Feiyang Chen <chris.chenfeiyang@xxxxxxxxx> 于2021年10月14日周四 下午4:32写道：
>
> Convert MIPS syscall to use the generic entry infrastructure from
> kernel/entry/*.
>
> There are a few special things on MIPS:
>
> - There is one type of syscall on MIPS32 (scall32-o32) and three types
> of syscalls on MIPS64 (scall64-o32, scall64-n32 and scall64-n64). Now
> convert to C code to handle different types of syscalls.
>
> - For some special syscalls (e.g. fork, clone, clone3 and sysmips),
> save_static_function() wrapper is used to save static registers. Now
> SAVE_STATIC is used in handle_sys before calling do_syscall(), so the
> save_static_function() wrapper can be removed.
>
> - For sigreturn/rt_sigreturn and sysmips, inline assembly is used to
> jump to syscall_exit directly for skipping setting the error flag and
> restoring all registers. Now use regs->regs[27] to mark whether to
> handle the error flag and restore all registers in handle_sys, so these
> functions can return normally as other architecture.
>
> Signed-off-by: Feiyang Chen <chenfeiyang@xxxxxxxxxxx>
> Signed-off-by: Yanteng Si <siyanteng@xxxxxxxxxxx>
> Reviewed-by: Huacai Chen <chenhuacai@xxxxxxxxxx>
> ---
> arch/mips/Kconfig | 1 +
> arch/mips/include/asm/entry-common.h | 13 ++
> arch/mips/include/asm/ptrace.h | 8 +-
> arch/mips/include/asm/sim.h | 70 -------
> arch/mips/include/asm/syscall.h | 5 +
> arch/mips/include/asm/thread_info.h | 17 +-
> arch/mips/include/uapi/asm/ptrace.h | 7 +-
> arch/mips/kernel/Makefile | 14 +-
> arch/mips/kernel/entry.S | 75 ++------
> arch/mips/kernel/linux32.c | 1 -
> arch/mips/kernel/ptrace.c | 78 --------
> arch/mips/kernel/scall.S | 137 +++++++++++++
> arch/mips/kernel/scall32-o32.S | 223 ----------------------
> arch/mips/kernel/scall64-n32.S | 107 -----------
> arch/mips/kernel/scall64-n64.S | 116 -----------
> arch/mips/kernel/scall64-o32.S | 221 ---------------------
> arch/mips/kernel/signal.c | 37 ++--
> arch/mips/kernel/signal_n32.c | 16 +-
> arch/mips/kernel/signal_o32.c | 31 +--
> arch/mips/kernel/syscall.c | 148 +++++++++++---
> arch/mips/kernel/syscalls/syscall_n32.tbl | 8 +-
> arch/mips/kernel/syscalls/syscall_n64.tbl | 8 +-
> arch/mips/kernel/syscalls/syscall_o32.tbl | 8 +-
> 23 files changed, 354 insertions(+), 995 deletions(-)
> create mode 100644 arch/mips/include/asm/entry-common.h
> delete mode 100644 arch/mips/include/asm/sim.h
> create mode 100644 arch/mips/kernel/scall.S
> delete mode 100644 arch/mips/kernel/scall32-o32.S
> delete mode 100644 arch/mips/kernel/scall64-n32.S
> delete mode 100644 arch/mips/kernel/scall64-n64.S
> delete mode 100644 arch/mips/kernel/scall64-o32.S
>
> diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
> index 1291774a2fa5..debd125100ad 100644
> --- a/arch/mips/Kconfig
> +++ b/arch/mips/Kconfig
> @@ -32,6 +32,7 @@ config MIPS
> select GENERIC_ATOMIC64 if !64BIT
> select GENERIC_CMOS_UPDATE
> select GENERIC_CPU_AUTOPROBE
> + select GENERIC_ENTRY
> select GENERIC_GETTIMEOFDAY
> select GENERIC_IOMAP
> select GENERIC_IRQ_PROBE
> diff --git a/arch/mips/include/asm/entry-common.h b/arch/mips/include/asm/entry-common.h
> new file mode 100644
> index 000000000000..0fe2a098ded9
> --- /dev/null
> +++ b/arch/mips/include/asm/entry-common.h
> @@ -0,0 +1,13 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef ARCH_LOONGARCH_ENTRY_COMMON_H
a typo?
> +#define ARCH_LOONGARCH_ENTRY_COMMON_H
> +
> +#include <linux/sched.h>
> +#include <linux/processor.h>
> +
> +static inline bool on_thread_stack(void)
> +{
> + return !(((unsigned long)(current->stack) ^ current_stack_pointer) & ~(THREAD_SIZE - 1));
> +}
> +
> +#endif
> diff --git a/arch/mips/include/asm/ptrace.h b/arch/mips/include/asm/ptrace.h
> index daf3cf244ea9..1b8f9d2ddc44 100644
> --- a/arch/mips/include/asm/ptrace.h
> +++ b/arch/mips/include/asm/ptrace.h
> @@ -51,6 +51,11 @@ struct pt_regs {
> unsigned long __last[0];
> } __aligned(8);
>
> +static inline int regs_irqs_disabled(struct pt_regs *regs)
> +{
> + return arch_irqs_disabled_flags(regs->cp0_status);
> +}
> +
> static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
> {
> return regs->regs[29];
> @@ -156,9 +161,6 @@ static inline long regs_return_value(struct pt_regs *regs)
> #define instruction_pointer(regs) ((regs)->cp0_epc)
> #define profile_pc(regs) instruction_pointer(regs)
>
> -extern asmlinkage long syscall_trace_enter(struct pt_regs *regs, long syscall);
> -extern asmlinkage void syscall_trace_leave(struct pt_regs *regs);
> -
> extern void die(const char *, struct pt_regs *) __noreturn;
>
> static inline void die_if_kernel(const char *str, struct pt_regs *regs)
> diff --git a/arch/mips/include/asm/sim.h b/arch/mips/include/asm/sim.h
> deleted file mode 100644
> index 59f31a95facd..000000000000
> --- a/arch/mips/include/asm/sim.h
> +++ /dev/null
> @@ -1,70 +0,0 @@
> -/*
> - * This file is subject to the terms and conditions of the GNU General Public
> - * License. See the file "COPYING" in the main directory of this archive
> - * for more details.
> - *
> - * Copyright (C) 1999, 2000, 2003 Ralf Baechle
> - * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
> - */
> -#ifndef _ASM_SIM_H
> -#define _ASM_SIM_H
> -
> -
> -#include <asm/asm-offsets.h>
> -
> -#define __str2(x) #x
> -#define __str(x) __str2(x)
> -
> -#ifdef CONFIG_32BIT
> -
> -#define save_static_function(symbol) \
> -__asm__( \
> - ".text\n\t" \
> - ".globl\t__" #symbol "\n\t" \
> - ".align\t2\n\t" \
> - ".type\t__" #symbol ", @function\n\t" \
> - ".ent\t__" #symbol ", 0\n__" \
> - #symbol":\n\t" \
> - ".frame\t$29, 0, $31\n\t" \
> - "sw\t$16,"__str(PT_R16)"($29)\t\t\t# save_static_function\n\t" \
> - "sw\t$17,"__str(PT_R17)"($29)\n\t" \
> - "sw\t$18,"__str(PT_R18)"($29)\n\t" \
> - "sw\t$19,"__str(PT_R19)"($29)\n\t" \
> - "sw\t$20,"__str(PT_R20)"($29)\n\t" \
> - "sw\t$21,"__str(PT_R21)"($29)\n\t" \
> - "sw\t$22,"__str(PT_R22)"($29)\n\t" \
> - "sw\t$23,"__str(PT_R23)"($29)\n\t" \
> - "sw\t$30,"__str(PT_R30)"($29)\n\t" \
> - "j\t" #symbol "\n\t" \
> - ".end\t__" #symbol "\n\t" \
> - ".size\t__" #symbol",. - __" #symbol)
> -
> -#endif /* CONFIG_32BIT */
> -
> -#ifdef CONFIG_64BIT
> -
> -#define save_static_function(symbol) \
> -__asm__( \
> - ".text\n\t" \
> - ".globl\t__" #symbol "\n\t" \
> - ".align\t2\n\t" \
> - ".type\t__" #symbol ", @function\n\t" \
> - ".ent\t__" #symbol ", 0\n__" \
> - #symbol":\n\t" \
> - ".frame\t$29, 0, $31\n\t" \
> - "sd\t$16,"__str(PT_R16)"($29)\t\t\t# save_static_function\n\t" \
> - "sd\t$17,"__str(PT_R17)"($29)\n\t" \
> - "sd\t$18,"__str(PT_R18)"($29)\n\t" \
