Merge patch series "riscv: Add GENERIC_ENTRY support"

guoren@kernel.org <guoren@kernel.org> says:

From: Guo Ren <guoren@linux.alibaba.com>

The patches convert riscv to use the generic entry infrastructure from
kernel/entry/*. Some optimization for entry.S with new .macro and merge
ret_from_kernel_thread into ret_from_fork.

* b4-shazam-merge:
  riscv: entry: Consolidate general regs saving/restoring
  riscv: entry: Consolidate ret_from_kernel_thread into ret_from_fork
  riscv: entry: Remove extra level wrappers of trace_hardirqs_{on,off}
  riscv: entry: Convert to generic entry
  riscv: entry: Add noinstr to prevent instrumentation inserted
  riscv: ptrace: Remove duplicate operation

Link: https://lore.kernel.org/r/20230222033021.983168-1-guoren@kernel.orgSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

arch/riscv/Kconfig

@@ -60,6 +60,7 @@ 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

arch/riscv/include/asm/asm-prototypes.h

@@ -27,5 +27,7 @@ DECLARE_DO_ERROR_INFO(do_trap_break);
 
 asmlinkage unsigned long get_overflow_stack(void);
 asmlinkage void handle_bad_stack(struct pt_regs *regs);
+asmlinkage void do_page_fault(struct pt_regs *regs);
+asmlinkage void do_irq(struct pt_regs *regs);
 
 #endif /* _ASM_RISCV_PROTOTYPES_H */

arch/riscv/include/asm/asm.h

@@ -69,6 +69,7 @@
 #endif
 
 #ifdef __ASSEMBLY__
+#include <asm/asm-offsets.h>
 
 /* Common assembly source macros */
 
@@ -81,6 +82,66 @@
 	.endr
 .endm
 
+	/* save all GPs except x1 ~ x5 */
+	.macro save_from_x6_to_x31
+	REG_S x6,  PT_T1(sp)
+	REG_S x7,  PT_T2(sp)
+	REG_S x8,  PT_S0(sp)
+	REG_S x9,  PT_S1(sp)
+	REG_S x10, PT_A0(sp)
+	REG_S x11, PT_A1(sp)
+	REG_S x12, PT_A2(sp)
+	REG_S x13, PT_A3(sp)
+	REG_S x14, PT_A4(sp)
+	REG_S x15, PT_A5(sp)
+	REG_S x16, PT_A6(sp)
+	REG_S x17, PT_A7(sp)
+	REG_S x18, PT_S2(sp)
+	REG_S x19, PT_S3(sp)
+	REG_S x20, PT_S4(sp)
+	REG_S x21, PT_S5(sp)
+	REG_S x22, PT_S6(sp)
+	REG_S x23, PT_S7(sp)
+	REG_S x24, PT_S8(sp)
+	REG_S x25, PT_S9(sp)
+	REG_S x26, PT_S10(sp)
+	REG_S x27, PT_S11(sp)
+	REG_S x28, PT_T3(sp)
+	REG_S x29, PT_T4(sp)
+	REG_S x30, PT_T5(sp)
+	REG_S x31, PT_T6(sp)
+	.endm
+
+	/* restore all GPs except x1 ~ x5 */
+	.macro restore_from_x6_to_x31
+	REG_L x6,  PT_T1(sp)
+	REG_L x7,  PT_T2(sp)
+	REG_L x8,  PT_S0(sp)
+	REG_L x9,  PT_S1(sp)
+	REG_L x10, PT_A0(sp)
+	REG_L x11, PT_A1(sp)
+	REG_L x12, PT_A2(sp)
+	REG_L x13, PT_A3(sp)
+	REG_L x14, PT_A4(sp)
+	REG_L x15, PT_A5(sp)
+	REG_L x16, PT_A6(sp)
+	REG_L x17, PT_A7(sp)
+	REG_L x18, PT_S2(sp)
+	REG_L x19, PT_S3(sp)
+	REG_L x20, PT_S4(sp)
+	REG_L x21, PT_S5(sp)
+	REG_L x22, PT_S6(sp)
+	REG_L x23, PT_S7(sp)
+	REG_L x24, PT_S8(sp)
+	REG_L x25, PT_S9(sp)
+	REG_L x26, PT_S10(sp)
+	REG_L x27, PT_S11(sp)
+	REG_L x28, PT_T3(sp)
+	REG_L x29, PT_T4(sp)
+	REG_L x30, PT_T5(sp)
+	REG_L x31, PT_T6(sp)
+	.endm
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* _ASM_RISCV_ASM_H */

