1 /* Handle SVR4 shared libraries for GDB, the GNU Debugger.
3 Copyright (C) 1990-2014 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
22 #include "elf/external.h"
23 #include "elf/common.h"
34 #include "gdbthread.h"
37 #include "gdb_assert.h"
41 #include "solib-svr4.h"
43 #include "bfd-target.h"
47 #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);
54 static void svr4_free_library_list (void *p_list
);
56 /* Link map info to include in an allocated so_list entry. */
60 /* Amount by which addresses in the binary should be relocated to
61 match the inferior. The direct inferior value is L_ADDR_INFERIOR.
62 When prelinking is involved and the prelink base address changes,
63 we may need a different offset - the recomputed offset is in L_ADDR.
64 It is commonly the same value. It is cached as we want to warn about
65 the difference and compute it only once. L_ADDR is valid
67 CORE_ADDR l_addr
, l_addr_inferior
;
68 unsigned int l_addr_p
: 1;
70 /* The target location of lm. */
73 /* Values read in from inferior's fields of the same name. */
74 CORE_ADDR l_ld
, l_next
, l_prev
, l_name
;
77 /* On SVR4 systems, a list of symbols in the dynamic linker where
78 GDB can try to place a breakpoint to monitor shared library
81 If none of these symbols are found, or other errors occur, then
82 SVR4 systems will fall back to using a symbol as the "startup
83 mapping complete" breakpoint address. */
85 static const char * const solib_break_names
[] =
91 "__dl_rtld_db_dlactivity",
97 static const char * const bkpt_names
[] =
105 static const char * const main_name_list
[] =
111 /* What to do when a probe stop occurs. */
115 /* Something went seriously wrong. Stop using probes and
116 revert to using the older interface. */
117 PROBES_INTERFACE_FAILED
,
119 /* No action is required. The shared object list is still
123 /* The shared object list should be reloaded entirely. */
126 /* Attempt to incrementally update the shared object list. If
127 the update fails or is not possible, fall back to reloading
132 /* A probe's name and its associated action. */
136 /* The name of the probe. */
139 /* What to do when a probe stop occurs. */
140 enum probe_action action
;
143 /* A list of named probes and their associated actions. If all
144 probes are present in the dynamic linker then the probes-based
145 interface will be used. */
147 static const struct probe_info probe_info
[] =
149 { "init_start", DO_NOTHING
},
150 { "init_complete", FULL_RELOAD
},
151 { "map_start", DO_NOTHING
},
152 { "map_failed", DO_NOTHING
},
153 { "reloc_complete", UPDATE_OR_RELOAD
},
154 { "unmap_start", DO_NOTHING
},
155 { "unmap_complete", FULL_RELOAD
},
158 #define NUM_PROBES ARRAY_SIZE (probe_info)
160 /* Return non-zero if GDB_SO_NAME and INFERIOR_SO_NAME represent
161 the same shared library. */
164 svr4_same_1 (const char *gdb_so_name
, const char *inferior_so_name
)
166 if (strcmp (gdb_so_name
, inferior_so_name
) == 0)
169 /* On Solaris, when starting inferior we think that dynamic linker is
170 /usr/lib/ld.so.1, but later on, the table of loaded shared libraries
171 contains /lib/ld.so.1. Sometimes one file is a link to another, but
172 sometimes they have identical content, but are not linked to each
173 other. We don't restrict this check for Solaris, but the chances
174 of running into this situation elsewhere are very low. */
175 if (strcmp (gdb_so_name
, "/usr/lib/ld.so.1") == 0
176 && strcmp (inferior_so_name
, "/lib/ld.so.1") == 0)
179 /* Similarly, we observed the same issue with sparc64, but with
180 different locations. */
181 if (strcmp (gdb_so_name
, "/usr/lib/sparcv9/ld.so.1") == 0
182 && strcmp (inferior_so_name
, "/lib/sparcv9/ld.so.1") == 0)
189 svr4_same (struct so_list
*gdb
, struct so_list
*inferior
)
191 return (svr4_same_1 (gdb
->so_original_name
, inferior
->so_original_name
));
194 static struct lm_info
*
195 lm_info_read (CORE_ADDR lm_addr
)
197 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
199 struct lm_info
*lm_info
;
200 struct cleanup
*back_to
;
202 lm
= xmalloc (lmo
->link_map_size
);
203 back_to
= make_cleanup (xfree
, lm
);
205 if (target_read_memory (lm_addr
, lm
, lmo
->link_map_size
) != 0)
207 warning (_("Error reading shared library list entry at %s"),
208 paddress (target_gdbarch (), lm_addr
)),
213 struct type
*ptr_type
= builtin_type (target_gdbarch ())->builtin_data_ptr
;
215 lm_info
= xzalloc (sizeof (*lm_info
));
216 lm_info
->lm_addr
= lm_addr
;
218 lm_info
->l_addr_inferior
= extract_typed_address (&lm
[lmo
->l_addr_offset
],
220 lm_info
->l_ld
= extract_typed_address (&lm
[lmo
->l_ld_offset
], ptr_type
);
221 lm_info
->l_next
= extract_typed_address (&lm
[lmo
->l_next_offset
],
223 lm_info
->l_prev
= extract_typed_address (&lm
[lmo
->l_prev_offset
],
225 lm_info
->l_name
= extract_typed_address (&lm
[lmo
->l_name_offset
],
229 do_cleanups (back_to
);
235 has_lm_dynamic_from_link_map (void)
237 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
239 return lmo
->l_ld_offset
>= 0;
243 lm_addr_check (const struct so_list
*so
, bfd
*abfd
)
245 if (!so
->lm_info
->l_addr_p
)
247 struct bfd_section
*dyninfo_sect
;
248 CORE_ADDR l_addr
, l_dynaddr
, dynaddr
;
250 l_addr
= so
->lm_info
->l_addr_inferior
;
252 if (! abfd
|| ! has_lm_dynamic_from_link_map ())
255 l_dynaddr
= so
->lm_info
->l_ld
;
257 dyninfo_sect
= bfd_get_section_by_name (abfd
, ".dynamic");
258 if (dyninfo_sect
== NULL
)
261 dynaddr
= bfd_section_vma (abfd
, dyninfo_sect
);
263 if (dynaddr
+ l_addr
!= l_dynaddr
)
265 CORE_ADDR align
= 0x1000;
266 CORE_ADDR minpagesize
= align
;
268 if (bfd_get_flavour (abfd
) == bfd_target_elf_flavour
)
270 Elf_Internal_Ehdr
*ehdr
= elf_tdata (abfd
)->elf_header
;
271 Elf_Internal_Phdr
*phdr
= elf_tdata (abfd
)->phdr
;
276 for (i
= 0; i
< ehdr
->e_phnum
; i
++)
277 if (phdr
[i
].p_type
== PT_LOAD
&& phdr
[i
].p_align
> align
)
278 align
= phdr
[i
].p_align
;
280 minpagesize
= get_elf_backend_data (abfd
)->minpagesize
;
283 /* Turn it into a mask. */
286 /* If the changes match the alignment requirements, we
287 assume we're using a core file that was generated by the
288 same binary, just prelinked with a different base offset.
289 If it doesn't match, we may have a different binary, the
290 same binary with the dynamic table loaded at an unrelated
291 location, or anything, really. To avoid regressions,
292 don't adjust the base offset in the latter case, although
293 odds are that, if things really changed, debugging won't
296 One could expect more the condition
297 ((l_addr & align) == 0 && ((l_dynaddr - dynaddr) & align) == 0)
298 but the one below is relaxed for PPC. The PPC kernel supports
299 either 4k or 64k page sizes. To be prepared for 64k pages,
300 PPC ELF files are built using an alignment requirement of 64k.
301 However, when running on a kernel supporting 4k pages, the memory
302 mapping of the library may not actually happen on a 64k boundary!
304 (In the usual case where (l_addr & align) == 0, this check is
305 equivalent to the possibly expected check above.)
307 Even on PPC it must be zero-aligned at least for MINPAGESIZE. */
309 l_addr
= l_dynaddr
- dynaddr
;
311 if ((l_addr
& (minpagesize
- 1)) == 0
312 && (l_addr
& align
) == ((l_dynaddr
- dynaddr
) & align
))
315 printf_unfiltered (_("Using PIC (Position Independent Code) "
316 "prelink displacement %s for \"%s\".\n"),
317 paddress (target_gdbarch (), l_addr
),
322 /* There is no way to verify the library file matches. prelink
323 can during prelinking of an unprelinked file (or unprelinking
324 of a prelinked file) shift the DYNAMIC segment by arbitrary
325 offset without any page size alignment. There is no way to
326 find out the ELF header and/or Program Headers for a limited
327 verification if it they match. One could do a verification
328 of the DYNAMIC segment. Still the found address is the best
329 one GDB could find. */
331 warning (_(".dynamic section for \"%s\" "
332 "is not at the expected address "
333 "(wrong library or version mismatch?)"), so
->so_name
);
338 so
->lm_info
->l_addr
= l_addr
;
339 so
->lm_info
->l_addr_p
= 1;
342 return so
->lm_info
->l_addr
;
345 /* Per pspace SVR4 specific data. */
349 CORE_ADDR debug_base
; /* Base of dynamic linker structures. */
351 /* Validity flag for debug_loader_offset. */
352 int debug_loader_offset_p
;
354 /* Load address for the dynamic linker, inferred. */
355 CORE_ADDR debug_loader_offset
;
357 /* Name of the dynamic linker, valid if debug_loader_offset_p. */
358 char *debug_loader_name
;
360 /* Load map address for the main executable. */
361 CORE_ADDR main_lm_addr
;
363 CORE_ADDR interp_text_sect_low
;
364 CORE_ADDR interp_text_sect_high
;
365 CORE_ADDR interp_plt_sect_low
;
366 CORE_ADDR interp_plt_sect_high
;
368 /* Nonzero if the list of objects was last obtained from the target
369 via qXfer:libraries-svr4:read. */
372 /* Table of struct probe_and_action instances, used by the
373 probes-based interface to map breakpoint addresses to probes
374 and their associated actions. Lookup is performed using
375 probe_and_action->probe->address. */
378 /* List of objects loaded into the inferior, used by the probes-
380 struct so_list
*solib_list
;
383 /* Per-program-space data key. */
384 static const struct program_space_data
*solib_svr4_pspace_data
;
386 /* Free the probes table. */
389 free_probes_table (struct svr4_info
*info
)
391 if (info
->probes_table
== NULL
)
394 htab_delete (info
->probes_table
);
395 info
->probes_table
= NULL
;
398 /* Free the solib list. */
401 free_solib_list (struct svr4_info
*info
)
403 svr4_free_library_list (&info
->solib_list
);
404 info
->solib_list
= NULL
;
408 svr4_pspace_data_cleanup (struct program_space
*pspace
, void *arg
)
410 struct svr4_info
*info
= arg
;
412 free_probes_table (info
);
413 free_solib_list (info
);
418 /* Get the current svr4 data. If none is found yet, add it now. This
419 function always returns a valid object. */
421 static struct svr4_info
*
424 struct svr4_info
*info
;
426 info
= program_space_data (current_program_space
, solib_svr4_pspace_data
);
430 info
= XCNEW (struct svr4_info
);
431 set_program_space_data (current_program_space
, solib_svr4_pspace_data
, info
);
435 /* Local function prototypes */
437 static int match_main (const char *);
439 /* Read program header TYPE from inferior memory. The header is found
440 by scanning the OS auxillary vector.
