From 5c3885291ffdae7d69304eafb03507a5ba384a5c Mon Sep 17 00:00:00 2001 From: Doug Kwan Date: Wed, 26 May 2010 03:33:59 +0000 Subject: [PATCH] 2010-05-26 Doug Kwan * arm.cc (Arm_scan_relocatable_relocs): New class. (Target_arm::relocate_special_relocatable): New method. (Arm_relocate_functions::arm_branch_common): Handle relocatable link. (Arm_relocate_functions::thumb_branch_common): Same. (Target_arm::scan_relocatable_relocs): Use Arm_scan_relocatable_relocs instead of Default_scan_relocatable_relocs. * target-reloc.h (relocate_for_relocatable): Let target handle relocation strategy Relocatable_relocs::RELOC_SPECIAL. * target.h (Sized_target::relocate_special_relocatable): New method. --- gold/ChangeLog | 12 ++ gold/arm.cc | 395 ++++++++++++++++++++++++++++++++++++++++++++++++++-- gold/target-reloc.h | 15 +- gold/target.h | 30 ++++ 4 files changed, 443 insertions(+), 9 deletions(-) diff --git a/gold/ChangeLog b/gold/ChangeLog index a76baf8..e2b009d 100644 --- a/gold/ChangeLog +++ b/gold/ChangeLog @@ -1,3 +1,15 @@ +2010-05-26 Doug Kwan + + * arm.cc (Arm_scan_relocatable_relocs): New class. + (Target_arm::relocate_special_relocatable): New method. + (Arm_relocate_functions::arm_branch_common): Handle relocatable link. + (Arm_relocate_functions::thumb_branch_common): Same. + (Target_arm::scan_relocatable_relocs): Use Arm_scan_relocatable_relocs + instead of Default_scan_relocatable_relocs. + * target-reloc.h (relocate_for_relocatable): Let target handle + relocation strategy Relocatable_relocs::RELOC_SPECIAL. + * target.h (Sized_target::relocate_special_relocatable): New method. + 2010-05-25 Viktor Kutuzov * timer.cc: Only #include if HAVE_TIMES is defined. diff --git a/gold/arm.cc b/gold/arm.cc index 8bcd5d2..88102dc 100644 --- a/gold/arm.cc +++ b/gold/arm.cc @@ -1956,6 +1956,79 @@ class Arm_output_data_got : public Output_data_got<32, big_endian> std::vector static_relocs_; }; +// The ARM target has many relocation types with odd-sizes or incontigious +// bits. The default handling of relocatable relocation cannot process these +// relocations. So we have to extend the default code. + +template +class Arm_scan_relocatable_relocs : + public Default_scan_relocatable_relocs +{ + public: + // Return the strategy to use for a local symbol which is a section + // symbol, given the relocation type. + inline Relocatable_relocs::Reloc_strategy + local_section_strategy(unsigned int r_type, Relobj*) + { + if (sh_type == elfcpp::SHT_RELA) + return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_RELA; + else + { + if (r_type == elfcpp::R_ARM_TARGET1 + || r_type == elfcpp::R_ARM_TARGET2) + { + const Target_arm* arm_target = + Target_arm::default_target(); + r_type = arm_target->get_real_reloc_type(r_type); + } + + switch(r_type) + { + // Relocations that write nothing. These exclude R_ARM_TARGET1 + // and R_ARM_TARGET2. + case elfcpp::R_ARM_NONE: + case elfcpp::R_ARM_V4BX: + case elfcpp::R_ARM_TLS_GOTDESC: + case elfcpp::R_ARM_TLS_CALL: + case elfcpp::R_ARM_TLS_DESCSEQ: + case elfcpp::R_ARM_THM_TLS_CALL: + case elfcpp::R_ARM_GOTRELAX: + case elfcpp::R_ARM_GNU_VTENTRY: + case elfcpp::R_ARM_GNU_VTINHERIT: + case elfcpp::R_ARM_THM_TLS_DESCSEQ16: + case elfcpp::R_ARM_THM_TLS_DESCSEQ32: + return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_0; + // These should have been converted to something else above. + case elfcpp::R_ARM_TARGET1: + case elfcpp::R_ARM_TARGET2: + gold_unreachable(); + // Relocations that write full 32 bits. + case elfcpp::R_ARM_ABS32: + case elfcpp::R_ARM_REL32: + case elfcpp::R_ARM_SBREL32: + case elfcpp::R_ARM_GOTOFF32: + case elfcpp::R_ARM_BASE_PREL: + case elfcpp::R_ARM_GOT_BREL: + case elfcpp::R_ARM_BASE_ABS: + case elfcpp::R_ARM_ABS32_NOI: + case elfcpp::R_ARM_REL32_NOI: + case elfcpp::R_ARM_PLT32_ABS: + case elfcpp::R_ARM_GOT_ABS: + case elfcpp::R_ARM_GOT_PREL: + case elfcpp::R_ARM_TLS_GD32: + case elfcpp::R_ARM_TLS_LDM32: + case elfcpp::R_ARM_TLS_LDO32: + case elfcpp::R_ARM_TLS_IE32: + case elfcpp::R_ARM_TLS_LE32: + return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_4; + default: + // For all other static relocations, return RELOC_SPECIAL. + return Relocatable_relocs::RELOC_SPECIAL; + } + } + } +}; + // Utilities for manipulating integers of up to 32-bits namespace utils @@ -2189,6 +2262,21 @@ class Target_arm : public Sized_target<32, big_endian> unsigned char* reloc_view, section_size_type reloc_view_size); + // Perform target-specific processing in a relocatable link. This is + // only used if we use the relocation strategy RELOC_SPECIAL. + void + relocate_special_relocatable(const Relocate_info<32, big_endian>* relinfo, + unsigned int sh_type, + const unsigned char* preloc_in, + size_t relnum, + Output_section* output_section, + off_t offset_in_output_section, + unsigned char* view, + typename elfcpp::Elf_types<32>::Elf_Addr + view_address, + section_size_type view_size, + unsigned char* preloc_out); + // Return whether SYM is defined by the ABI. bool do_is_defined_by_abi(Symbol* sym) const @@ -3725,6 +3813,7 @@ Arm_relocate_functions::arm_branch_common( Target_arm::default_target(); if (is_weakly_undefined_without_plt) { + gold_assert(!parameters->options().relocatable()); Valtype cond = val & 0xf0000000U; if (arm_target->may_use_arm_nop()) val = cond | 0x0320f000; @@ -3742,8 +3831,11 @@ Arm_relocate_functions::arm_branch_common( // to switch mode. bool may_use_blx = arm_target->may_use_blx(); Reloc_stub* stub = NULL; - if (utils::has_overflow<26>(branch_offset) - || ((thumb_bit != 0) && !(may_use_blx && r_type == elfcpp::R_ARM_CALL))) + + if (!parameters->options().relocatable() + && (utils::has_overflow<26>(branch_offset) + || ((thumb_bit != 0) + && !(may_use_blx && r_type == elfcpp::R_ARM_CALL)))) { Valtype unadjusted_branch_target = psymval->value(object, 0); @@ -3850,6 +3942,7 @@ Arm_relocate_functions::thumb_branch_common( Target_arm::default_target(); if (is_weakly_undefined_without_plt) { + gold_assert(!parameters->options().relocatable()); if (arm_target->may_use_thumb2_nop()) { elfcpp::Swap<16, big_endian>::writeval(wv, 0xf3af); @@ -3876,11 +3969,12 @@ Arm_relocate_functions::thumb_branch_common( // We need a stub if the branch offset is too large or if we need // to switch mode. bool thumb2 = arm_target->using_thumb2(); - if ((!thumb2 && utils::has_overflow<23>(branch_offset)) - || (thumb2 && utils::has_overflow<25>(branch_offset)) - || ((thumb_bit == 0) - && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx) - || r_type == elfcpp::R_ARM_THM_JUMP24))) + if (!parameters->options().relocatable() + && ((!thumb2 && utils::has_overflow<23>(branch_offset)) + || (thumb2 && utils::has_overflow<25>(branch_offset)) + || ((thumb_bit == 0) + && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx) + || r_type == elfcpp::R_ARM_THM_JUMP24)))) { Arm_address unadjusted_branch_target = psymval->value(object, 0); @@ -8919,7 +9013,7 @@ Target_arm::scan_relocatable_relocs( { gold_assert(sh_type == elfcpp::SHT_REL); - typedef gold::Default_scan_relocatable_relocs Scan_relocatable_relocs; gold::scan_relocatable_relocs<32, big_endian, elfcpp::SHT_REL, @@ -8971,6 +9065,291 @@ Target_arm::relocate_for_relocatable( reloc_view_size); } +// Perform target-specific processing in a relocatable link. This is +// only used if we use the relocation strategy RELOC_SPECIAL. + +template +void +Target_arm::relocate_special_relocatable( + const