--- /dev/null
+// arm.cc -- arm target support for gold.
+
+// Copyright 2009 Free Software Foundation, Inc.
+// Written by Doug Kwan <dougkwan@google.com> based on the i386 code
+// by Ian Lance Taylor <iant@google.com>.
+
+// This file is part of gold.
+
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
+// MA 02110-1301, USA.
+
+#include "gold.h"
+
+#include <cstring>
+#include <limits>
+#include <cstdio>
+#include <string>
+
+#include "elfcpp.h"
+#include "parameters.h"
+#include "reloc.h"
+#include "arm.h"
+#include "object.h"
+#include "symtab.h"
+#include "layout.h"
+#include "output.h"
+#include "copy-relocs.h"
+#include "target.h"
+#include "target-reloc.h"
+#include "target-select.h"
+#include "tls.h"
+#include "defstd.h"
+#include "gc.h"
+
+namespace
+{
+
+using namespace gold;
+
+template<bool big_endian>
+class Output_data_plt_arm;
+
+// The arm target class.
+//
+// This is a very simple port of gold for ARM-EABI. It is intended for
+// supporting Android only for the time being. Only these relocation types
+// are supported.
+//
+// R_ARM_NONE
+// R_ARM_ABS32
+// R_ARM_ABS32_NOI
+// R_ARM_ABS16
+// R_ARM_ABS12
+// R_ARM_ABS8
+// R_ARM_THM_ABS5
+// R_ARM_BASE_ABS
+// R_ARM_REL32
+// R_ARM_THM_CALL
+// R_ARM_COPY
+// R_ARM_GLOB_DAT
+// R_ARM_BASE_PREL
+// R_ARM_JUMP_SLOT
+// R_ARM_RELATIVE
+// R_ARM_GOTOFF32
+// R_ARM_GOT_BREL
+// R_ARM_GOT_PREL
+// R_ARM_PLT32
+// R_ARM_CALL
+// R_ARM_JUMP24
+// R_ARM_TARGET1
+// R_ARM_PREL31
+// R_ARM_ABS8
+// R_ARM_MOVW_ABS_NC
+// R_ARM_MOVT_ABS
+// R_ARM_THM_MOVW_ABS_NC
+// R_ARM_THM_MOVT_ABS
+// R_ARM_MOVW_PREL_NC
+// R_ARM_MOVT_PREL
+// R_ARM_THM_MOVW_PREL_NC
+// R_ARM_THM_MOVT_PREL
+//
+// TODOs:
+// - Generate various branch stubs.
+// - Support interworking.
+// - Define section symbols __exidx_start and __exidx_stop.
+// - Support more relocation types as needed.
+// - Make PLTs more flexible for different architecture features like
+// Thumb-2 and BE8.
+// There are probably a lot more.
+
+// Utilities for manipulating integers of up to 32-bits
+
+namespace utils
+{
+ // Sign extend an n-bit unsigned integer stored in an uint32_t into
+ // an int32_t. NO_BITS must be between 1 to 32.
+ template<int no_bits>
+ static inline int32_t
+ sign_extend(uint32_t bits)
+ {
+ gold_assert(no_bits >= 0 && no_bits <= 32);
+ if (no_bits == 32)
+ return static_cast<int32_t>(bits);
+ uint32_t mask = (~((uint32_t) 0)) >> (32 - no_bits);
+ bits &= mask;
+ uint32_t top_bit = 1U << (no_bits - 1);
+ int32_t as_signed = static_cast<int32_t>(bits);
+ return (bits & top_bit) ? as_signed + (-top_bit * 2) : as_signed;
+ }
+
+ // Detects overflow of an NO_BITS integer stored in a uint32_t.
+ template<int no_bits>
+ static inline bool
+ has_overflow(uint32_t bits)
+ {
+ gold_assert(no_bits >= 0 && no_bits <= 32);
+ if (no_bits == 32)
+ return false;
+ int32_t max = (1 << (no_bits - 1)) - 1;
+ int32_t min = -(1 << (no_bits - 1));
+ int32_t as_signed = static_cast<int32_t>(bits);
+ return as_signed > max || as_signed < min;
+ }
+
+ // Detects overflow of an NO_BITS integer stored in a uint32_t when it
+ // fits in the given number of bits as either a signed or unsigned value.
+ // For example, has_signed_unsigned_overflow<8> would check
+ // -128 <= bits <= 255
+ template<int no_bits>
+ static inline bool
+ has_signed_unsigned_overflow(uint32_t bits)
+ {
+ gold_assert(no_bits >= 2 && no_bits <= 32);
+ if (no_bits == 32)
+ return false;
+ int32_t max = static_cast<int32_t>((1U << no_bits) - 1);
+ int32_t min = -(1 << (no_bits - 1));
+ int32_t as_signed = static_cast<int32_t>(bits);
+ return as_signed > max || as_signed < min;
+ }
+
+ // Select bits from A and B using bits in MASK. For each n in [0..31],
+ // the n-th bit in the result is chosen from the n-th bits of A and B.
+ // A zero selects A and a one selects B.
+ static inline uint32_t
+ bit_select(uint32_t a, uint32_t b, uint32_t mask)
+ { return (a & ~mask) | (b & mask); }
+};
+
+template<bool big_endian>
+class Target_arm : public Sized_target<32, big_endian>
+{
+ public:
+ typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
+ Reloc_section;
+
+ Target_arm()
+ : Sized_target<32, big_endian>(&arm_info),
+ got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL),
+ copy_relocs_(elfcpp::R_ARM_COPY), dynbss_(NULL)
+ { }
+
+ // Process the relocations to determine unreferenced sections for
+ // garbage collection.
+ void
+ gc_process_relocs(const General_options& options,
+ Symbol_table* symtab,
+ Layout* layout,
+ Sized_relobj<32, big_endian>* object,
+ unsigned int data_shndx,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ bool needs_special_offset_handling,
+ size_t local_symbol_count,
+ const unsigned char* plocal_symbols);
+
+ // Scan the relocations to look for symbol adjustments.
+ void
+ scan_relocs(const General_options& options,
+ Symbol_table* symtab,
+ Layout* layout,
+ Sized_relobj<32, big_endian>* object,
+ unsigned int data_shndx,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ bool needs_special_offset_handling,
+ size_t local_symbol_count,
+ const unsigned char* plocal_symbols);
+
+ // Finalize the sections.
+ void
+ do_finalize_sections(Layout*);
+
+ // Return the value to use for a dynamic symbol which requires special
+ // treatment.
+ uint64_t
+ do_dynsym_value(const Symbol*) const;
+
+ // Relocate a section.
+ void
+ relocate_section(const Relocate_info<32, big_endian>*,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ bool needs_special_offset_handling,
+ unsigned char* view,
+ elfcpp::Elf_types<32>::Elf_Addr view_address,
+ section_size_type view_size,
+ const Reloc_symbol_changes*);
+
+ // Scan the relocs during a relocatable link.
+ void
+ scan_relocatable_relocs(const General_options& options,
+ Symbol_table* symtab,
+ Layout* layout,
+ Sized_relobj<32, big_endian>* object,
+ unsigned int data_shndx,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ bool needs_special_offset_handling,
+ size_t local_symbol_count,
+ const unsigned char* plocal_symbols,
+ Relocatable_relocs*);
+
+ // Relocate a section during a relocatable link.
+ void
+ relocate_for_relocatable(const Relocate_info<32, big_endian>*,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ off_t offset_in_output_section,
+ const Relocatable_relocs*,
+ unsigned char* view,
+ elfcpp::Elf_types<32>::Elf_Addr view_address,
+ section_size_type view_size,
+ unsigned char* reloc_view,
+ section_size_type reloc_view_size);
+
+ // Return whether SYM is defined by the ABI.
+ bool
+ do_is_defined_by_abi(Symbol* sym) const
+ { return strcmp(sym->name(), "__tls_get_addr") == 0; }
+
+ // Return the size of the GOT section.
+ section_size_type
+ got_size()
+ {
+ gold_assert(this->got_ != NULL);
+ return this->got_->data_size();
+ }
+
+ // Map platform-specific reloc types
+ static unsigned int
+ get_real_reloc_type (unsigned int r_type);
+
+ private:
+ // The class which scans relocations.
+ class Scan
+ {
+ public:
+ Scan()
+ : issued_non_pic_error_(false)
+ { }
+
+ inline void
+ local(const General_options& options, Symbol_table* symtab,
+ Layout* layout, Target_arm* target,
+ Sized_relobj<32, big_endian>* object,
+ unsigned int data_shndx,
+ Output_section* output_section,
+ const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
+ const elfcpp::Sym<32, big_endian>& lsym);
+
+ inline void
+ global(const General_options& options, Symbol_table* symtab,
+ Layout* layout, Target_arm* target,
+ Sized_relobj<32, big_endian>* object,
+ unsigned int data_shndx,
+ Output_section* output_section,
+ const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
+ Symbol* gsym);
+
+ private:
+ static void
+ unsupported_reloc_local(Sized_relobj<32, big_endian>*,
+ unsigned int r_type);
+
+ static void
+ unsupported_reloc_global(Sized_relobj<32, big_endian>*,
+ unsigned int r_type, Symbol*);
+
+ void
+ check_non_pic(Relobj*, unsigned int r_type);
+
+ // Almost identical to Symbol::needs_plt_entry except that it also
+ // handles STT_ARM_TFUNC.
