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| author | Han Shen <shenhan@chromium.org> | 2014-10-15 15:23:01 -0700 |
|---|---|---|
| committer | Han Shen <shenhan@chromium.org> | 2014-10-15 15:23:01 -0700 |
| commit | 83a01957175f787ad5d7ac06885a2c0213e21028 (patch) | |
| tree | 239879bde0c3e44f2e1e5d8a9e66694b9a5e7ef6 | |
| parent | 44ee4a526db6160b302417127e736b73fc00ee87 (diff) | |
| download | gdb-83a01957175f787ad5d7ac06885a2c0213e21028.zip gdb-83a01957175f787ad5d7ac06885a2c0213e21028.tar.gz gdb-83a01957175f787ad5d7ac06885a2c0213e21028.tar.bz2 | |
Here we have the patch for gold aarch64 backend to support relaxation.
In short relaxation is the linker's generation of stubs that fixes the
out-of-range jumps/branches in the original object file.
With this implementation, we are able to link a 456MB aarch64 application.
Tested:
1) Build natively on x86_64 and aarch64 machines.
2) Pass unit tests regarding relaxation.
| -rw-r--r-- | gold/ChangeLog | 27 | ||||
| -rw-r--r-- | gold/aarch64-reloc.def | 77 | ||||
| -rw-r--r-- | gold/aarch64.cc | 2163 |
3 files changed, 2189 insertions, 78 deletions
diff --git a/gold/ChangeLog b/gold/ChangeLog index f636afa..c2c3253 100644 --- a/gold/ChangeLog +++ b/gold/ChangeLog @@ -1,3 +1,30 @@ +2014-09-22 Han Shen <shenhan@google.com> + Jing Yu <jingyu@google.com> + + Patch for gold aarch64 backend to support relaxation. + * aarch64-reloc.def: Change format. + * aarch64.cc (class Reloc_stub): New class. + (class Stub_table): New class. + (class AArch64_relobj): New class. + (class AArch64_input_section): New class. + (class AArch64_output_section): New class. + (Target_aarch64::new_stub_table): New method. + (Target_aarch64::new_aarch64_input_section): New method. + (Target_aarch64::find_aarch64_input_section): New method. + (Target_aarch64::scan_section_for_stubs): New method. + (Target_aarch64::scan_reloc_section_for_stubs): New method. + (Target_aarch64::relocate_stub): New method. + (Target_aarch64::current_target): New method. + (Target_aarch64::do_make_elf_object): New method. + (Target_aarch64::do_may_relax): New method. + (Target_aarch64::do_relax): New method. + (Target_aarch64::group_sections): New method. + (Target_aarch64::scan_reloc_for_stub): New method. + (Target_aarch64::do_make_output_section): New method. + (Target_aarch64::stub_tables_): New data member. + (Target_aarch64::aarch64_input_section_map_): New data member. + (AArch64_relocate_functions::maybe_apply_stub): New method. + 2014-09-30 Cary Coutant <ccoutant@google.com> PR gold/17432 diff --git a/gold/aarch64-reloc.def b/gold/aarch64-reloc.def index b9ce49e..214dc22 100644 --- a/gold/aarch64-reloc.def +++ b/gold/aarch64-reloc.def @@ -22,54 +22,53 @@ // // // -// Insn modified by relocation, see enum Reloc_inst -------------------------------------------------------------------------+ -// Symbol reference type -----------------------------------------------------------------------------+ | -// Portion off X to retrieve -------------------------------------------------------------------+ | | -// Checking function, see Note(A)---------------------------------------+ | | | -// Group index---------------------------------------------------+ | | | | -// Implemented----------------------------------------------+ | | | | | -// Class-------------------------------------+ | | | | | | -// Type----------------------------+ | | | | | | | -// Name | | | | | | | | -// | | | | | | | | | -ARD(ABS64 , STATIC , DATA , Y, -1, 0,0 , 0,0 , Symbol::ABSOLUTE_REF , DATA ) -ARD(ABS32 , STATIC , DATA , Y, -1, 31,32 , 0,0 , Symbol::ABSOLUTE_REF , DATA ) -ARD(ABS16 , STATIC , DATA , Y, -1, 15,16 , 0,0 , Symbol::ABSOLUTE_REF , DATA ) -ARD(PREL64 , STATIC , DATA , Y, -1, 0,0 , 0,0 , Symbol::RELATIVE_REF , DATA ) -ARD(PREL32 , STATIC , DATA , Y, -1, 31,32 , 0,0 , Symbol::RELATIVE_REF , DATA ) -ARD(PREL16 , STATIC , DATA , Y, -1, 15,16 , 0,0 , Symbol::RELATIVE_REF , DATA ) +// Insn modified by relocation, see enum Reloc_inst -------------------------------------------------------------------------------------------------+ +// Symbol reference type -----------------------------------------------------------------------------+ | +// Portion off X to retrieve -------------------------------------------------------------------+ | | +// Checking function, see Note(A)---------------------------------------+ | | | +// Group index---------------------------------------------------+ | | | | +// Implemented----------------------------------------------+ | | | | | +// Class-------------------------------------+ | | | | | | +// Type----------------------------+ | | | | | | | +// Name | | | | | | | | +// | | | | | | | | | +ARD(ABS64 , STATIC , DATA , Y, -1, 0,0 , 0,0 , Symbol::ABSOLUTE_REF , DATA ) +ARD(ABS32 , STATIC , DATA , Y, -1, 31,32 , 0,0 , Symbol::ABSOLUTE_REF , DATA ) +ARD(ABS16 , STATIC , DATA , Y, -1, 15,16 , 0,0 , Symbol::ABSOLUTE_REF , DATA ) +ARD(PREL64 , STATIC , DATA , Y, -1, 0,0 , 0,0 , Symbol::RELATIVE_REF , DATA ) +ARD(PREL32 , STATIC , DATA , Y, -1, 31,32 , 0,0 , Symbol::RELATIVE_REF , DATA ) +ARD(PREL16 , STATIC , DATA , Y, -1, 15,16 , 0,0 , Symbol::RELATIVE_REF , DATA ) // Above