> - "sd\t$19,"__str(PT_R19)"($29)\n\t" \
> - "sd\t$20,"__str(PT_R20)"($29)\n\t" \
> - "sd\t$21,"__str(PT_R21)"($29)\n\t" \
> - "sd\t$22,"__str(PT_R22)"($29)\n\t" \
> - "sd\t$23,"__str(PT_R23)"($29)\n\t" \
> - "sd\t$30,"__str(PT_R30)"($29)\n\t" \
> - "j\t" #symbol "\n\t" \
> - ".end\t__" #symbol "\n\t" \
> - ".size\t__" #symbol",. - __" #symbol)
> -
> -#endif /* CONFIG_64BIT */
> -
> -#endif /* _ASM_SIM_H */
> diff --git a/arch/mips/include/asm/syscall.h b/arch/mips/include/asm/syscall.h
> index 25fa651c937d..02ca0d659428 100644
> --- a/arch/mips/include/asm/syscall.h
> +++ b/arch/mips/include/asm/syscall.h
> @@ -157,4 +157,9 @@ static inline int syscall_get_arch(struct task_struct *task)
> return arch;
> }
>
> +static inline bool arch_syscall_is_vdso_sigreturn(struct pt_regs *regs)
> +{
> + return false;
> +}
> +
> #endif /* __ASM_MIPS_SYSCALL_H */
> diff --git a/arch/mips/include/asm/thread_info.h b/arch/mips/include/asm/thread_info.h
> index 0b17aaa9e012..5a5237413065 100644
> --- a/arch/mips/include/asm/thread_info.h
> +++ b/arch/mips/include/asm/thread_info.h
> @@ -29,7 +29,8 @@ struct thread_info {
> __u32 cpu; /* current CPU */
> int preempt_count; /* 0 => preemptable, <0 => BUG */
> struct pt_regs *regs;
> - long syscall; /* syscall number */
> + unsigned long syscall; /* syscall number */
> + unsigned long syscall_work; /* SYSCALL_WORK_ flags */
> };
>
> /*
> @@ -69,6 +70,8 @@ static inline struct thread_info *current_thread_info(void)
> return __current_thread_info;
> }
>
> +register unsigned long current_stack_pointer __asm__("$29");
> +
> #endif /* !__ASSEMBLY__ */
>
> /* thread information allocation */
> @@ -149,22 +152,10 @@ static inline struct thread_info *current_thread_info(void)
> #define _TIF_MSA_CTX_LIVE (1<<TIF_MSA_CTX_LIVE)
> #define _TIF_SYSCALL_TRACEPOINT (1<<TIF_SYSCALL_TRACEPOINT)
>
> -#define _TIF_WORK_SYSCALL_ENTRY (_TIF_NOHZ | _TIF_SYSCALL_TRACE | \
> - _TIF_SYSCALL_AUDIT | \
> - _TIF_SYSCALL_TRACEPOINT | _TIF_SECCOMP)
> -
> -/* work to do in syscall_trace_leave() */
> -#define _TIF_WORK_SYSCALL_EXIT (_TIF_NOHZ | _TIF_SYSCALL_TRACE | \
> - _TIF_SYSCALL_AUDIT | _TIF_SYSCALL_TRACEPOINT)
> -
> /* work to do on interrupt/exception return */
> #define _TIF_WORK_MASK \
> (_TIF_SIGPENDING | _TIF_NEED_RESCHED | _TIF_NOTIFY_RESUME | \
> _TIF_UPROBE | _TIF_NOTIFY_SIGNAL)
> -/* work to do on any return to u-space */
> -#define _TIF_ALLWORK_MASK (_TIF_NOHZ | _TIF_WORK_MASK | \
> - _TIF_WORK_SYSCALL_EXIT | \
> - _TIF_SYSCALL_TRACEPOINT)
>
> /*
> * We stash processor id into a COP0 register to retrieve it fast
> diff --git a/arch/mips/include/uapi/asm/ptrace.h b/arch/mips/include/uapi/asm/ptrace.h
> index f3c025445e45..27e2c85398bc 100644
> --- a/arch/mips/include/uapi/asm/ptrace.h
> +++ b/arch/mips/include/uapi/asm/ptrace.h
> @@ -102,8 +102,9 @@ struct pt_watch_regs {
> };
> };
>
> -#define PTRACE_GET_WATCH_REGS 0xd0
> -#define PTRACE_SET_WATCH_REGS 0xd1
> -
> +#define PTRACE_SYSEMU 0x1f
> +#define PTRACE_SYSEMU_SINGLESTEP 0x20
> +#define PTRACE_GET_WATCH_REGS 0xd0
> +#define PTRACE_SET_WATCH_REGS 0xd1
>
> #endif /* _UAPI_ASM_PTRACE_H */
> diff --git a/arch/mips/kernel/Makefile b/arch/mips/kernel/Makefile
> index 814b3da30501..44875660f6ae 100644
> --- a/arch/mips/kernel/Makefile
> +++ b/arch/mips/kernel/Makefile
> @@ -5,10 +5,10 @@
>
> extra-y := head.o vmlinux.lds
>
> -obj-y += branch.o cmpxchg.o elf.o entry.o genex.o idle.o irq.o \
> - process.o prom.o ptrace.o reset.o setup.o signal.o \
> - syscall.o time.o topology.o traps.o unaligned.o watch.o \
> - vdso.o cacheinfo.o
> +obj-y += branch.o cacheinfo.o cmpxchg.o elf.o entry.o genex.o \
> + idle.o irq.o process.o prom.o ptrace.o reset.o scall.o \
> + setup.o signal.o syscall.o time.o topology.o traps.o \
> + unaligned.o watch.o vdso.o
>
> ifdef CONFIG_CPU_R3K_TLB
> obj-y += cpu-r3k-probe.o
> @@ -76,11 +76,9 @@ obj-$(CONFIG_IRQ_TXX9) += irq_txx9.o
> obj-$(CONFIG_IRQ_GT641XX) += irq-gt641xx.o
>
> obj-$(CONFIG_KPROBES) += kprobes.o
> -obj-$(CONFIG_32BIT) += scall32-o32.o
> -obj-$(CONFIG_64BIT) += scall64-n64.o
> obj-$(CONFIG_MIPS32_COMPAT) += linux32.o ptrace32.o signal32.o
> -obj-$(CONFIG_MIPS32_N32) += scall64-n32.o signal_n32.o
> -obj-$(CONFIG_MIPS32_O32) += scall64-o32.o signal_o32.o
> +obj-$(CONFIG_MIPS32_N32) += signal_n32.o
> +obj-$(CONFIG_MIPS32_O32) += signal_o32.o
>
> obj-$(CONFIG_KGDB) += kgdb.o
> obj-$(CONFIG_PROC_FS) += proc.o
> diff --git a/arch/mips/kernel/entry.S b/arch/mips/kernel/entry.S
> index 4b896f5023ff..1a2aec9dab1b 100644
> --- a/arch/mips/kernel/entry.S
> +++ b/arch/mips/kernel/entry.S
> @@ -72,49 +72,32 @@ FEXPORT(ret_from_kernel_thread)
> jal schedule_tail # a0 = struct task_struct *prev
> move a0, s1
> jal s0
> - j syscall_exit
> + move a0, sp
> + jal syscall_exit_to_user_mode
> +
> + .set noat
> + RESTORE_STATIC
> + RESTORE_SOME
> + RESTORE_SP_AND_RET
> + .set at
>
> FEXPORT(ret_from_fork)
> jal schedule_tail # a0 = struct task_struct *prev
> -
> -FEXPORT(syscall_exit)
> -#ifdef CONFIG_DEBUG_RSEQ
> move a0, sp
> - jal rseq_syscall
> -#endif
> - local_irq_disable # make sure need_resched and
> - # signals dont change between
> - # sampling and return
> - LONG_L a2, TI_FLAGS($28) # current->work
> - li t0, _TIF_ALLWORK_MASK
> - and t0, a2, t0
> - bnez t0, syscall_exit_work
> + jal syscall_exit_to_user_mode
>
> -restore_all: # restore full frame
> .set noat
> - RESTORE_TEMP
> - RESTORE_AT
> RESTORE_STATIC
> -restore_partial: # restore partial frame
> -#ifdef CONFIG_TRACE_IRQFLAGS
> - SAVE_STATIC
> - SAVE_AT
> - SAVE_TEMP
> - LONG_L v0, PT_STATUS(sp)
> -#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
> - and v0, ST0_IEP
> -#else
> - and v0, ST0_IE
> -#endif
> - beqz v0, 1f
> - jal trace_hardirqs_on
> - b 2f
> -1: jal trace_hardirqs_off
> -2:
> + RESTORE_SOME
> + RESTORE_SP_AND_RET
> + .set at
> +
> +restore_all: # restore full frame
> + .set noat
> RESTORE_TEMP
> RESTORE_AT
> RESTORE_STATIC
> -#endif
> +restore_partial: # restore partial frame
> RESTORE_SOME
> RESTORE_SP_AND_RET
> .set at
> @@ -143,32 +126,6 @@ work_notifysig: # deal with pending signals and
> jal do_notify_resume # a2 already loaded
> j resume_userspace_check
>
> -FEXPORT(syscall_exit_partial)
> -#ifdef CONFIG_DEBUG_RSEQ
> - move a0, sp
> - jal rseq_syscall
> -#endif
> - local_irq_disable # make sure need_resched doesn't
> - # change between and return
> - LONG_L a2, TI_FLAGS($28) # current->work
> - li t0, _TIF_ALLWORK_MASK
> - and t0, a2
> - beqz t0, restore_partial
> - SAVE_STATIC
> -syscall_exit_work:
> - LONG_L t0, PT_STATUS(sp) # returning to kernel mode?
