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gold: Add sparc IFUNC support to Gold. 

elfcpp/

	* sparc.h (R_SPARC_JMP_IREL): New relocation.

gold/

	* sparc.cc (class Target_sparc): Add rela_ifunc_.
	(Target_sparc::Target_sparc): Initialize new field.
	(Target_sparc::do_plt_section_for_global): New function.
	(Target_sparc::do_plt_section_for_local): New function.
	(Target_sparc::reloc_needs_plt_for_ifunc): New function.
	(Target_sparc::make_plt_section): New function, broken out of
	make_plt_entry.  Use ORDER_NON_RELRO_FIRST for ".plt".
	(Target_sparc::make_plt_entry): Call make_plt_section.
	(Target_sparc::make_local_ifunc_plt_entry): New function.
	(Target_sparc::rela_ifunc_section): New function.
	(Target_sparc::plt_section): Remove const.
	(Output_data_plt_sparc): Update declarations.  Define Global_ifunc
	and Local_ifunc types.  Add global_ifuncs_, local_ifuncs_, ifunc_rel_,
	and ifunc_count_ fields.
	(Output_data_plt_sparc::Output_data_plt_sparc): Initialize new fields.
	(Output_data_plt_sparc::add_entry): Handle IFUNC symbols.
	(Output_data_plt_sparc::add_local_ifunc_entry): New function.
	(Output_data_plt_sparc::rela_ifunc): New function.
	(Output_data_plt_sparc::emit_pending_ifunc_relocs): New function.
	(Output_data_plt_sparc::has_ifunc_section): New function.
	(Output_data_plt_sparc::entry_count): Include ifunc_count_.
	(Output_data_plt_sparc::address_for_global): New function.
	(Output_data_plt_sparc::address_for_local): New function.
	(Output_data_plt_sparc::plt_index_to_offset): New function.
	(Output_data_plt_sparc::set_final_data_size): Use plt_index_to_offset
	and entry_count.
	(Output_data_plt_sparc::do_write): Use first_plt_entry_offset and
	entry_count.
	(Target_sparc::Scan::get_reference_flags): Add R_SPARC_IRELATIVE and
	R_SPARC_JMP_IREL to switch.
	(Target_sparc::Scan::check_non_pic): Likewise.
	(Target_sparc::Scan::local): Handle IFUNC symbols.
	(Target_sparc::Scan::local): Likewise.
	(Target_sparc::Relocate::relocate): Likewise, use plt_address_for_global
	and plt_address_for_local.
	(Target_sparc::do_finalize_sections): Call emit_pending_ifunc_relocs.
	Define __rel_iplt_start and __rel_iplt_end if doing a static link.
This commit is contained in:
David S. Miller 2012-04-17 01:57:23 +00:00
parent 13cf9988bc
commit 8c2bf391c4
4 changed files with 559 additions and 80 deletions
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4
elfcpp/ChangeLog
View File

@ -1,3 +1,7 @@
2012-04-16 David S. Miller <davem@davemloft.net>
* sparc.h (R_SPARC_JMP_IREL): New relocation.
2012-04-12 David S. Miller <davem@davemloft.net>
* sparc.h (R_SPARC_WDISP10): New relocation.

1
elfcpp/sparc.h
View File

@ -142,6 +142,7 @@ enum
R_SPARC_SIZE64 = 87, // size of symbol, 64-bit
R_SPARC_WDISP10 = 88, // PC relative 10 bit shifted
R_SPARC_JMP_IREL = 248, // Create PLT slot to IFUNC function
R_SPARC_IRELATIVE = 249, // Adjust indirectly by program base
// GNU vtable garbage collection extensions.

38
gold/ChangeLog
View File

@ -1,5 +1,43 @@
2012-04-16 David S. Miller <davem@davemloft.net>
* sparc.cc (class Target_sparc): Add rela_ifunc_.
(Target_sparc::Target_sparc): Initialize new field.
(Target_sparc::do_plt_section_for_global): New function.
(Target_sparc::do_plt_section_for_local): New function.
(Target_sparc::reloc_needs_plt_for_ifunc): New function.
(Target_sparc::make_plt_section): New function, broken out of
make_plt_entry. Use ORDER_NON_RELRO_FIRST for ".plt".
(Target_sparc::make_plt_entry): Call make_plt_section.
(Target_sparc::make_local_ifunc_plt_entry): New function.
(Target_sparc::rela_ifunc_section): New function.
(Target_sparc::plt_section): Remove const.
(Output_data_plt_sparc): Update declarations. Define Global_ifunc
and Local_ifunc types. Add global_ifuncs_, local_ifuncs_, ifunc_rel_,
and ifunc_count_ fields.
(Output_data_plt_sparc::Output_data_plt_sparc): Initialize new fields.
