OpenE2K/binutils-gdb
12
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity
4fc1b9d43c
binutils-gdb/gold/aarch64.cc
Alan Modra b90efa5b79 ChangeLog rotatation and copyright year update
2015-01-02 00:53:45 +10:30

6730 lines
208 KiB
C++
Raw Blame History

// aarch64.cc -- aarch64 target support for gold.
// Copyright (C) 2014-2015 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 the symbol.
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_;
}; // End of Output_data_got_aarch64
template<int size, bool big_endian>
class AArch64_input_section;
template<int size, bool big_endian>
class AArch64_output_section;
// Reloc stub class.
template<int size, bool big_endian>
class Reloc_stub
{
public:
typedef Reloc_stub<size, big_endian> This;
typedef typename elfcpp::Elf_types<size>::Elf_Addr AArch64_address;
// Do not change the value of the enums, they are used to index into
// stub_insns array.
typedef enum
{
ST_NONE = 0,
// Using adrp/add pair, 4 insns (including alignment) without mem access,
// the fastest stub. This has a limited jump distance, which is tested by
// aarch64_valid_for_adrp_p.
ST_ADRP_BRANCH = 1,
// Using ldr-absolute-address/br-register, 4 insns with 1 mem access,
// unlimited in jump distance.
ST_LONG_BRANCH_ABS = 2,
// Using ldr/calculate-pcrel/jump, 8 insns (including alignment) with 1 mem
// access, slowest one. Only used in position independent executables.
ST_LONG_BRANCH_PCREL = 3,
} Stub_type;
// Branch range. This is used to calculate the section group size, as well as
// determine whether a stub is needed.
static const int MAX_BRANCH_OFFSET = ((1 << 25) - 1) << 2;
static const int MIN_BRANCH_OFFSET = -((1 << 25) << 2);
// Constant used to determine if an offset fits in the adrp instruction
// encoding.
static const int MAX_ADRP_IMM = (1 << 20) - 1;
static const int MIN_ADRP_IMM = -(1 << 20);
static const int BYTES_PER_INSN = 4;
static const int STUB_ADDR_ALIGN = 4;
// Determine whether the offset fits in the jump/branch instruction.
static bool
aarch64_valid_branch_offset_p(int64_t offset)
{ return offset >= MIN_BRANCH_OFFSET && offset <= MAX_BRANCH_OFFSET; }
// Determine whether the offset fits in the adrp immediate field.
static bool
aarch64_valid_for_adrp_p(AArch64_address location, AArch64_address dest)
{
typedef AArch64_relocate_functions<size, big_endian> Reloc;
int64_t adrp_imm = (Reloc::Page(dest) - Reloc::Page(location)) >> 12;
return adrp_imm >= MIN_ADRP_IMM && adrp_imm <= MAX_ADRP_IMM;
}
// Determine the stub type for a certain relocation or ST_NONE, if no stub is
// needed.
static Stub_type
stub_type_for_reloc(unsigned int r_type, AArch64_address address,
AArch64_address target);
Reloc_stub(Stub_type stub_type)
: stub_type_(stub_type), offset_(invalid_offset),
destination_address_(invalid_address)
{ }
~Reloc_stub()
{ }
// Return offset of code stub from beginning of its containing stub table.
section_offset_type
offset() const
{
gold_assert(this->offset_ != invalid_offset);
return this->offset_;
}
// Set offset of code stub from beginning of its containing stub table.
void
set_offset(section_offset_type offset)
{ this->offset_ = offset; }
// Return destination address.
AArch64_address
destination_address() const
{
gold_assert(this->destination_address_ != this->invalid_address);
return this->destination_address_;
}
// Set destination address.
void
set_destination_address(AArch64_address address)
{
gold_assert(address != this->invalid_address);
this->destination_address_ = address;
}
// Reset the destination address.
void
reset_destination_address()
{ this->destination_address_ = this->invalid_address; }
// Return the stub type.
Stub_type
stub_type() const
{ return stub_type_; }
// Return the stub size.
uint32_t
stub_size() const
{ return this->stub_insn_number() * BYTES_PER_INSN; }
// Return the instruction number of this stub instance.
int
stub_insn_number() const
{ return stub_insns_[this->stub_type_][0]; }
// Note the first "insn" is the number of total insns in this array.
const uint32_t*
stub_insns() const
{ return stub_insns_[this->stub_type_]; }
// Write stub to output file.
void
write(unsigned char* view, section_size_type view_size)
{ this->do_write(view, view_size); }
// The key class used to index the stub instance in the stub table's stub map.
class Key
{
public:
Key(Stub_type stub_type, const Symbol* symbol, const Relobj* relobj,
unsigned int r_sym, int32_t addend)
: stub_type_(stub_type), addend_(addend)
{
if (symbol != NULL)
{
this->r_sym_ = Reloc_stub::invalid_index;
this->u_.symbol = symbol;
}
else
{
gold_assert(relobj != NULL && r_sym != invalid_index);
this->r_sym_ = r_sym;
this->u_.relobj = relobj;
}
}
~Key()
{ }
// Return stub type.
Stub_type
stub_type() const
{ return this->stub_type_; }
// Return the local symbol index or invalid_index.
unsigned int
r_sym() const
{ return this->r_sym_; }
// Return the symbol if there is one.
const Symbol*
symbol() const
{ return this->r_sym_ == invalid_index ? this->u_.symbol : NULL; }
// Return the relobj if there is one.
const Relobj*
relobj() const
{ return this->r_sym_ != invalid_index ? this->u_.relobj : NULL; }
// Whether this equals to another key k.
bool
eq(const Key& k) const
{
return ((this->stub_type_ == k.stub_type_)
&& (this->r_sym_ == k.r_sym_)
&& ((this->r_sym_ != Reloc_stub::invalid_index)
? (this->u_.relobj == k.u_.relobj)
: (this->u_.symbol == k.u_.symbol))
&& (this->addend_ == k.addend_));
}
// Return a hash value.
size_t
hash_value() const
{
size_t name_hash_value = gold::string_hash<char>(
(this->r_sym_ != Reloc_stub::invalid_index)
? this->u_.relobj->name().c_str()
: this->u_.symbol->name());
// We only have 4 stub types.
size_t stub_type_hash_value = 0x03 & this->stub_type_;
return (name_hash_value
^ stub_type_hash_value
^ ((this->r_sym_ & 0x3fff) << 2)
^ ((this->addend_ & 0xffff) << 16));
}
// Functors for STL associative containers.
struct hash
{
size_t
operator()(const Key& k) const
{ return k.hash_value(); }
};
struct equal_to
{
bool
operator()(const Key& k1, const Key& k2) const
{ return k1.eq(k2); }
};
private:
// Stub type.
const Stub_type stub_type_;
// If this is a local symbol, this is the index in the defining object.
// Otherwise, it is invalid_index for a global symbol.
unsigned int r_sym_;
// If r_sym_ is an invalid index, this points to a global symbol.
// Otherwise, it points to a relobj. We used the unsized and target
// independent Symbol and Relobj classes instead of Sized_symbol<32> and
// Arm_relobj, in order to avoid making the stub class a template
// as most of the stub machinery is endianness-neutral. However, it
// may require a bit of casting done by users of this class.
union
{
const Symbol* symbol;
const Relobj* relobj;
} u_;
// Addend associated with a reloc.
int32_t addend_;
}; // End of inner class Reloc_stub::Key
protected:
// This may be overridden in the child class.
virtual void
do_write(unsigned char*, section_size_type);
private:
static const section_offset_type invalid_offset =
static_cast<section_offset_type>(-1);
static const unsigned int invalid_index = static_cast<unsigned int>(-1);
static const AArch64_address invalid_address =
static_cast<AArch64_address>(-1);
static const uint32_t stub_insns_[][10];
const Stub_type stub_type_;
section_offset_type offset_;
AArch64_address destination_address_;
}; // End of Reloc_stub
// Write data to output file.
template<int size, bool big_endian>
void
Reloc_stub<size, big_endian>::
do_write(unsigned char* view, section_size_type)
{
typedef typename elfcpp::Swap<32, big_endian>::Valtype Insntype;
const uint32_t* insns = this->stub_insns();
uint32_t num_insns = this->stub_insn_number();
Insntype* ip = reinterpret_cast<Insntype*>(view);
for (uint32_t i = 1; i <= num_insns; ++i)
elfcpp::Swap<32, big_endian>::writeval(ip + i - 1, insns[i]);
}
// Stubs instructions definition.
template<int size, bool big_endian>
const uint32_t
Reloc_stub<size, big_endian>::stub_insns_[][10] =
{
// The first element of each group is the num of the insns.
// ST_NONE
{0, 0},
// ST_ADRP_BRANCH
{
4,
0x90000010, /* adrp ip0, X */
/* ADR_PREL_PG_HI21(X) */
0x91000210, /* add ip0, ip0, :lo12:X */
/* ADD_ABS_LO12_NC(X) */
0xd61f0200, /* br ip0 */
0x00000000, /* alignment padding */
},
// ST_LONG_BRANCH_ABS
{
4,
0x58000050, /* ldr ip0, 0x8 */
0xd61f0200, /* br ip0 */
0x00000000, /* address field */
0x00000000, /* address fields */
},
// ST_LONG_BRANCH_PCREL
{
8,
0x58000090, /* ldr ip0, 0x10 */
0x10000011, /* adr ip1, #0 */
0x8b110210, /* add ip0, ip0, ip1 */
0xd61f0200, /* br ip0 */
0x00000000, /* address field */
0x00000000, /* address field */
0x00000000, /* alignment padding */
0x00000000, /* alignment padding */
}
};
// Determine the stub type for a certain relocation or ST_NONE, if no stub is
// needed.
template<int size, bool big_endian>
inline
typename Reloc_stub<size, big_endian>::Stub_type
Reloc_stub<size, big_endian>::stub_type_for_reloc(
unsigned int r_type, AArch64_address location, AArch64_address dest)
{
int64_t branch_offset = 0;
switch(r_type)
{
case elfcpp::R_AARCH64_CALL26:
case elfcpp::R_AARCH64_JUMP26:
branch_offset = dest - location;
break;
default:
gold_unreachable();
}
if (aarch64_valid_branch_offset_p(branch_offset))
return ST_NONE;
if (aarch64_valid_for_adrp_p(location, dest))
return ST_ADRP_BRANCH;
if (parameters->options().output_is_position_independent()
&& parameters->options().output_is_executable())
return ST_LONG_BRANCH_PCREL;
return ST_LONG_BRANCH_ABS;
}
// A class to hold stubs for the ARM target.
template<int size, bool big_endian>
class Stub_table : public Output_data
{
public:
typedef Target_aarch64<size, big_endian> The_target_aarch64;
typedef typename elfcpp::Elf_types<size>::Elf_Addr AArch64_address;
typedef AArch64_input_section<size, big_endian> The_aarch64_input_section;
typedef Reloc_stub<size, big_endian> The_reloc_stub;
typedef typename The_reloc_stub::Key The_reloc_stub_key;
typedef typename The_reloc_stub_key::hash The_reloc_stub_key_hash;
typedef typename The_reloc_stub_key::equal_to The_reloc_stub_key_equal_to;
typedef Stub_table<size, big_endian> The_stub_table;
typedef Unordered_map<The_reloc_stub_key, The_reloc_stub*,
The_reloc_stub_key_hash, The_reloc_stub_key_equal_to>
Reloc_stub_map;
typedef typename Reloc_stub_map::const_iterator Reloc_stub_map_const_iter;
typedef Relocate_info<size, big_endian> The_relocate_info;
Stub_table(The_aarch64_input_section* owner)
: Output_data(), owner_(owner), reloc_stubs_size_(0), prev_data_size_(0)
{ }
~Stub_table()
{ }
The_aarch64_input_section*
owner() const
{ return owner_; }
// Whether this stub table is empty.
bool
empty() const
{ return reloc_stubs_.empty(); }
// Return the current data size.
off_t
current_data_size() const
{ return this->current_data_size_for_child(); }
// Add a STUB using KEY. The caller is responsible for avoiding addition
// if a STUB with the same key has already been added.
void
add_reloc_stub(The_reloc_stub* stub, const The_reloc_stub_key& key);
// Finalize stubs. No-op here, just for completeness.
void
finalize_stubs()
{ }
// Look up a relocation stub using KEY. Return NULL if there is none.
The_reloc_stub*
find_reloc_stub(The_reloc_stub_key& key)
{
Reloc_stub_map_const_iter p = this->reloc_stubs_.find(key);
return (p != this->reloc_stubs_.end()) ? p->second : NULL;
}
// Relocate stubs in this stub table.
void
relocate_stubs(const The_relocate_info*,
The_target_aarch64*,
Output_section*,
unsigned char*,
AArch64_address,
section_size_type);
// Update data size at the end of a relaxation pass. Return true if data size
// is different from that of the previous relaxation pass.
bool
update_data_size_changed_p()
{
// No addralign changed here.
off_t s = this->reloc_stubs_size_;
bool changed = (s != this->prev_data_size_);
this->prev_data_size_ = s;
return changed;
}
protected:
// Write out section contents.
void
do_write(Output_file*);
// Return the required alignment.
uint64_t
do_addralign() const
{ return The_reloc_stub::STUB_ADDR_ALIGN; }
// Reset address and file offset.
void
do_reset_address_and_file_offset()
{ this->set_current_data_size_for_child(this->prev_data_size_); }
// Set final data size.
void
set_final_data_size()
{ this->set_data_size(this->current_data_size()); }
private:
// Relocate one stub.
void
relocate_stub(The_reloc_stub*,
const The_relocate_info*,
The_target_aarch64*,
Output_section*,
unsigned char*,
AArch64_address,
section_size_type);
private:
// Owner of this stub table.
The_aarch64_input_section* owner_;
// The relocation stubs.
Reloc_stub_map reloc_stubs_;
// Size of reloc stubs.
off_t reloc_stubs_size_;
// data size of this in the previous pass.
off_t prev_data_size_;
}; // End of Stub_table
// Add a STUB using KEY. The caller is responsible for avoiding addition
// if a STUB with the same key has already been added.
template<int size, bool big_endian>
void
Stub_table<size, big_endian>::add_reloc_stub(
The_reloc_stub* stub, const The_reloc_stub_key& key)
{
gold_assert(stub->stub_type() == key.stub_type());
this->reloc_stubs_[key] = stub;
// Assign stub offset early. We can do this because we never remove
// reloc stubs and they are in the beginning of the stub table.
this->reloc_stubs_size_ = align_address(this->reloc_stubs_size_,
The_reloc_stub::STUB_ADDR_ALIGN);
stub->set_offset(this->reloc_stubs_size_);
this->reloc_stubs_size_ += stub->stub_size();
}
// Relocate all stubs in this stub table.
template<int size, bool big_endian>
void
Stub_table<size, big_endian>::
relocate_stubs(const The_relocate_info* relinfo,
The_target_aarch64* target_aarch64,
Output_section* output_section,
unsigned char* view,
AArch64_address address,
section_size_type view_size)
{
// "view_size" is the total size of the stub_table.
gold_assert(address == this->address() &&
view_size == static_cast<section_size_type>(this->data_size()));
for(Reloc_stub_map_const_iter p = this->reloc_stubs_.begin();
p != this->reloc_stubs_.end(); ++p)
relocate_stub(p->second, relinfo, target_aarch64, output_section,
view, address, view_size);
}
// Relocate one stub. This is a helper for Stub_table::relocate_stubs().
template<int size, bool big_endian>
void
Stub_table<size, big_endian>::
relocate_stub(The_reloc_stub* stub,
const The_relocate_info* relinfo,
The_target_aarch64* target_aarch64,
Output_section* output_section,
unsigned char* view,
AArch64_address address,
section_size_type view_size)
{
// "offset" is the offset from the beginning of the stub_table.
section_size_type offset = stub->offset();
section_size_type stub_size = stub->stub_size();
// "view_size" is the total size of the stub_table.
gold_assert(offset + stub_size <= view_size);
target_aarch64->relocate_stub(stub, relinfo, output_section,
view + offset, address + offset, view_size);
}
// Write out the stubs to file.
template<int size, bool big_endian>
void
Stub_table<size, big_endian>::do_write(Output_file* of)
{
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);
// Write relocation stubs.
for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
p != this->reloc_stubs_.end(); ++p)
{
The_reloc_stub* stub = p->second;
AArch64_address address = this->address() + stub->offset();
gold_assert(address ==
align_address(address, The_reloc_stub::STUB_ADDR_ALIGN));
stub->write(oview + stub->offset(), stub->stub_size());
}
of->write_output_view(this->offset(), oview_size, oview);
}
// AArch64_relobj class.
template<int size, bool big_endian>
class AArch64_relobj : public Sized_relobj_file<size, big_endian>
{
public:
typedef AArch64_relobj<size, big_endian> This;
typedef Target_aarch64<size, big_endian> The_target_aarch64;
typedef AArch64_input_section<size, big_endian> The_aarch64_input_section;
typedef typename elfcpp::Elf_types<size>::Elf_Addr AArch64_address;
typedef Stub_table<size, big_endian> The_stub_table;
typedef std::vector<The_stub_table*> Stub_table_list;
static const AArch64_address invalid_address =
static_cast<AArch64_address>(-1);
AArch64_relobj(const std::string& name, Input_file* input_file, off_t offset,
const typename elfcpp::Ehdr<size, big_endian>& ehdr)
: Sized_relobj_file<size, big_endian>(name, input_file, offset, ehdr),
stub_tables_()
{ }
~AArch64_relobj()
{ }
// Return the stub table of the SHNDX-th section if there is one.
