// aarch64.cc -- aarch64 target support for gold.
// Copyright (C) 2014 Free Software Foundation, Inc.
// Written by Jing Yu <jingyu@google.com> and Han Shen <shenhan@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 "elfcpp.h"
#include "dwarf.h"
#include "parameters.h"
#include "reloc.h"
#include "aarch64.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 "freebsd.h"
#include "nacl.h"
#include "gc.h"
#include "icf.h"
#include "aarch64-reloc-property.h"
// The first three .got.plt entries are reserved.
const int32_t AARCH64_GOTPLT_RESERVE_COUNT = 3;
namespace
{
using namespace gold;
template<int size, bool big_endian>
class Output_data_plt_aarch64;
template<int size, bool big_endian>
class Output_data_plt_aarch64_standard;
template<int size, bool big_endian>
class Target_aarch64;
template<int size, bool big_endian>
class AArch64_relocate_functions;
// Output_data_got_aarch64 class.
template<int size, bool big_endian>
class Output_data_got_aarch64 : public Output_data_got<size, big_endian>
{
public:
typedef typename elfcpp::Elf_types<size>::Elf_Addr Valtype;
Output_data_got_aarch64(Symbol_table* symtab, Layout* layout)
: Output_data_got<size, big_endian>(),
symbol_table_(symtab), layout_(layout)
{ }
// Add a static entry for the GOT entry at OFFSET. GSYM is a global
// symbol and R_TYPE is the code of a dynamic relocation that needs to be
// applied in a static link.
void
add_static_reloc(unsigned int got_offset, unsigned int r_type, Symbol* gsym)
{ this->static_relocs_.push_back(Static_reloc(got_offset, r_type, gsym)); }
// Add a static reloc for the GOT entry at OFFSET. RELOBJ is an object
// defining a local symbol with INDEX. R_TYPE is the code of a dynamic
// relocation that needs to be applied in a static link.
void
add_static_reloc(unsigned int got_offset, unsigned int r_type,
Sized_relobj_file<size, big_endian>* relobj,
unsigned int index)
{
this->static_relocs_.push_back(Static_reloc(got_offset, r_type, relobj,
index));
}
protected:
// Write out the GOT table.
void
do_write(Output_file* of) {
// The first entry in the GOT is the address of the .dynamic section.
gold_assert(this->data_size() >= size / 8);
Output_section* dynamic = this->layout_->dynamic_section();
Valtype dynamic_addr = dynamic == NULL ? 0 : dynamic->address();
this->replace_constant(0, dynamic_addr);
Output_data_got<size, big_endian>::do_write(of);
// Handling static relocs
if (this->static_relocs_.empty())
return;
typedef typename elfcpp::Elf_types<size>::Elf_Addr AArch64_address;
gold_assert(parameters->doing_static_link());
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);
Output_segment* tls_segment = this->layout_->tls_segment();
gold_assert(tls_segment != NULL);
AArch64_address aligned_tcb_address =
align_address(Target_aarch64<size,big_endian>::TCB_SIZE,
tls_segment->maximum_alignment());
for (size_t i = 0; i < this->static_relocs_.size(); ++i)
{
Static_reloc& reloc(this->static_relocs_[i]);
AArch64_address value;
if (!reloc.symbol_is_global())
{
Sized_relobj_file<size, big_endian>* object = reloc.relobj();
const Symbol_value<size>* psymval =
reloc.relobj()->local_symbol(reloc.index());
// We are doing static linking. Issue an error and skip this
// relocation if the symbol is undefined or in a discarded_section.
bool is_ordinary;
unsigned int shndx = psymval->input_shndx(&is_ordinary);
if ((shndx == elfcpp::SHN_UNDEF)
|| (is_ordinary
&& shndx != elfcpp::SHN_UNDEF
&& !object->is_section_included(shndx)
&& !this->symbol_table_->is_section_folded(object, shndx)))
{
gold_error(_("undefined or discarded local symbol %u from "
" object %s in GOT"),
reloc.index(), reloc.relobj()->name().c_str());
continue;
}
value = psymval->value(object, 0);
}
else
{
const Symbol* gsym = reloc.symbol();
gold_assert(gsym != NULL);
if (gsym->is_forwarder())
gsym = this->symbol_table_->resolve_forwards(gsym);
// We are doing static linking. Issue an error and skip this
// relocation if the symbol is undefined or in a discarded_section
// unless it is a weakly_undefined symbol.
if ((gsym->is_defined_in_discarded_section()
|| gsym->is_undefined())
&& !gsym->is_weak_undefined())
{
gold_error(_("undefined or discarded symbol %s in GOT"),
gsym->name());
continue;
}
if (!gsym->is_weak_undefined())
{
const Sized_symbol<size>* sym =
static_cast<const Sized_symbol<size>*>(gsym);
value = sym->value();
}
else
value = 0;
}
unsigned got_offset = reloc.got_offset();
gold_assert(got_offset < oview_size);
typedef typename elfcpp::Swap<size, big_endian>::Valtype Valtype;
Valtype* wv = reinterpret_cast<Valtype*>(oview + got_offset);
Valtype x;
switch (reloc.r_type())
{
case elfcpp::R_AARCH64_TLS_DTPREL64:
x = value;
break;
case elfcpp::R_AARCH64_TLS_TPREL64:
x = value + aligned_tcb_address;
break;
default:
gold_unreachable();
}
elfcpp::Swap<size, big_endian>::writeval(wv, x);
}
of->write_output_view(offset, oview_size, oview);
}
private:
// Symbol table of the output object.
Symbol_table* symbol_table_;
// A pointer to the Layout class, so that we can find the .dynamic
// section when we write out the GOT section.
Layout* layout_;
// This class represent dynamic relocations that need to be applied by
// gold because we are using TLS relocations in a static link.
class Static_reloc
{
public:
Static_reloc(unsigned int got_offset, unsigned int r_type, Symbol* gsym)
: got_offset_(got_offset), r_type_(r_type), symbol_is_global_(true)
{ this->u_.global.symbol = gsym; }
Static_reloc(unsigned int got_offset, unsigned int r_type,
Sized_relobj_file<size, big_endian>* relobj, unsigned int index)
: got_offset_(got_offset), r_type_(r_type), symbol_is_global_(false)
{
this->u_.local.relobj = relobj;
this->u_.local.index = index;
}
// Return the GOT offset.
unsigned int
got_offset() const
{ return this->got_offset_; }
// Relocation type.
unsigned int
r_type() const
{ return this->r_type_; }
// Whether the symbol is global or not.
bool
symbol_is_global() const
{ return this->symbol_is_global_; }
// For a relocation against a global symbol, the global symbol.
Symbol*
symbol() const
{
gold_assert(this->symbol_is_global_);
return this->u_.global.symbol;
}
// For a relocation against a local symbol, the defining object.
Sized_relobj_file<size, big_endian>*
relobj() const
{
gold_assert(!this->symbol_is_global_);
return this->u_.local.relobj;
}
// For a relocation against a local symbol, the local symbol index.
unsigned int
index() const
{
gold_assert(!this->symbol_is_global_);
return this->u_.local.index;
}
private:
// GOT offset of the entry to which this relocation is applied.
unsigned int got_offset_;
// Type of relocation.
unsigned int r_type_;
// Whether this relocation is against a global symbol.
bool symbol_is_global_;
// A global or local symbol.
union
{
struct
{
// For a global symbol, the symbol itself.
Symbol* symbol;
} global;
struct
{
// For a local symbol, the object defining object.
Sized_relobj_file<size, big_endian>* relobj;
// For a local symbol, the symbol index.
unsigned int index;
} local;
} u_;
}; // End of inner class Static_reloc
std::vector<Static_reloc> static_relocs_;
};
AArch64_reloc_property_table* aarch64_reloc_property_table = NULL;
// The aarch64 target class.
// See the ABI at
// http://infocenter.arm.com/help/topic/com.arm.doc.ihi0056b/IHI0056B_aaelf64.pdf
template<int size, bool big_endian>
class Target_aarch64 : public Sized_target<size, big_endian>
{
public:
typedef Target_aarch64<size,big_endian> This;
typedef Output_data_reloc<elfcpp::SHT_RELA, true, size, big_endian>
Reloc_section;
typedef typename elfcpp::Elf_types<size>::Elf_Addr Address;
const static int TCB_SIZE = size / 8 * 2;
Target_aarch64(const Target::Target_info* info = &aarch64_info)
: Sized_target<size, big_endian>(info),
got_(NULL), plt_(NULL), got_plt_(NULL),
global_offset_table_(NULL), rela_dyn_(NULL),
copy_relocs_(elfcpp::R_AARCH64_COPY)
{ }
// Scan the relocations to determine unreferenced sections for
// garbage collection.
void
gc_process_relocs(Symbol_table* symtab,
Layout* layout,
Sized_relobj_file<size, 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(Symbol_table* symtab,
Layout* layout,
Sized_relobj_file<size, 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*, const Input_objects*, Symbol_table*);
// Relocate a section.
void
relocate_section(const Relocate_info<size, 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,
typename elfcpp::Elf_types<size>::Elf_Addr view_address,
section_size_type view_size,
const Reloc_symbol_changes*);
// Scan the relocs during a relocatable link.
void
scan_relocatable_relocs(Symbol_table* symtab,
Layout* layout,
Sized_relobj_file<size, 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_relocs(
const Relocate_info<size, big_endian>*,
unsigned int sh_type,
const unsigned char* prelocs,
size_t reloc_count,
Output_section* output_section,
typename elfcpp::Elf_types<size>::Elf_Off offset_in_output_section,
const Relocatable_relocs*,
unsigned char* view,
typename elfcpp::Elf_types<size>::Elf_Addr view_address,
section_size_type view_size,
unsigned char* reloc_view,
section_size_type reloc_view_size);
// Return the PLT section.
uint64_t
do_plt_address_for_global(const Symbol* gsym) const
{ return this->plt_section()->address_for_global(gsym); }
uint64_t
do_plt_address_for_local(const Relobj* relobj, unsigned int symndx) const
{ return this->plt_section()->address_for_local(relobj, symndx); }
// Return the number of entries in the PLT.
unsigned int
plt_entry_count() const;
//Return the offset of the first non-reserved PLT entry.
unsigned int
first_plt_entry_offset() const;
// Return the size of each PLT entry.
