CET shouldn't be enabled in 32-bit run-time libraries by defualt

ENDBR32 and RDSSPD are multi-byte NOPs on x86-64 processors and
newer x86 processors, starting Pentium Pro.  They are UD on older
32-bit processors. Detect this at configure time and adjust the
default value for enable_cet. GCC will enable CET in 32-bit run-time
libraries in any case if --enable-cet is used to configure GCC.

	PR target/84148
	* config/cet.m4: Check if target support multi-byte NOPS (SSE).
	* libatomic/configure: Regenerate.
	* libbacktrace/configure: Likewise.
	* libgcc/configure: Likewise.
	* libgfortran/configure: Likewise.
	* libgomp/configure: Likewise.
	* libitm/configure: Likewise.
	* libmpx/configure: Likewise.
	* libobjc/configure: Likewise.
	* libquadmath/configure: Likewise.
	* libsanitizer/configure: Likewise.
	* libssp/configure: Likewise.
	* libstdc++-v3/configure: Likewise.
	* libvtv/configure: Likewise.

From-SVN: r257809

2 files changed, 23 insertions, 3 deletions

diff --git a/libobjc/ChangeLog b/libobjc/ChangeLog
index 50d07690e71..b5422e3845f 100644
--- a/libobjc/ChangeLog
+++ b/libobjc/ChangeLog
@@ -1,3 +1,8 @@
+2018-02-14  Igor Tsimbalist  <igor.v.tsimbalist@intel.com>
+
+	PR target/84148
+	* configure: Regenerate.
+
 2018-01-03  Jakub Jelinek  <jakub@redhat.com>
 
 	Update copyright years.
diff --git a/libobjc/configure b/libobjc/configure
index 3a2b2e36634..ce52fab100c 100755
--- a/libobjc/configure
+++ b/libobjc/configure
@@ -3369,18 +3369,28 @@ else
 fi
 
 
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for CET support" >&5
+$as_echo_n "checking for CET support... " >&6; }
+
 case "$host" in
   i[34567]86-*-linux* | x86_64-*-linux*)
     case "$enable_cet" in
       default)
-	# Check if assembler supports CET.
+	# Check if target supports multi-byte NOPs
+	# and if assembler supports CET insn.
 	cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
 main ()
 {
+
+#if !defined(__SSE2__)
+#error target does not support multi-byte NOPs
+#else
 asm ("setssbsy");
+#endif
+
   ;
   return 0;
 }
@@ -3420,6 +3430,11 @@ rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
 esac
 if test x$enable_cet = xyes; then
   CET_FLAGS="-fcf-protection -mcet"
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
 fi
 
 XCFLAGS="$XCFLAGS $CET_FLAGS"
@@ -10668,7 +10683,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 10671 "configure"
+#line 10686 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -10774,7 +10789,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 10777 "configure"
+#line 10792 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H