diff options
Diffstat (limited to 'ld/ldelf.c')
| -rw-r--r-- | ld/ldelf.c | 411 |
1 files changed, 228 insertions, 183 deletions
diff --git a/ld/ldelf.c b/ld/ldelf.c index d15f027e91a..4094640b3f7 100644 --- a/ld/ldelf.c +++ b/ld/ldelf.c @@ -71,10 +71,26 @@ ldelf_after_parse (void) einfo (_("%P: warning: -z dynamic-undefined-weak ignored\n")); link_info.dynamic_undefined_weak = 0; } + + /* Disable DT_RELR if not building PIE nor shared library. */ + if (!bfd_link_pic (&link_info)) + link_info.enable_dt_relr = 0; + + /* Add 3 spare tags for DT_RELR, DT_RELRSZ and DT_RELRENT. */ + if (link_info.enable_dt_relr) + link_info.spare_dynamic_tags += 3; + after_parse_default (); if (link_info.commonpagesize > link_info.maxpagesize) - einfo (_("%F%P: common page size (0x%v) > maximum page size (0x%v)\n"), - link_info.commonpagesize, link_info.maxpagesize); + { + if (!link_info.commonpagesize_is_set) + link_info.commonpagesize = link_info.maxpagesize; + else if (!link_info.maxpagesize_is_set) + link_info.maxpagesize = link_info.commonpagesize; + else + einfo (_("%F%P: common page size (0x%v) > maximum page size (0x%v)\n"), + link_info.commonpagesize, link_info.maxpagesize); + } } /* Handle the generation of DT_NEEDED tags. */ @@ -989,173 +1005,15 @@ ldelf_check_needed (lang_input_statement_type *s) } } -/* This is called after all the input files have been opened. */ - -void -ldelf_after_open (int use_libpath, int native, int is_linux, int is_freebsd, - int elfsize, const char *prefix) +static void +ldelf_handle_dt_needed (struct elf_link_hash_table *htab, + int use_libpath, int native, int is_linux, + int is_freebsd, int elfsize, const char *prefix) { struct bfd_link_needed_list *needed, *l; - struct elf_link_hash_table *htab; - asection *s; bfd *abfd; bfd **save_input_bfd_tail; - after_open_default (); - - htab = elf_hash_table (&link_info); - if (!is_elf_hash_table (&htab->root)) - return; - - if (command_line.out_implib_filename) - { - unlink_if_ordinary (command_line.out_implib_filename); - link_info.out_implib_bfd - = bfd_openw (command_line.out_implib_filename, - bfd_get_target (link_info.output_bfd)); - - if (link_info.out_implib_bfd == NULL) - { - einfo (_("%F%P: %s: can't open for writing: %E\n"), - command_line.out_implib_filename); - } - } - - if (ldelf_emit_note_gnu_build_id != NULL) - { - /* Find an ELF input. */ - for (abfd = link_info.input_bfds; - abfd != (bfd *) NULL; abfd = abfd->link.next) - if (bfd_get_flavour (abfd) == bfd_target_elf_flavour - && bfd_count_sections (abfd) != 0 - && !bfd_input_just_syms (abfd)) - break; - - /* PR 10555: If there are no ELF input files do not try to - create a .note.gnu-build-id section. */ - if (abfd == NULL - || !ldelf_setup_build_id (abfd)) - { - free ((char *) ldelf_emit_note_gnu_build_id); - ldelf_emit_note_gnu_build_id = NULL; - } - } - - get_elf_backend_data (link_info.output_bfd)->setup_gnu_properties (&link_info); - - /* Do not allow executable files to be used as inputs to the link. */ - for (abfd = link_info.input_bfds; abfd; abfd = abfd->link.next) - { - /* Discard input .note.gnu.build-id sections. */ - s = bfd_get_section_by_name (abfd, ".note.gnu.build-id"); - while (s != NULL) - { - if (s != elf_tdata (link_info.output_bfd)->o->build_id.sec) - s->flags |= SEC_EXCLUDE; - s = bfd_get_next_section_by_name (NULL, s); - } - - if (abfd->xvec->flavour == bfd_target_elf_flavour - && !bfd_input_just_syms (abfd) - && elf_tdata (abfd) != NULL - /* FIXME: Maybe check for other non-supportable types as well ? */ - && (elf_tdata (abfd)->elf_header->e_type == ET_EXEC - || (elf_tdata (abfd)->elf_header->e_type == ET_DYN - && elf_tdata (abfd)->is_pie))) - einfo (_("%F%P: cannot use executable file '%pB' as input to a link\n"), - abfd); - } - - if (bfd_link_relocatable (&link_info)) - { - if (link_info.execstack == !link_info.noexecstack) - { - /* PR ld/16744: If "-z [no]execstack" has been specified on the - command line and we are perfoming a relocatable link then no - PT_GNU_STACK segment will be created and so the - linkinfo.