442 If TYPE == -1, return the program headers instead of the contents of
445 Return a pointer to allocated memory holding the program header contents,
446 or NULL on failure. If sucessful, and unless P_SECT_SIZE is NULL, the
447 size of those contents is returned to P_SECT_SIZE. Likewise, the target
448 architecture size (32-bit or 64-bit) is returned to P_ARCH_SIZE. */
451 read_program_header (int type
, int *p_sect_size
, int *p_arch_size
)
453 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch ());
454 CORE_ADDR at_phdr
, at_phent
, at_phnum
, pt_phdr
= 0;
455 int arch_size
, sect_size
;
460 /* Get required auxv elements from target. */
461 if (target_auxv_search (¤t_target
, AT_PHDR
, &at_phdr
) <= 0)
463 if (target_auxv_search (¤t_target
, AT_PHENT
, &at_phent
) <= 0)
465 if (target_auxv_search (¤t_target
, AT_PHNUM
, &at_phnum
) <= 0)
467 if (!at_phdr
|| !at_phnum
)
470 /* Determine ELF architecture type. */
471 if (at_phent
== sizeof (Elf32_External_Phdr
))
473 else if (at_phent
== sizeof (Elf64_External_Phdr
))
478 /* Find the requested segment. */
482 sect_size
= at_phent
* at_phnum
;
484 else if (arch_size
== 32)
486 Elf32_External_Phdr phdr
;
489 /* Search for requested PHDR. */
490 for (i
= 0; i
< at_phnum
; i
++)
494 if (target_read_memory (at_phdr
+ i
* sizeof (phdr
),
495 (gdb_byte
*)&phdr
, sizeof (phdr
)))
498 p_type
= extract_unsigned_integer ((gdb_byte
*) phdr
.p_type
,
501 if (p_type
== PT_PHDR
)
504 pt_phdr
= extract_unsigned_integer ((gdb_byte
*) phdr
.p_vaddr
,
515 /* Retrieve address and size. */
516 sect_addr
= extract_unsigned_integer ((gdb_byte
*)phdr
.p_vaddr
,
518 sect_size
= extract_unsigned_integer ((gdb_byte
*)phdr
.p_memsz
,
523 Elf64_External_Phdr phdr
;
526 /* Search for requested PHDR. */
527 for (i
= 0; i
< at_phnum
; i
++)
531 if (target_read_memory (at_phdr
+ i
* sizeof (phdr
),
532 (gdb_byte
*)&phdr
, sizeof (phdr
)))
535 p_type
= extract_unsigned_integer ((gdb_byte
*) phdr
.p_type
,
538 if (p_type
== PT_PHDR
)
541 pt_phdr
= extract_unsigned_integer ((gdb_byte
*) phdr
.p_vaddr
,
552 /* Retrieve address and size. */
553 sect_addr
= extract_unsigned_integer ((gdb_byte
*)phdr
.p_vaddr
,
555 sect_size
= extract_unsigned_integer ((gdb_byte
*)phdr
.p_memsz
,
559 /* PT_PHDR is optional, but we really need it
560 for PIE to make this work in general. */
564 /* at_phdr is real address in memory. pt_phdr is what pheader says it is.
565 Relocation offset is the difference between the two. */
566 sect_addr
= sect_addr
+ (at_phdr
- pt_phdr
);
569 /* Read in requested program header. */
570 buf
= xmalloc (sect_size
);
571 if (target_read_memory (sect_addr
, buf
, sect_size
))
578 *p_arch_size
= arch_size
;
580 *p_sect_size
= sect_size
;
586 /* Return program interpreter string. */
588 find_program_interpreter (void)
590 gdb_byte
*buf
= NULL
;
592 /* If we have an exec_bfd, use its section table. */
594 && bfd_get_flavour (exec_bfd
) == bfd_target_elf_flavour
)
596 struct bfd_section
*interp_sect
;
598 interp_sect
= bfd_get_section_by_name (exec_bfd
, ".interp");
599 if (interp_sect
!= NULL
)
601 int sect_size
= bfd_section_size (exec_bfd
, interp_sect
);
603 buf
= xmalloc (sect_size
);
604 bfd_get_section_contents (exec_bfd
, interp_sect
, buf
, 0, sect_size
);
608 /* If we didn't find it, use the target auxillary vector. */
610 buf
= read_program_header (PT_INTERP
, NULL
, NULL
);
616 /* Scan for DYNTAG in .dynamic section of ABFD. If DYNTAG is found 1 is
617 returned and the corresponding PTR is set. */
620 scan_dyntag (int dyntag
, bfd
*abfd
, CORE_ADDR
*ptr
)
622 int arch_size
, step
, sect_size
;
624 CORE_ADDR dyn_ptr
, dyn_addr
;
625 gdb_byte
*bufend
, *bufstart
, *buf
;
626 Elf32_External_Dyn
*x_dynp_32
;
627 Elf64_External_Dyn
*x_dynp_64
;
628 struct bfd_section
*sect
;
629 struct target_section
*target_section
;
634 if (bfd_get_flavour (abfd
) != bfd_target_elf_flavour
)
637 arch_size
= bfd_get_arch_size (abfd
);
641 /* Find the start address of the .dynamic section. */
642 sect
= bfd_get_section_by_name (abfd
, ".dynamic");
646 for (target_section
= current_target_sections
->sections
;
647 target_section
< current_target_sections
->sections_end
;
649 if (sect
== target_section
->the_bfd_section
)
651 if (target_section
< current_target_sections
->sections_end
)
652 dyn_addr
= target_section
->addr
;
655 /* ABFD may come from OBJFILE acting only as a symbol file without being
656 loaded into the target (see add_symbol_file_command). This case is
657 such fallback to the file VMA address without the possibility of
658 having the section relocated to its actual in-memory address. */
660 dyn_addr
= bfd_section_vma (abfd
, sect
);
663 /* Read in .dynamic from the BFD. We will get the actual value
664 from memory later. */
665 sect_size
= bfd_section_size (abfd
, sect
);
666 buf
= bufstart
= alloca (sect_size
);
667 if (!bfd_get_section_contents (abfd
, sect
,
671 /* Iterate over BUF and scan for DYNTAG. If found, set PTR and return. */
672 step
= (arch_size
== 32) ? sizeof (Elf32_External_Dyn
)
673 : sizeof (Elf64_External_Dyn
);
674 for (bufend
= buf
+ sect_size
;
680 x_dynp_32
= (Elf32_External_Dyn
*) buf
;
681 dyn_tag
= bfd_h_get_32 (abfd
, (bfd_byte
*) x_dynp_32
->d_tag
);
682 dyn_ptr
= bfd_h_get_32 (abfd
, (bfd_byte
*) x_dynp_32
->d_un
.d_ptr
);
686 x_dynp_64
= (Elf64_External_Dyn
*) buf
;
687 dyn_tag
= bfd_h_get_64 (abfd
, (bfd_byte
*) x_dynp_64
->d_tag
);
688 dyn_ptr
= bfd_h_get_64 (abfd
, (bfd_byte
*) x_dynp_64
->d_un
.d_ptr
);
690 if (dyn_tag
== DT_NULL
)
692 if (dyn_tag
== dyntag
)
694 /* If requested, try to read the runtime value of this .dynamic
698 struct type
*ptr_type
;
702 ptr_type
= builtin_type (target_gdbarch ())->builtin_data_ptr
;
703 ptr_addr
= dyn_addr
+ (buf
- bufstart
) + arch_size
/ 8;
704 if (target_read_memory (ptr_addr
, ptr_buf
, arch_size
/ 8) == 0)
705 dyn_ptr
= extract_typed_address (ptr_buf
, ptr_type
);
715 /* Scan for DYNTAG in .dynamic section of the target's main executable,
716 found by consulting the OS auxillary vector. If DYNTAG is found 1 is
717 returned and the corresponding PTR is set. */
720 scan_dyntag_auxv (int dyntag
, CORE_ADDR
*ptr
)
722 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch ());
723 int sect_size
, arch_size
, step
;
726 gdb_byte
*bufend
, *bufstart
, *buf
;
728 /* Read in .dynamic section. */
729 buf
= bufstart
= read_program_header (PT_DYNAMIC
, §_size
, &arch_size
);
733 /* Iterate over BUF and scan for DYNTAG. If found, set PTR and return. */
734 step
= (arch_size
== 32) ? sizeof (Elf32_External_Dyn
)
735 : sizeof (Elf64_External_Dyn
);
736 for (bufend
= buf
+ sect_size
;
742 Elf32_External_Dyn
*dynp
= (Elf32_External_Dyn
*) buf
;
744 dyn_tag
= extract_unsigned_integer ((gdb_byte
*) dynp
->d_tag
,
746 dyn_ptr
= extract_unsigned_integer ((gdb_byte
*) dynp
->d_un
.d_ptr
,
751 Elf64_External_Dyn
*dynp
= (Elf64_External_Dyn
*) buf
;
753 dyn_tag
= extract_unsigned_integer ((gdb_byte
*) dynp
->d_tag
,
755 dyn_ptr
= extract_unsigned_integer ((gdb_byte
*) dynp
->d_un
.d_ptr
,
758 if (dyn_tag
== DT_NULL
)
761 if (dyn_tag
== dyntag
)
775 /* Locate the base address of dynamic linker structs for SVR4 elf
778 For SVR4 elf targets the address of the dynamic linker's runtime
779 structure is contained within the dynamic info section in the
780 executable file. The dynamic section is also mapped into the
781 inferior address space. Because the runtime loader fills in the
782 real address before starting the inferior, we have to read in the
783 dynamic info section from the inferior address space.
784 If there are any errors while trying to find the address, we
785 silently return 0, otherwise the found address is returned. */
788 elf_locate_base (void)
790 struct bound_minimal_symbol msymbol
;
793 /* Look for DT_MIPS_RLD_MAP first. MIPS executables use this
794 instead of DT_DEBUG, although they sometimes contain an unused
796 if (scan_dyntag (DT_MIPS_RLD_MAP
, exec_bfd
, &dyn_ptr
)
797 || scan_dyntag_auxv (DT_MIPS_RLD_MAP
, &dyn_ptr
))
799 struct type
*ptr_type
= builtin_type (target_gdbarch ())->builtin_data_ptr
;
801 int pbuf_size
= TYPE_LENGTH (ptr_type
);
803 pbuf
= alloca (pbuf_size
);
804 /* DT_MIPS_RLD_MAP contains a pointer to the address
805 of the dynamic link structure. */
806 if (target_read_memory (dyn_ptr
, pbuf
, pbuf_size
))
808 return extract_typed_address (pbuf
, ptr_type
);
812 if (scan_dyntag (DT_DEBUG
, exec_bfd
, &dyn_ptr
)
813 || scan_dyntag_auxv (DT_DEBUG
, &dyn_ptr
))
816 /* This may be a static executable. Look for the symbol
817 conventionally named _r_debug, as a last resort. */
818 msymbol
= lookup_minimal_symbol ("_r_debug", NULL
, symfile_objfile
);
819 if (msymbol
.minsym
!= NULL
)
820 return BMSYMBOL_VALUE_ADDRESS (msymbol
);
822 /* DT_DEBUG entry not found. */
826 /* Locate the base address of dynamic linker structs.
828 For both the SunOS and SVR4 shared library implementations, if the
829 inferior executable has been linked dynamically, there is a single
830 address somewhere in the inferior's data space which is the key to
831 locating all of the dynamic linker's runtime structures. This
832 address is the value of the debug base symbol. The job of this
833 function is to find and return that address, or to return 0 if there
834 is no such address (the executable is statically linked for example).
836 For SunOS, the job is almost trivial, since the dynamic linker and
837 all of it's structures are statically linked to the executable at
838 link time. Thus the symbol for the address we are looking for has
839 already been added to the minimal symbol table for the executable's
840 objfile at the time the symbol file's symbols were read, and all we
841 have to do is look it up there. Note that we explicitly do NOT want
842 to find the copies in the shared library.
844 The SVR4 version is a bit more complicated because the address
845 is contained somewhere in the dynamic info section. We have to go
846 to a lot more work to discover the address of the debug base symbol.
847 Because of this complexity, we cache the value we find and return that
848 value on subsequent invocations. Note there is no copy in the
849 executable symbol tables. */
852 locate_base (struct svr4_info
*info
)
854 /* Check to see if we have a currently valid address, and if so, avoid
855 doing all this work again and just return the cached address. If
856 we have no cached address, try to locate it in the dynamic info
857 section for ELF executables. There's no point in doing any of this
858 though if we don't have some link map offsets to work with. */
860 if (info
->debug_base
== 0 && svr4_have_link_map_offsets ())
861 info
->debug_base
= elf_locate_base ();
862 return info
->debug_base
;
865 /* Find the first element in the inferior's dynamic link map, and
866 return its address in the inferior. Return zero if the address
867 could not be determined.
869 FIXME: Perhaps we should validate the info somehow, perhaps by
870 checking r_version for a known version number, or r_state for
874 solib_svr4_r_map (struct svr4_info
*info
)
876 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
877 struct type
*ptr_type
= builtin_type (target_gdbarch ())->builtin_data_ptr
;
879 volatile struct gdb_exception ex
;
881 TRY_CATCH (ex
, RETURN_MASK_ERROR
)
883 addr
= read_memory_typed_address (info
->debug_base
+ lmo
->r_map_offset
,
886 exception_print (gdb_stderr
, ex
);
890 /* Find r_brk from the inferior's debug base. */
893 solib_svr4_r_brk (struct svr4_info
*info
)
895 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
896 struct type
*ptr_type
= builtin_type (target_gdbarch ())->builtin_data_ptr
;
898 return read_memory_typed_address (info
->debug_base
+ lmo
->r_brk_offset
,
902 /* Find the link map for the dynamic linker (if it is not in the
903 normal list of loaded shared objects). */
906 solib_svr4_r_ldsomap (struct svr4_info
*info
)
908 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
909 struct type
*ptr_type
= builtin_type (target_gdbarch ())->builtin_data_ptr
;
910 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch ());
913 /* Check version, and return zero if `struct r_debug' doesn't have
914 the r_ldsomap member. */
916 = read_memory_unsigned_integer (info
->debug_base
+ lmo
->r_version_offset
,
917 lmo
->r_version_size
, byte_order
);
918 if (version
< 2 || lmo
->r_ldsomap_offset
== -1)
921 return read_memory_typed_address (info
->debug_base
+ lmo
->r_ldsomap_offset
,
925 /* On Solaris systems with some versions of the dynamic linker,
926 ld.so's l_name pointer points to the SONAME in the string table
927 rather than into writable memory. So that GDB can find shared
928 libraries when loading a core file generated by gcore, ensure that
929 memory areas containing the l_name string are saved in the core
933 svr4_keep_data_in_core (CORE_ADDR vaddr
, unsigned long size
)
935 struct svr4_info
*info
;
938 struct cleanup
*old_chain
;
941 info
= get_svr4_info ();
943 info
->debug_base
= 0;
945 if (!info
->debug_base
)
948 ldsomap
= solib_svr4_r_ldsomap (info
);
952 new = XCNEW (struct so_list
);
953 old_chain
= make_cleanup (xfree
, new);
954 new->lm_info
= lm_info_read (ldsomap
);
955 make_cleanup (xfree
, new->lm_info
);
956 name_lm
= new->lm_info
? new->lm_info
->l_name
: 0;
957 do_cleanups (old_chain
);
959 return (name_lm
>= vaddr
&& name_lm
< vaddr
+ size
);
962 /* Implement the "open_symbol_file_object" target_so_ops method.
