Add -z noextern-protected-data to ld for ELF/x86

Address of protected data defined in the shared library may be external,
i.e., due to copy relocation.  By default, linker backend checks if
relocations against protected data symbols are valid for building shared
library and issues an error if relocation isn't allowed.  The new option
override linker backend default.  When -z noextern-protected-data is used,
updates on protected data symbols by another module won't be visibile
to the resulting shared library.  This option is specific to ELF/i386
and ELF/x86-64.

bfd/

	PR ld/pr17709
	* elflink.c (_bfd_elf_adjust_dynamic_copy): Check
	info->extern_protected_data when warning copy relocs against
	protected symbols.
	(_bfd_elf_symbol_refs_local_p): Check info->extern_protected_data
	when checking protected non-function symbols.

include/

	PR ld/pr17709
	* bfdlink.h (bfd_link_info): Add extern_protected_data.

ld/

	PR ld/pr17709
	* ld.texinfo: Document "-z noextern-protected-data".
	* ldmain.c (main): Initialize link_info.extern_protected_data
	to -1.
	* lexsup.c (elf_shlib_list_options): Add
	"-z [no]extern-protected-data".
	* emulparams/elf32_x86_64.sh: Source extern_protected_data.sh.
	* emulparams/elf_i386.sh: Likewise.
	* emulparams/elf_i386_be.sh: Likewise.
	* emulparams/elf_i386_chaos.sh: Likewise.
	* emulparams/elf_i386_ldso.sh: Likewise.
	* emulparams/elf_i386_vxworks.sh: Likewise.
	* emulparams/elf_k1om.sh: Likewise.
	* emulparams/elf_l1om.sh: Likewise.
	* emulparams/elf_x86_64.sh: Source extern_protected_data.sh.
	(PARSE_AND_LIST_OPTIONS): Renamed to ...
	(PARSE_AND_LIST_OPTIONS_BNDPLT): This.
	(PARSE_AND_LIST_ARGS_CASE_Z): Renamed to ...
	(PARSE_AND_LIST_ARGS_CASE_Z_BNDPLT): This.
	(PARSE_AND_LIST_OPTIONS): Append $PARSE_AND_LIST_OPTIONS_BNDPLT.
	(PARSE_AND_LIST_ARGS_CASE_Z): Append
	$PARSE_AND_LIST_ARGS_CASE_Z_BNDPLT.
	* emulparams/extern_protected_data.sh: New file.

ld/testsuite/

	PR ld/pr17709
	* ld-i386/i386.exp: Run protected6b.
	* ld-i386/protected6b.d: New file.
	* ld-x86-64/protected6b.d: Likewise.
	* ld-x86-64/x86-64.exp:  Run protected6b.

22 files changed, 105 insertions, 4 deletions

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 55c37f0..056833e 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,12 @@
+2015-04-14  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR ld/pr17709
+	* elflink.c (_bfd_elf_adjust_dynamic_copy): Check
+	info->extern_protected_data when warning copy relocs against
+	protected symbols.
+	(_bfd_elf_symbol_refs_local_p): Check info->extern_protected_data
+	when checking protected non-function symbols.
+
 2015-04-13  John Baldwin  <jhb@FreeBSD.org>
 
 	* elf.c (elfcore_grok_note): Recognize NT_X86_XSTATE on
diff --git a/bfd/elflink.c b/bfd/elflink.c
index e3d1abe..ea9246b 100644
--- a/bfd/elflink.c
+++ b/bfd/elflink.c
@@ -2675,7 +2675,9 @@ _bfd_elf_adjust_dynamic_copy (struct bfd_link_info *info,
 
   /* No error if extern_protected_data is true.  */
   if (h->protected_def
-      && !get_elf_backend_data (dynbss->owner)->extern_protected_data)
+      && (!info->extern_protected_data
+	  || (info->extern_protected_data < 0
+	      && !get_elf_backend_data (dynbss->owner)->extern_protected_data)))
     info->callbacks->einfo
       (_("%P: copy reloc against protected `%T' is dangerous\n"),
        h->root.root.string);
@@ -2837,7 +2839,10 @@ _bfd_elf_symbol_refs_local_p (struct elf_link_hash_entry *h,
 
   /* If extern_protected_data is false, STV_PROTECTED non-function
      symbols are local.  */
-  if (!bed->extern_protected_data && !bed->is_function_type (h->type))
+  if ((!info->extern_protected_data
+       || (info->extern_protected_data < 0
+	   && !bed->extern_protected_data))
+      && !bed->is_function_type (h->type))
     return TRUE;
 
