1 /* Read ELF (Executable and Linking Format) object files for GDB.
3 Copyright (C) 1991-2012 Free Software Foundation, Inc.
5 Written by Fred Fish at Cygnus Support.
7 This file is part of GDB.
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program. If not, see <http://www.gnu.org/licenses/>. */
24 #include "gdb_string.h"
26 #include "elf/common.h"
27 #include "elf/internal.h"
33 #include "stabsread.h"
34 #include "gdb-stabs.h"
35 #include "complaints.h"
38 #include "filenames.h"
40 #include "arch-utils.h"
44 #include "gdbthread.h"
48 extern void _initialize_elfread (void);
50 /* Forward declarations. */
51 static const struct sym_fns elf_sym_fns_gdb_index
;
52 static const struct sym_fns elf_sym_fns_lazy_psyms
;
54 /* The struct elfinfo is available only during ELF symbol table and
55 psymtab reading. It is destroyed at the completion of psymtab-reading.
56 It's local to elf_symfile_read. */
60 asection
*stabsect
; /* Section pointer for .stab section */
61 asection
*stabindexsect
; /* Section pointer for .stab.index section */
62 asection
*mdebugsect
; /* Section pointer for .mdebug section */
65 /* Per-objfile data for probe info. */
67 static const struct objfile_data
*probe_key
= NULL
;
69 static void free_elfinfo (void *);
71 /* Minimal symbols located at the GOT entries for .plt - that is the real
72 pointer where the given entry will jump to. It gets updated by the real
73 function address during lazy ld.so resolving in the inferior. These
74 minimal symbols are indexed for <tab>-completion. */
76 #define SYMBOL_GOT_PLT_SUFFIX "@got.plt"
78 /* Locate the segments in ABFD. */
80 static struct symfile_segment_data
*
81 elf_symfile_segments (bfd
*abfd
)
83 Elf_Internal_Phdr
*phdrs
, **segments
;
85 int num_phdrs
, num_segments
, num_sections
, i
;
87 struct symfile_segment_data
*data
;
89 phdrs_size
= bfd_get_elf_phdr_upper_bound (abfd
);
93 phdrs
= alloca (phdrs_size
);
94 num_phdrs
= bfd_get_elf_phdrs (abfd
, phdrs
);
99 segments
= alloca (sizeof (Elf_Internal_Phdr
*) * num_phdrs
);
100 for (i
= 0; i
< num_phdrs
; i
++)
101 if (phdrs
[i
].p_type
== PT_LOAD
)
102 segments
[num_segments
++] = &phdrs
[i
];
104 if (num_segments
== 0)
107 data
= XZALLOC (struct symfile_segment_data
);
108 data
->num_segments
= num_segments
;
109 data
->segment_bases
= XCALLOC (num_segments
, CORE_ADDR
);
110 data
->segment_sizes
= XCALLOC (num_segments
, CORE_ADDR
);
112 for (i
= 0; i
< num_segments
; i
++)
114 data
->segment_bases
[i
] = segments
[i
]->p_vaddr
;
115 data
->segment_sizes
[i
] = segments
[i
]->p_memsz
;
118 num_sections
= bfd_count_sections (abfd
);
119 data
->segment_info
= XCALLOC (num_sections
, int);
121 for (i
= 0, sect
= abfd
->sections
; sect
!= NULL
; i
++, sect
= sect
->next
)
126 if ((bfd_get_section_flags (abfd
, sect
) & SEC_ALLOC
) == 0)
129 vma
= bfd_get_section_vma (abfd
, sect
);
131 for (j
= 0; j
< num_segments
; j
++)
132 if (segments
[j
]->p_memsz
> 0
133 && vma
>= segments
[j
]->p_vaddr
134 && (vma
- segments
[j
]->p_vaddr
) < segments
[j
]->p_memsz
)
136 data
->segment_info
[i
] = j
+ 1;
140 /* We should have found a segment for every non-empty section.
141 If we haven't, we will not relocate this section by any
142 offsets we apply to the segments. As an exception, do not
143 warn about SHT_NOBITS sections; in normal ELF execution
144 environments, SHT_NOBITS means zero-initialized and belongs
145 in a segment, but in no-OS environments some tools (e.g. ARM
146 RealView) use SHT_NOBITS for uninitialized data. Since it is
147 uninitialized, it doesn't need a program header. Such
148 binaries are not relocatable. */
149 if (bfd_get_section_size (sect
) > 0 && j
== num_segments
150 && (bfd_get_section_flags (abfd
, sect
) & SEC_LOAD
) != 0)
151 warning (_("Loadable section \"%s\" outside of ELF segments"),
152 bfd_section_name (abfd
, sect
));
158 /* We are called once per section from elf_symfile_read. We
159 need to examine each section we are passed, check to see
160 if it is something we are interested in processing, and
161 if so, stash away some access information for the section.
163 For now we recognize the dwarf debug information sections and
164 line number sections from matching their section names. The
165 ELF definition is no real help here since it has no direct
166 knowledge of DWARF (by design, so any debugging format can be
169 We also recognize the ".stab" sections used by the Sun compilers
170 released with Solaris 2.
172 FIXME: The section names should not be hardwired strings (what
173 should they be? I don't think most object file formats have enough
174 section flags to specify what kind of debug section it is.
178 elf_locate_sections (bfd
*ignore_abfd
, asection
*sectp
, void *eip
)
182 ei
= (struct elfinfo
*) eip
;
183 if (strcmp (sectp
->name
, ".stab") == 0)
185 ei
->stabsect
= sectp
;
187 else if (strcmp (sectp
->name
, ".stab.index") == 0)
189 ei
->stabindexsect
= sectp
;
191 else if (strcmp (sectp
->name
, ".mdebug") == 0)
193 ei
->mdebugsect
= sectp
;
197 static struct minimal_symbol
*
198 record_minimal_symbol (const char *name
, int name_len
, int copy_name
,
200 enum minimal_symbol_type ms_type
,
201 asection
*bfd_section
, struct objfile
*objfile
)
203 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
205 if (ms_type
== mst_text
|| ms_type
== mst_file_text
206 || ms_type
== mst_text_gnu_ifunc
)
207 address
= gdbarch_smash_text_address (gdbarch
, address
);
209 return prim_record_minimal_symbol_full (name
, name_len
, copy_name
, address
,
210 ms_type
, bfd_section
->index
,
211 bfd_section
, objfile
);
214 /* Read the symbol table of an ELF file.
216 Given an objfile, a symbol table, and a flag indicating whether the
217 symbol table contains regular, dynamic, or synthetic symbols, add all
218 the global function and data symbols to the minimal symbol table.
