From 70256ad8ae2e7d73d603434bb2144912de0e9d89 Mon Sep 17 00:00:00 2001 From: Andreas Jaeger Date: Tue, 23 Jan 2001 10:49:50 +0000 Subject: [PATCH] 2001-01-22 Bo Thorsen * elf64-x86-64.c: Added PIC support for X86-64. (elf64_x86_64_link_hash_newfunc): Function added. (elf64_x86_64_link_hash_table_create): Likewise. (elf64_x86_64_check_relocs): Likewise. (elf64_x86_64_gc_mark_hook): Likewise. (elf64_x86_64_gc_sweep_hook): Likewise. (elf64_x86_64_adjust_dynamic_symbol): Likewise. (elf64_x86_64_size_dynamic_sections): Likewise. (elf64_x86_64_discard_copies): Likewise. (elf64_x86_64_finish_dynamic_symbol): Likewise. (elf64_x86_64_finish_dynamic_sections): Likewise. (elf64_x86_64_relocate_section): Add relocation of PIC sections. --- bfd/ChangeLog | 15 + bfd/elf64-x86-64.c | 1501 ++++++++++++++++++++++++++++++++++++++++++-- 2 files changed, 1468 insertions(+), 48 deletions(-) diff --git a/bfd/ChangeLog b/bfd/ChangeLog index 594893bcd7f..e1e2ec5b6e2 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,18 @@ +2001-01-22 Bo Thorsen + + * elf64-x86-64.c: Added PIC support for X86-64. + (elf64_x86_64_link_hash_newfunc): Function added. + (elf64_x86_64_link_hash_table_create): Likewise. + (elf64_x86_64_check_relocs): Likewise. + (elf64_x86_64_gc_mark_hook): Likewise. + (elf64_x86_64_gc_sweep_hook): Likewise. + (elf64_x86_64_adjust_dynamic_symbol): Likewise. + (elf64_x86_64_size_dynamic_sections): Likewise. + (elf64_x86_64_discard_copies): Likewise. + (elf64_x86_64_finish_dynamic_symbol): Likewise. + (elf64_x86_64_finish_dynamic_sections): Likewise. + (elf64_x86_64_relocate_section): Add relocation of PIC sections. + 2001-01-21 Maciej W. Rozycki * Makefile.am (install-data-local): Make use of $(DESTDIR). diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c index 0b561f7a004..8cd904dcd18 100644 --- a/bfd/elf64-x86-64.c +++ b/bfd/elf64-x86-64.c @@ -1,5 +1,5 @@ /* X86-64 specific support for 64-bit ELF - Copyright 2000 Free Software Foundation, Inc. + Copyright 2000, 2001 Free Software Foundation, Inc. Contributed by Jan Hubicka . This file is part of BFD, the Binary File Descriptor library. @@ -34,7 +34,8 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ /* The relocation "howto" table. Order of fields: type, size, bitsize, pc_relative, complain_on_overflow, special_function, name, partial_inplace, src_mask, dst_pack, pcrel_offset */ -static reloc_howto_type x86_64_elf_howto_table[] = { +static reloc_howto_type x86_64_elf_howto_table[] = +{ HOWTO(R_X86_64_NONE, 0,0, 0,false,0,complain_overflow_dont, 0, "R_X86_64_NONE", false,0x00000000,0x00000000,false), HOWTO(R_X86_64_64, 0,4,64,false,0,complain_overflow_bitfield,0, "R_X86_64_64", false,MINUS_ONE ,MINUS_ONE ,false), HOWTO(R_X86_64_PC32, 0,4,32,true ,0,complain_overflow_signed ,0, "R_X86_64_PC32", false,0xffffffff,0xffffffff,true), @@ -54,29 +55,30 @@ static reloc_howto_type x86_64_elf_howto_table[] = { }; /* Map BFD relocs to the x86_64 elf relocs. */ -struct elf_reloc_map { +struct elf_reloc_map +{ bfd_reloc_code_real_type bfd_reloc_val; unsigned char elf_reloc_val; }; static CONST struct elf_reloc_map x86_64_reloc_map[] = { - { BFD_RELOC_NONE, R_X86_64_NONE, }, - { BFD_RELOC_64, R_X86_64_64, }, - { BFD_RELOC_32_PCREL, R_X86_64_PC32, }, - { BFD_RELOC_X86_64_GOT32, R_X86_64_GOT32,}, - { BFD_RELOC_X86_64_PLT32, R_X86_64_PLT32,}, - { BFD_RELOC_X86_64_COPY, R_X86_64_COPY, }, - { BFD_RELOC_X86_64_GLOB_DAT, R_X86_64_GLOB_DAT, }, - { BFD_RELOC_X86_64_JUMP_SLOT, R_X86_64_JUMP_SLOT, }, - { BFD_RELOC_X86_64_RELATIVE, R_X86_64_RELATIVE, }, - { BFD_RELOC_X86_64_GOTPCREL, R_X86_64_GOTPCREL, }, - { BFD_RELOC_32, R_X86_64_32, }, - { BFD_RELOC_X86_64_32S, R_X86_64_32S, }, - { BFD_RELOC_16, R_X86_64_16, }, - { BFD_RELOC_16_PCREL, R_X86_64_PC16, }, - { BFD_RELOC_8, R_X86_64_8, }, - { BFD_RELOC_8_PCREL, R_X86_64_PC8, }, + { BFD_RELOC_NONE, R_X86_64_NONE, }, + { BFD_RELOC_64, R_X86_64_64, }, + { BFD_RELOC_32_PCREL, R_X86_64_PC32, }, + { BFD_RELOC_X86_64_GOT32, R_X86_64_GOT32,}, + { BFD_RELOC_X86_64_PLT32, R_X86_64_PLT32,}, + { BFD_RELOC_X86_64_COPY, R_X86_64_COPY, }, + { BFD_RELOC_X86_64_GLOB_DAT, R_X86_64_GLOB_DAT, }, + { BFD_RELOC_X86_64_JUMP_SLOT, R_X86_64_JUMP_SLOT, }, + { BFD_RELOC_X86_64_RELATIVE, R_X86_64_RELATIVE, }, + { BFD_RELOC_X86_64_GOTPCREL, R_X86_64_GOTPCREL, }, + { BFD_RELOC_32, R_X86_64_32, }, + { BFD_RELOC_X86_64_32S, R_X86_64_32S, }, + { BFD_RELOC_16, R_X86_64_16, }, + { BFD_RELOC_16_PCREL, R_X86_64_PC16, }, + { BFD_RELOC_8, R_X86_64_8, }, + { BFD_RELOC_8_PCREL, R_X86_64_PC8, }, }; static reloc_howto_type *elf64_x86_64_reloc_type_lookup @@ -85,9 +87,22 @@ static void elf64_x86_64_info_to_howto PARAMS ((bfd *, arelent *, Elf64_Internal_Rela *)); static struct bfd_link_hash_table *elf64_x86_64_link_hash_table_create PARAMS ((bfd *)); + +static struct bfd_hash_entry *elf64_x86_64_link_hash_newfunc + PARAMS ((struct bfd_hash_entry *, struct bfd_hash_table *, const char *)); +static boolean elf64_x86_64_adjust_dynamic_symbol + PARAMS ((struct bfd_link_info *, struct elf_link_hash_entry *)); + +static boolean elf64_x86_64_size_dynamic_sections + PARAMS ((bfd *, struct bfd_link_info *)); static boolean elf64_x86_64_relocate_section PARAMS ((bfd *, struct bfd_link_info *, bfd *, asection *, bfd_byte *, Elf_Internal_Rela *, Elf_Internal_Sym *, asection **)); +static boolean elf64_x86_64_finish_dynamic_symbol + PARAMS ((bfd *, struct bfd_link_info *, struct elf_link_hash_entry *, + Elf_Internal_Sym *sym)); +static boolean elf64_x86_64_finish_dynamic_sections + PARAMS ((bfd *, struct bfd_link_info *)); /* Given a BFD reloc type, return a HOWTO structure. */ static reloc_howto_type * @@ -121,21 +136,129 @@ elf64_x86_64_info_to_howto (abfd, cache_ptr, dst) cache_ptr->howto = &x86_64_elf_howto_table[r_type]; BFD_ASSERT (r_type == cache_ptr->howto->type); } + +/* Functions for the x86-64 ELF linker. */ + +/* The name of the dynamic interpreter. This is put in the .interp + section. */ + +#define ELF_DYNAMIC_INTERPRETER "/lib/libd64.so.1" + +/* The size in bytes of an entry in the global offset table. */ + +#define GOT_ENTRY_SIZE 8 -/* Hash table functions - these will be used by dynamic linking code and - right now they are needed to keep ld happy. */ +/* The size in bytes of an entry in the procedure linkage table. */ -/* x86_64 ELF linker hash table. */ +#define PLT_ENTRY_SIZE 16 + +/* The first entry in a procedure linkage table looks like this. See the + SVR4 ABI i386 supplement and the x86-64 ABI to see how this works. */ + +static const bfd_byte elf64_x86_64_plt0_entry[PLT_ENTRY_SIZE] = +{ + 0xff, 0xb3, 8, 0, 0, 0, /* pushq GOT+8(%rip) */ + 0xff, 0xa3, 16, 0, 0, 0, /* jmp GOT+16(%rip) */ + 0, 0, 0, 0 /* pad out to 16 bytes. */ +}; + +/* Subsequent entries in a procedure linkage table look like this. */ + +static const bfd_byte elf64_x86_64_plt_entry[PLT_ENTRY_SIZE] = +{ + 0xff, 0xa3, /* jmp *name@GOTPC(%rip) */ + 0, 0, 0, 0, /* replaced with offset to this symbol in .got. */ + 0x68, /* pushq immediate */ + 0, 0, 0, 0, /* replaced with index into relocation table. */ + 0xe9, /* jmp relative */ + 0, 0, 0, 0 /* replaced with offset to start of .plt0. */ +}; + +/* The x86-64 linker needs to keep track of the number of relocs that + it decides to copy in check_relocs for each symbol. This is so + that it can discard PC relative relocs if it doesn't need them when + linking with -Bsymbolic. We store the information in a field + extending the regular ELF linker hash table. */ + +/* This structure keeps track of the number of PC relative relocs we + have copied for a given symbol. */ + +struct elf64_x86_64_pcrel_relocs_copied +{ + /* Next section. */ + struct elf64_x86_64_pcrel_relocs_copied *next; + /* A section in dynobj. */ + asection *section; + /* Number of relocs copied in this section. */ + bfd_size_type count; +}; + +/* x86-64 ELF linker hash entry. */ + +struct elf64_x86_64_link_hash_entry +{ + struct elf_link_hash_entry root; + + /* Number of PC relative relocs copied for this symbol. */ + struct elf64_x86_64_pcrel_relocs_copied *pcrel_relocs_copied; +}; + +/* x86-64 ELF linker hash table. */ struct elf64_x86_64_link_hash_table { struct elf_link_hash_table root; }; -/* Get the X86-64 ELF linker hash table from a link_info structure. */ +/* Declare this now that the above structures are defined. */ + +static boolean elf64_x86_64_discard_copies + PARAMS ((struct elf64_x86_64_link_hash_entry *, PTR)); + +/* Traverse an x86-64 ELF linker hash table. */ + +#define elf64_x86_64_link_hash_traverse(table, func, info) \ + (elf_link_hash_traverse \ + (&(table)->root, \ + (boolean (*) PARAMS ((struct elf_link_hash_entry *, PTR))) (func), \ + (info))) + +/* Get the x86-64 ELF linker hash table from a link_info structure. */ #define elf64_x86_64_hash_table(p) \ ((struct elf64_x86_64_link_hash_table *) ((p)->hash)) +/* Create an entry in an x86-64 ELF linker hash table. */ + +static struct bfd_hash_entry * +elf64_x86_64_link_hash_newfunc (entry, table, string) + struct bfd_hash_entry *entry; + struct bfd_hash_table *table; + const char *string; +{ + struct elf64_x86_64_link_hash_entry *ret = + (struct elf64_x86_64_link_hash_entry *) entry; + + /* Allocate the structure if it has not already been allocated by a + subclass. */ + if (ret == (struct elf64_x86_64_link_hash_entry *) NULL) + ret = ((struct elf64_x86_64_link_hash_entry *) + bfd_hash_allocate (table, + sizeof (struct elf64_x86_64_link_hash_entry))); + if (ret == (struct elf64_x86_64_link_hash_entry *) NULL) + return (struct bfd_hash_entry *) ret; + + /* Call the allocation method of the superclass. */ + ret = ((struct elf64_x86_64_link_hash_entry *) + _bfd_elf_link_hash_newfunc ((struct bfd_hash_entry *) ret, + table, string)); + if (ret != (struct elf64_x86_64_link_hash_entry *) NULL) + { + ret->pcrel_relocs_copied = NULL; + } + + return (struct bfd_hash_entry *) ret; +} + /* Create an X86-64 ELF linker hash table. */ static struct bfd_link_hash_table * @@ -150,7 +273,7 @@ elf64_x86_64_link_hash_table_create (abfd) return NULL; if (! _bfd_elf_link_hash_table_init (&ret->root, abfd, - _bfd_elf_link_hash_newfunc)) + elf64_x86_64_link_hash_newfunc)) { bfd_release (abfd, ret); return NULL; @@ -168,6 +291,789 @@ elf64_x86_64_elf_object_p (abfd) return true; } +/* Look through the relocs for a section during the first phase, and + allocate space in the global offset table or procedure linkage + table. */ + +static boolean +elf64_x86_64_check_relocs (abfd, info, sec, relocs) + bfd *abfd; + struct bfd_link_info *info; + asection *sec; + const Elf_Internal_Rela *relocs; +{ + bfd *dynobj; + Elf_Internal_Shdr *symtab_hdr; + struct elf_link_hash_entry **sym_hashes; + bfd_signed_vma *local_got_refcounts; + const Elf_Internal_Rela *rel; + const Elf_Internal_Rela *rel_end; + asection *sgot; + asection *srelgot; + asection *sreloc; + + if (info->relocateable) + return true; + + dynobj = elf_hash_table (info)->dynobj; + symtab_hdr = &elf_tdata (abfd)->symtab_hdr; + sym_hashes = elf_sym_hashes (abfd); + local_got_refcounts = elf_local_got_refcounts (abfd); + + sgot = srelgot = sreloc = NULL; + rel_end = relocs + sec->reloc_count; + for (rel = relocs; rel < rel_end; rel++) + { + unsigned long r_symndx; + struct elf_link_hash_entry *h; + + r_symndx = ELF64_R_SYM (rel->r_info); + if (r_symndx < symtab_hdr->sh_info) + h = NULL; + else + h = sym_hashes[r_symndx - symtab_hdr->sh_info]; + + /* Some relocs require a global offset table. */ + if (dynobj == NULL) + { + switch (ELF64_R_TYPE (rel->r_info)) + { + case R_X86_64_GOT32: + case R_X86_64_GOTPCREL: + elf_hash_table (info)->dynobj = dynobj = abfd; + if (! _bfd_elf_create_got_section (dynobj, info)) + return false; + break; + } + } + + switch (ELF64_R_TYPE (rel->r_info)) + { + case R_X86_64_GOT32: + /* This symbol requires a global offset table entry. */ + + if (sgot == NULL) + { + sgot = bfd_get_section_by_name (dynobj, ".got"); + BFD_ASSERT (sgot != NULL); + } + + if (srelgot == NULL && (h != NULL || info->shared)) + { + srelgot = bfd_get_section_by_name (dynobj, ".rela.got"); + if (srelgot == NULL) + { + srelgot = bfd_make_section (dynobj, ".rela.got"); + if (srelgot == NULL + || ! bfd_set_section_flags (dynobj, srelgot, + (SEC_ALLOC + | SEC_LOAD + | SEC_HAS_CONTENTS + | SEC_IN_MEMORY + | SEC_LINKER_CREATED + | SEC_READONLY)) + || ! bfd_set_section_alignment (dynobj, srelgot, 2)) + return false; + } + } + + if (h != NULL) + { + if (h->got.refcount == -1) + { + h->got.refcount = 1; + + /* Make sure this symbol is output as a dynamic symbol. */ + if (h->dynindx == -1) + { + if (! bfd_elf64_link_record_dynamic_symbol (info, h)) + return false; + } + + sgot->_raw_size += GOT_ENTRY_SIZE; + srelgot->_raw_size += sizeof (Elf64_External_Rela); + } + else + h->got.refcount += 1; + } + else + { + /* This is a global offset table entry for a local symbol. */ + if (local_got_refcounts == NULL) + { + size_t size; + + size = symtab_hdr->sh_info * sizeof (bfd_signed_vma); + local_got_refcounts = ((bfd_signed_vma *) + bfd_alloc (abfd, size)); + if (local_got_refcounts == NULL) + return false; + elf_local_got_refcounts (abfd) = local_got_refcounts; + memset (local_got_refcounts, -1, size); + } + if (local_got_refcounts[r_symndx] == -1) + { + local_got_refcounts[r_symndx] = 1; + + sgot->_raw_size += GOT_ENTRY_SIZE; + if (info->shared) + { + /* If we are generating a shared object, we need to + output a R_X86_64_RELATIVE reloc so that the dynamic + linker can adjust this GOT entry. */ + srelgot->_raw_size += sizeof (Elf64_External_Rela); + } + } + else + local_got_refcounts[r_symndx] += 1; + } + break; + + case R_X86_64_PLT32: + /* This symbol requires a procedure linkage table entry. We + actually build the entry in adjust_dynamic_symbol, + because this might be a case of linking PIC code which is + never referenced by a dynamic object, in which case we + don't need to generate a procedure linkage table entry + after all. */ + + /* If this is a local symbol, we resolve it directly without + creating a procedure linkage table entry. */ + if (h == NULL) + continue; + + if (h->plt.refcount == -1) + { + h->plt.refcount = 1; + h->elf_link_hash_flags |= ELF_LINK_HASH_NEEDS_PLT; + } + else + h->plt.refcount += 1; + break; + + case R_X86_64_32: + case R_X86_64_32S: + case R_X86_64_PC32: + if (h != NULL) + h->elf_link_hash_flags |= ELF_LINK_NON_GOT_REF; + + /* If we are creating a shared library, and this is a reloc + against a global symbol, or a non PC relative reloc + against a local symbol, then we need to copy the reloc + into the shared library. However, if we are linking with + -Bsymbolic, we do not need to copy a reloc against a + global symbol which is defined in an object we are + including in the link (i.e., DEF_REGULAR is set). At + this point we have not seen all the input files, so it is + possible that DEF_REGULAR is not set now but will be set + later (it is never cleared). We account for that + possibility below by storing information in the + pcrel_relocs_copied field of the hash table entry. + A similar situation occurs when creating shared libraries + and symbol visibility changes render the symbol local. */ + if (info->shared + && (sec->flags & SEC_ALLOC) != 0 + && (ELF64_R_TYPE (rel->r_info) != R_X86_64_PC32 + || (h != NULL + && (! info->symbolic + || (h->elf_link_hash_flags + & ELF_LINK_HASH_DEF_REGULAR) == 0)))) + { + /* When creating a shared object, we must copy these + reloc types into the output file. We create a reloc + section in dynobj and make room for this reloc. */ + if (sreloc == NULL) + { + const char *name; + + name = (bfd_elf_string_from_elf_section + (abfd, + elf_elfheader (abfd)->e_shstrndx, + elf_section_data (sec)->rel_hdr.sh_name)); + if (name == NULL) + return false; + + BFD_ASSERT (strncmp (name, ".rela", 5) == 0 + && strcmp (bfd_get_section_name (abfd, sec), + name + 5) == 0); + + sreloc = bfd_get_section_by_name (dynobj, name); + if (sreloc == NULL) + { + flagword flags; + + sreloc = bfd_make_section (dynobj, name); + flags = (SEC_HAS_CONTENTS | SEC_READONLY + | SEC_IN_MEMORY | SEC_LINKER_CREATED); + if ((sec->flags & SEC_ALLOC) != 0) + flags |= SEC_ALLOC | SEC_LOAD; + if (sreloc == NULL + || ! bfd_set_section_flags (dynobj, sreloc, flags) + || ! bfd_set_section_alignment (dynobj, sreloc, 2)) + return false; + } + } + + sreloc->_raw_size += sizeof (Elf64_External_Rela); + + /* If this is a global symbol, we count the number of PC + relative relocations we have entered for this symbol, + so that we can discard them later as necessary. Note + that this function is only called if we are using an + elf64_x86_64 linker hash table, which means that h is + really a pointer to an elf64_x86_64_link_hash_entry. */ + if (h != NULL + && ELF64_R_TYPE (rel->r_info) == R_X86_64_PC32) + { + struct elf64_x86_64_link_hash_entry *eh; + struct elf64_x86_64_pcrel_relocs_copied *p; + + eh = (struct elf64_x86_64_link_hash_entry *) h; + + for (p = eh->pcrel_relocs_copied; p != NULL; p = p->next) + if (p->section == sreloc) + break; + + if (p == NULL) + { + p = ((struct elf64_x86_64_pcrel_relocs_copied *) + bfd_alloc (dynobj, sizeof *p)); + if (p == NULL) + return false; + p->next = eh->pcrel_relocs_copied; + eh->pcrel_relocs_copied = p; + p->section = sreloc; + p->count = 0; + } + + ++p->count; + } + } + break; + } + } + + return true; +} + +/* Return the section that should be marked against GC for a given + relocation. */ + +static asection * +elf64_x86_64_gc_mark_hook (abfd, info, rel, h, sym) + bfd *abfd; + struct bfd_link_info *info ATTRIBUTE_UNUSED; + Elf_Internal_Rela *rel ATTRIBUTE_UNUSED; + struct elf_link_hash_entry *h; + Elf_Internal_Sym *sym; +{ + if (h != NULL) + { + switch (h->root.type) + { + case bfd_link_hash_defined: + case bfd_link_hash_defweak: + return h->root.u.def.section; + + case bfd_link_hash_common: + return h->root.u.c.p->section; + + default: + break; + } + } + else + { + if (!(elf_bad_symtab (abfd) + && ELF_ST_BIND (sym->st_info) != STB_LOCAL) + && ! ((sym->st_shndx <= 0 || sym->st_shndx >= SHN_LORESERVE) + && sym->st_shndx != SHN_COMMON)) + { + return bfd_section_from_elf_index (abfd, sym->st_shndx); + } + } + + return NULL; +} + +/* Update the got entry reference counts for the section being removed. */ + +static boolean +elf64_x86_64_gc_sweep_hook (abfd, info, sec, relocs) + bfd *abfd; + struct bfd_link_info *info ATTRIBUTE_UNUSED; + asection *sec; + const Elf_Internal_Rela *relocs; +{ + Elf_Internal_Shdr *symtab_hdr; + struct elf_link_hash_entry **sym_hashes; + bfd_signed_vma *local_got_refcounts; + const Elf_Internal_Rela *rel, *relend; + unsigned long r_symndx; + struct elf_link_hash_entry *h; + bfd *dynobj; + asection *sgot; + asection *srelgot; + + symtab_hdr = &elf_tdata (abfd)->symtab_hdr; + sym_hashes = elf_sym_hashes (abfd); + local_got_refcounts = elf_local_got_refcounts (abfd); + + dynobj = elf_hash_table (info)->dynobj; + if (dynobj == NULL) + return true; + + sgot = bfd_get_section_by_name (dynobj, ".got"); + srelgot = bfd_get_section_by_name (dynobj, ".rela.got"); + + relend = relocs + sec->reloc_count; + for (rel = relocs; rel < relend; rel++) + switch (ELF64_R_TYPE (rel->r_info)) + { + case R_X86_64_GOT32: + case R_X86_64_GOTPCREL: + r_symndx = ELF64_R_SYM (rel->r_info); + if (r_symndx >= symtab_hdr->sh_info) + { + h = sym_hashes[r_symndx - symtab_hdr->sh_info]; + if (h->got.refcount > 0) + { + h->got.refcount -= 1; + if (h->got.refcount == 0) + { + sgot->_raw_size -= GOT_ENTRY_SIZE; + srelgot->_raw_size -= sizeof (Elf64_External_Rela); + } + } + } + else if (local_got_refcounts != NULL) + { + if (local_got_refcounts[r_symndx] > 0) + { + local_got_refcounts[r_symndx] -= 1; + if (local_got_refcounts[r_symndx] == 0) + { + sgot->_raw_size -= GOT_ENTRY_SIZE; + if (info->shared) + srelgot->_raw_size -= sizeof (Elf64_External_Rela); + } + } + } + break; + + case R_X86_64_PLT32: + r_symndx = ELF64_R_SYM (rel->r_info); + if (r_symndx >= symtab_hdr->sh_info) + { + h = sym_hashes[r_symndx - symtab_hdr->sh_info]; + if (h->plt.refcount > 0) + h->plt.refcount -= 1; + } + break; + + default: + break; + } + + return true; +} + +/* Adjust a symbol defined by a dynamic object and referenced by a + regular object. The current definition is in some section of the + dynamic object, but we're not including those sections. We have to + change the definition to something the rest of the link can + understand. */ + +static boolean +elf64_x86_64_adjust_dynamic_symbol (info, h) + struct bfd_link_info *info; + struct elf_link_hash_entry *h; +{ + bfd *dynobj; + asection *s; + unsigned int power_of_two; + + dynobj = elf_hash_table (info)->dynobj; + + /* Make sure we know what is going on here. */ + BFD_ASSERT (dynobj != NULL + && ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) + || h->weakdef != NULL + || ((h->elf_link_hash_flags + & ELF_LINK_HASH_DEF_DYNAMIC) != 0 + && (h->elf_link_hash_flags + & ELF_LINK_HASH_REF_REGULAR) != 0 + && (h->elf_link_hash_flags + & ELF_LINK_HASH_DEF_REGULAR) == 0))); + + /* If this is a function, put it in the procedure linkage table. We + will fill in the contents of the procedure linkage table later, + when we know the address of the .got section. */ + if (h->type == STT_FUNC + || (h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) != 0) + { + if (! elf_hash_table (info)->dynamic_sections_created) + { + /* FIXME: These are the sparc64 comment and then the i386 comment. + How we need to deal with this and why remains to be seen. */ + /* This case can occur if we saw a WPLT30 reloc in an input + file, but none of the input files were dynamic objects. + In such a case, we don't actually need to build a + procedure linkage table, and we can just do a WDISP30 + reloc instead. */ + /* This case can occur if we saw a PLT32 reloc in an input + file, but the symbol was never referred to by a dynamic + object, or if all references were garbage collected. In + such a case, we don't actually need to build a procedure + linkage table, and we can just do a PC32 reloc instead. */ + /* i386 code: */ + h->plt.offset = (bfd_vma) -1; + h->elf_link_hash_flags &= ~ELF_LINK_HASH_NEEDS_PLT; + return true; + } + + /* Make sure this symbol is output as a dynamic symbol. */ + if (h->dynindx == -1) + { + if (! bfd_elf64_link_record_dynamic_symbol (info, h)) + return false; + } + + s = bfd_get_section_by_name (dynobj, ".plt"); + BFD_ASSERT (s != NULL); + + /* If this is the first .plt entry, make room for the special + first entry. */ + if (s->_raw_size == 0) + s->_raw_size = PLT_ENTRY_SIZE; + + /* If this symbol is not defined in a regular file, and we are + not generating a shared library, then set the symbol to this + location in the .plt. This is required to make function + pointers compare as equal between the normal executable and + the shared library. */ + if (! info->shared + && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0) + { + h->root.u.def.section = s; + h->root.u.def.value = s->_raw_size; + } + + h->plt.offset = s->_raw_size; + + /* Make room for this entry. */ + s->_raw_size += PLT_ENTRY_SIZE; + + /* We also need to make an entry in the .rela.plt section. */ + s = bfd_get_section_by_name (dynobj, ".rela.plt"); + BFD_ASSERT (s != NULL); + s->_raw_size += sizeof (Elf64_External_Rela); + + return true; + } + + /* If this is a weak symbol, and there is a real definition, the + processor independent code will have arranged for us to see the + real definition first, and we can just use the same value. */ + if (h->weakdef != NULL) + { + BFD_ASSERT (h->weakdef->root.type == bfd_link_hash_defined + || h->weakdef->root.type == bfd_link_hash_defweak); + h->root.u.def.section = h->weakdef->root.u.def.section; + h->root.u.def.value = h->weakdef->root.u.def.value; + return true; + } + + /* This is a reference to a symbol defined by a dynamic object which + is not a function. */ + + /* If we are creating a shared library, we must presume that the + only references to the symbol are via the global offset table. + For such cases we need not do anything here; the relocations will + be handled correctly by relocate_section. */ + if (info->shared) + return true; + + /* If there are no references to this symbol that do not use the + GOT, we don't need to generate a copy reloc. */ + if ((h->elf_link_hash_flags & ELF_LINK_NON_GOT_REF) == 0) + return true; + + /* We must allocate the symbol in our .dynbss section, which will + become part of the .bss section of the executable. There will be + an entry for this symbol in the .dynsym section. The dynamic + object will contain position independent code, so all references + from the dynamic object to this symbol will go through the global + offset table. The dynamic linker will use the .dynsym entry to + determine the address it must put in the global offset table, so + both the dynamic object and the regular object will refer to the + same memory location for the variable. */ + + s = bfd_get_section_by_name (dynobj, ".dynbss"); + BFD_ASSERT (s != NULL); + + /* We must generate a R_X86_64_COPY reloc to tell the dynamic linker + to copy the initial value out of the dynamic object and into the + runtime process image. We need to remember the offset into the + .rela.bss section we are going to use. */ + if ((h->root.u.def.section->flags & SEC_ALLOC) != 