unsigned int
plt_entry_size() const;
unsigned int
tcb_size() const { return This::TCB_SIZE; }
protected:
void
do_select_as_default_target()
{
gold_assert(aarch64_reloc_property_table == NULL);
aarch64_reloc_property_table = new AArch64_reloc_property_table();
}
virtual Output_data_plt_aarch64<size, big_endian>*
do_make_data_plt(Layout* layout, Output_data_space* got_plt)
{
return new Output_data_plt_aarch64_standard<size, big_endian>(layout,
got_plt);
}
Output_data_plt_aarch64<size, big_endian>*
make_data_plt(Layout* layout, Output_data_space* got_plt)
{
return this->do_make_data_plt(layout, got_plt);
}
private:
// The class which scans relocations.
class Scan
{
public:
Scan()
: issued_non_pic_error_(false)
{ }
inline void
local(Symbol_table* symtab, Layout* layout, Target_aarch64* target,
Sized_relobj_file<size, big_endian>* object,
unsigned int data_shndx,
Output_section* output_section,
const elfcpp::Rela<size, big_endian>& reloc, unsigned int r_type,
const elfcpp::Sym<size, big_endian>& lsym,
bool is_discarded);
inline void
global(Symbol_table* symtab, Layout* layout, Target_aarch64* target,
Sized_relobj_file<size, big_endian>* object,
unsigned int data_shndx,
Output_section* output_section,
const elfcpp::Rela<size, big_endian>& reloc, unsigned int r_type,
Symbol* gsym);
inline bool
local_reloc_may_be_function_pointer(Symbol_table* , Layout* ,
Target_aarch64<size, big_endian>* ,
Sized_relobj_file<size, big_endian>* ,
unsigned int ,
Output_section* ,
const elfcpp::Rela<size, big_endian>& ,
unsigned int r_type,
const elfcpp::Sym<size, big_endian>&);
inline bool
global_reloc_may_be_function_pointer(Symbol_table* , Layout* ,
Target_aarch64<size, big_endian>* ,
Sized_relobj_file<size, big_endian>* ,
unsigned int ,
Output_section* ,
const elfcpp::Rela<size, big_endian>& ,
unsigned int r_type,
Symbol* gsym);
private:
static void
unsupported_reloc_local(Sized_relobj_file<size, big_endian>*,
unsigned int r_type);
static void
unsupported_reloc_global(Sized_relobj_file<size, big_endian>*,
unsigned int r_type, Symbol*);
inline bool
possible_function_pointer_reloc(unsigned int r_type);
void
check_non_pic(Relobj*, unsigned int r_type);
// 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()
{ }
// Do a relocation. Return false if the caller should not issue
// any warnings about this relocation.
inline bool
relocate(const Relocate_info<size, big_endian>*, Target_aarch64*,
Output_section*,
size_t relnum, const elfcpp::Rela<size, big_endian>&,
unsigned int r_type, const Sized_symbol<size>*,
const Symbol_value<size>*,
unsigned char*, typename elfcpp::Elf_types<size>::Elf_Addr,
section_size_type);
private:
inline typename AArch64_relocate_functions<size,big_endian>::Status
relocate_tls(const Relocate_info<size,big_endian>*,
Target_aarch64<size, big_endian>*,
size_t,
const elfcpp::Rela<size, big_endian>&,
unsigned int r_type, const Sized_symbol<size>*,
const Symbol_value<size>*,
unsigned char*,
typename elfcpp::Elf_types<size>::Elf_Addr);
}; // End of class Relocate
// 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*);
};
// Adjust TLS relocation type based on the options and whether this
// is a local symbol.
static tls::Tls_optimization
optimize_tls_reloc(bool is_final, int r_type);
// Get the GOT section, creating it if necessary.
Output_data_got_aarch64<size, 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 the PLT section.
void
make_plt_section(Symbol_table* symtab, Layout* layout);
// Create a PLT entry for a global symbol.
void
make_plt_entry(Symbol_table*, Layout*, Symbol*);
// Get the PLT section.
Output_data_plt_aarch64<size, big_endian>*
plt_section() const
{
gold_assert(this->plt_ != NULL);
return this->plt_;
}
// Get the dynamic reloc section, creating it if necessary.
Reloc_section*
rela_dyn_section(Layout*);
// Add a potential copy relocation.
void
copy_reloc(Symbol_table* symtab, Layout* layout,
Sized_relobj_file<size, big_endian>* object,
unsigned int shndx, Output_section* output_section,
Symbol* sym, const elfcpp::Rela<size, big_endian>& reloc)
{
this->copy_relocs_.copy_reloc(symtab, layout,
symtab->get_sized_symbol<size>(sym),
object, shndx, output_section,
reloc, this->rela_dyn_section(layout));
}
// Information about this specific target which we pass to the
// general Target structure.
static const Target::Target_info aarch64_info;
// The types of GOT entries needed for this platform.
// These values are exposed to the ABI in an incremental link.
// Do not renumber existing values without changing the version
// number of the .gnu_incremental_inputs section.
enum Got_type
{
GOT_TYPE_STANDARD = 0, // GOT entry for a regular symbol
GOT_TYPE_TLS_OFFSET = 1, // GOT entry for TLS offset
GOT_TYPE_TLS_PAIR = 2, // GOT entry for TLS module/offset pair
GOT_TYPE_TLS_DESC = 3 // GOT entry for TLS_DESC pair
};
// The GOT section.
Output_data_got_aarch64<size, big_endian>* got_;
// The PLT section.
Output_data_plt_aarch64<size, big_endian>* plt_;
// The GOT PLT section.
Output_data_space* got_plt_;
// The _GLOBAL_OFFSET_TABLE_ symbol.
Symbol* global_offset_table_;
// The dynamic reloc section.
Reloc_section* rela_dyn_;
// Relocs saved to avoid a COPY reloc.
Copy_relocs<elfcpp::SHT_RELA, size, big_endian> copy_relocs_;
}; // End of Target_aarch64
template<>
const Target::Target_info Target_aarch64<64, false>::aarch64_info =
{
64, // size
false, // is_big_endian
elfcpp::EM_AARCH64, // machine_code
false, // has_make_symbol
false, // has_resolve
false, // has_code_fill
true, // is_default_stack_executable
false, // can_icf_inline_merge_sections
'\0', // wrap_char
"/lib/ld.so.1", // program interpreter
0x400000, // default_text_segment_address
0x1000, // abi_pagesize (overridable by -z max-page-size)
0x1000, // common_pagesize (overridable by -z common-page-size)
false, // isolate_execinstr
0, // rosegment_gap
elfcpp::SHN_UNDEF, // small_common_shndx
elfcpp::SHN_UNDEF, // large_common_shndx
0, // small_common_section_flags
0, // large_common_section_flags
NULL, // attributes_section
NULL, // attributes_vendor
"_start" // entry_symbol_name
};
template<>
const Target::Target_info Target_aarch64<32, false>::aarch64_info =
{
32, // size
false, // is_big_endian
elfcpp::EM_AARCH64, // machine_code
false, // has_make_symbol
false, // has_resolve
false, // has_code_fill
true, // is_default_stack_executable
false, // can_icf_inline_merge_sections
'\0', // wrap_char
"/lib/ld.so.1", // program interpreter
0x400000, // default_text_segment_address
0x1000, // abi_pagesize (overridable by -z max-page-size)
0x1000, // common_pagesize (overridable by -z common-page-size)
false, // isolate_execinstr
0, // rosegment_gap
elfcpp::SHN_UNDEF, // small_common_shndx
elfcpp::SHN_UNDEF, // large_common_shndx
0, // small_common_section_flags
0, // large_common_section_flags
NULL, // attributes_section
NULL, // attributes_vendor
"_start" // entry_symbol_name
};
template<>
const Target::Target_info Target_aarch64<64, true>::aarch64_info =
{
64, // size
true, // is_big_endian
elfcpp::EM_AARCH64, // machine_code
false, // has_make_symbol
false, // has_resolve
false, // has_code_fill
true, // is_default_stack_executable
false, // can_icf_inline_merge_sections
'\0', // wrap_char
"/lib/ld.so.1", // program interpreter
0x400000, // default_text_segment_address
0x1000, // abi_pagesize (overridable by -z max-page-size)
0x1000, // common_pagesize (overridable by -z common-page-size)
false, // isolate_execinstr
0, // rosegment_gap
elfcpp::SHN_UNDEF, // small_common_shndx
elfcpp::SHN_UNDEF, // large_common_shndx
0, // small_common_section_flags
0, // large_common_section_flags
NULL, // attributes_section
NULL, // attributes_vendor
"_start" // entry_symbol_name
};
template<>
const Target::Target_info Target_aarch64<32, true>::aarch64_info =
{
32, // size
true, // is_big_endian
elfcpp::EM_AARCH64, // machine_code
false, // has_make_symbol
false, // has_resolve
false, // has_code_fill
true, // is_default_stack_executable
false, // can_icf_inline_merge_sections
'\0', // wrap_char
"/lib/ld.so.1", // program interpreter
0x400000, // default_text_segment_address
0x1000, // abi_pagesize (overridable by -z max-page-size)
0x1000, // common_pagesize (overridable by -z common-page-size)
false, // isolate_execinstr
0, // rosegment_gap
elfcpp::SHN_UNDEF, // small_common_shndx
elfcpp::SHN_UNDEF, // large_common_shndx
0, // small_common_section_flags
0, // large_common_section_flags
NULL, // attributes_section
NULL, // attributes_vendor
"_start" // entry_symbol_name
};
// Get the GOT section, creating it if necessary.
template<int size, bool big_endian>
Output_data_got_aarch64<size, big_endian>*
Target_aarch64<size, big_endian>::got_section(Symbol_table* symtab,
Layout* layout)
{
if (this->got_ == NULL)
{
gold_assert(symtab != NULL && layout != NULL);
// When using -z now, we can treat .got.plt as a relro section.
// Without -z now, it is modified after program startup by lazy
// PLT relocations.
bool is_got_plt_relro = parameters->options().now();
Output_section_order got_order = (is_got_plt_relro
? ORDER_RELRO
: ORDER_RELRO_LAST);
Output_section_order got_plt_order = (is_got_plt_relro
? ORDER_RELRO
: ORDER_NON_RELRO_FIRST);
// Layout of .got and .got.plt sections.
// .got[0] &_DYNAMIC <-_GLOBAL_OFFSET_TABLE_
// ...
