// x86_64.cc -- x86_64 target support for gold.
-// Copyright 2006, 2007, 2008 Free Software Foundation, Inc.
+// Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
#include "target-reloc.h"
#include "target-select.h"
#include "tls.h"
+#include "freebsd.h"
+#include "gc.h"
+#include "icf.h"
namespace
{
// http://people.redhat.com/drepper/tls.pdf
// http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
-class Target_x86_64 : public Sized_target<64, false>
+class Target_x86_64 : public Target_freebsd<64, false>
{
public:
// In the x86_64 ABI (p 68), it says "The AMD64 ABI architectures
typedef Output_data_reloc<elfcpp::SHT_RELA, true, 64, false> Reloc_section;
Target_x86_64()
- : Sized_target<64, false>(&x86_64_info),
- got_(NULL), plt_(NULL), got_plt_(NULL), rela_dyn_(NULL),
- copy_relocs_(elfcpp::R_X86_64_COPY), dynbss_(NULL),
- got_mod_index_offset_(-1U), tls_base_symbol_defined_(false)
+ : Target_freebsd<64, false>(&x86_64_info),
+ got_(NULL), plt_(NULL), got_plt_(NULL), global_offset_table_(NULL),
+ rela_dyn_(NULL), copy_relocs_(elfcpp::R_X86_64_COPY), dynbss_(NULL),
+ got_mod_index_offset_(-1U), tlsdesc_reloc_info_(),
+ tls_base_symbol_defined_(false)
{ }
+ // This function should be defined in targets that can use relocation
+ // types to determine (implemented in local_reloc_may_be_function_pointer
+ // and global_reloc_may_be_function_pointer)
+ // if a function's pointer is taken. ICF uses this in safe mode to only
+ // fold those functions whose pointer is defintely not taken. For x86_64
+ // pie binaries, safe ICF cannot be done by looking at relocation types.
+ inline bool
+ can_check_for_function_pointers() const
+ { return !parameters->options().pie(); }
+
+ // Hook for a new output section.
+ void
+ do_new_output_section(Output_section*) const;
+
+ // Scan the relocations to look for symbol adjustments.
+ void
+ gc_process_relocs(Symbol_table* symtab,
+ Layout* layout,
+ Sized_relobj<64, 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<64, 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<64>::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<64, 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 the symbol index to use for a target specific relocation.
+ // The only target specific relocation is R_X86_64_TLSDESC for a
+ // local symbol, which is an absolute reloc.
+ unsigned int
+ do_reloc_symbol_index(void*, unsigned int r_type) const
+ {
+ gold_assert(r_type == elfcpp::R_X86_64_TLSDESC);
+ return 0;
+ }
+
+ // Return the addend to use for a target specific relocation.
+ uint64_t
+ do_reloc_addend(void* arg, unsigned int r_type, uint64_t addend) 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()
return this->got_->data_size();
}
+ // Add a new reloc argument, returning the index in the vector.
+ size_t
+ add_tlsdesc_info(Sized_relobj<64, false>* object, unsigned int r_sym)
+ {
+ this->tlsdesc_reloc_info_.push_back(Tlsdesc_info(object, r_sym));
+ return this->tlsdesc_reloc_info_.size() - 1;
+ }
+
private:
// The class which scans relocations.
class Scan
{ }
inline void
- local(const General_options& options, Symbol_table* symtab,
- Layout* layout, Target_x86_64* target,
+ local(Symbol_table* symtab, Layout* layout, Target_x86_64* target,
Sized_relobj<64, false>* object,
unsigned int data_shndx,
Output_section* output_section,
const elfcpp::Sym<64, false>& lsym);
inline void
- global(const General_options& options, Symbol_table* symtab,
- Layout* layout, Target_x86_64* target,
+ global(Symbol_table* symtab, Layout* layout, Target_x86_64* target,
Sized_relobj<64, false>* object,
unsigned int data_shndx,
Output_section* output_section,
const elfcpp::Rela<64, false>& reloc, unsigned int r_type,
Symbol* gsym);
+ inline bool
+ local_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
+ Target_x86_64* target,
+ Sized_relobj<64, false>* object,
+ unsigned int data_shndx,
+ Output_section* output_section,
+ const elfcpp::Rela<64, false>& reloc,
+ unsigned int r_type,
+ const elfcpp::Sym<64, false>& lsym);
+
+ inline bool
+ global_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
+ Target_x86_64* target,
+ Sized_relobj<64, false>* object,
+ unsigned int data_shndx,
+ Output_section* output_section,
+ const elfcpp::Rela<64, false>& reloc,
+ unsigned int r_type,
+ Symbol* gsym);
+
private:
static void
unsupported_reloc_local(Sized_relobj<64, false>*, unsigned int r_type);
void
check_non_pic(Relobj*, unsigned int r_type);
+ inline bool
+ possible_function_pointer_reloc(unsigned int r_type);
+
// Whether we have issued an error about a non-PIC compilation.
