Re: [PATCH V4 5/8] riscv: convert to generic entry

Yipeng Zou
2022-09-15T13:50:48Z

I test this patch,  its work without any error.

Tested-by: Yipeng Zou <zouyipeng@huawei.com>

在 2022/9/8 10:25, guoren@kernel.org 写道:
> From: Guo Ren <guoren@linux.alibaba.com>
>
> This patch converts riscv to use the generic entry infrastructure from
> kernel/entry/*. The generic entry makes maintainers' work easier and
> codes more elegant. Here are the changes than before:
>
> - More clear entry.S with handle_exception and ret_from_exception
> - Get rid of complex custom signal implementation
> - More readable syscall procedure
> - Little modification on ret_from_fork & ret_from_kernel_thread
> - Wrap with irqentry_enter/exit and syscall_enter/exit_from_user_mode
> - Use the standard preemption code instead of custom
>
> Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
> Signed-off-by: Guo Ren <guoren@kernel.org>
> Suggested-by: Huacai Chen <chenhuacai@kernel.org>
> ---
> arch/riscv/Kconfig | 1 +
> arch/riscv/include/asm/csr.h | 1 -
> arch/riscv/include/asm/entry-common.h | 8 +
> arch/riscv/include/asm/ptrace.h | 10 +-
> arch/riscv/include/asm/stacktrace.h | 5 +
> arch/riscv/include/asm/syscall.h | 6 +
> arch/riscv/include/asm/thread_info.h | 13 +-
> arch/riscv/kernel/entry.S | 228 +++-----------------------
> arch/riscv/kernel/irq.c | 15 ++
> arch/riscv/kernel/ptrace.c | 40 -----
> arch/riscv/kernel/signal.c | 21 +--
> arch/riscv/kernel/sys_riscv.c | 27 +++
> arch/riscv/kernel/traps.c | 11 ++
> arch/riscv/mm/fault.c | 12 +-
> 14 files changed, 117 insertions(+), 281 deletions(-)
> create mode 100644 arch/riscv/include/asm/entry-common.h
>
> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> index ed66c31e4655..a07bb3b73b5b 100644
> --- a/arch/riscv/Kconfig
> +++ b/arch/riscv/Kconfig
> @@ -56,6 +56,7 @@ config RISCV
> select GENERIC_ATOMIC64 if !64BIT
> select GENERIC_CLOCKEVENTS_BROADCAST if SMP
> select GENERIC_EARLY_IOREMAP
> + select GENERIC_ENTRY
> select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
> select GENERIC_IDLE_POLL_SETUP
> select GENERIC_IOREMAP if MMU
> diff --git a/arch/riscv/include/asm/csr.h b/arch/riscv/include/asm/csr.h
> index 0e571f6483d9..7c2b8cdb7b77 100644
> --- a/arch/riscv/include/asm/csr.h
> +++ b/arch/riscv/include/asm/csr.h
> @@ -40,7 +40,6 @@
> #define SR_UXL _AC(0x300000000, UL) /* XLEN mask for U-mode */
> #define SR_UXL_32 _AC(0x100000000, UL) /* XLEN = 32 for U-mode */
> #define SR_UXL_64 _AC(0x200000000, UL) /* XLEN = 64 for U-mode */
> -#define SR_UXL_SHIFT 32
> #endif
>
> /* SATP flags */
> diff --git a/arch/riscv/include/asm/entry-common.h b/arch/riscv/include/asm/entry-common.h
> new file mode 100644
> index 000000000000..1636ac2af28e
> --- /dev/null
> +++ b/arch/riscv/include/asm/entry-common.h
> @@ -0,0 +1,8 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +
> +#ifndef _ASM_RISCV_ENTRY_COMMON_H
> +#define _ASM_RISCV_ENTRY_COMMON_H
> +
> +#include <asm/stacktrace.h>
> +
> +#endif /* _ASM_RISCV_ENTRY_COMMON_H */
> diff --git a/arch/riscv/include/asm/ptrace.h b/arch/riscv/include/asm/ptrace.h
> index 6ecd461129d2..4e46a611f255 100644
> --- a/arch/riscv/include/asm/ptrace.h
> +++ b/arch/riscv/include/asm/ptrace.h