+ static bool
+ symbol_needs_plt_entry(const Symbol* sym)
+ {
+ // An undefined symbol from an executable does not need a PLT entry.
+ if (sym->is_undefined() && !parameters->options().shared())
+ return false;
+
+ return (!parameters->doing_static_link()
+ && (sym->type() == elfcpp::STT_FUNC
+ || sym->type() == elfcpp::STT_ARM_TFUNC)
+ && (sym->is_from_dynobj()
+ || sym->is_undefined()
+ || sym->is_preemptible()));
+ }
+
+ // Whether we have issued an error about a non-PIC compilation.
+ bool issued_non_pic_error_;
+ };
+
+ // The class which implements relocation.
+ class Relocate
+ {
+ public:
+ Relocate()
+ { }
+
+ ~Relocate()
+ { }
+
+ // Return whether the static relocation needs to be applied.
+ inline bool
+ should_apply_static_reloc(const Sized_symbol<32>* gsym,
+ int ref_flags,
+ bool is_32bit,
+ Output_section* output_section);
+
+ // Do a relocation. Return false if the caller should not issue
+ // any warnings about this relocation.
+ inline bool
+ relocate(const Relocate_info<32, big_endian>*, Target_arm*,
+ Output_section*, size_t relnum,
+ const elfcpp::Rel<32, big_endian>&,
+ unsigned int r_type, const Sized_symbol<32>*,
+ const Symbol_value<32>*,
+ unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
+ section_size_type);
+
+ // Return whether we want to pass flag NON_PIC_REF for this
+ // reloc.
+ static inline bool
+ reloc_is_non_pic (unsigned int r_type)
+ {
+ switch (r_type)
+ {
+ case elfcpp::R_ARM_REL32:
+ case elfcpp::R_ARM_THM_CALL:
+ case elfcpp::R_ARM_CALL:
+ case elfcpp::R_ARM_JUMP24:
+ case elfcpp::R_ARM_PREL31:
+ case elfcpp::R_ARM_THM_ABS5:
+ case elfcpp::R_ARM_ABS8:
+ case elfcpp::R_ARM_ABS12:
+ case elfcpp::R_ARM_ABS16:
+ case elfcpp::R_ARM_BASE_ABS:
+ return true;
+ default:
+ return false;
+ }
+ }
+ };
+
+ // A class which returns the size required for a relocation type,
+ // used while scanning relocs during a relocatable link.
+ class Relocatable_size_for_reloc
+ {
+ public:
+ unsigned int
+ get_size_for_reloc(unsigned int, Relobj*);
+ };
+
+ // Get the GOT section, creating it if necessary.
+ Output_data_got<32, big_endian>*
+ got_section(Symbol_table*, Layout*);
+
+ // Get the GOT PLT section.
+ Output_data_space*
+ got_plt_section() const
+ {
+ gold_assert(this->got_plt_ != NULL);
+ return this->got_plt_;
+ }
+
+ // Create a PLT entry for a global symbol.
+ void
+ make_plt_entry(Symbol_table*, Layout*, Symbol*);
+
+ // Get the PLT section.
+ const Output_data_plt_arm<big_endian>*
+ plt_section() const
+ {
+ gold_assert(this->plt_ != NULL);
+ return this->plt_;
+ }
+
+ // Get the dynamic reloc section, creating it if necessary.
+ Reloc_section*
+ rel_dyn_section(Layout*);
+
+ // Return true if the symbol may need a COPY relocation.
+ // References from an executable object to non-function symbols
+ // defined in a dynamic object may need a COPY relocation.
+ bool
+ may_need_copy_reloc(Symbol* gsym)
+ {
+ return (gsym->type() != elfcpp::STT_ARM_TFUNC
+ && gsym->may_need_copy_reloc());
+ }
+
+ // Add a potential copy relocation.
+ void
+ copy_reloc(Symbol_table* symtab, Layout* layout,
+ Sized_relobj<32, big_endian>* object,
+ unsigned int shndx, Output_section* output_section,
+ Symbol* sym, const elfcpp::Rel<32, big_endian>& reloc)
+ {
+ this->copy_relocs_.copy_reloc(symtab, layout,
+ symtab->get_sized_symbol<32>(sym),
+ object, shndx, output_section, reloc,
+ this->rel_dyn_section(layout));
+ }
+
+ // Information about this specific target which we pass to the
+ // general Target structure.
+ static const Target::Target_info arm_info;
+
+ // The types of GOT entries needed for this platform.
+ enum Got_type
+ {
+ GOT_TYPE_STANDARD = 0 // GOT entry for a regular symbol
+ };
+
+ // The GOT section.
+ Output_data_got<32, big_endian>* got_;
+ // The PLT section.
+ Output_data_plt_arm<big_endian>* plt_;
+ // The GOT PLT section.
+ Output_data_space* got_plt_;
+ // The dynamic reloc section.
+ Reloc_section* rel_dyn_;
+ // Relocs saved to avoid a COPY reloc.
+ Copy_relocs<elfcpp::SHT_REL, 32, big_endian> copy_relocs_;
+ // Space for variables copied with a COPY reloc.
+ Output_data_space* dynbss_;
+};
+
+template<bool big_endian>
+const Target::Target_info Target_arm<big_endian>::arm_info =
+{
+ 32, // size
+ big_endian, // is_big_endian
+ elfcpp::EM_ARM, // machine_code
+ false, // has_make_symbol
+ false, // has_resolve
+ false, // has_code_fill
+ true, // is_default_stack_executable
+ '\0', // wrap_char
+ "/usr/lib/libc.so.1", // dynamic_linker
+ 0x8000, // default_text_segment_address
+ 0x1000, // abi_pagesize (overridable by -z max-page-size)
+ 0x1000, // common_pagesize (overridable by -z common-page-size)
+ elfcpp::SHN_UNDEF, // small_common_shndx
+ elfcpp::SHN_UNDEF, // large_common_shndx
+ 0, // small_common_section_flags
+ 0 // large_common_section_flags
+};
+
+// Arm relocate functions class
+//
+
+template<bool big_endian>
+class Arm_relocate_functions : public Relocate_functions<32, big_endian>
+{
+ public:
+ typedef enum
+ {
+ STATUS_OKAY, // No error during relocation.
+ STATUS_OVERFLOW, // Relocation oveflow.
+ STATUS_BAD_RELOC // Relocation cannot be applied.
+ } Status;
+
+ private:
+ typedef Relocate_functions<32, big_endian> Base;
+ typedef Arm_relocate_functions<big_endian> This;
+
+ // Get an symbol value of *PSYMVAL with an ADDEND. This is a wrapper
+ // to Symbol_value::value(). If HAS_THUMB_BIT is true, that LSB is used
+ // to distinguish ARM and THUMB functions and it is treated specially.
+ static inline Symbol_value<32>::Value
+ arm_symbol_value (const Sized_relobj<32, big_endian> *object,
+ const Symbol_value<32>* psymval,
+ Symbol_value<32>::Value addend,
+ bool has_thumb_bit)
+ {
+ typedef Symbol_value<32>::Value Valtype;
+
+ if (has_thumb_bit)
+ {
+ Valtype raw = psymval->value(object, 0);
+ Valtype thumb_bit = raw & 1;
+ return ((raw & ~((Valtype) 1)) + addend) | thumb_bit;
+ }
+ else
+ return psymval->value(object, addend);
+ }
+
+ // Encoding of imm16 argument for movt and movw ARM instructions
+ // from ARM ARM:
+ //
+ // imm16 := imm4 | imm12
+ //
+ // f e d c b a 9 8 7 6 5 4 3 2 1 0 f e d c b a 9 8 7 6 5 4 3 2 1 0
+ // +-------+---------------+-------+-------+-----------------------+
+ // | | |imm4 | |imm12 |
+ // +-------+---------------+-------+-------+-----------------------+
+
+ // Extract the relocation addend from VAL based on the ARM
+ // instruction encoding described above.
+ static inline typename elfcpp::Swap<32, big_endian>::Valtype
+ extract_arm_movw_movt_addend(
+ typename elfcpp::Swap<32, big_endian>::Valtype val)
+ {
+ // According to the Elf ABI for ARM Architecture the immediate
+ // field is sign-extended to form the addend.
+ return utils::sign_extend<16>(((val >> 4) & 0xf000) | (val & 0xfff));
+ }
+
+ // Insert X into VAL based on the ARM instruction encoding described
+ // above.
