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Diffstat (limited to 'gold/aarch64.cc')
| -rw-r--r-- | gold/aarch64.cc | 1447 |
1 files changed, 1447 insertions, 0 deletions
diff --git a/gold/aarch64.cc b/gold/aarch64.cc new file mode 100644 index 0000000..17fe031 --- /dev/null +++ b/gold/aarch64.cc @@ -0,0 +1,1447 @@ +// aarch64.cc -- aarch64 target support for gold. + +// Copyright (C) 2014 Free Software Foundation, Inc. +// Written by Jing Yu <jingyu@google.com>. + +// This file is part of gold. + +// 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 3 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., 51 Franklin Street - Fifth Floor, Boston, +// MA 02110-1301, USA. + +#include "gold.h" + +#include <cstring> + +#include "elfcpp.h" +#include "dwarf.h" +#include "parameters.h" +#include "reloc.h" +#include "aarch64.h" +#include "object.h" +#include "symtab.h" +#include "layout.h" +#include "output.h" +#include "copy-relocs.h" +#include "target.h" +#include "target-reloc.h" +#include "target-select.h" +#include "tls.h" +#include "freebsd.h" +#include "nacl.h" +#include "gc.h" +#include "icf.h" + +// The first three .got.plt entries are reserved. +const int32_t AARCH64_GOTPLT_RESERVE_COUNT = 3; + +namespace +{ + +using namespace gold; + +template<int size, bool big_endian> +class Output_data_plt_aarch64; + +template<int size, bool big_endian> +class Output_data_plt_aarch64_standard; + +template<int size, bool big_endian> +class Target_aarch64; + +// Output_data_got_aarch64 class. + +template<int size, bool big_endian> +class Output_data_got_aarch64 : public Output_data_got<size, big_endian> +{ + public: + typedef typename elfcpp::Elf_types<size>::Elf_Addr Valtype; + Output_data_got_aarch64(Symbol_table* symtab, Layout* layout) + : Output_data_got<size, big_endian>(), layout_(layout) + { } + + protected: + // Write out the GOT table. + void + do_write(Output_file* of) { + // The first entry in the GOT is the address of the .dynamic section. + gold_assert(this->data_size() >= size / 8); + Output_section* dynamic = this->layout_->dynamic_section(); + Valtype dynamic_addr = dynamic == NULL ? 0 : dynamic->address(); + this->replace_constant(0, dynamic_addr); + Output_data_got<size, big_endian>::do_write(of); + } + + private: + // A pointer to the Layout class, so that we can find the .dynamic + // section when we write out the GOT section. + Layout* layout_; +}; + +// The aarch64 target class. +// See the ABI at +// http://infocenter.arm.com/help/topic/com.arm.doc.ihi0056b/IHI0056B_aaelf64.pdf +template<int size, bool big_endian> +class Target_aarch64 : public Sized_target<size, big_endian> +{ + public: + typedef Output_data_reloc<elfcpp::SHT_RELA, true, size, big_endian> + Reloc_section; + typedef typename elfcpp::Elf_types<size>::Elf_Addr Address; + + Target_aarch64(const Target::Target_info* info = &aarch64_info) + : Sized_target<size, big_endian>(info), + got_(NULL), plt_(NULL), got_plt_(NULL), + global_offset_table_(NULL), rela_dyn_(NULL), + copy_relocs_(elfcpp::R_AARCH64_COPY) + { } + + // Scan the relocations to determine unreferenced sections for + // garbage collection. + void + gc_process_relocs(Symbol_table* symtab, + Layout* layout, + Sized_relobj_file<size, big_endian>* object, + unsigned int data_shndx, + unsigned int sh_type, + const unsigned char* prelocs, + size_t reloc_count, + Output_section* output_section, + bool needs_special_offset_handling, + size_t local_symbol_count, + const unsigned char* plocal_symbols); + + // Scan the relocations to look for symbol adjustments. + void + scan_relocs(Symbol_table* symtab, + Layout* layout, + Sized_relobj_file<size, big_endian>* object, + unsigned int data_shndx, + unsigned int sh_type, + const unsigned char* prelocs, + size_t reloc_count, + Output_section* output_section, + bool needs_special_offset_handling, + size_t local_symbol_count, + const unsigned char* plocal_symbols); + + // Finalize the sections. + void + do_finalize_sections(Layout*, const Input_objects*, Symbol_table*); + + // Relocate a section. + void + relocate_section(const Relocate_info<size, big_endian>*, + unsigned int sh_type, + const unsigned char* prelocs, + size_t reloc_count, + Output_section* output_section, + bool needs_special_offset_handling, + unsigned char* view, + typename elfcpp::Elf_types<size>::Elf_Addr view_address, + section_size_type view_size, + const Reloc_symbol_changes*); + + // Scan the relocs during a relocatable link. + void + scan_relocatable_relocs(Symbol_table* symtab, + Layout* layout, + Sized_relobj_file<size, big_endian>* object, + unsigned int data_shndx, + unsigned int sh_type, + const unsigned char* prelocs, + size_t reloc_count, + Output_section* output_section, + bool needs_special_offset_handling, + size_t local_symbol_count, + const unsigned char* plocal_symbols, + Relocatable_relocs*); + + // Relocate a section during a relocatable link. + void + relocate_relocs( + const Relocate_info<size, big_endian>*, + unsigned int sh_type, + const unsigned char* prelocs, + size_t reloc_count, + Output_section* output_section, + typename elfcpp::Elf_types<size>::Elf_Off