// i386.cc -- i386 target support for gold.
+// Copyright 2006, 2007, 2008 Free Software Foundation, Inc.
+
+// This file is part of gold.
+
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
+// MA 02110-1301, USA.
+
#include "gold.h"
+
+#include <cstring>
+
#include "elfcpp.h"
+#include "parameters.h"
+#include "reloc.h"
+#include "i386.h"
+#include "object.h"
+#include "symtab.h"
+#include "layout.h"
+#include "output.h"
#include "target.h"
+#include "target-reloc.h"
#include "target-select.h"
+#include "tls.h"
namespace
{
using namespace gold;
+class Output_data_plt_i386;
+
// The i386 target class.
+// TLS info comes from
+// 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>
{
public:
+ typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
+
Target_i386()
- : Sized_target<32, false>(&i386_info)
+ : Sized_target<32, false>(&i386_info),
+ got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL),
+ copy_relocs_(NULL), dynbss_(NULL), got_mod_index_offset_(-1U)
{ }
+ // Scan the relocations to look for symbol adjustments.
+ void
+ scan_relocs(const General_options& options,
+ 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);
+
+ // Finalize the sections.
+ void
+ do_finalize_sections(Layout*);
+
+ // Return the value to use for a dynamic which requires special
+ // treatment.
+ uint64_t
+ do_dynsym_value(const Symbol*) const;
+
+ // Relocate a section.
+ void
+ relocate_section(const Relocate_info<32, false>*,
+ 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<32>::Elf_Addr view_address,
+ section_size_type view_size);
+
+ // Scan the relocs during a relocatable link.
+ void
+ scan_relocatable_relocs(const General_options& options,
+ 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,
+ Relocatable_relocs*);
+
+ // Relocate a section during a relocatable link.
+ void
+ relocate_for_relocatable(const Relocate_info<32, false>*,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ off_t offset_in_output_section,
+ const Relocatable_relocs*,
+ unsigned char* view,
+ elfcpp::Elf_types<32>::Elf_Addr view_address,
+ section_size_type view_size,
+ unsigned char* reloc_view,
+ section_size_type reloc_view_size);
+
+ // Return a string used to fill a code section with nops.
+ std::string
+ do_code_fill(section_size_type length) const;
+
+ // Return whether SYM is defined by the ABI.
+ bool
+ do_is_defined_by_abi(Symbol* sym) const
+ { return strcmp(sym->name(), "___tls_get_addr") == 0; }
+
+ // Return the size of the GOT section.
+ section_size_type
+ got_size()
+ {
+ gold_assert(this->got_ != NULL);
+ return this->got_->data_size();
+ }
+
private:
+ // The class which scans relocations.
+ struct Scan
+ {
+ inline void
+ local(const General_options& options, 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 void
+ global(const General_options& options, 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);
+
+ static void
+ unsupported_reloc_local(Sized_relobj<32, false>*, unsigned int r_type);
+
+ static void
+ unsupported_reloc_global(Sized_relobj<32, false>*, unsigned int r_type,
+ Symbol*);
+ };
+
+ // The class which implements relocation.
+ class Relocate
+ {
+ public:
+ Relocate()
+ : skip_call_tls_get_addr_(false),
+ local_dynamic_type_(LOCAL_DYNAMIC_NONE)
+ { }
+
+ ~Relocate()
+ {
+ if (this->skip_call_tls_get_addr_)
+ {
+ // FIXME: This needs to specify the location somehow.
+ gold_error(_("missing expected TLS relocation"));
+ }
+ }
+
+ // Return whether the static relocation needs to be applied.
+ inline bool
+ should_apply_static_reloc(const Sized_symbol<32>* gsym,
+ int ref_flags,
+ bool is_32bit);
+
+ // 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>&,
+ unsigned int r_type, const Sized_symbol<32>*,
+ const Symbol_value<32>*,
+ unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
+ section_size_type);
+
+ private:
+ // Do a TLS relocation.
+ inline void
+ relocate_tls(const Relocate_info<32, false>*, Target_i386* target,
+ 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,
+ section_size_type);
+
+ // Do a TLS General-Dynamic to Initial-Exec transition.
+ inline void
+ tls_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
+ Output_segment* tls_segment,
+ const elfcpp::Rel<32, false>&, unsigned int r_type,
+ elfcpp::Elf_types<32>::Elf_Addr value,
+ unsigned char* view,
+ section_size_type view_size);
+
+ // Do a TLS General-Dynamic to Local-Exec transition.
+ inline void
+ tls_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
+ Output_segment* tls_segment,
+ const elfcpp::Rel<32, false>&, unsigned int r_type,
+ elfcpp::Elf_types<32>::Elf_Addr value,
+ unsigned char* view,
+ section_size_type view_size);
+
+ // Do a TLS Local-Dynamic to Local-Exec transition.
+ inline void
+ tls_ld_to_le(const Relocate_info<32, false>*, size_t relnum,
+ Output_segment* tls_segment,
+ const elfcpp::Rel<32, false>&, unsigned int r_type,
+ elfcpp::Elf_types<32>::Elf_Addr value,
+ unsigned char* view,
+ section_size_type view_size);
+
+ // Do a TLS Initial-Exec to Local-Exec transition.
+ static inline void
+ tls_ie_to_le(const Relocate_info<32, false>*, size_t relnum,
+ Output_segment* tls_segment,
+ const elfcpp::Rel<32, false>&, unsigned int r_type,
+ elfcpp::Elf_types<32>::Elf_Addr value,
+ unsigned char* view,
+ section_size_type view_size);
+
+ // We need to keep track of which type of local dynamic relocation
+ // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
+ enum Local_dynamic_type
+ {
+ LOCAL_DYNAMIC_NONE,
+ LOCAL_DYNAMIC_SUN,
+ LOCAL_DYNAMIC_GNU
+ };
+
+ // 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_;
+ // The type of local dynamic relocation we have seen in the section
+ // being relocated, if any.
+ Local_dynamic_type local_dynamic_type_;
+ };
+
+ // A class which returns the size required for a relocation type,
+ // used while scanning relocs during a relocatable link.
+ class Relocatable_size_for_reloc
+ {
+ public:
+ unsigned int
+ get_size_for_reloc(unsigned int, Relobj*);
+ };
+
+ // Adjust TLS relocation type based on the options and whether this
+ // is a local symbol.
+ static tls::Tls_optimization
+ optimize_tls_reloc(bool is_final, int r_type);
+
+ // Get the GOT section, creating it if necessary.
+ Output_data_got<32, false>*
+ got_section(Symbol_table*, Layout*);
+
+ // Get the GOT PLT section.
+ Output_data_space*
+ got_plt_section() const
+ {
+ gold_assert(this->got_plt_ != NULL);
+ return this->got_plt_;
+ }
+
+ // Create a PLT entry for a global symbol.
+ void
+ make_plt_entry(Symbol_table*, Layout*, Symbol*);
+
+ // Create a GOT entry for the TLS module index.
+ unsigned int
+ got_mod_index_entry(Symbol_table* symtab, Layout* layout,
+ Sized_relobj<32, false>* object);
+
+ // Get the PLT section.
+ const Output_data_plt_i386*
+ plt_section() const
+ {
+ gold_assert(this->plt_ != NULL);
+ return this->plt_;
+ }
+
+ // Get the dynamic reloc section, creating it if necessary.
+ 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);
+ }
+
+ // Copy a relocation against a global symbol.
+ void
+ copy_reloc(const General_options*, Symbol_table*, Layout*,
+ Sized_relobj<32, false>*, unsigned int,
+ Output_section*, Symbol*, const elfcpp::Rel<32, false>&);
+
+ // Information about this specific target which we pass to the
+ // general Target structure.
static const Target::Target_info i386_info;
+
+ // The types of GOT entries needed for this platform.
+ enum Got_type
+ {
+ GOT_TYPE_STANDARD = 0, // GOT entry for a regular symbol
+ GOT_TYPE_TLS_OFFSET = 1, // GOT entry for TLS offset
+ GOT_TYPE_TLS_PAIR = 2, // GOT entry for TLS module/offset pair
+ GOT_TYPE_TLS_DESC = 3 // GOT entry for TLS_DESC pair
+ };
+
+ // The GOT section.
+ Output_data_got<32, false>* got_;
+ // The PLT section.
+ Output_data_plt_i386* plt_;
+ // The GOT PLT section.
+ Output_data_space* got_plt_;
+ // The dynamic reloc section.
+ Reloc_section* rel_dyn_;
+ // Relocs saved to avoid a COPY reloc.
+ Copy_relocs<32, false>* copy_relocs_;
+ // Space for variables copied with a COPY reloc.
+ Output_data_space* dynbss_;
+ // Offset of the GOT entry for the TLS module index;
+ unsigned int got_mod_index_offset_;
};
const Target::Target_info Target_i386::i386_info =
{
- 32, // size
- false, // is_big_endian
- false, // has_make_symbol
- false, // has_resolve,
- 0x08048000, // text_segment_address,
- 0x1000, // abi_pagesize
- 0x1000 // common_pagesize
+ 32, // size
+ false, // is_big_endian
+ elfcpp::EM_386, // machine_code
+ false, // has_make_symbol
+ false, // has_resolve
+ true, // has_code_fill
+ true, // is_default_stack_executable
+ "/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)
};
+// Get the GOT section, creating it if necessary.