// .gotplt[0] reserved for ld.so (&linkmap) <--DT_PLTGOT
// .gotplt[1] reserved for ld.so (resolver)
// .gotplt[2] reserved
// Generate .got section.
this->got_ = new Output_data_got_aarch64<size, big_endian>(symtab,
layout);
layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
(elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
this->got_, got_order, true);
// The first word of GOT is reserved for the address of .dynamic.
// We put 0 here now. The value will be replaced later in
// Output_data_got_aarch64::do_write.
this->got_->add_constant(0);
// Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
// _GLOBAL_OFFSET_TABLE_ value points to the start of the .got section,
// even if there is a .got.plt section.
this->global_offset_table_ =
symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
Symbol_table::PREDEFINED,
this->got_,
0, 0, elfcpp::STT_OBJECT,
elfcpp::STB_LOCAL,
elfcpp::STV_HIDDEN, 0,
false, false);
// Generate .got.plt section.
this->got_plt_ = new Output_data_space(size / 8, "** GOT PLT");
layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
(elfcpp::SHF_ALLOC
| elfcpp::SHF_WRITE),
this->got_plt_, got_plt_order,
is_got_plt_relro);
// The first three entries are reserved.
this->got_plt_->set_current_data_size(
AARCH64_GOTPLT_RESERVE_COUNT * (size / 8));
if (!is_got_plt_relro)
{
// Those bytes can go into the relro segment.
layout->increase_relro(
AARCH64_GOTPLT_RESERVE_COUNT * (size / 8));
}
}
return this->got_;
}
// Get the dynamic reloc section, creating it if necessary.
template<int size, bool big_endian>
typename Target_aarch64<size, big_endian>::Reloc_section*
Target_aarch64<size, big_endian>::rela_dyn_section(Layout* layout)
{
if (this->rela_dyn_ == NULL)
{
gold_assert(layout != NULL);
this->rela_dyn_ = new Reloc_section(parameters->options().combreloc());
layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA,
elfcpp::SHF_ALLOC, this->rela_dyn_,
ORDER_DYNAMIC_RELOCS, false);
}
return this->rela_dyn_;
}
// A class to handle the PLT data.
// This is an abstract base class that handles most of the linker details
// but does not know the actual contents of PLT entries. The derived
// classes below fill in those details.
template<int size, bool big_endian>
class Output_data_plt_aarch64 : public Output_section_data
{
public:
typedef Output_data_reloc<elfcpp::SHT_RELA, true, size, big_endian>
Reloc_section;
typedef typename elfcpp::Elf_types<size>::Elf_Addr Address;
Output_data_plt_aarch64(Layout* layout,
uint64_t addralign,
Output_data_space* got_plt)
: Output_section_data(addralign),
got_plt_(got_plt),
count_(0)
{ this->init(layout); }
// Initialize the PLT section.
void
init(Layout* layout);
// Add an entry to the PLT.
void
add_entry(Symbol* gsym);
// Return the .rela.plt section data.
Reloc_section*
rela_plt()
{ return this->rel_; }
// Return whether we created a section for IRELATIVE relocations.
bool
has_irelative_section() const
{ return this->irelative_rel_ != NULL; }
// Return the number of PLT entries.
unsigned int
entry_count() const
{ return this->count_; }
// Return the offset of the first non-reserved PLT entry.
unsigned int
first_plt_entry_offset()
{ return this->do_first_plt_entry_offset(); }
// Return the size of a PLT entry.
unsigned int
get_plt_entry_size() const
{ return this->do_get_plt_entry_size(); }
// Return the PLT address to use for a global symbol.
uint64_t
address_for_global(const Symbol*);
// Return the PLT address to use for a local symbol.
uint64_t
address_for_local(const Relobj*, unsigned int symndx);
protected:
// Fill in the first PLT entry.
void
fill_first_plt_entry(unsigned char* pov,
Address got_address,
Address plt_address)
{ this->do_fill_first_plt_entry(pov, got_address, plt_address); }
// Fill in a normal PLT entry.
void
fill_plt_entry(unsigned char* pov,
Address got_address,
Address plt_address,
unsigned int got_offset,
unsigned int plt_offset)
{
this->do_fill_plt_entry(pov, got_address, plt_address,
got_offset, plt_offset);
}
virtual unsigned int
do_first_plt_entry_offset() const = 0;
virtual unsigned int
do_get_plt_entry_size() const = 0;
virtual void
do_fill_first_plt_entry(unsigned char* pov,
Address got_addr,
Address plt_addr) = 0;
virtual void
do_fill_plt_entry(unsigned char* pov,
Address got_address,
Address plt_address,
unsigned int got_offset,
unsigned int plt_offset) = 0;
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:
// Set the final size.
void
set_final_data_size();
// Write out the PLT data.
void
do_write(Output_file*);
// The reloc section.
Reloc_section* rel_;
// The IRELATIVE relocs, if necessary. These must follow the
// regular PLT relocations.
Reloc_section* irelative_rel_;
// The .got section.
Output_data_got_aarch64<size, big_endian>* got_;
// The .got.plt section.
Output_data_space* got_plt_;
// The number of PLT entries.
unsigned int count_;
};
// Initialize the PLT section.
template<int size, bool big_endian>
void
Output_data_plt_aarch64<size, big_endian>::init(Layout* layout)
{
this->rel_ = new Reloc_section(false);
layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
elfcpp::SHF_ALLOC, this->rel_,
ORDER_DYNAMIC_PLT_RELOCS, false);
}
template<int size, bool big_endian>
void
Output_data_plt_aarch64<size, big_endian>::do_adjust_output_section(
Output_section* os)
{
os->set_entsize(this->get_plt_entry_size());
}
// Add an entry to the PLT.
template<int size, bool big_endian>
void
Output_data_plt_aarch64<size, big_endian>::add_entry(Symbol* gsym)
{
gold_assert(!gsym->has_plt_offset());
gsym->set_plt_offset((this->count_) * this->get_plt_entry_size()
+ this->first_plt_entry_offset());
++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 + size / 8);
// Every PLT entry needs a reloc.
gsym->set_needs_dynsym_entry();
this->rel_->add_global(gsym, elfcpp::R_AARCH64_JUMP_SLOT,
this->got_plt_, got_offset, 0);
// 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.
}
// Return the PLT address to use for a global symbol.
template<int size, bool big_endian>
uint64_t
Output_data_plt_aarch64<size, big_endian>::address_for_global(
const Symbol* gsym)
{
uint64_t offset = 0;
if (gsym->type() == elfcpp::STT_GNU_IFUNC
&& gsym->can_use_relative_reloc(false))
offset = (this->first_plt_entry_offset() +
this->count_ * this->get_plt_entry_size());
return this->address() + offset + gsym->plt_offset();
}
// Return the PLT address to use for a local symbol. These are always
// IRELATIVE relocs.
template<int size, bool big_endian>
uint64_t
Output_data_plt_aarch64<size, big_endian>::address_for_local(
const Relobj* object,
unsigned int r_sym)
{
return (this->address()
+ this->first_plt_entry_offset()
+ this->count_ * this->get_plt_entry_size()
+ object->local_plt_offset(r_sym));
}
// Set the final size.
template<int size, bool big_endian>
void
Output_data_plt_aarch64<size, big_endian>::set_final_data_size()
{
this->set_data_size(this->first_plt_entry_offset()
+ this->count_ * this->get_plt_entry_size());
}
template<int size, bool big_endian>
class Output_data_plt_aarch64_standard :
public Output_data_plt_aarch64<size, big_endian>
{
public:
typedef typename elfcpp::Elf_types<size>::Elf_Addr Address;
Output_data_plt_aarch64_standard(Layout* layout, Output_data_space* got_plt)
: Output_data_plt_aarch64<size, big_endian>(layout,
size == 32 ? 4 : 8,
got_plt)
{ }
protected:
// Return the offset of the first non-reserved PLT entry.
virtual unsigned int
do_first_plt_entry_offset() const
{ return this->first_plt_entry_size; }
// Return the size of a PLT entry
virtual unsigned int
do_get_plt_entry_size() const
{ return this->plt_entry_size; }
virtual void
do_fill_first_plt_entry(unsigned char* pov,
Address got_address,
Address plt_address);
virtual void
do_fill_plt_entry(unsigned char* pov,
Address got_address,
Address plt_address,
unsigned int got_offset,
unsigned int plt_offset);
private:
// The size of the first plt entry size.
static const int first_plt_entry_size = 32;
// The size of the plt entry size.
static const int plt_entry_size = 16;
// Template for the first PLT entry.
static const uint32_t first_plt_entry[first_plt_entry_size / 4];
// Template for subsequent PLT entries.
static const uint32_t plt_entry[plt_entry_size / 4];
};
// The first entry in the PLT for an executable.
