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 if ((l_addr
& (minpagesize
- 1)) == 0
241 && (l_addr
& align
) == ((l_dynaddr
- dynaddr
) & align
))
243 l_addr
= l_dynaddr
- dynaddr
;
246 printf_unfiltered (_("Using PIC (Position Independent Code) "
247 "prelink displacement %s for \"%s\".\n"),
248 paddress (target_gdbarch
, l_addr
),
252 warning (_(".dynamic section for \"%s\" "
253 "is not at the expected address "
254 "(wrong library or version mismatch?)"), so
->so_name
);
258 so
->lm_info
->l_addr
= l_addr
;
261 return so
->lm_info
->l_addr
;
265 LM_NEXT (struct so_list
*so
)
267 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
268 struct type
*ptr_type
= builtin_type (target_gdbarch
)->builtin_data_ptr
;
270 return extract_typed_address (so
->lm_info
->lm
+ lmo
->l_next_offset
,
275 LM_PREV (struct so_list
*so
)
277 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
278 struct type
*ptr_type
= builtin_type (target_gdbarch
)->builtin_data_ptr
;
280 return extract_typed_address (so
->lm_info
->lm
+ lmo
->l_prev_offset
,
285 LM_NAME (struct so_list
*so
)
287 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
288 struct type
*ptr_type
= builtin_type (target_gdbarch
)->builtin_data_ptr
;
290 return extract_typed_address (so
->lm_info
->lm
+ lmo
->l_name_offset
,
295 IGNORE_FIRST_LINK_MAP_ENTRY (struct so_list
*so
)
297 /* Assume that everything is a library if the dynamic loader was loaded
298 late by a static executable. */
299 if (exec_bfd
&& bfd_get_section_by_name (exec_bfd
, ".dynamic") == NULL
)
302 return LM_PREV (so
) == 0;
305 /* Per pspace SVR4 specific data. */
309 CORE_ADDR debug_base
; /* Base of dynamic linker structures. */
311 /* Validity flag for debug_loader_offset. */
312 int debug_loader_offset_p
;
314 /* Load address for the dynamic linker, inferred. */
315 CORE_ADDR debug_loader_offset
;
317 /* Name of the dynamic linker, valid if debug_loader_offset_p. */
318 char *debug_loader_name
;
320 /* Load map address for the main executable. */
321 CORE_ADDR main_lm_addr
;
323 CORE_ADDR interp_text_sect_low
;
324 CORE_ADDR interp_text_sect_high
;
325 CORE_ADDR interp_plt_sect_low
;
326 CORE_ADDR interp_plt_sect_high
;
329 /* Per-program-space data key. */
330 static const struct program_space_data
*solib_svr4_pspace_data
;
333 svr4_pspace_data_cleanup (struct program_space
*pspace
, void *arg
)
335 struct svr4_info
*info
;
337 info
= program_space_data (pspace
, solib_svr4_pspace_data
);
341 /* Get the current svr4 data. If none is found yet, add it now. This
342 function always returns a valid object. */
344 static struct svr4_info
*
347 struct svr4_info
*info
;
349 info
= program_space_data (current_program_space
, solib_svr4_pspace_data
);
353 info
= XZALLOC (struct svr4_info
);
354 set_program_space_data (current_program_space
, solib_svr4_pspace_data
, info
);
358 /* Local function prototypes */
360 static int match_main (const char *);
366 bfd_lookup_symbol -- lookup the value for a specific symbol
370 CORE_ADDR bfd_lookup_symbol (bfd *abfd, char *symname)
374 An expensive way to lookup the value of a single symbol for
375 bfd's that are only temporary anyway. This is used by the
376 shared library support to find the address of the debugger
377 notification routine in the shared library.
379 The returned symbol may be in a code or data section; functions
380 will normally be in a code section, but may be in a data section
381 if this architecture uses function descriptors.
383 Note that 0 is specifically allowed as an error return (no
388 bfd_lookup_symbol (bfd
*abfd
, const char *symname
)
392 asymbol
**symbol_table
;
393 unsigned int number_of_symbols
;
395 struct cleanup
*back_to
;
396 CORE_ADDR symaddr
= 0;
398 storage_needed
= bfd_get_symtab_upper_bound (abfd
);
400 if (storage_needed
> 0)
402 symbol_table
= (asymbol
**) xmalloc (storage_needed
);
403 back_to
= make_cleanup (xfree
, symbol_table
);
404 number_of_symbols
= bfd_canonicalize_symtab (abfd
, symbol_table
);
406 for (i
= 0; i
< number_of_symbols
; i
++)
408 sym
= *symbol_table
++;
409 if (strcmp (sym
->name
, symname
) == 0
410 && (sym
->section
->flags
& (SEC_CODE
| SEC_DATA
)) != 0)
412 /* BFD symbols are section relative. */
413 symaddr
= sym
->value
+ sym
->section
->vma
;
417 do_cleanups (back_to
);
423 /* On FreeBSD, the dynamic linker is stripped by default. So we'll
424 have to check the dynamic string table too. */
426 storage_needed
= bfd_get_dynamic_symtab_upper_bound (abfd
);
428 if (storage_needed
> 0)
430 symbol_table
= (asymbol
**) xmalloc (storage_needed
);
431 back_to
= make_cleanup (xfree
, symbol_table
);
432 number_of_symbols
= bfd_canonicalize_dynamic_symtab (abfd
, symbol_table
);
434 for (i
= 0; i
< number_of_symbols
; i
++)
436 sym
= *symbol_table
++;
438 if (strcmp (sym
->name
, symname
) == 0
439 && (sym
->section
->flags
& (SEC_CODE
| SEC_DATA
)) != 0)
441 /* BFD symbols are section relative. */
442 symaddr
= sym
->value
+ sym
->section
->vma
;
446 do_cleanups (back_to
);
453 /* Read program header TYPE from inferior memory. The header is found
454 by scanning the OS auxillary vector.
456 If TYPE == -1, return the program headers instead of the contents of
459 Return a pointer to allocated memory holding the program header contents,
460 or NULL on failure. If sucessful, and unless P_SECT_SIZE is NULL, the
461 size of those contents is returned to P_SECT_SIZE. Likewise, the target
462 architecture size (32-bit or 64-bit) is returned to P_ARCH_SIZE. */
465 read_program_header (int type
, int *p_sect_size
, int *p_arch_size
)
467 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch
);
468 CORE_ADDR at_phdr
, at_phent
, at_phnum
;
469 int arch_size
, sect_size
;
473 /* Get required auxv elements from target. */
474 if (target_auxv_search (¤t_target
, AT_PHDR
, &at_phdr
) <= 0)
476 if (target_auxv_search (¤t_target
, AT_PHENT
, &at_phent
) <= 0)
478 if (target_auxv_search (¤t_target
, AT_PHNUM
, &at_phnum
) <= 0)
480 if (!at_phdr
|| !at_phnum
)
483 /* Determine ELF architecture type. */
484 if (at_phent
== sizeof (Elf32_External_Phdr
))
486 else if (at_phent
== sizeof (Elf64_External_Phdr
))
491 /* Find the requested segment. */
495 sect_size
= at_phent
* at_phnum
;
497 else if (arch_size
== 32)
499 Elf32_External_Phdr phdr
;
502 /* Search for requested PHDR. */
503 for (i
= 0; i
< at_phnum
; i
++)
505 if (target_read_memory (at_phdr
+ i
* sizeof (phdr
),
506 (gdb_byte
*)&phdr
, sizeof (phdr
)))
509 if (extract_unsigned_integer ((gdb_byte
*)phdr
.p_type
,
510 4, byte_order
) == type
)
517 /* Retrieve address and size. */
518 sect_addr
= extract_unsigned_integer ((gdb_byte
*)phdr
.p_vaddr
,
520 sect_size
= extract_unsigned_integer ((gdb_byte
*)phdr
.p_memsz
,
525 Elf64_External_Phdr phdr
;
528 /* Search for requested PHDR. */
529 for (i
= 0; i
< at_phnum
; i
++)
531 if (target_read_memory (at_phdr
+ i
* sizeof (phdr
),
532 (gdb_byte
*)&phdr
, sizeof (phdr
)))
535 if (extract_unsigned_integer ((gdb_byte
*)phdr
.p_type
,
536 4, byte_order
) == type
)
543 /* Retrieve address and size. */
544 sect_addr
= extract_unsigned_integer ((gdb_byte
*)phdr
.p_vaddr
,
546 sect_size
= extract_unsigned_integer ((gdb_byte
*)phdr
.p_memsz
,
550 /* Read in requested program header. */
551 buf
= xmalloc (sect_size
);
552 if (target_read_memory (sect_addr
, buf
, sect_size
))
559 *p_arch_size
= arch_size
;
561 *p_sect_size
= sect_size
;
567 /* Return program interpreter string. */
569 find_program_interpreter (void)
571 gdb_byte
*buf
= NULL
;
573 /* If we have an exec_bfd, use its section table. */
575 && bfd_get_flavour (exec_bfd
) == bfd_target_elf_flavour
)
577 struct bfd_section
*interp_sect
;
579 interp_sect
= bfd_get_section_by_name (exec_bfd
, ".interp");
580 if (interp_sect
!= NULL
)
582 int sect_size
= bfd_section_size (exec_bfd
, interp_sect
