// i386.cc -- i386 target support for gold.
-// Copyright 2006, 2007, 2008 Free Software Foundation, Inc.
+// Copyright 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
// This file is part of gold.
#include "target-reloc.h"
#include "target-select.h"
#include "tls.h"
+#include "freebsd.h"
+#include "gc.h"
namespace
{
// http://people.redhat.com/drepper/tls.pdf
// http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
-class Target_i386 : public Sized_target<32, false>
+class Target_i386 : public Target_freebsd<32, false>
{
public:
typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
Target_i386()
- : Sized_target<32, false>(&i386_info),
- got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL),
+ : Target_freebsd<32, false>(&i386_info),
+ 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
+ gc_process_relocs(Symbol_table* symtab,
+ Layout* layout,
+ Sized_relobj<32, false>* object,
+ unsigned int data_shndx,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ bool needs_special_offset_handling,
+ size_t local_symbol_count,
+ const unsigned char* plocal_symbols);
+
// Scan the relocations to look for symbol adjustments.
void
- scan_relocs(const General_options& options,
- Symbol_table* symtab,
+ scan_relocs(Symbol_table* symtab,
Layout* layout,
Sized_relobj<32, false>* object,
unsigned int data_shndx,
// Finalize the sections.
void
- do_finalize_sections(Layout*);
+ do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
// Return the value to use for a dynamic which requires special
// treatment.
bool needs_special_offset_handling,
unsigned char* view,
elfcpp::Elf_types<32>::Elf_Addr view_address,
- section_size_type view_size);
+ section_size_type view_size,
+ const Reloc_symbol_changes*);
// Scan the relocs during a relocatable link.
void
- scan_relocatable_relocs(const General_options& options,
- Symbol_table* symtab,
+ scan_relocatable_relocs(Symbol_table* symtab,
Layout* layout,
Sized_relobj<32, false>* object,
unsigned int data_shndx,
// Return whether SYM is defined by the ABI.
bool
- do_is_defined_by_abi(Symbol* sym) const
+ do_is_defined_by_abi(const Symbol* sym) const
{ return strcmp(sym->name(), "___tls_get_addr") == 0; }
+ // Return whether a symbol name implies a local label. The UnixWare
+ // 2.1 cc generates temporary symbols that start with .X, so we
+ // recognize them here. FIXME: do other SVR4 compilers also use .X?.
+ // If so, we should move the .X recognition into
+ // Target::do_is_local_label_name.
+ bool
+ do_is_local_label_name(const char* name) const
+ {
+ if (name[0] == '.' && name[1] == 'X')
+ return true;
+ 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,
+ section_offset_type fnoffset, section_size_type fnsize,
+ unsigned char* view, section_size_type view_size,
+ std::string* from, std::string* to) const;
+
// Return the size of the GOT section.
section_size_type
- got_size()
+ got_size() const
{
gold_assert(this->got_ != NULL);
return this->got_->data_size();
}
+ // Return the number of entries in the GOT.
+ unsigned int
+ got_entry_count() const
+ {
+ if (this->got_ == NULL)
+ return 0;
+ return this->got_size() / 4;
+ }
+
+ // Return the number of entries in the PLT.
+ unsigned int
+ plt_entry_count() const;
+
+ // Return the offset of the first non-reserved PLT entry.
+ unsigned int
+ first_plt_entry_offset() const;
+
+ // Return the size of each PLT entry.
+ unsigned int
+ plt_entry_size() const;
+
private:
// The class which scans relocations.
struct Scan
{
inline void
- local(const General_options& options, Symbol_table* symtab,
- Layout* layout, Target_i386* target,
+ local(Symbol_table* symtab, Layout* layout, Target_i386* target,
Sized_relobj<32, false>* object,
unsigned int data_shndx,
Output_section* output_section,
const elfcpp::Sym<32, false>& lsym);
inline void
- global(const General_options& options, Symbol_table* symtab,
- Layout* layout, Target_i386* target,
+ global(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
+ 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);
inline bool
should_apply_static_reloc(const Sized_symbol<32>* gsym,
int ref_flags,
- bool is_32bit);
+ bool is_32bit,
+ Output_section* output_section);
// Do a relocation. Return false if the caller should not issue
// any warnings about this relocation.
inline bool
- relocate(const Relocate_info<32, false>*, Target_i386*, size_t relnum,
- const elfcpp::Rel<32, false>&,
+ relocate(const Relocate_info<32, false>*, Target_i386*, Output_section*,
+ size_t relnum, const elfcpp::Rel<32, false>&,
unsigned int r_type, const Sized_symbol<32>*,
const Symbol_value<32>*,
unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
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*);
- // Define the _TLS_MODULE_BASE_ symbol at the end of the TLS segment.
+ // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
void
define_tls_base_symbol(Symbol_table*, Layout*);
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*);
- // Return true if the symbol may need a COPY relocation.
- // References from an executable object to non-function symbols
- // defined in a dynamic object may need a COPY relocation.
- bool
- may_need_copy_reloc(Symbol* gsym)
- {
- return (!parameters->options().shared()
- && gsym->is_from_dynobj()
- && gsym->type() != elfcpp::STT_FUNC);
- }
+ // 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, Relobj* object,
+ copy_reloc(Symbol_table* symtab, Layout* layout,
+ Sized_relobj<32, false>* object,
unsigned int shndx, Output_section* output_section,
Symbol* sym, const elfcpp::Rel<32, false>& reloc)
{
static const Target::Target_info i386_info;
// The types of GOT entries needed for this platform.
+ // These values are exposed to the ABI in an incremental link.
+ // Do not renumber existing values without changing the version
+ // number of the .gnu_incremental_inputs section.
enum Got_type
{
GOT_TYPE_STANDARD = 0, // GOT entry for a regular symbol
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.
"/usr/lib/libc.so.1", // dynamic_linker
0x08048000, // default_text_segment_address
0x1000, // abi_pagesize (overridable by -z max-page-size)
- 0x1000 // common_pagesize (overridable by -z common-page-size)
+ 0x1000, // common_pagesize (overridable by -z common-page-size)
+ elfcpp::SHN_UNDEF, // small_common_shndx
+ elfcpp::SHN_UNDEF, // large_common_shndx
+ 0, // small_common_section_flags
+ 0, // large_common_section_flags
+ NULL, // attributes_section
+ NULL // attributes_vendor
};
// Get the GOT section, creating it if necessary.
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_);
- 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.
- this->got_plt_ = new Output_data_space(4);
- os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
- (elfcpp::SHF_ALLOC
- | elfcpp::SHF_WRITE),
- this->got_plt_);
- os->set_is_relro();
+ layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
+ (elfcpp::SHF_ALLOC
+ | elfcpp::SHF_WRITE),
+ this->got_, ORDER_RELRO_LAST, true);
+
+ this->got_plt_ = new Output_data_space(4, "** GOT PLT");
+ layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
+ (elfcpp::SHF_ALLOC
+ | elfcpp::SHF_WRITE),
+ this->got_plt_, ORDER_NON_RELRO_FIRST,
+ false);
// 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_,
+ ORDER_NON_RELRO_FIRST, false);
}
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_);
+ elfcpp::SHF_ALLOC, this->rel_dyn_,
+ ORDER_DYNAMIC_RELOCS, 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*);
+
+ // 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 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_);
+ elfcpp::SHF_ALLOC, this->rel_,
+ ORDER_DYNAMIC_PLT_RELOCS, 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_,
+ ORDER_DYNAMIC_PLT_RELOCS, 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] =
elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address();
elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address();
- if (parameters->options().shared())
+ if (parameters->options().output_is_position_independent())
memcpy(pov, dyn_first_plt_entry, plt_entry_size);
else
{
{
// Set and adjust the PLT entry itself.
- if (parameters->options().shared())
+ if (parameters->options().output_is_position_independent())
{
memcpy(pov, dyn_plt_entry, plt_entry_size);
elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset);
layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
(elfcpp::SHF_ALLOC
| elfcpp::SHF_EXECINSTR),
- this->plt_);
+ this->plt_, ORDER_PLT, false);
}
this->plt_->add_entry(gsym);
}
-// Define the _TLS_MODULE_BASE_ symbol at the end of the TLS segment.
+// Return the number of entries in the PLT.
+
+unsigned int
+Target_i386::plt_entry_count() const
+{
+ if (this->plt_ == NULL)
+ return 0;
+ return this->plt_->entry_count();
+}
+
+// Return the offset of the first non-reserved PLT entry.
+
+unsigned int
+Target_i386::first_plt_entry_offset() const
+{
+ return Output_data_plt_i386::first_plt_entry_offset();
+}
+
+// Return the size of each PLT entry.
