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// s390.cc -- s390 target support for gold.
// Copyright (C) 2015-2016 Free Software Foundation, Inc.
// Written by Marcin Koƛcielnicki <koriakin@0x04.net>.
// 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 "s390.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 "gc.h"
#include "icf.h"
namespace
{
using namespace gold;
// A class to handle the .got.plt section.
template<int size>
class Output_data_got_plt_s390 : public Output_section_data_build
{
public:
Output_data_got_plt_s390(Layout* layout)
: Output_section_data_build(size/8),
layout_(layout)
{ }
Output_data_got_plt_s390(Layout* layout, off_t data_size)
: Output_section_data_build(data_size, size/8),
layout_(layout)
{ }
protected:
// Write out the PLT data.
void
do_write(Output_file*);
// Write to a map file.
void
do_print_to_mapfile(Mapfile* mapfile) const
{ mapfile->print_output_data(this, "** GOT PLT"); }
private:
// A pointer to the Layout class, so that we can find the .dynamic
// section when we write out the GOT PLT section.
Layout* layout_;
};
// A class to handle the PLT data.
template<int size>
class Output_data_plt_s390 : public Output_section_data
{
public:
typedef Output_data_reloc<elfcpp::SHT_RELA, true, size, true>
Reloc_section;
Output_data_plt_s390(Layout* layout,
Output_data_got<size, true>* got,
Output_data_got_plt_s390<size>* got_plt,
Output_data_space* got_irelative)
: Output_section_data(4), layout_(layout),
irelative_rel_(NULL), got_(got), got_plt_(got_plt),
got_irelative_(got_irelative), count_(0),
irelative_count_(0), free_list_()
{ this->init(layout); }
Output_data_plt_s390(Layout* layout,
Output_data_got<size, true>* got,
Output_data_got_plt_s390<size>* got_plt,
Output_data_space* got_irelative,
unsigned int plt_count)
: Output_section_data((plt_count + 1) * plt_entry_size,
4, false),
layout_(layout), irelative_rel_(NULL), got_(got),
got_plt_(got_plt), got_irelative_(got_irelative), count_(plt_count),
irelative_count_(0), free_list_()
{
this->init(layout);
// Initialize the free list and reserve the first entry.
this->free_list_.init((plt_count + 1) * plt_entry_size, false);
this->free_list_.remove(0, plt_entry_size);
}
// 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*, Layout*,
Sized_relobj_file<size, true>*, unsigned int);
// Add the relocation for a PLT entry.
void
add_relocation(Symbol_table*, Layout*, Symbol*, unsigned int);
// Return the .rela.plt section data.
Reloc_section*
rela_plt()
{ return this->rel_; }
// 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()
{ return plt_entry_size; }
// Return the size of a PLT entry.
unsigned int
get_plt_entry_size() const
{ return plt_entry_size; }
// Reserve a slot in the PLT for an existing symbol in an incremental update.
void
reserve_slot(unsigned int plt_index)
{
this->free_list_.remove((plt_index + 1) * plt_entry_size,
(plt_index + 2) * plt_entry_size);
}
// Return the PLT address to use for a global symbol.
uint64_t
address_for_global(const Symbol*);
// Return the PLT address to use for a local symbol.
uint64_t
address_for_local(const Relobj*, unsigned int symndx);
// Add .eh_frame information for the PLT.
void
add_eh_frame(Layout* layout)
{
(void)layout;
layout->add_eh_frame_for_plt(this,
plt_eh_frame_cie,
plt_eh_frame_cie_size,
plt_eh_frame_fde,
plt_eh_frame_fde_size);
}
protected:
// Fill in the first PLT entry.
void
fill_first_plt_entry(unsigned char* pov,
typename elfcpp::Elf_types<size>::Elf_Addr got_address,
typename elfcpp::Elf_types<size>::Elf_Addr plt_address);
// Fill in a normal PLT entry. Returns the offset into the entry that
// should be the initial GOT slot value.
unsigned int
fill_plt_entry(unsigned char* pov,
typename elfcpp::Elf_types<size>::Elf_Addr got_address,
typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
unsigned int got_offset,
unsigned int plt_offset,
unsigned int plt_rel_offset);
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*);
// A pointer to the Layout class, so that we can find the .dynamic
// section when we write out the GOT PLT section.
Layout* layout_;
// The reloc section.
Reloc_section* rel_;
// The IRELATIVE relocs, if necessary. These must follow the
// regular PLT relocations.
Reloc_section* irelative_rel_;
// The .got section.
Output_data_got<size, true>* got_;
// The .got.plt section.
Output_data_got_plt_s390<size>* 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_TILEGX_IRELATIVE relocs. These
// follow the regular PLT entries.
unsigned int irelative_count_;
// List of available regions within the section, for incremental
// update links.
Free_list free_list_;
// The size of an entry in the PLT.
static const int plt_entry_size = 0x20;
// The first entry in the PLT.
static const unsigned char first_plt_entry_32_abs[plt_entry_size];
static const unsigned char first_plt_entry_32_pic[plt_entry_size];
static const unsigned char first_plt_entry_64[plt_entry_size];
// Other entries in the PLT for an executable.
static const unsigned char plt_entry_32_abs[plt_entry_size];
static const unsigned char plt_entry_32_pic12[plt_entry_size];
static const unsigned char plt_entry_32_pic16[plt_entry_size];
static const unsigned char plt_entry_32_pic[plt_entry_size];
static const unsigned char plt_entry_64[plt_entry_size];
// The .eh_frame unwind information for the PLT.
static const int plt_eh_frame_cie_size = 12;
static const unsigned char plt_eh_frame_cie[plt_eh_frame_cie_size];
static const int plt_eh_frame_fde_size = 12;
static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
};
template<int size>
class Target_s390 : public Sized_target<size, true>
{
public:
typedef Output_data_reloc<elfcpp::SHT_RELA, true, size, true> Reloc_section;
Target_s390()
: Sized_target<size, true>(&s390_info),
got_(NULL), plt_(NULL), got_plt_(NULL), got_irelative_(NULL),
global_offset_table_(NULL), rela_dyn_(NULL),
rela_irelative_(NULL), copy_relocs_(elfcpp::R_390_COPY),
got_mod_index_offset_(-1U), tls_base_symbol_defined_(false),
layout_(NULL)
{ }
// Scan the relocations to look for symbol adjustments.
void
gc_process_relocs(Symbol_table* symtab,
Layout* layout,
Sized_relobj_file<size, true>* 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, true>* 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, true>*,
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, true>* 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*);
// Scan the relocs for --emit-relocs.
void
emit_relocs_scan(Symbol_table* symtab,
Layout* layout,
Sized_relobj_file<size, true>* 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_syms,
Relocatable_relocs* rr);
// Return a string used to fill a code section with nops.
std::string
do_code_fill(section_size_type length) const;
// Emit relocations for a section.
void
relocate_relocs(
const Relocate_info<size, true>*,
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,
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 whether SYM is defined by the ABI.
bool
do_is_defined_by_abi(const Symbol* sym) const
{ return strcmp(sym->name(), "__tls_get_offset") == 0; }
// Return the PLT address to use for a global symbol.
uint64_t
do_plt_address_for_global(const Symbol* gsym) const
{ return this->plt_section()->address_for_global(gsym); }
uint64_t
do_plt_address_for_local(const Relobj* relobj, unsigned int symndx) const
{ return this->plt_section()->address_for_local(relobj, symndx); }
// Return the offset to use for the GOT_INDX'th got entry which is
// for a local tls symbol specified by OBJECT, SYMNDX.
int64_t
do_tls_offset_for_local(const Relobj* object,
unsigned int symndx,
unsigned int got_indx) const;
// Return the offset to use for the GOT_INDX'th got entry which is
// for global tls symbol GSYM.
int64_t
do_tls_offset_for_global(Symbol* gsym, unsigned int got_indx) const;
// 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 whether SYM is call to a non-split function.
bool
do_is_call_to_non_split(const Symbol* sym, const unsigned char* preloc,
const unsigned char* view,
section_size_type view_size) const;
// Adjust -fsplit-stack code which calls non-split-stack code.
void
do_calls_non_split(Relobj* object, unsigned int shndx,
section_offset_type fnoffset, section_size_type fnsize,
const unsigned char* prelocs, size_t reloc_count,
unsigned char* view, section_size_type view_size,
std::string* from, std::string* to) const;
// Return the size of the GOT section.
section_size_type
got_size() const
{
gold_assert(this->got_ != NULL);
return this->got_->data_size();
}
// Return the number of entries in the GOT.
unsigned int
got_entry_count() const
{
if (this->got_ == NULL)
return 0;
return this->got_size() / (size / 8);
}
// 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 the GOT section for an incremental update.
