linux/arch/loongarch/kernel/entry.S
Tiezhu Yang cb8a2ef084 LoongArch: Add ORC stack unwinder support
The kernel CONFIG_UNWINDER_ORC option enables the ORC unwinder, which is
similar in concept to a DWARF unwinder. The difference is that the format
of the ORC data is much simpler than DWARF, which in turn allows the ORC
unwinder to be much simpler and faster.

The ORC data consists of unwind tables which are generated by objtool.
After analyzing all the code paths of a .o file, it determines information
about the stack state at each instruction address in the file and outputs
that information to the .orc_unwind and .orc_unwind_ip sections.

The per-object ORC sections are combined at link time and are sorted and
post-processed at boot time. The unwinder uses the resulting data to
correlate instruction addresses with their stack states at run time.

Most of the logic are similar with x86, in order to get ra info before ra
is saved into stack, add ra_reg and ra_offset into orc_entry. At the same
time, modify some arch-specific code to silence the objtool warnings.

Co-developed-by: Jinyang He <hejinyang@loongson.cn>
Signed-off-by: Jinyang He <hejinyang@loongson.cn>
Co-developed-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2024-03-11 22:23:47 +08:00

101 lines
2.1 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>
#include <asm/unwind_hints.h>
.text
.cfi_sections .debug_frame
.align 5
SYM_CODE_START(handle_syscall)
UNWIND_HINT_UNDEFINED
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
UNWIND_HINT_REGS
#ifdef CONFIG_KGDB
li.w t1, CSR_CRMD_WE
csrxchg t1, t1, LOONGARCH_CSR_CRMD
#endif
move u0, t0
li.d tp, ~_THREAD_MASK
and tp, tp, sp
move a0, sp
bl do_syscall
RESTORE_ALL_AND_RET
SYM_CODE_END(handle_syscall)
_ASM_NOKPROBE(handle_syscall)
SYM_CODE_START(ret_from_fork)
UNWIND_HINT_REGS
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)
UNWIND_HINT_REGS
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)