> - andi t0, t0, KU_USER
> - beqz t0, resume_kernel
> - li t0, _TIF_WORK_SYSCALL_EXIT
> - and t0, a2 # a2 is preloaded with TI_FLAGS
> - beqz t0, work_pending # trace bit set?
> - local_irq_enable # could let syscall_trace_leave()
> - # call schedule() instead
> - TRACE_IRQS_ON
> - move a0, sp
> - jal syscall_trace_leave
> - b resume_userspace
> -
> #if defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_MIPSR5) || \
> defined(CONFIG_CPU_MIPSR6) || defined(CONFIG_MIPS_MT)
>
> diff --git a/arch/mips/kernel/linux32.c b/arch/mips/kernel/linux32.c
> index 6b61be486303..2b4b1fc1ff1b 100644
> --- a/arch/mips/kernel/linux32.c
> +++ b/arch/mips/kernel/linux32.c
> @@ -38,7 +38,6 @@
> #include <net/scm.h>
>
> #include <asm/compat-signal.h>
> -#include <asm/sim.h>
> #include <linux/uaccess.h>
> #include <asm/mmu_context.h>
> #include <asm/mman.h>
> diff --git a/arch/mips/kernel/ptrace.c b/arch/mips/kernel/ptrace.c
> index db7c5be1d4a3..04c08e41cfd3 100644
> --- a/arch/mips/kernel/ptrace.c
> +++ b/arch/mips/kernel/ptrace.c
> @@ -46,9 +46,6 @@
> #include <asm/bootinfo.h>
> #include <asm/reg.h>
>
> -#define CREATE_TRACE_POINTS
> -#include <trace/events/syscalls.h>
> -
> /*
> * Called by kernel/ptrace.c when detaching..
> *
> @@ -1305,78 +1302,3 @@ long arch_ptrace(struct task_struct *child, long request,
> out:
> return ret;
> }
> -
> -/*
> - * Notification of system call entry/exit
> - * - triggered by current->work.syscall_trace
> - */
> -asmlinkage long syscall_trace_enter(struct pt_regs *regs, long syscall)
> -{
> - user_exit();
> -
> - current_thread_info()->syscall = syscall;
> -
> - if (test_thread_flag(TIF_SYSCALL_TRACE)) {
> - if (tracehook_report_syscall_entry(regs))
> - return -1;
> - syscall = current_thread_info()->syscall;
> - }
> -
> -#ifdef CONFIG_SECCOMP
> - if (unlikely(test_thread_flag(TIF_SECCOMP))) {
> - int ret, i;
> - struct seccomp_data sd;
> - unsigned long args[6];
> -
> - sd.nr = syscall;
> - sd.arch = syscall_get_arch(current);
> - syscall_get_arguments(current, regs, args);
> - for (i = 0; i < 6; i++)
> - sd.args[i] = args[i];
> - sd.instruction_pointer = KSTK_EIP(current);
> -
> - ret = __secure_computing(&sd);
> - if (ret == -1)
> - return ret;
> - syscall = current_thread_info()->syscall;
> - }
> -#endif
> -
> - if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
> - trace_sys_enter(regs, regs->regs[2]);
> -
> - audit_syscall_entry(syscall, regs->regs[4], regs->regs[5],
> - regs->regs[6], regs->regs[7]);
> -
> - /*
> - * Negative syscall numbers are mistaken for rejected syscalls, but
> - * won't have had the return value set appropriately, so we do so now.
> - */
> - if (syscall < 0)
> - syscall_set_return_value(current, regs, -ENOSYS, 0);
> - return syscall;
> -}
> -
> -/*
> - * Notification of system call entry/exit
> - * - triggered by current->work.syscall_trace
> - */
> -asmlinkage void syscall_trace_leave(struct pt_regs *regs)
> -{
> - /*
> - * We may come here right after calling schedule_user()
> - * or do_notify_resume(), in which case we can be in RCU
> - * user mode.
> - */
> - user_exit();
> -
> - audit_syscall_exit(regs);
> -
> - if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
> - trace_sys_exit(regs, regs_return_value(regs));
> -
> - if (test_thread_flag(TIF_SYSCALL_TRACE))
> - tracehook_report_syscall_exit(regs, 0);
> -
> - user_enter();
> -}
> diff --git a/arch/mips/kernel/scall.S b/arch/mips/kernel/scall.S
> new file mode 100644
> index 000000000000..fae8d99f0458
> --- /dev/null
> +++ b/arch/mips/kernel/scall.S
> @@ -0,0 +1,137 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 1995, 96, 97, 98, 99, 2000, 01, 02 by Ralf Baechle
> + * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
> + * Copyright (C) 2001 MIPS Technologies, Inc.
> + * Copyright (C) 2004 Thiemo Seufer
> + * Copyright (C) 2014 Imagination Technologies Ltd.
> + */
> +#include <linux/errno.h>
> +#include <asm/asm.h>
> +#include <asm/asmmacro.h>
> +#include <asm/irqflags.h>
> +#include <asm/mipsregs.h>
> +#include <asm/regdef.h>
> +#include <asm/stackframe.h>
> +#include <asm/asm-offsets.h>
> +#include <asm/sysmips.h>
> +#include <asm/thread_info.h>
> +#include <asm/unistd.h>
> +#include <asm/war.h>
> +
> + .align 5
> +NESTED(handle_sys, PT_SIZE, sp)
> + .set noat
> + SAVE_SOME
> + SAVE_STATIC
> + CLI
> + .set at
> +
> + move a0, sp
> + jal do_syscall
> + beqz v0, 1f # restore all registers?
> + nop
> +
> + .set noat
> + RESTORE_TEMP
> + RESTORE_STATIC
> + RESTORE_AT
> +1: RESTORE_SOME
> + RESTORE_SP_AND_RET
> + .set at
> + END(handle_sys)
> +
> +#ifdef CONFIG_32BIT
> +LEAF(sys_syscall)
> + subu t0, a0, __NR_O32_Linux # check syscall number
> + sltiu v0, t0, __NR_O32_Linux_syscalls
> + beqz t0, einval # do not recurse
> + sll t1, t0, 2
> + beqz v0, einval
> + lw t2, sys_call_table(t1) # syscall routine
> +
> + move a0, a1 # shift argument registers
> + move a1, a2
> + move a2, a3
> + lw a3, 16(sp)
> + lw t4, 20(sp)
> + lw t5, 24(sp)
> + lw t6, 28(sp)
> + sw t4, 16(sp)
> + sw t5, 20(sp)
> + sw t6, 24(sp)
> + jr t2
> + /* Unreached */
> +
> +einval: li v0, -ENOSYS
> + jr ra
> + END(sys_syscall)
> +
> +#ifdef CONFIG_MIPS_MT_FPAFF
> + /*
> + * For FPU affinity scheduling on MIPS MT processors, we need to
> + * intercept sys_sched_xxxaffinity() calls until we get a proper hook
> + * in kernel/sched/core.c. Considered only temporary we only support
> + * these hooks for the 32-bit kernel - there is no MIPS64 MT processor
> + * atm.
> + */
> +#define sys_sched_setaffinity mipsmt_sys_sched_setaffinity
> +#define sys_sched_getaffinity mipsmt_sys_sched_getaffinity
> +#endif /* CONFIG_MIPS_MT_FPAFF */
> +
> +#define __SYSCALL_WITH_COMPAT(nr, native, compat) __SYSCALL(nr, native)
> +#define __SYSCALL(nr, entry) PTR entry
> + .align 2
> + .type sys_call_table, @object
> +EXPORT(sys_call_table)
> +#include <asm/syscall_table_o32.h>
> +#endif /* CONFIG_32BIT */
> +
> +#ifdef CONFIG_64BIT
> +#ifdef CONFIG_MIPS32_O32
> +LEAF(sys32_syscall)
> + subu t0, a0, __NR_O32_Linux # check syscall number
> + sltiu v0, t0, __NR_O32_Linux_syscalls
> + beqz t0, einval # do not recurse
> + dsll t1, t0, 3
> + beqz v0, einval
> + ld t2, sys32_call_table(t1) # syscall routine
> +
> + move a0, a1 # shift argument registers
> + move a1, a2
> + move a2, a3
> + move a3, a4
> + move a4, a5
> + move a5, a6
> + move a6, a7
> + jr t2
> + /* Unreached */
> +
> +einval: li v0, -ENOSYS
> + jr ra
> + END(sys32_syscall)
> +
> +#define __SYSCALL_WITH_COMPAT(nr, native, compat) __SYSCALL(nr, compat)
> +#define __SYSCALL(nr, entry) PTR entry
> + .align 3
> + .type sys32_call_table,@object
> +EXPORT(sys32_call_table)
> +#include <asm/syscall_table_o32.h>
> +#endif /* CONFIG_MIPS32_O32 */
> +
> +#ifdef CONFIG_MIPS32_N32
> +#undef __SYSCALL
> +#define __SYSCALL(nr, entry) PTR entry
> + .align 3
> + .type sysn32_call_table, @object
> +EXPORT(sysn32_call_table)
> +#include <asm/syscall_table_n32.h>
> +#endif /* CONFIG_MIPS32_N32 */
> +
> +#undef __SYSCALL
> +#define __SYSCALL(nr, entry) PTR entry
> + .align 3
> + .type sys_call_table, @object
> +EXPORT(sys_call_table)
> +#include <asm/syscall_table_n64.h>
> +#endif /* CONFIG_64BIT */
> diff --git a/arch/mips/kernel/scall32-o32.S b/arch/mips/kernel/scall32-o32.S
> deleted file mode 100644
> index b1b2e106f711..000000000000
> --- a/arch/mips/kernel/scall32-o32.S
> +++ /dev/null
> @@ -1,223 +0,0 @@
> -/*
> - * This file is subject to the terms and conditions of the GNU General Public
> - * License. See the file "COPYING" in the main directory of this archive
> - * for more details.
