| /* ELF linking support for BFD. |
| Copyright 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003 |
| Free Software Foundation, Inc. |
| |
| This file is part of BFD, the Binary File Descriptor library. |
| |
| This program is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program; if not, write to the Free Software |
| Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ |
| |
| #include "bfd.h" |
| #include "sysdep.h" |
| #include "bfdlink.h" |
| #include "libbfd.h" |
| #define ARCH_SIZE 0 |
| #include "elf-bfd.h" |
| |
| bfd_boolean |
| _bfd_elf_create_got_section (bfd *abfd, struct bfd_link_info *info) |
| { |
| flagword flags; |
| asection *s; |
| struct elf_link_hash_entry *h; |
| struct bfd_link_hash_entry *bh; |
| const struct elf_backend_data *bed = get_elf_backend_data (abfd); |
| int ptralign; |
| |
| /* This function may be called more than once. */ |
| s = bfd_get_section_by_name (abfd, ".got"); |
| if (s != NULL && (s->flags & SEC_LINKER_CREATED) != 0) |
| return TRUE; |
| |
| switch (bed->s->arch_size) |
| { |
| case 32: |
| ptralign = 2; |
| break; |
| |
| case 64: |
| ptralign = 3; |
| break; |
| |
| default: |
| bfd_set_error (bfd_error_bad_value); |
| return FALSE; |
| } |
| |
| flags = (SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS | SEC_IN_MEMORY |
| | SEC_LINKER_CREATED); |
| |
| s = bfd_make_section (abfd, ".got"); |
| if (s == NULL |
| || !bfd_set_section_flags (abfd, s, flags) |
| || !bfd_set_section_alignment (abfd, s, ptralign)) |
| return FALSE; |
| |
| if (bed->want_got_plt) |
| { |
| s = bfd_make_section (abfd, ".got.plt"); |
| if (s == NULL |
| || !bfd_set_section_flags (abfd, s, flags) |
| || !bfd_set_section_alignment (abfd, s, ptralign)) |
| return FALSE; |
| } |
| |
| if (bed->want_got_sym) |
| { |
| /* Define the symbol _GLOBAL_OFFSET_TABLE_ at the start of the .got |
| (or .got.plt) section. We don't do this in the linker script |
| because we don't want to define the symbol if we are not creating |
| a global offset table. */ |
| bh = NULL; |
| if (!(_bfd_generic_link_add_one_symbol |
| (info, abfd, "_GLOBAL_OFFSET_TABLE_", BSF_GLOBAL, s, |
| bed->got_symbol_offset, NULL, FALSE, bed->collect, &bh))) |
| return FALSE; |
| h = (struct elf_link_hash_entry *) bh; |
| h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR; |
| h->type = STT_OBJECT; |
| |
| if (! info->executable |
| && ! _bfd_elf_link_record_dynamic_symbol (info, h)) |
| return FALSE; |
| |
| elf_hash_table (info)->hgot = h; |
| } |
| |
| /* The first bit of the global offset table is the header. */ |
| s->_raw_size += bed->got_header_size + bed->got_symbol_offset; |
| |
| return TRUE; |
| } |
| |
| /* Create some sections which will be filled in with dynamic linking |
| information. ABFD is an input file which requires dynamic sections |
| to be created. The dynamic sections take up virtual memory space |
| when the final executable is run, so we need to create them before |
| addresses are assigned to the output sections. We work out the |
| actual contents and size of these sections later. */ |
| |
| bfd_boolean |
| _bfd_elf_link_create_dynamic_sections (bfd *abfd, struct bfd_link_info *info) |
| { |
| flagword flags; |
| register asection *s; |
| struct elf_link_hash_entry *h; |
| struct bfd_link_hash_entry *bh; |
| const struct elf_backend_data *bed; |
| |
| if (! is_elf_hash_table (info->hash)) |
| return FALSE; |
| |
| if (elf_hash_table (info)->dynamic_sections_created) |
| return TRUE; |
| |
| /* Make sure that all dynamic sections use the same input BFD. */ |
| if (elf_hash_table (info)->dynobj == NULL) |
| elf_hash_table (info)->dynobj = abfd; |
| else |
| abfd = elf_hash_table (info)->dynobj; |
| |
| /* Note that we set the SEC_IN_MEMORY flag for all of these |
| sections. */ |
| flags = (SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS |
| | SEC_IN_MEMORY | SEC_LINKER_CREATED); |
| |
| /* A dynamically linked executable has a .interp section, but a |
| shared library does not. */ |
| if (info->executable) |
| { |
| s = bfd_make_section (abfd, ".interp"); |
| if (s == NULL |
| || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)) |
| return FALSE; |
| } |
| |
| if (! info->traditional_format) |
| { |
| s = bfd_make_section (abfd, ".eh_frame_hdr"); |
| if (s == NULL |
| || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY) |
| || ! bfd_set_section_alignment (abfd, s, 2)) |
| return FALSE; |
| elf_hash_table (info)->eh_info.hdr_sec = s; |
| } |
| |
| bed = get_elf_backend_data (abfd); |
| |
| /* Create sections to hold version informations. These are removed |
| if they are not needed. */ |
| s = bfd_make_section (abfd, ".gnu.version_d"); |
| if (s == NULL |
| || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY) |
| || ! bfd_set_section_alignment (abfd, s, bed->s->log_file_align)) |
| return FALSE; |
| |
| s = bfd_make_section (abfd, ".gnu.version"); |
| if (s == NULL |
| || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY) |
| || ! bfd_set_section_alignment (abfd, s, 1)) |
| return FALSE; |
| |
| s = bfd_make_section (abfd, ".gnu.version_r"); |
| if (s == NULL |
| || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY) |
| || ! bfd_set_section_alignment (abfd, s, bed->s->log_file_align)) |
| return FALSE; |
| |
| s = bfd_make_section (abfd, ".dynsym"); |
| if (s == NULL |
| || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY) |
| || ! bfd_set_section_alignment (abfd, s, bed->s->log_file_align)) |
| return FALSE; |
| |
| s = bfd_make_section (abfd, ".dynstr"); |
| if (s == NULL |
| || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)) |
| return FALSE; |
| |
| /* Create a strtab to hold the dynamic symbol names. */ |
| if (elf_hash_table (info)->dynstr == NULL) |
| { |
| elf_hash_table (info)->dynstr = _bfd_elf_strtab_init (); |
| if (elf_hash_table (info)->dynstr == NULL) |
| return FALSE; |
| } |
| |
| s = bfd_make_section (abfd, ".dynamic"); |
| if (s == NULL |
| || ! bfd_set_section_flags (abfd, s, flags) |
| || ! bfd_set_section_alignment (abfd, s, bed->s->log_file_align)) |
| return FALSE; |
| |
| /* The special symbol _DYNAMIC is always set to the start of the |
| .dynamic section. This call occurs before we have processed the |
| symbols for any dynamic object, so we don't have to worry about |
| overriding a dynamic definition. We could set _DYNAMIC in a |
| linker script, but we only want to define it if we are, in fact, |
| creating a .dynamic section. We don't want to define it if there |
| is no .dynamic section, since on some ELF platforms the start up |
| code examines it to decide how to initialize the process. */ |
| bh = NULL; |
| if (! (_bfd_generic_link_add_one_symbol |
| (info, abfd, "_DYNAMIC", BSF_GLOBAL, s, 0, NULL, FALSE, |
| get_elf_backend_data (abfd)->collect, &bh))) |
| return FALSE; |
| h = (struct elf_link_hash_entry *) bh; |
| h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR; |
| h->type = STT_OBJECT; |
| |
| if (! info->executable |
| && ! _bfd_elf_link_record_dynamic_symbol (info, h)) |
| return FALSE; |
| |
| s = bfd_make_section (abfd, ".hash"); |
| if (s == NULL |
| || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY) |
| || ! bfd_set_section_alignment (abfd, s, bed->s->log_file_align)) |
| return FALSE; |
| elf_section_data (s)->this_hdr.sh_entsize = bed->s->sizeof_hash_entry; |
| |
| /* Let the backend create the rest of the sections. This lets the |
| backend set the right flags. The backend will normally create |
| the .got and .plt sections. */ |
| if (! (*bed->elf_backend_create_dynamic_sections) (abfd, info)) |
| return FALSE; |
| |
| elf_hash_table (info)->dynamic_sections_created = TRUE; |
| |
| return TRUE; |
| } |
| |
| /* Create dynamic sections when linking against a dynamic object. */ |
| |
| bfd_boolean |
| _bfd_elf_create_dynamic_sections (bfd *abfd, struct bfd_link_info *info) |
| { |
| flagword flags, pltflags; |
| asection *s; |
| const struct elf_backend_data *bed = get_elf_backend_data (abfd); |
| |
| /* We need to create .plt, .rel[a].plt, .got, .got.plt, .dynbss, and |
| .rel[a].bss sections. */ |
| |
| flags = (SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS | SEC_IN_MEMORY |
| | SEC_LINKER_CREATED); |
| |
| pltflags = flags; |
| pltflags |= SEC_CODE; |
| if (bed->plt_not_loaded) |
| pltflags &= ~ (SEC_CODE | SEC_LOAD | SEC_HAS_CONTENTS); |
| if (bed->plt_readonly) |
| pltflags |= SEC_READONLY; |
| |
| s = bfd_make_section (abfd, ".plt"); |
| if (s == NULL |
| || ! bfd_set_section_flags (abfd, s, pltflags) |
| || ! bfd_set_section_alignment (abfd, s, bed->plt_alignment)) |
| return FALSE; |
| |
| if (bed->want_plt_sym) |
| { |
| /* Define the symbol _PROCEDURE_LINKAGE_TABLE_ at the start of the |
| .plt section. */ |
| struct elf_link_hash_entry *h; |
| struct bfd_link_hash_entry *bh = NULL; |
| |
| if (! (_bfd_generic_link_add_one_symbol |
| (info, abfd, "_PROCEDURE_LINKAGE_TABLE_", BSF_GLOBAL, s, 0, NULL, |
| FALSE, get_elf_backend_data (abfd)->collect, &bh))) |
| return FALSE; |
| h = (struct elf_link_hash_entry *) bh; |
| h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR; |
| h->type = STT_OBJECT; |
| |
| if (! info->executable |
| && ! _bfd_elf_link_record_dynamic_symbol (info, h)) |
| return FALSE; |
| } |
| |
| s = bfd_make_section (abfd, |
| bed->default_use_rela_p ? ".rela.plt" : ".rel.plt"); |
| if (s == NULL |
| || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY) |
| || ! bfd_set_section_alignment (abfd, s, bed->s->log_file_align)) |
| return FALSE; |
| |
| if (! _bfd_elf_create_got_section (abfd, info)) |
| return FALSE; |
| |
| if (bed->want_dynbss) |
| { |
| /* The .dynbss section is a place to put symbols which are defined |
| by dynamic objects, are referenced by regular objects, and are |
| not functions. We must allocate space for them in the process |
| image and use a R_*_COPY reloc to tell the dynamic linker to |
| initialize them at run time. The linker script puts the .dynbss |
| section into the .bss section of the final image. */ |
| s = bfd_make_section (abfd, ".dynbss"); |
| if (s == NULL |
| || ! bfd_set_section_flags (abfd, s, SEC_ALLOC | SEC_LINKER_CREATED)) |
| return FALSE; |
| |
| /* The .rel[a].bss section holds copy relocs. This section is not |
| normally needed. We need to create it here, though, so that the |