bool issued_non_pic_error_;
};
{
public:
Relocate()
- : skip_call_tls_get_addr_(false)
+ : skip_call_tls_get_addr_(false), saw_tls_block_reloc_(false)
{ }
~Relocate()
// Do a relocation. Return false if the caller should not issue
// any warnings about this relocation.
inline bool
- relocate(const Relocate_info<64, false>*, Target_x86_64*, size_t relnum,
- const elfcpp::Rela<64, false>&,
+ relocate(const Relocate_info<64, false>*, Target_x86_64*, Output_section*,
+ size_t relnum, const elfcpp::Rela<64, false>&,
unsigned int r_type, const Sized_symbol<64>*,
const Symbol_value<64>*,
unsigned char*, elfcpp::Elf_types<64>::Elf_Addr,
// This is set if we should skip the next reloc, which should be a
// PLT32 reloc against ___tls_get_addr.
bool skip_call_tls_get_addr_;
+
+ // This is set if we see a relocation which could load the address
+ // of the TLS block. Whether we see such a relocation determines
+ // how we handle the R_X86_64_DTPOFF32 relocation, which is used
+ // in debugging sections.
+ bool saw_tls_block_reloc_;
};
// A class which returns the size required for a relocation type,
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*);
Reloc_section*
rela_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 TLSDESC relocations.
+ Reloc_section*
+ rela_tlsdesc_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<64, false>* object,
unsigned int shndx, Output_section* output_section,
Symbol* sym, const elfcpp::Rela<64, false>& reloc)
{
GOT_TYPE_TLS_DESC = 3 // GOT entry for TLS_DESC pair
};
+ // This type is used as the argument to the target specific
+ // relocation routines. The only target specific reloc is
+ // R_X86_64_TLSDESC against a local symbol.
+ struct Tlsdesc_info
+ {
+ Tlsdesc_info(Sized_relobj<64, false>* a_object, unsigned int a_r_sym)
+ : object(a_object), r_sym(a_r_sym)
+ { }
+
+ // The object in which the local symbol is defined.
+ Sized_relobj<64, false>* object;
+ // The local symbol index in the object.
+ unsigned int r_sym;
+ };
+
// The GOT section.
Output_data_got<64, false>* got_;
// The PLT section.
Output_data_plt_x86_64* plt_;
// The GOT PLT section.
Output_data_space* got_plt_;
+ // The _GLOBAL_OFFSET_TABLE_ symbol.
+ Symbol* global_offset_table_;
// The dynamic reloc section.
Reloc_section* rela_dyn_;
// Relocs saved to avoid a COPY reloc.
Output_data_space* dynbss_;
// Offset of the GOT entry for the TLS module index.
unsigned int got_mod_index_offset_;
+ // We handle R_X86_64_TLSDESC against a local symbol as a target
+ // specific relocation. Here we store the object and local symbol
+ // index for the relocation.
+ std::vector<Tlsdesc_info> tlsdesc_reloc_info_;
// True if the _TLS_MODULE_BASE_ symbol has been defined.
bool tls_base_symbol_defined_;
};
"/lib/ld64.so.1", // program interpreter
0x400000, // 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_X86_64_LCOMMON, // large_common_shndx
+ 0, // small_common_section_flags
+ elfcpp::SHF_X86_64_LARGE, // large_common_section_flags
+ NULL, // attributes_section
+ NULL // attributes_vendor
};
+// This is called when a new output section is created. This is where
+// we handle the SHF_X86_64_LARGE.
