1 /* Read ELF (Executable and Linking Format) object files for GDB.
3 Copyright (C) 1991-2013 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"
49 extern void _initialize_elfread (void);
51 /* Forward declarations. */
52 static const struct sym_fns elf_sym_fns_gdb_index
;
53 static const struct sym_fns elf_sym_fns_lazy_psyms
;
55 /* The struct elfinfo is available only during ELF symbol table and
56 psymtab reading. It is destroyed at the completion of psymtab-reading.
57 It's local to elf_symfile_read. */
61 asection
*stabsect
; /* Section pointer for .stab section */
62 asection
*stabindexsect
; /* Section pointer for .stab.index section */
63 asection
*mdebugsect
; /* Section pointer for .mdebug section */
66 /* Per-objfile data for probe info. */
68 static const struct objfile_data
*probe_key
= NULL
;
70 static void free_elfinfo (void *);
72 /* Minimal symbols located at the GOT entries for .plt - that is the real
73 pointer where the given entry will jump to. It gets updated by the real
74 function address during lazy ld.so resolving in the inferior. These
75 minimal symbols are indexed for <tab>-completion. */
77 #define SYMBOL_GOT_PLT_SUFFIX "@got.plt"
79 /* Locate the segments in ABFD. */
81 static struct symfile_segment_data
*
82 elf_symfile_segments (bfd
*abfd
)
84 Elf_Internal_Phdr
*phdrs
, **segments
;
86 int num_phdrs
, num_segments
, num_sections
, i
;
88 struct symfile_segment_data
*data
;
90 phdrs_size
= bfd_get_elf_phdr_upper_bound (abfd
);
94 phdrs
= alloca (phdrs_size
);
95 num_phdrs
= bfd_get_elf_phdrs (abfd
, phdrs
);
100 segments
= alloca (sizeof (Elf_Internal_Phdr
*) * num_phdrs
);
101 for (i
= 0; i
< num_phdrs
; i
++)
102 if (phdrs
[i
].p_type
== PT_LOAD
)
103 segments
[num_segments
++] = &phdrs
[i
];
105 if (num_segments
== 0)
108 data
= XZALLOC (struct symfile_segment_data
);
109 data
->num_segments
= num_segments
;
110 data
->segment_bases
= XCALLOC (num_segments
, CORE_ADDR
);
111 data
->segment_sizes
= XCALLOC (num_segments
, CORE_ADDR
);
113 for (i
= 0; i
< num_segments
; i
++)
115 data
->segment_bases
[i
] = segments
[i
]->p_vaddr
;
116 data
->segment_sizes
[i
] = segments
[i
]->p_memsz
;
119 num_sections
= bfd_count_sections (abfd
);
120 data
->segment_info
= XCALLOC (num_sections
, int);
122 for (i
= 0, sect
= abfd
->sections
; sect
!= NULL
; i
++, sect
= sect
->next
)
127 if ((bfd_get_section_flags (abfd
, sect
) & SEC_ALLOC
) == 0)
130 vma
= bfd_get_section_vma (abfd
, sect
);
132 for (j
= 0; j
< num_segments
; j
++)
133 if (segments
[j
]->p_memsz
> 0
134 && vma
>= segments
[j
]->p_vaddr
135 && (vma
- segments
[j
]->p_vaddr
) < segments
[j
]->p_memsz
)
137 data
->segment_info
[i
] = j
+ 1;
141 /* We should have found a segment for every non-empty section.
142 If we haven't, we will not relocate this section by any
143 offsets we apply to the segments. As an exception, do not
144 warn about SHT_NOBITS sections; in normal ELF execution
145 environments, SHT_NOBITS means zero-initialized and belongs
146 in a segment, but in no-OS environments some tools (e.g. ARM
147 RealView) use SHT_NOBITS for uninitialized data. Since it is
148 uninitialized, it doesn't need a program header. Such
149 binaries are not relocatable. */
150 if (bfd_get_section_size (sect
) > 0 && j
== num_segments
151 && (bfd_get_section_flags (abfd
, sect
) & SEC_LOAD
) != 0)
152 warning (_("Loadable section \"%s\" outside of ELF segments"),
153 bfd_section_name (abfd
, sect
));
159 /* We are called once per section from elf_symfile_read. We
160 need to examine each section we are passed, check to see
161 if it is something we are interested in processing, and
162 if so, stash away some access information for the section.
164 For now we recognize the dwarf debug information sections and
165 line number sections from matching their section names. The
166 ELF definition is no real help here since it has no direct
167 knowledge of DWARF (by design, so any debugging format can be
170 We also recognize the ".stab" sections used by the Sun compilers
171 released with Solaris 2.
173 FIXME: The section names should not be hardwired strings (what
174 should they be? I don't think most object file formats have enough
175 section flags to specify what kind of debug section it is.
179 elf_locate_sections (bfd
*ignore_abfd
, asection
*sectp
, void *eip
)
183 ei
= (struct elfinfo
*) eip
;
184 if (strcmp (sectp
->name
, ".stab") == 0)
186 ei
->stabsect
= sectp
;
188 else if (strcmp (sectp
->name
, ".stab.index") == 0)
190 ei
->stabindexsect
= sectp
;
192 else if (strcmp (sectp
->name
, ".mdebug") == 0)
194 ei
->mdebugsect
= sectp
;
198 static struct minimal_symbol
*
199 record_minimal_symbol (const char *name
, int name_len
, int copy_name
,
201 enum minimal_symbol_type ms_type
,
202 asection
*bfd_section
, struct objfile
*objfile
)
204 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
206 if (ms_type
== mst_text
|| ms_type
== mst_file_text
207 || ms_type
== mst_text_gnu_ifunc
)
208 address
= gdbarch_addr_bits_remove (gdbarch
, address
);
210 return prim_record_minimal_symbol_full (name
, name_len
, copy_name
, address
,
211 ms_type
, bfd_section
->index
,
212 bfd_section
, objfile
);
215 /* Read the symbol table of an ELF file.
217 Given an objfile, a symbol table, and a flag indicating whether the
218 symbol table contains regular, dynamic, or synthetic symbols, add all
219 the global function and data symbols to the minimal symbol table.
221 In stabs-in-ELF, as implemented by Sun, there are some local symbols
222 defined in the ELF symbol table, which can be used to locate
223 the beginnings of sections from each ".o" file that was linked to
224 form the executable objfile. We gather any such info and record it
225 in data structures hung off the objfile's private data. */
229 #define ST_SYNTHETIC 2
232 elf_symtab_read (struct objfile
*objfile
, int type
,
233 long number_of_symbols
, asymbol
**symbol_table
,
236 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
241 enum minimal_symbol_type ms_type
;
242 /* If sectinfo is nonNULL, it contains section info that should end up
243 filed in the objfile. */
244 struct stab_section_info
*sectinfo
= NULL
;
245 /* If filesym is nonzero, it points to a file symbol, but we haven't
246 seen any section info for it yet. */
247 asymbol
*filesym
= 0;
248 /* Name of filesym. This is either a constant string or is saved on
249 the objfile's filename cache. */
250 const char *filesymname
= "";
251 struct dbx_symfile_info
*dbx
= DBX_SYMFILE_INFO (objfile
);
252 int stripped
= (bfd_get_symcount (objfile
->obfd
) == 0);
254 for (i
= 0; i
< number_of_symbols
; i
++)
256 sym
= symbol_table
[i
];
257 if (sym
->name
== NULL
|| *sym
->name
== '\0')
259 /* Skip names that don't exist (shouldn't happen), or names
260 that are null strings (may happen). */
264 /* Skip "special" symbols, e.g. ARM mapping symbols. These are
265 symbols which do not correspond to objects in the symbol table,
266 but have some other target-specific meaning. */
267 if (bfd_is_target_special_symbol (objfile
->obfd
, sym
))
269 if (gdbarch_record_special_symbol_p (gdbarch
))
270 gdbarch_record_special_symbol (gdbarch
, objfile
, sym
);
274 offset
= ANOFFSET (objfile
->section_offsets
, sym
->section
->index
);
275 if (type
== ST_DYNAMIC
276 && sym
->section
== bfd_und_section_ptr
277 && (sym
->flags
& BSF_FUNCTION
))
279 struct minimal_symbol
*msym
;
280 bfd
*abfd
= objfile
->obfd
;
283 /* Symbol is a reference to a function defined in
285 If its value is non zero then it is usually the address
286 of the corresponding entry in the procedure linkage table,
287 plus the desired section offset.