964 If no open symbol file, attempt to locate and open the main symbol
965 file. On SVR4 systems, this is the first link map entry. If its
966 name is here, we can open it. Useful when attaching to a process
967 without first loading its symbol file. */
970 open_symbol_file_object (void *from_ttyp
)
972 CORE_ADDR lm
, l_name
;
975 int from_tty
= *(int *)from_ttyp
;
976 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
977 struct type
*ptr_type
= builtin_type (target_gdbarch ())->builtin_data_ptr
;
978 int l_name_size
= TYPE_LENGTH (ptr_type
);
979 gdb_byte
*l_name_buf
= xmalloc (l_name_size
);
980 struct cleanup
*cleanups
= make_cleanup (xfree
, l_name_buf
);
981 struct svr4_info
*info
= get_svr4_info ();
984 if (!query (_("Attempt to reload symbols from process? ")))
986 do_cleanups (cleanups
);
990 /* Always locate the debug struct, in case it has moved. */
991 info
->debug_base
= 0;
992 if (locate_base (info
) == 0)
994 do_cleanups (cleanups
);
995 return 0; /* failed somehow... */
998 /* First link map member should be the executable. */
999 lm
= solib_svr4_r_map (info
);
1002 do_cleanups (cleanups
);
1003 return 0; /* failed somehow... */
1006 /* Read address of name from target memory to GDB. */
1007 read_memory (lm
+ lmo
->l_name_offset
, l_name_buf
, l_name_size
);
1009 /* Convert the address to host format. */
1010 l_name
= extract_typed_address (l_name_buf
, ptr_type
);
1014 do_cleanups (cleanups
);
1015 return 0; /* No filename. */
1018 /* Now fetch the filename from target memory. */
1019 target_read_string (l_name
, &filename
, SO_NAME_MAX_PATH_SIZE
- 1, &errcode
);
1020 make_cleanup (xfree
, filename
);
1024 warning (_("failed to read exec filename from attached file: %s"),
1025 safe_strerror (errcode
));
1026 do_cleanups (cleanups
);
1030 /* Have a pathname: read the symbol file. */
1031 symbol_file_add_main (filename
, from_tty
);
1033 do_cleanups (cleanups
);
1037 /* Data exchange structure for the XML parser as returned by
1038 svr4_current_sos_via_xfer_libraries. */
1040 struct svr4_library_list
1042 struct so_list
*head
, **tailp
;
1044 /* Inferior address of struct link_map used for the main executable. It is
1045 NULL if not known. */
1049 /* Implementation for target_so_ops.free_so. */
1052 svr4_free_so (struct so_list
*so
)
1054 xfree (so
->lm_info
);
1057 /* Implement target_so_ops.clear_so. */
1060 svr4_clear_so (struct so_list
*so
)
1062 if (so
->lm_info
!= NULL
)
1063 so
->lm_info
->l_addr_p
= 0;
1066 /* Free so_list built so far (called via cleanup). */
1069 svr4_free_library_list (void *p_list
)
1071 struct so_list
*list
= *(struct so_list
**) p_list
;
1073 while (list
!= NULL
)
1075 struct so_list
*next
= list
->next
;
1082 /* Copy library list. */
1084 static struct so_list
*
1085 svr4_copy_library_list (struct so_list
*src
)
1087 struct so_list
*dst
= NULL
;
1088 struct so_list
**link
= &dst
;
1092 struct so_list
*new;
1094 new = xmalloc (sizeof (struct so_list
));
1095 memcpy (new, src
, sizeof (struct so_list
));
1097 new->lm_info
= xmalloc (sizeof (struct lm_info
));
1098 memcpy (new->lm_info
, src
->lm_info
, sizeof (struct lm_info
));
1110 #ifdef HAVE_LIBEXPAT
1112 #include "xml-support.h"
1114 /* Handle the start of a <library> element. Note: new elements are added
1115 at the tail of the list, keeping the list in order. */
1118 library_list_start_library (struct gdb_xml_parser
*parser
,
1119 const struct gdb_xml_element
*element
,
1120 void *user_data
, VEC(gdb_xml_value_s
) *attributes
)
1122 struct svr4_library_list
*list
= user_data
;
1123 const char *name
= xml_find_attribute (attributes
, "name")->value
;
1124 ULONGEST
*lmp
= xml_find_attribute (attributes
, "lm")->value
;
1125 ULONGEST
*l_addrp
= xml_find_attribute (attributes
, "l_addr")->value
;
1126 ULONGEST
*l_ldp
= xml_find_attribute (attributes
, "l_ld")->value
;
1127 struct so_list
*new_elem
;
1129 new_elem
= XCNEW (struct so_list
);
1130 new_elem
->lm_info
= XCNEW (struct lm_info
);
1131 new_elem
->lm_info
->lm_addr
= *lmp
;
1132 new_elem
->lm_info
->l_addr_inferior
= *l_addrp
;
1133 new_elem
->lm_info
->l_ld
= *l_ldp
;
1135 strncpy (new_elem
->so_name
, name
, sizeof (new_elem
->so_name
) - 1);
1136 new_elem
->so_name
[sizeof (new_elem
->so_name
) - 1] = 0;
1137 strcpy (new_elem
->so_original_name
, new_elem
->so_name
);
1139 *list
->tailp
= new_elem
;
1140 list
->tailp
= &new_elem
->next
;
1143 /* Handle the start of a <library-list-svr4> element. */
1146 svr4_library_list_start_list (struct gdb_xml_parser
*parser
,
1147 const struct gdb_xml_element
*element
,
1148 void *user_data
, VEC(gdb_xml_value_s
) *attributes
)
1150 struct svr4_library_list
*list
= user_data
;
1151 const char *version
= xml_find_attribute (attributes
, "version")->value
;
1152 struct gdb_xml_value
*main_lm
= xml_find_attribute (attributes
, "main-lm");
1154 if (strcmp (version
, "1.0") != 0)
1155 gdb_xml_error (parser
,
1156 _("SVR4 Library list has unsupported version \"%s\""),
1160 list
->main_lm
= *(ULONGEST
*) main_lm
->value
;
1163 /* The allowed elements and attributes for an XML library list.
1164 The root element is a <library-list>. */
1166 static const struct gdb_xml_attribute svr4_library_attributes
[] =
1168 { "name", GDB_XML_AF_NONE
, NULL
, NULL
},
1169 { "lm", GDB_XML_AF_NONE
, gdb_xml_parse_attr_ulongest
, NULL
},
1170 { "l_addr", GDB_XML_AF_NONE
, gdb_xml_parse_attr_ulongest
, NULL
},
1171 { "l_ld", GDB_XML_AF_NONE
, gdb_xml_parse_attr_ulongest
, NULL
},
1172 { NULL
, GDB_XML_AF_NONE
, NULL
, NULL
}
1175 static const struct gdb_xml_element svr4_library_list_children
[] =
1178 "library", svr4_library_attributes
, NULL
,
1179 GDB_XML_EF_REPEATABLE
| GDB_XML_EF_OPTIONAL
,
1180 library_list_start_library
, NULL
1182 { NULL
, NULL
, NULL
, GDB_XML_EF_NONE
, NULL
, NULL
}
1185 static const struct gdb_xml_attribute svr4_library_list_attributes
[] =
1187 { "version", GDB_XML_AF_NONE
, NULL
, NULL
},
1188 { "main-lm", GDB_XML_AF_OPTIONAL
, gdb_xml_parse_attr_ulongest
, NULL
},
1189 { NULL
, GDB_XML_AF_NONE
, NULL
, NULL
}
1192 static const struct gdb_xml_element svr4_library_list_elements
[] =
1194 { "library-list-svr4", svr4_library_list_attributes
, svr4_library_list_children
,
1195 GDB_XML_EF_NONE
, svr4_library_list_start_list
, NULL
},
1196 { NULL
, NULL
, NULL
, GDB_XML_EF_NONE
, NULL
, NULL
}
1199 /* Parse qXfer:libraries:read packet into *SO_LIST_RETURN. Return 1 if
1201 Return 0 if packet not supported, *SO_LIST_RETURN is not modified in such
1202 case. Return 1 if *SO_LIST_RETURN contains the library list, it may be
1203 empty, caller is responsible for freeing all its entries. */
1206 svr4_parse_libraries (const char *document
, struct svr4_library_list
*list
)
1208 struct cleanup
*back_to
= make_cleanup (svr4_free_library_list
,
1211 memset (list
, 0, sizeof (*list
));
1212 list
->tailp
= &list
->head
;
1213 if (gdb_xml_parse_quick (_("target library list"), "library-list.dtd",
1214 svr4_library_list_elements
, document
, list
) == 0)
1216 /* Parsed successfully, keep the result. */
1217 discard_cleanups (back_to
);
1221 do_cleanups (back_to
);
1225 /* Attempt to get so_list from target via qXfer:libraries-svr4:read packet.
1227 Return 0 if packet not supported, *SO_LIST_RETURN is not modified in such
1228 case. Return 1 if *SO_LIST_RETURN contains the library list, it may be
1229 empty, caller is responsible for freeing all its entries.
1231 Note that ANNEX must be NULL if the remote does not explicitly allow
1232 qXfer:libraries-svr4:read packets with non-empty annexes. Support for
1233 this can be checked using target_augmented_libraries_svr4_read (). */
1236 svr4_current_sos_via_xfer_libraries (struct svr4_library_list
*list
,
1239 char *svr4_library_document
;
1241 struct cleanup
*back_to
;
1243 gdb_assert (annex
== NULL
|| target_augmented_libraries_svr4_read ());
1245 /* Fetch the list of shared libraries. */
1246 svr4_library_document
= target_read_stralloc (¤t_target
,
1247 TARGET_OBJECT_LIBRARIES_SVR4
,
1249 if (svr4_library_document
== NULL
)
1252 back_to
= make_cleanup (xfree
, svr4_library_document
);
1253 result
= svr4_parse_libraries (svr4_library_document
, list
);
1254 do_cleanups (back_to
);
1262 svr4_current_sos_via_xfer_libraries (struct svr4_library_list
*list
,
1270 /* If no shared library information is available from the dynamic
1271 linker, build a fallback list from other sources. */
1273 static struct so_list
*
1274 svr4_default_sos (void)
1276 struct svr4_info
*info
= get_svr4_info ();
1277 struct so_list
*new;
1279 if (!info
->debug_loader_offset_p
)
1282 new = XCNEW (struct so_list
);
1284 new->lm_info
= xzalloc (sizeof (struct lm_info
));
1286 /* Nothing will ever check the other fields if we set l_addr_p. */
1287 new->lm_info
->l_addr
= info
->debug_loader_offset
;
1288 new->lm_info
->l_addr_p
= 1;
1290 strncpy (new->so_name
, info
->debug_loader_name
, SO_NAME_MAX_PATH_SIZE
- 1);
1291 new->so_name
[SO_NAME_MAX_PATH_SIZE
- 1] = '\0';
1292 strcpy (new->so_original_name
, new->so_name
);
1297 /* Read the whole inferior libraries chain starting at address LM.