+
+unsigned int
+Target_i386::plt_entry_size() const
+{
+ return Output_data_plt_i386::get_plt_entry_size();
+}
+
+// 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
Target_i386::define_tls_base_symbol(Symbol_table* symtab, Layout* layout)
Output_segment* tls_segment = layout->tls_segment();
if (tls_segment != NULL)
{
+ 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,
elfcpp::STV_HIDDEN, 0,
- Symbol::SEGMENT_END, true);
+ (is_exec
+ ? Symbol::SEGMENT_END
+ : Symbol::SEGMENT_START),
+ true);
}
this->tls_base_symbol_defined_ = true;
}
// Scan a relocation for a local symbol.
inline void
-Target_i386::Scan::local(const General_options&,
- Symbol_table* symtab,
+Target_i386::Scan::local(Symbol_table* symtab,
Layout* layout,
Target_i386* target,
Sized_relobj<32, false>* object,
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
-Target_i386::Scan::global(const General_options&,
- Symbol_table* symtab,
+Target_i386::Scan::global(Symbol_table* symtab,
Layout* layout,
Target_i386* target,
Sized_relobj<32, false>* object,
// Make a dynamic relocation if necessary.
if (gsym->needs_dynamic_reloc(Symbol::ABSOLUTE_REF))
{
- if (target->may_need_copy_reloc(gsym))
+ if (gsym->may_need_copy_reloc())
{
target->copy_reloc(symtab, layout, object,
data_shndx, output_section, gsym, reloc);
}
// 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))
{
- if (target->may_need_copy_reloc(gsym))
+ if (gsym->may_need_copy_reloc())
{
target->copy_reloc(symtab, layout, object,
data_shndx, output_section, gsym, reloc);
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)
}
}
+// Process relocations for gc.
+
+void
+Target_i386::gc_process_relocs(Symbol_table* symtab,
+ Layout* layout,
+ Sized_relobj<32, false>* object,
+ unsigned int data_shndx,
+ unsigned int,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ bool needs_special_offset_handling,
+ size_t local_symbol_count,
+ const unsigned char* plocal_symbols)
+{
+ gold::gc_process_relocs<32, false, Target_i386, elfcpp::SHT_REL,
+ Target_i386::Scan,
+ Target_i386::Relocatable_size_for_reloc>(
+ symtab,
+ layout,
+ this,
+ object,
+ data_shndx,
+ prelocs,
+ reloc_count,
+ output_section,
+ needs_special_offset_handling,
+ local_symbol_count,
+ plocal_symbols);
+}
+
// Scan relocations for a section.
void
-Target_i386::scan_relocs(const General_options& options,
- Symbol_table* symtab,
+Target_i386::scan_relocs(Symbol_table* symtab,
Layout* layout,
Sized_relobj<32, false>* object,
unsigned int data_shndx,
gold::scan_relocs<32, false, Target_i386, elfcpp::SHT_REL,
Target_i386::Scan>(
- options,
symtab,
layout,
this,
// Finalize the sections.
void
-Target_i386::do_finalize_sections(Layout* layout)
+Target_i386::do_finalize_sections(
+ Layout* layout,
+ const Input_objects*,
+ 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)
- odyn->add_section_address(elfcpp::DT_PLTGOT, this->got_plt_);
-
- if (this->plt_ != 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)
- {
- 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.
inline bool
Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol<32>* gsym,
int ref_flags,
- bool is_32bit)
+ bool is_32bit,
+ Output_section* output_section)
{
+ // If the output section is not allocated, then we didn't call
+ // scan_relocs, we didn't create a dynamic reloc, and we must apply
+ // the reloc here.
+ if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
+ return true;
+
// For local symbols, we will have created a non-RELATIVE dynamic
// relocation only if (a) the output is position independent,
// (b) the relocation is absolute (not pc- or segment-relative), and
inline bool
Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo,
Target_i386* target,
+ Output_section *output_section,
size_t relnum,
const elfcpp::Rel<32, false>& rel,
unsigned int r_type,
{
if (this->skip_call_tls_get_addr_)
{
- if (r_type != elfcpp::R_386_PLT32
+ if ((r_type != elfcpp::R_386_PLT32
+ && r_type != elfcpp::R_386_PC32)
|| gsym == NULL
|| strcmp(gsym->name(), "___tls_get_addr") != 0)
gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
// Pick the value to use for symbols defined in shared objects.
Symbol_value<32> symval;
- bool is_nonpic = (r_type == elfcpp::R_386_PC8
- || r_type == elfcpp::R_386_PC16
- || r_type == elfcpp::R_386_PC32);
if (gsym != NULL
- && (gsym->is_from_dynobj()
- || (parameters->options().shared()
- && (gsym->is_undefined() || gsym->is_preemptible())))
- && gsym->has_plt_offset()
- && (!is_nonpic || !parameters->options().shared()))
+ && 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());
break;
case elfcpp::R_386_32:
- if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true))
+ if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true,
+ output_section))
Relocate_functions<32, false>::rel32(view, object, psymval);
break;
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))
+ if (should_apply_static_reloc(gsym, ref_flags, true, output_section))
Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
}
break;
case elfcpp::R_386_16:
- if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false))
+ if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
+ output_section))
Relocate_functions<32, false>::rel16(view, object, psymval);
break;
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))
+ if (should_apply_static_reloc(gsym, ref_flags, false, output_section))
Relocate_functions<32, false>::pcrel16(view, object, psymval, address);
}
break;
case elfcpp::R_386_8:
- if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false))
+ if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
+ output_section))
Relocate_functions<32, false>::rel8(view, object, psymval);
break;
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))
+ if (should_apply_static_reloc(gsym, ref_flags, false,
+ output_section))
Relocate_functions<32, false>::pcrel8(view, object, psymval, address);
}
break;
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)
{
break;
case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
- // This reloc can appear in debugging sections, in which case we
- // won't see the TLS_LDM reloc. The local_dynamic_type field
- // tells us this.
