// aarch64.cc -- aarch64 target support for gold. // Copyright (C) 2014-2015 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) { } // Add a static entry for the GOT entry at OFFSET. GSYM is a global // symbol and R_TYPE is the code of a dynamic relocation that needs to be // applied in a static link. void add_static_reloc(unsigned int got_offset, unsigned int r_type, Symbol* gsym) { this->static_relocs_.push_back(Static_reloc(got_offset, r_type, gsym)); } // Add a static reloc for the GOT entry at OFFSET. RELOBJ is an object // defining a local symbol with INDEX. R_TYPE is the code of a dynamic // relocation that needs to be applied in a static link. void add_static_reloc(unsigned int got_offset, unsigned int r_type, Sized_relobj_file* relobj, unsigned int index) { this->static_relocs_.push_back(Static_reloc(got_offset, r_type, relobj, index)); } 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); // Handling static relocs if (this->static_relocs_.empty()) return; typedef typename elfcpp::Elf_types::Elf_Addr AArch64_address; gold_assert(parameters->doing_static_link()); 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); Output_segment* tls_segment = this->layout_->tls_segment(); gold_assert(tls_segment != NULL); AArch64_address aligned_tcb_address = align_address(Target_aarch64::TCB_SIZE, tls_segment->maximum_alignment()); for (size_t i = 0; i < this->static_relocs_.size(); ++i) { Static_reloc& reloc(this->static_relocs_[i]); AArch64_address value; if (!reloc.symbol_is_global()) { Sized_relobj_file* object = reloc.relobj(); const Symbol_value* psymval = reloc.relobj()->local_symbol(reloc.index()); // We are doing static linking. Issue an error and skip this // relocation if the symbol is undefined or in a discarded_section. bool is_ordinary; unsigned int shndx = psymval->input_shndx(&is_ordinary); if ((shndx == elfcpp::SHN_UNDEF) || (is_ordinary && shndx != elfcpp::SHN_UNDEF && !object->is_section_included(shndx) && !this->symbol_table_->is_section_folded(object, shndx))) { gold_error(_("undefined or discarded local symbol %u from " " object %s in GOT"), reloc.index(), reloc.relobj()->name().c_str()); continue; } value = psymval->value(object, 0); } else { const Symbol* gsym = reloc.symbol(); gold_assert(gsym != NULL); if (gsym->is_forwarder()) gsym = this->symbol_table_->resolve_forwards(gsym); // We are doing static linking. Issue an error and skip this // relocation if the symbol is undefined or in a discarded_section // unless it is a weakly_undefined symbol. if ((gsym->is_defined_in_discarded_section() || gsym->is_undefined()) && !gsym->is_weak_undefined()) { gold_error(_("undefined or discarded symbol %s in GOT"), gsym->name()); continue; } if (!gsym->is_weak_undefined()) { const Sized_symbol* sym = static_cast*>(gsym); value = sym->value(); } else value = 0; } unsigned got_offset = reloc.got_offset(); gold_assert(got_offset < oview_size); typedef typename elfcpp::Swap::Valtype Valtype; Valtype* wv = reinterpret_cast(oview + got_offset); Valtype x; switch (reloc.r_type()) { case elfcpp::R_AARCH64_TLS_DTPREL64: x = value; break; case elfcpp::R_AARCH64_TLS_TPREL64: x = value + aligned_tcb_address; break; default: gold_unreachable(); } elfcpp::Swap::writeval(wv, x); } of->write_output_view(offset, oview_size, oview); } 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_; // This class represent dynamic relocations that need to be applied by // gold because we are using TLS relocations in a static link. class Static_reloc { public: Static_reloc(unsigned int got_offset, unsigned int r_type, Symbol* gsym) : got_offset_(got_offset), r_type_(r_type), symbol_is_global_(true) { this->u_.global.symbol = gsym; } Static_reloc(unsigned int got_offset, unsigned int r_type, Sized_relobj_file* relobj, unsigned int index) : got_offset_(got_offset), r_type_(r_type), symbol_is_global_(false) { this->u_.local.relobj = relobj; this->u_.local.index = index; } // Return the GOT offset. unsigned int got_offset() const { return this->got_offset_; } // Relocation type. unsigned int r_type() const { return this->r_type_; } // Whether the symbol is global or not. bool symbol_is_global() const { return this->symbol_is_global_; } // For a relocation against a global symbol, the global symbol. Symbol* symbol() const { gold_assert(this->symbol_is_global_); return this->u_.global.symbol; } // For a relocation against a local symbol, the defining object. Sized_relobj_file* relobj() const { gold_assert(!this->symbol_is_global_); return this->u_.local.relobj; } // For a relocation against a local symbol, the local symbol index. unsigned int index() const { gold_assert(!this->symbol_is_global_); return this->u_.local.index; } private: // GOT offset of the entry to which this relocation is applied. unsigned int got_offset_; // Type of relocation. unsigned int r_type_; // Whether this relocation is against a global symbol. bool symbol_is_global_; // A global or local symbol. union { struct { // For a global symbol, the symbol itself. Symbol* symbol; } global; struct { // For a local symbol, the object defining the symbol. Sized_relobj_file* relobj; // For a local symbol, the symbol index. unsigned int index; } local; } u_; }; // End of inner class Static_reloc std::vector static_relocs_; }; // End of Output_data_got_aarch64 template class AArch64_input_section; template class AArch64_output_section; // Reloc stub class. template class Reloc_stub { public: typedef Reloc_stub This; typedef typename elfcpp::Elf_types::Elf_Addr AArch64_address; // Do not change the value of the enums, they are used to index into // stub_insns array. typedef enum { ST_NONE = 0, // Using adrp/add pair, 4 insns (including alignment) without mem access, // the fastest stub. This has a limited jump distance, which is tested by // aarch64_valid_for_adrp_p. ST_ADRP_BRANCH = 1, // Using ldr-absolute-address/br-register, 4 insns with 1 mem access, // unlimited in jump distance. ST_LONG_BRANCH_ABS = 2, // Using ldr/calculate-pcrel/jump, 8 insns (including alignment) with 1 mem // access, slowest one. Only used in position independent executables. ST_LONG_BRANCH_PCREL = 3, } Stub_type; // Branch range. This is used to calculate the section group size, as well as // determine whether a stub is needed. static const int MAX_BRANCH_OFFSET = ((1 << 25) - 1) << 2; static const int MIN_BRANCH_OFFSET = -((1 << 25) << 2); // Constant used to determine if an offset fits in the adrp instruction // encoding. static const int MAX_ADRP_IMM = (1 << 20) - 1; static const int MIN_ADRP_IMM = -(1 << 20); static const int BYTES_PER_INSN = 4; static const int STUB_ADDR_ALIGN = 4; // Determine whether the offset fits in the jump/branch instruction. static bool aarch64_valid_branch_offset_p(int64_t offset) { return offset >= MIN_BRANCH_OFFSET && offset <= MAX_BRANCH_OFFSET; } // Determine whether the offset fits in the adrp immediate field. static bool aarch64_valid_for_adrp_p(AArch64_address location, AArch64_address dest) { typedef AArch64_relocate_functions Reloc; int64_t adrp_imm = (Reloc::Page(dest) - Reloc::Page(location)) >> 12; return adrp_imm >= MIN_ADRP_IMM && adrp_imm <= MAX_ADRP_IMM; } // Determine the stub type for a certain relocation or ST_NONE, if no stub is // needed. static Stub_type stub_type_for_reloc(unsigned int r_type, AArch64_address address, AArch64_address target); Reloc_stub(Stub_type stub_type) : stub_type_(stub_type), offset_(invalid_offset), destination_address_(invalid_address) { } ~Reloc_stub() { } // Return offset of code stub from beginning of its containing stub table. section_offset_type offset() const { gold_assert(this->offset_ != invalid_offset); return this->offset_; } // Set offset of code stub from beginning of its containing stub table. void set_offset(section_offset_type offset) { this->offset_ = offset; } // Return destination address. AArch64_address destination_address() const { gold_assert(this->destination_address_ != this->invalid_address); return this->destination_address_; } // Set destination address. void set_destination_address(AArch64_address address) { gold_assert(address != this->invalid_address); this->destination_address_ = address; } // Reset the destination address. void reset_destination_address() { this->destination_address_ = this->invalid_address; } // Return the stub type. Stub_type stub_type() const { return stub_type_; } // Return the stub size. uint32_t stub_size() const { return this->stub_insn_number() * BYTES_PER_INSN; } // Return the instruction number of this stub instance. int stub_insn_number() const { return stub_insns_[this->stub_type_][0]; } // Note the first "insn" is the number of total insns in this array. const uint32_t* stub_insns() const { return stub_insns_[this->stub_type_]; } // Write stub to output file. void write(unsigned char* view, section_size_type view_size) { this->do_write(view, view_size); } // The key class used to index the stub instance in the stub table's stub map. class Key { public: Key(Stub_type stub_type, const Symbol* symbol, const Relobj* relobj, unsigned int r_sym, int32_t addend) : stub_type_(stub_type), addend_(addend) { if (symbol != NULL) { this->r_sym_ = Reloc_stub::invalid_index; this->u_.symbol = symbol; } else { gold_assert(relobj != NULL && r_sym != invalid_index); this->r_sym_ = r_sym; this->u_.relobj = relobj; } } ~Key() { } // Return stub type. Stub_type stub_type() const { return this->stub_type_; } // Return the local symbol index or invalid_index. unsigned int r_sym() const { return this->r_sym_; } // Return the symbol if there is one. const Symbol* symbol() const { return this->r_sym_ == invalid_index ? this->u_.symbol : NULL; } // Return the relobj if there is one. const Relobj* relobj() const { return this->r_sym_ != invalid_index ? this->u_.relobj : NULL; } // Whether this equals to another key k. bool eq(const Key& k) const { return ((this->stub_type_ == k.stub_type_) && (this->r_sym_ == k.r_sym_) && ((this->r_sym_ != Reloc_stub::invalid_index) ? (this->u_.relobj == k.u_.relobj) : (this->u_.symbol == k.u_.symbol)) && (this->addend_ == k.addend_)); } // Return a hash value. size_t hash_value() const { size_t name_hash_value = gold::string_hash( (this->r_sym_ != Reloc_stub::invalid_index) ? this->u_.relobj->name().c_str() : this->u_.symbol->name()); // We only have 4 stub types. size_t stub_type_hash_value = 0x03 & this->stub_type_; return (name_hash_value ^ stub_type_hash_value ^ ((this->r_sym_ & 0x3fff) << 2) ^ ((this->addend_ & 0xffff) << 16)); } // Functors for STL associative containers. struct hash { size_t operator()(const Key& k) const { return k.hash_value(); } }; struct equal_to { bool operator()(const Key& k1, const Key& k2) const { return k1.eq(k2); } }; private: // Stub type. const Stub_type stub_type_; // If this is a local symbol, this is the index in the defining object. // Otherwise, it is invalid_index for a global symbol. unsigned int r_sym_; // If r_sym_ is an invalid index, this points to a global symbol. // Otherwise, it points to a relobj. We used the unsized and target // independent Symbol and Relobj classes instead of Sized_symbol<32> and // Arm_relobj, in order to avoid making the stub class a template // as most of the stub machinery is endianness-neutral. However, it // may require a bit of casting done by users of this class. union { const Symbol* symbol; const Relobj* relobj; } u_; // Addend associated with a reloc. int32_t addend_; }; // End of inner class Reloc_stub::Key protected: // This may be overridden in the child class. virtual void do_write(unsigned char*, section_size_type); private: static const section_offset_type invalid_offset = static_cast(-1); static const unsigned int invalid_index = static_cast(-1); static const AArch64_address invalid_address = static_cast(-1); static const uint32_t stub_insns_[][10]; const Stub_type stub_type_; section_offset_type offset_; AArch64_address destination_address_; }; // End of Reloc_stub // Write data to output file. template void Reloc_stub:: do_write(unsigned char* view, section_size_type) { typedef typename elfcpp::Swap<32, big_endian>::Valtype Insntype; const uint32_t* insns = this->stub_insns(); uint32_t num_insns = this->stub_insn_number(); Insntype* ip = reinterpret_cast(view); for (uint32_t i = 1; i <= num_insns; ++i) elfcpp::Swap<32, big_endian>::writeval(ip + i - 1, insns[i]); } // Stubs instructions definition. template const uint32_t Reloc_stub::stub_insns_[][10] = { // The first element of each group is the num of the insns. // ST_NONE {0, 0}, // ST_ADRP_BRANCH { 4, 0x90000010, /* adrp ip0, X */ /* ADR_PREL_PG_HI21(X) */ 0x91000210, /* add ip0, ip0, :lo12:X */ /* ADD_ABS_LO12_NC(X) */ 0xd61f0200, /* br ip0 */ 0x00000000, /* alignment padding */ }, // ST_LONG_BRANCH_ABS { 4, 0x58000050, /* ldr ip0, 0x8 */ 0xd61f0200, /* br ip0 */ 0x00000000, /* address field */ 0x00000000, /* address fields */ }, // ST_LONG_BRANCH_PCREL { 8, 0x58000090, /* ldr ip0, 0x10 */ 0x10000011, /* adr ip1, #0 */ 0x8b110210, /* add ip0, ip0, ip1 */ 0xd61f0200, /* br ip0 */ 0x00000000, /* address field */ 0x00000000, /* address field */ 0x00000000, /* alignment padding */ 0x00000000, /* alignment padding */ } }; // Determine the stub type for a certain relocation or ST_NONE, if no stub is // needed. template inline typename Reloc_stub::Stub_type Reloc_stub::stub_type_for_reloc( unsigned int r_type, AArch64_address location, AArch64_address dest) { int64_t branch_offset = 0; switch(r_type) { case elfcpp::R_AARCH64_CALL26: case elfcpp::R_AARCH64_JUMP26: branch_offset = dest - location; break; default: gold_unreachable(); } if (aarch64_valid_branch_offset_p(branch_offset)) return ST_NONE; if (aarch64_valid_for_adrp_p(location, dest)) return ST_ADRP_BRANCH; if (parameters->options().output_is_position_independent() && parameters->options().output_is_executable()) return ST_LONG_BRANCH_PCREL; return ST_LONG_BRANCH_ABS; } // A class to hold stubs for the ARM target. template class Stub_table : public Output_data { public: typedef Target_aarch64 The_target_aarch64; typedef typename elfcpp::Elf_types::Elf_Addr AArch64_address; typedef AArch64_input_section The_aarch64_input_section; typedef Reloc_stub The_reloc_stub; typedef typename The_reloc_stub::Key The_reloc_stub_key; typedef typename The_reloc_stub_key::hash The_reloc_stub_key_hash; typedef typename The_reloc_stub_key::equal_to The_reloc_stub_key_equal_to; typedef Stub_table The_stub_table; typedef Unordered_map Reloc_stub_map; typedef typename Reloc_stub_map::const_iterator Reloc_stub_map_const_iter; typedef Relocate_info The_relocate_info; Stub_table(The_aarch64_input_section* owner) : Output_data(), owner_(owner), reloc_stubs_size_(0), prev_data_size_(0) { } ~Stub_table() { } The_aarch64_input_section* owner() const { return owner_; } // Whether this stub table is empty. bool empty() const { return reloc_stubs_.empty(); } // Return the current data size. off_t current_data_size() const { return this->current_data_size_for_child(); } // Add a STUB using KEY. The caller is responsible for avoiding addition // if a STUB with the same key has already been added. void add_reloc_stub(The_reloc_stub* stub, const The_reloc_stub_key& key); // Finalize stubs. No-op here, just for completeness. void finalize_stubs() { } // Look up a relocation stub using KEY. Return NULL if there is none. The_reloc_stub* find_reloc_stub(The_reloc_stub_key& key) { Reloc_stub_map_const_iter p = this->reloc_stubs_.find(key); return (p != this->reloc_stubs_.end()) ? p->second : NULL; } // Relocate stubs in this stub table. void relocate_stubs(const The_relocate_info*, The_target_aarch64*, Output_section*, unsigned char*, AArch64_address, section_size_type); // Update data size at the end of a relaxation pass. Return true if data size // is different from that of the previous relaxation pass. bool update_data_size_changed_p() { // No addralign changed here. off_t s = this->reloc_stubs_size_; bool changed = (s != this->prev_data_size_); this->prev_data_size_ = s; return changed; } protected: // Write out section contents. void do_write(Output_file*); // Return the required alignment. uint64_t do_addralign() const { return The_reloc_stub::STUB_ADDR_ALIGN; } // Reset address and file offset. void do_reset_address_and_file_offset() { this->set_current_data_size_for_child(this->prev_data_size_); } // Set final data size. void set_final_data_size() { this->set_data_size(this->current_data_size()); } private: // Relocate one stub. void relocate_stub(The_reloc_stub*, const The_relocate_info*, The_target_aarch64*, Output_section*, unsigned char*, AArch64_address, section_size_type); private: // Owner of this stub table. The_aarch64_input_section* owner_; // The relocation