template<int size, bool big_endian>
class Stub_table;
+inline bool
+is_branch_reloc(unsigned int r_type);
+
template<int size, bool big_endian>
class Powerpc_relobj : public Sized_relobj_file<size, big_endian>
{
void
do_function_location(Symbol_location*) const;
+ bool
+ do_can_check_for_function_pointers() const
+ { return true; }
+
// Relocate a section.
void
relocate_section(const Relocate_info<size, big_endian>*,
unsigned int ,
Output_section* ,
const elfcpp::Rela<size, big_endian>& ,
- unsigned int ,
+ unsigned int r_type,
const elfcpp::Sym<size, big_endian>&)
- { return false; }
+ {
+ // PowerPC64 .opd is not folded, so any identical function text
+ // may be folded and we'll still keep function addresses distinct.
+ // That means no reloc is of concern here.
+ if (size == 64)
+ return false;
+ // For 32-bit, conservatively assume anything but calls to
+ // function code might be taking the address of the function.
+ return !is_branch_reloc(r_type);
+ }
inline bool
global_reloc_may_be_function_pointer(Symbol_table* , Layout* ,
Sized_relobj_file<size, big_endian>* ,
unsigned int ,
Output_section* ,
- const elfcpp::Rela<size,
- big_endian>& ,
- unsigned int , Symbol*)
- { return false; }
+ const elfcpp::Rela<size, big_endian>& ,
+ unsigned int r_type,
+ Symbol*)
+ {
+ // As above.
+ if (size == 64)
+ return false;
+ return !is_branch_reloc(r_type);
+ }
+
+ static bool
+ reloc_needs_plt_for_ifunc(Sized_relobj_file<size, big_endian>* object,
+ unsigned int r_type, bool report_err);
private:
static void
void
check_non_pic(Relobj*, unsigned int r_type);
- bool
- reloc_needs_plt_for_ifunc(Sized_relobj_file<size, big_endian>* object,
- unsigned int r_type);
-
// Whether we have issued an error about a non-PIC compilation.
bool issued_non_pic_error_;
};
Reloc_section*
rela_dyn_section(Layout*);
+ // Similarly, but for ifunc symbols get the one for ifunc.
+ Reloc_section*
+ rela_dyn_section(Symbol_table*, Layout*, bool for_ifunc);
+
// Copy a relocation against a global symbol.
void
copy_reloc(Symbol_table* symtab, Layout* layout,
// The GOT section.
Output_data_got_powerpc<size, big_endian>* got_;
- // The PLT section.
+ // The PLT section. This is a container for a table of addresses,
+ // and their relocations. Each address in the PLT has a dynamic
+ // relocation (R_*_JMP_SLOT) and each address will have a
+ // corresponding entry in .glink for lazy resolution of the PLT.
+ // ppc32 initialises the PLT to point at the .glink entry, while
+ // ppc64 leaves this to ld.so. To make a call via the PLT, the
+ // linker adds a stub that loads the PLT entry into ctr then
+ // branches to ctr. There may be more than one stub for each PLT
+ // entry. DT_JMPREL points at the first PLT dynamic relocation and
+ // DT_PLTRELSZ gives the total size of PLT dynamic relocations.
Output_data_plt_powerpc<size, big_endian>* plt_;
- // The IPLT section.
+ // The IPLT section. Like plt_, this is a container for a table of
+ // addresses and their relocations, specifically for STT_GNU_IFUNC
+ // functions that resolve locally (STT_GNU_IFUNC functions that
+ // don't resolve locally go in PLT). Unlike plt_, these have no
+ // entry in .glink for lazy resolution, and the relocation section
+ // does not have a 1-1 correspondence with IPLT addresses. In fact,
+ // the relocation section may contain relocations against
+ // STT_GNU_IFUNC symbols at locations outside of IPLT. The
+ // relocation section will appear at the end of other dynamic
+ // relocations, so that ld.so applies these relocations after other
+ // dynamic relocations. In a static executable, the relocation
+ // section is emitted and marked with __rela_iplt_start and
+ // __rela_iplt_end symbols.
