1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_STACKPROTECTOR_H
3 #define _ASM_STACKPROTECTOR_H 1
4 
5 #include <linux/random.h>
6 #include <linux/version.h>
7 
8 extern unsigned long __stack_chk_guard;
9 
10 /*
11  * Initialize the stackprotector canary value.
12  *
13  * NOTE: this must only be called from functions that never return,
14  * and it must always be inlined.
15  */
16 static __always_inline void boot_init_stack_canary(void)
17 {
18 	unsigned long canary;
19 
20 	/* Try to get a semi random initial value. */
21 	get_random_bytes(&canary, sizeof(canary));
22 	canary ^= LINUX_VERSION_CODE;
23 	canary &= CANARY_MASK;
24 
25 	current->stack_canary = canary;
26 	__stack_chk_guard = current->stack_canary;
27 }
28 
29 #endif /* __ASM_SH_STACKPROTECTOR_H */
30