stubs. Reloc_stub_map reloc_stubs_; // Size of reloc stubs. off_t reloc_stubs_size_; // data size of this in the previous pass. off_t prev_data_size_; }; // End of Stub_table // Add a STUB using KEY. The caller is responsible for avoiding addition // if a STUB with the same key has already been added. template void Stub_table::add_reloc_stub( The_reloc_stub* stub, const The_reloc_stub_key& key) { gold_assert(stub->stub_type() == key.stub_type()); this->reloc_stubs_[key] = stub; // Assign stub offset early. We can do this because we never remove // reloc stubs and they are in the beginning of the stub table. this->reloc_stubs_size_ = align_address(this->reloc_stubs_size_, The_reloc_stub::STUB_ADDR_ALIGN); stub->set_offset(this->reloc_stubs_size_); this->reloc_stubs_size_ += stub->stub_size(); } // Relocate all stubs in this stub table. template void Stub_table:: relocate_stubs(const The_relocate_info* relinfo, The_target_aarch64* target_aarch64, Output_section* output_section, unsigned char* view, AArch64_address address, section_size_type view_size) { // "view_size" is the total size of the stub_table. gold_assert(address == this->address() && view_size == static_cast(this->data_size())); for(Reloc_stub_map_const_iter p = this->reloc_stubs_.begin(); p != this->reloc_stubs_.end(); ++p) relocate_stub(p->second, relinfo, target_aarch64, output_section, view, address, view_size); } // Relocate one stub. This is a helper for Stub_table::relocate_stubs(). template void Stub_table:: relocate_stub(The_reloc_stub* stub, const The_relocate_info* relinfo, The_target_aarch64* target_aarch64, Output_section* output_section, unsigned char* view, AArch64_address address, section_size_type view_size) { // "offset" is the offset from the beginning of the stub_table. section_size_type offset = stub->offset(); section_size_type stub_size = stub->stub_size(); // "view_size" is the total size of the stub_table. gold_assert(offset + stub_size <= view_size); target_aarch64->relocate_stub(stub, relinfo, output_section, view + offset, address + offset, view_size); } // Write out the stubs to file. template void Stub_table::do_write(Output_file* of) { 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); // Write relocation stubs. for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin(); p != this->reloc_stubs_.end(); ++p) { The_reloc_stub* stub = p->second; AArch64_address address = this->address() + stub->offset(); gold_assert(address == align_address(address, The_reloc_stub::STUB_ADDR_ALIGN)); stub->write(oview + stub->offset(), stub->stub_size()); } of->write_output_view(this->offset(), oview_size, oview); } // AArch64_relobj class. template class AArch64_relobj : public Sized_relobj_file { public: typedef AArch64_relobj This; typedef Target_aarch64 The_target_aarch64; typedef AArch64_input_section The_aarch64_input_section; typedef typename elfcpp::Elf_types::Elf_Addr AArch64_address; typedef Stub_table The_stub_table; typedef std::vector Stub_table_list; static const AArch64_address invalid_address = static_cast(-1); AArch64_relobj(const std::string& name, Input_file* input_file, off_t offset, const typename elfcpp::Ehdr& ehdr) : Sized_relobj_file(name, input_file, offset, ehdr), stub_tables_() { } ~AArch64_relobj() { } // Return the stub table of the SHNDX-th section if there is one. The_stub_table* stub_table(unsigned int shndx) const { gold_assert(shndx < this->stub_tables_.size()); return this->stub_tables_[shndx]; } // Set STUB_TABLE to be the stub_table of the SHNDX-th section. void set_stub_table(unsigned int shndx, The_stub_table* stub_table) { gold_assert(shndx < this->stub_tables_.size()); this->stub_tables_[shndx] = stub_table; } // Scan all relocation sections for stub generation. void scan_sections_for_stubs(The_target_aarch64*, const Symbol_table*, const Layout*); // Whether a section is a scannable text section. bool text_section_is_scannable(const elfcpp::Shdr&, unsigned int, const Output_section*, const Symbol_table*); // Convert regular input section with index SHNDX to a relaxed section. void convert_input_section_to_relaxed_section(unsigned /* shndx */) { // The stubs have relocations and we need to process them after writing // out the stubs. So relocation now must follow section write. this->set_relocs_must_follow_section_writes(); } protected: // Post constructor setup. void do_setup() { // Call parent's setup method. Sized_relobj_file::do_setup(); // Initialize look-up tables. this->stub_tables_.resize(this->shnum()); } virtual void do_relocate_sections( const Symbol_table* symtab, const Layout* layout, const unsigned char* pshdrs, Output_file* of, typename Sized_relobj_file::Views* pviews); private: // Whether a section needs to be scanned for relocation stubs. bool section_needs_reloc_stub_scanning(const elfcpp::Shdr&, const Relobj::Output_sections&, const Symbol_table*, const unsigned char*); // List of stub tables. Stub_table_list stub_tables_; }; // End of AArch64_relobj // Relocate sections. template void AArch64_relobj::do_relocate_sections( const Symbol_table* symtab, const Layout* layout, const unsigned char* pshdrs, Output_file* of, typename Sized_relobj_file::Views* pviews) { // Call parent to relocate sections. Sized_relobj_file::do_relocate_sections(symtab, layout, pshdrs, of, pviews); // We do not generate stubs if doing a relocatable link. if (parameters->options().relocatable()) return; Relocate_info relinfo; relinfo.symtab = symtab; relinfo.layout = layout; relinfo.object = this; // Relocate stub tables. unsigned int shnum = this->shnum(); The_target_aarch64* target = The_target_aarch64::current_target(); for (unsigned int i = 1; i < shnum; ++i) { The_aarch64_input_section* aarch64_input_section = target->find_aarch64_input_section(this, i); if (aarch64_input_section != NULL && aarch64_input_section->is_stub_table_owner() && !aarch64_input_section->stub_table()->empty()) { Output_section* os = this->output_section(i); gold_assert(os != NULL); relinfo.reloc_shndx = elfcpp::SHN_UNDEF; relinfo.reloc_shdr = NULL; relinfo.data_shndx = i; relinfo.data_shdr = pshdrs + i * elfcpp::Elf_sizes::shdr_size; typename Sized_relobj_file::View_size& view_struct = (*pviews)[i]; gold_assert(view_struct.view != NULL); The_stub_table* stub_table = aarch64_input_section->stub_table(); off_t offset = stub_table->address() - view_struct.address; unsigned char* view = view_struct.view + offset; AArch64_address address = stub_table->address(); section_size_type view_size = stub_table->data_size(); stub_table->relocate_stubs(&relinfo, target, os, view, address, view_size); } } } // Determine if an input section is scannable for stub processing. SHDR is // the header of the section and SHNDX is the section index. OS is the output // section for the input section and SYMTAB is the global symbol table used to // look up ICF information. template bool AArch64_relobj::text_section_is_scannable( const elfcpp::Shdr& text_shdr, unsigned int text_shndx, const Output_section* os, const Symbol_table* symtab) { // Skip any empty sections, unallocated sections or sections whose // type are not SHT_PROGBITS. if (text_shdr.get_sh_size() == 0 || (text_shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0 || text_shdr.get_sh_type() != elfcpp::SHT_PROGBITS) return false; // Skip any discarded or ICF'ed sections. if (os == NULL || symtab->is_section_folded(this, text_shndx)) return false; // Skip exception frame. if (strcmp(os->name(), ".eh_frame") == 0) return false ; gold_assert(!this->is_output_section_offset_invalid(text_shndx) || os->find_relaxed_input_section(this, text_shndx) != NULL); return true; } // Determine if we want to scan the SHNDX-th section for relocation stubs. // This is a helper for AArch64_relobj::scan_sections_for_stubs(). template bool AArch64_relobj::section_needs_reloc_stub_scanning( const elfcpp::Shdr& shdr, const Relobj::Output_sections& out_sections, const Symbol_table* symtab, const unsigned char* pshdrs) { unsigned int sh_type = shdr.get_sh_type(); if (sh_type != elfcpp::SHT_RELA) return false; // Ignore empty section. off_t sh_size = shdr.get_sh_size(); if (sh_size == 0) return false; // Ignore reloc section with unexpected symbol table. The // error will be reported in the final link. if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx()) return false; gold_assert(sh_type == elfcpp::SHT_RELA); unsigned int reloc_size = elfcpp::Elf_sizes::rela_size; // Ignore reloc section with unexpected entsize or uneven size. // The error will be reported in the final link. if (reloc_size != shdr.get_sh_entsize() || sh_size % reloc_size != 0) return false; // Ignore reloc section with bad info. This error will be // reported in the final link. unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_info()); if (text_shndx >= this->shnum()) return false; const unsigned int shdr_size = elfcpp::Elf_sizes::shdr_size; const elfcpp::Shdr text_shdr(pshdrs + text_shndx * shdr_size); return this->text_section_is_scannable(text_shdr, text_shndx, out_sections[text_shndx], symtab); } // Scan relocations for stub generation. template void AArch64_relobj::scan_sections_for_stubs( The_target_aarch64* target, const Symbol_table* symtab, const Layout* layout) { unsigned int shnum = this->shnum(); const unsigned int shdr_size = elfcpp::Elf_sizes::shdr_size; // Read the section headers. const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(), shnum * shdr_size, true, true); // To speed up processing, we set up hash tables for fast lookup of // input offsets to output addresses. this->initialize_input_to_output_maps(); const Relobj::Output_sections& out_sections(this->output_sections()); Relocate_info relinfo; relinfo.symtab = symtab; relinfo.layout = layout; relinfo.object = this; // Do relocation stubs scanning. const unsigned char* p = pshdrs + shdr_size; for (unsigned int i = 1; i < shnum; ++i, p += shdr_size) { const elfcpp::Shdr shdr(p); if (this->section_needs_reloc_stub_scanning(shdr, out_sections, symtab, pshdrs)) { unsigned int index = this->adjust_shndx(shdr.get_sh_info()); AArch64_address output_offset = this->get_output_section_offset(index); AArch64_address output_address; if (output_offset != invalid_address) { output_address = out_sections[index]->address() + output_offset; } else { // Currently this only happens for a relaxed section. const Output_relaxed_input_section* poris = out_sections[index]->find_relaxed_input_section(this, index); gold_assert(poris != NULL); output_address = poris->address(); } // Get the relocations. const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(), shdr.get_sh_size(), true, false); // Get the section contents. section_size_type input_view_size = 0; const unsigned char* input_view = this->section_contents(index, &input_view_size, false); relinfo.reloc_shndx = i; relinfo.data_shndx = index; unsigned int sh_type = shdr.get_sh_type(); unsigned int reloc_size; gold_assert (sh_type == elfcpp::SHT_RELA); reloc_size = elfcpp::Elf_sizes::rela_size; Output_section* os = out_sections[index]; target->scan_section_for_stubs(&relinfo, sh_type, prelocs, shdr.get_sh_size() / reloc_size, os, output_offset == invalid_address, input_view, output_address, input_view_size); } } } // A class to wrap an ordinary input section containing executable code. template class AArch64_input_section : public Output_relaxed_input_section { public: typedef Stub_table The_stub_table; AArch64_input_section(Relobj* relobj, unsigned int shndx) : Output_relaxed_input_section(relobj, shndx, 1), stub_table_(NULL), original_contents_(NULL), original_size_(0), original_addralign_(1) { } ~AArch64_input_section() { delete[] this->original_contents_; } // Initialize. void init(); // Set the stub_table. void set_stub_table(The_stub_table* st) { this->stub_table_ = st; } // Whether this is a stub table owner. bool is_stub_table_owner() const { return this->stub_table_ != NULL && this->stub_table_->owner() == this; } // Return the original size of the section. uint32_t original_size() const { return this->original_size_; } // Return the stub table. The_stub_table* stub_table() { return stub_table_; } protected: // Write out this input section. void do_write(Output_file*); // Return required alignment of this. uint64_t do_addralign() const { if (this->is_stub_table_owner()) return std::max(this->stub_table_->addralign(), static_cast(this->original_addralign_)); else return this->original_addralign_; } // Finalize data size. void set_final_data_size(); // Reset address and file offset. void do_reset_address_and_file_offset(); // Output offset. bool do_output_offset(const Relobj* object, unsigned int shndx, section_offset_type offset, section_offset_type* poutput) const { if ((object == this->relobj()) && (shndx == this->shndx()) && (offset >= 0) && (offset <= convert_types(this->original_size_))) { *poutput = offset; return true; } else return false; } private: // Copying is not allowed. AArch64_input_section(const AArch64_input_section&); AArch64_input_section& operator=(const AArch64_input_section&); // The relocation stubs. The_stub_table* stub_table_; // Original section contents. We have to make a copy here since the file // containing the original section may not be locked when we need to access // the contents. unsigned char* original_contents_; // Section size of the original input section. uint32_t original_size_; // Address alignment of the original input section. uint32_t original_addralign_; }; // End of AArch64_input_section // Finalize data size. template void AArch64_input_section::set_final_data_size() { off_t off = convert_types(this->original_size_); if (this->is_stub_table_owner()) { this->stub_table_->finalize_data_size(); off = align_address(off, this->stub_table_->addralign()); off += this->stub_table_->data_size(); } this->set_data_size(off); } // Reset address and file offset. template void AArch64_input_section::do_reset_address_and_file_offset() { // Size of the original input section contents. off_t off = convert_types(this->original_size_); // If this is a stub table owner, account for the stub table size. if (this->is_stub_table_owner()) { The_stub_table* stub_table = this->stub_table_; // Reset the stub table's address and file offset. The // current data size for child will be updated after that. stub_table_->reset_address_and_file_offset(); off = align_address(off, stub_table_->addralign()); off += stub_table->current_data_size(); } this->set_current_data_size(off); } // Initialize an Arm_input_section. template void AArch64_input_section::init() { Relobj* relobj = this->relobj(); unsigned int shndx = this->shndx(); // We have to cache original size, alignment and contents to avoid locking // the original file. this->original_addralign_ = convert_types(relobj->section_addralign(shndx)); // This is not efficient but we expect only a small number of relaxed // input sections for stubs. section_size_type section_size; const unsigned char* section_contents = relobj->section_contents(shndx, §ion_size, false); this->original_size_ = convert_types(relobj->section_size(shndx)); gold_assert(this->original_contents_ == NULL); this->original_contents_ = new unsigned char[section_size]; memcpy(this->original_contents_, section_contents, section_size); // We want to make this look like the original input section after // output sections are finalized. Output_section* os = relobj->output_section(shndx); off_t offset = relobj->output_section_offset(shndx); gold_assert(os != NULL && !relobj->is_output_section_offset_invalid(shndx)); this->set_address(os->address() + offset); this->set_file_offset(os->offset() + offset); this->set_current_data_size(this->original_size_); this->finalize_data_size(); } // Write data to output file. template void AArch64_input_section::do_write(Output_file* of) { // We have to write out the original section content. gold_assert(this->original_contents_ != NULL); of->write(this->offset(), this->original_contents_, this->original_size_); // If this owns a stub table and it is not empty, write it. if (this->is_stub_table_owner() && !this->stub_table_->empty()) this->stub_table_->write(of); } // Arm output section class. This is defined mainly to add a number of stub // generation methods. template class AArch64_output_section : public Output_section { public: typedef Target_aarch64 The_target_aarch64; typedef AArch64_relobj The_aarch64_relobj; typedef Stub_table The_stub_table; typedef AArch64_input_section The_aarch64_input_section; public: AArch64_output_section(const char* name, elfcpp::Elf_Word type, elfcpp::Elf_Xword flags) : Output_section(name, type, flags) { } ~AArch64_output_section() {} // Group input sections for stub generation. void