1298 Expect the first entry in the chain's previous entry to be PREV_LM.
1299 Add the entries to the tail referenced by LINK_PTR_PTR. Ignore the
1300 first entry if IGNORE_FIRST and set global MAIN_LM_ADDR according
1301 to it. Returns nonzero upon success. If zero is returned the
1302 entries stored to LINK_PTR_PTR are still valid although they may
1303 represent only part of the inferior library list. */
1306 svr4_read_so_list (CORE_ADDR lm
, CORE_ADDR prev_lm
,
1307 struct so_list
***link_ptr_ptr
, int ignore_first
)
1309 CORE_ADDR first_l_name
= 0;
1312 for (; lm
!= 0; prev_lm
= lm
, lm
= next_lm
)
1314 struct so_list
*new;
1315 struct cleanup
*old_chain
;
1319 new = XCNEW (struct so_list
);
1320 old_chain
= make_cleanup_free_so (new);
1322 new->lm_info
= lm_info_read (lm
);
1323 if (new->lm_info
== NULL
)
1325 do_cleanups (old_chain
);
1329 next_lm
= new->lm_info
->l_next
;
1331 if (new->lm_info
->l_prev
!= prev_lm
)
1333 warning (_("Corrupted shared library list: %s != %s"),
1334 paddress (target_gdbarch (), prev_lm
),
1335 paddress (target_gdbarch (), new->lm_info
->l_prev
));
1336 do_cleanups (old_chain
);
1340 /* For SVR4 versions, the first entry in the link map is for the
1341 inferior executable, so we must ignore it. For some versions of
1342 SVR4, it has no name. For others (Solaris 2.3 for example), it
1343 does have a name, so we can no longer use a missing name to
1344 decide when to ignore it. */
1345 if (ignore_first
&& new->lm_info
->l_prev
== 0)
1347 struct svr4_info
*info
= get_svr4_info ();
1349 first_l_name
= new->lm_info
->l_name
;
1350 info
->main_lm_addr
= new->lm_info
->lm_addr
;
1351 do_cleanups (old_chain
);
1355 /* Extract this shared object's name. */
1356 target_read_string (new->lm_info
->l_name
, &buffer
,
1357 SO_NAME_MAX_PATH_SIZE
- 1, &errcode
);
1360 /* If this entry's l_name address matches that of the
1361 inferior executable, then this is not a normal shared
1362 object, but (most likely) a vDSO. In this case, silently
1363 skip it; otherwise emit a warning. */
1364 if (first_l_name
== 0 || new->lm_info
->l_name
!= first_l_name
)
1365 warning (_("Can't read pathname for load map: %s."),
1366 safe_strerror (errcode
));
1367 do_cleanups (old_chain
);
1371 strncpy (new->so_name
, buffer
, SO_NAME_MAX_PATH_SIZE
- 1);
1372 new->so_name
[SO_NAME_MAX_PATH_SIZE
- 1] = '\0';
1373 strcpy (new->so_original_name
, new->so_name
);
1376 /* If this entry has no name, or its name matches the name
1377 for the main executable, don't include it in the list. */
1378 if (! new->so_name
[0] || match_main (new->so_name
))
1380 do_cleanups (old_chain
);
1384 discard_cleanups (old_chain
);
1386 **link_ptr_ptr
= new;
1387 *link_ptr_ptr
= &new->next
;
1393 /* Read the full list of currently loaded shared objects directly
1394 from the inferior, without referring to any libraries read and
1395 stored by the probes interface. Handle special cases relating
1396 to the first elements of the list. */
1398 static struct so_list
*
1399 svr4_current_sos_direct (struct svr4_info
*info
)
1402 struct so_list
*head
= NULL
;
1403 struct so_list
**link_ptr
= &head
;
1404 struct cleanup
*back_to
;
1406 struct svr4_library_list library_list
;
1408 /* Fall back to manual examination of the target if the packet is not
1409 supported or gdbserver failed to find DT_DEBUG. gdb.server/solib-list.exp
1410 tests a case where gdbserver cannot find the shared libraries list while
1411 GDB itself is able to find it via SYMFILE_OBJFILE.
1413 Unfortunately statically linked inferiors will also fall back through this
1414 suboptimal code path. */
1416 info
->using_xfer
= svr4_current_sos_via_xfer_libraries (&library_list
,
1418 if (info
->using_xfer
)
1420 if (library_list
.main_lm
)
1421 info
->main_lm_addr
= library_list
.main_lm
;
1423 return library_list
.head
? library_list
.head
: svr4_default_sos ();
1426 /* Always locate the debug struct, in case it has moved. */
1427 info
->debug_base
= 0;
1430 /* If we can't find the dynamic linker's base structure, this
1431 must not be a dynamically linked executable. Hmm. */
1432 if (! info
->debug_base
)
1433 return svr4_default_sos ();
1435 /* Assume that everything is a library if the dynamic loader was loaded
1436 late by a static executable. */
1437 if (exec_bfd
&& bfd_get_section_by_name (exec_bfd
, ".dynamic") == NULL
)
1442 back_to
= make_cleanup (svr4_free_library_list
, &head
);
1444 /* Walk the inferior's link map list, and build our list of
1445 `struct so_list' nodes. */
1446 lm
= solib_svr4_r_map (info
);
1448 svr4_read_so_list (lm
, 0, &link_ptr
, ignore_first
);
1450 /* On Solaris, the dynamic linker is not in the normal list of
1451 shared objects, so make sure we pick it up too. Having
1452 symbol information for the dynamic linker is quite crucial
1453 for skipping dynamic linker resolver code. */
1454 lm
= solib_svr4_r_ldsomap (info
);
1456 svr4_read_so_list (lm
, 0, &link_ptr
, 0);
1458 discard_cleanups (back_to
);
1461 return svr4_default_sos ();
1466 /* Implement the "current_sos" target_so_ops method. */
1468 static struct so_list
*
1469 svr4_current_sos (void)
1471 struct svr4_info
*info
= get_svr4_info ();
1473 /* If the solib list has been read and stored by the probes
1474 interface then we return a copy of the stored list. */
1475 if (info
->solib_list
!= NULL
)
1476 return svr4_copy_library_list (info
->solib_list
);
1478 /* Otherwise obtain the solib list directly from the inferior. */
1479 return svr4_current_sos_direct (info
);
1482 /* Get the address of the link_map for a given OBJFILE. */
1485 svr4_fetch_objfile_link_map (struct objfile
*objfile
)
1488 struct svr4_info
*info
= get_svr4_info ();
1490 /* Cause svr4_current_sos() to be run if it hasn't been already. */
1491 if (info
->main_lm_addr
== 0)
1492 solib_add (NULL
, 0, ¤t_target
, auto_solib_add
);
1494 /* svr4_current_sos() will set main_lm_addr for the main executable. */
1495 if (objfile
== symfile_objfile
)
1496 return info
->main_lm_addr
;
1498 /* The other link map addresses may be found by examining the list
1499 of shared libraries. */
1500 for (so
= master_so_list (); so
; so
= so
->next
)
1501 if (so
->objfile
== objfile
)
1502 return so
->lm_info
->lm_addr
;
1508 /* On some systems, the only way to recognize the link map entry for
1509 the main executable file is by looking at its name. Return
1510 non-zero iff SONAME matches one of the known main executable names. */
1513 match_main (const char *soname
)
1515 const char * const *mainp
;
1517 for (mainp
= main_name_list
; *mainp
!= NULL
; mainp
++)
1519 if (strcmp (soname
, *mainp
) == 0)
1526 /* Return 1 if PC lies in the dynamic symbol resolution code of the
1527 SVR4 run time loader. */
1530 svr4_in_dynsym_resolve_code (CORE_ADDR pc
)
1532 struct svr4_info
*info
= get_svr4_info ();
1534 return ((pc
>= info
->interp_text_sect_low
1535 && pc
< info
->interp_text_sect_high
)
1536 || (pc
>= info
->interp_plt_sect_low
1537 && pc
< info
->interp_plt_sect_high
)
1538 || in_plt_section (pc
)
1539 || in_gnu_ifunc_stub (pc
));
1542 /* Given an executable's ABFD and target, compute the entry-point
1546 exec_entry_point (struct bfd
*abfd
, struct target_ops
*targ
)
1550 /* KevinB wrote ... for most targets, the address returned by
1551 bfd_get_start_address() is the entry point for the start
1552 function. But, for some targets, bfd_get_start_address() returns
1553 the address of a function descriptor from which the entry point
1554 address may be extracted. This address is extracted by
1555 gdbarch_convert_from_func_ptr_addr(). The method
1556 gdbarch_convert_from_func_ptr_addr() is the merely the identify
1557 function for targets which don't use function descriptors. */
1558 addr
= gdbarch_convert_from_func_ptr_addr (target_gdbarch (),
1559 bfd_get_start_address (abfd
),
1561 return gdbarch_addr_bits_remove (target_gdbarch (), addr
);
1564 /* A probe and its associated action. */
1566 struct probe_and_action
1569 struct probe
*probe
;
1571 /* The relocated address of the probe. */
1575 enum probe_action action
;
1578 /* Returns a hash code for the probe_and_action referenced by p. */
1581 hash_probe_and_action (const void *p
)
1583 const struct probe_and_action
*pa
= p
;
1585 return (hashval_t
) pa
->address
;
1588 /* Returns non-zero if the probe_and_actions referenced by p1 and p2
1592 equal_probe_and_action (const void *p1
, const void *p2
)
1594 const struct probe_and_action
*pa1
= p1
;
1595 const struct probe_and_action
*pa2
= p2
;
1597 return pa1
->address
== pa2
->address
;
1600 /* Register a solib event probe and its associated action in the
1604 register_solib_event_probe (struct probe
*probe
, CORE_ADDR address
,
1605 enum probe_action action
)
1607 struct svr4_info
*info
= get_svr4_info ();
1608 struct probe_and_action lookup
, *pa
;
1611 /* Create the probes table, if necessary. */
1612 if (info
->probes_table
== NULL
)
1613 info
->probes_table
= htab_create_alloc (1, hash_probe_and_action
,
1614 equal_probe_and_action
,
1615 xfree
, xcalloc
, xfree
);
1617 lookup
.probe
= probe
;
1618 lookup
.address
= address
;
1619 slot
= htab_find_slot (info
->probes_table
, &lookup
, INSERT
);
1620 gdb_assert (*slot
== HTAB_EMPTY_ENTRY
);
1622 pa
= XCNEW (struct probe_and_action
);
1624 pa
->address
= address
;
1625 pa
->action
= action
;
1630 /* Get the solib event probe at the specified location, and the
1631 action associated with it. Returns NULL if no solib event probe
1634 static struct probe_and_action
*
1635 solib_event_probe_at (struct svr4_info
*info
, CORE_ADDR address
)
1637 struct probe_and_action lookup
;
1640 lookup
.address
= address
;
1641 slot
= htab_find_slot (info
->probes_table
, &lookup
, NO_INSERT
);
1646 return (struct probe_and_action
*) *slot
;
1649 /* Decide what action to take when the specified solib event probe is
1652 static enum probe_action
1653 solib_event_probe_action (struct probe_and_action
*pa
)
1655 enum probe_action action
;
1656 unsigned probe_argc
;
1657 struct frame_info
*frame
= get_current_frame ();
1659 action
= pa
->action
;
1660 if (action
== DO_NOTHING
|| action
== PROBES_INTERFACE_FAILED
)
1663 gdb_assert (action
== FULL_RELOAD
|| action
== UPDATE_OR_RELOAD
);
1665 /* Check that an appropriate number of arguments has been supplied.