Output_data_plt_powerpc<size, big_endian>* iplt_;
// Section holding long branch destinations.
Output_data_brlt_powerpc<size, big_endian>* brlt_section_;
return this->rela_dyn_;
}
+// Similarly, but for ifunc symbols get the one for ifunc.
+
+template<int size, bool big_endian>
+typename Target_powerpc<size, big_endian>::Reloc_section*
+Target_powerpc<size, big_endian>::rela_dyn_section(Symbol_table* symtab,
+ Layout* layout,
+ bool for_ifunc)
+{
+ if (!for_ifunc)
+ return this->rela_dyn_section(layout);
+
+ if (this->iplt_ == NULL)
+ this->make_iplt_section(symtab, layout);
+ return this->iplt_->rel_plt();
+}
+
class Stub_control
{
public:
else
off += i->data_size();
}
- // If .brlt is part of this output section, then we have just
- // done the offset adjustment.
+ // If .branch_lt is part of this output section, then we have
+ // just done the offset adjustment.
os->clear_section_offsets_need_adjustment();
}
unsigned int
entry_count() const
{
+ if (this->current_data_size() == 0)
+ return 0;
return ((this->current_data_size() - this->initial_plt_entry_size_)
/ plt_entry_size);
}
void
Output_data_plt_powerpc<size, big_endian>::do_write(Output_file* of)
{
- if (size == 32)
+ if (size == 32 && this->name_[3] != 'I')
{
const section_size_type offset = this->offset();
const section_size_type oview_size
// Ensure that .rela.dyn always appears before .rela.plt This is
// necessary due to how, on PowerPC and some other targets, .rela.dyn
- // needs to include .rela.plt in it's range.
+ // needs to include .rela.plt in its range.
this->rela_dyn_section(layout);
Reloc_section* plt_rel = new Reloc_section(false);
bool is_pic = parameters->options().output_is_position_independent();
if (is_pic)
{
- // When PIC we can't fill in .brlt (like .plt it can be a
- // bss style section) but must initialise at runtime via
+ // When PIC we can't fill in .branch_lt (like .plt it can be
+ // a bss style section) but must initialise at runtime via
// dynamic relocats.
this->rela_dyn_section(layout);
brlt_rel = new Reloc_section(false);
this->plt_->output_section()
->add_output_section_data(this->brlt_section_);
else
- layout->add_output_section_data(".brlt",
+ layout->add_output_section_data(".branch_lt",
(is_pic ? elfcpp::SHT_NOBITS
: elfcpp::SHT_PROGBITS),
elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
}
}
-// Write out .brlt when non-PIC.
+// Write out .branch_lt when non-PIC.
template<int size, bool big_endian>
void
{
if (this->plt_ == NULL)
return 0;
- unsigned int count = this->plt_->entry_count();
- if (this->iplt_ != NULL)
- count += this->iplt_->entry_count();
- return count;
+ return this->plt_->entry_count();
}
// Return the offset of the first non-reserved PLT entry.
bool
Target_powerpc<size, big_endian>::Scan::reloc_needs_plt_for_ifunc(
Sized_relobj_file<size, big_endian>* object,
- unsigned int r_type)
+ unsigned int r_type,
+ bool report_err)
{
// In non-pic code any reference will resolve to the plt call stub
// for the ifunc symbol.
switch (r_type)
{
- // Word size refs from data sections are OK.
+ // Word size refs from data sections are OK, but don't need a PLT entry.
case elfcpp::R_POWERPC_ADDR32:
case elfcpp::R_POWERPC_UADDR32:
if (size == 32)
- return true;
+ return false;
break;
case elfcpp::R_PPC64_ADDR64:
case elfcpp::R_PPC64_UADDR64:
if (size == 64)
- return true;
+ return false;
break;
- // GOT refs are good.
