1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * GCC stack protector support.
4  *
5  */
6 
7 #ifndef _ASM_STACKPROTECTOR_H
8 #define _ASM_STACKPROTECTOR_H
9 
10 #include <linux/random.h>
11 #include <linux/version.h>
12 #include <asm/reg.h>
13 #include <asm/current.h>
14 #include <asm/paca.h>
15 
16 /*
17  * Initialize the stackprotector canary value.
18  *
19  * NOTE: this must only be called from functions that never return,
20  * and it must always be inlined.
21  */
22 static __always_inline void boot_init_stack_canary(void)
23 {
24 	unsigned long canary;
25 
26 	/* Try to get a semi random initial value. */
27 	canary = get_random_canary();
28 	canary ^= mftb();
29 	canary ^= LINUX_VERSION_CODE;
30 	canary &= CANARY_MASK;
31 
32 	current->stack_canary = canary;
33 #ifdef CONFIG_PPC64
34 	get_paca()->canary = canary;
35 #endif
36 }
37 
38 #endif	/* _ASM_STACKPROTECTOR_H */
39