(Output_data_plt_sparc::add_entry): Handle IFUNC symbols.
(Output_data_plt_sparc::add_local_ifunc_entry): New function.
(Output_data_plt_sparc::rela_ifunc): New function.
(Output_data_plt_sparc::emit_pending_ifunc_relocs): New function.
(Output_data_plt_sparc::has_ifunc_section): New function.
(Output_data_plt_sparc::entry_count): Include ifunc_count_.
(Output_data_plt_sparc::address_for_global): New function.
(Output_data_plt_sparc::address_for_local): New function.
(Output_data_plt_sparc::plt_index_to_offset): New function.
(Output_data_plt_sparc::set_final_data_size): Use plt_index_to_offset
and entry_count.
(Output_data_plt_sparc::do_write): Use first_plt_entry_offset and
entry_count.
(Target_sparc::Scan::get_reference_flags): Add R_SPARC_IRELATIVE and
R_SPARC_JMP_IREL to switch.
(Target_sparc::Scan::check_non_pic): Likewise.
(Target_sparc::Scan::local): Handle IFUNC symbols.
(Target_sparc::Scan::local): Likewise.
(Target_sparc::Relocate::relocate): Likewise, use plt_address_for_global
and plt_address_for_local.
(Target_sparc::do_finalize_sections): Call emit_pending_ifunc_relocs.
Define __rel_iplt_start and __rel_iplt_end if doing a static link.
* output.h (Output_reloc): Allow use_plt_offset for global relocs too.
(class Output_data_reloc): Adjust calls to Output_reloc_type.
(Output_data_reloc::add_global_relative): (RELA only) Add use_plt_offset.

596
gold/sparc.cc
View File

@ -1,6 +1,6 @@
// sparc.cc -- sparc target support for gold.
// Copyright 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
// Copyright 2008, 2009, 2010, 2011, 2012 Free Software Foundation, Inc.
// Written by David S. Miller <davem@davemloft.net>.
// This file is part of gold.
@ -58,7 +58,7 @@ class Target_sparc : public Sized_target<size, big_endian>
Target_sparc()
: Sized_target<size, big_endian>(&sparc_info),
got_(NULL), plt_(NULL), rela_dyn_(NULL),
got_(NULL), plt_(NULL), rela_dyn_(NULL), rela_ifunc_(NULL),
copy_relocs_(elfcpp::R_SPARC_COPY), dynbss_(NULL),
got_mod_index_offset_(-1U), tls_get_addr_sym_(NULL)
{
@ -154,6 +154,15 @@ class Target_sparc : public Sized_target<size, big_endian>
return strcmp(sym->name(), "___tls_get_addr") == 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 whether there is a GOT section.
bool
has_got_section() const
@ -256,6 +265,10 @@ class Target_sparc : public Sized_target<size, big_endian>
void
check_non_pic(Relobj*, unsigned int r_type);
bool
reloc_needs_plt_for_ifunc(Sized_relobj_file<size, big_endian>*,
unsigned int r_type);
// Whether we have issued an error about a non-PIC compilation.
bool issued_non_pic_error_;
};
@ -320,10 +333,20 @@ class Target_sparc : public Sized_target<size, big_endian>
Output_data_got<size, big_endian>*
got_section(Symbol_table*, Layout*);
// Create the PLT section.
void
make_plt_section(Symbol_table* symtab, Layout* layout);
// Create a PLT entry for a global symbol.
void
make_plt_entry(Symbol_table*, Layout*, Symbol*);
// Create a PLT entry for a local STT_GNU_IFUNC symbol.
void
make_local_ifunc_plt_entry(Symbol_table*, Layout*,
Sized_relobj_file<size, big_endian>* relobj,
unsigned int local_sym_index);
// Create a GOT entry for the TLS module index.
unsigned int
got_mod_index_entry(Symbol_table* symtab, Layout* layout,
@ -341,7 +364,7 @@ class Target_sparc : public Sized_target<size, big_endian>
}
// Get the PLT section.
const Output_data_plt_sparc<size, big_endian>*
Output_data_plt_sparc<size, big_endian>*
plt_section() const
{
gold_assert(this->plt_ != NULL);
@ -352,6 +375,10 @@ class Target_sparc : public Sized_target<size, big_endian>
Reloc_section*
rela_dyn_section(Layout*);
// Get the section to use for IFUNC relocations.
Reloc_section*
rela_ifunc_section(Layout*);
// Copy a relocation against a global symbol.
void
copy_reloc(Symbol_table* symtab, Layout* layout,
@ -386,6 +413,8 @@ class Target_sparc : public Sized_target<size, big_endian>
Output_data_plt_sparc<size, big_endian>* plt_;
// The dynamic reloc section.
Reloc_section* rela_dyn_;
// The section to use for IFUNC relocs.
