Target_arm(const Target::Target_info* info = &arm_info)
: Sized_target<32, big_endian>(info),
- got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL),
- copy_relocs_(elfcpp::R_ARM_COPY),
+ got_(NULL), plt_(NULL), got_plt_(NULL), got_irelative_(NULL),
+ rel_dyn_(NULL), rel_irelative_(NULL), copy_relocs_(elfcpp::R_ARM_COPY),
got_mod_index_offset_(-1U), tls_base_symbol_defined_(false),
stub_tables_(), stub_factory_(Stub_factory::get_instance()),
should_force_pic_veneer_(false),
uint64_t
do_dynsym_value(const Symbol*) const;
+ // Return the plt address for globals. Since we have irelative plt entries,
+ // address calculation is not as straightforward as plt_address + plt_offset.
+ uint64_t
+ do_plt_address_for_global(const Symbol* gsym) const
+ { return this->plt_section()->address_for_global(gsym); }
+
+ // Return the plt address for locals. Since we have irelative plt entries,
+ // address calculation is not as straightforward as plt_address + plt_offset.
+ uint64_t
+ do_plt_address_for_local(const Relobj* relobj, unsigned int symndx) const
+ { return this->plt_section()->address_for_local(relobj, symndx); }
+
// Relocate a section.
void
relocate_section(const Relocate_info<32, big_endian>*,
unsigned int
plt_entry_size() const;
+ // Get the section to use for IRELATIVE relocations, create it if necessary.
+ Reloc_section*
+ rel_irelative_section(Layout*);
+
// Map platform-specific reloc types
static unsigned int
get_real_reloc_type(unsigned int r_type);
protected:
// Make the PLT-generator object.
Output_data_plt_arm<big_endian>*
- make_data_plt(Layout* layout, Output_data_space* got_plt)
- { return this->do_make_data_plt(layout, got_plt); }
+ make_data_plt(Layout* layout,
+ Arm_output_data_got<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); }
// Make an ELF object.
Object*
do_define_standard_symbols(Symbol_table*, Layout*);
virtual Output_data_plt_arm<big_endian>*
- do_make_data_plt(Layout* layout, Output_data_space* got_plt)
+ do_make_data_plt(Layout* layout,
+ Arm_output_data_got<big_endian>* got,
+ Output_data_space* got_plt,
+ Output_data_space* got_irelative)
{
- return new Output_data_plt_arm_standard<big_endian>(layout, got_plt);
+ gold_assert(got_plt != NULL && got_irelative != NULL);
+ return new Output_data_plt_arm_standard<big_endian>(
+ layout, got, got_plt, got_irelative);
}
private:
if (sym->is_undefined() && !parameters->options().shared())
return false;
+ if (sym->type() == elfcpp::STT_GNU_IFUNC)
+ return true;
+
return (!parameters->doing_static_link()
&& (sym->type() == elfcpp::STT_FUNC
|| sym->type() == elfcpp::STT_ARM_TFUNC)
inline bool
possible_function_pointer_reloc(unsigned int r_type);
+ // Whether a plt entry is needed for ifunc.
+ bool
+ reloc_needs_plt_for_ifunc(Sized_relobj_file<32, big_endian>*,
+ unsigned int r_type);
+
// Whether we have issued an error about a non-PIC compilation.
bool issued_non_pic_error_;
};
return this->got_plt_;
}
+ // Create the PLT section.
+ void
+ make_plt_section(Symbol_table* symtab, Layout* layout);
+
// Create a PLT entry for a global symbol.
void
make_plt_entry(Symbol_table*, Layout*, Symbol*);
+ // Create a PLT entry for a local STT_GNU_IFUNC symbol.
+ void
+ make_local_ifunc_plt_entry(Symbol_table*, Layout*,
+ Sized_relobj_file<32, 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*);
Output_data_plt_arm<big_endian>* plt_;
// The GOT PLT section.
Output_data_space* got_plt_;
+ // The GOT section for IRELATIVE relocations.
+ Output_data_space* got_irelative_;
// The dynamic reloc section.
Reloc_section* rel_dyn_;
+ // The section to use for IRELATIVE relocs.
+ Reloc_section* rel_irelative_;
// Relocs saved to avoid a COPY reloc.
