[thirdparty/kernel/linux.git] / arch / mips / include / asm / stackprotector.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * GCC stack protector support.
 *
 * (This is directly adopted from the ARM implementation)
 *
 * 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 MIPS.  This unfortunately means that on SMP
 * we cannot have a different canary value per task.
 */

#ifndef _ASM_STACKPROTECTOR_H
#define _ASM_STACKPROTECTOR_H 1

#include <linux/random.h>
#include <linux/version.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)
{
	unsigned long canary;

	/* Try to get a semi random initial value. */
	get_random_bytes(&canary, sizeof(canary));
	canary ^= LINUX_VERSION_CODE;

	current->stack_canary = canary;
	__stack_chk_guard = current->stack_canary;
}

#endif	/* _ASM_STACKPROTECTOR_H */
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
36ecafc5 GF	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
	21	extern 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	*/
	29	static __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 */