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.

10 files changed, 22 insertions, 2 deletions

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;
+'