Reloc_section* rela_ifunc_;
// Relocs saved to avoid a COPY reloc.
Copy_relocs<elfcpp::SHT_RELA, size, big_endian> copy_relocs_;
// Space for variables copied with a COPY reloc.
@ -1145,6 +1174,30 @@ Target_sparc<size, big_endian>::rela_dyn_section(Layout* layout)
return this->rela_dyn_;
}
// Get the section to use for IFUNC relocs, creating it if
// necessary. These go in .rela.dyn, but only after all other dynamic
// relocations. They need to follow the other dynamic relocations so
// that they can refer to global variables initialized by those
// relocs.
template<int size, bool big_endian>
typename Target_sparc<size, big_endian>::Reloc_section*
Target_sparc<size, big_endian>::rela_ifunc_section(Layout* layout)
{
if (this->rela_ifunc_ == NULL)
{
// Make sure we have already created the dynamic reloc section.
this->rela_dyn_section(layout);
this->rela_ifunc_ = new Reloc_section(false);
layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA,
elfcpp::SHF_ALLOC, this->rela_ifunc_,
ORDER_DYNAMIC_RELOCS, false);
gold_assert(this->rela_dyn_->output_section()
== this->rela_ifunc_->output_section());
}
return this->rela_ifunc_;
}
// A class to handle the PLT data.
template<int size, bool big_endian>
@ -1157,7 +1210,13 @@ class Output_data_plt_sparc : public Output_section_data
Output_data_plt_sparc(Layout*);
// Add an entry to the PLT.
void add_entry(Symbol* gsym);
void add_entry(Symbol_table* symtab, Layout* 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, big_endian>* relobj,
unsigned int local_sym_index);
// Return the .rela.plt section data.
const Reloc_section* rel_plt() const
@ -1165,10 +1224,22 @@ class Output_data_plt_sparc : public Output_section_data
return this->rel_;
}
// Return where the IFUNC relocations should go.
Reloc_section*
rela_ifunc(Symbol_table*, Layout*);
void
emit_pending_ifunc_relocs();
// Return whether we created a section for IFUNC relocations.
bool
has_ifunc_section() const
{ return this->ifunc_rel_ != NULL; }
// Return the number of PLT entries.
unsigned int
entry_count() const
{ return this->count_; }
{ return this->count_ + this->ifunc_count_; }
// Return the offset of the first non-reserved PLT entry.
static unsigned int
@ -1180,6 +1251,14 @@ class Output_data_plt_sparc : public Output_section_data
get_plt_entry_size()
{ return base_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);
protected:
void do_adjust_output_section(Output_section* os);
@ -1199,34 +1278,69 @@ class Output_data_plt_sparc : public Output_section_data
(plt_entries_per_block
* (plt_insn_chunk_size + plt_pointer_chunk_size));
section_offset_type
plt_index_to_offset(unsigned int index)
{
section_offset_type offset;
if (size == 32 || index < 32768)
offset = index * base_plt_entry_size;
else
{
unsigned int ext_index = index - 32768;
offset = (32768 * base_plt_entry_size)
+ ((ext_index / plt_entries_per_block)
* plt_block_size)
+ ((ext_index % plt_entries_per_block)
* plt_insn_chunk_size);
}
return offset;
}
// Set the final size.
void
set_final_data_size()
{
unsigned int full_count = this->count_ + 4;
unsigned int full_count = this->entry_count() + 4;
unsigned int extra = (size == 32 ? 4 : 0);
section_offset_type sz = plt_index_to_offset(full_count) + extra;
if (size == 32 || full_count < 32768)
this->set_data_size((full_count * base_plt_entry_size) + extra);
else
{
unsigned int ext_cnt = full_count - 32768;
this->set_data_size((32768 * base_plt_entry_size)
+ (ext_cnt
* (plt_insn_chunk_size
+ plt_pointer_chunk_size)));
}
return this->set_data_size(sz);
}
// Write out the PLT data.
void
do_write(Output_file*);
struct Global_ifunc
{
Reloc_section* rel;
Symbol* gsym;
unsigned int plt_index;
};
struct Local_ifunc
{
Reloc_section* rel;
Sized_relobj_file<size, big_endian>* object;
unsigned int local_sym_index;
unsigned int plt_index;
};
// The reloc section.
Reloc_section* rel_;
// The IFUNC relocations, if necessary. These must follow the
// regular relocations.
Reloc_section* ifunc_rel_;
// The number of PLT entries.
unsigned int count_;
// The number of PLT entries for IFUNC symbols.
unsigned int ifunc_count_;
// Global STT_GNU_IFUNC symbols.
std::vector<Global_ifunc> global_ifuncs_;
// Local STT_GNU_IFUNC symbols.
std::vector<Local_ifunc> local_ifuncs_;
};
// Define the constants as required by C++ standard.