offset_in_output_section, + const Relocatable_relocs*, + unsigned char* view, + typename elfcpp::Elf_types<size>::Elf_Addr view_address, + section_size_type view_size, + unsigned char* reloc_view, + section_size_type reloc_view_size); + + // Return the number of entries in the PLT. + unsigned int + plt_entry_count() const; + + //Return the offset of the first non-reserved PLT entry. + unsigned int + first_plt_entry_offset() const; + + // Return the size of each PLT entry. + unsigned int + plt_entry_size() const; + + private: + // The class which scans relocations. + class Scan + { + public: + Scan() + : issued_non_pic_error_(false) + { } + + static inline int + get_reference_flags(unsigned int r_type); + + inline void + local(Symbol_table* symtab, Layout* layout, Target_aarch64* target, + Sized_relobj_file<size, big_endian>* object, + unsigned int data_shndx, + Output_section* output_section, + const elfcpp::Rela<size, big_endian>& reloc, unsigned int r_type, + const elfcpp::Sym<size, big_endian>& lsym, + bool is_discarded); + + inline void + global(Symbol_table* symtab, Layout* layout, Target_aarch64* target, + Sized_relobj_file<size, big_endian>* object, + unsigned int data_shndx, + Output_section* output_section, + const elfcpp::Rela<size, big_endian>& reloc, unsigned int r_type, + Symbol* gsym); + + inline bool + local_reloc_may_be_function_pointer(Symbol_table* , Layout* , + Target_aarch64<size, big_endian>* , + Sized_relobj_file<size, big_endian>* , + unsigned int , + Output_section* , + const elfcpp::Rela<size, big_endian>& , + unsigned int r_type, + const elfcpp::Sym<size, big_endian>&); + + inline bool + global_reloc_may_be_function_pointer(Symbol_table* , Layout* , + Target_aarch64<size, big_endian>* , + Sized_relobj_file<size, big_endian>* , + unsigned int , + Output_section* , + const elfcpp::Rela<size, big_endian>& , + unsigned int r_type, + Symbol* gsym); + + private: + static void + unsupported_reloc_local(Sized_relobj_file<size, big_endian>*, + unsigned int r_type); + + static void + unsupported_reloc_global(Sized_relobj_file<size, big_endian>*, + unsigned int r_type, Symbol*); + + inline bool + possible_function_pointer_reloc(unsigned int r_type); + + void + check_non_pic(Relobj*, unsigned int r_type); + + // Whether we have issued an error about a non-PIC compilation. + bool issued_non_pic_error_; + }; + + // The class which implements relocation. + class Relocate + { + public: + Relocate() + { } + + ~Relocate() + { } + + // Do a relocation. Return false if the caller should not issue + // any warnings about this relocation. + inline bool + relocate(const Relocate_info<size, big_endian>*, Target_aarch64*, + Output_section*, + size_t relnum, const elfcpp::Rela<size, big_endian>&, + unsigned int r_type, const Sized_symbol<size>*, + const Symbol_value<size>*, + unsigned char*, typename elfcpp::Elf_types<size>::Elf_Addr, + section_size_type); + + }; + + // A class which returns the size required for a relocation type, + // used while scanning relocs during a relocatable link. + class Relocatable_size_for_reloc + { + public: + unsigned int + get_size_for_reloc(unsigned int, Relobj*); + }; + + // Adjust TLS relocation type based on the options and whether this + // is a local symbol. + static tls::Tls_optimization + optimize_tls_reloc(bool is_final, int r_type); + + // Get the GOT section, creating it if necessary. + Output_data_got_aarch64<size, big_endian>* + got_section(Symbol_table*, Layout*); + + // Get the GOT PLT section. + Output_data_space* + got_plt_section() const + { + gold_assert(this->got_plt_ != NULL); + return this->got_plt_; + } + + // Create the PLT section. + void + make_plt_section(Symbol_table* symtab, Layout* layout); + + // Create a PLT entry for a global symbol. + void + make_plt_entry(Symbol_table*, Layout*, Symbol*); + + // Get the PLT section. + Output_data_plt_aarch64<size, big_endian>* + plt_section() const + { + gold_assert(this->plt_ != NULL); + return this->plt_; + } + + // Get the dynamic reloc section, creating it if necessary. + Reloc_section* + rela_dyn_section(Layout*); + + // Add a potential copy relocation. + void + copy_reloc(Symbol_table* symtab, Layout* layout, + Sized_relobj_file<size, big_endian>* object, + unsigned int shndx, Output_section* output_section, + Symbol* sym, const elfcpp::Rela<size, big_endian>& reloc) + { + this->copy_relocs_.copy_reloc(symtab, layout, + symtab->get_sized_symbol<size>(sym), + object, shndx, output_section, + reloc, this->rela_dyn_section(layout)); + } + + // Information about this specific target which we pass to the + // general Target structure. + static const Target::Target_info aarch64_info; + + // The types of GOT entries needed for this platform. + // These values are exposed to the ABI in an incremental link. + // Do not renumber existing values without changing the version + // number of the .gnu_incremental_inputs section. + enum Got_type + { + GOT_TYPE_STANDARD = 0, // GOT entry for a regular symbol + GOT_TYPE_TLS_OFFSET = 1, // GOT entry for TLS offset + GOT_TYPE_TLS_PAIR = 2, // GOT entry for TLS module/offset pair + GOT_TYPE_TLS_DESC = 3 // GOT entry for TLS_DESC pair + }; + + // The GOT section. + Output_data_got_aarch64<size, big_endian>* got_; + // The PLT section. + Output_data_plt_aarch64<size, big_endian>* plt_; + // The GOT PLT section. + Output_data_space* got_plt_; + // The _GLOBAL_OFFSET_TABLE_ symbol. + Symbol* global_offset_table_; + // The dynamic reloc section. + Reloc_section* rela_dyn_; + // Relocs saved to avoid a COPY reloc. + Copy_relocs<elfcpp::SHT_RELA, size, big_endian> copy_relocs_; +}; + +template<> +const Target::Target_info Target_aarch64<64, false>::aarch64_info = +{ + 64, // size + false, // is_big_endian + elfcpp::EM_AARCH64, // machine_code + false, // has_make_symbol + false, // has_resolve + false, // has_code_fill + true, // is_default_stack_executable + false, // can_icf_inline_merge_sections + '\0', // wrap_char + "/lib/ld.so.1", // program interpreter + 0x400000, // default_text_segment_address + 0x1000, // abi_pagesize (overridable by -z max-page-size) + 0x1000, // common_pagesize (overridable by -z common-page-size) + false, // isolate_execinstr + 0, // rosegment_gap + elfcpp::SHN_UNDEF, // small_common_shndx + elfcpp::SHN_UNDEF, // large_common_shndx + 0, // small_common_section_flags + 0, // large_common_section_flags + NULL, // attributes_section + NULL, // attributes_vendor + "_start" // entry_symbol_name +}; + +template<> +const Target::Target_info Target_aarch64<32, false>::aarch64_info = +{ + 32, // size + false, // is_big_endian + elfcpp::EM_AARCH64, // machine_code + false, // has_make_symbol + false, // has_resolve + false, // has_code_fill + true, // is_default_stack_executable + false, // can_icf_inline_merge_sections + '\0', // wrap_char + "/lib/ld.so.1", // program interpreter + 0x400000, // default_text_segment_address + 0x1000, // abi_pagesize (overridable by -z max-page-size) + 0x1000, // common_pagesize (overridable by -z common-page-size) + false, // isolate_execinstr + 0, // rosegment_gap + elfcpp::SHN_UNDEF, // small_common_shndx + elfcpp::SHN_UNDEF, // large_common_shndx + 0, // small_common_section_flags + 0, // large_common_section_flags + NULL, // attributes_section + NULL, // attributes_vendor + "_start" // entry_symbol_name +}; + +template<> +const Target::Target_info Target_aarch64<64, true>::aarch64_info = +{ + 64, // size + true, // is_big_endian + elfcpp::EM_AARCH64, // machine_code + false, // has_make_symbol + false, // has_resolve + false, // has_code_fill + true, // is_default_stack_executable + false, // can_icf_inline_merge_sections + '\0', // wrap_char + "/lib/ld.so.1", // program interpreter + 0x400000, // default_text_segment_address + 0x1000, // abi_pagesize (overridable by -z max-page-size) + 0x1000, // common_pagesize (overridable by -z common-page-size) + false, // isolate_execinstr + 0, // rosegment_gap + elfcpp::SHN_UNDEF, // small_common_shndx + elfcpp::SHN_UNDEF, // large_common_shndx + 0, // small_common_section_flags + 0, // large_common_section_flags + NULL, // attributes_section + NULL, // attributes_vendor + "_start" // entry_symbol_name +}; + +template<> +const Target::Target_info Target_aarch64<32, true>::aarch64_info = +{ + 32, // size + true, // is_big_endian + elfcpp::EM_AARCH64, // machine_code + false, // has_make_symbol + false, // has_resolve + false, // has_code_fill + true, // is_default_stack_executable + false, // can_icf_inline_merge_sections + '\0', // wrap_char + "/lib/ld.so.1", // program interpreter + 0x400000, // default_text_segment_address + 0x1000, // abi_pagesize (overridable by -z max-page-size) + 0x1000, // common_pagesize (overridable by -z common-page-size) + false, // isolate_execinstr + 0, // rosegment_gap + elfcpp::SHN_UNDEF, // small_common_shndx + elfcpp::SHN_UNDEF, // large_common_shndx + 0, // small_common_section_flags + 0, // large_common_section_flags + NULL, // attributes_section + NULL, // attributes_vendor + "_start" // entry_symbol_name +}; + +// Get the GOT section, creating it if necessary. + +template<int size, bool big_endian> +Output_data_got_aarch64<size, big_endian>* +Target_aarch64<size, big_endian>::got_section(Symbol_table* symtab, + Layout* layout) +{ + if (this->got_ == NULL) + { + gold_assert(symtab != NULL && layout != NULL); + + // When using -z now, we can treat .got.plt as a relro section. + // Without -z now, it is modified after program startup by lazy + // PLT relocations. + bool is_got_plt_relro = parameters->options().now(); + Output_section_order got_order = (is_got_plt_relro + ? ORDER_RELRO + : ORDER_RELRO_LAST); + Output_section_order got_plt_order = (is_got_plt_relro + ? ORDER_RELRO + : ORDER_NON_RELRO_FIRST); + + // Layout of .got and .got.plt sections. + // .got[0] &_DYNAMIC <-_GLOBAL_OFFSET_TABLE_ + // ... + // .gotplt[0] reserved for ld.so (&linkmap) <--DT_PLTGOT + // .gotplt[1] reserved for ld.so (resolver) + // .gotplt[2] reserved + + // Generate .got section. + this->got_ = new Output_data_got_aarch64<size, big_endian>(symtab, + layout); + layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS, + (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE), + this->got_, got_order, true); + // The