1 /* 2 * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved. 3 * 4 * SPDX-License-Identifier: BSD-3-Clause 5 */ 6 7 #include <stdint.h> 8 9 #include <arch_helpers.h> 10 #include <plat/common/platform.h> 11 12 #define RANDOM_CANARY_VALUE ((u_register_t) 3288484550995823360ULL) 13 plat_get_stack_protector_canary(void)14u_register_t plat_get_stack_protector_canary(void) 15 { 16 /* 17 * Ideally, a random number should be returned instead of the 18 * combination of a timer's value and a compile-time constant. As the 19 * FVP does not have any random number generator, this is better than 20 * nothing but not necessarily really secure. 21 */ 22 return RANDOM_CANARY_VALUE ^ read_cntpct_el0(); 23 } 24 25