> @@ -53,6 +53,9 @@ struct pt_regs {
> unsigned long orig_a0;
> };
>
> +#define PTRACE_SYSEMU 0x1f
> +#define PTRACE_SYSEMU_SINGLESTEP 0x20
> +
> #ifdef CONFIG_64BIT
> #define REG_FMT "%016lx"
> #else
> @@ -121,8 +124,6 @@ extern unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
>
> void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
> unsigned long frame_pointer);
> -int do_syscall_trace_enter(struct pt_regs *regs);
> -void do_syscall_trace_exit(struct pt_regs *regs);
>
> /**
> * regs_get_register() - get register value from its offset
> @@ -172,6 +173,11 @@ static inline unsigned long regs_get_kernel_argument(struct pt_regs *regs,
> return 0;
> }
>
> +static inline int regs_irqs_disabled(struct pt_regs *regs)
> +{
> + return !(regs->status & SR_IE);
> +}
> +
> #endif /* __ASSEMBLY__ */
>
> #endif /* _ASM_RISCV_PTRACE_H */
> diff --git a/arch/riscv/include/asm/stacktrace.h b/arch/riscv/include/asm/stacktrace.h
> index 3450c1912afd..f7e8ef2418b9 100644
> --- a/arch/riscv/include/asm/stacktrace.h
> +++ b/arch/riscv/include/asm/stacktrace.h
> @@ -16,4 +16,9 @@ extern void notrace walk_stackframe(struct task_struct *task, struct pt_regs *re
> extern void dump_backtrace(struct pt_regs *regs, struct task_struct *task,
> const char *loglvl);
>
> +static inline bool on_thread_stack(void)
> +{
> + return !(((unsigned long)(current->stack) ^ current_stack_pointer) & ~(THREAD_SIZE - 1));
> +}
> +
> #endif /* _ASM_RISCV_STACKTRACE_H */
> diff --git a/arch/riscv/include/asm/syscall.h b/arch/riscv/include/asm/syscall.h
> index 384a63b86420..6c573f18030b 100644
> --- a/arch/riscv/include/asm/syscall.h
> +++ b/arch/riscv/include/asm/syscall.h
> @@ -74,5 +74,11 @@ static inline int syscall_get_arch(struct task_struct *task)
> #endif
> }
>
> +static inline bool arch_syscall_is_vdso_sigreturn(struct pt_regs *regs)
> +{
> + return false;
> +}
> +
> asmlinkage long sys_riscv_flush_icache(uintptr_t, uintptr_t, uintptr_t);
> +asmlinkage void do_sys_ecall_u(struct pt_regs *regs);
> #endif /* _ASM_RISCV_SYSCALL_H */
> diff --git a/arch/riscv/include/asm/thread_info.h b/arch/riscv/include/asm/thread_info.h
> index 67322f878e0d..7de4fb96f0b5 100644
> --- a/arch/riscv/include/asm/thread_info.h
> +++ b/arch/riscv/include/asm/thread_info.h
> @@ -66,6 +66,7 @@ struct thread_info {
> long kernel_sp; /* Kernel stack pointer */
> long user_sp; /* User stack pointer */
> int cpu;
> + unsigned long syscall_work; /* SYSCALL_WORK_ flags */
> };
>
> /*
> @@ -88,26 +89,18 @@ struct thread_info {
> * - pending work-to-be-done flags are in lowest half-word
> * - other flags in upper half-word(s)
> */
> -#define TIF_SYSCALL_TRACE 0 /* syscall trace active */
> #define TIF_NOTIFY_RESUME 1 /* callback before returning to user */
> #define TIF_SIGPENDING 2 /* signal pending */
> #define TIF_NEED_RESCHED 3 /* rescheduling necessary */
> #define TIF_RESTORE_SIGMASK 4 /* restore signal mask in do_signal() */
> #define TIF_MEMDIE 5 /* is terminating due to OOM killer */
> -#define TIF_SYSCALL_TRACEPOINT 6 /* syscall tracepoint instrumentation */
> -#define TIF_SYSCALL_AUDIT 7 /* syscall auditing */
> -#define TIF_SECCOMP 8 /* syscall secure computing */