+
+Output_data_got<32, false>*
+Target_i386::got_section(Symbol_table* symtab, Layout* layout)
+{
+ if (this->got_ == NULL)
+ {
+ gold_assert(symtab != NULL && layout != NULL);
+
+ this->got_ = new Output_data_got<32, false>();
+
+ layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
+ elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
+ this->got_);
+
+ // 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);
+ layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
+ elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
+ this->got_plt_);
+
+ // The first three entries are reserved.
+ this->got_plt_->set_current_data_size(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);
+ }
+
+ return this->got_;
+}
+
+// Get the dynamic reloc section, creating it if necessary.
+
+Target_i386::Reloc_section*
+Target_i386::rel_dyn_section(Layout* layout)
+{
+ if (this->rel_dyn_ == NULL)
+ {
+ gold_assert(layout != NULL);
+ this->rel_dyn_ = new Reloc_section();
+ layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
+ elfcpp::SHF_ALLOC, this->rel_dyn_);
+ }
+ return this->rel_dyn_;
+}
+
+// A class to handle the PLT data.
+
+class Output_data_plt_i386 : public Output_section_data
+{
+ public:
+ typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
+
+ Output_data_plt_i386(Layout*, Output_data_space*);
+
+ // Add an entry to the PLT.
+ void
+ add_entry(Symbol* gsym);
+
+ // Return the .rel.plt section data.
+ const Reloc_section*
+ rel_plt() const
+ { return this->rel_; }
+
+ protected:
+ void
+ do_adjust_output_section(Output_section* os);
+
+ private:
+ // The size of an entry in the PLT.
+ static const int plt_entry_size = 16;
+
+ // The first entry in the PLT for an executable.
+ static unsigned char exec_first_plt_entry[plt_entry_size];
+
+ // The first entry in the PLT for a shared object.
+ static unsigned char dyn_first_plt_entry[plt_entry_size];
+
+ // Other entries in the PLT for an executable.
+ static unsigned char exec_plt_entry[plt_entry_size];
+
+ // Other entries in the PLT for a shared object.
+ static unsigned char dyn_plt_entry[plt_entry_size];
+
+ // Set the final size.
+ void
+ set_final_data_size()
+ { this->set_data_size((this->count_ + 1) * plt_entry_size); }
+
+ // Write out the PLT data.
+ void
+ do_write(Output_file*);
+
+ // The reloc section.
+ Reloc_section* rel_;
+ // The .got.plt section.
+ Output_data_space* got_plt_;
+ // The number of PLT entries.
+ unsigned int count_;
+};
+
+// Create the PLT section. The ordinary .got section is an argument,
+// since we need to refer to the start. We also create our own .got
+// section just for PLT entries.
+
+Output_data_plt_i386::Output_data_plt_i386(Layout* layout,
+ Output_data_space* got_plt)
+ : Output_section_data(4), got_plt_(got_plt), count_(0)
+{
+ this->rel_ = new Reloc_section();
+ layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
+ elfcpp::SHF_ALLOC, this->rel_);
+}
+
+void
+Output_data_plt_i386::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);
+}
+
+// Add an entry to the PLT.
+
+void
+Output_data_plt_i386::add_entry(Symbol* gsym)
+{
+ gold_assert(!gsym->has_plt_offset());
+
+ // Note that when setting the PLT offset we skip the initial
+ // reserved PLT entry.
+ gsym->set_plt_offset((this->count_ + 1) * plt_entry_size);
+
+ ++this->count_;
+
+ section_offset_type got_offset = this->got_plt_->current_data_size();
+
+ // Every PLT entry needs a GOT entry which points back to the PLT
+ // entry (this will be changed by the dynamic linker, normally
+ // lazily when the function is called).
+ this->got_plt_->set_current_data_size(got_offset + 4);
+
+ // Every PLT entry needs a reloc.
+ gsym->set_needs_dynsym_entry();
+ this->rel_->add_global(gsym, elfcpp::R_386_JUMP_SLOT, this->got_plt_,
+ got_offset);
+
+ // 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.
+}
+
+// The first entry in the PLT for an executable.
+
+unsigned char Output_data_plt_i386::exec_first_plt_entry[plt_entry_size] =
+{
+ 0xff, 0x35, // pushl contents of memory address
+ 0, 0, 0, 0, // replaced with address of .got + 4
+ 0xff, 0x25, // jmp indirect
+ 0, 0, 0, 0, // replaced with address of .got + 8
+ 0, 0, 0, 0 // unused
+};
+
+// The first entry in the PLT for a shared object.
+
+unsigned char Output_data_plt_i386::dyn_first_plt_entry[plt_entry_size] =
+{
+ 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
+ 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx)
+ 0, 0, 0, 0 // unused
+};
+
+// Subsequent entries in the PLT for an executable.
+
+unsigned char Output_data_plt_i386::exec_plt_entry[plt_entry_size] =
+{
+ 0xff, 0x25, // jmp indirect
+ 0, 0, 0, 0, // replaced with address of symbol in .got
+ 0x68, // pushl immediate
+ 0, 0, 0, 0, // replaced with offset into relocation table
+ 0xe9, // jmp relative
+ 0, 0, 0, 0 // replaced with offset to start of .plt
+};
+
+// Subsequent entries in the PLT for a shared object.
+
+unsigned char Output_data_plt_i386::dyn_plt_entry[plt_entry_size] =
+{
+ 0xff, 0xa3, // jmp *offset(%ebx)
+ 0, 0, 0, 0, // replaced with offset of symbol in .got
+ 0x68, // pushl immediate
+ 0, 0, 0, 0, // replaced with offset into relocation table
+ 0xe9, // jmp relative
+ 0, 0, 0, 0 // replaced with offset to start of .plt
+};
+
+// Write out the PLT. This uses the hand-coded instructions above,
+// and adjusts them as needed. This is all specified by the i386 ELF
+// Processor Supplement.
+
+void
+Output_data_plt_i386::do_write(Output_file* of)
+{
+ const off_t offset = this->offset();
+ const section_size_type oview_size =
+ convert_to_section_size_type(this->data_size());
+ unsigned char* const oview = of->get_output_view(offset, oview_size);
+
+ const off_t got_file_offset = this->got_plt_->offset();
+ const section_size_type got_size =
+ convert_to_section_size_type(this->got_plt_->data_size());
+ unsigned char* const got_view = of->get_output_view(got_file_offset,
+ got_size);
+
+ unsigned char* pov = oview;
+
+ 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())
+ memcpy(pov, dyn_first_plt_entry, plt_entry_size);
+ else
+ {
+ memcpy(pov, exec_first_plt_entry, plt_entry_size);
+ elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4);
+ elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8);
+ }
+ pov += plt_entry_size;
+
+ unsigned char* got_pov = got_view;
+
+ memset(got_pov, 0, 12);
+ got_pov += 12;
+
+ const int rel_size = elfcpp::Elf_sizes<32>::rel_size;
+
+ unsigned int plt_offset = plt_entry_size;
+ unsigned int plt_rel_offset = 0;
+ unsigned int got_offset = 12;
+ const unsigned int count = this->count_;
+ for (unsigned int i = 0;
+ i < count;
+ ++i,
+ pov += plt_entry_size,
+ got_pov += 4,
+ plt_offset += plt_entry_size,
+ plt_rel_offset += rel_size,
+ got_offset += 4)
+ {
+ // Set and adjust the PLT entry itself.
+
+ if (parameters->options().shared())
+ {
+ memcpy(pov, dyn_plt_entry, plt_entry_size);
+ elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset);
+ }
+ else
+ {
+ memcpy(pov, exec_plt_entry, plt_entry_size);
+ elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
+ (got_address
+ + got_offset));
+ }
+
+ elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset);
+ elfcpp::Swap<32, false>::writeval(pov + 12,
+ - (plt_offset + plt_entry_size));
+
+ // Set the entry in the GOT.
+ elfcpp::Swap<32, false>::writeval(got_pov, plt_address + plt_offset + 6);
+ }
+
+ gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
+ gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
+
+ of->write_output_view(offset, oview_size, oview);
+ of->write_output_view(got_file_offset, got_size, got_view);
+}
+
+// Create a PLT entry for a global symbol.
+
+void
+Target_i386::make_plt_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym)
+{
+ if (gsym->has_plt_offset())
+ return;
+
+ if (this->plt_ == NULL)
+ {
+ // Create the GOT sections first.
+ this->got_section(symtab, layout);
+
+ this->plt_ = new Output_data_plt_i386(layout, this->got_plt_);
+ layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
+ (elfcpp::SHF_ALLOC
+ | elfcpp::SHF_EXECINSTR),
+ this->plt_);
+ }
+
+ this->plt_->add_entry(gsym);
+}
+
+// Create a GOT entry for the TLS module index.
