1 /* Handle SVR4 shared libraries for GDB, the GNU Debugger.
3 Copyright (C) 1990-2022 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"
36 #include "observable.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
);
53 static void probes_table_remove_objfile_probes (struct objfile
*objfile
);
54 static void svr4_iterate_over_objfiles_in_search_order (
55 struct gdbarch
*gdbarch
, iterate_over_objfiles_in_search_order_cb_ftype
*cb
,
56 void *cb_data
, struct objfile
*objfile
);
59 /* On SVR4 systems, a list of symbols in the dynamic linker where
60 GDB can try to place a breakpoint to monitor shared library
63 If none of these symbols are found, or other errors occur, then
64 SVR4 systems will fall back to using a symbol as the "startup
65 mapping complete" breakpoint address. */
67 static const char * const solib_break_names
[] =
73 "__dl_rtld_db_dlactivity",
79 static const char * const bkpt_names
[] =
87 static const char * const main_name_list
[] =
93 /* What to do when a probe stop occurs. */
97 /* Something went seriously wrong. Stop using probes and
98 revert to using the older interface. */
99 PROBES_INTERFACE_FAILED
,
101 /* No action is required. The shared object list is still
105 /* The shared object list should be reloaded entirely. */
108 /* Attempt to incrementally update the shared object list. If
109 the update fails or is not possible, fall back to reloading
114 /* A probe's name and its associated action. */
118 /* The name of the probe. */
121 /* What to do when a probe stop occurs. */
122 enum probe_action action
;
125 /* A list of named probes and their associated actions. If all
126 probes are present in the dynamic linker then the probes-based
127 interface will be used. */
129 static const struct probe_info probe_info
[] =
131 { "init_start", DO_NOTHING
},
132 { "init_complete", FULL_RELOAD
},
133 { "map_start", DO_NOTHING
},
134 { "map_failed", DO_NOTHING
},
135 { "reloc_complete", UPDATE_OR_RELOAD
},
136 { "unmap_start", DO_NOTHING
},
137 { "unmap_complete", FULL_RELOAD
},
140 #define NUM_PROBES ARRAY_SIZE (probe_info)
142 /* Return non-zero if GDB_SO_NAME and INFERIOR_SO_NAME represent
143 the same shared library. */
146 svr4_same_1 (const char *gdb_so_name
, const char *inferior_so_name
)
148 if (strcmp (gdb_so_name
, inferior_so_name
) == 0)
151 /* On Solaris, when starting inferior we think that dynamic linker is
152 /usr/lib/ld.so.1, but later on, the table of loaded shared libraries
153 contains /lib/ld.so.1. Sometimes one file is a link to another, but
154 sometimes they have identical content, but are not linked to each
155 other. We don't restrict this check for Solaris, but the chances
156 of running into this situation elsewhere are very low. */
157 if (strcmp (gdb_so_name
, "/usr/lib/ld.so.1") == 0
158 && strcmp (inferior_so_name
, "/lib/ld.so.1") == 0)
161 /* Similarly, we observed the same issue with amd64 and sparcv9, but with
162 different locations. */
163 if (strcmp (gdb_so_name
, "/usr/lib/amd64/ld.so.1") == 0
164 && strcmp (inferior_so_name
, "/lib/amd64/ld.so.1") == 0)
167 if (strcmp (gdb_so_name
, "/usr/lib/sparcv9/ld.so.1") == 0
168 && strcmp (inferior_so_name
, "/lib/sparcv9/ld.so.1") == 0)
175 svr4_same (struct so_list
*gdb
, struct so_list
*inferior
)
177 return (svr4_same_1 (gdb
->so_original_name
, inferior
->so_original_name
));
180 static std::unique_ptr
<lm_info_svr4
>
181 lm_info_read (CORE_ADDR lm_addr
)
183 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
184 std::unique_ptr
<lm_info_svr4
> lm_info
;
186 gdb::byte_vector
lm (lmo
->link_map_size
);
188 if (target_read_memory (lm_addr
, lm
.data (), lmo
->link_map_size
) != 0)
189 warning (_("Error reading shared library list entry at %s"),
190 paddress (target_gdbarch (), lm_addr
));
193 struct type
*ptr_type
= builtin_type (target_gdbarch ())->builtin_data_ptr
;
195 lm_info
.reset (new lm_info_svr4
);
196 lm_info
->lm_addr
= lm_addr
;
198 lm_info
->l_addr_inferior
= extract_typed_address (&lm
[lmo
->l_addr_offset
],
200 lm_info
->l_ld
= extract_typed_address (&lm
[lmo
->l_ld_offset
], ptr_type
);
201 lm_info
->l_next
= extract_typed_address (&lm
[lmo
->l_next_offset
],
203 lm_info
->l_prev
= extract_typed_address (&lm
[lmo
->l_prev_offset
],
205 lm_info
->l_name
= extract_typed_address (&lm
[lmo
->l_name_offset
],
213 has_lm_dynamic_from_link_map (void)
215 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
217 return lmo
->l_ld_offset
>= 0;
221 lm_addr_check (const struct so_list
*so
, bfd
*abfd
)
223 lm_info_svr4
*li
= (lm_info_svr4
*) so
->lm_info
;
227 struct bfd_section
*dyninfo_sect
;
228 CORE_ADDR l_addr
, l_dynaddr
, dynaddr
;
230 l_addr
= li
->l_addr_inferior
;
232 if (! abfd
|| ! has_lm_dynamic_from_link_map ())
235 l_dynaddr
= li
->l_ld
;
237 dyninfo_sect
= bfd_get_section_by_name (abfd
, ".dynamic");
238 if (dyninfo_sect
== NULL
)
241 dynaddr
= bfd_section_vma (dyninfo_sect
);
243 if (dynaddr
+ l_addr
!= l_dynaddr
)
245 CORE_ADDR align
= 0x1000;
246 CORE_ADDR minpagesize
= align
;
248 if (bfd_get_flavour (abfd
) == bfd_target_elf_flavour
)
250 Elf_Internal_Ehdr
*ehdr
= elf_tdata (abfd
)->elf_header
;
251 Elf_Internal_Phdr
*phdr
= elf_tdata (abfd
)->phdr
;
256 for (i
= 0; i
< ehdr
->e_phnum
; i
++)
257 if (phdr
[i
].p_type
== PT_LOAD
&& phdr
[i
].p_align
> align
)
258 align
= phdr
[i
].p_align
;
260 minpagesize
= get_elf_backend_data (abfd
)->minpagesize
;
263 /* Turn it into a mask. */
266 /* If the changes match the alignment requirements, we
267 assume we're using a core file that was generated by the
268 same binary, just prelinked with a different base offset.
269 If it doesn't match, we may have a different binary, the
270 same binary with the dynamic table loaded at an unrelated
271 location, or anything, really. To avoid regressions,
272 don't adjust the base offset in the latter case, although
273 odds are that, if things really changed, debugging won't
276 One could expect more the condition
277 ((l_addr & align) == 0 && ((l_dynaddr - dynaddr) & align) == 0)
278 but the one below is relaxed for PPC. The PPC kernel supports
279 either 4k or 64k page sizes. To be prepared for 64k pages,
280 PPC ELF files are built using an alignment requirement of 64k.
281 However, when running on a kernel supporting 4k pages, the memory
282 mapping of the library may not actually happen on a 64k boundary!
284 (In the usual case where (l_addr & align) == 0, this check is
285 equivalent to the possibly expected check above.)
287 Even on PPC it must be zero-aligned at least for MINPAGESIZE. */
289 l_addr
= l_dynaddr
- dynaddr
;
291 if ((l_addr
& (minpagesize
- 1)) == 0
292 && (l_addr
& align
) == ((l_dynaddr
- dynaddr
) & align
))
295 gdb_printf (_("Using PIC (Position Independent Code) "
296 "prelink displacement %s for \"%s\".\n"),
297 paddress (target_gdbarch (), l_addr
),
302 /* There is no way to verify the library file matches. prelink
303 can during prelinking of an unprelinked file (or unprelinking
304 of a prelinked file) shift the DYNAMIC segment by arbitrary
305 offset without any page size alignment. There is no way to
306 find out the ELF header and/or Program Headers for a limited
307 verification if it they match. One could do a verification
308 of the DYNAMIC segment. Still the found address is the best
309 one GDB could find. */
311 warning (_(".dynamic section for \"%s\" "
312 "is not at the expected address "
313 "(wrong library or version mismatch?)"), so
->so_name
);
325 /* Per pspace SVR4 specific data. */
329 svr4_info () = default;
332 /* Base of dynamic linker structures. */
333 CORE_ADDR debug_base
= 0;
335 /* Validity flag for debug_loader_offset. */
336 int debug_loader_offset_p
= 0;
338 /* Load address for the dynamic linker, inferred. */
339 CORE_ADDR debug_loader_offset
= 0;
341 /* Name of the dynamic linker, valid if debug_loader_offset_p. */
342 char *debug_loader_name
= nullptr;
344 /* Load map address for the main executable. */
345 CORE_ADDR main_lm_addr
= 0;
347 CORE_ADDR interp_text_sect_low
= 0;
348 CORE_ADDR interp_text_sect_high
= 0;
349 CORE_ADDR interp_plt_sect_low
= 0;
350 CORE_ADDR interp_plt_sect_high
= 0;
352 /* Nonzero if the list of objects was last obtained from the target
353 via qXfer:libraries-svr4:read. */
356 /* Table of struct probe_and_action instances, used by the
357 probes-based interface to map breakpoint addresses to probes
358 and their associated actions. Lookup is performed using
359 probe_and_action->prob->address. */
360 htab_up probes_table
;
362 /* List of objects loaded into the inferior, used by the probes-
364 struct so_list
*solib_list
= nullptr;
367 /* Per-program-space data key. */
368 static const struct program_space_key
<svr4_info
> solib_svr4_pspace_data
;
370 /* Free the probes table. */
373 free_probes_table (struct svr4_info
*info
)
375 info
->probes_table
.reset (nullptr);
378 /* Free the solib list. */
381 free_solib_list (struct svr4_info
*info
)
383 svr4_free_library_list (&info
->solib_list
);
384 info
->solib_list
= NULL
;
387 svr4_info::~svr4_info ()
389 free_solib_list (this);
392 /* Get the svr4 data for program space PSPACE. If none is found yet, add it now.
393 This function always returns a valid object. */
395 static struct svr4_info
*
396 get_svr4_info (program_space
*pspace
)
398 struct svr4_info
*info
= solib_svr4_pspace_data
.get (pspace
);
401 info
= solib_svr4_pspace_data
.emplace (pspace
);
406 /* Local function prototypes */
408 static int match_main (const char *);
410 /* Read program header TYPE from inferior memory. The header is found
411 by scanning the OS auxiliary vector.
413 If TYPE == -1, return the program headers instead of the contents of
416 Return vector of bytes holding the program header contents, or an empty
417 optional on failure. If successful and P_ARCH_SIZE is non-NULL, the target
418 architecture size (32-bit or 64-bit) is returned to *P_ARCH_SIZE. Likewise,
419 the base address of the section is returned in *BASE_ADDR. */
421 static gdb::optional
<gdb::byte_vector
>
422 read_program_header (int type
, int *p_arch_size
, CORE_ADDR
*base_addr
)
424 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch ());
425 CORE_ADDR at_phdr
, at_phent
, at_phnum
, pt_phdr
= 0;
426 int arch_size
, sect_size
;
430 /* Get required auxv elements from target. */
431 if (target_auxv_search (current_inferior ()->top_target (),
432 AT_PHDR
, &at_phdr
) <= 0)
434 if (target_auxv_search (current_inferior ()->top_target (),
435 AT_PHENT
, &at_phent
) <= 0)
437 if (target_auxv_search (current_inferior ()->top_target (),
438 AT_PHNUM
, &at_phnum
) <= 0)
440 if (!at_phdr
|| !at_phnum
)
443 /* Determine ELF architecture type. */
444 if (at_phent
== sizeof (Elf32_External_Phdr
))
446 else if (at_phent
== sizeof (Elf64_External_Phdr
))
451 /* Find the requested segment. */
455 sect_size
= at_phent
* at_phnum
;
457 else if (arch_size
== 32)
459 Elf32_External_Phdr phdr
;
462 /* Search for requested PHDR. */
463 for (i
= 0; i
< at_phnum
; i
++)
467 if (target_read_memory (at_phdr
+ i
* sizeof (phdr
),
468 (gdb_byte
*)&phdr
, sizeof (phdr
)))
471 p_type
= extract_unsigned_integer ((gdb_byte
*) phdr
.p_type
,
474 if (p_type
== PT_PHDR
)
477 pt_phdr
= extract_unsigned_integer ((gdb_byte
*) phdr
.p_vaddr
,
488 /* Retrieve address and size. */
489 sect_addr
= extract_unsigned_integer ((gdb_byte
*)phdr
.p_vaddr
,
491 sect_size
= extract_unsigned_integer ((gdb_byte
*)phdr
.p_memsz
,
496 Elf64_External_Phdr phdr
;
499 /* Search for requested PHDR. */
500 for (i
= 0; i
< at_phnum
; i
++)
504 if (target_read_memory (at_phdr
+ i
* sizeof (phdr
),
505 (gdb_byte
*)&phdr
, sizeof (phdr
)))
508 p_type
= extract_unsigned_integer ((gdb_byte
*) phdr
.p_type
,
511 if (p_type
== PT_PHDR
)
514 pt_phdr
= extract_unsigned_integer ((gdb_byte
*) phdr
.p_vaddr
,
525 /* Retrieve address and size. */
526 sect_addr
= extract_unsigned_integer ((gdb_byte
*)phdr
.p_vaddr
,
528 sect_size
= extract_unsigned_integer ((gdb_byte
*)phdr
.p_memsz
,
532 /* PT_PHDR is optional, but we really need it
533 for PIE to make this work in general. */
537 /* at_phdr is real address in memory. pt_phdr is what pheader says it is.