> #define TIF_NOTIFY_SIGNAL 9 /* signal notifications exist */
> #define TIF_UPROBE 10 /* uprobe breakpoint or singlestep */
> #define TIF_32BIT 11 /* compat-mode 32bit process */
>
> -#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
> #define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
> #define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
> #define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
> -#define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT)
> -#define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT)
> -#define _TIF_SECCOMP (1 << TIF_SECCOMP)
> #define _TIF_NOTIFY_SIGNAL (1 << TIF_NOTIFY_SIGNAL)
> #define _TIF_UPROBE (1 << TIF_UPROBE)
>
> @@ -115,8 +108,4 @@ struct thread_info {
> (_TIF_NOTIFY_RESUME | _TIF_SIGPENDING | _TIF_NEED_RESCHED | \
> _TIF_NOTIFY_SIGNAL | _TIF_UPROBE)
>
> -#define _TIF_SYSCALL_WORK \
> - (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_TRACEPOINT | _TIF_SYSCALL_AUDIT | \
> - _TIF_SECCOMP)
> -
> #endif /* _ASM_RISCV_THREAD_INFO_H */
> diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S
> index b9eda3fcbd6d..5f49517cd3a2 100644
> --- a/arch/riscv/kernel/entry.S
> +++ b/arch/riscv/kernel/entry.S
> @@ -14,10 +14,6 @@
> #include <asm/asm-offsets.h>
> #include <asm/errata_list.h>
>
> -#if !IS_ENABLED(CONFIG_PREEMPTION)
> -.set resume_kernel, restore_all
> -#endif
> -
> ENTRY(handle_exception)
> /*
> * If coming from userspace, preserve the user thread pointer and load
> @@ -106,19 +102,8 @@ _save_context:
> .option norelax
> la gp, __global_pointer$
> .option pop
> -
> -#ifdef CONFIG_TRACE_IRQFLAGS
> - call __trace_hardirqs_off
> -#endif
> -
> -#ifdef CONFIG_CONTEXT_TRACKING_USER
> - /* If previous state is in user mode, call user_exit_callable(). */
> - li a0, SR_PP
> - and a0, s1, a0
> - bnez a0, skip_context_tracking
> - call user_exit_callable
> -skip_context_tracking:
> -#endif
> + move a0, sp /* pt_regs */
> + la ra, ret_from_exception
>
> /*
> * MSB of cause differentiates between
> @@ -126,134 +111,26 @@ skip_context_tracking:
> */
> bge s4, zero, 1f
>
> - la ra, ret_from_exception
> -
> /* Handle interrupts */
> - move a0, sp /* pt_regs */
> - la a1, generic_handle_arch_irq
> - jr a1
> + tail do_riscv_irq
> 1:
> - /*
> - * Exceptions run with interrupts enabled or disabled depending on the
> - * state of SR_PIE in m/sstatus.
> - */
> - andi t0, s1, SR_PIE
> - beqz t0, 1f
> - /* kprobes, entered via ebreak, must have interrupts disabled. */
> - li t0, EXC_BREAKPOINT
> - beq s4, t0, 1f
> -#ifdef CONFIG_TRACE_IRQFLAGS
> - call __trace_hardirqs_on
> -#endif
> - csrs CSR_STATUS, SR_IE
> -
> -1:
> - la ra, ret_from_exception
> - /* Handle syscalls */
> - li t0, EXC_SYSCALL
> - beq s4, t0, handle_syscall
> -
> /* Handle other exceptions */
> slli t0, s4, RISCV_LGPTR
> la t1, excp_vect_table
> la t2, excp_vect_table_end
> - move a0, sp /* pt_regs */
> add t0, t1, t0
> /* Check if exception code lies within bounds */
> - bgeu t0, t2, 1f
> + bgeu t0, t2, 2f
> REG_L t0, 0(t0)
> jr t0
> -1:
> +2:
> tail do_trap_unknown
> +END(handle_exception)
>
> -handle_syscall:
> -#ifdef CONFIG_RISCV_M_MODE
> - /*
> - * When running is M-Mode (no MMU config), MPIE does not get set.
