binutils: Fix gold linking errors due to unresolved R_ARM_MOVW_ABS_NC

This issue has been seen in multiple times e.g. http://patchwork.openembedded.org/patch/103083/ https://www.mail-archive.com/openembedded-core@lists.openembedded.org/msg72513.html (From OE-Core rev: 9db094039ed7bce34006cc21bb65cd800fbfee7d) Signed-off-by: Khem Raj <raj.khem@gmail.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
author: Khem Raj <raj.khem@gmail.com> 2016-01-14 03:58:10 -0800
committer: Richard Purdie <richard.purdie@linuxfoundation.org> 2016-01-24 09:40:31 +0000
commit: 136db70700ce198f793935d0683ce4e1f1acf471 (patch)
tree: 4d197ae3c35c91a8dee182f21158873abd6e1fa5
parent: 704e34213ed2925ab3ac135717861c4ff466e8ab (diff)
download: poky-136db70700ce198f793935d0683ce4e1f1acf471.tar.gz
2 files changed, 1005 insertions, 0 deletions
diff --git a/meta/recipes-devtools/binutils/binutils-2.25.1.inc b/meta/recipes-devtools/binutils/binutils-2.25.1.inc
index bf29da16f5..dc23c4d9d9 100644
--- a/meta/recipes-devtools/binutils/binutils-2.25.1.inc
+++ b/meta/recipes-devtools/binutils/binutils-2.25.1.inc
@@ -35,6 +35,7 @@ SRC_URI = "\
     file://0013-Fix-an-internal-error-in-do_print_to_mapfile-seen-wi.patch \
     file://0014-gold-arm-Skip-pic-check-for-R_ARM_REL32.patch \
     file://0015-Fix-dynamic-list-so-that-symbols-not-in-the-list-are.patch \
+     file://0016-This-patch-adds-IFUNC-support-for-arm-gold-backend.patch \
     file://binutils-octeon3.patch \
     file://add-thunderx-support-for-gas.patch \
     "
diff --git a/meta/recipes-devtools/binutils/binutils/0016-This-patch-adds-IFUNC-support-for-arm-gold-backend.patch b/meta/recipes-devtools/binutils/binutils/0016-This-patch-adds-IFUNC-support-for-arm-gold-backend.patch
new file mode 100644
index 0000000000..dcac308bcc
--- /dev/null
+++ b/meta/recipes-devtools/binutils/binutils/0016-This-patch-adds-IFUNC-support-for-arm-gold-backend.patch
@@ -0,0 +1,1004 @@
+From b780c9e06cabe6d8e301aaf46f33f116f3224021 Mon Sep 17 00:00:00 2001
+From: Han Shen <shenhan@google.com>
+Date: Thu, 29 Jan 2015 10:00:46 -0800
+Subject: [PATCH] This patch adds IFUNC support for arm gold backend.
+This is a feature required in chromeos arm development work.
+Tested:
+1) Built passed all-gold on x86_64 machine
+2) Tested with basic gold aarch64 ifunc unittests -
+   a) global ifunc, statically/non-statically linked
+   b) local ifunc, statically/non-statically linked
+   c) global/local, other shared library routine mixed,
+   statically/non-statically linked
+   d) arm/thumb mode ifunc
+   e) linking chrome browser passed
+---
+Upstream-Status: Backport
+Signed-off-by: Khem Raj <raj.khem@gmail.com>
+ elfcpp/arm.h    |   5 +-
+ gold/aarch64.cc |   2 +-
+ gold/arm.cc     | 593 +++++++++++++++++++++++++++++++++++++++++++++++++++-----
+ gold/output.h   |  11 ++
+ 4 files changed, 561 insertions(+), 50 deletions(-)
+diff --git a/elfcpp/arm.h b/elfcpp/arm.h
+index 8c6b6bf..1c13dc9 100644
+--- a/elfcpp/arm.h
+++ b/elfcpp/arm.h
+@@ -192,11 +192,12 @@ enum
+   R_ARM_PRIVATE_14 = 126,
+   R_ARM_PRIVATE_15 = 127,
+   R_ARM_ME_TOO = 128,          // Obsolete
+-  R_ARM_THM_TLS_DESCSEQ16 = 129,// Static      Thumb16 
+  R_ARM_THM_TLS_DESCSEQ16 = 129,// Static      Thumb16
+   R_ARM_THM_TLS_DESCSEQ32 = 130,// Static      Thumb32
+   // 131 - 139                 Unallocated
+   // 140 - 159                 Dynamic         Reserved for future allocation
+-  // 160 - 255                 Unallocated
+  R_ARM_IRELATIVE = 160,       // Dynamic
+  // 161 - 255                 Unallocated
+ };
+ 
+ // e_flags values used for ARM.  We only support flags defined in AAELF.
+diff --git a/gold/aarch64.cc b/gold/aarch64.cc
+index afb9024..7fbbdbd 100644
+--- a/gold/aarch64.cc
+++ b/gold/aarch64.cc
+@@ -1226,7 +1226,7 @@ class Output_data_plt_aarch64 : public Output_section_data
+   // The number of PLT entries.
+   unsigned int count_;
+ 
+-  // Number of PLT entries with R_X86_64_IRELATIVE relocs.  These
+  // Number of PLT entries with R_AARCH64_IRELATIVE relocs.  These
+   // follow the regular PLT entries.