| linker will map it to an output section. We can't just create it |
| only if we need it, because we will not know whether we need it |
| until we have seen all the input files, and the first time the |
| main linker code calls BFD after examining all the input files |
| (size_dynamic_sections) the input sections have already been |
| mapped to the output sections. If the section turns out not to |
| be needed, we can discard it later. We will never need this |
| section when generating a shared object, since they do not use |
| copy relocs. */ |
| if (! info->shared) |
| { |
| s = bfd_make_section (abfd, |
| (bed->default_use_rela_p |
| ? ".rela.bss" : ".rel.bss")); |
| if (s == NULL |
| || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY) |
| || ! bfd_set_section_alignment (abfd, s, bed->s->log_file_align)) |
| return FALSE; |
| } |
| } |
| |
| return TRUE; |
| } |
| |
| /* Record a new dynamic symbol. We record the dynamic symbols as we |
| read the input files, since we need to have a list of all of them |
| before we can determine the final sizes of the output sections. |
| Note that we may actually call this function even though we are not |
| going to output any dynamic symbols; in some cases we know that a |
| symbol should be in the dynamic symbol table, but only if there is |
| one. */ |
| |
| bfd_boolean |
| _bfd_elf_link_record_dynamic_symbol (struct bfd_link_info *info, |
| struct elf_link_hash_entry *h) |
| { |
| if (h->dynindx == -1) |
| { |
| struct elf_strtab_hash *dynstr; |
| char *p; |
| const char *name; |
| bfd_size_type indx; |
| |
| /* XXX: The ABI draft says the linker must turn hidden and |
| internal symbols into STB_LOCAL symbols when producing the |
| DSO. However, if ld.so honors st_other in the dynamic table, |
| this would not be necessary. */ |
| switch (ELF_ST_VISIBILITY (h->other)) |
| { |
| case STV_INTERNAL: |
| case STV_HIDDEN: |
| if (h->root.type != bfd_link_hash_undefined |
| && h->root.type != bfd_link_hash_undefweak) |
| { |
| h->elf_link_hash_flags |= ELF_LINK_FORCED_LOCAL; |
| return TRUE; |
| } |
| |
| default: |
| break; |
| } |
| |
| h->dynindx = elf_hash_table (info)->dynsymcount; |
| ++elf_hash_table (info)->dynsymcount; |
| |
| dynstr = elf_hash_table (info)->dynstr; |
| if (dynstr == NULL) |
| { |
| /* Create a strtab to hold the dynamic symbol names. */ |
| elf_hash_table (info)->dynstr = dynstr = _bfd_elf_strtab_init (); |
| if (dynstr == NULL) |
| return FALSE; |
| } |
| |
| /* We don't put any version information in the dynamic string |
| table. */ |
| name = h->root.root.string; |
| p = strchr (name, ELF_VER_CHR); |
| if (p != NULL) |
| /* We know that the p points into writable memory. In fact, |
| there are only a few symbols that have read-only names, being |
| those like _GLOBAL_OFFSET_TABLE_ that are created specially |
| by the backends. Most symbols will have names pointing into |
| an ELF string table read from a file, or to objalloc memory. */ |
| *p = 0; |
| |
| indx = _bfd_elf_strtab_add (dynstr, name, p != NULL); |
| |
| if (p != NULL) |
| *p = ELF_VER_CHR; |
| |
| if (indx == (bfd_size_type) -1) |
| return FALSE; |
| h->dynstr_index = indx; |
| } |
| |
| return TRUE; |
| } |
| |
| /* Record an assignment to a symbol made by a linker script. We need |
| this in case some dynamic object refers to this symbol. */ |
| |
| bfd_boolean |
| bfd_elf_record_link_assignment (bfd *output_bfd ATTRIBUTE_UNUSED, |
| struct bfd_link_info *info, |
| const char *name, |
| bfd_boolean provide) |
| { |
| struct elf_link_hash_entry *h; |
| |
| if (!is_elf_hash_table (info->hash)) |
| return TRUE; |
| |
| h = elf_link_hash_lookup (elf_hash_table (info), name, TRUE, TRUE, FALSE); |
| if (h == NULL) |
| return FALSE; |
| |
| if (h->root.type == bfd_link_hash_new) |
| h->elf_link_hash_flags &= ~ELF_LINK_NON_ELF; |
| |
| /* If this symbol is being provided by the linker script, and it is |
| currently defined by a dynamic object, but not by a regular |
| object, then mark it as undefined so that the generic linker will |
| force the correct value. */ |
| if (provide |
| && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0 |
| && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0) |
| h->root.type = bfd_link_hash_undefined; |
| |
| /* If this symbol is not being provided by the linker script, and it is |
| currently defined by a dynamic object, but not by a regular object, |
| then clear out any version information because the symbol will not be |
| associated with the dynamic object any more. */ |
| if (!provide |
| && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0 |
| && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0) |
| h->verinfo.verdef = NULL; |
| |
| h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR; |
| |
| if (((h->elf_link_hash_flags & (ELF_LINK_HASH_DEF_DYNAMIC |
| | ELF_LINK_HASH_REF_DYNAMIC)) != 0 |
| || info->shared) |
| && h->dynindx == -1) |
| { |
| if (! _bfd_elf_link_record_dynamic_symbol (info, h)) |
| return FALSE; |
| |
| /* If this is a weak defined symbol, and we know a corresponding |
| real symbol from the same dynamic object, make sure the real |
| symbol is also made into a dynamic symbol. */ |
| if (h->weakdef != NULL |
| && h->weakdef->dynindx == -1) |
| { |
| if (! _bfd_elf_link_record_dynamic_symbol (info, h->weakdef)) |
| return FALSE; |
| } |
| } |
| |
| return TRUE; |
| } |
| |
| /* Record a new local dynamic symbol. Returns 0 on failure, 1 on |
| success, and 2 on a failure caused by attempting to record a symbol |
| in a discarded section, eg. a discarded link-once section symbol. */ |
| |
| int |
| elf_link_record_local_dynamic_symbol (struct bfd_link_info *info, |
| bfd *input_bfd, |
| long input_indx) |
| { |
| bfd_size_type amt; |
| struct elf_link_local_dynamic_entry *entry; |
| struct elf_link_hash_table *eht; |
| struct elf_strtab_hash *dynstr; |
| unsigned long dynstr_index; |
| char *name; |
| Elf_External_Sym_Shndx eshndx; |
| char esym[sizeof (Elf64_External_Sym)]; |
| |
| if (! is_elf_hash_table (info->hash)) |
| return 0; |
| |
| /* See if the entry exists already. */ |
| for (entry = elf_hash_table (info)->dynlocal; entry ; entry = entry->next) |
| if (entry->input_bfd == input_bfd && entry->input_indx == input_indx) |
| return 1; |
| |
| amt = sizeof (*entry); |
| entry = bfd_alloc (input_bfd, amt); |
| if (entry == NULL) |
| return 0; |
| |
| /* Go find the symbol, so that we can find it's name. */ |
| if (!bfd_elf_get_elf_syms (input_bfd, &elf_tdata (input_bfd)->symtab_hdr, |
| 1, input_indx, &entry->isym, esym, &eshndx)) |
| { |
| bfd_release (input_bfd, entry); |
| return 0; |
| } |
| |
| if (entry->isym.st_shndx != SHN_UNDEF |
| && (entry->isym.st_shndx < SHN_LORESERVE |
| || entry->isym.st_shndx > SHN_HIRESERVE)) |
| { |
| asection *s; |
| |
| s = bfd_section_from_elf_index (input_bfd, entry->isym.st_shndx); |
| if (s == NULL || bfd_is_abs_section (s->output_section)) |
| { |
| /* We can still bfd_release here as nothing has done another |
| bfd_alloc. We can't do this later in this function. */ |
| bfd_release (input_bfd, entry); |
| return 2; |
| } |
| } |
| |
| name = (bfd_elf_string_from_elf_section |
| (input_bfd, elf_tdata (input_bfd)->symtab_hdr.sh_link, |
| entry->isym.st_name)); |
| |
| dynstr = elf_hash_table (info)->dynstr; |
| if (dynstr == NULL) |
| { |
| /* Create a strtab to hold the dynamic symbol names. */ |
| elf_hash_table (info)->dynstr = dynstr = _bfd_elf_strtab_init (); |
| if (dynstr == NULL) |
| return 0; |
| } |
| |
| dynstr_index = _bfd_elf_strtab_add (dynstr, name, FALSE); |
| if (dynstr_index == (unsigned long) -1) |
| return 0; |
| entry->isym.st_name = dynstr_index; |
| |
| eht = elf_hash_table (info); |
| |
| entry->next = eht->dynlocal; |
| eht->dynlocal = entry; |
| entry->input_bfd = input_bfd; |
| entry->input_indx = input_indx; |
| eht->dynsymcount++; |
| |
| /* Whatever binding the symbol had before, it's now local. */ |
| entry->isym.st_info |
| = ELF_ST_INFO (STB_LOCAL, ELF_ST_TYPE (entry->isym.st_info)); |
| |
| /* The dynindx will be set at the end of size_dynamic_sections. */ |
| |
| return 1; |
| } |
| |
| /* Return the dynindex of a local dynamic symbol. */ |
| |
| long |
| _bfd_elf_link_lookup_local_dynindx (struct bfd_link_info *info, |
| bfd *input_bfd, |
| long input_indx) |
| { |
| struct elf_link_local_dynamic_entry *e; |
| |
| for (e = elf_hash_table (info)->dynlocal; e ; e = e->next) |
| if (e->input_bfd == input_bfd && e->input_indx == input_indx) |
| return e->dynindx; |
| return -1; |
| } |
| |
| /* This function is used to renumber the dynamic symbols, if some of |
| them are removed because they are marked as local. This is called |
| via elf_link_hash_traverse. */ |
| |
| static bfd_boolean |
| elf_link_renumber_hash_table_dynsyms (struct elf_link_hash_entry *h, |
| void *data) |
| { |
| size_t *count = data; |
| |
| if (h->root.type == bfd_link_hash_warning) |
| h = (struct elf_link_hash_entry *) h->root.u.i.link; |
| |
| if (h->dynindx != -1) |
| h->dynindx = ++(*count); |
| |
| return TRUE; |
| } |
| |
| /* Assign dynsym indices. In a shared library we generate a section |
| symbol for each output section, which come first. Next come all of |
| the back-end allocated local dynamic syms, followed by the rest of |
| the global symbols. */ |
| |
| unsigned long |
| _bfd_elf_link_renumber_dynsyms (bfd *output_bfd, struct bfd_link_info *info) |
| { |
| unsigned long dynsymcount = 0; |
| |
| if (info->shared) |
| { |
| asection *p; |
| for (p = output_bfd->sections; p ; p = p->next) |
| if ((p->flags & SEC_EXCLUDE) == 0) |
| elf_section_data (p)->dynindx = ++dynsymcount; |
| } |
| |
| if (elf_hash_table (info)->dynlocal) |
| { |
| struct elf_link_local_dynamic_entry *p; |
| for (p = elf_hash_table (info)->dynlocal; p ; p = p->next) |
| p->dynindx = ++dynsymcount; |
| } |
| |
| elf_link_hash_traverse (elf_hash_table (info), |
| elf_link_renumber_hash_table_dynsyms, |
| &dynsymcount); |
| |
| /* There is an unused NULL entry at the head of the table which |
| we must account for in our count. Unless there weren't any |
| symbols, which means we'll have no table at all. */ |
| if (dynsymcount != 0) |
| ++dynsymcount; |
| |
| return elf_hash_table (info)->dynsymcount = dynsymcount; |
| } |
| |
| /* This function is called when we want to define a new symbol. It |