+
+unsigned int
+Target_i386::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
+ Sized_relobj<32, false>* object)
+{
+ if (this->got_mod_index_offset_ == -1U)
+ {
+ gold_assert(symtab != NULL && layout != NULL && object != NULL);
+ Reloc_section* rel_dyn = this->rel_dyn_section(layout);
+ Output_data_got<32, false>* got = this->got_section(symtab, layout);
+ unsigned int got_offset = got->add_constant(0);
+ rel_dyn->add_local(object, 0, elfcpp::R_386_TLS_DTPMOD32, got,
+ got_offset);
+ got->add_constant(0);
+ this->got_mod_index_offset_ = got_offset;
+ }
+ return this->got_mod_index_offset_;
+}
+
+// Handle a relocation against a non-function symbol defined in a
+// dynamic object. The traditional way to handle this is to generate
+// a COPY relocation to copy the variable at runtime from the shared
+// object into the executable's data segment. However, this is
+// undesirable in general, as if the size of the object changes in the
+// dynamic object, the executable will no longer work correctly. If
+// this relocation is in a writable section, then we can create a
+// dynamic reloc and the dynamic linker will resolve it to the correct
+// address at runtime. However, we do not want do that if the
+// relocation is in a read-only section, as it would prevent the
+// readonly segment from being shared. And if we have to eventually
+// generate a COPY reloc, then any dynamic relocations will be
+// useless. So this means that if this is a writable section, we need
+// to save the relocation until we see whether we have to create a
+// COPY relocation for this symbol for any other relocation.
+
+void
+Target_i386::copy_reloc(const General_options* options,
+ Symbol_table* symtab,
+ Layout* layout,
+ Sized_relobj<32, false>* object,
+ unsigned int data_shndx,
+ Output_section* output_section,
+ Symbol* gsym,
+ const elfcpp::Rel<32, false>& rel)
+{
+ Sized_symbol<32>* ssym = symtab->get_sized_symbol<32>(gsym);
+
+ if (!Copy_relocs<32, false>::need_copy_reloc(options, object,
+ data_shndx, ssym))
+ {
+ // So far we do not need a COPY reloc. Save this relocation.
+ // If it turns out that we never need a COPY reloc for this
+ // symbol, then we will emit the relocation.
+ if (this->copy_relocs_ == NULL)
+ this->copy_relocs_ = new Copy_relocs<32, false>();
+ this->copy_relocs_->save(ssym, object, data_shndx, output_section, rel);
+ }
+ else
+ {
+ // Allocate space for this symbol in the .bss section.
+
+ elfcpp::Elf_types<32>::Elf_WXword symsize = ssym->symsize();
+
+ // There is no defined way to determine the required alignment
+ // of the symbol. We pick the alignment based on the size. We
+ // set an arbitrary maximum of 256.
+ unsigned int align;
+ for (align = 1; align < 512; align <<= 1)
+ if ((symsize & align) != 0)
+ break;
+
+ if (this->dynbss_ == NULL)
+ {
+ this->dynbss_ = new Output_data_space(align);
+ layout->add_output_section_data(".bss",
+ elfcpp::SHT_NOBITS,
+ (elfcpp::SHF_ALLOC
+ | elfcpp::SHF_WRITE),
+ this->dynbss_);
+ }
+
+ Output_data_space* dynbss = this->dynbss_;
+
+ if (align > dynbss->addralign())
+ dynbss->set_space_alignment(align);
+
+ section_size_type dynbss_size =
+ convert_to_section_size_type(dynbss->current_data_size());
+ dynbss_size = align_address(dynbss_size, align);
+ section_size_type offset = dynbss_size;
+ dynbss->set_current_data_size(dynbss_size + symsize);
+
+ symtab->define_with_copy_reloc(ssym, dynbss, offset);
+
+ // Add the COPY reloc.
+ Reloc_section* rel_dyn = this->rel_dyn_section(layout);
+ rel_dyn->add_global(ssym, elfcpp::R_386_COPY, dynbss, offset);
+ }
+}
+
+// Optimize the TLS relocation type based on what we know about the
+// symbol. IS_FINAL is true if the final address of this symbol is
+// known at link time.
+
+tls::Tls_optimization
+Target_i386::optimize_tls_reloc(bool is_final, int r_type)
+{
+ // If we are generating a shared library, then we can't do anything
+ // in the linker.
+ if (parameters->options().shared())
+ return tls::TLSOPT_NONE;
+
+ switch (r_type)
+ {
+ case elfcpp::R_386_TLS_GD:
+ case elfcpp::R_386_TLS_GOTDESC:
+ case elfcpp::R_386_TLS_DESC_CALL:
+ // These are General-Dynamic which permits fully general TLS
+ // access. Since we know that we are generating an executable,
+ // we can convert this to Initial-Exec. If we also know that
+ // this is a local symbol, we can further switch to Local-Exec.
+ if (is_final)
+ return tls::TLSOPT_TO_LE;
+ return tls::TLSOPT_TO_IE;
+
+ case elfcpp::R_386_TLS_LDM:
+ // This is Local-Dynamic, which refers to a local symbol in the
+ // dynamic TLS block. Since we know that we generating an
+ // executable, we can switch to Local-Exec.
+ return tls::TLSOPT_TO_LE;
+
+ case elfcpp::R_386_TLS_LDO_32:
+ // Another type of Local-Dynamic relocation.
+ return tls::TLSOPT_TO_LE;
+
+ case elfcpp::R_386_TLS_IE:
+ case elfcpp::R_386_TLS_GOTIE:
+ case elfcpp::R_386_TLS_IE_32:
+ // These are Initial-Exec relocs which get the thread offset
+ // from the GOT. If we know that we are linking against the
+ // local symbol, we can switch to Local-Exec, which links the
+ // thread offset into the instruction.
+ if (is_final)
+ return tls::TLSOPT_TO_LE;
+ return tls::TLSOPT_NONE;
+
+ case elfcpp::R_386_TLS_LE:
+ case elfcpp::R_386_TLS_LE_32:
+ // When we already have Local-Exec, there is nothing further we
+ // can do.
+ return tls::TLSOPT_NONE;
+
+ default:
+ gold_unreachable();
+ }
+}
+
+// Report an unsupported relocation against a local symbol.
+
+void
+Target_i386::Scan::unsupported_reloc_local(Sized_relobj<32, false>* object,
+ unsigned int r_type)
+{
+ gold_error(_("%s: unsupported reloc %u against local symbol"),
+ object->name().c_str(), r_type);
+}
+
+// Scan a relocation for a local symbol.
+
+inline void
+Target_i386::Scan::local(const General_options&,
+ 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)
+{
+ switch (r_type)
+ {
+ case elfcpp::R_386_NONE:
+ case elfcpp::R_386_GNU_VTINHERIT:
+ case elfcpp::R_386_GNU_VTENTRY:
+ break;
+
+ case elfcpp::R_386_32:
+ // If building a shared library (or a position-independent
+ // executable), we need to create a dynamic relocation for
+ // this location. The relocation applied at link time will
+ // apply the link-time value, so we flag the location with
+ // an R_386_RELATIVE relocation so the dynamic loader can
+ // relocate it easily.
+ if (parameters->options().output_is_position_independent())
+ {
+ Reloc_section* rel_dyn = target->rel_dyn_section(layout);
+ unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
+ rel_dyn->add_local_relative(object, r_sym, elfcpp::R_386_RELATIVE,
+ output_section, data_shndx,
+ reloc.get_r_offset());
+ }
+ break;
+
+ case elfcpp::R_386_16:
+ case elfcpp::R_386_8:
+ // If building a shared library (or a position-independent
+ // executable), we need to create a dynamic relocation for
+ // this location. Because the addend needs to remain in the
+ // data section, we need to be careful not to apply this
+ // relocation statically.
+ if (parameters->options().output_is_position_independent())
+ {
+ Reloc_section* rel_dyn = target->rel_dyn_section(layout);
+ if (lsym.get_st_type() != elfcpp::STT_SECTION)
+ {
+ unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
+ rel_dyn->add_local(object, r_sym, r_type, output_section,
+ data_shndx, reloc.get_r_offset());
+ }
+ else
+ {
+ gold_assert(lsym.get_st_value() == 0);
+ rel_dyn->add_local_section(object, lsym.get_st_shndx(),
+ r_type, output_section,
+ data_shndx, reloc.get_r_offset());
+ }
+ }
+ break;
+
+ case elfcpp::R_386_PC32:
+ case elfcpp::R_386_PC16:
+ case elfcpp::R_386_PC8:
+ break;
+
+ case elfcpp::R_386_PLT32:
+ // Since we know this is a local symbol, we can handle this as a
+ // PC32 reloc.
+ break;
+
+ case elfcpp::R_386_GOTOFF:
+ case elfcpp::R_386_GOTPC:
+ // We need a GOT section.
+ target->got_section(symtab, layout);
+ break;
+
+ case elfcpp::R_386_GOT32:
+ {
+ // The symbol requires a GOT entry.
+ Output_data_got<32, false>* got = target->got_section(symtab, layout);
+ unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
+ if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
+ {
+ // If we are generating a shared object, we need to add a
+ // dynamic RELATIVE relocation for this symbol's GOT entry.
+ if (parameters->options().output_is_position_independent())
+ {
+ Reloc_section* rel_dyn = target->rel_dyn_section(layout);
+ unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
+ rel_dyn->add_local_relative(
+ object, r_sym, elfcpp::R_386_RELATIVE, got,
+ object->local_got_offset(r_sym, GOT_TYPE_STANDARD));
+ }
+ }
+ }
+ break;
+
+ // These are relocations which should only be seen by the
+ // dynamic linker, and should never be seen here.