@ -1253,7 +1367,8 @@ const unsigned int Output_data_plt_sparc<size, big_endian>::plt_block_size;
template<int size, bool big_endian>
Output_data_plt_sparc<size, big_endian>::Output_data_plt_sparc(Layout* layout)
: Output_section_data(size == 32 ? 4 : 8), count_(0)
: Output_section_data(size == 32 ? 4 : 8), ifunc_rel_(NULL),
count_(0), ifunc_count_(0), global_ifuncs_(), local_ifuncs_()
{
this->rel_ = new Reloc_section(false);
layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
@ -1272,40 +1387,173 @@ Output_data_plt_sparc<size, big_endian>::do_adjust_output_section(Output_section
template<int size, bool big_endian>
void
Output_data_plt_sparc<size, big_endian>::add_entry(Symbol* gsym)
Output_data_plt_sparc<size, big_endian>::add_entry(Symbol_table* symtab,
Layout* layout,
Symbol* gsym)
{
gold_assert(!gsym->has_plt_offset());
unsigned int index = this->count_ + 4;
section_offset_type plt_offset;
unsigned int index;
if (size == 32 || index < 32768)
plt_offset = index * base_plt_entry_size;
if (gsym->type() == elfcpp::STT_GNU_IFUNC
&& gsym->can_use_relative_reloc(false))
{
index = this->ifunc_count_;
plt_offset = plt_index_to_offset(index);
gsym->set_plt_offset(plt_offset);
++this->ifunc_count_;
Reloc_section* rel = this->rela_ifunc(symtab, layout);
struct Global_ifunc gi;
gi.rel = rel;
gi.gsym = gsym;
gi.plt_index = index;
this->global_ifuncs_.push_back(gi);
}
else
{
unsigned int ext_index = index - 32768;
plt_offset = (32768 * base_plt_entry_size)
+ ((ext_index / plt_entries_per_block)
* plt_block_size)
+ ((ext_index % plt_entries_per_block)
* plt_insn_chunk_size);
plt_offset = plt_index_to_offset(this->count_ + 4);
gsym->set_plt_offset(plt_offset);
++this->count_;
gsym->set_needs_dynsym_entry();
this->rel_->add_global(gsym, elfcpp::R_SPARC_JMP_SLOT, this,
plt_offset, 0);
}
gsym->set_plt_offset(plt_offset);
++this->count_;
// Every PLT entry needs a reloc.
gsym->set_needs_dynsym_entry();
this->rel_->add_global(gsym, elfcpp::R_SPARC_JMP_SLOT, this,
plt_offset, 0);
// 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.
}
template<int size, bool big_endian>
unsigned int
Output_data_plt_sparc<size, big_endian>::add_local_ifunc_entry(
Symbol_table* symtab,
Layout* layout,
Sized_relobj_file<size, big_endian>* relobj,
unsigned int local_sym_index)
{
unsigned int index = this->ifunc_count_;
section_offset_type plt_offset;
plt_offset = plt_index_to_offset(index);
++this->ifunc_count_;
Reloc_section* rel = this->rela_ifunc(symtab, layout);
struct Local_ifunc li;
li.rel = rel;
li.object = relobj;
li.local_sym_index = local_sym_index;
li.plt_index = index;
this->local_ifuncs_.push_back(li);
return plt_offset;
}
// Emit any pending IFUNC plt relocations.
template<int size, bool big_endian>
void
Output_data_plt_sparc<size, big_endian>::emit_pending_ifunc_relocs()
{
// Emit any pending IFUNC relocs.
for (typename std::vector<Global_ifunc>::const_iterator p =
this->global_ifuncs_.begin();
p != this->global_ifuncs_.end();
++p)
{
section_offset_type plt_offset;
unsigned int index;
index = this->count_ + p->plt_index + 4;
plt_offset = this->plt_index_to_offset(index);
p->rel->add_symbolless_global_addend(p->gsym, elfcpp::R_SPARC_JMP_IREL,
this, plt_offset, 0);
}
for (typename std::vector<Local_ifunc>::const_iterator p =
this->local_ifuncs_.begin();
p != this->local_ifuncs_.end();
++p)
{
section_offset_type plt_offset;
unsigned int index;
index = this->count_ + p->plt_index + 4;
plt_offset = this->plt_index_to_offset(index);
p->rel->add_symbolless_local_addend(p->object, p->local_sym_index,
elfcpp::R_SPARC_JMP_IREL,
this, plt_offset, 0);
}
}
// Return where the IFUNC relocations should go in the PLT. These
// follow the non-IFUNC relocations.
