Backport trunk patch for not applying dynamic relocs.

Note, there is a small change from the origin patch - while in the
upstream patch, the option --no-apply-dynamic is default off, it is on
by default in this CL.

This should not bring any changes to android or chromeos, because the
relocation value this CL changes is not used by chromeos, and is not
used by android either (after the fix in bionic months ago).

The backported patch is -

  commit 0eccf19f96d6218dd7c2f8d13f0546c2b942cc08
  Author: Cary Coutant <ccoutant@gmail.com>
  Date:   Thu Nov 5 12:24:14 2015 -0800

      Add aarch64-specific --no-apply-dynamic-relocs option.

      With --no-apply-dynamic-relocs on aarch64 targets, gold will not
      apply
      link-time values for absolute relocations that become dynamic
      relocations.
      This provides a workaround for broken Android dynamic linkers that
      use
      the link-time value as an extra addend to the relocation.

      gold/
          PR gold/19163
          * aarch64.cc (Target_aarch64::Relocate::relocate): Don't apply
          certain relocations if --no-apply-dynamic-relocs is set.
          * options.h (--apply-dynamic-relocs): New aarch64-specific
          option.

Tested - build whole toolchain and built android N9 image.

Change-Id: Ida524bbee2a83574cd9e78ffdad9270787327c78

3 files changed, 40 insertions, 1 deletions

diff --git a/binutils-2.25/gold/ChangeLog b/binutils-2.25/gold/ChangeLog
index 24e87559..bf9cc55c 100644
--- a/binutils-2.25/gold/ChangeLog
+++ b/binutils-2.25/gold/ChangeLog
@@ -1,4 +1,11 @@
-2015-10.27  Han Shen  <shenhan@google.com>
+2015-11-05  Cary Coutant  <ccoutant@gmail.com>
+
+	PR gold/19163
+	* aarch64.cc (Target_aarch64::Relocate::relocate): Don't apply
+	certain relocations if --no-apply-dynamic-relocs is set.
+	* options.h (--apply-dynamic-relocs): New aarch64-specific option.
+
+2015-10-27  Han Shen  <shenhan@google.com>
 
 	PR gold/19042 - unsupported reloc 311/312.
 
diff --git a/binutils-2.25/gold/aarch64.cc b/binutils-2.25/gold/aarch64.cc
index 1148bf7f..1cc68d1e 100644
--- a/binutils-2.25/gold/aarch64.cc
+++ b/binutils-2.25/gold/aarch64.cc
@@ -6907,16 +6907,41 @@ Target_aarch64<size, big_endian>::Relocate::relocate(
       break;
 
     case elfcpp::R_AARCH64_ABS64:
+      if (!parameters->options().apply_dynamic_relocs()
+          && parameters->options().output_is_position_independent()
+          && gsym != NULL
+          && gsym->needs_dynamic_reloc(reloc_property->reference_flags())
+          && !gsym->can_use_relative_reloc(false))
+        // We have generated an absolute dynamic relocation, so do not
+        // apply the relocation statically. (Works around bugs in older
+        // Android dynamic linkers.)
+        break;
       reloc_status = Reloc::template rela_ua<64>(
 	view, object, psymval, addend, reloc_property);
       break;
 
     case elfcpp::R_AARCH64_ABS32:
+      if (!parameters->options().apply_dynamic_relocs()
+          && parameters->options().output_is_position_independent()
+          && gsym != NULL
+          && gsym->needs_dynamic_reloc(reloc_property->reference_flags()))
+        // We have generated an absolute dynamic relocation, so do not
+        // apply the relocation statically. (Works around bugs in older
+        // Android dynamic linkers.)
+        break;
       reloc_status = Reloc::template rela_ua<32>(
 	view, object, psymval, addend, reloc_property);
       break;
 
     case elfcpp::R_AARCH64_ABS16:
+      if (!parameters->options().apply_dynamic_relocs()
+          && parameters->options().output_is_position_independent()
+          && gsym != NULL
+          && gsym->needs_dynamic_reloc(reloc_property->reference_flags()))
+        // We have generated an absolute dynamic relocation, so do not
+        // apply the relocation statically. (Works around bugs in older
+        // Android dynamic linkers.)
+        break;
       reloc_status = Reloc::template rela_ua<16>(
 	view, object, psymval, addend, reloc_property);
       break;
diff --git a/binutils-2.25/gold/options.h b/binutils-2.25/gold/options.h
index 6502e1fc..db5254b8 100644
--- a/binutils-2.25/gold/options.h
+++ b/binutils-2.25/gold/options.h
@@ -644,6 +644,13 @@ class General_options
 	      N_("Allow unresolved references in shared libraries"),
 	      N_("Do not allow unresolved references in shared libraries"));
 
+  // Note: this is cherry-picked from upstream patch 0eccf19f9. But the default
+  // value is changed from "true" to "false".
+  DEFINE_bool(apply_dynamic_relocs, options::TWO_DASHES, '\0', false,
+	      N_("Apply link-time values for dynamic relocations (default)"),
+	      N_("(aarch64 only) Do not apply link-time values "
+		 "for dynamic relocations"));
+
   DEFINE_bool(as_needed, options::TWO_DASHES, '\0', false,
 	      N_("Only set DT_NEEDED for shared libraries if used"),
 	      N_("Always DT_NEEDED for shared libraries"));