Copy_relocs<elfcpp::SHT_REL, 32, big_endian> copy_relocs_;
// Offset of the GOT entry for the TLS module index.
elfcpp::STB_LOCAL,
elfcpp::STV_HIDDEN, 0,
false, 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(4, "** 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);
+
}
return this->got_;
}
if (this->rel_dyn_ == NULL)
{
gold_assert(layout != NULL);
+ // Create both relocation sections in the same place, so as to ensure
+ // their relative order in the output section.
this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
+ this->rel_irelative_ = new Reloc_section(false);
layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
elfcpp::SHF_ALLOC, this->rel_dyn_,
ORDER_DYNAMIC_RELOCS, false);
+ layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
+ elfcpp::SHF_ALLOC, this->rel_irelative_,
+ ORDER_DYNAMIC_RELOCS, false);
}
return this->rel_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<bool big_endian>
+typename Target_arm<big_endian>::Reloc_section*
+Target_arm<big_endian>::rel_irelative_section(Layout* layout)
+{
+ if (this->rel_irelative_ == NULL)
+ {
+ // Delegate the creation to rel_dyn_section so as to ensure their order in
+ // the output section.
+ this->rel_dyn_section(layout);
+ gold_assert(this->rel_irelative_ != NULL
+ && (this->rel_dyn_->output_section()
+ == this->rel_irelative_->output_section()));
+ }
+ return this->rel_irelative_;
+}
+
+
// Insn_template methods.
// Return byte size of an instruction template.
class Output_data_plt_arm : public Output_section_data
{
public:
+ // Unlike aarch64, which records symbol value in "addend" field of relocations
+ // and could be done at the same time an IRelative reloc is created for the
+ // symbol, arm puts the symbol value into "GOT" table, which, however, is
+ // issued later in Output_data_plt_arm::do_write(). So we have a struct here
+ // to keep necessary symbol information for later use in do_write. We usually
+ // have only a very limited number of ifuncs, so the extra data required here
+ // is also limited.
+
+ struct IRelative_data
+ {
+ IRelative_data(Sized_symbol<32>* sized_symbol)
+ : symbol_is_global_(true)
+ {
+ u_.global = sized_symbol;
+ }
+
+ IRelative_data(Sized_relobj_file<32, big_endian>* relobj,
+ unsigned int index)
+ : symbol_is_global_(false)
+ {
+ u_.local.relobj = relobj;
+ u_.local.index = index;
+ }
+
+ union
+ {
+ Sized_symbol<32>* global;
+
+ struct
+ {
+ Sized_relobj_file<32, big_endian>* relobj;
+ unsigned int index;
+ } local;
+ } u_;
+
+ bool symbol_is_global_;
+ };
+
typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
Reloc_section;
- Output_data_plt_arm(Layout*, uint64_t addralign, Output_data_space*);
+ Output_data_plt_arm(Layout* layout, uint64_t addralign,
+ Arm_output_data_got<big_endian>* got,
+ Output_data_space* got_plt,
+ Output_data_space* got_irelative);
// Add an entry to the PLT.
void
- add_entry(Symbol* gsym);
+ add_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym);
+
+ // Add the relocation for a plt entry.
+ void
+ add_relocation(Symbol_table* symtab, Layout* layout,
+ Symbol* gsym, unsigned int got_offset);
+
+ // 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<32, big_endian>* relobj,
+ unsigned int local_sym_index);
// Return the .rel.plt section data.
const Reloc_section*
rel_plt() const
{ return this->rel_; }
+ // Return the PLT relocation container for IRELATIVE.
+ Reloc_section*
+ rel_irelative(Symbol_table*, Layout*);
+
// Return the number of PLT entries.
unsigned int
entry_count() const
- { return this->count_; }
+ { return this->count_ + this->irelative_count_; }
// Return the offset of the first non-reserved PLT entry.
unsigned int
get_plt_entry_size() const
{ return this->do_get_plt_entry_size(); }
+ // Return the PLT address for globals.
+ uint32_t
+ address_for_global(const Symbol*) const;
+
+ // Return the PLT address for locals.
