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Diffstat (limited to 'plat/arm/board/corstone700/corstone700_stack_protector.c')
-rw-r--r--plat/arm/board/corstone700/corstone700_stack_protector.c35
1 files changed, 35 insertions, 0 deletions
diff --git a/plat/arm/board/corstone700/corstone700_stack_protector.c b/plat/arm/board/corstone700/corstone700_stack_protector.c
new file mode 100644
index 0000000000..6fd09da5b6
--- /dev/null
+++ b/plat/arm/board/corstone700/corstone700_stack_protector.c
@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2020, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <stdint.h>
+
+#include <arch_helpers.h>
+#include <plat/common/platform.h>
+
+static uint32_t plat_generate_random_number(void)
+{
+ uintptr_t return_addr = (uintptr_t)__builtin_return_address(0U);
+ uintptr_t frame_addr = (uintptr_t)__builtin_frame_address(0U);
+ uint64_t cntpct = read_cntpct_el0();
+
+ /* Generate 32-bit pattern: saving the 2 least significant bytes
+ * in random_lo and random_hi
+ */
+ uint16_t random_lo = (uint16_t)(
+ (((uint64_t)return_addr) << 13) ^ frame_addr ^ cntpct
+ );
+
+ uint16_t random_hi = (uint16_t)(
+ (((uint64_t)frame_addr) << 15) ^ return_addr ^ cntpct
+ );
+
+ return (((uint32_t)random_hi) << 16) | random_lo;
+}
+
+u_register_t plat_get_stack_protector_canary(void)
+{
+ return plat_generate_random_number(); /* a 32-bit pattern is returned */
+}