+   unsigned int irelative_count_;
+ 
+diff --git a/gold/arm.cc b/gold/arm.cc
+index 6c472bb..8719cc9 100644
+--- a/gold/arm.cc
+++ b/gold/arm.cc
+@@ -2119,8 +2119,8 @@ class Target_arm : public Sized_target<32, big_endian>
+ 
+   Target_arm(const Target::Target_info* info = &arm_info)
+     : Sized_target<32, big_endian>(info),
+-      got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL),
+-      copy_relocs_(elfcpp::R_ARM_COPY),
+      got_(NULL), plt_(NULL), got_plt_(NULL), got_irelative_(NULL),
+      rel_dyn_(NULL), rel_irelative_(NULL), copy_relocs_(elfcpp::R_ARM_COPY),
+       got_mod_index_offset_(-1U), tls_base_symbol_defined_(false),
+       stub_tables_(), stub_factory_(Stub_factory::get_instance()),
+       should_force_pic_veneer_(false),
+@@ -2258,6 +2258,18 @@ class Target_arm : public Sized_target<32, big_endian>
+   uint64_t
+   do_dynsym_value(const Symbol*) const;
+ 
+  // Return the plt address for globals. Since we have irelative plt entries,
+  // address calculation is not as straightforward as plt_address + plt_offset.
+  uint64_t
+  do_plt_address_for_global(const Symbol* gsym) const
+  { return this->plt_section()->address_for_global(gsym); }
+
+  // Return the plt address for locals. Since we have irelative plt entries,
+  // address calculation is not as straightforward as plt_address + plt_offset.
+  uint64_t
+  do_plt_address_for_local(const Relobj* relobj, unsigned int symndx) const
+  { return this->plt_section()->address_for_local(relobj, symndx); }
+
+   // Relocate a section.
+   void
+   relocate_section(const Relocate_info<32, big_endian>*,
+@@ -2357,6 +2369,10 @@ class Target_arm : public Sized_target<32, big_endian>
+   unsigned int
+   plt_entry_size() const;
+ 
+  // Get the section to use for IRELATIVE relocations, create it if necessary.
+  Reloc_section*
+  rel_irelative_section(Layout*);
+
+   // Map platform-specific reloc types
+   static unsigned int
+   get_real_reloc_type(unsigned int r_type);
+@@ -2448,8 +2464,11 @@ class Target_arm : public Sized_target<32, big_endian>
+  protected:
+   // Make the PLT-generator object.
+   Output_data_plt_arm<big_endian>*
+-  make_data_plt(Layout* layout, Output_data_space* got_plt)
+-  { return this->do_make_data_plt(layout, got_plt); }
+  make_data_plt(Layout* layout,
+               Arm_output_data_got<big_endian>* got,
+               Output_data_space* got_plt,
+               Output_data_space* got_irelative)
+  { return this->do_make_data_plt(layout, got, got_plt, got_irelative); }
+ 
+   // Make an ELF object.
+   Object*
+@@ -2530,9 +2549,14 @@ class Target_arm : public Sized_target<32, big_endian>
+   do_define_standard_symbols(Symbol_table*, Layout*);
+ 
+   virtual Output_data_plt_arm<big_endian>*
+-  do_make_data_plt(Layout* layout, Output_data_space* got_plt)
+  do_make_data_plt(Layout* layout,
+                  Arm_output_data_got<big_endian>* got,
+                  Output_data_space* got_plt,
+                  Output_data_space* got_irelative)
+   {
+-    return new Output_data_plt_arm_standard<big_endian>(layout, got_plt);
+    gold_assert(got_plt != NULL && got_irelative != NULL);
+    return new Output_data_plt_arm_standard<big_endian>(
+       layout, got, got_plt, got_irelative);
+   }
+ 
+  private:
+@@ -2602,6 +2626,9 @@ class Target_arm : public Sized_target<32, big_endian>
+       if (sym->is_undefined() && !parameters->options().shared())
+        return false;
+ 
+      if (sym->type() == elfcpp::STT_GNU_IFUNC)
+       return true;
+
+       return (!parameters->doing_static_link()
+              && (sym->type() == elfcpp::STT_FUNC
+                  || sym->type() == elfcpp::STT_ARM_TFUNC)
+@@ -2613,6 +2640,11 @@ class Target_arm : public Sized_target<32, big_endian>
+     inline bool
+     possible_function_pointer_reloc(unsigned int r_type);
+ 
+    // Whether a plt entry is needed for ifunc.
+    bool
+    reloc_needs_plt_for_ifunc(Sized_relobj_file<32, big_endian>*,
+                             unsigned int r_type);
+
+     // Whether we have issued an error about a non-PIC compilation.
+     bool issued_non_pic_error_;
+   };
+@@ -2718,10 +2750,20 @@ class Target_arm : public Sized_target<32, big_endian>
+     return this->got_plt_;
+   }
+ 
+  // Create the PLT section.
+  void
+  make_plt_section(Symbol_table* symtab, Layout* layout);
+
+   // Create a PLT entry for a global symbol.
+   void
+   make_plt_entry(Symbol_table*, Layout*, Symbol*);
+ 
+  // Create a PLT entry for a local STT_GNU_IFUNC symbol.
+  void
+  make_local_ifunc_plt_entry(Symbol_table*, Layout*,
+                            Sized_relobj_file<32, big_endian>* relobj,
+                            unsigned int local_sym_index);
+
+   // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
+   void
+   define_tls_base_symbol(Symbol_table*, Layout*);
+@@ -2903,8 +2945,12 @@ class Target_arm : public Sized_target<32, big_endian>
+   Output_data_plt_arm<big_endian>* plt_;
+   // The GOT PLT section.