is from Table 4-6, Data relocations, 257-262. -ARD(ADR_PREL_PG_HI21 , STATIC , AARCH64 , Y, -1, 32,32 , 12,32 , Symbol::RELATIVE_REF , ADRP ) -ARD(ADR_PREL_PG_HI21_NC , STATIC , AARCH64 , Y, -1, 0,0 , 12,32 , Symbol::RELATIVE_REF , ADRP ) -ARD(LDST8_ABS_LO12_NC , STATIC , AARCH64 , Y, -1, 0,0 , 0,11 , Symbol::ABSOLUTE_REF , LDST ) -ARD(LDST16_ABS_LO12_NC , STATIC , AARCH64 , Y, -1, 0,RL_CHECK_ALIGN2 , 1,11 , Symbol::ABSOLUTE_REF , LDST ) -ARD(LDST32_ABS_LO12_NC , STATIC , AARCH64 , Y, -1, 0,RL_CHECK_ALIGN4 , 2,11 , Symbol::ABSOLUTE_REF , LDST ) -ARD(LDST64_ABS_LO12_NC , STATIC , AARCH64 , Y, -1, 0,RL_CHECK_ALIGN8 , 3,11 , Symbol::ABSOLUTE_REF , LDST ) -ARD(LDST128_ABS_LO12_NC , STATIC , AARCH64 , Y, -1, 0,RL_CHECK_ALIGN16 , 4,11 , Symbol::ABSOLUTE_REF , LDST ) -ARD(ADD_ABS_LO12_NC , STATIC , AARCH64 , Y, -1, 0,0 , 0,11 , Symbol::ABSOLUTE_REF , ADD ) -ARD(ADR_GOT_PAGE , STATIC , AARCH64 , Y, -1, 32,32 , 12,32 , Symbol::RELATIVE_REF , ADRP ) -ARD(LD64_GOT_LO12_NC , STATIC , AARCH64 , Y, -1, 0,RL_CHECK_ALIGN8 , 3,11 , Symbol::ABSOLUTE_REF , LDST ) +ARD(ADR_PREL_PG_HI21 , STATIC , AARCH64 , Y, -1, 32,32 , 12,32 , Symbol::RELATIVE_REF , ADRP ) +ARD(ADR_PREL_PG_HI21_NC , STATIC , AARCH64 , Y, -1, 0,0 , 12,32 , Symbol::RELATIVE_REF , ADRP ) +ARD(LDST8_ABS_LO12_NC , STATIC , AARCH64 , Y, -1, 0,0 , 0,11 , Symbol::ABSOLUTE_REF , LDST ) +ARD(LDST16_ABS_LO12_NC , STATIC , AARCH64 , Y, -1, 0,RL_CHECK_ALIGN2 , 1,11 , Symbol::ABSOLUTE_REF , LDST ) +ARD(LDST32_ABS_LO12_NC , STATIC , AARCH64 , Y, -1, 0,RL_CHECK_ALIGN4 , 2,11 , Symbol::ABSOLUTE_REF , LDST ) +ARD(LDST64_ABS_LO12_NC , STATIC , AARCH64 , Y, -1, 0,RL_CHECK_ALIGN8 , 3,11 , Symbol::ABSOLUTE_REF , LDST ) +ARD(LDST128_ABS_LO12_NC , STATIC , AARCH64 , Y, -1, 0,RL_CHECK_ALIGN16 , 4,11 , Symbol::ABSOLUTE_REF , LDST ) +ARD(ADD_ABS_LO12_NC , STATIC , AARCH64 , Y, -1, 0,0 , 0,11 , Symbol::ABSOLUTE_REF , ADD ) +ARD(ADR_GOT_PAGE , STATIC , AARCH64 , Y, -1, 32,32 , 12,32 , Symbol::RELATIVE_REF , ADRP ) +ARD(LD64_GOT_LO12_NC , STATIC , AARCH64 , Y, -1, 0,RL_CHECK_ALIGN8 , 3,11 , Symbol::ABSOLUTE_REF , LDST ) ARD(TSTBR14 , STATIC , CFLOW , N, -1, 15,15 , 2,15 , (Symbol::FUNCTION_CALL|Symbol::ABSOLUTE_REF) , TBZNZ ) ARD(CONDBR19 , STATIC , CFLOW , N, -1, 20,20 , 2,20 , (Symbol::FUNCTION_CALL|Symbol::ABSOLUTE_REF) , CONDB ) -ARD(CALL26 , STATIC , CFLOW , Y, -1, 27,27 , 2,27 , (Symbol::FUNCTION_CALL|Symbol::RELATIVE_REF) , CALL ) -ARD(JUMP26 , STATIC , CFLOW , Y, -1, 27,27 , 2,27 , (Symbol::FUNCTION_CALL|Symbol::RELATIVE_REF) , B ) +ARD(CALL26 , STATIC , CFLOW , Y, -1, 27,27 , 2,27 , (Symbol::FUNCTION_CALL|Symbol::RELATIVE_REF) , CALL ) +ARD(JUMP26 , STATIC , CFLOW , Y, -1, 27,27 , 2,27 , (Symbol::FUNCTION_CALL|Symbol::RELATIVE_REF) , B ) // Above is from Table 4-10, Relocations for control-flow instructions, // 279-283. -ARD(TLSGD_ADR_PAGE21 , STATIC , AARCH64 , Y, -1, 32,32 , 12,32 , Symbol::ABSOLUTE_REF , ADRP ) -ARD(TLSGD_ADD_LO12_NC , STATIC , AARCH64 , Y, -1, 0,0 , 0,11 , Symbol::ABSOLUTE_REF , ADD ) - -ARD(TLSIE_MOVW_GOTTPREL_G1 , STATIC , AARCH64 , N, -1, 0,0 , 16,31 , Symbol::ABSOLUTE_REF , MOVW ) -ARD(TLSIE_MOVW_GOTTPREL_G0_NC , STATIC , AARCH64 , N, -1, 0,0 , 0,15 , Symbol::ABSOLUTE_REF , MOVW ) -ARD(TLSIE_ADR_GOTTPREL_PAGE21 , STATIC , AARCH64 , Y, -1, 32,32 , 12,32 , Symbol::ABSOLUTE_REF , ADRP ) -ARD(TLSIE_LD64_GOTTPREL_LO12_NC , STATIC , AARCH64 , Y, -1, 0,RL_CHECK_ALIGN8 , 3,11 , Symbol::ABSOLUTE_REF , LDST ) -ARD(TLSIE_LD_GOTTPREL_PREL19 , STATIC , AARCH64 , N, -1, 20,20 , 2,20 , Symbol::ABSOLUTE_REF , LD ) +ARD(TLSGD_ADR_PAGE21 , STATIC , AARCH64 , Y, -1, 32,32 , 12,32 , Symbol::ABSOLUTE_REF , ADRP ) +ARD(TLSGD_ADD_LO12_NC , STATIC , AARCH64 , Y, -1, 0,0 , 0,11 , Symbol::ABSOLUTE_REF , ADD ) +ARD(TLSIE_MOVW_GOTTPREL_G1 , STATIC , AARCH64 , N, -1, 0,0 , 16,31 , Symbol::ABSOLUTE_REF , MOVW ) +ARD(TLSIE_MOVW_GOTTPREL_G0_NC , STATIC , AARCH64 , N, -1, 0,0 , 0,15 , Symbol::ABSOLUTE_REF , MOVW ) +ARD(TLSIE_ADR_GOTTPREL_PAGE21 , STATIC , AARCH64 , Y, -1, 32,32 , 12,32 , Symbol::ABSOLUTE_REF , ADRP ) +ARD(TLSIE_LD64_GOTTPREL_LO12_NC , STATIC , AARCH64 , Y, -1, 0,RL_CHECK_ALIGN8 , 3,11 , Symbol::ABSOLUTE_REF , LDST ) +ARD(TLSIE_LD_GOTTPREL_PREL19 , STATIC , AARCH64 , N, -1, 20,20 , 2,20 , Symbol::ABSOLUTE_REF , LD ) // Above is from Table 4-17, Initial Exec TLS relocations, 539-543. -ARD(TLSLE_ADD_TPREL_HI12 , STATIC , AARCH64 , Y, -1, 0,24 , 12,23 , Symbol::ABSOLUTE_REF , ADD ) -ARD(TLSLE_ADD_TPREL_LO12 , STATIC , AARCH64 , Y, -1, 0,12 , 0,11 , Symbol::ABSOLUTE_REF , ADD ) -ARD(TLSLE_ADD_TPREL_LO12_NC , STATIC , AARCH64 , Y, -1, 0,0 , 0,11 , Symbol::ABSOLUTE_REF , ADD ) +ARD(TLSLE_ADD_TPREL_HI12 , STATIC , AARCH64 , Y, -1, 0,24 , 12,23 , Symbol::ABSOLUTE_REF , ADD ) +ARD(TLSLE_ADD_TPREL_LO12 , STATIC , AARCH64 , Y, -1, 0,12 , 0,11 , Symbol::ABSOLUTE_REF , ADD ) +ARD(TLSLE_ADD_TPREL_LO12_NC , STATIC , AARCH64 , Y, -1, 0,0 , 0,11 , Symbol::ABSOLUTE_REF , ADD ) // Above is from Table 4-18, Local Exec TLS relocations, 544-571. ARD(TLSDESC_ADR_PAGE21 , STATIC , AARCH64 , Y, -1, 32,32 , 12,32 , Symbol::RELATIVE_REF , ADRP ) diff --git a/gold/aarch64.cc b/gold/aarch64.cc index afb9024..7ce295a 100644 --- a/gold/aarch64.cc +++ b/gold/aarch64.cc @@ -47,6 +47,7 @@ // The first three .got.plt entries are reserved. const int32_t AARCH64_GOTPLT_RESERVE_COUNT = 3; + namespace { @@ -124,7 +125,7 @@ class Output_data_got_aarch64 : public Output_data_got<size, big_endian> gold_assert(tls_segment != NULL); AArch64_address aligned_tcb_address = - align_address(Target_aarch64<size,big_endian>::TCB_SIZE, + align_address(Target_aarch64<size, big_endian>::TCB_SIZE, tls_segment->maximum_alignment()); for (size_t i = 0; i < this->static_relocs_.size(); ++i) @@ -287,7 +288,7 @@ class Output_data_got_aarch64 : public Output_data_got<size, big_endian> } global; struct { - // For a local symbol, the object defining object. + // For a local symbol, the object defining the symbol. Sized_relobj_file<size, big_endian>* relobj; // For a local symbol, the symbol index. unsigned int index; @@ -299,6 +300,1323 @@ class Output_data_got_aarch64 : public Output_data_got<size, big_endian> }; // End of Output_data_got_aarch64 +template<int size, bool big_endian> +class AArch64_input_section; + + +template<int size, bool big_endian> +class AArch64_output_section; + + +// Reloc stub class. + +template<int size, bool big_endian> +class Reloc_stub +{ + public: + typedef Reloc_stub<size, big_endian> This; + typedef typename elfcpp::Elf_types<size>::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<size, big_endian> 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<char>( + (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<section_offset_type>(-1); + static const unsigned int invalid_index = static_cast<unsigned int>(-1); + static const AArch64_address invalid_address = + static_cast<AArch64_address>(-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<int size, bool big_endian> +void +Reloc_stub<size, big_endian>:: +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<Insntype*>(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<int size, bool big_endian> +const uint32_t +Reloc_stub<size, big_endian>::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<int size, bool big_endian> +inline +typename Reloc_stub<size, big_endian>::Stub_type +Reloc_stub<size, big_endian>::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_assert(false); + } + + 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<int size, bool big_endian> +class Stub_table : public Output_data +{ + public: + typedef Target_aarch64<size, big_endian> The_target_aarch64; + typedef typename elfcpp::Elf_types<size>::Elf_Addr AArch64_address; + typedef AArch64_input_section<size, big_endian> The_aarch64_input_section; + typedef Reloc_stub<size, big_endian> 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<size, big_endian> The_stub_table; + typedef Unordered_map<The_reloc_stub_key, The_reloc_stub*, + The_reloc_stub_key_hash, The_reloc_stub_key_equal_to> + Reloc_stub_map; + typedef typename Reloc_stub_map::const_iterator Reloc_stub_map_const_iter; + typedef Relocate_info<size, big_endian> 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<int size, bool big_endian> +void +Stub_table<size, big_endian>::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<int size, bool big_endian> +void +Stub_table<size, big_endian>:: +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<section_size_type>(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<int size, bool big_endian> +void +Stub_table<size, big_endian>:: +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<int size, bool big_endian> +void +Stub_table<size, big_endian>::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<int size, bool big_endian> +class AArch64_relobj : public Sized_relobj_file<size, big_endian> +{ + public: + typedef AArch64_relobj<size, big_endian> This; + typedef Target_aarch64<size, big_endian> The_target_aarch64; + typedef AArch64_input_section<size, big_endian> The_aarch64_input_section; + typedef typename elfcpp::Elf_types<size>::Elf_Addr AArch64_address; + typedef Stub_table<size, big_endian> The_stub_table; + typedef std::vector<The_stub_table*> Stub_table_list; + static const AArch64_address invalid_address = + static_cast<AArch64_address>(-1); + + AArch64_relobj(const std::string& name, Input_file* input_file, off_t offset, + const typename elfcpp::Ehdr<size, big_endian>& ehdr) + : Sized_relobj_file<size, big_endian>(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<size, big_endian>&, 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<size, big_endian>::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<size, big_endian>::Views* pviews); + + private: + // Whether a section needs to be scanned for relocation stubs. + bool + section_needs_reloc_stub_scanning(const elfcpp::Shdr<size, big_endian>&, + 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<int size, bool big_endian> +void +AArch64_relobj<size, big_endian>::do_relocate_sections( + const Symbol_table* symtab, const Layout* layout, + const unsigned char* pshdrs, Output_file* of, + typename Sized_relobj_file<size, big_endian>::Views* pviews) +{ + // Call parent to relocate sections. + Sized_relobj_file<size, big_endian>::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<size, big_endian> 