From a21620630edb456511a2467466814ecffa158b2f Mon Sep 17 00:00:00 2001 From: Ian Lance Taylor Date: Wed, 20 Jan 2010 16:49:09 +0000 Subject: [PATCH] * gold/arm.cc: Added support for R_ARM_V4BX relocation (class Arm_v4bx_stub): New class. (DEF_STUBS): Updated definition to support v4_veneer_bx. (Stub_factory::make_arm_v4bx_stub): New method. (Stub_factory::elf32_arm_stub_v4_veneer_bx): New veneer template. (Stub_table::empty): Handle v4bx stubs. (Stub_table::add_arm_v4bx_stub): New method. (Stub_table::find_arm_v4bx_stub): New method. (Arm_relocate_functions::v4bx): New method. (Target_arm::fix_v4bx): New method. (Target_arm::Target_arm): Handle R_ARM_V4BX. (Stub_table::relocate_stubs): Likewise. (Stub_table::do_write): Likewise. (Stub_table::update_data_size_and_addralign): Likewise. (Stub_table::finalize_stubs): Likewise. (Target_arm::Scan::local): Likewise. (Target_arm::Scan::global): Likewise. (Target_arm::do_finalize_sections): Likewise. (Target_arm::Relocate::relocate): Likewise. (Target_arm::Relocatable_size_for_reloc::get_size_for_reloc): Likewise. (Target_arm::scan_reloc_for_stub): Likewise. (Target_arm::scan_reloc_section_for_stubs): Likewise. --- gold/ChangeLog | 26 +++++ gold/arm.cc | 276 +++++++++++++++++++++++++++++++++++++++++++++++-- 2 files changed, 296 insertions(+), 6 deletions(-) diff --git a/gold/ChangeLog b/gold/ChangeLog index 2bf56d4140..0752d081f5 100644 --- a/gold/ChangeLog +++ b/gold/ChangeLog @@ -1,3 +1,29 @@ +2010-01-20 Viktor Kutuzov + + * gold/arm.cc: Added support for R_ARM_V4BX relocation + (class Arm_v4bx_stub): New class. + (DEF_STUBS): Updated definition to support v4_veneer_bx. + (Stub_factory::make_arm_v4bx_stub): New method. + (Stub_factory::elf32_arm_stub_v4_veneer_bx): New veneer template. + (Stub_table::empty): Handle v4bx stubs. + (Stub_table::add_arm_v4bx_stub): New method. + (Stub_table::find_arm_v4bx_stub): New method. + (Arm_relocate_functions::v4bx): New method. + (Target_arm::fix_v4bx): New method. + (Target_arm::Target_arm): Handle R_ARM_V4BX. + (Stub_table::relocate_stubs): Likewise. + (Stub_table::do_write): Likewise. + (Stub_table::update_data_size_and_addralign): Likewise. + (Stub_table::finalize_stubs): Likewise. + (Target_arm::Scan::local): Likewise. + (Target_arm::Scan::global): Likewise. + (Target_arm::do_finalize_sections): Likewise. + (Target_arm::Relocate::relocate): Likewise. + (Target_arm::Relocatable_size_for_reloc::get_size_for_reloc): + Likewise. + (Target_arm::scan_reloc_for_stub): Likewise. + (Target_arm::scan_reloc_section_for_stubs): Likewise. + 2010-01-19 Ian Lance Taylor * output.cc (Output_section_headers::do_sized_write): Write large diff --git a/gold/arm.cc b/gold/arm.cc index 1ab909e5e3..87459a5f13 100644 --- a/gold/arm.cc +++ b/gold/arm.cc @@ -122,6 +122,7 @@ const int32_t THM2_MAX_BWD_BRANCH_OFFSET = (-(1 << 24) + 4); // R_ARM_MOVT_PREL // R_ARM_THM_MOVW_PREL_NC // R_ARM_THM_MOVT_PREL +// R_ARM_V4BX // R_ARM_THM_JUMP6 // R_ARM_THM_JUMP8 // R_ARM_THM_JUMP11 @@ -254,7 +255,8 @@ class Insn_template DEF_STUB(a8_veneer_b_cond) \ DEF_STUB(a8_veneer_b) \ DEF_STUB(a8_veneer_bl) \ - DEF_STUB(a8_veneer_blx) + DEF_STUB(a8_veneer_blx) \ + DEF_STUB(v4_veneer_bx) // Stub types. @@ -275,7 +277,7 @@ typedef enum arm_stub_cortex_a8_last = arm_stub_a8_veneer_blx, // Last stub