The_stub_table*
stub_table(unsigned int shndx) const
{
gold_assert(shndx < this->stub_tables_.size());
return this->stub_tables_[shndx];
}
// Set STUB_TABLE to be the stub_table of the SHNDX-th section.
void
set_stub_table(unsigned int shndx, The_stub_table* stub_table)
{
gold_assert(shndx < this->stub_tables_.size());
this->stub_tables_[shndx] = stub_table;
}
// Scan all relocation sections for stub generation.
void
scan_sections_for_stubs(The_target_aarch64*, const Symbol_table*,
const Layout*);
// Whether a section is a scannable text section.
bool
text_section_is_scannable(const elfcpp::Shdr<size, big_endian>&, unsigned int,
const Output_section*, const Symbol_table*);
// Convert regular input section with index SHNDX to a relaxed section.
void
convert_input_section_to_relaxed_section(unsigned /* shndx */)
{
// The stubs have relocations and we need to process them after writing
// out the stubs. So relocation now must follow section write.
this->set_relocs_must_follow_section_writes();
}
protected:
// Post constructor setup.
void
do_setup()
{
// Call parent's setup method.
Sized_relobj_file<size, big_endian>::do_setup();
// Initialize look-up tables.
this->stub_tables_.resize(this->shnum());
}
virtual void
do_relocate_sections(
const Symbol_table* symtab, const Layout* layout,
const unsigned char* pshdrs, Output_file* of,
typename Sized_relobj_file<size, big_endian>::Views* pviews);
private:
// Whether a section needs to be scanned for relocation stubs.
bool
section_needs_reloc_stub_scanning(const elfcpp::Shdr<size, big_endian>&,
const Relobj::Output_sections&,
const Symbol_table*, const unsigned char*);
// List of stub tables.
Stub_table_list stub_tables_;
}; // End of AArch64_relobj
// Relocate sections.
template<int size, bool big_endian>
void
AArch64_relobj<size, big_endian>::do_relocate_sections(
const Symbol_table* symtab, const Layout* layout,
const unsigned char* pshdrs, Output_file* of,
typename Sized_relobj_file<size, big_endian>::Views* pviews)
{
// Call parent to relocate sections.
Sized_relobj_file<size, big_endian>::do_relocate_sections(symtab, layout,
pshdrs, of, pviews);
// We do not generate stubs if doing a relocatable link.
if (parameters->options().relocatable())
return;
Relocate_info<size, big_endian> relinfo;
relinfo.symtab = symtab;
relinfo.layout = layout;
relinfo.object = this;
// Relocate stub tables.
unsigned int shnum = this->shnum();
The_target_aarch64* target = The_target_aarch64::current_target();
for (unsigned int i = 1; i < shnum; ++i)
{
The_aarch64_input_section* aarch64_input_section =
target->find_aarch64_input_section(this, i);
if (aarch64_input_section != NULL
&& aarch64_input_section->is_stub_table_owner()
&& !aarch64_input_section->stub_table()->empty())
{
Output_section* os = this->output_section(i);
gold_assert(os != NULL);
relinfo.reloc_shndx = elfcpp::SHN_UNDEF;
relinfo.reloc_shdr = NULL;
relinfo.data_shndx = i;
relinfo.data_shdr = pshdrs + i * elfcpp::Elf_sizes<size>::shdr_size;
typename Sized_relobj_file<size, big_endian>::View_size&
view_struct = (*pviews)[i];
gold_assert(view_struct.view != NULL);
The_stub_table* stub_table = aarch64_input_section->stub_table();
off_t offset = stub_table->address() - view_struct.address;
unsigned char* view = view_struct.view + offset;
AArch64_address address = stub_table->address();
section_size_type view_size = stub_table->data_size();
stub_table->relocate_stubs(&relinfo, target, os, view, address,
view_size);
}
}
}
// Determine if an input section is scannable for stub processing. SHDR is
// the header of the section and SHNDX is the section index. OS is the output
// section for the input section and SYMTAB is the global symbol table used to
// look up ICF information.
template<int size, bool big_endian>
bool
AArch64_relobj<size, big_endian>::text_section_is_scannable(
const elfcpp::Shdr<size, big_endian>& text_shdr,
unsigned int text_shndx,
const Output_section* os,
const Symbol_table* symtab)
{
// Skip any empty sections, unallocated sections or sections whose
// type are not SHT_PROGBITS.
if (text_shdr.get_sh_size() == 0
|| (text_shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0
|| text_shdr.get_sh_type() != elfcpp::SHT_PROGBITS)
return false;
// Skip any discarded or ICF'ed sections.
if (os == NULL || symtab->is_section_folded(this, text_shndx))
return false;
// Skip exception frame.
if (strcmp(os->name(), ".eh_frame") == 0)
return false ;
gold_assert(!this->is_output_section_offset_invalid(text_shndx) ||
os->find_relaxed_input_section(this, text_shndx) != NULL);
return true;
}
// Determine if we want to scan the SHNDX-th section for relocation stubs.
// This is a helper for AArch64_relobj::scan_sections_for_stubs().
template<int size, bool big_endian>
bool
AArch64_relobj<size, big_endian>::section_needs_reloc_stub_scanning(
const elfcpp::Shdr<size, big_endian>& shdr,
const Relobj::Output_sections& out_sections,
const Symbol_table* symtab,
const unsigned char* pshdrs)
{
unsigned int sh_type = shdr.get_sh_type();
if (sh_type != elfcpp::SHT_RELA)
return false;
// Ignore empty section.
off_t sh_size = shdr.get_sh_size();
if (sh_size == 0)
return false;
// Ignore reloc section with unexpected symbol table. The
// error will be reported in the final link.
if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx())
return false;
gold_assert(sh_type == elfcpp::SHT_RELA);
unsigned int reloc_size = elfcpp::Elf_sizes<size>::rela_size;
// Ignore reloc section with unexpected entsize or uneven size.
// The error will be reported in the final link.
if (reloc_size != shdr.get_sh_entsize() || sh_size % reloc_size != 0)
return false;
// Ignore reloc section with bad info. This error will be
// reported in the final link.
unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_info());
if (text_shndx >= this->shnum())
return false;
const unsigned int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
const elfcpp::Shdr<size, big_endian> text_shdr(pshdrs +
text_shndx * shdr_size);
return this->text_section_is_scannable(text_shdr, text_shndx,
out_sections[text_shndx], symtab);
}
// Scan relocations for stub generation.
template<int size, bool big_endian>
void
AArch64_relobj<size, big_endian>::scan_sections_for_stubs(
The_target_aarch64* target,
const Symbol_table* symtab,
const Layout* layout)
{
unsigned int shnum = this->shnum();
const unsigned int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
// Read the section headers.
const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
shnum * shdr_size,
true, true);
// To speed up processing, we set up hash tables for fast lookup of
// input offsets to output addresses.
this->initialize_input_to_output_maps();
const Relobj::Output_sections& out_sections(this->output_sections());
Relocate_info<size, big_endian> relinfo;
relinfo.symtab = symtab;
relinfo.layout = layout;
relinfo.object = this;
// Do relocation stubs scanning.
const unsigned char* p = pshdrs + shdr_size;
for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
{
const elfcpp::Shdr<size, big_endian> shdr(p);
if (this->section_needs_reloc_stub_scanning(shdr, out_sections, symtab,
pshdrs))
{
unsigned int index = this->adjust_shndx(shdr.get_sh_info());
AArch64_address output_offset =
this->get_output_section_offset(index);
AArch64_address output_address;
if (output_offset != invalid_address)
{
output_address = out_sections[index]->address() + output_offset;
}
else
{
// Currently this only happens for a relaxed section.
const Output_relaxed_input_section* poris =
out_sections[index]->find_relaxed_input_section(this, index);
gold_assert(poris != NULL);
output_address = poris->address();
}
// Get the relocations.
const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(),
shdr.get_sh_size(),
true, false);
// Get the section contents.
section_size_type input_view_size = 0;
const unsigned char* input_view =
this->section_contents(index, &input_view_size, false);
relinfo.reloc_shndx = i;
relinfo.data_shndx = index;
unsigned int sh_type = shdr.get_sh_type();
unsigned int reloc_size;
gold_assert (sh_type == elfcpp::SHT_RELA);
reloc_size = elfcpp::Elf_sizes<size>::rela_size;
Output_section* os = out_sections[index];
target->scan_section_for_stubs(&relinfo, sh_type, prelocs,
shdr.get_sh_size() / reloc_size,
os,
output_offset == invalid_address,
input_view, output_address,
input_view_size);
}
}
}
// A class to wrap an ordinary input section containing executable code.
template<int size, bool big_endian>
class AArch64_input_section : public Output_relaxed_input_section
{
public:
typedef Stub_table<size, big_endian> The_stub_table;
AArch64_input_section(Relobj* relobj, unsigned int shndx)
: Output_relaxed_input_section(relobj, shndx, 1),
stub_table_(NULL),
original_contents_(NULL), original_size_(0),
original_addralign_(1)
{ }
~AArch64_input_section()
{ delete[] this->original_contents_; }
// Initialize.
void
init();
// Set the stub_table.
void
set_stub_table(The_stub_table* st)
{ this->stub_table_ = st; }
// Whether this is a stub table owner.
bool
is_stub_table_owner() const
{ return this->stub_table_ != NULL && this->stub_table_->owner() == this; }
// Return the original size of the section.
uint32_t
original_size() const
{ return this->original_size_; }
// Return the stub table.
The_stub_table*
stub_table()
{ return stub_table_; }
protected:
// Write out this input section.
void
do_write(Output_file*);
// Return required alignment of this.
uint64_t
do_addralign() const
{
if (this->is_stub_table_owner())
return std::max(this->stub_table_->addralign(),
static_cast<uint64_t>(this->original_addralign_));
else
return this->original_addralign_;
}
// Finalize data size.
void
set_final_data_size();
// Reset address and file offset.
void
do_reset_address_and_file_offset();
// Output offset.
bool
do_output_offset(const Relobj* object, unsigned int shndx,
section_offset_type offset,
section_offset_type* poutput) const
{
if ((object == this->relobj())
&& (shndx == this->shndx())
&& (offset >= 0)
&& (offset <=
convert_types<section_offset_type, uint32_t>(this->original_size_)))
{
*poutput = offset;
return true;
}
else
return false;
}
private:
// Copying is not allowed.
AArch64_input_section(const AArch64_input_section&);
AArch64_input_section& operator=(const AArch64_input_section&);
// The relocation stubs.
The_stub_table* stub_table_;
// Original section contents. We have to make a copy here since the file
// containing the original section may not be locked when we need to access
// the contents.
unsigned char* original_contents_;
// Section size of the original input section.
uint32_t original_size_;
// Address alignment of the original input section.
uint32_t original_addralign_;
}; // End of AArch64_input_section
// Finalize data size.
template<int size, bool big_endian>
void
AArch64_input_section<size, big_endian>::set_final_data_size()
{
off_t off = convert_types<off_t, uint64_t>(this->original_size_);
if (this->is_stub_table_owner())
{
this->stub_table_->finalize_data_size();
off = align_address(off, this->stub_table_->addralign());
off += this->stub_table_->data_size();
}
this->set_data_size(off);
}
// Reset address and file offset.
template<int size, bool big_endian>
void
AArch64_input_section<size, big_endian>::do_reset_address_and_file_offset()
{
// Size of the original input section contents.
off_t off = convert_types<off_t, uint64_t>(this->original_size_);
// If this is a stub table owner, account for the stub table size.
if (this->is_stub_table_owner())
{
The_stub_table* stub_table = this->stub_table_;
// Reset the stub table's address and file offset. The
// current data size for child will be updated after that.
stub_table_->reset_address_and_file_offset();
off = align_address(off, stub_table_->addralign());
off += stub_table->current_data_size();
}
this->set_current_data_size(off);
}
// Initialize an Arm_input_section.
template<int size, bool big_endian>
void
AArch64_input_section<size, big_endian>::init()
{
Relobj* relobj = this->relobj();
unsigned int shndx = this->shndx();
// We have to cache original size, alignment and contents to avoid locking
// the original file.
this->original_addralign_ =
convert_types<uint32_t, uint64_t>(relobj->section_addralign(shndx));
// This is not efficient but we expect only a small number of relaxed
// input sections for stubs.
section_size_type section_size;
const unsigned char* section_contents =
relobj->section_contents(shndx, &section_size, false);
this->original_size_ =
convert_types<uint32_t, uint64_t>(relobj->section_size(shndx));
gold_assert(this->original_contents_ == NULL);
this->original_contents_ = new unsigned char[section_size];
memcpy(this->original_contents_, section_contents, section_size);
// We want to make this look like the original input section after
// output sections are finalized.
Output_section* os = relobj->output_section(shndx);
off_t offset = relobj->output_section_offset(shndx);
gold_assert(os != NULL && !relobj->is_output_section_offset_invalid(shndx));
this->set_address(os->address() + offset);
this->set_file_offset(os->offset() + offset);
this->set_current_data_size(this->original_size_);
this->finalize_data_size();
}
// Write data to output file.
template<int size, bool big_endian>
void
AArch64_input_section<size, big_endian>::do_write(Output_file* of)
{
// We have to write out the original section content.
gold_assert(this->original_contents_ != NULL);
of->write(this->offset(), this->original_contents_,
this->original_size_);
// If this owns a stub table and it is not empty, write it.
if (this->is_stub_table_owner() && !this->stub_table_->empty())
this->stub_table_->write(of);
}
// Arm output section class. This is defined mainly to add a number of stub
// generation methods.
template<int size, bool big_endian>
class AArch64_output_section : public Output_section
{
public:
typedef Target_aarch64<size, big_endian> The_target_aarch64;
typedef AArch64_relobj<size, big_endian> The_aarch64_relobj;
typedef Stub_table<size, big_endian> The_stub_table;
typedef AArch64_input_section<size, big_endian> The_aarch64_input_section;
public:
AArch64_output_section(const char* name, elfcpp::Elf_Word type,
elfcpp::Elf_Xword flags)
: Output_section(name, type, flags)
{ }
~AArch64_output_section() {}
// Group input sections for stub generation.
void
group_sections(section_size_type, bool, Target_aarch64<size, big_endian>*,
const Task*);
private:
typedef Output_section::Input_section Input_section;
typedef Output_section::Input_section_list Input_section_list;
// Create a stub group.
void
create_stub_group(Input_section_list::const_iterator,
Input_section_list::const_iterator,
Input_section_list::const_iterator,
The_target_aarch64*,
std::vector<Output_relaxed_input_section*>&,
const Task*);
}; // End of AArch64_output_section
// Create a stub group for input sections from FIRST to LAST. OWNER points to
// the input section that will be the owner of the stub table.
template<int size, bool big_endian> void
AArch64_output_section<size, big_endian>::create_stub_group(
Input_section_list::const_iterator first,
Input_section_list::const_iterator last,
Input_section_list::const_iterator owner,
The_target_aarch64* target,
std::vector<Output_relaxed_input_section*>& new_relaxed_sections,
const Task* task)
{
// Currently we convert ordinary input sections into relaxed sections only
// at this point.
The_aarch64_input_section* input_section;
if (owner->is_relaxed_input_section())
gold_unreachable();
else
{
gold_assert(owner->is_input_section());
// Create a new relaxed input section. We need to lock the original
// file.
Task_lock_obj<Object> tl(task, owner->relobj());
input_section =
target->new_aarch64_input_section(owner->relobj(), owner->shndx());
new_relaxed_sections.push_back(input_section);
}
// Create a stub table.
The_stub_table* stub_table =
target->new_stub_table(input_section);
input_section->set_stub_table(stub_table);
Input_section_list::const_iterator p = first;
// Look for input sections or relaxed input sections in [first ... last].
do
{
if (p->is_input_section() || p->is_relaxed_input_section())
{
// The stub table information for input sections live
// in their objects.
The_aarch64_relobj* aarch64_relobj =
static_cast<The_aarch64_relobj*>(p->relobj());
aarch64_relobj->set_stub_table(p->shndx(), stub_table);
}
}
while (p++ != last);
}
// Group input sections for stub generation. GROUP_SIZE is roughly the limit of
// stub groups. We grow a stub group by adding input section until the size is
// just below GROUP_SIZE. The last input section will be converted into a stub
// table owner. If STUB_ALWAYS_AFTER_BRANCH is false, we also add input sectiond
// after the stub table, effectively doubling the group size.