288 If its value is zero then the dynamic linker has to resolve
289 the symbol. We are unable to find any meaningful address
290 for this symbol in the executable file, so we skip it. */
291 symaddr
= sym
->value
;
295 /* sym->section is the undefined section. However, we want to
296 record the section where the PLT stub resides with the
297 minimal symbol. Search the section table for the one that
298 covers the stub's address. */
299 for (sect
= abfd
->sections
; sect
!= NULL
; sect
= sect
->next
)
301 if ((bfd_get_section_flags (abfd
, sect
) & SEC_ALLOC
) == 0)
304 if (symaddr
>= bfd_get_section_vma (abfd
, sect
)
305 && symaddr
< bfd_get_section_vma (abfd
, sect
)
306 + bfd_get_section_size (sect
))
312 /* On ia64-hpux, we have discovered that the system linker
313 adds undefined symbols with nonzero addresses that cannot
314 be right (their address points inside the code of another
315 function in the .text section). This creates problems
316 when trying to determine which symbol corresponds to
319 We try to detect those buggy symbols by checking which
320 section we think they correspond to. Normally, PLT symbols
321 are stored inside their own section, and the typical name
322 for that section is ".plt". So, if there is a ".plt"
323 section, and yet the section name of our symbol does not
324 start with ".plt", we ignore that symbol. */
325 if (strncmp (sect
->name
, ".plt", 4) != 0
326 && bfd_get_section_by_name (abfd
, ".plt") != NULL
)
329 symaddr
+= ANOFFSET (objfile
->section_offsets
, sect
->index
);
331 msym
= record_minimal_symbol
332 (sym
->name
, strlen (sym
->name
), copy_names
,
333 symaddr
, mst_solib_trampoline
, sect
, objfile
);
335 msym
->filename
= filesymname
;
339 /* If it is a nonstripped executable, do not enter dynamic
340 symbols, as the dynamic symbol table is usually a subset
341 of the main symbol table. */
342 if (type
== ST_DYNAMIC
&& !stripped
)
344 if (sym
->flags
& BSF_FILE
)
346 /* STT_FILE debugging symbol that helps stabs-in-elf debugging.
347 Chain any old one onto the objfile; remember new sym. */
348 if (sectinfo
!= NULL
)
350 sectinfo
->next
= dbx
->stab_section_info
;
351 dbx
->stab_section_info
= sectinfo
;
355 filesymname
= bcache (filesym
->name
, strlen (filesym
->name
) + 1,
356 objfile
->per_bfd
->filename_cache
);
358 else if (sym
->flags
& BSF_SECTION_SYM
)
360 else if (sym
->flags
& (BSF_GLOBAL
| BSF_LOCAL
| BSF_WEAK
))
362 struct minimal_symbol
*msym
;
364 /* Select global/local/weak symbols. Note that bfd puts abs
365 symbols in their own section, so all symbols we are
366 interested in will have a section. */
367 /* Bfd symbols are section relative. */
368 symaddr
= sym
->value
+ sym
->section
->vma
;
369 /* Relocate all non-absolute and non-TLS symbols by the
371 if (sym
->section
!= bfd_abs_section_ptr
372 && !(sym
->section
->flags
& SEC_THREAD_LOCAL
))
376 /* For non-absolute symbols, use the type of the section
377 they are relative to, to intuit text/data. Bfd provides
378 no way of figuring this out for absolute symbols. */
379 if (sym
->section
== bfd_abs_section_ptr
)
381 /* This is a hack to get the minimal symbol type
382 right for Irix 5, which has absolute addresses
383 with special section indices for dynamic symbols.
385 NOTE: uweigand-20071112: Synthetic symbols do not
386 have an ELF-private part, so do not touch those. */
387 unsigned int shndx
= type
== ST_SYNTHETIC
? 0 :
388 ((elf_symbol_type
*) sym
)->internal_elf_sym
.st_shndx
;
398 case SHN_MIPS_ACOMMON
:
405 /* If it is an Irix dynamic symbol, skip section name
406 symbols, relocate all others by section offset. */
407 if (ms_type
!= mst_abs
)
409 if (sym
->name
[0] == '.')
414 else if (sym
->section
->flags
& SEC_CODE
)
416 if (sym
->flags
& (BSF_GLOBAL
| BSF_WEAK
))
418 if (sym
->flags
& BSF_GNU_INDIRECT_FUNCTION
)
419 ms_type
= mst_text_gnu_ifunc
;
423 /* The BSF_SYNTHETIC check is there to omit ppc64 function
424 descriptors mistaken for static functions starting with 'L'.
426 else if ((sym
->name
[0] == '.' && sym
->name
[1] == 'L'
427 && (sym
->flags
& BSF_SYNTHETIC
) == 0)
428 || ((sym
->flags
& BSF_LOCAL
)
429 && sym
->name
[0] == '$'
430 && sym
->name
[1] == 'L'))
431 /* Looks like a compiler-generated label. Skip
432 it. The assembler should be skipping these (to
433 keep executables small), but apparently with
434 gcc on the (deleted) delta m88k SVR4, it loses.
435 So to have us check too should be harmless (but
436 I encourage people to fix this in the assembler
437 instead of adding checks here). */
441 ms_type
= mst_file_text
;
444 else if (sym
->section
->flags
& SEC_ALLOC
)
446 if (sym
->flags
& (BSF_GLOBAL
| BSF_WEAK
))
448 if (sym
->section
->flags
& SEC_LOAD
)
457 else if (sym
->flags
& BSF_LOCAL
)
459 /* Named Local variable in a Data section.
460 Check its name for stabs-in-elf. */
461 int special_local_sect
;
463 if (strcmp ("Bbss.bss", sym
->name
) == 0)
464 special_local_sect
= SECT_OFF_BSS (objfile
);
465 else if (strcmp ("Ddata.data", sym
->name
) == 0)
466 special_local_sect
= SECT_OFF_DATA (objfile
);
467 else if (strcmp ("Drodata.rodata", sym
->name
) == 0)
468 special_local_sect
= SECT_OFF_RODATA (objfile
);
470 special_local_sect
= -1;
471 if (special_local_sect
>= 0)
473 /* Found a special local symbol. Allocate a
474 sectinfo, if needed, and fill it in. */
475 if (sectinfo
== NULL
)
480 max_index
= SECT_OFF_BSS (objfile
);
481 if (objfile
->sect_index_data
> max_index
)
482 max_index
= objfile
->sect_index_data
;
483 if (objfile
->sect_index_rodata
> max_index
)
484 max_index
= objfile
->sect_index_rodata
;
486 /* max_index is the largest index we'll
487 use into this array, so we must
488 allocate max_index+1 elements for it.