220 In stabs-in-ELF, as implemented by Sun, there are some local symbols
221 defined in the ELF symbol table, which can be used to locate
222 the beginnings of sections from each ".o" file that was linked to
223 form the executable objfile. We gather any such info and record it
224 in data structures hung off the objfile's private data. */
228 #define ST_SYNTHETIC 2
231 elf_symtab_read (struct objfile
*objfile
, int type
,
232 long number_of_symbols
, asymbol
**symbol_table
,
235 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
240 enum minimal_symbol_type ms_type
;
241 /* If sectinfo is nonNULL, it contains section info that should end up
242 filed in the objfile. */
243 struct stab_section_info
*sectinfo
= NULL
;
244 /* If filesym is nonzero, it points to a file symbol, but we haven't
245 seen any section info for it yet. */
246 asymbol
*filesym
= 0;
247 /* Name of filesym. This is either a constant string or is saved on
248 the objfile's filename cache. */
249 const char *filesymname
= "";
250 struct dbx_symfile_info
*dbx
= objfile
->deprecated_sym_stab_info
;
251 int stripped
= (bfd_get_symcount (objfile
->obfd
) == 0);
253 for (i
= 0; i
< number_of_symbols
; i
++)
255 sym
= symbol_table
[i
];
256 if (sym
->name
== NULL
|| *sym
->name
== '\0')
258 /* Skip names that don't exist (shouldn't happen), or names
259 that are null strings (may happen). */
263 /* Skip "special" symbols, e.g. ARM mapping symbols. These are
264 symbols which do not correspond to objects in the symbol table,
265 but have some other target-specific meaning. */
266 if (bfd_is_target_special_symbol (objfile
->obfd
, sym
))
268 if (gdbarch_record_special_symbol_p (gdbarch
))
269 gdbarch_record_special_symbol (gdbarch
, objfile
, sym
);
273 offset
= ANOFFSET (objfile
->section_offsets
, sym
->section
->index
);
274 if (type
== ST_DYNAMIC
275 && sym
->section
== bfd_und_section_ptr
276 && (sym
->flags
& BSF_FUNCTION
))
278 struct minimal_symbol
*msym
;
279 bfd
*abfd
= objfile
->obfd
;
282 /* Symbol is a reference to a function defined in
284 If its value is non zero then it is usually the address
285 of the corresponding entry in the procedure linkage table,
286 plus the desired section offset.
287 If its value is zero then the dynamic linker has to resolve
288 the symbol. We are unable to find any meaningful address
289 for this symbol in the executable file, so we skip it. */
290 symaddr
= sym
->value
;
294 /* sym->section is the undefined section. However, we want to
295 record the section where the PLT stub resides with the
296 minimal symbol. Search the section table for the one that
297 covers the stub's address. */
298 for (sect
= abfd
->sections
; sect
!= NULL
; sect
= sect
->next
)
300 if ((bfd_get_section_flags (abfd
, sect
) & SEC_ALLOC
) == 0)
303 if (symaddr
>= bfd_get_section_vma (abfd
, sect
)
304 && symaddr
< bfd_get_section_vma (abfd
, sect
)
305 + bfd_get_section_size (sect
))
311 /* On ia64-hpux, we have discovered that the system linker
312 adds undefined symbols with nonzero addresses that cannot
313 be right (their address points inside the code of another
314 function in the .text section). This creates problems
315 when trying to determine which symbol corresponds to
318 We try to detect those buggy symbols by checking which
319 section we think they correspond to. Normally, PLT symbols
320 are stored inside their own section, and the typical name
321 for that section is ".plt". So, if there is a ".plt"
322 section, and yet the section name of our symbol does not
323 start with ".plt", we ignore that symbol. */
324 if (strncmp (sect
->name
, ".plt", 4) != 0
325 && bfd_get_section_by_name (abfd
, ".plt") != NULL
)
328 symaddr
+= ANOFFSET (objfile
->section_offsets
, sect
->index
);
330 msym
= record_minimal_symbol
331 (sym
->name
, strlen (sym
->name
), copy_names
,
332 symaddr
, mst_solib_trampoline
, sect
, objfile
);
334 msym
->filename
= filesymname
;
338 /* If it is a nonstripped executable, do not enter dynamic
339 symbols, as the dynamic symbol table is usually a subset
340 of the main symbol table. */
341 if (type
== ST_DYNAMIC
&& !stripped
)
343 if (sym
->flags
& BSF_FILE
)
345 /* STT_FILE debugging symbol that helps stabs-in-elf debugging.
346 Chain any old one onto the objfile; remember new sym. */
347 if (sectinfo
!= NULL
)
349 sectinfo
->next
= dbx
->stab_section_info
;
350 dbx
->stab_section_info
= sectinfo
;
354 filesymname
= bcache (filesym
->name
, strlen (filesym
->name
) + 1,
355 objfile
->filename_cache
);
357 else if (sym
->flags
& BSF_SECTION_SYM
)
359 else if (sym
->flags
& (BSF_GLOBAL
| BSF_LOCAL
| BSF_WEAK
))
361 struct minimal_symbol
*msym
;
363 /* Select global/local/weak symbols. Note that bfd puts abs
364 symbols in their own section, so all symbols we are
365 interested in will have a section. */
366 /* Bfd symbols are section relative. */
367 symaddr
= sym
->value
+ sym
->section
->vma
;
368 /* Relocate all non-absolute and non-TLS symbols by the
370 if (sym
->section
!= bfd_abs_section_ptr
371 && !(sym
->section
->flags
& SEC_THREAD_LOCAL
))
375 /* For non-absolute symbols, use the type of the section
376 they are relative to, to intuit text/data. Bfd provides
377 no way of figuring this out for absolute symbols. */
378 if (sym
->section
== bfd_abs_section_ptr
)
380 /* This is a hack to get the minimal symbol type
381 right for Irix 5, which has absolute addresses
382 with special section indices for dynamic symbols.
384 NOTE: uweigand-20071112: Synthetic symbols do not
385 have an ELF-private part, so do not touch those. */
386 unsigned int shndx
= type
== ST_SYNTHETIC
? 0 :
387 ((elf_symbol_type
*) sym
)->internal_elf_sym
.st_shndx
;
397 case SHN_MIPS_ACOMMON
:
404 /* If it is an Irix dynamic symbol, skip section name
405 symbols, relocate all others by section offset. */
406 if (ms_type
!= mst_abs
)
408 if (sym
->name
[0] == '.')
413 else if (sym
->section
->flags
& SEC_CODE
)
415 if (sym
->flags
& (BSF_GLOBAL
| BSF_WEAK
))
417 if (sym
->flags
& BSF_GNU_INDIRECT_FUNCTION
)
418 ms_type
= mst_text_gnu_ifunc
;
422 /* The BSF_SYNTHETIC check is there to omit ppc64 function
423 descriptors mistaken for static functions starting with 'L'.
425 else if ((sym
->name
[0] == '.' && sym
->name
[1] == 'L'
426 && (sym
->flags
& BSF_SYNTHETIC
) == 0)
427 || ((sym
->flags
& BSF_LOCAL
)
428 && sym
->name
[0] == '$'
429 && sym
->name
[1] == 'L'))
430 /* Looks like a compiler-generated label. Skip
431 it. The assembler should be skipping these (to
432 keep executables small), but apparently with
433 gcc on the (deleted) delta m88k SVR4, it loses.
434 So to have us check too should be harmless (but
435 I encourage people to fix this in the assembler
436 instead of adding checks here). */
440 ms_type
= mst_file_text
;
443 else if (sym
->section
->flags
& SEC_ALLOC
)
445 if (sym
->flags
& (BSF_GLOBAL
| BSF_WEAK
))
447 if (sym
->section
->flags
& SEC_LOAD
)
456 else if (sym
->flags
& BSF_LOCAL
)
458 /* Named Local variable in a Data section.
459 Check its name for stabs-in-elf. */
460 int special_local_sect
;
462 if (strcmp ("Bbss.bss", sym
->name
) == 0)
463 special_local_sect
= SECT_OFF_BSS (objfile
);
464 else if (strcmp ("Ddata.data", sym
->name
) == 0)
465 special_local_sect
= SECT_OFF_DATA (objfile
);
466 else if (strcmp ("Drodata.rodata", sym
->name
) == 0)
467 special_local_sect
= SECT_OFF_RODATA (objfile
);
469 special_local_sect
= -1;
470 if (special_local_sect
>= 0)
472 /* Found a special local symbol. Allocate a
473 sectinfo, if needed, and fill it in. */
474 if (sectinfo
== NULL
)
479 max_index
= SECT_OFF_BSS (objfile
);
480 if (objfile
->sect_index_data
> max_index
)
481 max_index
= objfile
->sect_index_data
;
482 if (objfile
->sect_index_rodata
> max_index
)
483 max_index
= objfile
->sect_index_rodata
;
485 /* max_index is the largest index we'll
486 use into this array, so we must
487 allocate max_index+1 elements for it.
