1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0 */ 2*4882a593Smuzhiyun #ifndef _ASM_STACKPROTECTOR_H 3*4882a593Smuzhiyun #define _ASM_STACKPROTECTOR_H 1 4*4882a593Smuzhiyun 5*4882a593Smuzhiyun #include <linux/random.h> 6*4882a593Smuzhiyun #include <linux/version.h> 7*4882a593Smuzhiyun 8*4882a593Smuzhiyun extern unsigned long __stack_chk_guard; 9*4882a593Smuzhiyun 10*4882a593Smuzhiyun /* 11*4882a593Smuzhiyun * Initialize the stackprotector canary value. 12*4882a593Smuzhiyun * 13*4882a593Smuzhiyun * NOTE: this must only be called from functions that never return, 14*4882a593Smuzhiyun * and it must always be inlined. 15*4882a593Smuzhiyun */ boot_init_stack_canary(void)16*4882a593Smuzhiyunstatic __always_inline void boot_init_stack_canary(void) 17*4882a593Smuzhiyun { 18*4882a593Smuzhiyun unsigned long canary; 19*4882a593Smuzhiyun 20*4882a593Smuzhiyun /* Try to get a semi random initial value. */ 21*4882a593Smuzhiyun get_random_bytes(&canary, sizeof(canary)); 22*4882a593Smuzhiyun canary ^= LINUX_VERSION_CODE; 23*4882a593Smuzhiyun canary &= CANARY_MASK; 24*4882a593Smuzhiyun 25*4882a593Smuzhiyun current->stack_canary = canary; 26*4882a593Smuzhiyun __stack_chk_guard = current->stack_canary; 27*4882a593Smuzhiyun } 28*4882a593Smuzhiyun 29*4882a593Smuzhiyun #endif /* __ASM_SH_STACKPROTECTOR_H */ 30