+
+void
+Target_x86_64::do_new_output_section(Output_section *os) const
+{
+ if ((os->flags() & elfcpp::SHF_X86_64_LARGE) != 0)
+ os->set_is_large_section();
+}
+
// Get the GOT section, creating it if necessary.
Output_data_got<64, false>*
this->got_ = new Output_data_got<64, false>();
- layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
- elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
- this->got_);
+ Output_section* os;
+ os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
+ (elfcpp::SHF_ALLOC
+ | elfcpp::SHF_WRITE),
+ this->got_, false, true, true,
+ false);
- // 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(8);
- layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
- elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
- this->got_plt_);
+ this->got_plt_ = new Output_data_space(8, "** GOT PLT");
+ os = 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 * 8);
+ // Those bytes can go into the relro segment.
+ layout->increase_relro(3 * 8);
+
// 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);
}
return this->got_;
gold_assert(layout != NULL);
this->rela_dyn_ = new Reloc_section(parameters->options().combreloc());
layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA,
- elfcpp::SHF_ALLOC, this->rela_dyn_);
+ elfcpp::SHF_ALLOC, this->rela_dyn_, true,
+ false, false, false);
}
return this->rela_dyn_;
}
get_tlsdesc_plt_offset() const
{ return (this->count_ + 1) * plt_entry_size; }
- // Return the .rel.plt section data.
+ // Return the .rela.plt section data.
const Reloc_section*
- rel_plt() const
+ rela_plt() const
{ return this->rel_; }
+ // Return where the TLSDESC relocations should go.
+ Reloc_section*
+ rela_tlsdesc(Layout*);
+
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 TLSDESC relocs, if necessary. These must follow the regular
+ // PLT relocs.
+ Reloc_section* tlsdesc_rel_;
// The .got section.
Output_data_got<64, false>* got_;
// The .got.plt section.
Output_data_plt_x86_64::Output_data_plt_x86_64(Layout* layout,
Output_data_got<64, false>* got,
Output_data_space* got_plt)
- : Output_section_data(8), got_(got), got_plt_(got_plt), count_(0),
- tlsdesc_got_offset_(-1U)
+ : Output_section_data(8), tlsdesc_rel_(NULL), got_(got), got_plt_(got_plt),
+ count_(0), tlsdesc_got_offset_(-1U)
{
this->rel_ = new Reloc_section(false);
layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
- elfcpp::SHF_ALLOC, this->rel_);
+ elfcpp::SHF_ALLOC, this->rel_, true,
+ false, false, false);
}
void
Output_data_plt_x86_64::do_adjust_output_section(Output_section* os)
{
- // UnixWare sets the entsize of .plt to 4, and so does the old GNU
- // linker, and so do we.
- os->set_entsize(4);
+ os->set_entsize(plt_entry_size);
}
// Add an entry to the PLT.
// appear in the relocations.
}
+// Return where the TLSDESC relocations should go, creating it if
+// necessary. These follow the JUMP_SLOT relocations.
+
+Output_data_plt_x86_64::Reloc_section*
+Output_data_plt_x86_64::rela_tlsdesc(Layout* layout)
+{
+ if (this->tlsdesc_rel_ == NULL)
+ {
+ this->tlsdesc_rel_ = new Reloc_section(false);
+ layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
+ elfcpp::SHF_ALLOC, this->tlsdesc_rel_,
+ true, false, false, false);
+ gold_assert(this->tlsdesc_rel_->output_section() ==
+ this->rel_->output_section());
+ }
+ return this->tlsdesc_rel_;
+}
+
// Set the final size.
void
Output_data_plt_x86_64::set_final_data_size()
unsigned char* pov = oview;
// The base address of the .plt section.
- elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address();
+ elfcpp::Elf_types<64>::Elf_Addr plt_address = this->address();
// The base address of the .got section.
