1 files changed, 20 insertions, 4 deletions

diff --git a/configure.ac b/configure.ac
index 952dec3b8..9a7a9d65e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -3,12 +3,27 @@ AC_INIT(firejail, 0.9.53, netblue30@yahoo.com, , http://firejail.wordpress.com)
 AC_CONFIG_SRCDIR([src/firejail/main.c])
 #AC_CONFIG_HEADERS([config.h])
 
-
 AC_PROG_CC
 #AC_PROG_CXX
 AC_PROG_INSTALL
 AC_PROG_RANLIB
 
+HAVE_SPECTRE="no"
+AC_MSG_CHECKING(for Spectre mitigation support in gcc compiler)
+AS_IF([test "$CC" = "gcc"], [
+        HAVE_SPECTRE="yes"
+        $CC -mindirect-branch=thunk -c dummy.c || HAVE_SPECTRE="no"
+        rm -f dummy.o
+])
+AS_IF([test "$HAVE_SPECTRE" = "yes"], [
+        AC_MSG_RESULT(yes)
+        EXTRA_CFLAGS+=" -mindirect-branch=thunk "
+])
+AS_IF([test "$HAVE_SPECTRE" = "no"], [
+        AC_MSG_RESULT(... not available)
+])
+AC_SUBST([EXTRA_CFLAGS])
+
 HAVE_APPARMOR=""
 AC_ARG_ENABLE([apparmor],
     AS_HELP_STRING([--enable-apparmor], [enable apparmor]))
@@ -17,13 +32,12 @@ AS_IF([test "x$enable_apparmor" = "xyes"], [
         AC_SUBST(HAVE_APPARMOR)
 ])
 
-
 AS_IF([test "x$enable_apparmor" = "xyes"], [
         AC_CHECK_HEADER(sys/apparmor.h, , [AC_MSG_ERROR(
         [Couldn't find sys/apparmor.h... please install apparmor user space library and development files] )])
 ])
 AS_IF([test "x$enable_apparmor" = "xyes"], [
-        EXTRA_LDFLAGS+="-lapparmor "
+        EXTRA_LDFLAGS+=" -lapparmor "
 ])
 AC_SUBST([EXTRA_LDFLAGS])
 
@@ -142,7 +156,7 @@ AC_ARG_ENABLE([gcov],
     AS_HELP_STRING([--enable-gcov], [Gcov instrumentation]))
 AS_IF([test "x$enable_gcov" = "xyes"], [
         HAVE_GCOV="--coverage -DHAVE_GCOV "
-        EXTRA_LDFLAGS+="-lgcov --coverage "
+        EXTRA_LDFLAGS+=" -lgcov --coverage "
         AC_SUBST(HAVE_GCOV)
 ])
 
@@ -198,7 +212,9 @@ echo "   file transfer support: $HAVE_FILE_TRANSFER"
 echo "   overlayfs support: $HAVE_OVERLAYFS"
 echo "   git install support: $HAVE_GIT_INSTALL"
 echo "   busybox workaround: $BUSYBOX_WORKAROUND"
+echo "   Spectre compiler patch: $HAVE_SPECTRE"
 echo "   EXTRA_LDFLAGS: $EXTRA_LDFLAGS"
+echo "   EXTRA_CFLAGS: $EXTRA_CFLAGS"
 echo "   fatal warnings: $HAVE_FATAL_WARNINGS"
 echo "   Gcov instrumentation: $HAVE_GCOV"
 echo "   Install contrib scripts: $HAVE_CONTRIB_INSTALL"