[no]execstack values set in _handle_option() will have no - effect. Instead we create a .note.GNU-stack section in much the - same way as the assembler does with its --[no]execstack option. */ - flagword flags = SEC_READONLY | (link_info.execstack ? SEC_CODE : 0); - (void) bfd_make_section_with_flags (link_info.input_bfds, - ".note.GNU-stack", flags); - } - return; - } - - if (!link_info.traditional_format) - { - bfd *elfbfd = NULL; - bool warn_eh_frame = false; - int seen_type = 0; - - for (abfd = link_info.input_bfds; abfd; abfd = abfd->link.next) - { - int type = 0; - - if (bfd_input_just_syms (abfd)) - continue; - - for (s = abfd->sections; s && type < COMPACT_EH_HDR; s = s->next) - { - const char *name = bfd_section_name (s); - - if (bfd_is_abs_section (s->output_section)) - continue; - if (startswith (name, ".eh_frame_entry")) - type = COMPACT_EH_HDR; - else if (strcmp (name, ".eh_frame") == 0 && s->size > 8) - type = DWARF2_EH_HDR; - } - - if (type != 0) - { - if (seen_type == 0) - { - seen_type = type; - } - else if (seen_type != type) - { - einfo (_("%F%P: compact frame descriptions incompatible with" - " DWARF2 .eh_frame from %pB\n"), - type == DWARF2_EH_HDR ? abfd : elfbfd); - break; - } - - if (!elfbfd - && (type == COMPACT_EH_HDR - || link_info.eh_frame_hdr_type != 0)) - { - if (bfd_get_flavour (abfd) == bfd_target_elf_flavour) - elfbfd = abfd; - - warn_eh_frame = true; - } - } - - if (seen_type == COMPACT_EH_HDR) - link_info.eh_frame_hdr_type = COMPACT_EH_HDR; - } - if (elfbfd) - { - const struct elf_backend_data *bed; - - bed = get_elf_backend_data (elfbfd); - s = bfd_make_section_with_flags (elfbfd, ".eh_frame_hdr", - bed->dynamic_sec_flags - | SEC_READONLY); - if (s != NULL - && bfd_set_section_alignment (s, 2)) - { - htab->eh_info.hdr_sec = s; - warn_eh_frame = false; - } - } - if (warn_eh_frame) - einfo (_("%P: warning: cannot create .eh_frame_hdr section," - " --eh-frame-hdr ignored\n")); - } - /* Get the list of files which appear in DT_NEEDED entries in dynamic objects included in the link (often there will be none). For each such file, we want to track down the corresponding @@ -1179,10 +1037,12 @@ ldelf_after_open (int use_libpath, int native, int is_linux, int is_freebsd, && (bfd_elf_get_dyn_lib_class (l->by) & DYN_AS_NEEDED) != 0) continue; - /* Skip the lib if --no-copy-dt-needed-entries and - --allow-shlib-undefined is in effect. */ + /* Skip the lib if --no-copy-dt-needed-entries and when we are + handling DT_NEEDED entries or --allow-shlib-undefined is in + effect. */ if (l->by != NULL - && link_info.unresolved_syms_in_shared_libs == RM_IGNORE + && (htab->handling_dt_needed + || link_info.unresolved_syms_in_shared_libs == RM_IGNORE) && (bfd_elf_get_dyn_lib_class (l->by) & DYN_NO_ADD_NEEDED) != 0) continue; @@ -1322,23 +1182,214 @@ ldelf_after_open (int use_libpath, int native, int is_linux, int is_freebsd, l->name, l->by); } - for (abfd = link_info.input_bfds; abfd; abfd = abfd->link.next) - if (bfd_get_format (abfd) == bfd_object - && ((abfd->flags) & DYNAMIC) != 0 - && bfd_get_flavour (abfd) == bfd_target_elf_flavour - && (elf_dyn_lib_class (abfd) & (DYN_AS_NEEDED | DYN_NO_NEEDED)) == 0 - && elf_dt_name (abfd) != NULL) - { - if (bfd_elf_add_dt_needed_tag (abfd, &link_info) < 0) - einfo (_("%F%P: failed to add DT_NEEDED dynamic tag\n")); - } + /* Don't add DT_NEEDED when loading shared objects from DT_NEEDED for + plugin symbol resolution while handling DT_NEEDED entries. */ + if (!htab->handling_dt_needed) + for (abfd = link_info.input_bfds; abfd; abfd = abfd->link.next) + if (bfd_get_format (abfd) == bfd_object + && ((abfd->flags) & DYNAMIC) != 0 + && bfd_get_flavour (abfd) == bfd_target_elf_flavour + && (elf_dyn_lib_class (abfd) & (DYN_AS_NEEDED | DYN_NO_NEEDED)) == 0 + && elf_dt_name (abfd) != NULL) + { + if (bfd_elf_add_dt_needed_tag (abfd, &link_info) < 0) + einfo (_("%F%P: failed to add DT_NEEDED dynamic tag\n")); + } link_info.input_bfds_tail = save_input_bfd_tail; *save_input_bfd_tail = NULL; +} + +/* This is called before calling plugin 'all symbols read' hook. */ + +void +ldelf_before_plugin_all_symbols_read (int use_libpath, int native, + int is_linux, int is_freebsd, + int elfsize, const char *prefix) +{ + struct elf_link_hash_table *htab = elf_hash_table (&link_info); + + if (!is_elf_hash_table (&htab->root)) + return; + + htab->handling_dt_needed = true; + ldelf_handle_dt_needed (htab, use_libpath, native, is_linux, + is_freebsd, elfsize, prefix); + htab->handling_dt_needed = false; +} + +/* This is called after all the input files have been opened and all + symbols have been loaded. */ + +void +ldelf_after_open (int use_libpath, int native, int is_linux, int is_freebsd, + int elfsize, const char *prefix) +{ + struct elf_link_hash_table *htab; + asection *s; + bfd *abfd; + + after_open_default (); + + htab = elf_hash_table (&link_info); + if (!is_elf_hash_table (&htab->root)) + return; + + if (command_line.out_implib_filename) + { + unlink_if_ordinary (command_line.out_implib_filename); + link_info.out_implib_bfd + = bfd_openw (command_line.out_implib_filename, + bfd_get_target (link_info.output_bfd)); + + if (link_info.out_implib_bfd == NULL) + { + einfo (_("%F%P: %s: can't open for writing: %E\n"), + command_line.out_implib_filename); + } + } + + if (ldelf_emit_note_gnu_build_id != NULL) + { + /* Find an ELF input. */ + for (abfd = link_info.input_bfds; + abfd != (bfd *) NULL; abfd = abfd->link.next) + if (bfd_get_flavour (abfd) == bfd_target_elf_flavour + && bfd_count_sections (abfd) != 0 + && !bfd_input_just_syms (abfd)) + break; + + /* PR 10555: If there are no ELF input files do not try to + create a .note.gnu-build-id section. */ + if (abfd == NULL + || !ldelf_setup_build_id (abfd)) + { + free ((char *) ldelf_emit_note_gnu_build_id); + ldelf_emit_note_gnu_build_id = NULL; + } + } + + get_elf_backend_data (link_info.output_bfd)->setup_gnu_properties (&link_info); + + /* Do not allow executable files to be used as inputs to the link. */ + for (abfd = link_info.input_bfds; abfd; abfd = abfd->link.next) + { + /* Discard input .note.gnu.build-id sections. */ + s = bfd_get_section_by_name (abfd, ".note.gnu.build-id"); + while (s != NULL) + { + if (s != elf_tdata (link_info.output_bfd)->o->build_id.sec) + s->flags |= SEC_EXCLUDE; + s = bfd_get_next_section_by_name (NULL, s); + } + + if (abfd->xvec->flavour == bfd_target_elf_flavour + && !bfd_input_just_syms (abfd) + && elf_tdata (abfd) != NULL + /* FIXME: Maybe check for other non-supportable types as well ? */ + && (elf_tdata (abfd)->elf_header->e_type == ET_EXEC + || (elf_tdata (abfd)->elf_header->e_type == ET_DYN + && elf_tdata (abfd)->is_pie))) + einfo (_("%F%P: cannot use executable file '%pB' as input to a link\n"), + abfd); + } + + if (bfd_link_relocatable (&link_info)) + { + if (link_info.execstack == !link_info.noexecstack) + { + /* PR ld/16744: If "-z [no]execstack" has been specified on the + command line and we are perfoming a relocatable link then no + PT_GNU_STACK segment will be created and so the + linkinfo.