| handles the various cases which arise when we find a definition in |
| a dynamic object, or when there is already a definition in a |
| dynamic object. The new symbol is described by NAME, SYM, PSEC, |
| and PVALUE. We set SYM_HASH to the hash table entry. We set |
| OVERRIDE if the old symbol is overriding a new definition. We set |
| TYPE_CHANGE_OK if it is OK for the type to change. We set |
| SIZE_CHANGE_OK if it is OK for the size to change. By OK to |
| change, we mean that we shouldn't warn if the type or size does |
| change. DT_NEEDED indicates if it comes from a DT_NEEDED entry of |
| a shared object. */ |
| |
| bfd_boolean |
| _bfd_elf_merge_symbol (bfd *abfd, |
| struct bfd_link_info *info, |
| const char *name, |
| Elf_Internal_Sym *sym, |
| asection **psec, |
| bfd_vma *pvalue, |
| struct elf_link_hash_entry **sym_hash, |
| bfd_boolean *skip, |
| bfd_boolean *override, |
| bfd_boolean *type_change_ok, |
| bfd_boolean *size_change_ok, |
| bfd_boolean dt_needed) |
| { |
| asection *sec; |
| struct elf_link_hash_entry *h; |
| struct elf_link_hash_entry *flip; |
| int bind; |
| bfd *oldbfd; |
| bfd_boolean newdyn, olddyn, olddef, newdef, newdyncommon, olddyncommon; |
| bfd_boolean newweakdef, oldweakdef, newweakundef, oldweakundef; |
| |
| *skip = FALSE; |
| *override = FALSE; |
| |
| sec = *psec; |
| bind = ELF_ST_BIND (sym->st_info); |
| |
| if (! bfd_is_und_section (sec)) |
| h = elf_link_hash_lookup (elf_hash_table (info), name, TRUE, FALSE, FALSE); |
| else |
| h = ((struct elf_link_hash_entry *) |
| bfd_wrapped_link_hash_lookup (abfd, info, name, TRUE, FALSE, FALSE)); |
| if (h == NULL) |
| return FALSE; |
| *sym_hash = h; |
| |
| /* This code is for coping with dynamic objects, and is only useful |
| if we are doing an ELF link. */ |
| if (info->hash->creator != abfd->xvec) |
| return TRUE; |
| |
| /* For merging, we only care about real symbols. */ |
| |
| while (h->root.type == bfd_link_hash_indirect |
| || h->root.type == bfd_link_hash_warning) |
| h = (struct elf_link_hash_entry *) h->root.u.i.link; |
| |
| /* If we just created the symbol, mark it as being an ELF symbol. |
| Other than that, there is nothing to do--there is no merge issue |
| with a newly defined symbol--so we just return. */ |
| |
| if (h->root.type == bfd_link_hash_new) |
| { |
| h->elf_link_hash_flags &=~ ELF_LINK_NON_ELF; |
| return TRUE; |
| } |
| |
| /* OLDBFD is a BFD associated with the existing symbol. */ |
| |
| switch (h->root.type) |
| { |
| default: |
| oldbfd = NULL; |
| break; |
| |
| case bfd_link_hash_undefined: |
| case bfd_link_hash_undefweak: |
| oldbfd = h->root.u.undef.abfd; |
| break; |
| |
| case bfd_link_hash_defined: |
| case bfd_link_hash_defweak: |
| oldbfd = h->root.u.def.section->owner; |
| break; |
| |
| case bfd_link_hash_common: |
| oldbfd = h->root.u.c.p->section->owner; |
| break; |
| } |
| |
| /* In cases involving weak versioned symbols, we may wind up trying |
| to merge a symbol with itself. Catch that here, to avoid the |
| confusion that results if we try to override a symbol with |
| itself. The additional tests catch cases like |
| _GLOBAL_OFFSET_TABLE_, which are regular symbols defined in a |
| dynamic object, which we do want to handle here. */ |
| if (abfd == oldbfd |
| && ((abfd->flags & DYNAMIC) == 0 |
| || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)) |
| return TRUE; |
| |
| /* NEWDYN and OLDDYN indicate whether the new or old symbol, |
| respectively, is from a dynamic object. */ |
| |
| if ((abfd->flags & DYNAMIC) != 0) |
| newdyn = TRUE; |
| else |
| newdyn = FALSE; |
| |
| if (oldbfd != NULL) |
| olddyn = (oldbfd->flags & DYNAMIC) != 0; |
| else |
| { |
| asection *hsec; |
| |
| /* This code handles the special SHN_MIPS_{TEXT,DATA} section |
| indices used by MIPS ELF. */ |
| switch (h->root.type) |
| { |
| default: |
| hsec = NULL; |
| break; |
| |
| case bfd_link_hash_defined: |
| case bfd_link_hash_defweak: |
| hsec = h->root.u.def.section; |
| break; |
| |
| case bfd_link_hash_common: |
| hsec = h->root.u.c.p->section; |
| break; |
| } |
| |
| if (hsec == NULL) |
| olddyn = FALSE; |
| else |
| olddyn = (hsec->symbol->flags & BSF_DYNAMIC) != 0; |
| } |
| |
| /* NEWDEF and OLDDEF indicate whether the new or old symbol, |
| respectively, appear to be a definition rather than reference. */ |
| |
| if (bfd_is_und_section (sec) || bfd_is_com_section (sec)) |
| newdef = FALSE; |
| else |
| newdef = TRUE; |
| |
| if (h->root.type == bfd_link_hash_undefined |
| || h->root.type == bfd_link_hash_undefweak |
| || h->root.type == bfd_link_hash_common) |
| olddef = FALSE; |
| else |
| olddef = TRUE; |
| |
| /* We need to remember if a symbol has a definition in a dynamic |
| object or is weak in all dynamic objects. Internal and hidden |
| visibility will make it unavailable to dynamic objects. */ |
| if (newdyn && (h->elf_link_hash_flags & ELF_LINK_DYNAMIC_DEF) == 0) |
| { |
| if (!bfd_is_und_section (sec)) |
| h->elf_link_hash_flags |= ELF_LINK_DYNAMIC_DEF; |
| else |
| { |
| /* Check if this symbol is weak in all dynamic objects. If it |
| is the first time we see it in a dynamic object, we mark |
| if it is weak. Otherwise, we clear it. */ |
| if ((h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) == 0) |
| { |
| if (bind == STB_WEAK) |
| h->elf_link_hash_flags |= ELF_LINK_DYNAMIC_WEAK; |
| } |
| else if (bind != STB_WEAK) |
| h->elf_link_hash_flags &= ~ELF_LINK_DYNAMIC_WEAK; |
| } |
| } |
| |
| /* If the old symbol has non-default visibility, we ignore the new |
| definition from a dynamic object. */ |
| if (newdyn |
| && ELF_ST_VISIBILITY (h->other) != STV_DEFAULT |
| && !bfd_is_und_section (sec)) |
| { |
| *skip = TRUE; |
| /* Make sure this symbol is dynamic. */ |
| h->elf_link_hash_flags |= ELF_LINK_HASH_REF_DYNAMIC; |
| /* A protected symbol has external availability. Make sure it is |
| recorded as dynamic. |
| |
| FIXME: Should we check type and size for protected symbol? */ |
| if (ELF_ST_VISIBILITY (h->other) == STV_PROTECTED) |
| return _bfd_elf_link_record_dynamic_symbol (info, h); |
| else |
| return TRUE; |
| } |
| else if (!newdyn |
| && ELF_ST_VISIBILITY (sym->st_other) != STV_DEFAULT |
| && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0) |
| { |
| /* If the new symbol with non-default visibility comes from a |
| relocatable file and the old definition comes from a dynamic |
| object, we remove the old definition. */ |
| if ((*sym_hash)->root.type == bfd_link_hash_indirect) |
| h = *sym_hash; |
| h->root.type = bfd_link_hash_new; |
| h->root.u.undef.abfd = NULL; |
| if (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) |
| { |
| h->elf_link_hash_flags &= ~ELF_LINK_HASH_DEF_DYNAMIC; |
| h->elf_link_hash_flags |= (ELF_LINK_HASH_REF_DYNAMIC |
| | ELF_LINK_DYNAMIC_DEF); |
| } |
| /* FIXME: Should we check type and size for protected symbol? */ |
| h->size = 0; |
| h->type = 0; |
| return TRUE; |
| } |
| |
| /* We need to treat weak definition right, depending on if there is a |
| definition from a dynamic object. */ |
| if (bind == STB_WEAK) |
| { |
| if (olddef) |
| { |
| newweakdef = TRUE; |
| newweakundef = FALSE; |
| } |
| else |
| { |
| newweakdef = FALSE; |
| newweakundef = TRUE; |
| } |
| } |
| else |
| newweakdef = newweakundef = FALSE; |
| |
| /* If the new weak definition comes from a relocatable file and the |
| old symbol comes from a dynamic object, we treat the new one as |
| strong. */ |
| if (newweakdef && !newdyn && olddyn) |
| newweakdef = FALSE; |
| |
| if (h->root.type == bfd_link_hash_defweak) |
| { |
| oldweakdef = TRUE; |
| oldweakundef = FALSE; |
| } |
| else if (h->root.type == bfd_link_hash_undefweak) |
| { |
| oldweakdef = FALSE; |
| oldweakundef = TRUE; |
| } |
| else |
| oldweakdef = oldweakundef = FALSE; |
| |
| /* If the old weak definition comes from a relocatable file and the |
| new symbol comes from a dynamic object, we treat the old one as |
| strong. */ |
| if (oldweakdef && !olddyn && newdyn) |
| oldweakdef = FALSE; |
| |
| /* NEWDYNCOMMON and OLDDYNCOMMON indicate whether the new or old |
| symbol, respectively, appears to be a common symbol in a dynamic |
| object. If a symbol appears in an uninitialized section, and is |
| not weak, and is not a function, then it may be a common symbol |
| which was resolved when the dynamic object was created. We want |
| to treat such symbols specially, because they raise special |
| considerations when setting the symbol size: if the symbol |
| appears as a common symbol in a regular object, and the size in |
| the regular object is larger, we must make sure that we use the |
| larger size. This problematic case can always be avoided in C, |
| but it must be handled correctly when using Fortran shared |
| libraries. |
| |
| Note that if NEWDYNCOMMON is set, NEWDEF will be set, and |
| likewise for OLDDYNCOMMON and OLDDEF. |
| |
| Note that this test is just a heuristic, and that it is quite |
| possible to have an uninitialized symbol in a shared object which |
| is really a definition, rather than a common symbol. This could |
| lead to some minor confusion when the symbol really is a common |
| symbol in some regular object. However, I think it will be |
| harmless. */ |
| |
| if (newdyn |
| && newdef |
| && (sec->flags & SEC_ALLOC) != 0 |
| && (sec->flags & SEC_LOAD) == 0 |
| && sym->st_size > 0 |
| && !newweakdef |
| && !newweakundef |
| && ELF_ST_TYPE (sym->st_info) != STT_FUNC) |
| newdyncommon = TRUE; |
| else |
| newdyncommon = FALSE; |
| |
| if (olddyn |
| && olddef |
| && h->root.type == bfd_link_hash_defined |
| && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0 |
| && (h->root.u.def.section->flags & SEC_ALLOC) != 0 |
| && (h->root.u.def.section->flags & SEC_LOAD) == 0 |
| && h->size > 0 |
| && h->type != STT_FUNC) |
| olddyncommon = TRUE; |
| else |
| olddyncommon = FALSE; |
| |
| /* It's OK to change the type if either the existing symbol or the |
| new symbol is weak unless it comes from a DT_NEEDED entry of |
| a shared object, in which case, the DT_NEEDED entry may not be |
| required at the run time. The type change is also OK if the |
| old symbol is undefined and the new symbol is defined. */ |
| |
| if ((! dt_needed && oldweakdef) |
| || oldweakundef |
| || newweakdef |
| || newweakundef |
| || (newdef |
| && (h->root.type == bfd_link_hash_undefined |