Relocate_info<32, big_endian>* relinfo, + unsigned int sh_type, + const unsigned char* preloc_in, + size_t relnum, + Output_section* output_section, + off_t offset_in_output_section, + unsigned char* view, + elfcpp::Elf_types<32>::Elf_Addr view_address, + section_size_type, + unsigned char* preloc_out) +{ + // We can only handle REL type relocation sections. + gold_assert(sh_type == elfcpp::SHT_REL); + + typedef typename Reloc_types::Reloc Reltype; + typedef typename Reloc_types::Reloc_write + Reltype_write; + const Arm_address invalid_address = static_cast(0) - 1; + + const Arm_relobj* object = + Arm_relobj::as_arm_relobj(relinfo->object); + const unsigned int local_count = object->local_symbol_count(); + + Reltype reloc(preloc_in); + Reltype_write reloc_write(preloc_out); + + elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info(); + const unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info); + const unsigned int r_type = elfcpp::elf_r_type<32>(r_info); + + const Arm_reloc_property* arp = + arm_reloc_property_table->get_implemented_static_reloc_property(r_type); + gold_assert(arp != NULL); + + // Get the new symbol index. + // We only use RELOC_SPECIAL strategy in local relocations. + gold_assert(r_sym < local_count); + + // We are adjusting a section symbol. We need to find + // the symbol table index of the section symbol for + // the output section corresponding to input section + // in which this symbol is defined. + bool is_ordinary; + unsigned int shndx = object->local_symbol_input_shndx(r_sym, &is_ordinary); + gold_assert(is_ordinary); + Output_section* os = object->output_section(shndx); + gold_assert(os != NULL); + gold_assert(os->needs_symtab_index()); + unsigned int new_symndx = os->symtab_index(); + + // Get the new offset--the location in the output section where + // this relocation should be applied. + + Arm_address offset = reloc.get_r_offset(); + Arm_address new_offset; + if (offset_in_output_section != invalid_address) + new_offset = offset + offset_in_output_section; + else + { + section_offset_type sot_offset = + convert_types(offset); + section_offset_type new_sot_offset = + output_section->output_offset(object, relinfo->data_shndx, + sot_offset); + gold_assert(new_sot_offset != -1); + new_offset = new_sot_offset; + } + + // In an object file, r_offset is an offset within the section. + // In an executable or dynamic object, generated by + // --emit-relocs, r_offset is an absolute address. + if (!parameters->options().relocatable()) + { + new_offset += view_address; + if (offset_in_output_section != invalid_address) + new_offset -= offset_in_output_section; + } + + reloc_write.put_r_offset(new_offset); + reloc_write.put_r_info(elfcpp::elf_r_info<32>(new_symndx, r_type)); + + // Handle the reloc addend. + // The relocation uses a section symbol in the input file. + // We are adjusting it to use a section symbol in the output + // file. The input section symbol refers to some address in + // the input section. We need the relocation in the output + // file to refer to that same address. This adjustment to + // the addend is the same calculation we use for a simple + // absolute relocation for the input section symbol. + + const Symbol_value<32>* psymval = object->local_symbol(r_sym); + + // Handle THUMB bit. + Symbol_value<32> symval; + Arm_address thumb_bit = + object->local_symbol_is_thumb_function(r_sym) ? 