+ case elfcpp::R_386_COPY:
+ case elfcpp::R_386_GLOB_DAT:
+ case elfcpp::R_386_JUMP_SLOT:
+ case elfcpp::R_386_RELATIVE:
+ case elfcpp::R_386_TLS_TPOFF:
+ case elfcpp::R_386_TLS_DTPMOD32:
+ case elfcpp::R_386_TLS_DTPOFF32:
+ case elfcpp::R_386_TLS_TPOFF32:
+ case elfcpp::R_386_TLS_DESC:
+ gold_error(_("%s: unexpected reloc %u in object file"),
+ object->name().c_str(), r_type);
+ break;
+
+ // These are initial TLS relocs, which are expected when
+ // linking.
+ case elfcpp::R_386_TLS_GD: // Global-dynamic
+ case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
+ case elfcpp::R_386_TLS_DESC_CALL:
+ case elfcpp::R_386_TLS_LDM: // Local-dynamic
+ case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
+ case elfcpp::R_386_TLS_IE: // Initial-exec
+ case elfcpp::R_386_TLS_IE_32:
+ case elfcpp::R_386_TLS_GOTIE:
+ case elfcpp::R_386_TLS_LE: // Local-exec
+ case elfcpp::R_386_TLS_LE_32:
+ {
+ bool output_is_shared = parameters->options().shared();
+ const tls::Tls_optimization optimized_type
+ = Target_i386::optimize_tls_reloc(!output_is_shared, r_type);
+ switch (r_type)
+ {
+ case elfcpp::R_386_TLS_GD: // Global-dynamic
+ if (optimized_type == tls::TLSOPT_NONE)
+ {
+ // Create a pair of GOT entries for the module index and
+ // dtv-relative offset.
+ Output_data_got<32, false>* got
+ = target->got_section(symtab, layout);
+ unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
+ got->add_local_pair_with_rel(object, r_sym,
+ lsym.get_st_shndx(),
+ GOT_TYPE_TLS_PAIR,
+ target->rel_dyn_section(layout),
+ elfcpp::R_386_TLS_DTPMOD32, 0);
+ }
+ else if (optimized_type != tls::TLSOPT_TO_LE)
+ unsupported_reloc_local(object, r_type);
+ break;
+
+ case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva)
+ case elfcpp::R_386_TLS_DESC_CALL:
+ // FIXME: If not relaxing to LE, we need to generate
+ // a GOT entry with an R_386_TLS_DESC reloc.
+ if (optimized_type != tls::TLSOPT_TO_LE)
+ unsupported_reloc_local(object, r_type);
+ break;
+
+ case elfcpp::R_386_TLS_LDM: // Local-dynamic
+ if (optimized_type == tls::TLSOPT_NONE)
+ {
+ // Create a GOT entry for the module index.
+ target->got_mod_index_entry(symtab, layout, object);
+ }
+ else if (optimized_type != tls::TLSOPT_TO_LE)
+ unsupported_reloc_local(object, r_type);
+ break;
+
+ case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
+ break;
+
+ case elfcpp::R_386_TLS_IE: // Initial-exec
+ case elfcpp::R_386_TLS_IE_32:
+ case elfcpp::R_386_TLS_GOTIE:
+ layout->set_has_static_tls();
+ if (optimized_type == tls::TLSOPT_NONE)
+ {
+ // For the R_386_TLS_IE relocation, we need to create a
+ // dynamic relocation when building a shared library.
+ if (r_type == elfcpp::R_386_TLS_IE
+ && parameters->options().shared())
+ {
+ Reloc_section* rel_dyn = target->rel_dyn_section(layout);
+ unsigned int r_sym
+ = elfcpp::elf_r_sym<32>(reloc.get_r_info());
+ rel_dyn->add_local_relative(object, r_sym,
+ elfcpp::R_386_RELATIVE,
+ output_section, data_shndx,
+ reloc.get_r_offset());
+ }
+ // Create a GOT entry for the tp-relative offset.
+ Output_data_got<32, false>* got
+ = target->got_section(symtab, layout);
+ unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
+ unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
+ ? elfcpp::R_386_TLS_TPOFF32
+ : elfcpp::R_386_TLS_TPOFF);
+ got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET,
+ target->rel_dyn_section(layout),
+ dyn_r_type);
+ }
+ else if (optimized_type != tls::TLSOPT_TO_LE)
+ unsupported_reloc_local(object, r_type);
+ break;
+
+ case elfcpp::R_386_TLS_LE: // Local-exec
+ case elfcpp::R_386_TLS_LE_32:
+ layout->set_has_static_tls();
+ if (output_is_shared)
+ {
+ // We need to create a dynamic relocation.
+ gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
+ unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
+ unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
+ ? elfcpp::R_386_TLS_TPOFF32
+ : elfcpp::R_386_TLS_TPOFF);
+ Reloc_section* rel_dyn = target->rel_dyn_section(layout);
+ rel_dyn->add_local(object, r_sym, dyn_r_type, output_section,
+ data_shndx, reloc.get_r_offset());
+ }
+ break;
+
+ default:
+ gold_unreachable();
+ }
+ }
+ break;
+
+ case elfcpp::R_386_32PLT:
+ case elfcpp::R_386_TLS_GD_32:
+ case elfcpp::R_386_TLS_GD_PUSH:
+ case elfcpp::R_386_TLS_GD_CALL:
+ case elfcpp::R_386_TLS_GD_POP:
+ case elfcpp::R_386_TLS_LDM_32:
+ case elfcpp::R_386_TLS_LDM_PUSH:
+ case elfcpp::R_386_TLS_LDM_CALL:
+ case elfcpp::R_386_TLS_LDM_POP:
+ case elfcpp::R_386_USED_BY_INTEL_200:
+ default:
+ unsupported_reloc_local(object, r_type);
+ break;
+ }
+}
+
+// Report an unsupported relocation against a global symbol.
+
+void
+Target_i386::Scan::unsupported_reloc_global(Sized_relobj<32, false>* object,
+ unsigned int r_type,
+ Symbol* gsym)
+{
+ gold_error(_("%s: unsupported reloc %u against global symbol %s"),
+ object->name().c_str(), r_type, gsym->demangled_name().c_str());
+}
+
+// Scan a relocation for a global symbol.
+
+inline void
+Target_i386::Scan::global(const General_options& options,
+ 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)
+{
+ switch (r_type)
+ {
+ case elfcpp::R_386_NONE:
+ case elfcpp::R_386_GNU_VTINHERIT:
+ case elfcpp::R_386_GNU_VTENTRY:
+ break;
+
+ case elfcpp::R_386_32:
+ case elfcpp::R_386_16:
+ case elfcpp::R_386_8:
+ {
+ // Make a PLT entry if necessary.
+ if (gsym->needs_plt_entry())
+ {
+ target->make_plt_entry(symtab, layout, gsym);
+ // Since this is not a PC-relative relocation, we may be
+ // taking the address of a function. In that case we need to
+ // set the entry in the dynamic symbol table to the address of
+ // the PLT entry.
+ if (gsym->is_from_dynobj() && !parameters->options().shared())
+ gsym->set_needs_dynsym_value();
+ }
+ // Make a dynamic relocation if necessary.
+ if (gsym->needs_dynamic_reloc(Symbol::ABSOLUTE_REF))
+ {
+ if (target->may_need_copy_reloc(gsym))
+ {
+ target->copy_reloc(&options, symtab, layout, object,
+ data_shndx, output_section, gsym, reloc);
+ }
+ else if (r_type == elfcpp::R_386_32
+ && gsym->can_use_relative_reloc(false))
+ {
+ Reloc_section* rel_dyn = target->rel_dyn_section(layout);
+ rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
+ output_section, object,
+ data_shndx, reloc.get_r_offset());
+ }
+ else
+ {
+ Reloc_section* rel_dyn = target->rel_dyn_section(layout);
+ rel_dyn->add_global(gsym, r_type, output_section, object,
+ data_shndx, reloc.get_r_offset());
+ }
+ }
+ }
+ break;
+
+ case elfcpp::R_386_PC32:
+ case elfcpp::R_386_PC16:
+ case elfcpp::R_386_PC8:
+ {
+ // Make a PLT entry if necessary.
+ if (gsym->needs_plt_entry())
+ {
+ // These relocations are used for function calls only in
+ // non-PIC code. For a 32-bit relocation in a shared library,
+ // we'll need a text relocation anyway, so we can skip the
+ // PLT entry and let the dynamic linker bind the call directly
+ // to the target. For smaller relocations, we should use a
+ // PLT entry to ensure that the call can reach.
+ if (!parameters->options().shared()
+ || r_type != elfcpp::R_386_PC32)
+ 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)
+ flags |= Symbol::FUNCTION_CALL;
+ if (gsym->needs_dynamic_reloc(flags))
+ {
+ if (target->may_need_copy_reloc(gsym))
+ {
+ target->copy_reloc(&options, symtab, layout, object,
+ data_shndx, output_section, gsym, reloc);
+ }
+ else
+ {
+ Reloc_section* rel_dyn = target->rel_dyn_section(layout);
+ rel_dyn->add_global(gsym, r_type, output_section, object,
+ data_shndx, reloc.get_r_offset());
+ }
+ }
+ }
+ break;
+
+ case elfcpp::R_386_GOT32:
+ {
+ // The symbol requires a GOT entry.