Output_data_got_base*
init_got_plt_for_update(Symbol_table* symtab,
Layout* layout,
unsigned int got_count,
unsigned int plt_count);
// Reserve a GOT entry for a local symbol, and regenerate any
// necessary dynamic relocations.
void
reserve_local_got_entry(unsigned int got_index,
Sized_relobj<size, true>* obj,
unsigned int r_sym,
unsigned int got_type);
// Reserve a GOT entry for a global symbol, and regenerate any
// necessary dynamic relocations.
void
reserve_global_got_entry(unsigned int got_index, Symbol* gsym,
unsigned int got_type);
// Register an existing PLT entry for a global symbol.
void
register_global_plt_entry(Symbol_table*, Layout*, unsigned int plt_index,
Symbol* gsym);
// Force a COPY relocation for a given symbol.
void
emit_copy_reloc(Symbol_table*, Symbol*, Output_section*, off_t);
// Apply an incremental relocation.
void
apply_relocation(const Relocate_info<size, true>* relinfo,
typename elfcpp::Elf_types<size>::Elf_Addr r_offset,
unsigned int r_type,
typename elfcpp::Elf_types<size>::Elf_Swxword r_addend,
const Symbol* gsym,
unsigned char* view,
typename elfcpp::Elf_types<size>::Elf_Addr address,
section_size_type view_size);
private:
// The class which scans relocations.
class Scan
{
public:
Scan()
: issued_non_pic_error_(false)
{ }
static inline int
get_reference_flags(unsigned int r_type);
inline void
local(Symbol_table* symtab, Layout* layout, Target_s390* target,
Sized_relobj_file<size, true>* object,
unsigned int data_shndx,
Output_section* output_section,
const elfcpp::Rela<size, true>& reloc, unsigned int r_type,
const elfcpp::Sym<size, true>& lsym,
bool is_discarded);
inline void
global(Symbol_table* symtab, Layout* layout, Target_s390* target,
Sized_relobj_file<size, true>* object,
unsigned int data_shndx,
Output_section* output_section,
const elfcpp::Rela<size, true>& reloc, unsigned int r_type,
Symbol* gsym);
inline bool
local_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
Target_s390* target,
Sized_relobj_file<size, true>* object,
unsigned int data_shndx,
Output_section* output_section,
const elfcpp::Rela<size, true>& reloc,
unsigned int r_type,
const elfcpp::Sym<size, true>& lsym);
inline bool
global_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
Target_s390* target,
Sized_relobj_file<size, true>* object,
unsigned int data_shndx,
Output_section* output_section,
const elfcpp::Rela<size, true>& reloc,
unsigned int r_type,
Symbol* gsym);
private:
static void
unsupported_reloc_local(Sized_relobj_file<size, true>*,
unsigned int r_type);
static void
unsupported_reloc_global(Sized_relobj_file<size, true>*,
unsigned int r_type, Symbol*);
void
check_non_pic(Relobj*, unsigned int r_type);
inline bool
possible_function_pointer_reloc(unsigned int r_type);
bool
reloc_needs_plt_for_ifunc(Sized_relobj_file<size, true>*,
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:
// Do a relocation. Return false if the caller should not issue
// any warnings about this relocation.
inline bool
relocate(const Relocate_info<size, true>*, unsigned int,
Target_s390*, Output_section*, size_t, const unsigned char*,
const Sized_symbol<size>*, const Symbol_value<size>*,
unsigned char*, typename elfcpp::Elf_types<size>::Elf_Addr,
section_size_type);
private:
// Do a TLS relocation.
inline typename elfcpp::Elf_types<size>::Elf_Addr
relocate_tls(const Relocate_info<size, true>*, Target_s390*,
size_t relnum, const elfcpp::Rela<size, true>&,
unsigned int r_type, const Sized_symbol<size>*,
const Symbol_value<size>*,
unsigned char*, section_size_type);
// Do a TLS General-Dynamic to Initial-Exec transition.
inline void
tls_gd_to_ie(const Relocate_info<size, true>*, size_t relnum,
const elfcpp::Rela<size, true>&,
unsigned char* view,
section_size_type view_size);
// Do a TLS General-Dynamic to Local-Exec transition.
inline void
tls_gd_to_le(const Relocate_info<size, true>*, size_t relnum,
const elfcpp::Rela<size, true>&,
unsigned char* view,
section_size_type view_size);
// Do a TLS Local-Dynamic to Local-Exec transition.
inline void
tls_ld_to_le(const Relocate_info<size, true>*, size_t relnum,
const elfcpp::Rela<size, true>&,
unsigned char* view,
section_size_type view_size);
// Do a TLS Initial-Exec to Local-Exec transition.
static inline void
tls_ie_to_le(const Relocate_info<size, true>*, size_t relnum,
const elfcpp::Rela<size, true>&,
unsigned char* view,
section_size_type view_size);
};
// 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.
const Output_data_got<size, true>*
got_section() const
{
gold_assert(this->got_ != NULL);
return this->got_;
}
// Get the GOT section, creating it if necessary.
Output_data_got<size, true>*
got_section(Symbol_table*, Layout*);
typename elfcpp::Elf_types<size>::Elf_Addr
got_address() const
{
gold_assert(this->got_ != NULL);
return this->got_plt_->address();
}
typename elfcpp::Elf_types<size>::Elf_Addr
got_main_offset() const
{
gold_assert(this->got_ != NULL);
return this->got_->address() - this->got_address();
}
// 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, true>* relobj,
unsigned int local_sym_index);
// Create a GOT entry for the TLS module index.
unsigned int
got_mod_index_entry(Symbol_table* symtab, Layout* layout,
Sized_relobj_file<size, true>* object);
// Get the PLT section.
Output_data_plt_s390<size>*
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 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, true>* object,
unsigned int shndx, Output_section* output_section,
Symbol* sym, const elfcpp::Rela<size, true>& reloc)
{
unsigned int r_type = elfcpp::elf_r_type<size>(reloc.get_r_info());
this->copy_relocs_.copy_reloc(symtab, layout,
symtab->get_sized_symbol<size>(sym),
object, shndx, output_section,
r_type, reloc.get_r_offset(),
reloc.get_r_addend(),
this->rela_dyn_section(layout));
}
// A function for targets to call. Return whether BYTES/LEN matches
// VIEW/VIEW_SIZE at OFFSET. Like the one in Target, but takes
// an unsigned char * parameter.
bool
match_view_u(const unsigned char* view, section_size_type view_size,
section_offset_type offset, const unsigned char* bytes, size_t len) const
{
return this->match_view(view, view_size, offset,
reinterpret_cast<const char*>(bytes), len);
}
// Information about this specific target which we pass to the
// general Target structure.
static Target::Target_info s390_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
};
// The GOT section.
Output_data_got<size, true>* got_;
// The PLT section.
Output_data_plt_s390<size>* plt_;
// The GOT PLT section.
Output_data_got_plt_s390<size>* got_plt_;
// The GOT section for IRELATIVE relocations.
Output_data_space* got_irelative_;
// 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, true> copy_relocs_;
// Offset of the GOT entry for the TLS module index.
unsigned int got_mod_index_offset_;
// True if the _TLS_MODULE_BASE_ symbol has been defined.
bool tls_base_symbol_defined_;
// For use in do_tls_offset_for_*
Layout *layout_;
// Code sequences for -fsplit-stack matching.
static const unsigned char ss_code_bras_8[];
static const unsigned char ss_code_l_basr[];
static const unsigned char ss_code_a_basr[];
static const unsigned char ss_code_larl[];
static const unsigned char ss_code_brasl[];
static const unsigned char ss_code_jg[];
static const unsigned char ss_code_jgl[];
// Variable code sequence matchers for -fsplit-stack.