488 However, 'struct stab_section_info'
489 already includes one element, so we
490 need to allocate max_index aadditional
492 size
= (sizeof (struct stab_section_info
)
493 + (sizeof (CORE_ADDR
) * max_index
));
494 sectinfo
= (struct stab_section_info
*)
496 memset (sectinfo
, 0, size
);
497 sectinfo
->num_sections
= max_index
;
500 complaint (&symfile_complaints
,
501 _("elf/stab section information %s "
502 "without a preceding file symbol"),
508 (char *) filesym
->name
;
511 if (sectinfo
->sections
[special_local_sect
] != 0)
512 complaint (&symfile_complaints
,
513 _("duplicated elf/stab section "
514 "information for %s"),
516 /* BFD symbols are section relative. */
517 symaddr
= sym
->value
+ sym
->section
->vma
;
518 /* Relocate non-absolute symbols by the
520 if (sym
->section
!= bfd_abs_section_ptr
)
522 sectinfo
->sections
[special_local_sect
] = symaddr
;
523 /* The special local symbols don't go in the
524 minimal symbol table, so ignore this one. */
527 /* Not a special stabs-in-elf symbol, do regular
528 symbol processing. */
529 if (sym
->section
->flags
& SEC_LOAD
)
531 ms_type
= mst_file_data
;
535 ms_type
= mst_file_bss
;
540 ms_type
= mst_unknown
;
545 /* FIXME: Solaris2 shared libraries include lots of
546 odd "absolute" and "undefined" symbols, that play
547 hob with actions like finding what function the PC
548 is in. Ignore them if they aren't text, data, or bss. */
549 /* ms_type = mst_unknown; */
550 continue; /* Skip this symbol. */
552 msym
= record_minimal_symbol
553 (sym
->name
, strlen (sym
->name
), copy_names
, symaddr
,
554 ms_type
, sym
->section
, objfile
);
558 /* Pass symbol size field in via BFD. FIXME!!! */
559 elf_symbol_type
*elf_sym
;
561 /* NOTE: uweigand-20071112: A synthetic symbol does not have an
562 ELF-private part. However, in some cases (e.g. synthetic
563 'dot' symbols on ppc64) the udata.p entry is set to point back
564 to the original ELF symbol it was derived from. Get the size
566 if (type
!= ST_SYNTHETIC
)
567 elf_sym
= (elf_symbol_type
*) sym
;
569 elf_sym
= (elf_symbol_type
*) sym
->udata
.p
;
572 MSYMBOL_SIZE(msym
) = elf_sym
->internal_elf_sym
.st_size
;
574 msym
->filename
= filesymname
;
575 gdbarch_elf_make_msymbol_special (gdbarch
, sym
, msym
);
578 /* For @plt symbols, also record a trampoline to the
579 destination symbol. The @plt symbol will be used in
580 disassembly, and the trampoline will be used when we are
581 trying to find the target. */
582 if (msym
&& ms_type
== mst_text
&& type
== ST_SYNTHETIC
)
584 int len
= strlen (sym
->name
);
586 if (len
> 4 && strcmp (sym
->name
+ len
- 4, "@plt") == 0)
588 struct minimal_symbol
*mtramp
;
590 mtramp
= record_minimal_symbol (sym
->name
, len
- 4, 1,
592 mst_solib_trampoline
,
593 sym
->section
, objfile
);
596 MSYMBOL_SIZE (mtramp
) = MSYMBOL_SIZE (msym
);
597 mtramp
->filename
= filesymname
;
598 gdbarch_elf_make_msymbol_special (gdbarch
, sym
, mtramp
);
606 /* Build minimal symbols named `function@got.plt' (see SYMBOL_GOT_PLT_SUFFIX)
607 for later look ups of which function to call when user requests
608 a STT_GNU_IFUNC function. As the STT_GNU_IFUNC type is found at the target
609 library defining `function' we cannot yet know while reading OBJFILE which
610 of the SYMBOL_GOT_PLT_SUFFIX entries will be needed and later
611 DYN_SYMBOL_TABLE is no longer easily available for OBJFILE. */
614 elf_rel_plt_read (struct objfile
*objfile
, asymbol
**dyn_symbol_table
)
616 bfd
*obfd
= objfile
->obfd
;
617 const struct elf_backend_data
*bed
= get_elf_backend_data (obfd
);
618 asection
*plt
, *relplt
, *got_plt
;
621 bfd_size_type reloc_count
, reloc
;
622 char *string_buffer
= NULL
;
623 size_t string_buffer_size
= 0;
624 struct cleanup
*back_to
;
625 struct gdbarch
*gdbarch
= objfile
->gdbarch
;
626 struct type
*ptr_type
= builtin_type (gdbarch
)->builtin_data_ptr
;
627 size_t ptr_size
= TYPE_LENGTH (ptr_type
);
629 if (objfile
->separate_debug_objfile_backlink
)
632 plt
= bfd_get_section_by_name (obfd
, ".plt");
635 plt_elf_idx
= elf_section_data (plt
)->this_idx
;
637 got_plt
= bfd_get_section_by_name (obfd
, ".got.plt");
641 /* This search algorithm is from _bfd_elf_canonicalize_dynamic_reloc. */
642 for (relplt
= obfd
->sections
; relplt
!= NULL
; relplt
= relplt
->next
)
643 if (elf_section_data (relplt
)->this_hdr
.sh_info
== plt_elf_idx
644 && (elf_section_data (relplt
)->this_hdr
.sh_type
== SHT_REL
645 || elf_section_data (relplt
)->this_hdr
.sh_type
== SHT_RELA
))
650 if (! bed
->s
->slurp_reloc_table (obfd
, relplt
, dyn_symbol_table
, TRUE
))
653 back_to
= make_cleanup (free_current_contents
, &string_buffer
);
655 reloc_count
= relplt
->size
/ elf_section_data (relplt
)->this_hdr
.sh_entsize
;
656 for (reloc
= 0; reloc
< reloc_count
; reloc
++)
658 const char *name
, *name_got_plt
;
659 struct minimal_symbol
*msym
;
661 const size_t got_suffix_len
= strlen (SYMBOL_GOT_PLT_SUFFIX
);
664 name
= bfd_asymbol_name (*relplt
->relocation
[reloc
].sym_ptr_ptr
);
665 name_len
= strlen (name
);
666 address
= relplt
->relocation
[reloc
].address
;
668 /* Does the pointer reside in the .got.plt section? */
669 if (!(bfd_get_section_vma (obfd
, got_plt
) <= address
670 && address
< bfd_get_section_vma (obfd
, got_plt
)
671 + bfd_get_section_size (got_plt
)))
674 /* We cannot check if NAME is a reference to mst_text_gnu_ifunc as in
675 OBJFILE the symbol is undefined and the objfile having NAME defined
676 may not yet have been loaded. */
678 if (string_buffer_size
< name_len
+ got_suffix_len
+ 1)
680 string_buffer_size
= 2 * (name_len
+ got_suffix_len
);
681 string_buffer
= xrealloc (string_buffer
, string_buffer_size
);
683 memcpy (string_buffer
, name
, name_len
);
684 memcpy (&string_buffer
[name_len
], SYMBOL_GOT_PLT_SUFFIX
,
687 msym
= record_minimal_symbol (string_buffer
, name_len
+ got_suffix_len
,
688 1, address
, mst_slot_got_plt
, got_plt
,
691 MSYMBOL_SIZE (msym
) = ptr_size
;
694 do_cleanups (back_to
);
697 /* The data pointer is htab_t for gnu_ifunc_record_cache_unchecked. */
699 static const struct objfile_data
*elf_objfile_gnu_ifunc_cache_data
;
701 /* Map function names to CORE_ADDR in elf_objfile_gnu_ifunc_cache_data. */
703 struct elf_gnu_ifunc_cache
705 /* This is always a function entry address, not a function descriptor. */
711 /* htab_hash for elf_objfile_gnu_ifunc_cache_data. */
714 elf_gnu_ifunc_cache_hash (const void *a_voidp
)
716 const struct elf_gnu_ifunc_cache
*a
= a_voidp
;
718 return htab_hash_string (a
->name
);
721 /* htab_eq for elf_objfile_gnu_ifunc_cache_data. */
724 elf_gnu_ifunc_cache_eq (const void *a_voidp
, const void *b_voidp
)
726 const struct elf_gnu_ifunc_cache
*a
= a_voidp
;
727 const struct elf_gnu_ifunc_cache
*b
= b_voidp
;
729 return strcmp (a
->name
, b
->name
) == 0;
732 /* Record the target function address of a STT_GNU_IFUNC function NAME is the
733 function entry address ADDR. Return 1 if NAME and ADDR are considered as
734 valid and therefore they were successfully recorded, return 0 otherwise.