538 Relocation offset is the difference between the two. */
539 sect_addr
= sect_addr
+ (at_phdr
- pt_phdr
);
542 /* Read in requested program header. */
543 gdb::byte_vector
buf (sect_size
);
544 if (target_read_memory (sect_addr
, buf
.data (), sect_size
))
548 *p_arch_size
= arch_size
;
550 *base_addr
= sect_addr
;
556 /* Return program interpreter string. */
557 static gdb::optional
<gdb::byte_vector
>
558 find_program_interpreter (void)
560 /* If we have a current exec_bfd, use its section table. */
561 if (current_program_space
->exec_bfd ()
562 && (bfd_get_flavour (current_program_space
->exec_bfd ())
563 == bfd_target_elf_flavour
))
565 struct bfd_section
*interp_sect
;
567 interp_sect
= bfd_get_section_by_name (current_program_space
->exec_bfd (),
569 if (interp_sect
!= NULL
)
571 int sect_size
= bfd_section_size (interp_sect
);
573 gdb::byte_vector
buf (sect_size
);
574 bfd_get_section_contents (current_program_space
->exec_bfd (),
575 interp_sect
, buf
.data (), 0, sect_size
);
580 /* If we didn't find it, use the target auxiliary vector. */
581 return read_program_header (PT_INTERP
, NULL
, NULL
);
585 /* Scan for DESIRED_DYNTAG in .dynamic section of the target's main executable,
586 found by consulting the OS auxillary vector. If DESIRED_DYNTAG is found, 1
587 is returned and the corresponding PTR is set. */
590 scan_dyntag_auxv (const int desired_dyntag
, CORE_ADDR
*ptr
,
593 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch ());
599 /* Read in .dynamic section. */
600 gdb::optional
<gdb::byte_vector
> ph_data
601 = read_program_header (PT_DYNAMIC
, &arch_size
, &base_addr
);
605 /* Iterate over BUF and scan for DYNTAG. If found, set PTR and return. */
606 step
= (arch_size
== 32) ? sizeof (Elf32_External_Dyn
)
607 : sizeof (Elf64_External_Dyn
);
608 for (gdb_byte
*buf
= ph_data
->data (), *bufend
= buf
+ ph_data
->size ();
609 buf
< bufend
; buf
+= step
)
613 Elf32_External_Dyn
*dynp
= (Elf32_External_Dyn
*) buf
;
615 current_dyntag
= extract_unsigned_integer ((gdb_byte
*) dynp
->d_tag
,
617 dyn_ptr
= extract_unsigned_integer ((gdb_byte
*) dynp
->d_un
.d_ptr
,
622 Elf64_External_Dyn
*dynp
= (Elf64_External_Dyn
*) buf
;
624 current_dyntag
= extract_unsigned_integer ((gdb_byte
*) dynp
->d_tag
,
626 dyn_ptr
= extract_unsigned_integer ((gdb_byte
*) dynp
->d_un
.d_ptr
,
629 if (current_dyntag
== DT_NULL
)
632 if (current_dyntag
== desired_dyntag
)
638 *ptr_addr
= base_addr
+ buf
- ph_data
->data ();
647 /* Locate the base address of dynamic linker structs for SVR4 elf
650 For SVR4 elf targets the address of the dynamic linker's runtime
651 structure is contained within the dynamic info section in the
652 executable file. The dynamic section is also mapped into the
653 inferior address space. Because the runtime loader fills in the
654 real address before starting the inferior, we have to read in the
655 dynamic info section from the inferior address space.
656 If there are any errors while trying to find the address, we
657 silently return 0, otherwise the found address is returned. */
660 elf_locate_base (void)
662 struct bound_minimal_symbol msymbol
;
663 CORE_ADDR dyn_ptr
, dyn_ptr_addr
;
665 /* Look for DT_MIPS_RLD_MAP first. MIPS executables use this
666 instead of DT_DEBUG, although they sometimes contain an unused
668 if (gdb_bfd_scan_elf_dyntag (DT_MIPS_RLD_MAP
,
669 current_program_space
->exec_bfd (),
671 || scan_dyntag_auxv (DT_MIPS_RLD_MAP
, &dyn_ptr
, NULL
))
673 struct type
*ptr_type
= builtin_type (target_gdbarch ())->builtin_data_ptr
;
675 int pbuf_size
= TYPE_LENGTH (ptr_type
);
677 pbuf
= (gdb_byte
*) alloca (pbuf_size
);
678 /* DT_MIPS_RLD_MAP contains a pointer to the address
679 of the dynamic link structure. */
680 if (target_read_memory (dyn_ptr
, pbuf
, pbuf_size
))
682 return extract_typed_address (pbuf
, ptr_type
);
685 /* Then check DT_MIPS_RLD_MAP_REL. MIPS executables now use this form
686 because of needing to support PIE. DT_MIPS_RLD_MAP will also exist
688 if (gdb_bfd_scan_elf_dyntag (DT_MIPS_RLD_MAP_REL
,
689 current_program_space
->exec_bfd (),
690 &dyn_ptr
, &dyn_ptr_addr
)
691 || scan_dyntag_auxv (DT_MIPS_RLD_MAP_REL
, &dyn_ptr
, &dyn_ptr_addr
))
693 struct type
*ptr_type
= builtin_type (target_gdbarch ())->builtin_data_ptr
;
695 int pbuf_size
= TYPE_LENGTH (ptr_type
);
697 pbuf
= (gdb_byte
*) alloca (pbuf_size
);
698 /* DT_MIPS_RLD_MAP_REL contains an offset from the address of the
699 DT slot to the address of the dynamic link structure. */
700 if (target_read_memory (dyn_ptr
+ dyn_ptr_addr
, pbuf
, pbuf_size
))
702 return extract_typed_address (pbuf
, ptr_type
);
706 if (gdb_bfd_scan_elf_dyntag (DT_DEBUG
, current_program_space
->exec_bfd (),
708 || scan_dyntag_auxv (DT_DEBUG
, &dyn_ptr
, NULL
))
711 /* This may be a static executable. Look for the symbol
712 conventionally named _r_debug, as a last resort. */
713 msymbol
= lookup_minimal_symbol ("_r_debug", NULL
,
714 current_program_space
->symfile_object_file
);
715 if (msymbol
.minsym
!= NULL
)
716 return BMSYMBOL_VALUE_ADDRESS (msymbol
);
718 /* DT_DEBUG entry not found. */
722 /* Locate the base address of dynamic linker structs.
724 For both the SunOS and SVR4 shared library implementations, if the
725 inferior executable has been linked dynamically, there is a single
726 address somewhere in the inferior's data space which is the key to
727 locating all of the dynamic linker's runtime structures. This
728 address is the value of the debug base symbol. The job of this
729 function is to find and return that address, or to return 0 if there
730 is no such address (the executable is statically linked for example).
732 For SunOS, the job is almost trivial, since the dynamic linker and
733 all of it's structures are statically linked to the executable at
734 link time. Thus the symbol for the address we are looking for has
735 already been added to the minimal symbol table for the executable's
736 objfile at the time the symbol file's symbols were read, and all we
737 have to do is look it up there. Note that we explicitly do NOT want
738 to find the copies in the shared library.
740 The SVR4 version is a bit more complicated because the address
741 is contained somewhere in the dynamic info section. We have to go
742 to a lot more work to discover the address of the debug base symbol.
743 Because of this complexity, we cache the value we find and return that
744 value on subsequent invocations. Note there is no copy in the
745 executable symbol tables. */
748 locate_base (struct svr4_info
*info
)
750 /* Check to see if we have a currently valid address, and if so, avoid
751 doing all this work again and just return the cached address. If
752 we have no cached address, try to locate it in the dynamic info
753 section for ELF executables. There's no point in doing any of this
754 though if we don't have some link map offsets to work with. */
756 if (info
->debug_base
== 0 && svr4_have_link_map_offsets ())
757 info
->debug_base
= elf_locate_base ();
758 return info
->debug_base
;
761 /* Find the first element in the inferior's dynamic link map, and
762 return its address in the inferior. Return zero if the address
763 could not be determined.
765 FIXME: Perhaps we should validate the info somehow, perhaps by
766 checking r_version for a known version number, or r_state for
770 solib_svr4_r_map (struct svr4_info
*info
)
772 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
773 struct type
*ptr_type
= builtin_type (target_gdbarch ())->builtin_data_ptr
;
778 addr
= read_memory_typed_address (info
->debug_base
+ lmo
->r_map_offset
,
781 catch (const gdb_exception_error
&ex
)
783 exception_print (gdb_stderr
, ex
);
789 /* Find r_brk from the inferior's debug base. */
792 solib_svr4_r_brk (struct svr4_info
*info
)
794 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
795 struct type
*ptr_type
= builtin_type (target_gdbarch ())->builtin_data_ptr
;
797 return read_memory_typed_address (info
->debug_base
+ lmo
->r_brk_offset
,
801 /* Find the link map for the dynamic linker (if it is not in the
802 normal list of loaded shared objects). */
805 solib_svr4_r_ldsomap (struct svr4_info
*info
)
807 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
808 struct type
*ptr_type
= builtin_type (target_gdbarch ())->builtin_data_ptr
;
809 enum bfd_endian byte_order
= type_byte_order (ptr_type
);
810 ULONGEST version
= 0;
814 /* Check version, and return zero if `struct r_debug' doesn't have
815 the r_ldsomap member. */
817 = read_memory_unsigned_integer (info
->debug_base
+ lmo
->r_version_offset
,
818 lmo
->r_version_size
, byte_order
);
820 catch (const gdb_exception_error
&ex
)
822 exception_print (gdb_stderr
, ex
);
825 if (version
< 2 || lmo
->r_ldsomap_offset
== -1)
828 return read_memory_typed_address (info
->debug_base
+ lmo
->r_ldsomap_offset
,
832 /* On Solaris systems with some versions of the dynamic linker,
833 ld.so's l_name pointer points to the SONAME in the string table
834 rather than into writable memory. So that GDB can find shared
835 libraries when loading a core file generated by gcore, ensure that
836 memory areas containing the l_name string are saved in the core
840 svr4_keep_data_in_core (CORE_ADDR vaddr
, unsigned long size
)
842 struct svr4_info
*info
;
846 info
= get_svr4_info (current_program_space
);
848 info
->debug_base
= 0;
850 if (!info
->debug_base
)
853 ldsomap
= solib_svr4_r_ldsomap (info
);
857 std::unique_ptr
<lm_info_svr4
> li
= lm_info_read (ldsomap
);
858 name_lm
= li
!= NULL
? li
->l_name
: 0;
860 return (name_lm
>= vaddr
&& name_lm
< vaddr
+ size
);
866 open_symbol_file_object (int from_tty
)
868 CORE_ADDR lm
, l_name
;
869 struct link_map_offsets
*lmo
= svr4_fetch_link_map_offsets ();
870 struct type
*ptr_type
= builtin_type (target_gdbarch ())->builtin_data_ptr
;
871 int l_name_size
= TYPE_LENGTH (ptr_type
);
872 gdb::byte_vector
l_name_buf (l_name_size
);
873 struct svr4_info
*info
= get_svr4_info (current_program_space
);
874 symfile_add_flags add_flags
= 0;
877 add_flags
|= SYMFILE_VERBOSE
;
879 if (current_program_space
->symfile_object_file
)
880 if (!query (_("Attempt to reload symbols from process? ")))
883 /* Always locate the debug struct, in case it has moved. */
884 info
->debug_base
= 0;
885 if (locate_base (info
) == 0)
886 return 0; /* failed somehow... */
888 /* First link map member should be the executable. */
889 lm
= solib_svr4_r_map (info
);
891 return 0; /* failed somehow... */
893 /* Read address of name from target memory to GDB. */
894 read_memory (lm
+ lmo
->l_name_offset
, l_name_buf
.data (), l_name_size
);
896 /* Convert the address to host format. */
897 l_name
= extract_typed_address (l_name_buf
.data (), ptr_type
);
900 return 0; /* No filename. */
902 /* Now fetch the filename from target memory. */
903 gdb::unique_xmalloc_ptr
<char> filename
904 = target_read_string (l_name
, SO_NAME_MAX_PATH_SIZE
- 1);
906 if (filename
== nullptr)
908 warning (_("failed to read exec filename from attached file"));
912 /* Have a pathname: read the symbol file. */
913 symbol_file_add_main (filename
.get (), add_flags
);
918 /* Data exchange structure for the XML parser as returned by
919 svr4_current_sos_via_xfer_libraries. */
921 struct svr4_library_list
923 struct so_list
*head
, **tailp
;
925 /* Inferior address of struct link_map used for the main executable. It is
926 NULL if not known. */
930 /* This module's 'free_objfile' observer. */
933 svr4_free_objfile_observer (struct objfile
*objfile
)
935 probes_table_remove_objfile_probes (objfile
);
938 /* Implementation for target_so_ops.free_so. */
941 svr4_free_so (struct so_list
*so
)
943 lm_info_svr4
*li
= (lm_info_svr4
*) so
->lm_info
;
948 /* Implement target_so_ops.clear_so. */
951 svr4_clear_so (struct so_list
*so
)
953 lm_info_svr4
*li
= (lm_info_svr4
*) so
->lm_info
;
959 /* Free so_list built so far (called via cleanup). */
962 svr4_free_library_list (void *p_list
)
964 struct so_list
*list
= *(struct so_list
**) p_list
;
968 struct so_list
*next
= list
->next
;
975 /* Copy library list. */
977 static struct so_list
*
978 svr4_copy_library_list (struct so_list
*src
)
980 struct so_list
*dst
= NULL
;
981 struct so_list
**link
= &dst
;
985 struct so_list
*newobj
;
987 newobj
= XNEW (struct so_list
);
988 memcpy (newobj
, src
, sizeof (struct so_list
));
990 lm_info_svr4
*src_li
= (lm_info_svr4
*) src
->lm_info
;
991 newobj
->lm_info
= new lm_info_svr4 (*src_li
);
995 link
= &newobj
->next
;
1003 #ifdef HAVE_LIBEXPAT
1005 #include "xml-support.h"
1007 /* Handle the start of a <library> element. Note: new elements are added
1008 at the tail of the list, keeping the list in order. */
1011 library_list_start_library (struct gdb_xml_parser
*parser
,
1012 const struct gdb_xml_element
*element
,
1014 std::vector
<gdb_xml_value
> &attributes
)
1016 struct svr4_library_list
*list
= (struct svr4_library_list
*) user_data
;
1018 = (const char *) xml_find_attribute (attributes
, "name")->value
.get ();
1020 = (ULONGEST
*) xml_find_attribute (attributes
, "lm")->value
.get ();
1022 = (ULONGEST
*) xml_find_attribute (attributes
, "l_addr")->value
.get ();
1024 = (ULONGEST
*) xml_find_attribute (attributes
, "l_ld")->value
.get ();
1025 struct so_list
*new_elem
;
1027 new_elem
= XCNEW (struct so_list
);
1028 lm_info_svr4
*li
= new lm_info_svr4
;
1029 new_elem
->lm_info
= li
;
1031 li
->l_addr_inferior
= *l_addrp
;
1034 strncpy (new_elem
->so_name
, name
, sizeof (new_elem
->so_name
) - 1);
1035 new_elem
->so_name
[sizeof (new_elem
->so_name
) - 1] = 0;
1036 strcpy (new_elem
->so_original_name
, new_elem
->so_name
);
1038 *list
->tailp
= new_elem
;
1039 list
->tailp
= &new_elem
->next
;
1042 /* Handle the start of a <library-list-svr4> element. */
1045 svr4_library_list_start_list (struct gdb_xml_parser
*parser
,
1046 const struct gdb_xml_element
*element
,
1048 std::vector
<gdb_xml_value
> &attributes
)
1050 struct svr4_library_list
*list
= (struct svr4_library_list
*) user_data
;
1052 = (const char *) xml_find_attribute (attributes
, "version")->value
.get ();
1053 struct gdb_xml_value
*main_lm
= xml_find_attribute (attributes
, "main-lm");
1055 if (strcmp (version
, "1.0") != 0)
1056 gdb_xml_error (parser
,
1057 _("SVR4 Library list has unsupported version \"%s\""),
1061 list
->main_lm
= *(ULONGEST
*) main_lm
->value
.get ();
1064 /* The allowed elements and attributes for an XML library list.