- elfcpp::Elf_types<32>::Elf_Addr got_base = this->got_->address();
+ elfcpp::Elf_types<64>::Elf_Addr got_base = this->got_->address();
// The base address of the PLT portion of the .got section,
// which is where the GOT pointer will point, and where the
// three reserved GOT entries are located.
- elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address();
+ elfcpp::Elf_types<64>::Elf_Addr got_address = this->got_plt_->address();
memcpy(pov, first_plt_entry, plt_entry_size);
// We do a jmp relative to the PC at the end of this instruction.
- elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 8
- - (plt_address + 6));
- elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 16
- - (plt_address + 12));
+ elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
+ (got_address + 8
+ - (plt_address + 6)));
+ elfcpp::Swap<32, false>::writeval(pov + 8,
+ (got_address + 16
+ - (plt_address + 12)));
pov += plt_entry_size;
unsigned char* got_pov = got_view;
layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
(elfcpp::SHF_ALLOC
| elfcpp::SHF_EXECINSTR),
- this->plt_);
+ this->plt_, false, false, false, false);
}
}
+// Return the section for TLSDESC relocations.
+
+Target_x86_64::Reloc_section*
+Target_x86_64::rela_tlsdesc_section(Layout* layout) const
+{
+ return this->plt_section()->rela_tlsdesc(layout);
+}
+
// Create a PLT entry for a global symbol.
void
this->plt_->add_entry(gsym);
}
-// Define the _TLS_MODULE_BASE_ symbol at the end of the TLS segment.
+// Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
void
Target_x86_64::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;
}
// error per object file.
if (this->issued_non_pic_error_)
return;
+ gold_assert(parameters->options().output_is_position_independent());
object->error(_("requires unsupported dynamic reloc; "
"recompile with -fPIC"));
this->issued_non_pic_error_ = true;
// Scan a relocation for a local symbol.
inline void
-Target_x86_64::Scan::local(const General_options&,
- Symbol_table* symtab,
+Target_x86_64::Scan::local(Symbol_table* symtab,
Layout* layout,
Target_x86_64* target,
Sized_relobj<64, false>* object,
Output_data_got<64, false>* got
= target->got_section(symtab, layout);
unsigned int r_sym = elfcpp::elf_r_sym<64>(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_rela(object, r_sym,
- shndx,
- GOT_TYPE_TLS_DESC,
- target->rela_dyn_section(layout),
- elfcpp::R_X86_64_TLSDESC, 0);
+ if (!object->local_has_got_offset(r_sym, GOT_TYPE_TLS_DESC))
+ {
+ unsigned int got_offset = got->add_constant(0);
+ got->add_constant(0);
+ object->set_local_got_offset(r_sym, GOT_TYPE_TLS_DESC,
+ got_offset);
+ Reloc_section* rt = target->rela_tlsdesc_section(layout);
+ // We store the arguments we need in a vector, and
+ // use the index into the vector as the parameter
+ // to pass to the target specific routines.
+ uintptr_t intarg = target->add_tlsdesc_info(object, r_sym);
+ void* arg = reinterpret_cast<void*>(intarg);
+ rt->add_target_specific(elfcpp::R_X86_64_TLSDESC, arg,
+ got, got_offset, 0);
+ }
}
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());
}
+// Returns true if this relocation type could be that of a function pointer
+// only if the target is not position-independent code.
+inline bool
+Target_x86_64::Scan::possible_function_pointer_reloc(unsigned int r_type)
+{
+ if (parameters->options().shared())
+ return false;
+
+ switch (r_type)
+ {
+ case elfcpp::R_X86_64_64:
+ case elfcpp::R_X86_64_32:
+ case elfcpp::R_X86_64_32S:
+ case elfcpp::R_X86_64_16:
+ case elfcpp::R_X86_64_8:
+ {
+ return true;
+ }
+ }
+ return false;
+}
+
+// For safe ICF, scan a relocation for a local symbol to check if it
+// corresponds to a function pointer being taken. In that case mark
+// the function whose pointer was taken as not foldable.
