2226 lines
67 KiB
C++
2226 lines
67 KiB
C++
// arm.cc -- arm target support for gold.
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// Copyright 2009 Free Software Foundation, Inc.
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// Written by Doug Kwan <dougkwan@google.com> based on the i386 code
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// by Ian Lance Taylor <iant@google.com>.
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// This file is part of gold.
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// This program is free software; you can redistribute it and/or modify
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// it under the terms of the GNU General Public License as published by
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// the Free Software Foundation; either version 3 of the License, or
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// (at your option) any later version.
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// This program is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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// You should have received a copy of the GNU General Public License
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// along with this program; if not, write to the Free Software
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// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
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// MA 02110-1301, USA.
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#include "gold.h"
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#include <cstring>
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#include <limits>
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#include <cstdio>
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#include <string>
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#include "elfcpp.h"
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#include "parameters.h"
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#include "reloc.h"
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#include "arm.h"
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#include "object.h"
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#include "symtab.h"
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#include "layout.h"
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#include "output.h"
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#include "copy-relocs.h"
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#include "target.h"
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#include "target-reloc.h"
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#include "target-select.h"
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#include "tls.h"
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#include "defstd.h"
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namespace
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{
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using namespace gold;
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template<bool big_endian>
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class Output_data_plt_arm;
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// The arm target class.
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//
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// This is a very simple port of gold for ARM-EABI. It is intended for
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// supporting Android only for the time being. Only these relocation types
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// are supported.
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//
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// R_ARM_NONE
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// R_ARM_ABS32
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// R_ARM_REL32
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// R_ARM_THM_CALL
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// R_ARM_COPY
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// R_ARM_GLOB_DAT
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// R_ARM_BASE_PREL
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// R_ARM_JUMP_SLOT
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// R_ARM_RELATIVE
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// R_ARM_GOTOFF32
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// R_ARM_GOT_BREL
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// R_ARM_GOT_PREL
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// R_ARM_PLT32
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// R_ARM_CALL
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// R_ARM_JUMP24
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// R_ARM_TARGET1
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// R_ARM_PREL31
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// R_ARM_ABS8
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// R_ARM_MOVW_ABS_NC
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// R_ARM_MOVT_ABS
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// R_ARM_THM_MOVW_ABS_NC
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// R_ARM_THM_MOVT_ABS
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//
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// TODOs:
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// - Generate various branch stubs.
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// - Support interworking.
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// - Define section symbols __exidx_start and __exidx_stop.
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// - Support more relocation types as needed.
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// - Make PLTs more flexible for different architecture features like
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// Thumb-2 and BE8.
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// There are probably a lot more.
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// Utilities for manipulating integers of up to 32-bits
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namespace utils
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{
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// Sign extend an n-bit unsigned integer stored in an uint32_t into
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// an int32_t. NO_BITS must be between 1 to 32.
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template<int no_bits>
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static inline int32_t
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sign_extend(uint32_t bits)
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{
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gold_assert(no_bits >= 0 && no_bits <= 32);
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if (no_bits == 32)
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return static_cast<int32_t>(bits);
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uint32_t mask = (~((uint32_t) 0)) >> (32 - no_bits);
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bits &= mask;
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uint32_t top_bit = 1U << (no_bits - 1);
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int32_t as_signed = static_cast<int32_t>(bits);
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return (bits & top_bit) ? as_signed + (-top_bit * 2) : as_signed;
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}
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// Detects overflow of an NO_BITS integer stored in a uint32_t.
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template<int no_bits>
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static inline bool
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has_overflow(uint32_t bits)
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{
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gold_assert(no_bits >= 0 && no_bits <= 32);
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if (no_bits == 32)
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return false;
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int32_t max = (1 << (no_bits - 1)) - 1;
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int32_t min = -(1 << (no_bits - 1));
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int32_t as_signed = static_cast<int32_t>(bits);
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return as_signed > max || as_signed < min;
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}
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// Detects overflow of an NO_BITS integer stored in a uint32_t when it
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// fits in the given number of bits as either a signed or unsigned value.