+   Output_data_space* got_plt_;
+  // The GOT section for IRELATIVE relocations.
+  Output_data_space* got_irelative_;
+   // The dynamic reloc section.
+   Reloc_section* rel_dyn_;
+  // The section to use for IRELATIVE relocs.
+  Reloc_section* rel_irelative_;
+   // Relocs saved to avoid a COPY reloc.
+   Copy_relocs<elfcpp::SHT_REL, 32, big_endian> copy_relocs_;
+   // Offset of the GOT entry for the TLS module index.
+@@ -4244,6 +4290,15 @@ Target_arm<big_endian>::got_section(Symbol_table* symtab, Layout* layout)
+                                    elfcpp::STB_LOCAL,
+                                    elfcpp::STV_HIDDEN, 0,
+                                    false, false);
+
+      // If there are any IRELATIVE relocations, they get GOT entries
+      // in .got.plt after the jump slot entries.
+      this->got_irelative_ = new Output_data_space(4, "** GOT IRELATIVE PLT");
+      layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
+                                     (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
+                                     this->got_irelative_,
+                                     got_order, is_got_relro);
+
+     }
+   return this->got_;
+ }
+@@ -4257,14 +4312,43 @@ Target_arm<big_endian>::rel_dyn_section(Layout* layout)
+   if (this->rel_dyn_ == NULL)
+     {
+       gold_assert(layout != NULL);
+      // Create both relocation sections in the same place, so as to ensure
+      // their relative order in the output section.
+       this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
+      this->rel_irelative_ = new Reloc_section(false);
+       layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
+                                      elfcpp::SHF_ALLOC, this->rel_dyn_,
+                                      ORDER_DYNAMIC_RELOCS, false);
+      layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
+                                     elfcpp::SHF_ALLOC, this->rel_irelative_,
+                                     ORDER_DYNAMIC_RELOCS, false);
+     }
+   return this->rel_dyn_;
+ }
+ 
+
+// Get the section to use for IRELATIVE relocs, creating it if necessary.  These
+// go in .rela.dyn, but only after all other dynamic relocations.  They need to
+// follow the other dynamic relocations so that they can refer to global
+// variables initialized by those relocs.
+
+template<bool big_endian>
+typename Target_arm<big_endian>::Reloc_section*
+Target_arm<big_endian>::rel_irelative_section(Layout* layout)
+{
+  if (this->rel_irelative_ == NULL)
+    {
+      // Delegate the creation to rel_dyn_section so as to ensure their order in
+      // the output section.
+      this->rel_dyn_section(layout);
+      gold_assert(this->rel_irelative_ != NULL
+                 && (this->rel_dyn_->output_section()
+                     == this->rel_irelative_->output_section()));
+    }
+  return this->rel_irelative_;
+}
+
+
+ // Insn_template methods.
+ 
+ // Return byte size of an instruction template.
+@@ -7221,24 +7305,80 @@ template<bool big_endian>
+ class Output_data_plt_arm : public Output_section_data
+ {
+  public:
+  // Unlike aarch64, which records symbol value in "addend" field of relocations
+  // and could be done at the same time an IRelative reloc is created for the
+  // symbol, arm puts the symbol value into "GOT" table, which, however, is
+  // issued later in Output_data_plt_arm::do_write(). So we have a struct here
+  // to keep necessary symbol information for later use in do_write. We usually
+  // have only a very limited number of ifuncs, so the extra data required here
+  // is also limited.
+
+  struct IRelative_data
+  {
+    IRelative_data(Sized_symbol<32>* sized_symbol)
+      : symbol_is_global_(true)
+    {
+      u_.global = sized_symbol;
+    }
+
+    IRelative_data(Sized_relobj_file<32, big_endian>* relobj,
+                  unsigned int index)
+      : symbol_is_global_(false)
+    {
+      u_.local.relobj = relobj;
+      u_.local.index = index;
+    }
+
+    union
+    {
+      Sized_symbol<32>* global;
+
+      struct
+      {
+       Sized_relobj_file<32, big_endian>* relobj;
+       unsigned int index;
+      } local;
+    } u_;
+
+    bool symbol_is_global_;
+  };
+
+   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
+     Reloc_section;
+ 
+-  Output_data_plt_arm(Layout*, uint64_t addralign, Output_data_space*);
+  Output_data_plt_arm(Layout* layout, uint64_t addralign,
+                     Arm_output_data_got<big_endian>* got,
+                     Output_data_space* got_plt,
+                     Output_data_space* got_irelative);
+ 
+   // Add an entry to the PLT.
+   void
+-  add_entry(Symbol* gsym);
+  add_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym);
+
+  // Add the relocation for a plt entry.
+  void
+  add_relocation(Symbol_table* symtab, Layout* layout,
+                Symbol* gsym, unsigned int got_offset);
+
+  // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.
+  unsigned int
+  add_local_ifunc_entry(Symbol_table* symtab, Layout*,
+                       Sized_relobj_file<32, big_endian>* relobj,
+                       unsigned int local_sym_index);
+ 
+   // Return the .rel.plt section data.
+   const Reloc_section*
+   rel_plt() const
+   { return this->rel_; }
+ 
+  // Return the PLT relocation container for IRELATIVE.
+  Reloc_section*
+  rel_irelative(Symbol_table*, Layout*);
+
+   // Return the number of PLT entries.