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 */

arch/riscv/include/asm/entry-common.h

+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef _ASM_RISCV_ENTRY_COMMON_H
+#define _ASM_RISCV_ENTRY_COMMON_H
+
+#include <asm/stacktrace.h>
+
+void handle_page_fault(struct pt_regs *regs);
+void handle_break(struct pt_regs *regs);
+
+#endif /* _ASM_RISCV_ENTRY_COMMON_H */

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_PIE);
+}
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* _ASM_RISCV_PTRACE_H */

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 */

arch/riscv/include/asm/syscall.h

@@ -74,5 +74,26 @@ static inline int syscall_get_arch(struct task_struct *task)
 #endif
 }
 
+typedef long (*syscall_t)(ulong, ulong, ulong, ulong, ulong, ulong, ulong);
+static inline void syscall_handler(struct pt_regs *regs, ulong syscall)
+{
+	syscall_t fn;
+
+#ifdef CONFIG_COMPAT
+	if ((regs->status & SR_UXL) == SR_UXL_32)
+		fn = compat_sys_call_table[syscall];
+	else
+#endif
+		fn = sys_call_table[syscall];
+
+	regs->a0 = fn(regs->orig_a0, regs->a1, regs->a2,
+		      regs->a3, regs->a4, regs->a5, regs->a6);
+}
+
+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);
 #endif	/* _ASM_RISCV_SYSCALL_H */

arch/riscv/include/asm/thread_info.h

@@ -67,6 +67,7 @@ struct thread_info {
 	long			kernel_sp;	/* Kernel stack pointer */
 	long			user_sp;	/* User stack pointer */
 	int			cpu;
+	unsigned long		syscall_work;	/* SYSCALL_WORK_ flags */
 };
 
 /*
@@ -89,26 +90,18 @@ 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)
 
@@ -116,8 +109,4 @@ 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 */

arch/riscv/kernel/Makefile

@@ -68,8 +68,6 @@ obj-$(CONFIG_CPU_PM)		+= suspend_entry.o suspend.o
 obj-$(CONFIG_FUNCTION_TRACER)	+= mcount.o ftrace.o
 obj-$(CONFIG_DYNAMIC_FTRACE)	+= mcount-dyn.o
 
-obj-$(CONFIG_TRACE_IRQFLAGS)	+= trace_irq.o
-
 obj-$(CONFIG_PERF_EVENTS)	+= perf_callchain.o
 obj-$(CONFIG_HAVE_PERF_REGS)	+= perf_regs.o
 obj-$(CONFIG_RISCV_SBI)		+= sbi.o

arch/riscv/kernel/head.h

@@ -10,7 +10,6 @@
 
 extern atomic_t hart_lottery;
 
-asmlinkage void do_page_fault(struct pt_regs *regs);
 asmlinkage void __init setup_vm(uintptr_t dtb_pa);
 #ifdef CONFIG_XIP_KERNEL
 asmlinkage void __init __copy_data(void);

arch/riscv/kernel/mcount-dyn.S

@@ -66,66 +66,17 @@
 	REG_S x3,  PT_GP(sp)
 	REG_S x4,  PT_TP(sp)
 	REG_S x5,  PT_T0(sp)
-	REG_S x6,  PT_T1(sp)
-	REG_S x7,  PT_T2(sp)
-	REG_S x8,  PT_S0(sp)
-	REG_S x9,  PT_S1(sp)
-	REG_S x10, PT_A0(sp)
-	REG_S x11, PT_A1(sp)
-	REG_S x12, PT_A2(sp)
-	REG_S x13, PT_A3(sp)
-	REG_S x14, PT_A4(sp)
-	REG_S x15, PT_A5(sp)
-	REG_S x16, PT_A6(sp)
-	REG_S x17, PT_A7(sp)
-	REG_S x18, PT_S2(sp)
-	REG_S x19, PT_S3(sp)
-	REG_S x20, PT_S4(sp)
-	REG_S x21, PT_S5(sp)
-	REG_S x22, PT_S6(sp)
-	REG_S x23, PT_S7(sp)
-	REG_S x24, PT_S8(sp)
-	REG_S x25, PT_S9(sp)
-	REG_S x26, PT_S10(sp)
-	REG_S x27, PT_S11(sp)
-	REG_S x28, PT_T3(sp)
-	REG_S x29, PT_T4(sp)
-	REG_S x30, PT_T5(sp)
-	REG_S x31, PT_T6(sp)
+	save_from_x6_to_x31
 	.endm
 
