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-rw-r--r--plat/common/aarch64/pauth.c29
1 files changed, 29 insertions, 0 deletions
diff --git a/plat/common/aarch64/pauth.c b/plat/common/aarch64/pauth.c
new file mode 100644
index 000000000..755574099
--- /dev/null
+++ b/plat/common/aarch64/pauth.c
@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2019, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <cdefs.h>
+#include <stdint.h>
+
+/*
+ * Instruction pointer authentication key A. The low 64-bit are at [0], and the
+ * high bits at [1].
+ */
+static uint64_t plat_apiakey[2];
+
+/*
+ * This is only a toy implementation to generate a seemingly random 128-bit key
+ * from sp and x30 values.
+ */
+uint64_t *plat_init_apiakey(void)
+{
+ uintptr_t return_addr = (uintptr_t)__builtin_return_address(0U);
+ uintptr_t frame_addr = (uintptr_t)__builtin_frame_address(0U);
+
+ plat_apiakey[0] = (return_addr << 13) ^ frame_addr;
+ plat_apiakey[1] = (frame_addr << 15) ^ return_addr;
+
+ return plat_apiakey;
+}