linux/arch/loongarch/kernel/entry.S
Tiezhu Yang fcf77d0162 LoongArch: Mark some assembler symbols as non-kprobe-able
Some assembler symbols are not kprobe safe, such as handle_syscall (used
as syscall exception handler), *memset*/*memcpy*/*memmove* (may cause
recursive exceptions), they can not be instrumented, just blacklist them
for kprobing.

Here is a related problem and discussion:
Link: https://lore.kernel.org/lkml/20230114143859.7ccc45c1c5d9ce302113ab0a@kernel.org/

Tested-by: Jeff Xie <xiehuan09@gmail.com>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-02-25 22:12:17 +08:00

91 lines
1.9 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
*
* Derived from MIPS:
* Copyright (C) 1994 - 2000, 2001, 2003 Ralf Baechle
* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
* Copyright (C) 2001 MIPS Technologies, Inc.
*/
#include <asm/asm.h>
#include <asm/asmmacro.h>
#include <asm/loongarch.h>
#include <asm/regdef.h>
#include <asm/stackframe.h>
#include <asm/thread_info.h>
.text
.cfi_sections .debug_frame
.align 5
SYM_FUNC_START(handle_syscall)
csrrd t0, PERCPU_BASE_KS
la.pcrel t1, kernelsp
add.d t1, t1, t0
move t2, sp
ld.d sp, t1, 0
addi.d sp, sp, -PT_SIZE
cfi_st t2, PT_R3
cfi_rel_offset sp, PT_R3
st.d zero, sp, PT_R0
csrrd t2, LOONGARCH_CSR_PRMD
st.d t2, sp, PT_PRMD
csrrd t2, LOONGARCH_CSR_CRMD
st.d t2, sp, PT_CRMD
csrrd t2, LOONGARCH_CSR_EUEN
st.d t2, sp, PT_EUEN
csrrd t2, LOONGARCH_CSR_ECFG
st.d t2, sp, PT_ECFG
csrrd t2, LOONGARCH_CSR_ESTAT
st.d t2, sp, PT_ESTAT
cfi_st ra, PT_R1
cfi_st a0, PT_R4
cfi_st a1, PT_R5
cfi_st a2, PT_R6
cfi_st a3, PT_R7
cfi_st a4, PT_R8
cfi_st a5, PT_R9
cfi_st a6, PT_R10
cfi_st a7, PT_R11
csrrd ra, LOONGARCH_CSR_ERA
st.d ra, sp, PT_ERA
cfi_rel_offset ra, PT_ERA
cfi_st tp, PT_R2
cfi_st u0, PT_R21
cfi_st fp, PT_R22
SAVE_STATIC
move u0, t0
li.d tp, ~_THREAD_MASK
and tp, tp, sp
move a0, sp
bl do_syscall
RESTORE_ALL_AND_RET
SYM_FUNC_END(handle_syscall)
_ASM_NOKPROBE(handle_syscall)
SYM_CODE_START(ret_from_fork)
bl schedule_tail # a0 = struct task_struct *prev
move a0, sp
bl syscall_exit_to_user_mode
RESTORE_STATIC
RESTORE_SOME
RESTORE_SP_AND_RET
SYM_CODE_END(ret_from_fork)
SYM_CODE_START(ret_from_kernel_thread)
bl schedule_tail # a0 = struct task_struct *prev
move a0, s1
jirl ra, s0, 0
move a0, sp
bl syscall_exit_to_user_mode
RESTORE_STATIC
RESTORE_SOME
RESTORE_SP_AND_RET
SYM_CODE_END(ret_from_kernel_thread)