);
584 buf
= xmalloc (sect_size
);
585 bfd_get_section_contents (exec_bfd
, interp_sect
, buf
, 0, sect_size
);
589 /* If we didn't find it, use the target auxillary vector. */
591 buf
= read_program_header (PT_INTERP
, NULL
, NULL
);
597 /* Scan for DYNTAG in .dynamic section of ABFD. If DYNTAG is found 1 is
598 returned and the corresponding PTR is set. */
601 scan_dyntag (int dyntag
, bfd
*abfd
, CORE_ADDR
*ptr
)
603 int arch_size
, step
, sect_size
;
605 CORE_ADDR dyn_ptr
, dyn_addr
;
606 gdb_byte
*bufend
, *bufstart
, *buf
;
607 Elf32_External_Dyn
*x_dynp_32
;
608 Elf64_External_Dyn
*x_dynp_64
;
609 struct bfd_section
*sect
;
610 struct target_section
*target_section
;
615 if (bfd_get_flavour (abfd
) != bfd_target_elf_flavour
)
618 arch_size
= bfd_get_arch_size (abfd
);
622 /* Find the start address of the .dynamic section. */
623 sect
= bfd_get_section_by_name (abfd
, ".dynamic");
627 for (target_section
= current_target_sections
->sections
;
628 target_section
< current_target_sections
->sections_end
;
630 if (sect
== target_section
->the_bfd_section
)
632 if (target_section
< current_target_sections
->sections_end
)
633 dyn_addr
= target_section
->addr
;
636 /* ABFD may come from OBJFILE acting only as a symbol file without being
637 loaded into the target (see add_symbol_file_command). This case is
638 such fallback to the file VMA address without the possibility of
639 having the section relocated to its actual in-memory address. */
641 dyn_addr
= bfd_section_vma (abfd
, sect
);
644 /* Read in .dynamic from the BFD. We will get the actual value
645 from memory later. */
646 sect_size
= bfd_section_size (abfd
, sect
);
647 buf
= bufstart
= alloca (sect_size
);
648 if (!bfd_get_section_contents (abfd
, sect
,
652 /* Iterate over BUF and scan for DYNTAG. If found, set PTR and return. */
653 step
= (arch_size
== 32) ? sizeof (Elf32_External_Dyn
)
654 : sizeof (Elf64_External_Dyn
);
655 for (bufend
= buf
+ sect_size
;
661 x_dynp_32
= (Elf32_External_Dyn
*) buf
;
662 dyn_tag
= bfd_h_get_32 (abfd
, (bfd_byte
*) x_dynp_32
->d_tag
);
663 dyn_ptr
= bfd_h_get_32 (abfd
, (bfd_byte
*) x_dynp_32
->d_un
.d_ptr
);
667 x_dynp_64
= (Elf64_External_Dyn
*) buf
;
668 dyn_tag
= bfd_h_get_64 (abfd
, (bfd_byte
*) x_dynp_64
->d_tag
);
669 dyn_ptr
= bfd_h_get_64 (abfd
, (bfd_byte
*) x_dynp_64
->d_un
.d_ptr
);
671 if (dyn_tag
== DT_NULL
)
673 if (dyn_tag
== dyntag
)
675 /* If requested, try to read the runtime value of this .dynamic
679 struct type
*ptr_type
;
683 ptr_type
= builtin_type (target_gdbarch
)->builtin_data_ptr
;
684 ptr_addr
= dyn_addr
+ (buf
- bufstart
) + arch_size
/ 8;
685 if (target_read_memory (ptr_addr
, ptr_buf
, arch_size
/ 8) == 0)
686 dyn_ptr
= extract_typed_address (ptr_buf
, ptr_type
);
696 /* Scan for DYNTAG in .dynamic section of the target's main executable,
697 found by consulting the OS auxillary vector. If DYNTAG is found 1 is
698 returned and the corresponding PTR is set. */
701 scan_dyntag_auxv (int dyntag
, CORE_ADDR
*ptr
)
703 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch
);
704 int sect_size
, arch_size
, step
;
707 gdb_byte
*bufend
, *bufstart
, *buf
;
709 /* Read in .dynamic section. */
710 buf
= bufstart
= read_program_header (PT_DYNAMIC
, §_size
, &arch_size
);
714 /* Iterate over BUF and scan for DYNTAG. If found, set PTR and return. */
715 step
= (arch_size
== 32) ? sizeof (Elf32_External_Dyn
)
716 : sizeof (Elf64_External_Dyn
);
717 for (bufend
= buf
+ sect_size
;
723 Elf32_External_Dyn
*dynp
= (Elf32_External_Dyn
*) buf
;
725 dyn_tag
= extract_unsigned_integer ((gdb_byte
*) dynp
->d_tag
,
727 dyn_ptr
= extract_unsigned_integer ((gdb_byte
*) dynp
->d_un
.d_ptr
,
732 Elf64_External_Dyn
*dynp
= (Elf64_External_Dyn
*) buf
;
734 dyn_tag
= extract_unsigned_integer ((gdb_byte
*) dynp
->d_tag
,
736 dyn_ptr
= extract_unsigned_integer ((gdb_byte
*) dynp
->d_un
.d_ptr
,
739 if (dyn_tag
== DT_NULL
)
742 if (dyn_tag
== dyntag
)
761 elf_locate_base -- locate the base address of dynamic linker structs
762 for SVR4 elf targets.
766 CORE_ADDR elf_locate_base (void)
770 For SVR4 elf targets the address of the dynamic linker's runtime
771 structure is contained within the dynamic info section in the
772 executable file. The dynamic section is also mapped into the
773 inferior address space. Because the runtime loader fills in the
774 real address before starting the inferior, we have to read in the
775 dynamic info section from the inferior address space.
776 If there are any errors while trying to find the address, we
777 silently return 0, otherwise the found address is returned.
782 elf_locate_base (void)
784 struct minimal_symbol
*msymbol
;
787 /* Look for DT_MIPS_RLD_MAP first. MIPS executables use this
788 instead of DT_DEBUG, although they sometimes contain an unused
790 if (scan_dyntag (DT_MIPS_RLD_MAP
, exec_bfd
, &dyn_ptr
)
791 || scan_dyntag_auxv (DT_MIPS_RLD_MAP
, &dyn_ptr
))
793 struct type
*ptr_type
= builtin_type (target_gdbarch
)->builtin_data_ptr
;
795 int pbuf_size
= TYPE_LENGTH (ptr_type
);
797 pbuf
= alloca (pbuf_size
);
798 /* DT_MIPS_RLD_MAP contains a pointer to the address
799 of the dynamic link structure. */
800 if (target_read_memory (dyn_ptr
, pbuf
, pbuf_size
))
802 return extract_typed_address (pbuf
, ptr_type
);
806 if (scan_dyntag (DT_DEBUG
, exec_bfd
, &dyn_ptr
)
807 || scan_dyntag_auxv (DT_DEBUG
, &dyn_ptr
))
810 /* This may be a static executable. Look for the symbol
811 conventionally named _r_debug, as a last resort. */
812 msymbol
= lookup_minimal_symbol ("_r_debug", NULL
, symfile_objfile
);
814 return SYMBOL_VALUE_ADDRESS (msymbol
);
816 /* DT_DEBUG entry not found. */
824 locate_base -- locate the base address of dynamic linker structs
828 CORE_ADDR locate_base (struct svr4_info *)
832 For both the SunOS and SVR4 shared library implementations, if the
833 inferior executable has been linked dynamically, there is a single
834 address somewhere in the inferior's data space which is the key to
835 locating all of the dynamic linker's runtime structures. This
836 address is the value of the debug base symbol. The job of this
837 function is to find and return that address, or to return 0 if there
838 is no such address (the executable is statically linked for example).
840 For SunOS, the job is almost trivial, since the dynamic linker and
841 all of it's structures are statically linked to the executable at
842 link time. Thus the symbol for the address we are looking for has
843 already been added to the minimal symbol table for the executable's
844 objfile at the time the symbol file's symbols were read, and all we
845 have to do is look it up there. Note that we explicitly do NOT want
846 to find the copies in the shared library.
848 The SVR4 version is a bit more complicated because the address
849 is contained somewhere in the dynamic info section. We have to go
850 to a lot more work to discover the address of the debug base symbol.
851 Because of this complexity, we cache the value we find and return that
852 value on subsequent invocations. Note there is no copy in the
853 executable symbol tables.
858 locate_base (struct svr4_info
*info
)
860 /* Check to see if we have a currently valid address, and if so, avoid
861 doing all this work again and just return the cached address. If
862 we have no cached address, try to locate it in the dynamic info
863 section for ELF executables. There's no point in doing any of this
864 though if we don't have some link map offsets to work with. */
866 if (info
->debug_base
== 0 && svr4_have_link_map_offsets ())
867 info
->debug_base
= elf_locate_base ();
868 return info
->debug_base
;
871 /* Find the first element in the inferior's dynamic link map, and
872 return its address in the inferior. Return zero if the address
873 could not be determined.