1065 The root element is a <library-list>. */
1067 static const struct gdb_xml_attribute svr4_library_attributes
[] =
1069 { "name", GDB_XML_AF_NONE
, NULL
, NULL
},
1070 { "lm", GDB_XML_AF_NONE
, gdb_xml_parse_attr_ulongest
, NULL
},
1071 { "l_addr", GDB_XML_AF_NONE
, gdb_xml_parse_attr_ulongest
, NULL
},
1072 { "l_ld", GDB_XML_AF_NONE
, gdb_xml_parse_attr_ulongest
, NULL
},
1073 { NULL
, GDB_XML_AF_NONE
, NULL
, NULL
}
1076 static const struct gdb_xml_element svr4_library_list_children
[] =
1079 "library", svr4_library_attributes
, NULL
,
1080 GDB_XML_EF_REPEATABLE
| GDB_XML_EF_OPTIONAL
,
1081 library_list_start_library
, NULL
1083 { NULL
, NULL
, NULL
, GDB_XML_EF_NONE
, NULL
, NULL
}
1086 static const struct gdb_xml_attribute svr4_library_list_attributes
[] =
1088 { "version", GDB_XML_AF_NONE
, NULL
, NULL
},
1089 { "main-lm", GDB_XML_AF_OPTIONAL
, gdb_xml_parse_attr_ulongest
, NULL
},
1090 { NULL
, GDB_XML_AF_NONE
, NULL
, NULL
}
1093 static const struct gdb_xml_element svr4_library_list_elements
[] =
1095 { "library-list-svr4", svr4_library_list_attributes
, svr4_library_list_children
,
1096 GDB_XML_EF_NONE
, svr4_library_list_start_list
, NULL
},
1097 { NULL
, NULL
, NULL
, GDB_XML_EF_NONE
, NULL
, NULL
}
1100 /* Parse qXfer:libraries:read packet into *SO_LIST_RETURN. Return 1 if
1102 Return 0 if packet not supported, *SO_LIST_RETURN is not modified in such
1103 case. Return 1 if *SO_LIST_RETURN contains the library list, it may be
1104 empty, caller is responsible for freeing all its entries. */
1107 svr4_parse_libraries (const char *document
, struct svr4_library_list
*list
)
1109 auto cleanup
= make_scope_exit ([&] ()
1111 svr4_free_library_list (&list
->head
);
1114 memset (list
, 0, sizeof (*list
));
1115 list
->tailp
= &list
->head
;
1116 if (gdb_xml_parse_quick (_("target library list"), "library-list-svr4.dtd",
1117 svr4_library_list_elements
, document
, list
) == 0)
1119 /* Parsed successfully, keep the result. */
1127 /* Attempt to get so_list from target via qXfer:libraries-svr4:read packet.
1129 Return 0 if packet not supported, *SO_LIST_RETURN is not modified in such
1130 case. Return 1 if *SO_LIST_RETURN contains the library list, it may be
1131 empty, caller is responsible for freeing all its entries.
1133 Note that ANNEX must be NULL if the remote does not explicitly allow
1134 qXfer:libraries-svr4:read packets with non-empty annexes. Support for
1135 this can be checked using target_augmented_libraries_svr4_read (). */
1138 svr4_current_sos_via_xfer_libraries (struct svr4_library_list
*list
,
1141 gdb_assert (annex
== NULL
|| target_augmented_libraries_svr4_read ());
1143 /* Fetch the list of shared libraries. */
1144 gdb::optional
<gdb::char_vector
> svr4_library_document
1145 = target_read_stralloc (current_inferior ()->top_target (),
1146 TARGET_OBJECT_LIBRARIES_SVR4
,
1148 if (!svr4_library_document
)
1151 return svr4_parse_libraries (svr4_library_document
->data (), list
);
1157 svr4_current_sos_via_xfer_libraries (struct svr4_library_list
*list
,
1165 /* If no shared library information is available from the dynamic
1166 linker, build a fallback list from other sources. */
1168 static struct so_list
*
1169 svr4_default_sos (svr4_info
*info
)
1171 struct so_list
*newobj
;
1173 if (!info
->debug_loader_offset_p
)
1176 newobj
= XCNEW (struct so_list
);
1177 lm_info_svr4
*li
= new lm_info_svr4
;
1178 newobj
->lm_info
= li
;
1180 /* Nothing will ever check the other fields if we set l_addr_p. */
1181 li
->l_addr
= info
->debug_loader_offset
;
1184 strncpy (newobj
->so_name
, info
->debug_loader_name
, SO_NAME_MAX_PATH_SIZE
- 1);
1185 newobj
->so_name
[SO_NAME_MAX_PATH_SIZE
- 1] = '\0';
1186 strcpy (newobj
->so_original_name
, newobj
->so_name
);
1191 /* Read the whole inferior libraries chain starting at address LM.
1192 Expect the first entry in the chain's previous entry to be PREV_LM.
1193 Add the entries to the tail referenced by LINK_PTR_PTR. Ignore the
1194 first entry if IGNORE_FIRST and set global MAIN_LM_ADDR according
1195 to it. Returns nonzero upon success. If zero is returned the
1196 entries stored to LINK_PTR_PTR are still valid although they may
1197 represent only part of the inferior library list. */
1200 svr4_read_so_list (svr4_info
*info
, CORE_ADDR lm
, CORE_ADDR prev_lm
,
1201 struct so_list
***link_ptr_ptr
, int ignore_first
)
1203 CORE_ADDR first_l_name
= 0;
1206 for (; lm
!= 0; prev_lm
= lm
, lm
= next_lm
)
1208 so_list_up
newobj (XCNEW (struct so_list
));
1210 lm_info_svr4
*li
= lm_info_read (lm
).release ();
1211 newobj
->lm_info
= li
;
1215 next_lm
= li
->l_next
;
1217 if (li
->l_prev
!= prev_lm
)
1219 warning (_("Corrupted shared library list: %s != %s"),
1220 paddress (target_gdbarch (), prev_lm
),
1221 paddress (target_gdbarch (), li
->l_prev
));
1225 /* For SVR4 versions, the first entry in the link map is for the
1226 inferior executable, so we must ignore it. For some versions of
1227 SVR4, it has no name. For others (Solaris 2.3 for example), it
1228 does have a name, so we can no longer use a missing name to
1229 decide when to ignore it. */
1230 if (ignore_first
&& li
->l_prev
== 0)
1232 first_l_name
= li
->l_name
;
1233 info
->main_lm_addr
= li
->lm_addr
;
1237 /* Extract this shared object's name. */
1238 gdb::unique_xmalloc_ptr
<char> buffer
1239 = target_read_string (li
->l_name
, SO_NAME_MAX_PATH_SIZE
- 1);
1240 if (buffer
== nullptr)
1242 /* If this entry's l_name address matches that of the
1243 inferior executable, then this is not a normal shared
1244 object, but (most likely) a vDSO. In this case, silently
1245 skip it; otherwise emit a warning. */
1246 if (first_l_name
== 0 || li
->l_name
!= first_l_name
)
1247 warning (_("Can't read pathname for load map."));
1251 strncpy (newobj
->so_name
, buffer
.get (), SO_NAME_MAX_PATH_SIZE
- 1);
1252 newobj
->so_name
[SO_NAME_MAX_PATH_SIZE
- 1] = '\0';
1253 strcpy (newobj
->so_original_name
, newobj
->so_name
);
1255 /* If this entry has no name, or its name matches the name
1256 for the main executable, don't include it in the list. */
1257 if (! newobj
->so_name
[0] || match_main (newobj
->so_name
))
1261 /* Don't free it now. */
1262 **link_ptr_ptr
= newobj
.release ();
1263 *link_ptr_ptr
= &(**link_ptr_ptr
)->next
;
1269 /* Read the full list of currently loaded shared objects directly
1270 from the inferior, without referring to any libraries read and
1271 stored by the probes interface. Handle special cases relating
1272 to the first elements of the list. */
1274 static struct so_list
*
1275 svr4_current_sos_direct (struct svr4_info
*info
)
1278 struct so_list
*head
= NULL
;
1279 struct so_list
**link_ptr
= &head
;
1281 struct svr4_library_list library_list
;
