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// arm.cc -- arm target support for gold. // Copyright 2009 Free Software Foundation, Inc. // Written by Doug Kwan <dougkwan@google.com> based on the i386 code // by Ian Lance Taylor <iant@google.com>. // This file is part of gold. // This program is free software; you can redistribute it and/or modify // it under the terms of the GNU General Public License as published by // the Free Software Foundation; either version 3 of the License, or // (at your option) any later version. // This program is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // You should have received a copy of the GNU General Public License // along with this program; if not, write to the Free Software // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, // MA 02110-1301, USA. #include "gold.h" #include <cstring> #include <limits> #include <cstdio> #include <string> #include "elfcpp.h" #include "parameters.h" #include "reloc.h" #include "arm.h" #include "object.h" #include "symtab.h" #include "layout.h" #include "output.h" #include "copy-relocs.h" #include "target.h" #include "target-reloc.h" #include "target-select.h" #include "tls.h" #include "defstd.h" #include "gc.h" namespace { using namespace gold; template<bool big_endian> class Output_data_plt_arm; // The arm target class. // // This is a very simple port of gold for ARM-EABI. It is intended for // supporting Android only for the time being. Only these relocation types // are supported. // // R_ARM_NONE // R_ARM_ABS32 // R_ARM_ABS32_NOI // R_ARM_ABS16 // R_ARM_ABS12 // R_ARM_ABS8 // R_ARM_THM_ABS5 // R_ARM_BASE_ABS // R_ARM_REL32 // R_ARM_THM_CALL // R_ARM_COPY // R_ARM_GLOB_DAT // R_ARM_BASE_PREL // R_ARM_JUMP_SLOT // R_ARM_RELATIVE // R_ARM_GOTOFF32 // R_ARM_GOT_BREL // R_ARM_GOT_PREL // R_ARM_PLT32 // R_ARM_CALL // R_ARM_JUMP24 // R_ARM_TARGET1 // R_ARM_PREL31 // R_ARM_ABS8 // R_ARM_MOVW_ABS_NC // R_ARM_MOVT_ABS // R_ARM_THM_MOVW_ABS_NC // R_ARM_THM_MOVT_ABS // R_ARM_MOVW_PREL_NC // R_ARM_MOVT_PREL // R_ARM_THM_MOVW_PREL_NC // R_ARM_THM_MOVT_PREL // // TODOs: // - Generate various branch stubs. // - Support interworking. // - Define section symbols __exidx_start and __exidx_stop. // - Support more relocation types as needed. // - Make PLTs more flexible for different architecture features like // Thumb-2 and BE8. // There are probably a lot more. // Utilities for manipulating integers of up to 32-bits namespace utils { // Sign extend an n-bit unsigned integer stored in an uint32_t into // an int32_t. NO_BITS must be between 1 to 32. template<int no_bits> static inline int32_t sign_extend(uint32_t bits) { gold_assert(no_bits >= 0 && no_bits <= 32); if (no_bits == 32) return static_cast<int32_t>(bits); uint32_t mask = (~((uint32_t) 0)) >> (32 - no_bits); bits &= mask; uint32_t top_bit = 1U << (no_bits - 1); int32_t as_signed = static_cast<int32_t>(bits); return (bits & top_bit) ? as_signed + (-top_bit * 2) : as_signed; } // Detects overflow of an NO_BITS integer stored in a uint32_t. template<int no_bits> static inline bool has_overflow(uint32_t bits) { gold_assert(no_bits >= 0 && no_bits <= 32); if (no_bits == 32) return false; int32_t max = (1 << (no_bits - 1)) - 1; int32_t min = -(1 << (no_bits - 1)); int32_t as_signed = static_cast<int32_t>(bits); return as_signed > max || as_signed < min; } // Detects overflow of an NO_BITS integer stored in a uint32_t when it // fits in the given number of bits as either a signed or unsigned value. // For example, has_signed_unsigned_overflow<8> would check // -128 <= bits <= 255 template<int no_bits> static inline bool has_signed_unsigned_overflow(uint32_t bits) { gold_assert(no_bits >= 2 && no_bits <= 32); if (no_bits == 32) return false; int32_t max = static_cast<int32_t>((1U << no_bits) - 1); int32_t min = -(1 << (no_bits - 1)); int32_t as_signed = static_cast<int32_t>(bits); return as_signed > max || as_signed < min; } // Select bits from A and B using bits in MASK. For each n in [0..31], // the n-th bit in the result is chosen from the n-th bits of A and B. // A zero selects A and a one selects B. static inline uint32_t bit_select(uint32_t a, uint32_t b, uint32_t mask) { return (a & ~mask) | (b & mask); } }; template<bool big_endian> class Target_arm : public Sized_target<32, big_endian> { public: typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian> Reloc_section; Target_arm() : Sized_target<32, big_endian>(&arm_info), got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL), copy_relocs_(elfcpp::R_ARM_COPY), dynbss_(NULL) { } // Process the relocations to determine unreferenced sections for // garbage collection. void gc_process_relocs(const General_options& options, Symbol_table* symtab, Layout* layout, Sized_relobj<32, big_endian>* object, unsigned int data_shndx, unsigned int sh_type, const unsigned char* prelocs, size_t reloc_count, Output_section* output_section, bool needs_special_offset_handling, size_t local_symbol_count, const unsigned char* plocal_symbols); // Scan the relocations to look for symbol adjustments. void scan_relocs(const General_options& options, Symbol_table* symtab, Layout* layout, Sized_relobj<32, big_endian>* object, unsigned int data_shndx, unsigned int sh_type, const unsigned char* prelocs, size_t reloc_count, Output_section* output_section, bool needs_special_offset_handling, size_t local_symbol_count, const unsigned char* plocal_symbols); // Finalize the sections. void do_finalize_sections(Layout*); // Return the value to use for a dynamic symbol which requires special // treatment. uint64_t do_dynsym_value(const Symbol*) const; // Relocate a section. void relocate_section(const Relocate_info<32, big_endian>*, unsigned int sh_type, const unsigned char* prelocs, size_t reloc_count, Output_section* output_section, bool needs_special_offset_handling, unsigned char* view, elfcpp::Elf_types<32>::Elf_Addr view_address, section_size_type view_size, const Reloc_symbol_changes*); // Scan the relocs during a relocatable link. void scan_relocatable_relocs(const General_options& options, Symbol_table* symtab, Layout* layout, Sized_relobj<32, big_endian>* object, unsigned int data_shndx, unsigned int sh_type, const unsigned char* prelocs, size_t reloc_count, Output_section* output_section, bool needs_special_offset_handling, size_t local_symbol_count, const unsigned char* plocal_symbols, Relocatable_relocs*); // Relocate a section during a relocatable link. void relocate_for_relocatable(const Relocate_info<32, big_endian>*, unsigned int sh_type, const unsigned char* prelocs, size_t reloc_count, Output_section* output_section, off_t offset_in_output_section, const Relocatable_relocs*, unsigned char* view, elfcpp::Elf_types<32>::Elf_Addr view_address, section_size_type view_size, unsigned char* reloc_view, section_size_type reloc_view_size); // Return whether SYM is defined by the ABI. bool do_is_defined_by_abi(Symbol* sym) const { return strcmp(sym->name(), "__tls_get_addr") == 0; } // Return the size of the GOT section. section_size_type got_size() { gold_assert(this->got_ != NULL); return this->got_->data_size(); } // Map platform-specific reloc types static unsigned int get_real_reloc_type (unsigned int r_type); private: // The class which scans relocations. class Scan { public: Scan() : issued_non_pic_error_(false) { } inline void local(const General_options& options, Symbol_table* symtab, Layout* layout, Target_arm* target, Sized_relobj<32, big_endian>* object, unsigned int data_shndx, Output_section* output_section, const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type, const elfcpp::Sym<32, big_endian>& lsym); inline void global(const General_options& options, Symbol_table* symtab, Layout* layout, Target_arm* target, Sized_relobj<32, big_endian>* object, unsigned int data_shndx, Output_section* output_section, const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type, Symbol* gsym); private: static void unsupported_reloc_local(Sized_relobj<32, big_endian>*, unsigned int r_type); static void unsupported_reloc_global(Sized_relobj<32, big_endian>*, unsigned int r_type, Symbol*); void check_non_pic(Relobj*, unsigned int r_type); // Almost identical to Symbol::needs_plt_entry except that it also // handles STT_ARM_TFUNC. static bool symbol_needs_plt_entry(const Symbol* sym) { // An undefined symbol from an executable does not need a PLT entry. if (sym->is_undefined() && !parameters->options().shared()) return false; return (!parameters->doing_static_link() && (sym->type() == elfcpp::STT_FUNC || sym->type() == elfcpp::STT_ARM_TFUNC) && (sym->is_from_dynobj() || sym->is_undefined() || sym->is_preemptible())); } // Whether we have