875 FIXME: Perhaps we should validate the info somehow, perhaps by
876 checking r_version for a known version number, or r_state for
880 solib_svr4_r_map (struct svr4_info
*info
)
882 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
883 struct type
*ptr_type
= builtin_type (target_gdbarch
)->builtin_data_ptr
;
885 volatile struct gdb_exception ex
;
887 TRY_CATCH (ex
, RETURN_MASK_ERROR
)
889 addr
= read_memory_typed_address (info
->debug_base
+ lmo
->r_map_offset
,
892 exception_print (gdb_stderr
, ex
);
896 /* Find r_brk from the inferior's debug base. */
899 solib_svr4_r_brk (struct svr4_info
*info
)
901 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
902 struct type
*ptr_type
= builtin_type (target_gdbarch
)->builtin_data_ptr
;
904 return read_memory_typed_address (info
->debug_base
+ lmo
->r_brk_offset
,
908 /* Find the link map for the dynamic linker (if it is not in the
909 normal list of loaded shared objects). */
912 solib_svr4_r_ldsomap (struct svr4_info
*info
)
914 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
915 struct type
*ptr_type
= builtin_type (target_gdbarch
)->builtin_data_ptr
;
916 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch
);
919 /* Check version, and return zero if `struct r_debug' doesn't have
920 the r_ldsomap member. */
922 = read_memory_unsigned_integer (info
->debug_base
+ lmo
->r_version_offset
,
923 lmo
->r_version_size
, byte_order
);
924 if (version
< 2 || lmo
->r_ldsomap_offset
== -1)
927 return read_memory_typed_address (info
->debug_base
+ lmo
->r_ldsomap_offset
,
931 /* On Solaris systems with some versions of the dynamic linker,
932 ld.so's l_name pointer points to the SONAME in the string table
933 rather than into writable memory. So that GDB can find shared
934 libraries when loading a core file generated by gcore, ensure that
935 memory areas containing the l_name string are saved in the core
939 svr4_keep_data_in_core (CORE_ADDR vaddr
, unsigned long size
)
941 struct svr4_info
*info
;
944 struct cleanup
*old_chain
;
945 struct link_map_offsets
*lmo
;
948 info
= get_svr4_info ();
950 info
->debug_base
= 0;
952 if (!info
->debug_base
)
955 ldsomap
= solib_svr4_r_ldsomap (info
);
959 lmo
= svr4_fetch_link_map_offsets ();
960 new = XZALLOC (struct so_list
);
961 old_chain
= make_cleanup (xfree
, new);
962 new->lm_info
= xmalloc (sizeof (struct lm_info
));
963 make_cleanup (xfree
, new->lm_info
);
964 new->lm_info
->l_addr
= (CORE_ADDR
)-1;
965 new->lm_info
->lm_addr
= ldsomap
;
966 new->lm_info
->lm
= xzalloc (lmo
->link_map_size
);
967 make_cleanup (xfree
, new->lm_info
->lm
);
968 read_memory (ldsomap
, new->lm_info
->lm
, lmo
->link_map_size
);
969 lm_name
= LM_NAME (new);
970 do_cleanups (old_chain
);
972 return (lm_name
>= vaddr
&& lm_name
< vaddr
+ size
);
979 open_symbol_file_object
983 void open_symbol_file_object (void *from_tty)
987 If no open symbol file, attempt to locate and open the main symbol
988 file. On SVR4 systems, this is the first link map entry. If its
989 name is here, we can open it. Useful when attaching to a process
990 without first loading its symbol file.
992 If FROM_TTYP dereferences to a non-zero integer, allow messages to
993 be printed. This parameter is a pointer rather than an int because
994 open_symbol_file_object() is called via catch_errors() and
995 catch_errors() requires a pointer argument. */
998 open_symbol_file_object (void *from_ttyp
)
1000 CORE_ADDR lm
, l_name
;
1003 int from_tty
= *(int *)from_ttyp
;
1004 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
1005 struct type
*ptr_type
= builtin_type (target_gdbarch
)->builtin_data_ptr
;
1006 int l_name_size
= TYPE_LENGTH (ptr_type
);
1007 gdb_byte
*l_name_buf
= xmalloc (l_name_size
);
1008 struct cleanup
*cleanups
= make_cleanup (xfree
, l_name_buf
);
1009 struct svr4_info
*info
= get_svr4_info ();
1011 if (symfile_objfile
)
1012 if (!query (_("Attempt to reload symbols from process? ")))
1015 /* Always locate the debug struct, in case it has moved. */
1016 info
->debug_base
= 0;
1017 if (locate_base (info
) == 0)
1018 return 0; /* failed somehow... */
1020 /* First link map member should be the executable. */
1021 lm
= solib_svr4_r_map (info
);
1023 return 0; /* failed somehow... */
1025 /* Read address of name from target memory to GDB. */
1026 read_memory (lm
+ lmo
->l_name_offset
, l_name_buf
, l_name_size
);
1028 /* Convert the address to host format. */
1029 l_name
= extract_typed_address (l_name_buf
, ptr_type
);
1031 /* Free l_name_buf. */
1032 do_cleanups (cleanups
);
1035 return 0; /* No filename. */
1037 /* Now fetch the filename from target memory. */
1038 target_read_string (l_name
, &filename
, SO_NAME_MAX_PATH_SIZE
- 1, &errcode
);
1039 make_cleanup (xfree
, filename
);
1043 warning (_("failed to read exec filename from attached file: %s"),
1044 safe_strerror (errcode
));
1048 /* Have a pathname: read the symbol file. */
1049 symbol_file_add_main (filename
, from_tty
);
1054 /* If no shared library information is available from the dynamic
1055 linker, build a fallback list from other sources. */
1057 static struct so_list
*
1058 svr4_default_sos (void)
1060 struct svr4_info
*info
= get_svr4_info ();
1062 struct so_list
*head
= NULL
;
1063 struct so_list
**link_ptr
= &head
;
1065 if (info
->debug_loader_offset_p
)
1067 struct so_list
*new = XZALLOC (struct so_list
);
1069 new->lm_info
= xmalloc (sizeof (struct lm_info
));
1071 /* Nothing will ever check the cached copy of the link
1072 map if we set l_addr. */
1073 new->lm_info
->l_addr
= info
->debug_loader_offset
;
1074 new->lm_info
->lm_addr
= 0;
1075 new->lm_info
->lm
= NULL
;
1077 strncpy (new->so_name
, info
->debug_loader_name
,
1078 SO_NAME_MAX_PATH_SIZE
- 1);
1079 new->so_name
[SO_NAME_MAX_PATH_SIZE
- 1] = '\0';
1080 strcpy (new->so_original_name
, new->so_name
);
1083 link_ptr
= &new->next
;
1091 current_sos -- build a list of currently loaded shared objects
1095 struct so_list *current_sos ()
1099 Build a list of `struct so_list' objects describing the shared
1100 objects currently loaded in the inferior. This list does not
1101 include an entry for the main executable file.