first word of GOT is reserved for the address of .dynamic. + // We put 0 here now. The value will be replaced later in + // Output_data_got_aarch64::do_write. + this->got_->add_constant(0); + + // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT. + // _GLOBAL_OFFSET_TABLE_ value points to the start of the .got section, + // even if there is a .got.plt section. + this->global_offset_table_ = + symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL, + Symbol_table::PREDEFINED, + this->got_, + 0, 0, elfcpp::STT_OBJECT, + elfcpp::STB_LOCAL, + elfcpp::STV_HIDDEN, 0, + false, false); + + // Generate .got.plt section. + this->got_plt_ = new Output_data_space(size / 8, "** GOT PLT"); + layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS, + (elfcpp::SHF_ALLOC + | elfcpp::SHF_WRITE), + this->got_plt_, got_plt_order, + is_got_plt_relro); + + // The first three entries are reserved. + this->got_plt_->set_current_data_size + (AARCH64_GOTPLT_RESERVE_COUNT * (size / 8)); + + if (!is_got_plt_relro) + { + // Those bytes can go into the relro segment. + layout->increase_relro + (AARCH64_GOTPLT_RESERVE_COUNT * (size / 8)); + } + + } + return this->got_; +} + +// Get the dynamic reloc section, creating it if necessary. + +template<int size, bool big_endian> +typename Target_aarch64<size, big_endian>::Reloc_section* +Target_aarch64<size, big_endian>::rela_dyn_section(Layout* layout) +{ + if (this->rela_dyn_ == NULL) + { + gold_assert(layout != NULL); + this->rela_dyn_ = new Reloc_section(parameters->options().combreloc()); + layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA, + elfcpp::SHF_ALLOC, this->rela_dyn_, + ORDER_DYNAMIC_RELOCS, false); + } + return this->rela_dyn_; +} + +// A class to handle the PLT data. +// This is an abstract base class that handles most of the linker details +// but does not know the actual contents of PLT entries. The derived +// classes below fill in those details. + +template<int size, bool big_endian> +class Output_data_plt_aarch64 : public Output_section_data +{ + public: + typedef Output_data_reloc<elfcpp::SHT_RELA, true, size, big_endian> + Reloc_section; + typedef typename elfcpp::Elf_types<size>::Elf_Addr Address; + + Output_data_plt_aarch64(Layout* layout, + uint64_t addralign, + Output_data_space* got_plt) + : Output_section_data(addralign), + got_plt_(got_plt), + count_(0) + { this->init(layout); } + + // Initialize the PLT section. + void + init(Layout* layout); + + // Add an entry to the PLT. + void + add_entry(Symbol* gsym); + + // Return the .rela.plt section data. + Reloc_section* + rela_plt() + { return this->rel_; } + + // Return the number of PLT entries. + unsigned int + entry_count() const + { return this->count_; } + + // Return the offset of the first non-reserved PLT entry. + unsigned int + first_plt_entry_offset() + { return this->do_first_plt_entry_offset(); } + + // Return the size of a PLT entry. + unsigned int + get_plt_entry_size() const + { return this->do_get_plt_entry_size(); } + + protected: + // Fill in the first PLT entry. + void + fill_first_plt_entry(unsigned char* pov, + Address got_address, + Address plt_address) + { this->do_fill_first_plt_entry(pov, got_address, plt_address); } + + // Fill in a normal PLT entry. + void + fill_plt_entry(unsigned char* pov, + Address got_address, + Address plt_address, + unsigned int got_offset, + unsigned int plt_offset) + { + this->do_fill_plt_entry(pov, got_address, plt_address, + got_offset, plt_offset); + } + + virtual unsigned int + do_first_plt_entry_offset() const = 0; + + virtual unsigned int + do_get_plt_entry_size() const = 0; + + virtual void + do_fill_first_plt_entry(unsigned char* pov, + Address got_addr, + Address plt_addr) = 0; + + virtual void + do_fill_plt_entry(unsigned char* pov, + Address got_address, + Address plt_address, + unsigned int got_offset, + unsigned int plt_offset) = 0; + + void + do_adjust_output_section(Output_section* os); + + // Write to a map file. + void + do_print_to_mapfile(Mapfile* mapfile) const + { mapfile->print_output_data(this, _("** PLT")); } + + private: + // Set the final size. + void + set_final_data_size(); + + // Write out the PLT data. + void + do_write(Output_file*); + + // The reloc section. + Reloc_section* rel_; + // The .got section. + Output_data_got_aarch64<size, big_endian>* got_; + // The .got.plt section. + Output_data_space* got_plt_; + // The number of PLT entries. + unsigned int count_; +}; + +// Initialize the PLT section. + +template<int size, bool big_endian> +void +Output_data_plt_aarch64<size, big_endian>::init(Layout* layout) +{ + this->rel_ = new Reloc_section(false); + layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA, + elfcpp::SHF_ALLOC, this->rel_, + ORDER_DYNAMIC_PLT_RELOCS, false); +} + +template<int size, bool big_endian> +void +Output_data_plt_aarch64<size, big_endian>::do_adjust_output_section( + Output_section* os) +{ + os->set_entsize(this->get_plt_entry_size()); +} + +// Add an entry to the PLT. + +template<int size, bool big_endian> +void +Output_data_plt_aarch64<size, big_endian>::add_entry(Symbol* gsym) +{ + gold_assert(!gsym->has_plt_offset()); + //TODO +} + +// Set the final size. +template<int size, bool big_endian> +void +Output_data_plt_aarch64<size, big_endian>::set_final_data_size() +{ + this->set_data_size(this->first_plt_entry_offset() + + this->count * this->get_plt_entry_size()); +} + +template<int size, bool big_endian> +class Output_data_plt_aarch64_standard : + public Output_data_plt_aarch64<size, big_endian> +{ + public: + typedef typename elfcpp::Elf_types<size>::Elf_Addr Address; + Output_data_plt_aarch64_standard(Layout* layout, Output_data_space* got_plt) + : Output_data_plt_aarch64<size, big_endian>(layout, + size == 32 ? 