xref: /OK3568_Linux_fs/kernel/arch/riscv/include/asm/stackprotector.h (revision 4882a59341e53eb6f0b4789bf948001014eff981) 
1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0 */
2*4882a593Smuzhiyun 
3*4882a593Smuzhiyun #ifndef _ASM_RISCV_STACKPROTECTOR_H
4*4882a593Smuzhiyun #define _ASM_RISCV_STACKPROTECTOR_H
5*4882a593Smuzhiyun 
6*4882a593Smuzhiyun #include <linux/random.h>
7*4882a593Smuzhiyun #include <linux/version.h>
8*4882a593Smuzhiyun 
9*4882a593Smuzhiyun extern unsigned long __stack_chk_guard;
10*4882a593Smuzhiyun 
11*4882a593Smuzhiyun /*
12*4882a593Smuzhiyun  * Initialize the stackprotector canary value.
13*4882a593Smuzhiyun  *
14*4882a593Smuzhiyun  * NOTE: this must only be called from functions that never return,
15*4882a593Smuzhiyun  * and it must always be inlined.
16*4882a593Smuzhiyun  */
boot_init_stack_canary(void)17*4882a593Smuzhiyun static __always_inline void boot_init_stack_canary(void)
18*4882a593Smuzhiyun {
19*4882a593Smuzhiyun 	unsigned long canary;
20*4882a593Smuzhiyun 
21*4882a593Smuzhiyun 	/* Try to get a semi random initial value. */
22*4882a593Smuzhiyun 	get_random_bytes(&canary, sizeof(canary));
23*4882a593Smuzhiyun 	canary ^= LINUX_VERSION_CODE;
24*4882a593Smuzhiyun 	canary &= CANARY_MASK;
25*4882a593Smuzhiyun 
26*4882a593Smuzhiyun 	current->stack_canary = canary;
27*4882a593Smuzhiyun 	__stack_chk_guard = current->stack_canary;
28*4882a593Smuzhiyun }
29*4882a593Smuzhiyun #endif /* _ASM_RISCV_STACKPROTECTOR_H */
30