template<>
const uint32_t
Output_data_plt_aarch64_standard<32, false>::
first_plt_entry[first_plt_entry_size / 4] =
{
0xa9bf7bf0, /* stp x16, x30, [sp, #-16]! */
0x90000010, /* adrp x16, PLT_GOT+0x8 */
0xb9400A11, /* ldr w17, [x16, #PLT_GOT+0x8] */
0x11002210, /* add w16, w16,#PLT_GOT+0x8 */
0xd61f0220, /* br x17 */
0xd503201f, /* nop */
0xd503201f, /* nop */
0xd503201f, /* nop */
};
template<>
const uint32_t
Output_data_plt_aarch64_standard<32, true>::
first_plt_entry[first_plt_entry_size / 4] =
{
0xa9bf7bf0, /* stp x16, x30, [sp, #-16]! */
0x90000010, /* adrp x16, PLT_GOT+0x8 */
0xb9400A11, /* ldr w17, [x16, #PLT_GOT+0x8] */
0x11002210, /* add w16, w16,#PLT_GOT+0x8 */
0xd61f0220, /* br x17 */
0xd503201f, /* nop */
0xd503201f, /* nop */
0xd503201f, /* nop */
};
template<>
const uint32_t
Output_data_plt_aarch64_standard<64, false>::
first_plt_entry[first_plt_entry_size / 4] =
{
0xa9bf7bf0, /* stp x16, x30, [sp, #-16]! */
0x90000010, /* adrp x16, PLT_GOT+16 */
0xf9400A11, /* ldr x17, [x16, #PLT_GOT+0x10] */
0x91004210, /* add x16, x16,#PLT_GOT+0x10 */
0xd61f0220, /* br x17 */
0xd503201f, /* nop */
0xd503201f, /* nop */
0xd503201f, /* nop */
};
template<>
const uint32_t
Output_data_plt_aarch64_standard<64, true>::
first_plt_entry[first_plt_entry_size / 4] =
{
0xa9bf7bf0, /* stp x16, x30, [sp, #-16]! */
0x90000010, /* adrp x16, PLT_GOT+16 */
0xf9400A11, /* ldr x17, [x16, #PLT_GOT+0x10] */
0x91004210, /* add x16, x16,#PLT_GOT+0x10 */
0xd61f0220, /* br x17 */
0xd503201f, /* nop */
0xd503201f, /* nop */
0xd503201f, /* nop */
};
template<>
const uint32_t
Output_data_plt_aarch64_standard<32, false>::
plt_entry[plt_entry_size / 4] =
{
0x90000010, /* adrp x16, PLTGOT + n * 4 */
0xb9400211, /* ldr w17, [w16, PLTGOT + n * 4] */
0x11000210, /* add w16, w16, :lo12:PLTGOT + n * 4 */
0xd61f0220, /* br x17. */
};
template<>
const uint32_t
Output_data_plt_aarch64_standard<32, true>::
plt_entry[plt_entry_size / 4] =
{
0x90000010, /* adrp x16, PLTGOT + n * 4 */
0xb9400211, /* ldr w17, [w16, PLTGOT + n * 4] */
0x11000210, /* add w16, w16, :lo12:PLTGOT + n * 4 */
0xd61f0220, /* br x17. */
};
template<>
const uint32_t
Output_data_plt_aarch64_standard<64, false>::
plt_entry[plt_entry_size / 4] =
{
0x90000010, /* adrp x16, PLTGOT + n * 8 */
0xf9400211, /* ldr x17, [x16, PLTGOT + n * 8] */
0x91000210, /* add x16, x16, :lo12:PLTGOT + n * 8 */
0xd61f0220, /* br x17. */
};
template<>
const uint32_t
Output_data_plt_aarch64_standard<64, true>::
plt_entry[plt_entry_size / 4] =
{
0x90000010, /* adrp x16, PLTGOT + n * 8 */
0xf9400211, /* ldr x17, [x16, PLTGOT + n * 8] */
0x91000210, /* add x16, x16, :lo12:PLTGOT + n * 8 */
0xd61f0220, /* br x17. */
};
template<int size, bool big_endian>
void
Output_data_plt_aarch64_standard<size, big_endian>::do_fill_first_plt_entry(
unsigned char* pov,
Address got_address,
Address plt_address)
{
// PLT0 of the small PLT looks like this in ELF64 -
// stp x16, x30, [sp, #-16]! Save the reloc and lr on stack.
// adrp x16, PLT_GOT + 16 Get the page base of the GOTPLT
// ldr x17, [x16, #:lo12:PLT_GOT+16] Load the address of the
// symbol resolver
// add x16, x16, #:lo12:PLT_GOT+16 Load the lo12 bits of the
// GOTPLT entry for this.
// br x17
// PLT0 will be slightly different in ELF32 due to different got entry
// size.
memcpy(pov, this->first_plt_entry, this->first_plt_entry_size);
Address gotplt_2nd_ent = got_address + (size / 8) * 2;
// Fill in the top 21 bits for this: ADRP x16, PLT_GOT + 8 * 2.
// ADRP: (PG(S+A)-PG(P)) >> 12) & 0x1fffff.
// FIXME: This only works for 64bit
AArch64_relocate_functions<size, big_endian>::adrp(pov + 4,
gotplt_2nd_ent, plt_address + 4);
// Fill in R_AARCH64_LDST8_LO12
elfcpp::Swap<32, big_endian>::writeval(
pov + 8,
((this->first_plt_entry[2] & 0xffc003ff)
| ((gotplt_2nd_ent & 0xff8) << 7)));
// Fill in R_AARCH64_ADD_ABS_LO12
elfcpp::Swap<32, big_endian>::writeval(
pov + 12,
((this->first_plt_entry[3] & 0xffc003ff)
| ((gotplt_2nd_ent & 0xfff) << 10)));
}
// Subsequent entries in the PLT for an executable.
// FIXME: This only works for 64bit
template<int size, bool big_endian>
void
Output_data_plt_aarch64_standard<size, big_endian>::do_fill_plt_entry(
unsigned char* pov,
Address got_address,
Address plt_address,
unsigned int got_offset,
unsigned int plt_offset)
{
memcpy(pov, this->plt_entry, this->plt_entry_size);
Address gotplt_entry_address = got_address + got_offset;
Address plt_entry_address = plt_address + plt_offset;
// Fill in R_AARCH64_PCREL_ADR_HI21
AArch64_relocate_functions<size, big_endian>::adrp(
pov,
gotplt_entry_address,
plt_entry_address);
// Fill in R_AARCH64_LDST64_ABS_LO12
elfcpp::Swap<32, big_endian>::writeval(
pov + 4,
((this->plt_entry[1] & 0xffc003ff)
| ((gotplt_entry_address & 0xff8) << 7)));
// Fill in R_AARCH64_ADD_ABS_LO12
elfcpp::Swap<32, big_endian>::writeval(
pov + 8,
((this->plt_entry[2] & 0xffc003ff)
| ((gotplt_entry_address & 0xfff) <<10)));
}
// Write out the PLT. This uses the hand-coded instructions above,
// and adjusts them as needed. This is specified by the AMD64 ABI.
template<int size, bool big_endian>
void
Output_data_plt_aarch64<size, 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;
// The base address of the .plt section.
typename elfcpp::Elf_types<size>::Elf_Addr plt_address = this->address();
// The base address of the PLT portion of the .got section.
typename elfcpp::Elf_types<size>::Elf_Addr got_address
= this->got_plt_->address();
this->fill_first_plt_entry(pov, got_address, plt_address);
pov += this->first_plt_entry_offset();
// The first three entries in .got.plt are reserved.
unsigned char* got_pov = got_view;
memset(got_pov, 0, size / 8 * AARCH64_GOTPLT_RESERVE_COUNT);
got_pov += (size / 8) * AARCH64_GOTPLT_RESERVE_COUNT;
unsigned int plt_offset = this->first_plt_entry_offset();
unsigned int got_offset = (size / 8) * AARCH64_GOTPLT_RESERVE_COUNT;
const unsigned int count = this->count_;
for (unsigned int plt_index = 0;
plt_index < count;
++plt_index,
pov += this->get_plt_entry_size(),
got_pov += size / 8,
plt_offset += this->get_plt_entry_size(),
got_offset += size / 8)
{
// Set and adjust the PLT entry itself.
this->fill_plt_entry(pov, got_address, plt_address,
got_offset, plt_offset);
// Set the entry in the GOT, which points to plt0.
elfcpp::Swap<size, 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);
}
// Telling how to update the immediate field of an instruction.
struct AArch64_howto
{
// The immediate field mask.
elfcpp::Elf_Xword dst_mask;
// The offset to apply relocation immediate
int doffset;
// The second part offset, if the immediate field has two parts.
// -1 if the immediate field has only one part.
int doffset2;
};
static const AArch64_howto aarch64_howto[AArch64_reloc_property::INST_NUM] =
{
{0, -1, -1}, // DATA
{0x1fffe0, 5, -1}, // MOVW [20:5]-imm16
{0xffffe0, 5, -1}, // LD [23:5]-imm19
{0x60ffffe0, 29, 5}, // ADR [30:29]-immlo [23:5]-immhi
{0x60ffffe0, 29, 5}, // ADRP [30:29]-immlo [23:5]-immhi
{0x3ffc00, 10, -1}, // ADD [21:10]-imm12
{0x3ffc00, 10, -1}, // LDST [21:10]-imm12
{0x7ffe0, 5, -1}, // TBZNZ [18:5]-imm14
{0xffffe0, 5, -1}, // CONDB [23:5]-imm19
{0x3ffffff, 0, -1}, // B [25:0]-imm26
{0x3ffffff, 0, -1}, // CALL [25:0]-imm26
};
// AArch64 relocate function class
template<int size, bool big_endian>
class AArch64_relocate_functions
{
public:
typedef enum
{
STATUS_OKAY, // No error during relocation.
STATUS_OVERFLOW, // Relocation overflow.
STATUS_BAD_RELOC, // Relocation cannot be applied.
} Status;
private:
typedef AArch64_relocate_functions<size, big_endian> This;
typedef typename elfcpp::Elf_types<size>::Elf_Addr Address;
// Return the page address of the address.
// Page(address) = address & ~0xFFF
static inline typename elfcpp::Swap<size, big_endian>::Valtype
Page(Address address)
{
return (address & (~static_cast<Address>(0xFFF)));
}
// Update instruction (pointed by view) with selected bits (immed).
// val = (val & ~dst_mask) | (immed << doffset)
template<int valsize>
static inline void
update_view(unsigned char* view,
typename elfcpp::Swap<size, big_endian>::Valtype immed,
elfcpp::Elf_Xword doffset,
elfcpp::Elf_Xword dst_mask)
{
typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype;
Valtype* wv = reinterpret_cast<Valtype*>(view);
Valtype val = elfcpp::Swap<valsize, big_endian>::readval(wv);
// Clear immediate fields.
val &= ~dst_mask;
elfcpp::Swap<valsize, big_endian>::writeval(wv,
static_cast<Valtype>(val | (immed << doffset)));
}
// Update two parts of an instruction (pointed by view) with selected
// bits (immed1 and immed2).
// val = (val & ~dst_mask) | (immed1 << doffset1) | (immed2 << doffset2)
template<int valsize>
static inline void
update_view_two_parts(
unsigned char* view,
typename elfcpp::Swap<size, big_endian>::Valtype immed1,
typename elfcpp::Swap<size, big_endian>::Valtype immed2,
elfcpp::Elf_Xword doffset1,
elfcpp::Elf_Xword doffset2,
elfcpp::Elf_Xword dst_mask)
{
typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype;
Valtype* wv = reinterpret_cast<Valtype*>(view);
Valtype val = elfcpp::Swap<valsize, big_endian>::readval(wv);
val &= ~dst_mask;
elfcpp::Swap<valsize, big_endian>::writeval(wv,
static_cast<Valtype>(val | (immed1 << doffset1) |
(immed2 << doffset2)));
}
// Update adr or adrp instruction with [32:12] of X.
