[GOLD] Make powerpc64 .branch_lt relro

Better security beats better placement for code optimization.

	* powerpc.cc (Target_powerpc::make_brlt_section): Make .branch_lt relro.

diff --git a/gold/ChangeLog b/gold/ChangeLog
index bba5942..0e6ec0c 100644 (file)
--- a/gold/ChangeLog
+++ b/gold/ChangeLog
@@ -1,3 +1,7 @@
+2018-04-05  Alan Modra  <amodra@gmail.com>
+
+       * powerpc.cc (Target_powerpc::make_brlt_section): Make .branch_lt relro.
+
 2018-04-04  Nick Clifton  <nickc@redhat.com>
 
        * po/es.po: Updated Spanish translation.

diff --git a/gold/powerpc.cc b/gold/powerpc.cc
index 39bda35..bddc2b8 100644 (file)
--- a/gold/powerpc.cc
+++ b/gold/powerpc.cc
@@ -4034,9 +4034,8 @@ Target_powerpc<size, big_endian>::make_brlt_section(Layout* layout)
       bool is_pic = parameters->options().output_is_position_independent();
       if (is_pic)
        {
-         // When PIC we can't fill in .branch_lt (like .plt it can be
-         // a bss style section) but must initialise at runtime via
-         // dynamic relocations.
+         // When PIC we can't fill in .branch_lt but must initialise at
+         // runtime via dynamic relocations.
          this->rela_dyn_section(layout);
          brlt_rel = new Reloc_section(false);
          if (this->rela_dyn_->output_section())
@@ -4050,13 +4049,11 @@ Target_powerpc<size, big_endian>::make_brlt_section(Layout* layout)
          ->add_output_section_data(this->brlt_section_);
       else
        layout->add_output_section_data(".branch_lt",
-                                       (is_pic ? elfcpp::SHT_NOBITS
-                                        : elfcpp::SHT_PROGBITS),
+                                       elfcpp::SHT_PROGBITS,
                                        elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
                                        this->brlt_section_,
-                                       (is_pic ? ORDER_SMALL_BSS
-                                        : ORDER_SMALL_DATA),
-                                       false);
+                                       ORDER_RELRO,
+                                       true);
     }
 }