| || h->root.type == bfd_link_hash_undefweak))) |
| *type_change_ok = TRUE; |
| |
| /* It's OK to change the size if either the existing symbol or the |
| new symbol is weak, or if the old symbol is undefined. */ |
| |
| if (*type_change_ok |
| || h->root.type == bfd_link_hash_undefined) |
| *size_change_ok = TRUE; |
| |
| /* If both the old and the new symbols look like common symbols in a |
| dynamic object, set the size of the symbol to the larger of the |
| two. */ |
| |
| if (olddyncommon |
| && newdyncommon |
| && sym->st_size != h->size) |
| { |
| /* Since we think we have two common symbols, issue a multiple |
| common warning if desired. Note that we only warn if the |
| size is different. If the size is the same, we simply let |
| the old symbol override the new one as normally happens with |
| symbols defined in dynamic objects. */ |
| |
| if (! ((*info->callbacks->multiple_common) |
| (info, h->root.root.string, oldbfd, bfd_link_hash_common, |
| h->size, abfd, bfd_link_hash_common, sym->st_size))) |
| return FALSE; |
| |
| if (sym->st_size > h->size) |
| h->size = sym->st_size; |
| |
| *size_change_ok = TRUE; |
| } |
| |
| /* If we are looking at a dynamic object, and we have found a |
| definition, we need to see if the symbol was already defined by |
| some other object. If so, we want to use the existing |
| definition, and we do not want to report a multiple symbol |
| definition error; we do this by clobbering *PSEC to be |
| bfd_und_section_ptr. |
| |
| We treat a common symbol as a definition if the symbol in the |
| shared library is a function, since common symbols always |
| represent variables; this can cause confusion in principle, but |
| any such confusion would seem to indicate an erroneous program or |
| shared library. We also permit a common symbol in a regular |
| object to override a weak symbol in a shared object. |
| |
| We prefer a non-weak definition in a shared library to a weak |
| definition in the executable unless it comes from a DT_NEEDED |
| entry of a shared object, in which case, the DT_NEEDED entry |
| may not be required at the run time. */ |
| |
| if (newdyn |
| && newdef |
| && (olddef |
| || (h->root.type == bfd_link_hash_common |
| && (newweakdef |
| || newweakundef |
| || ELF_ST_TYPE (sym->st_info) == STT_FUNC))) |
| && (!oldweakdef |
| || dt_needed |
| || newweakdef |
| || newweakundef)) |
| { |
| *override = TRUE; |
| newdef = FALSE; |
| newdyncommon = FALSE; |
| |
| *psec = sec = bfd_und_section_ptr; |
| *size_change_ok = TRUE; |
| |
| /* If we get here when the old symbol is a common symbol, then |
| we are explicitly letting it override a weak symbol or |
| function in a dynamic object, and we don't want to warn about |
| a type change. If the old symbol is a defined symbol, a type |
| change warning may still be appropriate. */ |
| |
| if (h->root.type == bfd_link_hash_common) |
| *type_change_ok = TRUE; |
| } |
| |
| /* Handle the special case of an old common symbol merging with a |
| new symbol which looks like a common symbol in a shared object. |
| We change *PSEC and *PVALUE to make the new symbol look like a |
| common symbol, and let _bfd_generic_link_add_one_symbol will do |
| the right thing. */ |
| |
| if (newdyncommon |
| && h->root.type == bfd_link_hash_common) |
| { |
| *override = TRUE; |
| newdef = FALSE; |
| newdyncommon = FALSE; |
| *pvalue = sym->st_size; |
| *psec = sec = bfd_com_section_ptr; |
| *size_change_ok = TRUE; |
| } |
| |
| /* If the old symbol is from a dynamic object, and the new symbol is |
| a definition which is not from a dynamic object, then the new |
| symbol overrides the old symbol. Symbols from regular files |
| always take precedence over symbols from dynamic objects, even if |
| they are defined after the dynamic object in the link. |
| |
| As above, we again permit a common symbol in a regular object to |
| override a definition in a shared object if the shared object |
| symbol is a function or is weak. |
| |
| As above, we permit a non-weak definition in a shared object to |
| override a weak definition in a regular object. */ |
| |
| flip = NULL; |
| if (! newdyn |
| && (newdef |
| || (bfd_is_com_section (sec) |
| && (oldweakdef || h->type == STT_FUNC))) |
| && olddyn |
| && olddef |
| && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0 |
| && ((!newweakdef && !newweakundef) || oldweakdef)) |
| { |
| /* Change the hash table entry to undefined, and let |
| _bfd_generic_link_add_one_symbol do the right thing with the |
| new definition. */ |
| |
| h->root.type = bfd_link_hash_undefined; |
| h->root.u.undef.abfd = h->root.u.def.section->owner; |
| *size_change_ok = TRUE; |
| |
| olddef = FALSE; |
| olddyncommon = FALSE; |
| |
| /* We again permit a type change when a common symbol may be |
| overriding a function. */ |
| |
| if (bfd_is_com_section (sec)) |
| *type_change_ok = TRUE; |
| |
| if ((*sym_hash)->root.type == bfd_link_hash_indirect) |
| flip = *sym_hash; |
| else |
| /* This union may have been set to be non-NULL when this symbol |
| was seen in a dynamic object. We must force the union to be |
| NULL, so that it is correct for a regular symbol. */ |
| h->verinfo.vertree = NULL; |
| } |
| |
| /* Handle the special case of a new common symbol merging with an |
| old symbol that looks like it might be a common symbol defined in |
| a shared object. Note that we have already handled the case in |
| which a new common symbol should simply override the definition |
| in the shared library. */ |
| |
| if (! newdyn |
| && bfd_is_com_section (sec) |
| && olddyncommon) |
| { |
| /* It would be best if we could set the hash table entry to a |
| common symbol, but we don't know what to use for the section |
| or the alignment. */ |
| if (! ((*info->callbacks->multiple_common) |
| (info, h->root.root.string, oldbfd, bfd_link_hash_common, |
| h->size, abfd, bfd_link_hash_common, sym->st_size))) |
| return FALSE; |
| |
| /* If the presumed common symbol in the dynamic object is |
| larger, pretend that the new symbol has its size. */ |
| |
| if (h->size > *pvalue) |
| *pvalue = h->size; |
| |
| /* FIXME: We no longer know the alignment required by the symbol |
| in the dynamic object, so we just wind up using the one from |
| the regular object. */ |
| |
| olddef = FALSE; |
| olddyncommon = FALSE; |
| |
| h->root.type = bfd_link_hash_undefined; |
| h->root.u.undef.abfd = h->root.u.def.section->owner; |
| |
| *size_change_ok = TRUE; |
| *type_change_ok = TRUE; |
| |
| if ((*sym_hash)->root.type == bfd_link_hash_indirect) |
| flip = *sym_hash; |
| else |
| h->verinfo.vertree = NULL; |
| } |
| |
| if (flip != NULL) |
| { |
| /* Handle the case where we had a versioned symbol in a dynamic |
| library and now find a definition in a normal object. In this |
| case, we make the versioned symbol point to the normal one. */ |
| const struct elf_backend_data *bed = get_elf_backend_data (abfd); |
| flip->root.type = h->root.type; |
| h->root.type = bfd_link_hash_indirect; |
| h->root.u.i.link = (struct bfd_link_hash_entry *) flip; |
| (*bed->elf_backend_copy_indirect_symbol) (bed, flip, h); |
| flip->root.u.undef.abfd = h->root.u.undef.abfd; |
| if (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) |
| { |
| h->elf_link_hash_flags &= ~ELF_LINK_HASH_DEF_DYNAMIC; |
| flip->elf_link_hash_flags |= ELF_LINK_HASH_REF_DYNAMIC; |
| } |
| } |
| |
| /* Handle the special case of a weak definition in a regular object |
| followed by a non-weak definition in a shared object. In this |
| case, we prefer the definition in the shared object unless it |
| comes from a DT_NEEDED entry of a shared object, in which case, |
| the DT_NEEDED entry may not be required at the run time. */ |
| if (olddef |
| && ! dt_needed |
| && oldweakdef |
| && newdef |
| && newdyn |
| && !newweakdef |
| && !newweakundef) |
| { |
| /* To make this work we have to frob the flags so that the rest |
| of the code does not think we are using the regular |
| definition. */ |
| if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0) |
| h->elf_link_hash_flags |= ELF_LINK_HASH_REF_REGULAR; |
| else if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0) |
| h->elf_link_hash_flags |= ELF_LINK_HASH_REF_DYNAMIC; |
| h->elf_link_hash_flags &= ~ (ELF_LINK_HASH_DEF_REGULAR |
| | ELF_LINK_HASH_DEF_DYNAMIC); |
| |
| /* If H is the target of an indirection, we want the caller to |
| use H rather than the indirect symbol. Otherwise if we are |
| defining a new indirect symbol we will wind up attaching it |
| to the entry we are overriding. */ |
| *sym_hash = h; |
| } |
| |
| /* Handle the special case of a non-weak definition in a shared |
| object followed by a weak definition in a regular object. In |
| this case we prefer the definition in the shared object. To make |
| this work we have to tell the caller to not treat the new symbol |
| as a definition. */ |
| if (olddef |
| && olddyn |
| && !oldweakdef |
| && newdef |
| && ! newdyn |
| && (newweakdef || newweakundef)) |
| *override = TRUE; |
| |
| return TRUE; |
| } |
| |
| /* This function is called to create an indirect symbol from the |
| default for the symbol with the default version if needed. The |
| symbol is described by H, NAME, SYM, PSEC, VALUE, and OVERRIDE. We |
| set DYNSYM if the new indirect symbol is dynamic. DT_NEEDED |
| indicates if it comes from a DT_NEEDED entry of a shared object. */ |
| |
| bfd_boolean |
| _bfd_elf_add_default_symbol (bfd *abfd, |
| struct bfd_link_info *info, |
| struct elf_link_hash_entry *h, |
| const char *name, |
| Elf_Internal_Sym *sym, |
| asection **psec, |
| bfd_vma *value, |
| bfd_boolean *dynsym, |
| bfd_boolean override, |
| bfd_boolean dt_needed) |
| { |
| bfd_boolean type_change_ok; |
| bfd_boolean size_change_ok; |
| bfd_boolean skip; |
| char *shortname; |
| struct elf_link_hash_entry *hi; |
| struct bfd_link_hash_entry *bh; |
| const struct elf_backend_data *bed; |
| bfd_boolean collect; |
| bfd_boolean dynamic; |
| char *p; |
| size_t len, shortlen; |
| asection *sec; |
| |
| /* If this symbol has a version, and it is the default version, we |
| create an indirect symbol from the default name to the fully |
| decorated name. This will cause external references which do not |
| specify a version to be bound to this version of the symbol. */ |