1283 /* Fall back to manual examination of the target if the packet is not
1284 supported or gdbserver failed to find DT_DEBUG. gdb.server/solib-list.exp
1285 tests a case where gdbserver cannot find the shared libraries list while
1286 GDB itself is able to find it via SYMFILE_OBJFILE.
1288 Unfortunately statically linked inferiors will also fall back through this
1289 suboptimal code path. */
1291 info
->using_xfer
= svr4_current_sos_via_xfer_libraries (&library_list
,
1293 if (info
->using_xfer
)
1295 if (library_list
.main_lm
)
1296 info
->main_lm_addr
= library_list
.main_lm
;
1298 return library_list
.head
? library_list
.head
: svr4_default_sos (info
);
1301 /* Always locate the debug struct, in case it has moved. */
1302 info
->debug_base
= 0;
1305 /* If we can't find the dynamic linker's base structure, this
1306 must not be a dynamically linked executable. Hmm. */
1307 if (! info
->debug_base
)
1308 return svr4_default_sos (info
);
1310 /* Assume that everything is a library if the dynamic loader was loaded
1311 late by a static executable. */
1312 if (current_program_space
->exec_bfd ()
1313 && bfd_get_section_by_name (current_program_space
->exec_bfd (),
1314 ".dynamic") == NULL
)
1319 auto cleanup
= make_scope_exit ([&] ()
1321 svr4_free_library_list (&head
);
1324 /* Walk the inferior's link map list, and build our list of
1325 `struct so_list' nodes. */
1326 lm
= solib_svr4_r_map (info
);
1328 svr4_read_so_list (info
, lm
, 0, &link_ptr
, ignore_first
);
1330 /* On Solaris, the dynamic linker is not in the normal list of
1331 shared objects, so make sure we pick it up too. Having
1332 symbol information for the dynamic linker is quite crucial
1333 for skipping dynamic linker resolver code. */
1334 lm
= solib_svr4_r_ldsomap (info
);
1336 svr4_read_so_list (info
, lm
, 0, &link_ptr
, 0);
1341 return svr4_default_sos (info
);
1346 /* Implement the main part of the "current_sos" target_so_ops
1349 static struct so_list
*
1350 svr4_current_sos_1 (svr4_info
*info
)
1352 /* If the solib list has been read and stored by the probes
1353 interface then we return a copy of the stored list. */
1354 if (info
->solib_list
!= NULL
)
1355 return svr4_copy_library_list (info
->solib_list
);
1357 /* Otherwise obtain the solib list directly from the inferior. */
1358 return svr4_current_sos_direct (info
);
1361 /* Implement the "current_sos" target_so_ops method. */
1363 static struct so_list
*
1364 svr4_current_sos (void)
1366 svr4_info
*info
= get_svr4_info (current_program_space
);
1367 struct so_list
*so_head
= svr4_current_sos_1 (info
);
1368 struct mem_range vsyscall_range
;
1370 /* Filter out the vDSO module, if present. Its symbol file would
1371 not be found on disk. The vDSO/vsyscall's OBJFILE is instead
1372 managed by symfile-mem.c:add_vsyscall_page. */
1373 if (gdbarch_vsyscall_range (target_gdbarch (), &vsyscall_range
)
1374 && vsyscall_range
.length
!= 0)
1376 struct so_list
**sop
;
1379 while (*sop
!= NULL
)
1381 struct so_list
*so
= *sop
;
1383 /* We can't simply match the vDSO by starting address alone,
1384 because lm_info->l_addr_inferior (and also l_addr) do not
1385 necessarily represent the real starting address of the
1386 ELF if the vDSO's ELF itself is "prelinked". The l_ld
1387 field (the ".dynamic" section of the shared object)
1388 always points at the absolute/resolved address though.
1389 So check whether that address is inside the vDSO's
1392 E.g., on Linux 3.16 (x86_64) the vDSO is a regular
1393 0-based ELF, and we see:
1396 33 AT_SYSINFO_EHDR System-supplied DSO's ELF header 0x7ffff7ffb000
1397 (gdb) p/x *_r_debug.r_map.l_next
1398 $1 = {l_addr = 0x7ffff7ffb000, ..., l_ld = 0x7ffff7ffb318, ...}
1400 And on Linux 2.6.32 (x86_64) we see:
1403 33 AT_SYSINFO_EHDR System-supplied DSO's ELF header 0x7ffff7ffe000
1404 (gdb) p/x *_r_debug.r_map.l_next
1405 $5 = {l_addr = 0x7ffff88fe000, ..., l_ld = 0x7ffff7ffe580, ... }
1407 Dumping that vDSO shows:
1409 (gdb) info proc mappings
1410 0x7ffff7ffe000 0x7ffff7fff000 0x1000 0 [vdso]
1411 (gdb) dump memory vdso.bin 0x7ffff7ffe000 0x7ffff7fff000
1412 # readelf -Wa vdso.bin
1414 Entry point address: 0xffffffffff700700
1417 [Nr] Name Type Address Off Size
1418 [ 0] NULL 0000000000000000 000000 000000
1419 [ 1] .hash HASH ffffffffff700120 000120 000038
1420 [ 2] .dynsym DYNSYM ffffffffff700158 000158 0000d8
1422 [ 9] .dynamic DYNAMIC ffffffffff700580 000580 0000f0
1425 lm_info_svr4
*li
= (lm_info_svr4
*) so
->lm_info
;
1427 if (address_in_mem_range (li
->l_ld
, &vsyscall_range
))
1441 /* Get the address of the link_map for a given OBJFILE. */
1444 svr4_fetch_objfile_link_map (struct objfile
*objfile
)
1446 struct svr4_info
*info
= get_svr4_info (objfile
->pspace
);
1448 /* Cause svr4_current_sos() to be run if it hasn't been already. */
1449 if (info
->main_lm_addr
== 0)
1450 solib_add (NULL
, 0, auto_solib_add
);
1452 /* svr4_current_sos() will set main_lm_addr for the main executable. */
1453 if (objfile
== current_program_space
->symfile_object_file
)
1454 return info
->main_lm_addr
;
1456 /* If OBJFILE is a separate debug object file, look for the
1457 original object file. */
1458 if (objfile
->separate_debug_objfile_backlink
!= NULL
)
1459 objfile
= objfile
->separate_debug_objfile_backlink
;
1461 /* The other link map addresses may be found by examining the list
1462 of shared libraries. */
1463 for (struct so_list
*so
: current_program_space
->solibs ())
1464 if (so
->objfile
== objfile
)
1466 lm_info_svr4
*li
= (lm_info_svr4
*) so
->lm_info
;
1475 /* On some systems, the only way to recognize the link map entry for
1476 the main executable file is by looking at its name. Return
1477 non-zero iff SONAME matches one of the known main executable names. */
1480 match_main (const char *soname
)
1482 const char * const *mainp
;
1484 for (mainp
= main_name_list
; *mainp
!= NULL
; mainp
++)
1486 if (strcmp (soname
, *mainp
) == 0)
1493 /* Return 1 if PC lies in the dynamic symbol resolution code of the
1494 SVR4 run time loader. */
1497 svr4_in_dynsym_resolve_code (CORE_ADDR pc
)
1499 struct svr4_info
*info
= get_svr4_info (current_program_space
);
1501 return ((pc
>= info
->interp_text_sect_low
1502 && pc
< info
->interp_text_sect_high
)
1503 || (pc
>= info
->interp_plt_sect_low
1504 && pc
< info
->interp_plt_sect_high
)
1505 || in_plt_section (pc
)
1506 || in_gnu_ifunc_stub (pc
));
1509 /* Given an executable's ABFD and target, compute the entry-point
1513 exec_entry_point (struct bfd
*abfd
, struct target_ops
*targ
)
1517 /* KevinB wrote ... for most targets, the address returned by
1518 bfd_get_start_address() is the entry point for the start
1519 function. But, for some targets, bfd_get_start_address() returns
1520 the address of a function descriptor from which the entry point
1521 address may be extracted. This address is extracted by
1522 gdbarch_convert_from_func_ptr_addr(). The method
1523 gdbarch_convert_from_func_ptr_addr() is the merely the identify
1524 function for targets which don't use function descriptors. */
1525 addr
= gdbarch_convert_from_func_ptr_addr (target_gdbarch (),
1526 bfd_get_start_address (abfd
),
1528 return gdbarch_addr_bits_remove (target_gdbarch (), addr
);
1531 /* A probe and its associated action. */
1533 struct probe_and_action
1538 /* The relocated address of the probe. */
1542 enum probe_action action
;
1544 /* The objfile where this probe was found. */
1545 struct objfile
*objfile
;
1548 /* Returns a hash code for the probe_and_action referenced by p. */
1551 hash_probe_and_action (const void *p
)
1553 const struct probe_and_action
*pa
= (const struct probe_and_action
*) p
;
1555 return (hashval_t
) pa
->address
;
1558 /* Returns non-zero if the probe_and_actions referenced by p1 and p2
1562 equal_probe_and_action (const void *p1
, const void *p2
)
1564 const struct probe_and_action
*pa1
= (const struct probe_and_action
*) p1
;
1565 const struct probe_and_action
*pa2
= (const struct probe_and_action
*) p2
;
1567 return pa1
->address
== pa2
->address
;
1570 /* Traversal function for probes_table_remove_objfile_probes. */
1573 probes_table_htab_remove_objfile_probes (void **slot
, void *info
)
1575 probe_and_action
*pa
= (probe_and_action
*) *slot
;
1576 struct objfile
*objfile
= (struct objfile
*) info
;
1578 if (pa
->objfile
== objfile
)
1579 htab_clear_slot (get_svr4_info (objfile
->pspace
)->probes_table
.get (),
1585 /* Remove all probes that belong to OBJFILE from the probes table. */
1588 probes_table_remove_objfile_probes (struct objfile
*objfile
)
1590 svr4_info
*info
= get_svr4_info (objfile
->pspace
);
1591 if (info
->probes_table
!= nullptr)
1592 htab_traverse_noresize (info
->probes_table
.get (),
1593 probes_table_htab_remove_objfile_probes
, objfile
);
1596 /* Register a solib event probe and its associated action in the
1600 register_solib_event_probe (svr4_info
*info
, struct objfile
*objfile
,
1601 probe
*prob
, CORE_ADDR address
,
1602 enum probe_action action
)
1604 struct probe_and_action lookup
, *pa
;
1607 /* Create the probes table, if necessary. */
1608 if (info
->probes_table
== NULL
)
1609 info
->probes_table
.reset (htab_create_alloc (1, hash_probe_and_action
,
1610 equal_probe_and_action
,
1611 xfree
, xcalloc
, xfree
));
1613 lookup
.address
= address
;
1614 slot
= htab_find_slot (info
->probes_table
.get (), &lookup
, INSERT
);
1615 gdb_assert (*slot
== HTAB_EMPTY_ENTRY
);
1617 pa
= XCNEW (struct probe_and_action
);
1619 pa
->address
= address
;
1620 pa
->action
= action
;
1621 pa
->objfile
= objfile
;
1626 /* Get the solib event probe at the specified location, and the
1627 action associated with it. Returns NULL if no solib event probe
1630 static struct probe_and_action
*
1631 solib_event_probe_at (struct svr4_info
*info
, CORE_ADDR address
)
1633 struct probe_and_action lookup
;
1636 lookup
.address
= address
;
1637 slot
= htab_find_slot (info
->probes_table
.get (), &lookup
, NO_INSERT
);
1642 return (struct probe_and_action
*) *slot
;
1645 /* Decide what action to take when the specified solib event probe is
1648 static enum probe_action
1649 solib_event_probe_action (struct probe_and_action
*pa
)
1651 enum probe_action action
;
1652 unsigned probe_argc
= 0;
1653 struct frame_info
*frame
= get_current_frame ();
1655 action
= pa
->action
;
1656 if (action
== DO_NOTHING
|| action
== PROBES_INTERFACE_FAILED
)
1659 gdb_assert (action
== FULL_RELOAD
|| action
== UPDATE_OR_RELOAD
);
1661 /* Check that an appropriate number of arguments has been supplied.
1663 arg0: Lmid_t lmid (mandatory)
1664 arg1: struct r_debug *debug_base (mandatory)
1665 arg2: struct link_map *new (optional, for incremental updates) */
1668 probe_argc
= pa
->prob
->get_argument_count (get_frame_arch (frame
));
1670 catch (const gdb_exception_error
&ex
)
1672 exception_print (gdb_stderr
, ex
);
1676 /* If get_argument_count throws an exception, probe_argc will be set
1677 to zero. However, if pa->prob does not have arguments, then
1678 get_argument_count will succeed but probe_argc will also be zero.