group_sections(section_size_type, bool, Target_aarch64*, const Task*); private: typedef Output_section::Input_section Input_section; typedef Output_section::Input_section_list Input_section_list; // Create a stub group. void create_stub_group(Input_section_list::const_iterator, Input_section_list::const_iterator, Input_section_list::const_iterator, The_target_aarch64*, std::vector&, const Task*); }; // End of AArch64_output_section // Create a stub group for input sections from FIRST to LAST. OWNER points to // the input section that will be the owner of the stub table. template void AArch64_output_section::create_stub_group( Input_section_list::const_iterator first, Input_section_list::const_iterator last, Input_section_list::const_iterator owner, The_target_aarch64* target, std::vector& new_relaxed_sections, const Task* task) { // Currently we convert ordinary input sections into relaxed sections only // at this point. The_aarch64_input_section* input_section; if (owner->is_relaxed_input_section()) gold_unreachable(); else { gold_assert(owner->is_input_section()); // Create a new relaxed input section. We need to lock the original // file. Task_lock_obj tl(task, owner->relobj()); input_section = target->new_aarch64_input_section(owner->relobj(), owner->shndx()); new_relaxed_sections.push_back(input_section); } // Create a stub table. The_stub_table* stub_table = target->new_stub_table(input_section); input_section->set_stub_table(stub_table); Input_section_list::const_iterator p = first; // Look for input sections or relaxed input sections in [first ... last]. do { if (p->is_input_section() || p->is_relaxed_input_section()) { // The stub table information for input sections live // in their objects. The_aarch64_relobj* aarch64_relobj = static_cast(p->relobj()); aarch64_relobj->set_stub_table(p->shndx(), stub_table); } } while (p++ != last); } // Group input sections for stub generation. GROUP_SIZE is roughly the limit of // stub groups. We grow a stub group by adding input section until the size is // just below GROUP_SIZE. The last input section will be converted into a stub // table owner. If STUB_ALWAYS_AFTER_BRANCH is false, we also add input sectiond // after the stub table, effectively doubling the group size. // // This is similar to the group_sections() function in elf32-arm.c but is // implemented differently. template void AArch64_output_section::group_sections( section_size_type group_size, bool stubs_always_after_branch, Target_aarch64* target, const Task* task) { typedef enum { NO_GROUP, FINDING_STUB_SECTION, HAS_STUB_SECTION } State; std::vector new_relaxed_sections; State state = NO_GROUP; section_size_type off = 0; section_size_type group_begin_offset = 0; section_size_type group_end_offset = 0; section_size_type stub_table_end_offset = 0; Input_section_list::const_iterator group_begin = this->input_sections().end(); Input_section_list::const_iterator stub_table = this->input_sections().end(); Input_section_list::const_iterator group_end = this->input_sections().end(); for (Input_section_list::const_iterator p = this->input_sections().begin(); p != this->input_sections().end(); ++p) { section_size_type section_begin_offset = align_address(off, p->addralign()); section_size_type section_end_offset = section_begin_offset + p->data_size(); // Check to see if we should group the previously seen sections. switch (state) { case NO_GROUP: break; case FINDING_STUB_SECTION: // Adding this section makes the group larger than GROUP_SIZE. if (section_end_offset - group_begin_offset >= group_size) { if (stubs_always_after_branch) { gold_assert(group_end != this->input_sections().end()); this->create_stub_group(group_begin, group_end, group_end, target, new_relaxed_sections, task); state = NO_GROUP; } else { // Input sections up to stub_group_size bytes after the stub // table can be handled by it too. state = HAS_STUB_SECTION; stub_table = group_end; stub_table_end_offset = group_end_offset; } } break; case HAS_STUB_SECTION: // Adding this section makes the post stub-section group larger // than GROUP_SIZE. gold_unreachable(); // NOT SUPPORTED YET. For completeness only. if (section_end_offset - stub_table_end_offset >= group_size) { gold_assert(group_end != this->input_sections().end()); this->create_stub_group(group_begin, group_end, stub_table, target, new_relaxed_sections, task); state = NO_GROUP; } break; default: gold_unreachable(); } // If we see an input section and currently there is no group, start // a new one. Skip any empty sections. We look at the data size // instead of calling p->relobj()->section_size() to avoid locking. if ((p->is_input_section() || p->is_relaxed_input_section()) && (p->data_size() != 0)) { if (state == NO_GROUP) { state = FINDING_STUB_SECTION; group_begin = p; group_begin_offset = section_begin_offset; } // Keep track of the last input section seen. group_end = p; group_end_offset = section_end_offset; } off = section_end_offset; } // Create a stub group for any ungrouped sections. if (state == FINDING_STUB_SECTION || state == HAS_STUB_SECTION) { gold_assert(group_end != this->input_sections().end()); this->create_stub_group(group_begin, group_end, (state == FINDING_STUB_SECTION ? group_end : stub_table), target, new_relaxed_sections, task); } if (!new_relaxed_sections.empty()) this->convert_input_sections_to_relaxed_sections(new_relaxed_sections); // Update the section offsets for (size_t i = 0; i < new_relaxed_sections.size(); ++i) { The_aarch64_relobj* relobj = static_cast( new_relaxed_sections[i]->relobj()); unsigned int shndx = new_relaxed_sections[i]->shndx(); // Tell AArch64_relobj that this input section is converted. relobj->convert_input_section_to_relaxed_section(shndx); } } // End of AArch64_output_section::group_sections 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 Target_aarch64 This; typedef Output_data_reloc Reloc_section; typedef Relocate_info The_relocate_info; typedef typename elfcpp::Elf_types::Elf_Addr Address; typedef AArch64_relobj The_aarch64_relobj; typedef Reloc_stub The_reloc_stub; typedef typename The_reloc_stub::Stub_type The_reloc_stub_type; typedef typename Reloc_stub::Key The_reloc_stub_key; typedef Stub_table The_stub_table; typedef std::vector Stub_table_list; typedef typename Stub_table_list::iterator Stub_table_iterator; typedef AArch64_input_section The_aarch64_input_section; typedef AArch64_output_section The_aarch64_output_section; typedef Unordered_map*, Section_id_hash> AArch64_input_section_map; const static int TCB_SIZE = size / 8 * 2; Target_aarch64(const Target::Target_info* info = &aarch64_info) : Sized_target(info), got_(NULL), plt_(NULL), got_plt_(NULL), got_irelative_(NULL), got_tlsdesc_(NULL), global_offset_table_(NULL), rela_dyn_(NULL), rela_irelative_(NULL), copy_relocs_(elfcpp::R_AARCH64_COPY), got_mod_index_offset_(-1U), tlsdesc_reloc_info_(), tls_base_symbol_defined_(false), stub_tables_(), stub_group_size_(0), aarch64_input_section_map_() { } // 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*); // Return the value to use for a dynamic which requires special // treatment. uint64_t do_dynsym_value(const Symbol*) const; // 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 symbol index to use for a target specific relocation. // The only target specific relocation is R_AARCH64_TLSDESC for a // local symbol, which is an absolute reloc. unsigned int do_reloc_symbol_index(void*, unsigned int r_type) const { gold_assert(r_type == elfcpp::R_AARCH64_TLSDESC); return 0; } // Return the addend to use for a target specific relocation. typename elfcpp::Elf_types::Elf_Addr do_reloc_addend(void* arg, unsigned int r_type, typename elfcpp::Elf_types::Elf_Addr addend) const; // 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); } // This function should be defined in targets that can use relocation // types to determine (implemented in local_reloc_may_be_function_pointer // and global_reloc_may_be_function_pointer) // if a function's pointer is taken. ICF uses this in safe mode to only // fold those functions whose pointer is defintely not taken. bool do_can_check_for_function_pointers() const { return true; } // 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; // Create a stub table. The_stub_table* new_stub_table(The_aarch64_input_section*); // Create an aarch64 input section. The_aarch64_input_section* new_aarch64_input_section(Relobj*, unsigned int); // Find an aarch64 input section instance for a given OBJ and SHNDX. The_aarch64_input_section* find_aarch64_input_section(Relobj*, unsigned int) const; // Return the thread control block size. unsigned int tcb_size() const { return This::TCB_SIZE; } // Scan a section for stub generation. void scan_section_for_stubs(const Relocate_info*, unsigned int, const unsigned char*, size_t, Output_section*, bool, const unsigned char*, Address, section_size_type); // Scan a relocation section for stub. template void scan_reloc_section_for_stubs( const The_relocate_info* relinfo, const unsigned char* prelocs, size_t reloc_count, Output_section* output_section, bool needs_special_offset_handling, const unsigned char* view, Address view_address, section_size_type); // Relocate a single stub. void relocate_stub(The_reloc_stub*, const Relocate_info*, Output_section*, unsigned char*, Address, section_size_type); // Get the default AArch64 target. static This* current_target() { gold_assert(parameters->target().machine_code() == elfcpp::EM_AARCH64 && parameters->target().get_size() == size && parameters->target().is_big_endian() == big_endian); return static_cast(parameters->sized_target()); } protected: void do_select_as_default_target() { gold_assert(aarch64_reloc_property_table == NULL); aarch64_reloc_property_table = new AArch64_reloc_property_table(); } // Add a new reloc argument, returning the index in the vector. size_t add_tlsdesc_info(Sized_relobj_file* object, unsigned int r_sym) { this->tlsdesc_reloc_info_.push_back(Tlsdesc_info(object, r_sym)); return this->tlsdesc_reloc_info_.size() - 1; } virtual Output_data_plt_aarch64* do_make_data_plt(Layout* layout, Output_data_got_aarch64* got, Output_data_space* got_plt, Output_data_space* got_irelative) { return new Output_data_plt_aarch64_standard( layout, got, got_plt, got_irelative); } // do_make_elf_object to override the same function in the base class. Object* do_make_elf_object(const std::string&, Input_file*, off_t, const elfcpp::Ehdr&); Output_data_plt_aarch64* make_data_plt(Layout* layout, Output_data_got_aarch64* got, Output_data_space* got_plt, Output_data_space* got_irelative) { return this->do_make_data_plt(layout, got, got_plt, got_irelative); } // We only need to generate stubs, and hence perform relaxation if we are // not doing relocatable linking. virtual bool do_may_relax() const { return !parameters->options().relocatable(); } // Relaxation hook. This is where we do stub generation. virtual bool do_relax(int, const Input_objects*, Symbol_table*, Layout*, const Task*); void group_sections(Layout* layout, section_size_type group_size, bool stubs_always_after_branch, const Task* task); void scan_reloc_for_stub(const The_relocate_info*, unsigned int, const Sized_symbol*, unsigned int, const Symbol_value*, typename elfcpp::Elf_types::Elf_Swxword, Address Elf_Addr); // Make an output section. Output_section* do_make_output_section(const char* name, elfcpp::Elf_Word type, elfcpp::Elf_Xword flags) { return new The_aarch64_output_section(name, type, flags); } 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); bool reloc_needs_plt_for_ifunc(Sized_relobj_file*, 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() : skip_call_tls_get_addr_(false) { } ~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); private: inline typename AArch64_relocate_functions::Status relocate_tls(const Relocate_info*, Target_aarch64*, size_t, const elfcpp::Rela&, unsigned int r_type, const Sized_symbol*, const Symbol_value*, unsigned char*, typename elfcpp::Elf_types::Elf_Addr); inline typename AArch64_relocate_functions::Status tls_gd_to_le( const Relocate_info*, Target_aarch64*, const elfcpp::Rela&, unsigned int, unsigned char*, const Symbol_value*); inline typename AArch64_relocate_functions::Status tls_ld_to_le( const Relocate_info*, Target_aarch64*, const elfcpp::Rela&, unsigned int, unsigned char*, const Symbol_value*); inline typename AArch64_relocate_functions::Status tls_ie_to_le( const Relocate_info*, Target_aarch64*, const elfcpp::Rela&, unsigned int, unsigned char*, const Symbol_value*); inline typename AArch64_relocate_functions::Status tls_desc_gd_to_le( const Relocate_info*, Target_aarch64*, const elfcpp::Rela&, unsigned int, unsigned char*, const Symbol_value*); inline typename AArch64_relocate_functions::Status tls_desc_gd_to_ie( const Relocate_info*, Target_aarch64*, const elfcpp::Rela&, unsigned int, unsigned char*, const Symbol_value*, typename elfcpp::Elf_types::Elf_Addr, typename elfcpp::Elf_types::Elf_Addr); bool skip_call_tls_get_addr_; }; // End of class Relocate // 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_; } // Get the GOT section for TLSDESC entries. Output_data_got* got_tlsdesc_section() const { gold_assert(this->got_tlsdesc_ != NULL); return this->got_tlsdesc_; } // 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*); // Create a PLT entry for a local STT_GNU_IFUNC symbol. void make_local_ifunc_plt_entry(Symbol_table*, Layout*, Sized_relobj_file* relobj, unsigned int local_sym_index); // Define the _TLS_MODULE_BASE_ symbol in the TLS segment. void define_tls_base_symbol(Symbol_table*, Layout*); // Create the reserved PLT and GOT entries for the TLS descriptor resolver. void reserve_tlsdesc_entries(Symbol_table* symtab, Layout* layout); // Create a GOT entry for the TLS module index. unsigned int got_mod_index_entry(Symbol_table* symtab, Layout* layout, Sized_relobj_file* object); // 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*); // Get the section to use for TLSDESC relocations. Reloc_section* rela_tlsdesc_section(Layout*) const; // Get the section to use for IRELATIVE relocations. Reloc_section* rela_irelative_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 }; // This type is used as the argument to the target specific // relocation routines. The only target specific reloc is // R_AARCh64_TLSDESC against a local symbol. struct Tlsdesc_info { Tlsdesc_info(Sized_relobj_file* a_object, unsigned int a_r_sym) : object(a_object), r_sym(a_r_sym) { } // The object in which the local symbol is defined. Sized_relobj_file* object; // The local symbol index in the object. unsigned int r_sym; }; // 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 GOT section for IRELATIVE relocations. Output_data_space* got_irelative_; // The GOT section for TLSDESC relocations. Output_data_got* got_tlsdesc_; // The _GLOBAL_OFFSET_TABLE_ symbol. Symbol* global_offset_table_; // The dynamic reloc section. Reloc_section* rela_dyn_; // The section to use for IRELATIVE relocs. Reloc_section* rela_irelative_; // Relocs saved to avoid a COPY reloc. Copy_relocs copy_relocs_; // Offset of the GOT entry for the TLS module index. unsigned int got_mod_index_offset_; // We handle R_AARCH64_TLSDESC against a local symbol as a target // specific relocation. Here we store the object and local symbol // index for the relocation. std::vector tlsdesc_reloc_info_; // True if the _TLS_MODULE_BASE_ symbol has been defined. bool tls_base_symbol_defined_; // List of stub_tables Stub_table_list stub_tables_; // Actual stub group size section_size_type stub_group_size_; AArch64_input_section_map aarch64_input_section_map_; }; // End of Target_aarch64 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 true, // 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 true, // 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 there are any IRELATIVE relocations, they get GOT entries // in .got.plt after the jump slot entries. this->got_irelative_ = new Output_data_space(size / 8, "** GOT IRELATIVE PLT"); layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS, (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE), this->got_irelative_, got_plt_order, is_got_plt_relro); // If there are any TLSDESC relocations, they get GOT entries in // .got.plt after the jump slot and IRELATIVE entries. this->got_tlsdesc_ = new Output_data_got(); layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS, (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE), this->got_tlsdesc_, got_plt_order, is_got_plt_relro); 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_; } // Get the section to use for IRELATIVE relocs, creating it if // necessary. These go in .rela.dyn, but only after all other dynamic // relocations. They need to