| p = strchr (name, ELF_VER_CHR); |
| if (p == NULL || p[1] != ELF_VER_CHR) |
| return TRUE; |
| |
| if (override) |
| { |
| /* We are overridden by an old definition. We need to check if we |
| need to create the indirect symbol from the default name. */ |
| hi = elf_link_hash_lookup (elf_hash_table (info), name, TRUE, |
| FALSE, FALSE); |
| BFD_ASSERT (hi != NULL); |
| if (hi == h) |
| return TRUE; |
| while (hi->root.type == bfd_link_hash_indirect |
| || hi->root.type == bfd_link_hash_warning) |
| { |
| hi = (struct elf_link_hash_entry *) hi->root.u.i.link; |
| if (hi == h) |
| return TRUE; |
| } |
| } |
| |
| bed = get_elf_backend_data (abfd); |
| collect = bed->collect; |
| dynamic = (abfd->flags & DYNAMIC) != 0; |
| |
| shortlen = p - name; |
| shortname = bfd_hash_allocate (&info->hash->table, shortlen + 1); |
| if (shortname == NULL) |
| return FALSE; |
| memcpy (shortname, name, shortlen); |
| shortname[shortlen] = '\0'; |
| |
| /* We are going to create a new symbol. Merge it with any existing |
| symbol with this name. For the purposes of the merge, act as |
| though we were defining the symbol we just defined, although we |
| actually going to define an indirect symbol. */ |
| type_change_ok = FALSE; |
| size_change_ok = FALSE; |
| sec = *psec; |
| if (!_bfd_elf_merge_symbol (abfd, info, shortname, sym, &sec, value, |
| &hi, &skip, &override, &type_change_ok, |
| &size_change_ok, dt_needed)) |
| return FALSE; |
| |
| if (skip) |
| goto nondefault; |
| |
| if (! override) |
| { |
| bh = &hi->root; |
| if (! (_bfd_generic_link_add_one_symbol |
| (info, abfd, shortname, BSF_INDIRECT, bfd_ind_section_ptr, |
| 0, name, FALSE, collect, &bh))) |
| return FALSE; |
| hi = (struct elf_link_hash_entry *) bh; |
| } |
| else |
| { |
| /* In this case the symbol named SHORTNAME is overriding the |
| indirect symbol we want to add. We were planning on making |
| SHORTNAME an indirect symbol referring to NAME. SHORTNAME |
| is the name without a version. NAME is the fully versioned |
| name, and it is the default version. |
| |
| Overriding means that we already saw a definition for the |
| symbol SHORTNAME in a regular object, and it is overriding |
| the symbol defined in the dynamic object. |
| |
| When this happens, we actually want to change NAME, the |
| symbol we just added, to refer to SHORTNAME. This will cause |
| references to NAME in the shared object to become references |
| to SHORTNAME in the regular object. This is what we expect |
| when we override a function in a shared object: that the |
| references in the shared object will be mapped to the |
| definition in the regular object. */ |
| |
| while (hi->root.type == bfd_link_hash_indirect |
| || hi->root.type == bfd_link_hash_warning) |
| hi = (struct elf_link_hash_entry *) hi->root.u.i.link; |
| |
| h->root.type = bfd_link_hash_indirect; |
| h->root.u.i.link = (struct bfd_link_hash_entry *) hi; |
| if (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) |
| { |
| h->elf_link_hash_flags &=~ ELF_LINK_HASH_DEF_DYNAMIC; |
| hi->elf_link_hash_flags |= ELF_LINK_HASH_REF_DYNAMIC; |
| if (hi->elf_link_hash_flags |
| & (ELF_LINK_HASH_REF_REGULAR |
| | ELF_LINK_HASH_DEF_REGULAR)) |
| { |
| if (! _bfd_elf_link_record_dynamic_symbol (info, hi)) |
| return FALSE; |
| } |
| } |
| |
| /* Now set HI to H, so that the following code will set the |
| other fields correctly. */ |
| hi = h; |
| } |
| |
| /* If there is a duplicate definition somewhere, then HI may not |
| point to an indirect symbol. We will have reported an error to |
| the user in that case. */ |
| |
| if (hi->root.type == bfd_link_hash_indirect) |
| { |
| struct elf_link_hash_entry *ht; |
| |
| /* If the symbol became indirect, then we assume that we have |
| not seen a definition before. */ |
| BFD_ASSERT ((hi->elf_link_hash_flags |
| & (ELF_LINK_HASH_DEF_DYNAMIC |
| | ELF_LINK_HASH_DEF_REGULAR)) == 0); |
| |
| ht = (struct elf_link_hash_entry *) hi->root.u.i.link; |
| (*bed->elf_backend_copy_indirect_symbol) (bed, ht, hi); |
| |
| /* See if the new flags lead us to realize that the symbol must |
| be dynamic. */ |
| if (! *dynsym) |
| { |
| if (! dynamic) |
| { |
| if (info->shared |
| || ((hi->elf_link_hash_flags |
| & ELF_LINK_HASH_REF_DYNAMIC) != 0)) |
| *dynsym = TRUE; |
| } |
| else |
| { |
| if ((hi->elf_link_hash_flags |
| & ELF_LINK_HASH_REF_REGULAR) != 0) |
| *dynsym = TRUE; |
| } |
| } |
| } |
| |
| /* We also need to define an indirection from the nondefault version |
| of the symbol. */ |
| |
| nondefault: |
| len = strlen (name); |
| shortname = bfd_hash_allocate (&info->hash->table, len); |
| if (shortname == NULL) |
| return FALSE; |
| memcpy (shortname, name, shortlen); |
| memcpy (shortname + shortlen, p + 1, len - shortlen); |
| |
| /* Once again, merge with any existing symbol. */ |
| type_change_ok = FALSE; |
| size_change_ok = FALSE; |
| sec = *psec; |
| if (!_bfd_elf_merge_symbol (abfd, info, shortname, sym, &sec, value, |
| &hi, &skip, &override, &type_change_ok, |
| &size_change_ok, dt_needed)) |
| return FALSE; |
| |
| if (skip) |
| return TRUE; |
| |
| if (override) |
| { |
| /* Here SHORTNAME is a versioned name, so we don't expect to see |
| the type of override we do in the case above unless it is |
| overridden by a versioned definition. */ |
| if (hi->root.type != bfd_link_hash_defined |
| && hi->root.type != bfd_link_hash_defweak) |
| (*_bfd_error_handler) |
| (_("%s: warning: unexpected redefinition of indirect versioned symbol `%s'"), |
| bfd_archive_filename (abfd), shortname); |
| } |
| else |
| { |
| bh = &hi->root; |
| if (! (_bfd_generic_link_add_one_symbol |
| (info, abfd, shortname, BSF_INDIRECT, |
| bfd_ind_section_ptr, 0, name, FALSE, collect, &bh))) |
| return FALSE; |
| hi = (struct elf_link_hash_entry *) bh; |
| |
| /* If there is a duplicate definition somewhere, then HI may not |
| point to an indirect symbol. We will have reported an error |
| to the user in that case. */ |
| |
| if (hi->root.type == bfd_link_hash_indirect) |
| { |
| /* If the symbol became indirect, then we assume that we have |
| not seen a definition before. */ |
| BFD_ASSERT ((hi->elf_link_hash_flags |
| & (ELF_LINK_HASH_DEF_DYNAMIC |
| | ELF_LINK_HASH_DEF_REGULAR)) == 0); |
| |
| (*bed->elf_backend_copy_indirect_symbol) (bed, h, hi); |
| |
| /* See if the new flags lead us to realize that the symbol |
| must be dynamic. */ |
| if (! *dynsym) |
| { |
| if (! dynamic) |
| { |
| if (info->shared |
| || ((hi->elf_link_hash_flags |
| & ELF_LINK_HASH_REF_DYNAMIC) != 0)) |
| *dynsym = TRUE; |
| } |
| else |
| { |
| if ((hi->elf_link_hash_flags |
| & ELF_LINK_HASH_REF_REGULAR) != 0) |
| *dynsym = TRUE; |
| } |
| } |
| } |
| } |
| |
| return TRUE; |
| } |
| |
| /* This routine is used to export all defined symbols into the dynamic |
| symbol table. It is called via elf_link_hash_traverse. */ |
| |
| bfd_boolean |
| _bfd_elf_export_symbol (struct elf_link_hash_entry *h, void *data) |
| { |
| struct elf_info_failed *eif = data; |
| |
| /* Ignore indirect symbols. These are added by the versioning code. */ |
| if (h->root.type == bfd_link_hash_indirect) |
| return TRUE; |
| |
| if (h->root.type == bfd_link_hash_warning) |
| h = (struct elf_link_hash_entry *) h->root.u.i.link; |
| |
| if (h->dynindx == -1 |
| && (h->elf_link_hash_flags |
| & (ELF_LINK_HASH_DEF_REGULAR | ELF_LINK_HASH_REF_REGULAR)) != 0) |
| { |
| struct bfd_elf_version_tree *t; |
| struct bfd_elf_version_expr *d; |
| |
| for (t = eif->verdefs; t != NULL; t = t->next) |
| { |
| if (t->globals.list != NULL) |
| { |
| d = (*t->match) (&t->globals, NULL, h->root.root.string); |
| if (d != NULL) |
| goto doit; |
| } |
| |
| if (t->locals.list != NULL) |
| { |
| d = (*t->match) (&t->locals, NULL, h->root.root.string); |
| if (d != NULL) |
| return TRUE; |
| } |
| } |
| |
| if (!eif->verdefs) |
| { |
| doit: |
| if (! _bfd_elf_link_record_dynamic_symbol (eif->info, h)) |
| { |
| eif->failed = TRUE; |
| return FALSE; |
| } |
| } |
| } |
| |
| return TRUE; |
| } |
| |
| /* Look through the symbols which are defined in other shared |
| libraries and referenced here. Update the list of version |
| dependencies. This will be put into the .gnu.version_r section. |
| This function is called via elf_link_hash_traverse. */ |
| |
| bfd_boolean |
| _bfd_elf_link_find_version_dependencies (struct elf_link_hash_entry *h, |
| void *data) |
| { |
| struct elf_find_verdep_info *rinfo = data; |
| Elf_Internal_Verneed *t; |
| Elf_Internal_Vernaux *a; |
| bfd_size_type amt; |
| |
| if (h->root.type == bfd_link_hash_warning) |
| h = (struct elf_link_hash_entry *) h->root.u.i.link; |
| |
| /* We only care about symbols defined in shared objects with version |
| information. */ |
| if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0 |
| || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0 |
| || h->dynindx == -1 |
| || h->verinfo.verdef == NULL) |
| return TRUE; |
| |
| /* See if we already know about this version. */ |
| for (t = elf_tdata (rinfo->output_bfd)->verref; t != NULL; t = t->vn_nextref) |
| { |
| if (t->vn_bfd != h->verinfo.verdef->vd_bfd) |
| continue; |
| |
| for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr) |
| if (a->vna_nodename == h->verinfo.verdef->vd_nodename) |
| return TRUE; |
| |
| break; |
| } |
| |
| /* This is a new version. Add it to tree we are building. */ |
| |
| if (t == NULL) |
| { |
| amt = sizeof *t; |
| t = bfd_zalloc (rinfo->output_bfd, amt); |
| if (t == NULL) |
| { |
| rinfo->failed = TRUE; |
| return FALSE; |
| } |
| |
| t->vn_bfd = h->verinfo.verdef->vd_bfd; |
| t->vn_nextref = elf_tdata (rinfo->output_bfd)->verref; |
| elf_tdata (rinfo->output_bfd)->verref = t; |
| } |
| |
| amt = sizeof *a; |
| a = bfd_zalloc (rinfo->output_bfd, amt); |
| |
| /* Note that we are copying a string pointer here, and testing it |
| above. If bfd_elf_string_from_elf_section is ever changed to |
| discard the string data when low in memory, this will have to be |
| fixed. */ |
| a->vna_nodename = h->verinfo.verdef->vd_nodename; |
| |
| a->vna_flags = h->verinfo.verdef->vd_flags; |
| a->vna_nextptr = t->vn_auxptr; |
| |
| h->verinfo.verdef->vd_exp_refno = rinfo->vers; |
| ++rinfo->vers; |
| |
| a->vna_other = h->verinfo.verdef->vd_exp_refno + 1; |
| |
| t->vn_auxptr = a; |
| |
| return TRUE; |
| } |
| |
| /* Figure out appropriate versions for all the symbols. We may not |