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// For example, has_signed_unsigned_overflow<8> would check
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// -128 <= bits <= 255
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template<int no_bits>
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static inline bool
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has_signed_unsigned_overflow(uint32_t bits)
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{
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gold_assert(no_bits >= 2 && no_bits <= 32);
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if (no_bits == 32)
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return false;
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int32_t max = static_cast<int32_t>((1U << no_bits) - 1);
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int32_t min = -(1 << (no_bits - 1));
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int32_t as_signed = static_cast<int32_t>(bits);
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return as_signed > max || as_signed < min;
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}
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// Select bits from A and B using bits in MASK. For each n in [0..31],
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// the n-th bit in the result is chosen from the n-th bits of A and B.
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// A zero selects A and a one selects B.
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static inline uint32_t
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bit_select(uint32_t a, uint32_t b, uint32_t mask)
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{ return (a & ~mask) | (b & mask); }
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};
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template<bool big_endian>
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class Target_arm : public Sized_target<32, big_endian>
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{
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public:
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typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
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Reloc_section;
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Target_arm()
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: Sized_target<32, big_endian>(&arm_info),
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got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL),
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copy_relocs_(elfcpp::R_ARM_COPY), dynbss_(NULL)
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{ }
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// Process the relocations to determine unreferenced sections for
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// garbage collection.
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void
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gc_process_relocs(const General_options& options,
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Symbol_table* symtab,
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Layout* layout,
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Sized_relobj<32, big_endian>* object,
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unsigned int data_shndx,
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unsigned int sh_type,
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const unsigned char* prelocs,
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size_t reloc_count,
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Output_section* output_section,
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bool needs_special_offset_handling,
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size_t local_symbol_count,
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const unsigned char* plocal_symbols);
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// Scan the relocations to look for symbol adjustments.
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void
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scan_relocs(const General_options& options,
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Symbol_table* symtab,
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Layout* layout,
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Sized_relobj<32, big_endian>* object,
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unsigned int data_shndx,
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unsigned int sh_type,
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const unsigned char* prelocs,
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size_t reloc_count,
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Output_section* output_section,
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bool needs_special_offset_handling,
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size_t local_symbol_count,
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const unsigned char* plocal_symbols);
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// Finalize the sections.
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void
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do_finalize_sections(Layout*);
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// Return the value to use for a dynamic symbol which requires special
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// treatment.
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uint64_t
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do_dynsym_value(const Symbol*) const;
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// Relocate a section.
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void
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relocate_section(const Relocate_info<32, big_endian>*,
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unsigned int sh_type,
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const unsigned char* prelocs,
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size_t reloc_count,
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Output_section* output_section,
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bool needs_special_offset_handling,
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unsigned char* view,
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elfcpp::Elf_types<32>::Elf_Addr view_address,
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section_size_type view_size,
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const Reloc_symbol_changes*);
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// Scan the relocs during a relocatable link.
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void
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scan_relocatable_relocs(const General_options& options,
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Symbol_table* symtab,
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Layout* layout,
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Sized_relobj<32, big_endian>* object,
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unsigned int data_shndx,
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unsigned int sh_type,
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const unsigned char* prelocs,
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size_t reloc_count,
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Output_section* output_section,
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bool needs_special_offset_handling,
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size_t local_symbol_count,
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const unsigned char* plocal_symbols,
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Relocatable_relocs*);
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// Relocate a section during a relocatable link.
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void
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relocate_for_relocatable(const Relocate_info<32, big_endian>*,
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unsigned int sh_type,
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const unsigned char* prelocs,
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size_t reloc_count,
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Output_section* output_section,
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off_t offset_in_output_section,
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const Relocatable_relocs*,
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unsigned char* view,
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elfcpp::Elf_types<32>::Elf_Addr view_address,
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section_size_type view_size,
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unsigned char* reloc_view,
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section_size_type reloc_view_size);
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// Return whether SYM is defined by the ABI.
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bool
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do_is_defined_by_abi(Symbol* sym) const
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{ return strcmp(sym->name(), "__tls_get_addr") == 0; }
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// Return the size of the GOT section.
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section_size_type
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got_size()
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{
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gold_assert(this->got_ != NULL);
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return this->got_->data_size();
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}
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// Map platform-specific reloc types
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static unsigned int
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get_real_reloc_type (unsigned int r_type);
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private:
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// The class which scans relocations.