1103 Note that we only gather information directly available from the
1104 inferior --- we don't examine any of the shared library files
1105 themselves. The declaration of `struct so_list' says which fields
1106 we provide values for. */
1108 static struct so_list
*
1109 svr4_current_sos (void)
1111 CORE_ADDR lm
, prev_lm
;
1112 struct so_list
*head
= 0;
1113 struct so_list
**link_ptr
= &head
;
1114 CORE_ADDR ldsomap
= 0;
1115 struct svr4_info
*info
;
1117 info
= get_svr4_info ();
1119 /* Always locate the debug struct, in case it has moved. */
1120 info
->debug_base
= 0;
1123 /* If we can't find the dynamic linker's base structure, this
1124 must not be a dynamically linked executable. Hmm. */
1125 if (! info
->debug_base
)
1126 return svr4_default_sos ();
1128 /* Walk the inferior's link map list, and build our list of
1129 `struct so_list' nodes. */
1131 lm
= solib_svr4_r_map (info
);
1135 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
1136 struct so_list
*new = XZALLOC (struct so_list
);
1137 struct cleanup
*old_chain
= make_cleanup (xfree
, new);
1140 new->lm_info
= xmalloc (sizeof (struct lm_info
));
1141 make_cleanup (xfree
, new->lm_info
);
1143 new->lm_info
->l_addr
= (CORE_ADDR
)-1;
1144 new->lm_info
->lm_addr
= lm
;
1145 new->lm_info
->lm
= xzalloc (lmo
->link_map_size
);
1146 make_cleanup (xfree
, new->lm_info
->lm
);
1148 read_memory (lm
, new->lm_info
->lm
, lmo
->link_map_size
);
1150 next_lm
= LM_NEXT (new);
1152 if (LM_PREV (new) != prev_lm
)
1154 warning (_("Corrupted shared library list"));
1159 /* For SVR4 versions, the first entry in the link map is for the
1160 inferior executable, so we must ignore it. For some versions of
1161 SVR4, it has no name. For others (Solaris 2.3 for example), it
1162 does have a name, so we can no longer use a missing name to
1163 decide when to ignore it. */
1164 else if (IGNORE_FIRST_LINK_MAP_ENTRY (new) && ldsomap
== 0)
1166 info
->main_lm_addr
= new->lm_info
->lm_addr
;
1174 /* Extract this shared object's name. */
1175 target_read_string (LM_NAME (new), &buffer
,
1176 SO_NAME_MAX_PATH_SIZE
- 1, &errcode
);
1178 warning (_("Can't read pathname for load map: %s."),
1179 safe_strerror (errcode
));
1182 strncpy (new->so_name
, buffer
, SO_NAME_MAX_PATH_SIZE
- 1);
1183 new->so_name
[SO_NAME_MAX_PATH_SIZE
- 1] = '\0';
1184 strcpy (new->so_original_name
, new->so_name
);
1188 /* If this entry has no name, or its name matches the name
1189 for the main executable, don't include it in the list. */
1190 if (! new->so_name
[0]
1191 || match_main (new->so_name
))
1197 link_ptr
= &new->next
;
1204 /* On Solaris, the dynamic linker is not in the normal list of
1205 shared objects, so make sure we pick it up too. Having
1206 symbol information for the dynamic linker is quite crucial
1207 for skipping dynamic linker resolver code. */
1208 if (lm
== 0 && ldsomap
== 0)
1210 lm
= ldsomap
= solib_svr4_r_ldsomap (info
);
1214 discard_cleanups (old_chain
);
1218 return svr4_default_sos ();
1223 /* Get the address of the link_map for a given OBJFILE. */
1226 svr4_fetch_objfile_link_map (struct objfile
*objfile
)
1229 struct svr4_info
*info
= get_svr4_info ();
1231 /* Cause svr4_current_sos() to be run if it hasn't been already. */
1232 if (info
->main_lm_addr
== 0)
1233 solib_add (NULL
, 0, ¤t_target
, auto_solib_add
);
1235 /* svr4_current_sos() will set main_lm_addr for the main executable. */
1236 if (objfile
== symfile_objfile
)
1237 return info
->main_lm_addr
;
1239 /* The other link map addresses may be found by examining the list
1240 of shared libraries. */
1241 for (so
= master_so_list (); so
; so
= so
->next
)
1242 if (so
->objfile
== objfile
)
1243 return so
->lm_info
->lm_addr
;
1249 /* On some systems, the only way to recognize the link map entry for
1250 the main executable file is by looking at its name. Return
1251 non-zero iff SONAME matches one of the known main executable names. */
1254 match_main (const char *soname
)
1256 const char * const *mainp
;
1258 for (mainp
= main_name_list
; *mainp
!= NULL
; mainp
++)
1260 if (strcmp (soname
, *mainp
) == 0)
1267 /* Return 1 if PC lies in the dynamic symbol resolution code of the
1268 SVR4 run time loader. */
1271 svr4_in_dynsym_resolve_code (CORE_ADDR pc
)
1273 struct svr4_info
*info
= get_svr4_info ();
1275 return ((pc
>= info
->interp_text_sect_low
1276 && pc
< info
->interp_text_sect_high
)
1277 || (pc
>= info
->interp_plt_sect_low
1278 && pc
< info
->interp_plt_sect_high
)
1279 || in_plt_section (pc
, NULL
)
1280 || in_gnu_ifunc_stub (pc
));
1283 /* Given an executable's ABFD and target, compute the entry-point
1287 exec_entry_point (struct bfd
*abfd
, struct target_ops
*targ
)
1289 /* KevinB wrote ... for most targets, the address returned by
1290 bfd_get_start_address() is the entry point for the start
1291 function. But, for some targets, bfd_get_start_address() returns
1292 the address of a function descriptor from which the entry point
1293 address may be extracted. This address is extracted by
1294 gdbarch_convert_from_func_ptr_addr(). The method
1295 gdbarch_convert_from_func_ptr_addr() is the merely the identify
1296 function for targets which don't use function descriptors. */
1297 return gdbarch_convert_from_func_ptr_addr (target_gdbarch
,
1298 bfd_get_start_address (abfd
),
1306 enable_break -- arrange for dynamic linker to hit breakpoint
1310 int enable_break (void)
1314 Both the SunOS and the SVR4 dynamic linkers have, as part of their
1315 debugger interface, support for arranging for the inferior to hit
1316 a breakpoint after mapping in the shared libraries. This function
1317 enables that breakpoint.
1319 For SunOS, there is a special flag location (in_debugger) which we
1320 set to 1. When the dynamic linker sees this flag set, it will set
1321 a breakpoint at a location known only to itself, after saving the
1322 original contents of that place and the breakpoint address itself,
1323 in it's own internal structures. When we resume the inferior, it
1324 will eventually take a SIGTRAP when it runs into the breakpoint.
1325 We handle this (in a different place) by restoring the contents of
1326 the breakpointed location (which is only known after it stops),
1327 chasing around to locate the shared libraries that have been
1328 loaded, then resuming.
1330 For SVR4, the debugger interface structure contains a member (r_brk)
1331 which is statically initialized at the time the shared library is
1332 built, to the offset of a function (_r_debug_state) which is guaran-
1333 teed to be called once before mapping in a library, and again when
1334 the mapping is complete. At the time we are examining this member,
1335 it contains only the unrelocated offset of the function, so we have
1336 to do our own relocation. Later, when the dynamic linker actually
1337 runs, it relocates r_brk to be the actual address of _r_debug_state().
1339 The debugger interface structure also contains an enumeration which
1340 is set to either RT_ADD or RT_DELETE prior to changing the mapping,
1341 depending upon whether or not the library is being mapped or unmapped,
1342 and then set to RT_CONSISTENT after the library is mapped/unmapped.
1346 enable_break (struct svr4_info
*info
, int from_tty
)
1348 struct minimal_symbol
*msymbol
;
1349 const char * const *bkpt_namep
;
1350 asection
*interp_sect
;
1351 gdb_byte
*interp_name
;
1354 info
->interp_text_sect_low
= info
->interp_text_sect_high
= 0;
1355 info
->interp_plt_sect_low
= info
->interp_plt_sect_high
= 0;
1357 /* If we already have a shared library list in the target, and
1358 r_debug contains r_brk, set the breakpoint there - this should
1359 mean r_brk has already been relocated. Assume the dynamic linker
1360 is the object containing r_brk. */
1362 solib_add (NULL
, from_tty
, ¤t_target
, auto_solib_add
);
1364 if (info
->debug_base
&& solib_svr4_r_map (info
) != 0)
1365 sym_addr
= solib_svr4_r_brk (info
);
1369 struct obj_section
*os
;
1371 sym_addr
= gdbarch_addr_bits_remove
1372 (target_gdbarch
, gdbarch_convert_from_func_ptr_addr (target_gdbarch
,
1376 /* On at least some versions of Solaris there's a dynamic relocation
1377 on _r_debug.r_brk and SYM_ADDR may not be relocated yet, e.g., if
1378 we get control before the dynamic linker has self-relocated.
1379 Check if SYM_ADDR is in a known section, if it is assume we can
1380 trust its value. This is just a heuristic though, it could go away
1381 or be replaced if it's getting in the way.
1383 On ARM we need to know whether the ISA of rtld_db_dlactivity (or
1384 however it's spelled in your particular system) is ARM or Thumb.
1385 That knowledge is encoded in the address, if it's Thumb the low bit
1386 is 1. However, we've stripped that info above and it's not clear
1387 what all the consequences are of passing a non-addr_bits_remove'd
1388 address to create_solib_event_breakpoint. The call to
1389 find_pc_section verifies we know about the address and have some
1390 hope of computing the right kind of breakpoint to use (via
1391 symbol info). It does mean that GDB needs to be pointed at a
1392 non-stripped version of the dynamic linker in order to obtain
1393 information it already knows about. Sigh. */
1395 os
= find_pc_section (sym_addr
);
1398 /* Record the relocated start and end address of the dynamic linker
1399 text and plt section for svr4_in_dynsym_resolve_code. */
1401 CORE_ADDR load_addr
;
1403 tmp_bfd
= os
->objfile
->obfd
;
1404 load_addr
= ANOFFSET (os
->objfile
->section_offsets
,
1405 os
->objfile
->sect_index_text
);
1407 interp_sect
= bfd_get_section_by_name (tmp_bfd
, ".text");
1410 info
->interp_text_sect_low
=
1411 bfd_section_vma (tmp_bfd
, interp_sect
) + load_addr
;
1412 info
->interp_text_sect_high
=
1413 info
->interp_text_sect_low
1414 + bfd_section_size (tmp_bfd
, interp_sect
);
1416 interp_sect
= bfd_get_section_by_name (tmp_bfd
, ".plt");
1419 info
->interp_plt_sect_low
=
1420 bfd_section_vma (tmp_bfd
, interp_sect
) + load_addr
;
1421 info
->interp_plt_sect_high
=
1422 info
->interp_plt_sect_low
1423 + bfd_section_size (tmp_bfd
, interp_sect
);
1426 create_solib_event_breakpoint (target_gdbarch
, sym_addr
);
1431 /* Find the program interpreter; if not found, warn the user and drop
1432 into the old breakpoint at symbol code. */
1433 interp_name
= find_program_interpreter ();
1436 CORE_ADDR load_addr
= 0;
1437 int load_addr_found
= 0;
1438 int loader_found_in_list
= 0;
1440 bfd
*tmp_bfd
= NULL
;
1441 struct target_ops
*tmp_bfd_target
;
1442 volatile struct gdb_exception ex
;
1446 /* Now we need to figure out where the dynamic linker was
1447 loaded so that we can load its symbols and place a breakpoint
1448 in the dynamic linker itself.