+
+inline bool
+Target_x86_64::Scan::local_reloc_may_be_function_pointer(
+ Symbol_table* ,
+ Layout* ,
+ Target_x86_64* ,
+ Sized_relobj<64, false>* ,
+ unsigned int ,
+ Output_section* ,
+ const elfcpp::Rela<64, false>& ,
+ unsigned int r_type,
+ const elfcpp::Sym<64, false>&)
+{
+ // When building a shared library, do not fold any local symbols as it is
+ // not possible to distinguish pointer taken versus a call by looking at
+ // the relocation types.
+ return (parameters->options().shared()
+ || possible_function_pointer_reloc(r_type));
+}
+
+// For safe ICF, scan a relocation for a global symbol to check if it
+// corresponds to a function pointer being taken. In that case mark
+// the function whose pointer was taken as not foldable.
+
+inline bool
+Target_x86_64::Scan::global_reloc_may_be_function_pointer(
+ Symbol_table*,
+ Layout* ,
+ Target_x86_64* ,
+ Sized_relobj<64, false>* ,
+ unsigned int ,
+ Output_section* ,
+ const elfcpp::Rela<64, false>& ,
+ unsigned int r_type,
+ Symbol* gsym)
+{
+ // When building a shared library, do not fold symbols whose visibility
+ // is hidden, internal or protected.
+ return ((parameters->options().shared()
+ && (gsym->visibility() == elfcpp::STV_INTERNAL
+ || gsym->visibility() == elfcpp::STV_PROTECTED
+ || gsym->visibility() == elfcpp::STV_HIDDEN))
+ || possible_function_pointer_reloc(r_type));
+}
+
// Scan a relocation for a global symbol.
inline void
-Target_x86_64::Scan::global(const General_options&,
- Symbol_table* symtab,
+Target_x86_64::Scan::global(Symbol_table* symtab,
Layout* layout,
Target_x86_64* target,
Sized_relobj<64, 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);
target->make_plt_entry(symtab, layout, gsym);
// 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);
// Create a double GOT entry with an R_X86_64_TLSDESC reloc.
Output_data_got<64, false>* got
= target->got_section(symtab, layout);
- got->add_global_pair_with_rela(gsym, GOT_TYPE_TLS_DESC,
- target->rela_dyn_section(layout),
+ Reloc_section *rt = target->rela_tlsdesc_section(layout);
+ got->add_global_pair_with_rela(gsym, GOT_TYPE_TLS_DESC, rt,
elfcpp::R_X86_64_TLSDESC, 0);
}
else if (optimized_type == tls::TLSOPT_TO_IE)
}
}
+void
+Target_x86_64::gc_process_relocs(Symbol_table* symtab,
+ Layout* layout,
+ Sized_relobj<64, 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)
+{
+
+ if (sh_type == elfcpp::SHT_REL)
+ {
+ return;
+ }
+
+ gold::gc_process_relocs<64, false, Target_x86_64, elfcpp::SHT_RELA,
+ Target_x86_64::Scan>(
+ 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_x86_64::scan_relocs(const General_options& options,
- Symbol_table* symtab,
+Target_x86_64::scan_relocs(Symbol_table* symtab,
Layout* layout,
Sized_relobj<64, false>* object,
unsigned int data_shndx,
gold::scan_relocs<64, false, Target_x86_64, elfcpp::SHT_RELA,
Target_x86_64::Scan>(
- options,
symtab,
layout,
this,
// Finalize the sections.
void
-Target_x86_64::do_finalize_sections(Layout* layout)
+Target_x86_64::do_finalize_sections(
+ Layout* layout,
+ const Input_objects*,
+ Symbol_table* symtab)
{
+ const Reloc_section* rel_plt = (this->plt_ == NULL
+ ? NULL
+ : this->plt_->rela_plt());
+ layout->add_target_dynamic_tags(false, this->got_plt_, rel_plt,
+ this->rela_dyn_, true, false);
+
// 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_RELA);
- if (this->plt_->has_tlsdesc_entry())
- {
- unsigned int plt_offset = this->plt_->get_tlsdesc_plt_offset();
- unsigned int got_offset = this->plt_->get_tlsdesc_got_offset();
- this->got_->finalize_data_size();
- odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_PLT,
- this->plt_, plt_offset);
- odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_GOT,
- this->got_, got_offset);
- }
- }
-
- if (this->rela_dyn_ != NULL)
- {
- const Output_data* od = this->rela_dyn_;
- odyn->add_section_address(elfcpp::DT_RELA, od);
- odyn->add_section_size(elfcpp::DT_RELASZ, od);
- odyn->add_constant(elfcpp::DT_RELAENT,
- elfcpp::Elf_sizes<64>::rela_size);
- }
-
- if (!parameters->options().shared())
+ if (this->plt_ != NULL
+ && this->plt_->output_section() != NULL
+ && this->plt_->has_tlsdesc_entry())
{
- // 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);
+ unsigned int plt_offset = this->plt_->get_tlsdesc_plt_offset();
+ unsigned int got_offset = this->plt_->get_tlsdesc_got_offset();
+ this->got_->finalize_data_size();
+ odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_PLT,
+ this->plt_, plt_offset);
+ odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_GOT,
+ this->got_, got_offset);
}
}
// relocs.
