// i386.cc -- i386 target support for gold.
-// Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
+// Copyright 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
Target_i386()
: Target_freebsd<32, false>(&i386_info),
- got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL),
+ got_(NULL), plt_(NULL), got_plt_(NULL), got_tlsdesc_(NULL),
+ global_offset_table_(NULL), rel_dyn_(NULL),
copy_relocs_(elfcpp::R_386_COPY), dynbss_(NULL),
got_mod_index_offset_(-1U), tls_base_symbol_defined_(false)
{ }
+ inline bool
+ can_check_for_function_pointers() const
+ { return true; }
+
// Process the relocations to determine unreferenced sections for
// garbage collection.
void
return Target::do_is_local_label_name(name);
}
+ // Return whether SYM is call to a non-split function.
+ bool
+ do_is_call_to_non_split(const Symbol* sym, unsigned int) const;
+
// Adjust -fstack-split code which calls non-stack-split code.
void
do_calls_non_split(Relobj* object, unsigned int shndx,
const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
Symbol* gsym);
+ inline bool
+ local_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
+ Target_i386* target,
+ Sized_relobj<32, false>* object,
+ unsigned int data_shndx,
+ Output_section* output_section,
+ const elfcpp::Rel<32, false>& reloc,
+ unsigned int r_type,
+ const elfcpp::Sym<32, false>& lsym);
+
+ inline bool
+ global_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
+ Target_i386* target,
+ Sized_relobj<32, false>* object,
+ unsigned int data_shndx,
+ Output_section* output_section,
+ const elfcpp::Rel<32, false>& reloc,
+ unsigned int r_type,
+ Symbol* gsym);
+
+ inline bool
+ possible_function_pointer_reloc(unsigned int r_type);
+
static void
unsupported_reloc_local(Sized_relobj<32, false>*, unsigned int r_type);
return this->got_plt_;
}
+ // Get the GOT section for TLSDESC entries.
+ Output_data_got<32, false>*
+ got_tlsdesc_section() const
+ {
+ gold_assert(this->got_tlsdesc_ != NULL);
+ return this->got_tlsdesc_;
+ }
+
// Create a PLT entry for a global symbol.
void
make_plt_entry(Symbol_table*, Layout*, Symbol*);
Sized_relobj<32, false>* object);
// Get the PLT section.
- const Output_data_plt_i386*
+ Output_data_plt_i386*
plt_section() const
{
gold_assert(this->plt_ != NULL);
Reloc_section*
rel_dyn_section(Layout*);
+ // Get the section to use for TLS_DESC relocations.
+ Reloc_section*
+ rel_tls_desc_section(Layout*) const;
+
// Add a potential copy relocation.
void
copy_reloc(Symbol_table* symtab, Layout* layout,
Output_data_plt_i386* plt_;
// The GOT PLT section.
Output_data_space* got_plt_;
+ // The GOT section for TLSDESC relocations.
+ Output_data_got<32, false>* got_tlsdesc_;
+ // The _GLOBAL_OFFSET_TABLE_ symbol.
+ Symbol* global_offset_table_;
// The dynamic reloc section.
Reloc_section* rel_dyn_;
// Relocs saved to avoid a COPY reloc.
this->got_ = new Output_data_got<32, false>();
- Output_section* os;
- os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
- (elfcpp::SHF_ALLOC
- | elfcpp::SHF_WRITE),
- this->got_, false);
- os->set_is_relro();
-
- // The old GNU linker creates a .got.plt section. We just
- // create another set of data in the .got section. Note that we
- // always create a PLT if we create a GOT, although the PLT
- // might be empty.
+ layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
+ (elfcpp::SHF_ALLOC
+ | elfcpp::SHF_WRITE),
+ this->got_, false, true, true, false);
+
this->got_plt_ = new Output_data_space(4, "** GOT PLT");
- os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
- (elfcpp::SHF_ALLOC
- | elfcpp::SHF_WRITE),
- this->got_plt_, false);
- os->set_is_relro();
+ layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
+ (elfcpp::SHF_ALLOC
+ | elfcpp::SHF_WRITE),
+ this->got_plt_, false, false, false,
+ true);
// The first three entries are reserved.
this->got_plt_->set_current_data_size(3 * 4);
+ // Those bytes can go into the relro segment.
+ layout->increase_relro(3 * 4);
+
// Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
- symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
- this->got_plt_,
- 0, 0, elfcpp::STT_OBJECT,
- elfcpp::STB_LOCAL,
- elfcpp::STV_HIDDEN, 0,
- false, false);
+ this->global_offset_table_ =
+ symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
+ Symbol_table::PREDEFINED,
+ this->got_plt_,
+ 0, 0, elfcpp::STT_OBJECT,
+ elfcpp::STB_LOCAL,
+ elfcpp::STV_HIDDEN, 0,
+ false, false);
+
+ // If there are any TLSDESC relocations, they get GOT entries in
+ // .got.plt after the jump slot entries.
+ this->got_tlsdesc_ = new Output_data_got<32, false>();
+ layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
+ (elfcpp::SHF_ALLOC
+ | elfcpp::SHF_WRITE),
+ this->got_tlsdesc_, false, false, false,
+ true);
}
return this->got_;
gold_assert(layout != NULL);
this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
- elfcpp::SHF_ALLOC, this->rel_dyn_, true);
+ elfcpp::SHF_ALLOC, this->rel_dyn_, true,
+ false, false, false);
}
return this->rel_dyn_;
}
rel_plt() const
{ return this->rel_; }
+ // Return where the TLS_DESC relocations should go.
+ Reloc_section*
+ rel_tls_desc(Layout*);
+
protected:
void
do_adjust_output_section(Output_section* os);
// 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.
Output_data_plt_i386::Output_data_plt_i386(Layout* layout,
Output_data_space* got_plt)
- : Output_section_data(4), got_plt_(got_plt), count_(0)
+ : Output_section_data(4), tls_desc_rel_(NULL), got_plt_(got_plt), count_(0)
{
this->rel_ = new Reloc_section(false);
layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
- elfcpp::SHF_ALLOC, this->rel_, true);
+ elfcpp::SHF_ALLOC, this->rel_, true,
+ false, false, false);
}
void
// appear in the relocations.
}
+// Return where the TLS_DESC relocations should go, creating it if
+// necessary. These follow the JUMP_SLOT relocations.
+
+Output_data_plt_i386::Reloc_section*
+Output_data_plt_i386::rel_tls_desc(Layout* layout)
+{
+ if (this->tls_desc_rel_ == NULL)
+ {
+ this->tls_desc_rel_ = new Reloc_section(false);
+ layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
+ elfcpp::SHF_ALLOC, this->tls_desc_rel_,
+ true, false, false, false);
+ gold_assert(this->tls_desc_rel_->output_section() ==
+ this->rel_->output_section());
+ }
+ return this->tls_desc_rel_;
+}
+
// The first entry in the PLT for an executable.
unsigned char Output_data_plt_i386::exec_first_plt_entry[plt_entry_size] =
layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
(elfcpp::SHF_ALLOC
| elfcpp::SHF_EXECINSTR),
- this->plt_, false);
+ this->plt_, false, false, false, false);
}
this->plt_->add_entry(gsym);
}
+// Get the section to use for TLS_DESC relocations.
+
+Target_i386::Reloc_section*
+Target_i386::rel_tls_desc_section(Layout* layout) const
+{
+ return this->plt_section()->rel_tls_desc(layout);
+}
+
// Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
void
{
bool is_exec = parameters->options().output_is_executable();
symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
+ Symbol_table::PREDEFINED,
tls_segment, 0, 0,
elfcpp::STT_TLS,
elfcpp::STB_LOCAL,
target->define_tls_base_symbol(symtab, layout);
if (optimized_type == tls::TLSOPT_NONE)
{
- // Create a double GOT entry with an R_386_TLS_DESC reloc.
- Output_data_got<32, false>* got
- = target->got_section(symtab, layout);
+ // Create a double GOT entry with an R_386_TLS_DESC
+ // reloc. The R_386_TLS_DESC reloc is resolved
+ // lazily, so the GOT entry needs to be in an area in
+ // .got.plt, not .got. Call got_section to make sure
+ // the section has been created.
+ target->got_section(symtab, layout);
+ Output_data_got<32, false>* got = target->got_tlsdesc_section();
unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
- unsigned int shndx = lsym.get_st_shndx();
- bool is_ordinary;
- shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
- if (!is_ordinary)
- object->error(_("local symbol %u has bad shndx %u"),
- r_sym, shndx);
- else
- got->add_local_pair_with_rel(object, r_sym, shndx,
- GOT_TYPE_TLS_DESC,
- target->rel_dyn_section(layout),
- elfcpp::R_386_TLS_DESC, 0);
+ if (!object->local_has_got_offset(r_sym, GOT_TYPE_TLS_DESC))
+ {
+ unsigned int got_offset = got->add_constant(0);
+ // The local symbol value is stored in the second
+ // GOT entry.
+ got->add_local(object, r_sym, GOT_TYPE_TLS_DESC);
+ // That set the GOT offset of the local symbol to
+ // point to the second entry, but we want it to
+ // point to the first.