//
// This is similar to the group_sections() function in elf32-arm.c but is
// implemented differently.
template<int size, bool big_endian>
void AArch64_output_section<size, big_endian>::group_sections(
section_size_type group_size,
bool stubs_always_after_branch,
Target_aarch64<size, big_endian>* target,
const Task* task)
{
typedef enum
{
NO_GROUP,
FINDING_STUB_SECTION,
HAS_STUB_SECTION
} State;
std::vector<Output_relaxed_input_section*> new_relaxed_sections;
State state = NO_GROUP;
section_size_type off = 0;
section_size_type group_begin_offset = 0;
section_size_type group_end_offset = 0;
section_size_type stub_table_end_offset = 0;
Input_section_list::const_iterator group_begin =
this->input_sections().end();
Input_section_list::const_iterator stub_table =
this->input_sections().end();
Input_section_list::const_iterator group_end = this->input_sections().end();
for (Input_section_list::const_iterator p = this->input_sections().begin();
p != this->input_sections().end();
++p)
{
section_size_type section_begin_offset =
align_address(off, p->addralign());
section_size_type section_end_offset =
section_begin_offset + p->data_size();
// Check to see if we should group the previously seen sections.
switch (state)
{
case NO_GROUP:
break;
case FINDING_STUB_SECTION:
// Adding this section makes the group larger than GROUP_SIZE.
if (section_end_offset - group_begin_offset >= group_size)
{
if (stubs_always_after_branch)
{
gold_assert(group_end != this->input_sections().end());
this->create_stub_group(group_begin, group_end, group_end,
target, new_relaxed_sections,
task);
state = NO_GROUP;
}
else
{
// Input sections up to stub_group_size bytes after the stub
// table can be handled by it too.
state = HAS_STUB_SECTION;
stub_table = group_end;
stub_table_end_offset = group_end_offset;
}
}
break;
case HAS_STUB_SECTION:
// Adding this section makes the post stub-section group larger
// than GROUP_SIZE.
gold_unreachable();
// NOT SUPPORTED YET. For completeness only.
if (section_end_offset - stub_table_end_offset >= group_size)
{
gold_assert(group_end != this->input_sections().end());
this->create_stub_group(group_begin, group_end, stub_table,
target, new_relaxed_sections, task);
state = NO_GROUP;
}
break;
default:
gold_unreachable();
}
// If we see an input section and currently there is no group, start
// a new one. Skip any empty sections. We look at the data size
// instead of calling p->relobj()->section_size() to avoid locking.
if ((p->is_input_section() || p->is_relaxed_input_section())
&& (p->data_size() != 0))
{
if (state == NO_GROUP)
{
state = FINDING_STUB_SECTION;
group_begin = p;
group_begin_offset = section_begin_offset;
}
// Keep track of the last input section seen.
group_end = p;
group_end_offset = section_end_offset;
}
off = section_end_offset;
}
// Create a stub group for any ungrouped sections.
if (state == FINDING_STUB_SECTION || state == HAS_STUB_SECTION)
{
gold_assert(group_end != this->input_sections().end());
this->create_stub_group(group_begin, group_end,
(state == FINDING_STUB_SECTION
? group_end
: stub_table),
target, new_relaxed_sections, task);
}
if (!new_relaxed_sections.empty())
this->convert_input_sections_to_relaxed_sections(new_relaxed_sections);
// Update the section offsets
for (size_t i = 0; i < new_relaxed_sections.size(); ++i)
{
The_aarch64_relobj* relobj = static_cast<The_aarch64_relobj*>(
new_relaxed_sections[i]->relobj());
unsigned int shndx = new_relaxed_sections[i]->shndx();
// Tell AArch64_relobj that this input section is converted.
relobj->convert_input_section_to_relaxed_section(shndx);
}
} // End of AArch64_output_section::group_sections
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 Relocate_info<size, big_endian> The_relocate_info;
typedef typename elfcpp::Elf_types<size>::Elf_Addr Address;
typedef AArch64_relobj<size, big_endian> The_aarch64_relobj;
typedef Reloc_stub<size, big_endian> The_reloc_stub;
typedef typename The_reloc_stub::Stub_type The_reloc_stub_type;
typedef typename Reloc_stub<size, big_endian>::Key The_reloc_stub_key;
typedef Stub_table<size, big_endian> The_stub_table;
typedef std::vector<The_stub_table*> Stub_table_list;
typedef typename Stub_table_list::iterator Stub_table_iterator;
typedef AArch64_input_section<size, big_endian> The_aarch64_input_section;
typedef AArch64_output_section<size, big_endian> The_aarch64_output_section;
typedef Unordered_map<Section_id,
AArch64_input_section<size, big_endian>*,
Section_id_hash> AArch64_input_section_map;
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), got_irelative_(NULL),
got_tlsdesc_(NULL), global_offset_table_(NULL), rela_dyn_(NULL),
rela_irelative_(NULL), copy_relocs_(elfcpp::R_AARCH64_COPY),
got_mod_index_offset_(-1U),
tlsdesc_reloc_info_(), tls_base_symbol_defined_(false),
stub_tables_(), stub_group_size_(0), aarch64_input_section_map_()
{ }
// 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*);
// Return the value to use for a dynamic which requires special
// treatment.
uint64_t
do_dynsym_value(const Symbol*) const;
// 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 symbol index to use for a target specific relocation.
// The only target specific relocation is R_AARCH64_TLSDESC for a
// local symbol, which is an absolute reloc.
unsigned int
do_reloc_symbol_index(void*, unsigned int r_type) const
{
gold_assert(r_type == elfcpp::R_AARCH64_TLSDESC);
return 0;
}
// Return the addend to use for a target specific relocation.
typename elfcpp::Elf_types<size>::Elf_Addr
do_reloc_addend(void* arg, unsigned int r_type,
typename elfcpp::Elf_types<size>::Elf_Addr addend) const;
// 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); }
// This function should be defined in targets that can use relocation
// types to determine (implemented in local_reloc_may_be_function_pointer
// and global_reloc_may_be_function_pointer)
// if a function's pointer is taken. ICF uses this in safe mode to only
// fold those functions whose pointer is defintely not taken.
bool
do_can_check_for_function_pointers() const
{ return true; }
// 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;
// Create a stub table.
The_stub_table*
new_stub_table(The_aarch64_input_section*);
// Create an aarch64 input section.
The_aarch64_input_section*
new_aarch64_input_section(Relobj*, unsigned int);
// Find an aarch64 input section instance for a given OBJ and SHNDX.
The_aarch64_input_section*
find_aarch64_input_section(Relobj*, unsigned int) const;
// Return the thread control block size.
unsigned int
tcb_size() const { return This::TCB_SIZE; }
// Scan a section for stub generation.
void
scan_section_for_stubs(const Relocate_info<size, big_endian>*, unsigned int,
const unsigned char*, size_t, Output_section*,
bool, const unsigned char*,
Address,
section_size_type);
// Scan a relocation section for stub.
template<int sh_type>
void
scan_reloc_section_for_stubs(
const The_relocate_info* relinfo,
const unsigned char* prelocs,
size_t reloc_count,
Output_section* output_section,
bool needs_special_offset_handling,
const unsigned char* view,
Address view_address,
section_size_type);
// Relocate a single stub.
void
relocate_stub(The_reloc_stub*, const Relocate_info<size, big_endian>*,
Output_section*, unsigned char*, Address,
section_size_type);
// Get the default AArch64 target.
static This*
current_target()
{
gold_assert(parameters->target().machine_code() == elfcpp::EM_AARCH64
&& parameters->target().get_size() == size
&& parameters->target().is_big_endian() == big_endian);
return static_cast<This*>(parameters->sized_target<size, big_endian>());
}
protected:
void
do_select_as_default_target()
{
gold_assert(aarch64_reloc_property_table == NULL);
aarch64_reloc_property_table = new AArch64_reloc_property_table();
}
// Add a new reloc argument, returning the index in the vector.
size_t
add_tlsdesc_info(Sized_relobj_file<size, big_endian>* object,
unsigned int r_sym)
{
this->tlsdesc_reloc_info_.push_back(Tlsdesc_info(object, r_sym));
return this->tlsdesc_reloc_info_.size() - 1;
}
virtual Output_data_plt_aarch64<size, big_endian>*
do_make_data_plt(Layout* layout,
Output_data_got_aarch64<size, big_endian>* got,
Output_data_space* got_plt,
Output_data_space* got_irelative)
{
return new Output_data_plt_aarch64_standard<size, big_endian>(
layout, got, got_plt, got_irelative);
}
// do_make_elf_object to override the same function in the base class.
Object*
do_make_elf_object(const std::string&, Input_file*, off_t,
const elfcpp::Ehdr<size, big_endian>&);
Output_data_plt_aarch64<size, big_endian>*
make_data_plt(Layout* layout,
Output_data_got_aarch64<size, big_endian>* got,
Output_data_space* got_plt,
Output_data_space* got_irelative)
{
return this->do_make_data_plt(layout, got, got_plt, got_irelative);
}
// We only need to generate stubs, and hence perform relaxation if we are
// not doing relocatable linking.
virtual bool
do_may_relax() const
{ return !parameters->options().relocatable(); }
// Relaxation hook. This is where we do stub generation.
virtual bool
do_relax(int, const Input_objects*, Symbol_table*, Layout*, const Task*);
void
group_sections(Layout* layout,
section_size_type group_size,
bool stubs_always_after_branch,
const Task* task);
void
scan_reloc_for_stub(const The_relocate_info*, unsigned int,
const Sized_symbol<size>*, unsigned int,
const Symbol_value<size>*,
typename elfcpp::Elf_types<size>::Elf_Swxword,
Address Elf_Addr);
// Make an output section.
Output_section*
do_make_output_section(const char* name, elfcpp::Elf_Word type,
elfcpp::Elf_Xword flags)
{ return new The_aarch64_output_section(name, type, flags); }
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);
bool
reloc_needs_plt_for_ifunc(Sized_relobj_file<size, big_endian>*,
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()
: skip_call_tls_get_addr_(false)
{ }
~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);
inline typename AArch64_relocate_functions<size, big_endian>::Status
tls_gd_to_le(
const Relocate_info<size, big_endian>*,
Target_aarch64<size, big_endian>*,
const elfcpp::Rela<size, big_endian>&,
unsigned int,
unsigned char*,
const Symbol_value<size>*);
inline typename AArch64_relocate_functions<size, big_endian>::Status
tls_ld_to_le(
const Relocate_info<size, big_endian>*,
Target_aarch64<size, big_endian>*,
const elfcpp::Rela<size, big_endian>&,
unsigned int,
unsigned char*,
const Symbol_value<size>*);
inline typename AArch64_relocate_functions<size, big_endian>::Status
tls_ie_to_le(
const Relocate_info<size, big_endian>*,
Target_aarch64<size, big_endian>*,
const elfcpp::Rela<size, big_endian>&,
unsigned int,
unsigned char*,
const Symbol_value<size>*);
inline typename AArch64_relocate_functions<size, big_endian>::Status
tls_desc_gd_to_le(
const Relocate_info<size, big_endian>*,
Target_aarch64<size, big_endian>*,
const elfcpp::Rela<size, big_endian>&,
unsigned int,
unsigned char*,
const Symbol_value<size>*);
inline typename AArch64_relocate_functions<size, big_endian>::Status
tls_desc_gd_to_ie(
const Relocate_info<size, big_endian>*,
Target_aarch64<size, big_endian>*,
const elfcpp::Rela<size, big_endian>&,
unsigned int,
unsigned char*,
const Symbol_value<size>*,
typename elfcpp::Elf_types<size>::Elf_Addr,
typename elfcpp::Elf_types<size>::Elf_Addr);
bool skip_call_tls_get_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_;
}
// Get the GOT section for TLSDESC entries.
Output_data_got<size, big_endian>*
got_tlsdesc_section() const
{
gold_assert(this->got_tlsdesc_ != NULL);
return this->got_tlsdesc_;
}
// 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*);
// Create a PLT entry for a local STT_GNU_IFUNC symbol.
void
make_local_ifunc_plt_entry(Symbol_table*, Layout*,
Sized_relobj_file<size, big_endian>* relobj,
unsigned int local_sym_index);
// Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
void
define_tls_base_symbol(Symbol_table*, Layout*);
// Create the reserved PLT and GOT entries for the TLS descriptor resolver.
void
reserve_tlsdesc_entries(Symbol_table* symtab, Layout* layout);
// Create a GOT entry for the TLS module index.
unsigned int
got_mod_index_entry(Symbol_table* symtab, Layout* layout,
Sized_relobj_file<size, big_endian>* object);
// 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*);
// Get the section to use for TLSDESC relocations.
Reloc_section*
rela_tlsdesc_section(Layout*) const;
// Get the section to use for IRELATIVE relocations.
Reloc_section*
rela_irelative_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
};
// This type is used as the argument to the target specific
// relocation routines. The only target specific reloc is
// R_AARCh64_TLSDESC against a local symbol.
struct Tlsdesc_info
{
Tlsdesc_info(Sized_relobj_file<size, big_endian>* a_object,
unsigned int a_r_sym)
: object(a_object), r_sym(a_r_sym)
{ }
// The object in which the local symbol is defined.
Sized_relobj_file<size, big_endian>* object;
// The local symbol index in the object.
unsigned int r_sym;
};
// 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 GOT section for IRELATIVE relocations.
Output_data_space* got_irelative_;
// The GOT section for TLSDESC relocations.
Output_data_got<size, big_endian>* got_tlsdesc_;
// The _GLOBAL_OFFSET_TABLE_ symbol.
Symbol* global_offset_table_;
// The dynamic reloc section.
Reloc_section* rela_dyn_;
// The section to use for IRELATIVE relocs.
Reloc_section* rela_irelative_;
// Relocs saved to avoid a COPY reloc.
Copy_relocs<elfcpp::SHT_RELA, size, big_endian> copy_relocs_;
// Offset of the GOT entry for the TLS module index.
unsigned int got_mod_index_offset_;
// We handle R_AARCH64_TLSDESC against a local symbol as a target
// specific relocation. Here we store the object and local symbol
// index for the relocation.
std::vector<Tlsdesc_info> tlsdesc_reloc_info_;
// True if the _TLS_MODULE_BASE_ symbol has been defined.
bool tls_base_symbol_defined_;
// List of stub_tables
Stub_table_list stub_tables_;
// Actual stub group size
section_size_type stub_group_size_;
AArch64_input_section_map aarch64_input_section_map_;
}; // 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
true, // 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
true, // 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 there are any IRELATIVE relocations, they get GOT entries
// in .got.plt after the jump slot entries.
this->got_irelative_ = new Output_data_space(size / 8,
"** GOT IRELATIVE PLT");
layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
(elfcpp::SHF_ALLOC
| elfcpp::SHF_WRITE),
this->got_irelative_,
got_plt_order,
is_got_plt_relro);
// If there are any TLSDESC relocations, they get GOT entries in
// .got.plt after the jump slot and IRELATIVE entries.
this->got_tlsdesc_ = new Output_data_got<size, big_endian>();
layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
(elfcpp::SHF_ALLOC
| elfcpp::SHF_WRITE),
this->got_tlsdesc_,
got_plt_order,
is_got_plt_relro);
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_;
}
// Get the section to use for IRELATIVE relocs, creating it if
// necessary. These go in .rela.dyn, but only after all other dynamic
// relocations. They need to follow the other dynamic relocations so
// that they can refer to global variables initialized by those
// relocs.
template<int size, bool big_endian>
typename Target_aarch64<size, big_endian>::Reloc_section*
Target_aarch64<size, big_endian>::rela_irelative_section(Layout* layout)
{
if (this->rela_irelative_ == NULL)
{
// Make sure we have already created the dynamic reloc section.
this->rela_dyn_section(layout);
this->rela_irelative_ = new Reloc_section(false);
layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA,
elfcpp::SHF_ALLOC, this->rela_irelative_,
ORDER_DYNAMIC_RELOCS, false);
gold_assert(this->rela_dyn_->output_section()
== this->rela_irelative_->output_section());
}
return this->rela_irelative_;
}
// do_make_elf_object to override the same function in the base class. We need
// to use a target-specific sub-class of Sized_relobj_file<size, big_endian> to
// store backend specific information. Hence we need to have our own ELF object
// creation.
template<int size, bool big_endian>
Object*
Target_aarch64<size, big_endian>::do_make_elf_object(
const std::string& name,
Input_file* input_file,
off_t offset, const elfcpp::Ehdr<size, big_endian>& ehdr)
{
int et = ehdr.get_e_type();
// ET_EXEC files are valid input for --just-symbols/-R,
// and we treat them as relocatable objects.
if (et == elfcpp::ET_EXEC && input_file->just_symbols())
return Sized_target<size, big_endian>::do_make_elf_object(
name, input_file, offset, ehdr);
else if (et == elfcpp::ET_REL)
{
AArch64_relobj<size, big_endian>* obj =
new AArch64_relobj<size, big_endian>(name, input_file, offset, ehdr);
obj->setup();
return obj;
}
else if (et == elfcpp::ET_DYN)
{
// Keep base implementation.
Sized_dynobj<size, big_endian>* obj =
new Sized_dynobj<size, big_endian>(name, input_file, offset, ehdr);
obj->setup();
return obj;
}
else
{
gold_error(_("%s: unsupported ELF file type %d"),
name.c_str(), et);
return NULL;
}
}
// Scan a relocation for stub generation.
template<int size, bool big_endian>
void
Target_aarch64<size, big_endian>::scan_reloc_for_stub(
const Relocate_info<size, big_endian>* relinfo,
unsigned int r_type,
const Sized_symbol<size>* gsym,
unsigned int r_sym,
const Symbol_value<size>* psymval,
typename elfcpp::Elf_types<size>::Elf_Swxword addend,
Address address)
{
const AArch64_relobj<size, big_endian>* aarch64_relobj =
static_cast<AArch64_relobj<size, big_endian>*>(relinfo->object);
Symbol_value<size> symval;
if (gsym != NULL)
{
const AArch64_reloc_property* arp = aarch64_reloc_property_table->
get_reloc_property(r_type);
if (gsym->use_plt_offset(arp->reference_flags()))
{
// This uses a PLT, change the symbol value.
symval.set_output_value(this->plt_section()->address()
+ gsym->plt_offset());
psymval = &symval;
}
else if (gsym->is_undefined())
// There is no need to generate a stub symbol is undefined.
return;
}
// Get the symbol value.
typename Symbol_value<size>::Value value = psymval->value(aarch64_relobj, 0);
// Owing to pipelining, the PC relative branches below actually skip
// two instructions when the branch offset is 0.