 	.macro RESTORE_ALL
-	REG_L t0,  PT_EPC(sp)
 	REG_L x1,  PT_RA(sp)
 	REG_L x2,  PT_SP(sp)
 	REG_L x3,  PT_GP(sp)
 	REG_L x4,  PT_TP(sp)
-	REG_L x6,  PT_T1(sp)
-	REG_L x7,  PT_T2(sp)
-	REG_L x8,  PT_S0(sp)
-	REG_L x9,  PT_S1(sp)
-	REG_L x10, PT_A0(sp)
-	REG_L x11, PT_A1(sp)
-	REG_L x12, PT_A2(sp)
-	REG_L x13, PT_A3(sp)
-	REG_L x14, PT_A4(sp)
-	REG_L x15, PT_A5(sp)
-	REG_L x16, PT_A6(sp)
-	REG_L x17, PT_A7(sp)
-	REG_L x18, PT_S2(sp)
-	REG_L x19, PT_S3(sp)
-	REG_L x20, PT_S4(sp)
-	REG_L x21, PT_S5(sp)
-	REG_L x22, PT_S6(sp)
-	REG_L x23, PT_S7(sp)
-	REG_L x24, PT_S8(sp)
-	REG_L x25, PT_S9(sp)
-	REG_L x26, PT_S10(sp)
-	REG_L x27, PT_S11(sp)
-	REG_L x28, PT_T3(sp)
-	REG_L x29, PT_T4(sp)
-	REG_L x30, PT_T5(sp)
-	REG_L x31, PT_T6(sp)
+	/* Restore t0 with PT_EPC */
+	REG_L x5,  PT_EPC(sp)
+	restore_from_x6_to_x31
 
 	addi	sp, sp, PT_SIZE_ON_STACK
 	.endm

arch/riscv/kernel/process.c

@@ -34,7 +34,6 @@ EXPORT_SYMBOL(__stack_chk_guard);
 #endif
 
 extern asmlinkage void ret_from_fork(void);
-extern asmlinkage void ret_from_kernel_thread(void);
 
 void arch_cpu_idle(void)
 {
@@ -173,7 +172,6 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 		/* Supervisor/Machine, irqs on: */
 		childregs->status = SR_PP | SR_PIE;
 
-		p->thread.ra = (unsigned long)ret_from_kernel_thread;
 		p->thread.s[0] = (unsigned long)args->fn;
 		p->thread.s[1] = (unsigned long)args->fn_arg;
 	} else {
@@ -183,8 +181,9 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 		if (clone_flags & CLONE_SETTLS)
 			childregs->tp = tls;
 		childregs->a0 = 0; /* Return value of fork() */
-		p->thread.ra = (unsigned long)ret_from_fork;
+		p->thread.s[0] = 0;
 	}
+	p->thread.ra = (unsigned long)ret_from_fork;
 	p->thread.sp = (unsigned long)childregs; /* kernel sp */
 	return 0;
 }

arch/riscv/kernel/ptrace.c

@@ -19,9 +19,6 @@
 #include <linux/sched.h>
 #include <linux/sched/task_stack.h>
 
-#define CREATE_TRACE_POINTS
-#include <trace/events/syscalls.h>
-
 enum riscv_regset {
 	REGSET_X,
 #ifdef CONFIG_FPU
@@ -212,7 +209,6 @@ unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
 
 void ptrace_disable(struct task_struct *child)
 {
-	clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 }
 
 long arch_ptrace(struct task_struct *child, long request,
@@ -229,46 +225,6 @@ 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,

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>
@@ -274,7 +275,7 @@ 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;
 
@@ -311,29 +312,3 @@ static void do_signal(struct pt_regs *regs)
 	 */
 	restore_saved_sigmask();
 }
-
-/*
- * Handle any pending work on the resume-to-userspace path, as indicated by
- * _TIF_WORK_MASK. Entered from assembly with IRQs off.
- */
-asmlinkage __visible void do_work_pending(struct pt_regs *regs,
-					  unsigned long thread_info_flags)
-{
-	do {
-		if (thread_info_flags & _TIF_NEED_RESCHED) {
-			schedule();
-		} else {
-			local_irq_enable();
-			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);
-		}
-		local_irq_disable();
-		thread_info_flags = read_thread_flags();
-	} while (thread_info_flags & _TIF_WORK_MASK);
-}

