linux/arch/loongarch/kernel/switch.S
Huacai Chen 09f33601bf LoongArch: Add basic STACKPROTECTOR support
Add basic stack protector support similar to other architectures. A
constant canary value is set at boot time, and with help of compiler's
-fstack-protector we can detect stack corruption.

Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-12-14 08:41:53 +08:00

43 lines
983 B
ArmAsm

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
*/
#include <asm/asm.h>
#include <asm/asmmacro.h>
#include <asm/asm-offsets.h>
#include <asm/loongarch.h>
#include <asm/regdef.h>
#include <asm/stackframe.h>
#include <asm/thread_info.h>
/*
* task_struct *__switch_to(task_struct *prev, task_struct *next,
* struct thread_info *next_ti)
*/
.align 5
SYM_FUNC_START(__switch_to)
csrrd t1, LOONGARCH_CSR_PRMD
stptr.d t1, a0, THREAD_CSRPRMD
cpu_save_nonscratch a0
stptr.d ra, a0, THREAD_REG01
stptr.d a3, a0, THREAD_SCHED_RA
stptr.d a4, a0, THREAD_SCHED_CFA
#if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_SMP)
la t7, __stack_chk_guard
LONG_L t8, a1, TASK_STACK_CANARY
LONG_S t8, t7, 0
#endif
move tp, a2
cpu_restore_nonscratch a1
li.w t0, _THREAD_SIZE
PTR_ADD t0, t0, tp
set_saved_sp t0, t1, t2
ldptr.d t1, a1, THREAD_CSRPRMD
csrwr t1, LOONGARCH_CSR_PRMD
jr ra
SYM_FUNC_END(__switch_to)