736 Function does not expect a duplicate entry. Use
737 elf_gnu_ifunc_resolve_by_cache first to check if the entry for NAME already
741 elf_gnu_ifunc_record_cache (const char *name
, CORE_ADDR addr
)
743 struct minimal_symbol
*msym
;
745 struct objfile
*objfile
;
747 struct elf_gnu_ifunc_cache entry_local
, *entry_p
;
750 msym
= lookup_minimal_symbol_by_pc (addr
);
753 if (SYMBOL_VALUE_ADDRESS (msym
) != addr
)
755 /* minimal symbols have always SYMBOL_OBJ_SECTION non-NULL. */
756 sect
= SYMBOL_OBJ_SECTION (msym
)->the_bfd_section
;
757 objfile
= SYMBOL_OBJ_SECTION (msym
)->objfile
;
759 /* If .plt jumps back to .plt the symbol is still deferred for later
760 resolution and it has no use for GDB. Besides ".text" this symbol can
761 reside also in ".opd" for ppc64 function descriptor. */
762 if (strcmp (bfd_get_section_name (objfile
->obfd
, sect
), ".plt") == 0)
765 htab
= objfile_data (objfile
, elf_objfile_gnu_ifunc_cache_data
);
768 htab
= htab_create_alloc_ex (1, elf_gnu_ifunc_cache_hash
,
769 elf_gnu_ifunc_cache_eq
,
770 NULL
, &objfile
->objfile_obstack
,
771 hashtab_obstack_allocate
,
772 dummy_obstack_deallocate
);
773 set_objfile_data (objfile
, elf_objfile_gnu_ifunc_cache_data
, htab
);
776 entry_local
.addr
= addr
;
777 obstack_grow (&objfile
->objfile_obstack
, &entry_local
,
778 offsetof (struct elf_gnu_ifunc_cache
, name
));
779 obstack_grow_str0 (&objfile
->objfile_obstack
, name
);
780 entry_p
= obstack_finish (&objfile
->objfile_obstack
);
782 slot
= htab_find_slot (htab
, entry_p
, INSERT
);
785 struct elf_gnu_ifunc_cache
*entry_found_p
= *slot
;
786 struct gdbarch
*gdbarch
= objfile
->gdbarch
;
788 if (entry_found_p
->addr
!= addr
)
790 /* This case indicates buggy inferior program, the resolved address
791 should never change. */
793 warning (_("gnu-indirect-function \"%s\" has changed its resolved "
794 "function_address from %s to %s"),
795 name
, paddress (gdbarch
, entry_found_p
->addr
),
796 paddress (gdbarch
, addr
));
799 /* New ENTRY_P is here leaked/duplicate in the OBJFILE obstack. */
806 /* Try to find the target resolved function entry address of a STT_GNU_IFUNC
807 function NAME. If the address is found it is stored to *ADDR_P (if ADDR_P
808 is not NULL) and the function returns 1. It returns 0 otherwise.
810 Only the elf_objfile_gnu_ifunc_cache_data hash table is searched by this
814 elf_gnu_ifunc_resolve_by_cache (const char *name
, CORE_ADDR
*addr_p
)
816 struct objfile
*objfile
;
818 ALL_PSPACE_OBJFILES (current_program_space
, objfile
)
821 struct elf_gnu_ifunc_cache
*entry_p
;
824 htab
= objfile_data (objfile
, elf_objfile_gnu_ifunc_cache_data
);
828 entry_p
= alloca (sizeof (*entry_p
) + strlen (name
));
829 strcpy (entry_p
->name
, name
);
831 slot
= htab_find_slot (htab
, entry_p
, NO_INSERT
);
835 gdb_assert (entry_p
!= NULL
);
838 *addr_p
= entry_p
->addr
;
845 /* Try to find the target resolved function entry address of a STT_GNU_IFUNC
846 function NAME. If the address is found it is stored to *ADDR_P (if ADDR_P
847 is not NULL) and the function returns 1. It returns 0 otherwise.
849 Only the SYMBOL_GOT_PLT_SUFFIX locations are searched by this function.
850 elf_gnu_ifunc_resolve_by_cache must have been already called for NAME to
851 prevent cache entries duplicates. */
854 elf_gnu_ifunc_resolve_by_got (const char *name
, CORE_ADDR
*addr_p
)
857 struct objfile
*objfile
;
858 const size_t got_suffix_len
= strlen (SYMBOL_GOT_PLT_SUFFIX
);
860 name_got_plt
= alloca (strlen (name
) + got_suffix_len
+ 1);
861 sprintf (name_got_plt
, "%s" SYMBOL_GOT_PLT_SUFFIX
, name
);
863 ALL_PSPACE_OBJFILES (current_program_space
, objfile
)
865 bfd
*obfd
= objfile
->obfd
;
866 struct gdbarch
*gdbarch
= objfile
->gdbarch
;
867 struct type
*ptr_type
= builtin_type (gdbarch
)->builtin_data_ptr
;
868 size_t ptr_size
= TYPE_LENGTH (ptr_type
);
869 CORE_ADDR pointer_address
, addr
;
871 gdb_byte
*buf
= alloca (ptr_size
);
872 struct minimal_symbol
*msym
;
874 msym
= lookup_minimal_symbol (name_got_plt
, NULL
, objfile
);
877 if (MSYMBOL_TYPE (msym
) != mst_slot_got_plt
)
879 pointer_address
= SYMBOL_VALUE_ADDRESS (msym
);
881 plt
= bfd_get_section_by_name (obfd
, ".plt");
885 if (MSYMBOL_SIZE (msym
) != ptr_size
)
887 if (target_read_memory (pointer_address
, buf
, ptr_size
) != 0)
889 addr
= extract_typed_address (buf
, ptr_type
);
890 addr
= gdbarch_convert_from_func_ptr_addr (gdbarch
, addr
,
895 if (elf_gnu_ifunc_record_cache (name
, addr
))
902 /* Try to find the target resolved function entry address of a STT_GNU_IFUNC
903 function NAME. If the address is found it is stored to *ADDR_P (if ADDR_P
904 is not NULL) and the function returns 1. It returns 0 otherwise.
