)[i
];
1808 buf_vaddr_p
= (gdb_byte
*) &phdrp
->p_vaddr
;
1809 buf_paddr_p
= (gdb_byte
*) &phdrp
->p_paddr
;
1810 phdr2p
= &((Elf64_External_Phdr
*) buf2
)[i
];
1812 /* PT_GNU_STACK is an exception by being never relocated by
1813 prelink as its addresses are always zero. */
1815 if (memcmp (phdrp
, phdr2p
, sizeof (*phdrp
)) == 0)
1818 /* Check also other adjustment combinations - PR 11786. */
1820 vaddr
= extract_unsigned_integer (buf_vaddr_p
, 8,
1822 vaddr
-= displacement
;
1823 store_unsigned_integer (buf_vaddr_p
, 8, byte_order
, vaddr
);
1825 paddr
= extract_unsigned_integer (buf_paddr_p
, 8,
1827 paddr
-= displacement
;
1828 store_unsigned_integer (buf_paddr_p
, 8, byte_order
, paddr
);
1830 if (memcmp (phdrp
, phdr2p
, sizeof (*phdrp
)) == 0)
1833 /* prelink can convert .plt SHT_NOBITS to SHT_PROGBITS. */
1834 plt2_asect
= bfd_get_section_by_name (exec_bfd
, ".plt");
1838 gdb_byte
*buf_filesz_p
= (gdb_byte
*) &phdrp
->p_filesz
;
1841 content2
= (bfd_get_section_flags (exec_bfd
, plt2_asect
)
1842 & SEC_HAS_CONTENTS
) != 0;
1844 filesz
= extract_unsigned_integer (buf_filesz_p
, 8,
1847 /* PLT2_ASECT is from on-disk file (exec_bfd) while
1848 FILESZ is from the in-memory image. */
1850 filesz
+= bfd_get_section_size (plt2_asect
);
1852 filesz
-= bfd_get_section_size (plt2_asect
);
1854 store_unsigned_integer (buf_filesz_p
, 8, byte_order
,
1857 if (memcmp (phdrp
, phdr2p
, sizeof (*phdrp
)) == 0)
1878 /* It can be printed repeatedly as there is no easy way to check
1879 the executable symbols/file has been already relocated to
1882 printf_unfiltered (_("Using PIE (Position Independent Executable) "
1883 "displacement %s for \"%s\".\n"),
1884 paddress (target_gdbarch
, displacement
),
1885 bfd_get_filename (exec_bfd
));
1888 *displacementp
= displacement
;
1892 /* Relocate the main executable. This function should be called upon
1893 stopping the inferior process at the entry point to the program.
1894 The entry point from BFD is compared to the AT_ENTRY of AUXV and if they are
1895 different, the main executable is relocated by the proper amount. */
1898 svr4_relocate_main_executable (void)
1900 CORE_ADDR displacement
;
1902 /* If we are re-running this executable, SYMFILE_OBJFILE->SECTION_OFFSETS
1903 probably contains the offsets computed using the PIE displacement
1904 from the previous run, which of course are irrelevant for this run.
1905 So we need to determine the new PIE displacement and recompute the
1906 section offsets accordingly, even if SYMFILE_OBJFILE->SECTION_OFFSETS
1907 already contains pre-computed offsets.
1909 If we cannot compute the PIE displacement, either:
1911 - The executable is not PIE.
1913 - SYMFILE_OBJFILE does not match the executable started in the target.
1914 This can happen for main executable symbols loaded at the host while
1915 `ld.so --ld-args main-executable' is loaded in the target.
1917 Then we leave the section offsets untouched and use them as is for
1920 - These section offsets were properly reset earlier, and thus
1921 already contain the correct values. This can happen for instance
1922 when reconnecting via the remote protocol to a target that supports
1923 the `qOffsets' packet.