1450 This address is stored on the stack. However, I've been unable
1451 to find any magic formula to find it for Solaris (appears to
1452 be trivial on GNU/Linux). Therefore, we have to try an alternate
1453 mechanism to find the dynamic linker's base address. */
1455 TRY_CATCH (ex
, RETURN_MASK_ALL
)
1457 tmp_bfd
= solib_bfd_open (interp_name
);
1459 if (tmp_bfd
== NULL
)
1460 goto bkpt_at_symbol
;
1462 /* Now convert the TMP_BFD into a target. That way target, as
1463 well as BFD operations can be used. Note that closing the
1464 target will also close the underlying bfd. */
1465 tmp_bfd_target
= target_bfd_reopen (tmp_bfd
);
1467 /* On a running target, we can get the dynamic linker's base
1468 address from the shared library table. */
1469 so
= master_so_list ();
1472 if (svr4_same_1 (interp_name
, so
->so_original_name
))
1474 load_addr_found
= 1;
1475 loader_found_in_list
= 1;
1476 load_addr
= LM_ADDR_CHECK (so
, tmp_bfd
);
1482 /* If we were not able to find the base address of the loader
1483 from our so_list, then try using the AT_BASE auxilliary entry. */
1484 if (!load_addr_found
)
1485 if (target_auxv_search (¤t_target
, AT_BASE
, &load_addr
) > 0)
1487 int addr_bit
= gdbarch_addr_bit (target_gdbarch
);
1489 /* Ensure LOAD_ADDR has proper sign in its possible upper bits so
1490 that `+ load_addr' will overflow CORE_ADDR width not creating
1491 invalid addresses like 0x101234567 for 32bit inferiors on 64bit
1494 if (addr_bit
< (sizeof (CORE_ADDR
) * HOST_CHAR_BIT
))
1496 CORE_ADDR space_size
= (CORE_ADDR
) 1 << addr_bit
;
1497 CORE_ADDR tmp_entry_point
= exec_entry_point (tmp_bfd
,
1500 gdb_assert (load_addr
< space_size
);
1502 /* TMP_ENTRY_POINT exceeding SPACE_SIZE would be for prelinked
1503 64bit ld.so with 32bit executable, it should not happen. */
1505 if (tmp_entry_point
< space_size
1506 && tmp_entry_point
+ load_addr
>= space_size
)
1507 load_addr
-= space_size
;
1510 load_addr_found
= 1;
1513 /* Otherwise we find the dynamic linker's base address by examining
1514 the current pc (which should point at the entry point for the
1515 dynamic linker) and subtracting the offset of the entry point.
1517 This is more fragile than the previous approaches, but is a good
1518 fallback method because it has actually been working well in
1520 if (!load_addr_found
)
1522 struct regcache
*regcache
1523 = get_thread_arch_regcache (inferior_ptid
, target_gdbarch
);
1525 load_addr
= (regcache_read_pc (regcache
)
1526 - exec_entry_point (tmp_bfd
, tmp_bfd_target
));
1529 if (!loader_found_in_list
)
1531 info
->debug_loader_name
= xstrdup (interp_name
);
1532 info
->debug_loader_offset_p
= 1;
1533 info
->debug_loader_offset
= load_addr
;
1534 solib_add (NULL
, from_tty
, ¤t_target
, auto_solib_add
);
1537 /* Record the relocated start and end address of the dynamic linker
1538 text and plt section for svr4_in_dynsym_resolve_code. */
1539 interp_sect
= bfd_get_section_by_name (tmp_bfd
, ".text");
1542 info
->interp_text_sect_low
=
1543 bfd_section_vma (tmp_bfd
, interp_sect
) + load_addr
;
1544 info
->interp_text_sect_high
=
1545 info
->interp_text_sect_low
1546 + bfd_section_size (tmp_bfd
, interp_sect
);
1548 interp_sect
= bfd_get_section_by_name (tmp_bfd
, ".plt");
1551 info
->interp_plt_sect_low
=
1552 bfd_section_vma (tmp_bfd
, interp_sect
) + load_addr
;
1553 info
->interp_plt_sect_high
=
1554 info
->interp_plt_sect_low
1555 + bfd_section_size (tmp_bfd
, interp_sect
);
1558 /* Now try to set a breakpoint in the dynamic linker. */
1559 for (bkpt_namep
= solib_break_names
; *bkpt_namep
!= NULL
; bkpt_namep
++)
1561 sym_addr
= bfd_lookup_symbol (tmp_bfd
, *bkpt_namep
);
1567 /* Convert 'sym_addr' from a function pointer to an address.
1568 Because we pass tmp_bfd_target instead of the current
1569 target, this will always produce an unrelocated value. */
1570 sym_addr
= gdbarch_convert_from_func_ptr_addr (target_gdbarch
,
1574 /* We're done with both the temporary bfd and target. Remember,
1575 closing the target closes the underlying bfd. */
1576 target_close (tmp_bfd_target
, 0);
1580 create_solib_event_breakpoint (target_gdbarch
, load_addr
+ sym_addr
);
1581 xfree (interp_name
);
1585 /* For whatever reason we couldn't set a breakpoint in the dynamic
1586 linker. Warn and drop into the old code. */
1588 xfree (interp_name
);
1589 warning (_("Unable to find dynamic linker breakpoint function.\n"
1590 "GDB will be unable to debug shared library initializers\n"
1591 "and track explicitly loaded dynamic code."));
1594 /* Scan through the lists of symbols, trying to look up the symbol and
1595 set a breakpoint there. Terminate loop when we/if we succeed. */
1597 for (bkpt_namep
= solib_break_names
; *bkpt_namep
!= NULL
; bkpt_namep
++)
1599 msymbol
= lookup_minimal_symbol (*bkpt_namep
, NULL
, symfile_objfile
);
1600 if ((msymbol
!= NULL
) && (SYMBOL_VALUE_ADDRESS (msymbol
) != 0))
1602 sym_addr
= SYMBOL_VALUE_ADDRESS (msymbol
);
1603 sym_addr
= gdbarch_convert_from_func_ptr_addr (target_gdbarch
,
1606 create_solib_event_breakpoint (target_gdbarch
, sym_addr
);
1611 if (!current_inferior ()->attach_flag
)
1613 for (bkpt_namep
= bkpt_names
; *bkpt_namep
!= NULL
; bkpt_namep
++)
1615 msymbol
= lookup_minimal_symbol (*bkpt_namep
, NULL
, symfile_objfile
);
1616 if ((msymbol
!= NULL
) && (SYMBOL_VALUE_ADDRESS (msymbol
) != 0))
1618 sym_addr
= SYMBOL_VALUE_ADDRESS (msymbol
);
1619 sym_addr
= gdbarch_convert_from_func_ptr_addr (target_gdbarch
,
1622 create_solib_event_breakpoint (target_gdbarch
, sym_addr
);
1634 special_symbol_handling -- additional shared library symbol handling
1638 void special_symbol_handling ()
1642 Once the symbols from a shared object have been loaded in the usual
1643 way, we are called to do any system specific symbol handling that
1646 For SunOS4, this consisted of grunging around in the dynamic
1647 linkers structures to find symbol definitions for "common" symbols
1648 and adding them to the minimal symbol table for the runtime common
1651 However, for SVR4, there's nothing to do.
1656 svr4_special_symbol_handling (void)
1660 /* Read the ELF program headers from ABFD. Return the contents and
1661 set *PHDRS_SIZE to the size of the program headers. */
1664 read_program_headers_from_bfd (bfd
*abfd
, int *phdrs_size
)
1666 Elf_Internal_Ehdr
*ehdr
;
1669 ehdr
= elf_elfheader (abfd
);
1671 *phdrs_size
= ehdr
->e_phnum
* ehdr
->e_phentsize
;
1672 if (*phdrs_size
== 0)
1675 buf
= xmalloc (*phdrs_size
);
1676 if (bfd_seek (abfd
, ehdr
->e_phoff
, SEEK_SET
) != 0
1677 || bfd_bread (buf
, *phdrs_size
, abfd
) != *phdrs_size
)
1686 /* Return 1 and fill *DISPLACEMENTP with detected PIE offset of inferior
1687 exec_bfd. Otherwise return 0.
1689 We relocate all of the sections by the same amount. This
1690 behavior is mandated by recent editions of the System V ABI.
1691 According to the System V Application Binary Interface,
1692 Edition 4.1, page 5-5:
1694 ... Though the system chooses virtual addresses for
1695 individual processes, it maintains the segments' relative
1696 positions. Because position-independent code uses relative
1697 addressesing between segments, the difference between
1698 virtual addresses in memory must match the difference
1699 between virtual addresses in the file. The difference
1700 between the virtual address of any segment in memory and
1701 the corresponding virtual address in the file is thus a
1702 single constant value for any one executable or shared
1703 object in a given process. This difference is the base
1704 address. One use of the base address is to relocate the
1705 memory image of the program during dynamic linking.