> - *
> - * Copyright (C) 1995-99, 2000- 02, 06 Ralf Baechle <ralf@xxxxxxxxxxxxxx>
> - * Copyright (C) 2001 MIPS Technologies, Inc.
> - * Copyright (C) 2004 Thiemo Seufer
> - * Copyright (C) 2014 Imagination Technologies Ltd.
> - */
> -#include <linux/errno.h>
> -#include <asm/asm.h>
> -#include <asm/asmmacro.h>
> -#include <asm/irqflags.h>
> -#include <asm/mipsregs.h>
> -#include <asm/regdef.h>
> -#include <asm/stackframe.h>
> -#include <asm/isadep.h>
> -#include <asm/sysmips.h>
> -#include <asm/thread_info.h>
> -#include <asm/unistd.h>
> -#include <asm/war.h>
> -#include <asm/asm-offsets.h>
> -
> - .align 5
> -NESTED(handle_sys, PT_SIZE, sp)
> - .set noat
> - SAVE_SOME
> - TRACE_IRQS_ON_RELOAD
> - STI
> - .set at
> -
> - lw t1, PT_EPC(sp) # skip syscall on return
> -
> - addiu t1, 4 # skip to next instruction
> - sw t1, PT_EPC(sp)
> -
> - sw a3, PT_R26(sp) # save a3 for syscall restarting
> -
> - /*
> - * More than four arguments. Try to deal with it by copying the
> - * stack arguments from the user stack to the kernel stack.
> - * This Sucks (TM).
> - */
> - lw t0, PT_R29(sp) # get old user stack pointer
> -
> - /*
> - * We intentionally keep the kernel stack a little below the top of
> - * userspace so we don't have to do a slower byte accurate check here.
> - */
> - addu t4, t0, 32
> - bltz t4, bad_stack # -> sp is bad
> -
> - /*
> - * Ok, copy the args from the luser stack to the kernel stack.
> - */
> -
> - .set push
> - .set noreorder
> - .set nomacro
> -
> -load_a4: user_lw(t5, 16(t0)) # argument #5 from usp
> -load_a5: user_lw(t6, 20(t0)) # argument #6 from usp
> -load_a6: user_lw(t7, 24(t0)) # argument #7 from usp
> -load_a7: user_lw(t8, 28(t0)) # argument #8 from usp
> -loads_done:
> -
> - sw t5, 16(sp) # argument #5 to ksp
> - sw t6, 20(sp) # argument #6 to ksp
> - sw t7, 24(sp) # argument #7 to ksp
> - sw t8, 28(sp) # argument #8 to ksp
> - .set pop
> -
> - .section __ex_table,"a"
> - PTR load_a4, bad_stack_a4
> - PTR load_a5, bad_stack_a5
> - PTR load_a6, bad_stack_a6
> - PTR load_a7, bad_stack_a7
> - .previous
> -
> - lw t0, TI_FLAGS($28) # syscall tracing enabled?
> - li t1, _TIF_WORK_SYSCALL_ENTRY
> - and t0, t1
> - bnez t0, syscall_trace_entry # -> yes
> -syscall_common:
> - subu v0, v0, __NR_O32_Linux # check syscall number
> - sltiu t0, v0, __NR_O32_Linux_syscalls
> - beqz t0, illegal_syscall
> -
> - sll t0, v0, 2
> - la t1, sys_call_table
> - addu t1, t0
> - lw t2, (t1) # syscall routine
> -
> - beqz t2, illegal_syscall
> -
> - jalr t2 # Do The Real Thing (TM)
> -
> - li t0, -EMAXERRNO - 1 # error?
> - sltu t0, t0, v0
> - sw t0, PT_R7(sp) # set error flag
> - beqz t0, 1f
> -
> - lw t1, PT_R2(sp) # syscall number
> - negu v0 # error
> - sw t1, PT_R0(sp) # save it for syscall restarting
> -1: sw v0, PT_R2(sp) # result
> -
> -o32_syscall_exit:
> - j syscall_exit_partial
> -
> -/* ------------------------------------------------------------------------ */
> -
> -syscall_trace_entry:
> - SAVE_STATIC
> - move a0, sp
> -
> - /*
> - * syscall number is in v0 unless we called syscall(__NR_###)
> - * where the real syscall number is in a0
> - */
> - move a1, v0
> - subu t2, v0, __NR_O32_Linux
> - bnez t2, 1f /* __NR_syscall at offset 0 */
> - lw a1, PT_R4(sp)
> -
> -1: jal syscall_trace_enter
> -
> - bltz v0, 1f # seccomp failed? Skip syscall
> -
> - RESTORE_STATIC
> - lw v0, PT_R2(sp) # Restore syscall (maybe modified)
> - lw a0, PT_R4(sp) # Restore argument registers
> - lw a1, PT_R5(sp)
> - lw a2, PT_R6(sp)
> - lw a3, PT_R7(sp)
> - j syscall_common
> -
> -1: j syscall_exit
> -
> -/* ------------------------------------------------------------------------ */
> -
> - /*
> - * Our open-coded access area sanity test for the stack pointer
> - * failed. We probably should handle this case a bit more drastic.
> - */
> -bad_stack:
> - li v0, EFAULT
> - sw v0, PT_R2(sp)
> - li t0, 1 # set error flag
> - sw t0, PT_R7(sp)
> - j o32_syscall_exit
> -
> -bad_stack_a4:
> - li t5, 0
> - b load_a5
> -
> -bad_stack_a5:
> - li t6, 0
> - b load_a6
> -
> -bad_stack_a6:
> - li t7, 0
> - b load_a7
> -
> -bad_stack_a7:
> - li t8, 0
> - b loads_done
> -
> - /*
> - * The system call does not exist in this kernel
> - */
> -illegal_syscall:
> - li v0, ENOSYS # error
> - sw v0, PT_R2(sp)
> - li t0, 1 # set error flag
> - sw t0, PT_R7(sp)
> - j o32_syscall_exit
> - END(handle_sys)
> -
> - LEAF(sys_syscall)
> - subu t0, a0, __NR_O32_Linux # check syscall number
> - sltiu v0, t0, __NR_O32_Linux_syscalls
> - beqz t0, einval # do not recurse
> - sll t1, t0, 2
> - beqz v0, einval
> - lw t2, sys_call_table(t1) # syscall routine
> -
> - move a0, a1 # shift argument registers
> - move a1, a2
> - move a2, a3
> - lw a3, 16(sp)
> - lw t4, 20(sp)
> - lw t5, 24(sp)
> - lw t6, 28(sp)
> - sw t4, 16(sp)
> - sw t5, 20(sp)
> - sw t6, 24(sp)
> - jr t2
> - /* Unreached */
> -
> -einval: li v0, -ENOSYS
> - jr ra
> - END(sys_syscall)
> -
> -#ifdef CONFIG_MIPS_MT_FPAFF
> - /*
> - * For FPU affinity scheduling on MIPS MT processors, we need to
> - * intercept sys_sched_xxxaffinity() calls until we get a proper hook
> - * in kernel/sched/core.c. Considered only temporary we only support
> - * these hooks for the 32-bit kernel - there is no MIPS64 MT processor
> - * atm.
> - */
> -#define sys_sched_setaffinity mipsmt_sys_sched_setaffinity
> -#define sys_sched_getaffinity mipsmt_sys_sched_getaffinity
> -#endif /* CONFIG_MIPS_MT_FPAFF */
> -
> -#define __SYSCALL_WITH_COMPAT(nr, native, compat) __SYSCALL(nr, native)
> -#define __SYSCALL(nr, entry) PTR entry
> - .align 2
> - .type sys_call_table, @object
> -EXPORT(sys_call_table)
> -#include <asm/syscall_table_o32.h>
> diff --git a/arch/mips/kernel/scall64-n32.S b/arch/mips/kernel/scall64-n32.S
> deleted file mode 100644
> index f650c55a17dc..000000000000
> --- a/arch/mips/kernel/scall64-n32.S
> +++ /dev/null
> @@ -1,107 +0,0 @@
> -/*
> - * This file is subject to the terms and conditions of the GNU General Public
> - * License. See the file "COPYING" in the main directory of this archive
> - * for more details.