> - * As a result, we need to force enable interrupts here because
> - * handle_exception did not do set SR_IE as it always sees SR_PIE
> - * being cleared.
> - */
> - csrs CSR_STATUS, SR_IE
> -#endif
> -#if defined(CONFIG_TRACE_IRQFLAGS) || defined(CONFIG_CONTEXT_TRACKING_USER)
> - /* Recover a0 - a7 for system calls */
> - REG_L a0, PT_A0(sp)
> - REG_L a1, PT_A1(sp)
> - REG_L a2, PT_A2(sp)
> - REG_L a3, PT_A3(sp)
> - REG_L a4, PT_A4(sp)
> - REG_L a5, PT_A5(sp)
> - REG_L a6, PT_A6(sp)
> - REG_L a7, PT_A7(sp)
> -#endif
> - /* save the initial A0 value (needed in signal handlers) */
> - REG_S a0, PT_ORIG_A0(sp)
> - /*
> - * Advance SEPC to avoid executing the original
> - * scall instruction on sret
> - */
> - addi s2, s2, 0x4
> - REG_S s2, PT_EPC(sp)
> - /* Trace syscalls, but only if requested by the user. */
> - REG_L t0, TASK_TI_FLAGS(tp)
> - andi t0, t0, _TIF_SYSCALL_WORK
> - bnez t0, handle_syscall_trace_enter
> -check_syscall_nr:
> - /* Check to make sure we don't jump to a bogus syscall number. */
> - li t0, __NR_syscalls
> - la s0, sys_ni_syscall
> - /*
> - * Syscall number held in a7.
> - * If syscall number is above allowed value, redirect to ni_syscall.
> - */
> - bgeu a7, t0, 3f
> -#ifdef CONFIG_COMPAT
> +ENTRY(ret_from_exception)
> REG_L s0, PT_STATUS(sp)
> - srli s0, s0, SR_UXL_SHIFT
> - andi s0, s0, (SR_UXL >> SR_UXL_SHIFT)
> - li t0, (SR_UXL_32 >> SR_UXL_SHIFT)
> - sub t0, s0, t0
> - bnez t0, 1f
> -
> - /* Call compat_syscall */
> - la s0, compat_sys_call_table
> - j 2f
> -1:
> -#endif
> - /* Call syscall */
> - la s0, sys_call_table
> -2:
> - slli t0, a7, RISCV_LGPTR
> - add s0, s0, t0
> - REG_L s0, 0(s0)
> -3:
> - jalr s0
>
> -ret_from_syscall:
> - /* Set user a0 to kernel a0 */
> - REG_S a0, PT_A0(sp)
> - /*
> - * We didn't execute the actual syscall.
> - * Seccomp already set return value for the current task pt_regs.
