blob: ae3ad80f51fe190d0c9bad22c54d95b8741a7910 [file] [log] [blame]
/* SPDX-License-Identifier: GPL-2.0 */
/*
* GCC stack protector support.
*
* Stack protector works by putting predefined pattern at the start of
* the stack frame and verifying that it hasn't been overwritten when
* returning from the function. The pattern is called stack canary
* and gcc expects it to be defined by a global variable called
* "__stack_chk_guard" on ARM. This unfortunately means that on SMP
* we cannot have a different canary value per task.
*/
#ifndef __ASM_STACKPROTECTOR_H
#define __ASM_STACKPROTECTOR_H
#include <asm/pointer_auth.h>
extern unsigned long __stack_chk_guard;
/*
* Initialize the stackprotector canary value.
*
* NOTE: this must only be called from functions that never return,
* and it must always be inlined.
*/
static __always_inline void boot_init_stack_canary(void)
{
#if defined(CONFIG_STACKPROTECTOR)
unsigned long canary = get_random_canary();
current->stack_canary = canary;
if (!IS_ENABLED(CONFIG_STACKPROTECTOR_PER_TASK))
__stack_chk_guard = current->stack_canary;
#endif
ptrauth_thread_init_kernel(current);
ptrauth_thread_switch_kernel(current);
ptrauth_enable();
}
#endif /* _ASM_STACKPROTECTOR_H */