1 /* Handle SVR4 shared libraries for GDB, the GNU Debugger.
3 Copyright (C) 1990-2015 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"
35 #include "gdbthread.h"
40 #include "solib-svr4.h"
42 #include "bfd-target.h"
49 static struct link_map_offsets
*svr4_fetch_link_map_offsets (void);
50 static int svr4_have_link_map_offsets (void);
51 static void svr4_relocate_main_executable (void);
52 static void svr4_free_library_list (void *p_list
);
54 /* Link map info to include in an allocated so_list entry. */
58 /* Amount by which addresses in the binary should be relocated to
59 match the inferior. The direct inferior value is L_ADDR_INFERIOR.
60 When prelinking is involved and the prelink base address changes,
61 we may need a different offset - the recomputed offset is in L_ADDR.
62 It is commonly the same value. It is cached as we want to warn about
63 the difference and compute it only once. L_ADDR is valid
65 CORE_ADDR l_addr
, l_addr_inferior
;
66 unsigned int l_addr_p
: 1;
68 /* The target location of lm. */
71 /* Values read in from inferior's fields of the same name. */
72 CORE_ADDR l_ld
, l_next
, l_prev
, l_name
;
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 /* What to do when a probe stop occurs. */
113 /* Something went seriously wrong. Stop using probes and
114 revert to using the older interface. */
115 PROBES_INTERFACE_FAILED
,
117 /* No action is required. The shared object list is still
121 /* The shared object list should be reloaded entirely. */
124 /* Attempt to incrementally update the shared object list. If
125 the update fails or is not possible, fall back to reloading
130 /* A probe's name and its associated action. */
134 /* The name of the probe. */
137 /* What to do when a probe stop occurs. */
138 enum probe_action action
;
141 /* A list of named probes and their associated actions. If all
142 probes are present in the dynamic linker then the probes-based
143 interface will be used. */
145 static const struct probe_info probe_info
[] =
147 { "init_start", DO_NOTHING
},
148 { "init_complete", FULL_RELOAD
},
149 { "map_start", DO_NOTHING
},
150 { "map_failed", DO_NOTHING
},
151 { "reloc_complete", UPDATE_OR_RELOAD
},
152 { "unmap_start", DO_NOTHING
},
153 { "unmap_complete", FULL_RELOAD
},
156 #define NUM_PROBES ARRAY_SIZE (probe_info)
158 /* Return non-zero if GDB_SO_NAME and INFERIOR_SO_NAME represent
159 the same shared library. */
162 svr4_same_1 (const char *gdb_so_name
, const char *inferior_so_name
)
164 if (strcmp (gdb_so_name
, inferior_so_name
) == 0)
167 /* On Solaris, when starting inferior we think that dynamic linker is
168 /usr/lib/ld.so.1, but later on, the table of loaded shared libraries
169 contains /lib/ld.so.1. Sometimes one file is a link to another, but
170 sometimes they have identical content, but are not linked to each
171 other. We don't restrict this check for Solaris, but the chances
172 of running into this situation elsewhere are very low. */
173 if (strcmp (gdb_so_name
, "/usr/lib/ld.so.1") == 0
174 && strcmp (inferior_so_name
, "/lib/ld.so.1") == 0)
177 /* Similarly, we observed the same issue with sparc64, but with
178 different locations. */
179 if (strcmp (gdb_so_name
, "/usr/lib/sparcv9/ld.so.1") == 0
180 && strcmp (inferior_so_name
, "/lib/sparcv9/ld.so.1") == 0)
187 svr4_same (struct so_list
*gdb
, struct so_list
*inferior
)
189 return (svr4_same_1 (gdb
->so_original_name
, inferior
->so_original_name
));
192 static struct lm_info
*
193 lm_info_read (CORE_ADDR lm_addr
)
195 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
197 struct lm_info
*lm_info
;
198 struct cleanup
*back_to
;
200 lm
= xmalloc (lmo
->link_map_size
);
201 back_to
= make_cleanup (xfree
, lm
);
203 if (target_read_memory (lm_addr
, lm
, lmo
->link_map_size
) != 0)
205 warning (_("Error reading shared library list entry at %s"),
206 paddress (target_gdbarch (), lm_addr
)),
211 struct type
*ptr_type
= builtin_type (target_gdbarch ())->builtin_data_ptr
;
213 lm_info
= xzalloc (sizeof (*lm_info
));
214 lm_info
->lm_addr
= lm_addr
;
216 lm_info
->l_addr_inferior
= extract_typed_address (&lm
[lmo
->l_addr_offset
],
218 lm_info
->l_ld
= extract_typed_address (&lm
[lmo
->l_ld_offset
], ptr_type
);
219 lm_info
->l_next
= extract_typed_address (&lm
[lmo
->l_next_offset
],
221 lm_info
->l_prev
= extract_typed_address (&lm
[lmo
->l_prev_offset
],
223 lm_info
->l_name
= extract_typed_address (&lm
[lmo
->l_name_offset
],
227 do_cleanups (back_to
);
233 has_lm_dynamic_from_link_map (void)
235 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
237 return lmo
->l_ld_offset
>= 0;
241 lm_addr_check (const struct so_list
*so
, bfd
*abfd
)
243 if (!so
->lm_info
->l_addr_p
)
245 struct bfd_section
*dyninfo_sect
;
246 CORE_ADDR l_addr
, l_dynaddr
, dynaddr
;
248 l_addr
= so
->lm_info
->l_addr_inferior
;
250 if (! abfd
|| ! has_lm_dynamic_from_link_map ())
253 l_dynaddr
= so
->lm_info
->l_ld
;
255 dyninfo_sect
= bfd_get_section_by_name (abfd
, ".dynamic");
256 if (dyninfo_sect
== NULL
)
259 dynaddr
= bfd_section_vma (abfd
, dyninfo_sect
);
261 if (dynaddr
+ l_addr
!= l_dynaddr
)
263 CORE_ADDR align
= 0x1000;
264 CORE_ADDR minpagesize
= align
;
266 if (bfd_get_flavour (abfd
) == bfd_target_elf_flavour
)
268 Elf_Internal_Ehdr
*ehdr
= elf_tdata (abfd
)->elf_header
;
269 Elf_Internal_Phdr
*phdr
= elf_tdata (abfd
)->phdr
;
274 for (i
= 0; i
< ehdr
->e_phnum
; i
++)
275 if (phdr
[i
].p_type
== PT_LOAD
&& phdr
[i
].p_align
> align
)
276 align
= phdr
[i
].p_align
;
278 minpagesize
= get_elf_backend_data (abfd
)->minpagesize
;
281 /* Turn it into a mask. */
284 /* If the changes match the alignment requirements, we
285 assume we're using a core file that was generated by the
286 same binary, just prelinked with a different base offset.
287 If it doesn't match, we may have a different binary, the
288 same binary with the dynamic table loaded at an unrelated
289 location, or anything, really. To avoid regressions,
290 don't adjust the base offset in the latter case, although
291 odds are that, if things really changed, debugging won't
294 One could expect more the condition
295 ((l_addr & align) == 0 && ((l_dynaddr - dynaddr) & align) == 0)
296 but the one below is relaxed for PPC. The PPC kernel supports
297 either 4k or 64k page sizes. To be prepared for 64k pages,
298 PPC ELF files are built using an alignment requirement of 64k.
299 However, when running on a kernel supporting 4k pages, the memory
300 mapping of the library may not actually happen on a 64k boundary!
302 (In the usual case where (l_addr & align) == 0, this check is
303 equivalent to the possibly expected check above.)
305 Even on PPC it must be zero-aligned at least for MINPAGESIZE. */
307 l_addr
= l_dynaddr
- dynaddr
;
309 if ((l_addr
& (minpagesize
- 1)) == 0
310 && (l_addr
& align
) == ((l_dynaddr
- dynaddr
) & align
))
313 printf_unfiltered (_("Using PIC (Position Independent Code) "
314 "prelink displacement %s for \"%s\".\n"),
315 paddress (target_gdbarch (), l_addr
),
320 /* There is no way to verify the library file matches. prelink
321 can during prelinking of an unprelinked file (or unprelinking
322 of a prelinked file) shift the DYNAMIC segment by arbitrary
323 offset without any page size alignment. There is no way to
324 find out the ELF header and/or Program Headers for a limited
325 verification if it they match. One could do a verification
326 of the DYNAMIC segment. Still the found address is the best
327 one GDB could find. */
329 warning (_(".dynamic section for \"%s\" "
330 "is not at the expected address "
331 "(wrong library or version mismatch?)"), so
->so_name
);
336 so
->lm_info
->l_addr
= l_addr
;
337 so
->lm_info
->l_addr_p
= 1;
340 return so
->lm_info
->l_addr
;
343 /* Per pspace SVR4 specific data. */
347 CORE_ADDR debug_base
; /* Base of dynamic linker structures. */
349 /* Validity flag for debug_loader_offset. */
350 int debug_loader_offset_p
;
352 /* Load address for the dynamic linker, inferred. */
353 CORE_ADDR debug_loader_offset
;
355 /* Name of the dynamic linker, valid if debug_loader_offset_p. */
356 char *debug_loader_name
;
358 /* Load map address for the main executable. */
359 CORE_ADDR main_lm_addr
;
361 CORE_ADDR interp_text_sect_low
;
362 CORE_ADDR interp_text_sect_high
;
363 CORE_ADDR interp_plt_sect_low
;
364 CORE_ADDR interp_plt_sect_high
;
366 /* Nonzero if the list of objects was last obtained from the target
367 via qXfer:libraries-svr4:read. */
370 /* Table of struct probe_and_action instances, used by the
371 probes-based interface to map breakpoint addresses to probes
372 and their associated actions. Lookup is performed using
373 probe_and_action->probe->address. */
376 /* List of objects loaded into the inferior, used by the probes-
378 struct so_list
*solib_list
;
381 /* Per-program-space data key. */
382 static const struct program_space_data
*solib_svr4_pspace_data
;
384 /* Free the probes table. */
387 free_probes_table (struct svr4_info
*info
)
389 if (info
->probes_table
== NULL
)
392 htab_delete (info
->probes_table
);
393 info
->probes_table
= NULL
;
396 /* Free the solib list. */
399 free_solib_list (struct svr4_info
*info
)
401 svr4_free_library_list (&info
->solib_list
);
402 info
->solib_list
= NULL
;
406 svr4_pspace_data_cleanup (struct program_space
*pspace
, void *arg
)
408 struct svr4_info
*info
= arg
;
410 free_probes_table (info
);
411 free_solib_list (info
);
416 /* Get the current svr4 data. If none is found yet, add it now. This
417 function always returns a valid object. */
419 static struct svr4_info
*
422 struct svr4_info
*info
;
424 info
= program_space_data (current_program_space
, solib_svr4_pspace_data
);
428 info
= XCNEW (struct svr4_info
);
429 set_program_space_data (current_program_space
, solib_svr4_pspace_data
, info
);
433 /* Local function prototypes */
435 static int match_main (const char *);
437 /* Read program header TYPE from inferior memory. The header is found
438 by scanning the OS auxillary vector.
440 If TYPE == -1, return the program headers instead of the contents of
443 Return a pointer to allocated memory holding the program header contents,
444 or NULL on failure. If sucessful, and unless P_SECT_SIZE is NULL, the
445 size of those contents is returned to P_SECT_SIZE. Likewise, the target
446 architecture size (32-bit or 64-bit) is returned to P_ARCH_SIZE. */
449 read_program_header (int type
, int *p_sect_size
, int *p_arch_size
)
451 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch ());
452 CORE_ADDR at_phdr
, at_phent
, at_phnum
, pt_phdr
= 0;
453 int arch_size
, sect_size
;
458 /* Get required auxv elements from target. */
459 if (target_auxv_search (¤t_target
, AT_PHDR
, &at_phdr
) <= 0)
461 if (target_auxv_search (¤t_target
, AT_PHENT
, &at_phent
) <= 0)
463 if (target_auxv_search (¤t_target
, AT_PHNUM
, &at_phnum
) <= 0)
465 if (!at_phdr
|| !at_phnum
)
468 /* Determine ELF architecture type. */
469 if (at_phent
== sizeof (Elf32_External_Phdr
))
471 else if (at_phent
== sizeof (Elf64_External_Phdr
))
476 /* Find the requested segment. */
480 sect_size
= at_phent
* at_phnum
;
482 else if (arch_size
== 32)
484 Elf32_External_Phdr phdr
;
487 /* Search for requested PHDR. */
488 for (i
= 0; i
< at_phnum
; i
++)
492 if (target_read_memory (at_phdr
+ i
* sizeof (phdr
),
493 (gdb_byte
*)&phdr
, sizeof (phdr
)))
496 p_type
= extract_unsigned_integer ((gdb_byte
*) phdr
.p_type
,
499 if (p_type
== PT_PHDR
)
502 pt_phdr
= extract_unsigned_integer ((gdb_byte
*) phdr
.p_vaddr
,
513 /* Retrieve address and size. */
514 sect_addr
= extract_unsigned_integer ((gdb_byte
*)phdr
.p_vaddr
,
516 sect_size
= extract_unsigned_integer ((gdb_byte
*)phdr
.p_memsz
,
521 Elf64_External_Phdr phdr
;
524 /* Search for requested PHDR. */
525 for (i
= 0; i
< at_phnum
; i
++)
529 if (target_read_memory (at_phdr
+ i
* sizeof (phdr
),
530 (gdb_byte
*)&phdr
, sizeof (phdr
)))
533 p_type
= extract_unsigned_integer ((gdb_byte
*) phdr
.p_type
,
536 if (p_type
== PT_PHDR
)
539 pt_phdr
= extract_unsigned_integer ((gdb_byte
*) phdr
.p_vaddr
,
550 /* Retrieve address and size. */
551 sect_addr
= extract_unsigned_integer ((gdb_byte
*)phdr
.p_vaddr
,
553 sect_size
= extract_unsigned_integer ((gdb_byte
*)phdr
.p_memsz
,
557 /* PT_PHDR is optional, but we really need it
558 for PIE to make this work in general. */
562 /* at_phdr is real address in memory. pt_phdr is what pheader says it is.