1667 arg0: Lmid_t lmid (mandatory)
1668 arg1: struct r_debug *debug_base (mandatory)
1669 arg2: struct link_map *new (optional, for incremental updates) */
1670 probe_argc
= get_probe_argument_count (pa
->probe
, frame
);
1671 if (probe_argc
== 2)
1672 action
= FULL_RELOAD
;
1673 else if (probe_argc
< 2)
1674 action
= PROBES_INTERFACE_FAILED
;
1679 /* Populate the shared object list by reading the entire list of
1680 shared objects from the inferior. Handle special cases relating
1681 to the first elements of the list. Returns nonzero on success. */
1684 solist_update_full (struct svr4_info
*info
)
1686 free_solib_list (info
);
1687 info
->solib_list
= svr4_current_sos_direct (info
);
1692 /* Update the shared object list starting from the link-map entry
1693 passed by the linker in the probe's third argument. Returns
1694 nonzero if the list was successfully updated, or zero to indicate
1698 solist_update_incremental (struct svr4_info
*info
, CORE_ADDR lm
)
1700 struct so_list
*tail
;
1703 /* svr4_current_sos_direct contains logic to handle a number of
1704 special cases relating to the first elements of the list. To
1705 avoid duplicating this logic we defer to solist_update_full
1706 if the list is empty. */
1707 if (info
->solib_list
== NULL
)
1710 /* Fall back to a full update if we are using a remote target
1711 that does not support incremental transfers. */
1712 if (info
->using_xfer
&& !target_augmented_libraries_svr4_read ())
1715 /* Walk to the end of the list. */
1716 for (tail
= info
->solib_list
; tail
->next
!= NULL
; tail
= tail
->next
)
1718 prev_lm
= tail
->lm_info
->lm_addr
;
1720 /* Read the new objects. */
1721 if (info
->using_xfer
)
1723 struct svr4_library_list library_list
;
1726 xsnprintf (annex
, sizeof (annex
), "start=%s;prev=%s",
1727 phex_nz (lm
, sizeof (lm
)),
1728 phex_nz (prev_lm
, sizeof (prev_lm
)));
1729 if (!svr4_current_sos_via_xfer_libraries (&library_list
, annex
))
1732 tail
->next
= library_list
.head
;
1736 struct so_list
**link
= &tail
->next
;
1738 /* IGNORE_FIRST may safely be set to zero here because the
1739 above check and deferral to solist_update_full ensures
1740 that this call to svr4_read_so_list will never see the
1742 if (!svr4_read_so_list (lm
, prev_lm
, &link
, 0))
1749 /* Disable the probes-based linker interface and revert to the
1750 original interface. We don't reset the breakpoints as the
1751 ones set up for the probes-based interface are adequate. */
1754 disable_probes_interface_cleanup (void *arg
)
1756 struct svr4_info
*info
= get_svr4_info ();
1758 warning (_("Probes-based dynamic linker interface failed.\n"
1759 "Reverting to original interface.\n"));
1761 free_probes_table (info
);
1762 free_solib_list (info
);
1765 /* Update the solib list as appropriate when using the
1766 probes-based linker interface. Do nothing if using the
1767 standard interface. */
1770 svr4_handle_solib_event (void)
1772 struct svr4_info
*info
= get_svr4_info ();
1773 struct probe_and_action
*pa
;
1774 enum probe_action action
;
1775 struct cleanup
*old_chain
, *usm_chain
;
1777 CORE_ADDR pc
, debug_base
, lm
= 0;
1779 struct frame_info
*frame
= get_current_frame ();
1781 /* Do nothing if not using the probes interface. */
1782 if (info
->probes_table
== NULL
)
1785 /* If anything goes wrong we revert to the original linker
1787 old_chain
= make_cleanup (disable_probes_interface_cleanup
, NULL
);
1789 pc
= regcache_read_pc (get_current_regcache ());
1790 pa
= solib_event_probe_at (info
, pc
);
1793 do_cleanups (old_chain
);
1797 action
= solib_event_probe_action (pa
);
1798 if (action
== PROBES_INTERFACE_FAILED
)
1800 do_cleanups (old_chain
);
1804 if (action
== DO_NOTHING
)
1806 discard_cleanups (old_chain
);
1810 /* evaluate_probe_argument looks up symbols in the dynamic linker
1811 using find_pc_section. find_pc_section is accelerated by a cache
1812 called the section map. The section map is invalidated every
1813 time a shared library is loaded or unloaded, and if the inferior
1814 is generating a lot of shared library events then the section map
1815 will be updated every time svr4_handle_solib_event is called.
1816 We called find_pc_section in svr4_create_solib_event_breakpoints,
1817 so we can guarantee that the dynamic linker's sections are in the
1818 section map. We can therefore inhibit section map updates across
1819 these calls to evaluate_probe_argument and save a lot of time. */
1820 inhibit_section_map_updates (current_program_space
);
1821 usm_chain
= make_cleanup (resume_section_map_updates_cleanup
,
1822 current_program_space
);
1824 val
= evaluate_probe_argument (pa
->probe
, 1, frame
);
1827 do_cleanups (old_chain
);
1831 debug_base
= value_as_address (val
);
1832 if (debug_base
== 0)
1834 do_cleanups (old_chain
);
1838 /* Always locate the debug struct, in case it moved. */
1839 info
->debug_base
= 0;
1840 if (locate_base (info
) == 0)
1842 do_cleanups (old_chain
);
1846 /* GDB does not currently support libraries loaded via dlmopen
1847 into namespaces other than the initial one. We must ignore
1848 any namespace other than the initial namespace here until
1849 support for this is added to GDB. */
1850 if (debug_base
!= info
->debug_base
)
1851 action
= DO_NOTHING
;
1853 if (action
== UPDATE_OR_RELOAD
)
1855 val
= evaluate_probe_argument (pa
->probe
, 2, frame
);
1857 lm
= value_as_address (val
);
1860 action
= FULL_RELOAD
;
1863 /* Resume section map updates. */
1864 do_cleanups (usm_chain
);
1866 if (action
== UPDATE_OR_RELOAD
)
1868 if (!solist_update_incremental (info
, lm
))
1869 action
= FULL_RELOAD
;
1872 if (action
== FULL_RELOAD
)
1874 if (!solist_update_full (info
))
1876 do_cleanups (old_chain
);
1881 discard_cleanups (old_chain
);
1884 /* Helper function for svr4_update_solib_event_breakpoints. */
1887 svr4_update_solib_event_breakpoint (struct breakpoint
*b
, void *arg
)
1889 struct bp_location
*loc
;
1891 if (b
->type
!= bp_shlib_event
)
1893 /* Continue iterating. */
1897 for (loc
= b
->loc
; loc
!= NULL
; loc
= loc
->next
)
1899 struct svr4_info
*info
;
1900 struct probe_and_action
*pa
;
1902 info
= program_space_data (loc
->pspace
, solib_svr4_pspace_data
);
1903 if (info
== NULL
|| info
->probes_table
== NULL
)
1906 pa
= solib_event_probe_at (info
, loc
->address
);
1910 if (pa
->action
== DO_NOTHING
)
1912 if (b
->enable_state
== bp_disabled
&& stop_on_solib_events
)
1913 enable_breakpoint (b
);
1914 else if (b
->enable_state
== bp_enabled
&& !stop_on_solib_events
)
1915 disable_breakpoint (b
);
1921 /* Continue iterating. */
1925 /* Enable or disable optional solib event breakpoints as appropriate.
1926 Called whenever stop_on_solib_events is changed. */
1929 svr4_update_solib_event_breakpoints (void)
1931 iterate_over_breakpoints (svr4_update_solib_event_breakpoint
, NULL
);
1934 /* Create and register solib event breakpoints. PROBES is an array
1935 of NUM_PROBES elements, each of which is vector of probes. A
1936 solib event breakpoint will be created and registered for each
1940 svr4_create_probe_breakpoints (struct gdbarch
*gdbarch
,
1941 VEC (probe_p
) **probes
,
1942 struct objfile
*objfile
)
1946 for (i
= 0; i
< NUM_PROBES
; i
++)
1948 enum probe_action action
= probe_info
[i
].action
;
1949 struct probe
*probe
;
1953 VEC_iterate (probe_p
, probes
[i
], ix
, probe
);
1956 CORE_ADDR address
= get_probe_address (probe
, objfile
);
1958 create_solib_event_breakpoint (gdbarch
, address
);
1959 register_solib_event_probe (probe
, address
, action
);
1963 svr4_update_solib_event_breakpoints ();
1966 /* Both the SunOS and the SVR4 dynamic linkers call a marker function
1967 before and after mapping and unmapping shared libraries. The sole
1968 purpose of this method is to allow debuggers to set a breakpoint so
1969 they can track these changes.
1971 Some versions of the glibc dynamic linker contain named probes
1972 to allow more fine grained stopping. Given the address of the
1973 original marker function, this function attempts to find these
1974 probes, and if found, sets breakpoints on those instead. If the
1975 probes aren't found, a single breakpoint is set on the original
1979 svr4_create_solib_event_breakpoints (struct gdbarch
*gdbarch
,
1982 struct obj_section
*os
;
1984 os
= find_pc_section (address
);
1989 for (with_prefix
= 0; with_prefix
<= 1; with_prefix
++)
1991 VEC (probe_p
) *probes
[NUM_PROBES
];
1992 int all_probes_found
= 1;
1993 int checked_can_use_probe_arguments
= 0;
1996 memset (probes
, 0, sizeof (probes
));
1997 for (i
= 0; i
< NUM_PROBES
; i
++)
1999 const char *name
= probe_info
[i
].name
;
2003 /* Fedora 17 and Red Hat Enterprise Linux 6.2-6.4
2004 shipped with an early version of the probes code in
2005 which the probes' names were prefixed with "rtld_"
2006 and the "map_failed" probe did not exist. The
2007 locations of the probes are otherwise the same, so
2008 we check for probes with prefixed names if probes
2009 with unprefixed names are not present. */
2012 xsnprintf (buf
, sizeof (buf
), "rtld_%s", name
);
2016 probes
[i
] = find_probes_in_objfile (os
->objfile
, "rtld", name
);
2018 /* The "map_failed" probe did not exist in early
2019 versions of the probes code in which the probes'
2020 names were prefixed with "rtld_". */
2021 if (strcmp (name
, "rtld_map_failed") == 0)
2024 if (VEC_empty (probe_p
, probes
[i
]))
2026 all_probes_found
= 0;
2030 /* Ensure probe arguments can be evaluated. */
2031 if (!checked_can_use_probe_arguments
)
2033 p
= VEC_index (probe_p
, probes
[i
], 0);
2034 if (!can_evaluate_probe_arguments (p
))
2036 all_probes_found
= 0;
2039 checked_can_use_probe_arguments
= 1;
2043 if (all_probes_found
)
2044 svr4_create_probe_breakpoints (gdbarch
, probes
, os
->objfile
);
2046 for (i
= 0; i
< NUM_PROBES
; i
++)
2047 VEC_free (probe_p
, probes
[i
]);
2049 if (all_probes_found
)
2054 create_solib_event_breakpoint (gdbarch
, address
);
2057 /* Helper function for gdb_bfd_lookup_symbol. */
2060 cmp_name_and_sec_flags (asymbol
*sym
, void *data
)
2062 return (strcmp (sym
->name
, (const char *) data
) == 0
2063 && (sym
->section
->flags
& (SEC_CODE
| SEC_DATA
)) != 0);
2065 /* Arrange for dynamic linker to hit breakpoint.
2067 Both the SunOS and the SVR4 dynamic linkers have, as part of their
2068 debugger interface, support for arranging for the inferior to hit
2069 a breakpoint after mapping in the shared libraries. This function
2070 enables that breakpoint.
2072 For SunOS, there is a special flag location (in_debugger) which we
2073 set to 1. When the dynamic linker sees this flag set, it will set
2074 a breakpoint at a location known only to itself, after saving the
2075 original contents of that place and the breakpoint address itself,
2076 in it's own internal structures. When we resume the inferior, it
2077 will eventually take a SIGTRAP when it runs into the breakpoint.
2078 We handle this (in a different place) by restoring the contents of
2079 the breakpointed location (which is only known after it stops),
2080 chasing around to locate the shared libraries that have been
2081 loaded, then resuming.
2083 For SVR4, the debugger interface structure contains a member (r_brk)
2084 which is statically initialized at the time the shared library is
2085 built, to the offset of a function (_r_debug_state) which is guaran-
2086 teed to be called once before mapping in a library, and again when
2087 the mapping is complete. At the time we are examining this member,
2088 it contains only the unrelocated offset of the function, so we have
2089 to do our own relocation. Later, when the dynamic linker actually
2090 runs, it relocates r_brk to be the actual address of _r_debug_state().
2092 The debugger interface structure also contains an enumeration which
2093 is set to either RT_ADD or RT_DELETE prior to changing the mapping,
2094 depending upon whether or not the library is being mapped or unmapped,
2095 and then set to RT_CONSISTENT after the library is mapped/unmapped. */
2098 enable_break (struct svr4_info
*info
, int from_tty
)
2100 struct bound_minimal_symbol msymbol
;
2101 const char * const *bkpt_namep
;
2102 asection
*interp_sect
;
2106 info
->interp_text_sect_low
= info
->interp_text_sect_high
= 0;
2107 info
->interp_plt_sect_low
= info
->interp_plt_sect_high
= 0;
2109 /* If we already have a shared library list in the target, and
2110 r_debug contains r_brk, set the breakpoint there - this should
2111 mean r_brk has already been relocated. Assume the dynamic linker
2112 is the object containing r_brk. */
2114 solib_add (NULL
, from_tty
, ¤t_target
, auto_solib_add
);
2116 if (info
->debug_base
&& solib_svr4_r_map (info
) != 0)
2117 sym_addr
= solib_svr4_r_brk (info
);
2121 struct obj_section
*os
;
2123 sym_addr
= gdbarch_addr_bits_remove
2124 (target_gdbarch (), gdbarch_convert_from_func_ptr_addr (target_gdbarch (),
2128 /* On at least some versions of Solaris there's a dynamic relocation
2129 on _r_debug.r_brk and SYM_ADDR may not be relocated yet, e.g., if
2130 we get control before the dynamic linker has self-relocated.
2131 Check if SYM_ADDR is in a known section, if it is assume we can
2132 trust its value. This is just a heuristic though, it could go away
2133 or be replaced if it's getting in the way.
2135 On ARM we need to know whether the ISA of rtld_db_dlactivity (or
2136 however it's spelled in your particular system) is ARM or Thumb.