+ uint32_t
+ address_for_local(const Relobj*, unsigned int symndx) const;
+
protected:
// Fill in the first PLT entry.
void
set_final_data_size()
{
this->set_data_size(this->first_plt_entry_offset()
- + this->count_ * this->get_plt_entry_size());
+ + ((this->count_ + this->irelative_count_)
+ * this->get_plt_entry_size()));
}
// Write out the PLT data.
void
do_write(Output_file*);
+ // Record irelative symbol data.
+ void insert_irelative_data(const IRelative_data& idata)
+ { irelative_data_vec_.push_back(idata); }
+
// 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.
+ Arm_output_data_got<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_ARM_IRELATIVE relocs. These
+ // follow the regular PLT entries.
+ unsigned int irelative_count_;
+ // Vector for irelative data.
+ typedef std::vector<IRelative_data> IRelative_data_vec;
+ IRelative_data_vec irelative_data_vec_;
};
// Create the PLT section. The ordinary .got section is an argument,
// section just for PLT entries.
template<bool big_endian>
-Output_data_plt_arm<big_endian>::Output_data_plt_arm(Layout* layout,
- uint64_t addralign,
- Output_data_space* got_plt)
- : Output_section_data(addralign), got_plt_(got_plt), count_(0)
+Output_data_plt_arm<big_endian>::Output_data_plt_arm(
+ Layout* layout, uint64_t addralign,
+ Arm_output_data_got<big_endian>* got,
+ Output_data_space* got_plt,
+ Output_data_space* got_irelative)
+ : Output_section_data(addralign), irelative_rel_(NULL),
+ got_(got), got_plt_(got_plt), got_irelative_(got_irelative),
+ count_(0), irelative_count_(0)
{
this->rel_ = new Reloc_section(false);
layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
template<bool big_endian>
void
-Output_data_plt_arm<big_endian>::add_entry(Symbol* gsym)
+Output_data_plt_arm<big_endian>::add_entry(Symbol_table* symtab,
+ Layout* layout,
+ Symbol* gsym)
{
gold_assert(!gsym->has_plt_offset());
- // Note that when setting the PLT offset we skip the initial
- // reserved PLT entry.
- gsym->set_plt_offset((this->count_) * this->get_plt_entry_size()
- + this->first_plt_entry_offset());
+ unsigned int* entry_count;
+ Output_section_data_build* got;
+
+ // We have 2 different types of plt entry here, normal and ifunc.
+
+ // For normal plt, the offset begins with first_plt_entry_offset(20), and the
+ // 1st entry offset would be 20, the second 32, third 44 ... etc.
+
+ // For ifunc plt, the offset begins with 0. So the first offset would 0,
+ // second 12, third 24 ... etc.
+
+ // IFunc plt entries *always* come after *normal* plt entries.
+
+ // Notice, when computing the plt address of a certain symbol, "plt_address +
+ // plt_offset" is no longer correct. Use target->plt_address_for_global() or
+ // target->plt_address_for_local() instead.
+
+ int begin_offset = 0;
+ if (gsym->type() == elfcpp::STT_GNU_IFUNC
+ && gsym->can_use_relative_reloc(false))
+ {
+ entry_count = &this->irelative_count_;
+ got = this->got_irelative_;
+ // For irelative plt entries, offset is relative to the end of normal plt
+ // entries, so it starts from 0.
+ begin_offset = 0;
+ // Record symbol information.
+ this->insert_irelative_data(
+ IRelative_data(symtab->get_sized_symbol<32>(gsym)));
+ }
+ else
+ {
+ entry_count = &this->count_;
+ got = this->got_plt_;
+ // Note that for normal plt entries, when setting the PLT offset we skip
+ // the initial reserved PLT entry.
+ begin_offset = this->first_plt_entry_offset();
+ }
+
+ gsym->set_plt_offset(begin_offset
+ + (*entry_count) * this->get_plt_entry_size());
- ++this->count_;
+ ++(*entry_count);
- section_offset_type got_offset = this->got_plt_->current_data_size();
+ 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).
- this->got_plt_->set_current_data_size(got_offset + 4);
+ got->set_current_data_size(got_offset + 4);
// Every PLT entry needs a reloc.