4 : 8, + got_plt) + { } + + protected: + // Return the offset of the first non-reserved PLT entry. + virtual unsigned int + do_first_plt_entry_offset() const + { return this->first_plt_entry_size; } + + // Return the size of a PLT entry + virtual unsigned int + do_get_plt_entry_size() const + { return this->plt_entry_size; } + + virtual void + do_fill_first_plt_entry(unsigned char* pov, + Address got_address, + Address plt_address); + + virtual void + do_fill_plt_entry(unsigned char* pov, + Address got_address, + Address plt_address, + unsigned int got_offset, + unsigned int plt_offset); + + private: + // The size of the first plt entry size. + static const int first_plt_entry_size = 32; + // The size of the plt entry size. + static const int plt_entry_size = 16; + // Template for the first PLT entry. + static const uint32_t first_plt_entry[first_plt_entry_size / 4]; + // Template for subsequent PLT entries. + static const uint32_t plt_entry[plt_entry_size / 4]; +}; + +// The first entry in the PLT for an executable. + +template<> +const uint32_t +Output_data_plt_aarch64_standard<32, false>:: + first_plt_entry[first_plt_entry_size / 4] = +{ + 0xa9bf7bf0, /* stp x16, x30, [sp, #-16]! */ + 0x90000010, /* adrp x16, PLT_GOT+0x8 */ + 0xb9400A11, /* ldr w17, [x16, #PLT_GOT+0x8] */ + 0x11002210, /* add w16, w16,#PLT_GOT+0x8 */ + 0xd61f0220, /* br x17 */ + 0xd503201f, /* nop */ + 0xd503201f, /* nop */ + 0xd503201f, /* nop */ +}; + +template<> +const uint32_t +Output_data_plt_aarch64_standard<32, true>:: + first_plt_entry[first_plt_entry_size / 4] = +{ + 0xa9bf7bf0, /* stp x16, x30, [sp, #-16]! */ + 0x90000010, /* adrp x16, PLT_GOT+0x8 */ + 0xb9400A11, /* ldr w17, [x16, #PLT_GOT+0x8] */ + 0x11002210, /* add w16, w16,#PLT_GOT+0x8 */ + 0xd61f0220, /* br x17 */ + 0xd503201f, /* nop */ + 0xd503201f, /* nop */ + 0xd503201f, /* nop */ +}; + +template<> +const uint32_t +Output_data_plt_aarch64_standard<64, false>:: + first_plt_entry[first_plt_entry_size / 4] = +{ + 0xa9bf7bf0, /* stp x16, x30, [sp, #-16]! */ + 0x90000010, /* adrp x16, PLT_GOT+16 */ + 0xf9400A11, /* ldr x17, [x16, #PLT_GOT+0x10] */ + 0x91004210, /* add x16, x16,#PLT_GOT+0x10 */ + 0xd61f0220, /* br x17 */ + 0xd503201f, /* nop */ + 0xd503201f, /* nop */ + 0xd503201f, /* nop */ +}; + +template<> +const uint32_t +Output_data_plt_aarch64_standard<64, true>:: + first_plt_entry[first_plt_entry_size / 4] = +{ + 0xa9bf7bf0, /* stp x16, x30, [sp, #-16]! */ + 0x90000010, /* adrp x16, PLT_GOT+16 */ + 0xf9400A11, /* ldr x17, [x16, #PLT_GOT+0x10] */ + 0x91004210, /* add x16, x16,#PLT_GOT+0x10 */ + 0xd61f0220, /* br x17 */ + 0xd503201f, /* nop */ + 0xd503201f, /* nop */ + 0xd503201f, /* nop */ +}; + +template<> +const uint32_t +Output_data_plt_aarch64_standard<32, false>:: + plt_entry[plt_entry_size / 4] = +{ + 0x90000010, /* adrp x16, PLTGOT + n * 4 */ + 0xb9400211, /* ldr w17, [w16, PLTGOT + n * 4] */ + 0x11000210, /* add w16, w16, :lo12:PLTGOT + n * 4 */ + 0xd61f0220, /* br x17. */ +}; + +template<> +const uint32_t +Output_data_plt_aarch64_standard<32, true>:: + plt_entry[plt_entry_size / 4] = +{ + 0x90000010, /* adrp x16, PLTGOT + n * 4 */ + 0xb9400211, /* ldr w17, [w16, PLTGOT + n * 4] */ + 0x11000210, /* add w16, w16, :lo12:PLTGOT + n * 4 */ + 0xd61f0220, /* br x17. */ +}; + +template<> +const uint32_t +Output_data_plt_aarch64_standard<64, false>:: + plt_entry[plt_entry_size / 4] = +{ + 0x90000010, /* adrp x16, PLTGOT + n * 8 */ + 0xf9400211, /* ldr x17, [x16, PLTGOT + n * 8] */ + 0x91000210, /* add x16, x16, :lo12:PLTGOT + n * 8 */ + 0xd61f0220, /* br x17. */ +}; + +template<> +const uint32_t +Output_data_plt_aarch64_standard<64, true>:: + plt_entry[plt_entry_size / 4] = +{ + 0x90000010, /* adrp x16, PLTGOT + n * 8 */ + 0xf9400211, /* ldr x17, [x16, PLTGOT + n * 8] */ + 0x91000210, /* add x16, x16, :lo12:PLTGOT + n * 8 */ + 0xd61f0220, /* br x17. */ +}; + +template<int size, bool big_endian> +void +Output_data_plt_aarch64_standard<size, big_endian>::do_fill_first_plt_entry( + unsigned char* pov, + Address /* got_address */, + Address /* plt_address */) +{ + // PLT0 of the small PLT looks like this in ELF64 - + // stp x16, x30, [sp, #-16]! Save the reloc and lr on stack. + // adrp x16, PLT_GOT + 16 Get the page base of the GOTPLT + // ldr x17, [x16, #:lo12:PLT_GOT+16] Load the address of the + // symbol resolver + // add x16, x16, #:lo12:PLT_GOT+16 Load the lo12 bits of the + // GOTPLT entry for this. + // br x17 + // PLT0 will be slightly