2137 That knowledge is encoded in the address, if it's Thumb the low bit
2138 is 1. However, we've stripped that info above and it's not clear
2139 what all the consequences are of passing a non-addr_bits_remove'd
2140 address to svr4_create_solib_event_breakpoints. The call to
2141 find_pc_section verifies we know about the address and have some
2142 hope of computing the right kind of breakpoint to use (via
2143 symbol info). It does mean that GDB needs to be pointed at a
2144 non-stripped version of the dynamic linker in order to obtain
2145 information it already knows about. Sigh. */
2147 os
= find_pc_section (sym_addr
);
2150 /* Record the relocated start and end address of the dynamic linker
2151 text and plt section for svr4_in_dynsym_resolve_code. */
2153 CORE_ADDR load_addr
;
2155 tmp_bfd
= os
->objfile
->obfd
;
2156 load_addr
= ANOFFSET (os
->objfile
->section_offsets
,
2157 SECT_OFF_TEXT (os
->objfile
));
2159 interp_sect
= bfd_get_section_by_name (tmp_bfd
, ".text");
2162 info
->interp_text_sect_low
=
2163 bfd_section_vma (tmp_bfd
, interp_sect
) + load_addr
;
2164 info
->interp_text_sect_high
=
2165 info
->interp_text_sect_low
2166 + bfd_section_size (tmp_bfd
, interp_sect
);
2168 interp_sect
= bfd_get_section_by_name (tmp_bfd
, ".plt");
2171 info
->interp_plt_sect_low
=
2172 bfd_section_vma (tmp_bfd
, interp_sect
) + load_addr
;
2173 info
->interp_plt_sect_high
=
2174 info
->interp_plt_sect_low
2175 + bfd_section_size (tmp_bfd
, interp_sect
);
2178 svr4_create_solib_event_breakpoints (target_gdbarch (), sym_addr
);
2183 /* Find the program interpreter; if not found, warn the user and drop
2184 into the old breakpoint at symbol code. */
2185 interp_name
= find_program_interpreter ();
2188 CORE_ADDR load_addr
= 0;
2189 int load_addr_found
= 0;
2190 int loader_found_in_list
= 0;
2192 bfd
*tmp_bfd
= NULL
;
2193 struct target_ops
*tmp_bfd_target
;
2194 volatile struct gdb_exception ex
;
2198 /* Now we need to figure out where the dynamic linker was
2199 loaded so that we can load its symbols and place a breakpoint
2200 in the dynamic linker itself.
2202 This address is stored on the stack. However, I've been unable
2203 to find any magic formula to find it for Solaris (appears to
2204 be trivial on GNU/Linux). Therefore, we have to try an alternate
2205 mechanism to find the dynamic linker's base address. */
2207 TRY_CATCH (ex
, RETURN_MASK_ALL
)
2209 tmp_bfd
= solib_bfd_open (interp_name
);
2211 if (tmp_bfd
== NULL
)
2212 goto bkpt_at_symbol
;
2214 /* Now convert the TMP_BFD into a target. That way target, as
2215 well as BFD operations can be used. */
2216 tmp_bfd_target
= target_bfd_reopen (tmp_bfd
);
2217 /* target_bfd_reopen acquired its own reference, so we can
2218 release ours now. */
2219 gdb_bfd_unref (tmp_bfd
);
2221 /* On a running target, we can get the dynamic linker's base
2222 address from the shared library table. */
2223 so
= master_so_list ();
2226 if (svr4_same_1 (interp_name
, so
->so_original_name
))
2228 load_addr_found
= 1;
2229 loader_found_in_list
= 1;
2230 load_addr
= lm_addr_check (so
, tmp_bfd
);
2236 /* If we were not able to find the base address of the loader
2237 from our so_list, then try using the AT_BASE auxilliary entry. */
2238 if (!load_addr_found
)
2239 if (target_auxv_search (¤t_target
, AT_BASE
, &load_addr
) > 0)
2241 int addr_bit
= gdbarch_addr_bit (target_gdbarch ());
2243 /* Ensure LOAD_ADDR has proper sign in its possible upper bits so
2244 that `+ load_addr' will overflow CORE_ADDR width not creating
2245 invalid addresses like 0x101234567 for 32bit inferiors on 64bit
2248 if (addr_bit
< (sizeof (CORE_ADDR
) * HOST_CHAR_BIT
))
2250 CORE_ADDR space_size
= (CORE_ADDR
) 1 << addr_bit
;
2251 CORE_ADDR tmp_entry_point
= exec_entry_point (tmp_bfd
,
2254 gdb_assert (load_addr
< space_size
);
2256 /* TMP_ENTRY_POINT exceeding SPACE_SIZE would be for prelinked
2257 64bit ld.so with 32bit executable, it should not happen. */
2259 if (tmp_entry_point
< space_size
2260 && tmp_entry_point
+ load_addr
>= space_size
)
2261 load_addr
-= space_size
;
2264 load_addr_found
= 1;
2267 /* Otherwise we find the dynamic linker's base address by examining
2268 the current pc (which should point at the entry point for the
2269 dynamic linker) and subtracting the offset of the entry point.
2271 This is more fragile than the previous approaches, but is a good
2272 fallback method because it has actually been working well in
2274 if (!load_addr_found
)
2276 struct regcache
*regcache
2277 = get_thread_arch_regcache (inferior_ptid
, target_gdbarch ());
2279 load_addr
= (regcache_read_pc (regcache
)
2280 - exec_entry_point (tmp_bfd
, tmp_bfd_target
));
2283 if (!loader_found_in_list
)
2285 info
->debug_loader_name
= xstrdup (interp_name
);
2286 info
->debug_loader_offset_p
= 1;
2287 info
->debug_loader_offset
= load_addr
;
2288 solib_add (NULL
, from_tty
, ¤t_target
, auto_solib_add
);
2291 /* Record the relocated start and end address of the dynamic linker
2292 text and plt section for svr4_in_dynsym_resolve_code. */
2293 interp_sect
= bfd_get_section_by_name (tmp_bfd
, ".text");
2296 info
->interp_text_sect_low
=
2297 bfd_section_vma (tmp_bfd
, interp_sect
) + load_addr
;
2298 info
->interp_text_sect_high
=
2299 info
->interp_text_sect_low
2300 + bfd_section_size (tmp_bfd
, interp_sect
);
2302 interp_sect
= bfd_get_section_by_name (tmp_bfd
, ".plt");
2305 info
->interp_plt_sect_low
=
2306 bfd_section_vma (tmp_bfd
, interp_sect
) + load_addr
;
2307 info
->interp_plt_sect_high
=
2308 info
->interp_plt_sect_low
2309 + bfd_section_size (tmp_bfd
, interp_sect
);
2312 /* Now try to set a breakpoint in the dynamic linker. */
2313 for (bkpt_namep
= solib_break_names
; *bkpt_namep
!= NULL
; bkpt_namep
++)
2315 sym_addr
= gdb_bfd_lookup_symbol (tmp_bfd
, cmp_name_and_sec_flags
,
2316 (void *) *bkpt_namep
);
2322 /* Convert 'sym_addr' from a function pointer to an address.
2323 Because we pass tmp_bfd_target instead of the current
2324 target, this will always produce an unrelocated value. */
2325 sym_addr
= gdbarch_convert_from_func_ptr_addr (target_gdbarch (),
2329 /* We're done with both the temporary bfd and target. Closing
2330 the target closes the underlying bfd, because it holds the
2331 only remaining reference. */
2332 target_close (tmp_bfd_target
);
2336 svr4_create_solib_event_breakpoints (target_gdbarch (),
2337 load_addr
+ sym_addr
);
2338 xfree (interp_name
);
2342 /* For whatever reason we couldn't set a breakpoint in the dynamic
2343 linker. Warn and drop into the old code. */
2345 xfree (interp_name
);
2346 warning (_("Unable to find dynamic linker breakpoint function.\n"
2347 "GDB will be unable to debug shared library initializers\n"
2348 "and track explicitly loaded dynamic code."));
2351 /* Scan through the lists of symbols, trying to look up the symbol and
2352 set a breakpoint there. Terminate loop when we/if we succeed. */
2354 for (bkpt_namep
= solib_break_names
; *bkpt_namep
!= NULL
; bkpt_namep
++)
2356 msymbol
= lookup_minimal_symbol (*bkpt_namep
, NULL
, symfile_objfile
);
2357 if ((msymbol
.minsym
!= NULL
)
2358 && (BMSYMBOL_VALUE_ADDRESS (msymbol
) != 0))
2360 sym_addr
= BMSYMBOL_VALUE_ADDRESS (msymbol
);
2361 sym_addr
= gdbarch_convert_from_func_ptr_addr (target_gdbarch (),
2364 svr4_create_solib_event_breakpoints (target_gdbarch (), sym_addr
);
2369 if (interp_name
!= NULL
&& !current_inferior ()->attach_flag
)
2371 for (bkpt_namep
= bkpt_names
; *bkpt_namep
!= NULL
; bkpt_namep
++)
2373 msymbol
= lookup_minimal_symbol (*bkpt_namep
, NULL
, symfile_objfile
);
2374 if ((msymbol
.minsym
!= NULL
)
2375 && (BMSYMBOL_VALUE_ADDRESS (msymbol
) != 0))
2377 sym_addr
= BMSYMBOL_VALUE_ADDRESS (msymbol
);
2378 sym_addr
= gdbarch_convert_from_func_ptr_addr (target_gdbarch (),
2381 svr4_create_solib_event_breakpoints (target_gdbarch (), sym_addr
);
2389 /* Implement the "special_symbol_handling" target_so_ops method. */
2392 svr4_special_symbol_handling (void)
2394 /* Nothing to do. */
2397 /* Read the ELF program headers from ABFD. Return the contents and
2398 set *PHDRS_SIZE to the size of the program headers. */
2401 read_program_headers_from_bfd (bfd
*abfd
, int *phdrs_size
)
2403 Elf_Internal_Ehdr
*ehdr
;
2406 ehdr
= elf_elfheader (abfd
);
2408 *phdrs_size
= ehdr
->e_phnum
* ehdr
->e_phentsize
;
2409 if (*phdrs_size
== 0)
2412 buf
= xmalloc (*phdrs_size
);
2413 if (bfd_seek (abfd
, ehdr
->e_phoff
, SEEK_SET
) != 0
2414 || bfd_bread (buf
, *phdrs_size
, abfd
) != *phdrs_size
)
2423 /* Return 1 and fill *DISPLACEMENTP with detected PIE offset of inferior
2424 exec_bfd. Otherwise return 0.
2426 We relocate all of the sections by the same amount. This
2427 behavior is mandated by recent editions of the System V ABI.
2428 According to the System V Application Binary Interface,
2429 Edition 4.1, page 5-5:
2431 ... Though the system chooses virtual addresses for
2432 individual processes, it maintains the segments' relative
2433 positions. Because position-independent code uses relative
2434 addressesing between segments, the difference between
2435 virtual addresses in memory must match the difference
2436 between virtual addresses in the file. The difference
2437 between the virtual address of any segment in memory and
2438 the corresponding virtual address in the file is thus a
2439 single constant value for any one executable or shared
2440 object in a given process. This difference is the base
2441 address. One use of the base address is to relocate the
2442 memory image of the program during dynamic linking.
2444 The same language also appears in Edition 4.0 of the System V
2445 ABI and is left unspecified in some of the earlier editions.
2447 Decide if the objfile needs to be relocated. As indicated above, we will
2448 only be here when execution is stopped. But during attachment PC can be at
2449 arbitrary address therefore regcache_read_pc can be misleading (contrary to
2450 the auxv AT_ENTRY value). Moreover for executable with interpreter section
2451 regcache_read_pc would point to the interpreter and not the main executable.
2453 So, to summarize, relocations are necessary when the start address obtained
2454 from the executable is different from the address in auxv AT_ENTRY entry.