0) + { + asection *srel; + + srel = bfd_get_section_by_name (dynobj, ".rela.bss"); + BFD_ASSERT (srel != NULL); + srel->_raw_size += sizeof (Elf64_External_Rela); + h->elf_link_hash_flags |= ELF_LINK_HASH_NEEDS_COPY; + } + + /* We need to figure out the alignment required for this symbol. I + have no idea how ELF linkers handle this. 16-bytes is the size + of the largest type that requires hard alignment -- long double. */ + /* FIXME: This is VERY ugly. Should be fixed for all architectures using + this construct. */ + power_of_two = bfd_log2 (h->size); + if (power_of_two > 4) + power_of_two = 4; + + /* Apply the required alignment. */ + s->_raw_size = BFD_ALIGN (s->_raw_size, (bfd_size_type) (1 << power_of_two)); + if (power_of_two > bfd_get_section_alignment (dynobj, s)) + { + if (! bfd_set_section_alignment (dynobj, s, power_of_two)) + return false; + } + + /* Define the symbol as being at this point in the section. */ + h->root.u.def.section = s; + h->root.u.def.value = s->_raw_size; + + /* Increment the section size to make room for the symbol. */ + s->_raw_size += h->size; + + return true; +} + +/* Set the sizes of the dynamic sections. */ + +static boolean +elf64_x86_64_size_dynamic_sections (output_bfd, info) + bfd *output_bfd; + struct bfd_link_info *info; +{ + bfd *dynobj; + asection *s; + boolean plt; + boolean relocs; + boolean reltext; + + dynobj = elf_hash_table (info)->dynobj; + BFD_ASSERT (dynobj != NULL); + + if (elf_hash_table (info)->dynamic_sections_created) + { + /* Set the contents of the .interp section to the interpreter. */ + if (! info->shared) + { + s = bfd_get_section_by_name (dynobj, ".interp"); + BFD_ASSERT (s != NULL); + s->_raw_size = sizeof ELF_DYNAMIC_INTERPRETER; + s->contents = (unsigned char *) ELF_DYNAMIC_INTERPRETER; + } + } + else + { + /* We may have created entries in the .rela.got section. + However, if we are not creating the dynamic sections, we will + not actually use these entries. Reset the size of .rela.got, + which will cause it to get stripped from the output file + below. */ + s = bfd_get_section_by_name (dynobj, ".rela.got"); + if (s != NULL) + s->_raw_size = 0; + } + + /* If this is a -Bsymbolic shared link, then we need to discard all + PC relative relocs against symbols defined in a regular object. + We allocated space for them in the check_relocs routine, but we + will not fill them in in the relocate_section routine. */ + if (info->shared) + elf64_x86_64_link_hash_traverse (elf64_x86_64_hash_table (info), + elf64_x86_64_discard_copies, + (PTR) info); + + /* The check_relocs and adjust_dynamic_symbol entry points have + determined the sizes of the various dynamic sections. Allocate + memory for them. */ + plt = relocs = reltext = false; + for (s = dynobj->sections; s != NULL; s = s->next) + { + const char *name; + boolean strip; + + if ((s->flags & SEC_LINKER_CREATED) == 0) + continue; + + /* It's OK to base decisions on the section name, because none + of the dynobj section names depend upon the input files. */ + name = bfd_get_section_name (dynobj, s); + + strip = false; + if (strcmp (name, ".plt") == 0) + { + if (s->_raw_size == 0) + { + /* Strip this section if we don't need it; see the + comment below. */ + strip = true; + } + else + { + /* Remember whether there is a PLT. */ + plt = true; + } + } + else if (strncmp (name, ".rela", 5) == 0) + { + if (s->_raw_size == 0) + { + /* If we don't need this section, strip it from the + output file. This is mostly to handle .rela.bss and + .rela.plt. We must create both sections in + create_dynamic_sections, because they must be created + before the linker maps input sections to output + sections. The linker does that before + adjust_dynamic_symbol is called, and it is that + function which decides whether anything needs to go + into these sections. */ + strip = true; + } + else + { + asection *target; + + /* Remember whether there are any reloc sections other + than .rela.plt. */ + if (strcmp (name, ".rela.plt") != 0) + { + const char *outname; + + relocs = true; + + /* If this relocation section applies to a read only + section, then we probably need a DT_TEXTREL + entry. The entries in the .rela.plt section + really apply to the .got section, which we + created ourselves and so know is not readonly. */ + outname = bfd_get_section_name (output_bfd, + s->output_section); + target = bfd_get_section_by_name (output_bfd, outname + 5); + if (target != NULL + && (target->flags & SEC_READONLY) != 0 + && (target->flags & SEC_ALLOC) != 0) + reltext = true; + } + + /* We use the reloc_count field as a counter if we need + to copy relocs into the output file. */ + s->reloc_count = 0; + } + } + else if (strncmp (name, ".got", 4) != 0) + { + /* It's not one of our sections, so don't allocate space. */ + continue; + } + + if (strip) + { + _bfd_strip_section_from_output (info, s); + continue; + } + + /* Allocate memory for the section contents. We use bfd_zalloc + here in case unused entries are not reclaimed before the + section's contents are written out. This should not happen, + but this way if it does, we get a R_X86_64_NONE reloc instead + of garbage. */ + s->contents = (bfd_byte *) bfd_zalloc (dynobj, s->_raw_size); + if (s->contents == NULL && s->_raw_size != 0) + return false; + } + + if (elf_hash_table (info)->dynamic_sections_created) + { + /* Add some entries to the .dynamic section. We fill in the + values later, in elf64_x86_64_finish_dynamic_sections, but we + must add the entries now so that we get the correct size for + the .dynamic section. The DT_DEBUG entry is filled in by the + dynamic linker and used by the debugger. */ + if (! info->shared) + { + if (! bfd_elf64_add_dynamic_entry (info, DT_DEBUG, 0)) + return false; + } + + if (plt) + { + /* FIXME: Are all these needed? */ + if (! bfd_elf64_add_dynamic_entry (info, DT_PLTGOT, 0) + || ! bfd_elf64_add_dynamic_entry (info, DT_PLTRELSZ, 0) + || ! bfd_elf64_add_dynamic_entry (info, DT_PLTREL, DT_REL) + || ! bfd_elf64_add_dynamic_entry (info, DT_JMPREL, 0)) + return false; + } + + if (relocs) + { + if (! bfd_elf64_add_dynamic_entry (info, DT_RELA, 0) + || ! bfd_elf64_add_dynamic_entry (info, DT_RELASZ, 0) + || ! bfd_elf64_add_dynamic_entry (info, DT_RELAENT, + sizeof (Elf64_External_Rela))) + return false; + } + + if (reltext) + { + if (! bfd_elf64_add_dynamic_entry (info, DT_TEXTREL, 0)) + return false; + info->flags |= DF_TEXTREL; + } + } + + return true; +} + +/* This function is called via elf64_x86_64_link_hash_traverse if we are + creating a shared object. In the -Bsymbolic case, it discards the + space allocated to copy PC relative relocs against symbols which + are defined in regular objects. For the normal non-symbolic case, + we also discard space for relocs that have become local due to + symbol visibility changes. We allocated space for them in the + check_relocs routine, but we won't fill them in in the + relocate_section routine. */ + +static boolean +elf64_x86_64_discard_copies (h, inf) + struct elf64_x86_64_link_hash_entry *h; + PTR inf; +{ + struct elf64_x86_64_pcrel_relocs_copied *s; + struct bfd_link_info *info = (struct bfd_link_info *) inf; + + /* If a symbol has been forced local or we have found a regular + definition for the symbolic link case, then we won't be needing + any relocs. */ + if ((h->root.elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0 + && ((h->root.elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0 + || info->symbolic)) + { + for (s = h->pcrel_relocs_copied; s != NULL; s = s->next) + s->section->_raw_size -= s->count * sizeof (Elf64_External_Rela); + } + + return true; +} + /* Relocate an x86_64 ELF section. */ static boolean @@ -186,8 +1092,10 @@ elf64_x86_64_relocate_section (output_bfd, info, input_bfd, input_section, Elf_Internal_Shdr *symtab_hdr; struct elf_link_hash_entry **sym_hashes; bfd_vma *local_got_offsets; + asection *sgot; + asection *splt; asection *sreloc; - Elf_Internal_Rela *rel; + Elf_Internal_Rela *rela; Elf_Internal_Rela *relend; dynobj = elf_hash_table (info)->dynobj; @@ -195,13 +1103,16 @@ elf64_x86_64_relocate_section (output_bfd, info, input_bfd, input_section, sym_hashes = elf_sym_hashes (input_bfd); local_got_offsets = elf_local_got_offsets (input_bfd); - sreloc = NULL; + sreloc = splt = sgot = NULL; if (dynobj != NULL) - abort (); + { + splt = bfd_get_section_by_name (dynobj, ".plt"); + sgot = bfd_get_section_by_name (dynobj, ".got"); + } - rel = relocs; + rela = relocs; relend = relocs + input_section->reloc_count; - for (; rel < relend; rel++) + for (; rela < relend; rela++) { int r_type; reloc_howto_type *howto; @@ -213,7 +1124,7 @@ elf64_x86_64_relocate_section (output_bfd, info, input_bfd, input_section, bfd_reloc_status_type r; unsigned int indx; - r_type = ELF64_R_TYPE (rel->r_info); + r_type = ELF64_R_TYPE (rela->r_info); if ((indx = (unsigned) r_type) >= R_X86_64_max) { @@ -222,7 +1133,7 @@ elf64_x86_64_relocate_section (output_bfd, info, input_bfd, input_section, } howto = x86_64_elf_howto_table + indx; - r_symndx = ELF64_R_SYM (rel->r_info); + r_symndx = ELF64_R_SYM (rela->r_info); if (info->relocateable) { @@ -236,7 +1147,7 @@ elf64_x86_64_relocate_section (output_bfd, info, input_bfd, input_section, if (ELF_ST_TYPE (sym->st_info) == STT_SECTION) { sec = local_sections[r_symndx]; - rel->r_addend += sec->output_offset + sym->st_value; + rela->r_addend += sec->output_offset + sym->st_value; } } @@ -280,24 +1191,269 @@ elf64_x86_64_relocate_section (output_bfd, info, input_bfd, input_section, } else if (h->root.type == bfd_link_hash_undefweak) relocation = 0; + else if (info->shared && !info->symbolic && !info->no_undefined + && ELF_ST_VISIBILITY (h->other) == STV_DEFAULT) + relocation = 0; else { if (! ((*info->callbacks->undefined_symbol) (info, h->root.root.string, input_bfd, - input_section, rel->r_offset, + input_section, rela->r_offset, (!info->shared || info->no_undefined || ELF_ST_VISIBILITY (h->other))))) return false; relocation = 0; } } - /* This function should support shared objects, but don't. */ + + /* When generating a shared object, the relocations handled here are + copied into the output file to be resolved at run time. */ + switch (r_type) + { + case R_X86_64_GOT32: + /* Relocation is to the entry for this symbol in the global + offset table. */ + BFD_ASSERT (sgot != NULL); + + if (h != NULL) + { + bfd_vma off = h->got.offset; + BFD_ASSERT (off != (bfd_vma) -1); + + if (! elf_hash_table (info)->dynamic_sections_created + || (info->shared + && (info->symbolic || h->dynindx == -1) + && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR))) + { + /* This is actually a static link, or it is a -Bsymbolic + link and the symbol is defined locally, or the symbol + was forced to be local because of a version file. We + must initialize this entry in the global offset table. + Since the offset must always be a multiple of 8, we + use the least significant bit to record whether we + have initialized it already. + + When doing a dynamic link, we create a .rela.got + relocation entry to initialize the value. This is + done in the finish_dynamic_symbol routine. */ + if ((off & 1) != 0) + off &= ~1; + else + { + bfd_put_64 (output_bfd, relocation, + sgot->contents + off); + h->got.offset |= 1; + } + } + relocation = sgot->output_offset + off; + } + else + { + bfd_vma off; + + BFD_ASSERT (local_got_offsets != NULL + && local_got_offsets[r_symndx] != (bfd_vma) -1); + + off = local_got_offsets[r_symndx]; + + /* The offset must always be a multiple of 8. We use + the least significant bit to record whether we have + already generated the necessary reloc. */ + if ((off & 1) != 0) + off &= ~1; + else + { + bfd_put_64 (output_bfd, relocation, sgot->contents + off); + if (info->shared) - abort (); + { + asection *srelgot; + Elf_Internal_Rela outrel; + + /* We need to generate a R_X86_64_RELATIVE reloc + for the dynamic linker. */ + srelgot = bfd_get_section_by_name (dynobj, ".rela.got"); + BFD_ASSERT (srelgot != NULL); + + outrel.r_offset = (sgot->output_section->vma + + sgot->output_offset + + off); + outrel.r_info = ELF64_R_INFO (0, R_X86_64_RELATIVE); + outrel.r_addend = relocation; + bfd_elf64_swap_reloca_out (output_bfd, &outrel, + (((Elf64_External_Rela *) + srelgot->contents) + + srelgot->reloc_count)); + ++srelgot->reloc_count; + } + + local_got_offsets[r_symndx] |= 1; + } + + relocation = sgot->output_offset + off; + } + + break; + + case R_X86_64_GOTPCREL: + /* Use global offset table as symbol value. */ + + if (sgot == NULL) + { + sgot = bfd_get_section_by_name (dynobj, ".got"); + BFD_ASSERT (sgot != NULL); + } + + relocation = sgot->output_section->vma + (h->got.offset & ~1); + + break; + + case R_X86_64_PLT32: + /* Relocation is to the entry for this symbol in the + procedure linkage table. */ + + /* Resolve a PLT32 reloc against a local symbol directly, + without using the procedure linkage table. */ + if (h == NULL) + break; + + if (h->plt.offset == (bfd_vma) -1 || splt == NULL) + { + /* We didn't make a PLT entry for this symbol. This + happens when statically linking PIC code, or when + using -Bsymbolic. */ + break; + } + + relocation = (splt->output_section->vma + + splt->output_offset + + h->plt.offset); + break; + + case R_X86_64_8: + case R_X86_64_16: + case R_X86_64_32: + case R_X86_64_PC8: + case R_X86_64_PC16: + case R_X86_64_PC32: + /* FIXME: The abi says the linker should make sure the value is + the same when it's zeroextended to 64 bit. */ + if (info->shared + && (input_section->flags & SEC_ALLOC) != 0 + && ((r_type != R_X86_64_PC8 && r_type != R_X86_64_PC16 + && r_type != R_X86_64_PC32) + || (h != NULL + && h->dynindx != -1 + && (! info->symbolic + || (h->elf_link_hash_flags + & ELF_LINK_HASH_DEF_REGULAR) == 0)))) + { + Elf_Internal_Rela outrel; + boolean skip, relocate; + + /* When generating a shared object, these relocations + are copied into the output file to be resolved at run + time. */ + + if (sreloc == NULL) + { + const char *name; + + name = (bfd_elf_string_from_elf_section + (input_bfd, + elf_elfheader (input_bfd)->e_shstrndx, + elf_section_data (input_section)->rel_hdr.sh_name)); + if (name == NULL) + return false; + + BFD_ASSERT (strncmp (name, ".rela", 5) == 0 + && strcmp (bfd_get_section_name (input_bfd, + input_section), + name + 5) == 0); + + sreloc = bfd_get_section_by_name (dynobj, name); + BFD_ASSERT (sreloc != NULL); + } + + skip = false; + + if (elf_section_data (input_section)->stab_info == NULL) + outrel.r_offset = rela->r_offset; + else + { + bfd_vma off; + + off = (_bfd_stab_section_offset + (output_bfd, &elf_hash_table (info)->stab_info, + input_section, + &elf_section_data (input_section)->stab_info, + rela->r_offset)); + if (off == (bfd_vma) -1) + skip = true; + outrel.r_offset = off; + } + + outrel.r_offset += (input_section->output_section->vma + + input_section->output_offset); + + if (skip) + { + memset (&outrel, 0, sizeof outrel); + relocate = false; + } + else if ((r_type == R_X86_64_PC8) || (r_type == R_X86_64_PC16) + || (r_type == R_X86_64_PC32)) + { + BFD_ASSERT (h != NULL && h->dynindx != -1); + relocate = false; + outrel.r_info = ELF64_R_INFO (h->dynindx, r_type); + outrel.r_addend = relocation + rela->r_addend; + } + else + { + /* h->dynindx may be -1 if this symbol was marked to + become local. */ + if (h == NULL + || ((info->symbolic || h->dynindx == -1) + && (h->elf_link_hash_flags + & ELF_LINK_HASH_DEF_REGULAR) != 0)) + { + relocate = true; + outrel.r_info = ELF64_R_INFO (0, R_X86_64_RELATIVE); + outrel.r_addend = relocation + rela->r_addend; + } + else + { + BFD_ASSERT (h->dynindx != -1); + relocate = false; + outrel.r_info = ELF64_R_INFO (h->dynindx, R_X86_64_32); + outrel.r_addend = relocation + rela->r_addend; + } + } + + bfd_elf64_swap_reloca_out (output_bfd, &outrel, + (((Elf64_External_Rela *) + sreloc->contents) + + sreloc->reloc_count)); + ++sreloc->reloc_count; + + /* If this reloc is against an external symbol, we do + not want to fiddle with the addend. Otherwise, we + need to include the symbol value so that it becomes + an addend for the dynamic reloc. */ + if (! relocate) + continue; + } + + break; + + default: + break; + } r = _bfd_final_link_relocate (howto, input_bfd, input_section, - contents, rel->r_offset, - relocation, rel->r_addend); + contents, rela->r_offset, + relocation, rela->r_addend); if (r != bfd_reloc_ok) { @@ -324,25 +1480,274 @@ elf64_x86_64_relocate_section (output_bfd, info, input_bfd, input_section, } if (! ((*info->callbacks->reloc_overflow) (info, name, howto->name, (bfd_vma) 0, - input_bfd, input_section, rel->r_offset))) + input_bfd, input_section, rela->r_offset))) return false; } break; } } } + + return true; +} + +/* Finish up dynamic symbol handling. We set the contents of various + dynamic sections here. */ + +static boolean +elf64_x86_64_finish_dynamic_symbol (output_bfd, info, h, sym) + bfd *output_bfd; + struct bfd_link_info *info; + struct elf_link_hash_entry *h; + Elf_Internal_Sym *sym; +{ + bfd *dynobj; + + dynobj = elf_hash_table (info)->dynobj; + + if (h->plt.offset != (bfd_vma) -1) + { + asection *splt; + asection *sgot; + asection *srela; + bfd_vma plt_index; + bfd_vma got_offset; + Elf_Internal_Rela rela; + + /* This symbol has an entry in the procedure linkage table. Set + it up. */ + + BFD_ASSERT (h->dynindx != -1); + + splt = bfd_get_section_by_name (dynobj, ".plt"); + sgot = bfd_get_section_by_name (dynobj, ".got.plt"); + srela = bfd_get_section_by_name (dynobj, ".rela.plt"); + BFD_ASSERT (splt != NULL && sgot != NULL && srela != NULL); + + /* Get the index in the procedure linkage table which + corresponds to this symbol. This is the index of this symbol + in all the symbols for which we are making plt entries. The + first entry in the procedure linkage table is reserved. */ + plt_index = h->plt.offset / PLT_ENTRY_SIZE - 1; + + /* Get the offset into the .got table of the entry that + corresponds to this function. Each .got entry is GOT_ENTRY_SIZE + bytes. The first three are reserved. */ + got_offset = (plt_index + 3) * GOT_ENTRY_SIZE; + + /* Fill in the entry in the procedure linkage table. */ + memcpy (splt->contents + h->plt.offset, elf64_x86_64_plt_entry, + PLT_ENTRY_SIZE); + + /* Insert the relocation positions of the plt section. The magic + numbers at the end of the statements are the positions of the + relocations in the plt section. */ + bfd_put_64 (output_bfd, got_offset, splt->contents + h->plt.offset + 2); + bfd_put_64 (output_bfd, plt_index * sizeof (Elf64_External_Rela), + splt->contents + h->plt.offset + 7); + bfd_put_64 (output_bfd, - (h->plt.offset + PLT_ENTRY_SIZE), + splt->contents + h->plt.offset + 12); + + /* Fill in the entry in the global offset table. */ + bfd_put_64 (output_bfd, (splt->output_section->vma + splt->output_offset + + h->plt.offset + 6), + sgot->contents + got_offset); + + /* Fill in the entry in the .rela.plt section. */ + rela.r_offset = (sgot->output_section->vma + + sgot->output_offset + + got_offset); + rela.r_info = ELF64_R_INFO (h->dynindx, R_X86_64_JUMP_SLOT); + rela.r_addend = 0; + bfd_elf64_swap_reloca_out (output_bfd, &rela, + ((Elf64_External_Rela *) srela->contents + + plt_index)); + + if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0) + { + /* Mark the symbol as undefined, rather than as defined in + the .plt section. Leave the value alone. */ + sym->st_shndx = SHN_UNDEF; + } + } + + if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_COPY) != 0) + { + asection *s; + Elf_Internal_Rela rela; + + /* This symbol needs a copy reloc. Set it up. */ + + BFD_ASSERT (h->dynindx != -1 + && (h->root.type == bfd_link_hash_defined + || h->root.type == bfd_link_hash_defweak)); + + s = bfd_get_section_by_name (h->root.u.def.section->owner, + ".rela.bss"); + BFD_ASSERT (s != NULL); + + rela.r_offset = (h->root.u.def.value + + h->root.u.def.section->output_section->vma + + h->root.u.def.section->output_offset); + rela.r_info = ELF64_R_INFO (h->dynindx, R_X86_64_COPY); + rela.r_addend = 0; + bfd_elf64_swap_reloca_out (output_bfd, &rela, + ((Elf64_External_Rela *) s->contents + + s->reloc_count)); + ++s->reloc_count; + } + + /* Mark _DYNAMIC and _GLOBAL_OFFSET_TABLE_ as absolute. */ + if (strcmp (h->root.root.string, "_DYNAMIC") == 0 + || strcmp (h->root.root.string, "_GLOBAL_OFFSET_TABLE_") == 0) + sym->st_shndx = SHN_ABS; + + return true; +} + +/* Finish up the dynamic sections. */ + +static boolean +elf64_x86_64_finish_dynamic_sections (output_bfd, info) + bfd *output_bfd; + struct bfd_link_info *info; +{ + bfd *dynobj; + asection *sdyn; + asection *sgot; + + dynobj = elf_hash_table (info)->dynobj; + + sdyn = bfd_get_section_by_name (dynobj, ".dynamic"); + + if (elf_hash_table (info)->dynamic_sections_created) + { + asection *splt; + Elf64_External_Dyn *dyncon, *dynconend; + + splt = bfd_get_section_by_name (dynobj, ".plt"); + BFD_ASSERT (splt != NULL && sdyn != NULL); + + dyncon = (Elf64_External_Dyn *) sdyn->contents; + dynconend = (Elf64_External_Dyn *) (sdyn->contents + sdyn->_raw_size); + for (; dyncon < dynconend; dyncon++) + { + Elf_Internal_Dyn dyn; + const char *name; + asection *s; + + bfd_elf64_swap_dyn_in (dynobj, dyncon, &dyn); + + switch (dyn.d_tag) + { + default: + break; + + case DT_PLTGOT: + name = ".got"; + goto get_vma; + + case DT_JMPREL: + name = ".rela.plt"; + + get_vma: + s = bfd_get_section_by_name (output_bfd, name); + BFD_ASSERT (s != NULL); + dyn.d_un.d_ptr = s->vma; + break; + + case DT_RELASZ: + /* FIXME: This comment and code is from elf64-alpha.c: */ + /* My interpretation of the TIS v1.1 ELF document indicates + that RELASZ should not include JMPREL. This is not what + the rest of the BFD does. It is, however, what the + glibc ld.so wants. Do this fixup here until we found + out who is right. */ + s = bfd_get_section_by_name (output_bfd, ".rela.plt"); + if (s) + { + /* Subtract JMPREL size from RELASZ. */ + dyn.d_un.d_val -= + (s->_cooked_size ? s->_cooked_size : s->_raw_size); + } + break; + + case DT_PLTRELSZ: + s = bfd_get_section_by_name (output_bfd, ".rela.plt"); + BFD_ASSERT (s != NULL); + dyn.d_un.d_val = + (s->_cooked_size != 0 ? s->_cooked_size : s->_raw_size); + break; + } + + bfd_elf64_swap_dyn_out (output_bfd, &dyn, dyncon); + } + + /* Initialize the contents of the .plt section. */ + if (splt->_raw_size > 0) + { + memcpy (splt->contents, elf64_x86_64_plt0_entry, PLT_ENTRY_SIZE); + } + + elf_section_data (splt->output_section)->this_hdr.sh_entsize = + PLT_ENTRY_SIZE; + } + + /* Set the first entry in the global offset table to the address of + the dynamic section. */ + sgot = bfd_get_section_by_name (dynobj, ".got"); + BFD_ASSERT (sgot != NULL); + if (sgot->_raw_size > 0) + { + if (sdyn == NULL) + bfd_put_64 (output_bfd, (bfd_vma) 0, sgot->contents); + else + bfd_put_64 (output_bfd, + sdyn->output_section->vma + sdyn->output_offset, + sgot->contents); + /* Write GOT[1] and GOT[2], needed for the linker. */ + bfd_put_64 (output_bfd, (bfd_vma) 0, sgot->contents + GOT_ENTRY_SIZE); + bfd_put_64 (output_bfd, (bfd_vma) 0, sgot->contents + GOT_ENTRY_SIZE*2); + } + + elf_section_data (sgot->output_section)->this_hdr.sh_entsize = + GOT_ENTRY_SIZE; + return true; } -#define TARGET_LITTLE_SYM bfd_elf64_x86_64_vec -#define TARGET_LITTLE_NAME "elf64-x86-64" -#define ELF_ARCH bfd_arch_i386 -#define ELF_MACHINE_CODE EM_X86_64 -#define ELF_MAXPAGESIZE 0x100000 -#define elf_info_to_howto elf64_x86_64_info_to_howto -#define bfd_elf64_bfd_reloc_type_lookup elf64_x86_64_reloc_type_lookup -#define elf_backend_object_p elf64_x86_64_elf_object_p -#define elf_backend_relocate_section elf64_x86_64_relocate_section -#define bfd_elf64_bfd_link_hash_table_create elf64_x86_64_link_hash_table_create + +#define TARGET_LITTLE_SYM bfd_elf64_x86_64_vec +#define TARGET_LITTLE_NAME "elf64-x86-64" +#define ELF_ARCH bfd_arch_i386 +#define ELF_MACHINE_CODE EM_X86_64 +#define ELF_MAXPAGESIZE 0x100000 + +#define elf_backend_can_gc_sections 1 +#define elf_backend_want_got_plt 1 +#define elf_backend_plt_readonly 1 +#define elf_backend_want_plt_sym 0 +#define elf_backend_got_header_size (GOT_ENTRY_SIZE*3) +#define elf_backend_plt_header_size PLT_ENTRY_SIZE + +#define elf_info_to_howto elf64_x86_64_info_to_howto +#define elf_backend_object_p elf64_x86_64_elf_object_p +#define elf_backend_relocate_section elf64_x86_64_relocate_section + +#define bfd_elf64_bfd_final_link _bfd_elf64_gc_common_final_link +#define bfd_elf64_bfd_link_hash_table_create \ + elf64_x86_64_link_hash_table_create +#define bfd_elf64_bfd_reloc_type_lookup elf64_x86_64_reloc_type_lookup + +#define elf_backend_adjust_dynamic_symbol elf64_x86_64_adjust_dynamic_symbol +#define elf_backend_check_relocs elf64_x86_64_check_relocs +#define elf_backend_create_dynamic_sections _bfd_elf_create_dynamic_sections +#define elf_backend_finish_dynamic_sections \ + elf64_x86_64_finish_dynamic_sections +#define elf_backend_finish_dynamic_symbol elf64_x86_64_finish_dynamic_symbol +#define elf_backend_gc_mark_hook elf64_x86_64_gc_mark_hook +#define elf_backend_gc_sweep_hook elf64_x86_64_gc_sweep_hook +#define elf_backend_relocate_section elf64_x86_64_relocate_section +#define elf_backend_size_dynamic_sections elf64_x86_64_size_dynamic_sections #include "elf64-target.h" -- 2.30.2