bool ss_match_st_r14(unsigned char* view,
section_size_type view_size,
section_offset_type *offset) const;
bool ss_match_l_r14(unsigned char* view,
section_size_type view_size,
section_offset_type *offset) const;
bool ss_match_mcount(unsigned char* view,
section_size_type view_size,
section_offset_type *offset) const;
bool ss_match_ear(unsigned char* view,
section_size_type view_size,
section_offset_type *offset) const;
bool ss_match_c(unsigned char* view,
section_size_type view_size,
section_offset_type *offset) const;
bool ss_match_l(unsigned char* view,
section_size_type view_size,
section_offset_type *offset,
int *guard_reg) const;
bool ss_match_ahi(unsigned char* view,
section_size_type view_size,
section_offset_type *offset,
int guard_reg,
uint32_t *arg) const;
bool ss_match_alfi(unsigned char* view,
section_size_type view_size,
section_offset_type *offset,
int guard_reg,
uint32_t *arg) const;
bool ss_match_cr(unsigned char* view,
section_size_type view_size,
section_offset_type *offset,
int guard_reg) const;
};
template<>
Target::Target_info Target_s390<32>::s390_info =
{
32, // size
true, // is_big_endian
elfcpp::EM_S390, // machine_code
false, // has_make_symbol
false, // has_resolve
true, // has_code_fill
true, // is_default_stack_executable
true, // can_icf_inline_merge_sections
'\0', // wrap_char
"/lib/ld.so.1", // dynamic_linker
0x00400000, // default_text_segment_address
4 * 1024, // abi_pagesize (overridable by -z max-page-size)
4 * 1024, // 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
32, // hash_entry_size
};
template<>
Target::Target_info Target_s390<64>::s390_info =
{
64, // size
true, // is_big_endian
elfcpp::EM_S390, // machine_code
false, // has_make_symbol
false, // has_resolve
true, // has_code_fill
true, // is_default_stack_executable
true, // can_icf_inline_merge_sections
'\0', // wrap_char
"/lib/ld64.so.1", // dynamic_linker
0x80000000ll, // default_text_segment_address
4 * 1024, // abi_pagesize (overridable by -z max-page-size)
4 * 1024, // 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
64, // hash_entry_size
};
template<int size>
class S390_relocate_functions
{
public:
enum Overflow_check
{
CHECK_NONE,
CHECK_SIGNED,
CHECK_UNSIGNED,
CHECK_BITFIELD,
CHECK_LOW_INSN,
CHECK_HIGH_INSN
};
enum Status
{
STATUS_OK,
STATUS_OVERFLOW
};
private:
typedef S390_relocate_functions<size> This;
typedef typename elfcpp::Elf_types<size>::Elf_Addr Address;
template<int valsize>
static inline bool
has_overflow_signed(Address value)
{
// limit = 1 << (valsize - 1) without shift count exceeding size of type
Address limit = static_cast<Address>(1) << ((valsize - 1) >> 1);
limit <<= ((valsize - 1) >> 1);
limit <<= ((valsize - 1) - 2 * ((valsize - 1) >> 1));
return value + limit > (limit << 1) - 1;
}
template<int valsize>
static inline bool
has_overflow_unsigned(Address value)
{
Address limit = static_cast<Address>(1) << ((valsize - 1) >> 1);
limit <<= ((valsize - 1) >> 1);
limit <<= ((valsize - 1) - 2 * ((valsize - 1) >> 1));
return value > (limit << 1) - 1;
}
template<int fieldsize>
static inline void
rela(unsigned char* view, Address mask, Address value)
{
typedef typename elfcpp::Swap<fieldsize, true>::Valtype Valtype;
Valtype* wv = reinterpret_cast<Valtype*>(view);
Valtype val = elfcpp::Swap<fieldsize, true>::readval(view);
val &= ~mask;
value &= mask;
elfcpp::Swap<fieldsize, true>::writeval(wv, val | value);
}
public:
// R_390_12, R_390_GOT12, R_390_GOTPLT12, R_390_GOTIE12
static inline Status
rela12(unsigned char* view, Address value)
{
if (This::template has_overflow_unsigned<12>(value))
return STATUS_OVERFLOW;
This::template rela<16>(view, 0x0fff, value);
return STATUS_OK;
}
// R_390_16, R_390_GOT16, R_390_GOTPLT16, R_390_GOTOFF16, R_390_PLTOFF16
static inline Status
rela16(unsigned char* view, Address value)
{
if (This::template has_overflow_signed<16>(value))
return STATUS_OVERFLOW;
This::template rela<16>(view, 0xffff, value);
return STATUS_OK;
}
// R_390_20, R_390_GOT20, R_390_GOTPLT20, R_390_GOTIE20
static inline Status
rela20(unsigned char* view, Address value)
{
if (This::template has_overflow_signed<20>(value))
return STATUS_OVERFLOW;
This::template rela<16>(view, 0x0fff, value);
This::template rela<16>(view + 2, 0xff00, value >> (12 - 8));
return STATUS_OK;
}
// R_390_PC12DBL, R_390_PLT12DBL
static inline Status
pcrela12dbl(unsigned char* view, Address value, Address address)
{
value -= address;
if ((value & 1) != 0)
return STATUS_OVERFLOW;
if (This::template has_overflow_signed<13>(value))
return STATUS_OVERFLOW;
value >>= 1;
This::template rela<16>(view, 0x0fff, value);
return STATUS_OK;
}
// R_390_PC16DBL, R_390_PLT16DBL
static inline Status
pcrela16dbl(unsigned char* view, Address value, Address address)
{
value -= address;
if ((value & 1) != 0)
return STATUS_OVERFLOW;
if (This::template has_overflow_signed<17>(value))
return STATUS_OVERFLOW;
value >>= 1;
This::template rela<16>(view, 0xffff, value);
return STATUS_OK;
}
// R_390_PC24DBL, R_390_PLT24DBL
static inline Status
pcrela24dbl(unsigned char* view, Address value, Address address)
{
value -= address;
if ((value & 1) != 0)
return STATUS_OVERFLOW;
if (This::template has_overflow_signed<25>(value))
return STATUS_OVERFLOW;
value >>= 1;
// Swap doesn't take 24-bit fields well...
This::template rela<8>(view, 0xff, value >> 16);
This::template rela<16>(view + 1, 0xffff, value);
return STATUS_OK;
}
// R_390_PC32DBL, R_390_PLT32DBL, R_390_GOTPCDBL, R_390_GOTENT, R_390_GOTPLTENT
static inline Status
pcrela32dbl(unsigned char* view, Address value, Address address)
{
Address reloc = value - address;
if ((reloc & 1) != 0)
{
gold_warning(_("R_390_PC32DBL target misaligned at %llx"), (long long)address);
// Wait for a fix for https://sourceware.org/bugzilla/show_bug.cgi?id=18960
// return STATUS_OVERFLOW;
}
if (This::template has_overflow_signed<33>(reloc))
return STATUS_OVERFLOW;
reloc >>= 1;
if (value < address && size == 32)
reloc |= 0x80000000;
This::template rela<32>(view, 0xffffffff, reloc);
return STATUS_OK;
}
};
// Initialize the PLT section.
template<int size>
void
Output_data_plt_s390<size>::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>
void
Output_data_plt_s390<size>::do_adjust_output_section(Output_section* os)
{
os->set_entsize(plt_entry_size);
}
// Add an entry to the PLT.
template<int size>
void
Output_data_plt_s390<size>::add_entry(Symbol_table* symtab, Layout* layout,
Symbol* gsym)
{
gold_assert(!gsym->has_plt_offset());
unsigned int plt_index;
off_t plt_offset;
section_offset_type got_offset;
unsigned int* pcount;
unsigned int offset;
unsigned int reserved;
Output_section_data_build* got;
if (gsym->type() == elfcpp::STT_GNU_IFUNC
&& gsym->can_use_relative_reloc(false))
{
pcount = &this->irelative_count_;
offset = 0;
reserved = 0;
got = this->got_irelative_;
}
else
{
pcount = &this->count_;
offset = 1;
reserved = 3;
got = this->got_plt_;
}
if (!this->is_data_size_valid())
{
// Note that when setting the PLT offset for a non-IRELATIVE
// entry we skip the initial reserved PLT entry.
plt_index = *pcount + offset;
plt_offset = plt_index * plt_entry_size;
++*pcount;
got_offset = (plt_index - offset + reserved) * size / 8;
gold_assert(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);
}
else
{
// FIXME: This is probably not correct for IRELATIVE relocs.
// For incremental updates, find an available slot.
plt_offset = this->free_list_.allocate(plt_entry_size,
plt_entry_size, 0);
if (plt_offset == -1)
gold_fallback(_("out of patch space (PLT);"
" relink with --incremental-full"));
// The GOT and PLT entries have a 1-1 correspondance, so the GOT offset
// can be calculated from the PLT index, adjusting for the three
// reserved entries at the beginning of the GOT.
plt_index = plt_offset / plt_entry_size - 1;
got_offset = (plt_index - offset + reserved) * size / 8;
}
gsym->set_plt_offset(plt_offset);
// 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>
unsigned int
Output_data_plt_s390<size>::add_local_ifunc_entry(
Symbol_table* symtab,
Layout* layout,
Sized_relobj_file<size, true>* relobj,
unsigned int local_sym_index)
{
unsigned int plt_offset = this->irelative_count_ * 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_390_IRELATIVE,
this->got_irelative_, got_offset, 0);
return plt_offset;
}
// Add the relocation for a PLT entry.
template<int size>
void
Output_data_plt_s390<size>::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_390_IRELATIVE,
this->got_irelative_, got_offset, 0);
}
else
{
gsym->set_needs_dynsym_entry();
this->rel_->add_global(gsym, elfcpp::R_390_JMP_SLOT, this->got_plt_,
got_offset, 0);
}
}
// Return where the IRELATIVE relocations should go in the PLT. These
// follow the JUMP_SLOT and the TLSDESC relocations.
