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author | Han Shen <shenhan@google.com> | 2014-10-29 11:28:46 -0700 |
---|---|---|
committer | Han Shen <shenhan@google.com> | 2014-10-29 11:31:36 -0700 |
commit | 9726c3c179e375cc0cc73a593adfaef8ed5735ab (patch) | |
tree | 2bc289a46829de9662092ccc35cc9a7c8cf391c5 /gold/aarch64.cc | |
parent | ab917dfb5ae0952c234a9bfa16bb3122fdfaf14c (diff) | |
download | gdb-9726c3c179e375cc0cc73a593adfaef8ed5735ab.zip gdb-9726c3c179e375cc0cc73a593adfaef8ed5735ab.tar.gz gdb-9726c3c179e375cc0cc73a593adfaef8ed5735ab.tar.bz2 |
Misc about gold for aarch64 backend.
The patch does the following things:
-- Add support for ifunc.
-- Enable safe icf
-- Add support for TLSLD relocations
R_AARCH64_TLSLD_ADR_PAGE21,
R_AARCH64_TLSLD_ADD_LO12_NC,
R_AARCH64_TLSLD_MOVW_DTPREL_G1,
R_AARCH64_TLSLD_MOVW_DTPREL_G0_NC.
(R_AARCH64_TLSLD_MOVW_* are used by LLVM.)
-- Add support for TLSLD->TLSLE relaxation.
-- Add support for R_AARCH64_LD_PREL_LO19, R_AARCH64_ADR_PREL_LO21.
-- Fix 2 encoding bugs in AArch64_relocate_functions::update_movnz.
-- Correct TLS relocation properties in gold/aarch64-reloc.def.
-- Update testsuite/icf_safe_so_test.cc, testsuite/icf_safe_test.sh.
gold/
2014-10-29 Han Shen <shenhan@google.com>
Jing Yu <jingyu@google.com>
* aarch64-reloc.def: Add LD_PREL_LO12, ADR_PREL_LO21,
TLSLD_ADR_PAGE21, TLSLD_ADD_LO12_NC, TLSLD_MOVW_DTPREL_G1,
TLSLD_MOVW_DTPREL_G0_NC. Change property of TLS relocations to
Symbol::TLS_REF.
* aarch64.cc (Target_aarch64::do_can_check_for_function_pointers): New
method.
(Target_aarch64::reloc_needs_plt_for_ifunc): New method.
(Target_aarch64::tls_ld_to_le): New method.
(Target_aarch64::aarch64_info): Enable can_icf_inline_merge_sections
for 64bit targets.
(Output_data_plt_aarch64::irelative_rel_): New data member.
(Output_data_plt_aarch64::add_entry): Add irelative entries to plt.
(Output_data_plt_aarch64::add_local_ifunc_entry): New method.
(Output_data_plt_aarch64::add_relocation): New method.
(Output_data_plt_aarch64::do_write): Add gold_assert on got_irelative
offset. Add got_irelative size to got size.
(AArch64_relocate_functions): Typedef AArch64_valtype. Replace long
type string with the new typename.
(AArch64_relocate_functions::update_adr): Replace parameter x with
immed.
(AArch64_relocate_functions::update_movnz): Correct wrong val mask.
(AArch64_relocate_functions::reloc_common): New method.
(AArch64_relocate_funcsions::rela_general): Extract common part out
into reloc_common method.
(AArch64_relocate_functions::rela_general): Likewise.
(AArch64_relocate_functions::pcrela_general): Likewise.
(AArch64_relocate_functions::adr): New method.
(AArch64_relocate_functions::adrp): Calculate immed before calling
update_adr.
(AArch64_relocate_functions::adrp): Likewise.
(AArch64_relocate_functions::movnz): Cast x to SignedW type when
comparing x to 0. Calculate immed from ~x when x < 0.
(Target_aarch64::optimize_tls_reloc): Add new cases for
TLSLD_ADR_PAGE21, TLSLD_ADD_LO12_NC, TLSLD_MOVW_DTPREL_G1,
TLSLD_MOVW_DTPREL_G0_NC.
(Target_aarch64::possible_function_pointer_reloc): Implement this
method.
(Target_aarch64::Scan::local_reloc_may_be_function_pointer): Update
comment.