+ // GOT refs are good, but also don't need a PLT entry.
case elfcpp::R_POWERPC_GOT16:
case elfcpp::R_POWERPC_GOT16_LO:
case elfcpp::R_POWERPC_GOT16_HI:
case elfcpp::R_POWERPC_GOT16_HA:
case elfcpp::R_PPC64_GOT16_DS:
case elfcpp::R_PPC64_GOT16_LO_DS:
- return true;
+ return false;
- // So are function calls.
+ // Function calls are good, and these do need a PLT entry.
case elfcpp::R_POWERPC_ADDR24:
case elfcpp::R_POWERPC_ADDR14:
case elfcpp::R_POWERPC_ADDR14_BRTAKEN:
// writable and non-executable to apply text relocations. So we'll
// segfault when trying to run the indirection function to resolve
// the reloc.
- gold_error(_("%s: unsupported reloc %u for IFUNC symbol"),
+ if (report_err)
+ gold_error(_("%s: unsupported reloc %u for IFUNC symbol"),
object->name().c_str(), r_type);
return false;
}
// 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))
+ if (is_ifunc && this->reloc_needs_plt_for_ifunc(object, r_type, true))
{
unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
target->push_branch(ppc_object, data_shndx, reloc.get_r_offset(),
if (parameters->options().output_is_position_independent()
|| (size == 64 && is_ifunc))
{
- Reloc_section* rela_dyn = target->rela_dyn_section(layout);
-
+ Reloc_section* rela_dyn = target->rela_dyn_section(symtab, layout,
+ is_ifunc);
if ((size == 32 && r_type == elfcpp::R_POWERPC_ADDR32)
|| (size == 64 && r_type == elfcpp::R_PPC64_ADDR64))
{
unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
- unsigned int dynrel = elfcpp::R_POWERPC_RELATIVE;
- if (is_ifunc)
- {
- rela_dyn = target->iplt_section()->rel_plt();
- dynrel = elfcpp::R_POWERPC_IRELATIVE;
- }
+ unsigned int dynrel = (is_ifunc ? elfcpp::R_POWERPC_IRELATIVE
+ : elfcpp::R_POWERPC_RELATIVE);
rela_dyn->add_local_relative(object, r_sym, dynrel,
output_section, data_shndx,
reloc.get_r_offset(),
case elfcpp::R_POWERPC_REL24:
case elfcpp::R_PPC_PLTREL24:
case elfcpp::R_PPC_LOCAL24PC:
- target->push_branch(ppc_object, data_shndx, reloc.get_r_offset(),
- r_type, elfcpp::elf_r_sym<size>(reloc.get_r_info()),
- reloc.get_r_addend());
- break;
-
case elfcpp::R_POWERPC_REL14:
case elfcpp::R_POWERPC_REL14_BRTAKEN:
case elfcpp::R_POWERPC_REL14_BRNTAKEN:
- target->push_branch(ppc_object, data_shndx, reloc.get_r_offset(),
- r_type, elfcpp::elf_r_sym<size>(reloc.get_r_info()),
- reloc.get_r_addend());
+ if (!is_ifunc)
+ target->push_branch(ppc_object, data_shndx, reloc.get_r_offset(),
+ r_type, elfcpp::elf_r_sym<size>(reloc.get_r_info()),
+ reloc.get_r_addend());
break;
case elfcpp::R_PPC64_REL64:
off = got->add_constant(0);
object->set_local_got_offset(r_sym, GOT_TYPE_STANDARD, off);
- Reloc_section* rela_dyn = target->rela_dyn_section(layout);
- unsigned int dynrel = elfcpp::R_POWERPC_RELATIVE;
- if (is_ifunc)
- {
- rela_dyn = target->iplt_section()->rel_plt();
- dynrel = elfcpp::R_POWERPC_IRELATIVE;
- }
+ Reloc_section* rela_dyn = target->rela_dyn_section(symtab, layout,
+ is_ifunc);
+ unsigned int dynrel = (is_ifunc ? elfcpp::R_POWERPC_IRELATIVE
+ : elfcpp::R_POWERPC_RELATIVE);
rela_dyn->add_local_relative(object, r_sym, dynrel,
got, off, 0, false);
}
= static_cast<Powerpc_relobj<size, big_endian>*>(object);
// 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))
+ bool is_ifunc = gsym->type() == elfcpp::STT_GNU_IFUNC;
+ if (is_ifunc && this->reloc_needs_plt_for_ifunc(object, r_type, true))
{
target->push_branch(ppc_object, data_shndx, reloc.get_r_offset(),
r_type, elfcpp::elf_r_sym<size>(reloc.get_r_info()),
// Make a PLT entry if necessary.
