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Diffstat (limited to 'sysdeps/unix/sysv/linux/x86_64/dl-cet.h')
-rw-r--r--sysdeps/unix/sysv/linux/x86_64/dl-cet.h47
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)