name : stackprotector.h /* SPDX-License-Identifier: GPL-2.0 */ #ifndef _LINUX_STACKPROTECTOR_H #define _LINUX_STACKPROTECTOR_H 1 #include <linux/compiler.h> #include <linux/sched.h> #include <linux/random.h> /* * On 64-bit architectures, protect against non-terminated C string overflows * by zeroing out the first byte of the canary; this leaves 56 bits of entropy. */ #ifdef CONFIG_64BIT # ifdef __LITTLE_ENDIAN # define CANARY_MASK 0xffffffffffffff00UL # else /* big endian, 64 bits: */ # define CANARY_MASK 0x00ffffffffffffffUL # endif #else /* 32 bits: */ # define CANARY_MASK 0xffffffffUL #endif static inline unsigned long get_random_canary(void) { return get_random_long() & CANARY_MASK; } #if defined(CONFIG_STACKPROTECTOR) || defined(CONFIG_ARM64_PTR_AUTH) # include <asm/stackprotector.h> #else static inline void boot_init_stack_canary(void) { } #endif #endif