template<int size>
typename Output_data_plt_s390<size>::Reloc_section*
Output_data_plt_s390<size>::rela_irelative(Symbol_table* symtab,
Layout* layout)
{
if (this->irelative_rel_ == NULL)
{
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_390_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>
uint64_t
Output_data_plt_s390<size>::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->count_ + 1) * 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>
uint64_t
Output_data_plt_s390<size>::address_for_local(const Relobj* object,
unsigned int r_sym)
{
return (this->address()
+ (this->count_ + 1) * plt_entry_size
+ object->local_plt_offset(r_sym));
}
// Set the final size.
template<int size>
void
Output_data_plt_s390<size>::set_final_data_size()
{
unsigned int count = this->count_ + this->irelative_count_;
this->set_data_size((count + 1) * plt_entry_size);
}
template<int size>
const unsigned char
Output_data_plt_s390<size>::first_plt_entry_32_abs[plt_entry_size] =
{
0x50, 0x10, 0xf0, 0x1c, // st %r1, 28(%r15)
0x0d, 0x10, // basr %r1, %r0
0x58, 0x10, 0x10, 0x12, // l %r1, 18(%r1)
0xd2, 0x03, 0xf0, 0x18, 0x10, 0x04, // mvc 24(4,%r15), 4(%r1)
0x58, 0x10, 0x10, 0x08, // l %r1, 8(%r1)
0x07, 0xf1, // br %r1
0x00, 0x00, // padding
0x00, 0x00, 0x00, 0x00, // _GLOBAL_OFFSET_TABLE_ (to fill)
0x00, 0x00, 0x00, 0x00, // padding
};
template<int size>
const unsigned char
Output_data_plt_s390<size>::first_plt_entry_32_pic[plt_entry_size] =
{
0x50, 0x10, 0xf0, 0x1c, // st %r1, 28(%r15)
0x58, 0x10, 0xc0, 0x04, // l %r1, 4(%r12)
0x50, 0x10, 0xf0, 0x18, // st %r1, 24(%r15)
0x58, 0x10, 0xc0, 0x08, // l %r1, 8(%r12)
0x07, 0xf1, // br %r1
0x00, 0x00, // padding
0x00, 0x00, 0x00, 0x00, // padding
0x00, 0x00, 0x00, 0x00, // padding
0x00, 0x00, 0x00, 0x00, // padding
};
template<int size>
const unsigned char
Output_data_plt_s390<size>::first_plt_entry_64[plt_entry_size] =
{
0xe3, 0x10, 0xf0, 0x38, 0x00, 0x24, // stg %r1, 56(%r15)
0xc0, 0x10, 0x00, 0x00, 0x00, 0x00, // larl %r1, _GLOBAL_OFFSET_TABLE_ (to fill)
0xd2, 0x07, 0xf0, 0x30, 0x10, 0x08, // mvc 48(8,%r15), 8(%r1)
0xe3, 0x10, 0x10, 0x10, 0x00, 0x04, // lg %r1, 16(%r1)
0x07, 0xf1, // br %r1
0x07, 0x00, // nopr
0x07, 0x00, // nopr
0x07, 0x00, // nopr
};
template<int size>
void
Output_data_plt_s390<size>::fill_first_plt_entry(
unsigned char* pov,
typename elfcpp::Elf_types<size>::Elf_Addr got_address,
typename elfcpp::Elf_types<size>::Elf_Addr plt_address)
{
if (size == 64)
{
memcpy(pov, first_plt_entry_64, plt_entry_size);
S390_relocate_functions<size>::pcrela32dbl(pov + 8, got_address, (plt_address + 6));
}
else if (!parameters->options().output_is_position_independent())
{
memcpy(pov, first_plt_entry_32_abs, plt_entry_size);
elfcpp::Swap<32, true>::writeval(pov + 24, got_address);
}
else
{
memcpy(pov, first_plt_entry_32_pic, plt_entry_size);
}
}
template<int size>
const unsigned char
Output_data_plt_s390<size>::plt_entry_32_abs[plt_entry_size] =
{
// first part
0x0d, 0x10, // basr %r1, %r0
0x58, 0x10, 0x10, 0x16, // l %r1, 22(%r1)
0x58, 0x10, 0x10, 0x00, // l %r1, 0(%r1)
0x07, 0xf1, // br %r1
// second part
0x0d, 0x10, // basr %r1, %r0
0x58, 0x10, 0x10, 0x0e, // l %r1, 14(%r1)
0xa7, 0xf4, 0x00, 0x00, // j first_plt_entry (to fill)
0x00, 0x00, // padding
0x00, 0x00, 0x00, 0x00, // _GLOBAL_OFFSET_TABLE_+sym@gotplt (to fill)
0x00, 0x00, 0x00, 0x00, // offset of relocation in .rela.plt (to fill)
};
template<int size>
const unsigned char
Output_data_plt_s390<size>::plt_entry_32_pic12[plt_entry_size] =
{
// first part
0x58, 0x10, 0xc0, 0x00, // l %r1, sym@gotplt(%r12) (to fill)
0x07, 0xf1, // br %r1
0x00, 0x00, // padding
0x00, 0x00, 0x00, 0x00, // padding
// second part
0x0d, 0x10, // basr %r1, %r0
0x58, 0x10, 0x10, 0x0e, // l %r1, 14(%r1)
0xa7, 0xf4, 0x00, 0x00, // j first_plt_entry (to fill)
0x00, 0x00, // padding
0x00, 0x00, 0x00, 0x00, // padding
0x00, 0x00, 0x00, 0x00, // offset of relocation in .rela.plt (to fill)
};
template<int size>
const unsigned char
Output_data_plt_s390<size>::plt_entry_32_pic16[plt_entry_size] =
{
// first part
0xa7, 0x18, 0x00, 0x00, // lhi %r1, sym@gotplt (to fill)
0x58, 0x11, 0xc0, 0x00, // l %r1, 0(%r1, %r12)
0x07, 0xf1, // br %r1
0x00, 0x00, // padding
// second part
0x0d, 0x10, // basr %r1, %r0
0x58, 0x10, 0x10, 0x0e, // l %r1, 14(%r1)
0xa7, 0xf4, 0x00, 0x00, // j first_plt_entry (to fill)
0x00, 0x00, // padding
0x00, 0x00, 0x00, 0x00, // padding
0x00, 0x00, 0x00, 0x00, // offset of relocation in .rela.plt (to fill)
};
template<int size>
const unsigned char
Output_data_plt_s390<size>::plt_entry_32_pic[plt_entry_size] =
{
// first part
0x0d, 0x10, // basr %r1, %r0
0x58, 0x10, 0x10, 0x16, // l %r1, 22(%r1)
0x58, 0x11, 0xc0, 0x00, // l %r1, 0(%r1, %r12)
0x07, 0xf1, // br %r1
// second part
0x0d, 0x10, // basr %r1, %r0
0x58, 0x10, 0x10, 0x0e, // l %r1, 14(%r1)
0xa7, 0xf4, 0x00, 0x00, // j first_plt_entry (to fill)
0x00, 0x00, // padding
0x00, 0x00, 0x00, 0x00, // sym@gotplt (to fill)
0x00, 0x00, 0x00, 0x00, // offset of relocation in .rela.plt (to fill)
};
template<int size>
const unsigned char
Output_data_plt_s390<size>::plt_entry_64[plt_entry_size] =
{
// first part
0xc0, 0x10, 0x00, 0x00, 0x00, 0x00, // larl %r1, _GLOBAL_OFFSET_TABLE_+off (to fill)
0xe3, 0x10, 0x10, 0x00, 0x00, 0x04, // lg %r1, 0(%r1)
0x07, 0xf1, // br %r1
// second part
0x0d, 0x10, // basr %r1, %r0
0xe3, 0x10, 0x10, 0x0c, 0x00, 0x14, // lgf %r1, 12(%r1)
0xc0, 0xf4, 0x00, 0x00, 0x00, 0x00, // jg first_plt_entry (to fill)
0x00, 0x00, 0x00, 0x00, // offset of relocation in .rela.plt (to fill)
};
template<int size>
unsigned int
Output_data_plt_s390<size>::fill_plt_entry(
unsigned char* pov,
typename elfcpp::Elf_types<size>::Elf_Addr got_address,
typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
unsigned int got_offset,
unsigned int plt_offset,
unsigned int plt_rel_offset)
{
if (size == 64)
{
memcpy(pov, plt_entry_64, plt_entry_size);
S390_relocate_functions<size>::pcrela32dbl(pov + 2, got_address + got_offset, plt_address + plt_offset);
S390_relocate_functions<size>::pcrela32dbl(pov + 24, plt_address, plt_address + plt_offset + 22);
}
else
{
if (!parameters->options().output_is_position_independent())
{
memcpy(pov, plt_entry_32_abs, plt_entry_size);
elfcpp::Swap<32, true>::writeval(pov + 24, got_address + got_offset);
}
else
{
if (got_offset < 0x1000)
{
memcpy(pov, plt_entry_32_pic12, plt_entry_size);
S390_relocate_functions<size>::rela12(pov + 2, got_offset);
}
else if (got_offset < 0x8000)
{
memcpy(pov, plt_entry_32_pic16, plt_entry_size);
S390_relocate_functions<size>::rela16(pov + 2, got_offset);
}
else
{
memcpy(pov, plt_entry_32_pic, plt_entry_size);
elfcpp::Swap<32, true>::writeval(pov + 24, got_offset);
}
}
typename elfcpp::Elf_types<size>::Elf_Addr target = plt_address;
if (plt_offset >= 0x10000)
{
// Would overflow pcrela16dbl - aim at the farthest previous jump
// we can reach.
if (plt_offset > 0x10000)
{
// Use the full range of pcrel16dbl.
target = plt_address + plt_offset - 0x10000 + 18;
}
else
{
// if plt_offset is exactly 0x10000, the above would aim at 18th byte
// of first_plt_entry, which doesn't have the jump back like the others.