1925 - The section offsets were not reset earlier, and the best we can
1926 hope is that the old offsets are still applicable to the new run. */
1928 if (! svr4_exec_displacement (&displacement
))
1931 /* Even DISPLACEMENT 0 is a valid new difference of in-memory vs. in-file
1934 if (symfile_objfile
)
1936 struct section_offsets
*new_offsets
;
1939 new_offsets
= alloca (symfile_objfile
->num_sections
1940 * sizeof (*new_offsets
));
1942 for (i
= 0; i
< symfile_objfile
->num_sections
; i
++)
1943 new_offsets
->offsets
[i
] = displacement
;
1945 objfile_relocate (symfile_objfile
, new_offsets
);
1951 for (asect
= exec_bfd
->sections
; asect
!= NULL
; asect
= asect
->next
)
1952 exec_set_section_address (bfd_get_filename (exec_bfd
), asect
->index
,
1953 (bfd_section_vma (exec_bfd
, asect
)
1958 /* Implement the "create_inferior_hook" target_solib_ops method.
1960 For SVR4 executables, this first instruction is either the first
1961 instruction in the dynamic linker (for dynamically linked
1962 executables) or the instruction at "start" for statically linked
1963 executables. For dynamically linked executables, the system
1964 first exec's /lib/libc.so.N, which contains the dynamic linker,
1965 and starts it running. The dynamic linker maps in any needed
1966 shared libraries, maps in the actual user executable, and then
1967 jumps to "start" in the user executable.
1969 We can arrange to cooperate with the dynamic linker to discover the
1970 names of shared libraries that are dynamically linked, and the base
1971 addresses to which they are linked.
1973 This function is responsible for discovering those names and
1974 addresses, and saving sufficient information about them to allow
1975 their symbols to be read at a later time.
1979 Between enable_break() and disable_break(), this code does not
1980 properly handle hitting breakpoints which the user might have
1981 set in the startup code or in the dynamic linker itself. Proper
1982 handling will probably have to wait until the implementation is
1983 changed to use the "breakpoint handler function" method.
1985 Also, what if child has exit()ed? Must exit loop somehow. */
1988 svr4_solib_create_inferior_hook (int from_tty
)
1990 #if defined(_SCO_DS)
1991 struct inferior
*inf
;
1992 struct thread_info
*tp
;
1993 #endif /* defined(_SCO_DS) */
1994 struct svr4_info
*info
;
1996 info
= get_svr4_info ();
1998 /* Relocate the main executable if necessary. */
1999 svr4_relocate_main_executable ();
2001 /* No point setting a breakpoint in the dynamic linker if we can't
2002 hit it (e.g., a core file, or a trace file). */
2003 if (!target_has_execution
)
2006 if (!svr4_have_link_map_offsets ())
2009 if (!enable_break (info
, from_tty
))
2012 #if defined(_SCO_DS)
2013 /* SCO needs the loop below, other systems should be using the
2014 special shared library breakpoints and the shared library breakpoint
2017 Now run the target. It will eventually hit the breakpoint, at
2018 which point all of the libraries will have been mapped in and we
2019 can go groveling around in the dynamic linker structures to find
2020 out what we need to know about them. */
2022 inf
= current_inferior ();
2023 tp
= inferior_thread ();
2025 clear_proceed_status ();
2026 inf
->control
.stop_soon
= STOP_QUIETLY
;
2027 tp
->suspend
.stop_signal
= TARGET_SIGNAL_0
;
2030 target_resume (pid_to_ptid (-1), 0, tp
->suspend
.stop_signal
);
2031 wait_for_inferior ();
2033 while (tp
->suspend
.stop_signal
!= TARGET_SIGNAL_TRAP
);
2034 inf
->control
.stop_soon
= NO_STOP_QUIETLY
;
2035 #endif /* defined(_SCO_DS) */
2039 svr4_clear_solib (void)
2041 struct svr4_info
*info
;
2043 info
= get_svr4_info ();
2044 info
->debug_base
= 0;
2045 info
->debug_loader_offset_p
= 0;
2046 info
->debug_loader_offset
= 0;
2047 xfree (info
->debug_loader_name
);
2048 info
->debug_loader_name
= NULL
;
2052 svr4_free_so (struct so_list
*so
)
2054 xfree (so
->lm_info
->lm
);
2055 xfree (so
->lm_info
);
2059 /* Clear any bits of ADDR that wouldn't fit in a target-format
2060 data pointer. "Data pointer" here refers to whatever sort of
2061 address the dynamic linker uses to manage its sections. At the
2062 moment, we don't support shared libraries on any processors where
2063 code and data pointers are different sizes.