563 Relocation offset is the difference between the two. */
564 sect_addr
= sect_addr
+ (at_phdr
- pt_phdr
);
567 /* Read in requested program header. */
568 buf
= xmalloc (sect_size
);
569 if (target_read_memory (sect_addr
, buf
, sect_size
))
576 *p_arch_size
= arch_size
;
578 *p_sect_size
= sect_size
;
584 /* Return program interpreter string. */
586 find_program_interpreter (void)
588 gdb_byte
*buf
= NULL
;
590 /* If we have an exec_bfd, use its section table. */
592 && bfd_get_flavour (exec_bfd
) == bfd_target_elf_flavour
)
594 struct bfd_section
*interp_sect
;
596 interp_sect
= bfd_get_section_by_name (exec_bfd
, ".interp");
597 if (interp_sect
!= NULL
)
599 int sect_size
= bfd_section_size (exec_bfd
, interp_sect
);
601 buf
= xmalloc (sect_size
);
602 bfd_get_section_contents (exec_bfd
, interp_sect
, buf
, 0, sect_size
);
606 /* If we didn't find it, use the target auxillary vector. */
608 buf
= read_program_header (PT_INTERP
, NULL
, NULL
);
614 /* Scan for DESIRED_DYNTAG in .dynamic section of ABFD. If DESIRED_DYNTAG is
615 found, 1 is returned and the corresponding PTR is set. */
618 scan_dyntag (const int desired_dyntag
, bfd
*abfd
, CORE_ADDR
*ptr
)
620 int arch_size
, step
, sect_size
;
622 CORE_ADDR dyn_ptr
, dyn_addr
;
623 gdb_byte
*bufend
, *bufstart
, *buf
;
624 Elf32_External_Dyn
*x_dynp_32
;
625 Elf64_External_Dyn
*x_dynp_64
;
626 struct bfd_section
*sect
;
627 struct target_section
*target_section
;
632 if (bfd_get_flavour (abfd
) != bfd_target_elf_flavour
)
635 arch_size
= bfd_get_arch_size (abfd
);
639 /* Find the start address of the .dynamic section. */
640 sect
= bfd_get_section_by_name (abfd
, ".dynamic");
644 for (target_section
= current_target_sections
->sections
;
645 target_section
< current_target_sections
->sections_end
;
647 if (sect
== target_section
->the_bfd_section
)
649 if (target_section
< current_target_sections
->sections_end
)
650 dyn_addr
= target_section
->addr
;
653 /* ABFD may come from OBJFILE acting only as a symbol file without being
654 loaded into the target (see add_symbol_file_command). This case is
655 such fallback to the file VMA address without the possibility of
656 having the section relocated to its actual in-memory address. */
658 dyn_addr
= bfd_section_vma (abfd
, sect
);
661 /* Read in .dynamic from the BFD. We will get the actual value
662 from memory later. */
663 sect_size
= bfd_section_size (abfd
, sect
);
664 buf
= bufstart
= alloca (sect_size
);
665 if (!bfd_get_section_contents (abfd
, sect
,
669 /* Iterate over BUF and scan for DYNTAG. If found, set PTR and return. */
670 step
= (arch_size
== 32) ? sizeof (Elf32_External_Dyn
)
671 : sizeof (Elf64_External_Dyn
);
672 for (bufend
= buf
+ sect_size
;
678 x_dynp_32
= (Elf32_External_Dyn
*) buf
;
679 current_dyntag
= bfd_h_get_32 (abfd
, (bfd_byte
*) x_dynp_32
->d_tag
);
680 dyn_ptr
= bfd_h_get_32 (abfd
, (bfd_byte
*) x_dynp_32
->d_un
.d_ptr
);
684 x_dynp_64
= (Elf64_External_Dyn
*) buf
;
685 current_dyntag
= bfd_h_get_64 (abfd
, (bfd_byte
*) x_dynp_64
->d_tag
);
686 dyn_ptr
= bfd_h_get_64 (abfd
, (bfd_byte
*) x_dynp_64
->d_un
.d_ptr
);
688 if (current_dyntag
== DT_NULL
)
690 if (current_dyntag
== desired_dyntag
)
692 /* If requested, try to read the runtime value of this .dynamic
696 struct type
*ptr_type
;
700 ptr_type
= builtin_type (target_gdbarch ())->builtin_data_ptr
;
701 ptr_addr
= dyn_addr
+ (buf
- bufstart
) + arch_size
/ 8;
702 if (target_read_memory (ptr_addr
, ptr_buf
, arch_size
/ 8) == 0)
703 dyn_ptr
= extract_typed_address (ptr_buf
, ptr_type
);
713 /* Scan for DESIRED_DYNTAG in .dynamic section of the target's main executable,
714 found by consulting the OS auxillary vector. If DESIRED_DYNTAG is found, 1
715 is returned and the corresponding PTR is set. */
718 scan_dyntag_auxv (const int desired_dyntag
, CORE_ADDR
*ptr
)
720 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch ());
721 int sect_size
, arch_size
, step
;
724 gdb_byte
*bufend
, *bufstart
, *buf
;
726 /* Read in .dynamic section. */
727 buf
= bufstart
= read_program_header (PT_DYNAMIC
, §_size
, &arch_size
);
731 /* Iterate over BUF and scan for DYNTAG. If found, set PTR and return. */
732 step
= (arch_size
== 32) ? sizeof (Elf32_External_Dyn
)
733 : sizeof (Elf64_External_Dyn
);
734 for (bufend
= buf
+ sect_size
;
740 Elf32_External_Dyn
*dynp
= (Elf32_External_Dyn
*) buf
;
742 current_dyntag
= extract_unsigned_integer ((gdb_byte
*) dynp
->d_tag
,
744 dyn_ptr
= extract_unsigned_integer ((gdb_byte
*) dynp
->d_un
.d_ptr
,
749 Elf64_External_Dyn
*dynp
= (Elf64_External_Dyn
*) buf
;
751 current_dyntag
= extract_unsigned_integer ((gdb_byte
*) dynp
->d_tag
,
753 dyn_ptr
= extract_unsigned_integer ((gdb_byte
*) dynp
->d_un
.d_ptr
,
756 if (current_dyntag
== DT_NULL
)
759 if (current_dyntag
== desired_dyntag
)
773 /* Locate the base address of dynamic linker structs for SVR4 elf
776 For SVR4 elf targets the address of the dynamic linker's runtime
777 structure is contained within the dynamic info section in the
778 executable file. The dynamic section is also mapped into the
779 inferior address space. Because the runtime loader fills in the
780 real address before starting the inferior, we have to read in the
781 dynamic info section from the inferior address space.
782 If there are any errors while trying to find the address, we
783 silently return 0, otherwise the found address is returned. */
786 elf_locate_base (void)
788 struct bound_minimal_symbol msymbol
;
791 /* Look for DT_MIPS_RLD_MAP first. MIPS executables use this
792 instead of DT_DEBUG, although they sometimes contain an unused
794 if (scan_dyntag (DT_MIPS_RLD_MAP
, exec_bfd
, &dyn_ptr
)
795 || scan_dyntag_auxv (DT_MIPS_RLD_MAP
, &dyn_ptr
))
797 struct type
*ptr_type
= builtin_type (target_gdbarch ())->builtin_data_ptr
;
799 int pbuf_size
= TYPE_LENGTH (ptr_type
);
801 pbuf
= alloca (pbuf_size
);
802 /* DT_MIPS_RLD_MAP contains a pointer to the address
803 of the dynamic link structure. */
804 if (target_read_memory (dyn_ptr
, pbuf
, pbuf_size
))
806 return extract_typed_address (pbuf
, ptr_type
);
810 if (scan_dyntag (DT_DEBUG
, exec_bfd
, &dyn_ptr
)
811 || scan_dyntag_auxv (DT_DEBUG
, &dyn_ptr
))
814 /* This may be a static executable. Look for the symbol
815 conventionally named _r_debug, as a last resort. */
816 msymbol
= lookup_minimal_symbol ("_r_debug", NULL
, symfile_objfile
);
817 if (msymbol
.minsym
!= NULL
)
818 return BMSYMBOL_VALUE_ADDRESS (msymbol
);
820 /* DT_DEBUG entry not found. */
824 /* Locate the base address of dynamic linker structs.
826 For both the SunOS and SVR4 shared library implementations, if the
827 inferior executable has been linked dynamically, there is a single
828 address somewhere in the inferior's data space which is the key to
829 locating all of the dynamic linker's runtime structures. This
830 address is the value of the debug base symbol. The job of this
831 function is to find and return that address, or to return 0 if there
832 is no such address (the executable is statically linked for example).
834 For SunOS, the job is almost trivial, since the dynamic linker and
835 all of it's structures are statically linked to the executable at
836 link time. Thus the symbol for the address we are looking for has
837 already been added to the minimal symbol table for the executable's
838 objfile at the time the symbol file's symbols were read, and all we
839 have to do is look it up there. Note that we explicitly do NOT want
840 to find the copies in the shared library.
842 The SVR4 version is a bit more complicated because the address
843 is contained somewhere in the dynamic info section. We have to go
844 to a lot more work to discover the address of the debug base symbol.
845 Because of this complexity, we cache the value we find and return that
846 value on subsequent invocations. Note there is no copy in the
847 executable symbol tables. */
850 locate_base (struct svr4_info
*info
)
852 /* Check to see if we have a currently valid address, and if so, avoid
853 doing all this work again and just return the cached address. If
854 we have no cached address, try to locate it in the dynamic info
855 section for ELF executables. There's no point in doing any of this
856 though if we don't have some link map offsets to work with. */
858 if (info
->debug_base
== 0 && svr4_have_link_map_offsets ())
859 info
->debug_base
= elf_locate_base ();
860 return info
->debug_base
;
863 /* Find the first element in the inferior's dynamic link map, and
864 return its address in the inferior. Return zero if the address
865 could not be determined.
867 FIXME: Perhaps we should validate the info somehow, perhaps by
868 checking r_version for a known version number, or r_state for
872 solib_svr4_r_map (struct svr4_info
*info
)
874 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
875 struct type
*ptr_type
= builtin_type (target_gdbarch ())->builtin_data_ptr
;
877 volatile struct gdb_exception ex
;
879 TRY_CATCH (ex
, RETURN_MASK_ERROR
)
881 addr
= read_memory_typed_address (info
->debug_base
+ lmo
->r_map_offset
,
884 exception_print (gdb_stderr
, ex
);
888 /* Find r_brk from the inferior's debug base. */
891 solib_svr4_r_brk (struct svr4_info
*info
)
893 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
894 struct type
*ptr_type
= builtin_type (target_gdbarch ())->builtin_data_ptr
;
896 return read_memory_typed_address (info
->debug_base
+ lmo
->r_brk_offset
,
900 /* Find the link map for the dynamic linker (if it is not in the
901 normal list of loaded shared objects). */
904 solib_svr4_r_ldsomap (struct svr4_info
*info
)
906 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
907 struct type
*ptr_type
= builtin_type (target_gdbarch ())->builtin_data_ptr
;
908 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch ());
911 /* Check version, and return zero if `struct r_debug' doesn't have
912 the r_ldsomap member. */
914 = read_memory_unsigned_integer (info
->debug_base
+ lmo
->r_version_offset
,
915 lmo
->r_version_size
, byte_order
);
916 if (version
< 2 || lmo
->r_ldsomap_offset
== -1)
919 return read_memory_typed_address (info
->debug_base
+ lmo
->r_ldsomap_offset
,
923 /* On Solaris systems with some versions of the dynamic linker,
924 ld.so's l_name pointer points to the SONAME in the string table
925 rather than into writable memory. So that GDB can find shared
926 libraries when loading a core file generated by gcore, ensure that
927 memory areas containing the l_name string are saved in the core
931 svr4_keep_data_in_core (CORE_ADDR vaddr
, unsigned long size
)
933 struct svr4_info
*info
;
936 struct cleanup
*old_chain
;
939 info
= get_svr4_info ();
941 info
->debug_base
= 0;
943 if (!info
->debug_base
)
946 ldsomap
= solib_svr4_r_ldsomap (info
);
950 new = XCNEW (struct so_list
);
951 old_chain
= make_cleanup (xfree
, new);
952 new->lm_info
= lm_info_read (ldsomap
);
953 make_cleanup (xfree
, new->lm_info
);
954 name_lm
= new->lm_info
? new->lm_info
->l_name
: 0;
955 do_cleanups (old_chain
);
957 return (name_lm
>= vaddr
&& name_lm
< vaddr
+ size
);
960 /* Implement the "open_symbol_file_object" target_so_ops method.