// In adr and adrp: [30:29] immlo [23:5] immhi
static inline void
update_adr(unsigned char* view,
typename elfcpp::Swap<size, big_endian>::Valtype x,
const AArch64_reloc_property* /* reloc_property */)
{
elfcpp::Elf_Xword dst_mask = (0x3 << 29) | (0x7ffff << 5);
typename elfcpp::Swap<32, big_endian>::Valtype immed =
(x >> 12) & 0x1fffff;
This::template update_view_two_parts<32>(
view,
immed & 0x3,
(immed & 0x1ffffc) >> 2,
29,
5,
dst_mask);
}
public:
// Do a simple rela relocation at unaligned addresses.
template<int valsize>
static inline typename This::Status
rela_ua(unsigned char* view,
const Sized_relobj_file<size, big_endian>* object,
const Symbol_value<size>* psymval,
typename elfcpp::Swap<size, big_endian>::Valtype addend,
const AArch64_reloc_property* reloc_property)
{
typedef typename elfcpp::Swap_unaligned<valsize, big_endian>::Valtype
Valtype;
typename elfcpp::Elf_types<size>::Elf_Addr x =
psymval->value(object, addend);
elfcpp::Swap_unaligned<valsize, big_endian>::writeval(view,
static_cast<Valtype>(x));
return (reloc_property->checkup_x_value(x)
? This::STATUS_OKAY
: This::STATUS_OVERFLOW);
}
// Do a simple pc-relative relocation at unaligned addresses.
template<int valsize>
static inline typename This::Status
pcrela_ua(unsigned char* view,
const Sized_relobj_file<size, big_endian>* object,
const Symbol_value<size>* psymval,
typename elfcpp::Swap<size, big_endian>::Valtype addend,
Address address,
const AArch64_reloc_property* reloc_property)
{
typedef typename elfcpp::Swap_unaligned<valsize, big_endian>::Valtype
Valtype;
Address x = psymval->value(object, addend) - address;
elfcpp::Swap_unaligned<valsize, big_endian>::writeval(view,
static_cast<Valtype>(x));
return (reloc_property->checkup_x_value(x)
? This::STATUS_OKAY
: This::STATUS_OVERFLOW);
}
// Do a simple rela relocation at aligned addresses.
template<int valsize>
static inline typename This::Status
rela(
unsigned char* view,
const Sized_relobj_file<size, big_endian>* object,
const Symbol_value<size>* psymval,
typename elfcpp::Swap<size, big_endian>::Valtype addend,
const AArch64_reloc_property* reloc_property)
{
typedef typename elfcpp::Swap<valsize, big_endian>::Valtype
Valtype;
Valtype* wv = reinterpret_cast<Valtype*>(view);
Address x = psymval->value(object, addend);
elfcpp::Swap<valsize, big_endian>::writeval(wv,
static_cast<Valtype>(x));
return (reloc_property->checkup_x_value(x)
? This::STATUS_OKAY
: This::STATUS_OVERFLOW);
}
// Do relocate. Update selected bits in text.
// new_val = (val & ~dst_mask) | (immed << doffset)
template<int valsize>
static inline typename This::Status
rela_general(unsigned char* view,
const Sized_relobj_file<size, big_endian>* object,
const Symbol_value<size>* psymval,
typename elfcpp::Swap<size, big_endian>::Valtype addend,
const AArch64_reloc_property* reloc_property)
{
// Calculate relocation.
Address x = psymval->value(object, addend);
// Select bits from X.
Address immed = reloc_property->select_x_value(x);
// Update view.
const AArch64_reloc_property::Reloc_inst inst =
reloc_property->reloc_inst();
// If it is a data relocation or instruction has 2 parts of immediate
// fields, you should not call rela_general.
gold_assert(aarch64_howto[inst].doffset2 == -1 &&
aarch64_howto[inst].doffset != -1);
This::template update_view<valsize>(view, immed,
aarch64_howto[inst].doffset,
aarch64_howto[inst].dst_mask);
// Do check overflow or alignment if needed.
return (reloc_property->checkup_x_value(x)
? This::STATUS_OKAY
: This::STATUS_OVERFLOW);
}
// Do relocate. Update selected bits in text.
// new val = (val & ~dst_mask) | (immed << doffset)
template<int valsize>
static inline typename This::Status
rela_general(
unsigned char* view,
typename elfcpp::Swap<size, big_endian>::Valtype s,
typename elfcpp::Swap<size, big_endian>::Valtype addend,
const AArch64_reloc_property* reloc_property)
{
// Calculate relocation.
Address x = s + addend;
// Select bits from X.
Address immed = reloc_property->select_x_value(x);
// Update view.
const AArch64_reloc_property::Reloc_inst inst =
reloc_property->reloc_inst();
// If it is a data relocation or instruction has 2 parts of immediate
// fields, you should not call rela_general.
gold_assert(aarch64_howto[inst].doffset2 == -1 &&
aarch64_howto[inst].doffset != -1);
This::template update_view<valsize>(view, immed,
aarch64_howto[inst].doffset,
aarch64_howto[inst].dst_mask);
// Do check overflow or alignment if needed.
return (reloc_property->checkup_x_value(x)
? This::STATUS_OKAY
: This::STATUS_OVERFLOW);
}
// Do address relative relocate. Update selected bits in text.
// new val = (val & ~dst_mask) | (immed << doffset)
template<int valsize>
static inline typename This::Status
pcrela_general(
unsigned char* view,
const Sized_relobj_file<size, big_endian>* object,
const Symbol_value<size>* psymval,
typename elfcpp::Swap<size, big_endian>::Valtype addend,
Address address,
const AArch64_reloc_property* reloc_property)
{
// Calculate relocation.
Address x = psymval->value(object, addend) - address;
// Select bits from X.
Address immed = reloc_property->select_x_value(x);
// Update view.
const AArch64_reloc_property::Reloc_inst inst =
reloc_property->reloc_inst();
// If it is a data relocation or instruction has 2 parts of immediate
// fields, you should not call pcrela_general.
gold_assert(aarch64_howto[inst].doffset2 == -1 &&
aarch64_howto[inst].doffset != -1);
This::template update_view<valsize>(view, immed,
aarch64_howto[inst].doffset,
aarch64_howto[inst].dst_mask);
// Do check overflow or alignment if needed.
return (reloc_property->checkup_x_value(x)
? This::STATUS_OKAY
: This::STATUS_OVERFLOW);
}
// Calculate PG(S+A) - PG(address), update adrp instruction.
// R_AARCH64_ADR_PREL_PG_HI21
static inline typename This::Status
adrp(
unsigned char* view,
Address sa,
Address address)
{
typename elfcpp::Swap<size, big_endian>::Valtype x =
This::Page(sa) - This::Page(address);
update_adr(view, x, NULL);
return (size == 64 && Bits<32>::has_overflow(x)
? This::STATUS_OVERFLOW
: This::STATUS_OKAY);
}
// Calculate PG(S+A) - PG(address), update adrp instruction.
// R_AARCH64_ADR_PREL_PG_HI21
static inline typename This::Status
adrp(unsigned char* view,
const Sized_relobj_file<size, big_endian>* object,
const Symbol_value<size>* psymval,
Address addend,
Address address,
const AArch64_reloc_property* reloc_property)
{
Address sa = psymval->value(object, addend);
typename elfcpp::Swap<size, big_endian>::Valtype x =
This::Page(sa) - This::Page(address);
update_adr(view, x, reloc_property);
return (reloc_property->checkup_x_value(x)
? This::STATUS_OKAY
: This::STATUS_OVERFLOW);
}
};
// Return the number of entries in the PLT.
template<int size, bool big_endian>
unsigned int
Target_aarch64<size, big_endian>::plt_entry_count() const
{
if (this->plt_ == NULL)
return 0;
return this->plt_->entry_count();
}
// Return the offset of the first non-reserved PLT entry.
template<int size, bool big_endian>
unsigned int
Target_aarch64<size, big_endian>::first_plt_entry_offset() const
{
return this->plt_->first_plt_entry_offset();
}
// Return the size of each PLT entry.
template<int size, bool big_endian>
unsigned int
Target_aarch64<size, big_endian>::plt_entry_size() const
{
return this->plt_->get_plt_entry_size();
}
// Optimize the TLS relocation type based on what we know about the
// symbol. IS_FINAL is true if the final address of this symbol is
// known at link time.
template<int size, bool big_endian>
tls::Tls_optimization
Target_aarch64<size, big_endian>::optimize_tls_reloc(bool /* is_final */,
int /* r_type */)
{
//TODO
return tls::TLSOPT_NONE;
}
// Returns true if this relocation type could be that of a function pointer.
template<int size, bool big_endian>
inline bool
Target_aarch64<size, big_endian>::Scan::possible_function_pointer_reloc(
unsigned int r_type)
{
switch (r_type)
{
case elfcpp::R_AARCH64_ABS64:
//TODO
{
return true;
}
}
return false;
}
// For safe ICF, scan a relocation for a local symbol to check if it
// corresponds to a function pointer being taken. In that case mark
// the function whose pointer was taken as not foldable.
template<int size, bool big_endian>
inline bool
Target_aarch64<size, big_endian>::Scan::local_reloc_may_be_function_pointer(
Symbol_table* ,
Layout* ,
Target_aarch64<size, big_endian>* ,
Sized_relobj_file<size, big_endian>* ,
unsigned int ,
Output_section* ,
const elfcpp::Rela<size, big_endian>& ,
unsigned int r_type,
const elfcpp::Sym<size, big_endian>&)
{
// When building a shared library, do not fold any local symbols as it is
// not possible to distinguish pointer taken versus a call by looking at
// the relocation types.
return (parameters->options().shared()
|| possible_function_pointer_reloc(r_type));
}
// For safe ICF, scan a relocation for a global symbol to check if it
// corresponds to a function pointer being taken. In that case mark
// the function whose pointer was taken as not foldable.
template<int size, bool big_endian>
inline bool
Target_aarch64<size, big_endian>::Scan::global_reloc_may_be_function_pointer(
Symbol_table* ,
Layout* ,
Target_aarch64<size, big_endian>* ,
Sized_relobj_file<size, big_endian>* ,
unsigned int ,
Output_section* ,
const elfcpp::Rela<size, big_endian>& ,
unsigned int r_type,
Symbol* gsym)
{
// When building a shared library, do not fold symbols whose visibility
// is hidden, internal or protected.
return ((parameters->options().shared()
&& (gsym->visibility() == elfcpp::STV_INTERNAL
|| gsym->visibility() == elfcpp::STV_PROTECTED
|| gsym->visibility() == elfcpp::STV_HIDDEN))
|| possible_function_pointer_reloc(r_type));
}
// Report an unsupported relocation against a local symbol.