Address destination = static_cast<Address>(-1);
switch (r_type)
{
case elfcpp::R_AARCH64_CALL26:
case elfcpp::R_AARCH64_JUMP26:
destination = value + addend;
break;
default:
gold_unreachable();
}
typename The_reloc_stub::Stub_type stub_type = The_reloc_stub::
stub_type_for_reloc(r_type, address, destination);
if (stub_type == The_reloc_stub::ST_NONE)
return ;
The_stub_table* stub_table = aarch64_relobj->stub_table(relinfo->data_shndx);
gold_assert(stub_table != NULL);
The_reloc_stub_key key(stub_type, gsym, aarch64_relobj, r_sym, addend);
The_reloc_stub* stub = stub_table->find_reloc_stub(key);
if (stub == NULL)
{
stub = new The_reloc_stub(stub_type);
stub_table->add_reloc_stub(stub, key);
}
stub->set_destination_address(destination);
} // End of Target_aarch64::scan_reloc_for_stub
// This function scans a relocation section for stub generation.
// The template parameter Relocate must be a class type which provides
// a single function, relocate(), which implements the machine
// specific part of a relocation.
// BIG_ENDIAN is the endianness of the data. SH_TYPE is the section type:
// SHT_REL or SHT_RELA.
// PRELOCS points to the relocation data. RELOC_COUNT is the number
// of relocs. OUTPUT_SECTION is the output section.
// NEEDS_SPECIAL_OFFSET_HANDLING is true if input offsets need to be
// mapped to output offsets.
// VIEW is the section data, VIEW_ADDRESS is its memory address, and
// VIEW_SIZE is the size. These refer to the input section, unless
// NEEDS_SPECIAL_OFFSET_HANDLING is true, in which case they refer to
// the output section.
template<int size, bool big_endian>
template<int sh_type>
void inline
Target_aarch64<size, big_endian>::scan_reloc_section_for_stubs(
const Relocate_info<size, big_endian>* relinfo,
const unsigned char* prelocs,
size_t reloc_count,
Output_section* /*output_section*/,
bool /*needs_special_offset_handling*/,
const unsigned char* /*view*/,
Address view_address,
section_size_type)
{
typedef typename Reloc_types<sh_type,size,big_endian>::Reloc Reltype;
const int reloc_size =
Reloc_types<sh_type,size,big_endian>::reloc_size;
AArch64_relobj<size, big_endian>* object =
static_cast<AArch64_relobj<size, big_endian>*>(relinfo->object);
unsigned int local_count = object->local_symbol_count();
gold::Default_comdat_behavior default_comdat_behavior;
Comdat_behavior comdat_behavior = CB_UNDETERMINED;
for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
{
Reltype reloc(prelocs);
typename elfcpp::Elf_types<size>::Elf_WXword r_info = reloc.get_r_info();
unsigned int r_sym = elfcpp::elf_r_sym<size>(r_info);
unsigned int r_type = elfcpp::elf_r_type<size>(r_info);
if (r_type != elfcpp::R_AARCH64_CALL26
&& r_type != elfcpp::R_AARCH64_JUMP26)
continue;
section_offset_type offset =
convert_to_section_size_type(reloc.get_r_offset());
// Get the addend.
typename elfcpp::Elf_types<size>::Elf_Swxword addend =
reloc.get_r_addend();
const Sized_symbol<size>* sym;
Symbol_value<size> symval;
const Symbol_value<size> *psymval;
bool is_defined_in_discarded_section;
unsigned int shndx;
if (r_sym < local_count)
{
sym = NULL;
psymval = object->local_symbol(r_sym);
// If the local symbol belongs to a section we are discarding,
// and that section is a debug section, try to find the
// corresponding kept section and map this symbol to its
// counterpart in the kept section. The symbol must not
// correspond to a section we are folding.
bool is_ordinary;
shndx = psymval->input_shndx(&is_ordinary);
is_defined_in_discarded_section =
(is_ordinary
&& shndx != elfcpp::SHN_UNDEF
&& !object->is_section_included(shndx)
&& !relinfo->symtab->is_section_folded(object, shndx));
// We need to compute the would-be final value of this local
// symbol.
if (!is_defined_in_discarded_section)
{
typedef Sized_relobj_file<size, big_endian> ObjType;
typename ObjType::Compute_final_local_value_status status =
object->compute_final_local_value(r_sym, psymval, &symval,
relinfo->symtab);
if (status == ObjType::CFLV_OK)
{
// Currently we cannot handle a branch to a target in
// a merged section. If this is the case, issue an error
// and also free the merge symbol value.
if (!symval.has_output_value())
{
const std::string& section_name =
object->section_name(shndx);
object->error(_("cannot handle branch to local %u "
"in a merged section %s"),
r_sym, section_name.c_str());
}
psymval = &symval;
}
else
{
// We cannot determine the final value.
continue;
}
}
}
else
{
const Symbol* gsym;
gsym = object->global_symbol(r_sym);
gold_assert(gsym != NULL);
if (gsym->is_forwarder())
gsym = relinfo->symtab->resolve_forwards(gsym);
sym = static_cast<const Sized_symbol<size>*>(gsym);
if (sym->has_symtab_index() && sym->symtab_index() != -1U)
symval.set_output_symtab_index(sym->symtab_index());
else
symval.set_no_output_symtab_entry();
// We need to compute the would-be final value of this global
// symbol.
const Symbol_table* symtab = relinfo->symtab;
const Sized_symbol<size>* sized_symbol =
symtab->get_sized_symbol<size>(gsym);
Symbol_table::Compute_final_value_status status;
typename elfcpp::Elf_types<size>::Elf_Addr value =
symtab->compute_final_value<size>(sized_symbol, &status);
// Skip this if the symbol has not output section.
if (status == Symbol_table::CFVS_NO_OUTPUT_SECTION)
continue;
symval.set_output_value(value);
if (gsym->type() == elfcpp::STT_TLS)
symval.set_is_tls_symbol();
else if (gsym->type() == elfcpp::STT_GNU_IFUNC)
symval.set_is_ifunc_symbol();
psymval = &symval;
is_defined_in_discarded_section =
(gsym->is_defined_in_discarded_section()
&& gsym->is_undefined());
shndx = 0;
}
Symbol_value<size> symval2;
if (is_defined_in_discarded_section)
{
if (comdat_behavior == CB_UNDETERMINED)
{
std::string name = object->section_name(relinfo->data_shndx);
comdat_behavior = default_comdat_behavior.get(name.c_str());
}
if (comdat_behavior == CB_PRETEND)
{
bool found;
typename elfcpp::Elf_types<size>::Elf_Addr value =
object->map_to_kept_section(shndx, &found);
if (found)
symval2.set_output_value(value + psymval->input_value());
else
symval2.set_output_value(0);
}
else
{
if (comdat_behavior == CB_WARNING)
gold_warning_at_location(relinfo, i, offset,
_("relocation refers to discarded "
"section"));
symval2.set_output_value(0);
}
symval2.set_no_output_symtab_entry();
psymval = &symval2;
}
// If symbol is a section symbol, we don't know the actual type of
// destination. Give up.
if (psymval->is_section_symbol())
continue;
this->scan_reloc_for_stub(relinfo, r_type, sym, r_sym, psymval,
addend, view_address + offset);
} // End of iterating relocs in a section
} // End of Target_aarch64::scan_reloc_section_for_stubs
// Scan an input section for stub generation.
template<int size, bool big_endian>
void
Target_aarch64<size, big_endian>::scan_section_for_stubs(
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,
const unsigned char* view,
Address view_address,
section_size_type view_size)
{
gold_assert(sh_type == elfcpp::SHT_RELA);
this->scan_reloc_section_for_stubs<elfcpp::SHT_RELA>(
relinfo,
prelocs,
reloc_count,
output_section,
needs_special_offset_handling,
view,
view_address,
view_size);
}
// Relocate a single stub.
template<int size, bool big_endian>
void Target_aarch64<size, big_endian>::
relocate_stub(The_reloc_stub* stub,
const The_relocate_info*,
Output_section*,
unsigned char* view,
Address address,
section_size_type)
{
typedef AArch64_relocate_functions<size, big_endian> The_reloc_functions;
typedef typename The_reloc_functions::Status The_reloc_functions_status;
typedef typename elfcpp::Swap<32,big_endian>::Valtype Insntype;
Insntype* ip = reinterpret_cast<Insntype*>(view);
int insn_number = stub->stub_insn_number();
const uint32_t* insns = stub->stub_insns();
// Check the insns are really those stub insns.
for (int i = 0; i < insn_number; ++i)
{
Insntype insn = elfcpp::Swap<32,big_endian>::readval(ip + i);
gold_assert(((uint32_t)insn == insns[i+1]));
}
Address dest = stub->destination_address();
switch(stub->stub_type())
{
case The_reloc_stub::ST_ADRP_BRANCH:
{
// 1st reloc is ADR_PREL_PG_HI21
The_reloc_functions_status status =
The_reloc_functions::adrp(view, dest, address);
// An error should never arise in the above step. If so, please
// check 'aarch64_valid_for_adrp_p'.
gold_assert(status == The_reloc_functions::STATUS_OKAY);
// 2nd reloc is ADD_ABS_LO12_NC
const AArch64_reloc_property* arp =
aarch64_reloc_property_table->get_reloc_property(
elfcpp::R_AARCH64_ADD_ABS_LO12_NC);
gold_assert(arp != NULL);
status = The_reloc_functions::template
rela_general<32>(view + 4, dest, 0, arp);
// An error should never arise, it is an "_NC" relocation.
gold_assert(status == The_reloc_functions::STATUS_OKAY);
}
break;
case The_reloc_stub::ST_LONG_BRANCH_ABS:
// 1st reloc is R_AARCH64_PREL64, at offset 8
elfcpp::Swap<64,big_endian>::writeval(view + 8, dest);
break;
case The_reloc_stub::ST_LONG_BRANCH_PCREL:
{
// "PC" calculation is the 2nd insn in the stub.
uint64_t offset = dest - (address + 4);
// Offset is placed at offset 4 and 5.
elfcpp::Swap<64,big_endian>::writeval(view + 16, offset);
}
break;
default:
gold_unreachable();
}
}
// 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_got_aarch64<size, big_endian>* got,
Output_data_space* got_plt,
Output_data_space* got_irelative)
: Output_section_data(addralign), tlsdesc_rel_(NULL), irelative_rel_(NULL),
got_(got), got_plt_(got_plt), got_irelative_(got_irelative),
count_(0), irelative_count_(0), tlsdesc_got_offset_(-1U)
{ this->init(layout); }
// Initialize the PLT section.
void
init(Layout* layout);
// Add an entry to the PLT.
void
add_entry(Symbol_table*, Layout*, Symbol* gsym);
// Add an entry to the PLT for a local STT_GNU_IFUNC symbol.
unsigned int
add_local_ifunc_entry(Symbol_table* symtab, Layout*,
Sized_relobj_file<size, big_endian>* relobj,
unsigned int local_sym_index);
// Add the relocation for a PLT entry.
void
add_relocation(Symbol_table*, Layout*, Symbol* gsym,
unsigned int got_offset);
// Add the reserved TLSDESC_PLT entry to the PLT.
void
reserve_tlsdesc_entry(unsigned int got_offset)
{ this->tlsdesc_got_offset_ = got_offset; }
// Return true if a TLSDESC_PLT entry has been reserved.
bool
has_tlsdesc_entry() const
{ return this->tlsdesc_got_offset_ != -1U; }
// Return the GOT offset for the reserved TLSDESC_PLT entry.
unsigned int
get_tlsdesc_got_offset() const
{ return this->tlsdesc_got_offset_; }
// Return the PLT offset of the reserved TLSDESC_PLT entry.
unsigned int
get_tlsdesc_plt_offset() const
{
return (this->first_plt_entry_offset() +
(this->count_ + this->irelative_count_)
* this->get_plt_entry_size());
}
// Return the .rela.plt section data.
Reloc_section*
rela_plt()
{ return this->rel_; }
// Return where the TLSDESC relocations should go.
Reloc_section*
rela_tlsdesc(Layout*);
// Return where the IRELATIVE relocations should go in the PLT
// relocations.
Reloc_section*
rela_irelative(Symbol_table*, Layout*);
// 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_ + this->irelative_count_; }
// Return the offset of the first non-reserved PLT entry.
unsigned int
first_plt_entry_offset() const
{ 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 reserved tlsdesc entry size.
unsigned int
get_plt_tlsdesc_entry_size() const
{ return this->do_get_plt_tlsdesc_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);
}
// Fill in the reserved TLSDESC PLT entry.
void
fill_tlsdesc_entry(unsigned char* pov,
Address gotplt_address,
Address plt_address,
Address got_base,
unsigned int tlsdesc_got_offset,
unsigned int plt_offset)
{
this->do_fill_tlsdesc_entry(pov, gotplt_address, plt_address, got_base,
tlsdesc_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 unsigned int
do_get_plt_tlsdesc_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;
virtual void
do_fill_tlsdesc_entry(unsigned char* pov,
Address gotplt_address,
Address plt_address,
Address got_base,
unsigned int tlsdesc_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 TLSDESC relocs, if necessary. These must follow the regular
// PLT relocs.
Reloc_section* tlsdesc_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 part of the .got.plt section used for IRELATIVE relocs.
Output_data_space* got_irelative_;
// The number of PLT entries.
unsigned int count_;
// Number of PLT entries with R_X86_64_IRELATIVE relocs. These
// follow the regular PLT entries.
unsigned int irelative_count_;
// GOT offset of the reserved TLSDESC_GOT entry for the lazy trampoline.
// Communicated to the loader via DT_TLSDESC_GOT. The magic value -1
// indicates an offset is not allocated.
unsigned int tlsdesc_got_offset_;
};
// 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_table* symtab,
Layout* layout, Symbol* gsym)
{
gold_assert(!gsym->has_plt_offset());
unsigned int* pcount;
unsigned int plt_reserved;
Output_section_data_build* got;
if (gsym->type() == elfcpp::STT_GNU_IFUNC
&& gsym->can_use_relative_reloc(false))
{
pcount = &this->irelative_count_;
plt_reserved = 0;
got = this->got_irelative_;
}
else
{
pcount = &this->count_;
plt_reserved = this->first_plt_entry_offset();
got = this->got_plt_;
}
gsym->set_plt_offset((*pcount) * this->get_plt_entry_size()
+ plt_reserved);
++*pcount;
section_offset_type got_offset = got->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).
got->set_current_data_size(got_offset + size / 8);
// Every PLT entry needs a reloc.
this->add_relocation(symtab, layout, gsym, 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.
}
// Add an entry to the PLT for a local STT_GNU_IFUNC symbol. Return
// the PLT offset.
template<int size, bool big_endian>
unsigned int
Output_data_plt_aarch64<size, big_endian>::add_local_ifunc_entry(
Symbol_table* symtab,
Layout* layout,
Sized_relobj_file<size, big_endian>* relobj,
unsigned int local_sym_index)
{
unsigned int plt_offset = this->irelative_count_ * this->get_plt_entry_size();
++this->irelative_count_;
section_offset_type got_offset = this->got_irelative_->current_data_size();
// Every PLT entry needs a GOT entry which points back to the PLT
// entry.
this->got_irelative_->set_current_data_size(got_offset + size / 8);
// Every PLT entry needs a reloc.
Reloc_section* rela = this->rela_irelative(symtab, layout);
rela->add_symbolless_local_addend(relobj, local_sym_index,
elfcpp::R_AARCH64_IRELATIVE,
this->got_irelative_, got_offset, 0);
return plt_offset;
}
// Add the relocation for a PLT entry.
template<int size, bool big_endian>
void
Output_data_plt_aarch64<size, big_endian>::add_relocation(
Symbol_table* symtab, Layout* layout, Symbol* gsym, unsigned int got_offset)
{
if (gsym->type() == elfcpp::STT_GNU_IFUNC
&& gsym->can_use_relative_reloc(false))
{
Reloc_section* rela = this->rela_irelative(symtab, layout);
rela->add_symbolless_global_addend(gsym, elfcpp::R_AARCH64_IRELATIVE,
this->got_irelative_, got_offset, 0);
}
else
{
gsym->set_needs_dynsym_entry();
this->rel_->add_global(gsym, elfcpp::R_AARCH64_JUMP_SLOT, this->got_plt_,
got_offset, 0);
}
}
// Return where the TLSDESC relocations should go, creating it if
// necessary. These follow the JUMP_SLOT relocations.
template<int size, bool big_endian>
typename Output_data_plt_aarch64<size, big_endian>::Reloc_section*
Output_data_plt_aarch64<size, big_endian>::rela_tlsdesc(Layout* layout)
{
if (this->tlsdesc_rel_ == NULL)
{
this->tlsdesc_rel_ = new Reloc_section(false);
layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
elfcpp::SHF_ALLOC, this->tlsdesc_rel_,
ORDER_DYNAMIC_PLT_RELOCS, false);
gold_assert(this->tlsdesc_rel_->output_section()
== this->rel_->output_section());
}
return this->tlsdesc_rel_;
}
// Return where the IRELATIVE relocations should go in the PLT. These
// follow the JUMP_SLOT and the TLSDESC relocations.
template<int size, bool big_endian>
typename Output_data_plt_aarch64<size, big_endian>::Reloc_section*
Output_data_plt_aarch64<size, big_endian>::rela_irelative(Symbol_table* symtab,
Layout* layout)
{
if (this->irelative_rel_ == NULL)
{
// Make sure we have a place for the TLSDESC relocations, in
// case we see any later on.
this->rela_tlsdesc(layout);
this->irelative_rel_ = new Reloc_section(false);
layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
elfcpp::SHF_ALLOC, this->irelative_rel_,
ORDER_DYNAMIC_PLT_RELOCS, false);
gold_assert(this->irelative_rel_->output_section()
== this->rel_->output_section());
if (parameters->doing_static_link())
{
// A statically linked executable will only have a .rela.plt
// section to hold R_AARCH64_IRELATIVE relocs for
// STT_GNU_IFUNC symbols. The library will use these
// symbols to locate the IRELATIVE relocs at program startup
// time.