962 If no open symbol file, attempt to locate and open the main symbol
963 file. On SVR4 systems, this is the first link map entry. If its
964 name is here, we can open it. Useful when attaching to a process
965 without first loading its symbol file. */
968 open_symbol_file_object (void *from_ttyp
)
970 CORE_ADDR lm
, l_name
;
973 int from_tty
= *(int *)from_ttyp
;
974 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
975 struct type
*ptr_type
= builtin_type (target_gdbarch ())->builtin_data_ptr
;
976 int l_name_size
= TYPE_LENGTH (ptr_type
);
977 gdb_byte
*l_name_buf
= xmalloc (l_name_size
);
978 struct cleanup
*cleanups
= make_cleanup (xfree
, l_name_buf
);
979 struct svr4_info
*info
= get_svr4_info ();
982 if (!query (_("Attempt to reload symbols from process? ")))
984 do_cleanups (cleanups
);
988 /* Always locate the debug struct, in case it has moved. */
989 info
->debug_base
= 0;
990 if (locate_base (info
) == 0)
992 do_cleanups (cleanups
);
993 return 0; /* failed somehow... */
996 /* First link map member should be the executable. */
997 lm
= solib_svr4_r_map (info
);
1000 do_cleanups (cleanups
);
1001 return 0; /* failed somehow... */
1004 /* Read address of name from target memory to GDB. */
1005 read_memory (lm
+ lmo
->l_name_offset
, l_name_buf
, l_name_size
);
1007 /* Convert the address to host format. */
1008 l_name
= extract_typed_address (l_name_buf
, ptr_type
);
1012 do_cleanups (cleanups
);
1013 return 0; /* No filename. */
1016 /* Now fetch the filename from target memory. */
1017 target_read_string (l_name
, &filename
, SO_NAME_MAX_PATH_SIZE
- 1, &errcode
);
1018 make_cleanup (xfree
, filename
);
1022 warning (_("failed to read exec filename from attached file: %s"),
1023 safe_strerror (errcode
));
1024 do_cleanups (cleanups
);
1028 /* Have a pathname: read the symbol file. */
1029 symbol_file_add_main (filename
, from_tty
);
1031 do_cleanups (cleanups
);
1035 /* Data exchange structure for the XML parser as returned by
1036 svr4_current_sos_via_xfer_libraries. */
1038 struct svr4_library_list
1040 struct so_list
*head
, **tailp
;
1042 /* Inferior address of struct link_map used for the main executable. It is
1043 NULL if not known. */
1047 /* Implementation for target_so_ops.free_so. */
1050 svr4_free_so (struct so_list
*so
)
1052 xfree (so
->lm_info
);
1055 /* Implement target_so_ops.clear_so. */
1058 svr4_clear_so (struct so_list
*so
)
1060 if (so
->lm_info
!= NULL
)
1061 so
->lm_info
->l_addr_p
= 0;
1064 /* Free so_list built so far (called via cleanup). */
1067 svr4_free_library_list (void *p_list
)
1069 struct so_list
*list
= *(struct so_list
**) p_list
;
1071 while (list
!= NULL
)
1073 struct so_list
*next
= list
->next
;
1080 /* Copy library list. */
1082 static struct so_list
*
1083 svr4_copy_library_list (struct so_list
*src
)
1085 struct so_list
*dst
= NULL
;
1086 struct so_list
**link
= &dst
;
1090 struct so_list
*new;
1092 new = xmalloc (sizeof (struct so_list
));
1093 memcpy (new, src
, sizeof (struct so_list
));
1095 new->lm_info
= xmalloc (sizeof (struct lm_info
));
1096 memcpy (new->lm_info
, src
->lm_info
, sizeof (struct lm_info
));
1108 #ifdef HAVE_LIBEXPAT
1110 #include "xml-support.h"
1112 /* Handle the start of a <library> element. Note: new elements are added
1113 at the tail of the list, keeping the list in order. */
1116 library_list_start_library (struct gdb_xml_parser
*parser
,
1117 const struct gdb_xml_element
*element
,
1118 void *user_data
, VEC(gdb_xml_value_s
) *attributes
)
1120 struct svr4_library_list
*list
= user_data
;
1121 const char *name
= xml_find_attribute (attributes
, "name")->value
;
1122 ULONGEST
*lmp
= xml_find_attribute (attributes
, "lm")->value
;
1123 ULONGEST
*l_addrp
= xml_find_attribute (attributes
, "l_addr")->value
;
1124 ULONGEST
*l_ldp
= xml_find_attribute (attributes
, "l_ld")->value
;
1125 struct so_list
*new_elem
;
1127 new_elem
= XCNEW (struct so_list
);
1128 new_elem
->lm_info
= XCNEW (struct lm_info
);
1129 new_elem
->lm_info
->lm_addr
= *lmp
;
1130 new_elem
->lm_info
->l_addr_inferior
= *l_addrp
;
1131 new_elem
->lm_info
->l_ld
= *l_ldp
;
1133 strncpy (new_elem
->so_name
, name
, sizeof (new_elem
->so_name
) - 1);
1134 new_elem
->so_name
[sizeof (new_elem
->so_name
) - 1] = 0;
1135 strcpy (new_elem
->so_original_name
, new_elem
->so_name
);
1137 *list
->tailp
= new_elem
;
1138 list
->tailp
= &new_elem
->next
;
1141 /* Handle the start of a <library-list-svr4> element. */
1144 svr4_library_list_start_list (struct gdb_xml_parser
*parser
,
1145 const struct gdb_xml_element
*element
,
1146 void *user_data
, VEC(gdb_xml_value_s
) *attributes
)
1148 struct svr4_library_list
*list
= user_data
;
1149 const char *version
= xml_find_attribute (attributes
, "version")->value
;
1150 struct gdb_xml_value
*main_lm
= xml_find_attribute (attributes
, "main-lm");
1152 if (strcmp (version
, "1.0") != 0)
1153 gdb_xml_error (parser
,
1154 _("SVR4 Library list has unsupported version \"%s\""),
1158 list
->main_lm
= *(ULONGEST
*) main_lm
->value
;
1161 /* The allowed elements and attributes for an XML library list.
1162 The root element is a <library-list>. */
1164 static const struct gdb_xml_attribute svr4_library_attributes
[] =
1166 { "name", GDB_XML_AF_NONE
, NULL
, NULL
},
1167 { "lm", GDB_XML_AF_NONE
, gdb_xml_parse_attr_ulongest
, NULL
},
1168 { "l_addr", GDB_XML_AF_NONE
, gdb_xml_parse_attr_ulongest
, NULL
},
1169 { "l_ld", GDB_XML_AF_NONE
, gdb_xml_parse_attr_ulongest
, NULL
},
1170 { NULL
, GDB_XML_AF_NONE
, NULL
, NULL
}
1173 static const struct gdb_xml_element svr4_library_list_children
[] =
1176 "library", svr4_library_attributes
, NULL
,
1177 GDB_XML_EF_REPEATABLE
| GDB_XML_EF_OPTIONAL
,
1178 library_list_start_library
, NULL
1180 { NULL
, NULL
, NULL
, GDB_XML_EF_NONE
, NULL
, NULL
}
1183 static const struct gdb_xml_attribute svr4_library_list_attributes
[] =
1185 { "version", GDB_XML_AF_NONE
, NULL
, NULL
},
1186 { "main-lm", GDB_XML_AF_OPTIONAL
, gdb_xml_parse_attr_ulongest
, NULL
},
1187 { NULL
, GDB_XML_AF_NONE
, NULL
, NULL
}
1190 static const struct gdb_xml_element svr4_library_list_elements
[] =
1192 { "library-list-svr4", svr4_library_list_attributes
, svr4_library_list_children
,
1193 GDB_XML_EF_NONE
, svr4_library_list_start_list
, NULL
},
1194 { NULL
, NULL
, NULL
, GDB_XML_EF_NONE
, NULL
, NULL
}
1197 /* Parse qXfer:libraries:read packet into *SO_LIST_RETURN. Return 1 if
1199 Return 0 if packet not supported, *SO_LIST_RETURN is not modified in such
1200 case. Return 1 if *SO_LIST_RETURN contains the library list, it may be
1201 empty, caller is responsible for freeing all its entries. */
1204 svr4_parse_libraries (const char *document
, struct svr4_library_list
*list
)
1206 struct cleanup
*back_to
= make_cleanup (svr4_free_library_list
,
1209 memset (list
, 0, sizeof (*list
));
1210 list
->tailp
= &list
->head
;
1211 if (gdb_xml_parse_quick (_("target library list"), "library-list-svr4.dtd",
1212 svr4_library_list_elements
, document
, list
) == 0)
1214 /* Parsed successfully, keep the result. */
1215 discard_cleanups (back_to
);
1219 do_cleanups (back_to
);
1223 /* Attempt to get so_list from target via qXfer:libraries-svr4:read packet.
1225 Return 0 if packet not supported, *SO_LIST_RETURN is not modified in such
1226 case. Return 1 if *SO_LIST_RETURN contains the library list, it may be
1227 empty, caller is responsible for freeing all its entries.
1229 Note that ANNEX must be NULL if the remote does not explicitly allow
1230 qXfer:libraries-svr4:read packets with non-empty annexes. Support for
1231 this can be checked using target_augmented_libraries_svr4_read (). */
1234 svr4_current_sos_via_xfer_libraries (struct svr4_library_list
*list
,
1237 char *svr4_library_document
;
1239 struct cleanup
*back_to
;
1241 gdb_assert (annex
== NULL
|| target_augmented_libraries_svr4_read ());
1243 /* Fetch the list of shared libraries. */
1244 svr4_library_document
= target_read_stralloc (¤t_target
,
1245 TARGET_OBJECT_LIBRARIES_SVR4
,
1247 if (svr4_library_document
== NULL
)
1250 back_to
= make_cleanup (xfree
, svr4_library_document
);
1251 result
= svr4_parse_libraries (svr4_library_document
, list
);
1252 do_cleanups (back_to
);
1260 svr4_current_sos_via_xfer_libraries (struct svr4_library_list
*list
,
1268 /* If no shared library information is available from the dynamic
1269 linker, build a fallback list from other sources. */
1271 static struct so_list
*
1272 svr4_default_sos (void)
1274 struct svr4_info
*info
= get_svr4_info ();
1275 struct so_list
*new;
1277 if (!info
->debug_loader_offset_p
)
1280 new = XCNEW (struct so_list
);
1282 new->lm_info
= xzalloc (sizeof (struct lm_info
));
1284 /* Nothing will ever check the other fields if we set l_addr_p. */
1285 new->lm_info
->l_addr
= info
->debug_loader_offset
;
1286 new->lm_info
->l_addr_p
= 1;
1288 strncpy (new->so_name
, info
->debug_loader_name
, SO_NAME_MAX_PATH_SIZE
- 1);
1289 new->so_name
[SO_NAME_MAX_PATH_SIZE
- 1] = '\0';
1290 strcpy (new->so_original_name
, new->so_name
);
1295 /* Read the whole inferior libraries chain starting at address LM.