906 Both the elf_objfile_gnu_ifunc_cache_data hash table and
907 SYMBOL_GOT_PLT_SUFFIX locations are searched by this function. */
910 elf_gnu_ifunc_resolve_name (const char *name
, CORE_ADDR
*addr_p
)
912 if (elf_gnu_ifunc_resolve_by_cache (name
, addr_p
))
915 if (elf_gnu_ifunc_resolve_by_got (name
, addr_p
))
921 /* Call STT_GNU_IFUNC - a function returning addresss of a real function to
922 call. PC is theSTT_GNU_IFUNC resolving function entry. The value returned
923 is the entry point of the resolved STT_GNU_IFUNC target function to call.
927 elf_gnu_ifunc_resolve_addr (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
929 const char *name_at_pc
;
930 CORE_ADDR start_at_pc
, address
;
931 struct type
*func_func_type
= builtin_type (gdbarch
)->builtin_func_func
;
932 struct value
*function
, *address_val
;
934 /* Try first any non-intrusive methods without an inferior call. */
936 if (find_pc_partial_function (pc
, &name_at_pc
, &start_at_pc
, NULL
)
937 && start_at_pc
== pc
)
939 if (elf_gnu_ifunc_resolve_name (name_at_pc
, &address
))
945 function
= allocate_value (func_func_type
);
946 set_value_address (function
, pc
);
948 /* STT_GNU_IFUNC resolver functions have no parameters. FUNCTION is the
949 function entry address. ADDRESS may be a function descriptor. */
951 address_val
= call_function_by_hand (function
, 0, NULL
);
952 address
= value_as_address (address_val
);
953 address
= gdbarch_convert_from_func_ptr_addr (gdbarch
, address
,
957 elf_gnu_ifunc_record_cache (name_at_pc
, address
);
962 /* Handle inferior hit of bp_gnu_ifunc_resolver, see its definition. */
965 elf_gnu_ifunc_resolver_stop (struct breakpoint
*b
)
967 struct breakpoint
*b_return
;
968 struct frame_info
*prev_frame
= get_prev_frame (get_current_frame ());
969 struct frame_id prev_frame_id
= get_stack_frame_id (prev_frame
);
970 CORE_ADDR prev_pc
= get_frame_pc (prev_frame
);
971 int thread_id
= pid_to_thread_id (inferior_ptid
);
973 gdb_assert (b
->type
== bp_gnu_ifunc_resolver
);
975 for (b_return
= b
->related_breakpoint
; b_return
!= b
;
976 b_return
= b_return
->related_breakpoint
)
978 gdb_assert (b_return
->type
== bp_gnu_ifunc_resolver_return
);
979 gdb_assert (b_return
->loc
!= NULL
&& b_return
->loc
->next
== NULL
);
980 gdb_assert (frame_id_p (b_return
->frame_id
));
982 if (b_return
->thread
== thread_id
983 && b_return
->loc
->requested_address
== prev_pc
984 && frame_id_eq (b_return
->frame_id
, prev_frame_id
))
990 struct symtab_and_line sal
;
992 /* No need to call find_pc_line for symbols resolving as this is only
993 a helper breakpointer never shown to the user. */
996 sal
.pspace
= current_inferior ()->pspace
;
998 sal
.section
= find_pc_overlay (sal
.pc
);
1000 b_return
= set_momentary_breakpoint (get_frame_arch (prev_frame
), sal
,
1002 bp_gnu_ifunc_resolver_return
);
1004 /* set_momentary_breakpoint invalidates PREV_FRAME. */
1007 /* Add new b_return to the ring list b->related_breakpoint. */
1008 gdb_assert (b_return
->related_breakpoint
== b_return
);
1009 b_return
->related_breakpoint
= b
->related_breakpoint
;
1010 b
->related_breakpoint
= b_return
;
1014 /* Handle inferior hit of bp_gnu_ifunc_resolver_return, see its definition. */
1017 elf_gnu_ifunc_resolver_return_stop (struct breakpoint
*b
)
1019 struct gdbarch
*gdbarch
= get_frame_arch (get_current_frame ());
1020 struct type
*func_func_type
= builtin_type (gdbarch
)->builtin_func_func
;
1021 struct type
*value_type
= TYPE_TARGET_TYPE (func_func_type
);
1022 struct regcache
*regcache
= get_thread_regcache (inferior_ptid
);
1023 struct value
*value
;
1024 CORE_ADDR resolved_address
, resolved_pc
;
1025 struct symtab_and_line sal
;
1026 struct symtabs_and_lines sals
, sals_end
;
1028 gdb_assert (b
->type
== bp_gnu_ifunc_resolver_return
);
1030 value
= allocate_value (value_type
);
1031 gdbarch_return_value (gdbarch
, func_func_type
, value_type
, regcache
,
1032 value_contents_raw (value
), NULL
);
1033 resolved_address
= value_as_address (value
);
1034 resolved_pc
= gdbarch_convert_from_func_ptr_addr (gdbarch
,
1038 while (b
->related_breakpoint
!= b
)
1040 struct breakpoint
*b_next
= b
->related_breakpoint
;
1044 case bp_gnu_ifunc_resolver
:
1046 case bp_gnu_ifunc_resolver_return
:
1047 delete_breakpoint (b
);
1050 internal_error (__FILE__
, __LINE__
,
1051 _("handle_inferior_event: Invalid "
1052 "gnu-indirect-function breakpoint type %d"),
1057 gdb_assert (b
->type
== bp_gnu_ifunc_resolver
);
1059 gdb_assert (current_program_space
== b
->pspace
|| b
->pspace
== NULL
);
1060 elf_gnu_ifunc_record_cache (b
->addr_string
, resolved_pc
);
1062 sal
= find_pc_line (resolved_pc
, 0);
1067 b
->type
= bp_breakpoint
;
1068 update_breakpoint_locations (b
, sals
, sals_end
);
1077 /* Locate NT_GNU_BUILD_ID from ABFD and return its content. */
1079 static struct build_id
*
1080 build_id_bfd_get (bfd
*abfd
)
1082 struct build_id
*retval
;
1084 if (!bfd_check_format (abfd
, bfd_object
)
1085 || bfd_get_flavour (abfd
) != bfd_target_elf_flavour
1086 || elf_tdata (abfd
)->build_id
== NULL
)
1089 retval
= xmalloc (sizeof *retval
- 1 + elf_tdata (abfd
)->build_id_size
);
1090 retval
->size
= elf_tdata (abfd
)->build_id_size
;
1091 memcpy (retval
->data
, elf_tdata (abfd
)->build_id
, retval
->size
);
1096 /* Return if FILENAME has NT_GNU_BUILD_ID matching the CHECK value. */
1099 build_id_verify (const char *filename
, struct build_id
*check
)
1102 struct build_id
*found
= NULL
;
1105 /* We expect to be silent on the non-existing files. */
1106 abfd
= bfd_open_maybe_remote (filename
);
1110 found
= build_id_bfd_get (abfd
);
1113 warning (_("File \"%s\" has no build-id, file skipped"), filename
);
1114 else if (found
->size
!= check
->size
1115 || memcmp (found
->data
, check
->data
, found
->size
) != 0)
1116 warning (_("File \"%s\" has a different build-id, file skipped"),
1121 gdb_bfd_close_or_warn (abfd
);
1129 build_id_to_debug_filename (struct build_id
*build_id
)
1131 char *link
, *debugdir
, *retval
= NULL
;
1132 VEC (char_ptr
) *debugdir_vec
;
1133 struct cleanup
*back_to
;
1136 /* DEBUG_FILE_DIRECTORY/.build-id/ab/cdef */