+ static inline typename elfcpp::Swap<32, big_endian>::Valtype
+ insert_val_arm_movw_movt(
+ typename elfcpp::Swap<32, big_endian>::Valtype val,
+ typename elfcpp::Swap<32, big_endian>::Valtype x)
+ {
+ val &= 0xfff0f000;
+ val |= x & 0x0fff;
+ val |= (x & 0xf000) << 4;
+ return val;
+ }
+
+ // Encoding of imm16 argument for movt and movw Thumb2 instructions
+ // from ARM ARM:
+ //
+ // imm16 := imm4 | i | imm3 | imm8
+ //
+ // f e d c b a 9 8 7 6 5 4 3 2 1 0 f e d c b a 9 8 7 6 5 4 3 2 1 0
+ // +---------+-+-----------+-------++-+-----+-------+---------------+
+ // | |i| |imm4 || |imm3 | |imm8 |
+ // +---------+-+-----------+-------++-+-----+-------+---------------+
+
+ // Extract the relocation addend from VAL based on the Thumb2
+ // instruction encoding described above.
+ static inline typename elfcpp::Swap<32, big_endian>::Valtype
+ extract_thumb_movw_movt_addend(
+ typename elfcpp::Swap<32, big_endian>::Valtype val)
+ {
+ // According to the Elf ABI for ARM Architecture the immediate
+ // field is sign-extended to form the addend.
+ return utils::sign_extend<16>(((val >> 4) & 0xf000)
+ | ((val >> 15) & 0x0800)
+ | ((val >> 4) & 0x0700)
+ | (val & 0x00ff));
+ }
+
+ // Insert X into VAL based on the Thumb2 instruction encoding
+ // described above.
+ static inline typename elfcpp::Swap<32, big_endian>::Valtype
+ insert_val_thumb_movw_movt(
+ typename elfcpp::Swap<32, big_endian>::Valtype val,
+ typename elfcpp::Swap<32, big_endian>::Valtype x)
+ {
+ val &= 0xfbf08f00;
+ val |= (x & 0xf000) << 4;
+ val |= (x & 0x0800) << 15;
+ val |= (x & 0x0700) << 4;
+ val |= (x & 0x00ff);
+ return val;
+ }
+
+ // FIXME: This probably only works for Android on ARM v5te. We should
+ // following GNU ld for the general case.
+ template<unsigned r_type>
+ static inline typename This::Status
+ arm_branch_common(unsigned char *view,
+ const Sized_relobj<32, big_endian>* object,
+ const Symbol_value<32>* psymval,
+ elfcpp::Elf_types<32>::Elf_Addr address,
+ bool has_thumb_bit)
+ {
+ typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
+ Valtype* wv = reinterpret_cast<Valtype*>(view);
+ Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
+
+ bool insn_is_b = (((val >> 28) & 0xf) <= 0xe)
+ && ((val & 0x0f000000UL) == 0x0a000000UL);
+ bool insn_is_uncond_bl = (val & 0xff000000UL) == 0xeb000000UL;
+ bool insn_is_cond_bl = (((val >> 28) & 0xf) < 0xe)
+ && ((val & 0x0f000000UL) == 0x0b000000UL);
+ bool insn_is_blx = (val & 0xfe000000UL) == 0xfa000000UL;
+ bool insn_is_any_branch = (val & 0x0e000000UL) == 0x0a000000UL;
+
+ if (r_type == elfcpp::R_ARM_CALL)
+ {
+ if (!insn_is_uncond_bl && !insn_is_blx)
+ return This::STATUS_BAD_RELOC;
+ }
+ else if (r_type == elfcpp::R_ARM_JUMP24)
+ {
+ if (!insn_is_b && !insn_is_cond_bl)
+ return This::STATUS_BAD_RELOC;
+ }
+ else if (r_type == elfcpp::R_ARM_PLT32)
+ {
+ if (!insn_is_any_branch)
+ return This::STATUS_BAD_RELOC;
+ }
+ else
+ gold_unreachable();
+
+ Valtype addend = utils::sign_extend<26>(val << 2);
+ Valtype x = (This::arm_symbol_value(object, psymval, addend, has_thumb_bit)
+ - address);
+
+ // If target has thumb bit set, we need to either turn the BL
+ // into a BLX (for ARMv5 or above) or generate a stub.
+ if (x & 1)
+ {
+ // Turn BL to BLX.
+ if (insn_is_uncond_bl)
+ val = (val & 0xffffff) | 0xfa000000 | ((x & 2) << 23);
+ else
+ return This::STATUS_BAD_RELOC;
+ }
+ else
+ gold_assert(!insn_is_blx);
+
+ val = utils::bit_select(val, (x >> 2), 0xffffffUL);
+ elfcpp::Swap<32, big_endian>::writeval(wv, val);
+ return (utils::has_overflow<26>(x)
+ ? This::STATUS_OVERFLOW : This::STATUS_OKAY);
+ }
+
+ public:
+
+ // R_ARM_ABS8: S + A
+ static inline typename This::Status
+ abs8(unsigned char *view,
+ const Sized_relobj<32, big_endian>* object,
+ const Symbol_value<32>* psymval)
+ {
+ typedef typename elfcpp::Swap<8, big_endian>::Valtype Valtype;
+ typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
+ Valtype* wv = reinterpret_cast<Valtype*>(view);
+ Valtype val = elfcpp::Swap<8, big_endian>::readval(wv);
+ Reltype addend = utils::sign_extend<8>(val);
+ Reltype x = This::arm_symbol_value(object, psymval, addend, false);
+ val = utils::bit_select(val, x, 0xffU);
+ elfcpp::Swap<8, big_endian>::writeval(wv, val);
+ return (utils::has_signed_unsigned_overflow<8>(x)
+ ? This::STATUS_OVERFLOW
+ : This::STATUS_OKAY);
+ }
+
+ // R_ARM_THM_ABS5: S + A
+ static inline typename This::Status
+ thm_abs5(unsigned char *view,
+ const Sized_relobj<32, big_endian>* object,
+ const Symbol_value<32>* psymval)
+ {
+ typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
+ typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
+ Valtype* wv = reinterpret_cast<Valtype*>(view);
+ Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
+ Reltype addend = (val & 0x7e0U) >> 6;
+ Reltype x = This::arm_symbol_value(object, psymval, addend, false);
+ val = utils::bit_select(val, x << 6, 0x7e0U);
+ elfcpp::Swap<16, big_endian>::writeval(wv, val);
+ return (utils::has_overflow<5>(x)
+ ? This::STATUS_OVERFLOW
+ : This::STATUS_OKAY);
+ }
+
+ // R_ARM_ABS12: S + A
+ static inline typename This::Status
+ abs12(unsigned char *view,
+ const Sized_relobj<32, big_endian>* object,
+ const Symbol_value<32>* psymval)
+ {
+ typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
+ typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
+ Valtype* wv = reinterpret_cast<Valtype*>(view);
+ Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
+ Reltype addend = val & 0x0fffU;
+ Reltype x = This::arm_symbol_value(object, psymval, addend, false);
+ val = utils::bit_select(val, x, 0x0fffU);
+ elfcpp::Swap<32, big_endian>::writeval(wv, val);
+ return (utils::has_overflow<12>(x)
+ ? This::STATUS_OVERFLOW
+ : This::STATUS_OKAY);
+ }
+
+ // R_ARM_ABS16: S + A
+ static inline typename This::Status
+ abs16(unsigned char *view,
+ const Sized_relobj<32, big_endian>* object,
+ const Symbol_value<32>* psymval)
+ {
+ typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
+ typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
+ Valtype* wv = reinterpret_cast<Valtype*>(view);
+ Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
+ Reltype addend = utils::sign_extend<16>(val);
+ Reltype x = This::arm_symbol_value(object, psymval, addend, false);
+ val = utils::bit_select(val, x, 0xffffU);
+ elfcpp::Swap<16, big_endian>::writeval(wv, val);
+ return (utils::has_signed_unsigned_overflow<16>(x)
+ ? This::STATUS_OVERFLOW
+ : This::STATUS_OKAY);
+ }
+
+ // R_ARM_ABS32: (S + A) | T
+ static inline typename This::Status
+ abs32(unsigned char *view,
+ const Sized_relobj<32, big_endian>* object,
+ const Symbol_value<32>* psymval,
+ bool has_thumb_bit)
+ {
+ typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
+ Valtype* wv = reinterpret_cast<Valtype*>(view);
+ Valtype addend = elfcpp::Swap<32, big_endian>::readval(wv);
+ Valtype x = This::arm_symbol_value(object, psymval, addend, has_thumb_bit);
+ elfcpp::Swap<32, big_endian>::writeval(wv, x);
+ return This::STATUS_OKAY;
+ }
+
+ // R_ARM_REL32: (S + A) | T - P
+ static inline typename This::Status
+ rel32(unsigned char *view,
+ const Sized_relobj<32, big_endian>* object,
+ const Symbol_value<32>* psymval,
+ elfcpp::Elf_types<32>::Elf_Addr address,
+ bool has_thumb_bit)
+ {
+ typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
+ Valtype* wv = reinterpret_cast<Valtype*>(view);
+ Valtype addend = elfcpp::Swap<32, big_endian>::readval(wv);
+ Valtype x = (This::arm_symbol_value(object, psymval, addend, has_thumb_bit)
+ - address);
+ elfcpp::Swap<32, big_endian>::writeval(wv, x);
+ return This::STATUS_OKAY;
+ }
+
+ // R_ARM_THM_CALL: (S + A) | T - P
+ static inline typename This::Status
+ thm_call(unsigned char *view,
+ const Sized_relobj<32, big_endian>* object,
+ const Symbol_value<32>* psymval,
+ elfcpp::Elf_types<32>::Elf_Addr address,
+ bool has_thumb_bit)
+ {
+ // A thumb call consists of two instructions.
+ typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
+ typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
+ Valtype* wv = reinterpret_cast<Valtype*>(view);
+ Valtype hi = elfcpp::Swap<16, big_endian>::readval(wv);
+ Valtype lo = elfcpp::Swap<16, big_endian>::readval(wv + 1);
+ // Must be a BL instruction. lo == 11111xxxxxxxxxxx.
+ gold_assert((lo & 0xf800) == 0xf800);
+ Reltype addend = utils::sign_extend<23>(((hi & 0x7ff) << 12)
+ | ((lo & 0x7ff) << 1));
+ Reltype x = (This::arm_symbol_value(object, psymval, addend, has_thumb_bit)
+ - address);
+
+ // If target has no thumb bit set, we need to either turn the BL
+ // into a BLX (for ARMv5 or above) or generate a stub.
+ if ((x & 1) == 0)
+ {
+ // This only works for ARMv5 and above with interworking enabled.
+ lo &= 0xefff;
+ }
+ hi = utils::bit_select(hi, (x >> 12), 0x7ffU);
+ lo = utils::bit_select(lo, (x >> 1), 0x7ffU);
+ elfcpp::Swap<16, big_endian>::writeval(wv, hi);
+ elfcpp::Swap<16, big_endian>::writeval(wv + 1, lo);
+ return (utils::has_overflow<23>(x)
+ ? This::STATUS_OVERFLOW
+ : This::STATUS_OKAY);
+ }
+
+ // R_ARM_BASE_PREL: B(S) + A - P
+ static inline typename This::Status
+ base_prel(unsigned char* view,
+ elfcpp::Elf_types<32>::Elf_Addr origin,
+ elfcpp::Elf_types<32>::Elf_Addr address)
+ {
+ Base::rel32(view, origin - address);
+ return STATUS_OKAY;
+ }
+
+ // R_ARM_BASE_ABS: B(S) + A
+ static inline typename This::Status
+ base_abs(unsigned char* view,
+ elfcpp::Elf_types<32>::Elf_Addr origin)
+ {
+ Base::rel32(view, origin);
+ return STATUS_OKAY;
+ }
+
+ // R_ARM_GOT_BREL: GOT(S) + A - GOT_ORG
+ static inline typename This::Status
+ got_brel(unsigned char* view,
+ typename elfcpp::Swap<32, big_endian>::Valtype got_offset)
+ {
+ Base::rel32(view, got_offset);
+ return This::STATUS_OKAY;
+ }
+
+ // R_ARM_GOT_PREL: GOT(S) + A – P
+ static inline typename This::Status
+ got_prel(unsigned char* view,
+ typename elfcpp::Swap<32, big_endian>::Valtype got_offset,
+ elfcpp::Elf_types<32>::Elf_Addr address)
+ {
+ Base::rel32(view, got_offset - address);
+ return This::STATUS_OKAY;
+ }
+
+ // R_ARM_PLT32: (S + A) | T - P
+ static inline typename This::Status
+ plt32(unsigned char *view,
+ const Sized_relobj<32, big_endian>* object,
+ const Symbol_value<32>* psymval,
+ elfcpp::Elf_types<32>::Elf_Addr address,
+ bool has_thumb_bit)
+ {
+ return arm_branch_common<elfcpp::R_ARM_PLT32>(view, object, psymval,
+ address, has_thumb_bit);
+ }
+
+ // R_ARM_CALL: (S + A) | T - P
+ static inline typename This::Status
+ call(unsigned char *view,
+ const Sized_relobj<32, big_endian>* object,
+ const Symbol_value<32>* psymval,
+ elfcpp::Elf_types<32>::Elf_Addr address,
+ bool has_thumb_bit)
+ {
+ return arm_branch_common<elfcpp::R_ARM_CALL>(view, object, psymval,
+ address, has_thumb_bit);
+ }
+
+ // R_ARM_JUMP24: (S + A) | T - P
+ static inline typename This::Status
+ jump24(unsigned char *view,
+ const Sized_relobj<32, big_endian>* object,
+ const Symbol_value<32>* psymval,
+ elfcpp::Elf_types<32>::Elf_Addr address,
+ bool has_thumb_bit)
+ {
+ return arm_branch_common<elfcpp::R_ARM_JUMP24>(view, object, psymval,
+ address, has_thumb_bit);
+ }
+
+ // R_ARM_PREL: (S + A) | T - P
+ static inline typename This::Status
+ prel31(unsigned char *view,
+ const Sized_relobj<32, big_endian>* object,
+ const Symbol_value<32>* psymval,
+ elfcpp::Elf_types<32>::Elf_Addr address,
+ bool has_thumb_bit)
+ {
+ typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
+ Valtype* wv = reinterpret_cast<Valtype*>(view);
+ Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
+ Valtype addend = utils::sign_extend<31>(val);
+ Valtype x = (This::arm_symbol_value(object, psymval, addend, has_thumb_bit)
+ - address);
+ val = utils::bit_select(val, x, 0x7fffffffU);
+ elfcpp::Swap<32, big_endian>::writeval(wv, val);
+ return (utils::has_overflow<31>(x) ?
+ This::STATUS_OVERFLOW : This::STATUS_OKAY);
+ }
+
+ // R_ARM_MOVW_ABS_NC: (S + A) | T
+ static inline typename This::Status
+ movw_abs_nc(unsigned char *view,
+ const Sized_relobj<32, big_endian>* object,
+ const Symbol_value<32>* psymval,
+ bool has_thumb_bit)
+ {
+ typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
+ Valtype* wv = reinterpret_cast<Valtype*>(view);
+ Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
+ Valtype addend = This::extract_arm_movw_movt_addend(val);
+ Valtype x = This::arm_symbol_value(object, psymval, addend, has_thumb_bit);
+ val = This::insert_val_arm_movw_movt(val, x);
+ elfcpp::Swap<32, big_endian>::writeval(wv, val);
+ return This::STATUS_OKAY;
+ }
+
+ // R_ARM_MOVT_ABS: S + A
+ static inline typename This::Status
+ movt_abs(unsigned char *view,
+ const Sized_relobj<32, big_endian>* object,
+ const Symbol_value<32>* psymval)
+ {
+ typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
+ Valtype* wv = reinterpret_cast<Valtype*>(view);
+ Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
+ Valtype addend = This::extract_arm_movw_movt_addend(val);
+ Valtype x = This::arm_symbol_value(object, psymval, addend, 0) >> 16;
+ val = This::insert_val_arm_movw_movt(val, x);
+ elfcpp::Swap<32, big_endian>::writeval(wv, val);
+ return This::STATUS_OKAY;
+ }
+
+ // R_ARM_THM_MOVW_ABS_NC: S + A | T
+ static inline typename This::Status
+ thm_movw_abs_nc(unsigned char *view,
+ const Sized_relobj<32, big_endian>* object,
+ const Symbol_value<32>* psymval,
+ bool has_thumb_bit)
+ {
+ typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
+ typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
+ Valtype* wv = reinterpret_cast<Valtype*>(view);
+ Reltype val = ((elfcpp::Swap<16, big_endian>::readval(wv) << 16)
+ | elfcpp::Swap<16, big_endian>::readval(wv + 1));
+ Reltype addend = extract_thumb_movw_movt_addend(val);
+ Reltype x = This::arm_symbol_value(object, psymval, addend, has_thumb_bit);
+ val = This::insert_val_thumb_movw_movt(val, x);
+ elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
+ elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
+ return This::STATUS_OKAY;
+ }
+
+ // R_ARM_THM_MOVT_ABS: S + A
+ static inline typename This::Status
+ thm_movt_abs(unsigned char *view,
+ const Sized_relobj<32, big_endian>* object,
+ const Symbol_value<32>* psymval)
+ {
+ typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
+ typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
+ Valtype* wv = reinterpret_cast<Valtype*>(view);
+ Reltype val = ((elfcpp::Swap<16, big_endian>::readval(wv) << 16)
+ | elfcpp::Swap<16, big_endian>::readval(wv + 1));
+ Reltype addend = This::extract_thumb_movw_movt_addend(val);
+ Reltype x = This::arm_symbol_value(object, psymval, addend, 0) >> 16;
+ val = This::insert_val_thumb_movw_movt(val, x);
+ elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
+ elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
+ return This::STATUS_OKAY;
+ }
+
+ // R_ARM_MOVW_PREL_NC: (S + A) | T - P
+ static inline typename This::Status
+ movw_prel_nc(unsigned char *view,
+ const Sized_relobj<32, big_endian>* object,
+ const Symbol_value<32>* psymval,
+ elfcpp::Elf_types<32>::Elf_Addr address,
+ bool has_thumb_bit)
+ {
+ typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
