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-rw-r--r--gold/i386.cc555
1 files changed, 439 insertions, 116 deletions
diff --git a/gold/i386.cc b/gold/i386.cc
index b272967..56d405b 100644
--- a/gold/i386.cc
+++ b/gold/i386.cc
@@ -45,7 +45,113 @@ namespace
using namespace gold;
-class Output_data_plt_i386;
+// A class to handle the PLT data.
+
+class Output_data_plt_i386 : public Output_section_data
+{
+ public:
+ typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
+
+ Output_data_plt_i386(Symbol_table*, Layout*, Output_data_space*);
+
+ // Add an entry to the PLT.
+ void
+ add_entry(Symbol* gsym);
+
+ // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.
+ unsigned int
+ add_local_ifunc_entry(Sized_relobj<32, false>* relobj,
+ unsigned int local_sym_index);
+
+ // Return the .rel.plt section data.
+ Reloc_section*
+ rel_plt() const
+ { return this->rel_; }
+
+ // Return where the TLS_DESC relocations should go.
+ Reloc_section*
+ rel_tls_desc(Layout*);
+
+ // Return the number of PLT entries.
+ unsigned int
+ entry_count() const
+ { return this->count_; }
+
+ // Return the offset of the first non-reserved PLT entry.
+ static unsigned int
+ first_plt_entry_offset()
+ { return plt_entry_size; }
+
+ // Return the size of a PLT entry.
+ static unsigned int
+ get_plt_entry_size()
+ { return plt_entry_size; }
+
+ protected:
+ 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:
+ // The size of an entry in the PLT.
+ static const int plt_entry_size = 16;
+
+ // The first entry in the PLT for an executable.
+ static unsigned char exec_first_plt_entry[plt_entry_size];
+
+ // The first entry in the PLT for a shared object.
+ static unsigned char dyn_first_plt_entry[plt_entry_size];
+
+ // Other entries in the PLT for an executable.
+ static unsigned char exec_plt_entry[plt_entry_size];
+
+ // Other entries in the PLT for a shared object.
+ static unsigned char dyn_plt_entry[plt_entry_size];
+
+ // Set the final size.
+ void
+ set_final_data_size()
+ { this->set_data_size((this->count_ + 1) * plt_entry_size); }
+
+ // Write out the PLT data.
+ void
+ do_write(Output_file*);
+
+ // We keep a list of global STT_GNU_IFUNC symbols, each with its
+ // offset in the GOT.
+ struct Global_ifunc
+ {
+ Symbol* sym;
+ unsigned int got_offset;
+ };
+
+ // We keep a list of local STT_GNU_IFUNC symbols, each with its
+ // offset in the GOT.
+ struct Local_ifunc
+ {
+ Sized_relobj<32, false>* object;
+ unsigned int local_sym_index;
+ unsigned int got_offset;
+ };
+
+ // The reloc section.
+ Reloc_section* rel_;
+ // The TLS_DESC relocations, if necessary. These must follow the
+ // regular PLT relocs.
+ Reloc_section* tls_desc_rel_;
+ // The .got.plt section.
+ Output_data_space* got_plt_;
+ // The number of PLT entries.
+ unsigned int count_;
+ // Global STT_GNU_IFUNC symbols.
+ std::vector<Global_ifunc> global_ifuncs_;
+ // Local STT_GNU_IFUNC symbols.
+ std::vector<Local_ifunc> local_ifuncs_;
+};
// The i386 target class.
// TLS info comes from
@@ -172,6 +278,15 @@ class Target_i386 : public Target_freebsd<32, false>
return Target::do_is_local_label_name(name);
}
+ // Return the PLT section.