1137 link
= alloca (strlen (debug_file_directory
) + (sizeof "/.build-id/" - 1) + 1
1138 + 2 * build_id
->size
+ (sizeof ".debug" - 1) + 1);
1140 /* Keep backward compatibility so that DEBUG_FILE_DIRECTORY being "" will
1141 cause "/.build-id/..." lookups. */
1143 debugdir_vec
= dirnames_to_char_ptr_vec (debug_file_directory
);
1144 back_to
= make_cleanup_free_char_ptr_vec (debugdir_vec
);
1146 for (ix
= 0; VEC_iterate (char_ptr
, debugdir_vec
, ix
, debugdir
); ++ix
)
1148 size_t debugdir_len
= strlen (debugdir
);
1149 gdb_byte
*data
= build_id
->data
;
1150 size_t size
= build_id
->size
;
1153 memcpy (link
, debugdir
, debugdir_len
);
1154 s
= &link
[debugdir_len
];
1155 s
+= sprintf (s
, "/.build-id/");
1159 s
+= sprintf (s
, "%02x", (unsigned) *data
++);
1164 s
+= sprintf (s
, "%02x", (unsigned) *data
++);
1165 strcpy (s
, ".debug");
1167 /* lrealpath() is expensive even for the usually non-existent files. */
1168 if (access (link
, F_OK
) == 0)
1169 retval
= lrealpath (link
);
1171 if (retval
!= NULL
&& !build_id_verify (retval
, build_id
))
1181 do_cleanups (back_to
);
1186 find_separate_debug_file_by_buildid (struct objfile
*objfile
)
1188 struct build_id
*build_id
;
1190 build_id
= build_id_bfd_get (objfile
->obfd
);
1191 if (build_id
!= NULL
)
1193 char *build_id_name
;
1195 build_id_name
= build_id_to_debug_filename (build_id
);
1197 /* Prevent looping on a stripped .debug file. */
1198 if (build_id_name
!= NULL
1199 && filename_cmp (build_id_name
, objfile
->name
) == 0)
1201 warning (_("\"%s\": separate debug info file has no debug info"),
1203 xfree (build_id_name
);
1205 else if (build_id_name
!= NULL
)
1206 return build_id_name
;
1211 /* Scan and build partial symbols for a symbol file.
1212 We have been initialized by a call to elf_symfile_init, which
1213 currently does nothing.
1215 SECTION_OFFSETS is a set of offsets to apply to relocate the symbols
1216 in each section. We simplify it down to a single offset for all
1219 This function only does the minimum work necessary for letting the
1220 user "name" things symbolically; it does not read the entire symtab.
1221 Instead, it reads the external and static symbols and puts them in partial
1222 symbol tables. When more extensive information is requested of a
1223 file, the corresponding partial symbol table is mutated into a full
1224 fledged symbol table by going back and reading the symbols
1227 We look for sections with specific names, to tell us what debug
1228 format to look for: FIXME!!!
1230 elfstab_build_psymtabs() handles STABS symbols;
1231 mdebug_build_psymtabs() handles ECOFF debugging information.
1233 Note that ELF files have a "minimal" symbol table, which looks a lot
1234 like a COFF symbol table, but has only the minimal information necessary
1235 for linking. We process this also, and use the information to
1236 build gdb's minimal symbol table. This gives us some minimal debugging
1237 capability even for files compiled without -g. */
1240 elf_symfile_read (struct objfile
*objfile
, int symfile_flags
)
1242 bfd
*synth_abfd
, *abfd
= objfile
->obfd
;
1244 struct cleanup
*back_to
;
1245 long symcount
= 0, dynsymcount
= 0, synthcount
, storage_needed
;
1246 asymbol
**symbol_table
= NULL
, **dyn_symbol_table
= NULL
;
1249 init_minimal_symbol_collection ();
1250 back_to
= make_cleanup_discard_minimal_symbols ();
1252 memset ((char *) &ei
, 0, sizeof (ei
));
1254 /* Allocate struct to keep track of the symfile. */
1255 objfile
->deprecated_sym_stab_info
= (struct dbx_symfile_info
*)
1256 xmalloc (sizeof (struct dbx_symfile_info
));
1257 memset ((char *) objfile
->deprecated_sym_stab_info
,
1258 0, sizeof (struct dbx_symfile_info
));
1259 make_cleanup (free_elfinfo
, (void *) objfile
);
1261 /* Process the normal ELF symbol table first. This may write some
1262 chain of info into the dbx_symfile_info in
1263 objfile->deprecated_sym_stab_info, which can later be used by
1264 elfstab_offset_sections. */
1266 storage_needed
= bfd_get_symtab_upper_bound (objfile
->obfd
);
1267 if (storage_needed
< 0)
1268 error (_("Can't read symbols from %s: %s"),
1269 bfd_get_filename (objfile
->obfd
),
1270 bfd_errmsg (bfd_get_error ()));
1272 if (storage_needed
> 0)
1274 symbol_table
= (asymbol
**) xmalloc (storage_needed
);
1275 make_cleanup (xfree
, symbol_table
);
1276 symcount
= bfd_canonicalize_symtab (objfile
->obfd
, symbol_table
);
1279 error (_("Can't read symbols from %s: %s"),
1280 bfd_get_filename (objfile
->obfd
),
1281 bfd_errmsg (bfd_get_error ()));
1283 elf_symtab_read (objfile
, ST_REGULAR
, symcount
, symbol_table
, 0);
1286 /* Add the dynamic symbols. */
1288 storage_needed
= bfd_get_dynamic_symtab_upper_bound (objfile
->obfd
);
1290 if (storage_needed
> 0)
1292 /* Memory gets permanently referenced from ABFD after
1293 bfd_get_synthetic_symtab so it must not get freed before ABFD gets.
1294 It happens only in the case when elf_slurp_reloc_table sees
1295 asection->relocation NULL. Determining which section is asection is
1296 done by _bfd_elf_get_synthetic_symtab which is all a bfd
1297 implementation detail, though. */
1299 dyn_symbol_table
= bfd_alloc (abfd
, storage_needed
);
1300 dynsymcount
= bfd_canonicalize_dynamic_symtab (objfile
->obfd
,
1303 if (dynsymcount
< 0)
1304 error (_("Can't read symbols from %s: %s"),
1305 bfd_get_filename (objfile
->obfd
),
1306 bfd_errmsg (bfd_get_error ()));
1308 elf_symtab_read (objfile
, ST_DYNAMIC
, dynsymcount
, dyn_symbol_table
, 0);
1310 elf_rel_plt_read (objfile
, dyn_symbol_table
);
1313 /* Contrary to binutils --strip-debug/--only-keep-debug the strip command from
1314 elfutils (eu-strip) moves even the .symtab section into the .debug file.
1316 bfd_get_synthetic_symtab on ppc64 for each function descriptor ELF symbol
1317 'name' creates a new BSF_SYNTHETIC ELF symbol '.name' with its code
1318 address. But with eu-strip files bfd_get_synthetic_symtab would fail to
1319 read the code address from .opd while it reads the .symtab section from
1320 a separate debug info file as the .opd section is SHT_NOBITS there.