template<int size, bool big_endian>
typename Output_data_plt_sparc<size, big_endian>::Reloc_section*
Output_data_plt_sparc<size, big_endian>::rela_ifunc(
Symbol_table* symtab,
Layout* layout)
{
if (this->ifunc_rel_ == NULL)
{
this->ifunc_rel_ = new Reloc_section(false);
layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
elfcpp::SHF_ALLOC, this->ifunc_rel_,
ORDER_DYNAMIC_PLT_RELOCS, false);
gold_assert(this->ifunc_rel_->output_section()
== this->rel_->output_section());
if (parameters->doing_static_link())
{
// A statically linked executable will only have a .rel.plt
// section to hold R_SPARC_IRELATIVE and R_SPARC_JMP_IREL
// relocs for STT_GNU_IFUNC symbols. The library will use
// these symbols to locate the IRELATIVE and JMP_IREL relocs
// at program startup time.
symtab->define_in_output_data("__rela_iplt_start", NULL,
Symbol_table::PREDEFINED,
this->ifunc_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->ifunc_rel_, 0, 0,
elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
elfcpp::STV_HIDDEN, 0, true, true);
}
}
return this->ifunc_rel_;
}
// Return the PLT address to use for a global symbol.
template<int size, bool big_endian>
uint64_t
Output_data_plt_sparc<size, big_endian>::address_for_global(const Symbol* gsym)
{
uint64_t offset = 0;
if (gsym->type() == elfcpp::STT_GNU_IFUNC
&& gsym->can_use_relative_reloc(false))
offset = plt_index_to_offset(this->count_ + 4);
return this->address() + offset;
}
// Return the PLT address to use for a local symbol. These are always
// IRELATIVE relocs.
template<int size, bool big_endian>
uint64_t
Output_data_plt_sparc<size, big_endian>::address_for_local(
const Relobj*,
unsigned int)
{
return this->address() + plt_index_to_offset(this->count_ + 4);
}
static const unsigned int sparc_nop = 0x01000000;
static const unsigned int sparc_sethi_g1 = 0x03000000;
static const unsigned int sparc_branch_always = 0x30800000;
@ -1331,10 +1579,10 @@ Output_data_plt_sparc<size, big_endian>::do_write(Output_file* of)
unsigned char* pov = oview;
memset(pov, 0, base_plt_entry_size * 4);
pov += base_plt_entry_size * 4;
pov += this->first_plt_entry_offset();
unsigned int plt_offset = base_plt_entry_size * 4;
const unsigned int count = this->count_;
const unsigned int count = this->entry_count();
if (size == 64)
{
@ -1454,6 +1702,38 @@ Output_data_plt_sparc<size, big_endian>::do_write(Output_file* of)
of->write_output_view(offset, oview_size, oview);
}
// Create the PLT section.
template<int size, bool big_endian>
void
Target_sparc<size, big_endian>::make_plt_section(Symbol_table* symtab,
Layout* layout)
{
// 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 Sparc 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_sparc<size, big_endian>(layout);
layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
(elfcpp::SHF_ALLOC
| elfcpp::SHF_EXECINSTR
| elfcpp::SHF_WRITE),
this->plt_, ORDER_NON_RELRO_FIRST, false);
// Define _PROCEDURE_LINKAGE_TABLE_ at the start of the .plt section.
symtab->define_in_output_data("_PROCEDURE_LINKAGE_TABLE_", NULL,
Symbol_table::PREDEFINED,
this->plt_,
0, 0, elfcpp::STT_OBJECT,
elfcpp::STB_LOCAL,
elfcpp::STV_HIDDEN, 0,
false, false);
}
// Create a PLT entry for a global symbol.
template<int size, bool big_endian>
@ -1466,33 +1746,29 @@ Target_sparc<size, big_endian>::make_plt_entry(Symbol_table* symtab,
return;
if (this->plt_ == NULL)
{
// Create the GOT sections first.
this->got_section(symtab, layout);
this->make_plt_section(symtab, layout);
// Ensure that .rela.dyn always appears before .rela.plt This is
// necessary due to how, on Sparc and some other targets, .rela.dyn
// needs to include .rela.plt in it's range.
this->rela_dyn_section(layout);
this->plt_->add_entry(symtab, layout, gsym);
}
this->plt_ = new Output_data_plt_sparc<size, big_endian>(layout);
layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
(elfcpp::SHF_ALLOC
| elfcpp::SHF_EXECINSTR
| elfcpp::SHF_WRITE),
this->plt_, ORDER_PLT, false);
// Make a PLT entry for a local STT_GNU_IFUNC symbol.