+ Output_data*
+ do_plt_section_for_global(const Symbol*) const
+ { return this->plt_section(); }
+
+ Output_data*
+ do_plt_section_for_local(const Relobj*, unsigned int) const
+ { return this->plt_section(); }
+
// Return whether SYM is call to a non-split function.
bool
do_is_call_to_non_split(const Symbol* sym, unsigned int) const;
@@ -255,6 +370,9 @@ class Target_i386 : public Target_freebsd<32, false>
inline bool
possible_function_pointer_reloc(unsigned int r_type);
+ bool
+ reloc_needs_plt_for_ifunc(Sized_relobj<32, false>*, unsigned int r_type);
+
static void
unsupported_reloc_local(Sized_relobj<32, false>*, unsigned int r_type);
@@ -415,10 +533,20 @@ class Target_i386 : public Target_freebsd<32, false>
return this->got_tlsdesc_;
}
+ // Create the PLT section.
+ void
+ make_plt_section(Symbol_table* symtab, Layout* layout);
+
// Create a PLT entry for a global symbol.
void
make_plt_entry(Symbol_table*, Layout*, Symbol*);
+ // Create a PLT entry for a local STT_GNU_IFUNC symbol.
+ void
+ make_local_ifunc_plt_entry(Symbol_table*, Layout*,
+ Sized_relobj<32, false>* relobj,
+ unsigned int local_sym_index);
+
// Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
void
define_tls_base_symbol(Symbol_table*, Layout*);
@@ -586,100 +714,38 @@ Target_i386::rel_dyn_section(Layout* layout)
return this->rel_dyn_;
}
-// A class to handle the PLT data.
-
-class Output_data_plt_i386 : public Output_section_data
-{
- public:
- typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
-
- Output_data_plt_i386(Layout*, Output_data_space*);
-
- // Add an entry to the PLT.
- void
- add_entry(Symbol* gsym);
-
- // Return the .rel.plt section data.
- const Reloc_section*
- rel_plt() const
- { return this->rel_; }
-
- // Return where the TLS_DESC relocations should go.
- Reloc_section*
- rel_tls_desc(Layout*);
-
- // Return the number of PLT entries.
- unsigned int
- entry_count() const
- { return this->count_; }
-
- // Return the offset of the first non-reserved PLT entry.
- static unsigned int
- first_plt_entry_offset()
- { return plt_entry_size; }
-
- // Return the size of a PLT entry.
- static unsigned int
- get_plt_entry_size()
- { return plt_entry_size; }
-
- protected:
- 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:
- // The size of an entry in the PLT.
- static const int plt_entry_size = 16;
-
- // The first entry in the PLT for an executable.
- static unsigned char exec_first_plt_entry[plt_entry_size];
-
- // The first entry in the PLT for a shared object.
- static unsigned char dyn_first_plt_entry[plt_entry_size];
-
- // Other entries in the PLT for an executable.
- static unsigned char exec_plt_entry[plt_entry_size];
-
- // Other entries in the PLT for a shared object.
- static unsigned char dyn_plt_entry[plt_entry_size];
-
- // Set the final size.
- void
- set_final_data_size()
- { this->set_data_size((this->count_ + 1) * plt_entry_size); }
-
- // Write out the PLT data.
- void
- do_write(Output_file*);
-
- // The reloc section.
- Reloc_section* rel_;
- // The TLS_DESC relocations, if necessary. These must follow the
- // regular PLT relocs.
- Reloc_section* tls_desc_rel_;
- // The .got.plt section.
- Output_data_space* got_plt_;
- // The number of PLT entries.
- unsigned int count_;
-};
-
// Create the PLT section. The ordinary .got section is an argument,
// since we need to refer to the start. We also create our own .got
// section just for PLT entries.
