Re: [PATCH -next V16 4/7] riscv: entry: Convert to generic entry

Conor Dooley
2023-02-05T10:43:54Z

Hey Guo Ren,

On 4 February 2023 08:02:10 GMT+01:00, guoren@kernel.org wrote:
>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:
>
> - More clear entry.S with handle_exception and ret_from_exception
> - Get rid of complex custom signal implementation
> - Move syscall procedure from assembly to C, which is much more
> readable.
> - Connect ret_from_fork & ret_from_kernel_thread to generic entry.
> - Wrap with irqentry_enter/exit and syscall_enter/exit_from_user_mode
> - Use the standard preemption code instead of custom
>
>Suggested-by: Huacai Chen <chenhuacai@kernel.org>
>Reviewed-by: Björn Töpel <bjorn@rivosinc.com>
>Tested-by: Yipeng Zou <zouyipeng@huawei.com>
>Tested-by: Jisheng Zhang <jszhang@kernel.org>
>Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
>Signed-off-by: Guo Ren <guoren@kernel.org>
>Cc: Ben Hutchings <ben@decadent.org.uk>
>---

Got some new errors added by this patch:
https://gist.github.com/conor-pwbot/3b300050a7a4a197bca809935584d809

Unfortunately I'm away from a computer at FOSDEM, so I haven't done any investigation
of the warnings.
Should be reproduceable with gcc-12 allmodconfig.

Thanks,
Conor.