1296 Expect the first entry in the chain's previous entry to be PREV_LM.
1297 Add the entries to the tail referenced by LINK_PTR_PTR. Ignore the
1298 first entry if IGNORE_FIRST and set global MAIN_LM_ADDR according
1299 to it. Returns nonzero upon success. If zero is returned the
1300 entries stored to LINK_PTR_PTR are still valid although they may
1301 represent only part of the inferior library list. */
1304 svr4_read_so_list (CORE_ADDR lm
, CORE_ADDR prev_lm
,
1305 struct so_list
***link_ptr_ptr
, int ignore_first
)
1307 CORE_ADDR first_l_name
= 0;
1310 for (; lm
!= 0; prev_lm
= lm
, lm
= next_lm
)
1312 struct so_list
*new;
1313 struct cleanup
*old_chain
;
1317 new = XCNEW (struct so_list
);
1318 old_chain
= make_cleanup_free_so (new);
1320 new->lm_info
= lm_info_read (lm
);
1321 if (new->lm_info
== NULL
)
1323 do_cleanups (old_chain
);
1327 next_lm
= new->lm_info
->l_next
;
1329 if (new->lm_info
->l_prev
!= prev_lm
)
1331 warning (_("Corrupted shared library list: %s != %s"),
1332 paddress (target_gdbarch (), prev_lm
),
1333 paddress (target_gdbarch (), new->lm_info
->l_prev
));
1334 do_cleanups (old_chain
);
1338 /* For SVR4 versions, the first entry in the link map is for the
1339 inferior executable, so we must ignore it. For some versions of
1340 SVR4, it has no name. For others (Solaris 2.3 for example), it
1341 does have a name, so we can no longer use a missing name to
1342 decide when to ignore it. */
1343 if (ignore_first
&& new->lm_info
->l_prev
== 0)
1345 struct svr4_info
*info
= get_svr4_info ();
1347 first_l_name
= new->lm_info
->l_name
;
1348 info
->main_lm_addr
= new->lm_info
->lm_addr
;
1349 do_cleanups (old_chain
);
1353 /* Extract this shared object's name. */
1354 target_read_string (new->lm_info
->l_name
, &buffer
,
1355 SO_NAME_MAX_PATH_SIZE
- 1, &errcode
);
1358 /* If this entry's l_name address matches that of the
1359 inferior executable, then this is not a normal shared
1360 object, but (most likely) a vDSO. In this case, silently
1361 skip it; otherwise emit a warning. */
1362 if (first_l_name
== 0 || new->lm_info
->l_name
!= first_l_name
)
1363 warning (_("Can't read pathname for load map: %s."),
1364 safe_strerror (errcode
));
1365 do_cleanups (old_chain
);
1369 strncpy (new->so_name
, buffer
, SO_NAME_MAX_PATH_SIZE
- 1);
1370 new->so_name
[SO_NAME_MAX_PATH_SIZE
- 1] = '\0';
1371 strcpy (new->so_original_name
, new->so_name
);
1374 /* If this entry has no name, or its name matches the name
1375 for the main executable, don't include it in the list. */
1376 if (! new->so_name
[0] || match_main (new->so_name
))
1378 do_cleanups (old_chain
);
1382 discard_cleanups (old_chain
);
1384 **link_ptr_ptr
= new;
1385 *link_ptr_ptr
= &new->next
;
1391 /* Read the full list of currently loaded shared objects directly
1392 from the inferior, without referring to any libraries read and
1393 stored by the probes interface. Handle special cases relating
1394 to the first elements of the list. */
1396 static struct so_list
*
1397 svr4_current_sos_direct (struct svr4_info
*info
)
1400 struct so_list
*head
= NULL
;
1401 struct so_list
**link_ptr
= &head
;
1402 struct cleanup
*back_to
;
1404 struct svr4_library_list library_list
;
1406 /* Fall back to manual examination of the target if the packet is not
1407 supported or gdbserver failed to find DT_DEBUG. gdb.server/solib-list.exp
1408 tests a case where gdbserver cannot find the shared libraries list while
1409 GDB itself is able to find it via SYMFILE_OBJFILE.
1411 Unfortunately statically linked inferiors will also fall back through this
1412 suboptimal code path. */
1414 info
->using_xfer
= svr4_current_sos_via_xfer_libraries (&library_list
,
1416 if (info
->using_xfer
)
1418 if (library_list
.main_lm
)
1419 info
->main_lm_addr
= library_list
.main_lm
;
1421 return library_list
.head
? library_list
.head
: svr4_default_sos ();
1424 /* Always locate the debug struct, in case it has moved. */
1425 info
->debug_base
= 0;
1428 /* If we can't find the dynamic linker's base structure, this
1429 must not be a dynamically linked executable. Hmm. */
1430 if (! info
->debug_base
)
1431 return svr4_default_sos ();
1433 /* Assume that everything is a library if the dynamic loader was loaded
1434 late by a static executable. */
1435 if (exec_bfd
&& bfd_get_section_by_name (exec_bfd
, ".dynamic") == NULL
)
1440 back_to
= make_cleanup (svr4_free_library_list
, &head
);
1442 /* Walk the inferior's link map list, and build our list of
1443 `struct so_list' nodes. */
1444 lm
= solib_svr4_r_map (info
);
1446 svr4_read_so_list (lm
, 0, &link_ptr
, ignore_first
);
1448 /* On Solaris, the dynamic linker is not in the normal list of
1449 shared objects, so make sure we pick it up too. Having
1450 symbol information for the dynamic linker is quite crucial
1451 for skipping dynamic linker resolver code. */
1452 lm
= solib_svr4_r_ldsomap (info
);
1454 svr4_read_so_list (lm
, 0, &link_ptr
, 0);
1456 discard_cleanups (back_to
);
1459 return svr4_default_sos ();
1464 /* Implement the main part of the "current_sos" target_so_ops
1467 static struct so_list
*
1468 svr4_current_sos_1 (void)
1470 struct svr4_info
*info
= get_svr4_info ();
1472 /* If the solib list has been read and stored by the probes
1473 interface then we return a copy of the stored list. */
1474 if (info
->solib_list
!= NULL
)
1475 return svr4_copy_library_list (info
->solib_list
);
1477 /* Otherwise obtain the solib list directly from the inferior. */
1478 return svr4_current_sos_direct (info
);
1481 /* Implement the "current_sos" target_so_ops method. */
1483 static struct so_list
*
1484 svr4_current_sos (void)
1486 struct so_list
*so_head
= svr4_current_sos_1 ();
1487 struct mem_range vsyscall_range
;
1489 /* Filter out the vDSO module, if present. Its symbol file would
1490 not be found on disk. The vDSO/vsyscall's OBJFILE is instead
1491 managed by symfile-mem.c:add_vsyscall_page. */
1492 if (gdbarch_vsyscall_range (target_gdbarch (), &vsyscall_range
)
1493 && vsyscall_range
.length
!= 0)
1495 struct so_list
**sop
;
1498 while (*sop
!= NULL
)
1500 struct so_list
*so
= *sop
;
1502 /* We can't simply match the vDSO by starting address alone,
1503 because lm_info->l_addr_inferior (and also l_addr) do not
1504 necessarily represent the real starting address of the
1505 ELF if the vDSO's ELF itself is "prelinked". The l_ld
1506 field (the ".dynamic" section of the shared object)
1507 always points at the absolute/resolved address though.
1508 So check whether that address is inside the vDSO's
1511 E.g., on Linux 3.16 (x86_64) the vDSO is a regular
1512 0-based ELF, and we see:
1515 33 AT_SYSINFO_EHDR System-supplied DSO's ELF header 0x7ffff7ffb000
1516 (gdb) p/x *_r_debug.r_map.l_next
1517 $1 = {l_addr = 0x7ffff7ffb000, ..., l_ld = 0x7ffff7ffb318, ...}
1519 And on Linux 2.6.32 (x86_64) we see:
1522 33 AT_SYSINFO_EHDR System-supplied DSO's ELF header 0x7ffff7ffe000
1523 (gdb) p/x *_r_debug.r_map.l_next
1524 $5 = {l_addr = 0x7ffff88fe000, ..., l_ld = 0x7ffff7ffe580, ... }
1526 Dumping that vDSO shows:
1528 (gdb) info proc mappings
1529 0x7ffff7ffe000 0x7ffff7fff000 0x1000 0 [vdso]
1530 (gdb) dump memory vdso.bin 0x7ffff7ffe000 0x7ffff7fff000
1531 # readelf -Wa vdso.bin
1533 Entry point address: 0xffffffffff700700
1536 [Nr] Name Type Address Off Size
1537 [ 0] NULL 0000000000000000 000000 000000
1538 [ 1] .hash HASH ffffffffff700120 000120 000038
1539 [ 2] .dynsym DYNSYM ffffffffff700158 000158 0000d8
1541 [ 9] .dynamic DYNAMIC ffffffffff700580 000580 0000f0
1543 if (address_in_mem_range (so
->lm_info
->l_ld
, &vsyscall_range
))
1557 /* Get the address of the link_map for a given OBJFILE. */
1560 svr4_fetch_objfile_link_map (struct objfile
*objfile
)
1563 struct svr4_info
*info
= get_svr4_info ();
1565 /* Cause svr4_current_sos() to be run if it hasn't been already. */
1566 if (info
->main_lm_addr
== 0)
1567 solib_add (NULL
, 0, ¤t_target
, auto_solib_add
);
1569 /* svr4_current_sos() will set main_lm_addr for the main executable. */
1570 if (objfile
== symfile_objfile
)
1571 return info
->main_lm_addr
;
1573 /* The other link map addresses may be found by examining the list
1574 of shared libraries. */
1575 for (so
= master_so_list (); so
; so
= so
->next
)
1576 if (so
->objfile
== objfile
)
1577 return so
->lm_info
->lm_addr
;
1583 /* On some systems, the only way to recognize the link map entry for
1584 the main executable file is by looking at its name. Return
1585 non-zero iff SONAME matches one of the known main executable names. */
1588 match_main (const char *soname
)
1590 const char * const *mainp
;
1592 for (mainp
= main_name_list
; *mainp
!= NULL
; mainp
++)
1594 if (strcmp (soname
, *mainp
) == 0)
1601 /* Return 1 if PC lies in the dynamic symbol resolution code of the
1602 SVR4 run time loader. */
1605 svr4_in_dynsym_resolve_code (CORE_ADDR pc
)
1607 struct svr4_info
*info
= get_svr4_info ();
1609 return ((pc
>= info
->interp_text_sect_low
1610 && pc
< info
->interp_text_sect_high
)
1611 || (pc
>= info
->interp_plt_sect_low
1612 && pc
< info
->interp_plt_sect_high
)
1613 || in_plt_section (pc
)
1614 || in_gnu_ifunc_stub (pc
));
1617 /* Given an executable's ABFD and target, compute the entry-point
1621 exec_entry_point (struct bfd
*abfd
, struct target_ops
*targ
)
1625 /* KevinB wrote ... for most targets, the address returned by
1626 bfd_get_start_address() is the entry point for the start
1627 function. But, for some targets, bfd_get_start_address() returns
1628 the address of a function descriptor from which the entry point
1629 address may be extracted. This address is extracted by
1630 gdbarch_convert_from_func_ptr_addr(). The method
1631 gdbarch_convert_from_func_ptr_addr() is the merely the identify
1632 function for targets which don't use function descriptors. */
1633 addr
= gdbarch_convert_from_func_ptr_addr (target_gdbarch (),
1634 bfd_get_start_address (abfd
),
1636 return gdbarch_addr_bits_remove (target_gdbarch (), addr
);
1639 /* A probe and its associated action. */
1641 struct probe_and_action
1644 struct probe
*probe
;
1646 /* The relocated address of the probe. */
1650 enum probe_action action
;
1653 /* Returns a hash code for the probe_and_action referenced by p. */
1656 hash_probe_and_action (const void *p
)
1658 const struct probe_and_action
*pa
= p
;
1660 return (hashval_t
) pa
->address
;
1663 /* Returns non-zero if the probe_and_actions referenced by p1 and p2
1667 equal_probe_and_action (const void *p1
, const void *p2
)
1669 const struct probe_and_action
*pa1
= p1
;
1670 const struct probe_and_action
*pa2
= p2
;
1672 return pa1
->address
== pa2
->address
;
1675 /* Register a solib event probe and its associated action in the
1679 register_solib_event_probe (struct probe
*probe
, CORE_ADDR address
,
1680 enum probe_action action
)
1682 struct svr4_info
*info
= get_svr4_info ();
1683 struct probe_and_action lookup
, *pa
;
1686 /* Create the probes table, if necessary. */
1687 if (info
->probes_table
== NULL
)
1688 info
->probes_table
= htab_create_alloc (1, hash_probe_and_action
,
1689 equal_probe_and_action
,
1690 xfree
, xcalloc
, xfree
);
1692 lookup
.probe
= probe
;
1693 lookup
.address
= address
;
1694 slot
= htab_find_slot (info
->probes_table
, &lookup
, INSERT
);
1695 gdb_assert (*slot
== HTAB_EMPTY_ENTRY
);
1697 pa
= XCNEW (struct probe_and_action
);
1699 pa
->address
= address
;
1700 pa
->action
= action
;
1705 /* Get the solib event probe at the specified location, and the
1706 action associated with it. Returns NULL if no solib event probe
1709 static struct probe_and_action
*
1710 solib_event_probe_at (struct svr4_info
*info
, CORE_ADDR address
)
1712 struct probe_and_action lookup
;
1715 lookup
.address
= address
;
1716 slot
= htab_find_slot (info
->probes_table
, &lookup
, NO_INSERT
);
1721 return (struct probe_and_action
*) *slot
;
1724 /* Decide what action to take when the specified solib event probe is
1727 static enum probe_action
1728 solib_event_probe_action (struct probe_and_action
*pa
)
1730 enum probe_action action
;
1731 unsigned probe_argc
;
1732 struct frame_info
*frame
= get_current_frame ();
1734 action
= pa
->action
;
1735 if (action
== DO_NOTHING
|| action
== PROBES_INTERFACE_FAILED
)
1738 gdb_assert (action
== FULL_RELOAD
|| action
== UPDATE_OR_RELOAD
);
1740 /* Check that an appropriate number of arguments has been supplied.