> - *
> - * Copyright (C) 1995, 96, 97, 98, 99, 2000, 01 by Ralf Baechle
> - * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
> - * Copyright (C) 2001 MIPS Technologies, Inc.
> - */
> -#include <linux/errno.h>
> -#include <asm/asm.h>
> -#include <asm/asmmacro.h>
> -#include <asm/irqflags.h>
> -#include <asm/mipsregs.h>
> -#include <asm/regdef.h>
> -#include <asm/stackframe.h>
> -#include <asm/thread_info.h>
> -#include <asm/unistd.h>
> -
> -#ifndef CONFIG_MIPS32_O32
> -/* No O32, so define handle_sys here */
> -#define handle_sysn32 handle_sys
> -#endif
> -
> - .align 5
> -NESTED(handle_sysn32, PT_SIZE, sp)
> -#ifndef CONFIG_MIPS32_O32
> - .set noat
> - SAVE_SOME
> - TRACE_IRQS_ON_RELOAD
> - STI
> - .set at
> -#endif
> -
> - dsubu t0, v0, __NR_N32_Linux # check syscall number
> - sltiu t0, t0, __NR_N32_Linux_syscalls
> -
> -#ifndef CONFIG_MIPS32_O32
> - ld t1, PT_EPC(sp) # skip syscall on return
> - daddiu t1, 4 # skip to next instruction
> - sd t1, PT_EPC(sp)
> -#endif
> - beqz t0, not_n32_scall
> -
> - sd a3, PT_R26(sp) # save a3 for syscall restarting
> -
> - li t1, _TIF_WORK_SYSCALL_ENTRY
> - LONG_L t0, TI_FLAGS($28) # syscall tracing enabled?
> - and t0, t1, t0
> - bnez t0, n32_syscall_trace_entry
> -
> -syscall_common:
> - dsll t0, v0, 3 # offset into table
> - ld t2, (sysn32_call_table - (__NR_N32_Linux * 8))(t0)
> -
> - jalr t2 # Do The Real Thing (TM)
> -
> - li t0, -EMAXERRNO - 1 # error?
> - sltu t0, t0, v0
> - sd t0, PT_R7(sp) # set error flag
> - beqz t0, 1f
> -
> - ld t1, PT_R2(sp) # syscall number
> - dnegu v0 # error
> - sd t1, PT_R0(sp) # save it for syscall restarting
> -1: sd v0, PT_R2(sp) # result
> -
> - j syscall_exit_partial
> -
> -/* ------------------------------------------------------------------------ */
> -
> -n32_syscall_trace_entry:
> - SAVE_STATIC
> - move a0, sp
> - move a1, v0
> - jal syscall_trace_enter
> -
> - bltz v0, 1f # seccomp failed? Skip syscall
> -
> - RESTORE_STATIC
> - ld v0, PT_R2(sp) # Restore syscall (maybe modified)
> - ld a0, PT_R4(sp) # Restore argument registers
> - ld a1, PT_R5(sp)
> - ld a2, PT_R6(sp)
> - ld a3, PT_R7(sp)
> - ld a4, PT_R8(sp)
> - ld a5, PT_R9(sp)
> -
> - dsubu t2, v0, __NR_N32_Linux # check (new) syscall number
> - sltiu t0, t2, __NR_N32_Linux_syscalls
> - beqz t0, not_n32_scall
> -
> - j syscall_common
> -
> -1: j syscall_exit
> -
> -not_n32_scall:
> - /* This is not an n32 compatibility syscall, pass it on to
> - the n64 syscall handlers. */
> - j handle_sys64
> -
> - END(handle_sysn32)
> -
> -#define __SYSCALL(nr, entry) PTR entry
> - .type sysn32_call_table, @object
> -EXPORT(sysn32_call_table)
> -#include <asm/syscall_table_n32.h>
> diff --git a/arch/mips/kernel/scall64-n64.S b/arch/mips/kernel/scall64-n64.S
> deleted file mode 100644
> index 5d7bfc65e4d0..000000000000
> --- a/arch/mips/kernel/scall64-n64.S
> +++ /dev/null
> @@ -1,116 +0,0 @@
> -/*
> - * This file is subject to the terms and conditions of the GNU General Public
> - * License. See the file "COPYING" in the main directory of this archive
> - * for more details.
> - *
> - * Copyright (C) 1995, 96, 97, 98, 99, 2000, 01, 02 by Ralf Baechle
> - * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
> - * Copyright (C) 2001 MIPS Technologies, Inc.
> - */
> -#include <linux/errno.h>
> -#include <asm/asm.h>
> -#include <asm/asmmacro.h>
> -#include <asm/irqflags.h>
> -#include <asm/mipsregs.h>
> -#include <asm/regdef.h>
> -#include <asm/stackframe.h>
> -#include <asm/asm-offsets.h>
> -#include <asm/sysmips.h>
> -#include <asm/thread_info.h>
> -#include <asm/unistd.h>
> -#include <asm/war.h>
> -
> -#ifndef CONFIG_MIPS32_COMPAT
> -/* Neither O32 nor N32, so define handle_sys here */
> -#define handle_sys64 handle_sys
> -#endif
> -
> - .align 5
> -NESTED(handle_sys64, PT_SIZE, sp)
> -#if !defined(CONFIG_MIPS32_O32) && !defined(CONFIG_MIPS32_N32)
> - /*
> - * When 32-bit compatibility is configured scall_o32.S
> - * already did this.
> - */
> - .set noat
> - SAVE_SOME
> - TRACE_IRQS_ON_RELOAD
> - STI
> - .set at
> -#endif
> -
> -#if !defined(CONFIG_MIPS32_O32) && !defined(CONFIG_MIPS32_N32)
> - ld t1, PT_EPC(sp) # skip syscall on return
> - daddiu t1, 4 # skip to next instruction
> - sd t1, PT_EPC(sp)
> -#endif
> -
> - sd a3, PT_R26(sp) # save a3 for syscall restarting
> -
> - li t1, _TIF_WORK_SYSCALL_ENTRY
> - LONG_L t0, TI_FLAGS($28) # syscall tracing enabled?
> - and t0, t1, t0
> - bnez t0, syscall_trace_entry
> -
> -syscall_common:
> - dsubu t2, v0, __NR_64_Linux
> - sltiu t0, t2, __NR_64_Linux_syscalls
> - beqz t0, illegal_syscall
> -
> - dsll t0, t2, 3 # offset into table
> - dla t2, sys_call_table
> - daddu t0, t2, t0
> - ld t2, (t0) # syscall routine
> - beqz t2, illegal_syscall
> -
> - jalr t2 # Do The Real Thing (TM)
> -
> - li t0, -EMAXERRNO - 1 # error?
> - sltu t0, t0, v0
> - sd t0, PT_R7(sp) # set error flag
> - beqz t0, 1f
> -
> - ld t1, PT_R2(sp) # syscall number
> - dnegu v0 # error
> - sd t1, PT_R0(sp) # save it for syscall restarting
> -1: sd v0, PT_R2(sp) # result
> -
> -n64_syscall_exit:
> - j syscall_exit_partial
> -
> -/* ------------------------------------------------------------------------ */
> -
> -syscall_trace_entry:
> - SAVE_STATIC
> - move a0, sp
> - move a1, v0
> - jal syscall_trace_enter
> -
> - bltz v0, 1f # seccomp failed? Skip syscall
> -
> - RESTORE_STATIC
> - ld v0, PT_R2(sp) # Restore syscall (maybe modified)
> - ld a0, PT_R4(sp) # Restore argument registers
> - ld a1, PT_R5(sp)
> - ld a2, PT_R6(sp)
> - ld a3, PT_R7(sp)
> - ld a4, PT_R8(sp)
> - ld a5, PT_R9(sp)
> - j syscall_common
> -
> -1: j syscall_exit
> -
> -illegal_syscall:
> - /* This also isn't a 64-bit syscall, throw an error. */
> - li v0, ENOSYS # error
> - sd v0, PT_R2(sp)
> - li t0, 1 # set error flag
> - sd t0, PT_R7(sp)
> - j n64_syscall_exit
> - END(handle_sys64)
> -
> -#define __SYSCALL(nr, entry) PTR entry
> - .align 3
> - .type sys_call_table, @object
> -EXPORT(sys_call_table)
> -#include <asm/syscall_table_n64.h>
> diff --git a/arch/mips/kernel/scall64-o32.S b/arch/mips/kernel/scall64-o32.S
> deleted file mode 100644
> index cedc8bd88804..000000000000
> --- a/arch/mips/kernel/scall64-o32.S
> +++ /dev/null
> @@ -1,221 +0,0 @@
> -/*
> - * This file is subject to the terms and conditions of the GNU General Public
> - * License. See the file "COPYING" in the main directory of this archive
> - * for more details.
> - *
> - * Copyright (C) 1995 - 2000, 2001 by Ralf Baechle
> - * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
> - * Copyright (C) 2001 MIPS Technologies, Inc.
> - * Copyright (C) 2004 Thiemo Seufer
> - *
> - * Hairy, the userspace application uses a different argument passing
> - * convention than the kernel, so we have to translate things from o32
> - * to ABI64 calling convention. 64-bit syscalls are also processed
> - * here for now.