if (this->copy_relocs_.any_saved_relocs())
this->copy_relocs_.emit(this->rela_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)
+ {
+ uint64_t data_size = this->got_plt_->current_data_size();
+ symtab->get_sized_symbol<64>(sym)->set_symsize(data_size);
+ }
}
// Perform a relocation.
inline bool
Target_x86_64::Relocate::relocate(const Relocate_info<64, false>* relinfo,
Target_x86_64* target,
+ Output_section*,
size_t relnum,
const elfcpp::Rela<64, false>& rela,
unsigned int r_type,
{
if (this->skip_call_tls_get_addr_)
{
- if (r_type != elfcpp::R_X86_64_PLT32
+ if ((r_type != elfcpp::R_X86_64_PLT32
+ && r_type != elfcpp::R_X86_64_PC32)
|| gsym == NULL
|| strcmp(gsym->name(), "__tls_get_addr") != 0)
{
// Pick the value to use for symbols defined in shared objects.
Symbol_value<64> symval;
if (gsym != NULL
- && (gsym->is_from_dynobj()
- || (parameters->options().shared()
- && (gsym->is_undefined() || gsym->is_preemptible())))
- && gsym->has_plt_offset())
+ && gsym->use_plt_offset(r_type == elfcpp::R_X86_64_PC64
+ || r_type == elfcpp::R_X86_64_PC32
+ || r_type == elfcpp::R_X86_64_PC16
+ || r_type == elfcpp::R_X86_64_PC8))
{
symval.set_output_value(target->plt_section()->address()
+ gsym->plt_offset());
elfcpp::Elf_types<64>::Elf_Addr value = psymval->value(relinfo->object, 0);
const bool is_final = (gsym == NULL
- ? !parameters->options().output_is_position_independent()
+ ? !parameters->options().shared()
: gsym->final_value_is_known());
const tls::Tls_optimization optimized_type
= Target_x86_64::optimize_tls_reloc(is_final, r_type);
switch (r_type)
{
case elfcpp::R_X86_64_TLSGD: // Global-dynamic
+ this->saw_tls_block_reloc_ = true;
if (optimized_type == tls::TLSOPT_TO_LE)
{
gold_assert(tls_segment != NULL);
case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url)
case elfcpp::R_X86_64_TLSDESC_CALL:
+ this->saw_tls_block_reloc_ = true;
if (optimized_type == tls::TLSOPT_TO_LE)
{
gold_assert(tls_segment != NULL);
break;
case elfcpp::R_X86_64_TLSLD: // Local-dynamic
+ this->saw_tls_block_reloc_ = true;
if (optimized_type == tls::TLSOPT_TO_LE)
{
gold_assert(tls_segment != NULL);
break;
case elfcpp::R_X86_64_DTPOFF32:
- gold_assert(tls_segment != NULL);
if (optimized_type == tls::TLSOPT_TO_LE)
- value -= tls_segment->memsz();
- Relocate_functions<64, false>::rela32(view, value, 0);
+ {
+ // This relocation type is used in debugging information.
+ // In that case we need to not optimize the value. If we
+ // haven't seen a TLSLD reloc, then we assume we should not
+ // optimize this reloc.