1742 arg0: Lmid_t lmid (mandatory)
1743 arg1: struct r_debug *debug_base (mandatory)
1744 arg2: struct link_map *new (optional, for incremental updates) */
1745 probe_argc
= get_probe_argument_count (pa
->probe
, frame
);
1746 if (probe_argc
== 2)
1747 action
= FULL_RELOAD
;
1748 else if (probe_argc
< 2)
1749 action
= PROBES_INTERFACE_FAILED
;
1754 /* Populate the shared object list by reading the entire list of
1755 shared objects from the inferior. Handle special cases relating
1756 to the first elements of the list. Returns nonzero on success. */
1759 solist_update_full (struct svr4_info
*info
)
1761 free_solib_list (info
);
1762 info
->solib_list
= svr4_current_sos_direct (info
);
1767 /* Update the shared object list starting from the link-map entry
1768 passed by the linker in the probe's third argument. Returns
1769 nonzero if the list was successfully updated, or zero to indicate
1773 solist_update_incremental (struct svr4_info
*info
, CORE_ADDR lm
)
1775 struct so_list
*tail
;
1778 /* svr4_current_sos_direct contains logic to handle a number of
1779 special cases relating to the first elements of the list. To
1780 avoid duplicating this logic we defer to solist_update_full
1781 if the list is empty. */
1782 if (info
->solib_list
== NULL
)
1785 /* Fall back to a full update if we are using a remote target
1786 that does not support incremental transfers. */
1787 if (info
->using_xfer
&& !target_augmented_libraries_svr4_read ())
1790 /* Walk to the end of the list. */
1791 for (tail
= info
->solib_list
; tail
->next
!= NULL
; tail
= tail
->next
)
1793 prev_lm
= tail
->lm_info
->lm_addr
;
1795 /* Read the new objects. */
1796 if (info
->using_xfer
)
1798 struct svr4_library_list library_list
;
1801 xsnprintf (annex
, sizeof (annex
), "start=%s;prev=%s",
1802 phex_nz (lm
, sizeof (lm
)),
1803 phex_nz (prev_lm
, sizeof (prev_lm
)));
1804 if (!svr4_current_sos_via_xfer_libraries (&library_list
, annex
))
1807 tail
->next
= library_list
.head
;
1811 struct so_list
**link
= &tail
->next
;
1813 /* IGNORE_FIRST may safely be set to zero here because the
1814 above check and deferral to solist_update_full ensures
1815 that this call to svr4_read_so_list will never see the
1817 if (!svr4_read_so_list (lm
, prev_lm
, &link
, 0))
1824 /* Disable the probes-based linker interface and revert to the
1825 original interface. We don't reset the breakpoints as the
1826 ones set up for the probes-based interface are adequate. */
1829 disable_probes_interface_cleanup (void *arg
)
1831 struct svr4_info
*info
= get_svr4_info ();
1833 warning (_("Probes-based dynamic linker interface failed.\n"
1834 "Reverting to original interface.\n"));
1836 free_probes_table (info
);
1837 free_solib_list (info
);
1840 /* Update the solib list as appropriate when using the
1841 probes-based linker interface. Do nothing if using the
1842 standard interface. */
1845 svr4_handle_solib_event (void)
1847 struct svr4_info
*info
= get_svr4_info ();
1848 struct probe_and_action
*pa
;
1849 enum probe_action action
;
1850 struct cleanup
*old_chain
, *usm_chain
;
1852 CORE_ADDR pc
, debug_base
, lm
= 0;
1854 struct frame_info
*frame
= get_current_frame ();
1856 /* Do nothing if not using the probes interface. */
1857 if (info
->probes_table
== NULL
)
1860 /* If anything goes wrong we revert to the original linker
1862 old_chain
= make_cleanup (disable_probes_interface_cleanup
, NULL
);
1864 pc
= regcache_read_pc (get_current_regcache ());
1865 pa
= solib_event_probe_at (info
, pc
);
1868 do_cleanups (old_chain
);
1872 action
= solib_event_probe_action (pa
);
1873 if (action
== PROBES_INTERFACE_FAILED
)
1875 do_cleanups (old_chain
);
1879 if (action
== DO_NOTHING
)
1881 discard_cleanups (old_chain
);
1885 /* evaluate_probe_argument looks up symbols in the dynamic linker
1886 using find_pc_section. find_pc_section is accelerated by a cache
1887 called the section map. The section map is invalidated every
1888 time a shared library is loaded or unloaded, and if the inferior
1889 is generating a lot of shared library events then the section map
1890 will be updated every time svr4_handle_solib_event is called.
1891 We called find_pc_section in svr4_create_solib_event_breakpoints,
1892 so we can guarantee that the dynamic linker's sections are in the
1893 section map. We can therefore inhibit section map updates across
1894 these calls to evaluate_probe_argument and save a lot of time. */
1895 inhibit_section_map_updates (current_program_space
);
1896 usm_chain
= make_cleanup (resume_section_map_updates_cleanup
,
1897 current_program_space
);
1899 val
= evaluate_probe_argument (pa
->probe
, 1, frame
);
1902 do_cleanups (old_chain
);
1906 debug_base
= value_as_address (val
);
1907 if (debug_base
== 0)
1909 do_cleanups (old_chain
);
1913 /* Always locate the debug struct, in case it moved. */
1914 info
->debug_base
= 0;
1915 if (locate_base (info
) == 0)
1917 do_cleanups (old_chain
);
1921 /* GDB does not currently support libraries loaded via dlmopen
1922 into namespaces other than the initial one. We must ignore
1923 any namespace other than the initial namespace here until
1924 support for this is added to GDB. */
1925 if (debug_base
!= info
->debug_base
)
1926 action
= DO_NOTHING
;
1928 if (action
== UPDATE_OR_RELOAD
)
1930 val
= evaluate_probe_argument (pa
->probe
, 2, frame
);
1932 lm
= value_as_address (val
);
1935 action
= FULL_RELOAD
;
1938 /* Resume section map updates. */
1939 do_cleanups (usm_chain
);
1941 if (action
== UPDATE_OR_RELOAD
)
1943 if (!solist_update_incremental (info
, lm
))
1944 action
= FULL_RELOAD
;
1947 if (action
== FULL_RELOAD
)
1949 if (!solist_update_full (info
))
1951 do_cleanups (old_chain
);
1956 discard_cleanups (old_chain
);
1959 /* Helper function for svr4_update_solib_event_breakpoints. */
1962 svr4_update_solib_event_breakpoint (struct breakpoint
*b
, void *arg
)
1964 struct bp_location
*loc
;
1966 if (b
->type
!= bp_shlib_event
)
1968 /* Continue iterating. */
1972 for (loc
= b
->loc
; loc
!= NULL
; loc
= loc
->next
)
1974 struct svr4_info
*info
;
1975 struct probe_and_action
*pa
;
1977 info
= program_space_data (loc
->pspace
, solib_svr4_pspace_data
);
1978 if (info
== NULL
|| info
->probes_table
== NULL
)
1981 pa
= solib_event_probe_at (info
, loc
->address
);
1985 if (pa
->action
== DO_NOTHING
)
1987 if (b
->enable_state
== bp_disabled
&& stop_on_solib_events
)
1988 enable_breakpoint (b
);
1989 else if (b
->enable_state
== bp_enabled
&& !stop_on_solib_events
)
1990 disable_breakpoint (b
);
1996 /* Continue iterating. */
2000 /* Enable or disable optional solib event breakpoints as appropriate.
2001 Called whenever stop_on_solib_events is changed. */
2004 svr4_update_solib_event_breakpoints (void)
2006 iterate_over_breakpoints (svr4_update_solib_event_breakpoint
, NULL
);
2009 /* Create and register solib event breakpoints. PROBES is an array
2010 of NUM_PROBES elements, each of which is vector of probes. A
2011 solib event breakpoint will be created and registered for each
2015 svr4_create_probe_breakpoints (struct gdbarch
*gdbarch
,
2016 VEC (probe_p
) **probes
,
2017 struct objfile
*objfile
)
2021 for (i
= 0; i
< NUM_PROBES
; i
++)
2023 enum probe_action action
= probe_info
[i
].action
;
2024 struct probe
*probe
;
2028 VEC_iterate (probe_p
, probes
[i
], ix
, probe
);
2031 CORE_ADDR address
= get_probe_address (probe
, objfile
);
2033 create_solib_event_breakpoint (gdbarch
, address
);
2034 register_solib_event_probe (probe
, address
, action
);
2038 svr4_update_solib_event_breakpoints ();
2041 /* Both the SunOS and the SVR4 dynamic linkers call a marker function
2042 before and after mapping and unmapping shared libraries. The sole
2043 purpose of this method is to allow debuggers to set a breakpoint so
2044 they can track these changes.
2046 Some versions of the glibc dynamic linker contain named probes
2047 to allow more fine grained stopping. Given the address of the
2048 original marker function, this function attempts to find these
2049 probes, and if found, sets breakpoints on those instead. If the
2050 probes aren't found, a single breakpoint is set on the original
2054 svr4_create_solib_event_breakpoints (struct gdbarch
*gdbarch
,
2057 struct obj_section
*os
;
2059 os
= find_pc_section (address
);
2064 for (with_prefix
= 0; with_prefix
<= 1; with_prefix
++)
2066 VEC (probe_p
) *probes
[NUM_PROBES
];
2067 int all_probes_found
= 1;
2068 int checked_can_use_probe_arguments
= 0;
2071 memset (probes
, 0, sizeof (probes
));
2072 for (i
= 0; i
< NUM_PROBES
; i
++)
2074 const char *name
= probe_info
[i
].name
;
2078 /* Fedora 17 and Red Hat Enterprise Linux 6.2-6.4
2079 shipped with an early version of the probes code in
2080 which the probes' names were prefixed with "rtld_"
2081 and the "map_failed" probe did not exist. The
2082 locations of the probes are otherwise the same, so
2083 we check for probes with prefixed names if probes
2084 with unprefixed names are not present. */
2087 xsnprintf (buf
, sizeof (buf
), "rtld_%s", name
);
2091 probes
[i
] = find_probes_in_objfile (os
->objfile
, "rtld", name
);
2093 /* The "map_failed" probe did not exist in early
2094 versions of the probes code in which the probes'
2095 names were prefixed with "rtld_". */
2096 if (strcmp (name
, "rtld_map_failed") == 0)
2099 if (VEC_empty (probe_p
, probes
[i
]))
2101 all_probes_found
= 0;
2105 /* Ensure probe arguments can be evaluated. */
2106 if (!checked_can_use_probe_arguments
)
2108 p
= VEC_index (probe_p
, probes
[i
], 0);
2109 if (!can_evaluate_probe_arguments (p
))
2111 all_probes_found
= 0;
2114 checked_can_use_probe_arguments
= 1;
2118 if (all_probes_found
)
2119 svr4_create_probe_breakpoints (gdbarch
, probes
, os
->objfile
);
2121 for (i
= 0; i
< NUM_PROBES
; i
++)
2122 VEC_free (probe_p
, probes
[i
]);
2124 if (all_probes_found
)
2129 create_solib_event_breakpoint (gdbarch
, address
);
2132 /* Helper function for gdb_bfd_lookup_symbol. */
2135 cmp_name_and_sec_flags (asymbol
*sym
, void *data
)
2137 return (strcmp (sym
->name
, (const char *) data
) == 0
2138 && (sym
->section
->flags
& (SEC_CODE
| SEC_DATA
)) != 0);
2140 /* Arrange for dynamic linker to hit breakpoint.
2142 Both the SunOS and the SVR4 dynamic linkers have, as part of their
2143 debugger interface, support for arranging for the inferior to hit
2144 a breakpoint after mapping in the shared libraries. This function
2145 enables that breakpoint.
2147 For SunOS, there is a special flag location (in_debugger) which we
2148 set to 1. When the dynamic linker sees this flag set, it will set
2149 a breakpoint at a location known only to itself, after saving the
2150 original contents of that place and the breakpoint address itself,
2151 in it's own internal structures. When we resume the inferior, it
2152 will eventually take a SIGTRAP when it runs into the breakpoint.
2153 We handle this (in a different place) by restoring the contents of
2154 the breakpointed location (which is only known after it stops),
2155 chasing around to locate the shared libraries that have been
2156 loaded, then resuming.
2158 For SVR4, the debugger interface structure contains a member (r_brk)
2159 which is statically initialized at the time the shared library is
2160 built, to the offset of a function (_r_debug_state) which is guaran-
2161 teed to be called once before mapping in a library, and again when
2162 the mapping is complete. At the time we are examining this member,
2163 it contains only the unrelocated offset of the function, so we have
2164 to do our own relocation. Later, when the dynamic linker actually
2165 runs, it relocates r_brk to be the actual address of _r_debug_state().
2167 The debugger interface structure also contains an enumeration which
2168 is set to either RT_ADD or RT_DELETE prior to changing the mapping,
2169 depending upon whether or not the library is being mapped or unmapped,
2170 and then set to RT_CONSISTENT after the library is mapped/unmapped. */
2173 enable_break (struct svr4_info
*info
, int from_tty
)
2175 struct bound_minimal_symbol msymbol
;
2176 const char * const *bkpt_namep
;
2177 asection
*interp_sect
;
2181 info
->interp_text_sect_low
= info
->interp_text_sect_high
= 0;
2182 info
->interp_plt_sect_low
= info
->interp_plt_sect_high
= 0;
2184 /* If we already have a shared library list in the target, and
2185 r_debug contains r_brk, set the breakpoint there - this should
2186 mean r_brk has already been relocated. Assume the dynamic linker
2187 is the object containing r_brk. */
2189 solib_add (NULL
, from_tty
, ¤t_target
, auto_solib_add
);
2191 if (info
->debug_base
&& solib_svr4_r_map (info
) != 0)
2192 sym_addr
= solib_svr4_r_brk (info
);
2196 struct obj_section
*os
;
2198 sym_addr
= gdbarch_addr_bits_remove
2199 (target_gdbarch (), gdbarch_convert_from_func_ptr_addr (target_gdbarch (),
2203 /* On at least some versions of Solaris there's a dynamic relocation
2204 on _r_debug.r_brk and SYM_ADDR may not be relocated yet, e.g., if
2205 we get control before the dynamic linker has self-relocated.