| have the version number script until we have read all of the input |
| files, so until that point we don't know which symbols should be |
| local. This function is called via elf_link_hash_traverse. */ |
| |
| bfd_boolean |
| _bfd_elf_link_assign_sym_version (struct elf_link_hash_entry *h, void *data) |
| { |
| struct elf_assign_sym_version_info *sinfo; |
| struct bfd_link_info *info; |
| const struct elf_backend_data *bed; |
| struct elf_info_failed eif; |
| char *p; |
| bfd_size_type amt; |
| |
| sinfo = data; |
| info = sinfo->info; |
| |
| if (h->root.type == bfd_link_hash_warning) |
| h = (struct elf_link_hash_entry *) h->root.u.i.link; |
| |
| /* Fix the symbol flags. */ |
| eif.failed = FALSE; |
| eif.info = info; |
| if (! _bfd_elf_fix_symbol_flags (h, &eif)) |
| { |
| if (eif.failed) |
| sinfo->failed = TRUE; |
| return FALSE; |
| } |
| |
| /* We only need version numbers for symbols defined in regular |
| objects. */ |
| if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0) |
| return TRUE; |
| |
| bed = get_elf_backend_data (sinfo->output_bfd); |
| p = strchr (h->root.root.string, ELF_VER_CHR); |
| if (p != NULL && h->verinfo.vertree == NULL) |
| { |
| struct bfd_elf_version_tree *t; |
| bfd_boolean hidden; |
| |
| hidden = TRUE; |
| |
| /* There are two consecutive ELF_VER_CHR characters if this is |
| not a hidden symbol. */ |
| ++p; |
| if (*p == ELF_VER_CHR) |
| { |
| hidden = FALSE; |
| ++p; |
| } |
| |
| /* If there is no version string, we can just return out. */ |
| if (*p == '\0') |
| { |
| if (hidden) |
| h->elf_link_hash_flags |= ELF_LINK_HIDDEN; |
| return TRUE; |
| } |
| |
| /* Look for the version. If we find it, it is no longer weak. */ |
| for (t = sinfo->verdefs; t != NULL; t = t->next) |
| { |
| if (strcmp (t->name, p) == 0) |
| { |
| size_t len; |
| char *alc; |
| struct bfd_elf_version_expr *d; |
| |
| len = p - h->root.root.string; |
| alc = bfd_malloc (len); |
| if (alc == NULL) |
| return FALSE; |
| memcpy (alc, h->root.root.string, len - 1); |
| alc[len - 1] = '\0'; |
| if (alc[len - 2] == ELF_VER_CHR) |
| alc[len - 2] = '\0'; |
| |
| h->verinfo.vertree = t; |
| t->used = TRUE; |
| d = NULL; |
| |
| if (t->globals.list != NULL) |
| d = (*t->match) (&t->globals, NULL, alc); |
| |
| /* See if there is anything to force this symbol to |
| local scope. */ |
| if (d == NULL && t->locals.list != NULL) |
| { |
| d = (*t->match) (&t->locals, NULL, alc); |
| if (d != NULL |
| && h->dynindx != -1 |
| && info->shared |
| && ! info->export_dynamic) |
| (*bed->elf_backend_hide_symbol) (info, h, TRUE); |
| } |
| |
| free (alc); |
| break; |
| } |
| } |
| |
| /* If we are building an application, we need to create a |
| version node for this version. */ |
| if (t == NULL && info->executable) |
| { |
| struct bfd_elf_version_tree **pp; |
| int version_index; |
| |
| /* If we aren't going to export this symbol, we don't need |
| to worry about it. */ |
| if (h->dynindx == -1) |
| return TRUE; |
| |
| amt = sizeof *t; |
| t = bfd_zalloc (sinfo->output_bfd, amt); |
| if (t == NULL) |
| { |
| sinfo->failed = TRUE; |
| return FALSE; |
| } |
| |
| t->name = p; |
| t->name_indx = (unsigned int) -1; |
| t->used = TRUE; |
| |
| version_index = 1; |
| /* Don't count anonymous version tag. */ |
| if (sinfo->verdefs != NULL && sinfo->verdefs->vernum == 0) |
| version_index = 0; |
| for (pp = &sinfo->verdefs; *pp != NULL; pp = &(*pp)->next) |
| ++version_index; |
| t->vernum = version_index; |
| |
| *pp = t; |
| |
| h->verinfo.vertree = t; |
| } |
| else if (t == NULL) |
| { |
| /* We could not find the version for a symbol when |
| generating a shared archive. Return an error. */ |
| (*_bfd_error_handler) |
| (_("%s: undefined versioned symbol name %s"), |
| bfd_get_filename (sinfo->output_bfd), h->root.root.string); |
| bfd_set_error (bfd_error_bad_value); |
| sinfo->failed = TRUE; |
| return FALSE; |
| } |
| |
| if (hidden) |
| h->elf_link_hash_flags |= ELF_LINK_HIDDEN; |
| } |
| |
| /* If we don't have a version for this symbol, see if we can find |
| something. */ |
| if (h->verinfo.vertree == NULL && sinfo->verdefs != NULL) |
| { |
| struct bfd_elf_version_tree *t; |
| struct bfd_elf_version_tree *local_ver; |
| struct bfd_elf_version_expr *d; |
| |
| /* See if can find what version this symbol is in. If the |
| symbol is supposed to be local, then don't actually register |
| it. */ |
| local_ver = NULL; |
| for (t = sinfo->verdefs; t != NULL; t = t->next) |
| { |
| if (t->globals.list != NULL) |
| { |
| bfd_boolean matched; |
| |
| matched = FALSE; |
| d = NULL; |
| while ((d = (*t->match) (&t->globals, d, |
| h->root.root.string)) != NULL) |
| if (d->symver) |
| matched = TRUE; |
| else |
| { |
| /* There is a version without definition. Make |
| the symbol the default definition for this |
| version. */ |
| h->verinfo.vertree = t; |
| local_ver = NULL; |
| d->script = 1; |
| break; |
| } |
| if (d != NULL) |
| break; |
| else if (matched) |
| /* There is no undefined version for this symbol. Hide the |
| default one. */ |
| (*bed->elf_backend_hide_symbol) (info, h, TRUE); |
| } |
| |
| if (t->locals.list != NULL) |
| { |
| d = NULL; |
| while ((d = (*t->match) (&t->locals, d, |
| h->root.root.string)) != NULL) |
| { |
| local_ver = t; |
| /* If the match is "*", keep looking for a more |
| explicit, perhaps even global, match. |
| XXX: Shouldn't this be !d->wildcard instead? */ |
| if (d->pattern[0] != '*' || d->pattern[1] != '\0') |
| break; |
| } |
| |
| if (d != NULL) |
| break; |
| } |
| } |
| |
| if (local_ver != NULL) |
| { |
| h->verinfo.vertree = local_ver; |
| if (h->dynindx != -1 |
| && info->shared |
| && ! info->export_dynamic) |
| { |
| (*bed->elf_backend_hide_symbol) (info, h, TRUE); |
| } |
| } |
| } |
| |
| return TRUE; |
| } |
| |
| /* Read and swap the relocs from the section indicated by SHDR. This |
| may be either a REL or a RELA section. The relocations are |
| translated into RELA relocations and stored in INTERNAL_RELOCS, |
| which should have already been allocated to contain enough space. |
| The EXTERNAL_RELOCS are a buffer where the external form of the |
| relocations should be stored. |
| |
| Returns FALSE if something goes wrong. */ |
| |
| static bfd_boolean |
| elf_link_read_relocs_from_section (bfd *abfd, |
| asection *sec, |
| Elf_Internal_Shdr *shdr, |
| void *external_relocs, |
| Elf_Internal_Rela *internal_relocs) |
| { |
| const struct elf_backend_data *bed; |
| void (*swap_in) (bfd *, const bfd_byte *, Elf_Internal_Rela *); |
| const bfd_byte *erela; |
| const bfd_byte *erelaend; |
| Elf_Internal_Rela *irela; |
| Elf_Internal_Shdr *symtab_hdr; |
| size_t nsyms; |
| |
| /* If there aren't any relocations, that's OK. */ |
| if (!shdr) |
| return TRUE; |
| |
| /* Position ourselves at the start of the section. */ |
| if (bfd_seek (abfd, shdr->sh_offset, SEEK_SET) != 0) |
| return FALSE; |
| |
| /* Read the relocations. */ |
| if (bfd_bread (external_relocs, shdr->sh_size, abfd) != shdr->sh_size) |
| return FALSE; |
| |
| symtab_hdr = &elf_tdata (abfd)->symtab_hdr; |
| nsyms = symtab_hdr->sh_size / symtab_hdr->sh_entsize; |
| |
| bed = get_elf_backend_data (abfd); |
| |
| /* Convert the external relocations to the internal format. */ |
| if (shdr->sh_entsize == bed->s->sizeof_rel) |
| swap_in = bed->s->swap_reloc_in; |
| else if (shdr->sh_entsize == bed->s->sizeof_rela) |
| swap_in = bed->s->swap_reloca_in; |
| else |
| { |
| bfd_set_error (bfd_error_wrong_format); |
| return FALSE; |
| } |
| |
| erela = external_relocs; |
| erelaend = erela + NUM_SHDR_ENTRIES (shdr) * shdr->sh_entsize; |
| irela = internal_relocs; |
| while (erela < erelaend) |
| { |
| bfd_vma r_symndx; |
| |
| (*swap_in) (abfd, erela, irela); |
| r_symndx = ELF32_R_SYM (irela->r_info); |
| if (bed->s->arch_size == 64) |
| r_symndx >>= 24; |
| if ((size_t) r_symndx >= nsyms) |
| { |
| (*_bfd_error_handler) |
| (_("%s: bad reloc symbol index (0x%lx >= 0x%lx) for offset 0x%lx in section `%s'"), |
| bfd_archive_filename (abfd), (unsigned long) r_symndx, |
| (unsigned long) nsyms, irela->r_offset, sec->name); |
| bfd_set_error (bfd_error_bad_value); |
| return FALSE; |
| } |
| irela += bed->s->int_rels_per_ext_rel; |
| erela += shdr->sh_entsize; |
| } |
| |
| return TRUE; |
| } |
| |
| /* Read and swap the relocs for a section O. They may have been |
| cached. If the EXTERNAL_RELOCS and INTERNAL_RELOCS arguments are |
| not NULL, they are used as buffers to read into. They are known to |
| be large enough. If the INTERNAL_RELOCS relocs argument is NULL, |
| the return value is allocated using either malloc or bfd_alloc, |
| according to the KEEP_MEMORY argument. If O has two relocation |
| sections (both REL and RELA relocations), then the REL_HDR |
| relocations will appear first in INTERNAL_RELOCS, followed by the |
| REL_HDR2 relocations. */ |
| |
| Elf_Internal_Rela * |
| _bfd_elf_link_read_relocs (bfd *abfd, |
| asection *o, |
| void *external_relocs, |
| Elf_Internal_Rela *internal_relocs, |
| bfd_boolean keep_memory) |
| { |
| Elf_Internal_Shdr *rel_hdr; |
| void *alloc1 = NULL; |
| Elf_Internal_Rela *alloc2 = NULL; |
| const struct elf_backend_data *bed = get_elf_backend_data (abfd); |
| |
| if (elf_section_data (o)->relocs != NULL) |
| return elf_section_data (o)->relocs; |
| |
| if (o->reloc_count == 0) |
| return NULL; |
| |
| rel_hdr = &elf_section_data (o)->rel_hdr; |
| |
| if (internal_relocs == NULL) |
| { |
| bfd_size_type size; |
| |
| size = o->reloc_count; |
| size *= bed->s->int_rels_per_ext_rel * sizeof (Elf_Internal_Rela); |
| if (keep_memory) |
| internal_relocs = bfd_alloc (abfd, size); |
| else |
| internal_relocs = alloc2 = bfd_malloc (size); |
| if (internal_relocs == NULL) |
| goto error_return; |
| } |
| |
| if (external_relocs == NULL) |
| { |
| bfd_size_type size = rel_hdr->sh_size; |
| |
| if (elf_section_data (o)->rel_hdr2) |
| size += elf_section_data (o)->rel_hdr2->sh_size; |
| alloc1 = bfd_malloc (size); |
| if (alloc1 == NULL) |
| goto error_return; |
| external_relocs = alloc1; |
| } |
| |
| if (!elf_link_read_relocs_from_section (abfd, o, rel_hdr, |
| external_relocs, |
| internal_relocs)) |
| goto error_return; |
| if (!elf_link_read_relocs_from_section |
| (abfd, o, |
| elf_section_data (o)->rel_hdr2, |
| ((bfd_byte *) external_relocs) + rel_hdr->sh_size, |