-Output_data_plt_i386::Output_data_plt_i386(Layout* layout,
+Output_data_plt_i386::Output_data_plt_i386(Symbol_table* symtab,
+ Layout* layout,
Output_data_space* got_plt)
- : Output_section_data(4), tls_desc_rel_(NULL), got_plt_(got_plt), count_(0)
+ : Output_section_data(4), tls_desc_rel_(NULL), got_plt_(got_plt), count_(0),
+ global_ifuncs_(), local_ifuncs_()
{
this->rel_ = new Reloc_section(false);
layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
elfcpp::SHF_ALLOC, this->rel_,
ORDER_DYNAMIC_PLT_RELOCS, false);
+
+ if (parameters->doing_static_link())
+ {
+ // A statically linked executable will only have a .rel.plt
+ // section to hold R_386_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->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->rel_, 0, 0, elfcpp::STT_NOTYPE,
+ elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN,
+ 0, true, true);
+ }
}
void
@@ -711,15 +777,58 @@ Output_data_plt_i386::add_entry(Symbol* gsym)
this->got_plt_->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_386_JUMP_SLOT, this->got_plt_,
- got_offset);
+ if (gsym->type() == elfcpp::STT_GNU_IFUNC
+ && gsym->can_use_relative_reloc(false))
+ {
+ this->rel_->add_symbolless_global_addend(gsym, elfcpp::R_386_IRELATIVE,
+ this->got_plt_, got_offset);
+ struct Global_ifunc gi;
+ gi.sym = gsym;
+ gi.got_offset = got_offset;
+ this->global_ifuncs_.push_back(gi);
+ }
+ else
+ {
+ gsym->set_needs_dynsym_entry();
+ this->rel_->add_global(gsym, elfcpp::R_386_JUMP_SLOT, this->got_plt_,
+ 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.
+
+unsigned int
+Output_data_plt_i386::add_local_ifunc_entry(Sized_relobj<32, false>* relobj,
+ unsigned int local_sym_index)
+{
+ unsigned int plt_offset = (this->count_ + 1) * plt_entry_size;
+ ++this->count_;
+
+ section_offset_type got_offset = this->got_plt_->current_data_size();
+
+ // Every PLT entry needs a GOT entry which points back to the PLT
+ // entry.
+ this->got_plt_->set_current_data_size(got_offset + 4);
+
+ // Every PLT entry needs a reloc.
+ this->rel_->add_symbolless_local_addend(relobj, local_sym_index,
+ elfcpp::R_386_IRELATIVE,
+ this->got_plt_, got_offset);
+
+ struct Local_ifunc li;
+ li.object = relobj;
+ li.local_sym_index = local_sym_index;
+ li.got_offset = got_offset;
+ this->local_ifuncs_.push_back(li);
+
+ return plt_offset;
+}
+
// Return where the TLS_DESC relocations should go, creating it if
// necessary. These follow the JUMP_SLOT relocations.
@@ -858,6 +967,32 @@ Output_data_plt_i386::do_write(Output_file* of)
elfcpp::Swap<32, false>::writeval(got_pov, plt_address + plt_offset + 6);
}
+ // If any STT_GNU_IFUNC symbols have PLT entries, we need to change
+ // the GOT to point to the actual symbol value, rather than point to
+ // the PLT entry. That will let the dynamic linker call the right
+ // function when resolving IRELATIVE relocations.
+ for (std::vector<Global_ifunc>::const_iterator p =
+ this->global_ifuncs_.begin();
+ p != this->global_ifuncs_.end();
+ ++p)
+ {
+ const Sized_symbol<32>* ssym =
+ static_cast<const Sized_symbol<32>*>(p->sym);
+ elfcpp::Swap<32, false>::writeval(got_view + p->got_offset,
+ ssym->value());
+ }
+
+ for (std::vector<Local_ifunc>::const_iterator p =
+ this->local_ifuncs_.begin();
+ p != this->local_ifuncs_.end();
+ ++p)
+ {
+ const Symbol_value<32>* psymval =
+ p->object->local_symbol(p->local_sym_index);
+ elfcpp::Swap<32, false>::writeval(got_view + p->got_offset,
+ psymval->value(p->object, 0));
+ }
+
gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
@@ -865,29 +1000,56 @@ Output_data_plt_i386::do_write(Output_file* of)
of->write_output_view(got_file_offset, got_size, got_view);
}
-// Create a PLT entry for a global symbol.