// Aim at the next entry instead.
target = plt_address + plt_offset - 0xffe0 + 18;
}
}
S390_relocate_functions<size>::pcrela16dbl(pov + 20, target, plt_address + plt_offset + 18);
}
elfcpp::Swap<32, true>::writeval(pov + 28, plt_rel_offset);
if (size == 64)
return 14;
else
return 12;
}
// The .eh_frame unwind information for the PLT.
template<>
const unsigned char
Output_data_plt_s390<32>::plt_eh_frame_cie[plt_eh_frame_cie_size] =
{
1, // CIE version.
'z', // Augmentation: augmentation size included.
'R', // Augmentation: FDE encoding included.
'\0', // End of augmentation string.
1, // Code alignment factor.
0x7c, // Data alignment factor.
14, // Return address column.
1, // Augmentation size.
(elfcpp::DW_EH_PE_pcrel // FDE encoding.
| elfcpp::DW_EH_PE_sdata4),
elfcpp::DW_CFA_def_cfa, 15, 0x60, // DW_CFA_def_cfa: r15 ofs 0x60.
};
template<>
const unsigned char
Output_data_plt_s390<64>::plt_eh_frame_cie[plt_eh_frame_cie_size] =
{
1, // CIE version.
'z', // Augmentation: augmentation size included.
'R', // Augmentation: FDE encoding included.
'\0', // End of augmentation string.
1, // Code alignment factor.
0x78, // Data alignment factor.
14, // Return address column.
1, // Augmentation size.
(elfcpp::DW_EH_PE_pcrel // FDE encoding.
| elfcpp::DW_EH_PE_sdata4),
elfcpp::DW_CFA_def_cfa, 15, 0xa0, // DW_CFA_def_cfa: r15 ofs 0xa0.
};
template<int size>
const unsigned char
Output_data_plt_s390<size>::plt_eh_frame_fde[plt_eh_frame_fde_size] =
{
0, 0, 0, 0, // Replaced with offset to .plt.
0, 0, 0, 0, // Replaced with size of .plt.
0, // Augmentation size.
elfcpp::DW_CFA_nop,
elfcpp::DW_CFA_nop,
elfcpp::DW_CFA_nop
};
// Write out the PLT. This uses the hand-coded instructions above,
// and adjusts them as needed.
template<int size>
void
Output_data_plt_s390<size>::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(parameters->incremental_update()
|| (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,
// which is where the GOT pointer will point, and where the
// three reserved GOT entries are located.
typename elfcpp::Elf_types<size>::Elf_Addr got_address
= this->got_plt_->address();
this->fill_first_plt_entry(pov, got_address, plt_address);
pov += this->get_plt_entry_size();
unsigned char* got_pov = got_view;
const int rel_size = elfcpp::Elf_sizes<size>::rela_size;
unsigned int plt_offset = this->get_plt_entry_size();
unsigned int plt_rel_offset = 0;
unsigned int got_offset = 3 * size / 8;
const unsigned int count = this->count_ + this->irelative_count_;
// The first three entries in the GOT are reserved, and are written
// by Output_data_got_plt_s390::do_write.
got_pov += 3 * size / 8;
for (unsigned int plt_index = 0;
plt_index < count;
++plt_index,
pov += plt_entry_size,
got_pov += size / 8,
plt_offset += plt_entry_size,
plt_rel_offset += rel_size,
got_offset += size / 8)
{
// Set and adjust the PLT entry itself.
unsigned int lazy_offset = this->fill_plt_entry(pov,
got_address, plt_address,
got_offset, plt_offset,
plt_rel_offset);
// Set the entry in the GOT.
elfcpp::Swap<size, true>::writeval(got_pov,
plt_address + plt_offset + lazy_offset);
}
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);
}
// Get the GOT section, creating it if necessary.
template<int size>
Output_data_got<size, true>*
Target_s390<size>::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 as a relro section.
// Without -z now, it is modified after program startup by lazy
// PLT relocations.
bool is_got_relro = parameters->options().now();
Output_section_order got_order = (is_got_relro
? ORDER_RELRO_LAST
: ORDER_DATA);
// The old GNU linker creates a .got.plt section. We just
// create another set of data in the .got section. Note that we
// always create a PLT if we create a GOT, although the PLT
// might be empty.
this->got_plt_ = new Output_data_got_plt_s390<size>(layout);
layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
(elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
this->got_plt_, got_order, is_got_relro);
// The first three entries are reserved.
this->got_plt_->set_current_data_size(3 * 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", elfcpp::SHT_PROGBITS,
(elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
this->got_irelative_,
got_order, is_got_relro);
// Unlike some targets (.e.g x86), S/390 does not use separate .got and
// .got.plt sections in output. The output .got section contains both
// PLT and non-PLT GOT entries.
this->got_ = new Output_data_got<size, true>();
layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
(elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
this->got_, got_order, is_got_relro);
// Define _GLOBAL_OFFSET_TABLE_ at the start of the GOT.
this->global_offset_table_ =
symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
Symbol_table::PREDEFINED,
this->got_plt_,
0, 0, elfcpp::STT_OBJECT,
elfcpp::STB_LOCAL,
elfcpp::STV_HIDDEN, 0,
false, false);
}
return this->got_;
}
// Get the dynamic reloc section, creating it if necessary.
template<int size>
typename Target_s390<size>::Reloc_section*
Target_s390<size>::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>
typename Target_s390<size>::Reloc_section*
Target_s390<size>::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_;
}
// Write the first three reserved words of the .got.plt section.
// The remainder of the section is written while writing the PLT
// in Output_data_plt_s390::do_write.
template<int size>
void
Output_data_got_plt_s390<size>::do_write(Output_file* of)
{
// The first entry in the GOT is the address of the .dynamic section
// aka the PT_DYNAMIC segment. The next two entries are reserved.
// We saved space for them when we created the section in
// Target_x86_64::got_section.
const off_t got_file_offset = this->offset();
gold_assert(this->data_size() >= 3 * size / 8);
unsigned char* const got_view =
of->get_output_view(got_file_offset, 3 * size / 8);
Output_section* dynamic = this->layout_->dynamic_section();
uint64_t dynamic_addr = dynamic == NULL ? 0 : dynamic->address();
elfcpp::Swap<size, true>::writeval(got_view, dynamic_addr);
memset(got_view + size / 8, 0, 2 * size / 8);
of->write_output_view(got_file_offset, 3 * size / 8, got_view);
}
// Create the PLT section.
template<int size>
void
Target_s390<size>::make_plt_section(Symbol_table* symtab, Layout* layout)
{
if (this->plt_ == NULL)
{
// Create the GOT sections first.
this->got_section(symtab, layout);
// Ensure that .rela.dyn always appears before .rela.plt This is
// necessary due to how, on 32-bit S/390 and some other targets,
// .rela.dyn needs to include .rela.plt in it's range.
this->rela_dyn_section(layout);
this->plt_ = new Output_data_plt_s390<size>(layout,
this->got_, this->got_plt_, this->got_irelative_);
// Add unwind information if requested.
if (parameters->options().ld_generated_unwind_info())
this->plt_->add_eh_frame(layout);
layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
(elfcpp::SHF_ALLOC
| elfcpp::SHF_EXECINSTR),
this->plt_, ORDER_PLT, false);
// Make the sh_info field of .rela.plt point to .plt.