| internal_relocs + (NUM_SHDR_ENTRIES (rel_hdr) |
| * bed->s->int_rels_per_ext_rel))) |
| goto error_return; |
| |
| /* Cache the results for next time, if we can. */ |
| if (keep_memory) |
| elf_section_data (o)->relocs = internal_relocs; |
| |
| if (alloc1 != NULL) |
| free (alloc1); |
| |
| /* Don't free alloc2, since if it was allocated we are passing it |
| back (under the name of internal_relocs). */ |
| |
| return internal_relocs; |
| |
| error_return: |
| if (alloc1 != NULL) |
| free (alloc1); |
| if (alloc2 != NULL) |
| free (alloc2); |
| return NULL; |
| } |
| |
| /* Compute the size of, and allocate space for, REL_HDR which is the |
| section header for a section containing relocations for O. */ |
| |
| bfd_boolean |
| _bfd_elf_link_size_reloc_section (bfd *abfd, |
| Elf_Internal_Shdr *rel_hdr, |
| asection *o) |
| { |
| bfd_size_type reloc_count; |
| bfd_size_type num_rel_hashes; |
| |
| /* Figure out how many relocations there will be. */ |
| if (rel_hdr == &elf_section_data (o)->rel_hdr) |
| reloc_count = elf_section_data (o)->rel_count; |
| else |
| reloc_count = elf_section_data (o)->rel_count2; |
| |
| num_rel_hashes = o->reloc_count; |
| if (num_rel_hashes < reloc_count) |
| num_rel_hashes = reloc_count; |
| |
| /* That allows us to calculate the size of the section. */ |
| rel_hdr->sh_size = rel_hdr->sh_entsize * reloc_count; |
| |
| /* The contents field must last into write_object_contents, so we |
| allocate it with bfd_alloc rather than malloc. Also since we |
| cannot be sure that the contents will actually be filled in, |
| we zero the allocated space. */ |
| rel_hdr->contents = bfd_zalloc (abfd, rel_hdr->sh_size); |
| if (rel_hdr->contents == NULL && rel_hdr->sh_size != 0) |
| return FALSE; |
| |
| /* We only allocate one set of hash entries, so we only do it the |
| first time we are called. */ |
| if (elf_section_data (o)->rel_hashes == NULL |
| && num_rel_hashes) |
| { |
| struct elf_link_hash_entry **p; |
| |
| p = bfd_zmalloc (num_rel_hashes * sizeof (struct elf_link_hash_entry *)); |
| if (p == NULL) |
| return FALSE; |
| |
| elf_section_data (o)->rel_hashes = p; |
| } |
| |
| return TRUE; |
| } |
| |
| /* Copy the relocations indicated by the INTERNAL_RELOCS (which |
| originated from the section given by INPUT_REL_HDR) to the |
| OUTPUT_BFD. */ |
| |
| bfd_boolean |
| _bfd_elf_link_output_relocs (bfd *output_bfd, |
| asection *input_section, |
| Elf_Internal_Shdr *input_rel_hdr, |
| Elf_Internal_Rela *internal_relocs) |
| { |
| Elf_Internal_Rela *irela; |
| Elf_Internal_Rela *irelaend; |
| bfd_byte *erel; |
| Elf_Internal_Shdr *output_rel_hdr; |
| asection *output_section; |
| unsigned int *rel_countp = NULL; |
| const struct elf_backend_data *bed; |
| void (*swap_out) (bfd *, const Elf_Internal_Rela *, bfd_byte *); |
| |
| output_section = input_section->output_section; |
| output_rel_hdr = NULL; |
| |
| if (elf_section_data (output_section)->rel_hdr.sh_entsize |
| == input_rel_hdr->sh_entsize) |
| { |
| output_rel_hdr = &elf_section_data (output_section)->rel_hdr; |
| rel_countp = &elf_section_data (output_section)->rel_count; |
| } |
| else if (elf_section_data (output_section)->rel_hdr2 |
| && (elf_section_data (output_section)->rel_hdr2->sh_entsize |
| == input_rel_hdr->sh_entsize)) |
| { |
| output_rel_hdr = elf_section_data (output_section)->rel_hdr2; |
| rel_countp = &elf_section_data (output_section)->rel_count2; |
| } |
| else |
| { |
| (*_bfd_error_handler) |
| (_("%s: relocation size mismatch in %s section %s"), |
| bfd_get_filename (output_bfd), |
| bfd_archive_filename (input_section->owner), |
| input_section->name); |
| bfd_set_error (bfd_error_wrong_object_format); |
| return FALSE; |
| } |
| |
| bed = get_elf_backend_data (output_bfd); |
| if (input_rel_hdr->sh_entsize == bed->s->sizeof_rel) |
| swap_out = bed->s->swap_reloc_out; |
| else if (input_rel_hdr->sh_entsize == bed->s->sizeof_rela) |
| swap_out = bed->s->swap_reloca_out; |
| else |
| abort (); |
| |
| erel = output_rel_hdr->contents; |
| erel += *rel_countp * input_rel_hdr->sh_entsize; |
| irela = internal_relocs; |
| irelaend = irela + (NUM_SHDR_ENTRIES (input_rel_hdr) |
| * bed->s->int_rels_per_ext_rel); |
| while (irela < irelaend) |
| { |
| (*swap_out) (output_bfd, irela, erel); |
| irela += bed->s->int_rels_per_ext_rel; |
| erel += input_rel_hdr->sh_entsize; |
| } |
| |
| /* Bump the counter, so that we know where to add the next set of |
| relocations. */ |
| *rel_countp += NUM_SHDR_ENTRIES (input_rel_hdr); |
| |
| return TRUE; |
| } |
| |
| /* Fix up the flags for a symbol. This handles various cases which |
| can only be fixed after all the input files are seen. This is |
| currently called by both adjust_dynamic_symbol and |
| assign_sym_version, which is unnecessary but perhaps more robust in |
| the face of future changes. */ |
| |
| bfd_boolean |
| _bfd_elf_fix_symbol_flags (struct elf_link_hash_entry *h, |
| struct elf_info_failed *eif) |
| { |
| /* If this symbol was mentioned in a non-ELF file, try to set |
| DEF_REGULAR and REF_REGULAR correctly. This is the only way to |
| permit a non-ELF file to correctly refer to a symbol defined in |
| an ELF dynamic object. */ |
| if ((h->elf_link_hash_flags & ELF_LINK_NON_ELF) != 0) |
| { |
| while (h->root.type == bfd_link_hash_indirect) |
| h = (struct elf_link_hash_entry *) h->root.u.i.link; |
| |
| if (h->root.type != bfd_link_hash_defined |
| && h->root.type != bfd_link_hash_defweak) |
| h->elf_link_hash_flags |= (ELF_LINK_HASH_REF_REGULAR |
| | ELF_LINK_HASH_REF_REGULAR_NONWEAK); |
| else |
| { |
| if (h->root.u.def.section->owner != NULL |
| && (bfd_get_flavour (h->root.u.def.section->owner) |
| == bfd_target_elf_flavour)) |
| h->elf_link_hash_flags |= (ELF_LINK_HASH_REF_REGULAR |
| | ELF_LINK_HASH_REF_REGULAR_NONWEAK); |
| else |
| h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR; |
| } |
| |
| if (h->dynindx == -1 |
| && ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0 |
| || (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) != 0)) |
| { |
| if (! _bfd_elf_link_record_dynamic_symbol (eif->info, h)) |
| { |
| eif->failed = TRUE; |
| return FALSE; |
| } |
| } |
| } |
| else |
| { |
| /* Unfortunately, ELF_LINK_NON_ELF is only correct if the symbol |
| was first seen in a non-ELF file. Fortunately, if the symbol |
| was first seen in an ELF file, we're probably OK unless the |
| symbol was defined in a non-ELF file. Catch that case here. |
| FIXME: We're still in trouble if the symbol was first seen in |
| a dynamic object, and then later in a non-ELF regular object. */ |
| if ((h->root.type == bfd_link_hash_defined |
| || h->root.type == bfd_link_hash_defweak) |
| && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0 |
| && (h->root.u.def.section->owner != NULL |
| ? (bfd_get_flavour (h->root.u.def.section->owner) |
| != bfd_target_elf_flavour) |
| : (bfd_is_abs_section (h->root.u.def.section) |
| && (h->elf_link_hash_flags |
| & ELF_LINK_HASH_DEF_DYNAMIC) == 0))) |
| h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR; |
| } |
| |
| /* If this is a final link, and the symbol was defined as a common |
| symbol in a regular object file, and there was no definition in |
| any dynamic object, then the linker will have allocated space for |
| the symbol in a common section but the ELF_LINK_HASH_DEF_REGULAR |
| flag will not have been set. */ |
| if (h->root.type == bfd_link_hash_defined |
| && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0 |
| && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) != 0 |
| && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0 |
| && (h->root.u.def.section->owner->flags & DYNAMIC) == 0) |
| h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR; |
| |
| /* If -Bsymbolic was used (which means to bind references to global |
| symbols to the definition within the shared object), and this |
| symbol was defined in a regular object, then it actually doesn't |
| need a PLT entry. Likewise, if the symbol has non-default |
| visibility. If the symbol has hidden or internal visibility, we |
| will force it local. */ |
| if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) != 0 |
| && eif->info->shared |
| && is_elf_hash_table (eif->info->hash) |
| && (eif->info->symbolic |
| || ELF_ST_VISIBILITY (h->other) != STV_DEFAULT) |
| && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0) |
| { |
| const struct elf_backend_data *bed; |
| bfd_boolean force_local; |
| |
| bed = get_elf_backend_data (elf_hash_table (eif->info)->dynobj); |
| |
| force_local = (ELF_ST_VISIBILITY (h->other) == STV_INTERNAL |
| || ELF_ST_VISIBILITY (h->other) == STV_HIDDEN); |
| (*bed->elf_backend_hide_symbol) (eif->info, h, force_local); |
| } |
| |
| /* If a weak undefined symbol has non-default visibility, we also |
| hide it from the dynamic linker. */ |
| if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT |
| && h->root.type == bfd_link_hash_undefweak) |
| { |
| const struct elf_backend_data *bed; |
| bed = get_elf_backend_data (elf_hash_table (eif->info)->dynobj); |
| (*bed->elf_backend_hide_symbol) (eif->info, h, TRUE); |
| } |
| |
| /* If this is a weak defined symbol in a dynamic object, and we know |
| the real definition in the dynamic object, copy interesting flags |
| over to the real definition. */ |
| if (h->weakdef != NULL) |
| { |
| struct elf_link_hash_entry *weakdef; |
| |
| weakdef = h->weakdef; |
| if (h->root.type == bfd_link_hash_indirect) |
| h = (struct elf_link_hash_entry *) h->root.u.i.link; |
| |
| BFD_ASSERT (h->root.type == bfd_link_hash_defined |
| || h->root.type == bfd_link_hash_defweak); |
| BFD_ASSERT (weakdef->root.type == bfd_link_hash_defined |
| || weakdef->root.type == bfd_link_hash_defweak); |
| BFD_ASSERT (weakdef->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC); |
| |
| /* If the real definition is defined by a regular object file, |
| don't do anything special. See the longer description in |
| _bfd_elf_adjust_dynamic_symbol, below. */ |
| if ((weakdef->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0) |
| h->weakdef = NULL; |
| else |
| { |
| const struct elf_backend_data *bed; |
| |
| bed = get_elf_backend_data (elf_hash_table (eif->info)->dynobj); |
| (*bed->elf_backend_copy_indirect_symbol) (bed, weakdef, h); |
| } |
| } |
| |