2206 Check if SYM_ADDR is in a known section, if it is assume we can
2207 trust its value. This is just a heuristic though, it could go away
2208 or be replaced if it's getting in the way.
2210 On ARM we need to know whether the ISA of rtld_db_dlactivity (or
2211 however it's spelled in your particular system) is ARM or Thumb.
2212 That knowledge is encoded in the address, if it's Thumb the low bit
2213 is 1. However, we've stripped that info above and it's not clear
2214 what all the consequences are of passing a non-addr_bits_remove'd
2215 address to svr4_create_solib_event_breakpoints. The call to
2216 find_pc_section verifies we know about the address and have some
2217 hope of computing the right kind of breakpoint to use (via
2218 symbol info). It does mean that GDB needs to be pointed at a
2219 non-stripped version of the dynamic linker in order to obtain
2220 information it already knows about. Sigh. */
2222 os
= find_pc_section (sym_addr
);
2225 /* Record the relocated start and end address of the dynamic linker
2226 text and plt section for svr4_in_dynsym_resolve_code. */
2228 CORE_ADDR load_addr
;
2230 tmp_bfd
= os
->objfile
->obfd
;
2231 load_addr
= ANOFFSET (os
->objfile
->section_offsets
,
2232 SECT_OFF_TEXT (os
->objfile
));
2234 interp_sect
= bfd_get_section_by_name (tmp_bfd
, ".text");
2237 info
->interp_text_sect_low
=
2238 bfd_section_vma (tmp_bfd
, interp_sect
) + load_addr
;
2239 info
->interp_text_sect_high
=
2240 info
->interp_text_sect_low
2241 + bfd_section_size (tmp_bfd
, interp_sect
);
2243 interp_sect
= bfd_get_section_by_name (tmp_bfd
, ".plt");
2246 info
->interp_plt_sect_low
=
2247 bfd_section_vma (tmp_bfd
, interp_sect
) + load_addr
;
2248 info
->interp_plt_sect_high
=
2249 info
->interp_plt_sect_low
2250 + bfd_section_size (tmp_bfd
, interp_sect
);
2253 svr4_create_solib_event_breakpoints (target_gdbarch (), sym_addr
);
2258 /* Find the program interpreter; if not found, warn the user and drop
2259 into the old breakpoint at symbol code. */
2260 interp_name
= find_program_interpreter ();
2263 CORE_ADDR load_addr
= 0;
2264 int load_addr_found
= 0;
2265 int loader_found_in_list
= 0;
2267 bfd
*tmp_bfd
= NULL
;
2268 struct target_ops
*tmp_bfd_target
;
2269 volatile struct gdb_exception ex
;
2273 /* Now we need to figure out where the dynamic linker was
2274 loaded so that we can load its symbols and place a breakpoint
2275 in the dynamic linker itself.
2277 This address is stored on the stack. However, I've been unable
2278 to find any magic formula to find it for Solaris (appears to
2279 be trivial on GNU/Linux). Therefore, we have to try an alternate
2280 mechanism to find the dynamic linker's base address. */
2282 TRY_CATCH (ex
, RETURN_MASK_ALL
)
2284 tmp_bfd
= solib_bfd_open (interp_name
);
2286 if (tmp_bfd
== NULL
)
2287 goto bkpt_at_symbol
;
2289 /* Now convert the TMP_BFD into a target. That way target, as
2290 well as BFD operations can be used. */
2291 tmp_bfd_target
= target_bfd_reopen (tmp_bfd
);
2292 /* target_bfd_reopen acquired its own reference, so we can
2293 release ours now. */
2294 gdb_bfd_unref (tmp_bfd
);
2296 /* On a running target, we can get the dynamic linker's base
2297 address from the shared library table. */
2298 so
= master_so_list ();
2301 if (svr4_same_1 (interp_name
, so
->so_original_name
))
2303 load_addr_found
= 1;
2304 loader_found_in_list
= 1;
2305 load_addr
= lm_addr_check (so
, tmp_bfd
);
2311 /* If we were not able to find the base address of the loader
2312 from our so_list, then try using the AT_BASE auxilliary entry. */
2313 if (!load_addr_found
)
2314 if (target_auxv_search (¤t_target
, AT_BASE
, &load_addr
) > 0)
2316 int addr_bit
= gdbarch_addr_bit (target_gdbarch ());
2318 /* Ensure LOAD_ADDR has proper sign in its possible upper bits so
2319 that `+ load_addr' will overflow CORE_ADDR width not creating
2320 invalid addresses like 0x101234567 for 32bit inferiors on 64bit
2323 if (addr_bit
< (sizeof (CORE_ADDR
) * HOST_CHAR_BIT
))
2325 CORE_ADDR space_size
= (CORE_ADDR
) 1 << addr_bit
;
2326 CORE_ADDR tmp_entry_point
= exec_entry_point (tmp_bfd
,
2329 gdb_assert (load_addr
< space_size
);
2331 /* TMP_ENTRY_POINT exceeding SPACE_SIZE would be for prelinked
2332 64bit ld.so with 32bit executable, it should not happen. */
2334 if (tmp_entry_point
< space_size
2335 && tmp_entry_point
+ load_addr
>= space_size
)
2336 load_addr
-= space_size
;
2339 load_addr_found
= 1;
2342 /* Otherwise we find the dynamic linker's base address by examining
2343 the current pc (which should point at the entry point for the
2344 dynamic linker) and subtracting the offset of the entry point.
2346 This is more fragile than the previous approaches, but is a good
2347 fallback method because it has actually been working well in
2349 if (!load_addr_found
)
2351 struct regcache
*regcache
2352 = get_thread_arch_regcache (inferior_ptid
, target_gdbarch ());
2354 load_addr
= (regcache_read_pc (regcache
)
2355 - exec_entry_point (tmp_bfd
, tmp_bfd_target
));
2358 if (!loader_found_in_list
)
2360 info
->debug_loader_name
= xstrdup (interp_name
);
2361 info
->debug_loader_offset_p
= 1;
2362 info
->debug_loader_offset
= load_addr
;
2363 solib_add (NULL
, from_tty
, ¤t_target
, auto_solib_add
);
2366 /* Record the relocated start and end address of the dynamic linker
2367 text and plt section for svr4_in_dynsym_resolve_code. */
2368 interp_sect
= bfd_get_section_by_name (tmp_bfd
, ".text");
2371 info
->interp_text_sect_low
=
2372 bfd_section_vma (tmp_bfd
, interp_sect
) + load_addr
;
2373 info
->interp_text_sect_high
=
2374 info
->interp_text_sect_low
2375 + bfd_section_size (tmp_bfd
, interp_sect
);
2377 interp_sect
= bfd_get_section_by_name (tmp_bfd
, ".plt");
2380 info
->interp_plt_sect_low
=
2381 bfd_section_vma (tmp_bfd
, interp_sect
) + load_addr
;
2382 info
->interp_plt_sect_high
=
2383 info
->interp_plt_sect_low
2384 + bfd_section_size (tmp_bfd
, interp_sect
);
2387 /* Now try to set a breakpoint in the dynamic linker. */
2388 for (bkpt_namep
= solib_break_names
; *bkpt_namep
!= NULL
; bkpt_namep
++)
2390 sym_addr
= gdb_bfd_lookup_symbol (tmp_bfd
, cmp_name_and_sec_flags
,
2391 (void *) *bkpt_namep
);
2397 /* Convert 'sym_addr' from a function pointer to an address.
2398 Because we pass tmp_bfd_target instead of the current
2399 target, this will always produce an unrelocated value. */
2400 sym_addr
= gdbarch_convert_from_func_ptr_addr (target_gdbarch (),
2404 /* We're done with both the temporary bfd and target. Closing
2405 the target closes the underlying bfd, because it holds the
2406 only remaining reference. */
2407 target_close (tmp_bfd_target
);
2411 svr4_create_solib_event_breakpoints (target_gdbarch (),
2412 load_addr
+ sym_addr
);
2413 xfree (interp_name
);
2417 /* For whatever reason we couldn't set a breakpoint in the dynamic
2418 linker. Warn and drop into the old code. */
2420 xfree (interp_name
);
2421 warning (_("Unable to find dynamic linker breakpoint function.\n"
2422 "GDB will be unable to debug shared library initializers\n"
2423 "and track explicitly loaded dynamic code."));
2426 /* Scan through the lists of symbols, trying to look up the symbol and
2427 set a breakpoint there. Terminate loop when we/if we succeed. */
2429 for (bkpt_namep
= solib_break_names
; *bkpt_namep
!= NULL
; bkpt_namep
++)
2431 msymbol
= lookup_minimal_symbol (*bkpt_namep
, NULL
, symfile_objfile
);
2432 if ((msymbol
.minsym
!= NULL
)
2433 && (BMSYMBOL_VALUE_ADDRESS (msymbol
) != 0))
2435 sym_addr
= BMSYMBOL_VALUE_ADDRESS (msymbol
);
2436 sym_addr
= gdbarch_convert_from_func_ptr_addr (target_gdbarch (),
2439 svr4_create_solib_event_breakpoints (target_gdbarch (), sym_addr
);
2444 if (interp_name
!= NULL
&& !current_inferior ()->attach_flag
)
2446 for (bkpt_namep
= bkpt_names
; *bkpt_namep
!= NULL
; bkpt_namep
++)
2448 msymbol
= lookup_minimal_symbol (*bkpt_namep
, NULL
, symfile_objfile
);
2449 if ((msymbol
.minsym
!= NULL
)
2450 && (BMSYMBOL_VALUE_ADDRESS (msymbol
) != 0))
2452 sym_addr
= BMSYMBOL_VALUE_ADDRESS (msymbol
);
2453 sym_addr
= gdbarch_convert_from_func_ptr_addr (target_gdbarch (),
2456 svr4_create_solib_event_breakpoints (target_gdbarch (), sym_addr
);
2464 /* Implement the "special_symbol_handling" target_so_ops method. */
2467 svr4_special_symbol_handling (void)
2469 /* Nothing to do. */
2472 /* Read the ELF program headers from ABFD. Return the contents and
2473 set *PHDRS_SIZE to the size of the program headers. */
2476 read_program_headers_from_bfd (bfd
*abfd
, int *phdrs_size
)
2478 Elf_Internal_Ehdr
*ehdr
;
2481 ehdr
= elf_elfheader (abfd
);
2483 *phdrs_size
= ehdr
->e_phnum
* ehdr
->e_phentsize
;
2484 if (*phdrs_size
== 0)
2487 buf
= xmalloc (*phdrs_size
);
2488 if (bfd_seek (abfd
, ehdr
->e_phoff
, SEEK_SET
) != 0
2489 || bfd_bread (buf
, *phdrs_size
, abfd
) != *phdrs_size
)
2498 /* Return 1 and fill *DISPLACEMENTP with detected PIE offset of inferior
2499 exec_bfd. Otherwise return 0.
2501 We relocate all of the sections by the same amount. This
2502 behavior is mandated by recent editions of the System V ABI.
2503 According to the System V Application Binary Interface,
2504 Edition 4.1, page 5-5:
2506 ... Though the system chooses virtual addresses for
2507 individual processes, it maintains the segments' relative
2508 positions. Because position-independent code uses relative
2509 addressesing between segments, the difference between
2510 virtual addresses in memory must match the difference
2511 between virtual addresses in the file. The difference
2512 between the virtual address of any segment in memory and
2513 the corresponding virtual address in the file is thus a
2514 single constant value for any one executable or shared
2515 object in a given process. This difference is the base
2516 address. One use of the base address is to relocate the
2517 memory image of the program during dynamic linking.
2519 The same language also appears in Edition 4.0 of the System V
2520 ABI and is left unspecified in some of the earlier editions.
2522 Decide if the objfile needs to be relocated. As indicated above, we will
2523 only be here when execution is stopped. But during attachment PC can be at
2524 arbitrary address therefore regcache_read_pc can be misleading (contrary to
2525 the auxv AT_ENTRY value). Moreover for executable with interpreter section
2526 regcache_read_pc would point to the interpreter and not the main executable.
2528 So, to summarize, relocations are necessary when the start address obtained
2529 from the executable is different from the address in auxv AT_ENTRY entry.
