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|
dnl
dnl GCC_CET_FLAGS
dnl (SHELL-CODE_HANDLER)
dnl
AC_DEFUN([GCC_CET_FLAGS],[dnl
GCC_ENABLE(cet, auto, ,[enable Intel CET in target libraries],
permit yes|no|auto)
AC_MSG_CHECKING([for CET support])
# NB: Avoid nested save_CFLAGS and save_LDFLAGS.
case "$host" in
i[[34567]]86-*-linux* | x86_64-*-linux*)
case "$enable_cet" in
auto)
# Check if target supports multi-byte NOPs
# and if compiler and assembler support CET insn.
cet_save_CFLAGS="$CFLAGS"
CFLAGS="$CFLAGS -fcf-protection"
AC_COMPILE_IFELSE(
[AC_LANG_PROGRAM(
[],
[
#if !defined(__SSE2__)
#error target does not support multi-byte NOPs
#else
asm ("setssbsy");
#endif
])],
[enable_cet=yes],
[enable_cet=no])
CFLAGS="$cet_save_CFLAGS"
;;
yes)
# Check if assembler supports CET.
AC_COMPILE_IFELSE(
[AC_LANG_PROGRAM(
[],
[asm ("setssbsy");])],
[],
[AC_MSG_ERROR([assembler with CET support is required for --enable-cet])])
;;
esac
;;
*)
enable_cet=no
;;
esac
if test x$enable_cet = xyes; then
$1="-fcf-protection -mshstk"
AC_MSG_RESULT([yes])
else
AC_MSG_RESULT([no])
fi
])
dnl
dnl GCC_CET_HOST_FLAGS
dnl (SHELL-CODE_HANDLER)
dnl
AC_DEFUN([GCC_CET_HOST_FLAGS],[dnl
GCC_ENABLE(cet, auto, ,[enable Intel CET in host libraries],
permit yes|no|auto)
AC_MSG_CHECKING([for CET support])
case "$host" in
i[[34567]]86-*-linux* | x86_64-*-linux*)
may_have_cet=yes
cet_save_CFLAGS="$CFLAGS"
CFLAGS="$CFLAGS -fcf-protection"
case "$enable_cet" in
auto)
# Check if target supports multi-byte NOPs
# and if compiler and assembler support CET.
AC_COMPILE_IFELSE(
[AC_LANG_PROGRAM(
[],
[
#if !defined(__SSE2__)
#error target does not support multi-byte NOPs
#else
asm ("setssbsy");
#endif
])],
[enable_cet=yes],
[enable_cet=no])
;;
yes)
# Check if compiler and assembler support CET.
AC_COMPILE_IFELSE(
[AC_LANG_PROGRAM(
[],
[asm ("setssbsy");])],
[support_cet=yes],
[support_cet=no])
if test $support_cet = "no"; then
if test x$enable_bootstrap != xno \
&& test -z "${with_build_subdir}" \
&& (test ! -f ../stage_current \
|| test `cat ../stage_current` != "stage1"); then
# Require CET support only for the final GCC build.
AC_MSG_ERROR([compiler and assembler with CET support are required for --enable-cet])
else
# Don't enable CET without CET support for non-bootstrap
# build, in stage1 nor for build support.
enable_cet=no
fi
fi
;;
esac
CFLAGS="$cet_save_CFLAGS"
;;
*)
may_have_cet=no
enable_cet=no
;;
esac
cet_save_CFLAGS="$CFLAGS"
CFLAGS="$CFLAGS -fcf-protection=none"
cet_save_LDFLAGS="$LDFLAGS"
LDFLAGS="$LDFLAGS -Wl,-z,ibt,-z,shstk"
if test x$may_have_cet = xyes; then
# Check whether -fcf-protection=none -Wl,-z,ibt,-z,shstk work.
AC_TRY_LINK(
[],[return 0;],
[may_have_cet=yes],
[may_have_cet=no])
fi
if test x$may_have_cet = xyes; then
if test x$cross_compiling = xno; then
AC_TRY_RUN([
int
main ()
{
asm ("endbr32");
return 0;
}
],
[have_multi_byte_nop=yes],
[have_multi_byte_nop=no])
have_cet=no
if test x$have_multi_byte_nop = xyes; then
AC_TRY_RUN([
static void
foo (void)
{
}
static void
__attribute__ ((noinline, noclone))
xxx (void (*f) (void))
{
f ();
}
static void
__attribute__ ((noinline, noclone))
bar (void)
{
xxx (foo);
}
int
main ()
{
bar ();
return 0;
}
],
[have_cet=no],
[have_cet=yes])
fi
if test x$enable_cet = xno -a x$have_cet = xyes; then
AC_MSG_ERROR([Intel CET must be enabled on Intel CET enabled host])
fi
fi
else
# Enable CET in cross compiler if possible so that it will run on both
# CET and non-CET hosts.
have_cet=yes
fi
if test x$enable_cet = xyes; then
$1="-fcf-protection"
AC_MSG_RESULT([yes])
else
AC_MSG_RESULT([no])
fi
CFLAGS="$cet_save_CFLAGS"
LDFLAGS="$cet_save_LDFLAGS"
])
|