(Target_aarch64::Scan::local): Add codes to handle STT_GNU_IFUNC
symbol. Add cases for TLSLD_ADR_PAGE21, TLSLD_ADD_LO12_NC,
TLSLD_MOVW_DTPREL_G1, TLSLD_MOVW_DTPREL_G0_NC.
(Target_aarch64::Scan::global): Add codes to handle STT_GNU_IFUNC
symbol. Add cases for TLSLD_ADR_PAGE21, TLSLD_ADD_LO12_NC,
TLSLD_MOVW_DTPREL_G1, TLSLD_MOVW_DTPREL_G0_NC.
(Target_aarch64::make_plt_entry): Call add_entry with two more
parameters.
(Target_aarch64::make_local_ifunc_plt_entry): New method.
(Target_aarch64::Relocate::relocate): Add cases for LD_PREL_LO19,
ADR_PREL_LO21, TLSLD_ADR_PAGE21, TLSLD_ADD_LO12_NC,
TLSLD_MOVW_DTPREL_G1, TLSLD_MOVW_DTPREL_G0_NC.
(Target_aarch64::Relocate::relocate_tls): Add cases for
TLSLD_ADR_PAGE21, TLSLD_ADD_LO12_NC, TLSLD_MOVW_DTPREL_G1,
TLSLD_MOVW_DTPREL_G0_NC.
* testsuite/icf_safe_so_test.cc: Correct test comment.
* testsuite/icf_safe_test.sh: Add AArch64 arch.
Diffstat (limited to 'gold/aarch64.cc')
-rw-r--r-- | gold/aarch64.cc | 688 |
1 files changed, 566 insertions, 122 deletions
diff --git a/gold/aarch64.cc b/gold/aarch64.cc index e2bdf95..125953a 100644 --- a/gold/aarch64.cc +++ b/gold/aarch64.cc @@ -525,7 +525,7 @@ class Reloc_stub { return k1.eq(k2); } }; - private: + private: // Stub type. const Stub_type stub_type_; // If this is a local symbol, this is the index in the defining object. @@ -645,7 +645,7 @@ Reloc_stub<size, big_endian>::stub_type_for_reloc( branch_offset = dest - location; break; default: - gold_assert(false); + gold_unreachable(); } if (aarch64_valid_branch_offset_p(branch_offset)) @@ -1762,6 +1762,15 @@ class Target_aarch64 : public Sized_target<size, big_endian> 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; @@ -1959,6 +1968,10 @@ class Target_aarch64 : public Sized_target<size, big_endian> void check_non_pic(Relobj*, unsigned int r_type); + bool + reloc_needs_plt_for_ifunc(Sized_relobj_file<size, big_endian>*, + unsigned int r_type); + // Whether we have issued an error about a non-PIC compilation. bool issued_non_pic_error_; }; @@ -2006,6 +2019,15 @@ class Target_aarch64 : public Sized_target<size, big_endian> const Symbol_value<size>*); inline typename AArch64_relocate_functions<size, big_endian>::Status + tls_ld_to_le( + 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 tls_ie_to_le( const Relocate_info<size, big_endian>*, Target_aarch64<size, big_endian>*, @@ -2206,7 +2228,7 @@ const Target::Target_info Target_aarch64<64, false>::aarch64_info = false, // has_resolve false, // has_code_fill true, // is_default_stack_executable - false, // can_icf_inline_merge_sections + true, // can_icf_inline_merge_sections '\0', // wrap_char "/lib/ld.so.1", // program interpreter 0x400000, // default_text_segment_address @@ -2260,7 +2282,7 @@ const Target::Target_info Target_aarch64<64, true>::aarch64_info = false, // has_resolve false, // has_code_fill true, // is_default_stack_executable - false, // can_icf_inline_merge_sections + true, // can_icf_inline_merge_sections '\0', // wrap_char "/lib/ld.so.1", // program interpreter 0x400000, // default_text_segment_address @@ -2530,7 +2552,7 @@ Target_aarch64<size, big_endian>::scan_reloc_for_stub( destination = value + addend; break; default: - gold_assert(false); + gold_unreachable(); } typename The_reloc_stub::Stub_type stub_type = The_reloc_stub:: @@ -2838,7 +2860,7 @@ relocate_stub(The_reloc_stub* stub, break; default: - gold_assert(false); + gold_unreachable(); } } @@ -2861,7 +2883,7 @@ class Output_data_plt_aarch64 : public Output_section_data Output_data_got_aarch64<size, big_endian>* got, Output_data_space* got_plt, Output_data_space* got_irelative) - : Output_section_data(addralign), tlsdesc_rel_(NULL), + : 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); } @@ -2872,7 +2894,18 @@ class Output_data_plt_aarch64 : public Output_section_data // Add an entry to the PLT. void - add_entry(Symbol* gsym); + 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<size, big_endian>* 