+   unsigned int
+   entry_count() const
+-  { return this->count_; }
+  { return this->count_ + this->irelative_count_; }
+ 
+   // Return the offset of the first non-reserved PLT entry.
+   unsigned int
+@@ -7250,6 +7390,14 @@ class Output_data_plt_arm : public Output_section_data
+   get_plt_entry_size() const
+   { return this->do_get_plt_entry_size(); }
+ 
+  // Return the PLT address for globals.
+  uint32_t
+  address_for_global(const Symbol*) const;
+
+  // Return the PLT address for locals.
+  uint32_t
+  address_for_local(const Relobj*, unsigned int symndx) const;
+
+  protected:
+   // Fill in the first PLT entry.
+   void
+@@ -7298,19 +7446,37 @@ class Output_data_plt_arm : public Output_section_data
+   set_final_data_size()
+   {
+     this->set_data_size(this->first_plt_entry_offset()
+-                       + this->count_ * this->get_plt_entry_size());
+                       + ((this->count_ + this->irelative_count_)
+                          * this->get_plt_entry_size()));
+   }
+ 
+   // Write out the PLT data.
+   void
+   do_write(Output_file*);
+ 
+  // Record irelative symbol data.
+  void insert_irelative_data(const IRelative_data& idata)
+  { irelative_data_vec_.push_back(idata); }
+
+   // The reloc section.
+   Reloc_section* rel_;
+  // The IRELATIVE relocs, if necessary.  These must follow the
+  // regular PLT relocations.
+  Reloc_section* irelative_rel_;
+  // The .got section.
+  Arm_output_data_got<big_endian>* got_;
+   // The .got.plt section.
+   Output_data_space* got_plt_;
+  // The part of the .got.plt section used for IRELATIVE relocs.
+  Output_data_space* got_irelative_;
+   // The number of PLT entries.
+   unsigned int count_;
+  // Number of PLT entries with R_ARM_IRELATIVE relocs.  These
+  // follow the regular PLT entries.
+  unsigned int irelative_count_;
+  // Vector for irelative data.
+  typedef std::vector<IRelative_data> IRelative_data_vec;
+  IRelative_data_vec irelative_data_vec_;
+ };
+ 
+ // Create the PLT section.  The ordinary .got section is an argument,
+@@ -7318,10 +7484,14 @@ class Output_data_plt_arm : public Output_section_data
+ // section just for PLT entries.
+ 
+ template<bool big_endian>
+-Output_data_plt_arm<big_endian>::Output_data_plt_arm(Layout* layout,
+-                                                    uint64_t addralign,
+-                                                    Output_data_space* got_plt)
+-  : Output_section_data(addralign), got_plt_(got_plt), count_(0)
+Output_data_plt_arm<big_endian>::Output_data_plt_arm(
+    Layout* layout, uint64_t addralign,
+    Arm_output_data_got<big_endian>* got,
+    Output_data_space* got_plt,
+    Output_data_space* got_irelative)
+  : Output_section_data(addralign), irelative_rel_(NULL),
+    got_(got), got_plt_(got_plt), got_irelative_(got_irelative),
+    count_(0), irelative_count_(0)
+ {
+   this->rel_ = new Reloc_section(false);
+   layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
+@@ -7340,40 +7510,210 @@ Output_data_plt_arm<big_endian>::do_adjust_output_section(Output_section* os)
+ 
+ template<bool big_endian>
+ void
+-Output_data_plt_arm<big_endian>::add_entry(Symbol* gsym)
+Output_data_plt_arm<big_endian>::add_entry(Symbol_table* symtab,
+                                          Layout* layout,
+                                          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_) * this->get_plt_entry_size()
+-                      + this->first_plt_entry_offset());
+  unsigned int* entry_count;
+  Output_section_data_build* got;
+
+  // We have 2 different types of plt entry here, normal and ifunc.
+
+  // For normal plt, the offset begins with first_plt_entry_offset(20), and the
+  // 1st entry offset would be 20, the second 32, third 44 ... etc.
+
+  // For ifunc plt, the offset begins with 0. So the first offset would 0,
+  // second 12, third 24 ... etc.
+
+  // IFunc plt entries *always* come after *normal* plt entries.
+
+  // Notice, when computing the plt address of a certain symbol, "plt_address +
+  // plt_offset" is no longer correct. Use target->plt_address_for_global() or
+  // target->plt_address_for_local() instead.
+
+  int begin_offset = 0;
+  if (gsym->type() == elfcpp::STT_GNU_IFUNC
+      && gsym->can_use_relative_reloc(false))
+    {
+      entry_count = &this->irelative_count_;
+      got = this->got_irelative_;
+      // For irelative plt entries, offset is relative to the end of normal plt
+      // entries, so it starts from 0.
+      begin_offset = 0;
+      // Record symbol information.
+      this->insert_irelative_data(
+         IRelative_data(symtab->get_sized_symbol<32>(gsym)));
+    }
+  else
+    {
+      entry_count = &this->count_;
+      got = this->got_plt_;
+      // Note that for normal plt entries, when setting the PLT offset we skip
+      // the initial reserved PLT entry.
+      begin_offset = this->first_plt_entry_offset();
+    }
+
+  gsym->set_plt_offset(begin_offset
+                      + (*entry_count) * this->get_plt_entry_size());
+ 
+-  ++this->count_;
+  ++(*entry_count);
+ 
+-  section_offset_type got_offset = this->got_plt_->current_data_size();
+  section_offset_type got_offset = got->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);
+  got->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_ARM_JUMP_SLOT, this->got_plt_,
+-                        got_offset);
+  this->add_relocation(symtab, layout, gsym, 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.