different in ELF32 due to different got entry + // size. + memcpy(pov, this->first_plt_entry, this->first_plt_entry_size); + // TODO +} + +// Subsequent entries in the PLT for an executable. + +template<int size, bool big_endian> +void +Output_data_plt_aarch64_standard<size, big_endian>::do_fill_plt_entry( + unsigned char* pov, + Address /* got_address*/, + Address /* plt_address */, + unsigned int /* got_offset */, + unsigned int /* plt_offset */) +{ + memcpy(pov, this->plt_entry, this->plt_entry_size); + //TODO +} + +// Write out the PLT. This uses the hand-coded instructions above, +// and adjusts them as needed. This is specified by the AMD64 ABI. + +template<int size, bool big_endian> +void +Output_data_plt_aarch64<size, big_endian>::do_write(Output_file* of) +{ + const off_t offset = this->offset(); + const section_size_type oview_size = + convert_to_section_size_type(this->data_size()); + unsigned char* const oview = of->get_output_view(offset, oview_size); + + const off_t got_file_offset = this->got_plt_->offset(); + const section_size_type got_size = + convert_to_section_size_type(this->got_plt_->data_size()); + unsigned char* const got_view = of->get_output_view(got_file_offset, + got_size); + + unsigned char* pov = oview; + + // The base address of the .plt section. + typename elfcpp::Elf_types<size>::Elf_Addr plt_address = this->address(); + // The base address of the .got section. + typename elfcpp::Elf_types<size>::Elf_Addr got_base = this->got_->address(); + // The base address of the PLT portion of the .got section. + typename elfcpp::Elf_types<size>::Elf_Addr got_address + = this->got_plt_->address(); + + this->fill_first_plt_entry(pov, got_address, plt_address); + pov += this->first_plt_entry_offset(); + + // The first three entries in .got.plt are reserved. + unsigned char* got_pov = got_view; + memset(got_pov, 0, size / 8 * AARCH64_GOTPLT_RESERVE_COUNT); + got_pov += (size / 8) * AARCH64_GOTPLT_RESERVE_COUNT; + + unsigned int plt_offset = this->first_plt_entry_offset(); + unsigned int got_offset = (size / 8) * AARCH64_GOTPLT_RESERVE_COUNT; + const unsigned int count = this->count_; + for (unsigned int plt_index = 0; + plt_index < count; + ++plt_index, + pov += this->get_plt_entry_size(), + got_pov += size / 8, + plt_offset += this->get_plt_entry_size(), + got_offset += size / 8) + { + // Set and adjust the PLT entry itself. + this->fill_plt_entry(pov, got_address, plt_address, + got_offset, plt_offset); + + // Set the entry in the GOT. + elfcpp::Swap<size, big_endian>::writeval(got_pov, + plt_address + plt_offset); + } + + gold_assert(static_cast<section_size_type>(pov - oview) == oview_size); + gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size); + + of->write_output_view(offset, oview_size, oview); + of->write_output_view(got_file_offset, got_size, got_view); +} + +// Return the number of entries in the PLT. + +template<int size, bool big_endian> +unsigned int +Target_aarch64<size, big_endian>::plt_entry_count() const +{ + if (this->plt_ == NULL) + return 0; + return this->plt_->entry_count(); +} + +// Return the offset of the first non-reserved PLT entry. + +template<int size, bool big_endian> +unsigned int +Target_aarch64<size, big_endian>::first_plt_entry_offset() const +{ + return this->plt_->first_plt_entry_offset(); +} + +// Return the size of each PLT entry. + +template<int size, bool big_endian> +unsigned int +Target_aarch64<size, big_endian>::plt_entry_size() const +{ + return this->plt_->get_plt_entry_size(); +} + +// Optimize the TLS relocation type based on what we know about the +// symbol. IS_FINAL is true if the final address of this symbol is +// known at link time. + +template<int size, bool big_endian> +tls::Tls_optimization +Target_aarch64<size, big_endian>::optimize_tls_reloc(bool /* is_final */, + int /* r_type */) +{ + //TODO + return tls::TLSOPT_NONE; +} + +// Get the Reference_flags for a particular relocation. +template<int size, bool big_endian> +int +Target_aarch64<size, big_endian>::Scan::get_reference_flags(unsigned int r_type) +{ + switch (r_type) + { + case elfcpp::R_AARCH64_NONE: + // No symbol reference. + return 0; + //TODO + default: + // Not expected. We will give an error later. + return 0; + } +} + +// Returns true if this relocation type could be that of a function pointer. + +template<int size, bool big_endian> +inline bool +Target_aarch64<size, big_endian>::Scan::possible_function_pointer_reloc( + unsigned int r_type) +{ + switch (r_type) + { + case elfcpp::R_AARCH64_ABS64: + //TODO + { + return true; + } + } + return false; +} + +// For safe ICF, scan a relocation for a local symbol to check if it +// corresponds to a function pointer being taken. In that case mark +// the function whose pointer was taken as not foldable. + +template<int size, bool big_endian> +inline bool +Target_aarch64<size, big_endian>::Scan::local_reloc_may_be_function_pointer( + Symbol_table* , + Layout* , + Target_aarch64<size, big_endian>* , + Sized_relobj_file<size, big_endian>* , + unsigned int , + Output_section* , + const elfcpp::Rela<size, big_endian>& , + unsigned int