1322 With SYNTH_ABFD the .opd section will be read from the original
1323 backlinked binary where it is valid. */
1325 if (objfile
->separate_debug_objfile_backlink
)
1326 synth_abfd
= objfile
->separate_debug_objfile_backlink
->obfd
;
1330 /* Add synthetic symbols - for instance, names for any PLT entries. */
1332 synthcount
= bfd_get_synthetic_symtab (synth_abfd
, symcount
, symbol_table
,
1333 dynsymcount
, dyn_symbol_table
,
1337 asymbol
**synth_symbol_table
;
1340 make_cleanup (xfree
, synthsyms
);
1341 synth_symbol_table
= xmalloc (sizeof (asymbol
*) * synthcount
);
1342 for (i
= 0; i
< synthcount
; i
++)
1343 synth_symbol_table
[i
] = synthsyms
+ i
;
1344 make_cleanup (xfree
, synth_symbol_table
);
1345 elf_symtab_read (objfile
, ST_SYNTHETIC
, synthcount
,
1346 synth_symbol_table
, 1);
1349 /* Install any minimal symbols that have been collected as the current
1350 minimal symbols for this objfile. The debug readers below this point
1351 should not generate new minimal symbols; if they do it's their
1352 responsibility to install them. "mdebug" appears to be the only one
1353 which will do this. */
1355 install_minimal_symbols (objfile
);
1356 do_cleanups (back_to
);
1358 /* Now process debugging information, which is contained in
1359 special ELF sections. */
1361 /* We first have to find them... */
1362 bfd_map_over_sections (abfd
, elf_locate_sections
, (void *) & ei
);
1364 /* ELF debugging information is inserted into the psymtab in the
1365 order of least informative first - most informative last. Since
1366 the psymtab table is searched `most recent insertion first' this
1367 increases the probability that more detailed debug information
1368 for a section is found.
1370 For instance, an object file might contain both .mdebug (XCOFF)
1371 and .debug_info (DWARF2) sections then .mdebug is inserted first
1372 (searched last) and DWARF2 is inserted last (searched first). If
1373 we don't do this then the XCOFF info is found first - for code in
1374 an included file XCOFF info is useless. */
1378 const struct ecoff_debug_swap
*swap
;
1380 /* .mdebug section, presumably holding ECOFF debugging
1382 swap
= get_elf_backend_data (abfd
)->elf_backend_ecoff_debug_swap
;
1384 elfmdebug_build_psymtabs (objfile
, swap
, ei
.mdebugsect
);
1390 /* Stab sections have an associated string table that looks like
1391 a separate section. */
1392 str_sect
= bfd_get_section_by_name (abfd
, ".stabstr");
1394 /* FIXME should probably warn about a stab section without a stabstr. */
1396 elfstab_build_psymtabs (objfile
,
1399 bfd_section_size (abfd
, str_sect
));
1402 if (dwarf2_has_info (objfile
, NULL
))
1404 /* elf_sym_fns_gdb_index cannot handle simultaneous non-DWARF debug
1405 information present in OBJFILE. If there is such debug info present
1406 never use .gdb_index. */
1408 if (!objfile_has_partial_symbols (objfile
)
1409 && dwarf2_initialize_objfile (objfile
))
1410 objfile
->sf
= &elf_sym_fns_gdb_index
;
1413 /* It is ok to do this even if the stabs reader made some
1414 partial symbols, because OBJF_PSYMTABS_READ has not been
1415 set, and so our lazy reader function will still be called
1417 objfile
->sf
= &elf_sym_fns_lazy_psyms
;
1420 /* If the file has its own symbol tables it has no separate debug
1421 info. `.dynsym'/`.symtab' go to MSYMBOLS, `.debug_info' goes to
1422 SYMTABS/PSYMTABS. `.gnu_debuglink' may no longer be present with
1423 `.note.gnu.build-id'. */
1424 else if (!objfile_has_partial_symbols (objfile
))
1428 debugfile
= find_separate_debug_file_by_buildid (objfile
);
1430 if (debugfile
== NULL
)
1431 debugfile
= find_separate_debug_file_by_debuglink (objfile
);
1435 bfd
*abfd
= symfile_bfd_open (debugfile
);
1437 symbol_file_add_separate (abfd
, symfile_flags
, objfile
);
1443 /* Callback to lazily read psymtabs. */
1446 read_psyms (struct objfile
*objfile
)
1448 if (dwarf2_has_info (objfile
, NULL
))
1449 dwarf2_build_psymtabs (objfile
);
1452 /* This cleans up the objfile's deprecated_sym_stab_info pointer, and
1453 the chain of stab_section_info's, that might be dangling from
1457 free_elfinfo (void *objp
)
1459 struct objfile
*objfile
= (struct objfile
*) objp
;
1460 struct dbx_symfile_info
*dbxinfo
= objfile
->deprecated_sym_stab_info
;
1461 struct stab_section_info
*ssi
, *nssi
;
1463 ssi
= dbxinfo
->stab_section_info
;
1471 dbxinfo
->stab_section_info
= 0; /* Just say No mo info about this. */
1475 /* Initialize anything that needs initializing when a completely new symbol
1476 file is specified (not just adding some symbols from another file, e.g. a
1479 We reinitialize buildsym, since we may be reading stabs from an ELF
1483 elf_new_init (struct objfile
*ignore
)
1485 stabsread_new_init ();
1486 buildsym_new_init ();
1489 /* Perform any local cleanups required when we are done with a particular
1490 objfile. I.E, we are in the process of discarding all symbol information
1491 for an objfile, freeing up all memory held for it, and unlinking the
1492 objfile struct from the global list of known objfiles. */
1495 elf_symfile_finish (struct objfile
*objfile
)
1497 if (objfile
->deprecated_sym_stab_info
!= NULL
)
1499 xfree (objfile
->deprecated_sym_stab_info
);
1502 dwarf2_free_objfile (objfile
);
1505 /* ELF specific initialization routine for reading symbols.
1507 It is passed a pointer to a struct sym_fns which contains, among other
1508 things, the BFD for the file whose symbols are being read, and a slot for
1509 a pointer to "private data" which we can fill with goodies.
1511 For now at least, we have nothing in particular to do, so this function is
1515 elf_symfile_init (struct objfile
*objfile
)
1517 /* ELF objects may be reordered, so set OBJF_REORDERED. If we
1518 find this causes a significant slowdown in gdb then we could
1519 set it in the debug symbol readers only when necessary. */
1520 objfile
->flags
|= OBJF_REORDERED
;
1523 /* When handling an ELF file that contains Sun STABS debug info,
1524 some of the debug info is relative to the particular chunk of the
1525 section that was generated in its individual .o file. E.g.