Output_section* rela_plt_os = this->plt_->rela_plt()->output_section();
rela_plt_os->set_info_section(this->plt_->output_section());
}
}
// Create a PLT entry for a global symbol.
template<int size>
void
Target_s390<size>::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>
void
Target_s390<size>::make_local_ifunc_plt_entry(
Symbol_table* symtab, Layout* layout,
Sized_relobj_file<size, true>* 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);
}
// Return the number of entries in the PLT.
template<int size>
unsigned int
Target_s390<size>::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>
unsigned int
Target_s390<size>::first_plt_entry_offset() const
{
return this->plt_->first_plt_entry_offset();
}
// Return the size of each PLT entry.
template<int size>
unsigned int
Target_s390<size>::plt_entry_size() const
{
return this->plt_->get_plt_entry_size();
}
// Create the GOT and PLT sections for an incremental update.
template<int size>
Output_data_got_base*
Target_s390<size>::init_got_plt_for_update(Symbol_table* symtab,
Layout* layout,
unsigned int got_count,
unsigned int plt_count)
{
gold_assert(this->got_ == NULL);
// Add the three reserved entries.
this->got_plt_ = new Output_data_got_plt_s390<size>(layout, (plt_count + 3) * size / 8);
layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
(elfcpp::SHF_ALLOC
| elfcpp::SHF_WRITE),
this->got_plt_, ORDER_NON_RELRO_FIRST,
false);
// 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(0, size / 8, "** GOT IRELATIVE PLT");
layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
this->got_irelative_,
ORDER_NON_RELRO_FIRST, false);
this->got_ = new Output_data_got<size, true>(got_count * size / 8);
layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
(elfcpp::SHF_ALLOC
| elfcpp::SHF_WRITE),
this->got_, ORDER_RELRO_LAST,
true);
// Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
this->global_offset_table_ =
symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
Symbol_table::PREDEFINED,
this->got_plt_,
0, 0, elfcpp::STT_OBJECT,
elfcpp::STB_LOCAL,
elfcpp::STV_HIDDEN, 0,
false, false);
// Create the PLT section.
this->plt_ = new Output_data_plt_s390<size>(layout,
this->got_, this->got_plt_, this->got_irelative_, plt_count);
// Add unwind information if requested.
if (parameters->options().ld_generated_unwind_info())
this->plt_->add_eh_frame(layout);
layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
elfcpp::SHF_ALLOC | elfcpp::SHF_EXECINSTR,
this->plt_, ORDER_PLT, false);
// Make the sh_info field of .rela.plt point to .plt.
Output_section* rela_plt_os = this->plt_->rela_plt()->output_section();
rela_plt_os->set_info_section(this->plt_->output_section());
// Create the rela_dyn section.
this->rela_dyn_section(layout);
return this->got_;
}
// Reserve a GOT entry for a local symbol, and regenerate any
// necessary dynamic relocations.
template<int size>
void
Target_s390<size>::reserve_local_got_entry(
unsigned int got_index,
Sized_relobj<size, true>* obj,
unsigned int r_sym,
unsigned int got_type)
{
unsigned int got_offset = got_index * size / 8;
Reloc_section* rela_dyn = this->rela_dyn_section(NULL);
this->got_->reserve_local(got_index, obj, r_sym, got_type);
switch (got_type)
{
case GOT_TYPE_STANDARD:
if (parameters->options().output_is_position_independent())
rela_dyn->add_local_relative(obj, r_sym, elfcpp::R_390_RELATIVE,
this->got_, got_offset, 0, false);
break;
case GOT_TYPE_TLS_OFFSET:
rela_dyn->add_local(obj, r_sym, elfcpp::R_390_TLS_TPOFF,
this->got_, got_offset, 0);
break;
case GOT_TYPE_TLS_PAIR:
this->got_->reserve_slot(got_index + 1);
rela_dyn->add_local(obj, r_sym, elfcpp::R_390_TLS_DTPMOD,
this->got_, got_offset, 0);
break;
default:
gold_unreachable();
}
}
// Reserve a GOT entry for a global symbol, and regenerate any
// necessary dynamic relocations.
template<int size>
void
Target_s390<size>::reserve_global_got_entry(unsigned int got_index,
Symbol* gsym,
unsigned int got_type)
{
unsigned int got_offset = got_index * size / 8;
Reloc_section* rela_dyn = this->rela_dyn_section(NULL);
this->got_->reserve_global(got_index, gsym, got_type);
switch (got_type)
{
case GOT_TYPE_STANDARD:
if (!gsym->final_value_is_known())
{
if (gsym->is_from_dynobj()
|| gsym->is_undefined()
|| gsym->is_preemptible()
|| gsym->type() == elfcpp::STT_GNU_IFUNC)
rela_dyn->add_global(gsym, elfcpp::R_390_GLOB_DAT,
this->got_, got_offset, 0);
else
rela_dyn->add_global_relative(gsym, elfcpp::R_390_RELATIVE,
this->got_, got_offset, 0, false);
}
break;
case GOT_TYPE_TLS_OFFSET:
rela_dyn->add_global_relative(gsym, elfcpp::R_390_TLS_TPOFF,
this->got_, got_offset, 0, false);
break;
case GOT_TYPE_TLS_PAIR:
this->got_->reserve_slot(got_index + 1);
rela_dyn->add_global_relative(gsym, elfcpp::R_390_TLS_DTPMOD,
this->got_, got_offset, 0, false);
rela_dyn->add_global_relative(gsym, elfcpp::R_390_TLS_DTPOFF,
this->got_, got_offset + size / 8, 0, false);
break;
default:
gold_unreachable();
}
}
// Register an existing PLT entry for a global symbol.
template<int size>
void
Target_s390<size>::register_global_plt_entry(Symbol_table* symtab,
Layout* layout,
unsigned int plt_index,
Symbol* gsym)
{
gold_assert(this->plt_ != NULL);
gold_assert(!gsym->has_plt_offset());
this->plt_->reserve_slot(plt_index);
gsym->set_plt_offset((plt_index + 1) * this->plt_entry_size());
unsigned int got_offset = (plt_index + 3) * size / 8;
this->plt_->add_relocation(symtab, layout, gsym, got_offset);
}
// Force a COPY relocation for a given symbol.
template<int size>
void
Target_s390<size>::emit_copy_reloc(
Symbol_table* symtab, Symbol* sym, Output_section* os, off_t offset)
{
this->copy_relocs_.emit_copy_reloc(symtab,
symtab->get_sized_symbol<size>(sym),
os,
offset,
this->rela_dyn_section(NULL));
}
// Create a GOT entry for the TLS module index.
template<int size>
unsigned int
Target_s390<size>::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
Sized_relobj_file<size, true>* 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<size, true>* got = this->got_section(symtab, layout);
unsigned int got_offset = got->add_constant(0);
rela_dyn->add_local(object, 0, elfcpp::R_390_TLS_DTPMOD, 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>
tls::Tls_optimization
Target_s390<size>::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_390_TLS_GD32:
case elfcpp::R_390_TLS_GD64:
case elfcpp::R_390_TLS_GDCALL:
// 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_390_TLS_LDM32:
case elfcpp::R_390_TLS_LDM64:
case elfcpp::R_390_TLS_LDO32:
case elfcpp::R_390_TLS_LDO64:
case elfcpp::R_390_TLS_LDCALL:
// This is Local-Dynamic, which refers to a local symbol 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_390_TLS_IE32:
case elfcpp::R_390_TLS_IE64:
case elfcpp::R_390_TLS_GOTIE32:
case elfcpp::R_390_TLS_GOTIE64:
case elfcpp::R_390_TLS_LOAD:
// 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_390_TLS_GOTIE12:
case elfcpp::R_390_TLS_IEENT:
case elfcpp::R_390_TLS_GOTIE20:
// These are Initial-Exec, but cannot be optimized.
return tls::TLSOPT_NONE;
case elfcpp::R_390_TLS_LE32:
case elfcpp::R_390_TLS_LE64:
// When we already have Local-Exec, there is nothing further we
// can do.
return tls::TLSOPT_NONE;
default:
gold_unreachable();
}
}
// Get the Reference_flags for a particular relocation.
template<int size>
int
Target_s390<size>::Scan::get_reference_flags(unsigned int r_type)
{
switch (r_type)
{
case elfcpp::R_390_NONE:
case elfcpp::R_390_GNU_VTINHERIT:
case elfcpp::R_390_GNU_VTENTRY:
case elfcpp::R_390_GOTPC:
case elfcpp::R_390_GOTPCDBL:
// No symbol reference.
return 0;
case elfcpp::R_390_64:
case elfcpp::R_390_32:
case elfcpp::R_390_20:
case elfcpp::R_390_16:
case elfcpp::R_390_12:
case elfcpp::R_390_8:
return Symbol::ABSOLUTE_REF;
case elfcpp::R_390_PC12DBL:
case elfcpp::R_390_PC16:
case elfcpp::R_390_PC16DBL:
case elfcpp::R_390_PC24DBL:
case elfcpp::R_390_PC32:
case elfcpp::R_390_PC32DBL:
case elfcpp::R_390_PC64:
case elfcpp::R_390_GOTOFF16:
case elfcpp::R_390_GOTOFF32:
case elfcpp::R_390_GOTOFF64:
return Symbol::RELATIVE_REF;
case elfcpp::R_390_PLT12DBL:
case elfcpp::R_390_PLT16DBL:
case elfcpp::R_390_PLT24DBL:
case elfcpp::R_390_PLT32:
case elfcpp::R_390_PLT32DBL:
case elfcpp::R_390_PLT64:
case elfcpp::R_390_PLTOFF16:
case elfcpp::R_390_PLTOFF32:
case elfcpp::R_390_PLTOFF64:
return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
case elfcpp::R_390_GOT12:
case elfcpp::R_390_GOT16:
case elfcpp::R_390_GOT20:
case elfcpp::R_390_GOT32:
case elfcpp::R_390_GOT64:
case elfcpp::R_390_GOTENT:
case elfcpp::R_390_GOTPLT12:
case elfcpp::R_390_GOTPLT16:
case elfcpp::R_390_GOTPLT20:
case elfcpp::R_390_GOTPLT32:
case elfcpp::R_390_GOTPLT64:
case elfcpp::R_390_GOTPLTENT:
// Absolute in GOT.