+// Create the PLT section.
void
-Target_i386::make_plt_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym)
+Target_i386::make_plt_section(Symbol_table* symtab, Layout* layout)
{
- if (gsym->has_plt_offset())
- return;
-
if (this->plt_ == NULL)
{
// Create the GOT sections first.
this->got_section(symtab, layout);
- this->plt_ = new Output_data_plt_i386(layout, this->got_plt_);
+ this->plt_ = new Output_data_plt_i386(symtab, layout, this->got_plt_);
layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
(elfcpp::SHF_ALLOC
| elfcpp::SHF_EXECINSTR),
this->plt_, ORDER_PLT, false);
+
+ // Make the sh_info field of .rel.plt point to .plt.
+ Output_section* rel_plt_os = this->plt_->rel_plt()->output_section();
+ rel_plt_os->set_info_section(this->plt_->output_section());
}
+}
+
+// Create a PLT entry for a global symbol.
+void
+Target_i386::make_plt_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym)
+{
+ if (gsym->has_plt_offset())
+ return;
+ if (this->plt_ == NULL)
+ this->make_plt_section(symtab, layout);
this->plt_->add_entry(gsym);
}
+// Make a PLT entry for a local STT_GNU_IFUNC symbol.
+
+void
+Target_i386::make_local_ifunc_plt_entry(Symbol_table* symtab, Layout* layout,
+ Sized_relobj<32, false>* 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(relobj,
+ local_sym_index);
+ relobj->set_local_plt_offset(local_sym_index, plt_offset);
+}
+
// Return the number of entries in the PLT.
unsigned int
@@ -1035,6 +1197,75 @@ Target_i386::Scan::unsupported_reloc_local(Sized_relobj<32, false>* object,
object->name().c_str(), r_type);
}
+// Return whether we need to make a PLT entry for a relocation of a
+// given type against a STT_GNU_IFUNC symbol.
+
+bool
+Target_i386::Scan::reloc_needs_plt_for_ifunc(Sized_relobj<32, false>* object,
+ unsigned int r_type)
+{
+ switch (r_type)
+ {
+ case elfcpp::R_386_NONE:
+ case elfcpp::R_386_GNU_VTINHERIT:
+ case elfcpp::R_386_GNU_VTENTRY:
+ return false;
+
+ case elfcpp::R_386_32:
+ case elfcpp::R_386_16:
+ case elfcpp::R_386_8:
+ case elfcpp::R_386_PC32:
+ case elfcpp::R_386_PC16:
+ case elfcpp::R_386_PC8:
+ case elfcpp::R_386_PLT32:
+ case elfcpp::R_386_GOTOFF:
+ case elfcpp::R_386_GOTPC:
+ case elfcpp::R_386_GOT32:
+ return true;
+
+ case elfcpp::R_386_COPY:
+ case elfcpp::R_386_GLOB_DAT:
+ case elfcpp::R_386_JUMP_SLOT:
+ case elfcpp::R_386_RELATIVE:
+ case elfcpp::R_386_IRELATIVE:
+ case elfcpp::R_386_TLS_TPOFF:
+ case elfcpp::R_386_TLS_DTPMOD32:
+ case elfcpp::R_386_TLS_DTPOFF32:
+ case elfcpp::R_386_TLS_TPOFF32:
+ case elfcpp::R_386_TLS_DESC:
+ // We will give an error later.
+ return false;
+
+ case elfcpp::R_386_TLS_GD:
+ case elfcpp::R_386_TLS_GOTDESC:
+ case elfcpp::R_386_TLS_DESC_CALL:
+ case elfcpp::R_386_TLS_LDM:
+ case elfcpp::R_386_TLS_LDO_32:
+ case elfcpp::R_386_TLS_IE:
+ case elfcpp::R_386_TLS_IE_32:
+ case elfcpp::R_386_TLS_GOTIE:
+ case elfcpp::R_386_TLS_LE:
+ case elfcpp::R_386_TLS_LE_32:
+ gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
+ object->name().c_str(), r_type);
+ return false;
+
+ case elfcpp::R_386_32PLT:
+ case elfcpp::R_386_TLS_GD_32:
+ case elfcpp::R_386_TLS_GD_PUSH:
+ case elfcpp::R_386_TLS_GD_CALL:
+ case elfcpp::R_386_TLS_GD_POP:
+ case elfcpp::R_386_TLS_LDM_32:
+ case elfcpp::R_386_TLS_LDM_PUSH:
+ case elfcpp::R_386_TLS_LDM_CALL:
+ case elfcpp::R_386_TLS_LDM_POP:
+ case elfcpp::R_386_USED_BY_INTEL_200:
+ default:
+ // We will give an error later.