+ Valtype* wv = reinterpret_cast<Valtype*>(view);
+ Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
+ Valtype addend = This::extract_arm_movw_movt_addend(val);
+ Valtype x = (This::arm_symbol_value(object, psymval, addend, has_thumb_bit)
+ - address);
+ val = This::insert_val_arm_movw_movt(val, x);
+ elfcpp::Swap<32, big_endian>::writeval(wv, val);
+ return This::STATUS_OKAY;
+ }
+
+ // R_ARM_MOVT_PREL: S + A - P
+ static inline typename This::Status
+ movt_prel(unsigned char *view,
+ const Sized_relobj<32, big_endian>* object,
+ const Symbol_value<32>* psymval,
+ elfcpp::Elf_types<32>::Elf_Addr address)
+ {
+ typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
+ Valtype* wv = reinterpret_cast<Valtype*>(view);
+ Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
+ Valtype addend = This::extract_arm_movw_movt_addend(val);
+ Valtype x = (This::arm_symbol_value(object, psymval, addend, 0)
+ - address) >> 16;
+ val = This::insert_val_arm_movw_movt(val, x);
+ elfcpp::Swap<32, big_endian>::writeval(wv, val);
+ return This::STATUS_OKAY;
+ }
+
+ // R_ARM_THM_MOVW_PREL_NC: (S + A) | T - P
+ static inline typename This::Status
+ thm_movw_prel_nc(unsigned char *view,
+ const Sized_relobj<32, big_endian>* object,
+ const Symbol_value<32>* psymval,
+ elfcpp::Elf_types<32>::Elf_Addr address,
+ bool has_thumb_bit)
+ {
+ typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
+ typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
+ Valtype* wv = reinterpret_cast<Valtype*>(view);
+ Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
+ | elfcpp::Swap<16, big_endian>::readval(wv + 1);
+ Reltype addend = This::extract_thumb_movw_movt_addend(val);
+ Reltype x = (This::arm_symbol_value(object, psymval, addend, has_thumb_bit)
+ - address);
+ val = This::insert_val_thumb_movw_movt(val, x);
+ elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
+ elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
+ return This::STATUS_OKAY;
+ }
+
+ // R_ARM_THM_MOVT_PREL: S + A - P
+ static inline typename This::Status
+ thm_movt_prel(unsigned char *view,
+ const Sized_relobj<32, big_endian>* object,
+ const Symbol_value<32>* psymval,
+ elfcpp::Elf_types<32>::Elf_Addr address)
+ {
+ typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
+ typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
+ Valtype* wv = reinterpret_cast<Valtype*>(view);
+ Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
+ | elfcpp::Swap<16, big_endian>::readval(wv + 1);
+ Reltype addend = This::extract_thumb_movw_movt_addend(val);
+ Reltype x = (This::arm_symbol_value(object, psymval, addend, 0)
+ - address) >> 16;
+ val = This::insert_val_thumb_movw_movt(val, x);
+ elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
+ elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
+ return This::STATUS_OKAY;
+ }
+};
+
+// Get the GOT section, creating it if necessary.
+
+template<bool big_endian>
+Output_data_got<32, big_endian>*
+Target_arm<big_endian>::got_section(Symbol_table* symtab, Layout* layout)
+{
+ if (this->got_ == NULL)
+ {
+ gold_assert(symtab != NULL && layout != NULL);
+
+ this->got_ = new Output_data_got<32, big_endian>();
+
+ Output_section* os;
+ os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
+ (elfcpp::SHF_ALLOC
+ | elfcpp::SHF_WRITE),
+ this->got_);
+ 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_ABS32_NOI:
+ case elfcpp::R_ARM_PC24:
+ // FIXME: The following 3 types are not supported by Android's dynamic
+ // linker.
+ case elfcpp::R_ARM_TLS_DTPMOD32:
+ case elfcpp::R_ARM_TLS_DTPOFF32:
+ case elfcpp::R_ARM_TLS_TPOFF32:
+ return;
+
+ default:
+ // This prevents us from issuing more than one error per reloc
+ // section. But we can still wind up issuing more than one
+ // error per object file.
+ if (this->issued_non_pic_error_)
+ return;
+ object->error(_("requires unsupported dynamic reloc; "
+ "recompile with -fPIC"));
+ this->issued_non_pic_error_ = true;
+ return;
+
+ case elfcpp::R_ARM_NONE:
+ gold_unreachable();
+ }
+}
+
+// Scan a relocation for a local symbol.
+// FIXME: This only handles a subset of relocation types used by Android
+// on ARM v5te devices.
+
+template<bool big_endian>
+inline void
+Target_arm<big_endian>::Scan::local(const General_options&,
+ Symbol_table* symtab,
+ Layout* layout,
+ Target_arm* target,
+ Sized_relobj<32, big_endian>* object,
+ unsigned int data_shndx,
+ Output_section* output_section,
+ const elfcpp::Rel<32, big_endian>& reloc,
+ unsigned int r_type,
+ const elfcpp::Sym<32, big_endian>&)
+{
+ r_type = get_real_reloc_type(r_type);
+ switch (r_type)
+ {
+ case elfcpp::R_ARM_NONE:
+ break;
+
+ case elfcpp::R_ARM_ABS32:
+ case elfcpp::R_ARM_ABS32_NOI:
+ // If building a shared library (or a position-independent
+ // executable), we need to create a dynamic relocation for
+ // this location. The relocation applied at link time will
+ // apply the link-time value, so we flag the location with
+ // an R_ARM_RELATIVE relocation so the dynamic loader can
+ // relocate it easily.
+ if (parameters->options().output_is_position_independent())
+ {
+ Reloc_section* rel_dyn = target->rel_dyn_section(layout);
+ unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
+ // If we are to add more other reloc types than R_ARM_ABS32,
+ // we need to add check_non_pic(object, r_type) here.
+ rel_dyn->add_local_relative(object, r_sym, elfcpp::R_ARM_RELATIVE,
+ output_section, data_shndx,
+ reloc.get_r_offset());
+ }
+ break;
+
+ case elfcpp::R_ARM_REL32:
+ case elfcpp::R_ARM_THM_CALL:
+ case elfcpp::R_ARM_CALL:
+ case elfcpp::R_ARM_PREL31:
+ case elfcpp::R_ARM_JUMP24:
+ case elfcpp::R_ARM_PLT32:
+ case elfcpp::R_ARM_THM_ABS5:
+ case elfcpp::R_ARM_ABS8:
+ case elfcpp::R_ARM_ABS12:
+ case elfcpp::R_ARM_ABS16:
+ case elfcpp::R_ARM_BASE_ABS:
+ case elfcpp::R_ARM_MOVW_ABS_NC:
+ case elfcpp::R_ARM_MOVT_ABS:
+ case elfcpp::R_ARM_THM_MOVW_ABS_NC:
+ case elfcpp::R_ARM_THM_MOVT_ABS:
+ case elfcpp::R_ARM_MOVW_PREL_NC:
+ case elfcpp::R_ARM_MOVT_PREL:
+ case elfcpp::R_ARM_THM_MOVW_PREL_NC:
+ case elfcpp::R_ARM_THM_MOVT_PREL:
+ break;
+
+ case elfcpp::R_ARM_GOTOFF32:
+ // We need a GOT section:
+ target->got_section(symtab, layout);
+ break;
+
+ case elfcpp::R_ARM_BASE_PREL:
+ // FIXME: What about this?
+ break;
+
+ case elfcpp::R_ARM_GOT_BREL:
+ case elfcpp::R_ARM_GOT_PREL:
+ {
+ // The symbol requires a GOT entry.
+ Output_data_got<32, big_endian>* got =
+ target->got_section(symtab, layout);
+ unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
+ if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
+ {
+ // If we are generating a shared object, we need to add a
+ // dynamic RELATIVE relocation for this symbol's GOT entry.
+ if (parameters->options().output_is_position_independent())
+ {
+ Reloc_section* rel_dyn = target->rel_dyn_section(layout);
+ unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
+ rel_dyn->add_local_relative(
+ object, r_sym, elfcpp::R_ARM_RELATIVE, got,
+ object->local_got_offset(r_sym, GOT_TYPE_STANDARD));
+ }
+ }
+ }
+ break;
+
+ case elfcpp::R_ARM_TARGET1:
+ // This should have been mapped to another type already.
+ // Fall through.