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<size>::shdr_size; + + typename Sized_relobj_file<size, big_endian>::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<int size, bool big_endian> +bool +AArch64_relobj<size, big_endian>::text_section_is_scannable( + const elfcpp::Shdr<size, big_endian>& 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<int size, bool big_endian> +bool +AArch64_relobj<size, big_endian>::section_needs_reloc_stub_scanning( + const elfcpp::Shdr<size, big_endian>& 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<size>::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<size>::shdr_size; + const elfcpp::Shdr<size, big_endian> 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<int size, bool big_endian> +void +AArch64_relobj<size, big_endian>::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<size>::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<size, big_endian> 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<size, big_endian> 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<size>::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<int size, bool big_endian> +class AArch64_input_section : public Output_relaxed_input_section +{ + public: + typedef Stub_table<size, big_endian> 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<uint64_t>(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<section_offset_type, uint32_t>(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<int size, bool big_endian> +void +AArch64_input_section<size, big_endian>::set_final_data_size() +{ + off_t off = convert_types<off_t, uint64_t>(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<int size, bool big_endian> +void +AArch64_input_section<size, big_endian>::do_reset_address_and_file_offset() +{ + // Size of the original input section contents. + off_t off = convert_types<off_t, uint64_t>(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<int size, bool big_endian> +void +AArch64_input_section<size, big_endian>::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<uint32_t, uint64_t>(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<uint32_t, uint64_t>(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<int size, bool big_endian> +void +AArch64_input_section<size, big_endian>::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<int size, bool big_endian> +class AArch64_output_section : public Output_section +{ + public: + typedef Target_aarch64<size, big_endian> The_target_aarch64; + typedef AArch64_relobj<size, big_endian> The_aarch64_relobj; + typedef Stub_table<size, big_endian> The_stub_table; + typedef AArch64_input_section<size, big_endian> 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<size, big_endian>*, + 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<Output_relaxed_input_section*>&, + 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<int size, bool big_endian> void +AArch64_output_section<size, big_endian>::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<Output_relaxed_input_section*>& 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<Object> 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<The_aarch64_relobj*>(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<int size, bool big_endian> +void AArch64_output_section<size, big_endian>::group_sections( + section_size_type group_size, + bool stubs_always_after_branch, + Target_aarch64<size, big_endian>* target, + const Task* task) +{ + typedef enum + { + NO_GROUP, + FINDING_STUB_SECTION, + HAS_STUB_SECTION + } State; + + std::vector<Output_relaxed_input_section*> 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<The_aarch64_relobj*>( + 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; @@ -309,10 +1627,23 @@ template<int size, bool big_endian> class Target_aarch64 : public Sized_target<size, big_endian> { public: - typedef Target_aarch64<size,big_endian> This; + typedef Target_aarch64<size, big_endian> This; typedef Output_data_reloc<elfcpp::SHT_RELA, true, size, big_endian> Reloc_section; + typedef Relocate_info<size, big_endian> The_relocate_info; typedef typename elfcpp::Elf_types<size>::Elf_Addr Address; + typedef AArch64_relobj<size, big_endian> The_aarch64_relobj; + typedef Reloc_stub<size, big_endian> The_reloc_stub; + typedef typename The_reloc_stub::Stub_type The_reloc_stub_type; + typedef typename Reloc_stub<size, big_endian>::Key The_reloc_stub_key; + typedef Stub_table<size, big_endian> The_stub_table; + typedef std::vector<The_stub_table*> Stub_table_list; + typedef typename Stub_table_list::iterator Stub_table_iterator; + typedef AArch64_input_section<size, big_endian> The_aarch64_input_section; + typedef AArch64_output_section<size, big_endian> The_aarch64_output_section; + typedef Unordered_map<Section_id, + AArch64_input_section<size, big_endian>*, + Section_id_hash> AArch64_input_section_map; const static int TCB_SIZE = size / 8 * 2; Target_aarch64(const Target::Target_info* info = &aarch64_info) @@ -320,8 +1651,9 @@ class Target_aarch64 : public Sized_target<size, big_endian> 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) + got_mod_index_offset_(-1U), + tlsdesc_reloc_info_(), tls_base_symbol_defined_(false), + stub_tables_(), aarch64_input_section_map_() { } // Scan