489 However, 'struct stab_section_info'
490 already includes one element, so we
491 need to allocate max_index aadditional
493 size
= (sizeof (struct stab_section_info
)
494 + (sizeof (CORE_ADDR
) * max_index
));
495 sectinfo
= (struct stab_section_info
*)
497 memset (sectinfo
, 0, size
);
498 sectinfo
->num_sections
= max_index
;
501 complaint (&symfile_complaints
,
502 _("elf/stab section information %s "
503 "without a preceding file symbol"),
509 (char *) filesym
->name
;
512 if (sectinfo
->sections
[special_local_sect
] != 0)
513 complaint (&symfile_complaints
,
514 _("duplicated elf/stab section "
515 "information for %s"),
517 /* BFD symbols are section relative. */
518 symaddr
= sym
->value
+ sym
->section
->vma
;
519 /* Relocate non-absolute symbols by the
521 if (sym
->section
!= bfd_abs_section_ptr
)
523 sectinfo
->sections
[special_local_sect
] = symaddr
;
524 /* The special local symbols don't go in the
525 minimal symbol table, so ignore this one. */
528 /* Not a special stabs-in-elf symbol, do regular
529 symbol processing. */
530 if (sym
->section
->flags
& SEC_LOAD
)
532 ms_type
= mst_file_data
;
536 ms_type
= mst_file_bss
;
541 ms_type
= mst_unknown
;
546 /* FIXME: Solaris2 shared libraries include lots of
547 odd "absolute" and "undefined" symbols, that play
548 hob with actions like finding what function the PC
549 is in. Ignore them if they aren't text, data, or bss. */
550 /* ms_type = mst_unknown; */
551 continue; /* Skip this symbol. */
553 msym
= record_minimal_symbol
554 (sym
->name
, strlen (sym
->name
), copy_names
, symaddr
,
555 ms_type
, sym
->section
, objfile
);
559 /* Pass symbol size field in via BFD. FIXME!!! */
560 elf_symbol_type
*elf_sym
;
562 /* NOTE: uweigand-20071112: A synthetic symbol does not have an
563 ELF-private part. However, in some cases (e.g. synthetic
564 'dot' symbols on ppc64) the udata.p entry is set to point back
565 to the original ELF symbol it was derived from. Get the size
567 if (type
!= ST_SYNTHETIC
)
568 elf_sym
= (elf_symbol_type
*) sym
;
570 elf_sym
= (elf_symbol_type
*) sym
->udata
.p
;
573 SET_MSYMBOL_SIZE (msym
, elf_sym
->internal_elf_sym
.st_size
);
575 msym
->filename
= filesymname
;
576 gdbarch_elf_make_msymbol_special (gdbarch
, sym
, msym
);
579 /* For @plt symbols, also record a trampoline to the
580 destination symbol. The @plt symbol will be used in
581 disassembly, and the trampoline will be used when we are
582 trying to find the target. */
583 if (msym
&& ms_type
== mst_text
&& type
== ST_SYNTHETIC
)
585 int len
= strlen (sym
->name
);
587 if (len
> 4 && strcmp (sym
->name
+ len
- 4, "@plt") == 0)
589 struct minimal_symbol
*mtramp
;
591 mtramp
= record_minimal_symbol (sym
->name
, len
- 4, 1,
593 mst_solib_trampoline
,
594 sym
->section
, objfile
);
597 SET_MSYMBOL_SIZE (mtramp
, MSYMBOL_SIZE (msym
));
598 mtramp
->created_by_gdb
= 1;
599 mtramp
->filename
= filesymname
;
600 gdbarch_elf_make_msymbol_special (gdbarch
, sym
, mtramp
);
608 /* Build minimal symbols named `function@got.plt' (see SYMBOL_GOT_PLT_SUFFIX)
609 for later look ups of which function to call when user requests
610 a STT_GNU_IFUNC function. As the STT_GNU_IFUNC type is found at the target
611 library defining `function' we cannot yet know while reading OBJFILE which
612 of the SYMBOL_GOT_PLT_SUFFIX entries will be needed and later
613 DYN_SYMBOL_TABLE is no longer easily available for OBJFILE. */
616 elf_rel_plt_read (struct objfile
*objfile
, asymbol
**dyn_symbol_table
)
618 bfd
*obfd
= objfile
->obfd
;
619 const struct elf_backend_data
*bed
= get_elf_backend_data (obfd
);
620 asection
*plt
, *relplt
, *got_plt
;
622 bfd_size_type reloc_count
, reloc
;
623 char *string_buffer
= NULL
;
624 size_t string_buffer_size
= 0;
625 struct cleanup
*back_to
;
626 struct gdbarch
*gdbarch
= objfile
->gdbarch
;
627 struct type
*ptr_type
= builtin_type (gdbarch
)->builtin_data_ptr
;
628 size_t ptr_size
= TYPE_LENGTH (ptr_type
);
630 if (objfile
->separate_debug_objfile_backlink
)
633 plt
= bfd_get_section_by_name (obfd
, ".plt");
636 plt_elf_idx
= elf_section_data (plt
)->this_idx
;
638 got_plt
= bfd_get_section_by_name (obfd
, ".got.plt");
642 /* This search algorithm is from _bfd_elf_canonicalize_dynamic_reloc. */
643 for (relplt
= obfd
->sections
; relplt
!= NULL
; relplt
= relplt
->next
)
644 if (elf_section_data (relplt
)->this_hdr
.sh_info
== plt_elf_idx
645 && (elf_section_data (relplt
)->this_hdr
.sh_type
== SHT_REL
646 || elf_section_data (relplt
)->this_hdr
.sh_type
== SHT_RELA
))
651 if (! bed
->s
->slurp_reloc_table (obfd
, relplt
, dyn_symbol_table
, TRUE
))
654 back_to
= make_cleanup (free_current_contents
, &string_buffer
);
656 reloc_count
= relplt
->size
/ elf_section_data (relplt
)->this_hdr
.sh_entsize
;
657 for (reloc
= 0; reloc
< reloc_count
; reloc
++)
660 struct minimal_symbol
*msym
;
662 const size_t got_suffix_len
= strlen (SYMBOL_GOT_PLT_SUFFIX
);
665 name
= bfd_asymbol_name (*relplt
->relocation
[reloc
].sym_ptr_ptr
);
666 name_len
= strlen (name
);
667 address
= relplt
->relocation
[reloc
].address
;
669 /* Does the pointer reside in the .got.plt section? */
670 if (!(bfd_get_section_vma (obfd
, got_plt
) <= address
671 && address
< bfd_get_section_vma (obfd
, got_plt
)
672 + bfd_get_section_size (got_plt
)))
675 /* We cannot check if NAME is a reference to mst_text_gnu_ifunc as in
676 OBJFILE the symbol is undefined and the objfile having NAME defined
677 may not yet have been loaded. */
679 if (string_buffer_size
< name_len
+ got_suffix_len
+ 1)
681 string_buffer_size
= 2 * (name_len
+ got_suffix_len
);
682 string_buffer
= xrealloc (string_buffer
, string_buffer_size
);
684 memcpy (string_buffer
, name
, name_len
);
685 memcpy (&string_buffer
[name_len
], SYMBOL_GOT_PLT_SUFFIX
,
688 msym
= record_minimal_symbol (string_buffer
, name_len
+ got_suffix_len
,
689 1, address
, mst_slot_got_plt
, got_plt
,
692 SET_MSYMBOL_SIZE (msym
, ptr_size
);
695 do_cleanups (back_to
);
698 /* The data pointer is htab_t for gnu_ifunc_record_cache_unchecked. */
700 static const struct objfile_data
*elf_objfile_gnu_ifunc_cache_data
;
702 /* Map function names to CORE_ADDR in elf_objfile_gnu_ifunc_cache_data. */
704 struct elf_gnu_ifunc_cache
706 /* This is always a function entry address, not a function descriptor. */
712 /* htab_hash for elf_objfile_gnu_ifunc_cache_data. */
715 elf_gnu_ifunc_cache_hash (const void *a_voidp
)
717 const struct elf_gnu_ifunc_cache
*a
= a_voidp
;
719 return htab_hash_string (a
->name
);
722 /* htab_eq for elf_objfile_gnu_ifunc_cache_data. */
725 elf_gnu_ifunc_cache_eq (const void *a_voidp
, const void *b_voidp
)
727 const struct elf_gnu_ifunc_cache
*a
= a_voidp
;
728 const struct elf_gnu_ifunc_cache
*b
= b_voidp
;
730 return strcmp (a
->name
, b
->name
) == 0;
733 /* Record the target function address of a STT_GNU_IFUNC function NAME is the
734 function entry address ADDR. Return 1 if NAME and ADDR are considered as
735 valid and therefore they were successfully recorded, return 0 otherwise.
