diff options
Diffstat (limited to 'plat/arm/board/corstone700/corstone700_stack_protector.c')
-rw-r--r-- | plat/arm/board/corstone700/corstone700_stack_protector.c | 35 |
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 */ +} |