// aarch64.cc -- aarch64 target support for gold. // Copyright (C) 2014 Free Software Foundation, Inc. // Written by Jing Yu and Han Shen . // 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 #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" #include "aarch64-reloc-property.h" // The first three .got.plt entries are reserved. const int32_t AARCH64_GOTPLT_RESERVE_COUNT = 3; namespace { using namespace gold; template class Output_data_plt_aarch64; template class Output_data_plt_aarch64_standard; template class Target_aarch64; template class AArch64_relocate_functions; // Output_data_got_aarch64 class. template class Output_data_got_aarch64 : public Output_data_got { public: typedef typename elfcpp::Elf_types::Elf_Addr Valtype; Output_data_got_aarch64(Symbol_table* symtab, Layout* layout) : Output_data_got(), symbol_table_(symtab), 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::do_write(of); } private: // Symbol table of the output object. Symbol_table* symbol_table_; // A pointer to the Layout class, so that we can find the .dynamic // section when we write out the GOT section. Layout* layout_; }; AArch64_reloc_property_table* aarch64_reloc_property_table = NULL; // The aarch64 target class. // See the ABI at // http://infocenter.arm.com/help/topic/com.arm.doc.ihi0056b/IHI0056B_aaelf64.pdf template class Target_aarch64 : public Sized_target { public: typedef Output_data_reloc Reloc_section; typedef typename elfcpp::Elf_types::Elf_Addr Address; Target_aarch64(const Target::Target_info* info = &aarch64_info) : Sized_target(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* 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* 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*, 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::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* 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*, unsigned int sh_type, const unsigned char* prelocs, size_t reloc_count, Output_section* output_section, typename elfcpp::Elf_types::Elf_Off offset_in_output_section, const Relocatable_relocs*, unsigned char* view, typename elfcpp::Elf_types::Elf_Addr view_address, section_size_type view_size, unsigned char* reloc_view, section_size_type reloc_view_size); // Return the PLT section. uint64_t do_plt_address_for_global(const Symbol* gsym) const { return this->plt_section()->address_for_global(gsym); } uint64_t do_plt_address_for_local(const Relobj* relobj, unsigned int symndx) const { return this->plt_section()->address_for_local(relobj, symndx); } // 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; protected: void do_select_as_default_target() { gold_assert(aarch64_reloc_property_table == NULL); aarch64_reloc_property_table = new AArch64_reloc_property_table(); } virtual Output_data_plt_aarch64* do_make_data_plt(Layout* layout, Output_data_space* got_plt) { return new Output_data_plt_aarch64_standard(layout, got_plt); } Output_data_plt_aarch64* make_data_plt(Layout* layout, Output_data_space* got_plt) { return this->do_make_data_plt(layout, got_plt); } private: // The class which scans relocations. class Scan { public: Scan() : issued_non_pic_error_(false) { } inline void local(Symbol_table* symtab, Layout* layout, Target_aarch64* target, Sized_relobj_file* object, unsigned int data_shndx, Output_section* output_section, const elfcpp::Rela& reloc, unsigned int r_type, const elfcpp::Sym& lsym, bool is_discarded); inline void global(Symbol_table* symtab, Layout* layout, Target_aarch64* target, Sized_relobj_file* object, unsigned int data_shndx, Output_section* output_section, const elfcpp::Rela& reloc, unsigned int r_type, Symbol* gsym); inline bool local_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_aarch64* , Sized_relobj_file* , unsigned int , Output_section* , const elfcpp::Rela& , unsigned int r_type, const elfcpp::Sym&); inline bool global_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_aarch64* , Sized_relobj_file* , unsigned int , Output_section* , const elfcpp::Rela& , unsigned int r_type, Symbol* gsym); private: static void unsupported_reloc_local(Sized_relobj_file*, unsigned int r_type); static void unsupported_reloc_global(Sized_relobj_file*, 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*, Target_aarch64*, Output_section*, size_t relnum, const elfcpp::Rela&, unsigned int r_type, const