2531 [ The astute reader will note that we also test to make sure that
2532 the executable in question has the DYNAMIC flag set. It is my
2533 opinion that this test is unnecessary (undesirable even). It
2534 was added to avoid inadvertent relocation of an executable
2535 whose e_type member in the ELF header is not ET_DYN. There may
2536 be a time in the future when it is desirable to do relocations
2537 on other types of files as well in which case this condition
2538 should either be removed or modified to accomodate the new file
2539 type. - Kevin, Nov 2000. ] */
2542 svr4_exec_displacement (CORE_ADDR
*displacementp
)
2544 /* ENTRY_POINT is a possible function descriptor - before
2545 a call to gdbarch_convert_from_func_ptr_addr. */
2546 CORE_ADDR entry_point
, displacement
;
2548 if (exec_bfd
== NULL
)
2551 /* Therefore for ELF it is ET_EXEC and not ET_DYN. Both shared libraries
2552 being executed themselves and PIE (Position Independent Executable)
2553 executables are ET_DYN. */
2555 if ((bfd_get_file_flags (exec_bfd
) & DYNAMIC
) == 0)
2558 if (target_auxv_search (¤t_target
, AT_ENTRY
, &entry_point
) <= 0)
2561 displacement
= entry_point
- bfd_get_start_address (exec_bfd
);
2563 /* Verify the DISPLACEMENT candidate complies with the required page
2564 alignment. It is cheaper than the program headers comparison below. */
2566 if (bfd_get_flavour (exec_bfd
) == bfd_target_elf_flavour
)
2568 const struct elf_backend_data
*elf
= get_elf_backend_data (exec_bfd
);
2570 /* p_align of PT_LOAD segments does not specify any alignment but
2571 only congruency of addresses:
2572 p_offset % p_align == p_vaddr % p_align
2573 Kernel is free to load the executable with lower alignment. */
2575 if ((displacement
& (elf
->minpagesize
- 1)) != 0)
2579 /* Verify that the auxilliary vector describes the same file as exec_bfd, by
2580 comparing their program headers. If the program headers in the auxilliary
2581 vector do not match the program headers in the executable, then we are
2582 looking at a different file than the one used by the kernel - for
2583 instance, "gdb program" connected to "gdbserver :PORT ld.so program". */
2585 if (bfd_get_flavour (exec_bfd
) == bfd_target_elf_flavour
)
2587 /* Be optimistic and clear OK only if GDB was able to verify the headers
2588 really do not match. */
2589 int phdrs_size
, phdrs2_size
, ok
= 1;
2590 gdb_byte
*buf
, *buf2
;
2593 buf
= read_program_header (-1, &phdrs_size
, &arch_size
);
2594 buf2
= read_program_headers_from_bfd (exec_bfd
, &phdrs2_size
);
2595 if (buf
!= NULL
&& buf2
!= NULL
)
2597 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch ());
2599 /* We are dealing with three different addresses. EXEC_BFD
2600 represents current address in on-disk file. target memory content
2601 may be different from EXEC_BFD as the file may have been prelinked
2602 to a different address after the executable has been loaded.
2603 Moreover the address of placement in target memory can be
2604 different from what the program headers in target memory say -
2605 this is the goal of PIE.
2607 Detected DISPLACEMENT covers both the offsets of PIE placement and
2608 possible new prelink performed after start of the program. Here
2609 relocate BUF and BUF2 just by the EXEC_BFD vs. target memory
2610 content offset for the verification purpose. */
2612 if (phdrs_size
!= phdrs2_size
2613 || bfd_get_arch_size (exec_bfd
) != arch_size
)
2615 else if (arch_size
== 32
2616 && phdrs_size
>= sizeof (Elf32_External_Phdr
)
2617 && phdrs_size
% sizeof (Elf32_External_Phdr
) == 0)
2619 Elf_Internal_Ehdr
*ehdr2
= elf_tdata (exec_bfd
)->elf_header
;
2620 Elf_Internal_Phdr
*phdr2
= elf_tdata (exec_bfd
)->phdr
;
2621 CORE_ADDR displacement
= 0;
2624 /* DISPLACEMENT could be found more easily by the difference of
2625 ehdr2->e_entry. But we haven't read the ehdr yet, and we
2626 already have enough information to compute that displacement
2627 with what we've read. */
2629 for (i
= 0; i
< ehdr2
->e_phnum
; i
++)
2630 if (phdr2
[i
].p_type
== PT_LOAD
)
2632 Elf32_External_Phdr
*phdrp
;
2633 gdb_byte
*buf_vaddr_p
, *buf_paddr_p
;
2634 CORE_ADDR vaddr
, paddr
;
2635 CORE_ADDR displacement_vaddr
= 0;
2636 CORE_ADDR displacement_paddr
= 0;
2638 phdrp
= &((Elf32_External_Phdr
*) buf
)[i
];
2639 buf_vaddr_p
= (gdb_byte
*) &phdrp
->p_vaddr
;
2640 buf_paddr_p
= (gdb_byte
*) &phdrp
->p_paddr
;
2642 vaddr
= extract_unsigned_integer (buf_vaddr_p
, 4,
2644 displacement_vaddr
= vaddr
- phdr2
[i
].p_vaddr
;
2646 paddr
= extract_unsigned_integer (buf_paddr_p
, 4,
2648 displacement_paddr
= paddr
- phdr2
[i
].p_paddr
;
2650 if (displacement_vaddr
== displacement_paddr
)
2651 displacement
= displacement_vaddr
;
2656 /* Now compare BUF and BUF2 with optional DISPLACEMENT. */
2658 for (i
= 0; i
< phdrs_size
/ sizeof (Elf32_External_Phdr
); i
++)
2660 Elf32_External_Phdr
*phdrp
;
2661 Elf32_External_Phdr
*phdr2p
;
2662 gdb_byte
*buf_vaddr_p
, *buf_paddr_p
;
2663 CORE_ADDR vaddr
, paddr
;
2664 asection
*plt2_asect
;
2666 phdrp
= &((Elf32_External_Phdr
*) buf
)[i
];
2667 buf_vaddr_p
= (gdb_byte
*) &phdrp
->p_vaddr
;
2668 buf_paddr_p
= (gdb_byte
*) &phdrp
->p_paddr
;
2669 phdr2p
= &((Elf32_External_Phdr
*) buf2
)[i
];
2671 /* PT_GNU_STACK is an exception by being never relocated by
2672 prelink as its addresses are always zero. */
2674 if (memcmp (phdrp
, phdr2p
, sizeof (*phdrp
)) == 0)
2677 /* Check also other adjustment combinations - PR 11786. */
2679 vaddr
= extract_unsigned_integer (buf_vaddr_p
, 4,
2681 vaddr
-= displacement
;
2682 store_unsigned_integer (buf_vaddr_p
, 4, byte_order
, vaddr
);
2684 paddr
= extract_unsigned_integer (buf_paddr_p
, 4,
2686 paddr
-= displacement
;
2687 store_unsigned_integer (buf_paddr_p
, 4, byte_order
, paddr
);
2689 if (memcmp (phdrp
, phdr2p
, sizeof (*phdrp
)) == 0)
2692 /* Strip modifies the flags and alignment of PT_GNU_RELRO.
2693 CentOS-5 has problems with filesz, memsz as well.
2695 if (phdr2
[i
].p_type
== PT_GNU_RELRO
)
2697 Elf32_External_Phdr tmp_phdr
= *phdrp
;
2698 Elf32_External_Phdr tmp_phdr2
= *phdr2p
;
2700 memset (tmp_phdr
.p_filesz
, 0, 4);
2701 memset (tmp_phdr
.p_memsz
, 0, 4);
2702 memset (tmp_phdr
.p_flags
, 0, 4);
2703 memset (tmp_phdr
.p_align
, 0, 4);
2704 memset (tmp_phdr2
.p_filesz
, 0, 4);
2705 memset (tmp_phdr2
.p_memsz
, 0, 4);
2706 memset (tmp_phdr2
.p_flags
, 0, 4);
2707 memset (tmp_phdr2
.p_align
, 0, 4);
2709 if (memcmp (&tmp_phdr
, &tmp_phdr2
, sizeof (tmp_phdr
))
2714 /* prelink can convert .plt SHT_NOBITS to SHT_PROGBITS. */
2715 plt2_asect
= bfd_get_section_by_name (exec_bfd
, ".plt");
2719 gdb_byte
*buf_filesz_p
= (gdb_byte
*) &phdrp
->p_filesz
;
2722 content2
= (bfd_get_section_flags (exec_bfd
, plt2_asect
)
2723 & SEC_HAS_CONTENTS
) != 0;
2725 filesz
= extract_unsigned_integer (buf_filesz_p
, 4,
2728 /* PLT2_ASECT is from on-disk file (exec_bfd) while
2729 FILESZ is from the in-memory image. */
2731 filesz
+= bfd_get_section_size (plt2_asect
);
2733 filesz
-= bfd_get_section_size (plt2_asect
);
2735 store_unsigned_integer (buf_filesz_p
, 4, byte_order
,
2738 if (memcmp (phdrp
, phdr2p
, sizeof (*phdrp
)) == 0)
2746 else if (arch_size
== 64
2747 && phdrs_size
>= sizeof (Elf64_External_Phdr
)
2748 && phdrs_size
% sizeof (Elf64_External_Phdr
) == 0)
2750 Elf_Internal_Ehdr
*ehdr2
= elf_tdata (exec_bfd
)->elf_header
;
2751 Elf_Internal_Phdr
*phdr2
= elf_tdata (exec_bfd
)->phdr
;
2752 CORE_ADDR displacement
= 0;
2755 /* DISPLACEMENT could be found more easily by the difference of
2756 ehdr2->e_entry. But we haven't read the ehdr yet, and we
2757 already have enough information to compute that displacement
2758 with what we've read. */
2760 for (i
= 0; i
< ehdr2
->e_phnum
; i
++)
2761 if (phdr2
[i
].p_type
== PT_LOAD
)
2763 Elf64_External_Phdr
*phdrp
;
2764 gdb_byte
*buf_vaddr_p
, *buf_paddr_p
;
2765 CORE_ADDR vaddr
, paddr
;
2766 CORE_ADDR displacement_vaddr
= 0;
2767 CORE_ADDR displacement_paddr
= 0;
2769 phdrp
= &((Elf64_External_Phdr
*) buf
)[i
];
2770 buf_vaddr_p
= (gdb_byte
*) &phdrp
->p_vaddr
;
2771 buf_paddr_p
= (gdb_byte
*) &phdrp
->p_paddr
;
2773 vaddr
= extract_unsigned_integer (buf_vaddr_p
, 8,
2775 displacement_vaddr
= vaddr
- phdr2
[i
].p_vaddr
;
2777 paddr
= extract_unsigned_integer (buf_paddr_p
, 8,
2779 displacement_paddr
= paddr
- phdr2
[i
].p_paddr
;
2781 if (displacement_vaddr
== displacement_paddr
)
2782 displacement
= displacement_vaddr
;
2787 /* Now compare BUF and BUF2 with optional DISPLACEMENT. */
2789 for (i
= 0; i
< phdrs_size
/ sizeof (Elf64_External_Phdr
); i
++)
2791 Elf64_External_Phdr
*phdrp
;
2792 Elf64_External_Phdr
*phdr2p
;
2793 gdb_byte
*buf_vaddr_p
, *buf_paddr_p
;
2794 CORE_ADDR vaddr
, paddr
;
2795 asection
*plt2_asect
;
2797 phdrp
= &((Elf64_External_Phdr
*) buf
)[i
];
2798 buf_vaddr_p
= (gdb_byte
*) &phdrp
->p_vaddr
;
2799 buf_paddr_p
= (gdb_byte
*) &phdrp
->p_paddr
;
2800 phdr2p
= &((Elf64_External_Phdr
*) buf2
)[i
];
2802 /* PT_GNU_STACK is an exception by being never relocated by
2803 prelink as its addresses are always zero. */
2805 if (memcmp (phdrp
, phdr2p
, sizeof (*phdrp
)) == 0)
2808 /* Check also other adjustment combinations - PR 11786. */
2810 vaddr
= extract_unsigned_integer (buf_vaddr_p
, 8,
2812 vaddr
-= displacement
;
2813 store_unsigned_integer (buf_vaddr_p
, 8, byte_order
, vaddr
);
2815 paddr
= extract_unsigned_integer (buf_paddr_p
, 8,
2817 paddr
-= displacement
;
2818 store_unsigned_integer (buf_paddr_p
, 8, byte_order
, paddr
);
2820 if (memcmp (phdrp
, phdr2p
, sizeof (*phdrp
)) == 0)
2823 /* Strip modifies the flags and alignment of PT_GNU_RELRO.
2824 CentOS-5 has problems with filesz, memsz as well.
2826 if (phdr2
[i
].p_type
== PT_GNU_RELRO
)
2828 Elf64_External_Phdr tmp_phdr
= *phdrp
;
2829 Elf64_External_Phdr tmp_phdr2
= *phdr2p
;
2831 memset (tmp_phdr
.p_filesz
, 0, 8);
2832 memset (tmp_phdr
.p_memsz
, 0, 8);
2833 memset (tmp_phdr
.p_flags
, 0, 4);
2834 memset (tmp_phdr
.p_align
, 0, 8);
2835 memset (tmp_phdr2
.p_filesz
, 0, 8);
2836 memset (tmp_phdr2
.p_memsz
, 0, 8);
2837 memset (tmp_phdr2
.p_flags
, 0, 4);
2838 memset (tmp_phdr2
.p_align
, 0, 8);
2840 if (memcmp (&tmp_phdr
, &tmp_phdr2
, sizeof (tmp_phdr
))
2845 /* prelink can convert .plt SHT_NOBITS to SHT_PROGBITS. */
2846 plt2_asect
= bfd_get_section_by_name (exec_bfd
, ".plt");
2850 gdb_byte
*buf_filesz_p
= (gdb_byte
*) &phdrp
->p_filesz
;
2853 content2
= (bfd_get_section_flags (exec_bfd
, plt2_asect
)
2854 & SEC_HAS_CONTENTS
) != 0;
2856 filesz
= extract_unsigned_integer (buf_filesz_p
, 8,
2859 /* PLT2_ASECT is from on-disk file (exec_bfd) while
2860 FILESZ is from the in-memory image. */
2862 filesz
+= bfd_get_section_size (plt2_asect
);
2864 filesz
-= bfd_get_section_size (plt2_asect
);
2866 store_unsigned_integer (buf_filesz_p
, 8, byte_order
,
2869 if (memcmp (phdrp
, phdr2p
, sizeof (*phdrp
)) == 0)
2890 /* It can be printed repeatedly as there is no easy way to check
2891 the executable symbols/file has been already relocated to
2894 printf_unfiltered (_("Using PIE (Position Independent Executable) "
2895 "displacement %s for \"%s\".\n"),
2896 paddress (target_gdbarch (), displacement
),
2897 bfd_get_filename (exec_bfd
));
2900 *displacementp
= displacement
;
2904 /* Relocate the main executable. This function should be called upon
2905 stopping the inferior process at the entry point to the program.