r_type, + const elfcpp::Sym<size, big_endian>&) +{ + // When building a shared library, do not fold any local symbols as it is + // not possible to distinguish pointer taken versus a call by looking at + // the relocation types. + return (parameters->options().shared() + || possible_function_pointer_reloc(r_type)); +} + +// For safe ICF, scan a relocation for a global symbol to check if it +// corresponds to a function pointer being taken. In that case mark +// the function whose pointer was taken as not foldable. + +template<int size, bool big_endian> +inline bool +Target_aarch64<size, big_endian>::Scan::global_reloc_may_be_function_pointer( + Symbol_table* , + Layout* , + Target_aarch64<size, big_endian>* , + Sized_relobj_file<size, big_endian>* , + unsigned int , + Output_section* , + const elfcpp::Rela<size, big_endian>& , + unsigned int r_type, + Symbol* gsym) +{ + // When building a shared library, do not fold symbols whose visibility + // is hidden, internal or protected. + return ((parameters->options().shared() + && (gsym->visibility() == elfcpp::STV_INTERNAL + || gsym->visibility() == elfcpp::STV_PROTECTED + || gsym->visibility() == elfcpp::STV_HIDDEN)) + || possible_function_pointer_reloc(r_type)); +} + +// Report an unsupported relocation against a local symbol. + +template<int size, bool big_endian> +void +Target_aarch64<size, big_endian>::Scan::unsupported_reloc_local( + Sized_relobj_file<size, big_endian>* object, + unsigned int r_type) +{ + gold_error(_("%s: unsupported reloc %u against local symbol"), + object->name().c_str(), r_type); +} + +// We are about to emit a dynamic relocation of type R_TYPE. If the +// dynamic linker does not support it, issue an error. + +template<int size, bool big_endian> +void +Target_aarch64<size, big_endian>::Scan::check_non_pic(Relobj* object, + unsigned int r_type) +{ + gold_assert(r_type != elfcpp::R_AARCH64_NONE); + + switch (r_type) + { + // These are the relocation types supported by glibc for AARCH64. + case elfcpp::R_AARCH64_NONE: + case elfcpp::R_AARCH64_COPY: + case elfcpp::R_AARCH64_GLOB_DAT: + case elfcpp::R_AARCH64_JUMP_SLOT: + case elfcpp::R_AARCH64_RELATIVE: + case elfcpp::R_AARCH64_TLS_DTPREL64: + case elfcpp::R_AARCH64_TLS_DTPMOD64: + case elfcpp::R_AARCH64_TLS_TPREL64: + case elfcpp::R_AARCH64_TLSDESC: + case elfcpp::R_AARCH64_IRELATIVE: + case elfcpp::R_AARCH64_ABS32: + case elfcpp::R_AARCH64_ABS64: + return; + + default: + break; + } + + // This prevents us from issuing more than one error per reloc + // section. But we can still wind up issuing more than one + // error per object file. + if (this->issued_non_pic_error_) + return; + gold_assert(parameters->options().output_is_position_independent()); + object->error(_("requires unsupported dynamic reloc; " + "recompile with -fPIC")); + this->issued_non_pic_error_ = true; + return; +} + +// Scan a relocation for a local symbol. + +template<int size, bool big_endian> +inline void +Target_aarch64<size, big_endian>::Scan::local( + Symbol_table* /* symtab */, + Layout* /* layout */, + Target_aarch64<size, big_endian>* /* target */, + Sized_relobj_file<size, big_endian>* /* object */, + unsigned int /* data_shndx */, + Output_section* /* output_section */, + const elfcpp::Rela<size, big_endian>& /* reloc */, + unsigned int r_type, + const elfcpp::Sym<size, big_endian>& /* lsym */, + bool is_discarded) +{ + if (is_discarded) + return; + + switch (r_type) + { + case elfcpp::R_AARCH64_NONE: + break; + + //TODO + } +} + + +// Report an unsupported relocation against a global symbol. + +template<int size, bool big_endian> +void +Target_aarch64<size, big_endian>::Scan::unsupported_reloc_global( + Sized_relobj_file<size, big_endian>* object, + unsigned int r_type, + Symbol* gsym) +{ + gold_error(_("%s: unsupported reloc %u against global symbol %s"), + object->name().c_str(), r_type, gsym->demangled_name().c_str()); +} + +template<int size, bool big_endian> +inline void +Target_aarch64<size, big_endian>::Scan::global( + Symbol_table* /* symtab */, + Layout* /* layout */, + Target_aarch64<size, big_endian>* /* target */, + Sized_relobj_file<size, big_endian>* /* object */, + unsigned int /* data_shndx */, + Output_section* /* output_section */, + const elfcpp::Rela<size, big_endian>& /* reloc */, + unsigned int /* r_type */, + Symbol* /* gsym */) +{ + //TODO + return; +} + +template<int size, bool big_endian> +void +Target_aarch64<size, big_endian>::gc_process_relocs( + Symbol_table* symtab, + Layout* layout, + Sized_relobj_file<size, big_endian>* object, + unsigned int data_shndx, + unsigned int sh_type, + const unsigned char* prelocs, + size_t reloc_count, + Output_section* output_section, + bool needs_special_offset_handling, + size_t local_symbol_count, + const unsigned char* plocal_symbols) +{ + if (sh_type == elfcpp::SHT_REL) + { + return; + } + + gold::gc_process_relocs<size, big_endian, + Target_aarch64<size, big_endian>, + elfcpp::SHT_RELA, + typename Target_aarch64<size, big_endian>::Scan, + typename