follow the other dynamic relocations so // that they can refer to global variables initialized by those // relocs. template typename Target_aarch64::Reloc_section* Target_aarch64::rela_irelative_section(Layout* layout) { if (this->rela_irelative_ == NULL) { // Make sure we have already created the dynamic reloc section. this->rela_dyn_section(layout); this->rela_irelative_ = new Reloc_section(false); layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA, elfcpp::SHF_ALLOC, this->rela_irelative_, ORDER_DYNAMIC_RELOCS, false); gold_assert(this->rela_dyn_->output_section() == this->rela_irelative_->output_section()); } return this->rela_irelative_; } // do_make_elf_object to override the same function in the base class. We need // to use a target-specific sub-class of Sized_relobj_file to // store backend specific information. Hence we need to have our own ELF object // creation. template Object* Target_aarch64::do_make_elf_object( const std::string& name, Input_file* input_file, off_t offset, const elfcpp::Ehdr& ehdr) { int et = ehdr.get_e_type(); // ET_EXEC files are valid input for --just-symbols/-R, // and we treat them as relocatable objects. if (et == elfcpp::ET_EXEC && input_file->just_symbols()) return Sized_target::do_make_elf_object( name, input_file, offset, ehdr); else if (et == elfcpp::ET_REL) { AArch64_relobj* obj = new AArch64_relobj(name, input_file, offset, ehdr); obj->setup(); return obj; } else if (et == elfcpp::ET_DYN) { // Keep base implementation. Sized_dynobj* obj = new Sized_dynobj(name, input_file, offset, ehdr); obj->setup(); return obj; } else { gold_error(_("%s: unsupported ELF file type %d"), name.c_str(), et); return NULL; } } // Scan a relocation for stub generation. template void Target_aarch64::scan_reloc_for_stub( const Relocate_info* relinfo, unsigned int r_type, const Sized_symbol* gsym, unsigned int r_sym, const Symbol_value* psymval, typename elfcpp::Elf_types::Elf_Swxword addend, Address address) { const AArch64_relobj* aarch64_relobj = static_cast*>(relinfo->object); Symbol_value symval; if (gsym != NULL) { const AArch64_reloc_property* arp = aarch64_reloc_property_table-> get_reloc_property(r_type); if (gsym->use_plt_offset(arp->reference_flags())) { // This uses a PLT, change the symbol value. symval.set_output_value(this->plt_section()->address() + gsym->plt_offset()); psymval = &symval; } else if (gsym->is_undefined()) // There is no need to generate a stub symbol is undefined. return; } // Get the symbol value. typename Symbol_value::Value value = psymval->value(aarch64_relobj, 0); // Owing to pipelining, the PC relative branches below actually skip // two instructions when the branch offset is 0. Address destination = static_cast
(-1); switch (r_type) { case elfcpp::R_AARCH64_CALL26: case elfcpp::R_AARCH64_JUMP26: destination = value + addend; break; default: gold_unreachable(); } typename The_reloc_stub::Stub_type stub_type = The_reloc_stub:: stub_type_for_reloc(r_type, address, destination); if (stub_type == The_reloc_stub::ST_NONE) return ; The_stub_table* stub_table = aarch64_relobj->stub_table(relinfo->data_shndx); gold_assert(stub_table != NULL); The_reloc_stub_key key(stub_type, gsym, aarch64_relobj, r_sym, addend); The_reloc_stub* stub = stub_table->find_reloc_stub(key); if (stub == NULL) { stub = new The_reloc_stub(stub_type); stub_table->add_reloc_stub(stub, key); } stub->set_destination_address(destination); } // End of Target_aarch64::scan_reloc_for_stub // This function scans a relocation section for stub generation. // The template parameter Relocate must be a class type which provides // a single function, relocate(), which implements the machine // specific part of a relocation. // BIG_ENDIAN is the endianness of the data. SH_TYPE is the section type: // SHT_REL or SHT_RELA. // PRELOCS points to the relocation data. RELOC_COUNT is the number // of relocs. OUTPUT_SECTION is the output section. // NEEDS_SPECIAL_OFFSET_HANDLING is true if input offsets need to be // mapped to output offsets. // VIEW is the section data, VIEW_ADDRESS is its memory address, and // VIEW_SIZE is the size. These refer to the input section, unless // NEEDS_SPECIAL_OFFSET_HANDLING is true, in which case they refer to // the output section. template template void inline Target_aarch64::scan_reloc_section_for_stubs( const Relocate_info* relinfo, const unsigned char* prelocs, size_t reloc_count, Output_section* /*output_section*/, bool /*needs_special_offset_handling*/, const unsigned char* /*view*/, Address view_address, section_size_type) { typedef typename Reloc_types::Reloc Reltype; const int reloc_size = Reloc_types::reloc_size; AArch64_relobj* object = static_cast*>(relinfo->object); unsigned int local_count = object->local_symbol_count(); gold::Default_comdat_behavior default_comdat_behavior; Comdat_behavior comdat_behavior = CB_UNDETERMINED; for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size) { Reltype reloc(prelocs); typename elfcpp::Elf_types::Elf_WXword r_info = reloc.get_r_info(); unsigned int r_sym = elfcpp::elf_r_sym(r_info); unsigned int r_type = elfcpp::elf_r_type(r_info); if (r_type != elfcpp::R_AARCH64_CALL26 && r_type != elfcpp::R_AARCH64_JUMP26) continue; section_offset_type offset = convert_to_section_size_type(reloc.get_r_offset()); // Get the addend. typename elfcpp::Elf_types::Elf_Swxword addend = reloc.get_r_addend(); const Sized_symbol* sym; Symbol_value symval; const Symbol_value *psymval; bool is_defined_in_discarded_section; unsigned int shndx; if (r_sym < local_count) { sym = NULL; psymval = object->local_symbol(r_sym); // If the local symbol belongs to a section we are discarding, // and that section is a debug section, try to find the // corresponding kept section and map this symbol to its // counterpart in the kept section. The symbol must not // correspond to a section we are folding. bool is_ordinary; shndx = psymval->input_shndx(&is_ordinary); is_defined_in_discarded_section = (is_ordinary && shndx != elfcpp::SHN_UNDEF && !object->is_section_included(shndx) && !relinfo->symtab->is_section_folded(object, shndx)); // We need to compute the would-be final value of this local // symbol. if (!is_defined_in_discarded_section) { typedef Sized_relobj_file ObjType; typename ObjType::Compute_final_local_value_status status = object->compute_final_local_value(r_sym, psymval, &symval, relinfo->symtab); if (status == ObjType::CFLV_OK) { // Currently we cannot handle a branch to a target in // a merged section. If this is the case, issue an error // and also free the merge symbol value. if (!symval.has_output_value()) { const std::string& section_name = object->section_name(shndx); object->error(_("cannot handle branch to local %u " "in a merged section %s"), r_sym, section_name.c_str()); } psymval = &symval; } else { // We cannot determine the final value. continue; } } } else { const Symbol* gsym; gsym = object->global_symbol(r_sym); gold_assert(gsym != NULL); if (gsym->is_forwarder()) gsym = relinfo->symtab->resolve_forwards(gsym); sym = static_cast*>(gsym); if (sym->has_symtab_index() && sym->symtab_index() != -1U) symval.set_output_symtab_index(sym->symtab_index()); else symval.set_no_output_symtab_entry(); // We need to compute the would-be final value of this global // symbol. const Symbol_table* symtab = relinfo->symtab; const Sized_symbol* sized_symbol = symtab->get_sized_symbol(gsym); Symbol_table::Compute_final_value_status status; typename elfcpp::Elf_types::Elf_Addr value = symtab->compute_final_value(sized_symbol, &status); // Skip this if the symbol has not output section. if (status == Symbol_table::CFVS_NO_OUTPUT_SECTION) continue; symval.set_output_value(value); if (gsym->type() == elfcpp::STT_TLS) symval.set_is_tls_symbol(); else if (gsym->type() == elfcpp::STT_GNU_IFUNC) symval.set_is_ifunc_symbol(); psymval = &symval; is_defined_in_discarded_section = (gsym->is_defined_in_discarded_section() && gsym->is_undefined()); shndx = 0; } Symbol_value symval2; if (is_defined_in_discarded_section) { if (comdat_behavior == CB_UNDETERMINED) { std::string name = object->section_name(relinfo->data_shndx); comdat_behavior = default_comdat_behavior.get(name.c_str()); } if (comdat_behavior == CB_PRETEND) { bool found; typename elfcpp::Elf_types::Elf_Addr value = object->map_to_kept_section(shndx, &found); if (found) symval2.set_output_value(value + psymval->input_value()); else symval2.set_output_value(0); } else { if (comdat_behavior == CB_WARNING) gold_warning_at_location(relinfo, i, offset, _("relocation refers to discarded " "section")); symval2.set_output_value(0); } symval2.set_no_output_symtab_entry(); psymval = &symval2; } // If symbol is a section symbol, we don't know the actual type of // destination. Give up. if (psymval->is_section_symbol()) continue; this->scan_reloc_for_stub(relinfo, r_type, sym, r_sym, psymval, addend, view_address + offset); } // End of iterating relocs in a section } // End of Target_aarch64::scan_reloc_section_for_stubs // Scan an input section for stub generation. template void Target_aarch64::scan_section_for_stubs( 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, const unsigned char* view, Address view_address, section_size_type view_size) { gold_assert(sh_type == elfcpp::SHT_RELA); this->scan_reloc_section_for_stubs( relinfo, prelocs, reloc_count, output_section, needs_special_offset_handling, view, view_address, view_size); } // Relocate a single stub. template void Target_aarch64:: relocate_stub(The_reloc_stub* stub, const The_relocate_info*, Output_section*, unsigned char* view, Address address, section_size_type) { typedef AArch64_relocate_functions The_reloc_functions; typedef typename The_reloc_functions::Status The_reloc_functions_status; typedef typename elfcpp::Swap<32,big_endian>::Valtype Insntype; Insntype* ip = reinterpret_cast(view); int insn_number = stub->stub_insn_number(); const uint32_t* insns = stub->stub_insns(); // Check the insns are really those stub insns. for (int i = 0; i < insn_number; ++i) { Insntype insn = elfcpp::Swap<32,big_endian>::readval(ip + i); gold_assert(((uint32_t)insn == insns[i+1])); } Address dest = stub->destination_address(); switch(stub->stub_type()) { case The_reloc_stub::ST_ADRP_BRANCH: { // 1st reloc is ADR_PREL_PG_HI21 The_reloc_functions_status status = The_reloc_functions::adrp(view, dest, address); // An error should never arise in the above step. If so, please // check 'aarch64_valid_for_adrp_p'. gold_assert(status == The_reloc_functions::STATUS_OKAY); // 2nd reloc is ADD_ABS_LO12_NC const AArch64_reloc_property* arp = aarch64_reloc_property_table->get_reloc_property( elfcpp::R_AARCH64_ADD_ABS_LO12_NC); gold_assert(arp != NULL); status = The_reloc_functions::template rela_general<32>(view + 4, dest, 0, arp); // An error should never arise, it is an "_NC" relocation. gold_assert(status == The_reloc_functions::STATUS_OKAY); } break; case The_reloc_stub::ST_LONG_BRANCH_ABS: // 1st reloc is R_AARCH64_PREL64, at offset 8 elfcpp::Swap<64,big_endian>::writeval(view + 8, dest); break; case The_reloc_stub::ST_LONG_BRANCH_PCREL: { // "PC" calculation is the 2nd insn in the stub. uint64_t offset = dest - (address + 4); // Offset is placed at offset 4 and 5. elfcpp::Swap<64,big_endian>::writeval(view + 16, offset); } break; default: gold_unreachable(); } } // 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_got_aarch64* got, Output_data_space* got_plt, Output_data_space* got_irelative) : Output_section_data(addralign), tlsdesc_rel_(NULL), irelative_rel_(NULL), got_(got), got_plt_(got_plt), got_irelative_(got_irelative), count_(0), irelative_count_(0), tlsdesc_got_offset_(-1U) { this->init(layout); } // Initialize the PLT section. void init(Layout* layout); // Add an entry to the PLT. void add_entry(Symbol_table*, Layout*, Symbol* gsym); // Add an entry to the PLT for a local STT_GNU_IFUNC symbol. unsigned int add_local_ifunc_entry(Symbol_table* symtab, Layout*, Sized_relobj_file* relobj, unsigned int local_sym_index); // Add the relocation for a PLT entry. void add_relocation(Symbol_table*, Layout*, Symbol* gsym, unsigned int got_offset); // Add the reserved TLSDESC_PLT entry to the PLT. void reserve_tlsdesc_entry(unsigned int got_offset) { this->tlsdesc_got_offset_ = got_offset; } // Return true if a TLSDESC_PLT entry has been reserved. bool has_tlsdesc_entry() const { return this->tlsdesc_got_offset_ != -1U; } // Return the GOT offset for the reserved TLSDESC_PLT entry. unsigned int get_tlsdesc_got_offset() const { return this->tlsdesc_got_offset_; } // Return the PLT offset of the reserved TLSDESC_PLT entry. unsigned int get_tlsdesc_plt_offset() const { return (this->first_plt_entry_offset() + (this->count_ + this->irelative_count_) * this->get_plt_entry_size()); } // Return the .rela.plt section data. Reloc_section* rela_plt() { return this->rel_; } // Return where the TLSDESC relocations should go. Reloc_section* rela_tlsdesc(Layout*); // Return where the IRELATIVE relocations should go in the PLT // relocations. Reloc_section* rela_irelative(Symbol_table*, Layout*); // 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_ + this->irelative_count_; } // Return the offset of the first non-reserved PLT entry. unsigned int first_plt_entry_offset() const { 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 reserved tlsdesc entry size. unsigned int get_plt_tlsdesc_entry_size() const { return this->do_get_plt_tlsdesc_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); } // Fill in the reserved TLSDESC PLT entry. void fill_tlsdesc_entry(unsigned char* pov, Address gotplt_address, Address plt_address, Address got_base, unsigned int tlsdesc_got_offset, unsigned int plt_offset) { this->do_fill_tlsdesc_entry(pov, gotplt_address, plt_address, got_base, tlsdesc_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 unsigned int do_get_plt_tlsdesc_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; virtual void do_fill_tlsdesc_entry(unsigned char* pov, Address gotplt_address, Address plt_address, Address got_base, unsigned int tlsdesc_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 TLSDESC relocs, if necessary. These must follow the regular // PLT relocs. Reloc_section* tlsdesc_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 part of the .got.plt section used for IRELATIVE relocs. Output_data_space* got_irelative_; // The number of PLT entries. unsigned int count_; // Number of PLT entries with R_AARCH64_IRELATIVE relocs. These // follow the regular PLT entries. unsigned int irelative_count_; // GOT offset of the reserved TLSDESC_GOT entry for the lazy trampoline. // Communicated to the loader via DT_TLSDESC_GOT. The magic value -1 // indicates an offset is not allocated. unsigned int tlsdesc_got_offset_; }; // 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_table* symtab, Layout* layout, Symbol* gsym) { gold_assert(!gsym->has_plt_offset()); unsigned int* pcount; unsigned int plt_reserved; Output_section_data_build* got; if (gsym->type() == elfcpp::STT_GNU_IFUNC && gsym->can_use_relative_reloc(false)) { pcount = &this->irelative_count_; plt_reserved = 0; got = this->got_irelative_; } else { pcount = &this->count_; plt_reserved = this->first_plt_entry_offset(); got = this->got_plt_; } gsym->set_plt_offset((*pcount) * this->get_plt_entry_size() + plt_reserved); ++*pcount; section_offset_type got_offset = got->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). got->set_current_data_size(got_offset + size / 8); // Every PLT entry needs a reloc. this->add_relocation(symtab, layout, gsym, got_offset); // 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. } // Add an entry to the PLT for a local STT_GNU_IFUNC symbol. Return // the PLT offset. template unsigned int Output_data_plt_aarch64::add_local_ifunc_entry( Symbol_table* symtab, Layout* layout, Sized_relobj_file* relobj, unsigned int local_sym_index) { unsigned int plt_offset = this->irelative_count_ * this->get_plt_entry_size(); ++this->irelative_count_; section_offset_type got_offset = this->got_irelative_->current_data_size(); // Every PLT entry needs a GOT entry which points back to the PLT // entry. this->got_irelative_->set_current_data_size(got_offset + size / 8); // Every PLT entry needs a reloc. Reloc_section* rela = this->rela_irelative(symtab, layout); rela->add_symbolless_local_addend(relobj, local_sym_index, elfcpp::R_AARCH64_IRELATIVE, this->got_irelative_, got_offset, 0); return plt_offset; } // Add the relocation for a PLT entry. template void Output_data_plt_aarch64::add_relocation( Symbol_table* symtab, Layout* layout, Symbol* gsym, unsigned int got_offset) { if (gsym->type() == elfcpp::STT_GNU_IFUNC && gsym->can_use_relative_reloc(false)) { Reloc_section* rela = this->rela_irelative(symtab, layout); rela->add_symbolless_global_addend(gsym, elfcpp::R_AARCH64_IRELATIVE, this->got_irelative_, got_offset, 0); } else { gsym->set_needs_dynsym_entry(); this->rel_->add_global(gsym, elfcpp::R_AARCH64_JUMP_SLOT, this->got_plt_, got_offset, 0); } } // Return where the TLSDESC relocations should go, creating it if // necessary. These follow the JUMP_SLOT relocations. template typename Output_data_plt_aarch64::Reloc_section* Output_data_plt_aarch64::rela_tlsdesc(Layout* layout) { if (this->tlsdesc_rel_ == NULL) { this->tlsdesc_rel_ = new Reloc_section(false); layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA, elfcpp::SHF_ALLOC, this->tlsdesc_rel_, ORDER_DYNAMIC_PLT_RELOCS, false); gold_assert(this->tlsdesc_rel_->output_section() == this->rel_->output_section()); } return this->tlsdesc_rel_; } // Return where the IRELATIVE relocations should go in the PLT. These // follow the JUMP_SLOT and the TLSDESC relocations. template typename Output_data_plt_aarch64::Reloc_section* Output_data_plt_aarch64::rela_irelative(Symbol_table* symtab, Layout* layout) { if (this->irelative_rel_ == NULL) { // Make sure we have a place for the TLSDESC relocations, in // case we see any later on. this->rela_tlsdesc(layout); this->irelative_rel_ = new Reloc_section(false); layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA, elfcpp::SHF_ALLOC, this->irelative_rel_, ORDER_DYNAMIC_PLT_RELOCS, false); gold_assert(this->irelative_rel_->output_section() == this->rel_->output_section()); if (parameters->doing_static_link()) { // A statically linked executable will only have a .rela.plt // section to hold R_AARCH64_IRELATIVE relocs for // STT_GNU_IFUNC symbols. The library will use these // symbols to locate the IRELATIVE relocs at program startup // time. symtab->define_in_output_data("__rela_iplt_start", NULL, Symbol_table::PREDEFINED, this->irelative_rel_, 0, 0, elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0, false, true); symtab->define_in_output_data("__rela_iplt_end", NULL, Symbol_table::PREDEFINED, this->irelative_rel_, 0, 0, elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0, true, true); } } return this->irelative_rel_; } // 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() { unsigned int count = this->count_ + this->irelative_count_; unsigned int extra_size = 0; if (this->has_tlsdesc_entry()) extra_size += this->get_plt_tlsdesc_entry_size(); this->set_data_size(this->first_plt_entry_offset() + count * this->get_plt_entry_size() + extra_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_got_aarch64* got, Output_data_space* got_plt, Output_data_space* got_irelative) : Output_data_plt_aarch64(layout, size == 32 ? 4 : 8, got, got_plt, got_irelative) { } 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; } // Return the size of a tlsdesc entry virtual unsigned int do_get_plt_tlsdesc_entry_size() const { return this->plt_tlsdesc_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); virtual void do_fill_tlsdesc_entry(unsigned char* pov, Address gotplt_address, Address plt_address, Address got_base, unsigned int tlsdesc_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; // The size of the plt tlsdesc entry size. static const int plt_tlsdesc_entry_size = 32; // 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 reserved TLSDESC entry in the PLT for an executable. static const uint32_t tlsdesc_plt_entry[plt_tlsdesc_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))); } template<> const uint32_t Output_data_plt_aarch64_standard<32, false>:: tlsdesc_plt_entry[plt_tlsdesc_entry_size / 4] = { 0xa9bf0fe2, /* stp x2, x3, [sp, #-16]! */ 0x90000002, /* adrp x2, 0 */ 0x90000003, /* adrp x3, 0 */ 0xb9400042, /* ldr w2, [w2, #0] */ 0x11000063, /* add w3, w3, 0 */ 0xd61f0040, /* br x2 */ 0xd503201f, /* nop */ 0xd503201f, /* nop */ }; template<> const uint32_t Output_data_plt_aarch64_standard<32, true>:: tlsdesc_plt_entry[plt_tlsdesc_entry_size / 4] = { 0xa9bf0fe2, /* stp x2, x3, [sp, #-16]! */ 0x90000002, /* adrp x2, 0 */ 0x90000003, /* adrp x3, 0 */ 0xb9400042, /* ldr w2, [w2, #0] */ 0x11000063, /* add w3, w3, 0 */ 0xd61f0040, /* br x2 */ 0xd503201f, /* nop */ 0xd503201f, /* nop */ }; template<> const uint32_t Output_data_plt_aarch64_standard<64, false>:: tlsdesc_plt_entry[plt_tlsdesc_entry_size / 4] = { 0xa9bf0fe2, /* stp x2, x3, [sp, #-16]! */ 0x90000002, /* adrp x2, 0 */ 0x90000003, /* adrp x3, 0 */ 0xf9400042, /* ldr x2, [x2, #0] */ 0x91000063, /* add x3, x3, 0 */ 0xd61f0040, /* br x2 */ 0xd503201f, /* nop */ 0xd503201f, /* nop */ }; template<> const uint32_t Output_data_plt_aarch64_standard<64, true>:: tlsdesc_plt_entry[plt_tlsdesc_entry_size / 4] = { 0xa9bf0fe2, /* stp x2, x3, [sp, #-16]! */ 0x90000002, /* adrp x2, 0 */ 0x90000003, /* adrp x3, 0 */ 0xf9400042, /* ldr x2, [x2, #0] */ 0x91000063, /* add x3, x3, 0 */ 0xd61f0040, /* br x2 */ 0xd503201f, /* nop */ 0xd503201f, /* nop */ }; template void Output_data_plt_aarch64_standard::do_fill_tlsdesc_entry( unsigned char* pov, Address gotplt_address, Address plt_address, Address got_base, unsigned int tlsdesc_got_offset, unsigned int plt_offset) { memcpy(pov, tlsdesc_plt_entry, plt_tlsdesc_entry_size); // move DT_TLSDESC_GOT address into x2 // move .got.plt address into x3 Address tlsdesc_got_entry = got_base + tlsdesc_got_offset; Address plt_entry_address = plt_address + plt_offset; // R_AARCH64_ADR_PREL_PG_HI21 AArch64_relocate_functions::adrp( pov + 4, tlsdesc_got_entry, plt_entry_address + 4); // R_AARCH64_ADR_PREL_PG_HI21 AArch64_relocate_functions::adrp( pov + 8, gotplt_address, plt_entry_address + 8); // R_AARCH64_LDST64_ABS_LO12 elfcpp::Swap<32, big_endian>::writeval( pov + 12, ((this->tlsdesc_plt_entry[3] & 0xffc003ff) | ((tlsdesc_got_entry & 0xff8) << 7))); // R_AARCH64_ADD_ABS_LO12 elfcpp::Swap<32, big_endian>::writeval( pov + 16, ((this->tlsdesc_plt_entry[4] & 0xffc003ff) | ((gotplt_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(); gold_assert(got_file_offset + this->got_plt_->data_size() == this->got_irelative_->offset()); const section_size_type got_size = convert_to_section_size_type(this->got_plt_->data_size() + this->got_irelative_->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 gotplt_address = this->got_plt_->address(); this->fill_first_plt_entry(pov, gotplt_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_ + this->irelative_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, gotplt_address, plt_address, got_offset, plt_offset); // Set the entry in the GOT, which points to plt0. elfcpp::Swap::writeval(got_pov, plt_address); } if (this->has_tlsdesc_entry()) { // Set and adjust the reserved TLSDESC PLT entry. unsigned int tlsdesc_got_offset = this->get_tlsdesc_got_offset(); // The base address of the .base section. typename elfcpp::Elf_types::Elf_Addr got_base = this->got_->address(); this->fill_tlsdesc_entry(pov, gotplt_address, plt_address, got_base, tlsdesc_got_offset, plt_offset); pov += this->get_plt_tlsdesc_entry_size(); } 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; typedef AArch64_relocate_functions This; typedef typename elfcpp::Elf_types::Elf_Addr Address; typedef Relocate_info The_relocate_info; typedef AArch64_relobj The_aarch64_relobj; typedef Reloc_stub The_reloc_stub; typedef typename The_reloc_stub::Stub_type The_reloc_stub_type; typedef Stub_table The_stub_table; typedef elfcpp::Rela The_rela; typedef typename elfcpp::Swap::Valtype AArch64_valtype; // Return the page address of the address. // Page(address) = address & ~0xFFF static inline AArch64_valtype Page(Address address) { return (address & (~static_cast
(0xFFF))); } private: // Update instruction (pointed by view) with selected bits (immed). // val = (val & ~dst_mask) | (immed << doffset) template static inline void update_view(unsigned char* view, AArch64_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, AArch64_valtype immed1, AArch64_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 immed. // In adr and adrp: [30:29] immlo [23:5] immhi static inline void update_adr(unsigned char* view, AArch64_valtype immed) { elfcpp::Elf_Xword dst_mask = (0x3 << 29) | (0x7ffff << 5); This::template update_view_two_parts<32>( view, immed & 0x3, (immed & 0x1ffffc) >> 2, 29, 5, dst_mask); } // Update movz/movn instruction with bits immed. // Set instruction to movz if is_movz is true, otherwise set instruction // to movn. static inline void update_movnz(unsigned char* view, AArch64_valtype immed, bool is_movz) { typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype; Valtype* wv = reinterpret_cast(view); Valtype val = elfcpp::Swap<32, big_endian>::readval(wv); const elfcpp::Elf_Xword doffset = aarch64_howto[AArch64_reloc_property::INST_MOVW].doffset; const elfcpp::Elf_Xword dst_mask = aarch64_howto[AArch64_reloc_property::INST_MOVW].dst_mask; // Clear immediate fields and opc code. val &= ~(dst_mask | (0x3 << 29)); // Set instruction to movz or movn. // movz: [30:29] is 10 movn: [30:29] is 00 if (is_movz) val |= (0x2 << 29); elfcpp::Swap<32, big_endian>::writeval(wv, static_cast(val | (immed << doffset))); } // Update selected bits in text. template static inline typename This::Status reloc_common(unsigned char* view, Address x, const AArch64_reloc_property* reloc_property) { // 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); } 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, AArch64_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, AArch64_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, AArch64_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, AArch64_valtype addend, const AArch64_reloc_property* reloc_property) { // Calculate relocation. Address x = psymval->value(object, addend); return This::template reloc_common(view, x, reloc_property); } // 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, AArch64_valtype s, AArch64_valtype addend, const AArch64_reloc_property* reloc_property) { // Calculate relocation. Address x = s + addend; return This::template reloc_common(view, x, reloc_property); } // 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, AArch64_valtype addend, Address address, const AArch64_reloc_property* reloc_property) { // Calculate relocation. Address x = psymval->value(object, addend) - address; return This::template reloc_common(view, x, reloc_property); } // Calculate (S + A) - address, update adr instruction. static inline typename This::Status adr(unsigned char* view, const Sized_relobj_file* object, const Symbol_value* psymval, Address addend, Address address, const AArch64_reloc_property* /* reloc_property */) { AArch64_valtype x = psymval->value(object, addend) - address; // Pick bits [20:0] of X. AArch64_valtype immed = x & 0x1fffff; update_adr(view, immed); // Check -2^20 <= X < 2^20 return (size == 64 && Bits<21>::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, Address sa, Address address) { AArch64_valtype x = This::Page(sa) - This::Page(address); // Pick [32:12] of X. AArch64_valtype immed = (x >> 12) & 0x1fffff; update_adr(view, immed); // Check -2^32 <= X < 2^32 return (size == 64 && Bits<33>::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); AArch64_valtype x = This::Page(sa) - This::Page(address); // Pick [32:12] of X. AArch64_valtype immed = (x >> 12) & 0x1fffff; update_adr(view, immed); return (reloc_property->checkup_x_value(x) ? This::STATUS_OKAY : This::STATUS_OVERFLOW); } // Update mov[n/z] instruction. Check overflow if needed. // If X >=0, set the instruction to movz and its immediate value to the // selected bits S. // If X < 0, set the instruction to movn and its immediate value to // NOT (selected bits of). static inline typename This::Status movnz(unsigned char* view, AArch64_valtype x, const AArch64_reloc_property* reloc_property) { // Select bits from X. Address immed; bool is_movz; typedef typename elfcpp::Elf_types::Elf_Swxword SignedW; if (static_cast(x) >= 0) { immed = reloc_property->select_x_value(x); is_movz = true; } else { immed = reloc_property->select_x_value(~x);; is_movz = false; } // Update movnz instruction. update_movnz(view, immed, is_movz); // Do check overflow or alignment if needed. return (reloc_property->checkup_x_value(x) ? This::STATUS_OKAY : This::STATUS_OVERFLOW); } static inline bool maybe_apply_stub(unsigned int, const The_relocate_info*, const The_rela&, unsigned char*, Address, const Sized_symbol*, const Symbol_value*, const Sized_relobj_file*, section_size_type); }; // End of AArch64_relocate_functions // For a certain relocation type (usually jump/branch), test to see if the // destination needs a stub to fulfil. If so, re-route the destination of the // original instruction to the stub, note, at this time, the stub has already // been generated. template bool AArch64_relocate_functions:: maybe_apply_stub(unsigned int r_type, const The_relocate_info* relinfo, const The_rela& rela, unsigned char* view, Address address, const Sized_symbol* gsym, const Symbol_value* psymval, const Sized_relobj_file* object, section_size_type current_group_size) { if (parameters->options().relocatable()) return false; typename elfcpp::Elf_types::Elf_Swxword addend = rela.get_r_addend(); Address branch_target = psymval->value(object, 0) + addend; The_reloc_stub_type stub_type = The_reloc_stub:: stub_type_for_reloc(r_type, address, branch_target); if (stub_type == The_reloc_stub::ST_NONE) return false; const The_aarch64_relobj* aarch64_relobj = static_cast(object); The_stub_table* stub_table = aarch64_relobj->stub_table(relinfo->data_shndx); gold_assert(stub_table != NULL); unsigned int r_sym = elfcpp::elf_r_sym(rela.get_r_info()); typename The_reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend); The_reloc_stub* stub = stub_table->find_reloc_stub(stub_key); gold_assert(stub != NULL); Address new_branch_target = stub_table->address() + stub->offset(); typename elfcpp::Swap::Valtype branch_offset = new_branch_target - address; const AArch64_reloc_property* arp = aarch64_reloc_property_table->get_reloc_property(r_type); gold_assert(arp != NULL); typename This::Status status = This::template rela_general<32>(view, branch_offset, 0, arp); if (status != This::STATUS_OKAY) gold_error(_("Stub is too far away, try a smaller value " "for '--stub-group-size'. The current value is 0x%lx."), static_cast(current_group_size)); return true; } // Group input sections for stub generation. // // We group input sections in an output section so that the total size, // including any padding space due to alignment is smaller than GROUP_SIZE // unless the only input section in group is bigger than GROUP_SIZE already. // Then an ARM stub table is created to follow the last input section // in group. For each group an ARM stub table is created an is placed // after the last group. If STUB_ALWAYS_AFTER_BRANCH is false, we further // extend the group after the stub table. template void Target_aarch64::group_sections( Layout* layout, section_size_type group_size, bool stubs_always_after_branch, const Task* task) { // Group input sections and insert stub table Layout::Section_list section_list; layout->get_executable_sections(§ion_list); for (Layout::Section_list::const_iterator p = section_list.begin(); p != section_list.end(); ++p) { AArch64_output_section* output_section = static_cast*>(*p); output_section->group_sections(group_size, stubs_always_after_branch, this, task); } } // Find the AArch64_input_section object corresponding to the SHNDX-th input // section of RELOBJ. template AArch64_input_section* Target_aarch64::find_aarch64_input_section( Relobj* relobj, unsigned int shndx) const { Section_id sid(relobj, shndx); typename AArch64_input_section_map::const_iterator p = this->aarch64_input_section_map_.find(sid); return (p != this->aarch64_input_section_map_.end()) ? p->second : NULL; } // Make a new AArch64_input_section object. template AArch64_input_section* Target_aarch64::new_aarch64_input_section( Relobj* relobj, unsigned int shndx) { Section_id sid(relobj, shndx); AArch64_input_section* input_section = new AArch64_input_section(relobj, shndx); input_section->init(); // Register new AArch64_input_section in map for look-up. std::pair ins = this->aarch64_input_section_map_.insert( std::make_pair(sid, input_section)); // Make sure that it we have not created another AArch64_input_section // for this input section already. gold_assert(ins.second); return input_section; } // Relaxation hook. This is where we do stub generation. template bool Target_aarch64::do_relax( int pass, const Input_objects* input_objects, Symbol_table* symtab, Layout* layout , const Task* task) { gold_assert(!parameters->options().relocatable()); if (pass == 1) { // We don't handle negative stub_group_size