+ }
+ 
+// Add an entry to the PLT for a local STT_GNU_IFUNC symbol.  Return
+// the PLT offset.
+
+template<bool big_endian>
+unsigned int
+Output_data_plt_arm<big_endian>::add_local_ifunc_entry(
+    Symbol_table* symtab,
+    Layout* layout,
+    Sized_relobj_file<32, big_endian>* relobj,
+    unsigned int local_sym_index)
+{
+  this->insert_irelative_data(IRelative_data(relobj, local_sym_index));
+
+  // Notice, when computingthe plt entry address, "plt_address + plt_offset" is
+  // no longer correct. Use target->plt_address_for_local() instead.
+  unsigned int plt_offset = this->irelative_count_ * this->get_plt_entry_size();
+  ++this->irelative_count_;
+
+  section_offset_type got_offset = this->got_irelative_->current_data_size();
+
+  // Every PLT entry needs a GOT entry which points back to the PLT
+  // entry.
+  this->got_irelative_->set_current_data_size(got_offset + 4);
+
+
+  // Every PLT entry needs a reloc.
+  Reloc_section* rel = this->rel_irelative(symtab, layout);
+  rel->add_symbolless_local_addend(relobj, local_sym_index,
+                                  elfcpp::R_ARM_IRELATIVE,
+                                  this->got_irelative_, got_offset);
+  return plt_offset;
+}
+
+
+// Add the relocation for a PLT entry.
+
+template<bool big_endian>
+void
+Output_data_plt_arm<big_endian>::add_relocation(
+    Symbol_table* symtab, Layout* layout, Symbol* gsym, unsigned int got_offset)
+{
+  if (gsym->type() == elfcpp::STT_GNU_IFUNC
+      && gsym->can_use_relative_reloc(false))
+    {
+      Reloc_section* rel = this->rel_irelative(symtab, layout);
+      rel->add_symbolless_global_addend(gsym, elfcpp::R_ARM_IRELATIVE,
+                                       this->got_irelative_, got_offset);
+    }
+  else
+    {
+      gsym->set_needs_dynsym_entry();
+      this->rel_->add_global(gsym, elfcpp::R_ARM_JUMP_SLOT, this->got_plt_,
+                            got_offset);
+    }
+}
+
+
+// Create the irelative relocation data.
+
+template<bool big_endian>
+typename Output_data_plt_arm<big_endian>::Reloc_section*
+Output_data_plt_arm<big_endian>::rel_irelative(Symbol_table* symtab,
+                                               Layout* layout)
+{
+  if (this->irelative_rel_ == NULL)
+    {
+      // Since irelative relocations goes into 'rel.dyn', we delegate the
+      // creation of irelative_rel_ to where rel_dyn section gets created.
+      Target_arm<big_endian>* arm_target =
+         Target_arm<big_endian>::default_target();
+      this->irelative_rel_ = arm_target->rel_irelative_section(layout);
+
+      // Make sure we have a place for the TLSDESC relocations, in
+      // case we see any later on.
+      // this->rel_tlsdesc(layout);
+      if (parameters->doing_static_link())
+       {
+         // A statically linked executable will only have a .rel.plt section to
+         // hold R_ARM_IRELATIVE relocs for STT_GNU_IFUNC symbols.  The library
+         // will use these symbols to locate the IRELATIVE relocs at program
+         // startup time.
+         symtab->define_in_output_data("__rel_iplt_start", NULL,
+                                       Symbol_table::PREDEFINED,
+                                       this->irelative_rel_, 0, 0,
+                                       elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
+                                       elfcpp::STV_HIDDEN, 0, false, true);
+         symtab->define_in_output_data("__rel_iplt_end", NULL,
+                                       Symbol_table::PREDEFINED,
+                                       this->irelative_rel_, 0, 0,
+                                       elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
+                                       elfcpp::STV_HIDDEN, 0, true, true);
+       }
+    }
+  return this->irelative_rel_;
+}
+
+
+// Return the PLT address for a global symbol.
+
+template<bool big_endian>
+uint32_t
+Output_data_plt_arm<big_endian>::address_for_global(const Symbol* gsym) const
+{
+  uint64_t begin_offset = 0;
+  if (gsym->type() == elfcpp::STT_GNU_IFUNC
+      && gsym->can_use_relative_reloc(false))
+    {
+      begin_offset = (this->first_plt_entry_offset() +
+                     this->count_ * this->get_plt_entry_size());
+    }
+  return this->address() + begin_offset + gsym->plt_offset();
+}
+
+
+// Return the PLT address for a local symbol.  These are always
+// IRELATIVE relocs.