737 Function does not expect a duplicate entry. Use
738 elf_gnu_ifunc_resolve_by_cache first to check if the entry for NAME already
742 elf_gnu_ifunc_record_cache (const char *name
, CORE_ADDR addr
)
744 struct minimal_symbol
*msym
;
746 struct objfile
*objfile
;
748 struct elf_gnu_ifunc_cache entry_local
, *entry_p
;
751 msym
= lookup_minimal_symbol_by_pc (addr
);
754 if (SYMBOL_VALUE_ADDRESS (msym
) != addr
)
756 /* minimal symbols have always SYMBOL_OBJ_SECTION non-NULL. */
757 sect
= SYMBOL_OBJ_SECTION (msym
)->the_bfd_section
;
758 objfile
= SYMBOL_OBJ_SECTION (msym
)->objfile
;
760 /* If .plt jumps back to .plt the symbol is still deferred for later
761 resolution and it has no use for GDB. Besides ".text" this symbol can
762 reside also in ".opd" for ppc64 function descriptor. */
763 if (strcmp (bfd_get_section_name (objfile
->obfd
, sect
), ".plt") == 0)
766 htab
= objfile_data (objfile
, elf_objfile_gnu_ifunc_cache_data
);
769 htab
= htab_create_alloc_ex (1, elf_gnu_ifunc_cache_hash
,
770 elf_gnu_ifunc_cache_eq
,
771 NULL
, &objfile
->objfile_obstack
,
772 hashtab_obstack_allocate
,
773 dummy_obstack_deallocate
);
774 set_objfile_data (objfile
, elf_objfile_gnu_ifunc_cache_data
, htab
);
777 entry_local
.addr
= addr
;
778 obstack_grow (&objfile
->objfile_obstack
, &entry_local
,
779 offsetof (struct elf_gnu_ifunc_cache
, name
));
780 obstack_grow_str0 (&objfile
->objfile_obstack
, name
);
781 entry_p
= obstack_finish (&objfile
->objfile_obstack
);
783 slot
= htab_find_slot (htab
, entry_p
, INSERT
);
786 struct elf_gnu_ifunc_cache
*entry_found_p
= *slot
;
787 struct gdbarch
*gdbarch
= objfile
->gdbarch
;
789 if (entry_found_p
->addr
!= addr
)
791 /* This case indicates buggy inferior program, the resolved address
792 should never change. */
794 warning (_("gnu-indirect-function \"%s\" has changed its resolved "
795 "function_address from %s to %s"),
796 name
, paddress (gdbarch
, entry_found_p
->addr
),
797 paddress (gdbarch
, addr
));
800 /* New ENTRY_P is here leaked/duplicate in the OBJFILE obstack. */
807 /* Try to find the target resolved function entry address of a STT_GNU_IFUNC
808 function NAME. If the address is found it is stored to *ADDR_P (if ADDR_P
809 is not NULL) and the function returns 1. It returns 0 otherwise.
811 Only the elf_objfile_gnu_ifunc_cache_data hash table is searched by this
815 elf_gnu_ifunc_resolve_by_cache (const char *name
, CORE_ADDR
*addr_p
)
817 struct objfile
*objfile
;
819 ALL_PSPACE_OBJFILES (current_program_space
, objfile
)
822 struct elf_gnu_ifunc_cache
*entry_p
;
825 htab
= objfile_data (objfile
, elf_objfile_gnu_ifunc_cache_data
);
829 entry_p
= alloca (sizeof (*entry_p
) + strlen (name
));
830 strcpy (entry_p
->name
, name
);
832 slot
= htab_find_slot (htab
, entry_p
, NO_INSERT
);
836 gdb_assert (entry_p
!= NULL
);
839 *addr_p
= entry_p
->addr
;
846 /* Try to find the target resolved function entry address of a STT_GNU_IFUNC
847 function NAME. If the address is found it is stored to *ADDR_P (if ADDR_P
848 is not NULL) and the function returns 1. It returns 0 otherwise.
850 Only the SYMBOL_GOT_PLT_SUFFIX locations are searched by this function.
851 elf_gnu_ifunc_resolve_by_cache must have been already called for NAME to
852 prevent cache entries duplicates. */
855 elf_gnu_ifunc_resolve_by_got (const char *name
, CORE_ADDR
*addr_p
)
858 struct objfile
*objfile
;
859 const size_t got_suffix_len
= strlen (SYMBOL_GOT_PLT_SUFFIX
);
861 name_got_plt
= alloca (strlen (name
) + got_suffix_len
+ 1);
862 sprintf (name_got_plt
, "%s" SYMBOL_GOT_PLT_SUFFIX
, name
);
864 ALL_PSPACE_OBJFILES (current_program_space
, objfile
)
866 bfd
*obfd
= objfile
->obfd
;
867 struct gdbarch
*gdbarch
= objfile
->gdbarch
;
868 struct type
*ptr_type
= builtin_type (gdbarch
)->builtin_data_ptr
;
869 size_t ptr_size
= TYPE_LENGTH (ptr_type
);
870 CORE_ADDR pointer_address
, addr
;
872 gdb_byte
*buf
= alloca (ptr_size
);
873 struct minimal_symbol
*msym
;
875 msym
= lookup_minimal_symbol (name_got_plt
, NULL
, objfile
);
878 if (MSYMBOL_TYPE (msym
) != mst_slot_got_plt
)
880 pointer_address
= SYMBOL_VALUE_ADDRESS (msym
);
882 plt
= bfd_get_section_by_name (obfd
, ".plt");
886 if (MSYMBOL_SIZE (msym
) != ptr_size
)
888 if (target_read_memory (pointer_address
, buf
, ptr_size
) != 0)
890 addr
= extract_typed_address (buf
, ptr_type
);
891 addr
= gdbarch_convert_from_func_ptr_addr (gdbarch
, addr
,
896 if (elf_gnu_ifunc_record_cache (name
, addr
))
903 /* Try to find the target resolved function entry address of a STT_GNU_IFUNC
904 function NAME. If the address is found it is stored to *ADDR_P (if ADDR_P
905 is not NULL) and the function returns 1. It returns 0 otherwise.
907 Both the elf_objfile_gnu_ifunc_cache_data hash table and
908 SYMBOL_GOT_PLT_SUFFIX locations are searched by this function. */
911 elf_gnu_ifunc_resolve_name (const char *name
, CORE_ADDR
*addr_p
)
913 if (elf_gnu_ifunc_resolve_by_cache (name
, addr_p
))
916 if (elf_gnu_ifunc_resolve_by_got (name
, addr_p
))
922 /* Call STT_GNU_IFUNC - a function returning addresss of a real function to
923 call. PC is theSTT_GNU_IFUNC resolving function entry. The value returned
924 is the entry point of the resolved STT_GNU_IFUNC target function to call.