| return TRUE; |
| } |
| |
| /* Make the backend pick a good value for a dynamic symbol. This is |
| called via elf_link_hash_traverse, and also calls itself |
| recursively. */ |
| |
| bfd_boolean |
| _bfd_elf_adjust_dynamic_symbol (struct elf_link_hash_entry *h, void *data) |
| { |
| struct elf_info_failed *eif = data; |
| bfd *dynobj; |
| const struct elf_backend_data *bed; |
| |
| if (! is_elf_hash_table (eif->info->hash)) |
| return FALSE; |
| |
| if (h->root.type == bfd_link_hash_warning) |
| { |
| h->plt = elf_hash_table (eif->info)->init_offset; |
| h->got = elf_hash_table (eif->info)->init_offset; |
| |
| /* When warning symbols are created, they **replace** the "real" |
| entry in the hash table, thus we never get to see the real |
| symbol in a hash traversal. So look at it now. */ |
| h = (struct elf_link_hash_entry *) h->root.u.i.link; |
| } |
| |
| /* Ignore indirect symbols. These are added by the versioning code. */ |
| if (h->root.type == bfd_link_hash_indirect) |
| return TRUE; |
| |
| /* Fix the symbol flags. */ |
| if (! _bfd_elf_fix_symbol_flags (h, eif)) |
| return FALSE; |
| |
| /* If this symbol does not require a PLT entry, and it is not |
| defined by a dynamic object, or is not referenced by a regular |
| object, ignore it. We do have to handle a weak defined symbol, |
| even if no regular object refers to it, if we decided to add it |
| to the dynamic symbol table. FIXME: Do we normally need to worry |
| about symbols which are defined by one dynamic object and |
| referenced by another one? */ |
| if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) == 0 |
| && ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0 |
| || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0 |
| || ((h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0 |
| && (h->weakdef == NULL || h->weakdef->dynindx == -1)))) |
| { |
| h->plt = elf_hash_table (eif->info)->init_offset; |
| return TRUE; |
| } |
| |
| /* If we've already adjusted this symbol, don't do it again. This |
| can happen via a recursive call. */ |
| if ((h->elf_link_hash_flags & ELF_LINK_HASH_DYNAMIC_ADJUSTED) != 0) |
| return TRUE; |
| |
| /* Don't look at this symbol again. Note that we must set this |
| after checking the above conditions, because we may look at a |
| symbol once, decide not to do anything, and then get called |
| recursively later after REF_REGULAR is set below. */ |
| h->elf_link_hash_flags |= ELF_LINK_HASH_DYNAMIC_ADJUSTED; |
| |
| /* If this is a weak definition, and we know a real definition, and |
| the real symbol is not itself defined by a regular object file, |
| then get a good value for the real definition. We handle the |
| real symbol first, for the convenience of the backend routine. |
| |
| Note that there is a confusing case here. If the real definition |
| is defined by a regular object file, we don't get the real symbol |
| from the dynamic object, but we do get the weak symbol. If the |
| processor backend uses a COPY reloc, then if some routine in the |
| dynamic object changes the real symbol, we will not see that |
| change in the corresponding weak symbol. This is the way other |
| ELF linkers work as well, and seems to be a result of the shared |
| library model. |
| |
| I will clarify this issue. Most SVR4 shared libraries define the |
| variable _timezone and define timezone as a weak synonym. The |
| tzset call changes _timezone. If you write |
| extern int timezone; |
| int _timezone = 5; |
| int main () { tzset (); printf ("%d %d\n", timezone, _timezone); } |
| you might expect that, since timezone is a synonym for _timezone, |
| the same number will print both times. However, if the processor |
| backend uses a COPY reloc, then actually timezone will be copied |
| into your process image, and, since you define _timezone |
| yourself, _timezone will not. Thus timezone and _timezone will |
| wind up at different memory locations. The tzset call will set |
| _timezone, leaving timezone unchanged. */ |
| |
| if (h->weakdef != NULL) |
| { |
| /* If we get to this point, we know there is an implicit |
| reference by a regular object file via the weak symbol H. |
| FIXME: Is this really true? What if the traversal finds |
| H->WEAKDEF before it finds H? */ |
| h->weakdef->elf_link_hash_flags |= ELF_LINK_HASH_REF_REGULAR; |
| |
| if (! _bfd_elf_adjust_dynamic_symbol (h->weakdef, eif)) |
| return FALSE; |
| } |
| |
| /* If a symbol has no type and no size and does not require a PLT |
| entry, then we are probably about to do the wrong thing here: we |
| are probably going to create a COPY reloc for an empty object. |
| This case can arise when a shared object is built with assembly |
| code, and the assembly code fails to set the symbol type. */ |
| if (h->size == 0 |
| && h->type == STT_NOTYPE |
| && (h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) == 0) |
| (*_bfd_error_handler) |
| (_("warning: type and size of dynamic symbol `%s' are not defined"), |
| h->root.root.string); |
| |
| dynobj = elf_hash_table (eif->info)->dynobj; |
| bed = get_elf_backend_data (dynobj); |
| if (! (*bed->elf_backend_adjust_dynamic_symbol) (eif->info, h)) |
| { |
| eif->failed = TRUE; |
| return FALSE; |
| } |
| |
| return TRUE; |
| } |
| |
| /* Adjust all external symbols pointing into SEC_MERGE sections |
| to reflect the object merging within the sections. */ |
| |
| bfd_boolean |
| _bfd_elf_link_sec_merge_syms (struct elf_link_hash_entry *h, void *data) |
| { |
| asection *sec; |
| |
| if (h->root.type == bfd_link_hash_warning) |
| h = (struct elf_link_hash_entry *) h->root.u.i.link; |
| |
| if ((h->root.type == bfd_link_hash_defined |
| || h->root.type == bfd_link_hash_defweak) |
| && ((sec = h->root.u.def.section)->flags & SEC_MERGE) |
| && sec->sec_info_type == ELF_INFO_TYPE_MERGE) |
| { |
| bfd *output_bfd = data; |
| |
| h->root.u.def.value = |
| _bfd_merged_section_offset (output_bfd, |
| &h->root.u.def.section, |
| elf_section_data (sec)->sec_info, |
| h->root.u.def.value, 0); |
| } |
| |
| return TRUE; |
| } |
| |
| /* Returns false if the symbol referred to by H should be considered |
| to resolve local to the current module, and true if it should be |
| considered to bind dynamically. */ |
| |
| bfd_boolean |
| _bfd_elf_dynamic_symbol_p (struct elf_link_hash_entry *h, |
| struct bfd_link_info *info, |
| bfd_boolean ignore_protected) |
| { |
| bfd_boolean binding_stays_local_p; |
| |
| if (h == NULL) |
| return FALSE; |
| |
| while (h->root.type == bfd_link_hash_indirect |
| || h->root.type == bfd_link_hash_warning) |
| h = (struct elf_link_hash_entry *) h->root.u.i.link; |
| |
| /* If it was forced local, then clearly it's not dynamic. */ |
| if (h->dynindx == -1) |
| return FALSE; |
| if (h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) |
| return FALSE; |
| |
| /* Identify the cases where name binding rules say that a |
| visible symbol resolves locally. */ |
| binding_stays_local_p = info->executable || info->symbolic; |
| |
| switch (ELF_ST_VISIBILITY (h->other)) |
| { |
| case STV_INTERNAL: |
| case STV_HIDDEN: |
| return FALSE; |
| |
| case STV_PROTECTED: |
| /* Proper resolution for function pointer equality may require |
| that these symbols perhaps be resolved dynamically, even though |
| we should be resolving them to the current module. */ |
| if (!ignore_protected) |
| binding_stays_local_p = TRUE; |
| break; |
| |
| default: |
| break; |
| } |
| |
| /* If it isn't defined locally, then clearly it's dynamic. */ |
| if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0) |
| return TRUE; |
| |
| /* Otherwise, the symbol is dynamic if binding rules don't tell |
| us that it remains local. */ |
| return !binding_stays_local_p; |
| } |
| |
| /* Return true if the symbol referred to by H should be considered |
| to resolve local to the current module, and false otherwise. Differs |
| from (the inverse of) _bfd_elf_dynamic_symbol_p in the treatment of |
| undefined symbols and weak symbols. */ |
| |
| bfd_boolean |
| _bfd_elf_symbol_refs_local_p (struct elf_link_hash_entry *h, |
| struct bfd_link_info *info, |
| bfd_boolean local_protected) |
| { |
| /* If it's a local sym, of course we resolve locally. */ |
| if (h == NULL) |
| return TRUE; |
| |
| /* If we don't have a definition in a regular file, then we can't |
| resolve locally. The sym is either undefined or dynamic. */ |
| if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0) |
| return FALSE; |
| |
| /* Forced local symbols resolve locally. */ |
| if ((h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0) |
| return TRUE; |
| |
| /* As do non-dynamic symbols. */ |
| if (h->dynindx == -1) |
| return TRUE; |
| |
| /* At this point, we know the symbol is defined and dynamic. In an |
| executable it must resolve locally, likewise when building symbolic |
| shared libraries. */ |
| if (info->executable || info->symbolic) |
| return TRUE; |
| |
| /* Now deal with defined dynamic symbols in shared libraries. Ones |
| with default visibility might not resolve locally. */ |
| if (ELF_ST_VISIBILITY (h->other) == STV_DEFAULT) |
| return FALSE; |
| |
| /* However, STV_HIDDEN or STV_INTERNAL ones must be local. */ |
| if (ELF_ST_VISIBILITY (h->other) != STV_PROTECTED) |
| return TRUE; |
| |
| /* Function pointer equality tests may require that STV_PROTECTED |
| symbols be treated as dynamic symbols, even when we know that the |
| dynamic linker will resolve them locally. */ |
| return local_protected; |
| } |
| |
| /* Caches some TLS segment info, and ensures that the TLS segment vma is |
| aligned. Returns the first TLS output section. */ |
| |
| struct bfd_section * |
| _bfd_elf_tls_setup (bfd *obfd, struct bfd_link_info *info) |
| { |
| struct bfd_section *sec, *tls; |
| unsigned int align = 0; |
| |
| for (sec = obfd->sections; sec != NULL; sec = sec->next) |
| if ((sec->flags & SEC_THREAD_LOCAL) != 0) |
| break; |
| tls = sec; |
| |
| for (; sec != NULL && (sec->flags & SEC_THREAD_LOCAL) != 0; sec = sec->next) |
| if (sec->alignment_power > align) |
| align = sec->alignment_power; |
| |
| elf_hash_table (info)->tls_sec = tls; |
| |
| /* Ensure the alignment of the first section is the largest alignment, |
| so that the tls segment starts aligned. */ |
| if (tls != NULL) |
| tls->alignment_power = align; |
| |
| return tls; |
| } |