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 @@ -3081,32 +3114,100 @@ Output_data_plt_aarch64<size, big_endian>::do_adjust_output_section( template<int size, bool big_endian> void -Output_data_plt_aarch64<size, big_endian>::add_entry(Symbol* gsym) +Output_data_plt_aarch64<size, big_endian>::add_entry(Symbol_table* symtab, + Layout* layout, Symbol* gsym) { gold_assert(!gsym->has_plt_offset()); - gsym->set_plt_offset((this->count_) * this->get_plt_entry_size() - + this->first_plt_entry_offset()); + unsigned int* pcount; + unsigned int plt_reserved; + Output_section_data_build* got; - ++this->count_; + 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_; + } - section_offset_type got_offset = this->got_plt_->current_data_size(); + 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). - this->got_plt_->set_current_data_size(got_offset + size / 8); + got->set_current_data_size(got_offset + size / 8); // Every PLT entry needs a reloc. - gsym->set_needs_dynsym_entry(); - this->rel_->add_global(gsym, elfcpp::R_AARCH64_JUMP_SLOT, - this->got_plt_, got_offset, 0); + 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<int size, bool big_endian> +unsigned int +Output_data_plt_aarch64<size, big_endian>::add_local_ifunc_entry( + Symbol_table* symtab, + Layout* layout, + Sized_relobj_file<size, big_endian>* 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<int size, bool big_endian> +void +Output_data_plt_aarch64<size, big_endian>::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. @@ -3588,8 +3689,12 @@ Output_data_plt_aarch64<size, big_endian>::do_write(Output_file* of) 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()); + 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); @@ -3697,11 +3802,12 @@ class AArch64_relocate_functions 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; + typedef typename elfcpp::Swap<size, big_endian>::Valtype AArch64_valtype; // Return the page address of the address. // Page(address) = address & ~0xFFF - static inline typename elfcpp::Swap<size, big_endian>::Valtype + static inline AArch64_valtype Page(Address address) { return (address & (~static_cast<Address>(0xFFF))); @@ -3714,7 +3820,7 @@ class AArch64_relocate_functions template<int valsize> static inline void update_view(unsigned char* view, - typename elfcpp::Swap<size, big_endian>::Valtype immed, + AArch64_valtype immed, elfcpp::Elf_Xword doffset, elfcpp::Elf_Xword dst_mask) { @@ -3736,8 +3842,8 @@ class AArch64_relocate_functions static inline void update_view_two_parts( unsigned char* view, - typename elfcpp::Swap<size, big_endian>::Valtype immed1, - typename elfcpp::Swap<size, big_endian>::Valtype immed2, + AArch64_valtype immed1, + AArch64_valtype immed2, elfcpp::Elf_Xword doffset1, elfcpp::Elf_Xword doffset2, elfcpp::Elf_Xword dst_mask) @@ -3751,17 +3857,13 @@ class AArch64_relocate_functions (immed2 << doffset2))); } - // Update adr or adrp instruction with [32:12] of X. + // 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, - typename elfcpp::Swap<size, big_endian>::Valtype x, - const AArch64_reloc_property* /* reloc_property */) + update_adr(unsigned char* view, AArch64_valtype immed) { elfcpp::Elf_Xword dst_mask = (0x3 << 29) | (0x7ffff << 5); - typename elfcpp::Swap<32, big_endian>::Valtype immed = - (x >> 12) & 0x1fffff; This::template update_view_two_parts<32>( view, immed & 0x3, @@ -3774,9 +3876,10 @@ class AArch64_relocate_functions // 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, - typename elfcpp::Swap<size, big_endian>::Valtype immed, + AArch64_valtype immed, bool is_movz) { typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype; @@ -3789,17 +3892,44 @@ class AArch64_relocate_functions aarch64_howto[AArch64_reloc_property::INST_MOVW].dst_mask; // Clear immediate fields and opc code. - val &= ~(dst_mask | (0x11 << 29)); + 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 |= (0x10 << 29); + val |= (0x2 << 29); elfcpp::Swap<32, big_endian>::writeval(wv, static_cast<Valtype>(val | (immed << doffset))); } + // Update selected bits in text. + + template<int valsize> + 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<valsize>(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. @@ -3809,7 +3939,7 @@ class AArch64_relocate_functions rela_ua(unsigned char* view, const Sized_relobj_file<size, big_endian>* object, const Symbol_value<size>* psymval, - typename elfcpp::Swap<size, big_endian>::Valtype addend, + AArch64_valtype addend, const AArch64_reloc_property* reloc_property) { typedef typename elfcpp::Swap_unaligned<valsize, big_endian>::Valtype @@ -3830,7 +3960,7 @@ class AArch64_relocate_functions pcrela_ua(unsigned char* view, const Sized_relobj_file<size, big_endian>* object, const Symbol_value<size>* psymval, - typename elfcpp::Swap<size, big_endian>::Valtype addend, + AArch64_valtype addend, Address address, const AArch64_reloc_property* reloc_property) { @@ -3852,15 +3982,13 @@ class AArch64_relocate_functions unsigned char* view, const Sized_relobj_file<size, big_endian>* object, const Symbol_value<size>* psymval, - typename elfcpp::Swap<size, big_endian>::Valtype addend, + AArch64_valtype addend, const AArch64_reloc_property* reloc_property) { - typedef typename elfcpp::Swap<valsize, big_endian>::Valtype - Valtype; + typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype; Valtype* wv = reinterpret_cast<Valtype*>(view); Address x = psymval->value(object, addend); - elfcpp::Swap<valsize, big_endian>::writeval(wv, - static_cast<Valtype>(x)); + elfcpp::Swap<valsize, big_endian>::writeval(wv,static_cast<Valtype>(x)); return (reloc_property->checkup_x_value(x) ? This::STATUS_OKAY : This::STATUS_OVERFLOW); @@ -3874,30 +4002,12 @@ class AArch64_relocate_functions rela_general(unsigned char* view, const Sized_relobj_file<size, big_endian>* object, const Symbol_value<size>* psymval, - typename elfcpp::Swap<size, big_endian>::Valtype addend, + AArch64_valtype addend, const AArch64_reloc_property* reloc_property) { // Calculate relocation. Address x = psymval->value(object, addend); - - // Select bits from X. - Address immed = reloc_property->select_x_value(x); - - // Update view. - const AArch64_reloc_property::Reloc_inst inst = - reloc_property->reloc_inst(); - // If it is a data relocation or instruction has 2 parts of immediate - // fields, you should not call rela_general. - gold_assert(aarch64_howto[inst].doffset2 == -1 && - aarch64_howto[inst].doffset != -1); - This::template update_view<valsize>(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); + return This::template reloc_common<valsize>(view, x, reloc_property); } // Do relocate. Update selected bits in text. @@ -3907,31 +4017,13 @@ class AArch64_relocate_functions static inline typename This::Status rela_general( unsigned char* view, - typename elfcpp::Swap<size, big_endian>::Valtype s, - typename elfcpp::Swap<size, big_endian>::Valtype addend, + AArch64_valtype s, + AArch64_valtype addend, const AArch64_reloc_property* reloc_property) { // Calculate relocation. Address x = s + addend; - - // Select bits from X. - Address immed = reloc_property->select_x_value(x); - - // Update view. - const AArch64_reloc_property::Reloc_inst inst = - reloc_property->reloc_inst(); - // If it is a data relocation or instruction has 2 parts of immediate - // fields, you should not call rela_general. - gold_assert(aarch64_howto[inst].doffset2 == -1 && - aarch64_howto[inst].doffset != -1); - This::template update_view<valsize>(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); + return This::template reloc_common<valsize>(view, x, reloc_property); } // Do address relative relocate. Update selected bits in text. @@ -3943,31 +4035,34 @@ class AArch64_relocate_functions unsigned char* view, const Sized_relobj_file<size, big_endian>* object, const Symbol_value<size>* psymval, - typename