type. - arm_stub_type_last = arm_stub_a8_veneer_blx + arm_stub_type_last = arm_stub_v4_veneer_bx } Stub_type; #undef DEF_STUB @@ -748,6 +750,64 @@ class Cortex_a8_stub : public Stub uint32_t original_insn_; }; +// ARMv4 BX Rx branch relocation stub class. +class Arm_v4bx_stub : public Stub +{ + public: + ~Arm_v4bx_stub() + { } + + // Return the associated register. + uint32_t + reg() const + { return this->reg_; } + + protected: + // Arm V4BX stubs are created via a stub factory. So these are protected. + Arm_v4bx_stub(const Stub_template* stub_template, const uint32_t reg) + : Stub(stub_template), reg_(reg) + { } + + friend class Stub_factory; + + // Return the relocation target address of the i-th relocation in the + // stub. + Arm_address + do_reloc_target(size_t) + { gold_unreachable(); } + + // This may be overridden in the child class. + virtual void + do_write(unsigned char* view, section_size_type view_size, bool big_endian) + { + if (big_endian) + this->do_fixed_endian_v4bx_write(view, view_size); + else + this->do_fixed_endian_v4bx_write(view, view_size); + } + + private: + // A template to implement do_write. + template + void inline + do_fixed_endian_v4bx_write(unsigned char* view, section_size_type) + { + const Insn_template* insns = this->stub_template()->insns(); + elfcpp::Swap<32, big_endian>::writeval(view, + (insns[0].data() + + (this->reg_ << 16))); + view += insns[0].size(); + elfcpp::Swap<32, big_endian>::writeval(view, + (insns[1].data() + this->reg_)); + view += insns[1].size(); + elfcpp::Swap<32, big_endian>::writeval(view, + (insns[2].data() + this->reg_)); + } + + // A register index (r0-r14), which is associated with the stub. + uint32_t reg_; +}; + // Stub factory class. class Stub_factory @@ -782,6 +842,16 @@ class Stub_factory source, destination, original_insn); } + // Make an ARM V4BX relocation stub. + // This method creates a stub from the arm_stub_v4_veneer_bx template only. + Arm_v4bx_stub* + make_arm_v4bx_stub(uint32_t reg) const + { + gold_assert(reg < 0xf); + return new Arm_v4bx_stub(this->stub_templates_[arm_stub_v4_veneer_bx], + reg); + } + private: // Constructor and destructor are protected since we only return a single // instance created in Stub_factory::get_instance(). @@ -804,7 +874,7 @@ class Stub_table : public Output_data public: Stub_table(Arm_input_section* owner) : Output_data(), owner_(owner), reloc_stubs_(), cortex_a8_stubs_(), - prev_data_size_(0), prev_addralign_(1) + arm_v4bx_stubs_(0xf), prev_data_size_(0), prev_addralign_(1) { } ~Stub_table() @@ -818,7 +888,11 @@ class Stub_table : public Output_data // Whether this stub table is empty. bool empty() const - { return this->reloc_stubs_.empty() && this->cortex_a8_stubs_.empty(); } + { + return (this->reloc_stubs_.empty() + && this->cortex_a8_stubs_.empty() + && this->arm_v4bx_stubs_.empty()); + } // Return the current data size. off_t @@ -845,6 +919,15 @@ class Stub_table : public Output_data this->cortex_a8_stubs_.insert(value); } + // Add an ARM V4BX relocation stub. A register index will be retrieved + // from the stub. + void + add_arm_v4bx_stub(Arm_v4bx_stub* stub) + { + gold_assert(stub != NULL && this->arm_v4bx_stubs_[stub->reg()] == NULL); + this->arm_v4bx_stubs_[stub->reg()] = stub; + } + // Remove all Cortex-A8 stubs. void