[no]execstack values set in _handle_option() will have no + effect. Instead we create a .note.GNU-stack section in much the + same way as the assembler does with its --[no]execstack option. */ + flagword flags = SEC_READONLY | (link_info.execstack ? SEC_CODE : 0); + (void) bfd_make_section_with_flags (link_info.input_bfds, + ".note.GNU-stack", flags); + } + return; + } + + if (!link_info.traditional_format) + { + bfd *elfbfd = NULL; + bool warn_eh_frame = false; + int seen_type = 0; + + for (abfd = link_info.input_bfds; abfd; abfd = abfd->link.next) + { + int type = 0; + + if (bfd_input_just_syms (abfd)) + continue; + + for (s = abfd->sections; s && type < COMPACT_EH_HDR; s = s->next) + { + const char *name = bfd_section_name (s); + + if (bfd_is_abs_section (s->output_section)) + continue; + if (startswith (name, ".eh_frame_entry")) + type = COMPACT_EH_HDR; + else if (strcmp (name, ".eh_frame") == 0 && s->size > 8) + type = DWARF2_EH_HDR; + } + + if (type != 0) + { + if (seen_type == 0) + { + seen_type = type; + } + else if (seen_type != type) + { + einfo (_("%F%P: compact frame descriptions incompatible with" + " DWARF2 .eh_frame from %pB\n"), + type == DWARF2_EH_HDR ? abfd : elfbfd); + break; + } + + if (!elfbfd + && (type == COMPACT_EH_HDR + || link_info.eh_frame_hdr_type != 0)) + { + if (bfd_get_flavour (abfd) == bfd_target_elf_flavour) + elfbfd = abfd; + + warn_eh_frame = true; + } + } + + if (seen_type == COMPACT_EH_HDR) + link_info.eh_frame_hdr_type = COMPACT_EH_HDR; + } + if (elfbfd) + { + const struct elf_backend_data *bed; + + bed = get_elf_backend_data (elfbfd); + s = bfd_make_section_with_flags (elfbfd, ".eh_frame_hdr", + bed->dynamic_sec_flags + | SEC_READONLY); + if (s != NULL + && bfd_set_section_alignment (s, 2)) + { + htab->eh_info.hdr_sec = s; + warn_eh_frame = false; + } + } + if (warn_eh_frame) + einfo (_("%P: warning: cannot create .eh_frame_hdr section," + " --eh-frame-hdr ignored\n")); + } if (link_info.eh_frame_hdr_type == COMPACT_EH_HDR) if (!bfd_elf_parse_eh_frame_entries (NULL, &link_info)) einfo (_("%F%P: failed to parse EH frame entries\n")); + + ldelf_handle_dt_needed (htab, use_libpath, native, is_linux, + is_freebsd, elfsize, prefix); } static bfd_size_type @@ -1591,11 +1642,6 @@ ldelf_before_allocation (char *audit, char *depaudit, || h->root.type == bfd_link_hash_undefweak || h->root.type == bfd_link_hash_common)) { - const struct elf_backend_data *bed; - bed = get_elf_backend_data (link_info.output_bfd); - (*bed->elf_backend_hide_symbol) (&link_info, h, true); - if (ELF_ST_VISIBILITY (h->other) != STV_INTERNAL) - h->other = (h->other & ~ELF_ST_VISIBILITY (-1)) | STV_HIDDEN; /* Don't leave the symbol undefined. Undefined hidden symbols typically won't have dynamic relocations, but we most likely will need dynamic relocations for @@ -1608,7 +1654,6 @@ ldelf_before_allocation (char *audit, char *depaudit, sizeof ehdr_start_save_u); ehdr_start->type = bfd_link_hash_defined; /* It will be converted to section-relative later. */ - ehdr_start->rel_from_abs = 1; ehdr_start->u.def.section = bfd_abs_section_ptr; ehdr_start->u.def.value = 0; } |