Sized_symbol*, const Symbol_value*, unsigned char*, typename elfcpp::Elf_types::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* 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* 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* object, unsigned int shndx, Output_section* output_section, Symbol* sym, const elfcpp::Rela& reloc) { this->copy_relocs_.copy_reloc(symtab, layout, symtab->get_sized_symbol(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* got_; // The PLT section. Output_data_plt_aarch64* 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 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 Output_data_got_aarch64* Target_aarch64::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(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 typename Target_aarch64::Reloc_section* Target_aarch64::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 class Output_data_plt_aarch64 : public Output_section_data { public: typedef Output_data_reloc Reloc_section; typedef typename elfcpp::Elf_types::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 whether we created a section for IRELATIVE relocations. bool has_irelative_section() const { return this->irelative_rel_ != NULL; } // 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(); } // Return the PLT address to use for a global symbol. uint64_t address_for_global(const Symbol*); // Return the PLT address to use for a local symbol. uint64_t address_for_local(const Relobj*, unsigned int symndx); 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 IRELATIVE relocs, if necessary. These must follow the // regular PLT relocations. Reloc_section* irelative_rel_; // The .got section. Output_data_got_aarch64* got_; // The .got.plt section. Output_data_space* got_plt_; // The number of PLT entries. unsigned int count_; }; // Initialize the PLT section. template void Output_data_plt_aarch64::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 void Output_data_plt_aarch64::do_adjust_output_section( Output_section* os) { os->set_entsize(this->get_plt_entry_size()); } // Add an entry to the PLT. template void Output_data_plt_aarch64::add_entry(Symbol* gsym) { gold_assert(!gsym->has_plt_offset()); gsym->set_plt_offset((this->count_) * this->get_plt_entry_size() + this->first_plt_entry_offset()); ++this->count_; section_offset_type got_offset = this->got_plt_->current_data_size(); // Every PLT entry needs a GOT entry which points back to the PLT // entry (this will be changed by the dynamic linker, normally // lazily when the function is called). this->got_plt_->set_current_data_size(got_offset + size / 8); // Every PLT entry needs a reloc. gsym->set_needs_dynsym_entry(); this->rel_->add_global(gsym, elfcpp::R_AARCH64_JUMP_SLOT, this->got_plt_, got_offset, 0); // Note that we don't need to save the symbol. The contents of the // PLT are independent of which symbols are used. The symbols only // appear in the relocations. } // Return the PLT address to use for a global symbol. template uint64_t Output_data_plt_aarch64::address_for_global( const Symbol* gsym) { uint64_t offset = 0; if (gsym->type() == elfcpp::STT_GNU_IFUNC && gsym->can_use_relative_reloc(false)) offset = (this->first_plt_entry_offset() + this->count_ * this->get_plt_entry_size()); return this->address() + offset + gsym->plt_offset(); } // Return the PLT address to use for a local symbol. These are always // IRELATIVE relocs. template uint64_t Output_data_plt_aarch64::address_for_local( const Relobj* object, unsigned int r_sym) { return (this->address() + this->first_plt_entry_offset() + this->count_ * this->get_plt_entry_size() + object->local_plt_offset(r_sym)); } // Set the final size. template void Output_data_plt_aarch64::set_final_data_size() { this->set_data_size(this->first_plt_entry_offset() + this->count_ * this->get_plt_entry_size()); } template class Output_data_plt_aarch64_standard : public Output_data_plt_aarch64 { public: typedef typename elfcpp::Elf_types::Elf_Addr Address; Output_data_plt_aarch64_standard(Layout* layout, Output_data_space* got_plt) : Output_data_plt_aarch64(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 void Output_data_plt_aarch64_standard::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); Address gotplt_2nd_ent = got_address + (size / 8) * 2; // Fill in the top 21 bits for this: ADRP x16, PLT_GOT + 8 * 