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class Scan
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{
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public:
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Scan()
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: issued_non_pic_error_(false)
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{ }
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inline void
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local(const General_options& options, Symbol_table* symtab,
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Layout* layout, Target_arm* target,
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Sized_relobj<32, big_endian>* object,
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unsigned int data_shndx,
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Output_section* output_section,
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const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
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const elfcpp::Sym<32, big_endian>& lsym);
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inline void
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global(const General_options& options, Symbol_table* symtab,
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Layout* layout, Target_arm* target,
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Sized_relobj<32, big_endian>* object,
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unsigned int data_shndx,
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Output_section* output_section,
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const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
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Symbol* gsym);
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private:
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static void
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unsupported_reloc_local(Sized_relobj<32, big_endian>*,
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unsigned int r_type);
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static void
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unsupported_reloc_global(Sized_relobj<32, big_endian>*,
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unsigned int r_type, Symbol*);
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void
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check_non_pic(Relobj*, unsigned int r_type);
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// Almost identical to Symbol::needs_plt_entry except that it also
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// handles STT_ARM_TFUNC.
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static bool
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symbol_needs_plt_entry(const Symbol* sym)
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{
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// An undefined symbol from an executable does not need a PLT entry.
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if (sym->is_undefined() && !parameters->options().shared())
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return false;
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return (!parameters->doing_static_link()
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&& (sym->type() == elfcpp::STT_FUNC
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|| sym->type() == elfcpp::STT_ARM_TFUNC)
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&& (sym->is_from_dynobj()
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|| sym->is_undefined()
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|| sym->is_preemptible()));
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}
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// Whether we have issued an error about a non-PIC compilation.
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bool issued_non_pic_error_;
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};
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// The class which implements relocation.
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class Relocate
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{
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public:
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Relocate()
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{ }
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~Relocate()
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{ }
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// Return whether the static relocation needs to be applied.
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inline bool
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should_apply_static_reloc(const Sized_symbol<32>* gsym,
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int ref_flags,
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bool is_32bit,
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Output_section* output_section);
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// Do a relocation. Return false if the caller should not issue
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// any warnings about this relocation.
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inline bool
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relocate(const Relocate_info<32, big_endian>*, Target_arm*,
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Output_section*, size_t relnum,
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const elfcpp::Rel<32, big_endian>&,
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unsigned int r_type, const Sized_symbol<32>*,
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const Symbol_value<32>*,
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unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
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section_size_type);
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// Return whether we want to pass flag NON_PIC_REF for this
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// reloc.
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static inline bool
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reloc_is_non_pic (unsigned int r_type)
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{
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switch (r_type)
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{
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case elfcpp::R_ARM_REL32:
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case elfcpp::R_ARM_THM_CALL:
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case elfcpp::R_ARM_CALL:
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case elfcpp::R_ARM_JUMP24:
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case elfcpp::R_ARM_PREL31:
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return true;
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default:
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return false;
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}
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}
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};
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// A class which returns the size required for a relocation type,
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// used while scanning relocs during a relocatable link.
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class Relocatable_size_for_reloc
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{
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public:
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unsigned int
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get_size_for_reloc(unsigned int, Relobj*);
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};
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// Get the GOT section, creating it if necessary.
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Output_data_got<32, big_endian>*
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got_section(Symbol_table*, Layout*);
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// Get the GOT PLT section.
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Output_data_space*
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got_plt_section() const
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{
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gold_assert(this->got_plt_ != NULL);
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return this->got_plt_;
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}
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// Create a PLT entry for a global symbol.
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void
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make_plt_entry(Symbol_table*, Layout*, Symbol*);
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// Get the PLT section.
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const Output_data_plt_arm<big_endian>*
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plt_section() const
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{
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gold_assert(this->plt_ != NULL);
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return this->plt_;
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}
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// Get the dynamic reloc section, creating it if necessary.
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Reloc_section*
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rel_dyn_section(Layout*);
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// Return true if the symbol may need a COPY relocation.
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// References from an executable object to non-function symbols
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// defined in a dynamic object may need a COPY relocation.
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bool
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may_need_copy_reloc(Symbol* gsym)
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{
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return (gsym->type() != elfcpp::STT_ARM_TFUNC
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&& gsym->may_need_copy_reloc());
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}
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// Add a potential copy relocation.