+
+template<bool big_endian>
+uint32_t
+Output_data_plt_arm<big_endian>::address_for_local(
+    const Relobj* object,
+    unsigned int r_sym) const
+{
+  return (this->address()
+         + this->first_plt_entry_offset()
+         + this->count_ * this->get_plt_entry_size()
+         + object->local_plt_offset(r_sym));
+}
+
+
+ template<bool big_endian>
+ class Output_data_plt_arm_standard : public Output_data_plt_arm<big_endian>
+ {
+  public:
+-  Output_data_plt_arm_standard(Layout* layout, Output_data_space* got_plt)
+-    : Output_data_plt_arm<big_endian>(layout, 4, got_plt)
+  Output_data_plt_arm_standard(Layout* layout,
+                              Arm_output_data_got<big_endian>* got,
+                              Output_data_space* got_plt,
+                              Output_data_space* got_irelative)
+    : Output_data_plt_arm<big_endian>(layout, 4, got, got_plt, got_irelative)
+   { }
+ 
+  protected:
+@@ -7485,8 +7825,11 @@ Output_data_plt_arm<big_endian>::do_write(Output_file* of)
+   unsigned char* const oview = of->get_output_view(offset, oview_size);
+ 
+   const off_t got_file_offset = this->got_plt_->offset();
+  gold_assert(got_file_offset + this->got_plt_->data_size()
+             == this->got_irelative_->offset());
+   const section_size_type got_size =
+-    convert_to_section_size_type(this->got_plt_->data_size());
+    convert_to_section_size_type(this->got_plt_->data_size()
+                                + this->got_irelative_->data_size());
+   unsigned char* const got_view = of->get_output_view(got_file_offset,
+                                                      got_size);
+   unsigned char* pov = oview;
+@@ -7505,7 +7848,8 @@ Output_data_plt_arm<big_endian>::do_write(Output_file* of)
+ 
+   unsigned int plt_offset = this->first_plt_entry_offset();
+   unsigned int got_offset = 12;
+-  const unsigned int count = this->count_;
+  const unsigned int count = this->count_ + this->irelative_count_;
+  gold_assert(this->irelative_count_ == this->irelative_data_vec_.size());
+   for (unsigned int i = 0;
+        i < count;
+        ++i,
+@@ -7518,8 +7862,33 @@ Output_data_plt_arm<big_endian>::do_write(Output_file* of)
+       this->fill_plt_entry(pov, got_address, plt_address,
+                           got_offset, plt_offset);
+ 
+-      // Set the entry in the GOT.
+-      elfcpp::Swap<32, big_endian>::writeval(got_pov, plt_address);
+      Arm_address value;
+      if (i < this->count_)
+       {
+         // For non-irelative got entries, the value is the beginning of plt.
+         value = plt_address;
+       }
+      else
+       {
+         // For irelative got entries, the value is the (global/local) symbol
+         // address.
+         const IRelative_data& idata =
+             this->irelative_data_vec_[i - this->count_];
+         if (idata.symbol_is_global_)
+           {
+             // Set the entry in the GOT for irelative symbols.  The content is
+             // the address of the ifunc, not the address of plt start.
+             const Sized_symbol<32>* sized_symbol = idata.u_.global;
+             gold_assert(sized_symbol->type() == elfcpp::STT_GNU_IFUNC);
+             value = sized_symbol->value();
+           }
+         else
+           {
+             value = idata.u_.local.relobj->local_symbol_value(
+                 idata.u_.local.index, 0);
+           }
+       }
+      elfcpp::Swap<32, big_endian>::writeval(got_pov, value);
+     }
+ 
+   gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
+@@ -7529,6 +7898,7 @@ Output_data_plt_arm<big_endian>::do_write(Output_file* of)
+   of->write_output_view(got_file_offset, got_size, got_view);
+ }
+ 
+
+ // Create a PLT entry for a global symbol.
+ 
+ template<bool big_endian>
+@@ -7540,20 +7910,58 @@ Target_arm<big_endian>::make_plt_entry(Symbol_table* symtab, Layout* layout,
+     return;
+ 
+   if (this->plt_ == NULL)
+    this->make_plt_section(symtab, layout);
+
+  this->plt_->add_entry(symtab, layout, gsym);
+}
+
+
+// Create the PLT section.
+template<bool big_endian>
+void
+Target_arm<big_endian>::make_plt_section(
+  Symbol_table* symtab, Layout* layout)
+{
+  if (this->plt_ == NULL)
+     {
+-      // Create the GOT sections first.
+      // Create the GOT section first.
+       this->got_section(symtab, layout);
+ 
+-      this->plt_ = this->make_data_plt(layout, this->got_plt_);
+      // GOT for irelatives is create along with got.plt.
+      gold_assert(this->got_ != NULL
+                 && this->got_plt_ != NULL
+                 && this->got_irelative_ != NULL);
+      this->plt_ = this->make_data_plt(layout, this->got_, this->got_plt_,
+                                      this->got_irelative_);
+ 
+       layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
+                                      (elfcpp::SHF_ALLOC
+                                       | elfcpp::SHF_EXECINSTR),
+                                      this->plt_, ORDER_PLT, false);
+     }
+-  this->plt_->add_entry(gsym);
+ }
+ 
+
+// Make a PLT entry for a local STT_GNU_IFUNC symbol.
+
+template<bool big_endian>
+void
+Target_arm<big_endian>::make_local_ifunc_plt_entry(
+    Symbol_table* symtab, Layout* layout,
+    Sized_relobj_file<32, big_endian>* relobj,
+    unsigned int local_sym_index)
+{
+  if (relobj->local_has_plt_offset(local_sym_index))
+    return;
+  if (this->plt_ == NULL)
+    this->make_plt_section(symtab, layout);
+  unsigned int plt_offset = this->plt_->add_local_ifunc_entry(symtab, layout,
+                                                             relobj,
+                                                             local_sym_index);
+  relobj->set_local_plt_offset(local_sym_index, plt_offset);
+}
+
+
+ // Return the number of entries in the PLT.