2. // ADRP: (PG(S+A)-PG(P)) >> 12) & 0x1fffff. // FIXME: This only works for 64bit AArch64_relocate_functions::adrp(pov + 4, gotplt_2nd_ent, plt_address + 4); // Fill in R_AARCH64_LDST8_LO12 elfcpp::Swap<32, big_endian>::writeval( pov + 8, ((this->first_plt_entry[2] & 0xffc003ff) | ((gotplt_2nd_ent & 0xff8) << 7))); // Fill in R_AARCH64_ADD_ABS_LO12 elfcpp::Swap<32, big_endian>::writeval( pov + 12, ((this->first_plt_entry[3] & 0xffc003ff) | ((gotplt_2nd_ent & 0xfff) << 10))); } // Subsequent entries in the PLT for an executable. // FIXME: This only works for 64bit template void Output_data_plt_aarch64_standard::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); Address gotplt_entry_address = got_address + got_offset; Address plt_entry_address = plt_address + plt_offset; // Fill in R_AARCH64_PCREL_ADR_HI21 AArch64_relocate_functions::adrp( pov, gotplt_entry_address, plt_entry_address); // Fill in R_AARCH64_LDST64_ABS_LO12 elfcpp::Swap<32, big_endian>::writeval( pov + 4, ((this->plt_entry[1] & 0xffc003ff) | ((gotplt_entry_address & 0xff8) << 7))); // Fill in R_AARCH64_ADD_ABS_LO12 elfcpp::Swap<32, big_endian>::writeval( pov + 8, ((this->plt_entry[2] & 0xffc003ff) | ((gotplt_entry_address & 0xfff) <<10))); } // Write out the PLT. This uses the hand-coded instructions above, // and adjusts them as needed. This is specified by the AMD64 ABI. template void Output_data_plt_aarch64::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::Elf_Addr plt_address = this->address(); // The base address of the PLT portion of the .got section. typename elfcpp::Elf_types::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, which points to plt0. elfcpp::Swap::writeval(got_pov, plt_address); } gold_assert(static_cast(pov - oview) == oview_size); gold_assert(static_cast(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); } // Telling how to update the immediate field of an instruction. struct AArch64_howto { // The immediate field mask. elfcpp::Elf_Xword dst_mask; // The offset to apply relocation immediate int doffset; // The second part offset, if the immediate field has two parts. // -1 if the immediate field has only one part. int doffset2; }; static const AArch64_howto aarch64_howto[AArch64_reloc_property::INST_NUM] = { {0, -1, -1}, // DATA {0x1fffe0, 5, -1}, // MOVW [20:5]-imm16 {0xffffe0, 5, -1}, // LD [23:5]-imm19 {0x60ffffe0, 29, 5}, // ADR [30:29]-immlo [23:5]-immhi {0x60ffffe0, 29, 5}, // ADRP [30:29]-immlo [23:5]-immhi {0x3ffc00, 10, -1}, // ADD [21:10]-imm12 {0x3ffc00, 10, -1}, // LDST [21:10]-imm12 {0x7ffe0, 5, -1}, // TBZNZ [18:5]-imm14 {0xffffe0, 5, -1}, // CONDB [23:5]-imm19 {0x3ffffff, 0, -1}, // B [25:0]-imm26 {0x3ffffff, 0, -1}, // CALL [25:0]-imm26 }; // AArch64 relocate function class template class AArch64_relocate_functions { public: typedef enum { STATUS_OKAY, // No error during relocation. STATUS_OVERFLOW, // Relocation overflow. STATUS_BAD_RELOC, // Relocation cannot be applied. } Status; private: typedef AArch64_relocate_functions This; typedef typename elfcpp::Elf_types::Elf_Addr Address; // Return the page address of the address. // Page(address) = address & ~0xFFF static inline typename elfcpp::Swap::Valtype Page(Address address) { return (address & (~static_cast
(0xFFF))); } // Update instruction (pointed by view) with selected bits (immed). // val = (val & ~dst_mask) | (immed << doffset) template static inline void update_view(unsigned char* view, typename elfcpp::Swap::Valtype immed, elfcpp::Elf_Xword doffset, elfcpp::Elf_Xword dst_mask) { typedef typename elfcpp::Swap::Valtype Valtype; Valtype* wv = reinterpret_cast(view); Valtype val = elfcpp::Swap::readval(wv); // Clear immediate fields. val &= ~dst_mask; elfcpp::Swap::writeval(wv, static_cast(val | (immed << doffset))); } // Update two parts of an instruction (pointed by view) with selected // bits (immed1 and immed2). // val = (val & ~dst_mask) | (immed1 << doffset1) | (immed2 << doffset2) template static inline void update_view_two_parts( unsigned char* view, typename elfcpp::Swap::Valtype immed1, typename elfcpp::Swap::Valtype immed2, elfcpp::Elf_Xword doffset1, elfcpp::Elf_Xword doffset2, elfcpp::Elf_Xword dst_mask) { typedef typename elfcpp::Swap::Valtype Valtype; Valtype* wv = reinterpret_cast(view); Valtype val = elfcpp::Swap::readval(wv); val &= ~dst_mask; elfcpp::Swap::writeval(wv, static_cast(val | (immed1 << doffset1) | (immed2 << doffset2))); } // Update adr or adrp instruction with [32:12] of X. // In adr and adrp: [30:29] immlo [23:5] immhi static inline void update_adr(unsigned char* view, typename elfcpp::Swap::Valtype x, const AArch64_reloc_property* /* reloc_property */) { elfcpp::Elf_Xword dst_mask = (0x3 << 29) | (0x7ffff << 5); typename elfcpp::Swap<32, big_endian>::Valtype immed = (x >> 12) & 0x1fffff; This::template update_view_two_parts<32>( view, immed & 0x3, (immed & 0x1ffffc) >> 2, 29, 5, dst_mask); } public: // Do a simple rela relocation at unaligned addresses. template static inline typename This::Status rela_ua(unsigned char* view, const Sized_relobj_file* object, const Symbol_value* psymval, typename elfcpp::Swap::Valtype addend, const AArch64_reloc_property* reloc_property) { typedef typename elfcpp::Swap_unaligned::Valtype Valtype; typename elfcpp::Elf_types::Elf_Addr x = psymval->value(object, addend); elfcpp::Swap_unaligned::writeval(view, static_cast(x)); return (reloc_property->checkup_x_value(x) ? This::STATUS_OKAY : This::STATUS_OVERFLOW); } // Do a simple pc-relative relocation at unaligned addresses. template static inline typename This::Status pcrela_ua(unsigned char* view, const Sized_relobj_file* object, const Symbol_value* psymval, typename elfcpp::Swap::Valtype addend, Address address, const AArch64_reloc_property* reloc_property) { typedef typename elfcpp::Swap_unaligned::Valtype Valtype; Address x = psymval->value(object, addend) - address; elfcpp::Swap_unaligned::writeval(view, static_cast(x)); return (reloc_property->checkup_x_value(x) ? This::STATUS_OKAY : This::STATUS_OVERFLOW); } // Do a simple rela relocation at aligned addresses. template static inline typename This::Status rela( unsigned char* view, const Sized_relobj_file* object, const Symbol_value* psymval, typename elfcpp::Swap::Valtype addend, const AArch64_reloc_property* reloc_property) { typedef typename elfcpp::Swap::Valtype Valtype; Valtype* wv = reinterpret_cast(view); Address x = psymval->value(object, addend); elfcpp::Swap::writeval(wv, static_cast(x)); return (reloc_property->checkup_x_value(x) ? This::STATUS_OKAY : This::STATUS_OVERFLOW); } // Do relocate. Update selected bits in text. // new_val = (val & ~dst_mask) | (immed << doffset) template static inline typename This::Status rela_general(unsigned char* view, const Sized_relobj_file* object, const Symbol_value* psymval, typename elfcpp::Swap::Valtype addend, const AArch64_reloc_property* reloc_property) { // Calculate relocation. Address x = psymval->value(object, addend); // Select bits from X. Address immed = reloc_property->select_x_value(x); // Update view. const AArch64_reloc_property::Reloc_inst inst = reloc_property->reloc_inst(); // If it is a data relocation or instruction has 2 parts of immediate // fields, you should not call rela_general. gold_assert(aarch64_howto[inst].doffset2 == -1 && aarch64_howto[inst].doffset != -1); This::template update_view(view, immed, aarch64_howto[inst].doffset, aarch64_howto[inst].dst_mask); // Do check overflow or alignment if needed. return (reloc_property->checkup_x_value(x) ? This::STATUS_OKAY : This::STATUS_OVERFLOW); } // Do relocate. Update selected bits in text. // new val = (val & ~dst_mask) | (immed << doffset) template static inline typename This::Status rela_general( unsigned char* view, typename elfcpp::Swap::Valtype s, typename elfcpp::Swap::Valtype addend, const AArch64_reloc_property* reloc_property) { // Calculate relocation. Address x = s + addend; // Select bits from X. Address immed = reloc_property->select_x_value(x); // Update view. const AArch64_reloc_property::Reloc_inst inst = reloc_property->reloc_inst(); // If it is a data relocation or instruction has 2 parts of immediate // fields, you should not call rela_general. gold_assert(aarch64_howto[inst].doffset2 == -1 && aarch64_howto[inst].doffset != -1); This::template update_view(view, immed, aarch64_howto[inst].doffset, aarch64_howto[inst].dst_mask); // Do check overflow or alignment if needed. return (reloc_property->checkup_x_value(x) ? This::STATUS_OKAY : This::STATUS_OVERFLOW); } // Do address relative relocate. Update selected bits in text. // new val = (val & ~dst_mask) | (immed << doffset) template static inline typename This::Status pcrela_general( unsigned char* view, const