// Define _PROCEDURE_LINKAGE_TABLE_ at the start of the .plt section.
symtab->define_in_output_data("_PROCEDURE_LINKAGE_TABLE_", NULL,
Symbol_table::PREDEFINED,
this->plt_,
0, 0, elfcpp::STT_OBJECT,
elfcpp::STB_LOCAL,
elfcpp::STV_HIDDEN, 0,
false, false);
}
this->plt_->add_entry(gsym);
template<int size, bool big_endian>
void
Target_sparc<size, big_endian>::make_local_ifunc_plt_entry(
Symbol_table* symtab,
Layout* layout,
Sized_relobj_file<size, big_endian>* relobj,
unsigned int local_sym_index)
{
if (relobj->local_has_plt_offset(local_sym_index))
return;
if (this->plt_ == NULL)
this->make_plt_section(symtab, layout);
unsigned int plt_offset = this->plt_->add_local_ifunc_entry(symtab, layout,
relobj,
local_sym_index);
relobj->set_local_plt_offset(local_sym_index, plt_offset);
}
// Return the number of entries in the PLT.
@ -1720,7 +1996,9 @@ Target_sparc<size, big_endian>::Scan::get_reference_flags(unsigned int r_type)
case elfcpp::R_SPARC_COPY:
case elfcpp::R_SPARC_GLOB_DAT:
case elfcpp::R_SPARC_JMP_SLOT:
case elfcpp::R_SPARC_JMP_IREL:
case elfcpp::R_SPARC_RELATIVE:
case elfcpp::R_SPARC_IRELATIVE:
case elfcpp::R_SPARC_TLS_DTPMOD64:
case elfcpp::R_SPARC_TLS_DTPMOD32:
case elfcpp::R_SPARC_TLS_DTPOFF64:
@ -1772,10 +2050,12 @@ Target_sparc<size, big_endian>::Scan::check_non_pic(Relobj* object, unsigned int
{
// These are the relocation types supported by glibc for sparc 64-bit.
case elfcpp::R_SPARC_RELATIVE:
case elfcpp::R_SPARC_IRELATIVE:
case elfcpp::R_SPARC_COPY:
case elfcpp::R_SPARC_64:
case elfcpp::R_SPARC_GLOB_DAT:
case elfcpp::R_SPARC_JMP_SLOT:
case elfcpp::R_SPARC_JMP_IREL:
case elfcpp::R_SPARC_TLS_DTPMOD64:
case elfcpp::R_SPARC_TLS_DTPOFF64:
case elfcpp::R_SPARC_TLS_TPOFF64:
@ -1812,10 +2092,12 @@ Target_sparc<size, big_endian>::Scan::check_non_pic(Relobj* object, unsigned int
{
// These are the relocation types supported by glibc for sparc 32-bit.
case elfcpp::R_SPARC_RELATIVE:
case elfcpp::R_SPARC_IRELATIVE:
case elfcpp::R_SPARC_COPY:
case elfcpp::R_SPARC_GLOB_DAT:
case elfcpp::R_SPARC_32:
case elfcpp::R_SPARC_JMP_SLOT:
case elfcpp::R_SPARC_JMP_IREL:
case elfcpp::R_SPARC_TLS_DTPMOD32:
case elfcpp::R_SPARC_TLS_DTPOFF32:
case elfcpp::R_SPARC_TLS_TPOFF32:
@ -1850,6 +2132,22 @@ Target_sparc<size, big_endian>::Scan::check_non_pic(Relobj* object, unsigned int
return;
}
// Return whether we need to make a PLT entry for a relocation of the
// given type against a STT_GNU_IFUNC symbol.
template<int size, bool big_endian>
bool
Target_sparc<size, big_endian>::Scan::reloc_needs_plt_for_ifunc(
Sized_relobj_file<size, 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 flags != 0;
}
// Scan a relocation for a local symbol.