+ return false;
+ }
+}
+
// Scan a relocation for a local symbol.
inline void
@@ -1048,6 +1279,14 @@ Target_i386::Scan::local(Symbol_table* symtab,
unsigned int r_type,
const elfcpp::Sym<32, false>& lsym)
{
+ // A local STT_GNU_IFUNC symbol may require a PLT entry.
+ if (lsym.get_st_type() == elfcpp::STT_GNU_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_386_NONE:
@@ -1066,9 +1305,9 @@ Target_i386::Scan::local(Symbol_table* symtab,
{
Reloc_section* rel_dyn = target->rel_dyn_section(layout);
unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
- rel_dyn->add_local_relative(object, r_sym, elfcpp::R_386_RELATIVE,
- output_section, data_shndx,
- reloc.get_r_offset());
+ rel_dyn->add_local_relative(object, r_sym, elfcpp::R_386_RELATIVE,
+ output_section, data_shndx,
+ reloc.get_r_offset());
}
break;
@@ -1125,17 +1364,27 @@ Target_i386::Scan::local(Symbol_table* symtab,
// The symbol requires a GOT entry.
Output_data_got<32, false>* got = target->got_section(symtab, layout);
unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
- if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
+
+ // 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 (lsym.get_st_type() == elfcpp::STT_GNU_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 RELATIVE relocation for this symbol's GOT entry.
if (parameters->options().output_is_position_independent())
{
Reloc_section* rel_dyn = target->rel_dyn_section(layout);
- unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
- rel_dyn->add_local_relative(
- object, r_sym, elfcpp::R_386_RELATIVE, got,
- object->local_got_offset(r_sym, GOT_TYPE_STANDARD));
+ unsigned int got_offset =
+ object->local_got_offset(r_sym, GOT_TYPE_STANDARD);
+ rel_dyn->add_local_relative(object, r_sym,
+ elfcpp::R_386_RELATIVE,
+ got, got_offset);
}
}
}
@@ -1147,6 +1396,7 @@ Target_i386::Scan::local(Symbol_table* symtab,
case elfcpp::R_386_GLOB_DAT:
case elfcpp::R_386_JUMP_SLOT:
case elfcpp::R_386_RELATIVE:
+ case elfcpp::R_386_IRELATIVE:
case elfcpp::R_386_TLS_TPOFF:
case elfcpp::R_386_TLS_DTPMOD32:
case elfcpp::R_386_TLS_DTPOFF32:
@@ -1394,6 +1644,11 @@ Target_i386::Scan::global(Symbol_table* symtab,
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_386_NONE:
@@ -1424,13 +1679,31 @@ Target_i386::Scan::global(Symbol_table* symtab,
target->copy_reloc(symtab, layout, object,
data_shndx, output_section, gsym, reloc);
}
+ else if (r_type == elfcpp::R_386_32
+ && 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_dyn = target->rel_dyn_section(layout);
+ rel_dyn->add_symbolless_global_addend(gsym,
+ elfcpp::R_386_IRELATIVE,
+ output_section,
+ object, data_shndx,
+ reloc.get_r_offset());
+ }
else if (r_type == elfcpp::R_386_32
&& gsym->can_use_relative_reloc(false))
{
Reloc_section* rel_dyn = target->rel_dyn_section(layout);
- rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
- output_section, object,
- data_shndx, reloc.get_r_offset());
+ rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
+ output_section, object,
+ data_shndx, reloc.get_r_offset());
}
else
{
@@ -1485,7 +1758,13 @@ Target_i386::Scan::global(Symbol_table* symtab,
// The symbol requires a GOT entry.