> arch/riscv/Kconfig | 1 +
> arch/riscv/include/asm/asm-prototypes.h | 2 +
> arch/riscv/include/asm/csr.h | 1 -
> arch/riscv/include/asm/entry-common.h | 11 ++
> arch/riscv/include/asm/ptrace.h | 10 +-
> arch/riscv/include/asm/stacktrace.h | 5 +
> arch/riscv/include/asm/syscall.h | 21 ++
> arch/riscv/include/asm/thread_info.h | 13 +-
> arch/riscv/kernel/entry.S | 242 ++++--------------------
> arch/riscv/kernel/head.h | 1 -
> arch/riscv/kernel/ptrace.c | 43 -----
> arch/riscv/kernel/signal.c | 29 +--
> arch/riscv/kernel/traps.c | 140 ++++++++++++--
> arch/riscv/mm/fault.c | 6 +-
> 14 files changed, 210 insertions(+), 315 deletions(-)
> create mode 100644 arch/riscv/include/asm/entry-common.h
>
>diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
>index 7c814fbf9527..cbac7b4e3e06 100644
>--- a/arch/riscv/Kconfig
>+++ b/arch/riscv/Kconfig
>@@ -58,6 +58,7 @@ 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/asm-prototypes.h b/arch/riscv/include/asm/asm-prototypes.h
>index ef386fcf3939..61ba8ed43d8f 100644
>--- a/arch/riscv/include/asm/asm-prototypes.h
>+++ b/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 */
>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..6e4dee49d84b
>--- /dev/null
>+++ b/arch/riscv/include/asm/entry-common.h
>@@ -0,0 +1,11 @@
>+/* 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 */
>diff --git a/arch/riscv/include/asm/ptrace.h b/arch/riscv/include/asm/ptrace.h
>index 6ecd461129d2..b5b0adcc85c1 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_PIE);
>+}
>+
> #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..736110e1fd78 100644
>--- a/arch/riscv/include/asm/syscall.h
>+++ b/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 */
>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 99d38fdf8b18..bc322f92ba34 100644
>--- a/arch/riscv/kernel/entry.S
>+++ b/arch/riscv/kernel/entry.S
>@@ -14,11 +14,7 @@
> #include <asm/asm-offsets.h>
> #include <asm/errata_list.h>
>
>-#if !IS_ENABLED(CONFIG_PREEMPTION)
>-.set resume_kernel, restore_all
>-#endif
>-
>-ENTRY(handle_exception)
>+SYM_CODE_START(handle_exception)
> /*
> * If coming from userspace, preserve the user thread pointer and load
> * the kernel thread pointer. If we came from the kernel, the scratch
>@@ -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
>@@ -126,38 +111,13 @@ 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
>-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
>-
>+ tail do_irq
> 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
>@@ -165,95 +125,17 @@ skip_context_tracking:
> jr t0
> 1:
> tail do_trap_unknown
>+SYM_CODE_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
>- 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
>-
>+/*
>+ * The ret_from_exception must be called with interrupt disabled. Here is the
>+ * caller list:
>+ * - handle_exception
>+ * - ret_from_fork
>+ * - ret_from_kernel_thread
>+ */
> SYM_CODE_START_NOALIGN(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 +143,7 @@ SYM_CODE_START_NOALIGN(ret_from_exception)
> #else
> andi s0, s0, SR_SPP
> #endif
>- bnez s0, resume_kernel
>-SYM_CODE_END(ret_from_exception)
>-
>- /* 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, resume_userspace_slow
>-resume_userspace:
>-#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
>@@ -282,18 +154,7 @@ 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
>@@ -356,47 +217,10 @@ 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
>-
>-resume_userspace_slow:
>- /* Enter slow path for supplementary processing */
>- move a0, sp /* pt_regs */
>- move a1, s0 /* current_thread_info->flags */
>- call do_work_pending
>- j resume_userspace
>-
>-/* 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
>+SYM_CODE_END(ret_from_exception)
>
> #ifdef CONFIG_VMAP_STACK
>-handle_kernel_stack_overflow:
>+SYM_CODE_START_LOCAL(handle_kernel_stack_overflow)
> /*
> * Takes the psuedo-spinlock for the shadow stack, in case multiple
> * harts are concurrently overflowing their kernel stacks. We could
>@@ -505,23 +329,25 @@ restore_caller_reg:
> REG_S s5, PT_TP(sp)
> move a0, sp
> tail handle_bad_stack
>+SYM_CODE_END(handle_kernel_stack_overflow)
> #endif
>
>-END(handle_exception)
>-
>-ENTRY(ret_from_fork)
>+SYM_CODE_START(ret_from_fork)
>+ call schedule_tail
>+ move a0, sp /* pt_regs */
> la ra, ret_from_exception
>- tail schedule_tail
>-ENDPROC(ret_from_fork)
>+ tail syscall_exit_to_user_mode
>+SYM_CODE_END(ret_from_fork)
>
>-ENTRY(ret_from_kernel_thread)
>+SYM_CODE_START(ret_from_kernel_thread)
> call schedule_tail
> /* Call fn(arg) */
>- la ra, ret_from_exception
> move a0, s1
>- jr s0
>-ENDPROC(ret_from_kernel_thread)
>-
>+ jalr s0
>+ move a0, sp /* pt_regs */
>+ la ra, ret_from_exception
>+ tail syscall_exit_to_user_mode
>+SYM_CODE_END(ret_from_kernel_thread)
>
> /*
> * Integer register context switch
>@@ -533,7 +359,7 @@ ENDPROC(ret_from_kernel_thread)
> * The value of a0 and a1 must be preserved by this function, as that's how
> * arguments are passed to schedule_tail.
> */
>-ENTRY(__switch_to)
>+SYM_FUNC_START(__switch_to)
> /* Save context into prev->thread */
> li a4, TASK_THREAD_RA
> add a3, a0, a4
>@@ -570,7 +396,7 @@ ENTRY(__switch_to)
> /* The offset of thread_info in task_struct is zero. */
> move tp, a1
> ret
>-ENDPROC(__switch_to)
>+SYM_FUNC_END(__switch_to)
>
> #ifndef CONFIG_MMU
> #define do_page_fault do_trap_unknown
>@@ -579,7 +405,7 @@ ENDPROC(__switch_to)
> .section ".rodata"
> .align LGREG
> /* Exception vector table */
>-ENTRY(excp_vect_table)
>+SYM_CODE_START(excp_vect_table)
> RISCV_PTR do_trap_insn_misaligned
> ALT_INSN_FAULT(RISCV_PTR do_trap_insn_fault)
> RISCV_PTR do_trap_insn_illegal
>@@ -588,7 +414,7 @@ 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_trap_ecall_u /* system call */
> RISCV_PTR do_trap_ecall_s
> RISCV_PTR do_trap_unknown
> RISCV_PTR do_trap_ecall_m
>@@ -598,11 +424,11 @@ ENTRY(excp_vect_table)
> RISCV_PTR do_trap_unknown
> RISCV_PTR do_page_fault /* store page fault */
> excp_vect_table_end:
>-END(excp_vect_table)
>+SYM_CODE_END(excp_vect_table)
>
> #ifndef CONFIG_MMU
>-ENTRY(__user_rt_sigreturn)
>+SYM_CODE_START(__user_rt_sigreturn)
> li a7, __NR_rt_sigreturn
> scall
>-END(__user_rt_sigreturn)
>+SYM_CODE_END(__user_rt_sigreturn)
> #endif
>diff --git a/arch/riscv/kernel/head.h b/arch/riscv/kernel/head.h
>index 726731ada534..a556fdaafed9 100644
>--- a/arch/riscv/kernel/head.h
>+++ b/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);
>diff --git a/arch/riscv/kernel/ptrace.c b/arch/riscv/kernel/ptrace.c
>index 44f4b1ca315d..23c48b14a0e7 100644
>--- a/arch/riscv/kernel/ptrace.c
>+++ b/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
>@@ -228,46 +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,
>diff --git a/arch/riscv/kernel/signal.c b/arch/riscv/kernel/signal.c
>index bfb2afa4135f..2e365084417e 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>
>@@ -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);
>-}
>diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c
>index 96ec76c54ff2..69d619ddbcd5 100644
>--- a/arch/riscv/kernel/traps.c
>+++ b/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;
>@@ -99,10 +101,18 @@ static void do_trap_error(struct pt_regs *regs, int signo, int code,
> #else
> #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,
>@@ -124,26 +134,50 @@ 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))
>+