template<int size, bool big_endian>
void
Target_aarch64<size, big_endian>::Scan::unsupported_reloc_local(
Sized_relobj_file<size, 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.
template<int size, bool big_endian>
void
Target_aarch64<size, big_endian>::Scan::check_non_pic(Relobj* object,
unsigned int r_type)
{
gold_assert(r_type != elfcpp::R_AARCH64_NONE);
switch (r_type)
{
// These are the relocation types supported by glibc for AARCH64.
case elfcpp::R_AARCH64_NONE:
case elfcpp::R_AARCH64_COPY:
case elfcpp::R_AARCH64_GLOB_DAT:
case elfcpp::R_AARCH64_JUMP_SLOT:
case elfcpp::R_AARCH64_RELATIVE:
case elfcpp::R_AARCH64_TLS_DTPREL64:
case elfcpp::R_AARCH64_TLS_DTPMOD64:
case elfcpp::R_AARCH64_TLS_TPREL64:
case elfcpp::R_AARCH64_TLSDESC:
case elfcpp::R_AARCH64_IRELATIVE:
case elfcpp::R_AARCH64_ABS32:
case elfcpp::R_AARCH64_ABS64:
return;
default:
break;
}
// 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;
gold_assert(parameters->options().output_is_position_independent());
object->error(_("requires unsupported dynamic reloc; "
"recompile with -fPIC"));
this->issued_non_pic_error_ = true;
return;
}
// Scan a relocation for a local symbol.
template<int size, bool big_endian>
inline void
Target_aarch64<size, big_endian>::Scan::local(
Symbol_table* symtab,
Layout* layout,
Target_aarch64<size, big_endian>* target,
Sized_relobj_file<size, big_endian>* object,
unsigned int data_shndx,
Output_section* output_section,
const elfcpp::Rela<size, big_endian>& rela,
unsigned int r_type,
const elfcpp::Sym<size, big_endian>& /* lsym */,
bool is_discarded)
{
if (is_discarded)
return;
typedef Output_data_reloc<elfcpp::SHT_RELA, true, size, big_endian>
Reloc_section;
switch (r_type)
{
case elfcpp::R_AARCH64_ABS32:
case elfcpp::R_AARCH64_ABS16:
if (parameters->options().output_is_position_independent())
{
gold_error(_("%s: unsupported reloc %u in pos independent link."),
object->name().c_str(), r_type);
}
break;
case elfcpp::R_AARCH64_ABS64:
// If building a shared library or pie, we need to mark this as a dynmic
// reloction, so that the dynamic loader can relocate it.
if (parameters->options().output_is_position_independent())
{
Reloc_section* rela_dyn = target->rela_dyn_section(layout);
unsigned int r_sym = elfcpp::elf_r_sym<64>(rela.get_r_info());
rela_dyn->add_local_relative(object, r_sym,
elfcpp::R_AARCH64_RELATIVE,
output_section,
data_shndx,
rela.get_r_offset(),
rela.get_r_addend(),
false /* is ifunc */);
}
break;
case elfcpp::R_AARCH64_PREL64:
case elfcpp::R_AARCH64_PREL32:
case elfcpp::R_AARCH64_PREL16:
break;
// Relocations to generate 19, 21 and 33-bit PC-relative address
case elfcpp::R_AARCH64_ADR_PREL_PG_HI21: // 275
case elfcpp::R_AARCH64_LDST8_ABS_LO12_NC: // 278
case elfcpp::R_AARCH64_LDST16_ABS_LO12_NC: // 284
case elfcpp::R_AARCH64_LDST32_ABS_LO12_NC: // 285
case elfcpp::R_AARCH64_LDST64_ABS_LO12_NC: // 286
case elfcpp::R_AARCH64_LDST128_ABS_LO12_NC: // 299
case elfcpp::R_AARCH64_ADD_ABS_LO12_NC: // 277
break;
// Control flow, pc-relative. We don't need to do anything for a relative
// addressing relocation against a local symbol if it does not reference
// the GOT.
case elfcpp::R_AARCH64_TSTBR14:
case elfcpp::R_AARCH64_CONDBR19:
case elfcpp::R_AARCH64_JUMP26:
case elfcpp::R_AARCH64_CALL26:
break;
case elfcpp::R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21:
case elfcpp::R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC:
{
layout->set_has_static_tls();
// Create a GOT entry for the tp-relative offset.
Output_data_got_aarch64<size, big_endian>* got =
target->got_section(symtab, layout);
unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
if (!parameters->doing_static_link())
{
got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET,
target->rela_dyn_section(layout),
elfcpp::R_AARCH64_TLS_TPREL64);
}
else if (!object->local_has_got_offset(r_sym,
GOT_TYPE_TLS_OFFSET))
{
got->add_local(object, r_sym, GOT_TYPE_TLS_OFFSET);
unsigned int got_offset =
object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET);
const elfcpp::Elf_Xword addend = rela.get_r_addend();
gold_assert(addend == 0);
got->add_static_reloc(got_offset, elfcpp::R_AARCH64_TLS_TPREL64,
object, r_sym);
}
}
break;
case elfcpp::R_AARCH64_TLSLE_ADD_TPREL_HI12:
case elfcpp::R_AARCH64_TLSLE_ADD_TPREL_LO12:
case elfcpp::R_AARCH64_TLSLE_ADD_TPREL_LO12_NC:
{
layout->set_has_static_tls();
bool output_is_shared = parameters->options().shared();
if (output_is_shared)
gold_error(_("%s: unsupported TLSLEreloc %u in shard code."),
object->name().c_str(), r_type);
}
break;
default:
unsupported_reloc_local(object, r_type);
}
}
// Report an unsupported relocation against a global symbol.
template<int size, bool big_endian>
void
Target_aarch64<size, big_endian>::Scan::unsupported_reloc_global(
Sized_relobj_file<size, 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());
}
template<int size, bool big_endian>
inline void
Target_aarch64<size, big_endian>::Scan::global(
Symbol_table* symtab,
Layout* layout,
Target_aarch64<size, big_endian>* target,
Sized_relobj_file<size, big_endian> * object,
unsigned int data_shndx,
Output_section* output_section,
const elfcpp::Rela<size, big_endian>& rela,
unsigned int r_type,
Symbol* gsym)
{
typedef Output_data_reloc<elfcpp::SHT_RELA, true, size, big_endian>
Reloc_section;
switch (r_type)
{
case elfcpp::R_AARCH64_ABS16:
case elfcpp::R_AARCH64_ABS32:
case elfcpp::R_AARCH64_ABS64:
{
// Make a PLT entry if necessary.
if (gsym->needs_plt_entry())
{
target->make_plt_entry(symtab, layout, gsym);
// Since this is not a PC-relative relocation, we may be
// taking the address of a function. In that case we need to
// set the entry in the dynamic symbol table to the address of
// the PLT entry.
if (gsym->is_from_dynobj() && !parameters->options().shared())
gsym->set_needs_dynsym_value();
}
// Make a dynamic relocation if necessary.
const AArch64_reloc_property* arp =
aarch64_reloc_property_table->get_reloc_property(r_type);
gold_assert(arp != NULL);
if (gsym->needs_dynamic_reloc(arp->reference_flags()))
{
if (!parameters->options().output_is_position_independent()
&& gsym->may_need_copy_reloc())
{
gold_error(
_("%s: unsupported reloc %u which may need copyreloc."),
object->name().c_str(), r_type);
}
else if (r_type == elfcpp::R_AARCH64_ABS64
&& gsym->can_use_relative_reloc(false))
{
Reloc_section* rela_dyn = target->rela_dyn_section(layout);
rela_dyn->add_global_relative(gsym,
elfcpp::R_AARCH64_RELATIVE,
output_section,
object,
data_shndx,
rela.get_r_offset(),
rela.get_r_addend(),
false);
}
else
{
check_non_pic(object, r_type);
Output_data_reloc<elfcpp::SHT_RELA, true, size, big_endian>*
rela_dyn = target->rela_dyn_section(layout);
rela_dyn->add_global(
gsym, r_type, output_section, object,
data_shndx, rela.get_r_offset(),rela.get_r_addend());
}
}
}
break;
case elfcpp::R_AARCH64_PREL16:
case elfcpp::R_AARCH64_PREL32:
case elfcpp::R_AARCH64_PREL64:
// This is used to fill the GOT absolute address.
if (gsym->needs_plt_entry())
{
target->make_plt_entry(symtab, layout, gsym);
}
break;
case elfcpp::R_AARCH64_ADR_PREL_PG_HI21:
case elfcpp::R_AARCH64_ADR_PREL_PG_HI21_NC:
case elfcpp::R_AARCH64_LDST8_ABS_LO12_NC: // 278
case elfcpp::R_AARCH64_LDST16_ABS_LO12_NC: // 284
case elfcpp::R_AARCH64_LDST32_ABS_LO12_NC: // 285
case elfcpp::R_AARCH64_LDST64_ABS_LO12_NC: // 286
case elfcpp::R_AARCH64_LDST128_ABS_LO12_NC: // 299
case elfcpp::R_AARCH64_ADD_ABS_LO12_NC:
{
// Do nothing here.
break;
}
case elfcpp::R_AARCH64_ADR_GOT_PAGE:
case elfcpp::R_AARCH64_LD64_GOT_LO12_NC:
{
// This pair of relocations is used to access a specific GOT entry.
// Note a GOT entry is an *address* to a symbol.
// The symbol requires a GOT entry
Output_data_got_aarch64<size, big_endian>* got =
target->got_section(symtab, layout);
if (gsym->final_value_is_known())
{
got->add_global(gsym, GOT_TYPE_STANDARD);
}
else
{
Reloc_section* rela_dyn = target->rela_dyn_section(layout);
if (gsym->is_from_dynobj()
|| gsym->is_undefined()
|| gsym->is_preemptible()
|| (gsym->visibility() == elfcpp::STV_PROTECTED
&& parameters->options().shared()))
got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
rela_dyn, elfcpp::R_AARCH64_GLOB_DAT);
else
{
// Not implemented yet.
gold_assert(false);
}
}
break;
}
case elfcpp::R_AARCH64_TSTBR14:
case elfcpp::R_AARCH64_CONDBR19:
case elfcpp::R_AARCH64_JUMP26:
case elfcpp::R_AARCH64_CALL26:
{
if (gsym->final_value_is_known())
break;
if (gsym->is_defined() &&
!gsym->is_from_dynobj() &&
!gsym->is_preemptible())
break;
// Make plt entry for function call.
const AArch64_reloc_property* arp =
aarch64_reloc_property_table->get_reloc_property(r_type);
gold_assert(arp != NULL);
target->make_plt_entry(symtab, layout, gsym);
break;
}
case elfcpp::R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21:
case elfcpp::R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC:
{
layout->set_has_static_tls();
// Create a GOT entry for the tp-relative offset.