+ 
+ template<bool big_endian>
+@@ -7823,6 +8231,7 @@ Target_arm<big_endian>::Scan::check_non_pic(Relobj* object,
+     case elfcpp::R_ARM_JUMP_SLOT:
+     case elfcpp::R_ARM_ABS32:
+     case elfcpp::R_ARM_ABS32_NOI:
+    case elfcpp::R_ARM_IRELATIVE:
+     case elfcpp::R_ARM_PC24:
+     // FIXME: The following 3 types are not supported by Android's dynamic
+     // linker.
+@@ -7853,6 +8262,27 @@ Target_arm<big_endian>::Scan::check_non_pic(Relobj* object,
+     }
+ }
+ 
+
+// Return whether we need to make a PLT entry for a relocation of the
+// given type against a STT_GNU_IFUNC symbol.
+
+template<bool big_endian>
+bool
+Target_arm<big_endian>::Scan::reloc_needs_plt_for_ifunc(
+    Sized_relobj_file<32, big_endian>* object,
+    unsigned int r_type)
+{
+  int flags = Scan::get_reference_flags(r_type);
+  if (flags & Symbol::TLS_REF)
+    {
+      gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
+                object->name().c_str(), r_type);
+      return false;
+    }
+  return flags != 0;
+}
+
+
+ // Scan a relocation for a local symbol.
+ // FIXME: This only handles a subset of relocation types used by Android
+ // on ARM v5te devices.
+@@ -7874,6 +8304,15 @@ Target_arm<big_endian>::Scan::local(Symbol_table* symtab,
+     return;
+ 
+   r_type = get_real_reloc_type(r_type);
+
+  // A local STT_GNU_IFUNC symbol may require a PLT entry.
+  bool is_ifunc = lsym.get_st_type() == elfcpp::STT_GNU_IFUNC;
+  if (is_ifunc && this->reloc_needs_plt_for_ifunc(object, r_type))
+    {
+      unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
+      target->make_local_ifunc_plt_entry(symtab, layout, object, r_sym);
+    }
+
+   switch (r_type)
+     {
+     case elfcpp::R_ARM_NONE:
+@@ -7898,7 +8337,7 @@ Target_arm<big_endian>::Scan::local(Symbol_table* symtab,
+          // we need to add check_non_pic(object, r_type) here.
+          rel_dyn->add_local_relative(object, r_sym, elfcpp::R_ARM_RELATIVE,
+                                      output_section, data_shndx,
+-                                     reloc.get_r_offset());
+                                     reloc.get_r_offset(), is_ifunc);
+        }
+       break;
+ 
+@@ -8265,6 +8704,11 @@ Target_arm<big_endian>::Scan::global(Symbol_table* symtab,
+       && strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
+     target->got_section(symtab, layout);
+ 
+  // A STT_GNU_IFUNC symbol may require a PLT entry.
+  if (gsym->type() == elfcpp::STT_GNU_IFUNC
+      && this->reloc_needs_plt_for_ifunc(object, r_type))
+    target->make_plt_entry(symtab, layout, gsym);
+
+   r_type = get_real_reloc_type(r_type);
+   switch (r_type)
+     {
+@@ -8309,6 +8753,24 @@ Target_arm<big_endian>::Scan::global(Symbol_table* symtab,
+              }
+            else if ((r_type == elfcpp::R_ARM_ABS32
+                      || r_type == elfcpp::R_ARM_ABS32_NOI)
+                    && gsym->type() == elfcpp::STT_GNU_IFUNC
+                    && gsym->can_use_relative_reloc(false)
+                    && !gsym->is_from_dynobj()
+                    && !gsym->is_undefined()
+                    && !gsym->is_preemptible())
+             {
+               // Use an IRELATIVE reloc for a locally defined STT_GNU_IFUNC
+               // symbol. This makes a function address in a PIE executable
+               // match the address in a shared library that it links against.
+               Reloc_section* rel_irelative =
+                   target->rel_irelative_section(layout);
+               unsigned int r_type = elfcpp::R_ARM_IRELATIVE;
+               rel_irelative->add_symbolless_global_addend(
+                   gsym, r_type, output_section, object,
+                   data_shndx, reloc.get_r_offset());
+             }
+           else if ((r_type == elfcpp::R_ARM_ABS32
+                     || r_type == elfcpp::R_ARM_ABS32_NOI)
+                     && gsym->can_use_relative_reloc(false))
+              {
+                Reloc_section* rel_dyn = target->rel_dyn_section(layout);
+@@ -8442,7 +8904,13 @@ Target_arm<big_endian>::Scan::global(Symbol_table* symtab,
+        Arm_output_data_got<big_endian>* got =
+          target->got_section(symtab, layout);
+        if (gsym->final_value_is_known())
+-         got->add_global(gsym, GOT_TYPE_STANDARD);
+         {
+           // For a STT_GNU_IFUNC symbol we want the PLT address.
+           if (gsym->type() == elfcpp::STT_GNU_IFUNC)
+             got->add_global_plt(gsym, GOT_TYPE_STANDARD);
+           else
+             got->add_global(gsym, GOT_TYPE_STANDARD);
+         }
+        else
+          {
+            // If this symbol is not fully resolved, we need to add a
+@@ -8452,12 +8920,29 @@ Target_arm<big_endian>::Scan::global(Symbol_table* symtab,
+                || gsym->is_undefined()
+                || gsym->is_preemptible()
+                || (gsym->visibility() == elfcpp::STV_PROTECTED
+-                   && parameters->options().shared()))
+                   && parameters->options().shared())
+               || (gsym->type() == elfcpp::STT_GNU_IFUNC
+                   && parameters->options().output_is_position_independent()))
+              got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
+                                       rel_dyn, elfcpp::R_ARM_GLOB_DAT);
+            else
+              {
+-               if (got->add_global(gsym, GOT_TYPE_STANDARD))
+               // For a STT_GNU_IFUNC symbol we want to write the PLT
+               // offset into the GOT, so that function pointer
+               // comparisons work correctly.