1679 Both cases happen because of different things, but they are
1680 treated equally here: action will be set to
1681 PROBES_INTERFACE_FAILED. */
1682 if (probe_argc
== 2)
1683 action
= FULL_RELOAD
;
1684 else if (probe_argc
< 2)
1685 action
= PROBES_INTERFACE_FAILED
;
1690 /* Populate the shared object list by reading the entire list of
1691 shared objects from the inferior. Handle special cases relating
1692 to the first elements of the list. Returns nonzero on success. */
1695 solist_update_full (struct svr4_info
*info
)
1697 free_solib_list (info
);
1698 info
->solib_list
= svr4_current_sos_direct (info
);
1703 /* Update the shared object list starting from the link-map entry
1704 passed by the linker in the probe's third argument. Returns
1705 nonzero if the list was successfully updated, or zero to indicate
1709 solist_update_incremental (struct svr4_info
*info
, CORE_ADDR lm
)
1711 struct so_list
*tail
;
1714 /* svr4_current_sos_direct contains logic to handle a number of
1715 special cases relating to the first elements of the list. To
1716 avoid duplicating this logic we defer to solist_update_full
1717 if the list is empty. */
1718 if (info
->solib_list
== NULL
)
1721 /* Fall back to a full update if we are using a remote target
1722 that does not support incremental transfers. */
1723 if (info
->using_xfer
&& !target_augmented_libraries_svr4_read ())
1726 /* Walk to the end of the list. */
1727 for (tail
= info
->solib_list
; tail
->next
!= NULL
; tail
= tail
->next
)
1730 lm_info_svr4
*li
= (lm_info_svr4
*) tail
->lm_info
;
1731 prev_lm
= li
->lm_addr
;
1733 /* Read the new objects. */
1734 if (info
->using_xfer
)
1736 struct svr4_library_list library_list
;
1739 xsnprintf (annex
, sizeof (annex
), "start=%s;prev=%s",
1740 phex_nz (lm
, sizeof (lm
)),
1741 phex_nz (prev_lm
, sizeof (prev_lm
)));
1742 if (!svr4_current_sos_via_xfer_libraries (&library_list
, annex
))
1745 tail
->next
= library_list
.head
;
1749 struct so_list
**link
= &tail
->next
;
1751 /* IGNORE_FIRST may safely be set to zero here because the
1752 above check and deferral to solist_update_full ensures
1753 that this call to svr4_read_so_list will never see the
1755 if (!svr4_read_so_list (info
, lm
, prev_lm
, &link
, 0))
1762 /* Disable the probes-based linker interface and revert to the
1763 original interface. We don't reset the breakpoints as the
1764 ones set up for the probes-based interface are adequate. */
1767 disable_probes_interface (svr4_info
*info
)
1769 warning (_("Probes-based dynamic linker interface failed.\n"
1770 "Reverting to original interface."));
1772 free_probes_table (info
);
1773 free_solib_list (info
);
1776 /* Update the solib list as appropriate when using the
1777 probes-based linker interface. Do nothing if using the
1778 standard interface. */
1781 svr4_handle_solib_event (void)
1783 struct svr4_info
*info
= get_svr4_info (current_program_space
);
1784 struct probe_and_action
*pa
;
1785 enum probe_action action
;
1786 struct value
*val
= NULL
;
1787 CORE_ADDR pc
, debug_base
, lm
= 0;
1788 struct frame_info
*frame
= get_current_frame ();
1790 /* Do nothing if not using the probes interface. */
1791 if (info
->probes_table
== NULL
)
1794 /* If anything goes wrong we revert to the original linker
1796 auto cleanup
= make_scope_exit ([info
] ()
1798 disable_probes_interface (info
);
1801 pc
= regcache_read_pc (get_current_regcache ());
1802 pa
= solib_event_probe_at (info
, pc
);
1806 action
= solib_event_probe_action (pa
);
1807 if (action
== PROBES_INTERFACE_FAILED
)
1810 if (action
== DO_NOTHING
)
1816 /* evaluate_argument looks up symbols in the dynamic linker
1817 using find_pc_section. find_pc_section is accelerated by a cache
1818 called the section map. The section map is invalidated every
1819 time a shared library is loaded or unloaded, and if the inferior
1820 is generating a lot of shared library events then the section map
1821 will be updated every time svr4_handle_solib_event is called.
1822 We called find_pc_section in svr4_create_solib_event_breakpoints,
1823 so we can guarantee that the dynamic linker's sections are in the
1824 section map. We can therefore inhibit section map updates across
1825 these calls to evaluate_argument and save a lot of time. */
1827 scoped_restore inhibit_updates
1828 = inhibit_section_map_updates (current_program_space
);
1832 val
= pa
->prob
->evaluate_argument (1, frame
);
1834 catch (const gdb_exception_error
&ex
)
1836 exception_print (gdb_stderr
, ex
);
1843 debug_base
= value_as_address (val
);
1844 if (debug_base
== 0)
1847 /* Always locate the debug struct, in case it moved. */
1848 info
->debug_base
= 0;
1849 if (locate_base (info
) == 0)
1851 /* It's possible for the reloc_complete probe to be triggered before
1852 the linker has set the DT_DEBUG pointer (for example, when the
1853 linker has finished relocating an LD_AUDIT library or its
1854 dependencies). Since we can't yet handle libraries from other link
1855 namespaces, we don't lose anything by ignoring them here. */
1856 struct value
*link_map_id_val
;
1859 link_map_id_val
= pa
->prob
->evaluate_argument (0, frame
);
1861 catch (const gdb_exception_error
)
1863 link_map_id_val
= NULL
;
1865 /* glibc and illumos' libc both define LM_ID_BASE as zero. */
1866 if (link_map_id_val
!= NULL
&& value_as_long (link_map_id_val
) != 0)
1867 action
= DO_NOTHING
;
1872 /* GDB does not currently support libraries loaded via dlmopen
1873 into namespaces other than the initial one. We must ignore
1874 any namespace other than the initial namespace here until
1875 support for this is added to GDB. */
1876 if (debug_base
!= info
->debug_base
)
1877 action
= DO_NOTHING
;
1879 if (action
== UPDATE_OR_RELOAD
)
1883 val
= pa
->prob
->evaluate_argument (2, frame
);
1885 catch (const gdb_exception_error
&ex
)
1887 exception_print (gdb_stderr
, ex
);
1892 lm
= value_as_address (val
);
1895 action
= FULL_RELOAD
;
1898 /* Resume section map updates. Closing the scope is
1902 if (action
== UPDATE_OR_RELOAD
)
1904 if (!solist_update_incremental (info
, lm
))
1905 action
= FULL_RELOAD
;
1908 if (action
== FULL_RELOAD
)
1910 if (!solist_update_full (info
))
1917 /* Helper function for svr4_update_solib_event_breakpoints. */
1920 svr4_update_solib_event_breakpoint (struct breakpoint
*b
)
1922 if (b
->type
!= bp_shlib_event
)
1924 /* Continue iterating. */
1928 for (bp_location
*loc
: b
->locations ())
1930 struct svr4_info
*info
;
1931 struct probe_and_action
*pa
;
1933 info
= solib_svr4_pspace_data
.get (loc
->pspace
);
1934 if (info
== NULL
|| info
->probes_table
== NULL
)
1937 pa
= solib_event_probe_at (info
, loc
->address
);
1941 if (pa
->action
== DO_NOTHING
)
1943 if (b
->enable_state
== bp_disabled
&& stop_on_solib_events
)
1944 enable_breakpoint (b
);
1945 else if (b
->enable_state
== bp_enabled
&& !stop_on_solib_events
)
1946 disable_breakpoint (b
);
1952 /* Continue iterating. */
1956 /* Enable or disable optional solib event breakpoints as appropriate.
1957 Called whenever stop_on_solib_events is changed. */
1960 svr4_update_solib_event_breakpoints (void)
1962 for (breakpoint
*bp
: all_breakpoints_safe ())
1963 svr4_update_solib_event_breakpoint (bp
);
1966 /* Create and register solib event breakpoints. PROBES is an array
1967 of NUM_PROBES elements, each of which is vector of probes. A
1968 solib event breakpoint will be created and registered for each
1972 svr4_create_probe_breakpoints (svr4_info
*info
, struct gdbarch
*gdbarch
,
1973 const std::vector
<probe
*> *probes
,
1974 struct objfile
*objfile
)
1976 for (int i
= 0; i
< NUM_PROBES
; i
++)
1978 enum probe_action action
= probe_info
[i
].action
;
1980 for (probe
*p
: probes
[i
])
1982 CORE_ADDR address
= p
->get_relocated_address (objfile
);
1984 create_solib_event_breakpoint (gdbarch
, address
);
1985 register_solib_event_probe (info
, objfile
, p
, address
, action
);
1989 svr4_update_solib_event_breakpoints ();
1992 /* Find all the glibc named probes. Only if all of the probes are found, then
1993 create them and return true. Otherwise return false. If WITH_PREFIX is set
1994 then add "rtld" to the front of the probe names. */
1996 svr4_find_and_create_probe_breakpoints (svr4_info
*info
,
1997 struct gdbarch
*gdbarch
,
1998 struct obj_section
*os
,
2001 std::vector
<probe
*> probes
[NUM_PROBES
];
2003 for (int i
= 0; i
< NUM_PROBES
; i
++)
2005 const char *name
= probe_info
[i
].name
;
2008 /* Fedora 17 and Red Hat Enterprise Linux 6.2-6.4 shipped with an early
2009 version of the probes code in which the probes' names were prefixed
2010 with "rtld_" and the "map_failed" probe did not exist. The locations
2011 of the probes are otherwise the same, so we check for probes with
2012 prefixed names if probes with unprefixed names are not present. */
2015 xsnprintf (buf
, sizeof (buf
), "rtld_%s", name
);
2019 probes
[i
] = find_probes_in_objfile (os
->objfile
, "rtld", name
);
2021 /* The "map_failed" probe did not exist in early
2022 versions of the probes code in which the probes'
2023 names were prefixed with "rtld_". */
2024 if (with_prefix
&& streq (name
, "rtld_map_failed"))
2027 /* Ensure at least one probe for the current name was found. */
2028 if (probes
[i
].empty ())
2031 /* Ensure probe arguments can be evaluated. */
2032 for (probe
*p
: probes
[i
])
2034 if (!p
->can_evaluate_arguments ())
2036 /* This will fail if the probe is invalid. This has been seen on Arm
2037 due to references to symbols that have been resolved away. */
2040 p
->get_argument_count (gdbarch
);
2042 catch (const gdb_exception_error
&ex
)
2044 exception_print (gdb_stderr
, ex
);
2045 warning (_("Initializing probes-based dynamic linker interface "
2046 "failed.\nReverting to original interface."));
2052 /* All probes found. Now create them. */
2053 svr4_create_probe_breakpoints (info
, gdbarch
, probes
, os
->objfile
);
2057 /* Both the SunOS and the SVR4 dynamic linkers call a marker function
2058 before and after mapping and unmapping shared libraries. The sole
2059 purpose of this method is to allow debuggers to set a breakpoint so
2060 they can track these changes.
2062 Some versions of the glibc dynamic linker contain named probes
2063 to allow more fine grained stopping. Given the address of the
2064 original marker function, this function attempts to find these
2065 probes, and if found, sets breakpoints on those instead. If the
2066 probes aren't found, a single breakpoint is set on the original
2070 svr4_create_solib_event_breakpoints (svr4_info
*info
, struct gdbarch
*gdbarch
,
2073 struct obj_section
*os
= find_pc_section (address
);
2076 || (!svr4_find_and_create_probe_breakpoints (info
, gdbarch
, os
, false)
2077 && !svr4_find_and_create_probe_breakpoints (info
, gdbarch
, os
, true)))
2078 create_solib_event_breakpoint (gdbarch
, address
);
2081 /* Helper function for gdb_bfd_lookup_symbol. */
2084 cmp_name_and_sec_flags (const asymbol
*sym
, const void *data
)
2086 return (strcmp (sym
->name
, (const char *) data
) == 0
2087 && (sym
->section
->flags
& (SEC_CODE
| SEC_DATA
)) != 0);
2089 /* Arrange for dynamic linker to hit breakpoint.
2091 Both the SunOS and the SVR4 dynamic linkers have, as part of their
2092 debugger interface, support for arranging for the inferior to hit
2093 a breakpoint after mapping in the shared libraries. This function
2094 enables that breakpoint.
2096 For SunOS, there is a special flag location (in_debugger) which we
2097 set to 1. When the dynamic linker sees this flag set, it will set
2098 a breakpoint at a location known only to itself, after saving the
2099 original contents of that place and the breakpoint address itself,
2100 in it's own internal structures. When we resume the inferior, it
2101 will eventually take a SIGTRAP when it runs into the breakpoint.
2102 We handle this (in a different place) by restoring the contents of
2103 the breakpointed location (which is only known after it stops),
2104 chasing around to locate the shared libraries that have been
2105 loaded, then resuming.
2107 For SVR4, the debugger interface structure contains a member (r_brk)
2108 which is statically initialized at the time the shared library is
2109 built, to the offset of a function (_r_debug_state) which is guaran-
2110 teed to be called once before mapping in a library, and again when
2111 the mapping is complete. At the time we are examining this member,
2112 it contains only the unrelocated offset of the function, so we have
2113 to do our own relocation. Later, when the dynamic linker actually
2114 runs, it relocates r_brk to be the actual address of _r_debug_state().
2116 The debugger interface structure also contains an enumeration which
2117 is set to either RT_ADD or RT_DELETE prior to changing the mapping,
2118 depending upon whether or not the library is being mapped or unmapped,
2119 and then set to RT_CONSISTENT after the library is mapped/unmapped. */
2122 enable_break (struct svr4_info
*info
, int from_tty
)
2124 struct bound_minimal_symbol msymbol
;
2125 const char * const *bkpt_namep
;
2126 asection
*interp_sect
;
2129 info
->interp_text_sect_low
= info
->interp_text_sect_high
= 0;
2130 info
->interp_plt_sect_low
= info
->interp_plt_sect_high
= 0;
2132 /* If we already have a shared library list in the target, and
2133 r_debug contains r_brk, set the breakpoint there - this should
2134 mean r_brk has already been relocated. Assume the dynamic linker
2135 is the object containing r_brk. */
2137 solib_add (NULL
, from_tty
, auto_solib_add
);
2139 if (info
->debug_base
&& solib_svr4_r_map (info
) != 0)
2140 sym_addr
= solib_svr4_r_brk (info
);
2144 struct obj_section
*os
;
2146 sym_addr
= gdbarch_addr_bits_remove
2148 gdbarch_convert_from_func_ptr_addr
2149 (target_gdbarch (), sym_addr
, current_inferior ()->top_target ()));
2151 /* On at least some versions of Solaris there's a dynamic relocation
2152 on _r_debug.r_brk and SYM_ADDR may not be relocated yet, e.g., if
2153 we get control before the dynamic linker has self-relocated.
2154 Check if SYM_ADDR is in a known section, if it is assume we can
2155 trust its value. This is just a heuristic though, it could go away
2156 or be replaced if it's getting in the way.
2158 On ARM we need to know whether the ISA of rtld_db_dlactivity (or
2159 however it's spelled in your particular system) is ARM or Thumb.