Output_data_got_aarch64<size, big_endian>* got
= target->got_section(symtab, layout);
if (!parameters->doing_static_link())
{
got->add_global_with_rel(
gsym, GOT_TYPE_TLS_OFFSET,
target->rela_dyn_section(layout),
elfcpp::R_AARCH64_TLS_TPREL64);
}
if (!gsym->has_got_offset(GOT_TYPE_TLS_OFFSET))
{
got->add_global(gsym, GOT_TYPE_TLS_OFFSET);
unsigned int got_offset =
gsym->got_offset(GOT_TYPE_TLS_OFFSET);
const elfcpp::Elf_Xword addend = rela.get_r_addend();
gold_assert(addend == 0);
got->add_static_reloc(got_offset,
elfcpp::R_AARCH64_TLS_TPREL64, gsym);
}
}
break;
case elfcpp::R_AARCH64_TLSLE_ADD_TPREL_HI12:
case elfcpp::R_AARCH64_TLSLE_ADD_TPREL_LO12:
case elfcpp::R_AARCH64_TLSLE_ADD_TPREL_LO12_NC:
layout->set_has_static_tls();
if (parameters->options().shared())
gold_error(_("%s: unsupported TLSLE reloc type %u in shared objects."),
object->name().c_str(), r_type);
break;
default:
const AArch64_reloc_property* arp =
aarch64_reloc_property_table->get_reloc_property(r_type);
gold_assert(arp != NULL);
gold_error(_("%s: unsupported reloc type in global scan"),
arp->name().c_str());
}
return;
} // End of Scan::global
// Create the PLT section.
template<int size, bool big_endian>
void
Target_aarch64<size, big_endian>::make_plt_section(
Symbol_table* symtab, Layout* layout)
{
if (this->plt_ == NULL)
{
// Create the GOT section first.
this->got_section(symtab, layout);
this->plt_ = this->make_data_plt(layout, this->got_plt_);
layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
(elfcpp::SHF_ALLOC
| elfcpp::SHF_EXECINSTR),
this->plt_, ORDER_PLT, false);
// Make the sh_info field of .rela.plt point to .plt.
Output_section* rela_plt_os = this->plt_->rela_plt()->output_section();
rela_plt_os->set_info_section(this->plt_->output_section());
}
}
// Create a PLT entry for a global symbol.
template<int size, bool big_endian>
void
Target_aarch64<size, big_endian>::make_plt_entry(
Symbol_table* symtab,
Layout* layout,
Symbol* gsym)
{
if (gsym->has_plt_offset())
return;
if (this->plt_ == NULL)
this->make_plt_section(symtab, layout);
this->plt_->add_entry(gsym);
}
template<int size, bool big_endian>
void
Target_aarch64<size, big_endian>::gc_process_relocs(
Symbol_table* symtab,
Layout* layout,
Sized_relobj_file<size, 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)
{
if (sh_type == elfcpp::SHT_REL)
{
return;
}
gold::gc_process_relocs<
size, big_endian,
Target_aarch64<size, big_endian>,
elfcpp::SHT_RELA,
typename Target_aarch64<size, big_endian>::Scan,
typename Target_aarch64<size, big_endian>::Relocatable_size_for_reloc>(
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<int size, bool big_endian>
void
Target_aarch64<size, big_endian>::scan_relocs(
Symbol_table* symtab,
Layout* layout,
Sized_relobj_file<size, 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)
{
if (sh_type == elfcpp::SHT_REL)
{
gold_error(_("%s: unsupported REL reloc section"),
object->name().c_str());
return;
}
gold::scan_relocs<size, big_endian, Target_aarch64, elfcpp::SHT_RELA, Scan>(
symtab,
layout,
this,
object,
data_shndx,
prelocs,
reloc_count,
output_section,
needs_special_offset_handling,
local_symbol_count,
plocal_symbols);
}
// Finalize the sections.
template<int size, bool big_endian>
void
Target_aarch64<size, big_endian>::do_finalize_sections(
Layout* layout,
const Input_objects*,
Symbol_table* symtab)
{
const Reloc_section* rel_plt = (this->plt_ == NULL
? NULL
: this->plt_->rela_plt());
layout->add_target_dynamic_tags(false, this->got_plt_, rel_plt,
this->rela_dyn_, true, false);
// Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
// the .got.plt section.
Symbol* sym = this->global_offset_table_;
if (sym != NULL)
{
uint64_t data_size = this->got_plt_->current_data_size();
symtab->get_sized_symbol<size>(sym)->set_symsize(data_size);
// If the .got section is more than 0x8000 bytes, we add
// 0x8000 to the value of _GLOBAL_OFFSET_TABLE_, so that 16
// bit relocations have a greater chance of working.
if (data_size >= 0x8000)
symtab->get_sized_symbol<size>(sym)->set_value(
symtab->get_sized_symbol<size>(sym)->value() + 0x8000);
}
if (parameters->doing_static_link()
&& (this->plt_ == NULL || !this->plt_->has_irelative_section()))
{
// If linking statically, make sure that the __rela_iplt symbols
// were defined if necessary, even if we didn't create a PLT.
static const Define_symbol_in_segment syms[] =
{
{
"__rela_iplt_start", // name
elfcpp::PT_LOAD, // segment_type
elfcpp::PF_W, // segment_flags_set
elfcpp::PF(0), // segment_flags_clear
0, // value
0, // size
elfcpp::STT_NOTYPE, // type
elfcpp::STB_GLOBAL, // binding
elfcpp::STV_HIDDEN, // visibility
0, // nonvis
Symbol::SEGMENT_START, // offset_from_base
true // only_if_ref
},
{
"__rela_iplt_end", // name
elfcpp::PT_LOAD, // segment_type
elfcpp::PF_W, // segment_flags_set
elfcpp::PF(0), // segment_flags_clear
0, // value
0, // size
elfcpp::STT_NOTYPE, // type
elfcpp::STB_GLOBAL, // binding
elfcpp::STV_HIDDEN, // visibility
0, // nonvis
Symbol::SEGMENT_START, // offset_from_base
true // only_if_ref
}
};
symtab->define_symbols(layout, 2, syms,
layout->script_options()->saw_sections_clause());
}
return;
}
// Perform a relocation.
template<int size, bool big_endian>
inline bool
Target_aarch64<size, big_endian>::Relocate::relocate(
const Relocate_info<size, big_endian>* relinfo,
Target_aarch64<size, big_endian>* target,
Output_section* ,
size_t relnum,
const elfcpp::Rela<size, big_endian>& rela,
unsigned int r_type,
const Sized_symbol<size>* gsym,
const Symbol_value<size>* psymval,
unsigned char* view,
typename elfcpp::Elf_types<size>::Elf_Addr address,
section_size_type /* view_size */)
{
if (view == NULL)
return true;
typedef AArch64_relocate_functions<size, big_endian> Reloc;
const AArch64_reloc_property* reloc_property =
aarch64_reloc_property_table->get_reloc_property(r_type);
if (reloc_property == NULL)
{
std::string reloc_name =
aarch64_reloc_property_table->reloc_name_in_error_message(r_type);
gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
_("cannot relocate %s in object file"),
reloc_name.c_str());
return true;
}
const Sized_relobj_file<size, big_endian>* object = relinfo->object;
// Pick the value to use for symbols defined in the PLT.
Symbol_value<size> symval;
if (gsym != NULL
&& gsym->use_plt_offset(reloc_property->reference_flags()))
{
symval.set_output_value(target->plt_address_for_global(gsym));
psymval = &symval;
}
else if (gsym == NULL && psymval->is_ifunc_symbol())
{
unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
if (object->local_has_plt_offset(r_sym))
{
symval.set_output_value(target->plt_address_for_local(object, r_sym));
psymval = &symval;
}
}
const elfcpp::Elf_Xword addend = rela.get_r_addend();
// Get the GOT offset if needed.
// For aarch64, the GOT pointer points to the start of the GOT section.