1707 The same language also appears in Edition 4.0 of the System V
1708 ABI and is left unspecified in some of the earlier editions.
1710 Decide if the objfile needs to be relocated. As indicated above, we will
1711 only be here when execution is stopped. But during attachment PC can be at
1712 arbitrary address therefore regcache_read_pc can be misleading (contrary to
1713 the auxv AT_ENTRY value). Moreover for executable with interpreter section
1714 regcache_read_pc would point to the interpreter and not the main executable.
1716 So, to summarize, relocations are necessary when the start address obtained
1717 from the executable is different from the address in auxv AT_ENTRY entry.
1719 [ The astute reader will note that we also test to make sure that
1720 the executable in question has the DYNAMIC flag set. It is my
1721 opinion that this test is unnecessary (undesirable even). It
1722 was added to avoid inadvertent relocation of an executable
1723 whose e_type member in the ELF header is not ET_DYN. There may
1724 be a time in the future when it is desirable to do relocations
1725 on other types of files as well in which case this condition
1726 should either be removed or modified to accomodate the new file
1727 type. - Kevin, Nov 2000. ] */
1730 svr4_exec_displacement (CORE_ADDR
*displacementp
)
1732 /* ENTRY_POINT is a possible function descriptor - before
1733 a call to gdbarch_convert_from_func_ptr_addr. */
1734 CORE_ADDR entry_point
, displacement
;
1736 if (exec_bfd
== NULL
)
1739 /* Therefore for ELF it is ET_EXEC and not ET_DYN. Both shared libraries
1740 being executed themselves and PIE (Position Independent Executable)
1741 executables are ET_DYN. */
1743 if ((bfd_get_file_flags (exec_bfd
) & DYNAMIC
) == 0)
1746 if (target_auxv_search (¤t_target
, AT_ENTRY
, &entry_point
) <= 0)
1749 displacement
= entry_point
- bfd_get_start_address (exec_bfd
);
1751 /* Verify the DISPLACEMENT candidate complies with the required page
1752 alignment. It is cheaper than the program headers comparison below. */
1754 if (bfd_get_flavour (exec_bfd
) == bfd_target_elf_flavour
)
1756 const struct elf_backend_data
*elf
= get_elf_backend_data (exec_bfd
);
1758 /* p_align of PT_LOAD segments does not specify any alignment but
1759 only congruency of addresses:
1760 p_offset % p_align == p_vaddr % p_align
1761 Kernel is free to load the executable with lower alignment. */
1763 if ((displacement
& (elf
->minpagesize
- 1)) != 0)
1767 /* Verify that the auxilliary vector describes the same file as exec_bfd, by
1768 comparing their program headers. If the program headers in the auxilliary
1769 vector do not match the program headers in the executable, then we are
1770 looking at a different file than the one used by the kernel - for
1771 instance, "gdb program" connected to "gdbserver :PORT ld.so program". */
1773 if (bfd_get_flavour (exec_bfd
) == bfd_target_elf_flavour
)
1775 /* Be optimistic and clear OK only if GDB was able to verify the headers
1776 really do not match. */
1777 int phdrs_size
, phdrs2_size
, ok
= 1;
1778 gdb_byte
*buf
, *buf2
;
1781 buf
= read_program_header (-1, &phdrs_size
, &arch_size
);
1782 buf2
= read_program_headers_from_bfd (exec_bfd
, &phdrs2_size
);
1783 if (buf
!= NULL
&& buf2
!= NULL
)
1785 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch
);
1787 /* We are dealing with three different addresses. EXEC_BFD
1788 represents current address in on-disk file. target memory content
1789 may be different from EXEC_BFD as the file may have been prelinked
1790 to a different address after the executable has been loaded.
1791 Moreover the address of placement in target memory can be
1792 different from what the program headers in target memory say -
1793 this is the goal of PIE.
1795 Detected DISPLACEMENT covers both the offsets of PIE placement and
1796 possible new prelink performed after start of the program. Here
1797 relocate BUF and BUF2 just by the EXEC_BFD vs. target memory
1798 content offset for the verification purpose. */
1800 if (phdrs_size
!= phdrs2_size
1801 || bfd_get_arch_size (exec_bfd
) != arch_size
)
1803 else if (arch_size
== 32
1804 && phdrs_size
>= sizeof (Elf32_External_Phdr
)
1805 && phdrs_size
% sizeof (Elf32_External_Phdr
) == 0)
1807 Elf_Internal_Ehdr
*ehdr2
= elf_tdata (exec_bfd
)->elf_header
;
1808 Elf_Internal_Phdr
*phdr2
= elf_tdata (exec_bfd
)->phdr
;
1809 CORE_ADDR displacement
= 0;
1812 /* DISPLACEMENT could be found more easily by the difference of
1813 ehdr2->e_entry. But we haven't read the ehdr yet, and we
1814 already have enough information to compute that displacement
1815 with what we've read. */
1817 for (i
= 0; i
< ehdr2
->e_phnum
; i
++)
1818 if (phdr2
[i
].p_type
== PT_LOAD
)
1820 Elf32_External_Phdr
*phdrp
;
1821 gdb_byte
*buf_vaddr_p
, *buf_paddr_p
;
1822 CORE_ADDR vaddr
, paddr
;
1823 CORE_ADDR displacement_vaddr
= 0;
1824 CORE_ADDR displacement_paddr
= 0;
1826 phdrp
= &((Elf32_External_Phdr
*) buf
)[i
];
1827 buf_vaddr_p
= (gdb_byte
*) &phdrp
->p_vaddr
;
1828 buf_paddr_p
= (gdb_byte
*) &phdrp
->p_paddr
;
1830 vaddr
= extract_unsigned_integer (buf_vaddr_p
, 4,
1832 displacement_vaddr
= vaddr
- phdr2
[i
].p_vaddr
;
1834 paddr
= extract_unsigned_integer (buf_paddr_p
, 4,
1836 displacement_paddr
= paddr
- phdr2
[i
].p_paddr
;
1838 if (displacement_vaddr
== displacement_paddr
)
1839 displacement
= displacement_vaddr
;
1844 /* Now compare BUF and BUF2 with optional DISPLACEMENT. */
1846 for (i
= 0; i
< phdrs_size
/ sizeof (Elf32_External_Phdr
); i
++)
1848 Elf32_External_Phdr
*phdrp
;
1849 Elf32_External_Phdr
*phdr2p
;
1850 gdb_byte
*buf_vaddr_p
, *buf_paddr_p
;
1851 CORE_ADDR vaddr
, paddr
;
1852 asection
*plt2_asect
;
1854 phdrp
= &((Elf32_External_Phdr
*) buf
)[i
];
1855 buf_vaddr_p
= (gdb_byte
*) &phdrp
->p_vaddr
;
1856 buf_paddr_p
= (gdb_byte
*) &phdrp
->p_paddr
;
1857 phdr2p
= &((Elf32_External_Phdr
*) buf2
)[i
];
1859 /* PT_GNU_STACK is an exception by being never relocated by
1860 prelink as its addresses are always zero. */
1862 if (memcmp (phdrp
, phdr2p
, sizeof (*phdrp
)) == 0)
1865 /* Check also other adjustment combinations - PR 11786. */
1867 vaddr
= extract_unsigned_integer (buf_vaddr_p
, 4,
1869 vaddr
-= displacement
;
1870 store_unsigned_integer (buf_vaddr_p
, 4, byte_order
, vaddr
);
1872 paddr
= extract_unsigned_integer (buf_paddr_p
, 4,
1874 paddr
-= displacement
;
1875 store_unsigned_integer (buf_paddr_p
, 4, byte_order
, paddr
);
1877 if (memcmp (phdrp
, phdr2p
, sizeof (*phdrp
)) == 0)
1880 /* prelink can convert .plt SHT_NOBITS to SHT_PROGBITS. */
1881 plt2_asect
= bfd_get_section_by_name (exec_bfd
, ".plt");
1885 gdb_byte
*buf_filesz_p
= (gdb_byte
*) &phdrp
->p_filesz
;
1888 content2
= (bfd_get_section_flags (exec_bfd
, plt2_asect
)
1889 & SEC_HAS_CONTENTS
) != 0;
1891 filesz
= extract_unsigned_integer (buf_filesz_p
, 4,
1894 /* PLT2_ASECT is from on-disk file (exec_bfd) while
1895 FILESZ is from the in-memory image. */
1897 filesz
+= bfd_get_section_size (plt2_asect
);
1899 filesz
-= bfd_get_section_size (plt2_asect
);
1901 store_unsigned_integer (buf_filesz_p
, 4, byte_order
,
1904 if (memcmp (phdrp
, phdr2p
, sizeof (*phdrp
)) == 0)
1912 else if (arch_size
== 64
1913 && phdrs_size
>= sizeof (Elf64_External_Phdr
)
1914 && phdrs_size
% sizeof (Elf64_External_Phdr
) == 0)
1916 Elf_Internal_Ehdr
*ehdr2
= elf_tdata (exec_bfd
)->elf_header
;
1917 Elf_Internal_Phdr
