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