+ case elfcpp::R_ARM_COPY:
+ case elfcpp::R_ARM_GLOB_DAT:
+ case elfcpp::R_ARM_JUMP_SLOT:
+ case elfcpp::R_ARM_RELATIVE:
+ // These are relocations which should only be seen by the
+ // dynamic linker, and should never be seen here.
+ gold_error(_("%s: unexpected reloc %u in object file"),
+ object->name().c_str(), r_type);
+ break;
+
+ default:
+ unsupported_reloc_local(object, r_type);
+ break;
+ }
+}
+
+// Report an unsupported relocation against a global symbol.
+
+template<bool big_endian>
+void
+Target_arm<big_endian>::Scan::unsupported_reloc_global(
+ Sized_relobj<32, big_endian>* object,
+ unsigned int r_type,
+ Symbol* gsym)
+{
+ gold_error(_("%s: unsupported reloc %u against global symbol %s"),
+ object->name().c_str(), r_type, gsym->demangled_name().c_str());
+}
+
+// Scan a relocation for a global symbol.
+// FIXME: This only handles a subset of relocation types used by Android
+// on ARM v5te devices.
+
+template<bool big_endian>
+inline void
+Target_arm<big_endian>::Scan::global(const General_options&,
+ Symbol_table* symtab,
+ Layout* layout,
+ Target_arm* target,
+ Sized_relobj<32, big_endian>* object,
+ unsigned int data_shndx,
+ Output_section* output_section,
+ const elfcpp::Rel<32, big_endian>& reloc,
+ unsigned int r_type,
+ Symbol* gsym)
+{
+ r_type = get_real_reloc_type(r_type);
+ switch (r_type)
+ {
+ case elfcpp::R_ARM_NONE:
+ break;
+
+ case elfcpp::R_ARM_ABS32:
+ case elfcpp::R_ARM_ABS32_NOI:
+ {
+ // Make a dynamic relocation if necessary.
+ if (gsym->needs_dynamic_reloc(Symbol::ABSOLUTE_REF))
+ {
+ if (target->may_need_copy_reloc(gsym))
+ {
+ target->copy_reloc(symtab, layout, object,
+ data_shndx, output_section, gsym, reloc);
+ }
+ else if (gsym->can_use_relative_reloc(false))
+ {
+ // If we are to add more other reloc types than R_ARM_ABS32,
+ // we need to add check_non_pic(object, r_type) here.
+ Reloc_section* rel_dyn = target->rel_dyn_section(layout);
+ rel_dyn->add_global_relative(gsym, elfcpp::R_ARM_RELATIVE,
+ output_section, object,
+ data_shndx, reloc.get_r_offset());
+ }
+ else
+ {
+ // If we are to add more other reloc types than R_ARM_ABS32,
+ // we need to add check_non_pic(object, r_type) here.
+ Reloc_section* rel_dyn = target->rel_dyn_section(layout);
+ rel_dyn->add_global(gsym, r_type, output_section, object,
+ data_shndx, reloc.get_r_offset());
+ }
+ }
+ }
+ break;
+
+ case elfcpp::R_ARM_MOVW_ABS_NC:
+ case elfcpp::R_ARM_MOVT_ABS:
+ case elfcpp::R_ARM_THM_MOVW_ABS_NC:
+ case elfcpp::R_ARM_THM_MOVT_ABS:
+ case elfcpp::R_ARM_MOVW_PREL_NC:
+ case elfcpp::R_ARM_MOVT_PREL:
+ case elfcpp::R_ARM_THM_MOVW_PREL_NC:
+ case elfcpp::R_ARM_THM_MOVT_PREL:
+ break;
+
+ case elfcpp::R_ARM_THM_ABS5:
+ case elfcpp::R_ARM_ABS8:
+ case elfcpp::R_ARM_ABS12:
+ case elfcpp::R_ARM_ABS16:
+ case elfcpp::R_ARM_BASE_ABS:
+ {
+ // No dynamic relocs of this kinds.
+ // Report the error in case of PIC.
+ int flags = Symbol::NON_PIC_REF;
+ if (gsym->type() == elfcpp::STT_FUNC
+ || gsym->type() == elfcpp::STT_ARM_TFUNC)
+ flags |= Symbol::FUNCTION_CALL;
+ if (gsym->needs_dynamic_reloc(flags))
+ check_non_pic(object, r_type);
+ }
+ break;
+
+ case elfcpp::R_ARM_REL32:
+ case elfcpp::R_ARM_PREL31:
+ {
+ // Make a dynamic relocation if necessary.
+ int flags = Symbol::NON_PIC_REF;
+ if (gsym->needs_dynamic_reloc(flags))
+ {
+ if (target->may_need_copy_reloc(gsym))
+ {
+ target->copy_reloc(symtab, layout, object,
+ data_shndx, output_section, gsym, reloc);
+ }
+ else
+ {
+ check_non_pic(object, r_type);
+ Reloc_section* rel_dyn = target->rel_dyn_section(layout);
+ rel_dyn->add_global(gsym, r_type, output_section, object,
+ data_shndx, reloc.get_r_offset());
+ }
+ }
+ }
+ break;
+
+ case elfcpp::R_ARM_JUMP24:
+ case elfcpp::R_ARM_THM_CALL:
+ case elfcpp::R_ARM_CALL:
+ {
+ if (Target_arm<big_endian>::Scan::symbol_needs_plt_entry(gsym))
+ target->make_plt_entry(symtab, layout, gsym);
+ // Make a dynamic relocation if necessary.
+ int flags = Symbol::NON_PIC_REF;
+ if (gsym->type() == elfcpp::STT_FUNC
+ || gsym->type() == elfcpp::STT_ARM_TFUNC)
+ flags |= Symbol::FUNCTION_CALL;
+ if (gsym->needs_dynamic_reloc(flags))
+ {
+ if (target->may_need_copy_reloc(gsym))
+ {
+ target->copy_reloc(symtab, layout, object,
+ data_shndx, output_section, gsym,
+ reloc);
+ }
+ else
+ {
+ check_non_pic(object, r_type);
+ Reloc_section* rel_dyn = target->rel_dyn_section(layout);
+ rel_dyn->add_global(gsym, r_type, output_section, object,
+ data_shndx, reloc.get_r_offset());
+ }
+ }
+ }
+ break;
+
+ case elfcpp::R_ARM_PLT32:
+ // If the symbol is fully resolved, this is just a relative
+ // local reloc. Otherwise we need a PLT entry.
+ if (gsym->final_value_is_known())
+ break;
+ // If building a shared library, we can also skip the PLT entry
+ // if the symbol is defined in the output file and is protected
+ // or hidden.
+ if (gsym->is_defined()
+ && !gsym->is_from_dynobj()
+ && !gsym->is_preemptible())
+ break;
+ target->make_plt_entry(symtab, layout, gsym);
+ break;
+
+ case elfcpp::R_ARM_GOTOFF32:
+ // We need a GOT section.
+ target->got_section(symtab, layout);
+ break;
+
+ case elfcpp::R_ARM_BASE_PREL:
+ // FIXME: What about this?
+ break;
+
+ case elfcpp::R_ARM_GOT_BREL:
+ case elfcpp::R_ARM_GOT_PREL:
+ {
+ // The symbol requires a GOT entry.
+ Output_data_got<32, big_endian>* got =
+ target->got_section(symtab, layout);
+ if (gsym->final_value_is_known())
+ got->add_global(gsym, GOT_TYPE_STANDARD);
+ else
+ {
+ // If this symbol is not fully resolved, we need to add a
+ // GOT entry with a dynamic relocation.
+ Reloc_section* rel_dyn = target->rel_dyn_section(layout);
+ if (gsym->is_from_dynobj()
+ || gsym->is_undefined()
+ || gsym->is_preemptible())
+ got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
+ rel_dyn, elfcpp::R_ARM_GLOB_DAT);
+ else
+ {
+ if (got->add_global(gsym, GOT_TYPE_STANDARD))
+ rel_dyn->add_global_relative(
+ gsym, elfcpp::R_ARM_RELATIVE, got,
+ gsym->got_offset(GOT_TYPE_STANDARD));
+ }
+ }
+ }
+ break;
+
+ case elfcpp::R_ARM_TARGET1:
+ // This should have been mapped to another type already.
+ // Fall through.
+ case elfcpp::R_ARM_COPY:
+ case elfcpp::R_ARM_GLOB_DAT:
+ case elfcpp::R_ARM_JUMP_SLOT:
+ case elfcpp::R_ARM_RELATIVE:
+ // These are relocations which should only be seen by the
+ // dynamic linker, and should never be seen here.
+ gold_error(_("%s: unexpected reloc %u in object file"),
+ object->name().c_str(), r_type);
+ break;
+
+ default:
+ unsupported_reloc_global(object, r_type, gsym);
+ break;
+ }
+}
+
+// Process relocations for gc.