+ if (this->saw_tls_block_reloc_)
+ {
+ gold_assert(tls_segment != NULL);
+ value -= tls_segment->memsz();
+ }
+ }
+ Relocate_functions<64, false>::rela32(view, value, addend);
break;
case elfcpp::R_X86_64_DTPOFF64:
- gold_assert(tls_segment != NULL);
if (optimized_type == tls::TLSOPT_TO_LE)
- value -= tls_segment->memsz();
- Relocate_functions<64, false>::rela64(view, value, 0);
+ {
+ // See R_X86_64_DTPOFF32, just above, for why we test this.
+ if (this->saw_tls_block_reloc_)
+ {
+ gold_assert(tls_segment != NULL);
+ value -= tls_segment->memsz();
+ }
+ }
+ Relocate_functions<64, false>::rela64(view, value, addend);
break;
case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
case elfcpp::R_X86_64_TPOFF32: // Local-exec
value -= tls_segment->memsz();
- Relocate_functions<64, false>::rela32(view, value, 0);
+ Relocate_functions<64, false>::rela32(view, value, addend);
break;
}
}
// Relocate section data.
void
-Target_x86_64::relocate_section(const Relocate_info<64, false>* relinfo,
- unsigned int sh_type,
- const unsigned char* prelocs,
- size_t reloc_count,
- Output_section* output_section,
- bool needs_special_offset_handling,
- unsigned char* view,
- elfcpp::Elf_types<64>::Elf_Addr address,
- section_size_type view_size)
+Target_x86_64::relocate_section(
+ const Relocate_info<64, false>* relinfo,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ bool needs_special_offset_handling,
+ unsigned char* view,
+ elfcpp::Elf_types<64>::Elf_Addr address,
+ section_size_type view_size,
+ const Reloc_symbol_changes* reloc_symbol_changes)
{
gold_assert(sh_type == elfcpp::SHT_RELA);
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_x86_64::scan_relocatable_relocs(const General_options& options,
- Symbol_table* symtab,
+Target_x86_64::scan_relocatable_relocs(Symbol_table* symtab,
Layout* layout,
Sized_relobj<64, false>* object,
unsigned int data_shndx,
gold::scan_relocatable_relocs<64, false, elfcpp::SHT_RELA,
Scan_relocatable_relocs>(
- options,
symtab,
layout,
object,
// Nop sequences of various lengths.
const char nop1[1] = { 0x90 }; // nop
const char nop2[2] = { 0x66, 0x90 }; // xchg %ax %ax
- const char nop3[3] = { 0x8d, 0x76, 0x00 }; // leal 0(%esi),%esi
- const char nop4[4] = { 0x8d, 0x74, 0x26, 0x00}; // leal 0(%esi,1),%esi
- const char nop5[5] = { 0x90, 0x8d, 0x74, 0x26, // nop
- 0x00 }; // leal 0(%esi,1),%esi
- const char nop6[6] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
+ const char nop3[3] = { 0x0f, 0x1f, 0x00 }; // nop (%rax)
+ const char nop4[4] = { 0x0f, 0x1f, 0x40, 0x00}; // nop 0(%rax)
+ const char nop5[5] = { 0x0f, 0x1f, 0x44, 0x00, // nop 0(%rax,%rax,1)
+ 0x00 };
+ const char nop6[6] = { 0x66, 0x0f, 0x1f, 0x44, // nopw 0(%rax,%rax,1)
0x00, 0x00 };
- const char nop7[7] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
+ const char nop7[7] = { 0x0f, 0x1f, 0x80, 0x00, // nopl 0L(%rax)
0x00, 0x00, 0x00 };
- const char nop8[8] = { 0x90, 0x8d, 0xb4, 0x26, // nop
- 0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
- const char nop9[9] = { 0x89, 0xf6, 0x8d, 0xbc, // movl %esi,%esi
- 0x27, 0x00, 0x00, 0x00, // leal 0L(%edi,1),%edi
+ const char nop8[8] = { 0x0f, 0x1f, 0x84, 0x00, // nopl 0L(%rax,%rax,1)
+ 0x00, 0x00, 0x00, 0x00 };
+ const char nop9[9] = { 0x66, 0x0f, 0x1f, 0x84, // nopw 0L(%rax,%rax,1)
+ 0x00, 0x00, 0x00, 0x00,
0x00 };
- const char nop10[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
- 0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
+ const char nop10[10] = { 0x66, 0x2e, 0x0f, 0x1f, // nopw %cs:0L(%rax,%rax,1)
+ 0x84, 0x00, 0x00, 0x00,
0x00, 0x00 };