remove_all_cortex_a8_stubs(); @@ -857,6 +940,15 @@ class Stub_table : public Output_data return (p != this->reloc_stubs_.end()) ? p->second : NULL; } + // Look up an arm v4bx relocation stub using the register index. + // Return NULL if there is none. + Arm_v4bx_stub* + find_arm_v4bx_stub(const uint32_t reg) const + { + gold_assert(reg < 0xf); + return this->arm_v4bx_stubs_[reg]; + } + // Relocate stubs in this stub table. void relocate_stubs(const Relocate_info<32, big_endian>*, @@ -916,6 +1008,8 @@ class Stub_table : public Output_data // List of Cortex-A8 stubs ordered by addresses of branches being // fixed up in output. typedef std::map Cortex_a8_stub_list; + // List of Arm V4BX relocation stubs ordered by associated registers. + typedef std::vector Arm_v4bx_stub_list; // Owner of this stub table. Arm_input_section* owner_; @@ -923,6 +1017,8 @@ class Stub_table : public Output_data Reloc_stub_map reloc_stubs_; // The cortex_a8_stubs. Cortex_a8_stub_list cortex_a8_stubs_; + // The Arm V4BX relocation stubs. + Arm_v4bx_stub_list arm_v4bx_stubs_; // data size of this in the previous pass. off_t prev_data_size_; // address alignment of this in the previous pass. @@ -1452,7 +1548,7 @@ class Target_arm : public Sized_target<32, big_endian> stub_factory_(Stub_factory::get_instance()), may_use_blx_(false), should_force_pic_veneer_(false), arm_input_section_map_(), attributes_section_data_(NULL), fix_cortex_a8_(false), - cortex_a8_relocs_info_() + cortex_a8_relocs_info_(), fix_v4bx_(0) { } // Whether we can use BLX. @@ -1685,6 +1781,14 @@ class Target_arm : public Sized_target<32, big_endian> fix_cortex_a8() const { return this->fix_cortex_a8_; } + // Whether we fix R_ARM_V4BX relocation. + // 0 - do not fix + // 1 - replace with MOV instruction (armv4 target) + // 2 - make interworking veneer (>= armv4t targets only) + int + fix_v4bx() const + { return this->fix_v4bx_; } + // Scan a span of THUMB code section for Cortex-A8 erratum. void scan_span_for_cortex_a8_erratum(Arm_relobj*, unsigned int, @@ -2048,6 +2152,8 @@ class Target_arm : public Sized_target<32, big_endian> bool fix_cortex_a8_; // Map addresses to relocs for Cortex-A8 erratum. Cortex_a8_relocs_info cortex_a8_relocs_info_; + // Whether we need to fix code for V4BX relocations. + int fix_v4bx_; }; template @@ -2745,6 +2851,49 @@ class Arm_relocate_functions : public Relocate_functions<32, big_endian> elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff); return This::STATUS_OKAY; } + + // R_ARM_V4BX + static inline typename This::Status + v4bx(const Relocate_info<32, big_endian>* relinfo, + unsigned char *view, + const Arm_relobj* object, + const Arm_address address, + const bool is_interworking) + { + + typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype; + Valtype* wv = reinterpret_cast(view); + Valtype val = elfcpp::Swap<32, big_endian>::readval(wv); + + // Ensure that we have a BX instruction. + gold_assert((val & 0x0ffffff0) == 0x012fff10); + const uint32_t reg = (val & 0xf); + if (is_interworking && reg != 0xf) + { + Stub_table* stub_table = + object->stub_table(relinfo->data_shndx); + gold_assert(stub_table != NULL); + + Arm_v4bx_stub* stub = stub_table->find_arm_v4bx_stub(reg); + gold_assert(stub != NULL); + + int32_t veneer_address = + stub_table->address() + stub->offset() - 