Sized_relobj_file* object, const Symbol_value* psymval, typename elfcpp::Swap::Valtype addend, Address address, const AArch64_reloc_property* reloc_property) { // Calculate relocation. Address x = psymval->value(object, addend) - address; // Select bits from X. Address immed = reloc_property->select_x_value(x); // Update view. const AArch64_reloc_property::Reloc_inst inst = reloc_property->reloc_inst(); // If it is a data relocation or instruction has 2 parts of immediate // fields, you should not call pcrela_general. gold_assert(aarch64_howto[inst].doffset2 == -1 && aarch64_howto[inst].doffset != -1); This::template update_view(view, immed, aarch64_howto[inst].doffset, aarch64_howto[inst].dst_mask); // Do check overflow or alignment if needed. return (reloc_property->checkup_x_value(x) ? This::STATUS_OKAY : This::STATUS_OVERFLOW); } // Calculate PG(S+A) - PG(address), update adrp instruction. // R_AARCH64_ADR_PREL_PG_HI21 static inline typename This::Status adrp( unsigned char* view, Address sa, Address address) { typename elfcpp::Swap::Valtype x = This::Page(sa) - This::Page(address); update_adr(view, x, NULL); return (size == 64 && Bits<32>::has_overflow(x) ? This::STATUS_OVERFLOW : This::STATUS_OKAY); } // Calculate PG(S+A) - PG(address), update adrp instruction. // R_AARCH64_ADR_PREL_PG_HI21 static inline typename This::Status adrp(unsigned char* view, const Sized_relobj_file* object, const Symbol_value* psymval, Address addend, Address address, const AArch64_reloc_property* reloc_property) { Address sa = psymval->value(object, addend); typename elfcpp::Swap::Valtype x = This::Page(sa) - This::Page(address); update_adr(view, x, reloc_property); return (reloc_property->checkup_x_value(x) ? This::STATUS_OKAY : This::STATUS_OVERFLOW); } }; // Return the number of entries in the PLT. template unsigned int Target_aarch64::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 unsigned int Target_aarch64::first_plt_entry_offset() const { return this->plt_->first_plt_entry_offset(); } // Return the size of each PLT entry. template unsigned int Target_aarch64::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 tls::Tls_optimization Target_aarch64::optimize_tls_reloc(bool /* is_final */, int /* r_type */) { //TODO return tls::TLSOPT_NONE; } // Returns true if this relocation type could be that of a function pointer. template inline bool Target_aarch64::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 inline bool Target_aarch64::Scan::local_reloc_may_be_function_pointer( Symbol_table* , Layout* , Target_aarch64* , Sized_relobj_file* , unsigned int , Output_section* , const elfcpp::Rela& , unsigned int r_type, const elfcpp::Sym&) { // 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 inline bool Target_aarch64::Scan::global_reloc_may_be_function_pointer( Symbol_table* , Layout* , Target_aarch64* , Sized_relobj_file* , unsigned int , Output_section* , const elfcpp::Rela& , 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 void Target_aarch64::Scan::unsupported_reloc_local( Sized_relobj_file* 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 void Target_aarch64::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 inline void Target_aarch64::Scan::local( Symbol_table* /* symtab */, Layout* /* layout */, Target_aarch64* /* target */, Sized_relobj_file* object, unsigned int /* data_shndx */, Output_section* /* output_section */, const elfcpp::Rela& /* reloc */, unsigned int r_type, const elfcpp::Sym& /* lsym */, bool is_discarded) { if (is_discarded) return; switch (r_type) { case elfcpp::R_AARCH64_ABS64: case elfcpp::R_AARCH64_ABS32: case elfcpp::R_AARCH64_ABS16: // If building a shared library or pie, we need to mark this as a dynmic // reloction, so that the dynamic loader can relocate it. // Not supported yet. if (parameters->options().output_is_position_independent()) { gold_error(_("%s: unsupported ABS64 relocation type for pie or " "shared library.