if (gsym->needs_plt_entry())
{
- target->push_branch(ppc_object, data_shndx, reloc.get_r_offset(),
- r_type,
- elfcpp::elf_r_sym<size>(reloc.get_r_info()),
- reloc.get_r_addend());
- target->make_plt_entry(symtab, layout, gsym);
+ if (!is_ifunc)
+ {
+ target->push_branch(ppc_object, data_shndx,
+ reloc.get_r_offset(), r_type,
+ elfcpp::elf_r_sym<size>(reloc.get_r_info()),
+ reloc.get_r_addend());
+ 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
}
// Make a dynamic relocation if necessary.
if (needs_dynamic_reloc<size>(gsym, Scan::get_reference_flags(r_type))
- || (size == 64 && gsym->type() == elfcpp::STT_GNU_IFUNC))
+ || (size == 64 && is_ifunc))
{
if (gsym->may_need_copy_reloc())
{
&& (gsym->can_use_relative_reloc(false)
|| data_shndx == ppc_object->opd_shndx())))
{
- Reloc_section* rela_dyn = target->rela_dyn_section(layout);
- unsigned int dynrel = elfcpp::R_POWERPC_RELATIVE;
- if (gsym->type() == elfcpp::STT_GNU_IFUNC)
- {
- rela_dyn = target->iplt_section()->rel_plt();
- dynrel = elfcpp::R_POWERPC_IRELATIVE;
- }
+ Reloc_section* rela_dyn
+ = target->rela_dyn_section(symtab, layout, is_ifunc);
+ unsigned int dynrel = (is_ifunc ? elfcpp::R_POWERPC_IRELATIVE
+ : elfcpp::R_POWERPC_RELATIVE);
rela_dyn->add_symbolless_global_addend(
gsym, dynrel, output_section, object, data_shndx,
reloc.get_r_offset(), reloc.get_r_addend());
}
else
{
- Reloc_section* rela_dyn = target->rela_dyn_section(layout);
+ Reloc_section* rela_dyn
+ = target->rela_dyn_section(symtab, layout, is_ifunc);
check_non_pic(object, r_type);
rela_dyn->add_global(gsym, r_type, output_section,
object, data_shndx,
case elfcpp::R_PPC_PLTREL24:
case elfcpp::R_POWERPC_REL24:
- target->push_branch(ppc_object, data_shndx, reloc.get_r_offset(),
- r_type, elfcpp::elf_r_sym<size>(reloc.get_r_info()),
- reloc.get_r_addend());
- if (gsym->needs_plt_entry()
- || (!gsym->final_value_is_known()
- && (gsym->is_undefined()
- || gsym->is_from_dynobj()
- || gsym->is_preemptible())))
- target->make_plt_entry(symtab, layout, gsym);
+ if (!is_ifunc)
+ {
+ target->push_branch(ppc_object, data_shndx, reloc.get_r_offset(),
+ r_type,
+ elfcpp::elf_r_sym<size>(reloc.get_r_info()),
+ reloc.get_r_addend());
+ if (gsym->needs_plt_entry()
+ || (!gsym->final_value_is_known()
+ && (gsym->is_undefined()
+ || gsym->is_from_dynobj()
+ || gsym->is_preemptible())))
+ target->make_plt_entry(symtab, layout, gsym);
+ }
// Fall thru
case elfcpp::R_PPC64_REL64:
}
else
{
- Reloc_section* rela_dyn = target->rela_dyn_section(layout);
+ Reloc_section* rela_dyn