2906 The entry point from BFD is compared to the AT_ENTRY of AUXV and if they are
2907 different, the main executable is relocated by the proper amount. */
2910 svr4_relocate_main_executable (void)
2912 CORE_ADDR displacement
;
2914 /* If we are re-running this executable, SYMFILE_OBJFILE->SECTION_OFFSETS
2915 probably contains the offsets computed using the PIE displacement
2916 from the previous run, which of course are irrelevant for this run.
2917 So we need to determine the new PIE displacement and recompute the
2918 section offsets accordingly, even if SYMFILE_OBJFILE->SECTION_OFFSETS
2919 already contains pre-computed offsets.
2921 If we cannot compute the PIE displacement, either:
2923 - The executable is not PIE.
2925 - SYMFILE_OBJFILE does not match the executable started in the target.
2926 This can happen for main executable symbols loaded at the host while
2927 `ld.so --ld-args main-executable' is loaded in the target.
2929 Then we leave the section offsets untouched and use them as is for
2932 - These section offsets were properly reset earlier, and thus
2933 already contain the correct values. This can happen for instance
2934 when reconnecting via the remote protocol to a target that supports
2935 the `qOffsets' packet.
2937 - The section offsets were not reset earlier, and the best we can
2938 hope is that the old offsets are still applicable to the new run. */
2940 if (! svr4_exec_displacement (&displacement
))
2943 /* Even DISPLACEMENT 0 is a valid new difference of in-memory vs. in-file
2946 if (symfile_objfile
)
2948 struct section_offsets
*new_offsets
;
2951 new_offsets
= alloca (symfile_objfile
->num_sections
2952 * sizeof (*new_offsets
));
2954 for (i
= 0; i
< symfile_objfile
->num_sections
; i
++)
2955 new_offsets
->offsets
[i
] = displacement
;
2957 objfile_relocate (symfile_objfile
, new_offsets
);
2963 for (asect
= exec_bfd
->sections
; asect
!= NULL
; asect
= asect
->next
)
2964 exec_set_section_address (bfd_get_filename (exec_bfd
), asect
->index
,
2965 (bfd_section_vma (exec_bfd
, asect
)
2970 /* Implement the "create_inferior_hook" target_solib_ops method.
2972 For SVR4 executables, this first instruction is either the first
2973 instruction in the dynamic linker (for dynamically linked
2974 executables) or the instruction at "start" for statically linked
2975 executables. For dynamically linked executables, the system
2976 first exec's /lib/libc.so.N, which contains the dynamic linker,
2977 and starts it running. The dynamic linker maps in any needed
2978 shared libraries, maps in the actual user executable, and then
2979 jumps to "start" in the user executable.
2981 We can arrange to cooperate with the dynamic linker to discover the
2982 names of shared libraries that are dynamically linked, and the base
2983 addresses to which they are linked.
2985 This function is responsible for discovering those names and
2986 addresses, and saving sufficient information about them to allow
2987 their symbols to be read at a later time. */
2990 svr4_solib_create_inferior_hook (int from_tty
)
2992 struct svr4_info
*info
;
2994 info
= get_svr4_info ();
2996 /* Clear the probes-based interface's state. */
2997 free_probes_table (info
);
2998 free_solib_list (info
);
3000 /* Relocate the main executable if necessary. */
3001 svr4_relocate_main_executable ();
3003 /* No point setting a breakpoint in the dynamic linker if we can't
3004 hit it (e.g., a core file, or a trace file). */
3005 if (!target_has_execution
)
3008 if (!svr4_have_link_map_offsets ())
3011 if (!enable_break (info
, from_tty
))
3016 svr4_clear_solib (void)
3018 struct svr4_info
*info
;
3020 info
= get_svr4_info ();
3021 info
->debug_base
= 0;
3022 info
->debug_loader_offset_p
= 0;
3023 info
->debug_loader_offset
= 0;
3024 xfree (info
->debug_loader_name
);
3025 info
->debug_loader_name
= NULL
;
3028 /* Clear any bits of ADDR that wouldn't fit in a target-format
3029 data pointer. "Data pointer" here refers to whatever sort of
3030 address the dynamic linker uses to manage its sections. At the
3031 moment, we don't support shared libraries on any processors where
3032 code and data pointers are different sizes.
3034 This isn't really the right solution. What we really need here is
3035 a way to do arithmetic on CORE_ADDR values that respects the
3036 natural pointer/address correspondence. (For example, on the MIPS,
3037 converting a 32-bit pointer to a 64-bit CORE_ADDR requires you to
3038 sign-extend the value. There, simply truncating the bits above
3039 gdbarch_ptr_bit, as we do below, is no good.) This should probably
3040 be a new gdbarch method or something. */
3042 svr4_truncate_ptr (CORE_ADDR addr
)
3044 if (gdbarch_ptr_bit (target_gdbarch ()) == sizeof (CORE_ADDR
) * 8)
3045 /* We don't need to truncate anything, and the bit twiddling below
3046 will fail due to overflow problems. */
3049 return addr
& (((CORE_ADDR
) 1 << gdbarch_ptr_bit (target_gdbarch ())) - 1);
3054 svr4_relocate_section_addresses (struct so_list
*so
,
3055 struct target_section
*sec
)
3057 bfd
*abfd
= sec
->the_bfd_section
->owner
;
3059 sec
->addr
= svr4_truncate_ptr (sec
->addr
+ lm_addr_check (so
, abfd
));
3060 sec
->endaddr
= svr4_truncate_ptr (sec
->endaddr
+ lm_addr_check (so
, abfd
));
3064 /* Architecture-specific operations. */
3066 /* Per-architecture data key. */
3067 static struct gdbarch_data
*solib_svr4_data
;
3069 struct solib_svr4_ops
3071 /* Return a description of the layout of `struct link_map'. */
3072 struct link_map_offsets
*(*fetch_link_map_offsets
)(void);
3075 /* Return a default for the architecture-specific operations. */
3078 solib_svr4_init (struct obstack
*obstack
)
3080 struct solib_svr4_ops
*ops
;
3082 ops
= OBSTACK_ZALLOC (obstack
, struct solib_svr4_ops
);
3083 ops
->fetch_link_map_offsets
= NULL
;
3087 /* Set the architecture-specific `struct link_map_offsets' fetcher for
3088 GDBARCH to FLMO. Also, install SVR4 solib_ops into GDBARCH. */
3091 set_solib_svr4_fetch_link_map_offsets (struct gdbarch
*gdbarch
,
3092 struct link_map_offsets
*(*flmo
) (void))
3094 struct solib_svr4_ops
*ops
= gdbarch_data (gdbarch
, solib_svr4_data
);
3096 ops
->fetch_link_map_offsets
= flmo
;
3098 set_solib_ops (gdbarch
, &svr4_so_ops
);
3101 /* Fetch a link_map_offsets structure using the architecture-specific
3102 `struct link_map_offsets' fetcher. */
3104 static struct link_map_offsets
*
3105 svr4_fetch_link_map_offsets (void)
3107 struct solib_svr4_ops
*ops
= gdbarch_data (target_gdbarch (), solib_svr4_data
);
3109 gdb_assert (ops
->fetch_link_map_offsets
);
3110 return ops
->fetch_link_map_offsets ();
3113 /* Return 1 if a link map offset fetcher has been defined, 0 otherwise. */
3116 svr4_have_link_map_offsets (void)
3118 struct solib_svr4_ops
*ops
= gdbarch_data (target_gdbarch (), solib_svr4_data
);
3120 return (ops
->fetch_link_map_offsets
!= NULL
);
3124 /* Most OS'es that have SVR4-style ELF dynamic libraries define a
3125 `struct r_debug' and a `struct link_map' that are binary compatible
3126 with the origional SVR4 implementation. */
3128 /* Fetch (and possibly build) an appropriate `struct link_map_offsets'
3129 for an ILP32 SVR4 system. */
3131 struct link_map_offsets
*
3132 svr4_ilp32_fetch_link_map_offsets (void)
3134 static struct link_map_offsets lmo
;
3135 static struct link_map_offsets
*lmp
= NULL
;
3141 lmo
.r_version_offset
= 0;
3142 lmo
.r_version_size
= 4;
3143 lmo
.r_map_offset
= 4;
3144 lmo
.r_brk_offset
= 8;
3145 lmo
.r_ldsomap_offset
= 20;
3147 /* Everything we need is in the first 20 bytes. */
3148 lmo
.link_map_size
= 20;
3149 lmo
.l_addr_offset
= 0;
3150 lmo
.l_name_offset
= 4;
3151 lmo
.l_ld_offset
= 8;
3152 lmo
.l_next_offset
= 12;
3153 lmo
.l_prev_offset
= 16;
3159 /* Fetch (and possibly build) an appropriate `struct link_map_offsets'
3160 for an LP64 SVR4 system. */
3162 struct link_map_offsets
*
3163 svr4_lp64_fetch_link_map_offsets (void)
3165 static struct link_map_offsets lmo
;
3166 static struct link_map_offsets
*lmp
= NULL
;
3172 lmo
.r_version_offset
= 0;
3173 lmo
.r_version_size
= 4;
3174 lmo
.r_map_offset
= 8;
3175 lmo
.r_brk_offset
= 16;
3176 lmo
.r_ldsomap_offset
= 40;
3178 /* Everything we need is in the first 40 bytes. */
3179 lmo
.link_map_size
= 40;
3180 lmo
.l_addr_offset
= 0;
3181 lmo
.l_name_offset
= 8;
3182 lmo
.l_ld_offset
= 16;
3183 lmo
.l_next_offset
= 24;
3184 lmo
.l_prev_offset
= 32;
3191 struct target_so_ops svr4_so_ops
;
3193 /* Lookup global symbol for ELF DSOs linked with -Bsymbolic. Those DSOs have a
3194 different rule for symbol lookup. The lookup begins here in the DSO, not in
3195 the main executable. */
3197 static struct symbol
*
3198 elf_lookup_lib_symbol (struct objfile
*objfile
,
3200 const domain_enum domain
)
3204 if (objfile
== symfile_objfile
)
3208 /* OBJFILE should have been passed as the non-debug one. */
3209 gdb_assert (objfile
->separate_debug_objfile_backlink
== NULL
);
3211 abfd
= objfile
->obfd
;
3214 if (abfd
== NULL
|| scan_dyntag (DT_SYMBOLIC
, abfd
, NULL
) != 1)
3217 return lookup_global_symbol_from_objfile (objfile
, name
, domain
);
3220 extern initialize_file_ftype _initialize_svr4_solib
; /* -Wmissing-prototypes */
3223 _initialize_svr4_solib (void)
3225 solib_svr4_data
= gdbarch_data_register_pre_init (solib_svr4_init
);
3226 solib_svr4_pspace_data
3227 = register_program_space_data_with_cleanup (NULL
, svr4_pspace_data_cleanup
);
3229 svr4_so_ops
.relocate_section_addresses
= svr4_relocate_section_addresses
;
3230 svr4_so_ops
.free_so
= svr4_free_so
;
3231 svr4_so_ops
.clear_so
= svr4_clear_so
;
3232 svr4_so_ops
.clear_solib
= svr4_clear_solib
;
3233 svr4_so_ops
.solib_create_inferior_hook
= svr4_solib_create_inferior_hook
;
3234 svr4_so_ops
.special_symbol_handling
= svr4_special_symbol_handling
;
3235 svr4_so_ops
.current_sos
= svr4_current_sos
;
3236 svr4_so_ops
.open_symbol_file_object
= open_symbol_file_object
;
3237 svr4_so_ops
.in_dynsym_resolve_code
= svr4_in_dynsym_resolve_code
;
3238 svr4_so_ops
.bfd_open
= solib_bfd_open
;
3239 svr4_so_ops
.lookup_lib_global_symbol
= elf_lookup_lib_symbol
;
3240 svr4_so_ops
.same
= svr4_same
;
3241 svr4_so_ops
.keep_data_in_core
= svr4_keep_data_in_core
;
3242 svr4_so_ops
.update_breakpoints
= svr4_update_solib_event_breakpoints
;
3243 svr4_so_ops
.handle_event
= svr4_handle_solib_event
;