> - */
> -#include <linux/errno.h>
> -#include <asm/asm.h>
> -#include <asm/asmmacro.h>
> -#include <asm/irqflags.h>
> -#include <asm/mipsregs.h>
> -#include <asm/regdef.h>
> -#include <asm/stackframe.h>
> -#include <asm/thread_info.h>
> -#include <asm/unistd.h>
> -#include <asm/sysmips.h>
> -
> - .align 5
> -NESTED(handle_sys, PT_SIZE, sp)
> - .set noat
> - SAVE_SOME
> - TRACE_IRQS_ON_RELOAD
> - STI
> - .set at
> - ld t1, PT_EPC(sp) # skip syscall on return
> -
> - dsubu t0, v0, __NR_O32_Linux # check syscall number
> - sltiu t0, t0, __NR_O32_Linux_syscalls
> - daddiu t1, 4 # skip to next instruction
> - sd t1, PT_EPC(sp)
> - beqz t0, not_o32_scall
> -#if 0
> - SAVE_ALL
> - move a1, v0
> - ASM_PRINT("Scall %ld\n")
> - RESTORE_ALL
> -#endif
> -
> - /* We don't want to stumble over broken sign extensions from
> - userland. O32 does never use the upper half. */
> - sll a0, a0, 0
> - sll a1, a1, 0
> - sll a2, a2, 0
> - sll a3, a3, 0
> -
> - sd a3, PT_R26(sp) # save a3 for syscall restarting
> -
> - /*
> - * More than four arguments. Try to deal with it by copying the
> - * stack arguments from the user stack to the kernel stack.
> - * This Sucks (TM).
> - *
> - * We intentionally keep the kernel stack a little below the top of
> - * userspace so we don't have to do a slower byte accurate check here.
> - */
> - ld t0, PT_R29(sp) # get old user stack pointer
> - daddu t1, t0, 32
> - bltz t1, bad_stack
> -
> -load_a4: lw a4, 16(t0) # argument #5 from usp
> -load_a5: lw a5, 20(t0) # argument #6 from usp
> -load_a6: lw a6, 24(t0) # argument #7 from usp
> -load_a7: lw a7, 28(t0) # argument #8 from usp
> -loads_done:
> -
> - .section __ex_table,"a"
> - PTR load_a4, bad_stack_a4
> - PTR load_a5, bad_stack_a5
> - PTR load_a6, bad_stack_a6
> - PTR load_a7, bad_stack_a7
> - .previous
> -
> - li t1, _TIF_WORK_SYSCALL_ENTRY
> - LONG_L t0, TI_FLAGS($28) # syscall tracing enabled?
> - and t0, t1, t0
> - bnez t0, trace_a_syscall
> -
> -syscall_common:
> - dsll t0, v0, 3 # offset into table
> - ld t2, (sys32_call_table - (__NR_O32_Linux * 8))(t0)
> -
> - jalr t2 # Do The Real Thing (TM)
> -
> - li t0, -EMAXERRNO - 1 # error?
> - sltu t0, t0, v0
> - sd t0, PT_R7(sp) # set error flag
> - beqz t0, 1f
> -
> - ld t1, PT_R2(sp) # syscall number
> - dnegu v0 # error
> - sd t1, PT_R0(sp) # save it for syscall restarting
> -1: sd v0, PT_R2(sp) # result
> -
> -o32_syscall_exit:
> - j syscall_exit_partial
> -
> -/* ------------------------------------------------------------------------ */
> -
> -trace_a_syscall:
> - SAVE_STATIC
> - sd a4, PT_R8(sp) # Save argument registers
> - sd a5, PT_R9(sp)
> - sd a6, PT_R10(sp)
> - sd a7, PT_R11(sp) # For indirect syscalls
> -
> - move a0, sp
> - /*
> - * absolute syscall number is in v0 unless we called syscall(__NR_###)
> - * where the real syscall number is in a0
> - * note: NR_syscall is the first O32 syscall but the macro is
> - * only defined when compiling with -mabi=32 (CONFIG_32BIT)
> - * therefore __NR_O32_Linux is used (4000)
> - */
> - .set push
> - .set reorder
> - subu t1, v0, __NR_O32_Linux
> - move a1, v0
> - bnez t1, 1f /* __NR_syscall at offset 0 */
> - ld a1, PT_R4(sp) /* Arg1 for __NR_syscall case */
> - .set pop
> -
> -1: jal syscall_trace_enter
> -
> - bltz v0, 1f # seccomp failed? Skip syscall
> -
> - RESTORE_STATIC
> - ld v0, PT_R2(sp) # Restore syscall (maybe modified)
> - ld a0, PT_R4(sp) # Restore argument registers
> - ld a1, PT_R5(sp)
> - ld a2, PT_R6(sp)
> - ld a3, PT_R7(sp)
> - ld a4, PT_R8(sp)
> - ld a5, PT_R9(sp)
> - ld a6, PT_R10(sp)
> - ld a7, PT_R11(sp) # For indirect syscalls
> -
> - dsubu t0, v0, __NR_O32_Linux # check (new) syscall number
> - sltiu t0, t0, __NR_O32_Linux_syscalls
> - beqz t0, not_o32_scall
> -
> - j syscall_common
> -
> -1: j syscall_exit
> -
> -/* ------------------------------------------------------------------------ */
> -
> - /*
> - * The stackpointer for a call with more than 4 arguments is bad.
> - */
> -bad_stack:
> - li v0, EFAULT
> - sd v0, PT_R2(sp)
> - li t0, 1 # set error flag
> - sd t0, PT_R7(sp)
> - j o32_syscall_exit
> -
> -bad_stack_a4:
> - li a4, 0
> - b load_a5
> -
> -bad_stack_a5:
> - li a5, 0
> - b load_a6
> -
> -bad_stack_a6:
> - li a6, 0
> - b load_a7
> -
> -bad_stack_a7:
> - li a7, 0
> - b loads_done
> -
> -not_o32_scall:
> - /*
> - * This is not an o32 compatibility syscall, pass it on
> - * to the 64-bit syscall handlers.
> - */
> -#ifdef CONFIG_MIPS32_N32
> - j handle_sysn32
> -#else
> - j handle_sys64
> -#endif
> - END(handle_sys)
> -
> -LEAF(sys32_syscall)
> - subu t0, a0, __NR_O32_Linux # check syscall number
> - sltiu v0, t0, __NR_O32_Linux_syscalls
> - beqz t0, einval # do not recurse
> - dsll t1, t0, 3
> - beqz v0, einval
> - ld t2, sys32_call_table(t1) # syscall routine
> -
> - move a0, a1 # shift argument registers
> - move a1, a2
> - move a2, a3
> - move a3, a4
> - move a4, a5
> - move a5, a6
> - move a6, a7
> - jr t2
> - /* Unreached */
> -
> -einval: li v0, -ENOSYS
> - jr ra
> - END(sys32_syscall)
> -
> -#define __SYSCALL_WITH_COMPAT(nr, native, compat) __SYSCALL(nr, compat)
> -#define __SYSCALL(nr, entry) PTR entry
> - .align 3
> - .type sys32_call_table,@object
> -EXPORT(sys32_call_table)
> -#include <asm/syscall_table_o32.h>
> diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c
> index c9b2a75563e1..314a6ffa0e07 100644
> --- a/arch/mips/kernel/signal.c
> +++ b/arch/mips/kernel/signal.c
> @@ -32,7 +32,6 @@
> #include <linux/bitops.h>
> #include <asm/cacheflush.h>
> #include <asm/fpu.h>
> -#include <asm/sim.h>
> #include <asm/ucontext.h>
> #include <asm/cpu-features.h>
> #include <asm/war.h>
> @@ -627,7 +626,7 @@ SYSCALL_DEFINE3(sigaction, int, sig, const struct sigaction __user *, act,
> #endif
>
> #ifdef CONFIG_TRAD_SIGNALS
> -asmlinkage void sys_sigreturn(void)
> +asmlinkage long sys_sigreturn(void)
> {
> struct sigframe __user *frame;
> struct pt_regs *regs;
> @@ -649,22 +648,17 @@ asmlinkage void sys_sigreturn(void)
> else if (sig)
> force_sig(sig);
>
> - /*
> - * Don't let your children do this ...
> - */
> - __asm__ __volatile__(
> - "move\t$29, %0\n\t"
> - "j\tsyscall_exit"
> - : /* no outputs */
> - : "r" (regs));
> - /* Unreached */
> + regs->regs[0] = 0; /* No syscall restarting */
> + regs->regs[27] = 1; /* return directly */
> + return regs->regs[2];
>
> badframe:
> force_sig(SIGSEGV);
> + return 0;
> }
> #endif /* CONFIG_TRAD_SIGNALS */
>
> -asmlinkage void sys_rt_sigreturn(void)
> +asmlinkage long sys_rt_sigreturn(void)
> {
> struct rt_sigframe __user *frame;
> struct pt_regs *regs;
> @@ -686,21 +680,16 @@ asmlinkage void sys_rt_sigreturn(void)
> else if (sig)
> force_sig(sig);
>
> + regs->regs[0] = 0; /* No syscall restarting */
> if (restore_altstack(&frame->rs_uc.uc_stack))
> goto badframe;
>
> - /*
> - * Don't let your children do this ...