\n"), object->name().c_str()); } break; // Relocations to generate 19, 21 and 33-bit PC-relative address case elfcpp::R_AARCH64_ADR_PREL_PG_HI21: // 275 case elfcpp::R_AARCH64_LDST8_ABS_LO12_NC: // 278 case elfcpp::R_AARCH64_LDST64_ABS_LO12_NC: // 286 case elfcpp::R_AARCH64_ADD_ABS_LO12_NC: // 277 break; // Control flow, pc-relative. We don't need to do anything for a relative // addressing relocation against a local symbol if it does not reference // the GOT. case elfcpp::R_AARCH64_CALL26: // 283 break; default: unsupported_reloc_local(object, r_type); } } // Report an unsupported relocation against a global symbol. template void Target_aarch64::Scan::unsupported_reloc_global( Sized_relobj_file* 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 inline void Target_aarch64::Scan::global( Symbol_table* symtab, Layout* layout, Target_aarch64* target, Sized_relobj_file* /* object */, unsigned int /* data_shndx */, Output_section* /* output_section */, const elfcpp::Rela& /* reloc */, unsigned int r_type, Symbol* gsym) { switch (r_type) { case elfcpp::R_AARCH64_ABS64: // This is used to fill the GOT absolute address. if (gsym->needs_plt_entry()) { target->make_plt_entry(symtab, layout, gsym); } break; case elfcpp::R_AARCH64_ADR_PREL_PG_HI21: case elfcpp::R_AARCH64_ADR_PREL_PG_HI21_NC: case elfcpp::R_AARCH64_ADD_ABS_LO12_NC: { // Do nothing here. break; } case elfcpp::R_AARCH64_ADR_GOT_PAGE: case elfcpp::R_AARCH64_LD64_GOT_LO12_NC: { // This pair of relocations is used to access a specific GOT entry. // Note a GOT entry is an *address* to a symbol. // The symbol requires a GOT entry Output_data_got_aarch64* got = target->got_section(symtab, layout); if (gsym->final_value_is_known()) { got->add_global(gsym, GOT_TYPE_STANDARD); } else { Reloc_section* rela_dyn = target->rela_dyn_section(layout); if (gsym->is_from_dynobj() || gsym->is_undefined() || gsym->is_preemptible() || (gsym->visibility() == elfcpp::STV_PROTECTED && parameters->options().shared())) got->add_global_with_rel(gsym, GOT_TYPE_STANDARD, rela_dyn, elfcpp::R_AARCH64_GLOB_DAT); else { // Not implemented yet. gold_assert(false); } } break; } case elfcpp::R_AARCH64_JUMP26: case elfcpp::R_AARCH64_CALL26: { if (gsym->final_value_is_known()) break; if (gsym->is_defined() && !gsym->is_from_dynobj() && !gsym->is_preemptible()) break; // Make plt entry for function call. const AArch64_reloc_property* arp = aarch64_reloc_property_table->get_reloc_property(r_type); gold_assert(arp != NULL); target->make_plt_entry(symtab, layout, gsym); break; } default: gold_error(_("%s: unsupported reloc type"), aarch64_reloc_property_table-> reloc_name_in_error_message(r_type).c_str()); } return; } // End of Scan::global // Create the PLT section. template void Target_aarch64::make_plt_section( Symbol_table* symtab, Layout* layout) { if (this->plt_ == NULL) { // Create the GOT section first. this->got_section(symtab, layout); this->plt_ = this->make_data_plt(layout, this->got_plt_); layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS, (elfcpp::SHF_ALLOC | elfcpp::SHF_EXECINSTR), this->plt_, ORDER_PLT, false); // Make the sh_info field of .rela.plt point to .plt. Output_section* rela_plt_os = this->plt_->rela_plt()->output_section(); rela_plt_os->set_info_section(this->plt_->output_section()); } } // Create a PLT entry for a global symbol. template void Target_aarch64::make_plt_entry( Symbol_table* symtab, Layout* layout, Symbol* gsym) { if (gsym->has_plt_offset()) return; if (this->plt_ == NULL) this->make_plt_section(symtab, layout); this->plt_->add_entry(gsym); } template void Target_aarch64::gc_process_relocs( Symbol_table* symtab, Layout* layout, Sized_relobj_file* 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, elfcpp::SHT_RELA, typename Target_aarch64::Scan, typename Target_aarch64::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 void Target_aarch64::scan_relocs( Symbol_table* symtab, Layout* layout, Sized_relobj_file* 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( symtab, layout, this, object, data_shndx, prelocs, reloc_count, output_section, needs_special_offset_handling, local_symbol_count, plocal_symbols); } // Finalize the sections. template void Target_aarch64::do_finalize_sections( Layout* layout, const Input_objects*, Symbol_table* symtab) { const Reloc_section* rel_plt = (this->plt_ == NULL ? NULL : this->plt_->rela_plt()); layout->add_target_dynamic_tags(false, this->got_plt_, rel_plt, this->rela_dyn_, true, false); // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of // the .got.plt section. Symbol* sym = this->global_offset_table_; if (sym != NULL) { uint64_t data_size = this->got_plt_->current_data_size(); symtab->get_sized_symbol(sym)->set_symsize(data_size); // If the .got section is more than 0x8000 bytes, we add // 