   /* Function pointer equality tests may require that STV_PROTECTED
diff --git a/include/ChangeLog b/include/ChangeLog
index 35da015..7d4919d 100644
--- a/include/ChangeLog
+++ b/include/ChangeLog
@@ -1,3 +1,8 @@
+2015-04-14  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR ld/pr17709
+	* bfdlink.h (bfd_link_info): Add extern_protected_data.
+
 2015-03-10  Matthew Wahab  <matthew.wahab@arm.com>
 
 	PR ld/16572
diff --git a/include/bfdlink.h b/include/bfdlink.h
index 6a02a3c..1b15826 100644
--- a/include/bfdlink.h
+++ b/include/bfdlink.h
@@ -517,6 +517,11 @@ struct bfd_link_info
      relaxation returning true in *AGAIN.  */
   int relax_trip;
 
+  /* > 0 to treat protected data defined in the shared library as
+     reference external.  0 to treat it as internal.  -1 to let
+     backend to decide.  */
+  int extern_protected_data;
+
   /* Non-zero if auto-import thunks for DATA items in pei386 DLLs
      should be generated/linked against.  Set to 1 if this feature
      is explicitly requested by the user, -1 if enabled by default.  */
diff --git a/ld/ChangeLog b/ld/ChangeLog
index bcad3f9..3e944fe 100644
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,3 +1,29 @@
+2015-04-14  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR ld/pr17709
+	* ld.texinfo: Document "-z noextern-protected-data".
+	* ldmain.c (main): Initialize link_info.extern_protected_data
+	to -1.
+	* lexsup.c (elf_shlib_list_options): Add
+	"-z [no]extern-protected-data".
+	* emulparams/elf32_x86_64.sh: Source extern_protected_data.sh.
+	* emulparams/elf_i386.sh: Likewise.
+	* emulparams/elf_i386_be.sh: Likewise.
+	* emulparams/elf_i386_chaos.sh: Likewise.
+	* emulparams/elf_i386_ldso.sh: Likewise.
+	* emulparams/elf_i386_vxworks.sh: Likewise.
+	* emulparams/elf_k1om.sh: Likewise.
+	* emulparams/elf_l1om.sh: Likewise.
+	* emulparams/elf_x86_64.sh: Source extern_protected_data.sh.
+	(PARSE_AND_LIST_OPTIONS): Renamed to ...
+	(PARSE_AND_LIST_OPTIONS_BNDPLT): This.
+	(PARSE_AND_LIST_ARGS_CASE_Z): Renamed to ...
+	(PARSE_AND_LIST_ARGS_CASE_Z_BNDPLT): This.
+	(PARSE_AND_LIST_OPTIONS): Append $PARSE_AND_LIST_OPTIONS_BNDPLT.
+	(PARSE_AND_LIST_ARGS_CASE_Z): Append
+	$PARSE_AND_LIST_ARGS_CASE_Z_BNDPLT.
+	* emulparams/extern_protected_data.sh: New file.
+
 2015-04-11  H.J. Lu  <hongjiu.lu@intel.com>
 