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void
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copy_reloc(Symbol_table* symtab, Layout* layout,
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Sized_relobj<32, big_endian>* object,
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unsigned int shndx, Output_section* output_section,
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Symbol* sym, const elfcpp::Rel<32, big_endian>& reloc)
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{
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this->copy_relocs_.copy_reloc(symtab, layout,
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symtab->get_sized_symbol<32>(sym),
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object, shndx, output_section, reloc,
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this->rel_dyn_section(layout));
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}
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// Information about this specific target which we pass to the
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// general Target structure.
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static const Target::Target_info arm_info;
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// The types of GOT entries needed for this platform.
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enum Got_type
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{
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GOT_TYPE_STANDARD = 0 // GOT entry for a regular symbol
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};
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// The GOT section.
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Output_data_got<32, big_endian>* got_;
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// The PLT section.
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Output_data_plt_arm<big_endian>* plt_;
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// The GOT PLT section.
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Output_data_space* got_plt_;
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// The dynamic reloc section.
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Reloc_section* rel_dyn_;
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// Relocs saved to avoid a COPY reloc.
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Copy_relocs<elfcpp::SHT_REL, 32, big_endian> copy_relocs_;
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// Space for variables copied with a COPY reloc.
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Output_data_space* dynbss_;
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};
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template<bool big_endian>
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const Target::Target_info Target_arm<big_endian>::arm_info =
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{
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32, // size
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big_endian, // is_big_endian
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elfcpp::EM_ARM, // machine_code
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false, // has_make_symbol
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false, // has_resolve
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false, // has_code_fill
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true, // is_default_stack_executable
|
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'\0', // wrap_char
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"/usr/lib/libc.so.1", // dynamic_linker
|
||
0x8000, // default_text_segment_address
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||
0x1000, // abi_pagesize (overridable by -z max-page-size)
|
||
0x1000, // common_pagesize (overridable by -z common-page-size)
|
||
elfcpp::SHN_UNDEF, // small_common_shndx
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||
elfcpp::SHN_UNDEF, // large_common_shndx
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||
0, // small_common_section_flags
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||
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
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||
{
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||
STATUS_OKAY, // No error during relocation.
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||
STATUS_OVERFLOW, // Relocation oveflow.
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||
STATUS_BAD_RELOC // Relocation cannot be applied.
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||
} 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, bool has_thumb_bit)
|
||
{
|
||
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, has_thumb_bit);
|
||
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_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_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;
|
||
}
|
||
|
||
};
|
||
|
||
// 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_);
|
||
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_);
|
||
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_);
|
||
}
|
||
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_);
|
||
}
|
||
|
||
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_);
|
||
}
|
||
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_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_ABS8:
|
||
if (parameters->options().output_is_position_independent())
|
||
{
|
||
// FIXME: Create a dynamic relocation for this location.
|
||
gold_error(_("%s: gold bug: need dynamic ABS8 reloc"),
|
||
object->name().c_str());
|
||
}
|
||
break;
|
||
|
||
case elfcpp::R_ARM_ABS32:
|
||
// 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_MOVW_ABS_NC:
|
||
case elfcpp::R_ARM_MOVT_ABS:
|
||
case elfcpp::R_ARM_THM_MOVW_ABS_NC:
|
||
case elfcpp::R_ARM_THM_MOVT_ABS:
|
||
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_ABS8:
|
||
// Make a dynamic relocation if necessary.
|
||
if (gsym->needs_dynamic_reloc(Symbol::ABSOLUTE_REF))
|
||
{
|
||
// FIXME: Create a dynamic relocation for this location.
|
||
gold_error(_("%s: gold bug: need dynamic ABS8 reloc for %s"),
|
||
object->name().c_str(), gsym->demangled_name().c_str());
|
||
}
|
||
break;
|
||
|
||
case elfcpp::R_ARM_ABS32:
|
||
{
|
||
// 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:
|
||
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)
|
||
odyn->add_section_address(elfcpp::DT_PLTGOT, this->got_plt_);
|
||
|
||
if (this->plt_ != 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)
|
||
{
|
||
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);
|
||
}
|
||
}
|
||
}
|
||
|
||
// 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,
|
||
has_thumb_bit);
|
||
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_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_REL32:
|
||
reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
|
||
address, has_thumb_bit);
|
||
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_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_ABS32:
|
||
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:
|
||
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.
|