return Symbol::ABSOLUTE_REF;
case elfcpp::R_390_TLS_GD32: // Global-dynamic
case elfcpp::R_390_TLS_GD64:
case elfcpp::R_390_TLS_GDCALL:
case elfcpp::R_390_TLS_LDM32: // Local-dynamic
case elfcpp::R_390_TLS_LDM64:
case elfcpp::R_390_TLS_LDO32:
case elfcpp::R_390_TLS_LDO64:
case elfcpp::R_390_TLS_LDCALL:
case elfcpp::R_390_TLS_IE32: // Initial-exec
case elfcpp::R_390_TLS_IE64:
case elfcpp::R_390_TLS_IEENT:
case elfcpp::R_390_TLS_GOTIE12:
case elfcpp::R_390_TLS_GOTIE20:
case elfcpp::R_390_TLS_GOTIE32:
case elfcpp::R_390_TLS_GOTIE64:
case elfcpp::R_390_TLS_LOAD:
case elfcpp::R_390_TLS_LE32: // Local-exec
case elfcpp::R_390_TLS_LE64:
return Symbol::TLS_REF;
case elfcpp::R_390_COPY:
case elfcpp::R_390_GLOB_DAT:
case elfcpp::R_390_JMP_SLOT:
case elfcpp::R_390_RELATIVE:
case elfcpp::R_390_IRELATIVE:
case elfcpp::R_390_TLS_TPOFF:
case elfcpp::R_390_TLS_DTPOFF:
case elfcpp::R_390_TLS_DTPMOD:
default:
// Not expected. We will give an error later.
return 0;
}
}
// Report an unsupported relocation against a local symbol.
template<int size>
void
Target_s390<size>::Scan::unsupported_reloc_local(
Sized_relobj_file<size, true>* 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>
void
Target_s390<size>::Scan::check_non_pic(Relobj* object, unsigned int r_type)
{
gold_assert(r_type != elfcpp::R_390_NONE);
if (size == 64)
{
switch (r_type)
{
// These are the relocation types supported by glibc for s390 64-bit.
case elfcpp::R_390_RELATIVE:
case elfcpp::R_390_IRELATIVE:
case elfcpp::R_390_COPY:
case elfcpp::R_390_GLOB_DAT:
case elfcpp::R_390_JMP_SLOT:
case elfcpp::R_390_TLS_DTPMOD:
case elfcpp::R_390_TLS_DTPOFF:
case elfcpp::R_390_TLS_TPOFF:
case elfcpp::R_390_8:
case elfcpp::R_390_16:
case elfcpp::R_390_32:
case elfcpp::R_390_64:
case elfcpp::R_390_PC16:
case elfcpp::R_390_PC16DBL:
case elfcpp::R_390_PC32:
case elfcpp::R_390_PC32DBL:
case elfcpp::R_390_PC64:
return;
default:
break;
}
}
else
{
switch (r_type)
{
// These are the relocation types supported by glibc for s390 32-bit.
case elfcpp::R_390_RELATIVE:
case elfcpp::R_390_IRELATIVE:
case elfcpp::R_390_COPY:
case elfcpp::R_390_GLOB_DAT:
case elfcpp::R_390_JMP_SLOT:
case elfcpp::R_390_TLS_DTPMOD:
case elfcpp::R_390_TLS_DTPOFF:
case elfcpp::R_390_TLS_TPOFF:
case elfcpp::R_390_8:
case elfcpp::R_390_16:
case elfcpp::R_390_32:
case elfcpp::R_390_PC16:
case elfcpp::R_390_PC16DBL:
case elfcpp::R_390_PC32:
case elfcpp::R_390_PC32DBL:
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
Target_s390<size>::Scan::reloc_needs_plt_for_ifunc(
Sized_relobj_file<size, true>* object,
unsigned int r_type)
{
int flags = Scan::get_reference_flags(r_type);
if (flags & Symbol::TLS_REF)
gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
object->name().c_str(), r_type);
return flags != 0;
}
// Scan a relocation for a local symbol.
template<int size>
inline void
Target_s390<size>::Scan::local(Symbol_table* symtab,
Layout* layout,
Target_s390<size>* target,
Sized_relobj_file<size, true>* object,
unsigned int data_shndx,
Output_section* output_section,
const elfcpp::Rela<size, true>& reloc,
unsigned int r_type,
const elfcpp::Sym<size, true>& lsym,
bool is_discarded)
{
if (is_discarded)
return;
// 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))
{
unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
target->make_local_ifunc_plt_entry(symtab, layout, object, r_sym);
}
switch (r_type)
{
case elfcpp::R_390_NONE:
case elfcpp::R_390_GNU_VTINHERIT:
case elfcpp::R_390_GNU_VTENTRY:
break;
case elfcpp::R_390_64:
// If building a shared library (or a position-independent
// executable), we need to create a dynamic relocation for this
// location. The relocation applied at link time will apply the
// link-time value, so we flag the location with an
// R_390_RELATIVE relocation so the dynamic loader can
// relocate it easily.
if (parameters->options().output_is_position_independent() && size == 64)
{
unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
Reloc_section* rela_dyn = target->rela_dyn_section(layout);
rela_dyn->add_local_relative(object, r_sym,
elfcpp::R_390_RELATIVE,
output_section, data_shndx,
reloc.get_r_offset(),
reloc.get_r_addend(), is_ifunc);
}
break;
case elfcpp::R_390_32:
case elfcpp::R_390_20:
case elfcpp::R_390_16:
case elfcpp::R_390_12:
case elfcpp::R_390_8:
if (parameters->options().output_is_position_independent())
{
if (size == 32 && r_type == elfcpp::R_390_32)
{
unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
Reloc_section* rela_dyn = target->rela_dyn_section(layout);
rela_dyn->add_local_relative(object, r_sym,
elfcpp::R_390_RELATIVE,
output_section, data_shndx,
reloc.get_r_offset(),
reloc.get_r_addend(), is_ifunc);
break;
}
check_non_pic(object, r_type);
Reloc_section* rela_dyn = target->rela_dyn_section(layout);
unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
if (lsym.get_st_type() != elfcpp::STT_SECTION)
rela_dyn->add_local(object, r_sym, r_type, output_section,
data_shndx, reloc.get_r_offset(),
reloc.get_r_addend());
else
{
gold_assert(lsym.get_st_value() == 0);
unsigned int shndx = lsym.get_st_shndx();
bool is_ordinary;
shndx = object->adjust_sym_shndx(r_sym, shndx,
&is_ordinary);
if (!is_ordinary)
object->error(_("section symbol %u has bad shndx %u"),
r_sym, shndx);
else
rela_dyn->add_local_section(object, shndx,
r_type, output_section,
data_shndx, reloc.get_r_offset(),
reloc.get_r_addend());
}
}
break;
case elfcpp::R_390_PC12DBL:
case elfcpp::R_390_PC16:
case elfcpp::R_390_PC16DBL:
case elfcpp::R_390_PC24DBL:
case elfcpp::R_390_PC32:
case elfcpp::R_390_PC32DBL:
case elfcpp::R_390_PC64:
break;
case elfcpp::R_390_PLT12DBL:
case elfcpp::R_390_PLT16DBL:
case elfcpp::R_390_PLT24DBL:
case elfcpp::R_390_PLT32:
case elfcpp::R_390_PLT32DBL:
case elfcpp::R_390_PLT64:
// Since we know this is a local symbol, we can handle this as a
// PC32 reloc.
break;
case elfcpp::R_390_GOTPC:
case elfcpp::R_390_GOTPCDBL:
case elfcpp::R_390_GOTOFF16:
case elfcpp::R_390_GOTOFF32:
case elfcpp::R_390_GOTOFF64:
case elfcpp::R_390_PLTOFF16:
case elfcpp::R_390_PLTOFF32:
case elfcpp::R_390_PLTOFF64:
// We need a GOT section.
target->got_section(symtab, layout);
// For PLTOFF*, we'd normally want a PLT section, but since we
// know this is a local symbol, no PLT is needed.
break;
case elfcpp::R_390_GOT12:
case elfcpp::R_390_GOT16:
case elfcpp::R_390_GOT20:
case elfcpp::R_390_GOT32:
case elfcpp::R_390_GOT64:
case elfcpp::R_390_GOTENT:
case elfcpp::R_390_GOTPLT12:
case elfcpp::R_390_GOTPLT16:
case elfcpp::R_390_GOTPLT20:
case elfcpp::R_390_GOTPLT32:
case elfcpp::R_390_GOTPLT64:
case elfcpp::R_390_GOTPLTENT:
{
// The symbol requires a GOT section.