symtab->define_in_output_data("__rela_iplt_start", NULL,
Symbol_table::PREDEFINED,
this->irelative_rel_, 0, 0,
elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
elfcpp::STV_HIDDEN, 0, false, true);
symtab->define_in_output_data("__rela_iplt_end", NULL,
Symbol_table::PREDEFINED,
this->irelative_rel_, 0, 0,
elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
elfcpp::STV_HIDDEN, 0, true, true);
}
}
return this->irelative_rel_;
}
// 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()
{
unsigned int count = this->count_ + this->irelative_count_;
unsigned int extra_size = 0;
if (this->has_tlsdesc_entry())
extra_size += this->get_plt_tlsdesc_entry_size();
this->set_data_size(this->first_plt_entry_offset()
+ count * this->get_plt_entry_size()
+ extra_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_got_aarch64<size, big_endian>* got,
Output_data_space* got_plt,
Output_data_space* got_irelative)
: Output_data_plt_aarch64<size, big_endian>(layout,
size == 32 ? 4 : 8,
got, got_plt,
got_irelative)
{ }
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; }
// Return the size of a tlsdesc entry
virtual unsigned int
do_get_plt_tlsdesc_entry_size() const
{ return this->plt_tlsdesc_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);
virtual void
do_fill_tlsdesc_entry(unsigned char* pov,
Address gotplt_address,
Address plt_address,
Address got_base,
unsigned int tlsdesc_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;
// The size of the plt tlsdesc entry size.
static const int plt_tlsdesc_entry_size = 32;
// 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 reserved TLSDESC entry in the PLT for an executable.
static const uint32_t tlsdesc_plt_entry[plt_tlsdesc_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)));
}
template<>
const uint32_t
Output_data_plt_aarch64_standard<32, false>::
tlsdesc_plt_entry[plt_tlsdesc_entry_size / 4] =
{
0xa9bf0fe2, /* stp x2, x3, [sp, #-16]! */
0x90000002, /* adrp x2, 0 */
0x90000003, /* adrp x3, 0 */
0xb9400042, /* ldr w2, [w2, #0] */
0x11000063, /* add w3, w3, 0 */
0xd61f0040, /* br x2 */
0xd503201f, /* nop */
0xd503201f, /* nop */
};
template<>
const uint32_t
Output_data_plt_aarch64_standard<32, true>::
tlsdesc_plt_entry[plt_tlsdesc_entry_size / 4] =
{
0xa9bf0fe2, /* stp x2, x3, [sp, #-16]! */
0x90000002, /* adrp x2, 0 */
0x90000003, /* adrp x3, 0 */
0xb9400042, /* ldr w2, [w2, #0] */
0x11000063, /* add w3, w3, 0 */
0xd61f0040, /* br x2 */
0xd503201f, /* nop */
0xd503201f, /* nop */
};
template<>
const uint32_t
Output_data_plt_aarch64_standard<64, false>::
tlsdesc_plt_entry[plt_tlsdesc_entry_size / 4] =
{
0xa9bf0fe2, /* stp x2, x3, [sp, #-16]! */
0x90000002, /* adrp x2, 0 */
0x90000003, /* adrp x3, 0 */
0xf9400042, /* ldr x2, [x2, #0] */
0x91000063, /* add x3, x3, 0 */
0xd61f0040, /* br x2 */
0xd503201f, /* nop */
0xd503201f, /* nop */
};
template<>
const uint32_t
Output_data_plt_aarch64_standard<64, true>::
tlsdesc_plt_entry[plt_tlsdesc_entry_size / 4] =
{
0xa9bf0fe2, /* stp x2, x3, [sp, #-16]! */
0x90000002, /* adrp x2, 0 */
0x90000003, /* adrp x3, 0 */
0xf9400042, /* ldr x2, [x2, #0] */
0x91000063, /* add x3, x3, 0 */
0xd61f0040, /* br x2 */
0xd503201f, /* nop */
0xd503201f, /* nop */
};
template<int size, bool big_endian>
void
Output_data_plt_aarch64_standard<size, big_endian>::do_fill_tlsdesc_entry(
unsigned char* pov,
Address gotplt_address,
Address plt_address,
Address got_base,
unsigned int tlsdesc_got_offset,
unsigned int plt_offset)
{
memcpy(pov, tlsdesc_plt_entry, plt_tlsdesc_entry_size);
// move DT_TLSDESC_GOT address into x2
// move .got.plt address into x3
Address tlsdesc_got_entry = got_base + tlsdesc_got_offset;
Address plt_entry_address = plt_address + plt_offset;
// R_AARCH64_ADR_PREL_PG_HI21
AArch64_relocate_functions<size, big_endian>::adrp(
pov + 4,
tlsdesc_got_entry,
plt_entry_address + 4);
// R_AARCH64_ADR_PREL_PG_HI21
AArch64_relocate_functions<size, big_endian>::adrp(
pov + 8,
gotplt_address,
plt_entry_address + 8);
// R_AARCH64_LDST64_ABS_LO12
elfcpp::Swap<32, big_endian>::writeval(
pov + 12,
((this->tlsdesc_plt_entry[3] & 0xffc003ff)
| ((tlsdesc_got_entry & 0xff8) << 7)));
// R_AARCH64_ADD_ABS_LO12
elfcpp::Swap<32, big_endian>::writeval(
pov + 16,
((this->tlsdesc_plt_entry[4] & 0xffc003ff)
| ((gotplt_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();
gold_assert(got_file_offset + this->got_plt_->data_size()
== this->got_irelative_->offset());
const section_size_type got_size =
convert_to_section_size_type(this->got_plt_->data_size()
+ this->got_irelative_->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 gotplt_address
= this->got_plt_->address();
this->fill_first_plt_entry(pov, gotplt_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_ + this->irelative_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, gotplt_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);
}
if (this->has_tlsdesc_entry())
{
// Set and adjust the reserved TLSDESC PLT entry.
unsigned int tlsdesc_got_offset = this->get_tlsdesc_got_offset();
// The base address of the .base section.
typename elfcpp::Elf_types<size>::Elf_Addr got_base =
this->got_->address();
this->fill_tlsdesc_entry(pov, gotplt_address, plt_address, got_base,
tlsdesc_got_offset, plt_offset);
pov += this->get_plt_tlsdesc_entry_size();
}
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;
typedef AArch64_relocate_functions<size, big_endian> This;
typedef typename elfcpp::Elf_types<size>::Elf_Addr Address;
typedef Relocate_info<size, big_endian> The_relocate_info;
typedef AArch64_relobj<size, big_endian> The_aarch64_relobj;
typedef Reloc_stub<size, big_endian> The_reloc_stub;
typedef typename The_reloc_stub::Stub_type The_reloc_stub_type;
typedef Stub_table<size, big_endian> The_stub_table;
typedef elfcpp::Rela<size, big_endian> The_rela;
typedef typename elfcpp::Swap<size, big_endian>::Valtype AArch64_valtype;
// Return the page address of the address.
// Page(address) = address & ~0xFFF
static inline AArch64_valtype
Page(Address address)
{
return (address & (~static_cast<Address>(0xFFF)));
}
private:
// 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,
AArch64_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,
AArch64_valtype immed1,
AArch64_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 immed.
// In adr and adrp: [30:29] immlo [23:5] immhi
static inline void
update_adr(unsigned char* view, AArch64_valtype immed)
{
elfcpp::Elf_Xword dst_mask = (0x3 << 29) | (0x7ffff << 5);
This::template update_view_two_parts<32>(
view,
immed & 0x3,
(immed & 0x1ffffc) >> 2,
29,
5,
dst_mask);
}
// Update movz/movn instruction with bits immed.
// Set instruction to movz if is_movz is true, otherwise set instruction
// to movn.
static inline void
update_movnz(unsigned char* view,
AArch64_valtype immed,
bool is_movz)
{
typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
Valtype* wv = reinterpret_cast<Valtype*>(view);
Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
const elfcpp::Elf_Xword doffset =
aarch64_howto[AArch64_reloc_property::INST_MOVW].doffset;
const elfcpp::Elf_Xword dst_mask =
aarch64_howto[AArch64_reloc_property::INST_MOVW].dst_mask;
// Clear immediate fields and opc code.
val &= ~(dst_mask | (0x3 << 29));
// Set instruction to movz or movn.
// movz: [30:29] is 10 movn: [30:29] is 00
if (is_movz)
val |= (0x2 << 29);
elfcpp::Swap<32, big_endian>::writeval(wv,
static_cast<Valtype>(val | (immed << doffset)));
}
// Update selected bits in text.
template<int valsize>
static inline typename This::Status
reloc_common(unsigned char* view, Address x,
const AArch64_reloc_property* reloc_property)
{
// 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);
}
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,
AArch64_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,
AArch64_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,
AArch64_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,
AArch64_valtype addend,
const AArch64_reloc_property* reloc_property)
{
// Calculate relocation.
Address x = psymval->value(object, addend);
return This::template reloc_common<valsize>(view, x, reloc_property);
}
// 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,
AArch64_valtype s,
AArch64_valtype addend,
const AArch64_reloc_property* reloc_property)
{
// Calculate relocation.
Address x = s + addend;
return This::template reloc_common<valsize>(view, x, reloc_property);
}
// 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,
AArch64_valtype addend,
Address address,
const AArch64_reloc_property* reloc_property)
{
// Calculate relocation.
Address x = psymval->value(object, addend) - address;
return This::template reloc_common<valsize>(view, x, reloc_property);
}
// Calculate (S + A) - address, update adr instruction.
static inline typename This::Status
adr(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 */)
{
AArch64_valtype x = psymval->value(object, addend) - address;
// Pick bits [20:0] of X.
AArch64_valtype immed = x & 0x1fffff;
update_adr(view, immed);
// Check -2^20 <= X < 2^20
return (size == 64 && Bits<21>::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,
Address sa,
Address address)
{
AArch64_valtype x = This::Page(sa) - This::Page(address);
// Pick [32:12] of X.
AArch64_valtype immed = (x >> 12) & 0x1fffff;
update_adr(view, immed);
// Check -2^32 <= X < 2^32
return (size == 64 && Bits<33>::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);
AArch64_valtype x = This::Page(sa) - This::Page(address);
// Pick [32:12] of X.
AArch64_valtype immed = (x >> 12) & 0x1fffff;
update_adr(view, immed);
return (reloc_property->checkup_x_value(x)
? This::STATUS_OKAY
: This::STATUS_OVERFLOW);
}
// Update mov[n/z] instruction. Check overflow if needed.
// If X >=0, set the instruction to movz and its immediate value to the
// selected bits S.
// If X < 0, set the instruction to movn and its immediate value to
// NOT (selected bits of).
static inline typename This::Status
movnz(unsigned char* view,
AArch64_valtype x,
const AArch64_reloc_property* reloc_property)
{
// Select bits from X.
Address immed;
bool is_movz;
typedef typename elfcpp::Elf_types<size>::Elf_Swxword SignedW;
if (static_cast<SignedW>(x) >= 0)
{
immed = reloc_property->select_x_value(x);
is_movz = true;
}
else
{
immed = reloc_property->select_x_value(~x);;
is_movz = false;
}
// Update movnz instruction.
update_movnz(view, immed, is_movz);
// Do check overflow or alignment if needed.
return (reloc_property->checkup_x_value(x)
? This::STATUS_OKAY
: This::STATUS_OVERFLOW);
}
static inline bool
maybe_apply_stub(unsigned int,
const The_relocate_info*,
const The_rela&,
unsigned char*,
Address,
const Sized_symbol<size>*,
const Symbol_value<size>*,
const Sized_relobj_file<size, big_endian>*,
section_size_type);
}; // End of AArch64_relocate_functions
// For a certain relocation type (usually jump/branch), test to see if the
// destination needs a stub to fulfil. If so, re-route the destination of the
// original instruction to the stub, note, at this time, the stub has already
// been generated.
template<int size, bool big_endian>
bool
AArch64_relocate_functions<size, big_endian>::
maybe_apply_stub(unsigned int r_type,
const The_relocate_info* relinfo,
const The_rela& rela,
unsigned char* view,
Address address,
const Sized_symbol<size>* gsym,
const Symbol_value<size>* psymval,
const Sized_relobj_file<size, big_endian>* object,
section_size_type current_group_size)
{
if (parameters->options().relocatable())
return false;
typename elfcpp::Elf_types<size>::Elf_Swxword addend = rela.get_r_addend();
Address branch_target = psymval->value(object, 0) + addend;
The_reloc_stub_type stub_type = The_reloc_stub::
stub_type_for_reloc(r_type, address, branch_target);
if (stub_type == The_reloc_stub::ST_NONE)
return false;
const The_aarch64_relobj* aarch64_relobj =
static_cast<const The_aarch64_relobj*>(object);
The_stub_table* stub_table = aarch64_relobj->stub_table(relinfo->data_shndx);
gold_assert(stub_table != NULL);
unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
typename The_reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
The_reloc_stub* stub = stub_table->find_reloc_stub(stub_key);
gold_assert(stub != NULL);
Address new_branch_target = stub_table->address() + stub->offset();
typename elfcpp::Swap<size, big_endian>::Valtype branch_offset =
new_branch_target - address;
const AArch64_reloc_property* arp =
aarch64_reloc_property_table->get_reloc_property(r_type);
gold_assert(arp != NULL);
typename This::Status status = This::template
rela_general<32>(view, branch_offset, 0, arp);
if (status != This::STATUS_OKAY)
gold_error(_("Stub is too far away, try a smaller value "
"for '--stub-group-size'. The current value is 0x%lx."),
static_cast<unsigned long>(current_group_size));
return true;
}
// Group input sections for stub generation.
//
// We group input sections in an output section so that the total size,
// including any padding space due to alignment is smaller than GROUP_SIZE
// unless the only input section in group is bigger than GROUP_SIZE already.
// Then an ARM stub table is created to follow the last input section
// in group. For each group an ARM stub table is created an is placed
// after the last group. If STUB_ALWAYS_AFTER_BRANCH is false, we further
// extend the group after the stub table.
template<int size, bool big_endian>
void
Target_aarch64<size, big_endian>::group_sections(
Layout* layout,
section_size_type group_size,
bool stubs_always_after_branch,
const Task* task)
{
// Group input sections and insert stub table
Layout::Section_list section_list;
layout->get_executable_sections(&section_list);
for (Layout::Section_list::const_iterator p = section_list.begin();
p != section_list.end();
++p)
{
AArch64_output_section<size, big_endian>* output_section =
static_cast<AArch64_output_section<size, big_endian>*>(*p);
output_section->group_sections(group_size, stubs_always_after_branch,
this, task);
}
}
// Find the AArch64_input_section object corresponding to the SHNDX-th input
// section of RELOBJ.
template<int size, bool big_endian>
AArch64_input_section<size, big_endian>*
Target_aarch64<size, big_endian>::find_aarch64_input_section(
Relobj* relobj, unsigned int shndx) const
{
Section_id sid(relobj, shndx);
typename AArch64_input_section_map::const_iterator p =
this->aarch64_input_section_map_.find(sid);
return (p != this->aarch64_input_section_map_.end()) ? p->second : NULL;
}
// Make a new AArch64_input_section object.
template<int size, bool big_endian>
AArch64_input_section<size, big_endian>*
Target_aarch64<size, big_endian>::new_aarch64_input_section(
Relobj* relobj, unsigned int shndx)
{
Section_id sid(relobj, shndx);
AArch64_input_section<size, big_endian>* input_section =
new AArch64_input_section<size, big_endian>(relobj, shndx);
input_section->init();
// Register new AArch64_input_section in map for look-up.
std::pair<typename AArch64_input_section_map::iterator,bool> ins =
this->aarch64_input_section_map_.insert(
std::make_pair(sid, input_section));
// Make sure that it we have not created another AArch64_input_section
// for this input section already.
gold_assert(ins.second);
return input_section;
}
// Relaxation hook. This is where we do stub generation.
template<int size, bool big_endian>
bool
Target_aarch64<size, big_endian>::do_relax(
int pass,
const Input_objects* input_objects,
Symbol_table* symtab,
Layout* layout ,
const Task* task)
{
gold_assert(!parameters->options().relocatable());
if (pass == 1)
{
// We don't handle negative stub_group_size right now.
this->stub_group_size_ = abs(parameters->options().stub_group_size());
if (this->stub_group_size_ == 1)
{
// Leave room for 4096 4-byte stub entries. If we exceed that, then we
// will fail to link. The user will have to relink with an explicit
// group size option.
this->stub_group_size_ = The_reloc_stub::MAX_BRANCH_OFFSET -
4096 * 4;
}
group_sections(layout, this->stub_group_size_, true, task);
}
else
{
// If this is not the first pass, addresses and file offsets have
// been reset at this point, set them here.
for (Stub_table_iterator sp = this->stub_tables_.begin();
sp != this->stub_tables_.end(); ++sp)
{
The_stub_table* stt = *sp;
The_aarch64_input_section* owner = stt->owner();
off_t off = align_address(owner->original_size(),
stt->addralign());
stt->set_address_and_file_offset(owner->address() + off,
owner->offset() + off);
}
}
// Scan relocs for relocation stubs
for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
op != input_objects->relobj_end();
++op)
{
The_aarch64_relobj* aarch64_relobj =
static_cast<The_aarch64_relobj*>(*op);
// Lock the object so we can read from it. This is only called
// single-threaded from Layout::finalize, so it is OK to lock.