issued an error about a non-PIC compilation. bool issued_non_pic_error_; }; // The class which implements relocation. class Relocate { public: Relocate() { } ~Relocate() { } // Return whether the static relocation needs to be applied. inline bool should_apply_static_reloc(const Sized_symbol<32>* gsym, int ref_flags, bool is_32bit, Output_section* output_section); // Do a relocation. Return false if the caller should not issue // any warnings about this relocation. inline bool relocate(const Relocate_info<32, big_endian>*, Target_arm*, Output_section*, size_t relnum, const elfcpp::Rel<32, big_endian>&, unsigned int r_type, const Sized_symbol<32>*, const Symbol_value<32>*, unsigned char*, elfcpp::Elf_types<32>::Elf_Addr, section_size_type); // Return whether we want to pass flag NON_PIC_REF for this // reloc. static inline bool reloc_is_non_pic (unsigned int r_type) { switch (r_type) { case elfcpp::R_ARM_REL32: case elfcpp::R_ARM_THM_CALL: case elfcpp::R_ARM_CALL: case elfcpp::R_ARM_JUMP24: case elfcpp::R_ARM_PREL31: case elfcpp::R_ARM_THM_ABS5: case elfcpp::R_ARM_ABS8: case elfcpp::R_ARM_ABS12: case elfcpp::R_ARM_ABS16: case elfcpp::R_ARM_BASE_ABS: return true; default: return false; } } }; // A class which returns the size required for a relocation type, // used while scanning relocs during a relocatable link. class Relocatable_size_for_reloc { public: unsigned int get_size_for_reloc(unsigned int, Relobj*); }; // Get the GOT section, creating it if necessary. Output_data_got<32, big_endian>* got_section(Symbol_table*, Layout*); // Get the GOT PLT section. Output_data_space* got_plt_section() const { gold_assert(this->got_plt_ != NULL); return this->got_plt_; } // Create a PLT entry for a global symbol. void make_plt_entry(Symbol_table*, Layout*, Symbol*); // Get the PLT section. const Output_data_plt_arm<big_endian>* plt_section() const { gold_assert(this->plt_ != NULL); return this->plt_; } // Get the dynamic reloc section, creating it if necessary. Reloc_section* rel_dyn_section(Layout*); // Return true if the symbol may need a COPY relocation. // References from an executable object to non-function symbols // defined in a dynamic object may need a COPY relocation. bool may_need_copy_reloc(Symbol* gsym) { return (gsym->type() != elfcpp::STT_ARM_TFUNC && gsym->may_need_copy_reloc()); } // Add a potential copy relocation. void copy_reloc(Symbol_table* symtab, Layout* layout, Sized_relobj<32, big_endian>* object, unsigned int shndx, Output_section* output_section, Symbol* sym, const elfcpp::Rel<32, big_endian>& reloc) { this->copy_relocs_.copy_reloc(symtab, layout, symtab->get_sized_symbol<32>(sym), object, shndx, output_section, reloc, this->rel_dyn_section(layout)); } // Information about this specific target which we pass to the // general Target structure. static const Target::Target_info arm_info; // The types of GOT entries needed for this platform. enum Got_type { GOT_TYPE_STANDARD = 0 // GOT entry for a regular symbol }; // The GOT section. Output_data_got<32, big_endian>* got_; // The PLT section. Output_data_plt_arm<big_endian>* plt_; // The GOT PLT section. Output_data_space* got_plt_; // The dynamic reloc section. Reloc_section* rel_dyn_; // Relocs saved to avoid a COPY reloc. Copy_relocs<elfcpp::SHT_REL, 32, big_endian> copy_relocs_; // Space for variables copied with a COPY reloc. Output_data_space* dynbss_; }; template<bool big_endian> const Target::Target_info Target_arm<big_endian>::arm_info = { 32, // size big_endian, // is_big_endian elfcpp::EM_ARM, // machine_code false, // has_make_symbol false, // has_resolve false, // has_code_fill true, // is_default_stack_executable '\0', // wrap_char "/usr/lib/libc.so.1", // dynamic_linker 0x8000, // default_text_segment_address 0x1000, // abi_pagesize (overridable by -z max-page-size) 0x1000, // common_pagesize (overridable by -z common-page-size) elfcpp::SHN_UNDEF, // small_common_shndx elfcpp::SHN_UNDEF, // large_common_shndx 0, // small_common_section_flags 0 // large_common_section_flags }; // Arm relocate functions class // template<bool big_endian> class Arm_relocate_functions : public Relocate_functions<32, big_endian> { public: typedef enum { STATUS_OKAY, // No error during relocation. STATUS_OVERFLOW, // Relocation oveflow. STATUS_BAD_RELOC // Relocation cannot be applied. } Status; private: typedef Relocate_functions<32, big_endian> Base; typedef Arm_relocate_functions<big_endian> This; // Get an symbol value of *PSYMVAL with an ADDEND. This is a wrapper // to Symbol_value::value(). If HAS_THUMB_BIT is true, that LSB is used // to distinguish ARM and THUMB functions and it is treated specially. static inline Symbol_value<32>::Value arm_symbol_value (const Sized_relobj<32, big_endian> *object, const Symbol_value<32>* psymval, Symbol_value<32>::Value addend, bool has_thumb_bit) { typedef Symbol_value<32>::Value Valtype; if (has_thumb_bit) { Valtype raw = psymval->value(object, 0); Valtype thumb_bit = raw & 1; return ((raw & ~((Valtype) 1)) + addend) | thumb_bit; } else return psymval->value(object, addend); } // Encoding of imm16 argument for movt and movw ARM instructions // from ARM ARM: // // imm16 := imm4 | imm12 // // f e d c b a 9 8 7 6 5 4 3 2 1 0 f e d c b a 9 8 7 6 5 4 3 2 1 0 // +-------+---------------+-------+-------+-----------------------+ // | | |imm4 | |imm12 | // +-------+---------------+-------+-------+-----------------------+ // Extract the relocation addend from VAL based on the ARM // instruction encoding described above. static inline typename elfcpp::Swap<32, big_endian>::Valtype extract_arm_movw_movt_addend( typename elfcpp::Swap<32, big_endian>::Valtype val) { // According to the Elf ABI for ARM Architecture the immediate // field is sign-extended to form the addend. return utils::sign_extend<16>(((val >> 4) & 0xf000) | (val & 0xfff)); } // Insert X into VAL based on the ARM instruction encoding described // above. static inline typename elfcpp::Swap<32, big_endian>::Valtype insert_val_arm_movw_movt( typename elfcpp::Swap<32, big_endian>::Valtype val, typename elfcpp::Swap<32, big_endian>::Valtype x) { val &= 0xfff0f000; val |= x & 0x0fff; val |= (x & 0xf000) << 4; return val; } // Encoding of imm16 argument for movt and movw Thumb2 instructions // from ARM ARM: // // imm16 := imm4 | i | imm3 | imm8 // // f e d c b a 9 8 7 6 5 4 3 2 1 0 f e d c b a 9 8 7 6 5 4 3 2 1 0 // +---------+-+-----------+-------++-+-----+-------+---------------+ // | |i| |imm4 || |imm3 | |imm8 | // +---------+-+-----------+-------++-+-----+-------+---------------+ // Extract the relocation addend from VAL based on the Thumb2 // instruction encoding described above. static inline typename elfcpp::Swap<32, big_endian>::Valtype extract_thumb_movw_movt_addend( typename elfcpp::Swap<32, big_endian>::Valtype val) { // According to the Elf ABI for ARM Architecture the immediate // field is sign-extended to form the addend. return utils::sign_extend<16>(((val >> 4) & 0xf000) | ((val >> 15) & 0x0800) | ((val >> 4) & 0x0700) | (val & 0x00ff)); } // Insert X into VAL based on the Thumb2 instruction encoding // described above. static inline typename elfcpp::Swap<32, big_endian>::Valtype insert_val_thumb_movw_movt( typename elfcpp::Swap<32, big_endian>::Valtype val, typename elfcpp::Swap<32, big_endian>::Valtype x) { val &= 0xfbf08f00; val |= (x & 0xf000) << 4; val |= (x & 0x0800) << 15; val |= (x & 0x0700) << 4; val |= (x & 0x00ff); return val; } // FIXME: This probably only works for Android on ARM v5te. We should // following GNU ld for the general case. template<unsigned r_type> static inline typename This::Status arm_branch_common(unsigned char *view, const Sized_relobj<32, big_endian>* object, const Symbol_value<32>* psymval, elfcpp::Elf_types<32>::Elf_Addr address, bool has_thumb_bit) { typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype; Valtype* wv = reinterpret_cast<Valtype*>(view); Valtype val = elfcpp::Swap<32, big_endian>::readval(wv); bool insn_is_b = (((val >> 28) & 0xf) <= 0xe) && ((val & 0x0f000000UL) == 0x0a000000UL); bool insn_is_uncond_bl = (val & 0xff000000UL) == 0xeb000000UL; bool insn_is_cond_bl = (((val >> 28) & 0xf) < 0xe) && ((val & 0x0f000000UL) == 0x0b000000UL); bool insn_is_blx = (val & 0xfe000000UL) == 0xfa000000UL; bool insn_is_any_branch = (val & 0x0e000000UL) == 0x0a000000UL; if (r_type == elfcpp::R_ARM_CALL) { if (!insn_is_uncond_bl && !insn_is_blx) return This::STATUS_BAD_RELOC; } else if (r_type == elfcpp::R_ARM_JUMP24) { if (!insn_is_b && !insn_is_cond_bl) return This::STATUS_BAD_RELOC; } else if (r_type == elfcpp::R_ARM_PLT32) { if (!insn_is_any_branch) return This::STATUS_BAD_RELOC; } else gold_unreachable(); Valtype