Output_data_got<32, false>* 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
@@ -1493,15 +1772,34 @@ Target_i386::Scan::global(Symbol_table* symtab,
Reloc_section* rel_dyn = target->rel_dyn_section(layout);
if (gsym->is_from_dynobj()
|| gsym->is_undefined()
- || gsym->is_preemptible())
+ || gsym->is_preemptible()
+ || (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_386_GLOB_DAT);
else
{
- if (got->add_global(gsym, GOT_TYPE_STANDARD))
- rel_dyn->add_global_relative(
- gsym, elfcpp::R_386_RELATIVE, got,
- gsym->got_offset(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)
+ {
+ unsigned int got_off = gsym->got_offset(GOT_TYPE_STANDARD);
+ rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
+ got, got_off);
+ }
}
}
}
@@ -1534,6 +1832,7 @@ Target_i386::Scan::global(Symbol_table* symtab,
case elfcpp::R_386_GLOB_DAT:
case elfcpp::R_386_JUMP_SLOT:
case elfcpp::R_386_RELATIVE:
+ case elfcpp::R_386_IRELATIVE:
case elfcpp::R_386_TLS_TPOFF:
case elfcpp::R_386_TLS_DTPMOD32:
case elfcpp::R_386_TLS_DTPOFF32:
@@ -1866,19 +2165,41 @@ Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo,
}
}
+ const Sized_relobj<32, false>* object = relinfo->object;
+
// Pick the value to use for symbols defined in shared objects.
Symbol_value<32> symval;
if (gsym != NULL
- && gsym->use_plt_offset(r_type == elfcpp::R_386_PC8
- || r_type == elfcpp::R_386_PC16
- || r_type == elfcpp::R_386_PC32))
+ && gsym->type() == elfcpp::STT_GNU_IFUNC
+ && r_type == elfcpp::R_386_32
+ && gsym->needs_dynamic_reloc(Symbol::ABSOLUTE_REF)
+ && gsym->can_use_relative_reloc(false)
+ && !gsym->is_from_dynobj()
+ && !gsym->is_undefined()
+ && !gsym->is_preemptible())
+ {
+ // In this case we are generating a R_386_IRELATIVE reloc. We
+ // want to use the real value of the symbol, not the PLT offset.
+ }
+ else if (gsym != NULL
+ && gsym->use_plt_offset(r_type == elfcpp::R_386_PC8
+ || r_type == elfcpp::R_386_PC16
+ || r_type == elfcpp::R_386_PC32))
{
symval.set_output_value(target->plt_section()->address()
+ gsym->plt_offset());
psymval = &symval;
}
-
- const Sized_relobj<32, false>* object = relinfo->object;
+ else if (gsym == NULL && psymval->is_ifunc_symbol())
+ {
+ unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
+ if (object->local_has_plt_offset(r_sym))
+ {
+ symval.set_output_value(target->plt_section()->address()
+ + object->local_plt_offset(r_sym));
+ psymval = &symval;
+ }
+ }
// Get the GOT offset if needed.
// The GOT pointer points to the end of the GOT section.
@@ -2001,6 +2322,7 @@ Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo,
case elfcpp::R_386_GLOB_DAT:
case elfcpp::R_386_JUMP_SLOT:
case elfcpp::R_386_RELATIVE:
+ case elfcpp::R_386_IRELATIVE:
// These are outstanding tls relocs, which are unexpected when
// linking.
case elfcpp::R_386_TLS_TPOFF:
@@ -2713,6 +3035,7 @@ Target_i386::Relocatable_size_for_reloc::get_size_for_reloc(
case elfcpp::R_386_GLOB_DAT:
case elfcpp::R_386_JUMP_SLOT:
case elfcpp::R_386_RELATIVE:
+ case elfcpp::R_386_IRELATIVE:
case elfcpp::R_386_TLS_TPOFF:
case elfcpp::R_386_TLS_DTPMOD32:
case elfcpp::R_386_TLS_DTPOFF32: