1/* SPDX-License-Identifier: GPL-2.0 */
 2/*
 3 * GCC stack protector support.
 4 *
 5 * (This is directly adopted from the ARM implementation)
 6 *
 7 * Stack protector works by putting predefined pattern at the start of
 8 * the stack frame and verifying that it hasn't been overwritten when
 9 * returning from the function.  The pattern is called stack canary
10 * and gcc expects it to be defined by a global variable called
11 * "__stack_chk_guard" on MIPS.  This unfortunately means that on SMP
12 * we cannot have a different canary value per task.
13 */
14
15#ifndef _ASM_STACKPROTECTOR_H
16#define _ASM_STACKPROTECTOR_H 1
17
18#include <linux/random.h>
19#include <linux/version.h>
20
21extern unsigned long __stack_chk_guard;
22
23/*
24 * Initialize the stackprotector canary value.
25 *
26 * NOTE: this must only be called from functions that never return,
27 * and it must always be inlined.
28 */
29static __always_inline void boot_init_stack_canary(void)
30{
31	unsigned long canary;
32
33	/* Try to get a semi random initial value. */
34	get_random_bytes(&canary, sizeof(canary));
35	canary ^= LINUX_VERSION_CODE;
36
37	current->stack_canary = canary;
38	__stack_chk_guard = current->stack_canary;
39}
40
41#endif	/* _ASM_STACKPROTECTOR_H */

 1/* SPDX-License-Identifier: GPL-2.0 */
 2/*
 3 * GCC stack protector support.
 4 *
 5 * (This is directly adopted from the ARM implementation)
 6 *
 7 * Stack protector works by putting predefined pattern at the start of
 8 * the stack frame and verifying that it hasn't been overwritten when
 9 * returning from the function.  The pattern is called stack canary
10 * and gcc expects it to be defined by a global variable called
11 * "__stack_chk_guard" on MIPS.  This unfortunately means that on SMP
12 * we cannot have a different canary value per task.
13 */
14
15#ifndef _ASM_STACKPROTECTOR_H
16#define _ASM_STACKPROTECTOR_H 1
17
 
 
 
18extern unsigned long __stack_chk_guard;
19
20/*
21 * Initialize the stackprotector canary value.
22 *
23 * NOTE: this must only be called from functions that never return,
24 * and it must always be inlined.
25 */
26static __always_inline void boot_init_stack_canary(void)
27{
28	unsigned long canary = get_random_canary();
 
 
 
 
29
30	current->stack_canary = canary;
31	__stack_chk_guard = current->stack_canary;
32}
33
34#endif	/* _ASM_STACKPROTECTOR_H */