2160 That knowledge is encoded in the address, if it's Thumb the low bit
2161 is 1. However, we've stripped that info above and it's not clear
2162 what all the consequences are of passing a non-addr_bits_remove'd
2163 address to svr4_create_solib_event_breakpoints. The call to
2164 find_pc_section verifies we know about the address and have some
2165 hope of computing the right kind of breakpoint to use (via
2166 symbol info). It does mean that GDB needs to be pointed at a
2167 non-stripped version of the dynamic linker in order to obtain
2168 information it already knows about. Sigh. */
2170 os
= find_pc_section (sym_addr
);
2173 /* Record the relocated start and end address of the dynamic linker
2174 text and plt section for svr4_in_dynsym_resolve_code. */
2176 CORE_ADDR load_addr
;
2178 tmp_bfd
= os
->objfile
->obfd
;
2179 load_addr
= os
->objfile
->text_section_offset ();
2181 interp_sect
= bfd_get_section_by_name (tmp_bfd
, ".text");
2184 info
->interp_text_sect_low
2185 = bfd_section_vma (interp_sect
) + load_addr
;
2186 info
->interp_text_sect_high
2187 = info
->interp_text_sect_low
+ bfd_section_size (interp_sect
);
2189 interp_sect
= bfd_get_section_by_name (tmp_bfd
, ".plt");
2192 info
->interp_plt_sect_low
2193 = bfd_section_vma (interp_sect
) + load_addr
;
2194 info
->interp_plt_sect_high
2195 = info
->interp_plt_sect_low
+ bfd_section_size (interp_sect
);
2198 svr4_create_solib_event_breakpoints (info
, target_gdbarch (), sym_addr
);
2203 /* Find the program interpreter; if not found, warn the user and drop
2204 into the old breakpoint at symbol code. */
2205 gdb::optional
<gdb::byte_vector
> interp_name_holder
2206 = find_program_interpreter ();
2207 if (interp_name_holder
)
2209 const char *interp_name
= (const char *) interp_name_holder
->data ();
2210 CORE_ADDR load_addr
= 0;
2211 int load_addr_found
= 0;
2212 int loader_found_in_list
= 0;
2213 struct target_ops
*tmp_bfd_target
;
2217 /* Now we need to figure out where the dynamic linker was
2218 loaded so that we can load its symbols and place a breakpoint
2219 in the dynamic linker itself.
2221 This address is stored on the stack. However, I've been unable
2222 to find any magic formula to find it for Solaris (appears to
2223 be trivial on GNU/Linux). Therefore, we have to try an alternate
2224 mechanism to find the dynamic linker's base address. */
2226 gdb_bfd_ref_ptr tmp_bfd
;
2229 tmp_bfd
= solib_bfd_open (interp_name
);
2231 catch (const gdb_exception
&ex
)
2235 if (tmp_bfd
== NULL
)
2236 goto bkpt_at_symbol
;
2238 /* Now convert the TMP_BFD into a target. That way target, as
2239 well as BFD operations can be used. */
2240 tmp_bfd_target
= target_bfd_reopen (tmp_bfd
);
2242 /* On a running target, we can get the dynamic linker's base
2243 address from the shared library table. */
2244 for (struct so_list
*so
: current_program_space
->solibs ())
2246 if (svr4_same_1 (interp_name
, so
->so_original_name
))
2248 load_addr_found
= 1;
2249 loader_found_in_list
= 1;
2250 load_addr
= lm_addr_check (so
, tmp_bfd
.get ());
2255 /* If we were not able to find the base address of the loader
2256 from our so_list, then try using the AT_BASE auxilliary entry. */
2257 if (!load_addr_found
)
2258 if (target_auxv_search (current_inferior ()->top_target (),
2259 AT_BASE
, &load_addr
) > 0)
2261 int addr_bit
= gdbarch_addr_bit (target_gdbarch ());
2263 /* Ensure LOAD_ADDR has proper sign in its possible upper bits so
2264 that `+ load_addr' will overflow CORE_ADDR width not creating
2265 invalid addresses like 0x101234567 for 32bit inferiors on 64bit
2268 if (addr_bit
< (sizeof (CORE_ADDR
) * HOST_CHAR_BIT
))
2270 CORE_ADDR space_size
= (CORE_ADDR
) 1 << addr_bit
;
2271 CORE_ADDR tmp_entry_point
= exec_entry_point (tmp_bfd
.get (),
2274 gdb_assert (load_addr
< space_size
);
2276 /* TMP_ENTRY_POINT exceeding SPACE_SIZE would be for prelinked
2277 64bit ld.so with 32bit executable, it should not happen. */
2279 if (tmp_entry_point
< space_size
2280 && tmp_entry_point
+ load_addr
>= space_size
)
2281 load_addr
-= space_size
;
2284 load_addr_found
= 1;
2287 /* Otherwise we find the dynamic linker's base address by examining
2288 the current pc (which should point at the entry point for the
2289 dynamic linker) and subtracting the offset of the entry point.
2291 This is more fragile than the previous approaches, but is a good
2292 fallback method because it has actually been working well in
2294 if (!load_addr_found
)
2296 struct regcache
*regcache
2297 = get_thread_arch_regcache (current_inferior ()->process_target (),
2298 inferior_ptid
, target_gdbarch ());
2300 load_addr
= (regcache_read_pc (regcache
)
2301 - exec_entry_point (tmp_bfd
.get (), tmp_bfd_target
));
2304 if (!loader_found_in_list
)
2306 info
->debug_loader_name
= xstrdup (interp_name
);
2307 info
->debug_loader_offset_p
= 1;
2308 info
->debug_loader_offset
= load_addr
;
2309 solib_add (NULL
, from_tty
, auto_solib_add
);
2312 /* Record the relocated start and end address of the dynamic linker
2313 text and plt section for svr4_in_dynsym_resolve_code. */
2314 interp_sect
= bfd_get_section_by_name (tmp_bfd
.get (), ".text");
2317 info
->interp_text_sect_low
2318 = bfd_section_vma (interp_sect
) + load_addr
;
2319 info
->interp_text_sect_high
2320 = info
->interp_text_sect_low
+ bfd_section_size (interp_sect
);
2322 interp_sect
= bfd_get_section_by_name (tmp_bfd
.get (), ".plt");
2325 info
->interp_plt_sect_low
2326 = bfd_section_vma (interp_sect
) + load_addr
;
2327 info
->interp_plt_sect_high
2328 = info
->interp_plt_sect_low
+ bfd_section_size (interp_sect
);
2331 /* Now try to set a breakpoint in the dynamic linker. */
2332 for (bkpt_namep
= solib_break_names
; *bkpt_namep
!= NULL
; bkpt_namep
++)
2334 sym_addr
= gdb_bfd_lookup_symbol (tmp_bfd
.get (),
2335 cmp_name_and_sec_flags
,
2342 /* Convert 'sym_addr' from a function pointer to an address.
2343 Because we pass tmp_bfd_target instead of the current
2344 target, this will always produce an unrelocated value. */
2345 sym_addr
= gdbarch_convert_from_func_ptr_addr (target_gdbarch (),
2349 /* We're done with both the temporary bfd and target. Closing
2350 the target closes the underlying bfd, because it holds the
2351 only remaining reference. */
2352 target_close (tmp_bfd_target
);
2356 svr4_create_solib_event_breakpoints (info
, target_gdbarch (),
2357 load_addr
+ sym_addr
);
2361 /* For whatever reason we couldn't set a breakpoint in the dynamic
2362 linker. Warn and drop into the old code. */
2364 warning (_("Unable to find dynamic linker breakpoint function.\n"
2365 "GDB will be unable to debug shared library initializers\n"
2366 "and track explicitly loaded dynamic code."));
2369 /* Scan through the lists of symbols, trying to look up the symbol and
2370 set a breakpoint there. Terminate loop when we/if we succeed. */
2372 objfile
*objf
= current_program_space
->symfile_object_file
;
2373 for (bkpt_namep
= solib_break_names
; *bkpt_namep
!= NULL
; bkpt_namep
++)
2375 msymbol
= lookup_minimal_symbol (*bkpt_namep
, NULL
, objf
);
2376 if ((msymbol
.minsym
!= NULL
)
2377 && (BMSYMBOL_VALUE_ADDRESS (msymbol
) != 0))
2379 sym_addr
= BMSYMBOL_VALUE_ADDRESS (msymbol
);
2380 sym_addr
= gdbarch_convert_from_func_ptr_addr
2381 (target_gdbarch (), sym_addr
, current_inferior ()->top_target ());
2382 svr4_create_solib_event_breakpoints (info
, target_gdbarch (),
2388 if (interp_name_holder
&& !current_inferior ()->attach_flag
)
2390 for (bkpt_namep
= bkpt_names
; *bkpt_namep
!= NULL
; bkpt_namep
++)
2392 msymbol
= lookup_minimal_symbol (*bkpt_namep
, NULL
, objf
);
2393 if ((msymbol
.minsym
!= NULL
)
2394 && (BMSYMBOL_VALUE_ADDRESS (msymbol
) != 0))
2396 sym_addr
= BMSYMBOL_VALUE_ADDRESS (msymbol
);
2397 sym_addr
= gdbarch_convert_from_func_ptr_addr
2398 (target_gdbarch (), sym_addr
,
2399 current_inferior ()->top_target ());
2400 svr4_create_solib_event_breakpoints (info
, target_gdbarch (),
2409 /* Read the ELF program headers from ABFD. */
2411 static gdb::optional
<gdb::byte_vector
>
2412 read_program_headers_from_bfd (bfd
*abfd
)
2414 Elf_Internal_Ehdr
*ehdr
= elf_elfheader (abfd
);
2415 int phdrs_size
= ehdr
->e_phnum
* ehdr
->e_phentsize
;
2416 if (phdrs_size
== 0)
2419 gdb::byte_vector
buf (phdrs_size
);
2420 if (bfd_seek (abfd
, ehdr
->e_phoff
, SEEK_SET
) != 0
2421 || bfd_bread (buf
.data (), phdrs_size
, abfd
) != phdrs_size
)
2427 /* Return 1 and fill *DISPLACEMENTP with detected PIE offset of inferior
2428 exec_bfd. Otherwise return 0.
2430 We relocate all of the sections by the same amount. This
2431 behavior is mandated by recent editions of the System V ABI.
2432 According to the System V Application Binary Interface,
2433 Edition 4.1, page 5-5:
2435 ... Though the system chooses virtual addresses for
2436 individual processes, it maintains the segments' relative
2437 positions. Because position-independent code uses relative
2438 addressing between segments, the difference between
2439 virtual addresses in memory must match the difference
2440 between virtual addresses in the file. The difference
2441 between the virtual address of any segment in memory and
2442 the corresponding virtual address in the file is thus a
2443 single constant value for any one executable or shared
2444 object in a given process. This difference is the base
2445 address. One use of the base address is to relocate the
2446 memory image of the program during dynamic linking.
2448 The same language also appears in Edition 4.0 of the System V
2449 ABI and is left unspecified in some of the earlier editions.
2451 Decide if the objfile needs to be relocated. As indicated above, we will
2452 only be here when execution is stopped. But during attachment PC can be at
2453 arbitrary address therefore regcache_read_pc can be misleading (contrary to
2454 the auxv AT_ENTRY value). Moreover for executable with interpreter section
2455 regcache_read_pc would point to the interpreter and not the main executable.
2457 So, to summarize, relocations are necessary when the start address obtained
2458 from the executable is different from the address in auxv AT_ENTRY entry.
2460 [ The astute reader will note that we also test to make sure that
2461 the executable in question has the DYNAMIC flag set. It is my
2462 opinion that this test is unnecessary (undesirable even). It
2463 was added to avoid inadvertent relocation of an executable
2464 whose e_type member in the ELF header is not ET_DYN. There may
2465 be a time in the future when it is desirable to do relocations
2466 on other types of files as well in which case this condition
2467 should either be removed or modified to accomodate the new file
2468 type. - Kevin, Nov 2000. ] */
2471 svr4_exec_displacement (CORE_ADDR
*displacementp
)
2473 /* ENTRY_POINT is a possible function descriptor - before
2474 a call to gdbarch_convert_from_func_ptr_addr. */
2475 CORE_ADDR entry_point
, exec_displacement
;
2477 if (current_program_space
->exec_bfd () == NULL
)
2480 /* Therefore for ELF it is ET_EXEC and not ET_DYN. Both shared libraries
2481 being executed themselves and PIE (Position Independent Executable)
2482 executables are ET_DYN. */
2484 if ((bfd_get_file_flags (current_program_space
->exec_bfd ()) & DYNAMIC
) == 0)
2487 if (target_auxv_search (current_inferior ()->top_target (),
2488 AT_ENTRY
, &entry_point
) <= 0)
2492 = entry_point
- bfd_get_start_address (current_program_space
->exec_bfd ());
2494 /* Verify the EXEC_DISPLACEMENT candidate complies with the required page
2495 alignment. It is cheaper than the program headers comparison below. */
2497 if (bfd_get_flavour (current_program_space
->exec_bfd ())
2498 == bfd_target_elf_flavour
)
2500 const struct elf_backend_data
*elf
2501 = get_elf_backend_data (current_program_space
->exec_bfd ());
2503 /* p_align of PT_LOAD segments does not specify any alignment but
2504 only congruency of addresses:
2505 p_offset % p_align == p_vaddr % p_align
2506 Kernel is free to load the executable with lower alignment. */
2508 if ((exec_displacement
& (elf
->minpagesize
- 1)) != 0)
2512 /* Verify that the auxilliary vector describes the same file as exec_bfd, by
2513 comparing their program headers. If the program headers in the auxilliary
2514 vector do not match the program headers in the executable, then we are
2515 looking at a different file than the one used by the kernel - for
2516 instance, "gdb program" connected to "gdbserver :PORT ld.so program". */
2518 if (bfd_get_flavour (current_program_space
->exec_bfd ())
2519 == bfd_target_elf_flavour
)
2521 /* Be optimistic and return 0 only if GDB was able to verify the headers
2522 really do not match. */
2525 gdb::optional
<gdb::byte_vector
> phdrs_target
2526 = read_program_header (-1, &arch_size
, NULL
);
2527 gdb::optional
<gdb::byte_vector
> phdrs_binary
2528 = read_program_headers_from_bfd (current_program_space
->exec_bfd ());
2529 if (phdrs_target
&& phdrs_binary
)
2531 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch ());
2533 /* We are dealing with three different addresses. EXEC_BFD
2534 represents current address in on-disk file. target memory content
2535 may be different from EXEC_BFD as the file may have been prelinked
2536 to a different address after the executable has been loaded.