the relocations to determine unreferenced sections for @@ -442,9 +1774,59 @@ class Target_aarch64 : public Sized_target<size, big_endian> 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<size, big_endian>*, unsigned int, + const unsigned char*, size_t, Output_section*, + bool, const unsigned char*, + Address, + section_size_type); + + // Scan a relocation section for stub. + template<int sh_type> + 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<size, big_endian>*, + 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<This*>(parameters->sized_target<size, big_endian>()); + } + protected: void do_select_as_default_target() @@ -472,6 +1854,12 @@ class Target_aarch64 : public Sized_target<size, big_endian> 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<size, big_endian>&); + Output_data_plt_aarch64<size, big_endian>* make_data_plt(Layout* layout, Output_data_got_aarch64<size, big_endian>* got, @@ -481,6 +1869,35 @@ class Target_aarch64 : public Sized_target<size, big_endian> 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<size>*, unsigned int, + const Symbol_value<size>*, + typename elfcpp::Elf_types<size>::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 @@ -569,8 +1986,8 @@ class Target_aarch64 : public Sized_target<size, big_endian> section_size_type); private: - inline typename AArch64_relocate_functions<size,big_endian>::Status - relocate_tls(const Relocate_info<size,big_endian>*, + inline typename AArch64_relocate_functions<size, big_endian>::Status + relocate_tls(const Relocate_info<size, big_endian>*, Target_aarch64<size, big_endian>*, size_t, const elfcpp::Rela<size, big_endian>&, @@ -579,36 +1996,36 @@ class Target_aarch64 : public Sized_target<size, big_endian> unsigned char*, typename elfcpp::Elf_types<size>::Elf_Addr); - inline typename AArch64_relocate_functions<size,big_endian>::Status + inline typename AArch64_relocate_functions<size, big_endian>::Status tls_gd_to_le( - const Relocate_info<size,big_endian>*, + const Relocate_info<size, big_endian>*, Target_aarch64<size, big_endian>*, const elfcpp::Rela<size, big_endian>&, unsigned int, unsigned char*, const Symbol_value<size>*); - inline typename AArch64_relocate_functions<size,big_endian>::Status + inline typename AArch64_relocate_functions<size, big_endian>::Status tls_ie_to_le( - const Relocate_info<size,big_endian>*, + const Relocate_info<size, big_endian>*, Target_aarch64<size, big_endian>*, const elfcpp::Rela<size, big_endian>&, unsigned int, unsigned char*, const Symbol_value<size>*); - inline typename AArch64_relocate_functions<size,big_endian>::Status + inline typename AArch64_relocate_functions<size, big_endian>::Status tls_desc_gd_to_le( - const Relocate_info<size,big_endian>*, + const Relocate_info<size, big_endian>*, Target_aarch64<size, big_endian>*, const elfcpp::Rela<size, big_endian>&, unsigned int, unsigned char*, const Symbol_value<size>*); - inline typename AArch64_relocate_functions<size,big_endian>::Status + inline typename AArch64_relocate_functions<size, big_endian>::Status tls_desc_gd_to_ie( - const Relocate_info<size,big_endian>*, + const Relocate_info<size, big_endian>*, Target_aarch64<size, big_endian>*, const elfcpp::Rela<size, big_endian>&, unsigned int, @@ -773,6 +2190,9 @@ class Target_aarch64 : public Sized_target<size, big_endian> std::vector<Tlsdesc_info> 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_; + AArch64_input_section_map aarch64_input_section_map_; }; // End of Target_aarch64 @@ -1022,6 +2442,407 @@ Target_aarch64<size, big_endian>::rela_irelative_section(Layout* layout) } +// 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<size, big_endian> to +// store backend specific information. Hence we need to have our own ELF object +// creation. + +template<int size, bool big_endian> +Object* +Target_aarch64<size, big_endian>::do_make_elf_object( + const std::string& name, + Input_file* input_file, + off_t offset, const elfcpp::Ehdr<size, big_endian>& 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<size, big_endian>::do_make_elf_object( + name, input_file, offset, ehdr); + else if (et == elfcpp::ET_REL) + { + AArch64_relobj<size, big_endian>* obj = + new AArch64_relobj<size, big_endian>(name, input_file, offset, ehdr); + obj->setup(); + return obj; + } + else if (et == elfcpp::ET_DYN) + { + // Keep base implementation. + Sized_dynobj<size, big_endian>* obj = + new Sized_dynobj<size, big_endian>(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<int size, bool big_endian> +void +Target_aarch64<size, big_endian>::scan_reloc_for_stub( + const Relocate_info<size, big_endian>* relinfo, + unsigned int r_type, + const Sized_symbol<size>* gsym, + unsigned int r_sym, + const Symbol_value<size>* psymval, + typename elfcpp::Elf_types<size>::Elf_Swxword addend, + Address address) +{ + const AArch64_relobj<size, big_endian>* aarch64_relobj = + static_cast<AArch64_relobj<size, big_endian>*>(relinfo->object); + + Symbol_value<size> 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<size>::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<Address>(-1); + switch (r_type) + { + case elfcpp::R_AARCH64_CALL26: + case elfcpp::R_AARCH64_JUMP26: + destination = value + addend; + break; + default: + gold_assert(false); + } + + 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<int size, bool big_endian> +template<int sh_type> +void inline +Target_aarch64<size, big_endian>::scan_reloc_section_for_stubs( + const Relocate_info<size, big_endian>* 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<sh_type,size,big_endian>::Reloc Reltype; + + const int reloc_size = + Reloc_types<sh_type,size,big_endian>::reloc_size; + AArch64_relobj<size, big_endian>* object = + static_cast<AArch64_relobj<size, big_endian>*>(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<size>::Elf_WXword r_info = reloc.get_r_info(); + unsigned int r_sym = elfcpp::elf_r_sym<size>(r_info); + unsigned int r_type = elfcpp::elf_r_type<size>(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<size>::Elf_Swxword addend = + reloc.get_r_addend(); + + const Sized_symbol<size>* sym; + Symbol_value<size> symval; + const Symbol_value<size> *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<size, big_endian> 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<const Sized_symbol<size>*>(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<size>* sized_symbol = + symtab->get_sized_symbol<size>(gsym); + Symbol_table::Compute_final_value_status status; + typename elfcpp::Elf_types<size>::Elf_Addr value = + symtab->compute_final_value<size>(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<size> 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<size>::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<int size, bool big_endian> +void +Target_aarch64<size, big_endian>::scan_section_for_stubs( + const Relocate_info<size, big_endian>* relinfo, + unsigned int sh_type, + const unsigned char* prelocs, + size_t reloc_count, + Output_section* output_section, + bool needs_special_offset_handling, + 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<elfcpp::SHT_RELA>( + relinfo, + prelocs, + reloc_count, + output_section, + needs_special_offset_handling, + view, + view_address, + view_size); +} + + +// Relocate a single stub. + +template<int size, bool big_endian> +void Target_aarch64<size, big_endian>:: +relocate_stub(The_reloc_stub* stub, + const The_relocate_info*, + Output_section*, + unsigned char* view, + Address address, + section_size_type) +{ + typedef AArch64_relocate_functions<size, big_endian> 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<Insntype*>(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_assert(false); + } +} + + // 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 @@ -1477,6 +3298,7 @@ Output_data_plt_aarch64_standard<32, false>:: 0xd503201f, /* nop */ }; + template<> const uint32_t Output_data_plt_aarch64_standard<32, true>:: @@ -1492,6 +3314,7 @@ Output_data_plt_aarch64_standard<32, true>:: 0xd503201f, /* nop */ }; + template<> const uint32_t Output_data_plt_aarch64_standard<64, false>:: @@ -1507,6 +3330,7 @@ Output_data_plt_aarch64_standard<64, false>:: 0xd503201f, /* nop */ }; + template<> const uint32_t Output_data_plt_aarch64_standard<64, true>:: @@ -1522,6 +3346,7 @@ Output_data_plt_aarch64_standard<64, true>:: 0xd503201f, /* nop */ }; + template<> const uint32_t Output_data_plt_aarch64_standard<32, false>:: @@ -1533,6 +3358,7 @@ Output_data_plt_aarch64_standard<32, false>:: 0xd61f0220, /* br x17. */ }; + template<> const uint32_t Output_data_plt_aarch64_standard<32, true>:: @@ -1544,6 +3370,7 @@ Output_data_plt_aarch64_standard<32, true>:: 0xd61f0220, /* br x17. */ }; + template<> const uint32_t Output_data_plt_aarch64_standard<64, false>:: @@ -1555,6 +3382,7 @@ Output_data_plt_aarch64_standard<64, false>:: 0xd61f0220, /* br x17. */ }; + template<> const uint32_t Output_data_plt_aarch64_standard<64, true>:: @@ -1566,6 +3394,7 @@ Output_data_plt_aarch64_standard<64, true>:: 0xd61f0220, /* br x17. */ }; + template<int size, bool big_endian> void Output_data_plt_aarch64_standard<size, big_endian>::do_fill_first_plt_entry( @@ -1605,6 +3434,7 @@ Output_data_plt_aarch64_standard<size, big_endian>::do_fill_first_plt_entry( | ((gotplt_2nd_ent & 0xfff) << 10))); } + // Subsequent entries in the PLT for an executable. // FIXME: This only works for 64bit @@ -1859,9 +3689,14 @@ class AArch64_relocate_functions STATUS_BAD_RELOC, // Relocation cannot be applied. } Status; - private: typedef AArch64_relocate_functions<size, big_endian> This; typedef typename elfcpp::Elf_types<size>::Elf_Addr Address; + typedef Relocate_info<size, big_endian> The_relocate_info; + typedef AArch64_relobj<size, big_endian> The_aarch64_relobj; + typedef Reloc_stub<size, big_endian> The_reloc_stub; + typedef typename The_reloc_stub::Stub_type The_reloc_stub_type; + typedef Stub_table<size, big_endian> The_stub_table; + typedef elfcpp::Rela<size, big_endian> The_rela; // Return the page address of the address. // Page(address) = address & ~0xFFF @@ -1872,6 +3707,7 @@ class AArch64_relocate_functions return (address & (~static_cast<Address>(0xFFF))); } + private: // Update instruction (pointed by view) with selected bits (immed). // val = (val & ~dst_mask) | (immed << doffset) @@ -2042,7 +3878,7 @@ class AArch64_relocate_functions const AArch64_reloc_property* reloc_property) { // Calculate relocation. - Address x = psymval->value(object, addend); + Address x = psymval->value(object, addend); // Select bits from X. Address immed = reloc_property->select_x_value(x); @@ -2144,9 +3980,10 @@ class AArch64_relocate_functions Address address) { typename elfcpp::Swap<size, big_endian>::Valtype x = - This::Page(sa) - This::Page(address); + This::Page(sa) - This::Page(address); update_adr(view, x, NULL); - return (size == 64 && Bits<32>::has_overflow(x) + // Check -2^32 <= X < 2^32 + return (size == 64 && Bits<33>::has_overflow((x)) ? This::STATUS_OVERFLOW : This::STATUS_OKAY); } @@ -2200,9 +4037,248 @@ class AArch64_relocate_functions : This::STATUS_OVERFLOW); } + static inline bool + maybe_apply_stub(unsigned int, + const The_relocate_info*, + const The_rela&, + unsigned char*, + Address, + const Sized_symbol<size>*, + const Symbol_value<size>*, + const Sized_relobj_file<size, big_endian>*); + }; // 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<int size, bool big_endian> +bool +AArch64_relocate_functions<size, big_endian>:: +maybe_apply_stub(unsigned int r_type, + const The_relocate_info* relinfo, + const The_rela& rela, + unsigned char* view, + Address address, + const Sized_symbol<size>* gsym, + const Symbol_value<size>* psymval, + const Sized_relobj_file<size, big_endian>* object) +{ + if (parameters->options().relocatable()) + return false; + + typename elfcpp::Elf_types<size>::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<const The_aarch64_relobj*>(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<size>(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<size, big_endian>::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); + 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'. For example, 0x2000000.")); + 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<int size, bool big_endian> +void +Target_aarch64<size, big_endian>::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<size, big_endian>* output_section = + static_cast<AArch64_output_section<size, big_endian>*>(*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<int size, bool big_endian> +AArch64_input_section<size, big_endian>* +Target_aarch64<size, big_endian>::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<int size, bool big_endian> +AArch64_input_section<size, big_endian>* +Target_aarch64<size, big_endian>::new_aarch64_input_section( + Relobj* relobj, unsigned int shndx) +{ + Section_id sid(relobj, shndx); + + AArch64_input_section<size, big_endian>* input_section = + new AArch64_input_section<size, big_endian>(relobj, shndx); + input_section->init(); + + // Register new AArch64_input_section in map for look-up. + std::pair<typename AArch64_input_section_map::iterator,bool> 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<int size, bool big_endian> +bool +Target_aarch64<size, big_endian>::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) + { + section_size_type stub_group_size = + parameters->options().stub_group_size(); + if (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. + stub_group_size = The_reloc_stub::MAX_BRANCH_OFFSET - 4096 * 4; + } + group_sections(layout, 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<The_aarch64_relobj*>(*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<Object> 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<int size, bool big_endian> +Stub_table<size, big_endian>* +Target_aarch64<size, big_endian>::new_stub_table( + AArch64_input_section<size, big_endian>* owner) +{ + Stub_table<size, big_endian>* stub_table = + new Stub_table<size, big_endian>(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<int size, bool big_endian> typename elfcpp::Elf_types<size>::Elf_Addr Target_aarch64<size, big_endian>::do_reloc_addend( @@ -3121,14 +5197,15 @@ Target_aarch64<size, big_endian>::scan_relocs( // pointers across shared library boundaries, as described in the // processor specific ABI supplement. -template<int size,bool big_endian> +template<int size, bool big_endian> uint64_t -Target_aarch64<size,big_endian>::do_dynsym_value(const Symbol* gsym) const +Target_aarch64<size, big_endian>::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<int size, bool big_endian> @@ -3352,14 +5429,17 @@ Target_aarch64<size, big_endian>::Relocate::relocate( 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_ADR_PREL_PG_HI21_NC: case elfcpp::R_AARCH64_ADR_PREL_PG_HI21: @@ -3391,10 +5471,14 @@ Target_aarch64<size, big_endian>::Relocate::relocate( // Return false to stop further processing this reloc. return false; } - // Continue. + // Fallthrough + case elfcpp::R_AARCH64_JUMP26: + if (Reloc::maybe_apply_stub(r_type, relinfo, rela, view, address, + gsym, psymval, object)) + break; + // Fallthrough case elfcpp::R_AARCH64_TSTBR14: case elfcpp::R_AARCH64_CONDBR19: - case elfcpp::R_AARCH64_JUMP26: reloc_status = Reloc::template pcrela_general<32>( view, object, psymval, addend, address, reloc_property); break; @@ -3477,9 +5561,9 @@ Target_aarch64<size, big_endian>::Relocate::relocate( template<int size, bool big_endian> inline -typename AArch64_relocate_functions<size,big_endian>::Status +typename AArch64_relocate_functions<size, big_endian>::Status Target_aarch64<size, big_endian>::Relocate::relocate_tls( - const Relocate_info<size,big_endian>* relinfo, + const Relocate_info<size, big_endian>* relinfo, Target_aarch64<size, big_endian>* target, size_t relnum, const elfcpp::Rela<size, big_endian>& rela, @@ -3488,7 +5572,7 @@ Target_aarch64<size, big_endian>::Relocate::relocate_tls( unsigned char* view, typename elfcpp::Elf_types<size>::Elf_Addr address) { - typedef AArch64_relocate_functions<size,big_endian> aarch64_reloc_funcs; + typedef AArch64_relocate_functions<size, big_endian> aarch64_reloc_funcs; typedef typename elfcpp::Elf_types<size>::Elf_Addr AArch64_address; Output_segment* tls_segment = relinfo->layout->tls_segment(); @@ -3503,7 +5587,7 @@ Target_aarch64<size, big_endian>::Relocate::relocate_tls( tls::Tls_optimization tlsopt = Target_aarch64<size, big_endian>:: optimize_tls_reloc(is_final, r_type); - Sized_relobj_file<size,big_endian>* object = relinfo->object; + Sized_relobj_file<size, big_endian>* object = relinfo->object; int tls_got_offset_type; switch (r_type) { @@ -3733,16 +5817,16 @@ Target_aarch64<size, big_endian>::Relocate::relocate_tls( template<int size, bool big_endian> inline -typename AArch64_relocate_functions<size,big_endian>::Status +typename AArch64_relocate_functions<size, big_endian>::Status Target_aarch64<size, big_endian>::Relocate::tls_gd_to_le( - const Relocate_info<size,big_endian>* relinfo, + const Relocate_info<size, big_endian>* relinfo, Target_aarch64<size, big_endian>* target, const elfcpp::Rela<size, big_endian>& rela, unsigned int r_type, unsigned char* view, const Symbol_value<size>* psymval) { - typedef AArch64_relocate_functions<size,big_endian> aarch64_reloc_funcs; + typedef AArch64_relocate_functions<size, big_endian> aarch64_reloc_funcs; typedef typename elfcpp::Swap<32, big_endian>::Valtype Insntype; typedef typename elfcpp::Elf_types<size>::Elf_Addr AArch64_address; @@ -3833,9 +5917,9 @@ Target_aarch64<size, big_endian>::Relocate::tls_gd_to_le( template<int size, bool big_endian> inline -typename AArch64_relocate_functions<size,big_endian>::Status +typename AArch64_relocate_functions<size, big_endian>::Status Target_aarch64<size, big_endian>::Relocate::tls_ie_to_le( - const Relocate_info<size,big_endian>* relinfo, + const Relocate_info<size, big_endian>* relinfo, Target_aarch64<size, big_endian>* target, const elfcpp::Rela<size, big_endian>& rela, unsigned int r_type, @@ -3844,7 +5928,7 @@ Target_aarch64<size, big_endian>::Relocate::tls_ie_to_le( { typedef typename elfcpp::Elf_types<size>::Elf_Addr AArch64_address; typedef typename elfcpp::Swap<32, big_endian>::Valtype Insntype; - typedef AArch64_relocate_functions<size,big_endian> aarch64_reloc_funcs; + typedef AArch64_relocate_functions<size, big_endian> aarch64_reloc_funcs; AArch64_address value = psymval->value(relinfo->object, 0); Output_segment* tls_segment = relinfo->layout->tls_segment(); @@ -3888,9 +5972,9 @@ Target_aarch64<size, big_endian>::Relocate::tls_ie_to_le( template<int size, bool big_endian> inline -typename AArch64_relocate_functions<size,big_endian>::Status +typename AArch64_relocate_functions<size, big_endian>::Status Target_aarch64<size, big_endian>::Relocate::tls_desc_gd_to_le( - const Relocate_info<size,big_endian>* relinfo, + const Relocate_info<size, big_endian>* relinfo, Target_aarch64<size, big_endian>* target, const elfcpp::Rela<size, big_endian>& rela, unsigned int r_type, @@ -3899,7 +5983,7 @@ Target_aarch64<size, big_endian>::Relocate::tls_desc_gd_to_le( { typedef typename elfcpp::Elf_types<size>::Elf_Addr AArch64_address; typedef typename elfcpp::Swap<32, big_endian>::Valtype Insntype; - typedef AArch64_relocate_functions<size,big_endian> aarch64_reloc_funcs; + typedef AArch64_relocate_functions<size, big_endian> aarch64_reloc_funcs; // TLSDESC-GD sequence is like: // adrp x0, :tlsdesc:v1 @@ -3961,9 +6045,9 @@ Target_aarch64<size, big_endian>::Relocate::tls_desc_gd_to_le( template<int size, bool big_endian> inline -typename AArch64_relocate_functions<size,big_endian>::Status +typename AArch64_relocate_functions<size, big_endian>::Status Target_aarch64<size, big_endian>::Relocate::tls_desc_gd_to_ie( - const Relocate_info<size,big_endian>* /* relinfo */, + const Relocate_info<size, big_endian>* /* relinfo */, Target_aarch64<size, big_endian>* /* target */, const elfcpp::Rela<size, big_endian>& rela, unsigned int r_type, @@ -3973,7 +6057,7 @@ Target_aarch64<size, big_endian>::Relocate::tls_desc_gd_to_ie( typename elfcpp::Elf_types<size>::Elf_Addr address) { typedef typename elfcpp::Swap<32, big_endian>::Valtype Insntype; - typedef AArch64_relocate_functions<size,big_endian> aarch64_reloc_funcs; + typedef AArch64_relocate_functions<size, big_endian> aarch64_reloc_funcs; // TLSDESC-GD sequence is like: // adrp x0, :tlsdesc:v1 @@ -4143,6 +6227,7 @@ Target_aarch64<size, big_endian>::relocate_relocs( reloc_view_size); } + // The selector for aarch64 object files. template<int size, bool big_endian> |