1526 offsets to static variables are relative to the start of the data
1527 segment *for that module before linking*. This information is
1528 painfully squirreled away in the ELF symbol table as local symbols
1529 with wierd names. Go get 'em when needed. */
1532 elfstab_offset_sections (struct objfile
*objfile
, struct partial_symtab
*pst
)
1534 const char *filename
= pst
->filename
;
1535 struct dbx_symfile_info
*dbx
= objfile
->deprecated_sym_stab_info
;
1536 struct stab_section_info
*maybe
= dbx
->stab_section_info
;
1537 struct stab_section_info
*questionable
= 0;
1540 /* The ELF symbol info doesn't include path names, so strip the path
1541 (if any) from the psymtab filename. */
1542 filename
= lbasename (filename
);
1544 /* FIXME: This linear search could speed up significantly
1545 if it was chained in the right order to match how we search it,
1546 and if we unchained when we found a match. */
1547 for (; maybe
; maybe
= maybe
->next
)
1549 if (filename
[0] == maybe
->filename
[0]
1550 && filename_cmp (filename
, maybe
->filename
) == 0)
1552 /* We found a match. But there might be several source files
1553 (from different directories) with the same name. */
1554 if (0 == maybe
->found
)
1556 questionable
= maybe
; /* Might use it later. */
1560 if (maybe
== 0 && questionable
!= 0)
1562 complaint (&symfile_complaints
,
1563 _("elf/stab section information questionable for %s"),
1565 maybe
= questionable
;
1570 /* Found it! Allocate a new psymtab struct, and fill it in. */
1572 pst
->section_offsets
= (struct section_offsets
*)
1573 obstack_alloc (&objfile
->objfile_obstack
,
1574 SIZEOF_N_SECTION_OFFSETS (objfile
->num_sections
));
1575 for (i
= 0; i
< maybe
->num_sections
; i
++)
1576 (pst
->section_offsets
)->offsets
[i
] = maybe
->sections
[i
];
1580 /* We were unable to find any offsets for this file. Complain. */
1581 if (dbx
->stab_section_info
) /* If there *is* any info, */
1582 complaint (&symfile_complaints
,
1583 _("elf/stab section information missing for %s"), filename
);
1586 /* Implementation of `sym_get_probes', as documented in symfile.h. */
1588 static VEC (probe_p
) *
1589 elf_get_probes (struct objfile
*objfile
)
1591 VEC (probe_p
) *probes_per_objfile
;
1593 /* Have we parsed this objfile's probes already? */
1594 probes_per_objfile
= objfile_data (objfile
, probe_key
);
1596 if (!probes_per_objfile
)
1599 const struct probe_ops
*probe_ops
;
1601 /* Here we try to gather information about all types of probes from the
1603 for (ix
= 0; VEC_iterate (probe_ops_cp
, all_probe_ops
, ix
, probe_ops
);
1605 probe_ops
->get_probes (&probes_per_objfile
, objfile
);
1607 if (probes_per_objfile
== NULL
)
1609 VEC_reserve (probe_p
, probes_per_objfile
, 1);
1610 gdb_assert (probes_per_objfile
!= NULL
);
1613 set_objfile_data (objfile
, probe_key
, probes_per_objfile
);
1616 return probes_per_objfile
;
1619 /* Implementation of `sym_get_probe_argument_count', as documented in
1623 elf_get_probe_argument_count (struct objfile
*objfile
,
1624 struct probe
*probe
)
1626 return probe
->pops
->get_probe_argument_count (probe
, objfile
);
1629 /* Implementation of `sym_evaluate_probe_argument', as documented in
1632 static struct value
*
1633 elf_evaluate_probe_argument (struct objfile
*objfile
,
1634 struct probe
*probe
,
1637 return probe
->pops
->evaluate_probe_argument (probe
, objfile
, n
);
1640 /* Implementation of `sym_compile_to_ax', as documented in symfile.h. */
1643 elf_compile_to_ax (struct objfile
*objfile
,
1644 struct probe
*probe
,
1645 struct agent_expr
*expr
,
1646 struct axs_value
*value
,
1649 probe
->pops
->compile_to_ax (probe
, objfile
, expr
, value
, n
);
1652 /* Implementation of `sym_relocate_probe', as documented in symfile.h. */
1655 elf_symfile_relocate_probe (struct objfile
*objfile
,
1656 struct section_offsets
*new_offsets
,
1657 struct section_offsets
*delta
)
1660 VEC (probe_p
) *probes
= objfile_data (objfile
, probe_key
);
1661 struct probe
*probe
;
1663 for (ix
= 0; VEC_iterate (probe_p
, probes
, ix
, probe
); ix
++)
1664 probe
->pops
->relocate (probe
, ANOFFSET (delta
, SECT_OFF_TEXT (objfile
)));
1667 /* Helper function used to free the space allocated for storing SystemTap
1668 probe information. */
1671 probe_key_free (struct objfile
*objfile
, void *d
)
1674 VEC (probe_p
) *probes
= d
;
1675 struct probe
*probe
;
1677 for (ix
= 0; VEC_iterate (probe_p
, probes
, ix
, probe
); ix
++)
1678 probe
->pops
->destroy (probe
);
1680 VEC_free (probe_p
, probes
);
1685 /* Implementation `sym_probe_fns', as documented in symfile.h. */
1687 static const struct sym_probe_fns elf_probe_fns
=
1689 elf_get_probes
, /* sym_get_probes */
1690 elf_get_probe_argument_count
, /* sym_get_probe_argument_count */
1691 elf_evaluate_probe_argument
, /* sym_evaluate_probe_argument */
1692 elf_compile_to_ax
, /* sym_compile_to_ax */
1693 elf_symfile_relocate_probe
, /* sym_relocate_probe */
1696 /* Register that we are able to handle ELF object file formats. */
1698 static const struct sym_fns elf_sym_fns
=
1700 bfd_target_elf_flavour
,
1701 elf_new_init
, /* init anything gbl to entire symtab */
1702 elf_symfile_init
, /* read initial info, setup for sym_read() */
1703 elf_symfile_read
, /* read a symbol file into symtab */
1704 NULL
, /* sym_read_psymbols */
1705 elf_symfile_finish
, /* finished with file, cleanup */
1706 default_symfile_offsets
, /* Translate ext. to int. relocation */
1707 elf_symfile_segments
, /* Get segment information from a file. */
1709 default_symfile_relocate
, /* Relocate a debug section. */
1710 &elf_probe_fns
, /* sym_probe_fns */
1714 /* The same as elf_sym_fns, but not registered and lazily reads
1717 static const struct sym_fns elf_sym_fns_lazy_psyms
=
1719 bfd_target_elf_flavour
,
1720 elf_new_init
, /* init anything gbl to entire symtab */
1721 elf_symfile_init
, /* read initial info, setup for sym_read() */
1722 elf_symfile_read
, /* read a symbol file into symtab */
1723 read_psyms
, /* sym_read_psymbols */
1724 elf_symfile_finish
, /* finished with file, cleanup */
1725 default_symfile_offsets
, /* Translate ext. to int. relocation */
1726 elf_symfile_segments
, /* Get segment information from a file. */
1728 default_symfile_relocate
, /* Relocate a debug section. */
1729 &elf_probe_fns
, /* sym_probe_fns */
1733 /* The same as elf_sym_fns, but not registered and uses the
1734 DWARF-specific GNU index rather than psymtab. */
1735 static const struct sym_fns elf_sym_fns_gdb_index
=
1737 bfd_target_elf_flavour
,
1738 elf_new_init
, /* init anything gbl to entire symab */
1739 elf_symfile_init
, /* read initial info, setup for sym_red() */
1740 elf_symfile_read
, /* read a symbol file into symtab */
1741 NULL
, /* sym_read_psymbols */
1742 elf_symfile_finish
, /* finished with file, cleanup */
1743 default_symfile_offsets
, /* Translate ext. to int. relocatin */
1744 elf_symfile_segments
, /* Get segment information from a file. */
1746 default_symfile_relocate
, /* Relocate a debug section. */
1747 &elf_probe_fns
, /* sym_probe_fns */
1748 &dwarf2_gdb_index_functions
1751 /* STT_GNU_IFUNC resolver vector to be installed to gnu_ifunc_fns_p. */
1753 static const struct gnu_ifunc_fns elf_gnu_ifunc_fns
=
1755 elf_gnu_ifunc_resolve_addr
,
1756 elf_gnu_ifunc_resolve_name
,
1757 elf_gnu_ifunc_resolver_stop
,
1758 elf_gnu_ifunc_resolver_return_stop
1762 _initialize_elfread (void)
1764 probe_key
= register_objfile_data_with_cleanup (NULL
, probe_key_free
);
1765 add_symtab_fns (&elf_sym_fns
);
1767 elf_objfile_gnu_ifunc_cache_data
= register_objfile_data ();
1768 gnu_ifunc_fns_p
= &elf_gnu_ifunc_fns
;