2456 [ The astute reader will note that we also test to make sure that
2457 the executable in question has the DYNAMIC flag set. It is my
2458 opinion that this test is unnecessary (undesirable even). It
2459 was added to avoid inadvertent relocation of an executable
2460 whose e_type member in the ELF header is not ET_DYN. There may
2461 be a time in the future when it is desirable to do relocations
2462 on other types of files as well in which case this condition
2463 should either be removed or modified to accomodate the new file
2464 type. - Kevin, Nov 2000. ] */
2467 svr4_exec_displacement (CORE_ADDR
*displacementp
)
2469 /* ENTRY_POINT is a possible function descriptor - before
2470 a call to gdbarch_convert_from_func_ptr_addr. */
2471 CORE_ADDR entry_point
, displacement
;
2473 if (exec_bfd
== NULL
)
2476 /* Therefore for ELF it is ET_EXEC and not ET_DYN. Both shared libraries
2477 being executed themselves and PIE (Position Independent Executable)
2478 executables are ET_DYN. */
2480 if ((bfd_get_file_flags (exec_bfd
) & DYNAMIC
) == 0)
2483 if (target_auxv_search (¤t_target
, AT_ENTRY
, &entry_point
) <= 0)
2486 displacement
= entry_point
- bfd_get_start_address (exec_bfd
);
2488 /* Verify the DISPLACEMENT candidate complies with the required page
2489 alignment. It is cheaper than the program headers comparison below. */
2491 if (bfd_get_flavour (exec_bfd
) == bfd_target_elf_flavour
)
2493 const struct elf_backend_data
*elf
= get_elf_backend_data (exec_bfd
);
2495 /* p_align of PT_LOAD segments does not specify any alignment but
2496 only congruency of addresses:
2497 p_offset % p_align == p_vaddr % p_align
2498 Kernel is free to load the executable with lower alignment. */
2500 if ((displacement
& (elf
->minpagesize
- 1)) != 0)
2504 /* Verify that the auxilliary vector describes the same file as exec_bfd, by
2505 comparing their program headers. If the program headers in the auxilliary
2506 vector do not match the program headers in the executable, then we are
2507 looking at a different file than the one used by the kernel - for
2508 instance, "gdb program" connected to "gdbserver :PORT ld.so program". */
2510 if (bfd_get_flavour (exec_bfd
) == bfd_target_elf_flavour
)
2512 /* Be optimistic and clear OK only if GDB was able to verify the headers
2513 really do not match. */
2514 int phdrs_size
, phdrs2_size
, ok
= 1;
2515 gdb_byte
*buf
, *buf2
;
2518 buf
= read_program_header (-1, &phdrs_size
, &arch_size
);
2519 buf2
= read_program_headers_from_bfd (exec_bfd
, &phdrs2_size
);
2520 if (buf
!= NULL
&& buf2
!= NULL
)
2522 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch ());
2524 /* We are dealing with three different addresses. EXEC_BFD
2525 represents current address in on-disk file. target memory content
2526 may be different from EXEC_BFD as the file may have been prelinked
2527 to a different address after the executable has been loaded.
2528 Moreover the address of placement in target memory can be
2529 different from what the program headers in target memory say -
2530 this is the goal of PIE.
2532 Detected DISPLACEMENT covers both the offsets of PIE placement and
2533 possible new prelink performed after start of the program. Here
2534 relocate BUF and BUF2 just by the EXEC_BFD vs. target memory
2535 content offset for the verification purpose. */
2537 if (phdrs_size
!= phdrs2_size
2538 || bfd_get_arch_size (exec_bfd
) != arch_size
)
2540 else if (arch_size
== 32
2541 && phdrs_size
>= sizeof (Elf32_External_Phdr
)
2542 && phdrs_size
% sizeof (Elf32_External_Phdr
) == 0)
2544 Elf_Internal_Ehdr
*ehdr2
= elf_tdata (exec_bfd
)->elf_header
;
2545 Elf_Internal_Phdr
*phdr2
= elf_tdata (exec_bfd
)->phdr
;
2546 CORE_ADDR displacement
= 0;
2549 /* DISPLACEMENT could be found more easily by the difference of
2550 ehdr2->e_entry. But we haven't read the ehdr yet, and we
2551 already have enough information to compute that displacement
2552 with what we've read. */
2554 for (i
= 0; i
< ehdr2
->e_phnum
; i
++)
2555 if (phdr2
[i
].p_type
== PT_LOAD
)
2557 Elf32_External_Phdr
*phdrp
;
2558 gdb_byte
*buf_vaddr_p
, *buf_paddr_p
;
2559 CORE_ADDR vaddr
, paddr
;
2560 CORE_ADDR displacement_vaddr
= 0;
2561 CORE_ADDR displacement_paddr
= 0;
2563 phdrp
= &((Elf32_External_Phdr
*) buf
)[i
];
2564 buf_vaddr_p
= (gdb_byte
*) &phdrp
->p_vaddr
;
2565 buf_paddr_p
= (gdb_byte
*) &phdrp
->p_paddr
;
2567 vaddr
= extract_unsigned_integer (buf_vaddr_p
, 4,
2569 displacement_vaddr
= vaddr
- phdr2
[i
].p_vaddr
;
2571 paddr
= extract_unsigned_integer (buf_paddr_p
, 4,
2573 displacement_paddr
= paddr
- phdr2
[i
].p_paddr
;
2575 if (displacement_vaddr
== displacement_paddr
)
2576 displacement
= displacement_vaddr
;
2581 /* Now compare BUF and BUF2 with optional DISPLACEMENT. */
2583 for (i
= 0; i
< phdrs_size
/ sizeof (Elf32_External_Phdr
); i
++)
2585 Elf32_External_Phdr
*phdrp
;
2586 Elf32_External_Phdr
*phdr2p
;
2587 gdb_byte
*buf_vaddr_p
, *buf_paddr_p
;
2588 CORE_ADDR vaddr
, paddr
;
2589 asection
*plt2_asect
;
2591 phdrp
= &((Elf32_External_Phdr
*) buf
)[i
];
2592 buf_vaddr_p
= (gdb_byte
*) &phdrp
->p_vaddr
;
2593 buf_paddr_p
= (gdb_byte
*) &phdrp
->p_paddr
;
2594 phdr2p
= &((Elf32_External_Phdr
*) buf2
)[i
];
2596 /* PT_GNU_STACK is an exception by being never relocated by
2597 prelink as its addresses are always zero. */
2599 if (memcmp (phdrp
, phdr2p
, sizeof (*phdrp
)) == 0)
2602 /* Check also other adjustment combinations - PR 11786. */
2604 vaddr
= extract_unsigned_integer (buf_vaddr_p
, 4,
2606 vaddr
-= displacement
;
2607 store_unsigned_integer (buf_vaddr_p
, 4, byte_order
, vaddr
);
2609 paddr
= extract_unsigned_integer (buf_paddr_p
, 4,
2611 paddr
-= displacement
;
2612 store_unsigned_integer (buf_paddr_p
, 4, byte_order
, paddr
);
2614 if (memcmp (phdrp
, phdr2p
, sizeof (*phdrp
)) == 0)
2617 /* Strip modifies the flags and alignment of PT_GNU_RELRO.
2618 CentOS-5 has problems with filesz, memsz as well.
2620 if (phdr2
[i
].p_type
== PT_GNU_RELRO
)
2622 Elf32_External_Phdr tmp_phdr
= *phdrp
;
2623 Elf32_External_Phdr tmp_phdr2
= *phdr2p
;
2625 memset (tmp_phdr
.p_filesz
, 0, 4);
2626 memset (tmp_phdr
.p_memsz
, 0, 4);
2627 memset (tmp_phdr
.p_flags
, 0, 4);
2628 memset (tmp_phdr
.p_align
, 0, 4);
2629 memset (tmp_phdr2
.p_filesz
, 0, 4);
2630 memset (tmp_phdr2
.p_memsz
, 0, 4);
2631 memset (tmp_phdr2
.p_flags
, 0, 4);
2632 memset (tmp_phdr2
.p_align
, 0, 4);
2634 if (memcmp (&tmp_phdr
, &tmp_phdr2
, sizeof (tmp_phdr
))
2639 /* prelink can convert .plt SHT_NOBITS to SHT_PROGBITS. */
2640 plt2_asect
= bfd_get_section_by_name (exec_bfd
, ".plt");
2644 gdb_byte
*buf_filesz_p
= (gdb_byte
*) &phdrp
->p_filesz
;
2647 content2
= (bfd_get_section_flags (exec_bfd
, plt2_asect
)
2648 & SEC_HAS_CONTENTS
) != 0;
2650 filesz
= extract_unsigned_integer (buf_filesz_p
, 4,
2653 /* PLT2_ASECT is from on-disk file (exec_bfd) while
2654 FILESZ is from the in-memory image. */
2656 filesz
+= bfd_get_section_size (plt2_asect
);
2658 filesz
-= bfd_get_section_size (plt2_asect
);
2660 store_unsigned_integer (buf_filesz_p
, 4, byte_order
,
2663 if (memcmp (phdrp
, phdr2p
, sizeof (*phdrp
)) == 0)
2671 else if (arch_size
== 64
2672 && phdrs_size
>= sizeof (Elf64_External_Phdr
)
2673 && phdrs_size
% sizeof (Elf64_External_Phdr
) == 0)
2675 Elf_Internal_Ehdr
*ehdr2
= elf_tdata (exec_bfd
)->elf_header
;
2676 Elf_Internal_Phdr
*phdr2
= elf_tdata (exec_bfd
)->phdr
;
2677 CORE_ADDR displacement
= 0;
2680 /* DISPLACEMENT could be found more easily by the difference of
2681 ehdr2->e_entry. But we haven't read the ehdr yet, and we
2682 already have enough information to compute that displacement
2683 with what we've read. */
2685 for (i
= 0; i
< ehdr2
->e_phnum
; i
++)
2686 if (phdr2
[i
].p_type
== PT_LOAD
)
2688 Elf64_External_Phdr
*phdrp
;
2689 gdb_byte
*buf_vaddr_p
, *buf_paddr_p
;
2690 CORE_ADDR vaddr
, paddr
;
2691 CORE_ADDR displacement_vaddr
= 0;
2692 CORE_ADDR displacement_paddr
= 0;
2694 phdrp
= &((Elf64_External_Phdr
*) buf
)[i
];
2695 buf_vaddr_p
= (gdb_byte
*) &phdrp
->p_vaddr
;
2696 buf_paddr_p
= (gdb_byte
*) &phdrp
->p_paddr
;
2698 vaddr
= extract_unsigned_integer (buf_vaddr_p
, 8,
2700 displacement_vaddr
= vaddr
- phdr2
[i
].p_vaddr
;
2702 paddr
= extract_unsigned_integer (buf_paddr_p
, 8,
2704 displacement_paddr
= paddr
- phdr2
[i
].p_paddr
;
2706 if (displacement_vaddr
== displacement_paddr
)
2707 displacement
= displacement_vaddr
;
2712 /* Now compare BUF and BUF2 with optional DISPLACEMENT. */
2714 for (i
= 0; i
< phdrs_size
/ sizeof (Elf64_External_Phdr
); i
++)
2716 Elf64_External_Phdr
*phdrp
;
2717 Elf64_External_Phdr
*phdr2p
;
2718 gdb_byte
*buf_vaddr_p
, *buf_paddr_p
;
2719 CORE_ADDR vaddr
, paddr
;
2720 asection
*plt2_asect
;
2722 phdrp
= &((Elf64_External_Phdr
*) buf
)[i
];
2723 buf_vaddr_p
= (gdb_byte
*) &phdrp
->p_vaddr
;
2724 buf_paddr_p
= (gdb_byte
*) &phdrp
->p_paddr
;
2725 phdr2p
= &((Elf64_External_Phdr
*) buf2
)[i
];
2727 /* PT_GNU_STACK is an exception by being never relocated by
2728 prelink as its addresses are always zero. */
2730 if (memcmp (phdrp
, phdr2p
, sizeof (*phdrp
)) == 0)
2733 /* Check also other adjustment combinations - PR 11786. */
2735 vaddr
= extract_unsigned_integer (buf_vaddr_p
, 8,
2737 vaddr
-= displacement
;
2738 store_unsigned_integer (buf_vaddr_p
, 8, byte_order
, vaddr
);
2740 paddr
= extract_unsigned_integer (buf_paddr_p
, 8,
2742 paddr
-= displacement
;
2743 store_unsigned_integer (buf_paddr_p
, 8, byte_order
, paddr
);
2745 if (memcmp (phdrp
, phdr2p
, sizeof (*phdrp
)) == 0)
2748 /* Strip modifies the flags and alignment of PT_GNU_RELRO.
2749 CentOS-5 has problems with filesz, memsz as well.
2751 if (phdr2
[i
].p_type
== PT_GNU_RELRO
)
2753 Elf64_External_Phdr tmp_phdr
= *phdrp
;
2754 Elf64_External_Phdr tmp_phdr2
= *phdr2p
;
2756 memset (tmp_phdr
.p_filesz
, 0, 8);
2757 memset (tmp_phdr
.p_memsz
, 0, 8);
2758 memset (tmp_phdr
.p_flags
, 0, 4);
2759 memset (tmp_phdr
.p_align
, 0, 8);
2760 memset (tmp_phdr2
.p_filesz
, 0, 8);
2761 memset (tmp_phdr2
.p_memsz
, 0, 8);
2762 memset (tmp_phdr2
.p_flags
, 0, 4);
2763 memset (tmp_phdr2
.p_align
, 0, 8);
2765 if (memcmp (&tmp_phdr
, &tmp_phdr2
, sizeof (tmp_phdr
))
2770 /* prelink can convert .plt SHT_NOBITS to SHT_PROGBITS. */
2771 plt2_asect
= bfd_get_section_by_name (exec_bfd
, ".plt");
2775 gdb_byte
*buf_filesz_p
= (gdb_byte
*) &phdrp
->p_filesz
;
2778 content2
= (bfd_get_section_flags (exec_bfd
, plt2_asect
)
2779 & SEC_HAS_CONTENTS
) != 0;
2781 filesz
= extract_unsigned_integer (buf_filesz_p
, 8,
2784 /* PLT2_ASECT is from on-disk file (exec_bfd) while
2785 FILESZ is from the in-memory image. */
2787 filesz
+= bfd_get_section_size (plt2_asect
);
2789 filesz
-= bfd_get_section_size (plt2_asect
);
2791 store_unsigned_integer (buf_filesz_p
, 8, byte_order
,
2794 if (memcmp (phdrp
, phdr2p
, sizeof (*phdrp
)) == 0)
2815 /* It can be printed repeatedly as there is no easy way to check
2816 the executable symbols/file has been already relocated to
2819 printf_unfiltered (_("Using PIE (Position Independent Executable) "
2820 "displacement %s for \"%s\".\n"),
2821 paddress (target_gdbarch (), displacement
),
2822 bfd_get_filename (exec_bfd
));
2825 *displacementp
= displacement
;
2829 /* Relocate the main executable. This function should be called upon
2830 stopping the inferior process at the entry point to the program.