- if (optimized_type == tls::TLSOPT_TO_LE
- && this->local_dynamic_type_ != LOCAL_DYNAMIC_NONE)
+ if (optimized_type == tls::TLSOPT_TO_LE)
{
- gold_assert(tls_segment != NULL);
- value -= tls_segment->memsz();
+ // This reloc can appear in debugging sections, in which
+ // case we must not convert to local-exec. We decide what
+ // to do based on whether the section is marked as
+ // containing executable code. That is what the GNU linker
+ // does as well.
+ elfcpp::Shdr<32, false> shdr(relinfo->data_shdr);
+ if ((shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0)
+ {
+ gold_assert(tls_segment != NULL);
+ value -= tls_segment->memsz();
+ }
}
Relocate_functions<32, false>::rel32(view, value);
break;
bool needs_special_offset_handling,
unsigned char* view,
elfcpp::Elf_types<32>::Elf_Addr address,
- section_size_type view_size)
+ section_size_type view_size,
+ const Reloc_symbol_changes* reloc_symbol_changes)
{
gold_assert(sh_type == elfcpp::SHT_REL);
needs_special_offset_handling,
view,
address,
- view_size);
+ view_size,
+ reloc_symbol_changes);
}
// Return the size of a relocation while scanning during a relocatable
// Scan the relocs during a relocatable link.
void
-Target_i386::scan_relocatable_relocs(const General_options& options,
- Symbol_table* symtab,
+Target_i386::scan_relocatable_relocs(Symbol_table* symtab,
Layout* layout,
Sized_relobj<32, false>* object,
unsigned int data_shndx,
gold::scan_relocatable_relocs<32, false, elfcpp::SHT_REL,
Scan_relocatable_relocs>(
- options,
symtab,
layout,
object,
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
+// that it has enough stack space to run some random function.
+
+void
+Target_i386::do_calls_non_split(Relobj* object, unsigned int shndx,
+ section_offset_type fnoffset,
+ section_size_type fnsize,
+ unsigned char* view,
+ section_size_type view_size,
+ std::string* from,
+ std::string* to) const
+{
+ // The function starts with a comparison of the stack pointer and a
+ // field in the TCB. This is followed by a jump.
+
+ // cmp %gs:NN,%esp
+ if (this->match_view(view, view_size, fnoffset, "\x65\x3b\x25", 3)
+ && fnsize > 7)
+ {
+ // We will call __morestack if the carry flag is set after this
+ // comparison. We turn the comparison into an stc instruction
+ // and some nops.
+ view[fnoffset] = '\xf9';
+ this->set_view_to_nop(view, view_size, fnoffset + 1, 6);
+ }
+ // lea NN(%esp),%ecx
+ // 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
+ // comparison. The offset is negative, so we decrease the
+ // offset by the amount of space we need for the stack. This
+ // means we will avoid calling __morestack if there happens to
+ // be plenty of space on the stack already.
+ unsigned char* pval = view + fnoffset + 3;
+ uint32_t val = elfcpp::Swap_unaligned<32, false>::readval(pval);
+ val -= parameters->options().split_stack_adjust_size();
+ elfcpp::Swap_unaligned<32, false>::writeval(pval, val);
+ }
+ else
+ {
+ if (!object->has_no_split_stack())
+ object->error(_("failed to match split-stack sequence at "
+ "section %u offset %0zx"),
+ shndx, static_cast<size_t>(fnoffset));
+ return;
+ }
+
+ // We have to change the function so that it calls
+ // __morestack_non_split instead of __morestack. The former will
+ // allocate additional stack space.
+ *from = "__morestack";
+ *to = "__morestack_non_split";
+}
+
// The selector for i386 object files.
-class Target_selector_i386 : public Target_selector
+class Target_selector_i386 : public Target_selector_freebsd
{
public:
Target_selector_i386()
- : Target_selector(elfcpp::EM_386, 32, false, "elf32-i386")
+ : Target_selector_freebsd(elfcpp::EM_386, 32, false,
+ "elf32-i386", "elf32-i386-freebsd")
{ }
Target*
projects / binutils.git / blobdiff