* options.h (class General_options): Add -z relro.

	* layout.cc (Layout::Layout): Initialize relro_segment_.
	(Layout::add_output_section_data): Return the output section.
	(Layout::make_output_section): Rcognize relro sections and mark
	them appropriately.
	(Layout::attach_allocated_section_to_segment): Put relro sections
	in a PT_GNU_RELRO segment.
	(Layout::create_initial_dynamic_sections): Mark the .dynamic
	section as relro.
	(Layout::segment_precedes): Sort PT_GNU_RELRO segments after
	PT_TLS segments.
	(Layout::linkonce_mapping): Map d.rel.ro.local to
	.data.rel.ro.local.
	(Layout::output_section_name): Us .data.rel.ro.local for any
	section which begins with that.
	* layout.h (class Layout): Update add_output_section_data
	declaration.  Add relro_segment_ field.
	* output.cc (Output_section::Output_section): Initialize is_relro_
	and is_relro_local_ fields.
	(Output_segment::add_output_section): Group relro sections.
	(Output_segment::is_first_section_relro): New function.
	(Output_segment::maximum_alignment): If there is a relro section,
	align the segment to the common page size.
	(Output_segment::set_section_addresses): Track whether we are
	looking at relro sections.  If the last section is a relro
	section, align to the common page size.
	(Output_segment::set_section_list_addresses): Add in_relro
	parameter.  Change all callers.  Align to the page size when
	moving from relro to non-relro section.
	(Output_segment::set_offset): Align memsz of a PT_GNU_RELRO
	segment.
	* output.h (class Output_section): Add is_relro_ and
	is_relro_local_ fields.
	(Output_section::is_relro): New function.
	(Output_section::set_is_relro): New function.
	(Output_section::is_relro_local): New function.
	(Output_section::set_is_relro_local): New function.
	(class Output_segment): Update declarations.
	* i386.cc (Target_i386::got_section): Mark .got section as relro.
	* sparc.cc (Target_sparc::got_section): Likewise.
	* x86_64.cc (Target_x86_64::got_section): Likewise.
	* testsuite/relro_test_main.cc: New file.
	* testsuite/relro_test.cc: New file.
	* testsuite/Makefile.am (check_PROGRAMS): Add relro_test.
	(relro_test_SOURCES, relro_test_DEPENDENCIES): New variables.
	(relro_test_LDFLAGS, relro_test_LDADD): New variables.
	(relro_test.so, relro_test_pic.o): New targets.
	* testsuite/Makefile.in: Rebuild.

1 files changed, 32 insertions, 1 deletions

diff --git a/gold/output.h b/gold/output.h
index b4dbbd1..a8f2f39 100644
--- a/gold/output.h
+++ b/gold/output.h
@@ -2028,6 +2028,29 @@ class Output_section : public Output_data
   set_must_sort_attached_input_sections()
   { this->must_sort_attached_input_sections_ = true; }
 
+  // Return whether this section holds relro data--data which has
+  // dynamic relocations but which may be marked read-only after the
+  // dynamic relocations have been completed.
+  bool
+  is_relro() const
+  { return this->is_relro_; }
+
+  // Record that this section holds relro data.
+  void
+  set_is_relro()
+  { this->is_relro_ = true; }
+
+  // True if this section holds relro local data--relro data for which
+  // the dynamic relocations are all RELATIVE relocations.
+  bool
+  is_relro_local() const
+  { return this->is_relro_local_; }
+
+  // Record that this section holds relro local data.
+  void
+  set_is_relro_local()
+  { this->is_relro_local_ = true; }
+
   // Return whether this section should be written after all the input
   // sections are complete.
   bool
@@ -2626,6 +2649,10 @@ class Output_section : public Output_data
   // True if the input sections attached to this output section have
   // already been sorted.
   bool attached_input_sections_are_sorted_ : 1;
+  // True if this section holds relro data.
+  bool is_relro_ : 1;
+  // True if this section holds relro local data.
+  bool is_relro_local_ : 1;
   // For SHT_TLS sections, the offset of this section relative to the base
   // of the TLS segment.
   uint64_t tls_offset_;
@@ -2785,11 +2812,15 @@ class Output_segment
   static uint64_t
   maximum_alignment_list(const Output_data_list*);
 
+  // Return whether the first data section is a relro section.
+  bool
+  is_first_section_relro() const;
+
   // Set the section addresses in an Output_data_list.
   uint64_t
   set_section_list_addresses(const Layout*, bool reset, Output_data_list*,
                              uint64_t addr, off_t* poff, unsigned int* pshndx,
-                             bool* in_tls);
+                             bool* in_tls, bool* in_relro);
 
   // Return the number of Output_sections in an Output_data_list.
   unsigned int