- const char nop11[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
- 0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
+ const char nop11[11] = { 0x66, 0x66, 0x2e, 0x0f, // data16
+ 0x1f, 0x84, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1)
0x00, 0x00, 0x00 };
- const char nop12[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
- 0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
+ const char nop12[12] = { 0x66, 0x66, 0x66, 0x2e, // data16; data16
+ 0x0f, 0x1f, 0x84, 0x00, // nopw %cs:0L(%rax,%rax,1)
0x00, 0x00, 0x00, 0x00 };
- const char nop13[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
- 0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
- 0x27, 0x00, 0x00, 0x00,
+ const char nop13[13] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16
+ 0x2e, 0x0f, 0x1f, 0x84, // nopw %cs:0L(%rax,%rax,1)
+ 0x00, 0x00, 0x00, 0x00,
0x00 };
- const char nop14[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
- 0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
- 0xbc, 0x27, 0x00, 0x00,
+ const char nop14[14] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16
+ 0x66, 0x2e, 0x0f, 0x1f, // data16
+ 0x84, 0x00, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1)
0x00, 0x00 };
- const char nop15[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
- 0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
- 0x90, 0x90, 0x90, 0x90,
- 0x90, 0x90, 0x90 };
+ const char nop15[15] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16
+ 0x66, 0x66, 0x2e, 0x0f, // data16; data16
+ 0x1f, 0x84, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1)
+ 0x00, 0x00, 0x00 };
const char* nops[16] = {
NULL,
return std::string(nops[length], length);
}
+// Return the addend to use for a target specific relocation. The
+// only target specific relocation is R_X86_64_TLSDESC for a local
+// symbol. We want to set the addend is the offset of the local
+// symbol in the TLS segment.
+
+uint64_t
+Target_x86_64::do_reloc_addend(void* arg, unsigned int r_type,
+ uint64_t) const
+{
+ gold_assert(r_type == elfcpp::R_X86_64_TLSDESC);
+ uintptr_t intarg = reinterpret_cast<uintptr_t>(arg);
+ gold_assert(intarg < this->tlsdesc_reloc_info_.size());
+ const Tlsdesc_info& ti(this->tlsdesc_reloc_info_[intarg]);
+ const Symbol_value<64>* psymval = ti.object->local_symbol(ti.r_sym);
+ gold_assert(psymval->is_tls_symbol());
+ // The value of a TLS symbol is the offset in the TLS segment.
+ return psymval->value(ti.object, 0);
+}
+
+// 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_x86_64::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 %fs:NN,%rsp
+ if (this->match_view(view, view_size, fnoffset, "\x64\x48\x3b\x24\x25", 5)
+ && fnsize > 9)
+ {
+ // 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, 8);
+ }
+ // lea NN(%rsp),%r10
+ // lea NN(%rsp),%r11
+ else if ((this->match_view(view, view_size, fnoffset,
+ "\x4c\x8d\x94\x24", 4)
+ || this->match_view(view, view_size, fnoffset,
+ "\x4c\x8d\x9c\x24", 4))
+ && fnsize > 8)
+ {
+ // 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 + 4;
+ 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 x86_64 object files.
-class Target_selector_x86_64 : public Target_selector
+class Target_selector_x86_64 : public Target_selector_freebsd
{
public:
Target_selector_x86_64()
- : Target_selector(elfcpp::EM_X86_64, 64, false, "elf64-x86-64")
+ : Target_selector_freebsd(elfcpp::EM_X86_64, 64, false, "elf64-x86-64",
+ "elf64-x86-64-freebsd")
{ }
Target*
do_instantiate_target()
{ return new Target_x86_64(); }
+
};
Target_selector_x86_64 target_selector_x86_64;
projects / binutils-gdb.git / blobdiff