template<int size, bool big_endian>
@ -1865,9 +2163,17 @@ Target_sparc<size, big_endian>::Scan::local(
unsigned int r_type,
const elfcpp::Sym<size, big_endian>& lsym)
{
bool is_ifunc = lsym.get_st_type() == elfcpp::STT_GNU_IFUNC;
unsigned int orig_r_type = r_type;
r_type &= 0xff;
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_SPARC_NONE:
@ -1891,7 +2197,7 @@ Target_sparc<size, big_endian>::Scan::local(
rela_dyn->add_local_relative(object, r_sym, elfcpp::R_SPARC_RELATIVE,
output_section, data_shndx,
reloc.get_r_offset(),
reloc.get_r_addend(), false);
reloc.get_r_addend(), is_ifunc);
}
break;
@ -1978,13 +2284,11 @@ Target_sparc<size, big_endian>::Scan::local(
if (!object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD))
{
Reloc_section* rela_dyn = target->rela_dyn_section(layout);
unsigned int off;
off = got->add_constant(0);
unsigned int off = got->add_constant(0);
object->set_local_got_offset(r_sym, GOT_TYPE_STANDARD, off);
rela_dyn->add_local_relative(object, r_sym,
elfcpp::R_SPARC_RELATIVE,
got, off, 0, false);
got, off, 0, is_ifunc);
}
}
else
@ -2126,7 +2430,9 @@ Target_sparc<size, big_endian>::Scan::local(
case elfcpp::R_SPARC_COPY:
case elfcpp::R_SPARC_GLOB_DAT:
case elfcpp::R_SPARC_JMP_SLOT:
case elfcpp::R_SPARC_JMP_IREL:
case elfcpp::R_SPARC_RELATIVE:
case elfcpp::R_SPARC_IRELATIVE:
case elfcpp::R_SPARC_TLS_DTPMOD64:
case elfcpp::R_SPARC_TLS_DTPMOD32:
case elfcpp::R_SPARC_TLS_DTPOFF64:
@ -2172,6 +2478,7 @@ Target_sparc<size, big_endian>::Scan::global(
Symbol* gsym)
{
unsigned int orig_r_type = r_type;
bool is_ifunc = gsym->type() == elfcpp::STT_GNU_IFUNC;
// A reference to _GLOBAL_OFFSET_TABLE_ implies that we need a got
// section. We check here to avoid creating a dynamic reloc against
@ -2181,6 +2488,12 @@ Target_sparc<size, big_endian>::Scan::global(
target->got_section(symtab, layout);
r_type &= 0xff;
// A STT_GNU_IFUNC symbol may require a PLT entry.
if (is_ifunc
&& this->reloc_needs_plt_for_ifunc(object, r_type))
target->make_plt_entry(symtab, layout, gsym);
switch (r_type)
{
case elfcpp::R_SPARC_NONE:
@ -2325,6 +2638,27 @@ Target_sparc<size, big_endian>::Scan::global(
target->copy_reloc(symtab, layout, object,
data_shndx, output_section, gsym, reloc);
}
else if (((size == 64 && r_type == elfcpp::R_SPARC_64)
|| (size == 32 && r_type == elfcpp::R_SPARC_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* rela_dyn =
target->rela_ifunc_section(layout);
unsigned int r_type = elfcpp::R_SPARC_IRELATIVE;
rela_dyn->add_symbolless_global_addend(gsym, r_type,
output_section, object,
data_shndx,
reloc.get_r_offset(),
reloc.get_r_addend());
}
else if ((r_type == elfcpp::R_SPARC_32
|| r_type == elfcpp::R_SPARC_64)
&& gsym->can_use_relative_reloc(false))
@ -2333,7 +2667,7 @@ Target_sparc<size, big_endian>::Scan::global(
rela_dyn->add_global_relative(gsym, elfcpp::R_SPARC_RELATIVE,
output_section, object,
data_shndx, reloc.get_r_offset(),
reloc.get_r_addend(), false);
reloc.get_r_addend(), is_ifunc);
}
else
{
@ -2370,24 +2704,68 @@ Target_sparc<size, big_endian>::Scan::global(
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
// dynamic relocation for it.
// GOT entry with a dynamic relocation.
bool is_ifunc = gsym->type() == elfcpp::STT_GNU_IFUNC;
// Use a GLOB_DAT rather than a RELATIVE reloc if:
//
// 1) The symbol may be defined in some other module.
//
// 2) We are building a shared library and this is a
// protected symbol; using GLOB_DAT means that the dynamic
// linker can use the address of the PLT in the main
// executable when appropriate so that function address
// comparisons work.
//
// 3) This is a STT_GNU_IFUNC symbol in position dependent
// code, again so that function address comparisons work.
Reloc_section* rela_dyn = target->rela_dyn_section(layout);
if (gsym->is_from_dynobj()
|| gsym->is_undefined()
|| gsym->is_preemptible())
got->add_global_with_rel(gsym, GOT_TYPE_STANDARD, rela_dyn,
elfcpp::R_SPARC_GLOB_DAT);
|| gsym->is_preemptible()
|| (gsym->visibility() == elfcpp::STV_PROTECTED
&& parameters->options().shared())
|| (gsym->type() == elfcpp::STT_GNU_IFUNC
&& parameters->options().output_is_position_independent()
&& !gsym->is_forced_local()))
{
unsigned int r_type = elfcpp::R_SPARC_GLOB_DAT;
// If this symbol is forced local, this relocation will
// not work properly. That's because ld.so on sparc
// (and 32-bit powerpc) expects st_value in the r_addend
// of relocations for STB_LOCAL symbols. Curiously the
// BFD linker does not promote global hidden symbols to be
// STB_LOCAL in the dynamic symbol table like Gold does.