> - */
> - __asm__ __volatile__(
> - "move\t$29, %0\n\t"
> - "j\tsyscall_exit"
> - : /* no outputs */
> - : "r" (regs));
> - /* Unreached */
> + regs->regs[27] = 1; /* return directly */
> + return regs->regs[2];
>
> badframe:
> force_sig(SIGSEGV);
> + return 0;
> }
>
> #ifdef CONFIG_TRAD_SIGNALS
> @@ -852,11 +841,11 @@ static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
> signal_setup_done(ret, ksig, 0);
> }
>
> -static void do_signal(struct pt_regs *regs)
> +void arch_do_signal_or_restart(struct pt_regs *regs, bool has_signal)
> {
> struct ksignal ksig;
>
> - if (get_signal(&ksig)) {
> + if (has_signal && get_signal(&ksig)) {
> /* Whee! Actually deliver the signal. */
> handle_signal(&ksig, regs);
> return;
> @@ -904,7 +893,7 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused,
>
> /* deal with pending signal delivery */
> if (thread_info_flags & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL))
> - do_signal(regs);
> + arch_do_signal_or_restart(regs, thread_info_flags & _TIF_SIGPENDING);
>
> if (thread_info_flags & _TIF_NOTIFY_RESUME)
> tracehook_notify_resume(regs);
> diff --git a/arch/mips/kernel/signal_n32.c b/arch/mips/kernel/signal_n32.c
> index 7bd00fad61af..e282f14747d2 100644
> --- a/arch/mips/kernel/signal_n32.c
> +++ b/arch/mips/kernel/signal_n32.c
> @@ -19,7 +19,6 @@
> #include <asm/asm.h>
> #include <asm/cacheflush.h>
> #include <asm/compat-signal.h>
> -#include <asm/sim.h>
> #include <linux/uaccess.h>
> #include <asm/ucontext.h>
> #include <asm/fpu.h>
> @@ -51,7 +50,7 @@ struct rt_sigframe_n32 {
> struct ucontextn32 rs_uc;
> };
>
> -asmlinkage void sysn32_rt_sigreturn(void)
> +asmlinkage long sysn32_rt_sigreturn(void)
> {
> struct rt_sigframe_n32 __user *frame;
> struct pt_regs *regs;
> @@ -73,21 +72,16 @@ asmlinkage void sysn32_rt_sigreturn(void)
> else if (sig)
> force_sig(sig);
>
> + regs->regs[0] = 0; /* No syscall restarting */
> if (compat_restore_altstack(&frame->rs_uc.uc_stack))
> goto badframe;
>
> - /*
> - * Don't let your children do this ...
> - */
> - __asm__ __volatile__(
> - "move\t$29, %0\n\t"
> - "j\tsyscall_exit"
> - : /* no outputs */
> - : "r" (regs));
> - /* Unreached */
> + regs->regs[27] = 1; /* return directly */
> + return regs->regs[2];
>
> badframe:
> force_sig(SIGSEGV);
> + return 0;
> }
>
> static int setup_rt_frame_n32(void *sig_return, struct ksignal *ksig,
> diff --git a/arch/mips/kernel/signal_o32.c b/arch/mips/kernel/signal_o32.c
> index 299a7a28ca33..ea6d12dd15cc 100644
> --- a/arch/mips/kernel/signal_o32.c
> +++ b/arch/mips/kernel/signal_o32.c
> @@ -17,7 +17,6 @@
> #include <asm/abi.h>
> #include <asm/compat-signal.h>
> #include <asm/dsp.h>
> -#include <asm/sim.h>
> #include <asm/unistd.h>
>
> #include "signal-common.h"
> @@ -151,7 +150,7 @@ static int setup_frame_32(void *sig_return, struct ksignal *ksig,
> return 0;
> }
>
> -asmlinkage void sys32_rt_sigreturn(void)
> +asmlinkage long sys32_rt_sigreturn(void)
> {
> struct rt_sigframe32 __user *frame;
> struct pt_regs *regs;
> @@ -173,21 +172,16 @@ asmlinkage void sys32_rt_sigreturn(void)
> else if (sig)
> force_sig(sig);
>
> + regs->regs[0] = 0; /* No syscall restarting */
> if (compat_restore_altstack(&frame->rs_uc.uc_stack))
> goto badframe;
>
> - /*
> - * Don't let your children do this ...
> - */
> - __asm__ __volatile__(
> - "move\t$29, %0\n\t"
> - "j\tsyscall_exit"
> - : /* no outputs */
> - : "r" (regs));
> - /* Unreached */
> + regs->regs[27] = 1; /* return directly */
> + return regs->regs[2];
>
> badframe:
> force_sig(SIGSEGV);
> + return 0;
> }
>
> static int setup_rt_frame_32(void *sig_return, struct ksignal *ksig,
> @@ -253,7 +247,7 @@ struct mips_abi mips_abi_32 = {
> };
>
>
> -asmlinkage void sys32_sigreturn(void)
> +asmlinkage long sys32_sigreturn(void)
> {
> struct sigframe32 __user *frame;
> struct pt_regs *regs;
> @@ -275,16 +269,11 @@ asmlinkage void sys32_sigreturn(void)
> else if (sig)
> force_sig(sig);
>
> - /*
> - * Don't let your children do this ...
> - */
> - __asm__ __volatile__(
> - "move\t$29, %0\n\t"
> - "j\tsyscall_exit"
> - : /* no outputs */
> - : "r" (regs));
> - /* Unreached */
> + regs->regs[0] = 0; /* No syscall restarting */
> + regs->regs[27] = 1; /* return directly */
> + return regs->regs[2];
>
> badframe:
> force_sig(SIGSEGV);
> + return 0;
> }
> diff --git a/arch/mips/kernel/syscall.c b/arch/mips/kernel/syscall.c
> index 2afa3eef486a..2653f82a8c99 100644
> --- a/arch/mips/kernel/syscall.c
> +++ b/arch/mips/kernel/syscall.c
> @@ -8,6 +8,7 @@
> * Copyright (C) 2001 MIPS Technologies, Inc.
> */
> #include <linux/capability.h>
> +#include <linux/entry-common.h>
> #include <linux/errno.h>
> #include <linux/linkage.h>
> #include <linux/fs.h>
> @@ -35,9 +36,9 @@
> #include <asm/cacheflush.h>
> #include <asm/asm-offsets.h>
> #include <asm/signal.h>
> -#include <asm/sim.h>
> #include <asm/shmparam.h>
> #include <asm/sync.h>
> +#include <asm/syscall.h>
> #include <asm/sysmips.h>
> #include <asm/switch_to.h>
>
> @@ -79,10 +80,6 @@ SYSCALL_DEFINE6(mips_mmap2, unsigned long, addr, unsigned long, len,
> pgoff >> (PAGE_SHIFT - 12));
> }
>
> -save_static_function(sys_fork);
> -save_static_function(sys_clone);
> -save_static_function(sys_clone3);
> -
> SYSCALL_DEFINE1(set_thread_area, unsigned long, addr)
> {
> struct thread_info *ti = task_thread_info(current);
> @@ -182,28 +179,11 @@ static inline int mips_atomic_set(unsigned long addr, unsigned long new)
> return err;
>
> regs = current_pt_regs();
> - regs->regs[2] = old;
> - regs->regs[7] = 0; /* No error */
> -
> - /*
> - * Don't let your children do this ...
> - */
> - __asm__ __volatile__(
> - " move $29, %0 \n"
> - " j syscall_exit \n"
> - : /* no outputs */
> - : "r" (regs));
> -
> - /* unreached. Honestly. */
> - unreachable();
> + regs->regs[7] = 0; /* no error */
> + regs->regs[27] = 1; /* return directly */
> + return old;
> }
>
> -/*
> - * mips_atomic_set() normally returns directly via syscall_exit potentially
> - * clobbering static registers, so be sure to preserve them.
> - */
> -save_static_function(sys_sysmips);
> -
> SYSCALL_DEFINE3(sysmips, long, cmd, long, arg1, long, arg2)
> {
> switch (cmd) {
> @@ -249,3 +229,121 @@ asmlinkage void bad_stack(void)
> {
> do_exit(SIGSEGV);
> }
> +
> +#if defined(CONFIG_32BIT) || defined(CONFIG_MIPS32_O32)
> +static inline int get_args(struct pt_regs *regs)
> +{
> + int *usp = (int *)regs->regs[29];
> +
> +#ifdef CONFIG_MIPS32_O32
> + /*
> + * Hairy, the userspace application uses a different argument passing
> + * convention than the kernel, so we have to translate things from o32
> + * to ABI64 calling convention.
> + *
> + * We don't want to stumble over broken sign extensions from userland.
> + * O32 does never use the upper half.
> + */
> + regs->regs[4] = (int)regs->regs[4];
> + regs->regs[5] = (int)regs->regs[5];
> + regs->regs[6] = (int)regs->regs[6];
> + regs->regs[7] = (int)regs->regs[7];
> +#endif
> +
> + /*
> + * More than four arguments. Try to deal with it by copying the
> + * stack arguments from the user stack to the kernel stack.