right now. this->stub_group_size_ = abs(parameters->options().stub_group_size()); if (this->stub_group_size_ == 1) { // Leave room for 4096 4-byte stub entries. If we exceed that, then we // will fail to link. The user will have to relink with an explicit // group size option. this->stub_group_size_ = The_reloc_stub::MAX_BRANCH_OFFSET - 4096 * 4; } group_sections(layout, this->stub_group_size_, true, task); } else { // If this is not the first pass, addresses and file offsets have // been reset at this point, set them here. for (Stub_table_iterator sp = this->stub_tables_.begin(); sp != this->stub_tables_.end(); ++sp) { The_stub_table* stt = *sp; The_aarch64_input_section* owner = stt->owner(); off_t off = align_address(owner->original_size(), stt->addralign()); stt->set_address_and_file_offset(owner->address() + off, owner->offset() + off); } } // Scan relocs for relocation stubs for (Input_objects::Relobj_iterator op = input_objects->relobj_begin(); op != input_objects->relobj_end(); ++op) { The_aarch64_relobj* aarch64_relobj = static_cast(*op); // Lock the object so we can read from it. This is only called // single-threaded from Layout::finalize, so it is OK to lock. Task_lock_obj tl(task, aarch64_relobj); aarch64_relobj->scan_sections_for_stubs(this, symtab, layout); } bool any_stub_table_changed = false; for (Stub_table_iterator siter = this->stub_tables_.begin(); siter != this->stub_tables_.end() && !any_stub_table_changed; ++siter) { The_stub_table* stub_table = *siter; if (stub_table->update_data_size_changed_p()) { The_aarch64_input_section* owner = stub_table->owner(); uint64_t address = owner->address(); off_t offset = owner->offset(); owner->reset_address_and_file_offset(); owner->set_address_and_file_offset(address, offset); any_stub_table_changed = true; } } // Do not continue relaxation. bool continue_relaxation = any_stub_table_changed; if (!continue_relaxation) for (Stub_table_iterator sp = this->stub_tables_.begin(); (sp != this->stub_tables_.end()); ++sp) (*sp)->finalize_stubs(); return continue_relaxation; } // Make a new Stub_table. template Stub_table* Target_aarch64::new_stub_table( AArch64_input_section* owner) { Stub_table* stub_table = new Stub_table(owner); stub_table->set_address(align_address( owner->address() + owner->data_size(), 8)); stub_table->set_file_offset(owner->offset() + owner->data_size()); stub_table->finalize_data_size(); this->stub_tables_.push_back(stub_table); return stub_table; } template typename elfcpp::Elf_types::Elf_Addr Target_aarch64::do_reloc_addend( void* arg, unsigned int r_type, typename elfcpp::Elf_types::Elf_Addr) const { gold_assert(r_type == elfcpp::R_AARCH64_TLSDESC); uintptr_t intarg = reinterpret_cast(arg); gold_assert(intarg < this->tlsdesc_reloc_info_.size()); const Tlsdesc_info& ti(this->tlsdesc_reloc_info_[intarg]); const Symbol_value* psymval = ti.object->local_symbol(ti.r_sym); gold_assert(psymval->is_tls_symbol()); // The value of a TLS symbol is the offset in the TLS segment. return psymval->value(ti.object, 0); } // 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(); } // Define the _TLS_MODULE_BASE_ symbol in the TLS segment. template void Target_aarch64::define_tls_base_symbol( Symbol_table* symtab, Layout* layout) { if (this->tls_base_symbol_defined_) return; Output_segment* tls_segment = layout->tls_segment(); if (tls_segment != NULL) { bool is_exec = parameters->options().output_is_executable(); symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL, Symbol_table::PREDEFINED, tls_segment, 0, 0, elfcpp::STT_TLS, elfcpp::STB_LOCAL, elfcpp::STV_HIDDEN, 0, (is_exec ? Symbol::SEGMENT_END : Symbol::SEGMENT_START), true); } this->tls_base_symbol_defined_ = true; } // Create the reserved PLT and GOT entries for the TLS descriptor resolver. template void Target_aarch64::reserve_tlsdesc_entries( Symbol_table* symtab, Layout* layout) { if (this->plt_ == NULL) this->make_plt_section(symtab, layout); if (!this->plt_->has_tlsdesc_entry()) { // Allocate the TLSDESC_GOT entry. Output_data_got_aarch64* got = this->got_section(symtab, layout); unsigned int got_offset = got->add_constant(0); // Allocate the TLSDESC_PLT entry. this->plt_->reserve_tlsdesc_entry(got_offset); } } // Create a GOT entry for the TLS module index. template unsigned int Target_aarch64::got_mod_index_entry( Symbol_table* symtab, Layout* layout, Sized_relobj_file* object) { if (this->got_mod_index_offset_ == -1U) { gold_assert(symtab != NULL && layout != NULL && object != NULL); Reloc_section* rela_dyn = this->rela_dyn_section(layout); Output_data_got_aarch64* got = this->got_section(symtab, layout); unsigned int got_offset = got->add_constant(0); rela_dyn->add_local(object, 0, elfcpp::R_AARCH64_TLS_DTPMOD64, got, got_offset, 0); got->add_constant(0); this->got_mod_index_offset_ = got_offset; } return this->got_mod_index_offset_; } // 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) { // If we are generating a shared library, then we can't do anything // in the linker if (parameters->options().shared()) return tls::TLSOPT_NONE; switch (r_type) { case elfcpp::R_AARCH64_TLSGD_ADR_PAGE21: case elfcpp::R_AARCH64_TLSGD_ADD_LO12_NC: case elfcpp::R_AARCH64_TLSDESC_LD_PREL19: case elfcpp::R_AARCH64_TLSDESC_ADR_PREL21: case elfcpp::R_AARCH64_TLSDESC_ADR_PAGE21: case elfcpp::R_AARCH64_TLSDESC_LD64_LO12: case elfcpp::R_AARCH64_TLSDESC_ADD_LO12: case elfcpp::R_AARCH64_TLSDESC_OFF_G1: case elfcpp::R_AARCH64_TLSDESC_OFF_G0_NC: case elfcpp::R_AARCH64_TLSDESC_LDR: case elfcpp::R_AARCH64_TLSDESC_ADD: case elfcpp::R_AARCH64_TLSDESC_CALL: // These are General-Dynamic which permits fully general TLS // access. Since we know that we are generating an executable, // we can convert this to Initial-Exec. If we also know that // this is a local symbol, we can further switch to Local-Exec. if (is_final) return tls::TLSOPT_TO_LE; return tls::TLSOPT_TO_IE; case elfcpp::R_AARCH64_TLSLD_ADR_PAGE21: case elfcpp::R_AARCH64_TLSLD_ADD_LO12_NC: case elfcpp::R_AARCH64_TLSLD_MOVW_DTPREL_G1: case elfcpp::R_AARCH64_TLSLD_MOVW_DTPREL_G0_NC: // These are Local-Dynamic, which refer to local symbols in the // dynamic TLS block. Since we know that we generating an // executable, we can switch to Local-Exec. return tls::TLSOPT_TO_LE; case elfcpp::R_AARCH64_TLSIE_MOVW_GOTTPREL_G1: case elfcpp::R_AARCH64_TLSIE_MOVW_GOTTPREL_G0_NC: case elfcpp::R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21: case elfcpp::R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC: case elfcpp::R_AARCH64_TLSIE_LD_GOTTPREL_PREL19: // These are Initial-Exec relocs which get the thread offset // from the GOT. If we know that we are linking against the // local symbol, we can switch to Local-Exec, which links the // thread offset into the instruction. if (is_final) return tls::TLSOPT_TO_LE; return tls::TLSOPT_NONE; case elfcpp::R_AARCH64_TLSLE_MOVW_TPREL_G2: case elfcpp::R_AARCH64_TLSLE_MOVW_TPREL_G1: case elfcpp::R_AARCH64_TLSLE_MOVW_TPREL_G1_NC: case elfcpp::R_AARCH64_TLSLE_MOVW_TPREL_G0: case elfcpp::R_AARCH64_TLSLE_MOVW_TPREL_G0_NC: case elfcpp::R_AARCH64_TLSLE_ADD_TPREL_HI12: case elfcpp::R_AARCH64_TLSLE_ADD_TPREL_LO12: case elfcpp::R_AARCH64_TLSLE_ADD_TPREL_LO12_NC: // When we already have Local-Exec, there is nothing further we // can do. return tls::TLSOPT_NONE; default: gold_unreachable(); } } // 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_ADR_PREL_PG_HI21: case elfcpp::R_AARCH64_ADR_PREL_PG_HI21_NC: case elfcpp::R_AARCH64_ADD_ABS_LO12_NC: case elfcpp::R_AARCH64_ADR_GOT_PAGE: case elfcpp::R_AARCH64_LD64_GOT_LO12_NC: { 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. 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; } // Return whether we need to make a PLT entry for a relocation of the // given type against a STT_GNU_IFUNC symbol. template bool Target_aarch64::Scan::reloc_needs_plt_for_ifunc( Sized_relobj_file* object, unsigned int r_type) { const AArch64_reloc_property* arp = aarch64_reloc_property_table->get_reloc_property(r_type); gold_assert(arp != NULL); int flags = arp->reference_flags(); if (flags & Symbol::TLS_REF) { gold_error(_("%s: unsupported TLS reloc %s for IFUNC symbol"), object->name().c_str(), arp->name().c_str()); return false; } return flags != 0; } // 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& rela, unsigned int r_type, const elfcpp::Sym& lsym, bool is_discarded) { if (is_discarded) return; typedef Output_data_reloc Reloc_section; Output_data_got_aarch64* got = target->got_section(symtab, layout); unsigned int r_sym = elfcpp::elf_r_sym(rela.get_r_info()); // A local STT_GNU_IFUNC symbol may require a PLT entry. bool is_ifunc = lsym.get_st_type() == elfcpp::STT_GNU_IFUNC; if (is_ifunc && this->reloc_needs_plt_for_ifunc(object, r_type)) target->make_local_ifunc_plt_entry(symtab, layout, object, r_sym); switch (r_type) { case elfcpp::R_AARCH64_ABS32: case elfcpp::R_AARCH64_ABS16: if (parameters->options().output_is_position_independent()) { gold_error(_("%s: unsupported reloc %u in pos independent link."), object->name().c_str(), r_type); } break; case elfcpp::R_AARCH64_ABS64: // If building a shared library or pie, we need to mark this as a dynmic // reloction, so that the dynamic loader can relocate it. if (parameters->options().output_is_position_independent()) { Reloc_section* rela_dyn = target->rela_dyn_section(layout); rela_dyn->add_local_relative(object, r_sym, elfcpp::R_AARCH64_RELATIVE, output_section, data_shndx, rela.get_r_offset(), rela.get_r_addend(), is_ifunc); } break; case elfcpp::R_AARCH64_PREL64: case elfcpp::R_AARCH64_PREL32: case elfcpp::R_AARCH64_PREL16: break; case elfcpp::R_AARCH64_LD_PREL_LO19: // 273 case elfcpp::R_AARCH64_ADR_PREL_LO21: // 274 case elfcpp::R_AARCH64_ADR_PREL_PG_HI21: // 275 case elfcpp::R_AARCH64_ADR_PREL_PG_HI21_NC: // 276 case elfcpp::R_AARCH64_ADD_ABS_LO12_NC: // 277 case elfcpp::R_AARCH64_LDST8_ABS_LO12_NC: // 278 case elfcpp::R_AARCH64_LDST16_ABS_LO12_NC: // 284 case elfcpp::R_AARCH64_LDST32_ABS_LO12_NC: // 285 case elfcpp::R_AARCH64_LDST64_ABS_LO12_NC: // 286 case elfcpp::R_AARCH64_LDST128_ABS_LO12_NC: // 299 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_TSTBR14: case elfcpp::R_AARCH64_CONDBR19: case elfcpp::R_AARCH64_JUMP26: case elfcpp::R_AARCH64_CALL26: break; case elfcpp::R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21: case elfcpp::R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC: { tls::Tls_optimization tlsopt = Target_aarch64:: optimize_tls_reloc(!parameters->options().shared(), r_type); if (tlsopt == tls::TLSOPT_TO_LE) break; layout->set_has_static_tls(); // Create a GOT entry for the tp-relative offset. if (!parameters->doing_static_link()) { got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET, target->rela_dyn_section(layout), elfcpp::R_AARCH64_TLS_TPREL64); } else if (!object->local_has_got_offset(r_sym, GOT_TYPE_TLS_OFFSET)) { got->add_local(object, r_sym, GOT_TYPE_TLS_OFFSET); unsigned int got_offset = object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET); const elfcpp::Elf_Xword addend = rela.get_r_addend(); gold_assert(addend == 0); got->add_static_reloc(got_offset, elfcpp::R_AARCH64_TLS_TPREL64, object, r_sym); } } break; case elfcpp::R_AARCH64_TLSGD_ADR_PAGE21: case elfcpp::R_AARCH64_TLSGD_ADD_LO12_NC: { tls::Tls_optimization tlsopt = Target_aarch64:: optimize_tls_reloc(!parameters->options().shared(), r_type); if (tlsopt == tls::TLSOPT_TO_LE) { layout->set_has_static_tls(); break; } gold_assert(tlsopt == tls::TLSOPT_NONE); got->add_local_pair_with_rel(object,r_sym, data_shndx, GOT_TYPE_TLS_PAIR, target->rela_dyn_section(layout), elfcpp::R_AARCH64_TLS_DTPMOD64); } break; case elfcpp::R_AARCH64_TLSLE_ADD_TPREL_HI12: case elfcpp::R_AARCH64_TLSLE_ADD_TPREL_LO12: case elfcpp::R_AARCH64_TLSLE_ADD_TPREL_LO12_NC: { layout->set_has_static_tls(); bool output_is_shared = parameters->options().shared(); if (output_is_shared) gold_error(_("%s: unsupported TLSLE reloc %u in shared code."), object->name().c_str(), r_type); } break; case elfcpp::R_AARCH64_TLSLD_ADR_PAGE21: case elfcpp::R_AARCH64_TLSLD_ADD_LO12_NC: { tls::Tls_optimization tlsopt = Target_aarch64:: optimize_tls_reloc(!parameters->options().shared(), r_type); if (tlsopt == tls::TLSOPT_NONE) { // Create a GOT entry for the module index. target->got_mod_index_entry(symtab, layout, object); } else if (tlsopt != tls::TLSOPT_TO_LE) unsupported_reloc_local(object, r_type); } break; case elfcpp::R_AARCH64_TLSLD_MOVW_DTPREL_G1: case elfcpp::R_AARCH64_TLSLD_MOVW_DTPREL_G0_NC: break; case elfcpp::R_AARCH64_TLSDESC_ADR_PAGE21: case elfcpp::R_AARCH64_TLSDESC_LD64_LO12: case elfcpp::R_AARCH64_TLSDESC_ADD_LO12: { tls::Tls_optimization tlsopt = Target_aarch64:: optimize_tls_reloc(!parameters->options().shared(), r_type); target->define_tls_base_symbol(symtab, layout); if (tlsopt == tls::TLSOPT_NONE) { // Create reserved PLT and GOT entries for the resolver. target->reserve_tlsdesc_entries(symtab, layout); // Generate a double GOT entry with an R_AARCH64_TLSDESC reloc. // The R_AARCH64_TLSDESC reloc is resolved lazily, so the GOT // entry needs to be in an area in .got.plt, not .got. Call // got_section to make sure the section has been created. target->got_section(symtab, layout); Output_data_got* got = target->got_tlsdesc_section(); unsigned int r_sym = elfcpp::elf_r_sym(rela.get_r_info()); if (!object->local_has_got_offset(r_sym, GOT_TYPE_TLS_DESC)) { unsigned int got_offset = got->add_constant(0); got->add_constant(0); object->set_local_got_offset(r_sym, GOT_TYPE_TLS_DESC, got_offset); Reloc_section* rt = target->rela_tlsdesc_section(layout); // We store the arguments we need in a vector, and use // the index into the vector as the parameter to pass // to the target specific routines. uintptr_t intarg = target->add_tlsdesc_info(object, r_sym); void* arg = reinterpret_cast(intarg); rt->add_target_specific(elfcpp::R_AARCH64_TLSDESC, arg, got, got_offset, 0); } } else if (tlsopt != tls::TLSOPT_TO_LE) unsupported_reloc_local(object, r_type); } break; case elfcpp::R_AARCH64_TLSDESC_CALL: 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& rela, unsigned int r_type, Symbol* gsym) { // A STT_GNU_IFUNC symbol may require a PLT entry. if (gsym->type() == elfcpp::STT_GNU_IFUNC && this->reloc_needs_plt_for_ifunc(object, r_type)) target->make_plt_entry(symtab, layout, gsym); typedef Output_data_reloc Reloc_section; const AArch64_reloc_property* arp = aarch64_reloc_property_table->get_reloc_property(r_type); gold_assert(arp != NULL); switch (r_type) { case elfcpp::R_AARCH64_ABS16: case elfcpp::R_AARCH64_ABS32: case elfcpp::R_AARCH64_ABS64: { // Make a PLT entry if necessary. if (gsym->needs_plt_entry()) { target->make_plt_entry(symtab, layout, gsym); // Since this is not a PC-relative relocation, we may be // taking the address of a function. In that case we need to // set the entry in the dynamic symbol table to the address of // the PLT entry. if (gsym->is_from_dynobj() && !parameters->options().shared()) gsym->set_needs_dynsym_value(); } // Make a dynamic relocation if necessary. if (gsym->needs_dynamic_reloc(arp->reference_flags())) { if (!parameters->options().output_is_position_independent() && gsym->may_need_copy_reloc()) { target->copy_reloc(symtab, layout, object, data_shndx, output_section, gsym, rela); } else if (r_type == elfcpp::R_AARCH64_ABS64 && gsym->type() == elfcpp::STT_GNU_IFUNC && gsym->can_use_relative_reloc(false) && !gsym->is_from_dynobj() && !gsym->is_undefined() && !gsym->is_preemptible()) { // Use an IRELATIVE reloc for a locally defined STT_GNU_IFUNC // symbol. This makes a function address in a PIE executable // match the address in a shared library that it links against. Reloc_section* rela_dyn = target->rela_irelative_section(layout); unsigned int r_type = elfcpp::R_AARCH64_IRELATIVE; rela_dyn->add_symbolless_global_addend(gsym, r_type, output_section, object, data_shndx, rela.get_r_offset(), rela.get_r_addend()); } else if (r_type == elfcpp::R_AARCH64_ABS64 && gsym->can_use_relative_reloc(false)) { Reloc_section* rela_dyn = target->rela_dyn_section(layout); rela_dyn->add_global_relative(gsym, elfcpp::R_AARCH64_RELATIVE, output_section, object, data_shndx, rela.get_r_offset(), rela.get_r_addend(), false); } else { check_non_pic(object, r_type); Output_data_reloc* rela_dyn = target->rela_dyn_section(layout); rela_dyn->add_global( gsym, r_type, output_section, object, data_shndx, rela.get_r_offset(),rela.get_r_addend()); } } } break; case elfcpp::R_AARCH64_PREL16: case elfcpp::R_AARCH64_PREL32: case elfcpp::R_AARCH64_PREL64: // 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_LD_PREL_LO19: // 273 case elfcpp::R_AARCH64_ADR_PREL_LO21: // 274 case elfcpp::R_AARCH64_ADR_PREL_PG_HI21: // 275 case