addend = utils::sign_extend<26>(val << 2); Valtype x = (This::arm_symbol_value(object, psymval, addend, has_thumb_bit) - address); // If target has thumb bit set, we need to either turn the BL // into a BLX (for ARMv5 or above) or generate a stub. if (x & 1) { // Turn BL to BLX. if (insn_is_uncond_bl) val = (val & 0xffffff) | 0xfa000000 | ((x & 2) << 23); else return This::STATUS_BAD_RELOC; } else gold_assert(!insn_is_blx); val = utils::bit_select(val, (x >> 2), 0xffffffUL); elfcpp::Swap<32, big_endian>::writeval(wv, val); return (utils::has_overflow<26>(x) ? This::STATUS_OVERFLOW : This::STATUS_OKAY); } public: // R_ARM_ABS8: S + A static inline typename This::Status abs8(unsigned char *view, const Sized_relobj<32, big_endian>* object, const Symbol_value<32>* psymval) { typedef typename elfcpp::Swap<8, big_endian>::Valtype Valtype; typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype; Valtype* wv = reinterpret_cast<Valtype*>(view); Valtype val = elfcpp::Swap<8, big_endian>::readval(wv); Reltype addend = utils::sign_extend<8>(val); Reltype x = This::arm_symbol_value(object, psymval, addend, false); val = utils::bit_select(val, x, 0xffU); elfcpp::Swap<8, big_endian>::writeval(wv, val); return (utils::has_signed_unsigned_overflow<8>(x) ? This::STATUS_OVERFLOW : This::STATUS_OKAY); } // R_ARM_THM_ABS5: S + A static inline typename This::Status thm_abs5(unsigned char *view, const Sized_relobj<32, big_endian>* object, const Symbol_value<32>* psymval) { typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype; typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype; Valtype* wv = reinterpret_cast<Valtype*>(view); Valtype val = elfcpp::Swap<16, big_endian>::readval(wv); Reltype addend = (val & 0x7e0U) >> 6; Reltype x = This::arm_symbol_value(object, psymval, addend, false); val = utils::bit_select(val, x << 6, 0x7e0U); elfcpp::Swap<16, big_endian>::writeval(wv, val); return (utils::has_overflow<5>(x) ? This::STATUS_OVERFLOW : This::STATUS_OKAY); } // R_ARM_ABS12: S + A static inline typename This::Status abs12(unsigned char *view, const Sized_relobj<32, big_endian>* object, const Symbol_value<32>* psymval) { typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype; typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype; Valtype* wv = reinterpret_cast<Valtype*>(view); Valtype val = elfcpp::Swap<32, big_endian>::readval(wv); Reltype addend = val & 0x0fffU; Reltype x = This::arm_symbol_value(object, psymval, addend, false); val = utils::bit_select(val, x, 0x0fffU); elfcpp::Swap<32, big_endian>::writeval(wv, val); return (utils::has_overflow<12>(x) ? This::STATUS_OVERFLOW : This::STATUS_OKAY); } // R_ARM_ABS16: S + A static inline typename This::Status abs16(unsigned char *view, const Sized_relobj<32, big_endian>* object, const Symbol_value<32>* psymval) { typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype; typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype; Valtype* wv = reinterpret_cast<Valtype*>(view); Valtype val = elfcpp::Swap<16, big_endian>::readval(wv); Reltype addend = utils::sign_extend<16>(val); Reltype x = This::arm_symbol_value(object, psymval, addend, false); val = utils::bit_select(val, x, 0xffffU); elfcpp::Swap<16, big_endian>::writeval(wv, val); return (utils::has_signed_unsigned_overflow<16>(x) ? This::STATUS_OVERFLOW : This::STATUS_OKAY); } // R_ARM_ABS32: (S + A) | T static inline typename This::Status abs32(unsigned char *view, const Sized_relobj<32, big_endian>* object, const Symbol_value<32>* psymval, bool has_thumb_bit) { typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype; Valtype* wv = reinterpret_cast<Valtype*>(view); Valtype addend = elfcpp::Swap<32, big_endian>::readval(wv); Valtype x = This::arm_symbol_value(object, psymval, addend, has_thumb_bit); elfcpp::Swap<32, big_endian>::writeval(wv, x); return This::STATUS_OKAY; } // R_ARM_REL32: (S + A) | T - P static inline typename This::Status rel32(unsigned char *view, const Sized_relobj<32, big_endian>* object, const Symbol_value<32>* psymval, elfcpp::Elf_types<32>::Elf_Addr address, bool has_thumb_bit) { typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype; Valtype* wv = reinterpret_cast<Valtype*>(view); Valtype addend = elfcpp::Swap<32, big_endian>::readval(wv); Valtype x = (This::arm_symbol_value(object, psymval, addend, has_thumb_bit) - address); elfcpp::Swap<32, big_endian>::writeval(wv, x); return This::STATUS_OKAY; } // R_ARM_THM_CALL: (S + A) | T - P static inline typename This::Status thm_call(unsigned char *view, const Sized_relobj<32, big_endian>* object, const Symbol_value<32>* psymval, elfcpp::Elf_types<32>::Elf_Addr address, bool has_thumb_bit) { // A thumb call consists of two instructions. typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype; typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype; Valtype* wv = reinterpret_cast<Valtype*>(view); Valtype hi = elfcpp::Swap<16, big_endian>::readval(wv); Valtype lo = elfcpp::Swap<16, big_endian>::readval(wv + 1); // Must be a BL instruction. lo == 11111xxxxxxxxxxx. gold_assert((lo & 0xf800) == 0xf800); Reltype addend = utils::sign_extend<23>(((hi & 0x7ff) << 12) | ((lo & 0x7ff) << 1)); Reltype x = (This::arm_symbol_value(object, psymval, addend, has_thumb_bit) - address); // If target has no thumb bit set, we need to either turn the BL // into a BLX (for ARMv5 or above) or generate a stub. if ((x & 1) == 0) { // This only works for ARMv5 and above with interworking enabled. lo &= 0xefff; } hi = utils::bit_select(hi, (x >> 12), 0x7ffU); lo = utils::bit_select(lo, (x >> 1), 0x7ffU); elfcpp::Swap<16, big_endian>::writeval(wv, hi); elfcpp::Swap<16, big_endian>::writeval(wv + 1, lo); return (utils::has_overflow<23>(x) ? This::STATUS_OVERFLOW : This::STATUS_OKAY); } // R_ARM_BASE_PREL: B(S) + A - P static inline typename This::Status base_prel(unsigned char* view, elfcpp::Elf_types<32>::Elf_Addr origin, elfcpp::Elf_types<32>::Elf_Addr address) { Base::rel32(view, origin - address); return STATUS_OKAY; } // R_ARM_BASE_ABS: B(S) + A static inline typename This::Status base_abs(unsigned char* view, elfcpp::Elf_types<32>::Elf_Addr origin) { Base::rel32(view, origin); return STATUS_OKAY; } // R_ARM_GOT_BREL: GOT(S) + A - GOT_ORG static inline typename This::Status got_brel(unsigned char* view, typename elfcpp::Swap<32, big_endian>::Valtype got_offset) { Base::rel32(view, got_offset); return This::STATUS_OKAY; } // R_ARM_GOT_PREL: GOT(S) + A – P static inline typename This::Status got_prel(unsigned char* view, typename elfcpp::Swap<32, big_endian>::Valtype got_offset, elfcpp::Elf_types<32>::Elf_Addr address) { Base::rel32(view, got_offset - address); return This::STATUS_OKAY; } // R_ARM_PLT32: (S + A) | T - P static inline typename This::Status plt32(unsigned char *view, const Sized_relobj<32, big_endian>* object, const Symbol_value<32>* psymval, elfcpp::Elf_types<32>::Elf_Addr address, bool has_thumb_bit) { return arm_branch_common<elfcpp::R_ARM_PLT32>(view, object, psymval, address, has_thumb_bit); } // R_ARM_CALL: (S + A) | T - P static inline typename This::Status call(unsigned char *view, const Sized_relobj<32, big_endian>* object, const Symbol_value<32>* psymval, elfcpp::Elf_types<32>::Elf_Addr address, bool has_thumb_bit) { return arm_branch_common<elfcpp::R_ARM_CALL>(view, object, psymval, address, has_thumb_bit); } // R_ARM_JUMP24: (S + A) | T - P static inline typename This::Status jump24(unsigned char *view, const Sized_relobj<32, big_endian>* object, const Symbol_value<32>* psymval, elfcpp::Elf_types<32>::Elf_Addr address, bool has_thumb_bit) { return arm_branch_common<elfcpp::R_ARM_JUMP24>(view, object, psymval, address, has_thumb_bit); } // R_ARM_PREL: (S + A) | T - P static inline typename This::Status prel31(unsigned char *view, const Sized_relobj<32, big_endian>* object, const Symbol_value<32>* psymval, elfcpp::Elf_types<32>::Elf_Addr address, bool has_thumb_bit) { typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype; Valtype* wv = reinterpret_cast<Valtype*>(view); Valtype val = elfcpp::Swap<32, big_endian>::readval(wv); Valtype addend = utils::sign_extend<31>(val); Valtype x = (This::arm_symbol_value(object, psymval, addend, has_thumb_bit) - address); val = utils::bit_select(val, x, 0x7fffffffU); elfcpp::Swap<32, big_endian>::writeval(wv, val); return (utils::has_overflow<31>(x) ? This::STATUS_OVERFLOW : This::STATUS_OKAY); } // R_ARM_MOVW_ABS_NC: (S + A) | T static inline typename This::Status movw_abs_nc(unsigned char *view, const Sized_relobj<32, big_endian>* object, const Symbol_value<32>* psymval, bool has_thumb_bit) { typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype; Valtype* wv = reinterpret_cast<Valtype*>(view); Valtype val = elfcpp::Swap<32, big_endian>::readval(wv); Valtype addend = This::extract_arm_movw_movt_addend(val); Valtype x = This::arm_symbol_value(object, psymval, addend, has_thumb_bit); val = This::insert_val_arm_movw_movt(val, x); elfcpp::Swap<32, big_endian>::writeval(wv, val); return This::STATUS_OKAY; } // R_ARM_MOVT_ABS: S + A static inline typename This::Status movt_abs(unsigned char *view, const Sized_relobj<32, big_endian>* object, const Symbol_value<32>* psymval) { typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype; Valtype* wv = reinterpret_cast<Valtype*>(view); Valtype val = elfcpp::Swap<32, big_endian>::readval(wv); Valtype addend = This::extract_arm_movw_movt_addend(val); Valtype x = This::arm_symbol_value(object, psymval, addend, 0) >> 16; val = This::insert_val_arm_movw_movt(val, x); elfcpp::Swap<32, big_endian>::writeval(wv, val); return This::STATUS_OKAY; } // R_ARM_THM_MOVW_ABS_NC: S + A | T static inline typename This::Status thm_movw_abs_nc(unsigned char *view, const Sized_relobj<32, big_endian>* object, const Symbol_value<32>* psymval, bool has_thumb_bit) { typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype; typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype; Valtype* wv = reinterpret_cast<Valtype*>(view); Reltype val = ((elfcpp::Swap<16, big_endian>::readval(wv) << 16) | elfcpp::Swap<16, big_endian>::readval(wv + 1)); Reltype addend = extract_thumb_movw_movt_addend(val); Reltype x = This::arm_symbol_value(object, psymval, addend, has_thumb_bit); val = This::insert_val_thumb_movw_movt(val, x); elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16); elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff); return This::STATUS_OKAY; } // R_ARM_THM_MOVT_ABS: S + A static inline typename This::Status thm_movt_abs(unsigned char *view, const Sized_relobj<32, big_endian>* object, const Symbol_value<32>* psymval) { typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype; typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype; Valtype* wv = reinterpret_cast<Valtype*>(view); Reltype val = ((elfcpp::Swap<16, big_endian>::readval(wv) << 16) | elfcpp::Swap<16, big_endian>::readval(wv + 1)); Reltype addend = This::extract_thumb_movw_movt_addend(val); Reltype x = This::arm_symbol_value(object, psymval, addend, 0) >> 16; val = This::insert_val_thumb_movw_movt(val, x); elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16); elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff); return This::STATUS_OKAY; } // R_ARM_MOVW_PREL_NC: (S + A) | T - P static inline typename This::Status movw_prel_nc(unsigned char *view, const Sized_relobj<32, big_endian>* object, const Symbol_value<32>* psymval, elfcpp::Elf_types<32>::Elf_Addr address, bool has_thumb_bit) { typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype; Valtype* wv = reinterpret_cast<Valtype*>(view); Valtype val = elfcpp::Swap<32, big_endian>::readval(wv); Valtype addend = This::extract_arm_movw_movt_addend(val); Valtype x = (This::arm_symbol_value(object, psymval, addend, has_thumb_bit) - address); val = This::insert_val_arm_movw_movt(val, x); elfcpp::Swap<32, big_endian>::writeval(wv, val); return This::STATUS_OKAY; } // R_ARM_MOVT_PREL: S + A - P static inline typename This::Status movt_prel(unsigned char *view, const Sized_relobj<32, big_endian>* object, const Symbol_value<32>* psymval, elfcpp::Elf_types<32>::Elf_Addr address) { typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype; Valtype* wv = reinterpret_cast<Valtype*>(view); Valtype val = elfcpp::Swap<32, big_endian>::readval(wv); Valtype addend = This::extract_arm_movw_movt_addend(val); Valtype x = (This::arm_symbol_value(object, psymval, addend, 0) - address) >> 16; val = This::insert_val_arm_movw_movt(val, x); elfcpp::Swap<32, big_endian>::writeval(wv, val); return This::STATUS_OKAY; } // R_ARM_THM_MOVW_PREL_NC: (S + A) | T - P static inline typename This::Status thm_movw_prel_nc(unsigned char *view, const Sized_relobj<32, big_endian>* object, const Symbol_value<32>* psymval, elfcpp::Elf_types<32>::Elf_Addr address, bool has_thumb_bit) { typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype; typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype; Valtype* wv = reinterpret_cast<Valtype*>(view); Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16) | elfcpp::Swap<16, big_endian>::readval(wv + 1); Reltype addend = This::extract_thumb_movw_movt_addend(val); Reltype x = (This::arm_symbol_value(object, psymval, addend, has_thumb_bit) - address); val = This::insert_val_thumb_movw_movt(val, x); elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16); elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff); return This::STATUS_OKAY; } // R_ARM_THM_MOVT_PREL: S + A - P static inline typename This::Status thm_movt_prel(unsigned char *view, const Sized_relobj<32, big_endian>* object, const Symbol_value<32>* psymval, elfcpp::Elf_types<32>::Elf_Addr address) { typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype; typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype; Valtype* wv = reinterpret_cast<Valtype*>(view); Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16) | elfcpp::Swap<16, big_endian>::readval(wv + 1); Reltype addend = This::extract_thumb_movw_movt_addend(val); Reltype x = (This::arm_symbol_value(object, psymval, addend, 0) - address) >> 16; val = This::insert_val_thumb_movw_movt(val, x); elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16); elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff); return This::STATUS_OKAY; } }; // Get the GOT section, creating it if necessary. template<bool big_endian> Output_data_got<32, big_endian>* Target_arm<big_endian>::got_section(Symbol_table* symtab, Layout* layout) { if (this->got_ == NULL) { gold_assert(symtab != NULL && layout != NULL); this->got_ = new Output_data_got<32, big_endian>(); Output_section* os; os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS, (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE), this->got_, false); os->set_is_relro(); // The old GNU linker creates a .got.plt section. We just // create another set of data in the .got section. Note that we // always create a PLT if we create a GOT, although the PLT // might be empty. this->got_plt_ = new Output_data_space(4, "** GOT PLT"); os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS, (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE), this->got_plt_, false); os->set_is_relro(); // The first three entries are reserved. this->got_plt_->set_current_data_size(3 * 4); // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT. symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL, this->got_plt_, 0, 0, elfcpp::STT_OBJECT, elfcpp::STB_LOCAL, elfcpp::STV_HIDDEN, 0, false, false); } return this->got_; } // Get the dynamic reloc section, creating it if necessary. template<bool big_endian> typename Target_arm<big_endian>::Reloc_section* Target_arm<big_endian>::rel_dyn_section(Layout* layout) { if (this->rel_dyn_ == NULL) { gold_assert(layout != NULL); this->rel_dyn_ = new Reloc_section(parameters->options().combreloc()); layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL, elfcpp::SHF_ALLOC, this->rel_dyn_, true); } return this->rel_dyn_; } // A class to handle the PLT data. template<bool big_endian> class Output_data_plt_arm : public Output_section_data { public: typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian> Reloc_section; Output_data_plt_arm(Layout*, Output_data_space*); // Add an entry to the PLT. void add_entry(Symbol* gsym); // Return the .rel.plt section data. const Reloc_section* rel_plt() const { return this->rel_; } protected: void do_adjust_output_section(Output_section* os); // Write to a map file. void do_print_to_mapfile(Mapfile* mapfile) const { mapfile->print_output_data(this, _("** PLT")); } private: // Template for the first PLT entry. static const uint32_t first_plt_entry[5]; // Template for subsequent PLT entries. static const uint32_t plt_entry[3]; // Set the final size. void set_final_data_size() { this->set_data_size(sizeof(first_plt_entry) + this->count_ * sizeof(plt_entry)); } // Write out the PLT data. void do_write(Output_file*); // The reloc section. Reloc_section* rel_; // The .got.plt section. Output_data_space* got_plt_; // The number of PLT entries. unsigned int count_; }; // Create the PLT section. The ordinary .got section is an argument, // since we need to refer to the start. We also create our own .got // section just for PLT entries. template<bool big_endian> Output_data_plt_arm<big_endian>::Output_data_plt_arm(Layout* layout, Output_data_space* got_plt) : Output_section_data(4), got_plt_(got_plt), count_(0) { this->rel_ = new Reloc_section(false); layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL, elfcpp::SHF_ALLOC, this->rel_, true); } template<bool big_endian> void Output_data_plt_arm<big_endian>::do_adjust_output_section(Output_section* os) { os->set_entsize(0); } // Add an entry to the PLT. template<bool big_endian> void Output_data_plt_arm<big_endian>::add_entry(Symbol* gsym) { gold_assert(!gsym->has_plt_offset()); // Note that when setting the PLT offset we skip the initial // reserved PLT entry. gsym->set_plt_offset((this->count_) * sizeof(plt_entry) + sizeof(first_plt_entry)); ++this->count_; section_offset_type got_offset = this->got_plt_->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 + 4); // Every PLT entry needs a reloc. gsym->set_needs_dynsym_entry(); this->rel_->add_global(gsym, elfcpp::R_ARM_JUMP_SLOT, this->got_plt_, 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. } // ARM PLTs. // FIXME: This is not very flexible. Right now this has only been tested // on armv5te. If we are to support additional architecture features like // Thumb-2 or BE8, we need to make this more flexible like GNU ld. // The first entry in the PLT. template<bool big_endian> const uint32_t Output_data_plt_arm<big_endian>::first_plt_entry[5] = { 0xe52de004, // str lr, [sp, #-4]! 0xe59fe004, // ldr lr, [pc, #4] 0xe08fe00e, // add lr, pc, lr 0xe5bef008, // ldr pc, [lr, #8]! 0x00000000, // &GOT[0] - . }; // Subsequent entries in the PLT. template<bool big_endian> const uint32_t Output_data_plt_arm<big_endian>::plt_entry[3] = { 0xe28fc600, // add ip, pc, #0xNN00000 0xe28cca00, // add ip, ip, #0xNN000 0xe5bcf000, // ldr pc, [ip, #0xNNN]! }; // Write out the PLT. This uses the hand-coded instructions above, // and adjusts them as needed. This is all specified by the arm ELF // Processor Supplement. template<bool big_endian> void Output_data_plt_arm<big_endian>::do_write(Output_file* of) { const off_t offset = this->offset(); const section_size_type oview_size = convert_to_section_size_type(this->data_size()); unsigned char* const oview = of->get_output_view(offset, oview_size); const off_t got_file_offset = this->got_plt_->offset(); const section_size_type got_size = convert_to_section_size_type(this->got_plt_->data_size()); unsigned char* const got_view = of->get_output_view(got_file_offset, got_size); unsigned char* pov = oview; elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address(); elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address(); // Write first PLT entry. All but the last word are constants. const size_t num_first_plt_words = (sizeof(first_plt_entry) / sizeof(plt_entry[0])); for (size_t i = 0; i < num_first_plt_words - 1; i++) elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]); // Last word in first PLT entry is &GOT[0] - . elfcpp::Swap<32, big_endian>::writeval(pov + 16, got_address - (plt_address + 16)); pov += sizeof(first_plt_entry); unsigned char* got_pov = got_view; memset(got_pov, 0, 12); got_pov += 12; const int rel_size = elfcpp::Elf_sizes<32>::rel_size; unsigned int plt_offset = sizeof(first_plt_entry); unsigned int plt_rel_offset = 0; unsigned int got_offset = 12; const unsigned int count = this->count_; for (unsigned int i = 0; i < count; ++i, pov += sizeof(plt_entry), got_pov += 4, plt_offset += sizeof(plt_entry), plt_rel_offset += rel_size, got_offset += 4) { // Set and adjust the PLT entry itself. int32_t offset = ((got_address + got_offset) - (plt_address + plt_offset + 8)); gold_assert(offset >= 0 && offset < 0x0fffffff); uint32_t plt_insn0 = plt_entry[0] | ((offset >> 20) & 0xff); elfcpp::Swap<32, big_endian>::writeval(pov, plt_insn0); uint32_t plt_insn1 = plt_entry[1] | ((offset >> 12) & 0xff); elfcpp::Swap<32, big_endian>::writeval(pov + 4, plt_insn1); uint32_t plt_insn2 = plt_entry[2] | (offset & 0xfff); elfcpp::Swap<32, big_endian>::writeval(pov + 8, plt_insn2); // Set the entry in the GOT. elfcpp::Swap<32, big_endian>::writeval(got_pov, plt_address); } gold_assert(static_cast<section_size_type>(pov - oview) == oview_size); gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size); of->write_output_view(offset, oview_size, oview); of->write_output_view(got_file_offset, got_size, got_view); } // Create a PLT entry for a global symbol. template<bool big_endian> void Target_arm<big_endian>::make_plt_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym) { if (gsym->has_plt_offset()) return; if (this->plt_ == NULL) { // Create the GOT sections first. this->got_section(symtab, layout); this->plt_ = new Output_data_plt_arm<big_endian>(layout, this->got_plt_); layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS, (elfcpp::SHF_ALLOC | elfcpp::SHF_EXECINSTR), this->plt_, false); } this->plt_->add_entry(gsym); } // Report an unsupported relocation against a local symbol. template<bool big_endian> void Target_arm<big_endian>::Scan::unsupported_reloc_local( Sized_relobj<32, big_endian>* object, unsigned int r_type) { gold_error(_("%s: unsupported reloc %u against local symbol"), object->name().c_str(), r_type); } // We are about to emit a dynamic relocation of type R_TYPE. If the // dynamic linker does not support it, issue an error. The GNU linker // only issues a non-PIC error for an allocated read-only section. // Here we know the section is allocated, but we don't know that it is // read-only. But we check for all the relocation types which the // glibc dynamic linker supports, so it seems appropriate to issue an // error even if the section is not read-only. template<bool big_endian> void Target_arm<big_endian>::Scan::check_non_pic(Relobj* object, unsigned int r_type) { switch (r_type) { // These are the relocation types supported by glibc for ARM. case elfcpp::R_ARM_RELATIVE: case elfcpp::R_ARM_COPY: case elfcpp::R_ARM_GLOB_DAT: case elfcpp::R_ARM_JUMP_SLOT: case elfcpp::R_ARM_ABS32: case elfcpp::R_ARM_ABS32_NOI: case elfcpp::R_ARM_PC24: // FIXME: The following 3 types are not supported by Android's dynamic // linker. case elfcpp::R_ARM_TLS_DTPMOD32: case elfcpp::R_ARM_TLS_DTPOFF32: case elfcpp::R_ARM_TLS_TPOFF32: return; default: // This prevents us from issuing more than one error per reloc // section. But we can still wind up issuing more than one // error per object file. if (this->issued_non_pic_error_) return; object->error(_("requires unsupported dynamic reloc; " "recompile with -fPIC")); this->issued_non_pic_error_ = true; return; case elfcpp::R_ARM_NONE: gold_unreachable(); } } // Scan a relocation for a local symbol. // FIXME: This only handles a subset of relocation types used by Android // on ARM v5te devices. template<bool big_endian> inline void Target_arm<big_endian>::Scan::local(const General_options&, Symbol_table* symtab, Layout* layout, Target_arm* target, Sized_relobj<32, big_endian>* object, unsigned int data_shndx, Output_section* output_section, const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type, const elfcpp::Sym<32, big_endian>&) { r_type = get_real_reloc_type(r_type); switch (r_type) { case elfcpp::R_ARM_NONE: break; case elfcpp::R_ARM_ABS32: case elfcpp::R_ARM_ABS32_NOI: // If building a shared library (or a position-independent // executable), we need to create a dynamic relocation for // this location. The relocation applied at link time will // apply the link-time value, so we flag the location with // an R_ARM_RELATIVE relocation so the dynamic loader can // relocate it easily. if (parameters->options().output_is_position_independent()) { Reloc_section* rel_dyn = target->rel_dyn_section(layout); unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info()); // If we are to add more other reloc types than R_ARM_ABS32, // we need to add check_non_pic(object, r_type) here. rel_dyn->add_local_relative(object, r_sym, elfcpp::R_ARM_RELATIVE, output_section, data_shndx, reloc.get_r_offset()); } break; case elfcpp::R_ARM_REL32: case elfcpp::R_ARM_THM_CALL: case elfcpp::R_ARM_CALL: case elfcpp::R_ARM_PREL31: case elfcpp::R_ARM_JUMP24: case elfcpp::R_ARM_PLT32: case elfcpp::R_ARM_THM_ABS5: case elfcpp::R_ARM_ABS8: case elfcpp::R_ARM_ABS12: case elfcpp::R_ARM_ABS16: case elfcpp::R_ARM_BASE_ABS: case elfcpp::R_ARM_MOVW_ABS_NC: case elfcpp::R_ARM_MOVT_ABS: case elfcpp::R_ARM_THM_MOVW_ABS_NC: case elfcpp::R_ARM_THM_MOVT_ABS: case elfcpp::R_ARM_MOVW_PREL_NC: case elfcpp::R_ARM_MOVT_PREL: case elfcpp::R_ARM_THM_MOVW_PREL_NC: case elfcpp::R_ARM_THM_MOVT_PREL: break; case elfcpp::R_ARM_GOTOFF32: // We need a GOT section: target->got_section(symtab, layout); break; case elfcpp::R_ARM_BASE_PREL: // FIXME: What about this? break; case elfcpp::R_ARM_GOT_BREL: case elfcpp::R_ARM_GOT_PREL: { // The symbol requires a GOT entry. Output_data_got<32, big_endian>* got = target->got_section(symtab, layout); unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info()); if (got->add_local(object, r_sym, GOT_TYPE_STANDARD)) { // If we are generating a shared object, we need to add a // dynamic RELATIVE relocation for this symbol's GOT entry. if (parameters->options().output_is_position_independent()) { Reloc_section* rel_dyn = target->rel_dyn_section(layout); unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info()); rel_dyn->add_local_relative( object, r_sym, elfcpp::R_ARM_RELATIVE, got, object->local_got_offset(r_sym, GOT_TYPE_STANDARD)); } } } break; case elfcpp::R_ARM_TARGET1: // This should have been mapped to another type already. // Fall through. case elfcpp::R_ARM_COPY: case elfcpp::R_ARM_GLOB_DAT: case elfcpp::R_ARM_JUMP_SLOT: case elfcpp::R_ARM_RELATIVE: // These are relocations which should only be seen by the // dynamic linker, and should never be seen here. gold_error(_("%s: unexpected reloc %u in object file"), object->name().c_str(), r_type); break; default: unsupported_reloc_local(object, r_type); break; } } // Report an unsupported relocation against a global symbol. template<bool big_endian> void Target_arm<big_endian>::Scan::unsupported_reloc_global( Sized_relobj<32, big_endian>* object, unsigned int r_type, Symbol* gsym) { gold_error(_("%s: unsupported reloc %u against global symbol %s"), object->name().c_str(), r_type, gsym->demangled_name().c_str()); } // Scan a relocation for a global symbol. // FIXME: This only handles a subset of relocation types used by Android // on ARM v5te devices. template<bool big_endian> inline void Target_arm<big_endian>::Scan::global(const General_options&, Symbol_table* symtab, Layout* layout, Target_arm* target, Sized_relobj<32, big_endian>* object, unsigned int data_shndx, Output_section* output_section, const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type, Symbol* gsym) { r_type = get_real_reloc_type(r_type); switch (r_type) { case elfcpp::R_ARM_NONE: break; case elfcpp::R_ARM_ABS32: case elfcpp::R_ARM_ABS32_NOI: { // Make a dynamic relocation if necessary. if (gsym->needs_dynamic_reloc(Symbol::ABSOLUTE_REF)) { if (target->may_need_copy_reloc(gsym)) { target->copy_reloc(symtab, layout, object, data_shndx, output_section, gsym, reloc); } else if (gsym->can_use_relative_reloc(false)) { // If we are to add more other reloc types than R_ARM_ABS32, // we need to add check_non_pic(object, r_type) here. Reloc_section* rel_dyn = target->rel_dyn_section(layout); rel_dyn->add_global_relative(gsym, elfcpp::R_ARM_RELATIVE, output_section, object, data_shndx, reloc.get_r_offset()); } else { // If we are to add more other reloc types than R_ARM_ABS32, // we need to add check_non_pic(object, r_type) here. Reloc_section* rel_dyn = target->rel_dyn_section(layout); rel_dyn->add_global(gsym, r_type, output_section, object, data_shndx, reloc.get_r_offset()); } } } break; case elfcpp::R_ARM_MOVW_ABS_NC: case elfcpp::R_ARM_MOVT_ABS: case elfcpp::R_ARM_THM_MOVW_ABS_NC: case elfcpp::R_ARM_THM_MOVT_ABS: case elfcpp::R_ARM_MOVW_PREL_NC: case elfcpp::R_ARM_MOVT_PREL: case elfcpp::R_ARM_THM_MOVW_PREL_NC: case elfcpp::R_ARM_THM_MOVT_PREL: break; case elfcpp::R_ARM_THM_ABS5: case elfcpp::R_ARM_ABS8: case elfcpp::R_ARM_ABS12: case elfcpp::R_ARM_ABS16: case elfcpp::R_ARM_BASE_ABS: { // No dynamic relocs of this kinds. // Report the error in case of PIC. int flags = Symbol::NON_PIC_REF; if (gsym->type() == elfcpp::STT_FUNC || gsym->type() == elfcpp::STT_ARM_TFUNC) flags |= Symbol::FUNCTION_CALL; if (gsym->needs_dynamic_reloc(flags)) check_non_pic(object, r_type); } break; case elfcpp::R_ARM_REL32: case elfcpp::R_ARM_PREL31: { // Make a dynamic relocation if necessary. int flags = Symbol::NON_PIC_REF; if (gsym->needs_dynamic_reloc(flags)) { if (target->may_need_copy_reloc(gsym)) { target->copy_reloc(symtab, layout, object, data_shndx, output_section, gsym, reloc); } else { check_non_pic(object, r_type); Reloc_section* rel_dyn = target->rel_dyn_section(layout); rel_dyn->add_global(gsym, r_type, output_section, object, data_shndx, reloc.get_r_offset()); } } } break; case elfcpp::R_ARM_JUMP24: case elfcpp::R_ARM_THM_CALL: case elfcpp::R_ARM_CALL: { if (Target_arm<big_endian>::Scan::symbol_needs_plt_entry(gsym)) target->make_plt_entry(symtab, layout, gsym); // Make a dynamic relocation if necessary. int flags = Symbol::NON_PIC_REF; if (gsym->type() == elfcpp::STT_FUNC || gsym->type() == elfcpp::STT_ARM_TFUNC) flags |= Symbol::FUNCTION_CALL; if (gsym->needs_dynamic_reloc(flags)) { if (target->may_need_copy_reloc(gsym)) { target->copy_reloc(symtab, layout, object, data_shndx, output_section, gsym, reloc); } else { check_non_pic(object, r_type); Reloc_section* rel_dyn = target->rel_dyn_section(layout); rel_dyn->add_global(gsym, r_type, output_section, object, data_shndx, reloc.get_r_offset()); } } } break; case elfcpp::R_ARM_PLT32: // If the symbol is fully resolved, this is just a relative // local reloc. Otherwise we need a PLT entry. if (gsym->final_value_is_known()) break; // If building a shared library, we can also skip the PLT entry // if the symbol is defined in the output file and is protected // or hidden. if (gsym->is_defined() && !gsym->is_from_dynobj() && !gsym->is_preemptible()) break; target->make_plt_entry(symtab, layout, gsym); break; case elfcpp::R_ARM_GOTOFF32: // We need a GOT section. target->got_section(symtab, layout); break; case elfcpp::R_ARM_BASE_PREL: // FIXME: What about this? break; case elfcpp::R_ARM_GOT_BREL: case elfcpp::R_ARM_GOT_PREL: { // The symbol requires a GOT entry. Output_data_got<32, big_endian>* got = target->got_section(symtab, layout); if (gsym->final_value_is_known()) got->add_global(gsym, GOT_TYPE_STANDARD); else { // If this symbol is not fully resolved, we need to add a // GOT entry with a dynamic relocation. Reloc_section* rel_dyn = target->rel_dyn_section(layout); if (gsym->is_from_dynobj() || gsym->is_undefined() || gsym->is_preemptible()) got->add_global_with_rel(gsym, GOT_TYPE_STANDARD, rel_dyn, elfcpp::R_ARM_GLOB_DAT); else { if (got->add_global(gsym, GOT_TYPE_STANDARD)) rel_dyn->add_global_relative( gsym, elfcpp::R_ARM_RELATIVE, got, gsym->got_offset(GOT_TYPE_STANDARD)); } } } break; case elfcpp::R_ARM_TARGET1: // This should have been mapped to another type already. // Fall through. case elfcpp::R_ARM_COPY: case elfcpp::R_ARM_GLOB_DAT: case elfcpp::R_ARM_JUMP_SLOT: case elfcpp::R_ARM_RELATIVE: // These are relocations which should only be seen by the // dynamic linker, and should never be seen here. gold_error(_("%s: unexpected reloc %u in object file"), object->name().c_str(), r_type); break; default: unsupported_reloc_global(object, r_type, gsym); break; } } // Process relocations for gc. template<bool big_endian> void Target_arm<big_endian>::gc_process_relocs(const General_options& options, Symbol_table* symtab, Layout* layout, Sized_relobj<32, big_endian>* object, unsigned int data_shndx, unsigned int, const unsigned char* prelocs, size_t reloc_count, Output_section* output_section, bool needs_special_offset_handling, size_t local_symbol_count, const unsigned char* plocal_symbols) { typedef Target_arm<big_endian> Arm; typedef typename Target_arm<big_endian>::Scan Scan; gold::gc_process_relocs<32, big_endian, Arm, elfcpp::SHT_REL, Scan>( options, symtab, layout, this, object, data_shndx, prelocs, reloc_count, output_section, needs_special_offset_handling, local_symbol_count, plocal_symbols); } // Scan relocations for a section. template<bool big_endian> void Target_arm<big_endian>::scan_relocs(const General_options& options, Symbol_table* symtab, Layout* layout, Sized_relobj<32, big_endian>* object, unsigned int data_shndx, unsigned int sh_type, const unsigned char* prelocs, size_t reloc_count, Output_section* output_section, bool needs_special_offset_handling, size_t local_symbol_count, const unsigned char* plocal_symbols) { typedef typename Target_arm<big_endian>::Scan Scan; if (sh_type == elfcpp::SHT_RELA) { gold_error(_("%s: unsupported RELA reloc section"), object->name().c_str()); return; } gold::scan_relocs<32, big_endian, Target_arm, elfcpp::SHT_REL, Scan>( options, symtab, layout, this, object, data_shndx, prelocs, reloc_count, output_section, needs_special_offset_handling, local_symbol_count, plocal_symbols); } // Finalize the sections. template<bool big_endian> void Target_arm<big_endian>::do_finalize_sections(Layout* layout) { // Fill in some more dynamic tags. Output_data_dynamic* const odyn = layout->dynamic_data(); if (odyn != NULL) { if (this->got_plt_ != NULL && this->got_plt_->output_section() != NULL) odyn->add_section_address(elfcpp::DT_PLTGOT, this->got_plt_); if (this->plt_ != NULL && this->plt_->output_section() != NULL) { const Output_data* od = this->plt_->rel_plt(); odyn->add_section_size(elfcpp::DT_PLTRELSZ, od); odyn->add_section_address(elfcpp::DT_JMPREL, od); odyn->add_constant(elfcpp::DT_PLTREL, elfcpp::DT_REL); } if (this->rel_dyn_ != NULL && this->rel_dyn_->output_section() != NULL) { const Output_data* od = this->rel_dyn_; odyn->add_section_address(elfcpp::DT_REL, od); odyn->add_section_size(elfcpp::DT_RELSZ, od); odyn->add_constant(elfcpp::DT_RELENT, elfcpp::Elf_sizes<32>::rel_size); } if (!parameters->options().shared()) { // The value of the DT_DEBUG tag is filled in by the dynamic // linker at run time, and used by the debugger. odyn->add_constant(elfcpp::DT_DEBUG, 0); } } // Emit any relocs we saved in an attempt to avoid generating COPY // relocs. if (this->copy_relocs_.any_saved_relocs()) this->copy_relocs_.emit(this->rel_dyn_section(layout)); // For the ARM target, we need to add a PT_ARM_EXIDX segment for // the .ARM.exidx section. if (!layout->script_options()->saw_phdrs_clause() && !parameters->options().relocatable()) { Output_section* exidx_section = layout->find_output_section(".ARM.exidx"); if (exidx_section != NULL && exidx_section->type() == elfcpp::SHT_ARM_EXIDX) { gold_assert(layout->find_output_segment(elfcpp::PT_ARM_EXIDX, 0, 0) == NULL); Output_segment* exidx_segment = layout->make_output_segment(elfcpp::PT_ARM_EXIDX, elfcpp::PF_R); exidx_segment->add_output_section(exidx_section, elfcpp::PF_R, false); } } } // Return whether a direct absolute static relocation needs to be applied. // In cases where Scan::local() or Scan::global() has created // a dynamic relocation other than R_ARM_RELATIVE, the addend // of the relocation is carried in the data, and we must not // apply the static relocation. template<bool big_endian> inline bool Target_arm<big_endian>::Relocate::should_apply_static_reloc( const Sized_symbol<32>* gsym, int ref_flags, bool is_32bit, Output_section* output_section) { // If the output section is not allocated, then we didn't call // scan_relocs, we didn't create a dynamic reloc, and we must apply // the reloc here. if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0) return true; // For local symbols, we will have created a non-RELATIVE dynamic // relocation only if (a) the output is position independent, // (b) the relocation is absolute (not pc- or segment-relative), and // (c) the relocation is not 32 bits wide. if (gsym == NULL) return !(parameters->options().output_is_position_independent() && (ref_flags & Symbol::ABSOLUTE_REF) && !is_32bit); // For global symbols, we use the same helper routines used in the // scan pass. If we did not create a dynamic relocation, or if we // created a RELATIVE dynamic relocation, we should apply the static // relocation. bool has_dyn = gsym->needs_dynamic_reloc(ref_flags); bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF) && gsym->can_use_relative_reloc(ref_flags & Symbol::FUNCTION_CALL); return !has_dyn || is_rel; } // Perform a relocation. template<bool big_endian> inline bool Target_arm<big_endian>::Relocate::relocate( const Relocate_info<32, big_endian>* relinfo, Target_arm* target, Output_section *output_section, size_t relnum, const elfcpp::Rel<32, big_endian>& rel, unsigned int r_type, const Sized_symbol<32>* gsym, const Symbol_value<32>* psymval, unsigned char* view, elfcpp::Elf_types<32>::Elf_Addr address, section_size_type /* view_size */ ) { typedef Arm_relocate_functions<big_endian> Arm_relocate_functions; r_type = get_real_reloc_type(r_type); // If this the symbol may be a Thumb function, set thumb bit to 1. bool has_thumb_bit = ((gsym != NULL) && (gsym->type() == elfcpp::STT_FUNC || gsym->type() == elfcpp::STT_ARM_TFUNC)); // Pick the value to use for symbols defined in shared objects. Symbol_value<32> symval; if (gsym != NULL && gsym->use_plt_offset(reloc_is_non_pic(r_type))) { symval.set_output_value(target->plt_section()->address() + gsym->plt_offset()); psymval = &symval; has_thumb_bit = 0; } const Sized_relobj<32, big_endian>* object = relinfo->object; // Get the GOT offset if needed. // The GOT pointer points to the end of the GOT section. // We need to subtract the size of the GOT section to get // the actual offset to use in the relocation. bool have_got_offset = false; unsigned int got_offset = 0; switch (r_type) { case elfcpp::R_ARM_GOT_BREL: case elfcpp::R_ARM_GOT_PREL: if (gsym != NULL) { gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD)); got_offset = (gsym->got_offset(GOT_TYPE_STANDARD) - target->got_size()); } else { unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info()); gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD)); got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD) - target->got_size()); } have_got_offset = true; break; default: break; } typename Arm_relocate_functions::Status reloc_status = Arm_relocate_functions::STATUS_OKAY; switch (r_type) { case elfcpp::R_ARM_NONE: break; case elfcpp::R_ARM_ABS8: if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false, output_section)) reloc_status = Arm_relocate_functions::abs8(view, object, psymval); break; case elfcpp::R_ARM_ABS12: if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false, output_section)) reloc_status = Arm_relocate_functions::abs12(view, object, psymval); break; case elfcpp::R_ARM_ABS16: if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false, output_section)) reloc_status = Arm_relocate_functions::abs16(view, object, psymval); break; case elfcpp::R_ARM_ABS32: if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true, output_section)) reloc_status = Arm_relocate_functions::abs32(view, object, psymval, has_thumb_bit); break; case elfcpp::R_ARM_ABS32_NOI: if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true, output_section)) // No thumb bit for this relocation: (S + A) reloc_status = Arm_relocate_functions::abs32(view, object, psymval, false); break; case elfcpp::R_ARM_MOVW_ABS_NC: if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true, output_section)) reloc_status = Arm_relocate_functions::movw_abs_nc(view, object, psymval, has_thumb_bit); else gold_error(_("relocation R_ARM_MOVW_ABS_NC cannot be used when making" "a shared object; recompile with -fPIC")); break; case elfcpp::R_ARM_MOVT_ABS: if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true, output_section)) reloc_status = Arm_relocate_functions::movt_abs(view, object, psymval); else gold_error(_("relocation R_ARM_MOVT_ABS cannot be used when making" "a shared object; recompile with -fPIC")); break; case elfcpp::R_ARM_THM_MOVW_ABS_NC: if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true, output_section)) reloc_status = Arm_relocate_functions::thm_movw_abs_nc(view, object, psymval, has_thumb_bit); else gold_error(_("relocation R_ARM_THM_MOVW_ABS_NC cannot be used when" "making a shared object; recompile with -fPIC")); break; case elfcpp::R_ARM_THM_MOVT_ABS: if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true, output_section)) reloc_status = Arm_relocate_functions::thm_movt_abs(view, object, psymval); else gold_error(_("relocation R_ARM_THM_MOVT_ABS cannot be used when" "making a shared object; recompile with -fPIC")); break; case elfcpp::R_ARM_MOVW_PREL_NC: reloc_status = Arm_relocate_functions::movw_prel_nc(view, object, psymval, address, has_thumb_bit); break; case elfcpp::R_ARM_MOVT_PREL: reloc_status = Arm_relocate_functions::movt_prel(view, object, psymval, address); break; case elfcpp::R_ARM_THM_MOVW_PREL_NC: reloc_status = Arm_relocate_functions::thm_movw_prel_nc(view, object, psymval, address, has_thumb_bit); break; case elfcpp::R_ARM_THM_MOVT_PREL: reloc_status = Arm_relocate_functions::thm_movt_prel(view, object, psymval, address); break; case elfcpp::R_ARM_REL32: reloc_status = Arm_relocate_functions::rel32(view, object, psymval, address, has_thumb_bit); break; case elfcpp::R_ARM_THM_ABS5: if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false, output_section)) reloc_status = Arm_relocate_functions::thm_abs5(view, object, psymval); break; case elfcpp::R_ARM_THM_CALL: reloc_status = Arm_relocate_functions::thm_call(view, object, psymval, address, has_thumb_bit); break; case elfcpp::R_ARM_GOTOFF32: { elfcpp::Elf_types<32>::Elf_Addr got_origin; got_origin = target->got_plt_section()->address(); reloc_status = Arm_relocate_functions::rel32(view, object, psymval, got_origin, has_thumb_bit); } break; case elfcpp::R_ARM_BASE_PREL: { uint32_t origin; // Get the addressing origin of the output segment defining the // symbol gsym (AAELF 4.6.1.2 Relocation types) gold_assert(gsym != NULL); if (gsym->source() == Symbol::IN_OUTPUT_SEGMENT) origin = gsym->output_segment()->vaddr(); else if (gsym->source () == Symbol::IN_OUTPUT_DATA) origin = gsym->output_data()->address(); else { gold_error_at_location(relinfo, relnum, rel.get_r_offset(), _("cannot find origin of R_ARM_BASE_PREL")); return true; } reloc_status = Arm_relocate_functions::base_prel(view, origin, address); } break; case elfcpp::R_ARM_BASE_ABS: { if (!should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true, output_section)) break; uint32_t origin; // Get the addressing origin of the output segment defining // the symbol gsym (AAELF 4.6.1.2 Relocation types). if (gsym == NULL) // R_ARM_BASE_ABS with the NULL symbol will give the // absolute address of the GOT origin (GOT_ORG) (see ARM IHI // 0044C (AAELF): 4.6.1.8 Proxy generating relocations). origin = target->got_plt_section()->address(); else if (gsym->source() == Symbol::IN_OUTPUT_SEGMENT) origin = gsym->output_segment()->vaddr(); else if (gsym->source () == Symbol::IN_OUTPUT_DATA) origin = gsym->output_data()->address(); else { gold_error_at_location(relinfo, relnum, rel.get_r_offset(), _("cannot find origin of R_ARM_BASE_ABS")); return true; } reloc_status = Arm_relocate_functions::base_abs(view, origin); } break; case elfcpp::R_ARM_GOT_BREL: gold_assert(have_got_offset); reloc_status = Arm_relocate_functions::got_brel(view, got_offset); break; case elfcpp::R_ARM_GOT_PREL: gold_assert(have_got_offset); // Get the address origin for GOT PLT, which is allocated right // after the GOT section, to calculate an absolute address of // the symbol GOT entry (got_origin + got_offset). elfcpp::Elf_types<32>::Elf_Addr got_origin; got_origin = target->got_plt_section()->address(); reloc_status = Arm_relocate_functions::got_prel(view, got_origin + got_offset, address); break; case elfcpp::R_ARM_PLT32: gold_assert(gsym == NULL || gsym->has_plt_offset() || gsym->final_value_is_known() || (gsym->is_defined() && !gsym->is_from_dynobj() && !gsym->is_preemptible())); reloc_status = Arm_relocate_functions::plt32(view, object, psymval, address, has_thumb_bit); break; case elfcpp::R_ARM_CALL: reloc_status = Arm_relocate_functions::call(view, object, psymval, address, has_thumb_bit); break; case elfcpp::R_ARM_JUMP24: reloc_status = Arm_relocate_functions::jump24(view, object, psymval, address, has_thumb_bit); break; case elfcpp::R_ARM_PREL31: reloc_status = Arm_relocate_functions::prel31(view, object, psymval, address, has_thumb_bit); break; case elfcpp::R_ARM_TARGET1: // This should have been mapped to another type already. // Fall through. case elfcpp::R_ARM_COPY: case elfcpp::R_ARM_GLOB_DAT: case elfcpp::R_ARM_JUMP_SLOT: case elfcpp::R_ARM_RELATIVE: // These are relocations which should only be seen by the // dynamic linker, and should never be seen here. gold_error_at_location(relinfo, relnum, rel.get_r_offset(), _("unexpected reloc %u in object file"), r_type); break; default: gold_error_at_location(relinfo, relnum, rel.get_r_offset(), _("unsupported reloc %u"), r_type); break; } // 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, rel.get_r_offset(), _("relocation overflow in relocation %u"), r_type); break; case Arm_relocate_functions::STATUS_BAD_RELOC: gold_error_at_location( relinfo, relnum, rel.get_r_offset(), _("unexpected opcode while processing relocation %u"), r_type); break; default: gold_unreachable(); } return true; } // Relocate section data. template<bool big_endian> void Target_arm<big_endian>::relocate_section( const Relocate_info<32, big_endian>* relinfo, unsigned int sh_type, const unsigned char* prelocs, size_t reloc_count, Output_section* output_section, bool needs_special_offset_handling, unsigned char* view, elfcpp::Elf_types<32>::Elf_Addr address, section_size_type view_size, const Reloc_symbol_changes* reloc_symbol_changes) { typedef typename Target_arm<big_endian>::Relocate Arm_relocate; gold_assert(sh_type == elfcpp::SHT_REL); gold::relocate_section<32, big_endian, Target_arm, elfcpp::SHT_REL, Arm_relocate>( relinfo, this, prelocs, reloc_count, output_section, needs_special_offset_handling, view, address, view_size, reloc_symbol_changes); } // Return the size of a relocation while scanning during a relocatable // link. template<bool big_endian> unsigned int Target_arm<big_endian>::Relocatable_size_for_reloc::get_size_for_reloc( unsigned int r_type, Relobj* object) { r_type = get_real_reloc_type(r_type); switch (r_type) { case elfcpp::R_ARM_NONE: return 0; case elfcpp::R_ARM_ABS8: return 1; case elfcpp::R_ARM_ABS16: case elfcpp::R_ARM_THM_ABS5: return 2; case elfcpp::R_ARM_ABS32: case elfcpp::R_ARM_ABS32_NOI: case elfcpp::R_ARM_ABS12: case elfcpp::R_ARM_BASE_ABS: case elfcpp::R_ARM_REL32: case elfcpp::R_ARM_THM_CALL: case elfcpp::R_ARM_GOTOFF32: case elfcpp::R_ARM_BASE_PREL: case elfcpp::R_ARM_GOT_BREL: case elfcpp::R_ARM_GOT_PREL: case elfcpp::R_ARM_PLT32: case elfcpp::R_ARM_CALL: case elfcpp::R_ARM_JUMP24: case elfcpp::R_ARM_PREL31: case elfcpp::R_ARM_MOVW_ABS_NC: case elfcpp::R_ARM_MOVT_ABS: case elfcpp::R_ARM_THM_MOVW_ABS_NC: case elfcpp::R_ARM_THM_MOVT_ABS: case elfcpp::R_ARM_MOVW_PREL_NC: case elfcpp::R_ARM_MOVT_PREL: case elfcpp::R_ARM_THM_MOVW_PREL_NC: case elfcpp::R_ARM_THM_MOVT_PREL: return 4; case elfcpp::R_ARM_TARGET1: // This should have been mapped to another type already. // Fall through. case elfcpp::R_ARM_COPY: case elfcpp::R_ARM_GLOB_DAT: case elfcpp::R_ARM_JUMP_SLOT: case elfcpp::R_ARM_RELATIVE: // These are relocations which should only be seen by the // dynamic linker, and should never be seen here. gold_error(_("%s: unexpected reloc %u in object file"), object->name().c_str(), r_type); return 0; default: object->error(_("unsupported reloc %u in object file"), r_type); return 0; } } // Scan the relocs during a relocatable link. template<bool big_endian> void Target_arm<big_endian>::scan_relocatable_relocs( const General_options& options, Symbol_table* symtab, Layout* layout, Sized_relobj<32, big_endian>* object, unsigned int data_shndx, unsigned int sh_type, const unsigned char* prelocs, size_t reloc_count, Output_section* output_section, bool needs_special_offset_handling, size_t local_symbol_count, const unsigned char* plocal_symbols, Relocatable_relocs* rr) { gold_assert(sh_type == elfcpp::SHT_REL); typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_REL, Relocatable_size_for_reloc> Scan_relocatable_relocs; gold::scan_relocatable_relocs<32, big_endian, elfcpp::SHT_REL, Scan_relocatable_relocs>( options, symtab, layout, object, data_shndx, prelocs, reloc_count, output_section, needs_special_offset_handling, local_symbol_count, plocal_symbols, rr); } // Relocate a section during a relocatable link. template<bool big_endian> void Target_arm<big_endian>::relocate_for_relocatable( const Relocate_info<32, big_endian>* relinfo, unsigned int sh_type, const unsigned char* prelocs, size_t reloc_count, Output_section* output_section, off_t offset_in_output_section, const Relocatable_relocs* rr, unsigned char* view, elfcpp::Elf_types<32>::Elf_Addr view_address, section_size_type view_size, unsigned char* reloc_view, section_size_type reloc_view_size) { gold_assert(sh_type == elfcpp::SHT_REL); gold::relocate_for_relocatable<32, big_endian, elfcpp::SHT_REL>( relinfo, prelocs, reloc_count, output_section, offset_in_output_section, rr, view, view_address, view_size, reloc_view, reloc_view_size); } // 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 // processor specific ABI supplement. template<bool big_endian> uint64_t Target_arm<big_endian>::do_dynsym_value(const Symbol* gsym) const { gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset()); return this->plt_section()->address() + gsym->plt_offset(); } // Map platform-specific relocs to real relocs // template<bool big_endian> unsigned int Target_arm<big_endian>::get_real_reloc_type (unsigned int r_type) { switch (r_type) { case elfcpp::R_ARM_TARGET1: // This is either R_ARM_ABS32 or R_ARM_REL32; return elfcpp::R_ARM_ABS32; case elfcpp::R_ARM_TARGET2: // This can be any reloc type but ususally is R_ARM_GOT_PREL return elfcpp::R_ARM_GOT_PREL; default: return r_type; } } // The selector for arm object files. template<bool big_endian> class Target_selector_arm : public Target_selector { public: Target_selector_arm() : Target_selector(elfcpp::EM_ARM, 32, big_endian, (big_endian ? "elf32-bigarm" : "elf32-littlearm")) { } Target* do_instantiate_target() { return new Target_arm<big_endian>(); } }; Target_selector_arm<false> target_selector_arm; Target_selector_arm<true> target_selector_armbe; } // End anonymous namespace.
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