Task_lock_obj<Object> tl(task, aarch64_relobj);
aarch64_relobj->scan_sections_for_stubs(this, symtab, layout);
}
bool any_stub_table_changed = false;
for (Stub_table_iterator siter = this->stub_tables_.begin();
siter != this->stub_tables_.end() && !any_stub_table_changed; ++siter)
{
The_stub_table* stub_table = *siter;
if (stub_table->update_data_size_changed_p())
{
The_aarch64_input_section* owner = stub_table->owner();
uint64_t address = owner->address();
off_t offset = owner->offset();
owner->reset_address_and_file_offset();
owner->set_address_and_file_offset(address, offset);
any_stub_table_changed = true;
}
}
// Do not continue relaxation.
bool continue_relaxation = any_stub_table_changed;
if (!continue_relaxation)
for (Stub_table_iterator sp = this->stub_tables_.begin();
(sp != this->stub_tables_.end());
++sp)
(*sp)->finalize_stubs();
return continue_relaxation;
}
// Make a new Stub_table.
template<int size, bool big_endian>
Stub_table<size, big_endian>*
Target_aarch64<size, big_endian>::new_stub_table(
AArch64_input_section<size, big_endian>* owner)
{
Stub_table<size, big_endian>* stub_table =
new Stub_table<size, big_endian>(owner);
stub_table->set_address(align_address(
owner->address() + owner->data_size(), 8));
stub_table->set_file_offset(owner->offset() + owner->data_size());
stub_table->finalize_data_size();
this->stub_tables_.push_back(stub_table);
return stub_table;
}
template<int size, bool big_endian>
typename elfcpp::Elf_types<size>::Elf_Addr
Target_aarch64<size, big_endian>::do_reloc_addend(
void* arg, unsigned int r_type,
typename elfcpp::Elf_types<size>::Elf_Addr) const
{
gold_assert(r_type == elfcpp::R_AARCH64_TLSDESC);
uintptr_t intarg = reinterpret_cast<uintptr_t>(arg);
gold_assert(intarg < this->tlsdesc_reloc_info_.size());
const Tlsdesc_info& ti(this->tlsdesc_reloc_info_[intarg]);
const Symbol_value<size>* psymval = ti.object->local_symbol(ti.r_sym);
gold_assert(psymval->is_tls_symbol());
// The value of a TLS symbol is the offset in the TLS segment.
return psymval->value(ti.object, 0);
}
// 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();
}
// Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
template<int size, bool big_endian>
void
Target_aarch64<size, big_endian>::define_tls_base_symbol(
Symbol_table* symtab, Layout* layout)
{
if (this->tls_base_symbol_defined_)
return;
Output_segment* tls_segment = layout->tls_segment();
if (tls_segment != NULL)
{
bool is_exec = parameters->options().output_is_executable();
symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
Symbol_table::PREDEFINED,
tls_segment, 0, 0,
elfcpp::STT_TLS,
elfcpp::STB_LOCAL,
elfcpp::STV_HIDDEN, 0,
(is_exec
? Symbol::SEGMENT_END
: Symbol::SEGMENT_START),
true);
}
this->tls_base_symbol_defined_ = true;
}
// Create the reserved PLT and GOT entries for the TLS descriptor resolver.
template<int size, bool big_endian>
void
Target_aarch64<size, big_endian>::reserve_tlsdesc_entries(
Symbol_table* symtab, Layout* layout)
{
if (this->plt_ == NULL)
this->make_plt_section(symtab, layout);
if (!this->plt_->has_tlsdesc_entry())
{
// Allocate the TLSDESC_GOT entry.
Output_data_got_aarch64<size, big_endian>* got =
this->got_section(symtab, layout);
unsigned int got_offset = got->add_constant(0);
// Allocate the TLSDESC_PLT entry.
this->plt_->reserve_tlsdesc_entry(got_offset);
}
}
// Create a GOT entry for the TLS module index.
template<int size, bool big_endian>
unsigned int
Target_aarch64<size, big_endian>::got_mod_index_entry(
Symbol_table* symtab, Layout* layout,
Sized_relobj_file<size, big_endian>* object)
{
if (this->got_mod_index_offset_ == -1U)
{
gold_assert(symtab != NULL && layout != NULL && object != NULL);
Reloc_section* rela_dyn = this->rela_dyn_section(layout);
Output_data_got_aarch64<size, big_endian>* got =
this->got_section(symtab, layout);
unsigned int got_offset = got->add_constant(0);
rela_dyn->add_local(object, 0, elfcpp::R_AARCH64_TLS_DTPMOD64, got,
got_offset, 0);
got->add_constant(0);
this->got_mod_index_offset_ = got_offset;
}
return this->got_mod_index_offset_;
}
// 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)
{
// If we are generating a shared library, then we can't do anything
// in the linker
if (parameters->options().shared())
return tls::TLSOPT_NONE;
switch (r_type)
{
case elfcpp::R_AARCH64_TLSGD_ADR_PAGE21:
case elfcpp::R_AARCH64_TLSGD_ADD_LO12_NC:
case elfcpp::R_AARCH64_TLSDESC_LD_PREL19:
case elfcpp::R_AARCH64_TLSDESC_ADR_PREL21:
case elfcpp::R_AARCH64_TLSDESC_ADR_PAGE21:
case elfcpp::R_AARCH64_TLSDESC_LD64_LO12:
case elfcpp::R_AARCH64_TLSDESC_ADD_LO12:
case elfcpp::R_AARCH64_TLSDESC_OFF_G1:
case elfcpp::R_AARCH64_TLSDESC_OFF_G0_NC:
case elfcpp::R_AARCH64_TLSDESC_LDR:
case elfcpp::R_AARCH64_TLSDESC_ADD:
case elfcpp::R_AARCH64_TLSDESC_CALL:
// These are General-Dynamic which permits fully general TLS
// access. Since we know that we are generating an executable,
// we can convert this to Initial-Exec. If we also know that
// this is a local symbol, we can further switch to Local-Exec.
if (is_final)
return tls::TLSOPT_TO_LE;
return tls::TLSOPT_TO_IE;
case elfcpp::R_AARCH64_TLSLD_ADR_PAGE21:
case elfcpp::R_AARCH64_TLSLD_ADD_LO12_NC:
case elfcpp::R_AARCH64_TLSLD_MOVW_DTPREL_G1:
case elfcpp::R_AARCH64_TLSLD_MOVW_DTPREL_G0_NC:
// These are Local-Dynamic, which refer to local symbols in the
// dynamic TLS block. Since we know that we generating an
// executable, we can switch to Local-Exec.
return tls::TLSOPT_TO_LE;
case elfcpp::R_AARCH64_TLSIE_MOVW_GOTTPREL_G1:
case elfcpp::R_AARCH64_TLSIE_MOVW_GOTTPREL_G0_NC:
case elfcpp::R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21:
case elfcpp::R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC:
case elfcpp::R_AARCH64_TLSIE_LD_GOTTPREL_PREL19:
// These are Initial-Exec relocs which get the thread offset
// from the GOT. If we know that we are linking against the
// local symbol, we can switch to Local-Exec, which links the
// thread offset into the instruction.
if (is_final)
return tls::TLSOPT_TO_LE;
return tls::TLSOPT_NONE;
case elfcpp::R_AARCH64_TLSLE_MOVW_TPREL_G2:
case elfcpp::R_AARCH64_TLSLE_MOVW_TPREL_G1:
case elfcpp::R_AARCH64_TLSLE_MOVW_TPREL_G1_NC:
case elfcpp::R_AARCH64_TLSLE_MOVW_TPREL_G0:
case elfcpp::R_AARCH64_TLSLE_MOVW_TPREL_G0_NC:
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:
// When we already have Local-Exec, there is nothing further we
// can do.
return tls::TLSOPT_NONE;
default:
gold_unreachable();
}
}
// 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_ADR_PREL_PG_HI21:
case elfcpp::R_AARCH64_ADR_PREL_PG_HI21_NC:
case elfcpp::R_AARCH64_ADD_ABS_LO12_NC:
case elfcpp::R_AARCH64_ADR_GOT_PAGE:
case elfcpp::R_AARCH64_LD64_GOT_LO12_NC:
{
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.
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;
}
// Return whether we need to make a PLT entry for a relocation of the
// given type against a STT_GNU_IFUNC symbol.
template<int size, bool big_endian>
bool
Target_aarch64<size, big_endian>::Scan::reloc_needs_plt_for_ifunc(
Sized_relobj_file<size, big_endian>* object,
unsigned int r_type)
{
const AArch64_reloc_property* arp =
aarch64_reloc_property_table->get_reloc_property(r_type);
gold_assert(arp != NULL);
int flags = arp->reference_flags();
if (flags & Symbol::TLS_REF)
{
gold_error(_("%s: unsupported TLS reloc %s for IFUNC symbol"),
object->name().c_str(), arp->name().c_str());
return false;
}
return flags != 0;
}
// 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;
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());
// A local STT_GNU_IFUNC symbol may require a PLT entry.
bool is_ifunc = lsym.get_st_type() == elfcpp::STT_GNU_IFUNC;
if (is_ifunc && this->reloc_needs_plt_for_ifunc(object, r_type))
target->make_local_ifunc_plt_entry(symtab, layout, object, r_sym);
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);
rela_dyn->add_local_relative(object, r_sym,
elfcpp::R_AARCH64_RELATIVE,
output_section,
data_shndx,
rela.get_r_offset(),
rela.get_r_addend(),
is_ifunc);
}
break;
case elfcpp::R_AARCH64_PREL64:
case elfcpp::R_AARCH64_PREL32:
case elfcpp::R_AARCH64_PREL16:
break;
case elfcpp::R_AARCH64_LD_PREL_LO19: // 273
case elfcpp::R_AARCH64_ADR_PREL_LO21: // 274
case elfcpp::R_AARCH64_ADR_PREL_PG_HI21: // 275
case elfcpp::R_AARCH64_ADR_PREL_PG_HI21_NC: // 276
case elfcpp::R_AARCH64_ADD_ABS_LO12_NC: // 277
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
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:
{
tls::Tls_optimization tlsopt = Target_aarch64<size, big_endian>::
optimize_tls_reloc(!parameters->options().shared(), r_type);
if (tlsopt == tls::TLSOPT_TO_LE)
break;
layout->set_has_static_tls();
// Create a GOT entry for the tp-relative offset.
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_TLSGD_ADR_PAGE21:
case elfcpp::R_AARCH64_TLSGD_ADD_LO12_NC:
{
tls::Tls_optimization tlsopt = Target_aarch64<size, big_endian>::
optimize_tls_reloc(!parameters->options().shared(), r_type);
if (tlsopt == tls::TLSOPT_TO_LE)
{
layout->set_has_static_tls();
break;
}
gold_assert(tlsopt == tls::TLSOPT_NONE);
got->add_local_pair_with_rel(object,r_sym, data_shndx,
GOT_TYPE_TLS_PAIR,
target->rela_dyn_section(layout),
elfcpp::R_AARCH64_TLS_DTPMOD64);
}
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 TLSLE reloc %u in shared code."),
object->name().c_str(), r_type);
}
break;
case elfcpp::R_AARCH64_TLSLD_ADR_PAGE21:
case elfcpp::R_AARCH64_TLSLD_ADD_LO12_NC:
{
tls::Tls_optimization tlsopt = Target_aarch64<size, big_endian>::
optimize_tls_reloc(!parameters->options().shared(), r_type);
if (tlsopt == tls::TLSOPT_NONE)
{
// Create a GOT entry for the module index.
target->got_mod_index_entry(symtab, layout, object);
}
else if (tlsopt != tls::TLSOPT_TO_LE)
unsupported_reloc_local(object, r_type);
}
break;
case elfcpp::R_AARCH64_TLSLD_MOVW_DTPREL_G1:
case elfcpp::R_AARCH64_TLSLD_MOVW_DTPREL_G0_NC:
break;
case elfcpp::R_AARCH64_TLSDESC_ADR_PAGE21:
case elfcpp::R_AARCH64_TLSDESC_LD64_LO12:
case elfcpp::R_AARCH64_TLSDESC_ADD_LO12:
{
tls::Tls_optimization tlsopt = Target_aarch64<size, big_endian>::
optimize_tls_reloc(!parameters->options().shared(), r_type);
target->define_tls_base_symbol(symtab, layout);
if (tlsopt == tls::TLSOPT_NONE)
{
// Create reserved PLT and GOT entries for the resolver.
target->reserve_tlsdesc_entries(symtab, layout);
// Generate a double GOT entry with an R_AARCH64_TLSDESC reloc.
// The R_AARCH64_TLSDESC reloc is resolved lazily, so the GOT
// entry needs to be in an area in .got.plt, not .got. Call
// got_section to make sure the section has been created.
target->got_section(symtab, layout);
Output_data_got<size, big_endian>* got =
target->got_tlsdesc_section();
unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
if (!object->local_has_got_offset(r_sym, GOT_TYPE_TLS_DESC))
{
unsigned int got_offset = got->add_constant(0);
got->add_constant(0);
object->set_local_got_offset(r_sym, GOT_TYPE_TLS_DESC,
got_offset);
Reloc_section* rt = target->rela_tlsdesc_section(layout);
// We store the arguments we need in a vector, and use
// the index into the vector as the parameter to pass
// to the target specific routines.
uintptr_t intarg = target->add_tlsdesc_info(object, r_sym);
void* arg = reinterpret_cast<void*>(intarg);
rt->add_target_specific(elfcpp::R_AARCH64_TLSDESC, arg,
got, got_offset, 0);
}
}
else if (tlsopt != tls::TLSOPT_TO_LE)
unsupported_reloc_local(object, r_type);
}
break;
case elfcpp::R_AARCH64_TLSDESC_CALL:
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)
{
// A STT_GNU_IFUNC symbol may require a PLT entry.
if (gsym->type() == elfcpp::STT_GNU_IFUNC
&& this->reloc_needs_plt_for_ifunc(object, r_type))
target->make_plt_entry(symtab, layout, gsym);
typedef Output_data_reloc<elfcpp::SHT_RELA, true, size, big_endian>
Reloc_section;
const AArch64_reloc_property* arp =
aarch64_reloc_property_table->get_reloc_property(r_type);
gold_assert(arp != NULL);
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.
if (gsym->needs_dynamic_reloc(arp->reference_flags()))
{
if (!parameters->options().output_is_position_independent()
&& gsym->may_need_copy_reloc())
{
target->copy_reloc(symtab, layout, object,
data_shndx, output_section, gsym, rela);
}
else if (r_type == elfcpp::R_AARCH64_ABS64
&& gsym->type() == elfcpp::STT_GNU_IFUNC
&& gsym->can_use_relative_reloc(false)
&& !gsym->is_from_dynobj()
&& !gsym->is_undefined()
&& !gsym->is_preemptible())
{
// Use an IRELATIVE reloc for a locally defined STT_GNU_IFUNC
// symbol. This makes a function address in a PIE executable
// match the address in a shared library that it links against.
Reloc_section* rela_dyn =
target->rela_irelative_section(layout);
unsigned int r_type = elfcpp::R_AARCH64_IRELATIVE;
rela_dyn->add_symbolless_global_addend(gsym, r_type,
output_section, object,
data_shndx,
rela.get_r_offset(),
rela.get_r_addend());
}
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_LD_PREL_LO19: // 273
case elfcpp::R_AARCH64_ADR_PREL_LO21: // 274
case elfcpp::R_AARCH64_ADR_PREL_PG_HI21: // 275
case elfcpp::R_AARCH64_ADR_PREL_PG_HI21_NC: // 276
case elfcpp::R_AARCH64_ADD_ABS_LO12_NC: // 277
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
{
if (gsym->needs_plt_entry())
target->make_plt_entry(symtab, layout, gsym);
// Make a dynamic relocation if necessary.
if (gsym->needs_dynamic_reloc(arp->reference_flags()))
{
if (parameters->options().output_is_executable()
&& gsym->may_need_copy_reloc())
{
target->copy_reloc(symtab, layout, object,
data_shndx, output_section, gsym, rela);
}
}
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())
{
// For a STT_GNU_IFUNC symbol we want the PLT address.
if (gsym->type() == elfcpp::STT_GNU_IFUNC)
got->add_global_plt(gsym, GOT_TYPE_STANDARD);
else
got->add_global(gsym, GOT_TYPE_STANDARD);
}
else
{
// If this symbol is not fully resolved, we need to add a dynamic
// relocation for it.
Reloc_section* rela_dyn = target->rela_dyn_section(layout);
// Use a GLOB_DAT rather than a RELATIVE reloc if:
//
// 1) The symbol may be defined in some other module.
// 2) We are building a shared library and this is a protected
// symbol; using GLOB_DAT means that the dynamic linker can use
// the address of the PLT in the main executable when appropriate
// so that function address comparisons work.
// 3) This is a STT_GNU_IFUNC symbol in position dependent code,
// again so that function address comparisons work.
if (gsym->is_from_dynobj()
|| gsym->is_undefined()
|| gsym->is_preemptible()
|| (gsym->visibility() == elfcpp::STV_PROTECTED
&& parameters->options().shared())
|| (gsym->type() == elfcpp::STT_GNU_IFUNC
&& parameters->options().output_is_position_independent()))
got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
rela_dyn, elfcpp::R_AARCH64_GLOB_DAT);
else
{
// For a STT_GNU_IFUNC symbol we want to write the PLT
// offset into the GOT, so that function pointer
// comparisons work correctly.
bool is_new;
if (gsym->type() != elfcpp::STT_GNU_IFUNC)
is_new = got->add_global(gsym, GOT_TYPE_STANDARD);
else
{
is_new = got->add_global_plt(gsym, GOT_TYPE_STANDARD);
// Tell the dynamic linker to use the PLT address
// when resolving relocations.
if (gsym->is_from_dynobj()
&& !parameters->options().shared())
gsym->set_needs_dynsym_value();
}
if (is_new)
{
rela_dyn->add_global_relative(
gsym, elfcpp::R_AARCH64_RELATIVE,
got,
gsym->got_offset(GOT_TYPE_STANDARD),
0,
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.
target->make_plt_entry(symtab, layout, gsym);
break;
}
case elfcpp::R_AARCH64_TLSGD_ADR_PAGE21:
case elfcpp::R_AARCH64_TLSGD_ADD_LO12_NC: // General dynamic
{
tls::Tls_optimization tlsopt = Target_aarch64<size, big_endian>::
optimize_tls_reloc(gsym->final_value_is_known(), r_type);
if (tlsopt == tls::TLSOPT_TO_LE)
{
layout->set_has_static_tls();
break;
}
gold_assert(tlsopt == tls::TLSOPT_NONE);
// General dynamic.