*phdr2
= elf_tdata (exec_bfd
)->phdr
;
1918 CORE_ADDR displacement
= 0;
1921 /* DISPLACEMENT could be found more easily by the difference of
1922 ehdr2->e_entry. But we haven't read the ehdr yet, and we
1923 already have enough information to compute that displacement
1924 with what we've read. */
1926 for (i
= 0; i
< ehdr2
->e_phnum
; i
++)
1927 if (phdr2
[i
].p_type
== PT_LOAD
)
1929 Elf64_External_Phdr
*phdrp
;
1930 gdb_byte
*buf_vaddr_p
, *buf_paddr_p
;
1931 CORE_ADDR vaddr
, paddr
;
1932 CORE_ADDR displacement_vaddr
= 0;
1933 CORE_ADDR displacement_paddr
= 0;
1935 phdrp
= &((Elf64_External_Phdr
*) buf
)[i
];
1936 buf_vaddr_p
= (gdb_byte
*) &phdrp
->p_vaddr
;
1937 buf_paddr_p
= (gdb_byte
*) &phdrp
->p_paddr
;
1939 vaddr
= extract_unsigned_integer (buf_vaddr_p
, 8,
1941 displacement_vaddr
= vaddr
- phdr2
[i
].p_vaddr
;
1943 paddr
= extract_unsigned_integer (buf_paddr_p
, 8,
1945 displacement_paddr
= paddr
- phdr2
[i
].p_paddr
;
1947 if (displacement_vaddr
== displacement_paddr
)
1948 displacement
= displacement_vaddr
;
1953 /* Now compare BUF and BUF2 with optional DISPLACEMENT. */
1955 for (i
= 0; i
< phdrs_size
/ sizeof (Elf64_External_Phdr
); i
++)
1957 Elf64_External_Phdr
*phdrp
;
1958 Elf64_External_Phdr
*phdr2p
;
1959 gdb_byte
*buf_vaddr_p
, *buf_paddr_p
;
1960 CORE_ADDR vaddr
, paddr
;
1961 asection
*plt2_asect
;
1963 phdrp
= &((Elf64_External_Phdr
*) buf
)[i
];
1964 buf_vaddr_p
= (gdb_byte
*) &phdrp
->p_vaddr
;
1965 buf_paddr_p
= (gdb_byte
*) &phdrp
->p_paddr
;
1966 phdr2p
= &((Elf64_External_Phdr
*) buf2
)[i
];
1968 /* PT_GNU_STACK is an exception by being never relocated by
1969 prelink as its addresses are always zero. */
1971 if (memcmp (phdrp
, phdr2p
, sizeof (*phdrp
)) == 0)
1974 /* Check also other adjustment combinations - PR 11786. */
1976 vaddr
= extract_unsigned_integer (buf_vaddr_p
, 8,
1978 vaddr
-= displacement
;
1979 store_unsigned_integer (buf_vaddr_p
, 8, byte_order
, vaddr
);
1981 paddr
= extract_unsigned_integer (buf_paddr_p
, 8,
1983 paddr
-= displacement
;
1984 store_unsigned_integer (buf_paddr_p
, 8, byte_order
, paddr
);
1986 if (memcmp (phdrp
, phdr2p
, sizeof (*phdrp
)) == 0)
1989 /* prelink can convert .plt SHT_NOBITS to SHT_PROGBITS. */
1990 plt2_asect
= bfd_get_section_by_name (exec_bfd
, ".plt");
1994 gdb_byte
*buf_filesz_p
= (gdb_byte
*) &phdrp
->p_filesz
;
1997 content2
= (bfd_get_section_flags (exec_bfd
, plt2_asect
)
1998 & SEC_HAS_CONTENTS
) != 0;
2000 filesz
= extract_unsigned_integer (buf_filesz_p
, 8,
2003 /* PLT2_ASECT is from on-disk file (exec_bfd) while
2004 FILESZ is from the in-memory image. */
2006 filesz
+= bfd_get_section_size (plt2_asect
);
2008 filesz
-= bfd_get_section_size (plt2_asect
);
2010 store_unsigned_integer (buf_filesz_p
, 8, byte_order
,
2013 if (memcmp (phdrp
, phdr2p
, sizeof (*phdrp
)) == 0)
2034 /* It can be printed repeatedly as there is no easy way to check
2035 the executable symbols/file has been already relocated to
2038 printf_unfiltered (_("Using PIE (Position Independent Executable) "
2039 "displacement %s for \"%s\".\n"),
2040 paddress (target_gdbarch
, displacement
),
2041 bfd_get_filename (exec_bfd
));
2044 *displacementp
= displacement
;
2048 /* Relocate the main executable. This function should be called upon
2049 stopping the inferior process at the entry point to the program.
2050 The entry point from BFD is compared to the AT_ENTRY of AUXV and if they are
2051 different, the main executable is relocated by the proper amount. */
2054 svr4_relocate_main_executable (void)
2056 CORE_ADDR displacement
;
2058 /* If we are re-running this executable, SYMFILE_OBJFILE->SECTION_OFFSETS
2059 probably contains the offsets computed using the PIE displacement
2060 from the previous run, which of course are irrelevant for this run.
2061 So we need to determine the new PIE displacement and recompute the
2062 section offsets accordingly, even if SYMFILE_OBJFILE->SECTION_OFFSETS
2063 already contains pre-computed offsets.
2065 If we cannot compute the PIE displacement, either:
2067 - The executable is not PIE.
2069 - SYMFILE_OBJFILE does not match the executable started in the target.
2070 This can happen for main executable symbols loaded at the host while
2071 `ld.so --ld-args main-executable' is loaded in the target.
2073 Then we leave the section offsets untouched and use them as is for
2076 - These section offsets were properly reset earlier, and thus
2077 already contain the correct values. This can happen for instance
2078 when reconnecting via the remote protocol to a target that supports
2079 the `qOffsets' packet.
2081 - The section offsets were not reset earlier, and the best we can
2082 hope is that the old offsets are still applicable to the new run. */
2084 if (! svr4_exec_displacement (&displacement
))
2087 /* Even DISPLACEMENT 0 is a valid new difference of in-memory vs. in-file
2090 if (symfile_objfile
)
2092 struct section_offsets
*new_offsets
;
2095 new_offsets
= alloca (symfile_objfile
->num_sections
2096 * sizeof (*new_offsets
));
2098 for (i
= 0; i
< symfile_objfile
->num_sections
; i
++)
2099 new_offsets
->offsets
[i
] = displacement
;
2101 objfile_relocate (symfile_objfile
, new_offsets
);
2107 for (asect
= exec_bfd
->sections
; asect
!= NULL
; asect
= asect
->next
)
2108 exec_set_section_address (bfd_get_filename (exec_bfd
), asect
->index
,
2109 (bfd_section_vma (exec_bfd
, asect
)
2118 svr4_solib_create_inferior_hook -- shared library startup support
2122 void svr4_solib_create_inferior_hook (int from_tty)
2126 When gdb starts up the inferior, it nurses it along (through the
2127 shell) until it is ready to execute it's first instruction. At this
2128 point, this function gets called via expansion of the macro
2129 SOLIB_CREATE_INFERIOR_HOOK.
2131 For SunOS executables, this first instruction is typically the
2132 one at "_start", or a similar text label, regardless of whether
2133 the executable is statically or dynamically linked. The runtime
2134 startup code takes care of dynamically linking in any shared
2135 libraries, once gdb allows the inferior to continue.
2137 For SVR4 executables, this first instruction is either the first
2138 instruction in the dynamic linker (for dynamically linked
2139 executables) or the instruction at "start" for statically linked
2140 executables. For dynamically linked executables, the system
2141 first exec's /lib/libc.so.N, which contains the dynamic linker,
2142 and starts it running. The dynamic linker maps in any needed
2143 shared libraries, maps in the actual user executable, and then
2144 jumps to "start" in the user executable.
2146 For both SunOS shared libraries, and SVR4 shared libraries, we
2147 can arrange to cooperate with the dynamic linker to discover the
2148 names of shared libraries that are dynamically linked, and the
2149 base addresses to which they are linked.
2151 This function is responsible for discovering those names and
2152 addresses, and saving sufficient information about them to allow
2153 their symbols to be read at a later time.
2157 Between enable_break() and disable_break(), this code does not
2158 properly handle hitting breakpoints which the user might have
2159 set in the startup code or in the dynamic linker itself. Proper
2160 handling will probably have to wait until the implementation is
2161 changed to use the "breakpoint handler function" method.