+ Output_data_got<32, false>* got = target->got_section(symtab, layout);
+ if (gsym->final_value_is_known())
+ got->add_global(gsym, GOT_TYPE_STANDARD);
+ else
+ {
+ // If this symbol is not fully resolved, we need to add a
+ // GOT entry with a dynamic relocation.
+ Reloc_section* rel_dyn = target->rel_dyn_section(layout);
+ if (gsym->is_from_dynobj()
+ || gsym->is_undefined()
+ || gsym->is_preemptible())
+ got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
+ rel_dyn, elfcpp::R_386_GLOB_DAT);
+ else
+ {
+ if (got->add_global(gsym, GOT_TYPE_STANDARD))
+ rel_dyn->add_global_relative(
+ gsym, elfcpp::R_386_RELATIVE, got,
+ gsym->got_offset(GOT_TYPE_STANDARD));
+ }
+ }
+ }
+ break;
+
+ case elfcpp::R_386_PLT32:
+ // If the symbol is fully resolved, this is just a PC32 reloc.
+ // Otherwise we need a PLT entry.
+ if (gsym->final_value_is_known())
+ break;
+ // If building a shared library, we can also skip the PLT entry
+ // if the symbol is defined in the output file and is protected
+ // or hidden.
+ if (gsym->is_defined()
+ && !gsym->is_from_dynobj()
+ && !gsym->is_preemptible())
+ break;
+ target->make_plt_entry(symtab, layout, gsym);
+ break;
+
+ case elfcpp::R_386_GOTOFF:
+ case elfcpp::R_386_GOTPC:
+ // We need a GOT section.
+ target->got_section(symtab, layout);
+ break;
+
+ // These are relocations which should only be seen by the
+ // dynamic linker, and should never be seen here.
+ case elfcpp::R_386_COPY:
+ case elfcpp::R_386_GLOB_DAT:
+ case elfcpp::R_386_JUMP_SLOT:
+ case elfcpp::R_386_RELATIVE:
+ case elfcpp::R_386_TLS_TPOFF:
+ case elfcpp::R_386_TLS_DTPMOD32:
+ case elfcpp::R_386_TLS_DTPOFF32:
+ case elfcpp::R_386_TLS_TPOFF32:
+ case elfcpp::R_386_TLS_DESC:
+ gold_error(_("%s: unexpected reloc %u in object file"),
+ object->name().c_str(), r_type);
+ break;
+
+ // These are initial tls relocs, which are expected when
+ // linking.
+ case elfcpp::R_386_TLS_GD: // Global-dynamic
+ case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
+ case elfcpp::R_386_TLS_DESC_CALL:
+ case elfcpp::R_386_TLS_LDM: // Local-dynamic
+ case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
+ case elfcpp::R_386_TLS_IE: // Initial-exec
+ case elfcpp::R_386_TLS_IE_32:
+ case elfcpp::R_386_TLS_GOTIE:
+ case elfcpp::R_386_TLS_LE: // Local-exec
+ case elfcpp::R_386_TLS_LE_32:
+ {
+ const bool is_final = gsym->final_value_is_known();
+ const tls::Tls_optimization optimized_type
+ = Target_i386::optimize_tls_reloc(is_final, r_type);
+ switch (r_type)
+ {
+ case elfcpp::R_386_TLS_GD: // Global-dynamic
+ if (optimized_type == tls::TLSOPT_NONE)
+ {
+ // Create a pair of GOT entries for the module index and
+ // dtv-relative offset.
+ Output_data_got<32, false>* got
+ = target->got_section(symtab, layout);
+ got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
+ target->rel_dyn_section(layout),
+ elfcpp::R_386_TLS_DTPMOD32,
+ elfcpp::R_386_TLS_DTPOFF32);
+ }
+ else if (optimized_type == tls::TLSOPT_TO_IE)
+ {
+ // Create a GOT entry for the tp-relative offset.
+ Output_data_got<32, false>* got
+ = target->got_section(symtab, layout);
+ got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
+ target->rel_dyn_section(layout),
+ elfcpp::R_386_TLS_TPOFF32);
+ }
+ else if (optimized_type != tls::TLSOPT_TO_LE)
+ unsupported_reloc_global(object, r_type, gsym);
+ break;
+
+ case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (~oliva url)
+ case elfcpp::R_386_TLS_DESC_CALL:
+ // FIXME: If not relaxing to LE, we need to generate
+ // a GOT entry with an R_386_TLS_DESC reloc.
+ if (optimized_type != tls::TLSOPT_TO_LE)
+ unsupported_reloc_global(object, r_type, gsym);
+ unsupported_reloc_global(object, r_type, gsym);
+ break;
+
+ case elfcpp::R_386_TLS_LDM: // Local-dynamic
+ if (optimized_type == tls::TLSOPT_NONE)
+ {
+ // Create a GOT entry for the module index.
+ target->got_mod_index_entry(symtab, layout, object);
+ }
+ else if (optimized_type != tls::TLSOPT_TO_LE)
+ unsupported_reloc_global(object, r_type, gsym);
+ break;
+
+ case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
+ break;
+
+ case elfcpp::R_386_TLS_IE: // Initial-exec
+ case elfcpp::R_386_TLS_IE_32:
+ case elfcpp::R_386_TLS_GOTIE:
+ layout->set_has_static_tls();
+ if (optimized_type == tls::TLSOPT_NONE)
+ {
+ // For the R_386_TLS_IE relocation, we need to create a
+ // dynamic relocation when building a shared library.
+ if (r_type == elfcpp::R_386_TLS_IE
+ && parameters->options().shared())
+ {
+ Reloc_section* rel_dyn = target->rel_dyn_section(layout);
+ rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
+ output_section, object,
+ data_shndx,
+ reloc.get_r_offset());
+ }
+ // Create a GOT entry for the tp-relative offset.
+ Output_data_got<32, false>* got
+ = target->got_section(symtab, layout);
+ unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
+ ? elfcpp::R_386_TLS_TPOFF32
+ : elfcpp::R_386_TLS_TPOFF);
+ got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
+ target->rel_dyn_section(layout),
+ dyn_r_type);
+ }
+ else if (optimized_type != tls::TLSOPT_TO_LE)
+ unsupported_reloc_global(object, r_type, gsym);
+ break;
+
+ case elfcpp::R_386_TLS_LE: // Local-exec
+ case elfcpp::R_386_TLS_LE_32:
+ layout->set_has_static_tls();
+ if (parameters->options().shared())
+ {
+ // We need to create a dynamic relocation.
+ unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
+ ? elfcpp::R_386_TLS_TPOFF32
+ : elfcpp::R_386_TLS_TPOFF);
+ Reloc_section* rel_dyn = target->rel_dyn_section(layout);
+ rel_dyn->add_global(gsym, dyn_r_type, output_section, object,
+ data_shndx, reloc.get_r_offset());
+ }
+ break;
+
+ default:
+ gold_unreachable();
+ }
+ }
+ break;
+
+ case elfcpp::R_386_32PLT:
+ case elfcpp::R_386_TLS_GD_32:
+ case elfcpp::R_386_TLS_GD_PUSH:
+ case elfcpp::R_386_TLS_GD_CALL:
+ case elfcpp::R_386_TLS_GD_POP:
+ case elfcpp::R_386_TLS_LDM_32:
+ case elfcpp::R_386_TLS_LDM_PUSH:
+ case elfcpp::R_386_TLS_LDM_CALL:
+ case elfcpp::R_386_TLS_LDM_POP:
+ case elfcpp::R_386_USED_BY_INTEL_200:
+ default:
+ unsupported_reloc_global(object, r_type, gsym);
+ break;
+ }
+}
+
+// Scan relocations for a section.
+
+void
+Target_i386::scan_relocs(const General_options& options,
+ 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)
+{
+ if (sh_type == elfcpp::SHT_RELA)
+ {
+ gold_error(_("%s: unsupported RELA reloc section"),
+ object->name().c_str());
+ return;
+ }
+
+ gold::scan_relocs<32, false, Target_i386, elfcpp::SHT_REL,
+ Target_i386::Scan>(
+ options,
+ symtab,
+ layout,
+ this,
+ object,
+ data_shndx,
+ prelocs,
+ reloc_count,
+ output_section,
+ needs_special_offset_handling,
+ local_symbol_count,
+ plocal_symbols);
+}
+
+// Finalize the sections.
+
+void
+Target_i386::do_finalize_sections(Layout* layout)
+{
+ // 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);
+ }
+ }
+
+ // Emit any relocs we saved in an attempt to avoid generating COPY
+ // relocs.
+ if (this->copy_relocs_ == NULL)
+ return;
+ if (this->copy_relocs_->any_to_emit())
+ {
+ Reloc_section* rel_dyn = this->rel_dyn_section(layout);
+ this->copy_relocs_->emit(rel_dyn);
+ }
+ delete this->copy_relocs_;
+ this->copy_relocs_ = NULL;
+}
+
+// Return whether a direct absolute static relocation needs to be applied.