> - * (If it was configured with SECCOMP_RET_ERRNO/TRACE)
> - */
> -ret_from_syscall_rejected:
> -#ifdef CONFIG_DEBUG_RSEQ
> - move a0, sp
> - call rseq_syscall
> -#endif
> - /* Trace syscalls, but only if requested by the user. */
> - REG_L t0, TASK_TI_FLAGS(tp)
> - andi t0, t0, _TIF_SYSCALL_WORK
> - bnez t0, handle_syscall_trace_exit
> -
> -ret_from_exception:
> - REG_L s0, PT_STATUS(sp)
> csrc CSR_STATUS, SR_IE
> -#ifdef CONFIG_TRACE_IRQFLAGS
> - call __trace_hardirqs_off
> -#endif
> #ifdef CONFIG_RISCV_M_MODE
> /* the MPP value is too large to be used as an immediate arg for addi */
> li t0, SR_MPP
> @@ -261,17 +138,7 @@ ret_from_exception:
> #else
> andi s0, s0, SR_SPP
> #endif
> - bnez s0, resume_kernel
> -
> -resume_userspace:
> - /* Interrupts must be disabled here so flags are checked atomically */
> - REG_L s0, TASK_TI_FLAGS(tp) /* current_thread_info->flags */
> - andi s1, s0, _TIF_WORK_MASK
> - bnez s1, work_pending
> -
> -#ifdef CONFIG_CONTEXT_TRACKING_USER
> - call user_enter_callable
> -#endif
> + bnez s0, 1f
>
> /* Save unwound kernel stack pointer in thread_info */
> addi s0, sp, PT_SIZE_ON_STACK
> @@ -282,19 +149,7 @@ resume_userspace:
> * structures again.
> */
> csrw CSR_SCRATCH, tp
> -
> -restore_all:
> -#ifdef CONFIG_TRACE_IRQFLAGS
> - REG_L s1, PT_STATUS(sp)
> - andi t0, s1, SR_PIE
> - beqz t0, 1f
> - call __trace_hardirqs_on
> - j 2f
> 1:
> - call __trace_hardirqs_off
> -2:
> -#endif
> - REG_L a0, PT_STATUS(sp)
> /*
> * The current load reservation is effectively part of the processor's
> * state, in the sense that load reservations cannot be shared between
> @@ -315,9 +170,11 @@ restore_all:
> REG_L a2, PT_EPC(sp)
> REG_SC x0, a2, PT_EPC(sp)
>
> - csrw CSR_STATUS, a0
> csrw CSR_EPC, a2
>
> + REG_L a0, PT_STATUS(sp)
> + csrw CSR_STATUS, a0
> +
> REG_L x1, PT_RA(sp)
> REG_L x3, PT_GP(sp)
> REG_L x4, PT_TP(sp)
> @@ -356,54 +213,10 @@ restore_all:
> #else
> sret
> #endif
> -
> -#if IS_ENABLED(CONFIG_PREEMPTION)
> -resume_kernel:
> - REG_L s0, TASK_TI_PREEMPT_COUNT(tp)
> - bnez s0, restore_all
> - REG_L s0, TASK_TI_FLAGS(tp)
> - andi s0, s0, _TIF_NEED_RESCHED
> - beqz s0, restore_all
> - call preempt_schedule_irq
> - j restore_all
> -#endif
> -
> -work_pending:
> - /* Enter slow path for supplementary processing */
> - la ra, ret_from_exception
> - andi s1, s0, _TIF_NEED_RESCHED
> - bnez s1, work_resched
> -work_notifysig:
> - /* Handle pending signals and notify-resume requests */
> - csrs CSR_STATUS, SR_IE /* Enable interrupts for do_notify_resume() */
> - move a0, sp /* pt_regs */
> - move a1, s0 /* current_thread_info->flags */
> - tail do_notify_resume
> -work_resched:
> - tail schedule
> -
> -/* Slow paths for ptrace. */
> -handle_syscall_trace_enter:
> - move a0, sp
> - call do_syscall_trace_enter
> - move t0, a0
> - REG_L a0, PT_A0(sp)
> - REG_L a1, PT_A1(sp)
> - REG_L a2, PT_A2(sp)
> - REG_L a3, PT_A3(sp)
> - REG_L a4, PT_A4(sp)
> - REG_L a5, PT_A5(sp)