0x8000 to the value of _GLOBAL_OFFSET_TABLE_, so that 16 // bit relocations have a greater chance of working. if (data_size >= 0x8000) symtab->get_sized_symbol(sym)->set_value( symtab->get_sized_symbol(sym)->value() + 0x8000); } if (parameters->doing_static_link() && (this->plt_ == NULL || !this->plt_->has_irelative_section())) { // If linking statically, make sure that the __rela_iplt symbols // were defined if necessary, even if we didn't create a PLT. static const Define_symbol_in_segment syms[] = { { "__rela_iplt_start", // name elfcpp::PT_LOAD, // segment_type elfcpp::PF_W, // segment_flags_set elfcpp::PF(0), // segment_flags_clear 0, // value 0, // size elfcpp::STT_NOTYPE, // type elfcpp::STB_GLOBAL, // binding elfcpp::STV_HIDDEN, // visibility 0, // nonvis Symbol::SEGMENT_START, // offset_from_base true // only_if_ref }, { "__rela_iplt_end", // name elfcpp::PT_LOAD, // segment_type elfcpp::PF_W, // segment_flags_set elfcpp::PF(0), // segment_flags_clear 0, // value 0, // size elfcpp::STT_NOTYPE, // type elfcpp::STB_GLOBAL, // binding elfcpp::STV_HIDDEN, // visibility 0, // nonvis Symbol::SEGMENT_START, // offset_from_base true // only_if_ref } }; symtab->define_symbols(layout, 2, syms, layout->script_options()->saw_sections_clause()); } return; } // Perform a relocation. template inline bool Target_aarch64::Relocate::relocate( const Relocate_info* relinfo, Target_aarch64* target, Output_section* , size_t relnum, const elfcpp::Rela& rela, unsigned int r_type, const Sized_symbol* gsym, const Symbol_value* psymval, unsigned char* view, typename elfcpp::Elf_types::Elf_Addr address, section_size_type /* view_size */) { if (view == NULL) return true; typedef AArch64_relocate_functions Reloc; const AArch64_reloc_property* reloc_property = aarch64_reloc_property_table->get_reloc_property(r_type); if (reloc_property == NULL) { std::string reloc_name = aarch64_reloc_property_table->reloc_name_in_error_message(r_type); gold_error_at_location(relinfo, relnum, rela.get_r_offset(), _("cannot relocate %s in object file"), reloc_name.c_str()); return true; } const Sized_relobj_file* object = relinfo->object; // Pick the value to use for symbols defined in the PLT. Symbol_value symval; if (gsym != NULL && gsym->use_plt_offset(reloc_property->reference_flags())) { symval.set_output_value(target->plt_address_for_global(gsym)); psymval = &symval; } else if (gsym == NULL && psymval->is_ifunc_symbol()) { unsigned int r_sym = elfcpp::elf_r_sym(rela.get_r_info()); if (object->local_has_plt_offset(r_sym)) { symval.set_output_value(target->plt_address_for_local(object, r_sym)); psymval = &symval; } } const elfcpp::Elf_Xword addend = rela.get_r_addend(); // Get the GOT offset if needed. // For aarch64, the GOT pointer points to the start of the GOT section. bool have_got_offset = false; int got_offset = 0; int got_base = (target->got_ != NULL ? (target->got_->current_data_size() >= 0x8000 ? 0x8000 : 0) : 0); switch (r_type) { case elfcpp::R_AARCH64_MOVW_GOTOFF_G0: case elfcpp::R_AARCH64_MOVW_GOTOFF_G0_NC: case elfcpp::R_AARCH64_MOVW_GOTOFF_G1: case elfcpp::R_AARCH64_MOVW_GOTOFF_G1_NC: case elfcpp::R_AARCH64_MOVW_GOTOFF_G2: case elfcpp::R_AARCH64_MOVW_GOTOFF_G2_NC: case elfcpp::R_AARCH64_MOVW_GOTOFF_G3: case elfcpp::R_AARCH64_GOTREL64: case elfcpp::R_AARCH64_GOTREL32: case elfcpp::R_AARCH64_GOT_LD_PREL19: case elfcpp::R_AARCH64_LD64_GOTOFF_LO15: case elfcpp::R_AARCH64_ADR_GOT_PAGE: case elfcpp::R_AARCH64_LD64_GOT_LO12_NC: case elfcpp::R_AARCH64_LD64_GOTPAGE_LO15: if (gsym != NULL) { gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD)); got_offset = gsym->got_offset(GOT_TYPE_STANDARD) - got_base; } else { unsigned int r_sym = elfcpp::elf_r_sym(rela.get_r_info()); gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD)); got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD) - got_base); } have_got_offset = true; break; default: break; } typename Reloc::Status reloc_status = Reloc::STATUS_OKAY; typename elfcpp::Elf_types::Elf_Addr value; switch (r_type) { case elfcpp::R_AARCH64_NONE: break; case elfcpp::R_AARCH64_ABS64: reloc_status = Reloc::template rela_ua<64>( view, object, psymval, addend, reloc_property); break; case elfcpp::R_AARCH64_ABS32: reloc_status = Reloc::template rela_ua<32>( view, object, psymval, addend, reloc_property); break; case elfcpp::R_AARCH64_ABS16: reloc_status = Reloc::template rela_ua<16>( view, object, psymval, addend, reloc_property); break; case elfcpp::R_AARCH64_PREL64: reloc_status = Reloc::template pcrela_ua<64>( view, object, psymval, addend, address, reloc_property); case elfcpp::R_AARCH64_PREL32: reloc_status = Reloc::template pcrela_ua<32>( view, object, psymval, addend, address, reloc_property); case elfcpp::R_AARCH64_PREL16: reloc_status = Reloc::template pcrela_ua<16>( view, object, psymval, addend, address, reloc_property); case elfcpp::R_AARCH64_ADR_PREL_PG_HI21_NC: case elfcpp::R_AARCH64_ADR_PREL_PG_HI21: reloc_status = Reloc::adrp(view, object, psymval, addend, address, reloc_property); break; case elfcpp::R_AARCH64_LDST8_ABS_LO12_NC: case elfcpp::R_AARCH64_LDST16_ABS_LO12_NC: case elfcpp::R_AARCH64_LDST32_ABS_LO12_NC: case elfcpp::R_AARCH64_LDST64_ABS_LO12_NC: case elfcpp::R_AARCH64_LDST128_ABS_LO12_NC: case elfcpp::R_AARCH64_ADD_ABS_LO12_NC: reloc_status = Reloc::template rela_general<32>( view, object, psymval, addend, reloc_property); break; case elfcpp::R_AARCH64_CALL26: case elfcpp::R_AARCH64_JUMP26: reloc_status = Reloc::template pcrela_general<32>( view, object, psymval, addend, address, reloc_property); break; case elfcpp::R_AARCH64_ADR_GOT_PAGE: gold_assert(have_got_offset); value = target->got_->address() + got_base + got_offset; reloc_status = Reloc::adrp(view, value + addend, address); break; case elfcpp::R_AARCH64_LD64_GOT_LO12_NC: gold_assert(have_got_offset); value = target->got_->address() + got_base + got_offset; reloc_status = Reloc::template rela_general<32>( view, value, addend, reloc_property); break; default: gold_error_at_location(relinfo, relnum, rela.get_r_offset(), _("unsupported reloc aaa %u"), r_type); break; } // Report any errors. switch (reloc_status) { case Reloc::STATUS_OKAY: break; case Reloc::STATUS_OVERFLOW: gold_error_at_location(relinfo, relnum, rela.get_r_offset(), _("relocation overflow in %s"), reloc_property->name().c_str()); break; case Reloc::STATUS_BAD_RELOC: gold_error_at_location( relinfo, relnum, rela.get_r_offset(), _("unexpected opcode while processing relocation %s"), reloc_property->name().c_str()); break; default: gold_unreachable(); } return true; } // Relocate section data. template void Target_aarch64::relocate_section( const Relocate_info* 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::Elf_Addr address, section_size_type view_size, const Reloc_symbol_changes* reloc_symbol_changes) { gold_assert(sh_type == elfcpp::SHT_RELA); typedef typename Target_aarch64::Relocate AArch64_relocate; gold::relocate_section( relinfo, this, prelocs, reloc_count, output_section, needs_special_offset_handling, view, address, view_size, reloc_symbol_changes); } // Return the size of a relocation while scanning during a relocatable // link. template unsigned int Target_aarch64::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 void Target_aarch64::scan_relocatable_relocs( Symbol_table* /* symtab */, Layout* /* layout */, Sized_relobj_file* /* 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 void Target_aarch64::relocate_relocs( const Relocate_info* /* relinfo */, unsigned int sh_type, const unsigned char* /* prelocs */, size_t /* reloc_count */, Output_section* /* output_section */, typename elfcpp::Elf_types::Elf_Off /* offset_in_output_section */, const Relocatable_relocs* /* rr */, unsigned char* /* view */, typename elfcpp::Elf_types::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 class Target_selector_aarch64 : public Target_selector { public: Target_selector_aarch64(); virtual Target* do_instantiate_target() { return new Target_aarch64(); } }; template<> Target_selector_aarch64<32, true>::Target_selector_aarch64() : Target_selector(elfcpp::EM_AARCH64, 32, true, "elf32-bigaarch64", "aarch64_elf32_be_vec") { } template<> Target_selector_aarch64<32, false>::Target_selector_aarch64() : Target_selector(elfcpp::EM_AARCH64, 32, false, "elf32-littleaarch64", "aarch64_elf32_le_vec") { } template<> Target_selector_aarch64<64, true>::Target_selector_aarch64() : Target_selector(elfcpp::EM_AARCH64, 64, true, "elf64-bigaarch64", "aarch64_elf64_be_vec") { } template<> Target_selector_aarch64<64, false>::Target_selector_aarch64() : Target_selector(elfcpp::EM_AARCH64, 64, false, "elf64-littleaarch64", "aarch64_elf64_le_vec") { } 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.