- gsym->set_needs_dynsym_entry();
- this->rel_->add_global(gsym, elfcpp::R_ARM_JUMP_SLOT, this->got_plt_,
- got_offset);
+ 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<bool big_endian>
+unsigned int
+Output_data_plt_arm<big_endian>::add_local_ifunc_entry(
+ Symbol_table* symtab,
+ Layout* layout,
+ Sized_relobj_file<32, big_endian>* relobj,
+ unsigned int local_sym_index)
+{
+ this->insert_irelative_data(IRelative_data(relobj, local_sym_index));
+
+ // Notice, when computingthe plt entry address, "plt_address + plt_offset" is
+ // no longer correct. Use target->plt_address_for_local() instead.
+ 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 + 4);
+
+
+ // Every PLT entry needs a reloc.
+ Reloc_section* rel = this->rel_irelative(symtab, layout);
+ rel->add_symbolless_local_addend(relobj, local_sym_index,
+ elfcpp::R_ARM_IRELATIVE,
+ this->got_irelative_, got_offset);
+ return plt_offset;
+}
+
+
+// Add the relocation for a PLT entry.
+
+template<bool big_endian>
+void
+Output_data_plt_arm<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* rel = this->rel_irelative(symtab, layout);
+ rel->add_symbolless_global_addend(gsym, elfcpp::R_ARM_IRELATIVE,
+ this->got_irelative_, got_offset);
+ }
+ else
+ {
+ gsym->set_needs_dynsym_entry();
+ this->rel_->add_global(gsym, elfcpp::R_ARM_JUMP_SLOT, this->got_plt_,
+ got_offset);
+ }
+}
+
+
+// Create the irelative relocation data.
+
+template<bool big_endian>
+typename Output_data_plt_arm<big_endian>::Reloc_section*
+Output_data_plt_arm<big_endian>::rel_irelative(Symbol_table* symtab,
+ Layout* layout)
+{
+ if (this->irelative_rel_ == NULL)
+ {
+ // Since irelative relocations goes into 'rel.dyn', we delegate the
+ // creation of irelative_rel_ to where rel_dyn section gets created.
+ Target_arm<big_endian>* arm_target =
+ Target_arm<big_endian>::default_target();
+ this->irelative_rel_ = arm_target->rel_irelative_section(layout);
+
+ // Make sure we have a place for the TLSDESC relocations, in
+ // case we see any later on.
+ // this->rel_tlsdesc(layout);
+ if (parameters->doing_static_link())
+ {
+ // A statically linked executable will only have a .rel.plt section to
+ // hold R_ARM_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("__rel_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("__rel_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 for a global symbol.
+
+template<bool big_endian>
+uint32_t
+Output_data_plt_arm<big_endian>::address_for_global(const Symbol* gsym) const
+{
+ uint64_t begin_offset = 0;
+ if (gsym->type() == elfcpp::STT_GNU_IFUNC
+ && gsym->can_use_relative_reloc(false))
+ {
+ begin_offset = (this->first_plt_entry_offset() +
+ this->count_ * this->get_plt_entry_size());
+ }
+ return this->address() + begin_offset + gsym->plt_offset();
+}
+
+
+// Return the PLT address for a local symbol. These are always
+// IRELATIVE relocs.
+
+template<bool big_endian>
+uint32_t
+Output_data_plt_arm<big_endian>::address_for_local(
+ const Relobj* object,
+ unsigned int r_sym) const
+{
+ return (this->address()
+ + this->first_plt_entry_offset()
+ + this->count_ * this->get_plt_entry_size()
+ + object->local_plt_offset(r_sym));
+}
+
+
template<bool big_endian>
class Output_data_plt_arm_standard : public Output_data_plt_arm<big_endian>
{
public:
- Output_data_plt_arm_standard(Layout* layout, Output_data_space* got_plt)
- : Output_data_plt_arm<big_endian>(layout, 4, got_plt)
+ Output_data_plt_arm_standard(Layout* layout,
+ Arm_output_data_got<big_endian>* got,
+ Output_data_space* got_plt,
+ Output_data_space* got_irelative)
+ : Output_data_plt_arm<big_endian>(layout, 4, got, got_plt, got_irelative)
{ }
protected:
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());
+ 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;
unsigned int plt_offset = this->first_plt_entry_offset();
unsigned int got_offset = 12;
- const unsigned int count = this->count_;
+ const unsigned int count = this->count_ + this->irelative_count_;
+ gold_assert(this->irelative_count_ == this->irelative_data_vec_.size());
for (unsigned int i = 0;
i < count;
++i,
this->fill_plt_entry(pov, got_address, plt_address,
got_offset, plt_offset);
- // Set the entry in the GOT.