928 elf_gnu_ifunc_resolve_addr (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
930 const char *name_at_pc
;
931 CORE_ADDR start_at_pc
, address
;
932 struct type
*func_func_type
= builtin_type (gdbarch
)->builtin_func_func
;
933 struct value
*function
, *address_val
;
935 /* Try first any non-intrusive methods without an inferior call. */
937 if (find_pc_partial_function (pc
, &name_at_pc
, &start_at_pc
, NULL
)
938 && start_at_pc
== pc
)
940 if (elf_gnu_ifunc_resolve_name (name_at_pc
, &address
))
946 function
= allocate_value (func_func_type
);
947 set_value_address (function
, pc
);
949 /* STT_GNU_IFUNC resolver functions have no parameters. FUNCTION is the
950 function entry address. ADDRESS may be a function descriptor. */
952 address_val
= call_function_by_hand (function
, 0, NULL
);
953 address
= value_as_address (address_val
);
954 address
= gdbarch_convert_from_func_ptr_addr (gdbarch
, address
,
958 elf_gnu_ifunc_record_cache (name_at_pc
, address
);
963 /* Handle inferior hit of bp_gnu_ifunc_resolver, see its definition. */
966 elf_gnu_ifunc_resolver_stop (struct breakpoint
*b
)
968 struct breakpoint
*b_return
;
969 struct frame_info
*prev_frame
= get_prev_frame (get_current_frame ());
970 struct frame_id prev_frame_id
= get_stack_frame_id (prev_frame
);
971 CORE_ADDR prev_pc
= get_frame_pc (prev_frame
);
972 int thread_id
= pid_to_thread_id (inferior_ptid
);
974 gdb_assert (b
->type
== bp_gnu_ifunc_resolver
);
976 for (b_return
= b
->related_breakpoint
; b_return
!= b
;
977 b_return
= b_return
->related_breakpoint
)
979 gdb_assert (b_return
->type
== bp_gnu_ifunc_resolver_return
);
980 gdb_assert (b_return
->loc
!= NULL
&& b_return
->loc
->next
== NULL
);
981 gdb_assert (frame_id_p (b_return
->frame_id
));
983 if (b_return
->thread
== thread_id
984 && b_return
->loc
->requested_address
== prev_pc
985 && frame_id_eq (b_return
->frame_id
, prev_frame_id
))
991 struct symtab_and_line sal
;
993 /* No need to call find_pc_line for symbols resolving as this is only
994 a helper breakpointer never shown to the user. */
997 sal
.pspace
= current_inferior ()->pspace
;
999 sal
.section
= find_pc_overlay (sal
.pc
);
1000 sal
.explicit_pc
= 1;
1001 b_return
= set_momentary_breakpoint (get_frame_arch (prev_frame
), sal
,
1003 bp_gnu_ifunc_resolver_return
);
1005 /* set_momentary_breakpoint invalidates PREV_FRAME. */
1008 /* Add new b_return to the ring list b->related_breakpoint. */
1009 gdb_assert (b_return
->related_breakpoint
== b_return
);
1010 b_return
->related_breakpoint
= b
->related_breakpoint
;
1011 b
->related_breakpoint
= b_return
;
1015 /* Handle inferior hit of bp_gnu_ifunc_resolver_return, see its definition. */
1018 elf_gnu_ifunc_resolver_return_stop (struct breakpoint
*b
)
1020 struct gdbarch
*gdbarch
= get_frame_arch (get_current_frame ());
1021 struct type
*func_func_type
= builtin_type (gdbarch
)->builtin_func_func
;
1022 struct type
*value_type
= TYPE_TARGET_TYPE (func_func_type
);
1023 struct regcache
*regcache
= get_thread_regcache (inferior_ptid
);
1024 struct value
*func_func
;
1025 struct value
*value
;
1026 CORE_ADDR resolved_address
, resolved_pc
;
1027 struct symtab_and_line sal
;
1028 struct symtabs_and_lines sals
, sals_end
;
1030 gdb_assert (b
->type
== bp_gnu_ifunc_resolver_return
);
1032 while (b
->related_breakpoint
!= b
)
1034 struct breakpoint
*b_next
= b
->related_breakpoint
;
1038 case bp_gnu_ifunc_resolver
:
1040 case bp_gnu_ifunc_resolver_return
:
1041 delete_breakpoint (b
);
1044 internal_error (__FILE__
, __LINE__
,
1045 _("handle_inferior_event: Invalid "
1046 "gnu-indirect-function breakpoint type %d"),
1051 gdb_assert (b
->type
== bp_gnu_ifunc_resolver
);
1052 gdb_assert (b
->loc
->next
== NULL
);
1054 func_func
= allocate_value (func_func_type
);
1055 set_value_address (func_func
, b
->loc
->related_address
);
1057 value
= allocate_value (value_type
);
1058 gdbarch_return_value (gdbarch
, func_func
, value_type
, regcache
,
1059 value_contents_raw (value
), NULL
);
1060 resolved_address
= value_as_address (value
);
1061 resolved_pc
= gdbarch_convert_from_func_ptr_addr (gdbarch
,
1065 gdb_assert (current_program_space
== b
->pspace
|| b
->pspace
== NULL
);
1066 elf_gnu_ifunc_record_cache (b
->addr_string
, resolved_pc
);
1068 sal
= find_pc_line (resolved_pc
, 0);
1073 b
->type
= bp_breakpoint
;
1074 update_breakpoint_locations (b
, sals
, sals_end
);
1077 /* Locate NT_GNU_BUILD_ID from ABFD and return its content. */
1079 static struct elf_build_id
*
1080 build_id_bfd_get (bfd
*abfd
)
1082 if (!bfd_check_format (abfd
, bfd_object
)
1083 || bfd_get_flavour (abfd
) != bfd_target_elf_flavour
1084 || elf_tdata (abfd
)->build_id
== NULL
1085 || elf_tdata (abfd
)->build_id
->u
.i
.size
== 0)
1088 return &elf_tdata (abfd
)->build_id
->u
.i
;
1091 /* Return if FILENAME has NT_GNU_BUILD_ID matching the CHECK value. */
1094 build_id_verify (const char *filename
, struct elf_build_id
*check
)
1097 struct elf_build_id
*found
;
1100 /* We expect to be silent on the non-existing files. */
1101 abfd
= gdb_bfd_open_maybe_remote (filename
);
1105 found
= build_id_bfd_get (abfd
);
1108 warning (_("File \"%s\" has no build-id, file skipped"), filename
);
1109 else if (found
->size
!= check
->size
1110 || memcmp (found
->data
, check
->data
, found
->size
) != 0)
1111 warning (_("File \"%s\" has a different build-id, file skipped"),
1116 gdb_bfd_unref (abfd
);
1122 build_id_to_debug_filename (struct elf_build_id
*build_id
)
1124 char *link
, *debugdir
, *retval
= NULL
;
1125 VEC (char_ptr
) *debugdir_vec
;
1126 struct cleanup
*back_to
;
1129 /* DEBUG_FILE_DIRECTORY/.build-id/ab/cdef */
1130 link
= alloca (strlen (debug_file_directory
) + (sizeof "/.build-id/" - 1) + 1
1131 + 2 * build_id
->size
+ (sizeof ".debug" - 1) + 1);
1133 /* Keep backward compatibility so that DEBUG_FILE_DIRECTORY being "" will
1134 cause "/.build-id/..." lookups. */
1136 debugdir_vec
= dirnames_to_char_ptr_vec (debug_file_directory
);
1137 back_to
= make_cleanup_free_char_ptr_vec (debugdir_vec
);
1139 for (ix
= 0; VEC_iterate (char_ptr
, debugdir_vec
, ix
, debugdir
); ++ix
)
1141 size_t debugdir_len
= strlen (debugdir
);
1142 gdb_byte
*data
= build_id
->data
;
1143 size_t size
= build_id
->size
;
1146 memcpy (link
, debugdir
, debugdir_len
);
1147 s
= &link
[debugdir_len
];
1148 s
+= sprintf (s
, "/.build-id/");
1152 s
+= sprintf (s
, "%02x", (unsigned) *data
++);
1157 s
+= sprintf (s
, "%02x", (unsigned) *data
++);
1158 strcpy (s
, ".debug");
1160 /* lrealpath() is expensive even for the usually non-existent files. */
1161 if (access (link
, F_OK
) == 0)
1162 retval
= lrealpath (link
);
1164 if (retval
!= NULL
&& !build_id_verify (retval
, build_id
))
1174 do_cleanups (back_to
);
1179 find_separate_debug_file_by_buildid (struct objfile
*objfile
)
1181 struct elf_build_id
*build_id
;
1183 build_id
= build_id_bfd_get (objfile
->obfd
);
1184 if (build_id
!= NULL
)
1186 char *build_id_name
;
1188 build_id_name
= build_id_to_debug_filename (build_id
);
1189 /* Prevent looping on a stripped .debug file. */
1190 if (build_id_name
!= NULL
1191 && filename_cmp (build_id_name
, objfile
->name
) == 0)
1193 warning (_("\"%s\": separate debug info file has no debug info"),
1195 xfree (build_id_name
);
1197 else if (build_id_name
!= NULL
)
1198 return build_id_name
;
1203 /* Scan and build partial symbols for a symbol file.