2065 This isn't really the right solution. What we really need here is
2066 a way to do arithmetic on CORE_ADDR values that respects the
2067 natural pointer/address correspondence. (For example, on the MIPS,
2068 converting a 32-bit pointer to a 64-bit CORE_ADDR requires you to
2069 sign-extend the value. There, simply truncating the bits above
2070 gdbarch_ptr_bit, as we do below, is no good.) This should probably
2071 be a new gdbarch method or something. */
2073 svr4_truncate_ptr (CORE_ADDR addr
)
2075 if (gdbarch_ptr_bit (target_gdbarch
) == sizeof (CORE_ADDR
) * 8)
2076 /* We don't need to truncate anything, and the bit twiddling below
2077 will fail due to overflow problems. */
2080 return addr
& (((CORE_ADDR
) 1 << gdbarch_ptr_bit (target_gdbarch
)) - 1);
2085 svr4_relocate_section_addresses (struct so_list
*so
,
2086 struct target_section
*sec
)
2088 sec
->addr
= svr4_truncate_ptr (sec
->addr
+ lm_addr_check (so
,
2090 sec
->endaddr
= svr4_truncate_ptr (sec
->endaddr
+ lm_addr_check (so
,
2095 /* Architecture-specific operations. */
2097 /* Per-architecture data key. */
2098 static struct gdbarch_data
*solib_svr4_data
;
2100 struct solib_svr4_ops
2102 /* Return a description of the layout of `struct link_map'. */
2103 struct link_map_offsets
*(*fetch_link_map_offsets
)(void);
2106 /* Return a default for the architecture-specific operations. */
2109 solib_svr4_init (struct obstack
*obstack
)
2111 struct solib_svr4_ops
*ops
;
2113 ops
= OBSTACK_ZALLOC (obstack
, struct solib_svr4_ops
);
2114 ops
->fetch_link_map_offsets
= NULL
;
2118 /* Set the architecture-specific `struct link_map_offsets' fetcher for
2119 GDBARCH to FLMO. Also, install SVR4 solib_ops into GDBARCH. */
2122 set_solib_svr4_fetch_link_map_offsets (struct gdbarch
*gdbarch
,
2123 struct link_map_offsets
*(*flmo
) (void))
2125 struct solib_svr4_ops
*ops
= gdbarch_data (gdbarch
, solib_svr4_data
);
2127 ops
->fetch_link_map_offsets
= flmo
;
2129 set_solib_ops (gdbarch
, &svr4_so_ops
);
2132 /* Fetch a link_map_offsets structure using the architecture-specific
2133 `struct link_map_offsets' fetcher. */
2135 static struct link_map_offsets
*
2136 svr4_fetch_link_map_offsets (void)
2138 struct solib_svr4_ops
*ops
= gdbarch_data (target_gdbarch
, solib_svr4_data
);
2140 gdb_assert (ops
->fetch_link_map_offsets
);
2141 return ops
->fetch_link_map_offsets ();
2144 /* Return 1 if a link map offset fetcher has been defined, 0 otherwise. */
2147 svr4_have_link_map_offsets (void)
2149 struct solib_svr4_ops
*ops
= gdbarch_data (target_gdbarch
, solib_svr4_data
);
2151 return (ops
->fetch_link_map_offsets
!= NULL
);
2155 /* Most OS'es that have SVR4-style ELF dynamic libraries define a
2156 `struct r_debug' and a `struct link_map' that are binary compatible
2157 with the origional SVR4 implementation. */
2159 /* Fetch (and possibly build) an appropriate `struct link_map_offsets'
2160 for an ILP32 SVR4 system. */
2162 struct link_map_offsets