+               bool is_new;
+               if (gsym->type() != elfcpp::STT_GNU_IFUNC)
+                 is_new = got->add_global(gsym, GOT_TYPE_STANDARD);
+               else
+                 {
+                   is_new = got->add_global_plt(gsym, GOT_TYPE_STANDARD);
+                   // Tell the dynamic linker to use the PLT address
+                   // when resolving relocations.
+                   if (gsym->is_from_dynobj()
+                       && !parameters->options().shared())
+                     gsym->set_needs_dynsym_value();
+                 }
+               if (is_new)
+                  rel_dyn->add_global_relative(
+                      gsym, elfcpp::R_ARM_RELATIVE, got,
+                      gsym->got_offset(GOT_TYPE_STANDARD));
+@@ -8919,8 +9404,7 @@ Target_arm<big_endian>::Relocate::relocate(
+          if (gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
+            {
+              // This uses a PLT, change the symbol value.
+-             symval.set_output_value(target->plt_section()->address()
+-                                     + gsym->plt_offset());
+             symval.set_output_value(target->plt_address_for_global(gsym));
+              psymval = &symval;
+            }
+          else if (gsym->is_weak_undefined())
+@@ -8958,6 +9442,13 @@ Target_arm<big_endian>::Relocate::relocate(
+          elfcpp::Elf_types<32>::Elf_WXword r_info = rel.get_r_info();
+          unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
+          thumb_bit = object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
+
+         if (psymval->is_ifunc_symbol() && object->local_has_plt_offset(r_sym))
+           {
+             symval.set_output_value(
+                 target->plt_address_for_local(object, r_sym));
+             psymval = &symval;
+           }
+        }
+     }
+   else
+@@ -9936,7 +10427,7 @@ uint64_t
+ Target_arm<big_endian>::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 this->plt_address_for_global(gsym);
+ }
+ 
+ // Map platform-specific relocs to real relocs
+@@ -11083,8 +11574,7 @@ Target_arm<big_endian>::scan_reloc_for_stub(
+       if (gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
+        {
+          // This uses a PLT, change the symbol value.
+-         symval.set_output_value(this->plt_section()->address()
+-                                 + gsym->plt_offset());
+         symval.set_output_value(this->plt_address_for_global(gsym));
+          psymval = &symval;
+          target_is_thumb = false;
+        }
+@@ -12187,8 +12677,13 @@ class Target_arm_nacl : public Target_arm<big_endian>
+ 
+  protected:
+   virtual Output_data_plt_arm<big_endian>*
+-  do_make_data_plt(Layout* layout, Output_data_space* got_plt)
+-  { return new Output_data_plt_arm_nacl<big_endian>(layout, got_plt); }
+  do_make_data_plt(
+                  Layout* layout,
+                  Arm_output_data_got<big_endian>* got,
+                  Output_data_space* got_plt,
+                  Output_data_space* got_irelative)
+  { return new Output_data_plt_arm_nacl<big_endian>(
+      layout, got, got_plt, got_irelative); }
+ 
+  private:
+   static const Target::Target_info arm_nacl_info;
+@@ -12225,8 +12720,12 @@ template<bool big_endian>
+ class Output_data_plt_arm_nacl : public Output_data_plt_arm<big_endian>
+ {
+  public:
+-  Output_data_plt_arm_nacl(Layout* layout, Output_data_space* got_plt)
+-    : Output_data_plt_arm<big_endian>(layout, 16, got_plt)
+  Output_data_plt_arm_nacl(
+      Layout* layout,
+      Arm_output_data_got<big_endian>* got,
+      Output_data_space* got_plt,
+      Output_data_space* got_irelative)
+    : Output_data_plt_arm<big_endian>(layout, 16, got, got_plt, got_irelative)
+   { }
+ 
+  protected:
+diff --git a/gold/output.h b/gold/output.h
+index ba0cdaa..599c2b7 100644
+--- a/gold/output.h
+++ b/gold/output.h
+@@ -1714,6 +1714,17 @@ class Output_data_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>
+                                    address, true, true, false, false));
+   }
+ 
+  void
+  add_local_relative(Sized_relobj<size, big_endian>* relobj,
+                    unsigned int local_sym_index, unsigned int type,
+                    Output_data* od, unsigned int shndx, Address address,
+                    bool use_plt_offset)
+  {
+    this->add(od, Output_reloc_type(relobj, local_sym_index, type, shndx,
+                                   address, true, true, false,
+                                   use_plt_offset));
+  }
+
+   // Add a local relocation which does not use a symbol for the relocation,
+   // but which gets its addend from a symbol.
+ 
+-- 
+2.7.0
author	Khem Raj <raj.khem@gmail.com>	2016-01-14 03:58:10 -0800
committer	Richard Purdie <richard.purdie@linuxfoundation.org>	2016-01-24 09:40:31 +0000
commit	136db70700ce198f793935d0683ce4e1f1acf471 (patch)
tree	4d197ae3c35c91a8dee182f21158873abd6e1fa5
parent	704e34213ed2925ab3ac135717861c4ff466e8ab (diff)
download	poky-136db70700ce198f793935d0683ce4e1f1acf471.tar.gz