1204 We have been initialized by a call to elf_symfile_init, which
1205 currently does nothing.
1207 SECTION_OFFSETS is a set of offsets to apply to relocate the symbols
1208 in each section. We simplify it down to a single offset for all
1211 This function only does the minimum work necessary for letting the
1212 user "name" things symbolically; it does not read the entire symtab.
1213 Instead, it reads the external and static symbols and puts them in partial
1214 symbol tables. When more extensive information is requested of a
1215 file, the corresponding partial symbol table is mutated into a full
1216 fledged symbol table by going back and reading the symbols
1219 We look for sections with specific names, to tell us what debug
1220 format to look for: FIXME!!!
1222 elfstab_build_psymtabs() handles STABS symbols;
1223 mdebug_build_psymtabs() handles ECOFF debugging information.
1225 Note that ELF files have a "minimal" symbol table, which looks a lot
1226 like a COFF symbol table, but has only the minimal information necessary
1227 for linking. We process this also, and use the information to
1228 build gdb's minimal symbol table. This gives us some minimal debugging
1229 capability even for files compiled without -g. */
1232 elf_symfile_read (struct objfile
*objfile
, int symfile_flags
)
1234 bfd
*synth_abfd
, *abfd
= objfile
->obfd
;
1236 struct cleanup
*back_to
;
1237 long symcount
= 0, dynsymcount
= 0, synthcount
, storage_needed
;
1238 asymbol
**symbol_table
= NULL
, **dyn_symbol_table
= NULL
;
1240 struct dbx_symfile_info
*dbx
;
1242 if (symtab_create_debug
)
1244 fprintf_unfiltered (gdb_stdlog
,
1245 "Reading minimal symbols of objfile %s ...\n",
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 dbx
= XCNEW (struct dbx_symfile_info
);
1256 set_objfile_data (objfile
, dbx_objfile_data_key
, dbx
);
1257 make_cleanup (free_elfinfo
, (void *) objfile
);
1259 /* Process the normal ELF symbol table first. This may write some
1260 chain of info into the dbx_symfile_info of the objfile, which can
1261 later be used by elfstab_offset_sections. */
1263 storage_needed
= bfd_get_symtab_upper_bound (objfile
->obfd
);
1264 if (storage_needed
< 0)
1265 error (_("Can't read symbols from %s: %s"),
1266 bfd_get_filename (objfile
->obfd
),
1267 bfd_errmsg (bfd_get_error ()));
1269 if (storage_needed
> 0)
1271 symbol_table
= (asymbol
**) xmalloc (storage_needed
);
1272 make_cleanup (xfree
, symbol_table
);
1273 symcount
= bfd_canonicalize_symtab (objfile
->obfd
, symbol_table
);
1276 error (_("Can't read symbols from %s: %s"),
1277 bfd_get_filename (objfile
->obfd
),
1278 bfd_errmsg (bfd_get_error ()));
1280 elf_symtab_read (objfile
, ST_REGULAR
, symcount
, symbol_table
, 0);
1283 /* Add the dynamic symbols. */
1285 storage_needed
= bfd_get_dynamic_symtab_upper_bound (objfile
->obfd
);
1287 if (storage_needed
> 0)
1289 /* Memory gets permanently referenced from ABFD after
1290 bfd_get_synthetic_symtab so it must not get freed before ABFD gets.
1291 It happens only in the case when elf_slurp_reloc_table sees
1292 asection->relocation NULL. Determining which section is asection is
1293 done by _bfd_elf_get_synthetic_symtab which is all a bfd
1294 implementation detail, though. */
1296 dyn_symbol_table
= bfd_alloc (abfd
, storage_needed
);
1297 dynsymcount
= bfd_canonicalize_dynamic_symtab (objfile
->obfd
,
1300 if (dynsymcount
< 0)
1301 error (_("Can't read symbols from %s: %s"),
1302 bfd_get_filename (objfile
->obfd
),
1303 bfd_errmsg (bfd_get_error ()));
1305 elf_symtab_read (objfile
, ST_DYNAMIC
, dynsymcount
, dyn_symbol_table
, 0);
1307 elf_rel_plt_read (objfile
, dyn_symbol_table
);
1310 /* Contrary to binutils --strip-debug/--only-keep-debug the strip command from
1311 elfutils (eu-strip) moves even the .symtab section into the .debug file.
1313 bfd_get_synthetic_symtab on ppc64 for each function descriptor ELF symbol
1314 'name' creates a new BSF_SYNTHETIC ELF symbol '.name' with its code
1315 address. But with eu-strip files bfd_get_synthetic_symtab would fail to
1316 read the code address from .opd while it reads the .symtab section from
1317 a separate debug info file as the .opd section is SHT_NOBITS there.
1319 With SYNTH_ABFD the .opd section will be read from the original
1320 backlinked binary where it is valid. */
1322 if (objfile
->separate_debug_objfile_backlink
)
1323 synth_abfd
= objfile
->separate_debug_objfile_backlink
->obfd
;
1327 /* Add synthetic symbols - for instance, names for any PLT entries. */
1329 synthcount
= bfd_get_synthetic_symtab (synth_abfd
, symcount
, symbol_table
,
1330 dynsymcount
, dyn_symbol_table
,
1334 asymbol
**synth_symbol_table
;
1337 make_cleanup (xfree
, synthsyms
);
1338 synth_symbol_table
= xmalloc (sizeof (asymbol
*) * synthcount
);
1339 for (i
= 0; i
< synthcount
; i
++)
1340 synth_symbol_table
[i
] = synthsyms
+ i
;
1341 make_cleanup (xfree
, synth_symbol_table
);
1342 elf_symtab_read (objfile
, ST_SYNTHETIC
, synthcount
,
1343 synth_symbol_table
, 1);
1346 /* Install any minimal symbols that have been collected as the current
1347 minimal symbols for this objfile. The debug readers below this point
1348 should not generate new minimal symbols; if they do it's their
1349 responsibility to install them. "mdebug" appears to be the only one
1350 which will do this. */
1352 install_minimal_symbols (objfile
);
1353 do_cleanups (back_to
);
1355 /* Now process debugging information, which is contained in
1356 special ELF sections. */
1358 /* We first have to find them... */
1359 bfd_map_over_sections (abfd
, elf_locate_sections
, (void *) & ei
);
1361 /* ELF debugging information is inserted into the psymtab in the
1362 order of least informative first - most informative last. Since
1363 the psymtab table is searched `most recent insertion first' this
1364 increases the probability that more detailed debug information
1365 for a section is found.