2537 Moreover the address of placement in target memory can be
2538 different from what the program headers in target memory say -
2539 this is the goal of PIE.
2541 Detected DISPLACEMENT covers both the offsets of PIE placement and
2542 possible new prelink performed after start of the program. Here
2543 relocate BUF and BUF2 just by the EXEC_BFD vs. target memory
2544 content offset for the verification purpose. */
2546 if (phdrs_target
->size () != phdrs_binary
->size ()
2547 || bfd_get_arch_size (current_program_space
->exec_bfd ()) != arch_size
)
2549 else if (arch_size
== 32
2550 && phdrs_target
->size () >= sizeof (Elf32_External_Phdr
)
2551 && phdrs_target
->size () % sizeof (Elf32_External_Phdr
) == 0)
2553 Elf_Internal_Ehdr
*ehdr2
2554 = elf_tdata (current_program_space
->exec_bfd ())->elf_header
;
2555 Elf_Internal_Phdr
*phdr2
2556 = elf_tdata (current_program_space
->exec_bfd ())->phdr
;
2557 CORE_ADDR displacement
= 0;
2560 /* DISPLACEMENT could be found more easily by the difference of
2561 ehdr2->e_entry. But we haven't read the ehdr yet, and we
2562 already have enough information to compute that displacement
2563 with what we've read. */
2565 for (i
= 0; i
< ehdr2
->e_phnum
; i
++)
2566 if (phdr2
[i
].p_type
== PT_LOAD
)
2568 Elf32_External_Phdr
*phdrp
;
2569 gdb_byte
*buf_vaddr_p
, *buf_paddr_p
;
2570 CORE_ADDR vaddr
, paddr
;
2571 CORE_ADDR displacement_vaddr
= 0;
2572 CORE_ADDR displacement_paddr
= 0;
2574 phdrp
= &((Elf32_External_Phdr
*) phdrs_target
->data ())[i
];
2575 buf_vaddr_p
= (gdb_byte
*) &phdrp
->p_vaddr
;
2576 buf_paddr_p
= (gdb_byte
*) &phdrp
->p_paddr
;
2578 vaddr
= extract_unsigned_integer (buf_vaddr_p
, 4,
2580 displacement_vaddr
= vaddr
- phdr2
[i
].p_vaddr
;
2582 paddr
= extract_unsigned_integer (buf_paddr_p
, 4,
2584 displacement_paddr
= paddr
- phdr2
[i
].p_paddr
;
2586 if (displacement_vaddr
== displacement_paddr
)
2587 displacement
= displacement_vaddr
;
2592 /* Now compare program headers from the target and the binary
2593 with optional DISPLACEMENT. */
2596 i
< phdrs_target
->size () / sizeof (Elf32_External_Phdr
);
2599 Elf32_External_Phdr
*phdrp
;
2600 Elf32_External_Phdr
*phdr2p
;
2601 gdb_byte
*buf_vaddr_p
, *buf_paddr_p
;
2602 CORE_ADDR vaddr
, paddr
;
2603 asection
*plt2_asect
;
2605 phdrp
= &((Elf32_External_Phdr
*) phdrs_target
->data ())[i
];
2606 buf_vaddr_p
= (gdb_byte
*) &phdrp
->p_vaddr
;
2607 buf_paddr_p
= (gdb_byte
*) &phdrp
->p_paddr
;
2608 phdr2p
= &((Elf32_External_Phdr
*) phdrs_binary
->data ())[i
];
2610 /* PT_GNU_STACK is an exception by being never relocated by
2611 prelink as its addresses are always zero. */
2613 if (memcmp (phdrp
, phdr2p
, sizeof (*phdrp
)) == 0)
2616 /* Check also other adjustment combinations - PR 11786. */
2618 vaddr
= extract_unsigned_integer (buf_vaddr_p
, 4,
2620 vaddr
-= displacement
;
2621 store_unsigned_integer (buf_vaddr_p
, 4, byte_order
, vaddr
);
2623 paddr
= extract_unsigned_integer (buf_paddr_p
, 4,
2625 paddr
-= displacement
;
2626 store_unsigned_integer (buf_paddr_p
, 4, byte_order
, paddr
);
2628 if (memcmp (phdrp
, phdr2p
, sizeof (*phdrp
)) == 0)
2631 /* Strip modifies the flags and alignment of PT_GNU_RELRO.
2632 CentOS-5 has problems with filesz, memsz as well.
2633 Strip also modifies memsz of PT_TLS.
2635 if (phdr2
[i
].p_type
== PT_GNU_RELRO
2636 || phdr2
[i
].p_type
== PT_TLS
)
2638 Elf32_External_Phdr tmp_phdr
= *phdrp
;
2639 Elf32_External_Phdr tmp_phdr2
= *phdr2p
;
2641 memset (tmp_phdr
.p_filesz
, 0, 4);
2642 memset (tmp_phdr
.p_memsz
, 0, 4);
2643 memset (tmp_phdr
.p_flags
, 0, 4);
2644 memset (tmp_phdr
.p_align
, 0, 4);
2645 memset (tmp_phdr2
.p_filesz
, 0, 4);
2646 memset (tmp_phdr2
.p_memsz
, 0, 4);
2647 memset (tmp_phdr2
.p_flags
, 0, 4);
2648 memset (tmp_phdr2
.p_align
, 0, 4);
2650 if (memcmp (&tmp_phdr
, &tmp_phdr2
, sizeof (tmp_phdr
))
2655 /* prelink can convert .plt SHT_NOBITS to SHT_PROGBITS. */
2656 bfd
*exec_bfd
= current_program_space
->exec_bfd ();
2657 plt2_asect
= bfd_get_section_by_name (exec_bfd
, ".plt");
2661 gdb_byte
*buf_filesz_p
= (gdb_byte
*) &phdrp
->p_filesz
;
2664 content2
= (bfd_section_flags (plt2_asect
)
2665 & SEC_HAS_CONTENTS
) != 0;
2667 filesz
= extract_unsigned_integer (buf_filesz_p
, 4,
2670 /* PLT2_ASECT is from on-disk file (exec_bfd) while
2671 FILESZ is from the in-memory image. */
2673 filesz
+= bfd_section_size (plt2_asect
);
2675 filesz
-= bfd_section_size (plt2_asect
);
2677 store_unsigned_integer (buf_filesz_p
, 4, byte_order
,
2680 if (memcmp (phdrp
, phdr2p
, sizeof (*phdrp
)) == 0)
2687 else if (arch_size
== 64
2688 && phdrs_target
->size () >= sizeof (Elf64_External_Phdr
)
2689 && phdrs_target
->size () % sizeof (Elf64_External_Phdr
) == 0)
2691 Elf_Internal_Ehdr
*ehdr2
2692 = elf_tdata (current_program_space
->exec_bfd ())->elf_header
;
2693 Elf_Internal_Phdr
*phdr2
2694 = elf_tdata (current_program_space
->exec_bfd ())->phdr
;
2695 CORE_ADDR displacement
= 0;
2698 /* DISPLACEMENT could be found more easily by the difference of
2699 ehdr2->e_entry. But we haven't read the ehdr yet, and we
2700 already have enough information to compute that displacement
2701 with what we've read. */
2703 for (i
= 0; i
< ehdr2
->e_phnum
; i
++)
2704 if (phdr2
[i
].p_type
== PT_LOAD
)
2706 Elf64_External_Phdr
*phdrp
;
2707 gdb_byte
*buf_vaddr_p
, *buf_paddr_p
;
2708 CORE_ADDR vaddr
, paddr
;
2709 CORE_ADDR displacement_vaddr
= 0;
2710 CORE_ADDR displacement_paddr
= 0;
2712 phdrp
= &((Elf64_External_Phdr
*) phdrs_target
->data ())[i
];
2713 buf_vaddr_p
= (gdb_byte
*) &phdrp
->p_vaddr
;
2714 buf_paddr_p
= (gdb_byte
*) &phdrp
->p_paddr
;
2716 vaddr
= extract_unsigned_integer (buf_vaddr_p
, 8,
2718 displacement_vaddr
= vaddr
- phdr2
[i
].p_vaddr
;
2720 paddr
= extract_unsigned_integer (buf_paddr_p
, 8,
2722 displacement_paddr
= paddr
- phdr2
[i
].p_paddr
;
2724 if (displacement_vaddr
== displacement_paddr
)
2725 displacement
= displacement_vaddr
;
2730 /* Now compare BUF and BUF2 with optional DISPLACEMENT. */
2733 i
< phdrs_target
->size () / sizeof (Elf64_External_Phdr
);
2736 Elf64_External_Phdr
*phdrp
;
2737 Elf64_External_Phdr
*phdr2p
;
2738 gdb_byte
*buf_vaddr_p
, *buf_paddr_p
;
2739 CORE_ADDR vaddr
, paddr
;
2740 asection
*plt2_asect
;
2742 phdrp
= &((Elf64_External_Phdr
*) phdrs_target
->data ())[i
];
2743 buf_vaddr_p
= (gdb_byte
*) &phdrp
->p_vaddr
;
2744 buf_paddr_p
= (gdb_byte
*) &phdrp
->p_paddr
;
2745 phdr2p
= &((Elf64_External_Phdr
*) phdrs_binary
->data ())[i
];
2747 /* PT_GNU_STACK is an exception by being never relocated by
2748 prelink as its addresses are always zero. */
2750 if (memcmp (phdrp
, phdr2p
, sizeof (*phdrp
)) == 0)
2753 /* Check also other adjustment combinations - PR 11786. */
2755 vaddr
= extract_unsigned_integer (buf_vaddr_p
, 8,
2757 vaddr
-= displacement
;
2758 store_unsigned_integer (buf_vaddr_p
, 8, byte_order
, vaddr
);
2760 paddr
= extract_unsigned_integer (buf_paddr_p
, 8,
2762 paddr
-= displacement
;
2763 store_unsigned_integer (buf_paddr_p
, 8, byte_order
, paddr
);
2765 if (memcmp (phdrp
, phdr2p
, sizeof (*phdrp
)) == 0)
2768 /* Strip modifies the flags and alignment of PT_GNU_RELRO.
2769 CentOS-5 has problems with filesz, memsz as well.
2770 Strip also modifies memsz of PT_TLS.
2772 if (phdr2
[i
].p_type
== PT_GNU_RELRO
2773 || phdr2
[i
].p_type
== PT_TLS
)
2775 Elf64_External_Phdr tmp_phdr
= *phdrp
;
2776 Elf64_External_Phdr tmp_phdr2
= *phdr2p
;
2778 memset (tmp_phdr
.p_filesz
, 0, 8);
2779 memset (tmp_phdr
.p_memsz
, 0, 8);
2780 memset (tmp_phdr
.p_flags
, 0, 4);
2781 memset (tmp_phdr
.p_align
, 0, 8);
2782 memset (tmp_phdr2
.p_filesz
, 0, 8);
2783 memset (tmp_phdr2
.p_memsz
, 0, 8);
2784 memset (tmp_phdr2
.p_flags
, 0, 4);
2785 memset (tmp_phdr2
.p_align
, 0, 8);
2787 if (memcmp (&tmp_phdr
, &tmp_phdr2
, sizeof (tmp_phdr
))
2792 /* prelink can convert .plt SHT_NOBITS to SHT_PROGBITS. */
2794 = bfd_get_section_by_name (current_program_space
->exec_bfd (),
2799 gdb_byte
*buf_filesz_p
= (gdb_byte
*) &phdrp
->p_filesz
;
2802 content2
= (bfd_section_flags (plt2_asect
)
2803 & SEC_HAS_CONTENTS
) != 0;
2805 filesz
= extract_unsigned_integer (buf_filesz_p
, 8,
2808 /* PLT2_ASECT is from on-disk file (current
2809 exec_bfd) while FILESZ is from the in-memory
2812 filesz
+= bfd_section_size (plt2_asect
);
2814 filesz
-= bfd_section_size (plt2_asect
);
2816 store_unsigned_integer (buf_filesz_p
, 8, byte_order
,
2819 if (memcmp (phdrp
, phdr2p
, sizeof (*phdrp
)) == 0)
2833 /* It can be printed repeatedly as there is no easy way to check
2834 the executable symbols/file has been already relocated to
2837 gdb_printf (_("Using PIE (Position Independent Executable) "
2838 "displacement %s for \"%s\".\n"),
2839 paddress (target_gdbarch (), exec_displacement
),
2840 bfd_get_filename (current_program_space
->exec_bfd ()));
2843 *displacementp
= exec_displacement
;
2847 /* Relocate the main executable. This function should be called upon
2848 stopping the inferior process at the entry point to the program.
