In init/main.c

1 /* 2      * Set up the the initial canary ASAP: 3 */ 4     boot_init_stack_canary();

in arch/arm/include/asm/stackprotector.h

1 /*  2  * Initialize the stackprotector canary value.  3  *  4  * NOTE: this must only be called from functions that never return,  5  * and it must always be inlined.  6  */  7 static __always_inline void boot_init_stack_canary(void)  8 {
    9     unsigned long canary; 10 11     /* Try to get a semi random initial value. */ 12     get_random_bytes(&canary, sizeof(canary)); 13     canary ^= LINUX_VERSION_CODE; 14 15     current->stack_canary = canary; 16     __stack_chk_guard = current->stack_canary; 17 }

得到随机数字&kernel version，用于版本检测？