+
+template<bool big_endian>
+void
+Target_arm<big_endian>::gc_process_relocs(const General_options& options,
+ Symbol_table* symtab,
+ Layout* layout,
+ Sized_relobj<32, big_endian>* object,
+ unsigned int data_shndx,
+ unsigned int,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ bool needs_special_offset_handling,
+ size_t local_symbol_count,
+ const unsigned char* plocal_symbols)
+{
+ typedef Target_arm<big_endian> Arm;
+ typedef typename Target_arm<big_endian>::Scan Scan;
+
+ gold::gc_process_relocs<32, big_endian, Arm, elfcpp::SHT_REL, Scan>(
+ options,
+ symtab,
+ layout,
+ this,
+ object,
+ data_shndx,
+ prelocs,
+ reloc_count,
+ output_section,
+ needs_special_offset_handling,
+ local_symbol_count,
+ plocal_symbols);
+}
+
+// Scan relocations for a section.
+
+template<bool big_endian>
+void
+Target_arm<big_endian>::scan_relocs(const General_options& options,
+ Symbol_table* symtab,
+ Layout* layout,
+ Sized_relobj<32, big_endian>* object,
+ unsigned int data_shndx,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ bool needs_special_offset_handling,
+ size_t local_symbol_count,
+ const unsigned char* plocal_symbols)
+{
+ typedef typename Target_arm<big_endian>::Scan Scan;
+ if (sh_type == elfcpp::SHT_RELA)
+ {
+ gold_error(_("%s: unsupported RELA reloc section"),
+ object->name().c_str());
+ return;
+ }
+
+ gold::scan_relocs<32, big_endian, Target_arm, elfcpp::SHT_REL, Scan>(
+ options,
+ symtab,
+ layout,
+ this,
+ object,
+ data_shndx,
+ prelocs,
+ reloc_count,
+ output_section,
+ needs_special_offset_handling,
+ local_symbol_count,
+ plocal_symbols);
+}
+
+// Finalize the sections.
+
+template<bool big_endian>
+void
+Target_arm<big_endian>::do_finalize_sections(Layout* layout)
+{
+ // Fill in some more dynamic tags.
+ Output_data_dynamic* const odyn = layout->dynamic_data();
+ if (odyn != NULL)
+ {
+ if (this->got_plt_ != NULL)
+ 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);
+ break;
+
+ case elfcpp::R_ARM_ABS12:
+ if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
+ output_section))
+ reloc_status = Arm_relocate_functions::abs12(view, object, psymval);
+ break;
+
+ case elfcpp::R_ARM_ABS16:
+ if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
+ output_section))
+ reloc_status = Arm_relocate_functions::abs16(view, object, psymval);
+ break;
+
+ case elfcpp::R_ARM_ABS32:
+ if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true,
+ output_section))
+ reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
+ has_thumb_bit);
+ break;
+
+ case elfcpp::R_ARM_ABS32_NOI:
+ if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true,
+ output_section))
+ // No thumb bit for this relocation: (S + A)
+ reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
+ false);
+ break;
+
+ case elfcpp::R_ARM_MOVW_ABS_NC:
+ if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true,
+ output_section))
+ reloc_status = Arm_relocate_functions::movw_abs_nc(view, object,
+ psymval,
+ has_thumb_bit);
+ else
+ gold_error(_("relocation R_ARM_MOVW_ABS_NC cannot be used when making"
+ "a shared object; recompile with -fPIC"));
+ break;
+
+ case elfcpp::R_ARM_MOVT_ABS:
+ if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true,
+ output_section))
+ reloc_status = Arm_relocate_functions::movt_abs(view, object, psymval);
+ else
+ gold_error(_("relocation R_ARM_MOVT_ABS cannot be used when making"
+ "a shared object; recompile with -fPIC"));
+ break;
+
+ case elfcpp::R_ARM_THM_MOVW_ABS_NC:
+ if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true,
+ output_section))
+ reloc_status = Arm_relocate_functions::thm_movw_abs_nc(view, object,
+ psymval,
+ has_thumb_bit);
+ else
+ gold_error(_("relocation R_ARM_THM_MOVW_ABS_NC cannot be used when"
+ "making a shared object; recompile with -fPIC"));
+ break;
+
+ case elfcpp::R_ARM_THM_MOVT_ABS:
+ if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true,
+ output_section))
+ reloc_status = Arm_relocate_functions::thm_movt_abs(view, object,
+ psymval);
+ else
+ gold_error(_("relocation R_ARM_THM_MOVT_ABS cannot be used when"
+ "making a shared object; recompile with -fPIC"));
+ break;
+
+ case elfcpp::R_ARM_MOVW_PREL_NC:
+ reloc_status = Arm_relocate_functions::movw_prel_nc(view, object,
+ psymval, address,
+ has_thumb_bit);
+ break;
+
+ case elfcpp::R_ARM_MOVT_PREL:
+ reloc_status = Arm_relocate_functions::movt_prel(view, object,
+ psymval, address);
+ break;
+
+ case elfcpp::R_ARM_THM_MOVW_PREL_NC:
+ reloc_status = Arm_relocate_functions::thm_movw_prel_nc(view, object,
+ psymval, address,
+ has_thumb_bit);
+ break;
+
+ case elfcpp::R_ARM_THM_MOVT_PREL:
+ reloc_status = Arm_relocate_functions::thm_movt_prel(view, object,
+ psymval, address);
+ break;
+
+ case elfcpp::R_ARM_REL32:
+ reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
+ address, has_thumb_bit);
+ break;
+
+ case elfcpp::R_ARM_THM_ABS5:
+ if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
+ output_section))
+ reloc_status = Arm_relocate_functions::thm_abs5(view, object, psymval);
+ break;
+
+ case elfcpp::R_ARM_THM_CALL:
+ reloc_status = Arm_relocate_functions::thm_call(view, object, psymval,
+ address, has_thumb_bit);
+ break;
+
+ case elfcpp::R_ARM_GOTOFF32:
+ {
+ elfcpp::Elf_types<32>::Elf_Addr got_origin;
+ got_origin = target->got_plt_section()->address();
+ reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
+ got_origin, has_thumb_bit);
+ }
+ break;
+
+ case elfcpp::R_ARM_BASE_PREL:
+ {
+ uint32_t origin;
+ // Get the addressing origin of the output segment defining the
+ // symbol gsym (AAELF 4.6.1.2 Relocation types)
+ gold_assert(gsym != NULL);
+ if (gsym->source() == Symbol::IN_OUTPUT_SEGMENT)
+ origin = gsym->output_segment()->vaddr();
+ else if (gsym->source () == Symbol::IN_OUTPUT_DATA)
+ origin = gsym->output_data()->address();
+ else
+ {
+ gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
+ _("cannot find origin of R_ARM_BASE_PREL"));
+ return true;
+ }
+ reloc_status = Arm_relocate_functions::base_prel(view, origin, address);
+ }
+ break;
+
+ case elfcpp::R_ARM_BASE_ABS:
+ {
+ if (!should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true,
+ output_section))
+ break;
+
+ uint32_t origin;
+ // Get the addressing origin of the output segment defining
+ // the symbol gsym (AAELF 4.6.1.2 Relocation types).
+ if (gsym == NULL)
+ // R_ARM_BASE_ABS with the NULL symbol will give the
+ // absolute address of the GOT origin (GOT_ORG) (see ARM IHI
+ // 0044C (AAELF): 4.6.1.8 Proxy generating relocations).
+ origin = target->got_plt_section()->address();
+ else if (gsym->source() == Symbol::IN_OUTPUT_SEGMENT)
+ origin = gsym->output_segment()->vaddr();
+ else if (gsym->source () == Symbol::IN_OUTPUT_DATA)
+ origin = gsym->output_data()->address();
+ else
+ {
+ gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
+ _("cannot find origin of R_ARM_BASE_ABS"));
+ return true;
+ }
+
+ reloc_status = Arm_relocate_functions::base_abs(view, origin);
+ }
+ break;
+
+ case elfcpp::R_ARM_GOT_BREL:
+ gold_assert(have_got_offset);
+ reloc_status = Arm_relocate_functions::got_brel(view, got_offset);
+ break;
+
+ case elfcpp::R_ARM_GOT_PREL:
+ gold_assert(have_got_offset);
+ // Get the address origin for GOT PLT, which is allocated right
+ // after the GOT section, to calculate an absolute address of
+ // the symbol GOT entry (got_origin + got_offset).
+ elfcpp::Elf_types<32>::Elf_Addr got_origin;
+ got_origin = target->got_plt_section()->address();
+ reloc_status = Arm_relocate_functions::got_prel(view,
+ got_origin + got_offset,
+ address);
+ break;
+
+ case elfcpp::R_ARM_PLT32:
+ gold_assert(gsym == NULL
+ || gsym->has_plt_offset()
+ || gsym->final_value_is_known()
+ || (gsym->is_defined()
+ && !gsym->is_from_dynobj()
+ && !gsym->is_preemptible()));
+ reloc_status = Arm_relocate_functions::plt32(view, object, psymval,
+ address, has_thumb_bit);
+ break;
+
+ case elfcpp::R_ARM_CALL:
+ reloc_status = Arm_relocate_functions::call(view, object, psymval,
+ address, has_thumb_bit);
+ break;
+
+ case elfcpp::R_ARM_JUMP24:
+ reloc_status = Arm_relocate_functions::jump24(view, object, psymval,
+ address, has_thumb_bit);
+ break;
+
+ case elfcpp::R_ARM_PREL31:
+ reloc_status = Arm_relocate_functions::prel31(view, object, psymval,
+ address, has_thumb_bit);
+ break;
+
+ case elfcpp::R_ARM_TARGET1:
+ // This should have been mapped to another type already.
+ // Fall through.
+ case elfcpp::R_ARM_COPY:
+ case elfcpp::R_ARM_GLOB_DAT:
+ case elfcpp::R_ARM_JUMP_SLOT:
+ case elfcpp::R_ARM_RELATIVE:
+ // These are relocations which should only be seen by the
+ // dynamic linker, and should never be seen here.
+ gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
+ _("unexpected reloc %u in object file"),
+ r_type);
+ break;
+
+ default:
+ gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
+ _("unsupported reloc %u"),
+ r_type);
+ break;
+ }
+
+ // Report any errors.
+ switch (reloc_status)
+ {
+ case Arm_relocate_functions::STATUS_OKAY:
+ break;
+ case Arm_relocate_functions::STATUS_OVERFLOW:
+ gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
+ _("relocation overflow in relocation %u"),
+ r_type);
+ break;
+ case Arm_relocate_functions::STATUS_BAD_RELOC:
+ gold_error_at_location(
+ relinfo,
+ relnum,
+ rel.get_r_offset(),
+ _("unexpected opcode while processing relocation %u"),
+ r_type);
+ break;
+ default:
+ gold_unreachable();
+ }
+
+ return true;
+}
+
+// Relocate section data.
+
+template<bool big_endian>
+void
+Target_arm<big_endian>::relocate_section(
+ const Relocate_info<32, big_endian>* relinfo,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ bool needs_special_offset_handling,
+ unsigned char* view,
+ elfcpp::Elf_types<32>::Elf_Addr address,
+ section_size_type view_size,
+ const Reloc_symbol_changes* reloc_symbol_changes)
+{
+ typedef typename Target_arm<big_endian>::Relocate Arm_relocate;
+ gold_assert(sh_type == elfcpp::SHT_REL);
+
+ gold::relocate_section<32, big_endian, Target_arm, elfcpp::SHT_REL,
+ Arm_relocate>(
+ relinfo,
+ this,
+ prelocs,
+ reloc_count,
+ output_section,
+ needs_special_offset_handling,
+ view,
+ address,
+ view_size,
+ reloc_symbol_changes);
+}
+
+// Return the size of a relocation while scanning during a relocatable
+// link.
+
+template<bool big_endian>
+unsigned int
+Target_arm<big_endian>::Relocatable_size_for_reloc::get_size_for_reloc(
+ unsigned int r_type,
+ Relobj* object)
+{
+ r_type = get_real_reloc_type(r_type);
+ switch (r_type)
+ {
+ case elfcpp::R_ARM_NONE:
+ return 0;
+
+ case elfcpp::R_ARM_ABS8:
+ return 1;
+
+ case elfcpp::R_ARM_ABS16:
+ case elfcpp::R_ARM_THM_ABS5:
+ return 2;
+
+ case elfcpp::R_ARM_ABS32:
+ case elfcpp::R_ARM_ABS32_NOI:
+ case elfcpp::R_ARM_ABS12:
+ case elfcpp::R_ARM_BASE_ABS:
+ case elfcpp::R_ARM_REL32:
+ case elfcpp::R_ARM_THM_CALL:
+ case elfcpp::R_ARM_GOTOFF32:
+ case elfcpp::R_ARM_BASE_PREL:
+ case elfcpp::R_ARM_GOT_BREL:
+ case elfcpp::R_ARM_GOT_PREL:
+ case elfcpp::R_ARM_PLT32:
+ case elfcpp::R_ARM_CALL:
+ case elfcpp::R_ARM_JUMP24:
+ case elfcpp::R_ARM_PREL31:
+ case elfcpp::R_ARM_MOVW_ABS_NC:
+ case elfcpp::R_ARM_MOVT_ABS:
+ case elfcpp::R_ARM_THM_MOVW_ABS_NC:
+ case elfcpp::R_ARM_THM_MOVT_ABS:
+ case elfcpp::R_ARM_MOVW_PREL_NC:
+ case elfcpp::R_ARM_MOVT_PREL:
+ case elfcpp::R_ARM_THM_MOVW_PREL_NC:
+ case elfcpp::R_ARM_THM_MOVT_PREL:
+ return 4;
+
+ case elfcpp::R_ARM_TARGET1:
+ // This should have been mapped to another type already.
+ // Fall through.
+ case elfcpp::R_ARM_COPY:
+ case elfcpp::R_ARM_GLOB_DAT:
+ case elfcpp::R_ARM_JUMP_SLOT:
+ case elfcpp::R_ARM_RELATIVE:
+ // These are relocations which should only be seen by the
+ // dynamic linker, and should never be seen here.
+ gold_error(_("%s: unexpected reloc %u in object file"),
+ object->name().c_str(), r_type);
+ return 0;
+
+ default:
+ object->error(_("unsupported reloc %u in object file"), r_type);
+ return 0;
+ }
+}
+
+// Scan the relocs during a relocatable link.
+
+template<bool big_endian>
+void
+Target_arm<big_endian>::scan_relocatable_relocs(
+ const General_options& options,
+ Symbol_table* symtab,
+ Layout* layout,
+ Sized_relobj<32, big_endian>* object,
+ unsigned int data_shndx,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ bool needs_special_offset_handling,
+ size_t local_symbol_count,
+ const unsigned char* plocal_symbols,
+ Relocatable_relocs* rr)
+{
+ gold_assert(sh_type == elfcpp::SHT_REL);
+
+ typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_REL,
+ Relocatable_size_for_reloc> Scan_relocatable_relocs;
+
+ gold::scan_relocatable_relocs<32, big_endian, elfcpp::SHT_REL,
+ Scan_relocatable_relocs>(
+ options,
+ symtab,
+ layout,
+ object,
+ data_shndx,
+ prelocs,
+ reloc_count,
+ output_section,
+ needs_special_offset_handling,
+ local_symbol_count,
+ plocal_symbols,
+ rr);
+}
+
+// Relocate a section during a relocatable link.
+
+template<bool big_endian>
+void
+Target_arm<big_endian>::relocate_for_relocatable(
+ const Relocate_info<32, big_endian>* relinfo,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ off_t offset_in_output_section,
+ const Relocatable_relocs* rr,
+ unsigned char* view,
+ elfcpp::Elf_types<32>::Elf_Addr view_address,
+ section_size_type view_size,
+ unsigned char* reloc_view,
+ section_size_type reloc_view_size)
+{
+ gold_assert(sh_type == elfcpp::SHT_REL);
+
+ gold::relocate_for_relocatable<32, big_endian, elfcpp::SHT_REL>(
+ relinfo,
+ prelocs,
+ reloc_count,
+ output_section,
+ offset_in_output_section,
+ rr,
+ view,
+ view_address,
+ view_size,
+ reloc_view,
+ reloc_view_size);
+}
+
+// Return the value to use for a dynamic symbol which requires special
+// treatment. This is how we support equality comparisons of function
+// pointers across shared library boundaries, as described in the
+// processor specific ABI supplement.
+
+template<bool big_endian>
+uint64_t
+Target_arm<big_endian>::do_dynsym_value(const Symbol* gsym) const
+{
+ gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
+ return this->plt_section()->address() + gsym->plt_offset();
+}
+
+// Map platform-specific relocs to real relocs
+//
+template<bool big_endian>
+unsigned int
+Target_arm<big_endian>::get_real_reloc_type (unsigned int r_type)
+{
+ switch (r_type)
+ {
+ case elfcpp::R_ARM_TARGET1:
+ // This is either R_ARM_ABS32 or R_ARM_REL32;
+ return elfcpp::R_ARM_ABS32;
+
+ case elfcpp::R_ARM_TARGET2:
+ // This can be any reloc type but ususally is R_ARM_GOT_PREL
+ return elfcpp::R_ARM_GOT_PREL;
+
+ default:
+ return r_type;
+ }
+}
+
+// The selector for arm object files.
+
+template<bool big_endian>
+class Target_selector_arm : public Target_selector
+{
+ public:
+ Target_selector_arm()
+ : Target_selector(elfcpp::EM_ARM, 32, big_endian,
+ (big_endian ? "elf32-bigarm" : "elf32-littlearm"))
+ { }
+
+ Target*
+ do_instantiate_target()
+ { return new Target_arm<big_endian>(); }
+};
+
+Target_selector_arm<false> target_selector_arm;
+Target_selector_arm<true> target_selector_armbe;
+
+} // End anonymous namespace.
projects / msp430-binutils.git / blobdiff