arch/riscv/kernel/trace_irq.c

-// SPDX-License-Identifier: GPL-2.0
-/*
- * Copyright (C) 2022 Changbin Du <changbin.du@gmail.com>
- */
-
-#include <linux/irqflags.h>
-#include <linux/kprobes.h>
-#include "trace_irq.h"
-
-/*
- * trace_hardirqs_on/off require the caller to setup frame pointer properly.
- * Otherwise, CALLER_ADDR1 might trigger an pagging exception in kernel.
- * Here we add one extra level so they can be safely called by low
- * level entry code which $fp is used for other purpose.
- */
-
-void __trace_hardirqs_on(void)
-{
-	trace_hardirqs_on();
-}
-NOKPROBE_SYMBOL(__trace_hardirqs_on);
-
-void __trace_hardirqs_off(void)
-{
-	trace_hardirqs_off();
-}
-NOKPROBE_SYMBOL(__trace_hardirqs_off);

arch/riscv/kernel/trace_irq.h

-/* SPDX-License-Identifier: GPL-2.0 */
-/*
- * Copyright (C) 2022 Changbin Du <changbin.du@gmail.com>
- */
-#ifndef __TRACE_IRQ_H
-#define __TRACE_IRQ_H
-
-void __trace_hardirqs_on(void);
-void __trace_hardirqs_off(void);
-
-#endif /* __TRACE_IRQ_H */

arch/riscv/kernel/traps.c

@@ -17,12 +17,14 @@
 #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>
 #include <asm/csr.h>
 #include <asm/processor.h>
 #include <asm/ptrace.h>
+#include <asm/syscall.h>
 #include <asm/thread_info.h>
 
 int show_unhandled_signals = 1;
@@ -119,14 +121,22 @@ static void do_trap_error(struct pt_regs *regs, int signo, int code,
 }
 
 #if defined(CONFIG_XIP_KERNEL) && defined(CONFIG_RISCV_ALTERNATIVE)
-#define __trap_section		__section(".xip.traps")
+#define __trap_section __noinstr_section(".xip.traps")
 #else
-#define __trap_section
+#define __trap_section noinstr
 #endif
-#define DO_ERROR_INFO(name, signo, code, str)				\
-asmlinkage __visible __trap_section void name(struct pt_regs *regs)	\
-{									\
-	do_trap_error(regs, signo, code, regs->epc, "Oops - " str);	\
+#define DO_ERROR_INFO(name, signo, code, str)					\
+asmlinkage __visible __trap_section void name(struct pt_regs *regs)		\
+{										\
+	if (user_mode(regs)) {							\
+		irqentry_enter_from_user_mode(regs);				\
+		do_trap_error(regs, signo, code, regs->epc, "Oops - " str);	\
+		irqentry_exit_to_user_mode(regs);				\
+	} else {								\
+		irqentry_state_t state = irqentry_nmi_enter(regs);		\
+		do_trap_error(regs, signo, code, regs->epc, "Oops - " str);	\
+		irqentry_nmi_exit(regs, state);					\
+	}									\
 }
 
 DO_ERROR_INFO(do_trap_unknown,
@@ -148,26 +158,50 @@ DO_ERROR_INFO(do_trap_store_misaligned,
 int handle_misaligned_load(struct pt_regs *regs);
 int handle_misaligned_store(struct pt_regs *regs);
 
-asmlinkage void __trap_section do_trap_load_misaligned(struct pt_regs *regs)
+asmlinkage __visible __trap_section void do_trap_load_misaligned(struct pt_regs *regs)
 {
-	if (!handle_misaligned_load(regs))
-		return;
-	do_trap_error(regs, SIGBUS, BUS_ADRALN, regs->epc,
-		      "Oops - load address misaligned");
+	if (user_mode(regs)) {
+		irqentry_enter_from_user_mode(regs);
+
+		if (handle_misaligned_load(regs))
+			do_trap_error(regs, SIGBUS, BUS_ADRALN, regs->epc,
+			      "Oops - load address misaligned");
+
+		irqentry_exit_to_user_mode(regs);
+	} else {
+		irqentry_state_t state = irqentry_nmi_enter(regs);
+
+		if (handle_misaligned_load(regs))
+			do_trap_error(regs, SIGBUS, BUS_ADRALN, regs->epc,
+			      "Oops - load address misaligned");
+
+		irqentry_nmi_exit(regs, state);
+	}
 }
 