elfcpp::R_AARCH64_ADR_PREL_PG_HI21_NC: // 276 case elfcpp::R_AARCH64_ADD_ABS_LO12_NC: // 277 case elfcpp::R_AARCH64_LDST8_ABS_LO12_NC: // 278 case elfcpp::R_AARCH64_LDST16_ABS_LO12_NC: // 284 case elfcpp::R_AARCH64_LDST32_ABS_LO12_NC: // 285 case elfcpp::R_AARCH64_LDST64_ABS_LO12_NC: // 286 case elfcpp::R_AARCH64_LDST128_ABS_LO12_NC: // 299 { if (gsym->needs_plt_entry()) target->make_plt_entry(symtab, layout, gsym); // Make a dynamic relocation if necessary. if (gsym->needs_dynamic_reloc(arp->reference_flags())) { if (parameters->options().output_is_executable() && gsym->may_need_copy_reloc()) { target->copy_reloc(symtab, layout, object, data_shndx, output_section, gsym, rela); } } 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()) { // For a STT_GNU_IFUNC symbol we want the PLT address. if (gsym->type() == elfcpp::STT_GNU_IFUNC) got->add_global_plt(gsym, GOT_TYPE_STANDARD); else got->add_global(gsym, GOT_TYPE_STANDARD); } else { // If this symbol is not fully resolved, we need to add a dynamic // relocation for it. Reloc_section* rela_dyn = target->rela_dyn_section(layout); // Use a GLOB_DAT rather than a RELATIVE reloc if: // // 1) The symbol may be defined in some other module. // 2) We are building a shared library and this is a protected // symbol; using GLOB_DAT means that the dynamic linker can use // the address of the PLT in the main executable when appropriate // so that function address comparisons work. // 3) This is a STT_GNU_IFUNC symbol in position dependent code, // again so that function address comparisons work. if (gsym->is_from_dynobj() || gsym->is_undefined() || gsym->is_preemptible() || (gsym->visibility() == elfcpp::STV_PROTECTED && parameters->options().shared()) || (gsym->type() == elfcpp::STT_GNU_IFUNC && parameters->options().output_is_position_independent())) got->add_global_with_rel(gsym, GOT_TYPE_STANDARD, rela_dyn, elfcpp::R_AARCH64_GLOB_DAT); else { // For a STT_GNU_IFUNC symbol we want to write the PLT // offset into the GOT, so that function pointer // comparisons work correctly. bool is_new; if (gsym->type() != elfcpp::STT_GNU_IFUNC) is_new = got->add_global(gsym, GOT_TYPE_STANDARD); else { is_new = got->add_global_plt(gsym, GOT_TYPE_STANDARD); // Tell the dynamic linker to use the PLT address // when resolving relocations. if (gsym->is_from_dynobj() && !parameters->options().shared()) gsym->set_needs_dynsym_value(); } if (is_new) { rela_dyn->add_global_relative( gsym, elfcpp::R_AARCH64_RELATIVE, got, gsym->got_offset(GOT_TYPE_STANDARD), 0, false); } } } break; } case elfcpp::R_AARCH64_TSTBR14: case elfcpp::R_AARCH64_CONDBR19: 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. target->make_plt_entry(symtab, layout, gsym); break; } case elfcpp::R_AARCH64_TLSGD_ADR_PAGE21: case elfcpp::R_AARCH64_TLSGD_ADD_LO12_NC: // General dynamic { tls::Tls_optimization tlsopt = Target_aarch64:: optimize_tls_reloc(gsym->final_value_is_known(), r_type); if (tlsopt == tls::TLSOPT_TO_LE) { layout->set_has_static_tls(); break; } gold_assert(tlsopt == tls::TLSOPT_NONE); // General dynamic. Output_data_got_aarch64* got = target->got_section(symtab, layout); // Create 2 consecutive entries for module index and offset. got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR, target->rela_dyn_section(layout), elfcpp::R_AARCH64_TLS_DTPMOD64, elfcpp::R_AARCH64_TLS_DTPREL64); } break; case elfcpp::R_AARCH64_TLSLD_ADR_PAGE21: case elfcpp::R_AARCH64_TLSLD_ADD_LO12_NC: // Local dynamic { tls::Tls_optimization tlsopt = Target_aarch64:: optimize_tls_reloc(!parameters->options().shared(), r_type); if (tlsopt == tls::TLSOPT_NONE) { // Create a GOT entry for the module index. target->got_mod_index_entry(symtab, layout, object); } else if (tlsopt != tls::TLSOPT_TO_LE) unsupported_reloc_local(object, r_type); } break; case elfcpp::R_AARCH64_TLSLD_MOVW_DTPREL_G1: case elfcpp::R_AARCH64_TLSLD_MOVW_DTPREL_G0_NC: // Other local dynamic break; case elfcpp::R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21: case elfcpp::R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC: // Initial executable { tls::Tls_optimization tlsopt = Target_aarch64:: optimize_tls_reloc(gsym->final_value_is_known(), r_type); if (tlsopt == tls::TLSOPT_TO_LE) break; layout->set_has_static_tls(); // Create a GOT entry for the tp-relative offset. Output_data_got_aarch64* got = target->got_section(symtab, layout); if (!parameters->doing_static_link()) { got->add_global_with_rel( gsym, GOT_TYPE_TLS_OFFSET, target->rela_dyn_section(layout), elfcpp::R_AARCH64_TLS_TPREL64); } if (!gsym->has_got_offset(GOT_TYPE_TLS_OFFSET)) { got->add_global(gsym, GOT_TYPE_TLS_OFFSET); unsigned int got_offset = gsym->got_offset(GOT_TYPE_TLS_OFFSET); const elfcpp::Elf_Xword addend = rela.get_r_addend(); gold_assert(addend == 0); got->add_static_reloc(got_offset, elfcpp::R_AARCH64_TLS_TPREL64, gsym); } } break; case elfcpp::R_AARCH64_TLSLE_ADD_TPREL_HI12: case elfcpp::R_AARCH64_TLSLE_ADD_TPREL_LO12: case elfcpp::R_AARCH64_TLSLE_ADD_TPREL_LO12_NC: // Local executable layout->set_has_static_tls(); if (parameters->options().shared()) gold_error(_("%s: unsupported TLSLE reloc type %u in shared objects."), object->name().c_str(), r_type); break; case elfcpp::R_AARCH64_TLSDESC_ADR_PAGE21: case elfcpp::R_AARCH64_TLSDESC_LD64_LO12: case elfcpp::R_AARCH64_TLSDESC_ADD_LO12: // TLS descriptor { target->define_tls_base_symbol(symtab, layout); tls::Tls_optimization tlsopt = Target_aarch64:: optimize_tls_reloc(gsym->final_value_is_known(), r_type); if (tlsopt == tls::TLSOPT_NONE) { // Create reserved PLT and GOT entries for the resolver. target->reserve_tlsdesc_entries(symtab, layout); // Create a double GOT entry with an R_AARCH64_TLSDESC // relocation. The R_AARCH64_TLSDESC is resolved lazily, so the GOT // entry needs to be in an area in .got.plt, not .got. Call // got_section to make sure the section has been created. target->got_section(symtab, layout); Output_data_got* got = target->got_tlsdesc_section(); Reloc_section* rt = target->rela_tlsdesc_section(layout); got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_DESC, rt, elfcpp::R_AARCH64_TLSDESC, 0); } else if (tlsopt == tls::TLSOPT_TO_IE) { // Create a GOT entry for the tp-relative offset. Output_data_got* got = target->got_section(symtab, layout); got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET, target->rela_dyn_section(layout), elfcpp::R_AARCH64_TLS_TPREL64); } else if (tlsopt != tls::TLSOPT_TO_LE) unsupported_reloc_global(object, r_type, gsym); } break; case elfcpp::R_AARCH64_TLSDESC_CALL: break; default: gold_error(_("%s: unsupported reloc type in global scan"), 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_, this->got_plt_, this->got_irelative_); 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()); } } // Return the section for TLSDESC relocations. template typename Target_aarch64::Reloc_section* Target_aarch64::rela_tlsdesc_section(Layout* layout) const { return this->plt_section()->rela_tlsdesc(layout); } // 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(symtab, layout, gsym); } // Make a PLT entry for a local STT_GNU_IFUNC symbol. template void Target_aarch64::make_local_ifunc_plt_entry( Symbol_table* symtab, Layout* layout, Sized_relobj_file* relobj, unsigned int local_sym_index) { if (relobj->local_has_plt_offset(local_sym_index)) return; if (this->plt_ == NULL) this->make_plt_section(symtab, layout); unsigned int plt_offset = this->plt_->add_local_ifunc_entry(symtab, layout, relobj, local_sym_index); relobj->set_local_plt_offset(local_sym_index, plt_offset); } 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); } // Return the value to use for a dynamic which requires special // treatment. This is how we support equality comparisons of function // pointers across shared library boundaries, as described in the // processor specific ABI supplement. template uint64_t Target_aarch64::do_dynsym_value(const Symbol* gsym) const { gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset()); return this->plt_address_for_global(gsym); } // 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); // Emit any relocs we saved in an attempt to avoid generating COPY // relocs. if (this->copy_relocs_.any_saved_relocs()) this->copy_relocs_.emit(this->rela_dyn_section(layout)); // Fill in some more dynamic tags. Output_data_dynamic* const odyn = layout->dynamic_data(); if (odyn != NULL) { if (this->plt_ != NULL && this->plt_->output_section() != NULL && this->plt_ ->has_tlsdesc_entry()) { unsigned int plt_offset = this->plt_->get_tlsdesc_plt_offset(); unsigned int got_offset = this->plt_->get_tlsdesc_got_offset(); this->got_->finalize_data_size(); odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_PLT, this->plt_, plt_offset); odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_GOT, this->got_, got_offset); } } // 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); break; case elfcpp::R_AARCH64_PREL32: reloc_status = Reloc::template pcrela_ua<32>( view, object, psymval, addend, address, reloc_property); break; case elfcpp::R_AARCH64_PREL16: reloc_status = Reloc::template pcrela_ua<16>( view, object, psymval, addend, address, reloc_property); break; case elfcpp::R_AARCH64_LD_PREL_LO19: reloc_status = Reloc::template pcrela_general<32>( view, object, psymval, addend, address, reloc_property); break; case elfcpp::R_AARCH64_ADR_PREL_LO21: reloc_status = Reloc::adr(view, object, psymval, addend, address, reloc_property); break; 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: if (this->skip_call_tls_get_addr_) { // Double check that the TLSGD insn has been optimized away. typedef typename elfcpp::Swap<32, big_endian>::Valtype Insntype; Insntype insn = elfcpp::Swap<32, big_endian>::readval( reinterpret_cast(view)); gold_assert((insn & 0xff000000) == 0x91000000); reloc_status = Reloc::STATUS_OKAY; this->skip_call_tls_get_addr_ = false; // Return false to stop further processing this reloc. return false; } // Fallthrough case elfcpp::R_AARCH64_JUMP26: if (Reloc::maybe_apply_stub(r_type, relinfo, rela, view, address, gsym, psymval, object, target->stub_group_size_)) break; // Fallthrough case elfcpp::R_AARCH64_TSTBR14: case elfcpp::R_AARCH64_CONDBR19: 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; case elfcpp::R_AARCH64_TLSGD_ADR_PAGE21: case elfcpp::R_AARCH64_TLSGD_ADD_LO12_NC: case elfcpp::R_AARCH64_TLSLD_ADR_PAGE21: case elfcpp::R_AARCH64_TLSLD_ADD_LO12_NC: case elfcpp::R_AARCH64_TLSLD_MOVW_DTPREL_G1: case elfcpp::R_AARCH64_TLSLD_MOVW_DTPREL_G0_NC: case elfcpp::R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21: case elfcpp::R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC: case elfcpp::R_AARCH64_TLSLE_ADD_TPREL_HI12: case elfcpp::R_AARCH64_TLSLE_ADD_TPREL_LO12: case elfcpp::R_AARCH64_TLSLE_ADD_TPREL_LO12_NC: case elfcpp::R_AARCH64_TLSDESC_ADR_PAGE21: case elfcpp::R_AARCH64_TLSDESC_LD64_LO12: case elfcpp::R_AARCH64_TLSDESC_ADD_LO12: case elfcpp::R_AARCH64_TLSDESC_CALL: reloc_status = relocate_tls(relinfo, target, relnum, rela, r_type, gsym, psymval, view, address); break; // These are dynamic relocations, which are unexpected when linking. 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_IRELATIVE: case elfcpp::R_AARCH64_TLS_DTPREL64: case elfcpp::R_AARCH64_TLS_DTPMOD64: case elfcpp::R_AARCH64_TLS_TPREL64: case elfcpp::R_AARCH64_TLSDESC: gold_error_at_location(relinfo, relnum, rela.get_r_offset(), _("unexpected reloc %u in object file"), r_type); break; default: gold_error_at_location(relinfo, relnum, rela.get_r_offset(), _("unsupported reloc %s"), reloc_property->name().c_str()); 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; } template inline typename AArch64_relocate_functions::Status Target_aarch64::Relocate::relocate_tls( const Relocate_info* relinfo, Target_aarch64* target, 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) { typedef AArch64_relocate_functions aarch64_reloc_funcs; typedef typename elfcpp::Elf_types::Elf_Addr AArch64_address; Output_segment* tls_segment = relinfo->layout->tls_segment(); const elfcpp::Elf_Xword addend = rela.get_r_addend(); const AArch64_reloc_property* reloc_property = aarch64_reloc_property_table->get_reloc_property(r_type); gold_assert(reloc_property != NULL); const bool is_final = (gsym == NULL ? !parameters->options().shared() : gsym->final_value_is_known()); tls::Tls_optimization tlsopt = Target_aarch64:: optimize_tls_reloc(is_final, r_type); Sized_relobj_file* object = relinfo->object; int tls_got_offset_type; switch (r_type) { case elfcpp::R_AARCH64_TLSGD_ADR_PAGE21: case elfcpp::R_AARCH64_TLSGD_ADD_LO12_NC: // Global-dynamic { if (tlsopt == tls::TLSOPT_TO_LE) { if (tls_segment == NULL) { gold_assert(parameters->errors()->error_count() > 0 || issue_undefined_symbol_error(gsym)); return aarch64_reloc_funcs::STATUS_BAD_RELOC; } return tls_gd_to_le(relinfo, target, rela, r_type, view, psymval); } else if (tlsopt == tls::TLSOPT_NONE) { tls_got_offset_type = GOT_TYPE_TLS_PAIR; // Firstly get the address for the got entry. typename elfcpp::Elf_types::Elf_Addr got_entry_address; if (gsym != NULL) { gold_assert(gsym->has_got_offset(tls_got_offset_type)); got_entry_address = target->got_->address() + gsym->got_offset(tls_got_offset_type); } else { unsigned int r_sym = elfcpp::elf_r_sym(rela.get_r_info()); gold_assert( object->local_has_got_offset(r_sym, tls_got_offset_type)); got_entry_address = target->got_->address() + object->local_got_offset(r_sym, tls_got_offset_type); } // Relocate the address into adrp/ld, adrp/add pair. switch (r_type) { case elfcpp::R_AARCH64_TLSGD_ADR_PAGE21: return aarch64_reloc_funcs::adrp( view, got_entry_address + addend, address); break; case elfcpp::R_AARCH64_TLSGD_ADD_LO12_NC: return aarch64_reloc_funcs::template rela_general<32>( view, got_entry_address, addend, reloc_property); break; default: gold_unreachable(); } } gold_error_at_location(relinfo, relnum, rela.get_r_offset(), _("unsupported gd_to_ie relaxation on %u"), r_type); } break; case elfcpp::R_AARCH64_TLSLD_ADR_PAGE21: case elfcpp::R_AARCH64_TLSLD_ADD_LO12_NC: // Local-dynamic { if (tlsopt == tls::TLSOPT_TO_LE) { if (tls_segment == NULL) { gold_assert(parameters->errors()->error_count() > 0 || issue_undefined_symbol_error(gsym)); return aarch64_reloc_funcs::STATUS_BAD_RELOC; } return this->tls_ld_to_le(relinfo, target, rela, r_type, view, psymval); } gold_assert(tlsopt == tls::TLSOPT_NONE); // Relocate the field with the offset of the GOT entry for // the module index. typename elfcpp::Elf_types::Elf_Addr got_entry_address; got_entry_address = (target->got_mod_index_entry(NULL, NULL, NULL) + target->got_->address()); switch (r_type) { case elfcpp::R_AARCH64_TLSLD_ADR_PAGE21: return aarch64_reloc_funcs::adrp( view, got_entry_address + addend, address); break; case elfcpp::R_AARCH64_TLSLD_ADD_LO12_NC: return aarch64_reloc_funcs::template rela_general<32>( view, got_entry_address, addend, reloc_property); break; default: gold_unreachable(); } } break; case elfcpp::R_AARCH64_TLSLD_MOVW_DTPREL_G1: case elfcpp::R_AARCH64_TLSLD_MOVW_DTPREL_G0_NC: // Other local-dynamic { AArch64_address value = psymval->value(object, 0); if (tlsopt == tls::TLSOPT_TO_LE) { if (tls_segment == NULL) { gold_assert(parameters->errors()->error_count() > 0 || issue_undefined_symbol_error(gsym)); return aarch64_reloc_funcs::STATUS_BAD_RELOC; } // If building executable, _TLS_MODULE_BASE_ points to segment // end. Thus we must subtract it from value. value -= tls_segment->memsz(); } switch (r_type) { case elfcpp::R_AARCH64_TLSLD_MOVW_DTPREL_G1: return aarch64_reloc_funcs::movnz(view, value + addend, reloc_property); break; case elfcpp::R_AARCH64_TLSLD_MOVW_DTPREL_G0_NC: return aarch64_reloc_funcs::template rela_general<32>( view, value, addend, reloc_property); break; default: gold_unreachable(); } // We should never reach here. } break; case elfcpp::R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21: case elfcpp::R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC: // Initial-exec { if (tlsopt == tls::TLSOPT_TO_LE) { if (tls_segment == NULL) { gold_assert(parameters->errors()->error_count() > 0 || issue_undefined_symbol_error(gsym)); return aarch64_reloc_funcs::STATUS_BAD_RELOC; } return tls_ie_to_le(relinfo, target, rela, r_type, view, psymval); } tls_got_offset_type = GOT_TYPE_TLS_OFFSET; // Firstly get the address for the got entry. typename elfcpp::Elf_types::Elf_Addr got_entry_address; if (gsym != NULL) { gold_assert(gsym->has_got_offset(tls_got_offset_type)); got_entry_address = target->got_->address() + gsym->got_offset(tls_got_offset_type); } else { unsigned int r_sym = elfcpp::elf_r_sym(rela.get_r_info()); gold_assert( object->local_has_got_offset(r_sym, tls_got_offset_type)); got_entry_address = target->got_->address() + object->local_got_offset(r_sym, tls_got_offset_type); } // Relocate the address into adrp/ld, adrp/add pair. switch (r_type) { case elfcpp::R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21: return aarch64_reloc_funcs::adrp(view, got_entry_address + addend, address); break; case elfcpp::R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC: return aarch64_reloc_funcs::template rela_general<32>( view, got_entry_address, addend, reloc_property); default: gold_unreachable(); } } // We shall never reach here. break; case elfcpp::R_AARCH64_TLSLE_ADD_TPREL_HI12: case elfcpp::R_AARCH64_TLSLE_ADD_TPREL_LO12: case elfcpp::R_AARCH64_TLSLE_ADD_TPREL_LO12_NC: { gold_assert(tls_segment != NULL); AArch64_address value = psymval->value(object, 0); if (!parameters->options().shared()) { AArch64_address aligned_tcb_size = align_address(target->tcb_size(), tls_segment->maximum_alignment()); return aarch64_reloc_funcs::template rela_general<32>(view, value + aligned_tcb_size, addend, reloc_property); } else gold_error(_("%s: unsupported reloc %u " "in non-static TLSLE mode."), object->name().c_str(), r_type); } break; case elfcpp::R_AARCH64_TLSDESC_ADR_PAGE21: case elfcpp::R_AARCH64_TLSDESC_LD64_LO12: case elfcpp::R_AARCH64_TLSDESC_ADD_LO12: case elfcpp::R_AARCH64_TLSDESC_CALL: { if (tlsopt == tls::TLSOPT_TO_LE) { if (tls_segment == NULL) { gold_assert(parameters->errors()->error_count() > 0 || issue_undefined_symbol_error(gsym)); return aarch64_reloc_funcs::STATUS_BAD_RELOC; } return tls_desc_gd_to_le(relinfo, target, rela, r_type, view, psymval); } else { tls_got_offset_type = (tlsopt == tls::TLSOPT_TO_IE ? GOT_TYPE_TLS_OFFSET : GOT_TYPE_TLS_DESC); unsigned int got_tlsdesc_offset = 0; if (r_type != elfcpp::R_AARCH64_TLSDESC_CALL && tlsopt == tls::TLSOPT_NONE) { // We created GOT entries in the .got.tlsdesc portion of the // .got.plt section, but the offset stored in the symbol is the // offset within .got.tlsdesc. got_tlsdesc_offset = (target->got_->data_size() + target->got_plt_section()->data_size()); } typename elfcpp::Elf_types::Elf_Addr got_entry_address; if (gsym != NULL) { gold_assert(gsym->has_got_offset(tls_got_offset_type)); got_entry_address = target->got_->address() + got_tlsdesc_offset + gsym->got_offset(tls_got_offset_type); } else { unsigned int r_sym = elfcpp::elf_r_sym(rela.get_r_info()); gold_assert( object->local_has_got_offset(r_sym, tls_got_offset_type)); got_entry_address = target->got_->address() + got_tlsdesc_offset + object->local_got_offset(r_sym, tls_got_offset_type); } if (tlsopt == tls::TLSOPT_TO_IE) { if (tls_segment == NULL) { gold_assert(parameters->errors()->error_count() > 0 || issue_undefined_symbol_error(gsym)); return aarch64_reloc_funcs::STATUS_BAD_RELOC; } return tls_desc_gd_to_ie(relinfo, target, rela, r_type, view, psymval, got_entry_address, address); } // Now do tlsdesc relocation. switch (r_type) { case elfcpp::R_AARCH64_TLSDESC_ADR_PAGE21: return aarch64_reloc_funcs::adrp(view, got_entry_address + addend, address); break; case elfcpp::R_AARCH64_TLSDESC_LD64_LO12: case elfcpp::R_AARCH64_TLSDESC_ADD_LO12: return aarch64_reloc_funcs::template rela_general<32>( view, got_entry_address, addend, reloc_property); break; case elfcpp::R_AARCH64_TLSDESC_CALL: return aarch64_reloc_funcs::STATUS_OKAY; break; default: gold_unreachable(); } } } break; default: gold_error(_("%s: unsupported TLS reloc %u."), object->name().c_str(), r_type); } return aarch64_reloc_funcs::STATUS_BAD_RELOC; } // End of relocate_tls. template inline typename AArch64_relocate_functions::Status Target_aarch64::Relocate::tls_gd_to_le( const Relocate_info* relinfo, Target_aarch64* target, const elfcpp::Rela& rela, unsigned int r_type, unsigned char* view, const Symbol_value* psymval) { typedef AArch64_relocate_functions aarch64_reloc_funcs; typedef typename elfcpp::Swap<32, big_endian>::Valtype Insntype; typedef typename elfcpp::Elf_types::Elf_Addr AArch64_address; Insntype* ip = reinterpret_cast(view); Insntype insn1 = elfcpp::Swap<32, big_endian>::readval(ip); Insntype insn2 = elfcpp::Swap<32, big_endian>::readval(ip + 1); Insntype insn3 = elfcpp::Swap<32, big_endian>::readval(ip + 2); if (r_type == elfcpp::R_AARCH64_TLSGD_ADD_LO12_NC) { // This is the 2nd relocs, optimization should already have been // done. gold_assert((insn1 & 0xfff00000) == 0x91400000); return aarch64_reloc_funcs::STATUS_OKAY; } // The original sequence is - // 90000000 adrp x0, 0
// 91000000 add x0, x0, #0x0 // 94000000 bl 0 <__tls_get_addr> // optimized to sequence - // d53bd040 mrs x0, tpidr_el0 // 91400000 add x0, x0, #0x0, lsl #12 // 91000000 add x0, x0, #0x0 // Unlike tls_ie_to_le, we change the 3 insns in one function call when we // encounter the first relocation "R_AARCH64_TLSGD_ADR_PAGE21". Because we // have to change "bl tls_get_addr", which does not have a corresponding tls // relocation type. So before proceeding, we need to make sure compiler // does not change the sequence. if(!(insn1 == 0x90000000 // adrp x0,0 && insn2 == 0x91000000 // add x0, x0, #0x0 && insn3 == 0x94000000)) // bl 0 { // Ideally we should give up gd_to_le relaxation and do gd access. // However the gd_to_le relaxation decision has been made early // in the scan stage, where we did not allocate any GOT entry for // this symbol. Therefore we have to exit and report error now. gold_error(_("unexpected reloc insn sequence while relaxing " "tls gd to le for reloc %u."), r_type); return aarch64_reloc_funcs::STATUS_BAD_RELOC; } // Write new insns. insn1 = 0xd53bd040; // mrs x0, tpidr_el0 insn2 = 0x91400000; // add x0, x0, #0x0, lsl #12 insn3 = 0x91000000; // add x0, x0, #0x0 elfcpp::Swap<32, big_endian>::writeval(ip, insn1); elfcpp::Swap<32, big_endian>::writeval(ip + 1, insn2); elfcpp::Swap<32, big_endian>::writeval(ip + 2, insn3); // Calculate tprel value. Output_segment* tls_segment = relinfo->layout->tls_segment(); gold_assert(tls_segment != NULL); AArch64_address value = psymval->value(relinfo->object, 0); const elfcpp::Elf_Xword addend = rela.get_r_addend(); AArch64_address aligned_tcb_size = align_address(target->tcb_size(), tls_segment->maximum_alignment()); AArch64_address x = value + aligned_tcb_size; // After new insns are written, apply TLSLE relocs. const AArch64_reloc_property* rp1 = aarch64_reloc_property_table->get_reloc_property( elfcpp::R_AARCH64_TLSLE_ADD_TPREL_HI12); const AArch64_reloc_property* rp2 = aarch64_reloc_property_table->get_reloc_property( elfcpp::R_AARCH64_TLSLE_ADD_TPREL_LO12); gold_assert(rp1 != NULL && rp2 != NULL); typename aarch64_reloc_funcs::Status s1 = aarch64_reloc_funcs::template rela_general<32>(view + 4, x, addend, rp1); if (s1 != aarch64_reloc_funcs::STATUS_OKAY) return s1; typename aarch64_reloc_funcs::Status s2 = aarch64_reloc_funcs::template rela_general<32>(view + 8, x, addend, rp2); this->skip_call_tls_get_addr_ = true; return s2; } // End of tls_gd_to_le template inline typename AArch64_relocate_functions::Status Target_aarch64::Relocate::tls_ld_to_le( const Relocate_info* relinfo, Target_aarch64* target, const elfcpp::Rela& rela, unsigned int r_type, unsigned char* view, const Symbol_value* psymval) { typedef AArch64_relocate_functions aarch64_reloc_funcs; typedef typename elfcpp::Swap<32, big_endian>::Valtype Insntype; typedef typename elfcpp::Elf_types::Elf_Addr AArch64_address; Insntype* ip = reinterpret_cast(view); Insntype insn1 = elfcpp::Swap<32, big_endian>::readval(ip); Insntype insn2 = elfcpp::Swap<32, big_endian>::readval(ip + 1); Insntype insn3 = elfcpp::Swap<32, big_endian>::readval(ip + 2); if (r_type == elfcpp::R_AARCH64_TLSLD_ADD_LO12_NC) { // This is the 2nd relocs, optimization should already have been // done. gold_assert((insn1 & 0xfff00000) == 0x91400000); return aarch64_reloc_funcs::STATUS_OKAY; } // The original sequence is - // 90000000 adrp x0, 0
// 91000000 add x0, x0, #0x0 // 94000000 bl 0 <__tls_get_addr> // optimized to sequence - // d53bd040 mrs x0, tpidr_el0 // 91400000 add x0, x0, #0x0, lsl #12 // 91000000 add x0, x0, #0x0 // Unlike tls_ie_to_le, we change the 3 insns in one function call when we // encounter the first relocation "R_AARCH64_TLSLD_ADR_PAGE21". Because we // have to change "bl tls_get_addr", which does not have a corresponding tls // relocation type. So before proceeding, we need to make sure compiler // does not change the sequence. if(!(insn1 == 0x90000000 // adrp x0,0 && insn2 == 0x91000000 // add x0, x0, #0x0 && insn3 == 0x94000000)) // bl 0 { // Ideally we should give up gd_to_le relaxation and do gd access. // However the gd_to_le relaxation decision has been made early // in the scan stage, where we did not allocate any GOT entry for // this symbol. Therefore we have to exit and report error now. gold_error(_("unexpected reloc insn sequence while relaxing " "tls gd to le for reloc %u."), r_type); return aarch64_reloc_funcs::STATUS_BAD_RELOC; } // Write new insns. insn1 = 0xd53bd040; // mrs x0, tpidr_el0 insn2 = 0x91400000; // add x0, x0, #0x0, lsl #12 insn3 = 0x91000000; // add x0, x0, #0x0 elfcpp::Swap<32, big_endian>::writeval(ip, insn1); elfcpp::Swap<32, big_endian>::writeval(ip + 1, insn2); elfcpp::Swap<32, big_endian>::writeval(ip + 2, insn3); // Calculate tprel value. Output_segment* tls_segment = relinfo->layout->tls_segment(); gold_assert(tls_segment != NULL); AArch64_address value = psymval->value(relinfo->object, 0); const elfcpp::Elf_Xword addend = rela.get_r_addend(); AArch64_address aligned_tcb_size = align_address(target->tcb_size(), tls_segment->maximum_alignment()); AArch64_address x = value + aligned_tcb_size; // After new insns are written, apply TLSLE relocs. const AArch64_reloc_property* rp1 = aarch64_reloc_property_table->get_reloc_property( elfcpp::R_AARCH64_TLSLE_ADD_TPREL_HI12); const AArch64_reloc_property* rp2 = aarch64_reloc_property_table->get_reloc_property( elfcpp::R_AARCH64_TLSLE_ADD_TPREL_LO12); gold_assert(rp1 != NULL && rp2 != NULL); typename aarch64_reloc_funcs::Status s1 = aarch64_reloc_funcs::template rela_general<32>(view + 4, x, addend, rp1); if (s1 != aarch64_reloc_funcs::STATUS_OKAY) return s1; typename aarch64_reloc_funcs::Status s2 = aarch64_reloc_funcs::template rela_general<32>(view + 8, x, addend, rp2); this->skip_call_tls_get_addr_ = true; return s2; } // End of tls_ld_to_le template inline typename AArch64_relocate_functions::Status Target_aarch64::Relocate::tls_ie_to_le( const Relocate_info* relinfo, Target_aarch64* target, const elfcpp::Rela& rela, unsigned int r_type, unsigned char* view, const Symbol_value* psymval) { typedef typename elfcpp::Elf_types::Elf_Addr AArch64_address; typedef typename elfcpp::Swap<32, big_endian>::Valtype Insntype; typedef AArch64_relocate_functions aarch64_reloc_funcs; AArch64_address value = psymval->value(relinfo->object, 0); Output_segment* tls_segment = relinfo->layout->tls_segment(); AArch64_address aligned_tcb_address = align_address(target->tcb_size(), tls_segment->maximum_alignment()); const elfcpp::Elf_Xword addend = rela.get_r_addend(); AArch64_address x = value + addend + aligned_tcb_address; // "x" is the offset to tp, we can only do this if x is within // range [0, 2^32-1] if (!(size == 32 || (size == 64 && (static_cast(x) >> 32) == 0))) { gold_error(_("TLS variable referred by reloc %u is too far from TP."), r_type); return aarch64_reloc_funcs::STATUS_BAD_RELOC; } Insntype* ip = reinterpret_cast(view); Insntype insn = elfcpp::Swap<32, big_endian>::readval(ip); unsigned int regno; Insntype newinsn; if (r_type == elfcpp::R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21) { // Generate movz. regno = (insn & 0x1f); newinsn = (0xd2a00000 | regno) | (((x >> 16) & 0xffff) << 5); } else if (r_type == elfcpp::R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC) { // Generate movk. regno = (insn & 0x1f); gold_assert(regno == ((insn >> 5) & 0x1f)); newinsn = (0xf2800000 | regno) | ((x & 0xffff) << 5); } else gold_unreachable(); elfcpp::Swap<32, big_endian>::writeval(ip, newinsn); return aarch64_reloc_funcs::STATUS_OKAY; } // End of tls_ie_to_le template inline typename AArch64_relocate_functions::Status Target_aarch64::Relocate::tls_desc_gd_to_le( const Relocate_info* relinfo, Target_aarch64* target, const elfcpp::Rela& rela, unsigned int r_type, unsigned char* view, const Symbol_value* psymval) { typedef typename elfcpp::Elf_types::Elf_Addr AArch64_address; typedef typename elfcpp::Swap<32, big_endian>::Valtype Insntype; typedef AArch64_relocate_functions aarch64_reloc_funcs; // TLSDESC-GD sequence is like: // adrp x0, :tlsdesc:v1 // ldr x1, [x0, #:tlsdesc_lo12:v1] // add x0, x0, :tlsdesc_lo12:v1 // .tlsdesccall v1 // blr x1 // After desc_gd_to_le optimization, the sequence will be like: // movz x0, #0x0, lsl #16 // movk x0, #0x10 // nop // nop // Calculate tprel value. Output_segment* tls_segment = relinfo->layout->tls_segment(); gold_assert(tls_segment != NULL); Insntype* ip = reinterpret_cast(view); const elfcpp::Elf_Xword addend = rela.get_r_addend(); AArch64_address value = psymval->value(relinfo->object, addend); AArch64_address aligned_tcb_size = align_address(target->tcb_size(), tls_segment->maximum_alignment()); AArch64_address x = value + aligned_tcb_size; // x is the offset to tp, we can only do this if x is within range // [0, 2^32-1]. If x is out of range, fail and exit. if (size == 64 && (static_cast(x) >> 32) != 0) { gold_error(_("TLS variable referred by reloc %u is too far from TP. " "We Can't do gd_to_le relaxation.\n"), r_type); return aarch64_reloc_funcs::STATUS_BAD_RELOC; } Insntype newinsn; switch (r_type) { case elfcpp::R_AARCH64_TLSDESC_ADD_LO12: case elfcpp::R_AARCH64_TLSDESC_CALL: // Change to nop newinsn = 0xd503201f; break; case elfcpp::R_AARCH64_TLSDESC_ADR_PAGE21: // Change to movz. newinsn = 0xd2a00000 | (((x >> 16) & 0xffff) << 5); break; case elfcpp::R_AARCH64_TLSDESC_LD64_LO12: // Change to movk. newinsn = 0xf2800000 | ((x & 0xffff) << 5); break; default: gold_error(_("unsupported tlsdesc gd_to_le optimization on reloc %u"), r_type); gold_unreachable(); } elfcpp::Swap<32, big_endian>::writeval(ip, newinsn); return aarch64_reloc_funcs::STATUS_OKAY; } // End of tls_desc_gd_to_le template inline typename AArch64_relocate_functions::Status Target_aarch64::Relocate::tls_desc_gd_to_ie( const Relocate_info* /* relinfo */, Target_aarch64* /* target */, const elfcpp::Rela& rela, unsigned int r_type, unsigned char* view, const Symbol_value* /* psymval */, typename elfcpp::Elf_types::Elf_Addr got_entry_address, typename elfcpp::Elf_types::Elf_Addr address) { typedef typename elfcpp::Swap<32, big_endian>::Valtype Insntype; typedef AArch64_relocate_functions aarch64_reloc_funcs; // TLSDESC-GD sequence is like: // adrp x0, :tlsdesc:v1 // ldr x1, [x0, #:tlsdesc_lo12:v1] // add x0, x0, :tlsdesc_lo12:v1 // .tlsdesccall v1 // blr x1 // After desc_gd_to_ie optimization, the sequence will be like: // adrp x0, :tlsie:v1 // ldr x0, [x0, :tlsie_lo12:v1] // nop // nop Insntype* ip = reinterpret_cast(view); const elfcpp::Elf_Xword addend = rela.get_r_addend(); Insntype newinsn; switch (r_type) { case elfcpp::R_AARCH64_TLSDESC_ADD_LO12: case elfcpp::R_AARCH64_TLSDESC_CALL: // Change to nop newinsn = 0xd503201f; elfcpp::Swap<32, big_endian>::writeval(ip, newinsn); break; case elfcpp::R_AARCH64_TLSDESC_ADR_PAGE21: { return aarch64_reloc_funcs::adrp(view, got_entry_address + addend, address); } break; case elfcpp::R_AARCH64_TLSDESC_LD64_LO12: { // Set ldr target register to be x0. Insntype insn = elfcpp::Swap<32, big_endian>::readval(ip); insn &= 0xffffffe0; elfcpp::Swap<32, big_endian>::writeval(ip, insn); // Do relocation. const AArch64_reloc_property* reloc_property = aarch64_reloc_property_table->get_reloc_property( elfcpp::R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC); return aarch64_reloc_funcs::template rela_general<32>( view, got_entry_address, addend, reloc_property); } break; default: gold_error(_("Don't support tlsdesc gd_to_ie optimization on reloc %u"), r_type); gold_unreachable(); } return aarch64_reloc_funcs::STATUS_OKAY; } // End of tls_desc_gd_to_ie // 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) { gold_assert(sh_type == elfcpp::SHT_RELA); typedef gold::Default_scan_relocatable_relocs Scan_relocatable_relocs; gold::scan_relocatable_relocs( symtab, layout, object, data_shndx, prelocs, reloc_count, output_section, needs_special_offset_handling, local_symbol_count, plocal_symbols, rr); } // 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) { gold_assert(sh_type == elfcpp::SHT_RELA); gold::relocate_relocs( relinfo, prelocs, reloc_count, output_section, offset_in_output_section, rr, view, view_address, view_size, reloc_view, reloc_view_size); } // 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.