2163 Also, what if child has exit()ed? Must exit loop somehow.
2167 svr4_solib_create_inferior_hook (int from_tty
)
2169 #if defined(_SCO_DS)
2170 struct inferior
*inf
;
2171 struct thread_info
*tp
;
2172 #endif /* defined(_SCO_DS) */
2173 struct svr4_info
*info
;
2175 info
= get_svr4_info ();
2177 /* Relocate the main executable if necessary. */
2178 svr4_relocate_main_executable ();
2180 if (!svr4_have_link_map_offsets ())
2183 if (!enable_break (info
, from_tty
))
2186 #if defined(_SCO_DS)
2187 /* SCO needs the loop below, other systems should be using the
2188 special shared library breakpoints and the shared library breakpoint
2191 Now run the target. It will eventually hit the breakpoint, at
2192 which point all of the libraries will have been mapped in and we
2193 can go groveling around in the dynamic linker structures to find
2194 out what we need to know about them. */
2196 inf
= current_inferior ();
2197 tp
= inferior_thread ();
2199 clear_proceed_status ();
2200 inf
->control
.stop_soon
= STOP_QUIETLY
;
2201 tp
->suspend
.stop_signal
= TARGET_SIGNAL_0
;
2204 target_resume (pid_to_ptid (-1), 0, tp
->suspend
.stop_signal
);
2205 wait_for_inferior (0);
2207 while (tp
->suspend
.stop_signal
!= TARGET_SIGNAL_TRAP
);
2208 inf
->control
.stop_soon
= NO_STOP_QUIETLY
;
2209 #endif /* defined(_SCO_DS) */
2213 svr4_clear_solib (void)
2215 struct svr4_info
*info
;
2217 info
= get_svr4_info ();
2218 info
->debug_base
= 0;
2219 info
->debug_loader_offset_p
= 0;
2220 info
->debug_loader_offset
= 0;
2221 xfree (info
->debug_loader_name
);
2222 info
->debug_loader_name
= NULL
;
2226 svr4_free_so (struct so_list
*so
)
2228 xfree (so
->lm_info
->lm
);
2229 xfree (so
->lm_info
);
2233 /* Clear any bits of ADDR that wouldn't fit in a target-format
2234 data pointer. "Data pointer" here refers to whatever sort of
2235 address the dynamic linker uses to manage its sections. At the
2236 moment, we don't support shared libraries on any processors where
2237 code and data pointers are different sizes.
2239 This isn't really the right solution. What we really need here is
2240 a way to do arithmetic on CORE_ADDR values that respects the
2241 natural pointer/address correspondence. (For example, on the MIPS,
2242 converting a 32-bit pointer to a 64-bit CORE_ADDR requires you to
2243 sign-extend the value. There, simply truncating the bits above
2244 gdbarch_ptr_bit, as we do below, is no good.) This should probably
2245 be a new gdbarch method or something. */
2247 svr4_truncate_ptr (CORE_ADDR addr
)
2249 if (gdbarch_ptr_bit (target_gdbarch
) == sizeof (CORE_ADDR
) * 8)
2250 /* We don't need to truncate anything, and the bit twiddling below
2251 will fail due to overflow problems. */
2254 return addr
& (((CORE_ADDR
) 1 << gdbarch_ptr_bit (target_gdbarch
)) - 1);
2259 svr4_relocate_section_addresses (struct so_list
*so
,
2260 struct target_section
*sec
)
2262 sec
->addr
= svr4_truncate_ptr (sec
->addr
+ LM_ADDR_CHECK (so
,
2264 sec
->endaddr
= svr4_truncate_ptr (sec
->endaddr
+ LM_ADDR_CHECK (so
,
2269 /* Architecture-specific operations. */
2271 /* Per-architecture data key. */
2272 static struct gdbarch_data
*solib_svr4_data
;
2274 struct solib_svr4_ops
2276 /* Return a description of the layout of `struct link_map'. */
2277 struct link_map_offsets
*(*fetch_link_map_offsets
)(void);
2280 /* Return a default for the architecture-specific operations. */
2283 solib_svr4_init (struct obstack
*obstack
)
2285 struct solib_svr4_ops
*ops
;
2287 ops
= OBSTACK_ZALLOC (obstack
, struct solib_svr4_ops
);
2288 ops
->fetch_link_map_offsets
= NULL
;
2292 /* Set the architecture-specific `struct link_map_offsets' fetcher for
2293 GDBARCH to FLMO. Also, install SVR4 solib_ops into GDBARCH. */
2296 set_solib_svr4_fetch_link_map_offsets (struct gdbarch
*gdbarch
,
2297 struct link_map_offsets
*(*flmo
) (void))
2299 struct solib_svr4_ops
*ops
= gdbarch_data (gdbarch
, solib_svr4_data
);
2301 ops
->fetch_link_map_offsets
= flmo
;
2303 set_solib_ops (gdbarch
, &svr4_so_ops
);
2306 /* Fetch a link_map_offsets structure using the architecture-specific
2307 `struct link_map_offsets' fetcher. */
2309 static struct link_map_offsets
*
2310 svr4_fetch_link_map_offsets (void)
2312 struct solib_svr4_ops
*ops
= gdbarch_data (target_gdbarch
, solib_svr4_data
);
2314 gdb_assert (ops
->fetch_link_map_offsets
);
2315 return ops
->fetch_link_map_offsets ();
2318 /* Return 1 if a link map offset fetcher has been defined, 0 otherwise. */
2321 svr4_have_link_map_offsets (void)
2323 struct solib_svr4_ops
*ops
= gdbarch_data (target_gdbarch
, solib_svr4_data
);
2325 return (ops
->fetch_link_map_offsets
!= NULL
);
2329 /* Most OS'es that have SVR4-style ELF dynamic libraries define a
2330 `struct r_debug' and a `struct link_map' that are binary compatible
2331 with the origional SVR4 implementation. */
2333 /* Fetch (and possibly build) an appropriate `struct link_map_offsets'
2334 for an ILP32 SVR4 system. */
2336 struct link_map_offsets
*
2337 svr4_ilp32_fetch_link_map_offsets (void)
2339 static struct link_map_offsets lmo
;
2340 static struct link_map_offsets
*lmp
= NULL
;
2346 lmo
.r_version_offset
= 0;
2347 lmo
.r_version_size
= 4;
2348 lmo
.r_map_offset
= 4;
2349 lmo
.r_brk_offset
= 8;
2350 lmo
.r_ldsomap_offset
= 20;
2352 /* Everything we need is in the first 20 bytes. */
2353 lmo
.link_map_size
= 20;
2354 lmo
.l_addr_offset
= 0;
2355 lmo
.l_name_offset
= 4;
2356 lmo
.l_ld_offset
= 8;
2357 lmo
.l_next_offset
= 12;
2358 lmo
.l_prev_offset
= 16;
2364 /* Fetch (and possibly build) an appropriate `struct link_map_offsets'
2365 for an LP64 SVR4 system. */
2367 struct link_map_offsets
*
2368 svr4_lp64_fetch_link_map_offsets (void)
2370 static struct link_map_offsets lmo
;
2371 static struct link_map_offsets
*lmp
= NULL
;
2377 lmo
.r_version_offset
= 0;
2378 lmo
.r_version_size
= 4;
2379 lmo
.r_map_offset
= 8;
2380 lmo
.r_brk_offset
= 16;
2381 lmo
.r_ldsomap_offset
= 40;
2383 /* Everything we need is in the first 40 bytes. */
2384 lmo
.link_map_size
= 40;
2385 lmo
.l_addr_offset
= 0;
2386 lmo
.l_name_offset
= 8;
2387 lmo
.l_ld_offset
= 16;
2388 lmo
.l_next_offset
= 24;
2389 lmo
.l_prev_offset
= 32;
2396 struct target_so_ops svr4_so_ops
;
2398 /* Lookup global symbol for ELF DSOs linked with -Bsymbolic. Those DSOs have a
2399 different rule for symbol lookup. The lookup begins here in the DSO, not in
2400 the main executable. */
2402 static struct symbol
*
2403 elf_lookup_lib_symbol (const struct objfile
*objfile
,
2405 const domain_enum domain
)
2409 if (objfile
== symfile_objfile
)
2413 /* OBJFILE should have been passed as the non-debug one. */
2414 gdb_assert (objfile
->separate_debug_objfile_backlink
== NULL
);
2416 abfd
= objfile
->obfd
;
2419 if (abfd
== NULL
|| scan_dyntag (DT_SYMBOLIC
, abfd
, NULL
) != 1)
2422 return lookup_global_symbol_from_objfile (objfile
, name
, domain
);
2425 extern initialize_file_ftype _initialize_svr4_solib
; /* -Wmissing-prototypes */
2428 _initialize_svr4_solib (void)
2430 solib_svr4_data
= gdbarch_data_register_pre_init (solib_svr4_init
);
2431 solib_svr4_pspace_data
2432 = register_program_space_data_with_cleanup (svr4_pspace_data_cleanup
);
2434 svr4_so_ops
.relocate_section_addresses
= svr4_relocate_section_addresses
;
2435 svr4_so_ops
.free_so
= svr4_free_so
;
2436 svr4_so_ops
.clear_solib
= svr4_clear_solib
;
2437 svr4_so_ops
.solib_create_inferior_hook
= svr4_solib_create_inferior_hook
;
2438 svr4_so_ops
.special_symbol_handling
= svr4_special_symbol_handling
;
2439 svr4_so_ops
.current_sos
= svr4_current_sos
;
2440 svr4_so_ops
.open_symbol_file_object
= open_symbol_file_object
;
2441 svr4_so_ops
.in_dynsym_resolve_code
= svr4_in_dynsym_resolve_code
;
2442 svr4_so_ops
.bfd_open
= solib_bfd_open
;
2443 svr4_so_ops
.lookup_lib_global_symbol
= elf_lookup_lib_symbol
;
2444 svr4_so_ops
.same
= svr4_same
;
2445 svr4_so_ops
.keep_data_in_core
= svr4_keep_data_in_core
;