bool have_got_offset = false;
int got_offset = 0;
int got_base = (target->got_ != NULL
? (target->got_->current_data_size() >= 0x8000
? 0x8000 : 0)
: 0);
switch (r_type)
{
case elfcpp::R_AARCH64_MOVW_GOTOFF_G0:
case elfcpp::R_AARCH64_MOVW_GOTOFF_G0_NC:
case elfcpp::R_AARCH64_MOVW_GOTOFF_G1:
case elfcpp::R_AARCH64_MOVW_GOTOFF_G1_NC:
case elfcpp::R_AARCH64_MOVW_GOTOFF_G2:
case elfcpp::R_AARCH64_MOVW_GOTOFF_G2_NC:
case elfcpp::R_AARCH64_MOVW_GOTOFF_G3:
case elfcpp::R_AARCH64_GOTREL64:
case elfcpp::R_AARCH64_GOTREL32:
case elfcpp::R_AARCH64_GOT_LD_PREL19:
case elfcpp::R_AARCH64_LD64_GOTOFF_LO15:
case elfcpp::R_AARCH64_ADR_GOT_PAGE:
case elfcpp::R_AARCH64_LD64_GOT_LO12_NC:
case elfcpp::R_AARCH64_LD64_GOTPAGE_LO15:
if (gsym != NULL)
{
gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
got_offset = gsym->got_offset(GOT_TYPE_STANDARD) - got_base;
}
else
{
unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.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)
- got_base);
}
have_got_offset = true;
break;
case elfcpp::R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21:
case elfcpp::R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC:
if (gsym != NULL)
{
gold_assert(gsym->has_got_offset(GOT_TYPE_TLS_OFFSET));
got_offset = gsym->got_offset(GOT_TYPE_TLS_OFFSET) - got_base;
}
else
{
unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_TLS_OFFSET));
got_offset = (object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET)
- got_base);
}
have_got_offset = true;
break;
default:
break;
}
typename Reloc::Status reloc_status = Reloc::STATUS_OKAY;
typename elfcpp::Elf_types<size>::Elf_Addr value;
switch (r_type)
{
case elfcpp::R_AARCH64_NONE:
break;
case elfcpp::R_AARCH64_ABS64:
reloc_status = Reloc::template rela_ua<64>(
view, object, psymval, addend, reloc_property);
break;
case elfcpp::R_AARCH64_ABS32:
reloc_status = Reloc::template rela_ua<32>(
view, object, psymval, addend, reloc_property);
break;
case elfcpp::R_AARCH64_ABS16:
reloc_status = Reloc::template rela_ua<16>(
view, object, psymval, addend, reloc_property);
break;
case elfcpp::R_AARCH64_PREL64:
reloc_status = Reloc::template pcrela_ua<64>(
view, object, psymval, addend, address, reloc_property);
case elfcpp::R_AARCH64_PREL32:
reloc_status = Reloc::template pcrela_ua<32>(
view, object, psymval, addend, address, reloc_property);
case elfcpp::R_AARCH64_PREL16:
reloc_status = Reloc::template pcrela_ua<16>(
view, object, psymval, addend, address, reloc_property);
case elfcpp::R_AARCH64_ADR_PREL_PG_HI21_NC:
case elfcpp::R_AARCH64_ADR_PREL_PG_HI21:
reloc_status = Reloc::adrp(view, object, psymval, addend, address,
reloc_property);
break;
case elfcpp::R_AARCH64_LDST8_ABS_LO12_NC:
case elfcpp::R_AARCH64_LDST16_ABS_LO12_NC:
case elfcpp::R_AARCH64_LDST32_ABS_LO12_NC:
case elfcpp::R_AARCH64_LDST64_ABS_LO12_NC:
case elfcpp::R_AARCH64_LDST128_ABS_LO12_NC:
case elfcpp::R_AARCH64_ADD_ABS_LO12_NC:
reloc_status = Reloc::template rela_general<32>(
view, object, psymval, addend, reloc_property);
break;
case elfcpp::R_AARCH64_TSTBR14:
case elfcpp::R_AARCH64_CONDBR19:
case elfcpp::R_AARCH64_CALL26:
case elfcpp::R_AARCH64_JUMP26:
reloc_status = Reloc::template pcrela_general<32>(
view, object, psymval, addend, address, reloc_property);
break;
case elfcpp::R_AARCH64_ADR_GOT_PAGE:
gold_assert(have_got_offset);
value = target->got_->address() + got_base + got_offset;
reloc_status = Reloc::adrp(view, value + addend, address);
break;
case elfcpp::R_AARCH64_LD64_GOT_LO12_NC:
gold_assert(have_got_offset);
value = target->got_->address() + got_base + got_offset;
reloc_status = Reloc::template rela_general<32>(
view, value, addend, reloc_property);
break;
case elfcpp::R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21:
case elfcpp::R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC:
reloc_status = relocate_tls(relinfo, target, relnum, rela, r_type,
gsym, psymval, view, address);
break;
case elfcpp::R_AARCH64_TLSLE_ADD_TPREL_HI12:
case elfcpp::R_AARCH64_TLSLE_ADD_TPREL_LO12:
case elfcpp::R_AARCH64_TLSLE_ADD_TPREL_LO12_NC:
reloc_status = relocate_tls(relinfo, target, relnum, rela, r_type,
gsym, psymval, view, address);
break;
default:
gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
_("unsupported reloc aaa %u"),
r_type);
break;
}
// Report any errors.
switch (reloc_status)
{
case Reloc::STATUS_OKAY:
break;
case Reloc::STATUS_OVERFLOW:
gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
_("relocation overflow in %s"),
reloc_property->name().c_str());
break;
case Reloc::STATUS_BAD_RELOC:
gold_error_at_location(
relinfo,
relnum,
rela.get_r_offset(),
_("unexpected opcode while processing relocation %s"),
reloc_property->name().c_str());
break;
default:
gold_unreachable();
}
return true;
}
template<int size, bool big_endian>
inline
typename AArch64_relocate_functions<size,big_endian>::Status
Target_aarch64<size, big_endian>::Relocate::relocate_tls(
const Relocate_info<size,big_endian> * relinfo,
Target_aarch64<size, big_endian> * target,
size_t /* relnum */,
const elfcpp::Rela<size, big_endian> & rela,
unsigned int r_type, const Sized_symbol<size> * gsym,
const Symbol_value<size> * psymval,
unsigned char * view,
typename elfcpp::Elf_types<size>::Elf_Addr address)
{
typedef AArch64_relocate_functions<size,big_endian> aarch64_reloc_funcs;
typedef typename elfcpp::Elf_types<size>::Elf_Addr AArch64_Addr;
const AArch64_reloc_property * reloc_property =
aarch64_reloc_property_table->get_reloc_property(r_type);
gold_assert(reloc_property != NULL);
Sized_relobj_file<size,big_endian> * object = relinfo->object;
switch (r_type)
{
case elfcpp::R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21:
case elfcpp::R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC:
{
// Not implemented - possible IE->LE relaxation opportunity:
// adrp xd, :gottprel:var => movz xd, :tprel_g1:var
typename elfcpp::Elf_types<size>::Elf_Addr got_entry_address;
if (gsym != NULL)
{
gold_assert(gsym->has_got_offset(GOT_TYPE_TLS_OFFSET));
got_entry_address = target->got_->address() +
gsym->got_offset(GOT_TYPE_TLS_OFFSET);
}
else
{
unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
gold_assert(
object->local_has_got_offset(r_sym, GOT_TYPE_TLS_OFFSET));
got_entry_address = target->got_->address() +
object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET);
}
if (r_type == elfcpp::R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21)
{
return aarch64_reloc_funcs::adrp(
view, got_entry_address, address);
}
else if (r_type == elfcpp::R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC)
{
return aarch64_reloc_funcs::template rela_general<64>(
view, got_entry_address, 0, reloc_property);
}
gold_assert(false);
}
break;
case elfcpp::R_AARCH64_TLSLE_ADD_TPREL_HI12:
case elfcpp::R_AARCH64_TLSLE_ADD_TPREL_LO12:
case elfcpp::R_AARCH64_TLSLE_ADD_TPREL_LO12_NC:
{
Output_segment * tls_segment = relinfo->layout->tls_segment();
gold_assert(tls_segment != NULL);
AArch64_Addr value = psymval->value(object, 0);
const elfcpp::Elf_Xword addend = rela.get_r_addend();
if (!parameters->options().shared())
{
AArch64_Addr aligned_tcb_size =
align_address(target->tcb_size(),
tls_segment->maximum_alignment());
return aarch64_reloc_funcs::template
rela_general<32>(view,
value + aligned_tcb_size,
addend,
reloc_property);
}
else
gold_error(_("%s: unsupported reloc %u "
"in non-static TLSLE mode."),
object->name().c_str(), r_type);
}
break;
default:
gold_error(_("%s: unsupported TLS reloc %u."),
object->name().c_str(), r_type);
}
return aarch64_reloc_funcs::STATUS_BAD_RELOC;
}
// Relocate section data.
template<int size, bool big_endian>
void
Target_aarch64<size, big_endian>::relocate_section(
const Relocate_info<size, 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,
typename elfcpp::Elf_types<size>::Elf_Addr address,
section_size_type view_size,
const Reloc_symbol_changes* reloc_symbol_changes)
{
gold_assert(sh_type == elfcpp::SHT_RELA);
typedef typename Target_aarch64<size, big_endian>::Relocate AArch64_relocate;
gold::relocate_section<size, big_endian, Target_aarch64, elfcpp::SHT_RELA,
AArch64_relocate, gold::Default_comdat_behavior>(
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<int size, bool big_endian>
unsigned int
Target_aarch64<size, big_endian>::Relocatable_size_for_reloc::
get_size_for_reloc(
unsigned int ,
Relobj* )
{
// We will never support SHT_REL relocations.
gold_unreachable();
return 0;
}
// Scan the relocs during a relocatable link.
template<int size, bool big_endian>
void
Target_aarch64<size, big_endian>::scan_relocatable_relocs(
Symbol_table* symtab,
Layout* layout,
Sized_relobj_file<size, 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_RELA);
typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_RELA,
Relocatable_size_for_reloc> Scan_relocatable_relocs;
gold::scan_relocatable_relocs<size, big_endian, elfcpp::SHT_RELA,
Scan_relocatable_relocs>(
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<int size, bool big_endian>
void
Target_aarch64<size, big_endian>::relocate_relocs(
const Relocate_info<size, big_endian>* relinfo,
unsigned int sh_type,
const unsigned char* prelocs,
size_t reloc_count,
Output_section* output_section,
typename elfcpp::Elf_types<size>::Elf_Off offset_in_output_section,
const Relocatable_relocs* rr,
unsigned char* view,
typename elfcpp::Elf_types<size>::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_RELA);
gold::relocate_relocs<size, big_endian, elfcpp::SHT_RELA>(
relinfo,
prelocs,
reloc_count,
output_section,
offset_in_output_section,
rr,
view,
view_address,
view_size,
reloc_view,
reloc_view_size);
}
// The selector for aarch64 object files.
template<int size, bool big_endian>
class Target_selector_aarch64 : public Target_selector
{
public:
Target_selector_aarch64();
virtual Target*
do_instantiate_target()
{ return new Target_aarch64<size, big_endian>(); }
};
template<>
Target_selector_aarch64<32, true>::Target_selector_aarch64()
: Target_selector(elfcpp::EM_AARCH64, 32, true,
"elf32-bigaarch64", "aarch64_elf32_be_vec")
{ }
template<>
Target_selector_aarch64<32, false>::Target_selector_aarch64()
: Target_selector(elfcpp::EM_AARCH64, 32, false,
"elf32-littleaarch64", "aarch64_elf32_le_vec")
{ }
template<>
Target_selector_aarch64<64, true>::Target_selector_aarch64()
: Target_selector(elfcpp::EM_AARCH64, 64, true,
"elf64-bigaarch64", "aarch64_elf64_be_vec")
{ }
template<>
Target_selector_aarch64<64, false>::Target_selector_aarch64()
: Target_selector(elfcpp::EM_AARCH64, 64, false,
"elf64-littleaarch64", "aarch64_elf64_le_vec")
{ }
Target_selector_aarch64<32, true> target_selector_aarch64elf32b;
Target_selector_aarch64<32, false> target_selector_aarch64elf32;
Target_selector_aarch64<64, true> target_selector_aarch64elfb;
Target_selector_aarch64<64, false> target_selector_aarch64elf;
} // End anonymous namespace.