> - REG_L a6, PT_A6(sp)
> - REG_L a7, PT_A7(sp)
> - bnez t0, ret_from_syscall_rejected
> - j check_syscall_nr
> -handle_syscall_trace_exit:
> - move a0, sp
> - call do_syscall_trace_exit
> - j ret_from_exception
> +END(ret_from_exception)
>
> #ifdef CONFIG_VMAP_STACK
> -handle_kernel_stack_overflow:
> +ENTRY(handle_kernel_stack_overflow)
> la sp, shadow_stack
> addi sp, sp, SHADOW_OVERFLOW_STACK_SIZE
>
> @@ -499,21 +312,24 @@ restore_caller_reg:
> REG_S s5, PT_TP(sp)
> move a0, sp
> tail handle_bad_stack
> +END(handle_kernel_stack_overflow)
> #endif
>
> -END(handle_exception)
> -
> ENTRY(ret_from_fork)
> + call schedule_tail
> + move a0, sp /* pt_regs */
> la ra, ret_from_exception
> - tail schedule_tail
> + tail syscall_exit_to_user_mode
> ENDPROC(ret_from_fork)
>
> ENTRY(ret_from_kernel_thread)
> call schedule_tail
> /* Call fn(arg) */
> - la ra, ret_from_exception
> move a0, s1
> - jr s0
> + jalr s0
> + move a0, sp /* pt_regs */
> + la ra, ret_from_exception
> + tail syscall_exit_to_user_mode
> ENDPROC(ret_from_kernel_thread)
>
>
> @@ -582,7 +398,7 @@ ENTRY(excp_vect_table)
> RISCV_PTR do_trap_load_fault
> RISCV_PTR do_trap_store_misaligned
> RISCV_PTR do_trap_store_fault
> - RISCV_PTR do_trap_ecall_u /* system call, gets intercepted */
> + RISCV_PTR do_sys_ecall_u /* system call */
> RISCV_PTR do_trap_ecall_s
> RISCV_PTR do_trap_unknown
> RISCV_PTR do_trap_ecall_m
> diff --git a/arch/riscv/kernel/irq.c b/arch/riscv/kernel/irq.c
> index 7207fa08d78f..24c2e1bd756a 100644
> --- a/arch/riscv/kernel/irq.c
> +++ b/arch/riscv/kernel/irq.c
> @@ -5,6 +5,7 @@
> * Copyright (C) 2018 Christoph Hellwig
> */
>
> +#include <linux/entry-common.h>
> #include <linux/interrupt.h>
> #include <linux/irqchip.h>
> #include <linux/seq_file.h>
> @@ -22,3 +23,17 @@ void __init init_IRQ(void)
> if (!handle_arch_irq)
> panic("No interrupt controller found.");
> }
> +
> +asmlinkage void noinstr do_riscv_irq(struct pt_regs *regs)
> +{
> + struct pt_regs *old_regs;
> + irqentry_state_t state = irqentry_enter(regs);
> +
> + irq_enter_rcu();
> + old_regs = set_irq_regs(regs);
> + handle_arch_irq(regs);
> + set_irq_regs(old_regs);
> + irq_exit_rcu();
> +
> + irqentry_exit(regs, state);
> +}
> diff --git a/arch/riscv/kernel/ptrace.c b/arch/riscv/kernel/ptrace.c
> index 44f4b1ca315d..4caed6c683e4 100644
> --- a/arch/riscv/kernel/ptrace.c
> +++ b/arch/riscv/kernel/ptrace.c
> @@ -228,46 +228,6 @@ long arch_ptrace(struct task_struct *child, long request,
> return ret;
> }
>
> -/*
> - * Allows PTRACE_SYSCALL to work. These are called from entry.S in
> - * {handle,ret_from}_syscall.
> - */
> -__visible int do_syscall_trace_enter(struct pt_regs *regs)
> -{
> - if (test_thread_flag(TIF_SYSCALL_TRACE))
> - if (ptrace_report_syscall_entry(regs))
> - return -1;
> -
> - /*
> - * Do the secure computing after ptrace; failures should be fast.
> - * If this fails we might have return value in a0 from seccomp
> - * (via SECCOMP_RET_ERRNO/TRACE).