2849 The entry point from BFD is compared to the AT_ENTRY of AUXV and if they are
2850 different, the main executable is relocated by the proper amount. */
2853 svr4_relocate_main_executable (void)
2855 CORE_ADDR displacement
;
2857 /* If we are re-running this executable, SYMFILE_OBJFILE->SECTION_OFFSETS
2858 probably contains the offsets computed using the PIE displacement
2859 from the previous run, which of course are irrelevant for this run.
2860 So we need to determine the new PIE displacement and recompute the
2861 section offsets accordingly, even if SYMFILE_OBJFILE->SECTION_OFFSETS
2862 already contains pre-computed offsets.
2864 If we cannot compute the PIE displacement, either:
2866 - The executable is not PIE.
2868 - SYMFILE_OBJFILE does not match the executable started in the target.
2869 This can happen for main executable symbols loaded at the host while
2870 `ld.so --ld-args main-executable' is loaded in the target.
2872 Then we leave the section offsets untouched and use them as is for
2875 - These section offsets were properly reset earlier, and thus
2876 already contain the correct values. This can happen for instance
2877 when reconnecting via the remote protocol to a target that supports
2878 the `qOffsets' packet.
2880 - The section offsets were not reset earlier, and the best we can
2881 hope is that the old offsets are still applicable to the new run. */
2883 if (! svr4_exec_displacement (&displacement
))
2886 /* Even DISPLACEMENT 0 is a valid new difference of in-memory vs. in-file
2889 objfile
*objf
= current_program_space
->symfile_object_file
;
2892 section_offsets
new_offsets (objf
->section_offsets
.size (),
2894 objfile_relocate (objf
, new_offsets
);
2896 else if (current_program_space
->exec_bfd ())
2900 bfd
*exec_bfd
= current_program_space
->exec_bfd ();
2901 for (asect
= exec_bfd
->sections
; asect
!= NULL
; asect
= asect
->next
)
2902 exec_set_section_address (bfd_get_filename (exec_bfd
), asect
->index
,
2903 bfd_section_vma (asect
) + displacement
);
2907 /* Implement the "create_inferior_hook" target_solib_ops method.
2909 For SVR4 executables, this first instruction is either the first
2910 instruction in the dynamic linker (for dynamically linked
2911 executables) or the instruction at "start" for statically linked
2912 executables. For dynamically linked executables, the system
2913 first exec's /lib/libc.so.N, which contains the dynamic linker,
2914 and starts it running. The dynamic linker maps in any needed
2915 shared libraries, maps in the actual user executable, and then
2916 jumps to "start" in the user executable.
2918 We can arrange to cooperate with the dynamic linker to discover the
2919 names of shared libraries that are dynamically linked, and the base
2920 addresses to which they are linked.
2922 This function is responsible for discovering those names and
2923 addresses, and saving sufficient information about them to allow
2924 their symbols to be read at a later time. */
2927 svr4_solib_create_inferior_hook (int from_tty
)
2929 struct svr4_info
*info
;
2931 info
= get_svr4_info (current_program_space
);
2933 /* Clear the probes-based interface's state. */
2934 free_probes_table (info
);
2935 free_solib_list (info
);
2937 /* Relocate the main executable if necessary. */
2938 svr4_relocate_main_executable ();
2940 /* No point setting a breakpoint in the dynamic linker if we can't
2941 hit it (e.g., a core file, or a trace file). */
2942 if (!target_has_execution ())
2945 if (!svr4_have_link_map_offsets ())
2948 if (!enable_break (info
, from_tty
))
2953 svr4_clear_solib (void)
2955 struct svr4_info
*info
;
2957 info
= get_svr4_info (current_program_space
);
2958 info
->debug_base
= 0;
2959 info
->debug_loader_offset_p
= 0;
2960 info
->debug_loader_offset
= 0;
2961 xfree (info
->debug_loader_name
);
2962 info
->debug_loader_name
= NULL
;
2965 /* Clear any bits of ADDR that wouldn't fit in a target-format
2966 data pointer. "Data pointer" here refers to whatever sort of
2967 address the dynamic linker uses to manage its sections. At the
2968 moment, we don't support shared libraries on any processors where
2969 code and data pointers are different sizes.
2971 This isn't really the right solution. What we really need here is
2972 a way to do arithmetic on CORE_ADDR values that respects the
2973 natural pointer/address correspondence. (For example, on the MIPS,
2974 converting a 32-bit pointer to a 64-bit CORE_ADDR requires you to
2975 sign-extend the value. There, simply truncating the bits above
2976 gdbarch_ptr_bit, as we do below, is no good.) This should probably
2977 be a new gdbarch method or something. */
2979 svr4_truncate_ptr (CORE_ADDR addr
)
2981 if (gdbarch_ptr_bit (target_gdbarch ()) == sizeof (CORE_ADDR
) * 8)
2982 /* We don't need to truncate anything, and the bit twiddling below
2983 will fail due to overflow problems. */
2986 return addr
& (((CORE_ADDR
) 1 << gdbarch_ptr_bit (target_gdbarch ())) - 1);
2991 svr4_relocate_section_addresses (struct so_list
*so
,
2992 struct target_section
*sec
)
2994 bfd
*abfd
= sec
->the_bfd_section
->owner
;
2996 sec
->addr
= svr4_truncate_ptr (sec
->addr
+ lm_addr_check (so
, abfd
));
2997 sec
->endaddr
= svr4_truncate_ptr (sec
->endaddr
+ lm_addr_check (so
, abfd
));
3001 /* Architecture-specific operations. */
3003 /* Per-architecture data key. */
3004 static struct gdbarch_data
*solib_svr4_data
;
3006 struct solib_svr4_ops
3008 /* Return a description of the layout of `struct link_map'. */
3009 struct link_map_offsets
*(*fetch_link_map_offsets
)(void);
3012 /* Return a default for the architecture-specific operations. */
3015 solib_svr4_init (struct obstack
*obstack
)
3017 struct solib_svr4_ops
*ops
;
3019 ops
= OBSTACK_ZALLOC (obstack
, struct solib_svr4_ops
);
3020 ops
->fetch_link_map_offsets
= NULL
;
3024 /* Set the architecture-specific `struct link_map_offsets' fetcher for
3025 GDBARCH to FLMO. Also, install SVR4 solib_ops into GDBARCH. */
3028 set_solib_svr4_fetch_link_map_offsets (struct gdbarch
*gdbarch
,
3029 struct link_map_offsets
*(*flmo
) (void))
3031 struct solib_svr4_ops
*ops
3032 = (struct solib_svr4_ops
*) gdbarch_data (gdbarch
, solib_svr4_data
);
3034 ops
->fetch_link_map_offsets
= flmo
;
3036 set_solib_ops (gdbarch
, &svr4_so_ops
);
3037 set_gdbarch_iterate_over_objfiles_in_search_order
3038 (gdbarch
, svr4_iterate_over_objfiles_in_search_order
);
3041 /* Fetch a link_map_offsets structure using the architecture-specific
3042 `struct link_map_offsets' fetcher. */
3044 static struct link_map_offsets
*
3045 svr4_fetch_link_map_offsets (void)
3047 struct solib_svr4_ops
*ops
3048 = (struct solib_svr4_ops
*) gdbarch_data (target_gdbarch (),
3051 gdb_assert (ops
->fetch_link_map_offsets
);
3052 return ops
->fetch_link_map_offsets ();
3055 /* Return 1 if a link map offset fetcher has been defined, 0 otherwise. */
3058 svr4_have_link_map_offsets (void)
3060 struct solib_svr4_ops
*ops
3061 = (struct solib_svr4_ops
*) gdbarch_data (target_gdbarch (),
3064 return (ops
->fetch_link_map_offsets
!= NULL
);
3068 /* Most OS'es that have SVR4-style ELF dynamic libraries define a
3069 `struct r_debug' and a `struct link_map' that are binary compatible
3070 with the original SVR4 implementation. */
3072 /* Fetch (and possibly build) an appropriate `struct link_map_offsets'
3073 for an ILP32 SVR4 system. */
3075 struct link_map_offsets
*
3076 svr4_ilp32_fetch_link_map_offsets (void)
3078 static struct link_map_offsets lmo
;
3079 static struct link_map_offsets
*lmp
= NULL
;
3085 lmo
.r_version_offset
= 0;
3086 lmo
.r_version_size
= 4;
3087 lmo
.r_map_offset
= 4;
3088 lmo
.r_brk_offset
= 8;
3089 lmo
.r_ldsomap_offset
= 20;
3091 /* Everything we need is in the first 20 bytes. */
3092 lmo
.link_map_size
= 20;
3093 lmo
.l_addr_offset
= 0;
3094 lmo
.l_name_offset
= 4;
3095 lmo
.l_ld_offset
= 8;
3096 lmo
.l_next_offset
= 12;
3097 lmo
.l_prev_offset
= 16;
3103 /* Fetch (and possibly build) an appropriate `struct link_map_offsets'
3104 for an LP64 SVR4 system. */
3106 struct link_map_offsets
*
3107 svr4_lp64_fetch_link_map_offsets (void)
3109 static struct link_map_offsets lmo
;
3110 static struct link_map_offsets
*lmp
= NULL
;
3116 lmo
.r_version_offset
= 0;
3117 lmo
.r_version_size
= 4;
3118 lmo
.r_map_offset
= 8;
3119 lmo
.r_brk_offset
= 16;
3120 lmo
.r_ldsomap_offset
= 40;
3122 /* Everything we need is in the first 40 bytes. */
3123 lmo
.link_map_size
= 40;
3124 lmo
.l_addr_offset
= 0;
3125 lmo
.l_name_offset
= 8;
3126 lmo
.l_ld_offset
= 16;
3127 lmo
.l_next_offset
= 24;
3128 lmo
.l_prev_offset
= 32;
3135 struct target_so_ops svr4_so_ops
;
3137 /* Search order for ELF DSOs linked with -Bsymbolic. Those DSOs have a
3138 different rule for symbol lookup. The lookup begins here in the DSO, not in
3139 the main executable. */
3142 svr4_iterate_over_objfiles_in_search_order
3143 (struct gdbarch
*gdbarch
,
3144 iterate_over_objfiles_in_search_order_cb_ftype
*cb
,
3145 void *cb_data
, struct objfile
*current_objfile
)
3147 bool checked_current_objfile
= false;
3148 if (current_objfile
!= nullptr)
3152 if (current_objfile
->separate_debug_objfile_backlink
!= nullptr)
3153 current_objfile
= current_objfile
->separate_debug_objfile_backlink
;
3155 if (current_objfile
== current_program_space
->symfile_object_file
)
3156 abfd
= current_program_space
->exec_bfd ();
3158 abfd
= current_objfile
->obfd
;
3161 && gdb_bfd_scan_elf_dyntag (DT_SYMBOLIC
, abfd
, nullptr, nullptr) == 1)
3163 checked_current_objfile
= true;
3164 if (cb (current_objfile
, cb_data
) != 0)
3169 for (objfile
*objfile
: current_program_space
->objfiles ())
3171 if (checked_current_objfile
&& objfile
== current_objfile
)
3173 if (cb (objfile
, cb_data
) != 0)
3178 void _initialize_svr4_solib ();
3180 _initialize_svr4_solib ()
3182 solib_svr4_data
= gdbarch_data_register_pre_init (solib_svr4_init
);
3184 svr4_so_ops
.relocate_section_addresses
= svr4_relocate_section_addresses
;
3185 svr4_so_ops
.free_so
= svr4_free_so
;
3186 svr4_so_ops
.clear_so
= svr4_clear_so
;
3187 svr4_so_ops
.clear_solib
= svr4_clear_solib
;
3188 svr4_so_ops
.solib_create_inferior_hook
= svr4_solib_create_inferior_hook
;
3189 svr4_so_ops
.current_sos
= svr4_current_sos
;
3190 svr4_so_ops
.open_symbol_file_object
= open_symbol_file_object
;
3191 svr4_so_ops
.in_dynsym_resolve_code
= svr4_in_dynsym_resolve_code
;
3192 svr4_so_ops
.bfd_open
= solib_bfd_open
;
3193 svr4_so_ops
.same
= svr4_same
;
3194 svr4_so_ops
.keep_data_in_core
= svr4_keep_data_in_core
;
3195 svr4_so_ops
.update_breakpoints
= svr4_update_solib_event_breakpoints
;
3196 svr4_so_ops
.handle_event
= svr4_handle_solib_event
;
3198 gdb::observers::free_objfile
.attach (svr4_free_objfile_observer
,