- elfcpp::Swap<32, big_endian>::writeval(got_pov, plt_address);
+ Arm_address value;
+ if (i < this->count_)
+ {
+ // For non-irelative got entries, the value is the beginning of plt.
+ value = plt_address;
+ }
+ else
+ {
+ // For irelative got entries, the value is the (global/local) symbol
+ // address.
+ const IRelative_data& idata =
+ this->irelative_data_vec_[i - this->count_];
+ if (idata.symbol_is_global_)
+ {
+ // Set the entry in the GOT for irelative symbols. The content is
+ // the address of the ifunc, not the address of plt start.
+ const Sized_symbol<32>* sized_symbol = idata.u_.global;
+ gold_assert(sized_symbol->type() == elfcpp::STT_GNU_IFUNC);
+ value = sized_symbol->value();
+ }
+ else
+ {
+ value = idata.u_.local.relobj->local_symbol_value(
+ idata.u_.local.index, 0);
+ }
+ }
+ elfcpp::Swap<32, big_endian>::writeval(got_pov, value);
}
gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
of->write_output_view(got_file_offset, got_size, got_view);
}
+
// Create a PLT entry for a global symbol.
template<bool big_endian>
if (gsym->has_plt_offset())
return;
+ if (this->plt_ == NULL)
+ this->make_plt_section(symtab, layout);
+
+ this->plt_->add_entry(symtab, layout, gsym);
+}
+
+
+// Create the PLT section.
+template<bool big_endian>
+void
+Target_arm<big_endian>::make_plt_section(
+ Symbol_table* symtab, Layout* layout)
+{
if (this->plt_ == NULL)
{
- // Create the GOT sections first.
+ // Create the GOT section first.
this->got_section(symtab, layout);
- this->plt_ = this->make_data_plt(layout, this->got_plt_);
+ // GOT for irelatives is create along with got.plt.
+ gold_assert(this->got_ != NULL
+ && this->got_plt_ != NULL
+ && this->got_irelative_ != NULL);
+ 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);
}
- this->plt_->add_entry(gsym);
}
+
+// Make a PLT entry for a local STT_GNU_IFUNC symbol.
+
+template<bool big_endian>
+void
+Target_arm<big_endian>::make_local_ifunc_plt_entry(
+ Symbol_table* symtab, Layout* layout,
+ Sized_relobj_file<32, 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);
+}
+
+
// Return the number of entries in the PLT.
template<bool big_endian>
case elfcpp::R_ARM_JUMP_SLOT:
case elfcpp::R_ARM_ABS32:
case elfcpp::R_ARM_ABS32_NOI:
+ case elfcpp::R_ARM_IRELATIVE:
case elfcpp::R_ARM_PC24:
// FIXME: The following 3 types are not supported by Android's dynamic
// linker.
}
}
+
+// Return whether we need to make a PLT entry for a relocation of the
+// given type against a STT_GNU_IFUNC symbol.
+
+template<bool big_endian>
+bool
+Target_arm<big_endian>::Scan::reloc_needs_plt_for_ifunc(
+ Sized_relobj_file<32, big_endian>* 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 false;
+ }
+ return flags != 0;
+}
+
+
// Scan a relocation for a local symbol.