elfcpp::Swap<size, big_endian>::Valtype addend, + 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<valsize>(view, x, 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<valsize>(view, immed, - aarch64_howto[inst].doffset, - aarch64_howto[inst].dst_mask); + // Calculate (S + A) - address, update adr instruction. - // Do check overflow or alignment if needed. - return (reloc_property->checkup_x_value(x) - ? This::STATUS_OKAY - : This::STATUS_OVERFLOW); + static inline typename This::Status + adr(unsigned char* view, + const Sized_relobj_file<size, big_endian>* object, + const Symbol_value<size>* 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. @@ -3979,9 +4074,10 @@ class AArch64_relocate_functions Address sa, Address address) { - typename elfcpp::Swap<size, big_endian>::Valtype x = - This::Page(sa) - This::Page(address); - update_adr(view, x, NULL); + 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 @@ -4000,9 +4096,10 @@ class AArch64_relocate_functions const AArch64_reloc_property* reloc_property) { Address sa = psymval->value(object, addend); - typename elfcpp::Swap<size, big_endian>::Valtype x = - This::Page(sa) - This::Page(address); - update_adr(view, x, reloc_property); + 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); @@ -4016,15 +4113,21 @@ class AArch64_relocate_functions static inline typename This::Status movnz(unsigned char* view, - typename elfcpp::Swap<size, big_endian>::Valtype x, + AArch64_valtype x, const AArch64_reloc_property* reloc_property) { // Select bits from X. - Address immed = reloc_property->select_x_value(x); - bool is_movz = true; - if (static_cast<int64_t>(x) < 0) + Address immed; + bool is_movz; + typedef typename elfcpp::Elf_types<size>::Elf_Swxword SignedW; + if (static_cast<SignedW>(x) >= 0) + { + immed = reloc_property->select_x_value(x); + is_movz = true; + } + else { - immed = ~immed; + immed = reloc_property->select_x_value(~x);; is_movz = false; } @@ -4433,6 +4536,15 @@ Target_aarch64<size, big_endian>::optimize_tls_reloc(bool 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: @@ -4472,8 +4584,11 @@ Target_aarch64<size, big_endian>::Scan::possible_function_pointer_reloc( { switch (r_type) { - case elfcpp::R_AARCH64_ABS64: - //TODO + 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; } @@ -4498,9 +4613,7 @@ Target_aarch64<size, big_endian>::Scan::local_reloc_may_be_function_pointer( unsigned int r_type, const elfcpp::Sym<size, big_endian>&) { - // When building a shared library, do not fold any local symbols as it is - // not possible to distinguish pointer taken versus a call by looking at - // the relocation types. + // When building a shared library, do not fold any local symbols. return (parameters->options().shared() || possible_function_pointer_reloc(r_type)); } @@ -4586,6 +4699,29 @@ Target_aarch64<size, big_endian>::Scan::check_non_pic(Relobj* object, return; } +// Return whether we need to make a PLT entry for a relocation of the +// given type against a STT_GNU_IFUNC symbol. + +template<int size, bool big_endian> +bool +Target_aarch64<size, big_endian>::Scan::reloc_needs_plt_for_ifunc( + Sized_relobj_file<size, big_endian>* 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<int size, bool big_endian> @@ -4599,7 +4735,7 @@ Target_aarch64<size, big_endian>::Scan::local( Output_section* output_section, const elfcpp::Rela<size, big_endian>& rela, unsigned int r_type, - const elfcpp::Sym<size, big_endian>& /* lsym */, + const elfcpp::Sym<size, big_endian>& lsym, bool is_discarded) { if (is_discarded) @@ -4611,6 +4747,11 @@ Target_aarch64<size, big_endian>::Scan::local( target->got_section(symtab, layout); unsigned int r_sym = elfcpp::elf_r_sym<size>(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: @@ -4634,7 +4775,7 @@ Target_aarch64<size, big_endian>::Scan::local( data_shndx, rela.get_r_offset(), rela.get_r_addend(), - false /* is ifunc */); + is_ifunc); } break; @@ -4725,6 +4866,25 @@ Target_aarch64<size, big_endian>::Scan::local( } break; + case elfcpp::R_AARCH64_TLSLD_ADR_PAGE21: + case elfcpp::R_AARCH64_TLSLD_ADD_LO12_NC: + { + tls::Tls_optimization tlsopt = Target_aarch64<size, big_endian>:: + 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: @@ -4801,6 +4961,11 @@ Target_aarch64<size, big_endian>::Scan::global( 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<elfcpp::SHT_RELA, true, size, big_endian> Reloc_section; const AArch64_reloc_property* arp = @@ -4834,6 +4999,25 @@ Target_aarch64<size, big_endian>::Scan::global( 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); @@ -4905,21 +5089,54 @@ Target_aarch64<size, big_endian>::Scan::global( target->got_section(symtab, layout); if (gsym->final_value_is_known()) { - got->add_global(gsym, GOT_TYPE_STANDARD); + // 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())) + && 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 { - if (got->add_global(gsym, GOT_TYPE_STANDARD)) + // 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, @@ -4974,10 +5191,29 @@ Target_aarch64<size, big_endian>::Scan::global( } break; + case elfcpp::R_AARCH64_TLSLD_ADR_PAGE21: + case elfcpp::R_AARCH64_TLSLD_ADD_LO12_NC: // Local dynamic + { + tls::Tls_optimization tlsopt = Target_aarch64<size, big_endian>:: + 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<size, big_endian>:: + tls::Tls_optimization tlsopt = Target_aarch64<size, big_endian>:: optimize_tls_reloc(gsym->final_value_is_known(), r_type); if (tlsopt == tls::TLSOPT_TO_LE) break; @@ -5113,7 +5349,26 @@ Target_aarch64<size, big_endian>::make_plt_entry( if (this->plt_ == NULL) this->make_plt_section(symtab, layout); - this->plt_->add_entry(gsym); + this->plt_->add_entry(symtab, layout, gsym); +} + +// Make a PLT entry for a local STT_GNU_IFUNC symbol. + +template<int size, bool big_endian> +void +Target_aarch64<size, big_endian>::make_local_ifunc_plt_entry( + Symbol_table* symtab, Layout* layout, + Sized_relobj_file<size, big_endian>* 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<int size, bool big_endian> @@ -5441,6 +5696,16 @@ Target_aarch64<size, big_endian>::Relocate::relocate( 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, @@ -5498,6 +5763,10 @@ Target_aarch64<size, big_endian>::Relocate::relocate( 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: @@ -5640,7 +5909,7 @@ Target_aarch64<size, big_endian>::Relocate::relocate_tls( break; default: - gold_assert(false); + gold_unreachable(); } } gold_error_at_location(relinfo, relnum, rela.get_r_offset(), @@ -5649,6 +5918,81 @@ Target_aarch64<size, big_endian>::Relocate::relocate_tls( } 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<size>::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 { @@ -5692,7 +6036,7 @@ Target_aarch64<size, big_endian>::Relocate::relocate_tls( return aarch64_reloc_funcs::template rela_general<32>( view, got_entry_address, addend, reloc_property); default: - gold_assert(false); + gold_unreachable(); } } // We shall never reach here. @@ -5918,6 +6262,106 @@ 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 +Target_aarch64<size, big_endian>::Relocate::tls_ld_to_le( + 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 typename elfcpp::Swap<32, big_endian>::Valtype Insntype; + typedef typename elfcpp::Elf_types<size>::Elf_Addr AArch64_address; + + Insntype* ip = reinterpret_cast<Insntype*>(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 <main> + // 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<int size, bool big_endian> +inline +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, Target_aarch64<size, big_endian>* target, @@ -5963,7 +6407,7 @@ Target_aarch64<size, big_endian>::Relocate::tls_ie_to_le( newinsn = (0xf2800000 | regno) | ((x & 0xffff) << 5); } else - gold_assert(false); + gold_unreachable(); elfcpp::Swap<32, big_endian>::writeval(ip, newinsn); return aarch64_reloc_funcs::STATUS_OKAY; |