+ object->set_local_got_offset(r_sym, GOT_TYPE_TLS_DESC,
+ got_offset);
+ Reloc_section* rt = target->rel_tls_desc_section(layout);
+ rt->add_absolute(elfcpp::R_386_TLS_DESC, got, got_offset);
+ }
}
else if (optimized_type != tls::TLSOPT_TO_LE)
unsupported_reloc_local(object, r_type);
object->name().c_str(), r_type, gsym->demangled_name().c_str());
}
+inline bool
+Target_i386::Scan::possible_function_pointer_reloc(unsigned int r_type)
+{
+ switch (r_type)
+ {
+ case elfcpp::R_386_32:
+ case elfcpp::R_386_16:
+ case elfcpp::R_386_8:
+ case elfcpp::R_386_GOTOFF:
+ case elfcpp::R_386_GOT32:
+ {
+ return true;
+ }
+ default:
+ return false;
+ }
+ return false;
+}
+
+inline bool
+Target_i386::Scan::local_reloc_may_be_function_pointer(
+ Symbol_table* ,
+ Layout* ,
+ Target_i386* ,
+ Sized_relobj<32, false>* ,
+ unsigned int ,
+ Output_section* ,
+ const elfcpp::Rel<32, false>& ,
+ unsigned int r_type,
+ const elfcpp::Sym<32, false>&)
+{
+ return possible_function_pointer_reloc(r_type);
+}
+
+inline bool
+Target_i386::Scan::global_reloc_may_be_function_pointer(
+ Symbol_table* ,
+ Layout* ,
+ Target_i386* ,
+ Sized_relobj<32, false>* ,
+ unsigned int ,
+ Output_section* ,
+ const elfcpp::Rel<32, false>& ,
+ unsigned int r_type,
+ Symbol*)
+{
+ return possible_function_pointer_reloc(r_type);
+}
+
// Scan a relocation for a global symbol.
inline void
}
// Make a dynamic relocation if necessary.
int flags = Symbol::NON_PIC_REF;
- if (gsym->type() == elfcpp::STT_FUNC)
+ if (gsym->is_func())
flags |= Symbol::FUNCTION_CALL;
if (gsym->needs_dynamic_reloc(flags))
{
target->define_tls_base_symbol(symtab, layout);
if (optimized_type == tls::TLSOPT_NONE)
{
- // Create a double GOT entry with an R_386_TLS_DESC reloc.
- Output_data_got<32, false>* got
- = target->got_section(symtab, layout);
- got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_DESC,
- target->rel_dyn_section(layout),
+ // Create a double GOT entry with an R_386_TLS_DESC
+ // reloc. The R_386_TLS_DESC reloc is resolved
+ // lazily, so the GOT entry needs to be in an area in
+ // .got.plt, not .got. Call got_section to make sure
+ // the section has been created.
+ target->got_section(symtab, layout);
+ Output_data_got<32, false>* got = target->got_tlsdesc_section();
+ Reloc_section* rt = target->rel_tls_desc_section(layout);
+ got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_DESC, rt,
elfcpp::R_386_TLS_DESC, 0);
}
else if (optimized_type == tls::TLSOPT_TO_IE)
const unsigned char* plocal_symbols)
{
gold::gc_process_relocs<32, false, Target_i386, elfcpp::SHT_REL,
- Target_i386::Scan>(
+ Target_i386::Scan,
+ Target_i386::Relocatable_size_for_reloc>(
symtab,
layout,
this,
Target_i386::do_finalize_sections(
Layout* layout,
const Input_objects*,
- Symbol_table*)
+ Symbol_table* symtab)
{
- // Fill in some more dynamic tags.
- Output_data_dynamic* const odyn = layout->dynamic_data();
- if (odyn != NULL)
- {
- if (this->got_plt_ != NULL
- && this->got_plt_->output_section() != NULL)
- odyn->add_section_address(elfcpp::DT_PLTGOT, this->got_plt_);
-
- if (this->plt_ != NULL
- && this->plt_->output_section() != NULL)
- {
- const Output_data* od = this->plt_->rel_plt();
- odyn->add_section_size(elfcpp::DT_PLTRELSZ, od);
- odyn->add_section_address(elfcpp::DT_JMPREL, od);
- odyn->add_constant(elfcpp::DT_PLTREL, elfcpp::DT_REL);
- }
-
- if (this->rel_dyn_ != NULL
- && this->rel_dyn_->output_section() != NULL)
- {
- const Output_data* od = this->rel_dyn_;
- odyn->add_section_address(elfcpp::DT_REL, od);
- odyn->add_section_size(elfcpp::DT_RELSZ, od);
- odyn->add_constant(elfcpp::DT_RELENT,
- elfcpp::Elf_sizes<32>::rel_size);
- }
-
- if (!parameters->options().shared())
- {
- // The value of the DT_DEBUG tag is filled in by the dynamic
- // linker at run time, and used by the debugger.
