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| author | Huacai Chen <chenhuacai@loongson.cn> | 2022-05-31 18:04:11 +0800 |
|---|---|---|
| committer | Huacai Chen <chenhuacai@loongson.cn> | 2022-06-03 20:09:28 +0800 |
| commit | be769645a2aef577f07afdcb4de8fad20b6d57c0 (patch) | |
| tree | 131a75f1b296d21c324143ae6502294c1c346135 /arch/loongarch/kernel/entry.S | |
| parent | 09cfefb7fa70c3af011b0db0a513fd80b2f18abc (diff) | |
| download | linux-be769645a2aef577f07afdcb4de8fad20b6d57c0.tar.bz2 | |
LoongArch: Add system call support
Add system call support and related uaccess.h for LoongArch.
Q: Why keep _ARCH_WANT_SYS_CLONE definition while there is clone3:
A: The latest glibc release has some basic support for clone3 but it is
not complete. E.g., pthread_create() and spawni() have converted to
use clone3 but fork() will still use clone. Moreover, some seccomp
related applications can still not work perfectly with clone3. E.g.,
Chromium sandbox cannot work at all and there is no solution for it,
which is more terrible than the fork() story [1].
[1] https://chromium-review.googlesource.com/c/chromium/src/+/2936184
Reviewed-by: WANG Xuerui <git@xen0n.name>
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Diffstat (limited to 'arch/loongarch/kernel/entry.S')
| -rw-r--r-- | arch/loongarch/kernel/entry.S | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/arch/loongarch/kernel/entry.S b/arch/loongarch/kernel/entry.S new file mode 100644 index 000000000000..d5b3dbcf5425 --- /dev/null +++ b/arch/loongarch/kernel/entry.S @@ -0,0 +1,89 @@ +/* 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.abs 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) + +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) |