// FIXME: This only handles a subset of relocation types used by Android
// on ARM v5te devices.
return;
r_type = get_real_reloc_type(r_type);
+
+ // 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<32>(reloc.get_r_info());
+ target->make_local_ifunc_plt_entry(symtab, layout, object, r_sym);
+ }
+
switch (r_type)
{
case elfcpp::R_ARM_NONE:
// we need to add check_non_pic(object, r_type) here.
rel_dyn->add_local_relative(object, r_sym, elfcpp::R_ARM_RELATIVE,
output_section, data_shndx,
- reloc.get_r_offset());
+ reloc.get_r_offset(), is_ifunc);
}
break;
&& strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
target->got_section(symtab, layout);
+ // 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);
+
r_type = get_real_reloc_type(r_type);
switch (r_type)
{
target->copy_reloc(symtab, layout, object,
data_shndx, output_section, gsym, reloc);
}
+ else if ((r_type == elfcpp::R_ARM_ABS32
+ || r_type == elfcpp::R_ARM_ABS32_NOI)
+ && 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* rel_irelative =
+ target->rel_irelative_section(layout);
+ unsigned int r_type = elfcpp::R_ARM_IRELATIVE;
+ rel_irelative->add_symbolless_global_addend(
+ gsym, r_type, output_section, object,
+ data_shndx, reloc.get_r_offset());
+ }
else if ((r_type == elfcpp::R_ARM_ABS32
|| r_type == elfcpp::R_ARM_ABS32_NOI)
&& gsym->can_use_relative_reloc(false))
Arm_output_data_got<big_endian>* got =
target->got_section(symtab, layout);
if (gsym->final_value_is_known())
- got->add_global(gsym, GOT_TYPE_STANDARD);
+ {
+ // 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
|| gsym->is_undefined()
|| gsym->is_preemptible()
|| (gsym->visibility() == elfcpp::STV_PROTECTED
- && parameters->options().shared()))
+ && parameters->options().shared())
+ || (gsym->type() == elfcpp::STT_GNU_IFUNC
+ && parameters->options().output_is_position_independent()))
got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
rel_dyn, elfcpp::R_ARM_GLOB_DAT);
else
{
- if (got->add_global(gsym, GOT_TYPE_STANDARD))
+ // 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)
rel_dyn->add_global_relative(
gsym, elfcpp::R_ARM_RELATIVE, got,
gsym->got_offset(GOT_TYPE_STANDARD));
if (gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
{
// This uses a PLT, change the symbol value.
- symval.set_output_value(target->plt_section()->address()
- + gsym->plt_offset());
+ symval.set_output_value(target->plt_address_for_global(gsym));
psymval = &symval;
}
else if (gsym->is_weak_undefined())
elfcpp::Elf_types<32>::Elf_WXword r_info = rel.get_r_info();
unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
thumb_bit = object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
+
+ if (psymval->is_ifunc_symbol() && object->local_has_plt_offset(r_sym))
+ {
+ symval.set_output_value(
+ target->plt_address_for_local(object, r_sym));
+ psymval = &symval;
+ }
}
}
else
Target_arm<big_endian>::do_dynsym_value(const Symbol* gsym) const
{
gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
- return this->plt_section()->address() + gsym->plt_offset();
+ return this->plt_address_for_global(gsym);
}
// Map platform-specific relocs to real relocs
if (gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
{
// This uses a PLT, change the symbol value.
- symval.set_output_value(this->plt_section()->address()
- + gsym->plt_offset());
+ symval.set_output_value(this->plt_address_for_global(gsym));
psymval = &symval;
target_is_thumb = false;
}
protected:
virtual Output_data_plt_arm<big_endian>*
- do_make_data_plt(Layout* layout, Output_data_space* got_plt)
- { return new Output_data_plt_arm_nacl<big_endian>(layout, got_plt); }
+ do_make_data_plt(
+ Layout* layout,
+ Arm_output_data_got<big_endian>* got,
+ Output_data_space* got_plt,
+ Output_data_space* got_irelative)
+ { return new Output_data_plt_arm_nacl<big_endian>(
+ layout, got, got_plt, got_irelative); }
private:
static const Target::Target_info arm_nacl_info;
class Output_data_plt_arm_nacl : public Output_data_plt_arm<big_endian>
{
public:
- Output_data_plt_arm_nacl(Layout* layout, Output_data_space* got_plt)
- : Output_data_plt_arm<big_endian>(layout, 16, got_plt)
+ Output_data_plt_arm_nacl(
+ Layout* layout,
+ Arm_output_data_got<big_endian>* got,
+ Output_data_space* got_plt,
+ Output_data_space* got_irelative)
+ : Output_data_plt_arm<big_endian>(layout, 16, got, got_plt, got_irelative)
{ }
protected:
projects / binutils-gdb.git / commitdiff