- odyn->add_constant(elfcpp::DT_DEBUG, 0);
- }
- }
+ const Reloc_section* rel_plt = (this->plt_ == NULL
+ ? NULL
+ : this->plt_->rel_plt());
+ layout->add_target_dynamic_tags(true, this->got_plt_, rel_plt,
+ this->rel_dyn_, true, false);
// Emit any relocs we saved in an attempt to avoid generating COPY
// relocs.
if (this->copy_relocs_.any_saved_relocs())
this->copy_relocs_.emit(this->rel_dyn_section(layout));
+
+ // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
+ // the .got.plt section.
+ Symbol* sym = this->global_offset_table_;
+ if (sym != NULL)
+ {
+ uint32_t data_size = this->got_plt_->current_data_size();
+ symtab->get_sized_symbol<32>(sym)->set_symsize(data_size);
+ }
}
// Return whether a direct absolute static relocation needs to be applied.
case elfcpp::R_386_PC32:
{
int ref_flags = Symbol::NON_PIC_REF;
- if (gsym != NULL && gsym->type() == elfcpp::STT_FUNC)
+ if (gsym != NULL && gsym->is_func())
ref_flags |= Symbol::FUNCTION_CALL;
if (should_apply_static_reloc(gsym, ref_flags, true, output_section))
Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
case elfcpp::R_386_PC16:
{
int ref_flags = Symbol::NON_PIC_REF;
- if (gsym != NULL && gsym->type() == elfcpp::STT_FUNC)
+ if (gsym != NULL && gsym->is_func())
ref_flags |= Symbol::FUNCTION_CALL;
if (should_apply_static_reloc(gsym, ref_flags, false, output_section))
Relocate_functions<32, false>::pcrel16(view, object, psymval, address);
case elfcpp::R_386_PC8:
{
int ref_flags = Symbol::NON_PIC_REF;
- if (gsym != NULL && gsym->type() == elfcpp::STT_FUNC)
+ if (gsym != NULL && gsym->is_func())
ref_flags |= Symbol::FUNCTION_CALL;
if (should_apply_static_reloc(gsym, ref_flags, false,
output_section))
elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
- const bool is_final =
- (gsym == NULL
- ? !parameters->options().output_is_position_independent()
- : gsym->final_value_is_known());
+ const bool is_final = (gsym == NULL
+ ? !parameters->options().shared()
+ : gsym->final_value_is_known());
const tls::Tls_optimization optimized_type
= Target_i386::optimize_tls_reloc(is_final, r_type);
switch (r_type)
unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
? GOT_TYPE_TLS_NOFFSET
: GOT_TYPE_TLS_DESC);
- unsigned int got_offset;
+ unsigned int got_offset = 0;
+ if (r_type == elfcpp::R_386_TLS_GOTDESC
+ && optimized_type == tls::TLSOPT_NONE)
+ {
+ // We created GOT entries in the .got.tlsdesc portion of
+ // the .got.plt section, but the offset stored in the
+ // symbol is the offset within .got.tlsdesc.
+ got_offset = (target->got_size()
+ + target->got_plt_section()->data_size());
+ }
if (gsym != NULL)
{
gold_assert(gsym->has_got_offset(got_type));
- got_offset = gsym->got_offset(got_type) - target->got_size();
+ got_offset += gsym->got_offset(got_type) - target->got_size();
}
else
{
unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
gold_assert(object->local_has_got_offset(r_sym, got_type));
- got_offset = (object->local_got_offset(r_sym, got_type)
- - target->got_size());
+ got_offset += (object->local_got_offset(r_sym, got_type)
+ - target->got_size());
}
if (optimized_type == tls::TLSOPT_TO_IE)
{
return std::string(nops[length], length);
}
+// Return whether SYM should be treated as a call to a non-split
+// function. We don't want that to be true of a call to a
+// get_pc_thunk function.
+
+bool
+Target_i386::do_is_call_to_non_split(const Symbol* sym, unsigned int) const
+{
+ return (sym->type() == elfcpp::STT_FUNC
+ && !is_prefix_of("__i686.get_pc_thunk.", sym->name()));
+}
+
// FNOFFSET in section SHNDX in OBJECT is the start of a function
// compiled with -fstack-split. The function calls non-stack-split
// code. We have to change the function so that it always ensures
this->set_view_to_nop(view, view_size, fnoffset + 1, 6);
}
// lea NN(%esp),%ecx
- else if (this->match_view(view, view_size, fnoffset, "\x8d\x8c\x24", 3)
+ // lea NN(%esp),%edx
+ else if ((this->match_view(view, view_size, fnoffset, "\x8d\x8c\x24", 3)
+ || this->match_view(view, view_size, fnoffset, "\x8d\x94\x24", 3))
&& fnsize > 7)
{
// This is loading an offset from the stack pointer for a
projects / binutils-gdb.git / blobdiff