cet.m4 revision 1.1.1.2
1dnl 2dnl GCC_CET_FLAGS 3dnl (SHELL-CODE_HANDLER) 4dnl 5AC_DEFUN([GCC_CET_FLAGS],[dnl 6GCC_ENABLE(cet, no, ,[enable Intel CET in target libraries], 7 permit yes|no|auto) 8AC_MSG_CHECKING([for CET support]) 9 10case "$host" in 11 i[[34567]]86-*-linux* | x86_64-*-linux*) 12 case "$enable_cet" in 13 auto) 14 # Check if target supports multi-byte NOPs 15 # and if assembler supports CET insn. 16 AC_COMPILE_IFELSE( 17 [AC_LANG_PROGRAM( 18 [], 19 [ 20#if !defined(__SSE2__) 21#error target does not support multi-byte NOPs 22#else 23asm ("setssbsy"); 24#endif 25 ])], 26 [enable_cet=yes], 27 [enable_cet=no]) 28 ;; 29 yes) 30 # Check if assembler supports CET. 31 AC_COMPILE_IFELSE( 32 [AC_LANG_PROGRAM( 33 [], 34 [asm ("setssbsy");])], 35 [], 36 [AC_MSG_ERROR([assembler with CET support is required for --enable-cet])]) 37 ;; 38 esac 39 ;; 40 *) 41 enable_cet=no 42 ;; 43esac 44if test x$enable_cet = xyes; then 45 $1="-fcf-protection -mshstk" 46 AC_MSG_RESULT([yes]) 47else 48 AC_MSG_RESULT([no]) 49fi 50]) 51 52dnl 53dnl GCC_CET_HOST_FLAGS 54dnl (SHELL-CODE_HANDLER) 55dnl 56AC_DEFUN([GCC_CET_HOST_FLAGS],[dnl 57GCC_ENABLE(cet, auto, ,[enable Intel CET in host libraries], 58 permit yes|no|auto) 59AC_MSG_CHECKING([for CET support]) 60 61case "$host" in 62 i[[34567]]86-*-linux* | x86_64-*-linux*) 63 may_have_cet=yes 64 save_CFLAGS="$CFLAGS" 65 CFLAGS="$CFLAGS -fcf-protection" 66 case "$enable_cet" in 67 auto) 68 # Check if target supports multi-byte NOPs 69 # and if assembler supports CET insn. 70 AC_COMPILE_IFELSE( 71 [AC_LANG_PROGRAM( 72 [], 73 [ 74#if !defined(__SSE2__) 75#error target does not support multi-byte NOPs 76#else 77asm ("setssbsy"); 78#endif 79 ])], 80 [enable_cet=yes], 81 [enable_cet=no]) 82 ;; 83 yes) 84 # Check if assembler supports CET. 85 AC_COMPILE_IFELSE( 86 [AC_LANG_PROGRAM( 87 [], 88 [asm ("setssbsy");])], 89 [], 90 [AC_MSG_ERROR([assembler with CET support is required for --enable-cet])]) 91 ;; 92 esac 93 CFLAGS="$save_CFLAGS" 94 ;; 95 *) 96 may_have_cet=no 97 enable_cet=no 98 ;; 99esac 100 101save_CFLAGS="$CFLAGS" 102CFLAGS="$CFLAGS -fcf-protection=none" 103save_LDFLAGS="$LDFLAGS" 104LDFLAGS="$LDFLAGS -Wl,-z,ibt,-z,shstk" 105if test x$may_have_cet = xyes; then 106 # Check whether -fcf-protection=none -Wl,-z,ibt,-z,shstk work. 107 AC_TRY_LINK( 108 [],[return 0;], 109 [may_have_cet=yes], 110 [may_have_cet=no]) 111fi 112 113if test x$may_have_cet = xyes; then 114 if test x$cross_compiling = xno; then 115 AC_TRY_RUN([ 116static void 117foo (void) 118{ 119} 120 121static void 122__attribute__ ((noinline, noclone)) 123xxx (void (*f) (void)) 124{ 125 f (); 126} 127 128static void 129__attribute__ ((noinline, noclone)) 130bar (void) 131{ 132 xxx (foo); 133} 134 135int 136main () 137{ 138 bar (); 139 return 0; 140} 141 ], 142 [have_cet=no], 143 [have_cet=yes]) 144 if test x$enable_cet = xno -a x$have_cet = xyes; then 145 AC_MSG_ERROR([Intel CET must be enabled on Intel CET enabled host]) 146 fi 147 fi 148else 149 # Enable CET in cross compiler if possible so that it will run on both 150 # CET and non-CET hosts. 151 have_cet=yes 152fi 153if test x$enable_cet = xyes; then 154 $1="-fcf-protection" 155 AC_MSG_RESULT([yes]) 156else 157 AC_MSG_RESULT([no]) 158fi 159CFLAGS="$save_CFLAGS" 160LDFLAGS="$save_LDFLAGS" 161]) 162