+// In cases where Scan::local() or Scan::global() has created
+// a dynamic relocation other than R_386_RELATIVE, the addend
+// of the relocation is carried in the data, and we must not
+// apply the static relocation.
+
+inline bool
+Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol<32>* gsym,
+ int ref_flags,
+ bool is_32bit)
+{
+ // 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
+ // (c) the relocation is not 32 bits wide.
+ if (gsym == NULL)
+ return !(parameters->options().output_is_position_independent()
+ && (ref_flags & Symbol::ABSOLUTE_REF)
+ && !is_32bit);
+
+ // For global symbols, we use the same helper routines used in the
+ // scan pass. If we did not create a dynamic relocation, or if we
+ // created a RELATIVE dynamic relocation, we should apply the static
+ // relocation.
+ bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
+ bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
+ && gsym->can_use_relative_reloc(ref_flags
+ & Symbol::FUNCTION_CALL);
+ return !has_dyn || is_rel;
+}
+
+// Perform a relocation.
+
+inline bool
+Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo,
+ Target_i386* target,
+ size_t relnum,
+ const elfcpp::Rel<32, false>& rel,
+ unsigned int r_type,
+ const Sized_symbol<32>* gsym,
+ const Symbol_value<32>* psymval,
+ unsigned char* view,
+ elfcpp::Elf_types<32>::Elf_Addr address,
+ section_size_type view_size)
+{
+ if (this->skip_call_tls_get_addr_)
+ {
+ if (r_type != elfcpp::R_386_PLT32
+ || gsym == NULL
+ || strcmp(gsym->name(), "___tls_get_addr") != 0)
+ gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
+ _("missing expected TLS relocation"));
+ else
+ {
+ this->skip_call_tls_get_addr_ = false;
+ return false;
+ }
+ }
+
+ // 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()))
+ {
+ symval.set_output_value(target->plt_section()->address()
+ + gsym->plt_offset());
+ psymval = &symval;
+ }
+
+ const Sized_relobj<32, false>* object = relinfo->object;
+
+ // Get the GOT offset if needed.
+ // The GOT pointer points to the end of the GOT section.
+ // We need to subtract the size of the GOT section to get
+ // the actual offset to use in the relocation.
+ bool have_got_offset = false;
+ unsigned int got_offset = 0;
+ switch (r_type)
+ {
+ case elfcpp::R_386_GOT32:
+ if (gsym != NULL)
+ {
+ gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
+ got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
+ - 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_STANDARD));
+ got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
+ - target->got_size());
+ }
+ have_got_offset = true;
+ break;
+
+ default:
+ break;
+ }
+
+ switch (r_type)
+ {
+ case elfcpp::R_386_NONE:
+ case elfcpp::R_386_GNU_VTINHERIT:
+ case elfcpp::R_386_GNU_VTENTRY:
+ break;
+
+ case elfcpp::R_386_32:
+ if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true))
+ 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)
+ ref_flags |= Symbol::FUNCTION_CALL;
+ if (should_apply_static_reloc(gsym, ref_flags, true))
+ 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))
+ 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)
+ ref_flags |= Symbol::FUNCTION_CALL;
+ if (should_apply_static_reloc(gsym, ref_flags, false))
+ Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
+ }
+ break;
+
+ case elfcpp::R_386_8:
+ if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false))
+ 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)
+ ref_flags |= Symbol::FUNCTION_CALL;
+ if (should_apply_static_reloc(gsym, ref_flags, false))
+ Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
+ }
+ break;
+
+ case elfcpp::R_386_PLT32:
+ gold_assert(gsym == NULL
+ || gsym->has_plt_offset()
+ || gsym->final_value_is_known()
+ || (gsym->is_defined()
+ && !gsym->is_from_dynobj()
+ && !gsym->is_preemptible()));
+ Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
+ break;
+
+ case elfcpp::R_386_GOT32:
+ gold_assert(have_got_offset);
+ Relocate_functions<32, false>::rel32(view, got_offset);
+ break;
+
+ case elfcpp::R_386_GOTOFF:
+ {
+ elfcpp::Elf_types<32>::Elf_Addr value;
+ value = (psymval->value(object, 0)
+ - target->got_plt_section()->address());
+ Relocate_functions<32, false>::rel32(view, value);
+ }
+ break;
+
+ case elfcpp::R_386_GOTPC:
+ {
+ elfcpp::Elf_types<32>::Elf_Addr value;
+ value = target->got_plt_section()->address();
+ Relocate_functions<32, false>::pcrel32(view, value, address);
+ }
+ break;
+
+ case elfcpp::R_386_COPY:
+ case elfcpp::R_386_GLOB_DAT:
+ case elfcpp::R_386_JUMP_SLOT:
+ case elfcpp::R_386_RELATIVE:
+ // These are outstanding tls relocs, which are unexpected when
+ // linking.
+ case elfcpp::R_386_TLS_TPOFF:
+ case elfcpp::R_386_TLS_DTPMOD32:
+ case elfcpp::R_386_TLS_DTPOFF32:
+ case elfcpp::R_386_TLS_TPOFF32:
+ case elfcpp::R_386_TLS_DESC:
+ gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
+ _("unexpected reloc %u in object file"),
+ r_type);
+ break;
+
+ // These are initial tls relocs, which are expected when
+ // linking.
+ case elfcpp::R_386_TLS_GD: // Global-dynamic
+ case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
+ case elfcpp::R_386_TLS_DESC_CALL:
+ case elfcpp::R_386_TLS_LDM: // Local-dynamic
+ case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
+ case elfcpp::R_386_TLS_IE: // Initial-exec
+ case elfcpp::R_386_TLS_IE_32:
+ case elfcpp::R_386_TLS_GOTIE:
+ case elfcpp::R_386_TLS_LE: // Local-exec
+ case elfcpp::R_386_TLS_LE_32:
+ this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
+ view, address, view_size);
+ break;
+
+ case elfcpp::R_386_32PLT:
+ case elfcpp::R_386_TLS_GD_32:
+ case elfcpp::R_386_TLS_GD_PUSH:
+ case elfcpp::R_386_TLS_GD_CALL:
+ case elfcpp::R_386_TLS_GD_POP:
+ case elfcpp::R_386_TLS_LDM_32:
+ case elfcpp::R_386_TLS_LDM_PUSH:
+ case elfcpp::R_386_TLS_LDM_CALL:
+ case elfcpp::R_386_TLS_LDM_POP:
+ case elfcpp::R_386_USED_BY_INTEL_200:
+ default:
+ gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
+ _("unsupported reloc %u"),
+ r_type);
+ break;
+ }
+
+ return true;
+}
+
+// Perform a TLS relocation.
+
+inline void
+Target_i386::Relocate::relocate_tls(const Relocate_info<32, false>* relinfo,
+ Target_i386* target,
+ size_t relnum,
+ const elfcpp::Rel<32, false>& rel,
+ unsigned int r_type,
+ const Sized_symbol<32>* gsym,
+ const Symbol_value<32>* psymval,
+ unsigned char* view,
+ elfcpp::Elf_types<32>::Elf_Addr,
+ section_size_type view_size)
+{
+ Output_segment* tls_segment = relinfo->layout->tls_segment();
+
+ const Sized_relobj<32, false>* object = relinfo->object;
+
+ 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 tls::Tls_optimization optimized_type
+ = Target_i386::optimize_tls_reloc(is_final, r_type);
+ switch (r_type)
+ {
+ case elfcpp::R_386_TLS_GD: // Global-dynamic
+ if (optimized_type == tls::TLSOPT_TO_LE)
+ {
+ gold_assert(tls_segment != NULL);
+ this->tls_gd_to_le(relinfo, relnum, tls_segment,
+ rel, r_type, value, view,
+ view_size);
+ break;
+ }
+ else
+ {
+ unsigned int got_offset;
+ if (gsym != NULL)
+ {
+ gold_assert(gsym->has_got_offset(GOT_TYPE_TLS_PAIR));
+ got_offset = (gsym->got_offset(GOT_TYPE_TLS_PAIR)
+ - 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_TLS_PAIR));
+ got_offset = (object->local_got_offset(r_sym, GOT_TYPE_TLS_PAIR)
+ - target->got_size());
+ }
+ if (optimized_type == tls::TLSOPT_TO_IE)
+ {
+ gold_assert(tls_segment != NULL);
+ this->tls_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type,
+ got_offset, view, view_size);
+ break;
+ }
+ else if (optimized_type == tls::TLSOPT_NONE)
+ {
+ // Relocate the field with the offset of the pair of GOT
+ // entries.
+ Relocate_functions<32, false>::rel32(view, got_offset);
+ break;
+ }
+ }
+ gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
+ _("unsupported reloc %u"),
+ r_type);
+ break;
+
+ case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
+ case elfcpp::R_386_TLS_DESC_CALL:
+ gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
+ _("unsupported reloc %u"),
+ r_type);
+ break;
+
+ case elfcpp::R_386_TLS_LDM: // Local-dynamic
+ if (this->local_dynamic_type_ == LOCAL_DYNAMIC_SUN)
+ {
+ gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
+ _("both SUN and GNU model "
+ "TLS relocations"));
+ break;
+ }
+ this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
+ if (optimized_type == tls::TLSOPT_TO_LE)
+ {
+ gold_assert(tls_segment != NULL);
+ this->tls_ld_to_le(relinfo, relnum, tls_segment, rel, r_type,
+ value, view, view_size);
+ break;
+ }
+ else if (optimized_type == tls::TLSOPT_NONE)
+ {
+ // Relocate the field with the offset of the GOT entry for
+ // the module index.