Target_aarch64<size, big_endian>::Relocatable_size_for_reloc>( + symtab, + layout, + this, + object, + data_shndx, + prelocs, + reloc_count, + output_section, + needs_special_offset_handling, + local_symbol_count, + plocal_symbols); +} + +// Scan relocations for a section. + +template<int size, bool big_endian> +void +Target_aarch64<size, big_endian>::scan_relocs( + Symbol_table* symtab, + Layout* layout, + Sized_relobj_file<size, big_endian>* object, + unsigned int data_shndx, + unsigned int sh_type, + const unsigned char* prelocs, + size_t reloc_count, + Output_section* output_section, + bool needs_special_offset_handling, + size_t local_symbol_count, + const unsigned char* plocal_symbols) +{ + if (sh_type == elfcpp::SHT_REL) + { + gold_error(_("%s: unsupported REL reloc section"), + object->name().c_str()); + return; + } + + gold::scan_relocs<size, big_endian, Target_aarch64<size, big_endian>, + elfcpp::SHT_RELA, + typename Target_aarch64<size, big_endian>::Scan>( + symtab, + layout, + this, + object, + data_shndx, + prelocs, + reloc_count, + output_section, + needs_special_offset_handling, + local_symbol_count, + plocal_symbols); +} + +// Finalize the sections. + +template<int size, bool big_endian> +void +Target_aarch64<size, big_endian>::do_finalize_sections( + Layout* /* layout */, + const Input_objects*, + Symbol_table* /* symtab */) +{ + //TODO + return; +} + +// Perform a relocation. + +template<int size, bool big_endian> +inline bool +Target_aarch64<size, big_endian>::Relocate::relocate( + const Relocate_info<size, big_endian>* /* relinfo */, + Target_aarch64<size, big_endian>* /* target */, + Output_section* , + size_t /* relnum */, + const elfcpp::Rela<size, big_endian>& /* rela */, + unsigned int /* r_type */, + const Sized_symbol<size>* /* gsym */, + const Symbol_value<size>* /* psymval */, + unsigned char* /* view */, + typename elfcpp::Elf_types<size>::Elf_Addr /* address */, + section_size_type /* view_size */) +{ + //TODO + return true; +} + +// Relocate section data. + +template<int size, bool big_endian> +void +Target_aarch64<size, big_endian>::relocate_section( + const Relocate_info<size, big_endian>* /* relinfo */, + unsigned int sh_type, + const unsigned char* /* prelocs */, + size_t /* reloc_count */, + Output_section* /* output_section */, + bool /*needs_special_offset_handling */, + unsigned char* /* view */, + typename elfcpp::Elf_types<size>::Elf_Addr /* address */, + section_size_type /* view_size */, + const Reloc_symbol_changes* /* reloc_symbol_changes */) +{ + //TODO + gold_assert(sh_type == elfcpp::SHT_RELA); +} + +// Return the size of a relocation while scanning during a relocatable +// link. + +template<int size, bool big_endian> +unsigned int +Target_aarch64<size, big_endian>::Relocatable_size_for_reloc:: +get_size_for_reloc( + unsigned int , + Relobj* ) +{ + // We will never support SHT_REL relocations. + gold_unreachable(); + return 0; +} + +// Scan the relocs during a relocatable link. + +template<int size, bool big_endian> +void +Target_aarch64<size, big_endian>::scan_relocatable_relocs( + Symbol_table* /* symtab */, + Layout* /* layout */, + Sized_relobj_file<size, big_endian>* /* object */, + unsigned int /* data_shndx */, + unsigned int sh_type, + const unsigned char* /* prelocs */, + size_t /* reloc_count */, + Output_section* /* output_section */, + bool /* needs_special_offset_handling */, + size_t /* local_symbol_count */, + const unsigned char* /* plocal_symbols */, + Relocatable_relocs* /* rr */) +{ + //TODO + gold_assert(sh_type == elfcpp::SHT_RELA); +} + +// Relocate a section during a relocatable link. + +template<int size, bool big_endian> +void +Target_aarch64<size, big_endian>::relocate_relocs( + const Relocate_info<size, big_endian>* /* relinfo */, + unsigned int sh_type, + const unsigned char* /* prelocs */, + size_t /* reloc_count */, + Output_section* /* output_section */, + typename elfcpp::Elf_types<size>::Elf_Off /* offset_in_output_section */, + const Relocatable_relocs* /* rr */, + unsigned char* /* view */, + typename elfcpp::Elf_types<size>::Elf_Addr /* view_address */, + section_size_type /* view_size */, + unsigned char* /* reloc_view */, + section_size_type /* reloc_view_size */) +{ + //TODO + gold_assert(sh_type == elfcpp::SHT_RELA); +} + + +// The selector for aarch64 object files. + +template<int size, bool big_endian> +class Target_selector_aarch64 : public Target_selector +{ + public: + Target_selector_aarch64() + : Target_selector(elfcpp::EM_AARCH64, size, big_endian, + (size == 64 + ? (big_endian ? "elf64-bigaarch64" + : "elf64-littleaarch64") + : (big_endian ? "elf32-bigaarch64" + : "elf32-littleaarch64")), + (size == 64 + ? (big_endian ? "aarch64_elf64_be_vec" + : "aarch64_elf64_le_vec") + : (big_endian ? "aarch64_elf32_be_vec" + : "aarch64_elf32_le_vec"))) + { } + + virtual Target* + do_instantiate_target() + { return new Target_aarch64<size, big_endian>(); } +}; + +Target_selector_aarch64<32, true> target_selector_aarch64elf32b; +Target_selector_aarch64<32, false> target_selector_aarch64elf32; +Target_selector_aarch64<64, true> target_selector_aarch64elfb; +Target_selector_aarch64<64, false> target_selector_aarch64elf; + + +} // End anonymous namespace. |