1367 For instance, an object file might contain both .mdebug (XCOFF)
1368 and .debug_info (DWARF2) sections then .mdebug is inserted first
1369 (searched last) and DWARF2 is inserted last (searched first). If
1370 we don't do this then the XCOFF info is found first - for code in
1371 an included file XCOFF info is useless. */
1375 const struct ecoff_debug_swap
*swap
;
1377 /* .mdebug section, presumably holding ECOFF debugging
1379 swap
= get_elf_backend_data (abfd
)->elf_backend_ecoff_debug_swap
;
1381 elfmdebug_build_psymtabs (objfile
, swap
, ei
.mdebugsect
);
1387 /* Stab sections have an associated string table that looks like
1388 a separate section. */
1389 str_sect
= bfd_get_section_by_name (abfd
, ".stabstr");
1391 /* FIXME should probably warn about a stab section without a stabstr. */
1393 elfstab_build_psymtabs (objfile
,
1396 bfd_section_size (abfd
, str_sect
));
1399 if (dwarf2_has_info (objfile
, NULL
))
1401 /* elf_sym_fns_gdb_index cannot handle simultaneous non-DWARF debug
1402 information present in OBJFILE. If there is such debug info present
1403 never use .gdb_index. */
1405 if (!objfile_has_partial_symbols (objfile
)
1406 && dwarf2_initialize_objfile (objfile
))
1407 objfile
->sf
= &elf_sym_fns_gdb_index
;
1410 /* It is ok to do this even if the stabs reader made some
1411 partial symbols, because OBJF_PSYMTABS_READ has not been
1412 set, and so our lazy reader function will still be called
1414 objfile
->sf
= &elf_sym_fns_lazy_psyms
;
1417 /* If the file has its own symbol tables it has no separate debug
1418 info. `.dynsym'/`.symtab' go to MSYMBOLS, `.debug_info' goes to
1419 SYMTABS/PSYMTABS. `.gnu_debuglink' may no longer be present with
1420 `.note.gnu.build-id'.
1422 .gnu_debugdata is !objfile_has_partial_symbols because it contains only
1423 .symtab, not .debug_* section. But if we already added .gnu_debugdata as
1424 an objfile via find_separate_debug_file_in_section there was no separate
1425 debug info available. Therefore do not attempt to search for another one,
1426 objfile->separate_debug_objfile->separate_debug_objfile GDB guarantees to
1427 be NULL and we would possibly violate it. */
1429 else if (!objfile_has_partial_symbols (objfile
)
1430 && objfile
->separate_debug_objfile
== NULL
1431 && objfile
->separate_debug_objfile_backlink
== NULL
)
1435 debugfile
= find_separate_debug_file_by_buildid (objfile
);
1437 if (debugfile
== NULL
)
1438 debugfile
= find_separate_debug_file_by_debuglink (objfile
);
1442 struct cleanup
*cleanup
= make_cleanup (xfree
, debugfile
);
1443 bfd
*abfd
= symfile_bfd_open (debugfile
);
1445 make_cleanup_bfd_unref (abfd
);
1446 symbol_file_add_separate (abfd
, symfile_flags
, objfile
);
1447 do_cleanups (cleanup
);
1451 if (symtab_create_debug
)
1452 fprintf_unfiltered (gdb_stdlog
, "Done reading minimal symbols.\n");
1455 /* Callback to lazily read psymtabs. */
1458 read_psyms (struct objfile
*objfile
)
1460 if (dwarf2_has_info (objfile
, NULL
))
1461 dwarf2_build_psymtabs (objfile
);
1464 /* This cleans up the objfile's dbx symfile info, and the chain of
1465 stab_section_info's, that might be dangling from it. */
1468 free_elfinfo (void *objp
)
1470 struct objfile
*objfile
= (struct objfile
*) objp
;
1471 struct dbx_symfile_info
*dbxinfo
= DBX_SYMFILE_INFO (objfile
);
1472 struct stab_section_info
*ssi
, *nssi
;
1474 ssi
= dbxinfo
->stab_section_info
;
1482 dbxinfo
->stab_section_info
= 0; /* Just say No mo info about this. */
1486 /* Initialize anything that needs initializing when a completely new symbol
1487 file is specified (not just adding some symbols from another file, e.g. a
1490 We reinitialize buildsym, since we may be reading stabs from an ELF
1494 elf_new_init (struct objfile
*ignore
)
1496 stabsread_new_init ();
1497 buildsym_new_init ();
1500 /* Perform any local cleanups required when we are done with a particular
1501 objfile. I.E, we are in the process of discarding all symbol information
1502 for an objfile, freeing up all memory held for it, and unlinking the
1503 objfile struct from the global list of known objfiles. */
1506 elf_symfile_finish (struct objfile
*objfile
)
1508 dwarf2_free_objfile (objfile
);
1511 /* ELF specific initialization routine for reading symbols.
1513 It is passed a pointer to a struct sym_fns which contains, among other
1514 things, the BFD for the file whose symbols are being read, and a slot for
1515 a pointer to "private data" which we can fill with goodies.
1517 For now at least, we have nothing in particular to do, so this function is
1521 elf_symfile_init (struct objfile
*objfile
)
1523 /* ELF objects may be reordered, so set OBJF_REORDERED. If we
1524 find this causes a significant slowdown in gdb then we could
1525 set it in the debug symbol readers only when necessary. */
1526 objfile
->flags
|= OBJF_REORDERED
;
1529 /* When handling an ELF file that contains Sun STABS debug info,
1530 some of the debug info is relative to the particular chunk of the
1531 section that was generated in its individual .o file. E.g.