Output_data_got_aarch64<size, big_endian>* got =
target->got_section(symtab, layout);
// Create 2 consecutive entries for module index and offset.
got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
target->rela_dyn_section(layout),
elfcpp::R_AARCH64_TLS_DTPMOD64,
elfcpp::R_AARCH64_TLS_DTPREL64);
}
break;
case elfcpp::R_AARCH64_TLSLD_ADR_PAGE21:
case elfcpp::R_AARCH64_TLSLD_ADD_LO12_NC: // Local dynamic
{
tls::Tls_optimization tlsopt = Target_aarch64<size, big_endian>::
optimize_tls_reloc(!parameters->options().shared(), r_type);
if (tlsopt == tls::TLSOPT_NONE)
{
// Create a GOT entry for the module index.
target->got_mod_index_entry(symtab, layout, object);
}
else if (tlsopt != tls::TLSOPT_TO_LE)
unsupported_reloc_local(object, r_type);
}
break;
case elfcpp::R_AARCH64_TLSLD_MOVW_DTPREL_G1:
case elfcpp::R_AARCH64_TLSLD_MOVW_DTPREL_G0_NC: // Other local dynamic
break;
case elfcpp::R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21:
case elfcpp::R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC: // Initial executable
{
tls::Tls_optimization tlsopt = Target_aarch64<size, big_endian>::
optimize_tls_reloc(gsym->final_value_is_known(), r_type);
if (tlsopt == tls::TLSOPT_TO_LE)
break;
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: // Local executable
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;
case elfcpp::R_AARCH64_TLSDESC_ADR_PAGE21:
case elfcpp::R_AARCH64_TLSDESC_LD64_LO12:
case elfcpp::R_AARCH64_TLSDESC_ADD_LO12: // TLS descriptor
{
target->define_tls_base_symbol(symtab, layout);
tls::Tls_optimization tlsopt = Target_aarch64<size, big_endian>::
optimize_tls_reloc(gsym->final_value_is_known(), r_type);
if (tlsopt == tls::TLSOPT_NONE)
{
// Create reserved PLT and GOT entries for the resolver.
target->reserve_tlsdesc_entries(symtab, layout);
// Create a double GOT entry with an R_AARCH64_TLSDESC
// relocation. The R_AARCH64_TLSDESC is resolved lazily, so the GOT
// entry needs to be in an area in .got.plt, not .got. Call
// got_section to make sure the section has been created.
target->got_section(symtab, layout);
Output_data_got<size, big_endian>* got =
target->got_tlsdesc_section();
Reloc_section* rt = target->rela_tlsdesc_section(layout);
got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_DESC, rt,
elfcpp::R_AARCH64_TLSDESC, 0);
}
else if (tlsopt == tls::TLSOPT_TO_IE)
{
// Create a GOT entry for the tp-relative offset.
Output_data_got<size, big_endian>* got
= target->got_section(symtab, layout);
got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
target->rela_dyn_section(layout),
elfcpp::R_AARCH64_TLS_TPREL64);
}
else if (tlsopt != tls::TLSOPT_TO_LE)
unsupported_reloc_global(object, r_type, gsym);
}
break;
case elfcpp::R_AARCH64_TLSDESC_CALL:
break;
default:
gold_error(_("%s: unsupported reloc type in global scan"),
aarch64_reloc_property_table->
reloc_name_in_error_message(r_type).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_, this->got_plt_,
this->got_irelative_);
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());
}
}
// Return the section for TLSDESC relocations.
template<int size, bool big_endian>
typename Target_aarch64<size, big_endian>::Reloc_section*
Target_aarch64<size, big_endian>::rela_tlsdesc_section(Layout* layout) const
{
return this->plt_section()->rela_tlsdesc(layout);
}
// 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(symtab, layout, gsym);
}
// Make a PLT entry for a local STT_GNU_IFUNC symbol.
template<int size, bool big_endian>
void
Target_aarch64<size, big_endian>::make_local_ifunc_plt_entry(
Symbol_table* symtab, Layout* layout,
Sized_relobj_file<size, big_endian>* relobj,
unsigned int local_sym_index)
{
if (relobj->local_has_plt_offset(local_sym_index))
return;
if (this->plt_ == NULL)
this->make_plt_section(symtab, layout);
unsigned int plt_offset = this->plt_->add_local_ifunc_entry(symtab, layout,
relobj,
local_sym_index);
relobj->set_local_plt_offset(local_sym_index, plt_offset);
}
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);
}
// Return the value to use for a dynamic 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<int size, bool big_endian>
uint64_t
Target_aarch64<size, big_endian>::do_dynsym_value(const Symbol* gsym) const
{
gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
return this->plt_address_for_global(gsym);
}
// 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);
// 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->rela_dyn_section(layout));
// Fill in some more dynamic tags.
Output_data_dynamic* const odyn = layout->dynamic_data();
if (odyn != NULL)
{
if (this->plt_ != NULL
&& this->plt_->output_section() != NULL
&& this->plt_ ->has_tlsdesc_entry())
{
unsigned int plt_offset = this->plt_->get_tlsdesc_plt_offset();
unsigned int got_offset = this->plt_->get_tlsdesc_got_offset();
this->got_->finalize_data_size();
odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_PLT,
this->plt_, plt_offset);
odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_GOT,
this->got_, got_offset);
}
}
// 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;
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);
break;
case elfcpp::R_AARCH64_PREL32:
reloc_status = Reloc::template pcrela_ua<32>(
view, object, psymval, addend, address, reloc_property);
break;
case elfcpp::R_AARCH64_PREL16:
reloc_status = Reloc::template pcrela_ua<16>(
view, object, psymval, addend, address, reloc_property);
break;
case elfcpp::R_AARCH64_LD_PREL_LO19:
reloc_status = Reloc::template pcrela_general<32>(
view, object, psymval, addend, address, reloc_property);
break;
case elfcpp::R_AARCH64_ADR_PREL_LO21:
reloc_status = Reloc::adr(view, object, psymval, addend,
address, reloc_property);
break;
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_CALL26:
if (this->skip_call_tls_get_addr_)
{
// Double check that the TLSGD insn has been optimized away.
typedef typename elfcpp::Swap<32, big_endian>::Valtype Insntype;
Insntype insn = elfcpp::Swap<32, big_endian>::readval(
reinterpret_cast<Insntype*>(view));
gold_assert((insn & 0xff000000) == 0x91000000);
reloc_status = Reloc::STATUS_OKAY;
this->skip_call_tls_get_addr_ = false;
// Return false to stop further processing this reloc.
return false;
}
// Fallthrough
case elfcpp::R_AARCH64_JUMP26:
if (Reloc::maybe_apply_stub(r_type, relinfo, rela, view, address,
gsym, psymval, object,
target->stub_group_size_))
break;
// Fallthrough
case elfcpp::R_AARCH64_TSTBR14:
case elfcpp::R_AARCH64_CONDBR19:
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_TLSGD_ADR_PAGE21:
case elfcpp::R_AARCH64_TLSGD_ADD_LO12_NC:
case elfcpp::R_AARCH64_TLSLD_ADR_PAGE21:
case elfcpp::R_AARCH64_TLSLD_ADD_LO12_NC:
case elfcpp::R_AARCH64_TLSLD_MOVW_DTPREL_G1:
case elfcpp::R_AARCH64_TLSLD_MOVW_DTPREL_G0_NC:
case elfcpp::R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21:
case elfcpp::R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC:
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:
case elfcpp::R_AARCH64_TLSDESC_ADR_PAGE21:
case elfcpp::R_AARCH64_TLSDESC_LD64_LO12:
case elfcpp::R_AARCH64_TLSDESC_ADD_LO12:
case elfcpp::R_AARCH64_TLSDESC_CALL:
reloc_status = relocate_tls(relinfo, target, relnum, rela, r_type,
gsym, psymval, view, address);
break;
// These are dynamic relocations, which are unexpected when linking.
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_IRELATIVE:
case elfcpp::R_AARCH64_TLS_DTPREL64:
case elfcpp::R_AARCH64_TLS_DTPMOD64:
case elfcpp::R_AARCH64_TLS_TPREL64:
case elfcpp::R_AARCH64_TLSDESC:
gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
_("unexpected reloc %u in object file"),
r_type);
break;
default:
gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
_("unsupported reloc %s"),
reloc_property->name().c_str());
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_address;
Output_segment* tls_segment = relinfo->layout->tls_segment();
const elfcpp::Elf_Xword addend = rela.get_r_addend();
const AArch64_reloc_property* reloc_property =
aarch64_reloc_property_table->get_reloc_property(r_type);
gold_assert(reloc_property != NULL);
const bool is_final = (gsym == NULL
? !parameters->options().shared()
: gsym->final_value_is_known());
tls::Tls_optimization tlsopt = Target_aarch64<size, big_endian>::
optimize_tls_reloc(is_final, r_type);
Sized_relobj_file<size, big_endian>* object = relinfo->object;
int tls_got_offset_type;
switch (r_type)
{
case elfcpp::R_AARCH64_TLSGD_ADR_PAGE21:
case elfcpp::R_AARCH64_TLSGD_ADD_LO12_NC: // Global-dynamic
{
if (tlsopt == tls::TLSOPT_TO_LE)
{
if (tls_segment == NULL)
{
gold_assert(parameters->errors()->error_count() > 0
|| issue_undefined_symbol_error(gsym));
return aarch64_reloc_funcs::STATUS_BAD_RELOC;
}
return tls_gd_to_le(relinfo, target, rela, r_type, view,
psymval);
}
else if (tlsopt == tls::TLSOPT_NONE)
{
tls_got_offset_type = GOT_TYPE_TLS_PAIR;
// Firstly get the address for the got entry.
typename elfcpp::Elf_types<size>::Elf_Addr got_entry_address;
if (gsym != NULL)
{
gold_assert(gsym->has_got_offset(tls_got_offset_type));
got_entry_address = target->got_->address() +
gsym->got_offset(tls_got_offset_type);
}
else
{
unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
gold_assert(
object->local_has_got_offset(r_sym, tls_got_offset_type));
got_entry_address = target->got_->address() +
object->local_got_offset(r_sym, tls_got_offset_type);
}
// Relocate the address into adrp/ld, adrp/add pair.
switch (r_type)
{
case elfcpp::R_AARCH64_TLSGD_ADR_PAGE21:
return aarch64_reloc_funcs::adrp(
view, got_entry_address + addend, address);
break;
case elfcpp::R_AARCH64_TLSGD_ADD_LO12_NC:
return aarch64_reloc_funcs::template rela_general<32>(
view, got_entry_address, addend, reloc_property);
break;
default:
gold_unreachable();
}
}
gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
_("unsupported gd_to_ie relaxation on %u"),
r_type);
}
break;
case elfcpp::R_AARCH64_TLSLD_ADR_PAGE21:
case elfcpp::R_AARCH64_TLSLD_ADD_LO12_NC: // Local-dynamic
{
if (tlsopt == tls::TLSOPT_TO_LE)
{
if (tls_segment == NULL)
{
gold_assert(parameters->errors()->error_count() > 0
|| issue_undefined_symbol_error(gsym));
return aarch64_reloc_funcs::STATUS_BAD_RELOC;
}
return this->tls_ld_to_le(relinfo, target, rela, r_type, view,
psymval);
}
gold_assert(tlsopt == tls::TLSOPT_NONE);
// Relocate the field with the offset of the GOT entry for
// the module index.
typename elfcpp::Elf_types<size>::Elf_Addr got_entry_address;
got_entry_address = (target->got_mod_index_entry(NULL, NULL, NULL) +
target->got_->address());
switch (r_type)
{
case elfcpp::R_AARCH64_TLSLD_ADR_PAGE21:
return aarch64_reloc_funcs::adrp(
view, got_entry_address + addend, address);
break;
case elfcpp::R_AARCH64_TLSLD_ADD_LO12_NC:
return aarch64_reloc_funcs::template rela_general<32>(
view, got_entry_address, addend, reloc_property);
break;
default:
gold_unreachable();
}
}
break;
case elfcpp::R_AARCH64_TLSLD_MOVW_DTPREL_G1:
case elfcpp::R_AARCH64_TLSLD_MOVW_DTPREL_G0_NC: // Other local-dynamic
{
AArch64_address value = psymval->value(object, 0);
if (tlsopt == tls::TLSOPT_TO_LE)
{
if (tls_segment == NULL)
{
gold_assert(parameters->errors()->error_count() > 0
|| issue_undefined_symbol_error(gsym));
return aarch64_reloc_funcs::STATUS_BAD_RELOC;
}
// If building executable, _TLS_MODULE_BASE_ points to segment
// end. Thus we must subtract it from value.
value -= tls_segment->memsz();
}
switch (r_type)
{
case elfcpp::R_AARCH64_TLSLD_MOVW_DTPREL_G1:
return aarch64_reloc_funcs::movnz(view, value + addend,
reloc_property);
break;
case elfcpp::R_AARCH64_TLSLD_MOVW_DTPREL_G0_NC:
return aarch64_reloc_funcs::template rela_general<32>(
view, value, addend, reloc_property);
break;
default:
gold_unreachable();
}
// We should never reach here.
}
break;
case elfcpp::R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21:
case elfcpp::R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC: // Initial-exec
{
if (tlsopt == tls::TLSOPT_TO_LE)
{
if (tls_segment == NULL)
{
gold_assert(parameters->errors()->error_count() > 0
|| issue_undefined_symbol_error(gsym));
return aarch64_reloc_funcs::STATUS_BAD_RELOC;
}
return tls_ie_to_le(relinfo, target, rela, r_type, view,
psymval);
}
tls_got_offset_type = GOT_TYPE_TLS_OFFSET;
// Firstly get the address for the got entry.
typename elfcpp::Elf_types<size>::Elf_Addr got_entry_address;
if (gsym != NULL)
{
gold_assert(gsym->has_got_offset(tls_got_offset_type));
got_entry_address = target->got_->address() +
gsym->got_offset(tls_got_offset_type);
}
else
{
unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
gold_assert(
object->local_has_got_offset(r_sym, tls_got_offset_type));
got_entry_address = target->got_->address() +
object->local_got_offset(r_sym, tls_got_offset_type);
}
// Relocate the address into adrp/ld, adrp/add pair.
switch (r_type)
{
case elfcpp::R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21:
return aarch64_reloc_funcs::adrp(view, got_entry_address + addend,
address);
break;
case elfcpp::R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC:
return aarch64_reloc_funcs::template rela_general<32>(
view, got_entry_address, addend, reloc_property);
default:
gold_unreachable();
}
}
// We shall never reach here.