1 : 0; + if (thumb_bit != 0 + && arp->uses_thumb_bit() + && ((psymval->value(object, 0) & 1) != 0)) + { + Arm_address stripped_value = + psymval->value(object, 0) & ~static_cast(1); + symval.set_output_value(stripped_value); + psymval = &symval; + } + + unsigned char* paddend = view + offset; + typename Arm_relocate_functions::Status reloc_status = + Arm_relocate_functions::STATUS_OKAY; + switch (r_type) + { + case elfcpp::R_ARM_ABS8: + reloc_status = Arm_relocate_functions::abs8(paddend, object, + psymval); + break; + + case elfcpp::R_ARM_ABS12: + reloc_status = Arm_relocate_functions::abs12(paddend, object, + psymval); + break; + + case elfcpp::R_ARM_ABS16: + reloc_status = Arm_relocate_functions::abs16(paddend, object, + psymval); + break; + + case elfcpp::R_ARM_THM_ABS5: + reloc_status = Arm_relocate_functions::thm_abs5(paddend, + object, + psymval); + break; + + case elfcpp::R_ARM_MOVW_ABS_NC: + case elfcpp::R_ARM_MOVW_PREL_NC: + case elfcpp::R_ARM_MOVW_BREL_NC: + case elfcpp::R_ARM_MOVW_BREL: + reloc_status = Arm_relocate_functions::movw( + paddend, object, psymval, 0, thumb_bit, arp->checks_overflow()); + break; + + case elfcpp::R_ARM_THM_MOVW_ABS_NC: + case elfcpp::R_ARM_THM_MOVW_PREL_NC: + case elfcpp::R_ARM_THM_MOVW_BREL_NC: + case elfcpp::R_ARM_THM_MOVW_BREL: + reloc_status = Arm_relocate_functions::thm_movw( + paddend, object, psymval, 0, thumb_bit, arp->checks_overflow()); + break; + + case elfcpp::R_ARM_THM_CALL: + case elfcpp::R_ARM_THM_XPC22: + case elfcpp::R_ARM_THM_JUMP24: + reloc_status = + Arm_relocate_functions::thumb_branch_common( + r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit, + false); + break; + + case elfcpp::R_ARM_PLT32: + case elfcpp::R_ARM_CALL: + case elfcpp::R_ARM_JUMP24: + case elfcpp::R_ARM_XPC25: + reloc_status = + Arm_relocate_functions::arm_branch_common( + r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit, + false); + break; + + case elfcpp::R_ARM_THM_JUMP19: + reloc_status = + Arm_relocate_functions::thm_jump19(paddend, object, + psymval, 0, thumb_bit); + break; + + case elfcpp::R_ARM_THM_JUMP6: + reloc_status = + Arm_relocate_functions::thm_jump6(paddend, object, psymval, + 0); + break; + + case elfcpp::R_ARM_THM_JUMP8: + reloc_status = + Arm_relocate_functions::thm_jump8(paddend, object, psymval, + 0); + break; + + case elfcpp::R_ARM_THM_JUMP11: + reloc_status = + Arm_relocate_functions::thm_jump11(paddend, object, psymval, + 0); + break; + + case elfcpp::R_ARM_PREL31: + reloc_status = + Arm_relocate_functions::prel31(paddend, object, psymval, 0, + thumb_bit); + break; + + case elfcpp::R_ARM_THM_PC8: + reloc_status = + Arm_relocate_functions::thm_pc8(paddend, object, psymval, + 0); + break; + + case elfcpp::R_ARM_THM_PC12: + reloc_status = + Arm_relocate_functions::thm_pc12(paddend, object, psymval, + 0); + break; + + case elfcpp::R_ARM_THM_ALU_PREL_11_0: + reloc_status = + Arm_relocate_functions::thm_alu11(paddend, object, psymval, + 0, thumb_bit); + break; + + // These relocation truncate relocation results so we cannot handle them + // in a relocatable link. + case elfcpp::R_ARM_MOVT_ABS: + case elfcpp::R_ARM_THM_MOVT_ABS: + case elfcpp::R_ARM_MOVT_PREL: + case elfcpp::R_ARM_MOVT_BREL: + case elfcpp::R_ARM_THM_MOVT_PREL: + case elfcpp::R_ARM_THM_MOVT_BREL: + case elfcpp::R_ARM_ALU_PC_G0_NC: + case elfcpp::R_ARM_ALU_PC_G0: + case elfcpp::R_ARM_ALU_PC_G1_NC: + case elfcpp::R_ARM_ALU_PC_G1: + case elfcpp::R_ARM_ALU_PC_G2: + case elfcpp::R_ARM_ALU_SB_G0_NC: + case elfcpp::R_ARM_ALU_SB_G0: + case elfcpp::R_ARM_ALU_SB_G1_NC: + case elfcpp::R_ARM_ALU_SB_G1: + case elfcpp::R_ARM_ALU_SB_G2: + case elfcpp::R_ARM_LDR_PC_G0: + case elfcpp::R_ARM_LDR_PC_G1: + case elfcpp::R_ARM_LDR_PC_G2: + case elfcpp::R_ARM_LDR_SB_G0: + case elfcpp::R_ARM_LDR_SB_G1: + case elfcpp::R_ARM_LDR_SB_G2: + case elfcpp::R_ARM_LDRS_PC_G0: + case elfcpp::R_ARM_LDRS_PC_G1: + case elfcpp::R_ARM_LDRS_PC_G2: + case elfcpp::R_ARM_LDRS_SB_G0: + case elfcpp::R_ARM_LDRS_SB_G1: + case elfcpp::R_ARM_LDRS_SB_G2: + case elfcpp::R_ARM_LDC_PC_G0: + case elfcpp::R_ARM_LDC_PC_G1: + case elfcpp::R_ARM_LDC_PC_G2: + case elfcpp::R_ARM_LDC_SB_G0: + case elfcpp::R_ARM_LDC_SB_G1: + case elfcpp::R_ARM_LDC_SB_G2: + gold_error(_("cannot handle %s in a relocatable link"), + arp->name().c_str()); + break; + + default: + gold_unreachable(); + } + + // Report any errors. + switch (reloc_status) + { + case Arm_relocate_functions::STATUS_OKAY: + break; + case Arm_relocate_functions::STATUS_OVERFLOW: + gold_error_at_location(relinfo, relnum, reloc.get_r_offset(), + _("relocation overflow in %s"), + arp->name().c_str()); + break; + case Arm_relocate_functions::STATUS_BAD_RELOC: + gold_error_at_location(relinfo, relnum, reloc.get_r_offset(), + _("unexpected opcode while processing relocation %s"), + arp->name().c_str()); + break; + default: + gold_unreachable(); + } +} + // Return the value to use for a dynamic symbol which requires special // treatment. This is how we support equality comparisons of function // pointers across shared library boundaries, as described in the diff --git a/gold/target-reloc.h b/gold/target-reloc.h index 04854d2..34c13e8 100644 --- a/gold/target-reloc.h +++ b/gold/target-reloc.h @@ -515,7 +515,7 @@ relocate_for_relocatable( const Relocatable_relocs* rr, unsigned char* view, typename elfcpp::Elf_types::Elf_Addr view_address, - section_size_type, + section_size_type view_size, unsigned char* reloc_view, section_size_type reloc_view_size) { @@ -537,6 +537,19 @@ relocate_for_relocatable( if (strategy == Relocatable_relocs::RELOC_DISCARD) continue; + if (strategy == Relocatable_relocs::RELOC_SPECIAL) + { + // Target wants to handle this relocation. + Sized_target* target = + parameters->sized_target(); + target->relocate_special_relocatable(relinfo, sh_type, prelocs, + i, output_section, + offset_in_output_section, + view, view_address, + view_size, pwrite); + pwrite += reloc_size; + continue; + } Reltype reloc(prelocs); Reltype_write reloc_write(pwrite); diff --git a/gold/target.h b/gold/target.h index f2fdcc9..a0ec0b3 100644 --- a/gold/target.h +++ b/gold/target.h @@ -687,7 +687,37 @@ class Sized_target : public Target section_size_type view_size, unsigned char* reloc_view, section_size_type reloc_view_size) = 0; + + // Perform target-specific processing in a relocatable link. This is + // only used if we use the relocation strategy RELOC_SPECIAL. + // RELINFO points to a Relocation_info structure. SH_TYPE is the relocation + // section type. PRELOC_IN points to the original relocation. RELNUM is + // the index number of the relocation in the relocation section. + // OUTPUT_SECTION is the output section to which the relocation is applied. + // OFFSET_IN_OUTPUT_SECTION is the offset of the relocation input section + // within the output section. VIEW points to the output view of the + // output section. VIEW_ADDRESS is output address of the view. VIEW_SIZE + // is the size of the output view and PRELOC_OUT points to the new + // relocation in the output object. + // + // A target only needs to override this if the generic code in + // target-reloc.h cannot handle some relocation types. + virtual void + relocate_special_relocatable(const Relocate_info* + /*relinfo */, + unsigned int /* sh_type */, + const unsigned char* /* preloc_in */, + size_t /* relnum */, + Output_section* /* output_section */, + off_t /* offset_in_output_section */, + unsigned char* /* view */, + typename elfcpp::Elf_types::Elf_Addr + /* view_address */, + section_size_type /* view_size */, + unsigned char* /* preloc_out*/) + { gold_unreachable(); } + protected: Sized_target(const Target::Target_info* pti) : Target(pti) -- 2.7.4