> + * This Sucks (TM).
> + *
> + * We intentionally keep the kernel stack a little below the top of
> + * userspace so we don't have to do a slower byte accurate check here.
> + */
> + if (!access_ok(usp, 32))
> + return -1;
> +
> + get_user(regs->regs[8], usp + 4);
> + get_user(regs->regs[9], usp + 5);
> + get_user(regs->regs[10], usp + 6);
> + get_user(regs->regs[11], usp + 7);
> +
> + return 0;
> +}
> +#endif
> +
> +typedef long (*sys_call_fn)(unsigned long, unsigned long,
> + unsigned long, unsigned long, unsigned long, unsigned long);
> +
> +long noinstr do_syscall(struct pt_regs *regs)
> +{
> + unsigned long nr;
> + unsigned long ret;
> + sys_call_fn syscall_fn = NULL;
> +
> + nr = regs->regs[2];
> + current_thread_info()->syscall = nr;
> + nr = syscall_enter_from_user_mode(regs, nr);
> +
> + regs->cp0_epc += 4; /* skip syscall on return */
> + /* skip to next instruction */
> + regs->regs[26] = regs->regs[7]; /* save a3 for syscall restarting */
> + regs->regs[27] = 0; /* do not return directly */
> +
> +#ifdef CONFIG_32BIT
> + if (nr >= __NR_O32_Linux && nr < __NR_O32_Linux + __NR_O32_Linux_syscalls) {
> + if (get_args(regs) < 0) {
> + ret = EFAULT;
> + goto error;
> + }
> + syscall_fn = (sys_call_fn)sys_call_table[nr - __NR_O32_Linux];
> + }
> +#endif
> +
> +#ifdef CONFIG_MIPS32_O32
> + if (nr >= __NR_O32_Linux && nr < __NR_O32_Linux + __NR_O32_Linux_syscalls) {
> + if (get_args(regs) < 0) {
> + ret = EFAULT;
> + goto error;
> + }
> + syscall_fn = (sys_call_fn)sys32_call_table[nr - __NR_O32_Linux];
> + }
> +#endif
> +
> +#ifdef CONFIG_MIPS32_N32
> + if (nr >= __NR_N32_Linux && nr < __NR_N32_Linux + __NR_N32_Linux_syscalls)
> + syscall_fn = (sys_call_fn)sysn32_call_table[nr - __NR_N32_Linux];
> +#endif
> +
> +#ifdef CONFIG_64BIT
> + if (nr >= __NR_64_Linux && nr < __NR_64_Linux + __NR_64_Linux_syscalls)
> + syscall_fn = (sys_call_fn)sys_call_table[nr - __NR_64_Linux];
> +#endif
> +
> + if (unlikely(!syscall_fn)) {
> + ret = ENOSYS;
> + goto error;
> + }
> +
> + ret = syscall_fn(regs->regs[4], regs->regs[5], regs->regs[6],
> + regs->regs[7], regs->regs[8], regs->regs[9]);
> +
> + if (regs->regs[27]) /* return directly? */
> + goto out;
> +
> + regs->regs[7] = 0; /* clear error flag */
> + if (ret >= -EMAXERRNO - 1) { /* error? */
> + regs->regs[0] = nr; /* save syscall number */
> + /* for syscall restarting */
> + ret = -ret;
> + goto error;
> + }
> +
> + goto out;
> +
> +error:
> + regs->regs[7] = 1; /* set error flag */
> +
> +out:
> + regs->regs[2] = ret;
> + syscall_exit_to_user_mode(regs);
> + return regs->regs[27];
> +}
> diff --git a/arch/mips/kernel/syscalls/syscall_n32.tbl b/arch/mips/kernel/syscalls/syscall_n32.tbl
> index 70e32de2bcaa..d9ae765e51f1 100644
> --- a/arch/mips/kernel/syscalls/syscall_n32.tbl
> +++ b/arch/mips/kernel/syscalls/syscall_n32.tbl
> @@ -62,8 +62,8 @@
> 52 n32 socketpair sys_socketpair
> 53 n32 setsockopt sys_setsockopt
> 54 n32 getsockopt sys_getsockopt
> -55 n32 clone __sys_clone
> -56 n32 fork __sys_fork
> +55 n32 clone sys_clone
> +56 n32 fork sys_fork
> 57 n32 execve compat_sys_execve
> 58 n32 exit sys_exit
> 59 n32 wait4 compat_sys_wait4
> @@ -207,7 +207,7 @@
> 196 n32 sched_getaffinity compat_sys_sched_getaffinity
> 197 n32 cacheflush sys_cacheflush
> 198 n32 cachectl sys_cachectl
> -199 n32 sysmips __sys_sysmips
> +199 n32 sysmips sys_sysmips
> 200 n32 io_setup compat_sys_io_setup
> 201 n32 io_destroy sys_io_destroy
> 202 n32 io_getevents sys_io_getevents_time32
> @@ -373,7 +373,7 @@
> 432 n32 fsmount sys_fsmount
> 433 n32 fspick sys_fspick
> 434 n32 pidfd_open sys_pidfd_open
> -435 n32 clone3 __sys_clone3
> +435 n32 clone3 sys_clone3
> 436 n32 close_range sys_close_range
> 437 n32 openat2 sys_openat2
> 438 n32 pidfd_getfd sys_pidfd_getfd
> diff --git a/arch/mips/kernel/syscalls/syscall_n64.tbl b/arch/mips/kernel/syscalls/syscall_n64.tbl
> index 1ca7bc337932..edec3e82d67a 100644
> --- a/arch/mips/kernel/syscalls/syscall_n64.tbl
> +++ b/arch/mips/kernel/syscalls/syscall_n64.tbl
> @@ -62,8 +62,8 @@
> 52 n64 socketpair sys_socketpair
> 53 n64 setsockopt sys_setsockopt
> 54 n64 getsockopt sys_getsockopt
> -55 n64 clone __sys_clone
> -56 n64 fork __sys_fork
> +55 n64 clone sys_clone
> +56 n64 fork sys_fork
> 57 n64 execve sys_execve
> 58 n64 exit sys_exit
> 59 n64 wait4 sys_wait4
> @@ -207,7 +207,7 @@
> 196 n64 sched_getaffinity sys_sched_getaffinity
> 197 n64 cacheflush sys_cacheflush
> 198 n64 cachectl sys_cachectl
> -199 n64 sysmips __sys_sysmips
> +199 n64 sysmips sys_sysmips
> 200 n64 io_setup sys_io_setup
> 201 n64 io_destroy sys_io_destroy
> 202 n64 io_getevents sys_io_getevents
> @@ -349,7 +349,7 @@
> 432 n64 fsmount sys_fsmount
> 433 n64 fspick sys_fspick
> 434 n64 pidfd_open sys_pidfd_open
> -435 n64 clone3 __sys_clone3
> +435 n64 clone3 sys_clone3
> 436 n64 close_range sys_close_range
> 437 n64 openat2 sys_openat2
> 438 n64 pidfd_getfd sys_pidfd_getfd
> diff --git a/arch/mips/kernel/syscalls/syscall_o32.tbl b/arch/mips/kernel/syscalls/syscall_o32.tbl
> index a61c35edaa74..89a1f267da6a 100644
> --- a/arch/mips/kernel/syscalls/syscall_o32.tbl
> +++ b/arch/mips/kernel/syscalls/syscall_o32.tbl
> @@ -9,7 +9,7 @@
> #
> 0 o32 syscall sys_syscall sys32_syscall
> 1 o32 exit sys_exit
> -2 o32 fork __sys_fork
> +2 o32 fork sys_fork
> 3 o32 read sys_read
> 4 o32 write sys_write
> 5 o32 open sys_open compat_sys_open
> @@ -131,7 +131,7 @@
> 117 o32 ipc sys_ipc compat_sys_ipc
> 118 o32 fsync sys_fsync
> 119 o32 sigreturn sys_sigreturn sys32_sigreturn
> -120 o32 clone __sys_clone
> +120 o32 clone sys_clone
> 121 o32 setdomainname sys_setdomainname
> 122 o32 uname sys_newuname
> 123 o32 modify_ldt sys_ni_syscall
> @@ -160,7 +160,7 @@
> 146 o32 writev sys_writev
> 147 o32 cacheflush sys_cacheflush
> 148 o32 cachectl sys_cachectl
> -149 o32 sysmips __sys_sysmips
> +149 o32 sysmips sys_sysmips
> 150 o32 unused150 sys_ni_syscall
> 151 o32 getsid sys_getsid
> 152 o32 fdatasync sys_fdatasync
> @@ -422,7 +422,7 @@
> 432 o32 fsmount sys_fsmount
> 433 o32 fspick sys_fspick
> 434 o32 pidfd_open sys_pidfd_open
> -435 o32 clone3 __sys_clone3
> +435 o32 clone3 sys_clone3
> 436 o32 close_range sys_close_range
> 437 o32 openat2 sys_openat2
> 438 o32 pidfd_getfd sys_pidfd_getfd
> --
> 2.27.0
>
--
YunQiang Su