> - */
> - if (secure_computing() == -1)
> - return -1;
> -
> -#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
> - if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
> - trace_sys_enter(regs, syscall_get_nr(current, regs));
> -#endif
> -
> - audit_syscall_entry(regs->a7, regs->a0, regs->a1, regs->a2, regs->a3);
> - return 0;
> -}
> -
> -__visible void do_syscall_trace_exit(struct pt_regs *regs)
> -{
> - audit_syscall_exit(regs);
> -
> - if (test_thread_flag(TIF_SYSCALL_TRACE))
> - ptrace_report_syscall_exit(regs, 0);
> -
> -#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
> - if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
> - trace_sys_exit(regs, regs_return_value(regs));
> -#endif
> -}
> -
> #ifdef CONFIG_COMPAT
> static int compat_riscv_gpr_get(struct task_struct *target,
> const struct user_regset *regset,
> diff --git a/arch/riscv/kernel/signal.c b/arch/riscv/kernel/signal.c
> index 5a2de6b6f882..5871eccbbd94 100644
> --- a/arch/riscv/kernel/signal.c
> +++ b/arch/riscv/kernel/signal.c
> @@ -12,6 +12,7 @@
> #include <linux/syscalls.h>
> #include <linux/resume_user_mode.h>
> #include <linux/linkage.h>
> +#include <linux/entry-common.h>
>
> #include <asm/ucontext.h>
> #include <asm/vdso.h>
> @@ -272,7 +273,7 @@ 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)
> {
> struct ksignal ksig;
>
> @@ -309,21 +310,3 @@ static void do_signal(struct pt_regs *regs)
> */
> restore_saved_sigmask();
> }
> -
> -/*
> - * notification of userspace execution resumption
> - * - triggered by the _TIF_WORK_MASK flags
> - */
> -asmlinkage __visible void do_notify_resume(struct pt_regs *regs,
> - unsigned long thread_info_flags)
> -{
> - if (thread_info_flags & _TIF_UPROBE)
> - uprobe_notify_resume(regs);
> -
> - /* Handle pending signal delivery */
> - if (thread_info_flags & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL))
> - do_signal(regs);
> -
> - if (thread_info_flags & _TIF_NOTIFY_RESUME)
> - resume_user_mode_work(regs);
> -}
> diff --git a/arch/riscv/kernel/sys_riscv.c b/arch/riscv/kernel/sys_riscv.c
> index 571556bb9261..41cc1c4bccb3 100644
> --- a/arch/riscv/kernel/sys_riscv.c
> +++ b/arch/riscv/kernel/sys_riscv.c
> @@ -5,8 +5,10 @@
> * Copyright (C) 2017 SiFive
> */
>
> +#include <linux/entry-common.h>
> #include <linux/syscalls.h>
> #include <asm/unistd.h>
> +#include <asm/syscall.h>
> #include <asm/cacheflush.h>
> #include <asm-generic/mman-common.h>
>
> @@ -72,3 +74,28 @@ SYSCALL_DEFINE3(riscv_flush_icache, uintptr_t, start, uintptr_t, end,
>
> return 0;
> }
> +
> +typedef long (*syscall_t)(ulong, ulong, ulong, ulong, ulong, ulong, ulong);
> +
> +asmlinkage void do_sys_ecall_u(struct pt_regs *regs)
> +{
> + syscall_t syscall;
> + ulong nr = regs->a7;
> +
> + regs->epc += 4;
> + regs->orig_a0 = regs->a0;
> + regs->a0 = -ENOSYS;
> +
> + nr = syscall_enter_from_user_mode(regs, nr);
> +#ifdef CONFIG_COMPAT
> + if ((regs->status & SR_UXL) == SR_UXL_32)
> + syscall = compat_sys_call_table[nr];
> + else
> +#endif
> + syscall = sys_call_table[nr];
> +
> + if (nr < NR_syscalls)
> + regs->a0 = syscall(regs->orig_a0, regs->a1, regs->a2,
> + regs->a3, regs->a4, regs->a5, regs->a6);
> + syscall_exit_to_user_mode(regs);
> +}
> diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c
> index 3ed3dbec250d..d24c6a9c2735 100644
> --- a/arch/riscv/kernel/traps.c
> +++ b/arch/riscv/kernel/traps.c
> @@ -17,6 +17,7 @@
> #include <linux/module.h>
> #include <linux/irq.h>
> #include <linux/kexec.h>
> +#include <linux/entry-common.h>
>
> #include <asm/asm-prototypes.h>
> #include <asm/bug.h>
> @@ -99,7 +100,9 @@ static void do_trap_error(struct pt_regs *regs, int signo, int code,
> #define DO_ERROR_INFO(name, signo, code, str) \
> asmlinkage __visible __trap_section void noinstr name(struct pt_regs *regs) \
> { \
> + irqentry_state_t state = irqentry_enter(regs); \
> do_trap_error(regs, signo, code, regs->epc, "Oops - " str); \
> + irqentry_exit(regs, state); \
> }
>
> DO_ERROR_INFO(do_trap_unknown,
> @@ -123,18 +126,22 @@ int handle_misaligned_store(struct pt_regs *regs);
>
> asmlinkage __trap_section void noinstr do_trap_load_misaligned(struct pt_regs *regs)
> {
> + irqentry_state_t state = irqentry_enter(regs);
> if (!handle_misaligned_load(regs))
> return;
> do_trap_error(regs, SIGBUS, BUS_ADRALN, regs->epc,
> "Oops - load address misaligned");
> + irqentry_exit(regs, state);
> }
>
> asmlinkage __trap_section void noinstr do_trap_store_misaligned(struct pt_regs *regs)
> {
> + irqentry_state_t state = irqentry_enter(regs);
> if (!handle_misaligned_store(regs))
> return;
> do_trap_error(regs, SIGBUS, BUS_ADRALN, regs->epc,
> "Oops - store (or AMO) address misaligned");
> + irqentry_exit(regs, state);
> }
> #endif
> DO_ERROR_INFO(do_trap_store_fault,
> @@ -158,6 +165,8 @@ static inline unsigned long get_break_insn_length(unsigned long pc)
>
> asmlinkage __visible __trap_section void noinstr do_trap_break(struct pt_regs *regs)
> {
> + irqentry_state_t state = irqentry_enter(regs);
> +
> #ifdef CONFIG_KPROBES
> if (kprobe_single_step_handler(regs))
> return;
> @@ -185,6 +194,8 @@ asmlinkage __visible __trap_section void noinstr do_trap_break(struct pt_regs *r
> regs->epc += get_break_insn_length(regs->epc);
> else
> die(regs, "Kernel BUG");
> +
> + irqentry_exit(regs, state);
> }
> NOKPROBE_SYMBOL(do_trap_break);
>
> diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c
> index c7829289e806..cc8e642a91ea 100644
> --- a/arch/riscv/mm/fault.c
> +++ b/arch/riscv/mm/fault.c
> @@ -15,6 +15,7 @@
> #include <linux/uaccess.h>
> #include <linux/kprobes.h>
> #include <linux/kfence.h>
> +#include <linux/entry-common.h>
>
> #include <asm/ptrace.h>
> #include <asm/tlbflush.h>
> @@ -203,7 +204,7 @@ static inline bool access_error(unsigned long cause, struct vm_area_struct *vma)
> * This routine handles page faults. It determines the address and the
> * problem, and then passes it off to one of the appropriate routines.
> */
> -asmlinkage void noinstr do_page_fault(struct pt_regs *regs)
> +static void __do_page_fault(struct pt_regs *regs)
> {
> struct task_struct *tsk;
> struct vm_area_struct *vma;
> @@ -350,4 +351,13 @@ asmlinkage void noinstr do_page_fault(struct pt_regs *regs)
> }
> return;
> }
> +
> +asmlinkage void noinstr do_page_fault(struct pt_regs *regs)
> +{
> + irqentry_state_t state = irqentry_enter(regs);
> +
> + __do_page_fault(regs);
> +
> + irqentry_exit(regs, state);
> +}
> NOKPROBE_SYMBOL(do_page_fault);

--
Regards,
Yipeng Zou