+ = target->rela_dyn_section(symtab, layout, is_ifunc);
check_non_pic(object, r_type);
rela_dyn->add_global(gsym, r_type, output_section, object,
data_shndx, reloc.get_r_offset(),
case elfcpp::R_POWERPC_REL14:
case elfcpp::R_POWERPC_REL14_BRTAKEN:
case elfcpp::R_POWERPC_REL14_BRNTAKEN:
- target->push_branch(ppc_object, data_shndx, reloc.get_r_offset(),
- r_type, elfcpp::elf_r_sym<size>(reloc.get_r_info()),
- reloc.get_r_addend());
+ if (!is_ifunc)
+ target->push_branch(ppc_object, data_shndx, reloc.get_r_offset(),
+ r_type, elfcpp::elf_r_sym<size>(reloc.get_r_info()),
+ reloc.get_r_addend());
break;
case elfcpp::R_POWERPC_REL16:
got = target->got_section(symtab, layout);
if (gsym->final_value_is_known())
{
- if (size == 32 && gsym->type() == elfcpp::STT_GNU_IFUNC)
+ if (size == 32 && is_ifunc)
got->add_global_plt(gsym, GOT_TYPE_STANDARD);
else
got->add_global(gsym, GOT_TYPE_STANDARD);
unsigned int off = got->add_constant(0);
gsym->set_got_offset(GOT_TYPE_STANDARD, off);
- Reloc_section* rela_dyn = target->rela_dyn_section(layout);
+ Reloc_section* rela_dyn
+ = target->rela_dyn_section(symtab, layout, is_ifunc);
+
if (gsym->can_use_relative_reloc(false)
&& !(size == 32
&& gsym->visibility() == elfcpp::STV_PROTECTED
&& parameters->options().shared()))
{
- unsigned int dynrel = elfcpp::R_POWERPC_RELATIVE;
- if (gsym->type() == elfcpp::STT_GNU_IFUNC)
- {
- rela_dyn = target->iplt_section()->rel_plt();
- dynrel = elfcpp::R_POWERPC_IRELATIVE;
- }
+ unsigned int dynrel = (is_ifunc ? elfcpp::R_POWERPC_IRELATIVE
+ : elfcpp::R_POWERPC_RELATIVE);
rela_dyn->add_global_relative(gsym, dynrel, got, off, 0, false);
}
else
{
Output_data_got_powerpc<size, big_endian>* got
= target->got_section(symtab, layout);
- got->add_global_pair_with_rel(gsym, GOT_TYPE_TLSGD,
- target->rela_dyn_section(layout),
+ Reloc_section* rela_dyn = target->rela_dyn_section(layout);
+ got->add_global_pair_with_rel(gsym, GOT_TYPE_TLSGD, rela_dyn,
elfcpp::R_POWERPC_DTPMOD,
elfcpp::R_POWERPC_DTPREL);
}
Address value = 0;
bool has_plt_value = false;
unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
- if (gsym != NULL
- ? use_plt_offset<size>(gsym, Scan::get_reference_flags(r_type))
- : object->local_has_plt_offset(r_sym))
+ if ((gsym != NULL
+ ? use_plt_offset<size>(gsym, Scan::get_reference_flags(r_type))
+ : object->local_has_plt_offset(r_sym))
+ && (!psymval->is_ifunc_symbol()
+ || Scan::reloc_needs_plt_for_ifunc(object, r_type, false)))
{
Stub_table<size, big_endian>* stub_table
= object->stub_table(relinfo->data_shndx);
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