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:
{
gold_assert(tls_segment != NULL);
AArch64_address value = psymval->value(object, 0);
if (!parameters->options().shared())
{
AArch64_address 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;
case elfcpp::R_AARCH64_TLSDESC_ADR_PAGE21:
case elfcpp::R_AARCH64_TLSDESC_LD64_LO12:
case elfcpp::R_AARCH64_TLSDESC_ADD_LO12:
case elfcpp::R_AARCH64_TLSDESC_CALL:
{
if (tlsopt == tls::TLSOPT_TO_LE)
{
if (tls_segment == NULL)
{
gold_assert(parameters->errors()->error_count() > 0
|| issue_undefined_symbol_error(gsym));
return aarch64_reloc_funcs::STATUS_BAD_RELOC;
}
return tls_desc_gd_to_le(relinfo, target, rela, r_type,
view, psymval);
}
else
{
tls_got_offset_type = (tlsopt == tls::TLSOPT_TO_IE
? GOT_TYPE_TLS_OFFSET
: GOT_TYPE_TLS_DESC);
unsigned int got_tlsdesc_offset = 0;
if (r_type != elfcpp::R_AARCH64_TLSDESC_CALL
&& tlsopt == tls::TLSOPT_NONE)
{
// We created GOT entries in the .got.tlsdesc portion of the
// .got.plt section, but the offset stored in the symbol is the
// offset within .got.tlsdesc.
got_tlsdesc_offset = (target->got_->data_size()
+ target->got_plt_section()->data_size());
}
typename elfcpp::Elf_types<size>::Elf_Addr got_entry_address;
if (gsym != NULL)
{
gold_assert(gsym->has_got_offset(tls_got_offset_type));
got_entry_address = target->got_->address()
+ got_tlsdesc_offset
+ gsym->got_offset(tls_got_offset_type);
}
else
{
unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
gold_assert(
object->local_has_got_offset(r_sym, tls_got_offset_type));
got_entry_address = target->got_->address() +
got_tlsdesc_offset +
object->local_got_offset(r_sym, tls_got_offset_type);
}
if (tlsopt == tls::TLSOPT_TO_IE)
{
if (tls_segment == NULL)
{
gold_assert(parameters->errors()->error_count() > 0
|| issue_undefined_symbol_error(gsym));
return aarch64_reloc_funcs::STATUS_BAD_RELOC;
}
return tls_desc_gd_to_ie(relinfo, target, rela, r_type,
view, psymval, got_entry_address,
address);
}
// Now do tlsdesc relocation.
switch (r_type)
{
case elfcpp::R_AARCH64_TLSDESC_ADR_PAGE21:
return aarch64_reloc_funcs::adrp(view,
got_entry_address + addend,
address);
break;
case elfcpp::R_AARCH64_TLSDESC_LD64_LO12:
case elfcpp::R_AARCH64_TLSDESC_ADD_LO12:
return aarch64_reloc_funcs::template rela_general<32>(
view, got_entry_address, addend, reloc_property);
break;
case elfcpp::R_AARCH64_TLSDESC_CALL:
return aarch64_reloc_funcs::STATUS_OKAY;
break;
default:
gold_unreachable();
}
}
}
break;
default:
gold_error(_("%s: unsupported TLS reloc %u."),
object->name().c_str(), r_type);
}
return aarch64_reloc_funcs::STATUS_BAD_RELOC;
} // End of relocate_tls.
template<int size, bool big_endian>
inline
typename AArch64_relocate_functions<size, big_endian>::Status
Target_aarch64<size, big_endian>::Relocate::tls_gd_to_le(
const Relocate_info<size, big_endian>* relinfo,
Target_aarch64<size, big_endian>* target,
const elfcpp::Rela<size, big_endian>& rela,
unsigned int r_type,
unsigned char* view,
const Symbol_value<size>* psymval)
{
typedef AArch64_relocate_functions<size, big_endian> aarch64_reloc_funcs;
typedef typename elfcpp::Swap<32, big_endian>::Valtype Insntype;
typedef typename elfcpp::Elf_types<size>::Elf_Addr AArch64_address;
Insntype* ip = reinterpret_cast<Insntype*>(view);
Insntype insn1 = elfcpp::Swap<32, big_endian>::readval(ip);
Insntype insn2 = elfcpp::Swap<32, big_endian>::readval(ip + 1);
Insntype insn3 = elfcpp::Swap<32, big_endian>::readval(ip + 2);
if (r_type == elfcpp::R_AARCH64_TLSGD_ADD_LO12_NC)
{
// This is the 2nd relocs, optimization should already have been
// done.
gold_assert((insn1 & 0xfff00000) == 0x91400000);
return aarch64_reloc_funcs::STATUS_OKAY;
}
// The original sequence is -
// 90000000 adrp x0, 0 <main>
// 91000000 add x0, x0, #0x0
// 94000000 bl 0 <__tls_get_addr>
// optimized to sequence -
// d53bd040 mrs x0, tpidr_el0
// 91400000 add x0, x0, #0x0, lsl #12
// 91000000 add x0, x0, #0x0
// Unlike tls_ie_to_le, we change the 3 insns in one function call when we
// encounter the first relocation "R_AARCH64_TLSGD_ADR_PAGE21". Because we
// have to change "bl tls_get_addr", which does not have a corresponding tls
// relocation type. So before proceeding, we need to make sure compiler
// does not change the sequence.
if(!(insn1 == 0x90000000 // adrp x0,0
&& insn2 == 0x91000000 // add x0, x0, #0x0
&& insn3 == 0x94000000)) // bl 0
{
// Ideally we should give up gd_to_le relaxation and do gd access.
// However the gd_to_le relaxation decision has been made early
// in the scan stage, where we did not allocate any GOT entry for
// this symbol. Therefore we have to exit and report error now.
gold_error(_("unexpected reloc insn sequence while relaxing "
"tls gd to le for reloc %u."), r_type);
return aarch64_reloc_funcs::STATUS_BAD_RELOC;
}
// Write new insns.
insn1 = 0xd53bd040; // mrs x0, tpidr_el0
insn2 = 0x91400000; // add x0, x0, #0x0, lsl #12
insn3 = 0x91000000; // add x0, x0, #0x0
elfcpp::Swap<32, big_endian>::writeval(ip, insn1);
elfcpp::Swap<32, big_endian>::writeval(ip + 1, insn2);
elfcpp::Swap<32, big_endian>::writeval(ip + 2, insn3);
// Calculate tprel value.
Output_segment* tls_segment = relinfo->layout->tls_segment();
gold_assert(tls_segment != NULL);
AArch64_address value = psymval->value(relinfo->object, 0);
const elfcpp::Elf_Xword addend = rela.get_r_addend();
AArch64_address aligned_tcb_size =
align_address(target->tcb_size(), tls_segment->maximum_alignment());
AArch64_address x = value + aligned_tcb_size;
// After new insns are written, apply TLSLE relocs.
const AArch64_reloc_property* rp1 =
aarch64_reloc_property_table->get_reloc_property(
elfcpp::R_AARCH64_TLSLE_ADD_TPREL_HI12);
const AArch64_reloc_property* rp2 =
aarch64_reloc_property_table->get_reloc_property(
elfcpp::R_AARCH64_TLSLE_ADD_TPREL_LO12);
gold_assert(rp1 != NULL && rp2 != NULL);
typename aarch64_reloc_funcs::Status s1 =
aarch64_reloc_funcs::template rela_general<32>(view + 4,
x,
addend,
rp1);
if (s1 != aarch64_reloc_funcs::STATUS_OKAY)
return s1;
typename aarch64_reloc_funcs::Status s2 =
aarch64_reloc_funcs::template rela_general<32>(view + 8,
x,
addend,
rp2);
this->skip_call_tls_get_addr_ = true;
return s2;
} // End of tls_gd_to_le
template<int size, bool big_endian>
inline
typename AArch64_relocate_functions<size, big_endian>::Status
Target_aarch64<size, big_endian>::Relocate::tls_ld_to_le(
const Relocate_info<size, big_endian>* relinfo,
Target_aarch64<size, big_endian>* target,
const elfcpp::Rela<size, big_endian>& rela,
unsigned int r_type,
unsigned char* view,
const Symbol_value<size>* psymval)
{
typedef AArch64_relocate_functions<size, big_endian> aarch64_reloc_funcs;
typedef typename elfcpp::Swap<32, big_endian>::Valtype Insntype;
typedef typename elfcpp::Elf_types<size>::Elf_Addr AArch64_address;
Insntype* ip = reinterpret_cast<Insntype*>(view);
Insntype insn1 = elfcpp::Swap<32, big_endian>::readval(ip);
Insntype insn2 = elfcpp::Swap<32, big_endian>::readval(ip + 1);
Insntype insn3 = elfcpp::Swap<32, big_endian>::readval(ip + 2);
if (r_type == elfcpp::R_AARCH64_TLSLD_ADD_LO12_NC)
{
// This is the 2nd relocs, optimization should already have been
// done.
gold_assert((insn1 & 0xfff00000) == 0x91400000);
return aarch64_reloc_funcs::STATUS_OKAY;
}
// The original sequence is -
// 90000000 adrp x0, 0 <main>
// 91000000 add x0, x0, #0x0
// 94000000 bl 0 <__tls_get_addr>
// optimized to sequence -
// d53bd040 mrs x0, tpidr_el0
// 91400000 add x0, x0, #0x0, lsl #12
// 91000000 add x0, x0, #0x0
// Unlike tls_ie_to_le, we change the 3 insns in one function call when we
// encounter the first relocation "R_AARCH64_TLSLD_ADR_PAGE21". Because we
// have to change "bl tls_get_addr", which does not have a corresponding tls
// relocation type. So before proceeding, we need to make sure compiler
// does not change the sequence.
if(!(insn1 == 0x90000000 // adrp x0,0
&& insn2 == 0x91000000 // add x0, x0, #0x0
&& insn3 == 0x94000000)) // bl 0
{
// Ideally we should give up gd_to_le relaxation and do gd access.
// However the gd_to_le relaxation decision has been made early
// in the scan stage, where we did not allocate any GOT entry for
// this symbol. Therefore we have to exit and report error now.
gold_error(_("unexpected reloc insn sequence while relaxing "
"tls gd to le for reloc %u."), r_type);
return aarch64_reloc_funcs::STATUS_BAD_RELOC;
}
// Write new insns.
insn1 = 0xd53bd040; // mrs x0, tpidr_el0
insn2 = 0x91400000; // add x0, x0, #0x0, lsl #12
insn3 = 0x91000000; // add x0, x0, #0x0
elfcpp::Swap<32, big_endian>::writeval(ip, insn1);
elfcpp::Swap<32, big_endian>::writeval(ip + 1, insn2);
elfcpp::Swap<32, big_endian>::writeval(ip + 2, insn3);
// Calculate tprel value.
Output_segment* tls_segment = relinfo->layout->tls_segment();
gold_assert(tls_segment != NULL);
AArch64_address value = psymval->value(relinfo->object, 0);
const elfcpp::Elf_Xword addend = rela.get_r_addend();
AArch64_address aligned_tcb_size =
align_address(target->tcb_size(), tls_segment->maximum_alignment());
AArch64_address x = value + aligned_tcb_size;
// After new insns are written, apply TLSLE relocs.
const AArch64_reloc_property* rp1 =
aarch64_reloc_property_table->get_reloc_property(
elfcpp::R_AARCH64_TLSLE_ADD_TPREL_HI12);
const AArch64_reloc_property* rp2 =
aarch64_reloc_property_table->get_reloc_property(
elfcpp::R_AARCH64_TLSLE_ADD_TPREL_LO12);
gold_assert(rp1 != NULL && rp2 != NULL);
typename aarch64_reloc_funcs::Status s1 =
aarch64_reloc_funcs::template rela_general<32>(view + 4,
x,
addend,
rp1);
if (s1 != aarch64_reloc_funcs::STATUS_OKAY)
return s1;
typename aarch64_reloc_funcs::Status s2 =
aarch64_reloc_funcs::template rela_general<32>(view + 8,
x,
addend,
rp2);
this->skip_call_tls_get_addr_ = true;
return s2;
} // End of tls_ld_to_le
template<int size, bool big_endian>
inline
typename AArch64_relocate_functions<size, big_endian>::Status
Target_aarch64<size, big_endian>::Relocate::tls_ie_to_le(
const Relocate_info<size, big_endian>* relinfo,
Target_aarch64<size, big_endian>* target,
const elfcpp::Rela<size, big_endian>& rela,
unsigned int r_type,
unsigned char* view,
const Symbol_value<size>* psymval)
{
typedef typename elfcpp::Elf_types<size>::Elf_Addr AArch64_address;
typedef typename elfcpp::Swap<32, big_endian>::Valtype Insntype;
typedef AArch64_relocate_functions<size, big_endian> aarch64_reloc_funcs;
AArch64_address value = psymval->value(relinfo->object, 0);
Output_segment* tls_segment = relinfo->layout->tls_segment();
AArch64_address aligned_tcb_address =
align_address(target->tcb_size(), tls_segment->maximum_alignment());
const elfcpp::Elf_Xword addend = rela.get_r_addend();
AArch64_address x = value + addend + aligned_tcb_address;
// "x" is the offset to tp, we can only do this if x is within
// range [0, 2^32-1]
if (!(size == 32 || (size == 64 && (static_cast<uint64_t>(x) >> 32) == 0)))
{
gold_error(_("TLS variable referred by reloc %u is too far from TP."),
r_type);
return aarch64_reloc_funcs::STATUS_BAD_RELOC;
}
Insntype* ip = reinterpret_cast<Insntype*>(view);
Insntype insn = elfcpp::Swap<32, big_endian>::readval(ip);
unsigned int regno;
Insntype newinsn;
if (r_type == elfcpp::R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21)
{
// Generate movz.
regno = (insn & 0x1f);
newinsn = (0xd2a00000 | regno) | (((x >> 16) & 0xffff) << 5);
}
else if (r_type == elfcpp::R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC)
{
// Generate movk.
regno = (insn & 0x1f);
gold_assert(regno == ((insn >> 5) & 0x1f));
newinsn = (0xf2800000 | regno) | ((x & 0xffff) << 5);
}
else
gold_unreachable();
elfcpp::Swap<32, big_endian>::writeval(ip, newinsn);
return aarch64_reloc_funcs::STATUS_OKAY;
} // End of tls_ie_to_le
template<int size, bool big_endian>
inline
typename AArch64_relocate_functions<size, big_endian>::Status
Target_aarch64<size, big_endian>::Relocate::tls_desc_gd_to_le(
const Relocate_info<size, big_endian>* relinfo,
Target_aarch64<size, big_endian>* target,
const elfcpp::Rela<size, big_endian>& rela,
unsigned int r_type,
unsigned char* view,
const Symbol_value<size>* psymval)
{
typedef typename elfcpp::Elf_types<size>::Elf_Addr AArch64_address;
typedef typename elfcpp::Swap<32, big_endian>::Valtype Insntype;
typedef AArch64_relocate_functions<size, big_endian> aarch64_reloc_funcs;
// TLSDESC-GD sequence is like:
// adrp x0, :tlsdesc:v1
// ldr x1, [x0, #:tlsdesc_lo12:v1]
// add x0, x0, :tlsdesc_lo12:v1
// .tlsdesccall v1
// blr x1
// After desc_gd_to_le optimization, the sequence will be like:
// movz x0, #0x0, lsl #16
// movk x0, #0x10
// nop
// nop
// Calculate tprel value.
Output_segment* tls_segment = relinfo->layout->tls_segment();
gold_assert(tls_segment != NULL);
Insntype* ip = reinterpret_cast<Insntype*>(view);
const elfcpp::Elf_Xword addend = rela.get_r_addend();
AArch64_address value = psymval->value(relinfo->object, addend);
AArch64_address aligned_tcb_size =
align_address(target->tcb_size(), tls_segment->maximum_alignment());
AArch64_address x = value + aligned_tcb_size;
// x is the offset to tp, we can only do this if x is within range
// [0, 2^32-1]. If x is out of range, fail and exit.
if (size == 64 && (static_cast<uint64_t>(x) >> 32) != 0)
{
gold_error(_("TLS variable referred by reloc %u is too far from TP. "
"We Can't do gd_to_le relaxation.\n"), r_type);
return aarch64_reloc_funcs::STATUS_BAD_RELOC;
}
Insntype newinsn;
switch (r_type)
{
case elfcpp::R_AARCH64_TLSDESC_ADD_LO12:
case elfcpp::R_AARCH64_TLSDESC_CALL:
// Change to nop
newinsn = 0xd503201f;
break;
case elfcpp::R_AARCH64_TLSDESC_ADR_PAGE21:
// Change to movz.
newinsn = 0xd2a00000 | (((x >> 16) & 0xffff) << 5);
break;
case elfcpp::R_AARCH64_TLSDESC_LD64_LO12:
// Change to movk.
newinsn = 0xf2800000 | ((x & 0xffff) << 5);
break;
default:
gold_error(_("unsupported tlsdesc gd_to_le optimization on reloc %u"),
r_type);
gold_unreachable();
}
elfcpp::Swap<32, big_endian>::writeval(ip, newinsn);
return aarch64_reloc_funcs::STATUS_OKAY;
} // End of tls_desc_gd_to_le
template<int size, bool big_endian>
inline
typename AArch64_relocate_functions<size, big_endian>::Status
Target_aarch64<size, big_endian>::Relocate::tls_desc_gd_to_ie(
const Relocate_info<size, big_endian>* /* relinfo */,
Target_aarch64<size, big_endian>* /* target */,
const elfcpp::Rela<size, big_endian>& rela,
unsigned int r_type,
unsigned char* view,
const Symbol_value<size>* /* psymval */,
typename elfcpp::Elf_types<size>::Elf_Addr got_entry_address,
typename elfcpp::Elf_types<size>::Elf_Addr address)
{
typedef typename elfcpp::Swap<32, big_endian>::Valtype Insntype;
typedef AArch64_relocate_functions<size, big_endian> aarch64_reloc_funcs;
// TLSDESC-GD sequence is like:
// adrp x0, :tlsdesc:v1
// ldr x1, [x0, #:tlsdesc_lo12:v1]
// add x0, x0, :tlsdesc_lo12:v1
// .tlsdesccall v1
// blr x1
// After desc_gd_to_ie optimization, the sequence will be like:
// adrp x0, :tlsie:v1
// ldr x0, [x0, :tlsie_lo12:v1]
// nop
// nop
Insntype* ip = reinterpret_cast<Insntype*>(view);
const elfcpp::Elf_Xword addend = rela.get_r_addend();
Insntype newinsn;
switch (r_type)
{
case elfcpp::R_AARCH64_TLSDESC_ADD_LO12:
case elfcpp::R_AARCH64_TLSDESC_CALL:
// Change to nop
newinsn = 0xd503201f;
elfcpp::Swap<32, big_endian>::writeval(ip, newinsn);
break;
case elfcpp::R_AARCH64_TLSDESC_ADR_PAGE21:
{
return aarch64_reloc_funcs::adrp(view, got_entry_address + addend,
address);
}
break;
case elfcpp::R_AARCH64_TLSDESC_LD64_LO12:
{
// Set ldr target register to be x0.
Insntype insn = elfcpp::Swap<32, big_endian>::readval(ip);
insn &= 0xffffffe0;
elfcpp::Swap<32, big_endian>::writeval(ip, insn);
// Do relocation.
const AArch64_reloc_property* reloc_property =
aarch64_reloc_property_table->get_reloc_property(
elfcpp::R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC);
return aarch64_reloc_funcs::template rela_general<32>(
view, got_entry_address, addend, reloc_property);
}
break;
default:
gold_error(_("Don't support tlsdesc gd_to_ie optimization on reloc %u"),
r_type);
gold_unreachable();
}
return aarch64_reloc_funcs::STATUS_OKAY;
} // End of tls_desc_gd_to_ie
// 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.
Reference in New Issue View Git Blame Copy Permalink