-asmlinkage void __trap_section do_trap_store_misaligned(struct pt_regs *regs)
+asmlinkage __visible __trap_section void do_trap_store_misaligned(struct pt_regs *regs)
 {
-	if (!handle_misaligned_store(regs))
-		return;
-	do_trap_error(regs, SIGBUS, BUS_ADRALN, regs->epc,
-		      "Oops - store (or AMO) address misaligned");
+	if (user_mode(regs)) {
+		irqentry_enter_from_user_mode(regs);
+
+		if (handle_misaligned_store(regs))
+			do_trap_error(regs, SIGBUS, BUS_ADRALN, regs->epc,
+				"Oops - store (or AMO) address misaligned");
+
+		irqentry_exit_to_user_mode(regs);
+	} else {
+		irqentry_state_t state = irqentry_nmi_enter(regs);
+
+		if (handle_misaligned_store(regs))
+			do_trap_error(regs, SIGBUS, BUS_ADRALN, regs->epc,
+				"Oops - store (or AMO) address misaligned");
+
+		irqentry_nmi_exit(regs, state);
+	}
 }
 #endif
 DO_ERROR_INFO(do_trap_store_fault,
 	SIGSEGV, SEGV_ACCERR, "store (or AMO) access fault");
-DO_ERROR_INFO(do_trap_ecall_u,
-	SIGILL, ILL_ILLTRP, "environment call from U-mode");
 DO_ERROR_INFO(do_trap_ecall_s,
 	SIGILL, ILL_ILLTRP, "environment call from S-mode");
 DO_ERROR_INFO(do_trap_ecall_m,
@@ -183,7 +217,7 @@ static inline unsigned long get_break_insn_length(unsigned long pc)
 	return GET_INSN_LENGTH(insn);
 }
 
-asmlinkage __visible __trap_section void do_trap_break(struct pt_regs *regs)
+void handle_break(struct pt_regs *regs)
 {
 #ifdef CONFIG_KPROBES
 	if (kprobe_single_step_handler(regs))
@@ -213,7 +247,77 @@ asmlinkage __visible __trap_section void do_trap_break(struct pt_regs *regs)
 	else
 		die(regs, "Kernel BUG");
 }
-NOKPROBE_SYMBOL(do_trap_break);
+
+asmlinkage __visible __trap_section void do_trap_break(struct pt_regs *regs)
+{
+	if (user_mode(regs)) {
+		irqentry_enter_from_user_mode(regs);
+
+		handle_break(regs);
+
+		irqentry_exit_to_user_mode(regs);
+	} else {
+		irqentry_state_t state = irqentry_nmi_enter(regs);
+
+		handle_break(regs);
+
+		irqentry_nmi_exit(regs, state);
+	}
+}
+
+asmlinkage __visible __trap_section void do_trap_ecall_u(struct pt_regs *regs)
+{
+	if (user_mode(regs)) {
+		ulong syscall = regs->a7;
+
+		syscall = syscall_enter_from_user_mode(regs, syscall);
+
+		regs->epc += 4;
+		regs->orig_a0 = regs->a0;
+
+		if (syscall < NR_syscalls)
+			syscall_handler(regs, syscall);
+		else
+			regs->a0 = -ENOSYS;
+
+		syscall_exit_to_user_mode(regs);
+	} else {
+		irqentry_state_t state = irqentry_nmi_enter(regs);
+
+		do_trap_error(regs, SIGILL, ILL_ILLTRP, regs->epc,
+			"Oops - environment call from U-mode");
+
+		irqentry_nmi_exit(regs, state);
+	}
+
+}
+
+#ifdef CONFIG_MMU
+asmlinkage __visible noinstr void do_page_fault(struct pt_regs *regs)
+{
+	irqentry_state_t state = irqentry_enter(regs);
+
+	handle_page_fault(regs);
+
+	local_irq_disable();
+
+	irqentry_exit(regs, state);
+}
+#endif
+
+asmlinkage __visible noinstr void do_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);
+}
 
 #ifdef CONFIG_GENERIC_BUG
 int is_valid_bugaddr(unsigned long pc)

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>
@@ -204,7 +205,7 @@ 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 do_page_fault(struct pt_regs *regs)
+void handle_page_fault(struct pt_regs *regs)
 {
 	struct task_struct *tsk;
 	struct vm_area_struct *vma;
@@ -251,7 +252,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
 	}
 #endif
 	/* Enable interrupts if they were enabled in the parent context. */
-	if (likely(regs->status & SR_PIE))
+	if (!regs_irqs_disabled(regs))
 		local_irq_enable();
 
 	/*
@@ -356,4 +357,3 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
 	}
 	return;
 }
-NOKPROBE_SYMBOL(do_page_fault);