*
2163 svr4_ilp32_fetch_link_map_offsets (void)
2165 static struct link_map_offsets lmo
;
2166 static struct link_map_offsets
*lmp
= NULL
;
2172 lmo
.r_version_offset
= 0;
2173 lmo
.r_version_size
= 4;
2174 lmo
.r_map_offset
= 4;
2175 lmo
.r_brk_offset
= 8;
2176 lmo
.r_ldsomap_offset
= 20;
2178 /* Everything we need is in the first 20 bytes. */
2179 lmo
.link_map_size
= 20;
2180 lmo
.l_addr_offset
= 0;
2181 lmo
.l_name_offset
= 4;
2182 lmo
.l_ld_offset
= 8;
2183 lmo
.l_next_offset
= 12;
2184 lmo
.l_prev_offset
= 16;
2190 /* Fetch (and possibly build) an appropriate `struct link_map_offsets'
2191 for an LP64 SVR4 system. */
2193 struct link_map_offsets
*
2194 svr4_lp64_fetch_link_map_offsets (void)
2196 static struct link_map_offsets lmo
;
2197 static struct link_map_offsets
*lmp
= NULL
;
2203 lmo
.r_version_offset
= 0;
2204 lmo
.r_version_size
= 4;
2205 lmo
.r_map_offset
= 8;
2206 lmo
.r_brk_offset
= 16;
2207 lmo
.r_ldsomap_offset
= 40;
2209 /* Everything we need is in the first 40 bytes. */
2210 lmo
.link_map_size
= 40;
2211 lmo
.l_addr_offset
= 0;
2212 lmo
.l_name_offset
= 8;
2213 lmo
.l_ld_offset
= 16;
2214 lmo
.l_next_offset
= 24;
2215 lmo
.l_prev_offset
= 32;
2222 struct target_so_ops svr4_so_ops
;
2224 /* Lookup global symbol for ELF DSOs linked with -Bsymbolic. Those DSOs have a
2225 different rule for symbol lookup. The lookup begins here in the DSO, not in
2226 the main executable. */
2228 static struct symbol
*
2229 elf_lookup_lib_symbol (const struct objfile
*objfile
,
2231 const domain_enum domain
)
2235 if (objfile
== symfile_objfile
)
2239 /* OBJFILE should have been passed as the non-debug one. */
2240 gdb_assert (objfile
->separate_debug_objfile_backlink
== NULL
);
2242 abfd
= objfile
->obfd
;
2245 if (abfd
== NULL
|| scan_dyntag (DT_SYMBOLIC
, abfd
, NULL
) != 1)
2248 return lookup_global_symbol_from_objfile (objfile
, name
, domain
);
2251 extern initialize_file_ftype _initialize_svr4_solib
; /* -Wmissing-prototypes */
2254 _initialize_svr4_solib (void)
2256 solib_svr4_data
= gdbarch_data_register_pre_init (solib_svr4_init
);
2257 solib_svr4_pspace_data
2258 = register_program_space_data_with_cleanup (svr4_pspace_data_cleanup
);
2260 svr4_so_ops
.relocate_section_addresses
= svr4_relocate_section_addresses
;
2261 svr4_so_ops
.free_so
= svr4_free_so
;
2262 svr4_so_ops
.clear_solib
= svr4_clear_solib
;
2263 svr4_so_ops
.solib_create_inferior_hook
= svr4_solib_create_inferior_hook
;
2264 svr4_so_ops
.special_symbol_handling
= svr4_special_symbol_handling
;
2265 svr4_so_ops
.current_sos
= svr4_current_sos
;
2266 svr4_so_ops
.open_symbol_file_object
= open_symbol_file_object
;
2267 svr4_so_ops
.in_dynsym_resolve_code
= svr4_in_dynsym_resolve_code
;
2268 svr4_so_ops
.bfd_open
= solib_bfd_open
;
2269 svr4_so_ops
.lookup_lib_global_symbol
= elf_lookup_lib_symbol
;
2270 svr4_so_ops
.same
= svr4_same
;
2271 svr4_so_ops
.keep_data_in_core
= svr4_keep_data_in_core
;