2831 The entry point from BFD is compared to the AT_ENTRY of AUXV and if they are
2832 different, the main executable is relocated by the proper amount. */
2835 svr4_relocate_main_executable (void)
2837 CORE_ADDR displacement
;
2839 /* If we are re-running this executable, SYMFILE_OBJFILE->SECTION_OFFSETS
2840 probably contains the offsets computed using the PIE displacement
2841 from the previous run, which of course are irrelevant for this run.
2842 So we need to determine the new PIE displacement and recompute the
2843 section offsets accordingly, even if SYMFILE_OBJFILE->SECTION_OFFSETS
2844 already contains pre-computed offsets.
2846 If we cannot compute the PIE displacement, either:
2848 - The executable is not PIE.
2850 - SYMFILE_OBJFILE does not match the executable started in the target.
2851 This can happen for main executable symbols loaded at the host while
2852 `ld.so --ld-args main-executable' is loaded in the target.
2854 Then we leave the section offsets untouched and use them as is for
2857 - These section offsets were properly reset earlier, and thus
2858 already contain the correct values. This can happen for instance
2859 when reconnecting via the remote protocol to a target that supports
2860 the `qOffsets' packet.
2862 - The section offsets were not reset earlier, and the best we can
2863 hope is that the old offsets are still applicable to the new run. */
2865 if (! svr4_exec_displacement (&displacement
))
2868 /* Even DISPLACEMENT 0 is a valid new difference of in-memory vs. in-file
2871 if (symfile_objfile
)
2873 struct section_offsets
*new_offsets
;
2876 new_offsets
= alloca (symfile_objfile
->num_sections
2877 * sizeof (*new_offsets
));
2879 for (i
= 0; i
< symfile_objfile
->num_sections
; i
++)
2880 new_offsets
->offsets
[i
] = displacement
;
2882 objfile_relocate (symfile_objfile
, new_offsets
);
2888 for (asect
= exec_bfd
->sections
; asect
!= NULL
; asect
= asect
->next
)
2889 exec_set_section_address (bfd_get_filename (exec_bfd
), asect
->index
,
2890 (bfd_section_vma (exec_bfd
, asect
)
2895 /* Implement the "create_inferior_hook" target_solib_ops method.
2897 For SVR4 executables, this first instruction is either the first
2898 instruction in the dynamic linker (for dynamically linked
2899 executables) or the instruction at "start" for statically linked
2900 executables. For dynamically linked executables, the system
2901 first exec's /lib/libc.so.N, which contains the dynamic linker,
2902 and starts it running. The dynamic linker maps in any needed
2903 shared libraries, maps in the actual user executable, and then
2904 jumps to "start" in the user executable.
2906 We can arrange to cooperate with the dynamic linker to discover the
2907 names of shared libraries that are dynamically linked, and the base
2908 addresses to which they are linked.
2910 This function is responsible for discovering those names and
2911 addresses, and saving sufficient information about them to allow
2912 their symbols to be read at a later time. */
2915 svr4_solib_create_inferior_hook (int from_tty
)
2917 struct svr4_info
*info
;
2919 info
= get_svr4_info ();
2921 /* Clear the probes-based interface's state. */
2922 free_probes_table (info
);
2923 free_solib_list (info
);
2925 /* Relocate the main executable if necessary. */
2926 svr4_relocate_main_executable ();
2928 /* No point setting a breakpoint in the dynamic linker if we can't
2929 hit it (e.g., a core file, or a trace file). */
2930 if (!target_has_execution
)
2933 if (!svr4_have_link_map_offsets ())
2936 if (!enable_break (info
, from_tty
))
2941 svr4_clear_solib (void)
2943 struct svr4_info
*info
;
2945 info
= get_svr4_info ();
2946 info
->debug_base
= 0;
2947 info
->debug_loader_offset_p
= 0;
2948 info
->debug_loader_offset
= 0;
2949 xfree (info
->debug_loader_name
);
2950 info
->debug_loader_name
= NULL
;
2953 /* Clear any bits of ADDR that wouldn't fit in a target-format
2954 data pointer. "Data pointer" here refers to whatever sort of
2955 address the dynamic linker uses to manage its sections. At the
2956 moment, we don't support shared libraries on any processors where
2957 code and data pointers are different sizes.
2959 This isn't really the right solution. What we really need here is
2960 a way to do arithmetic on CORE_ADDR values that respects the
2961 natural pointer/address correspondence. (For example, on the MIPS,
2962 converting a 32-bit pointer to a 64-bit CORE_ADDR requires you to
2963 sign-extend the value. There, simply truncating the bits above
2964 gdbarch_ptr_bit, as we do below, is no good.) This should probably
2965 be a new gdbarch method or something. */
2967 svr4_truncate_ptr (CORE_ADDR addr
)
2969 if (gdbarch_ptr_bit (target_gdbarch ()) == sizeof (CORE_ADDR
) * 8)
2970 /* We don't need to truncate anything, and the bit twiddling below
2971 will fail due to overflow problems. */
2974 return addr
& (((CORE_ADDR
) 1 << gdbarch_ptr_bit (target_gdbarch ())) - 1);
2979 svr4_relocate_section_addresses (struct so_list
*so
,
2980 struct target_section
*sec
)
2982 bfd
*abfd
= sec
->the_bfd_section
->owner
;
2984 sec
->addr
= svr4_truncate_ptr (sec
->addr
+ lm_addr_check (so
, abfd
));
2985 sec
->endaddr
= svr4_truncate_ptr (sec
->endaddr
+ lm_addr_check (so
, abfd
));
2989 /* Architecture-specific operations. */
2991 /* Per-architecture data key. */
2992 static struct gdbarch_data
*solib_svr4_data
;
2994 struct solib_svr4_ops
2996 /* Return a description of the layout of `struct link_map'. */
2997 struct link_map_offsets
*(*fetch_link_map_offsets
)(void);
3000 /* Return a default for the architecture-specific operations. */
3003 solib_svr4_init (struct obstack
*obstack
)
3005 struct solib_svr4_ops
*ops
;
3007 ops
= OBSTACK_ZALLOC (obstack
, struct solib_svr4_ops
);
3008 ops
->fetch_link_map_offsets
= NULL
;
3012 /* Set the architecture-specific `struct link_map_offsets' fetcher for
3013 GDBARCH to FLMO. Also, install SVR4 solib_ops into GDBARCH. */
3016 set_solib_svr4_fetch_link_map_offsets (struct gdbarch
*gdbarch
,
3017 struct link_map_offsets
*(*flmo
) (void))
3019 struct solib_svr4_ops
*ops
= gdbarch_data (gdbarch
, solib_svr4_data
);
3021 ops
->fetch_link_map_offsets
= flmo
;
3023 set_solib_ops (gdbarch
, &svr4_so_ops
);
3026 /* Fetch a link_map_offsets structure using the architecture-specific
3027 `struct link_map_offsets' fetcher. */
3029 static struct link_map_offsets
*
3030 svr4_fetch_link_map_offsets (void)
3032 struct solib_svr4_ops
*ops
= gdbarch_data (target_gdbarch (), solib_svr4_data
);
3034 gdb_assert (ops
->fetch_link_map_offsets
);
3035 return ops
->fetch_link_map_offsets ();
3038 /* Return 1 if a link map offset fetcher has been defined, 0 otherwise. */
3041 svr4_have_link_map_offsets (void)
3043 struct solib_svr4_ops
*ops
= gdbarch_data (target_gdbarch (), solib_svr4_data
);
3045 return (ops
->fetch_link_map_offsets
!= NULL
);
3049 /* Most OS'es that have SVR4-style ELF dynamic libraries define a
3050 `struct r_debug' and a `struct link_map' that are binary compatible
3051 with the origional SVR4 implementation. */
3053 /* Fetch (and possibly build) an appropriate `struct link_map_offsets'
3054 for an ILP32 SVR4 system. */
3056 struct link_map_offsets
*
3057 svr4_ilp32_fetch_link_map_offsets (void)
3059 static struct link_map_offsets lmo
;
3060 static struct link_map_offsets
*lmp
= NULL
;
3066 lmo
.r_version_offset
= 0;
3067 lmo
.r_version_size
= 4;
3068 lmo
.r_map_offset
= 4;
3069 lmo
.r_brk_offset
= 8;
3070 lmo
.r_ldsomap_offset
= 20;
3072 /* Everything we need is in the first 20 bytes. */
3073 lmo
.link_map_size
= 20;
3074 lmo
.l_addr_offset
= 0;
3075 lmo
.l_name_offset
= 4;
3076 lmo
.l_ld_offset
= 8;
3077 lmo
.l_next_offset
= 12;
3078 lmo
.l_prev_offset
= 16;
3084 /* Fetch (and possibly build) an appropriate `struct link_map_offsets'
3085 for an LP64 SVR4 system. */
3087 struct link_map_offsets
*
3088 svr4_lp64_fetch_link_map_offsets (void)
3090 static struct link_map_offsets lmo
;
3091 static struct link_map_offsets
*lmp
= NULL
;
3097 lmo
.r_version_offset
= 0;
3098 lmo
.r_version_size
= 4;
3099 lmo
.r_map_offset
= 8;
3100 lmo
.r_brk_offset
= 16;
3101 lmo
.r_ldsomap_offset
= 40;
3103 /* Everything we need is in the first 40 bytes. */
3104 lmo
.link_map_size
= 40;
3105 lmo
.l_addr_offset
= 0;
3106 lmo
.l_name_offset
= 8;
3107 lmo
.l_ld_offset
= 16;
3108 lmo
.l_next_offset
= 24;
3109 lmo
.l_prev_offset
= 32;
3116 struct target_so_ops svr4_so_ops
;
3118 /* Lookup global symbol for ELF DSOs linked with -Bsymbolic. Those DSOs have a
3119 different rule for symbol lookup. The lookup begins here in the DSO, not in
3120 the main executable. */
3122 static struct symbol
*
3123 elf_lookup_lib_symbol (const struct objfile
*objfile
,
3125 const domain_enum domain
)
3129 if (objfile
== symfile_objfile
)
3133 /* OBJFILE should have been passed as the non-debug one. */
3134 gdb_assert (objfile
->separate_debug_objfile_backlink
== NULL
);
3136 abfd
= objfile
->obfd
;
3139 if (abfd
== NULL
|| scan_dyntag (DT_SYMBOLIC
, abfd
, NULL
) != 1)
3142 return lookup_global_symbol_from_objfile (objfile
, name
, domain
);
3145 extern initialize_file_ftype _initialize_svr4_solib
; /* -Wmissing-prototypes */
3148 _initialize_svr4_solib (void)
3150 solib_svr4_data
= gdbarch_data_register_pre_init (solib_svr4_init
);
3151 solib_svr4_pspace_data
3152 = register_program_space_data_with_cleanup (NULL
, svr4_pspace_data_cleanup
);
3154 svr4_so_ops
.relocate_section_addresses
= svr4_relocate_section_addresses
;
3155 svr4_so_ops
.free_so
= svr4_free_so
;
3156 svr4_so_ops
.clear_so
= svr4_clear_so
;
3157 svr4_so_ops
.clear_solib
= svr4_clear_solib
;
3158 svr4_so_ops
.solib_create_inferior_hook
= svr4_solib_create_inferior_hook
;
3159 svr4_so_ops
.special_symbol_handling
= svr4_special_symbol_handling
;
3160 svr4_so_ops
.current_sos
= svr4_current_sos
;
3161 svr4_so_ops
.open_symbol_file_object
= open_symbol_file_object
;
3162 svr4_so_ops
.in_dynsym_resolve_code
= svr4_in_dynsym_resolve_code
;
3163 svr4_so_ops
.bfd_open
= solib_bfd_open
;
3164 svr4_so_ops
.lookup_lib_global_symbol
= elf_lookup_lib_symbol
;
3165 svr4_so_ops
.same
= svr4_same
;
3166 svr4_so_ops
.keep_data_in_core
= svr4_keep_data_in_core
;
3167 svr4_so_ops
.update_breakpoints
= svr4_update_solib_event_breakpoints
;
3168 svr4_so_ops
.handle_event
= svr4_handle_solib_event
;