+ unsigned int got_offset;
+ got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
+ - target->got_size());
+ Relocate_functions<32, false>::rel32(view, got_offset);
+ break;
+ }
+ gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
+ _("unsupported reloc %u"),
+ r_type);
+ 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)
+ {
+ gold_assert(tls_segment != NULL);
+ value -= tls_segment->memsz();
+ }
+ Relocate_functions<32, false>::rel32(view, value);
+ break;
+
+ case elfcpp::R_386_TLS_IE: // Initial-exec
+ case elfcpp::R_386_TLS_GOTIE:
+ case elfcpp::R_386_TLS_IE_32:
+ if (optimized_type == tls::TLSOPT_TO_LE)
+ {
+ gold_assert(tls_segment != NULL);
+ Target_i386::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment,
+ rel, r_type, value, view,
+ view_size);
+ break;
+ }
+ else if (optimized_type == tls::TLSOPT_NONE)
+ {
+ // Relocate the field with the offset of the GOT entry for
+ // the tp-relative offset of the symbol.
+ unsigned int got_offset;
+ if (gsym != NULL)
+ {
+ gold_assert(gsym->has_got_offset(GOT_TYPE_TLS_OFFSET));
+ got_offset = gsym->got_offset(GOT_TYPE_TLS_OFFSET);
+ }
+ 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_TLS_OFFSET));
+ got_offset = object->local_got_offset(r_sym,
+ GOT_TYPE_TLS_OFFSET);
+ }
+ // For the R_386_TLS_IE relocation, we need to apply the
+ // absolute address of the GOT entry.
+ if (r_type == elfcpp::R_386_TLS_IE)
+ got_offset += target->got_plt_section()->address();
+ // All GOT offsets are relative to the end of the GOT.
+ got_offset -= target->got_size();
+ Relocate_functions<32, false>::rel32(view, got_offset);
+ break;
+ }
+ gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
+ _("unsupported reloc %u"),
+ r_type);
+ break;
+
+ case elfcpp::R_386_TLS_LE: // Local-exec
+ // If we're creating a shared library, a dynamic relocation will
+ // have been created for this location, so do not apply it now.
+ if (!parameters->options().shared())
+ {
+ gold_assert(tls_segment != NULL);
+ value -= tls_segment->memsz();
+ Relocate_functions<32, false>::rel32(view, value);
+ }
+ break;
+
+ case elfcpp::R_386_TLS_LE_32:
+ // If we're creating a shared library, a dynamic relocation will
+ // have been created for this location, so do not apply it now.
+ if (!parameters->options().shared())
+ {
+ gold_assert(tls_segment != NULL);
+ value = tls_segment->memsz() - value;
+ Relocate_functions<32, false>::rel32(view, value);
+ }
+ break;
+ }
+}
+
+// Do a relocation in which we convert a TLS General-Dynamic to a
+// Local-Exec.
+
+inline void
+Target_i386::Relocate::tls_gd_to_le(const Relocate_info<32, false>* relinfo,
+ size_t relnum,
+ Output_segment* tls_segment,
+ const elfcpp::Rel<32, false>& rel,
+ unsigned int,
+ elfcpp::Elf_types<32>::Elf_Addr value,
+ unsigned char* view,
+ section_size_type view_size)
+{
+ // leal foo(,%reg,1),%eax; call ___tls_get_addr
+ // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
+ // leal foo(%reg),%eax; call ___tls_get_addr
+ // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
+
+ tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
+ tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
+
+ unsigned char op1 = view[-1];
+ unsigned char op2 = view[-2];
+
+ tls::check_tls(relinfo, relnum, rel.get_r_offset(),
+ op2 == 0x8d || op2 == 0x04);
+ tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
+
+ int roff = 5;
+
+ if (op2 == 0x04)
+ {
+ tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
+ tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
+ tls::check_tls(relinfo, relnum, rel.get_r_offset(),
+ ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
+ memcpy(view - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
+ }
+ else
+ {
+ tls::check_tls(relinfo, relnum, rel.get_r_offset(),
+ (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
+ if (rel.get_r_offset() + 9 < view_size
+ && view[9] == 0x90)
+ {
+ // There is a trailing nop. Use the size byte subl.
+ memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
+ roff = 6;
+ }
+ else
+ {
+ // Use the five byte subl.
+ memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
+ }
+ }
+
+ value = tls_segment->memsz() - value;
+ Relocate_functions<32, false>::rel32(view + roff, value);
+
+ // The next reloc should be a PLT32 reloc against __tls_get_addr.
+ // We can skip it.
+ this->skip_call_tls_get_addr_ = true;
+}
+
+// Do a relocation in which we convert a TLS General-Dynamic to an
+// Initial-Exec.
+
+inline void
+Target_i386::Relocate::tls_gd_to_ie(const Relocate_info<32, false>* relinfo,
+ size_t relnum,
+ Output_segment* tls_segment,
+ const elfcpp::Rel<32, false>& rel,
+ unsigned int,
+ elfcpp::Elf_types<32>::Elf_Addr value,
+ unsigned char* view,
+ section_size_type view_size)
+{
+ // leal foo(,%ebx,1),%eax; call ___tls_get_addr
+ // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
+
+ tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
+ tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
+
+ unsigned char op1 = view[-1];
+ unsigned char op2 = view[-2];
+
+ tls::check_tls(relinfo, relnum, rel.get_r_offset(),
+ op2 == 0x8d || op2 == 0x04);
+ tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
+
+ int roff = 5;
+
+ // FIXME: For now, support only one form.
+ tls::check_tls(relinfo, relnum, rel.get_r_offset(),
+ op1 == 0x8d && op2 == 0x04);
+
+ if (op2 == 0x04)
+ {
+ tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
+ tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
+ tls::check_tls(relinfo, relnum, rel.get_r_offset(),
+ ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
+ memcpy(view - 3, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
+ }
+ else
+ {
+ tls::check_tls(relinfo, relnum, rel.get_r_offset(),
+ (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
+ if (rel.get_r_offset() + 9 < view_size
+ && view[9] == 0x90)
+ {
+ // FIXME: This is not the right instruction sequence.
+ // There is a trailing nop. Use the size byte subl.
+ memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
+ roff = 6;
+ }
+ else
+ {
+ // FIXME: This is not the right instruction sequence.
+ // Use the five byte subl.
+ memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
+ }
+ }
+
+ value = tls_segment->memsz() - value;
+ Relocate_functions<32, false>::rel32(view + roff, value);
+
+ // The next reloc should be a PLT32 reloc against __tls_get_addr.
+ // We can skip it.
+ this->skip_call_tls_get_addr_ = true;
+}
+
+// Do a relocation in which we convert a TLS Local-Dynamic to a
+// Local-Exec.
+
+inline void
+Target_i386::Relocate::tls_ld_to_le(const Relocate_info<32, false>* relinfo,
+ size_t relnum,
+ Output_segment*,
+ const elfcpp::Rel<32, false>& rel,
+ unsigned int,
+ elfcpp::Elf_types<32>::Elf_Addr,
+ unsigned char* view,
+ section_size_type view_size)
+{
+ // leal foo(%reg), %eax; call ___tls_get_addr
+ // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
+
+ tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
+ tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
+
+ // FIXME: Does this test really always pass?
+ tls::check_tls(relinfo, relnum, rel.get_r_offset(),
+ view[-2] == 0x8d && view[-1] == 0x83);
+
+ tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
+
+ memcpy(view - 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
+
+ // The next reloc should be a PLT32 reloc against __tls_get_addr.
+ // We can skip it.
+ this->skip_call_tls_get_addr_ = true;
+}
+
+// Do a relocation in which we convert a TLS Initial-Exec to a
+// Local-Exec.
+
+inline void
+Target_i386::Relocate::tls_ie_to_le(const Relocate_info<32, false>* relinfo,
+ size_t relnum,
+ Output_segment* tls_segment,
+ const elfcpp::Rel<32, false>& rel,
+ unsigned int r_type,
+ elfcpp::Elf_types<32>::Elf_Addr value,
+ unsigned char* view,
+ section_size_type view_size)
+{
+ // We have to actually change the instructions, which means that we
+ // need to examine the opcodes to figure out which instruction we
+ // are looking at.