 	* plugin.c (plugin_load_plugins): Removed an extra ';'.
diff --git a/ld/emulparams/elf32_x86_64.sh b/ld/emulparams/elf32_x86_64.sh
index 11d17ad..8fd96fb 100644
--- a/ld/emulparams/elf32_x86_64.sh
+++ b/ld/emulparams/elf32_x86_64.sh
@@ -1,4 +1,5 @@
 . ${srcdir}/emulparams/plt_unwind.sh
+. ${srcdir}/emulparams/extern_protected_data.sh
 SCRIPT_NAME=elf
 ELFSIZE=32
 OUTPUT_FORMAT="elf32-x86-64"
diff --git a/ld/emulparams/elf_i386.sh b/ld/emulparams/elf_i386.sh
index 2ebfaac..ae87f6b 100644
--- a/ld/emulparams/elf_i386.sh
+++ b/ld/emulparams/elf_i386.sh
@@ -1,4 +1,5 @@
 . ${srcdir}/emulparams/plt_unwind.sh
+. ${srcdir}/emulparams/extern_protected_data.sh
 SCRIPT_NAME=elf
 OUTPUT_FORMAT="elf32-i386"
 NO_RELA_RELOCS=yes
diff --git a/ld/emulparams/elf_i386_be.sh b/ld/emulparams/elf_i386_be.sh
index 1e27faa..06a80c7 100644
--- a/ld/emulparams/elf_i386_be.sh
+++ b/ld/emulparams/elf_i386_be.sh
@@ -1,3 +1,4 @@
+. ${srcdir}/emulparams/extern_protected_data.sh
 SCRIPT_NAME=elf
 OUTPUT_FORMAT="elf32-i386"
 NO_RELA_RELOCS=yes
diff --git a/ld/emulparams/elf_i386_chaos.sh b/ld/emulparams/elf_i386_chaos.sh
index b3005e1..c59dbce 100644
--- a/ld/emulparams/elf_i386_chaos.sh
+++ b/ld/emulparams/elf_i386_chaos.sh
@@ -1,4 +1,5 @@
 . ${srcdir}/emulparams/plt_unwind.sh
+. ${srcdir}/emulparams/extern_protected_data.sh
 SCRIPT_NAME=elf_chaos
 OUTPUT_FORMAT="elf32-i386"
 TEXT_START_ADDR=0x40000000
diff --git a/ld/emulparams/elf_i386_ldso.sh b/ld/emulparams/elf_i386_ldso.sh
index e1a2cb7..7fd08fe 100644
--- a/ld/emulparams/elf_i386_ldso.sh
+++ b/ld/emulparams/elf_i386_ldso.sh
@@ -1,4 +1,5 @@
 . ${srcdir}/emulparams/plt_unwind.sh
+. ${srcdir}/emulparams/extern_protected_data.sh
 SCRIPT_NAME=elf
 OUTPUT_FORMAT="elf32-i386"
 NO_RELA_RELOCS=yes
diff --git a/ld/emulparams/elf_i386_vxworks.sh b/ld/emulparams/elf_i386_vxworks.sh
index 61839c8..306e8d3 100644
--- a/ld/emulparams/elf_i386_vxworks.sh
+++ b/ld/emulparams/elf_i386_vxworks.sh
@@ -11,3 +11,4 @@ GENERATE_SHLIB_SCRIPT=yes
 GENERATE_PIE_SCRIPT=yes
 NO_SMALL_DATA=yes
 . ${srcdir}/emulparams/vxworks.sh
+. ${srcdir}/emulparams/extern_protected_data.sh
diff --git a/ld/emulparams/elf_k1om.sh b/ld/emulparams/elf_k1om.sh
index 00bf2ca..0cd606a 100644
--- a/ld/emulparams/elf_k1om.sh
+++ b/ld/emulparams/elf_k1om.sh
@@ -1,4 +1,5 @@
 . ${srcdir}/emulparams/plt_unwind.sh
+. ${srcdir}/emulparams/extern_protected_data.sh
 SCRIPT_NAME=elf
 ELFSIZE=64
 OUTPUT_FORMAT="elf64-k1om"
diff --git a/ld/emulparams/elf_l1om.sh b/ld/emulparams/elf_l1om.sh
index abf59f1..1964e85 100644
--- a/ld/emulparams/elf_l1om.sh
+++ b/ld/emulparams/elf_l1om.sh
@@ -1,4 +1,5 @@
 . ${srcdir}/emulparams/plt_unwind.sh
+. ${srcdir}/emulparams/extern_protected_data.sh
 SCRIPT_NAME=elf
 ELFSIZE=64
 OUTPUT_FORMAT="elf64-l1om"
diff --git a/ld/emulparams/elf_x86_64.sh b/ld/emulparams/elf_x86_64.sh
index 984e5e9..a304771 100644
--- a/ld/emulparams/elf_x86_64.sh
+++ b/ld/emulparams/elf_x86_64.sh
@@ -1,4 +1,5 @@
 . ${srcdir}/emulparams/plt_unwind.sh
+. ${srcdir}/emulparams/extern_protected_data.sh
 SCRIPT_NAME=elf
 ELFSIZE=64
 OUTPUT_FORMAT="elf64-x86-64"
@@ -36,14 +37,16 @@ case "$target" in
     case "$EMULATION_NAME" in
       *64*)
         LIBPATH_SUFFIX=64
-	PARSE_AND_LIST_OPTIONS='
+	PARSE_AND_LIST_OPTIONS_BNDPLT='
   fprintf (file, _("\
   -z bndplt                   Always generate BND prefix in PLT entries\n"));
 '
-	PARSE_AND_LIST_ARGS_CASE_Z='
+	PARSE_AND_LIST_ARGS_CASE_Z_BNDPLT='
       else if (strcmp (optarg, "bndplt") == 0)
 	link_info.bndplt = TRUE;
 '
+	PARSE_AND_LIST_OPTIONS="$PARSE_AND_LIST_OPTIONS $PARSE_AND_LIST_OPTIONS_BNDPLT"
+	PARSE_AND_LIST_ARGS_CASE_Z="$PARSE_AND_LIST_ARGS_CASE_Z $PARSE_AND_LIST_ARGS_CASE_Z_BNDPLT"
         ;;
     esac
     ;;
diff --git a/ld/emulparams/extern_protected_data.sh b/ld/emulparams/extern_protected_data.sh
new file mode 100644
index 0000000..fd4bd3b
--- /dev/null
+++ b/ld/emulparams/extern_protected_data.sh
@@ -0,0 +1,9 @@
+PARSE_AND_LIST_OPTIONS='
+  fprintf (file, _("\
+  -z noextern-protected-data  Do not treat protected data symbol as external\n"));
+'
+
+PARSE_AND_LIST_ARGS_CASE_Z='
+      else if (strcmp (optarg, "noextern-protected-data") == 0)
+	link_info.extern_protected_data = FALSE;
+'
diff --git a/ld/ld.texinfo b/ld/ld.texinfo
index 5384c98..4348c88 100644
--- a/ld/ld.texinfo
+++ b/ld/ld.texinfo
@@ -1146,6 +1146,14 @@ Specifying zero will override any default non-zero sized
 @item bndplt
 Always generate BND prefix in PLT entries. Supported for Linux/x86_64.
 
