plat/arm/board/fvp/fvp_stack_protector.c

   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
  14 u_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