8 - address; + gold_assert((veneer_address <= ARM_MAX_FWD_BRANCH_OFFSET) + && (veneer_address >= ARM_MAX_BWD_BRANCH_OFFSET)); + // Replace with a branch to veneer (B ) + val = (val & 0xf0000000) | 0x0a000000 + | ((veneer_address >> 2) & 0x00ffffff); + } + else + { + // Preserve Rm (lowest four bits) and the condition code + // (highest four bits). Other bits encode MOV PC,Rm. + val = (val & 0xf000000f) | 0x01a0f000; + } + elfcpp::Swap<32, big_endian>::writeval(wv, val); + return This::STATUS_OKAY; + } }; // Relocate ARM long branches. This handles relocation types @@ -3676,6 +3825,15 @@ Stub_factory::Stub_factory() Insn_template::arm_rel_insn(0xea000000, -8) // b dest }; + // Stub used to provide an interworking for R_ARM_V4BX relocation + // (bx r[n] instruction). + static const Insn_template elf32_arm_stub_v4_veneer_bx[] = + { + Insn_template::arm_insn(0xe3100001), // tst r, #1 + Insn_template::arm_insn(0x01a0f000), // moveq pc, r + Insn_template::arm_insn(0xe12fff10) // bx r + }; + // Fill in the stub template look-up table. Stub templates are constructed // per instance of Stub_factory for fast look-up without locking // in a thread-enabled environment. @@ -3770,6 +3928,16 @@ Stub_table::relocate_stubs( ++p) this->relocate_stub(p->second, relinfo, arm_target, output_section, view, address, view_size); + + // Relocate all ARM V4BX stubs. + for (Arm_v4bx_stub_list::iterator p = this->arm_v4bx_stubs_.begin(); + p != this->arm_v4bx_stubs_.end(); + ++p) + { + if (*p != NULL) + this->relocate_stub(*p, relinfo, arm_target, output_section, view, + address, view_size); + } } // Write out the stubs to file. @@ -3811,6 +3979,22 @@ Stub_table::do_write(Output_file* of) big_endian); } + // Write ARM V4BX relocation stubs. + for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin(); + p != this->arm_v4bx_stubs_.end(); + ++p) + { + if (*p == NULL) + continue; + + Arm_address address = this->address() + (*p)->offset(); + gold_assert(address + == align_address(address, + (*p)->stub_template()->alignment())); + (*p)->write(oview + (*p)->offset(), (*p)->stub_template()->size(), + big_endian); + } + of->write_output_view(this->offset(), oview_size, oview); } @@ -3847,6 +4031,19 @@ Stub_table::update_data_size_and_addralign() + stub_template->size()); } + for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin(); + p != this->arm_v4bx_stubs_.end(); + ++p) + { + if (*p == NULL) + continue; + + const Stub_template* stub_template = (*p)->stub_template(); + addralign = std::max(addralign, stub_template->alignment()); + size = (align_address(size, stub_template->alignment()) + + stub_template->size()); + } + // Check if either data size or alignment changed in this pass. // Update prev_data_size_ and prev_addralign_. These will be used // as the current data size and address alignment for the next pass. @@ -3898,6 +4095,20 @@ Stub_table::finalize_stubs() arm_relobj->mark_section_for_cortex_a8_workaround(stub->shndx()); } + for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin(); + p != this->arm_v4bx_stubs_.end(); + ++p) + { + if (*p == NULL) + continue; + + const Stub_template* stub_template = (*p)->stub_template(); + uint64_t stub_addralign = stub_template->alignment(); + off = align_address(off, stub_addralign); + (*p)->set_offset(off); + off += stub_template->size(); + } + gold_assert(off <= this->prev_data_size_); } @@ -5204,6 +5415,7 @@ Target_arm::Scan::local(Symbol_table* symtab, case elfcpp::R_ARM_THM_JUMP6: case elfcpp::R_ARM_THM_JUMP8: case elfcpp::R_ARM_THM_JUMP11: + case elfcpp::R_ARM_V4BX: break; case elfcpp::R_ARM_GOTOFF32: @@ -5335,6 +5547,7 @@ Target_arm::Scan::global(Symbol_table* symtab, case elfcpp::R_ARM_THM_JUMP6: case elfcpp::R_ARM_THM_JUMP8: case elfcpp::R_ARM_THM_JUMP11: + case elfcpp::R_ARM_V4BX: break; case elfcpp::R_ARM_THM_ABS5: @@ -5603,6 +5816,13 @@ Target_arm::do_finalize_sections( || cpu_arch_profile_attr->int_value() == 0)); } + // Check if we can use V4BX interworking. + // The V4BX interworking stub contains BX instruction, + // which is not specified for some profiles. + if (this->fix_v4bx() == 2 && !this->may_use_blx()) + gold_error(_("unable to provide V4BX reloc interworking fix up; " + "the target profile does not support BX instruction")); + // Fill in some more dynamic tags. const Reloc_section* rel_plt = (this->plt_ == NULL ? NULL @@ -6090,6 +6310,13 @@ Target_arm::Relocate::relocate( address, thumb_bit); break; + case elfcpp::R_ARM_V4BX: + if (target->fix_v4bx() > 0) + reloc_status = + Arm_relocate_functions::v4bx(relinfo, view, object, address, + (target->fix_v4bx() == 2)); + break; + case elfcpp::R_ARM_TARGET1: // This should have been mapped to another type already. // Fall through. @@ -6238,6 +6465,7 @@ Target_arm::Relocatable_size_for_reloc::get_size_for_reloc( case elfcpp::R_ARM_MOVT_PREL: case elfcpp::R_ARM_THM_MOVW_PREL_NC: case elfcpp::R_ARM_THM_MOVT_PREL: + case elfcpp::R_ARM_V4BX: return 4; case elfcpp::R_ARM_TARGET1: @@ -7382,6 +7610,29 @@ Target_arm::scan_reloc_for_stub( const Arm_relobj* arm_relobj = Arm_relobj::as_arm_relobj(relinfo->object); + if (r_type == elfcpp::R_ARM_V4BX) + { + const uint32_t reg = (addend & 0xf); + if (this->fix_v4bx() == 2 && reg < 0xf) + { + // Try looking up an existing stub from a stub table. + Stub_table* stub_table = + arm_relobj->stub_table(relinfo->data_shndx); + gold_assert(stub_table != NULL); + + if (stub_table->find_arm_v4bx_stub(reg) == NULL) + { + // create a new stub and add it to stub table. + Arm_v4bx_stub* stub = + this->stub_factory().make_arm_v4bx_stub(reg); + gold_assert(stub != NULL); + stub_table->add_arm_v4bx_stub(stub); + } + } + + return; + } + bool target_is_thumb; Symbol_value<32> symval; if (gsym != NULL) @@ -7553,7 +7804,8 @@ Target_arm::scan_reloc_section_for_stubs( && (r_type != elfcpp::R_ARM_THM_CALL) && (r_type != elfcpp::R_ARM_THM_XPC22) && (r_type != elfcpp::R_ARM_THM_JUMP24) - && (r_type != elfcpp::R_ARM_THM_JUMP19)) + && (r_type != elfcpp::R_ARM_THM_JUMP19) + && (r_type != elfcpp::R_ARM_V4BX)) continue; section_offset_type offset = @@ -7568,6 +7820,18 @@ Target_arm::scan_reloc_section_for_stubs( continue; } + if (r_type == elfcpp::R_ARM_V4BX) + { + // Get the BX instruction. + typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype; + const Valtype* wv = reinterpret_cast(view + offset); + elfcpp::Elf_types<32>::Elf_Swxword insn = + elfcpp::Swap<32, big_endian>::readval(wv); + this->scan_reloc_for_stub(relinfo, r_type, NULL, 0, NULL, + insn, NULL); + continue; + } + // Get the addend. Stub_addend_reader stub_addend_reader; elfcpp::Elf_types<32>::Elf_Swxword addend =