+ if (r_type == elfcpp::R_386_TLS_IE)
+ {
+ // movl %gs:XX,%eax ==> movl $YY,%eax
+ // movl %gs:XX,%reg ==> movl $YY,%reg
+ // addl %gs:XX,%reg ==> addl $YY,%reg
+ tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -1);
+ tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
+
+ unsigned char op1 = view[-1];
+ if (op1 == 0xa1)
+ {
+ // movl XX,%eax ==> movl $YY,%eax
+ view[-1] = 0xb8;
+ }
+ else
+ {
+ tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
+
+ unsigned char op2 = view[-2];
+ if (op2 == 0x8b)
+ {
+ // movl XX,%reg ==> movl $YY,%reg
+ tls::check_tls(relinfo, relnum, rel.get_r_offset(),
+ (op1 & 0xc7) == 0x05);
+ view[-2] = 0xc7;
+ view[-1] = 0xc0 | ((op1 >> 3) & 7);
+ }
+ else if (op2 == 0x03)
+ {
+ // addl XX,%reg ==> addl $YY,%reg
+ tls::check_tls(relinfo, relnum, rel.get_r_offset(),
+ (op1 & 0xc7) == 0x05);
+ view[-2] = 0x81;
+ view[-1] = 0xc0 | ((op1 >> 3) & 7);
+ }
+ else
+ tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
+ }
+ }
+ else
+ {
+ // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
+ // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
+ // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
+ tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
+ tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
+
+ unsigned char op1 = view[-1];
+ unsigned char op2 = view[-2];
+ tls::check_tls(relinfo, relnum, rel.get_r_offset(),
+ (op1 & 0xc0) == 0x80 && (op1 & 7) != 4);
+ if (op2 == 0x8b)
+ {
+ // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
+ view[-2] = 0xc7;
+ view[-1] = 0xc0 | ((op1 >> 3) & 7);
+ }
+ else if (op2 == 0x2b)
+ {
+ // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
+ view[-2] = 0x81;
+ view[-1] = 0xe8 | ((op1 >> 3) & 7);
+ }
+ else if (op2 == 0x03)
+ {
+ // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
+ view[-2] = 0x81;
+ view[-1] = 0xc0 | ((op1 >> 3) & 7);
+ }
+ else
+ tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
+ }
+
+ value = tls_segment->memsz() - value;
+ if (r_type == elfcpp::R_386_TLS_IE || r_type == elfcpp::R_386_TLS_GOTIE)
+ value = - value;
+
+ Relocate_functions<32, false>::rel32(view, value);
+}
+
+// Relocate section data.
+
+void
+Target_i386::relocate_section(const Relocate_info<32, 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<32>::Elf_Addr address,
+ section_size_type view_size)
+{
+ gold_assert(sh_type == elfcpp::SHT_REL);
+
+ gold::relocate_section<32, false, Target_i386, elfcpp::SHT_REL,
+ Target_i386::Relocate>(
+ relinfo,
+ this,
+ prelocs,
+ reloc_count,
+ output_section,
+ needs_special_offset_handling,
+ view,
+ address,
+ view_size);
+}
+
+// Return the size of a relocation while scanning during a relocatable
+// link.
+
+unsigned int
+Target_i386::Relocatable_size_for_reloc::get_size_for_reloc(
+ unsigned int r_type,
+ Relobj* object)
+{
+ switch (r_type)
+ {
+ case elfcpp::R_386_NONE:
+ case elfcpp::R_386_GNU_VTINHERIT:
+ case elfcpp::R_386_GNU_VTENTRY:
+ case elfcpp::R_386_TLS_GD: // Global-dynamic
+ case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
+ case elfcpp::R_386_TLS_DESC_CALL:
+ case elfcpp::R_386_TLS_LDM: // Local-dynamic
+ case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
+ case elfcpp::R_386_TLS_IE: // Initial-exec
+ case elfcpp::R_386_TLS_IE_32:
+ case elfcpp::R_386_TLS_GOTIE:
+ case elfcpp::R_386_TLS_LE: // Local-exec
+ case elfcpp::R_386_TLS_LE_32:
+ return 0;
+
+ case elfcpp::R_386_32:
+ case elfcpp::R_386_PC32:
+ case elfcpp::R_386_GOT32:
+ case elfcpp::R_386_PLT32:
+ case elfcpp::R_386_GOTOFF:
+ case elfcpp::R_386_GOTPC:
+ return 4;
+
+ case elfcpp::R_386_16:
+ case elfcpp::R_386_PC16:
+ return 2;
+
+ case elfcpp::R_386_8:
+ case elfcpp::R_386_PC8:
+ return 1;
+
+ // These are relocations which should only be seen by the
+ // dynamic linker, and should never be seen here.
+ case elfcpp::R_386_COPY:
+ case elfcpp::R_386_GLOB_DAT:
+ case elfcpp::R_386_JUMP_SLOT:
+ case elfcpp::R_386_RELATIVE:
+ case elfcpp::R_386_TLS_TPOFF:
+ case elfcpp::R_386_TLS_DTPMOD32:
+ case elfcpp::R_386_TLS_DTPOFF32:
+ case elfcpp::R_386_TLS_TPOFF32:
+ case elfcpp::R_386_TLS_DESC:
+ object->error(_("unexpected reloc %u in object file"), r_type);
+ return 0;
+
+ case elfcpp::R_386_32PLT:
+ case elfcpp::R_386_TLS_GD_32:
+ case elfcpp::R_386_TLS_GD_PUSH:
+ case elfcpp::R_386_TLS_GD_CALL:
+ case elfcpp::R_386_TLS_GD_POP:
+ case elfcpp::R_386_TLS_LDM_32:
+ case elfcpp::R_386_TLS_LDM_PUSH:
+ case elfcpp::R_386_TLS_LDM_CALL:
+ case elfcpp::R_386_TLS_LDM_POP:
+ case elfcpp::R_386_USED_BY_INTEL_200:
+ default:
+ object->error(_("unsupported reloc %u in object file"), r_type);
+ return 0;
+ }
+}
+
+// Scan the relocs during a relocatable link.
+
+void
+Target_i386::scan_relocatable_relocs(const General_options& options,
+ 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,
+ Relocatable_relocs* rr)
+{
+ gold_assert(sh_type == elfcpp::SHT_REL);
+
+ typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_REL,
+ Relocatable_size_for_reloc> Scan_relocatable_relocs;
+
+ gold::scan_relocatable_relocs<32, false, elfcpp::SHT_REL,
+ Scan_relocatable_relocs>(
+ options,
+ symtab,
+ layout,
+ object,
+ data_shndx,
+ prelocs,
+ reloc_count,
+ output_section,
+ needs_special_offset_handling,
+ local_symbol_count,
+ plocal_symbols,
+ rr);
+}
+
+// Relocate a section during a relocatable link.
+
+void
+Target_i386::relocate_for_relocatable(
+ const Relocate_info<32, false>* relinfo,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ off_t offset_in_output_section,
+ const Relocatable_relocs* rr,
+ unsigned char* view,
+ elfcpp::Elf_types<32>::Elf_Addr view_address,
+ section_size_type view_size,
+ unsigned char* reloc_view,
+ section_size_type reloc_view_size)
+{
+ gold_assert(sh_type == elfcpp::SHT_REL);
+
+ gold::relocate_for_relocatable<32, false, elfcpp::SHT_REL>(
+ relinfo,
+ prelocs,
+ reloc_count,
+ output_section,
+ offset_in_output_section,
+ rr,
+ view,
+ view_address,
+ view_size,
+ reloc_view,
+ reloc_view_size);
+}
+
+// Return the value to use for a dynamic which requires special
+// treatment. This is how we support equality comparisons of function
+// pointers across shared library boundaries, as described in the
+// processor specific ABI supplement.
+
+uint64_t
+Target_i386::do_dynsym_value(const Symbol* gsym) const
+{
+ gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
+ return this->plt_section()->address() + gsym->plt_offset();
+}
+
+// Return a string used to fill a code section with nops to take up
+// the specified length.
+
+std::string
+Target_i386::do_code_fill(section_size_type length) const
+{
+ if (length >= 16)
+ {
+ // Build a jmp instruction to skip over the bytes.
+ unsigned char jmp[5];
+ jmp[0] = 0xe9;
+ elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
+ return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
+ + std::string(length - 5, '\0'));
+ }
+
+ // 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
+ 0x00, 0x00 };
+ const char nop7[7] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
+ 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
+ 0x00 };
+ const char nop10[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
+ 0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
+ 0x00, 0x00 };
+ const char nop11[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
+ 0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
+ 0x00, 0x00, 0x00 };
+ const char nop12[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
+ 0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
+ 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,
+ 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,
+ 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* nops[16] = {
+ NULL,
+ nop1, nop2, nop3, nop4, nop5, nop6, nop7,
+ nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
+ };
+
+ return std::string(nops[length], length);
+}
+
// The selector for i386 object files.
class Target_selector_i386 : public Target_selector
{ }
Target*
- recognize(int machine, int osabi, int abiversion) const;
+ recognize(int machine, int osabi, int abiversion);
+
+ Target*
+ recognize_by_name(const char* name);
+
+ private:
+ Target_i386* target_;
};
// Recognize an i386 object file when we already know that the machine
// number is EM_386.
Target*
-Target_selector_i386::recognize(int, int, int) const
+Target_selector_i386::recognize(int, int, int)
+{
+ if (this->target_ == NULL)
+ this->target_ = new Target_i386();
+ return this->target_;
+}
+
+Target*
+Target_selector_i386::recognize_by_name(const char* name)
{
- return new Target_i386();
+ if (strcmp(name, "elf32-i386") != 0)
+ return NULL;
+ if (this->target_ == NULL)
+ this->target_ = new Target_i386();
+ return this->target_;
}
Target_selector_i386 target_selector_i386;
projects / binutils.git / blobdiff