+@item noextern-protected-data
+Don't treat protected data symbol as external when building shared
+library.  This option overrides linker backend default.  It can be used
+to workaround incorrect relocations against protected data symbols
+generated by compiler.  Updates on protected data symbols by another
+module aren't visibile to the resulting shared library.  Supported for
+i386 and x86-64.
+
 @end table
 
 Other keywords are ignored for Solaris compatibility.
diff --git a/ld/ldmain.c b/ld/ldmain.c
index 6674a80..2ecb92d 100644
--- a/ld/ldmain.c
+++ b/ld/ldmain.c
@@ -285,6 +285,7 @@ main (int argc, char **argv)
   link_info.init_function = "_init";
   link_info.fini_function = "_fini";
   link_info.relax_pass = 1;
+  link_info.extern_protected_data = -1;
   link_info.pei386_auto_import = -1;
   link_info.spare_dynamic_tags = 5;
   link_info.path_separator = ':';
diff --git a/ld/testsuite/ChangeLog b/ld/testsuite/ChangeLog
index 8b45279..b35eb83 100644
--- a/ld/testsuite/ChangeLog
+++ b/ld/testsuite/ChangeLog
@@ -1,3 +1,11 @@
+2015-04-14  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR ld/pr17709
+	* ld-i386/i386.exp: Run protected6b.
+	* ld-i386/protected6b.d: New file.
+	* ld-x86-64/protected6b.d: Likewise.
+	* ld-x86-64/x86-64.exp:  Run protected6b.
+
 2015-04-11  H.J. Lu  <hongjiu.lu@intel.com>
 
 	* ld-i386/i386.exp: Run protected6a.
diff --git a/ld/testsuite/ld-i386/i386.exp b/ld/testsuite/ld-i386/i386.exp
index 0c0fd96..f214d89 100644
--- a/ld/testsuite/ld-i386/i386.exp
+++ b/ld/testsuite/ld-i386/i386.exp
@@ -237,6 +237,7 @@ run_dump_test "protected3"
 run_dump_test "protected4"
 run_dump_test "protected5"
 run_dump_test "protected6a"
+run_dump_test "protected6b"
 run_dump_test "tlspie1"
 run_dump_test "tlspie2"
 run_dump_test "nogot1"
diff --git a/ld/testsuite/ld-i386/protected6b.d b/ld/testsuite/ld-i386/protected6b.d
new file mode 100644
index 0000000..5642c60
--- /dev/null
+++ b/ld/testsuite/ld-i386/protected6b.d
@@ -0,0 +1,6 @@
+#source: protected6.s
+#as: --32
+#ld: -shared -melf_i386 -z noextern-protected-data
+#readelf: -r
+
+There are no relocations in this file.
diff --git a/ld/testsuite/ld-x86-64/protected6b.d b/ld/testsuite/ld-x86-64/protected6b.d
new file mode 100644
index 0000000..8b44331
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/protected6b.d
@@ -0,0 +1,6 @@
+#source: protected6.s
+#as: --64
+#ld: -shared -melf_x86_64 -z noextern-protected-data
+#readelf: -r
+
+There are no relocations in this file.
diff --git a/ld/testsuite/ld-x86-64/x86-64.exp b/ld/testsuite/ld-x86-64/x86-64.exp
index 213a4c0..8352ad9 100644
--- a/ld/testsuite/ld-x86-64/x86-64.exp
+++ b/ld/testsuite/ld-x86-64/x86-64.exp
@@ -221,6 +221,7 @@ run_dump_test "protected3-l1om"
 run_dump_test "protected4"
 run_dump_test "protected5"
 run_dump_test "protected6a"
+run_dump_test "protected6b"
 run_dump_test "protected7a"
 run_dump_test "protected7b"
 run_dump_test "tlsle1"