1532 offsets to static variables are relative to the start of the data
1533 segment *for that module before linking*. This information is
1534 painfully squirreled away in the ELF symbol table as local symbols
1535 with wierd names. Go get 'em when needed. */
1538 elfstab_offset_sections (struct objfile
*objfile
, struct partial_symtab
*pst
)
1540 const char *filename
= pst
->filename
;
1541 struct dbx_symfile_info
*dbx
= DBX_SYMFILE_INFO (objfile
);
1542 struct stab_section_info
*maybe
= dbx
->stab_section_info
;
1543 struct stab_section_info
*questionable
= 0;
1546 /* The ELF symbol info doesn't include path names, so strip the path
1547 (if any) from the psymtab filename. */
1548 filename
= lbasename (filename
);
1550 /* FIXME: This linear search could speed up significantly
1551 if it was chained in the right order to match how we search it,
1552 and if we unchained when we found a match. */
1553 for (; maybe
; maybe
= maybe
->next
)
1555 if (filename
[0] == maybe
->filename
[0]
1556 && filename_cmp (filename
, maybe
->filename
) == 0)
1558 /* We found a match. But there might be several source files
1559 (from different directories) with the same name. */
1560 if (0 == maybe
->found
)
1562 questionable
= maybe
; /* Might use it later. */
1566 if (maybe
== 0 && questionable
!= 0)
1568 complaint (&symfile_complaints
,
1569 _("elf/stab section information questionable for %s"),
1571 maybe
= questionable
;
1576 /* Found it! Allocate a new psymtab struct, and fill it in. */
1578 pst
->section_offsets
= (struct section_offsets
*)
1579 obstack_alloc (&objfile
->objfile_obstack
,
1580 SIZEOF_N_SECTION_OFFSETS (objfile
->num_sections
));
1581 for (i
= 0; i
< maybe
->num_sections
; i
++)
1582 (pst
->section_offsets
)->offsets
[i
] = maybe
->sections
[i
];
1586 /* We were unable to find any offsets for this file. Complain. */
1587 if (dbx
->stab_section_info
) /* If there *is* any info, */
1588 complaint (&symfile_complaints
,
1589 _("elf/stab section information missing for %s"), filename
);
1592 /* Implementation of `sym_get_probes', as documented in symfile.h. */
1594 static VEC (probe_p
) *
1595 elf_get_probes (struct objfile
*objfile
)
1597 VEC (probe_p
) *probes_per_objfile
;
1599 /* Have we parsed this objfile's probes already? */
1600 probes_per_objfile
= objfile_data (objfile
, probe_key
);
1602 if (!probes_per_objfile
)
1605 const struct probe_ops
*probe_ops
;
1607 /* Here we try to gather information about all types of probes from the
1609 for (ix
= 0; VEC_iterate (probe_ops_cp
, all_probe_ops
, ix
, probe_ops
);
1611 probe_ops
->get_probes (&probes_per_objfile
, objfile
);
1613 if (probes_per_objfile
== NULL
)
1615 VEC_reserve (probe_p
, probes_per_objfile
, 1);
1616 gdb_assert (probes_per_objfile
!= NULL
);
1619 set_objfile_data (objfile
, probe_key
, probes_per_objfile
);
1622 return probes_per_objfile
;
1625 /* Implementation of `sym_get_probe_argument_count', as documented in
1629 elf_get_probe_argument_count (struct probe
*probe
)
1631 return probe
->pops
->get_probe_argument_count (probe
);
1634 /* Implementation of `sym_evaluate_probe_argument', as documented in
1637 static struct value
*
1638 elf_evaluate_probe_argument (struct probe
*probe
, unsigned n
)
1640 return probe
->pops
->evaluate_probe_argument (probe
, n
);
1643 /* Implementation of `sym_compile_to_ax', as documented in symfile.h. */
1646 elf_compile_to_ax (struct probe
*probe
,
1647 struct agent_expr
*expr
,
1648 struct axs_value
*value
,
1651 probe
->pops
->compile_to_ax (probe
, expr
, value
, n
);
1654 /* Implementation of `sym_relocate_probe', as documented in symfile.h. */
1657 elf_symfile_relocate_probe (struct objfile
*objfile
,
1658 struct section_offsets
*new_offsets
,
1659 struct section_offsets
*delta
)
1662 VEC (probe_p
) *probes
= objfile_data (objfile
, probe_key
);
1663 struct probe
*probe
;
1665 for (ix
= 0; VEC_iterate (probe_p
, probes
, ix
, probe
); ix
++)
1666 probe
->pops
->relocate (probe
, ANOFFSET (delta
, SECT_OFF_TEXT (objfile
)));
1669 /* Helper function used to free the space allocated for storing SystemTap
1670 probe information. */
1673 probe_key_free (struct objfile
*objfile
, void *d
)
1676 VEC (probe_p
) *probes
= d
;
1677 struct probe
*probe
;
1679 for (ix
= 0; VEC_iterate (probe_p
, probes
, ix
, probe
); ix
++)
1680 probe
->pops
->destroy (probe
);
1682 VEC_free (probe_p
, probes
);
1687 /* Implementation `sym_probe_fns', as documented in symfile.h. */
1689 static const struct sym_probe_fns elf_probe_fns
=
1691 elf_get_probes
, /* sym_get_probes */
1692 elf_get_probe_argument_count
, /* sym_get_probe_argument_count */
1693 elf_evaluate_probe_argument
, /* sym_evaluate_probe_argument */
1694 elf_compile_to_ax
, /* sym_compile_to_ax */
1695 elf_symfile_relocate_probe
, /* sym_relocate_probe */
1698 /* Register that we are able to handle ELF object file formats. */
1700 static const struct sym_fns elf_sym_fns
=
1702 bfd_target_elf_flavour
,
1703 elf_new_init
, /* init anything gbl to entire symtab */
1704 elf_symfile_init
, /* read initial info, setup for sym_read() */
1705 elf_symfile_read
, /* read a symbol file into symtab */
1706 NULL
, /* sym_read_psymbols */
1707 elf_symfile_finish
, /* finished with file, cleanup */
1708 default_symfile_offsets
, /* Translate ext. to int. relocation */
1709 elf_symfile_segments
, /* Get segment information from a file. */
1711 default_symfile_relocate
, /* Relocate a debug section. */
1712 &elf_probe_fns
, /* sym_probe_fns */
1716 /* The same as elf_sym_fns, but not registered and lazily reads
1719 static const struct sym_fns elf_sym_fns_lazy_psyms
=
1721 bfd_target_elf_flavour
,
1722 elf_new_init
, /* init anything gbl to entire symtab */
1723 elf_symfile_init
, /* read initial info, setup for sym_read() */
1724 elf_symfile_read
, /* read a symbol file into symtab */
1725 read_psyms
, /* sym_read_psymbols */
1726 elf_symfile_finish
, /* finished with file, cleanup */
1727 default_symfile_offsets
, /* Translate ext. to int. relocation */
1728 elf_symfile_segments
, /* Get segment information from a file. */
1730 default_symfile_relocate
, /* Relocate a debug section. */
1731 &elf_probe_fns
, /* sym_probe_fns */
1735 /* The same as elf_sym_fns, but not registered and uses the
1736 DWARF-specific GNU index rather than psymtab. */
1737 static const struct sym_fns elf_sym_fns_gdb_index
=
1739 bfd_target_elf_flavour
,
1740 elf_new_init
, /* init anything gbl to entire symab */
1741 elf_symfile_init
, /* read initial info, setup for sym_red() */
1742 elf_symfile_read
, /* read a symbol file into symtab */
1743 NULL
, /* sym_read_psymbols */
1744 elf_symfile_finish
, /* finished with file, cleanup */
1745 default_symfile_offsets
, /* Translate ext. to int. relocatin */
1746 elf_symfile_segments
, /* Get segment information from a file. */
1748 default_symfile_relocate
, /* Relocate a debug section. */
1749 &elf_probe_fns
, /* sym_probe_fns */
1750 &dwarf2_gdb_index_functions
1753 /* STT_GNU_IFUNC resolver vector to be installed to gnu_ifunc_fns_p. */
1755 static const struct gnu_ifunc_fns elf_gnu_ifunc_fns
=
1757 elf_gnu_ifunc_resolve_addr
,
1758 elf_gnu_ifunc_resolve_name
,
1759 elf_gnu_ifunc_resolver_stop
,
1760 elf_gnu_ifunc_resolver_return_stop
1764 _initialize_elfread (void)
1766 probe_key
= register_objfile_data_with_cleanup (NULL
, probe_key_free
);
1767 add_symtab_fns (&elf_sym_fns
);
1769 elf_objfile_gnu_ifunc_cache_data
= register_objfile_data ();
1770 gnu_ifunc_fns_p
= &elf_gnu_ifunc_fns
;