diff options
Diffstat (limited to 'arch/arm/include/asm/stackprotector.h')
| -rw-r--r-- | arch/arm/include/asm/stackprotector.h | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/arch/arm/include/asm/stackprotector.h b/arch/arm/include/asm/stackprotector.h index de003327be97..0bd4979759f1 100644 --- a/arch/arm/include/asm/stackprotector.h +++ b/arch/arm/include/asm/stackprotector.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ /* * GCC stack protector support. * @@ -5,15 +6,16 @@ * the stack frame and verifying that it hasn't been overwritten when * returning from the function. The pattern is called stack canary * and gcc expects it to be defined by a global variable called - * "__stack_chk_guard" on ARM. This unfortunately means that on SMP - * we cannot have a different canary value per task. + * "__stack_chk_guard" on ARM. This prevents SMP systems from using a + * different value for each task unless we enable a GCC plugin that + * replaces these symbol references with references to each task's own + * value. */ #ifndef _ASM_STACKPROTECTOR_H #define _ASM_STACKPROTECTOR_H 1 -#include <linux/random.h> -#include <linux/version.h> +#include <asm/thread_info.h> extern unsigned long __stack_chk_guard; @@ -25,14 +27,12 @@ extern unsigned long __stack_chk_guard; */ static __always_inline void boot_init_stack_canary(void) { - unsigned long canary; - - /* Try to get a semi random initial value. */ - get_random_bytes(&canary, sizeof(canary)); - canary ^= LINUX_VERSION_CODE; + unsigned long canary = get_random_canary(); current->stack_canary = canary; +#ifndef CONFIG_STACKPROTECTOR_PER_TASK __stack_chk_guard = current->stack_canary; +#endif } #endif /* _ASM_STACKPROTECTOR_H */ |