Output_data_got<size, true>* got = target->got_section(symtab, layout);
// The symbol requires a GOT entry.
unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
// For a STT_GNU_IFUNC symbol we want the PLT offset. That
// lets function pointers compare correctly with shared
// libraries. Otherwise we would need an IRELATIVE reloc.
bool is_new;
if (is_ifunc)
is_new = got->add_local_plt(object, r_sym, GOT_TYPE_STANDARD);
else
is_new = got->add_local(object, r_sym, GOT_TYPE_STANDARD);
if (is_new)
{
// If we are generating a shared object, we need to add a
// dynamic relocation for this symbol's GOT entry.
if (parameters->options().output_is_position_independent())
{
Reloc_section* rela_dyn = target->rela_dyn_section(layout);
unsigned int got_offset =
object->local_got_offset(r_sym, GOT_TYPE_STANDARD);
rela_dyn->add_local_relative(object, r_sym,
elfcpp::R_390_RELATIVE,
got, got_offset, 0, is_ifunc);
}
}
// For GOTPLT*, we'd normally want a PLT section, but since
// we know this is a local symbol, no PLT is needed.
}
break;
case elfcpp::R_390_COPY:
case elfcpp::R_390_GLOB_DAT:
case elfcpp::R_390_JMP_SLOT:
case elfcpp::R_390_RELATIVE:
case elfcpp::R_390_IRELATIVE:
// These are outstanding tls relocs, which are unexpected when linking
case elfcpp::R_390_TLS_TPOFF:
case elfcpp::R_390_TLS_DTPOFF:
case elfcpp::R_390_TLS_DTPMOD:
gold_error(_("%s: unexpected reloc %u in object file"),
object->name().c_str(), r_type);
break;
// These are initial tls relocs, which are expected when linking
case elfcpp::R_390_TLS_GD32: // Global-dynamic
case elfcpp::R_390_TLS_GD64:
case elfcpp::R_390_TLS_GDCALL:
case elfcpp::R_390_TLS_LDM32: // Local-dynamic
case elfcpp::R_390_TLS_LDM64:
case elfcpp::R_390_TLS_LDO32:
case elfcpp::R_390_TLS_LDO64:
case elfcpp::R_390_TLS_LDCALL:
case elfcpp::R_390_TLS_IE32: // Initial-exec
case elfcpp::R_390_TLS_IE64:
case elfcpp::R_390_TLS_IEENT:
case elfcpp::R_390_TLS_GOTIE12:
case elfcpp::R_390_TLS_GOTIE20:
case elfcpp::R_390_TLS_GOTIE32:
case elfcpp::R_390_TLS_GOTIE64:
case elfcpp::R_390_TLS_LOAD:
case elfcpp::R_390_TLS_LE32: // Local-exec
case elfcpp::R_390_TLS_LE64:
{
bool output_is_shared = parameters->options().shared();
const tls::Tls_optimization optimized_type
= Target_s390<size>::optimize_tls_reloc(!output_is_shared,
r_type);
switch (r_type)
{
case elfcpp::R_390_TLS_GD32: // General-dynamic
case elfcpp::R_390_TLS_GD64:
case elfcpp::R_390_TLS_GDCALL:
if (optimized_type == tls::TLSOPT_NONE)
{
// Create a pair of GOT entries for the module index and
// dtv-relative offset.
Output_data_got<size, true>* got
= target->got_section(symtab, layout);
unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
unsigned int shndx = lsym.get_st_shndx();
bool is_ordinary;
shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
if (!is_ordinary)
object->error(_("local symbol %u has bad shndx %u"),
r_sym, shndx);
else
got->add_local_pair_with_rel(object, r_sym,
shndx,
GOT_TYPE_TLS_PAIR,
target->rela_dyn_section(layout),
elfcpp::R_390_TLS_DTPMOD);
}
else if (optimized_type != tls::TLSOPT_TO_LE)
unsupported_reloc_local(object, r_type);
break;
case elfcpp::R_390_TLS_LDM32: // Local-dynamic
case elfcpp::R_390_TLS_LDM64:
case elfcpp::R_390_TLS_LDCALL:
if (optimized_type == tls::TLSOPT_NONE)
{
// Create a GOT entry for the module index.
target->got_mod_index_entry(symtab, layout, object);
}
else if (optimized_type != tls::TLSOPT_TO_LE)
unsupported_reloc_local(object, r_type);
break;
case elfcpp::R_390_TLS_LDO32:
case elfcpp::R_390_TLS_LDO64:
break;
case elfcpp::R_390_TLS_IE32: // Initial-exec
case elfcpp::R_390_TLS_IE64:
// These two involve an absolute address
if (parameters->options().shared()
&& optimized_type == tls::TLSOPT_NONE)
{
if ((size == 32 && r_type == elfcpp::R_390_TLS_IE32) ||
(size == 64 && r_type == elfcpp::R_390_TLS_IE64))
{
// We need to create a dynamic relocation.
Reloc_section* rela_dyn = target->rela_dyn_section(layout);
unsigned int r_sym =
elfcpp::elf_r_sym<size>(reloc.get_r_info());
rela_dyn->add_local_relative(object, r_sym,
elfcpp::R_390_RELATIVE,
output_section, data_shndx,
reloc.get_r_offset(),
reloc.get_r_addend(), false);
}
else
{
unsupported_reloc_local(object, r_type);
}
}
// fall through
case elfcpp::R_390_TLS_IEENT:
case elfcpp::R_390_TLS_GOTIE12:
case elfcpp::R_390_TLS_GOTIE20:
case elfcpp::R_390_TLS_GOTIE32:
case elfcpp::R_390_TLS_GOTIE64:
case elfcpp::R_390_TLS_LOAD:
layout->set_has_static_tls();
if (optimized_type == tls::TLSOPT_NONE)
{
if (!output_is_shared)
{
// We're making an executable, and the symbol is local, but
// we cannot optimize to LE. Make a const GOT entry instead.
Output_data_got<size, true>* got
= target->got_section(symtab, layout);
unsigned int r_sym
= elfcpp::elf_r_sym<size>(reloc.get_r_info());
got->add_local_plt(object, r_sym, GOT_TYPE_TLS_OFFSET);
}
else
{
// Create a GOT entry for the tp-relative offset.
Output_data_got<size, true>* got
= target->got_section(symtab, layout);
unsigned int r_sym
= elfcpp::elf_r_sym<size>(reloc.get_r_info());
got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET,
target->rela_dyn_section(layout),
elfcpp::R_390_TLS_TPOFF);
}
}
else if (optimized_type != tls::TLSOPT_TO_LE)
unsupported_reloc_local(object, r_type);
break;
case elfcpp::R_390_TLS_LE32: // Local-exec
case elfcpp::R_390_TLS_LE64:
layout->set_has_static_tls();
if (output_is_shared)
{
// We need to create a dynamic relocation.
if ((size == 32 && r_type == elfcpp::R_390_TLS_LE32) ||
(size == 64 && r_type == elfcpp::R_390_TLS_LE64))
{
Reloc_section* rela_dyn = target->rela_dyn_section(layout);
unsigned int r_sym
= elfcpp::elf_r_sym<size>(reloc.get_r_info());
gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
rela_dyn->add_local(object, r_sym, elfcpp::R_390_TLS_TPOFF,
output_section, data_shndx,
reloc.get_r_offset(),
reloc.get_r_addend());
}
else
{
unsupported_reloc_local(object, r_type);
}
}
break;
default:
gold_unreachable();
}
}
break;
default:
gold_error(_("%s: unsupported reloc %u against local symbol"),
object->name().c_str(), r_type);
break;
}
}
// Scan a relocation for a global symbol.
template<int size>
inline void
Target_s390<size>::Scan::global(Symbol_table* symtab,
Layout* layout,
Target_s390<size>* target,
Sized_relobj_file<size, true>* object,
unsigned int data_shndx,
Output_section* output_section,
const elfcpp::Rela<size, true>& reloc,
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);
switch (r_type)
{
case elfcpp::R_390_NONE:
case elfcpp::R_390_GNU_VTINHERIT:
case elfcpp::R_390_GNU_VTENTRY:
break;
case elfcpp::R_390_64:
case elfcpp::R_390_32:
case elfcpp::R_390_20:
case elfcpp::R_390_16:
case elfcpp::R_390_12:
case elfcpp::R_390_8:
{
// 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();
}