From d8045f234d8865a7a7bfce71e81fcbeaf4098a7e Mon Sep 17 00:00:00 2001 From: Nick Clifton Date: Thu, 30 Apr 2009 15:47:13 +0000 Subject: include/elf 2009-04-30 Nick Clifton * common.h (STT_GNU_IFUNC): Define. elfcpp 2009-04-30 Nick Clifton * (enum STT): Add STT_GNU_IFUNC. gas 2009-04-30 Nick Clifton * config/obj-elf.c (obj_elf_type): Add support for a gnu_indirect_function type. * config/tc-i386.c (tc_i386_fix_adjustable): Do not adjust fixups against indirect function symbols. * doc/as.texinfo (.type): Document the support for the gnu_indirect_function symbol type. * NEWS: Mention the new feature. gas/testsuite 2009-04-30 Nick Clifton * gas/elf/elf.exp: Extend type test to include an ifunc symbol. Provide an alternative test for targets which do not support ifunc symbols. (type.s): Add entry for an ifunc symbol. (type.e): Add ifunc entry to expected symbol dump. (section2.e-armelf): Add entry for ifunc symbol. (type-noifunc.s): New file. (type-noifunc.e): New file. bfd/ 2009-04-30 Nick Clifton * elf-bfd.h (struct bfd_elf_section_data): Add indirect_relocs section pointer. (struct elf_obj_data): Add has_ifunc_symbols boolean. * elf.c (swap_out_syms): Convert BSF_GNU_INDIRECT_FUNCTION flags into a STT_GNU_IFUNC symbol type. (_bfd_elf_is_function_type): Accept STT_GNU_IFUNC as a function type. (_bfd_elf_set_osabi): Set the osasbi field to ELFOSABI_LINUX if the binary contains ifunc symbols. * elfcode.h (elf_slurp_symbol_table): Translate the STT_GNU_IFUNC symbol type into a BSF_GNU_INDIRECT_FUNCTION flag. * elf32-i386.c (is_indirect_function): New function. (elf_i386_check_relocs): Create an ifunc output section. (allocate_dynrelocs): Create dynamic relocs in the ifunc output section if necessary. (elf_i386_relocate_section): Emit a reloc against an ifunc symbol if necessary. (elf_i386_add_symbol_hook): New function. Set the has_ifunc_symbols field of the elf_obj_data structure if an ifunc symbol is encountered. (elf_backend_post_process_headers): Define. (elf_backend_add_symbol_hook): Define. (elf_i386_post_process_headers): Rename to elf_i388_fbsd_post_process_headers. * elf64-x86_64.c (IS_X86_64_PCREL_TYPE): New macro. (is_indirect_function): New function. (elf64_x86_64_check_relocs): Create an ifunc output section. (allocate_dynrelocs): Create dynamic relocs in the ifunc output section if necessary. (elf64_x86_64_relocate_section): Emit a reloc against an ifunc symbol if necessary. (elf_i386_add_symbol_hook): Set the has_ifunc_symbols field of the elf_obj_data structure if an ifunc symbol is encountered. (elf_backend_post_process_headers): Define. * elflink.c (_bfd_elf_adjust_dynamic_symbol): Always create a PLT if we have ifunc symbols to handle. (get_ifunc_reloc_section_name): New function. Computes the name for an ifunc section. (_bfd_elf_make_ifunc_reloc_section): New function. Creates a section to hold ifunc relocs. * syms.c (BSF_GNU_INDIRECT_FUNCTION): Define. (bfd_print_symbol_vandf): Handle ifunc symbols. (bfd_decode_symclass): Likewise. * bfd-in2.h: Regenerate. binutils 2009-04-30 Nick Clifton * readelf.c (dump_relocations): Display a relocation against an ifunc symbol as if it were a function invocation. (get_symbol_type): Handle STT_GNU_IFUNC. ld 2009-04-30 Nick Clifton * NEWS: Mention support for IFUNC symbols. ld/testsuite 2009-04-30 Nick Clifton * ld-ifunc: New directory. * ld-ifunc/ifunc.exp: New file: Run the IFUNC tests. * ld-ifunc/prog.c: New file. * ld-ifunc/lib.c: New file. --- bfd/elflink.c | 74 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 74 insertions(+) (limited to 'bfd/elflink.c') diff --git a/bfd/elflink.c b/bfd/elflink.c index 3f70d91..54ad2af 100644 --- a/bfd/elflink.c +++ b/bfd/elflink.c @@ -2749,6 +2749,13 @@ _bfd_elf_adjust_dynamic_symbol (struct elf_link_hash_entry *h, void *data) dynobj = elf_hash_table (eif->info)->dynobj; bed = get_elf_backend_data (dynobj); + + if (h->type == STT_GNU_IFUNC + && (bed->elf_osabi == ELFOSABI_LINUX + /* GNU/Linux is still using the default value 0. */ + || bed->elf_osabi == ELFOSABI_NONE)) + h->needs_plt = 1; + if (! (*bed->elf_backend_adjust_dynamic_symbol) (eif->info, h)) { eif->failed = TRUE; @@ -12533,3 +12540,70 @@ _bfd_elf_make_dynamic_reloc_section (asection * sec, return reloc_sec; } + +/* Returns the name of the ifunc using dynamic reloc section associated with SEC. */ +#define IFUNC_INFIX ".ifunc" + +static const char * +get_ifunc_reloc_section_name (bfd * abfd, + asection * sec) +{ + const char * dot; + char * name; + const char * base_name; + unsigned int strndx = elf_elfheader (abfd)->e_shstrndx; + unsigned int shnam = elf_section_data (sec)->rel_hdr.sh_name; + + base_name = bfd_elf_string_from_elf_section (abfd, strndx, shnam); + if (base_name == NULL) + return NULL; + + dot = strchr (base_name + 1, '.'); + name = bfd_alloc (abfd, strlen (base_name) + strlen (IFUNC_INFIX) + 1); + sprintf (name, "%.*s%s%s", (int)(dot - base_name), base_name, IFUNC_INFIX, dot); + + return name; +} + +/* Like _bfd_elf_make_dynamic_reloc_section but it creates a + section for holding relocs against symbols with the STT_GNU_IFUNC + type. The section is attached to the OWNER bfd but it is created + with a name based on SEC from ABFD. */ + +asection * +_bfd_elf_make_ifunc_reloc_section (bfd * abfd, + asection * sec, + bfd * owner, + unsigned int align) +{ + asection * reloc_sec = elf_section_data (sec)->indirect_relocs; + + if (reloc_sec == NULL) + { + const char * name = get_ifunc_reloc_section_name (abfd, sec); + + if (name == NULL) + return NULL; + + reloc_sec = bfd_get_section_by_name (owner, name); + + if (reloc_sec == NULL) + { + flagword flags; + + flags = (SEC_HAS_CONTENTS | SEC_READONLY | SEC_IN_MEMORY | SEC_LINKER_CREATED); + if ((sec->flags & SEC_ALLOC) != 0) + flags |= SEC_ALLOC | SEC_LOAD; + + reloc_sec = bfd_make_section_with_flags (owner, name, flags); + + if (reloc_sec != NULL + && ! bfd_set_section_alignment (owner, reloc_sec, align)) + reloc_sec = NULL; + } + + elf_section_data (sec)->indirect_relocs = reloc_sec; + } + + return reloc_sec; +} -- cgit v1.1