x86-64/cet: Move dl-cet.[ch] to x86_64 directories

Since CET is only enabled for x86-64, move dl-cet.[ch] to x86_64
directories.
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

1 files changed, 46 insertions, 1 deletions

diff --git a/sysdeps/unix/sysv/linux/x86_64/dl-cet.h b/sysdeps/unix/sysv/linux/x86_64/dl-cet.h
index c89dd6bd42..94e9b9aa86 100644
--- a/sysdeps/unix/sysv/linux/x86_64/dl-cet.h
+++ b/sysdeps/unix/sysv/linux/x86_64/dl-cet.h
@@ -15,8 +15,53 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
+#include <sys/prctl.h>
+#include <asm/prctl.h>
 #include <cpu-features-offsets.h>
-#include_next <dl-cet.h>
+
+static __always_inline int
+dl_cet_disable_cet (unsigned int cet_feature)
+{
+  if (cet_feature != GNU_PROPERTY_X86_FEATURE_1_SHSTK)
+    return -1;
+  long long int kernel_feature = ARCH_SHSTK_SHSTK;
+  return (int) INTERNAL_SYSCALL_CALL (arch_prctl, ARCH_SHSTK_DISABLE,
+				      kernel_feature);
+}
+
+static __always_inline int
+dl_cet_lock_cet (unsigned int cet_feature)
+{
+  if (cet_feature != GNU_PROPERTY_X86_FEATURE_1_SHSTK)
+    return -1;
+  /* Lock all SHSTK features.  */
+  long long int kernel_feature = -1;
+  return (int) INTERNAL_SYSCALL_CALL (arch_prctl, ARCH_SHSTK_LOCK,
+				      kernel_feature);
+}
+
+static __always_inline unsigned int
+dl_cet_get_cet_status (void)
+{
+  unsigned long long kernel_feature;
+  unsigned int status = 0;
+  if (INTERNAL_SYSCALL_CALL (arch_prctl, ARCH_SHSTK_STATUS,
+			     &kernel_feature) == 0)
+    {
+      if ((kernel_feature & ARCH_SHSTK_SHSTK) != 0)
+	status = GNU_PROPERTY_X86_FEATURE_1_SHSTK;
+    }
+  return status;
+}
+
+/* Enable shadow stack with a macro to avoid shadow stack underflow.  */
+#define ENABLE_X86_CET(cet_feature)				\
+  if ((cet_feature & GNU_PROPERTY_X86_FEATURE_1_SHSTK))		\
+    {								\
+      long long int kernel_feature = ARCH_SHSTK_SHSTK;		\
+      INTERNAL_SYSCALL_CALL (arch_prctl, ARCH_SHSTK_ENABLE,	\
+			     kernel_feature);			\
+    }
 
 #define X86_STRINGIFY_1(x)	#x
 #define X86_STRINGIFY(x)	X86_STRINGIFY_1 (x)