gold_assert(!gsym->is_forced_local());
got->add_global_with_rel(gsym, GOT_TYPE_STANDARD, rela_dyn,
r_type);
}
else if (!gsym->has_got_offset(GOT_TYPE_STANDARD))
{
unsigned int off = got->add_constant(0);
gsym->set_got_offset(GOT_TYPE_STANDARD, off);
if (is_ifunc)
{
// 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();
}
rela_dyn->add_global_relative(gsym, elfcpp::R_SPARC_RELATIVE,
got, off, 0, false);
got, off, 0, is_ifunc);
}
}
}
@ -2520,7 +2898,9 @@ Target_sparc<size, big_endian>::Scan::global(
case elfcpp::R_SPARC_COPY:
case elfcpp::R_SPARC_GLOB_DAT:
case elfcpp::R_SPARC_JMP_SLOT:
case elfcpp::R_SPARC_JMP_IREL:
case elfcpp::R_SPARC_RELATIVE:
case elfcpp::R_SPARC_IRELATIVE:
case elfcpp::R_SPARC_TLS_DTPMOD64:
case elfcpp::R_SPARC_TLS_DTPMOD32:
case elfcpp::R_SPARC_TLS_DTPOFF64:
@ -2620,8 +3000,11 @@ void
Target_sparc<size, big_endian>::do_finalize_sections(
Layout* layout,
const Input_objects*,
Symbol_table*)
Symbol_table* symtab)
{
if (this->plt_)
this->plt_->emit_pending_ifunc_relocs();
// Fill in some more dynamic tags.
const Reloc_section* rel_plt = (this->plt_ == NULL
? NULL
@ -2633,6 +3016,47 @@ Target_sparc<size, big_endian>::do_finalize_sections(
// relocs.
if (this->copy_relocs_.any_saved_relocs())
this->copy_relocs_.emit(this->rela_dyn_section(layout));
if (parameters->doing_static_link()
&& (this->plt_ == NULL || !this->plt_->has_ifunc_section()))
{
// If linking statically, make sure that the __rela_iplt symbols
// were defined if necessary, even if we didn't create a PLT.
static const Define_symbol_in_segment syms[] =
{
{
"__rela_iplt_start", // name
elfcpp::PT_LOAD, // segment_type
elfcpp::PF_W, // segment_flags_set
elfcpp::PF(0), // segment_flags_clear
0, // value
0, // size
elfcpp::STT_NOTYPE, // type
elfcpp::STB_GLOBAL, // binding
elfcpp::STV_HIDDEN, // visibility
0, // nonvis
Symbol::SEGMENT_START, // offset_from_base
true // only_if_ref
},
{
"__rela_iplt_end", // name
elfcpp::PT_LOAD, // segment_type
elfcpp::PF_W, // segment_flags_set
elfcpp::PF(0), // segment_flags_clear
0, // value
0, // size
elfcpp::STT_NOTYPE, // type
elfcpp::STB_GLOBAL, // binding
elfcpp::STV_HIDDEN, // visibility
0, // nonvis
Symbol::SEGMENT_START, // offset_from_base
true // only_if_ref
}
};
symtab->define_symbols(layout, 2, syms,
layout->script_options()->saw_sections_clause());
}
}
// Perform a relocation.
@ -2669,6 +3093,7 @@ Target_sparc<size, big_endian>::Relocate::relocate(
view -= 4;
typedef Sparc_relocate_functions<size, big_endian> Reloc;
const Sized_relobj_file<size, big_endian>* object = relinfo->object;
// Pick the value to use for symbols defined in shared objects.
Symbol_value<size> symval;
@ -2677,14 +3102,23 @@ Target_sparc<size, big_endian>::Relocate::relocate(
{
elfcpp::Elf_Xword value;
value = target->plt_section()->address() + gsym->plt_offset();
value = target->plt_address_for_global(gsym) + gsym->plt_offset();
symval.set_output_value(value);
psymval = &symval;
}
else if (gsym == NULL && psymval->is_ifunc_symbol())
{
unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
if (object->local_has_plt_offset(r_sym))
{
symval.set_output_value(target->plt_address_for_local(object, r_sym)
+ object->local_plt_offset(r_sym));
psymval = &symval;
}
}
const Sized_relobj_file<size, big_endian>* object = relinfo->object;
const elfcpp::Elf_Xword addend = rela.get_r_addend();
// Get the GOT offset if needed. Unlike i386 and x86_64, our GOT
@ -2995,7 +3429,9 @@ Target_sparc<size, big_endian>::Relocate::relocate(
case elfcpp::R_SPARC_COPY:
case elfcpp::R_SPARC_GLOB_DAT:
case elfcpp::R_SPARC_JMP_SLOT:
case elfcpp::R_SPARC_JMP_IREL:
case elfcpp::R_SPARC_RELATIVE:
case elfcpp::R_SPARC_IRELATIVE:
// These are outstanding tls relocs, which are unexpected when
// linking.
case elfcpp::R_SPARC_TLS_DTPMOD64: