[PATCH 0/3] arm64: entry: Convert to generic entry

[PATCH 0/3] arm64: entry: Convert to generic entry

[Jinjie Ruan]

Currently, x86, Riscv, Loongarch use the generic entry. Convert arm64
to use the generic entry infrastructure from kernel/entry/*. The generic
entry makes maintainers' work easier and codes more elegant, which aslo
removed a lot of duplicate code.

Jinjie Ruan (3):
  entry: Add some arch funcs to support arm64 to use generic entry
  arm64: Prepare to switch to generic entry
  arm64: entry: Convert to generic entry

 arch/arm64/Kconfig                    |   1 +
 arch/arm64/include/asm/entry-common.h |  60 +++++
 arch/arm64/include/asm/ptrace.h       |   5 +
 arch/arm64/include/asm/stacktrace.h   |   5 +-
 arch/arm64/include/asm/syscall.h      |   6 +-
 arch/arm64/include/asm/thread_info.h  |  23 +-
 arch/arm64/kernel/entry-common.c      | 355 ++++++--------------------
 arch/arm64/kernel/ptrace.c            |  78 +++---
 arch/arm64/kernel/signal.c            |   3 +-
 arch/arm64/kernel/syscall.c           |  18 +-
 include/linux/entry-common.h          |  51 ++++
 kernel/entry/common.c                 |  49 +++-
 12 files changed, 294 insertions(+), 360 deletions(-)
 create mode 100644 arch/arm64/include/asm/entry-common.h

-- 
2.34.1

[PATCH 1/3] entry: Add some arch funcs to support arm64 to use generic entry

[Jinjie Ruan]

Add some arch functions to support arm64 to use generic entry:

 - Add arch_prepare/post_report_syscall_entry/exit(),
   arch_enter_from_kernel_mode(), arch_exit_to_kernel_mode_prepare(),
   arch_irqentry_exit_need_resched() arch function to support
   architecture-related action, which do not affect existing architectures
   that use generic entry.

 - Make report_single_step() and syscall_exit_work() not static.

Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
 include/linux/entry-common.h | 51 ++++++++++++++++++++++++++++++++++++
 kernel/entry/common.c        | 49 +++++++++++++++++++++++++++++-----
 2 files changed, 94 insertions(+), 6 deletions(-)

diff --git a/include/linux/entry-common.h b/include/linux/entry-common.h
index b0fb775a600d..1be4c3d91995 100644
--- a/include/linux/entry-common.h
+++ b/include/linux/entry-common.h
@@ -84,6 +84,18 @@ static __always_inline void arch_enter_from_user_mode(struct pt_regs *regs);
 static __always_inline void arch_enter_from_user_mode(struct pt_regs *regs) {}
 #endif
 
+static __always_inline void arch_enter_from_kernel_mode(struct pt_regs *regs);
+
+#ifndef arch_enter_from_kernel_mode
+static __always_inline void arch_enter_from_kernel_mode(struct pt_regs *regs) {}
+#endif
+
+static __always_inline void arch_exit_to_kernel_mode_prepare(struct pt_regs *regs);
+
+#ifndef arch_exit_to_kernel_mode_prepare
+static __always_inline void arch_exit_to_kernel_mode_prepare(struct pt_regs *regs) {}
+#endif
+
 /**
  * enter_from_user_mode - Establish state when coming from user mode
  *
@@ -298,6 +310,42 @@ static __always_inline void arch_exit_to_user_mode(void) { }
  */
 void arch_do_signal_or_restart(struct pt_regs *regs);
 
+/**
+ * arch_irqentry_exit_need_resched - Architecture specific need resched function
+ */
+bool arch_irqentry_exit_need_resched(void);
+
+/**
+ * arch_prepare_report_syscall_entry - Architecture specific report_syscall_entry()
+ * prepare function
+ */
+unsigned long arch_prepare_report_syscall_entry(struct pt_regs *regs);
+
+/**
+ * arch_post_report_syscall_entry - Architecture specific report_syscall_entry()
+ * post function
+ */
+void arch_post_report_syscall_entry(struct pt_regs *regs, unsigned long saved_reg);
+
+/**
+ * arch_prepare_report_syscall_exit - Architecture specific report_syscall_exit()
+ * prepare function
+ */
+unsigned long arch_prepare_report_syscall_exit(struct pt_regs *regs, unsigned long work);
+
+/**
+ * arch_post_report_syscall_exit - Architecture specific report_syscall_exit()
+ * post function
+ */
+void arch_post_report_syscall_exit(struct pt_regs *regs, unsigned long saved_reg,
+				   unsigned long work);
+
+/**
+ * arch_forget_syscall - Architecture specific function called if
+ * ptrace_report_syscall_entry() return nonzero
+ */
+void arch_forget_syscall(struct pt_regs *regs);
+
 /**
  * exit_to_user_mode_loop - do any pending work before leaving to user space
  */
@@ -552,4 +600,7 @@ irqentry_state_t noinstr irqentry_nmi_enter(struct pt_regs *regs);
  */
 void noinstr irqentry_nmi_exit(struct pt_regs *regs, irqentry_state_t irq_state);
 
+bool report_single_step(unsigned long work);
+void syscall_exit_work(struct pt_regs *regs, unsigned long work);
+
 #endif
diff --git a/kernel/entry/common.c b/kernel/entry/common.c
index 90843cc38588..c524cf7f86f8 100644
--- a/kernel/entry/common.c
+++ b/kernel/entry/common.c
@@ -25,9 +25,14 @@ static inline void syscall_enter_audit(struct pt_regs *regs, long syscall)
 	}
 }
 
+unsigned long __weak arch_prepare_report_syscall_entry(struct pt_regs *regs) { return 0; }
+void __weak arch_post_report_syscall_entry(struct pt_regs *regs, unsigned long saved_reg) { }
+void __weak arch_forget_syscall(struct pt_regs *regs) { };
+
 long syscall_trace_enter(struct pt_regs *regs, long syscall,
 				unsigned long work)
 {
+	unsigned long saved_reg;
 	long ret = 0;
 
 	/*
@@ -42,8 +47,14 @@ long syscall_trace_enter(struct pt_regs *regs, long syscall,
 
 	/* Handle ptrace */
 	if (work & (SYSCALL_WORK_SYSCALL_TRACE | SYSCALL_WORK_SYSCALL_EMU)) {
+		saved_reg = arch_prepare_report_syscall_entry(regs);
 		ret = ptrace_report_syscall_entry(regs);
-		if (ret || (work & SYSCALL_WORK_SYSCALL_EMU))
+		if (ret) {
+			arch_forget_syscall(regs);
+			return -1L;
+		}
+		arch_post_report_syscall_entry(regs, saved_reg);
+		if (work & SYSCALL_WORK_SYSCALL_EMU)
 			return -1L;
 	}
 
@@ -138,7 +149,7 @@ __always_inline unsigned long exit_to_user_mode_loop(struct pt_regs *regs,
  * SINGLESTEP is set (i.e. PTRACE_SYSEMU_SINGLESTEP).  This syscall
  * instruction has been already reported in syscall_enter_from_user_mode().
  */
-static inline bool report_single_step(unsigned long work)
+inline bool report_single_step(unsigned long work)
 {
 	if (work & SYSCALL_WORK_SYSCALL_EMU)
 		return false;
@@ -146,8 +157,22 @@ static inline bool report_single_step(unsigned long work)
 	return work & SYSCALL_WORK_SYSCALL_EXIT_TRAP;
 }
 
-static void syscall_exit_work(struct pt_regs *regs, unsigned long work)
+unsigned long __weak arch_prepare_report_syscall_exit(struct pt_regs *regs,
+						      unsigned long work)
 {
+	return 0;
+}
+
+void __weak arch_post_report_syscall_exit(struct pt_regs *regs,
+					  unsigned long saved_reg,
+					  unsigned long work)
+{
+
+}
+
+void syscall_exit_work(struct pt_regs *regs, unsigned long work)
+{
+	unsigned long saved_reg;
 	bool step;
 
 	/*
@@ -169,8 +194,11 @@ static void syscall_exit_work(struct pt_regs *regs, unsigned long work)
 		trace_sys_exit(regs, syscall_get_return_value(current, regs));
 
 	step = report_single_step(work);
-	if (step || work & SYSCALL_WORK_SYSCALL_TRACE)
+	if (step || work & SYSCALL_WORK_SYSCALL_TRACE) {
+		saved_reg = arch_prepare_report_syscall_exit(regs, work);
 		ptrace_report_syscall_exit(regs, step);
+		arch_post_report_syscall_exit(regs, saved_reg, work);
+	}
 }
 
 /*
@@ -244,6 +272,8 @@ noinstr irqentry_state_t irqentry_enter(struct pt_regs *regs)
 		return ret;
 	}
 
+	arch_enter_from_kernel_mode(regs);
+
 	/*
 	 * If this entry hit the idle task invoke ct_irq_enter() whether
 	 * RCU is watching or not.
@@ -300,6 +330,8 @@ noinstr irqentry_state_t irqentry_enter(struct pt_regs *regs)
 	return ret;
 }
 
+bool __weak arch_irqentry_exit_need_resched(void) { return true; }
+
 void raw_irqentry_exit_cond_resched(void)
 {
 	if (!preempt_count()) {
@@ -307,7 +339,7 @@ void raw_irqentry_exit_cond_resched(void)
 		rcu_irq_exit_check_preempt();
 		if (IS_ENABLED(CONFIG_DEBUG_ENTRY))
 			WARN_ON_ONCE(!on_thread_stack());
-		if (need_resched())
+		if (need_resched() && arch_irqentry_exit_need_resched())
 			preempt_schedule_irq();
 	}
 }
@@ -332,7 +364,12 @@ noinstr void irqentry_exit(struct pt_regs *regs, irqentry_state_t state)
 	/* Check whether this returns to user mode */
 	if (user_mode(regs)) {
 		irqentry_exit_to_user_mode(regs);
-	} else if (!regs_irqs_disabled(regs)) {
+		return;
+	}
+
+	arch_exit_to_kernel_mode_prepare(regs);
+
+	if (!regs_irqs_disabled(regs)) {
 		/*
 		 * If RCU was not watching on entry this needs to be done
 		 * carefully and needs the same ordering of lockdep/tracing
-- 
2.34.1

[PATCH 2/3] arm64: Prepare to switch to generic entry

[Jinjie Ruan]

Prepare to switch to generic entry for arm64:

 - Implement regs_irqs_disabled() using interrupts_enabled() macro.

 - Make on_thread_stack() compatible with generic entry.

Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
 arch/arm64/include/asm/ptrace.h     | 5 +++++
 arch/arm64/include/asm/stacktrace.h | 5 ++++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/ptrace.h b/arch/arm64/include/asm/ptrace.h
index 47ec58031f11..1857748ff017 100644
--- a/arch/arm64/include/asm/ptrace.h
+++ b/arch/arm64/include/asm/ptrace.h
@@ -360,6 +360,11 @@ 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 !interrupts_enabled(regs);
+}
+
 /* We must avoid circular header include via sched.h */
 struct task_struct;
 int valid_user_regs(struct user_pt_regs *regs, struct task_struct *task);
diff --git a/arch/arm64/include/asm/stacktrace.h b/arch/arm64/include/asm/stacktrace.h
index 66ec8caa6ac0..36bc1831f906 100644
--- a/arch/arm64/include/asm/stacktrace.h
+++ b/arch/arm64/include/asm/stacktrace.h
@@ -57,7 +57,10 @@ static inline bool on_task_stack(const struct task_struct *tsk,
 	return stackinfo_on_stack(&info, sp, size);
 }
 
-#define on_thread_stack()	(on_task_stack(current, current_stack_pointer, 1))
+static __always_inline bool on_thread_stack(void)
+{
+	return on_task_stack(current, current_stack_pointer, 1);
+}
 
 #ifdef CONFIG_VMAP_STACK
 DECLARE_PER_CPU(unsigned long [OVERFLOW_STACK_SIZE/sizeof(long)], overflow_stack);
-- 
2.34.1

[PATCH 3/3] arm64: entry: Convert to generic entry

[Jinjie Ruan]

Currently, x86, Riscv, Loongarch use the generic entry. Convert arm64
to use the generic entry infrastructure from kernel/entry/*. The generic
entry makes maintainers' work easier and codes more elegant, which aslo
removed a lot of duplicate code. The changes are below:

 - Remove TIF_SYSCALL_TRACE/AUDIT/TRACEPOINT/SECCOMP, _TIF_WORK_MASK,
   _TIF_SYSCALL_WORK

 - Remove syscall_trace_enter/exit()

 - Remove *enter_from_kernel_mode(), *exit_to_kernel_mode()

 - Remove *enter_from_user_mode(), *exit_to_user_mode()

 - Remove arm64_enter_nmi(), arm64_exit_nmi()

 - Remove `sk_dynamic_irqentry_exit_cond_resched` logic for
   PREEMPT_DYNAMIC.

Tested ok with following test cases on Qemu cortex-a53 and HiSilicon
Kunpeng-920:
 - Run `perf top` command
 - Switch between different `dynamic preempt` mode
 - Use `pseudo nmi`
 - stress-ng CPU stress test.

Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Tested-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
 arch/arm64/Kconfig                    |   1 +
 arch/arm64/include/asm/entry-common.h |  60 +++++
 arch/arm64/include/asm/syscall.h      |   6 +-
 arch/arm64/include/asm/thread_info.h  |  23 +-
 arch/arm64/kernel/entry-common.c      | 355 ++++++--------------------
 arch/arm64/kernel/ptrace.c            |  78 +++---
 arch/arm64/kernel/signal.c            |   3 +-
 arch/arm64/kernel/syscall.c           |  18 +-
 8 files changed, 191 insertions(+), 353 deletions(-)
 create mode 100644 arch/arm64/include/asm/entry-common.h

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 5d91259ee7b5..e6ccc5ea06fe 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -138,6 +138,7 @@ config ARM64
 	select GENERIC_CPU_DEVICES
 	select GENERIC_CPU_VULNERABILITIES
 	select GENERIC_EARLY_IOREMAP
+	select GENERIC_ENTRY
 	select GENERIC_IDLE_POLL_SETUP
 	select GENERIC_IOREMAP
 	select GENERIC_IRQ_IPI
diff --git a/arch/arm64/include/asm/entry-common.h b/arch/arm64/include/asm/entry-common.h
new file mode 100644
index 000000000000..4de3b81c081f
--- /dev/null
+++ b/arch/arm64/include/asm/entry-common.h
@@ -0,0 +1,60 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef _ASM_ARM64_ENTRY_COMMON_H
+#define _ASM_ARM64_ENTRY_COMMON_H
+
+#include <linux/sched/signal.h>
+
+#include <asm/stacktrace.h>
+#include <asm/fpsimd.h>
+#include <asm/mte.h>
+#include <asm/daifflags.h>
+
+#define ARCH_EXIT_TO_USER_MODE_WORK (_TIF_MTE_ASYNC_FAULT | _TIF_FOREIGN_FPSTATE)
+
+static __always_inline void arch_enter_from_user_mode(struct pt_regs *regs)
+{
+	mte_disable_tco_entry(current);
+}
+
+#define arch_enter_from_user_mode arch_enter_from_user_mode
+
+static inline void arch_exit_to_user_mode_work(struct pt_regs *regs,
+					       unsigned long ti_work)
+{
+	if (ti_work & _TIF_MTE_ASYNC_FAULT) {
+		clear_thread_flag(TIF_MTE_ASYNC_FAULT);
+		send_sig_fault(SIGSEGV, SEGV_MTEAERR, (void __user *)NULL, current);
+	}
+
+	if (ti_work & _TIF_FOREIGN_FPSTATE)
+		fpsimd_restore_current_state();
+}
+
+#define arch_exit_to_user_mode_work arch_exit_to_user_mode_work
+
+static inline void arch_exit_to_user_mode_prepare(struct pt_regs *regs,
+						  unsigned long ti_work)
+{
+	local_daif_mask();
+	mte_check_tfsr_exit();
+}
+
+#define arch_exit_to_user_mode_prepare arch_exit_to_user_mode_prepare
+
+static __always_inline void arch_enter_from_kernel_mode(struct pt_regs *regs)
+{
+	mte_check_tfsr_entry();
+	mte_disable_tco_entry(current);
+}
+
+#define arch_enter_from_kernel_mode arch_enter_from_kernel_mode
+
+static __always_inline void arch_exit_to_kernel_mode_prepare(struct pt_regs *regs)
+{
+	mte_check_tfsr_exit();
+}
+
+#define arch_exit_to_kernel_mode_prepare arch_exit_to_kernel_mode_prepare
+
+#endif /* _ASM_ARM64_ENTRY_COMMON_H */
diff --git a/arch/arm64/include/asm/syscall.h b/arch/arm64/include/asm/syscall.h
index ab8e14b96f68..9891b15da4c3 100644
--- a/arch/arm64/include/asm/syscall.h
+++ b/arch/arm64/include/asm/syscall.h
@@ -85,7 +85,9 @@ static inline int syscall_get_arch(struct task_struct *task)
 	return AUDIT_ARCH_AARCH64;
 }
 
-int syscall_trace_enter(struct pt_regs *regs);
-void syscall_trace_exit(struct pt_regs *regs);
+static inline bool arch_syscall_is_vdso_sigreturn(struct pt_regs *regs)
+{
+	return false;
+}
 
 #endif	/* __ASM_SYSCALL_H */
diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h
index e72a3bf9e563..ec5d74c53bf9 100644
--- a/arch/arm64/include/asm/thread_info.h
+++ b/arch/arm64/include/asm/thread_info.h
@@ -43,6 +43,7 @@ struct thread_info {
 	void			*scs_sp;
 #endif
 	u32			cpu;
+	unsigned long		syscall_work;   /* SYSCALL_WORK_ flags */
 };
 
 #define thread_saved_pc(tsk)	\
@@ -64,11 +65,6 @@ void arch_setup_new_exec(void);
 #define TIF_UPROBE		4	/* uprobe breakpoint or singlestep */
 #define TIF_MTE_ASYNC_FAULT	5	/* MTE Asynchronous Tag Check Fault */
 #define TIF_NOTIFY_SIGNAL	6	/* signal notifications exist */
-#define TIF_SYSCALL_TRACE	8	/* syscall trace active */
-#define TIF_SYSCALL_AUDIT	9	/* syscall auditing */
-#define TIF_SYSCALL_TRACEPOINT	10	/* syscall tracepoint for ftrace */
-#define TIF_SECCOMP		11	/* syscall secure computing */
-#define TIF_SYSCALL_EMU		12	/* syscall emulation active */
 #define TIF_MEMDIE		18	/* is terminating due to OOM killer */
 #define TIF_FREEZE		19
 #define TIF_RESTORE_SIGMASK	20
@@ -86,27 +82,12 @@ void arch_setup_new_exec(void);
 #define _TIF_NEED_RESCHED	(1 << TIF_NEED_RESCHED)
 #define _TIF_NOTIFY_RESUME	(1 << TIF_NOTIFY_RESUME)
 #define _TIF_FOREIGN_FPSTATE	(1 << TIF_FOREIGN_FPSTATE)
-#define _TIF_SYSCALL_TRACE	(1 << TIF_SYSCALL_TRACE)
-#define _TIF_SYSCALL_AUDIT	(1 << TIF_SYSCALL_AUDIT)
-#define _TIF_SYSCALL_TRACEPOINT	(1 << TIF_SYSCALL_TRACEPOINT)
-#define _TIF_SECCOMP		(1 << TIF_SECCOMP)
-#define _TIF_SYSCALL_EMU	(1 << TIF_SYSCALL_EMU)
-#define _TIF_UPROBE		(1 << TIF_UPROBE)
-#define _TIF_SINGLESTEP		(1 << TIF_SINGLESTEP)
+#define _TIF_UPROBE            (1 << TIF_UPROBE)
 #define _TIF_32BIT		(1 << TIF_32BIT)
 #define _TIF_SVE		(1 << TIF_SVE)
 #define _TIF_MTE_ASYNC_FAULT	(1 << TIF_MTE_ASYNC_FAULT)
 #define _TIF_NOTIFY_SIGNAL	(1 << TIF_NOTIFY_SIGNAL)
 
-#define _TIF_WORK_MASK		(_TIF_NEED_RESCHED | _TIF_SIGPENDING | \
-				 _TIF_NOTIFY_RESUME | _TIF_FOREIGN_FPSTATE | \
-				 _TIF_UPROBE | _TIF_MTE_ASYNC_FAULT | \
-				 _TIF_NOTIFY_SIGNAL)
-
-#define _TIF_SYSCALL_WORK	(_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \
-				 _TIF_SYSCALL_TRACEPOINT | _TIF_SECCOMP | \
-				 _TIF_SYSCALL_EMU)
-
 #ifdef CONFIG_SHADOW_CALL_STACK
 #define INIT_SCS							\
 	.scs_base	= init_shadow_call_stack,			\
diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c
index b77a15955f28..784ca7ec47d6 100644
--- a/arch/arm64/kernel/entry-common.c
+++ b/arch/arm64/kernel/entry-common.c
@@ -14,6 +14,7 @@
 #include <linux/sched.h>
 #include <linux/sched/debug.h>
 #include <linux/thread_info.h>
+#include <linux/entry-common.h>
 
 #include <asm/cpufeature.h>
 #include <asm/daifflags.h>
@@ -28,201 +29,15 @@
 #include <asm/sysreg.h>
 #include <asm/system_misc.h>
 
-/*
- * Handle IRQ/context state management when entering from kernel mode.
- * Before this function is called it is not safe to call regular kernel code,
- * instrumentable code, or any code which may trigger an exception.
- *
- * This is intended to match the logic in irqentry_enter(), handling the kernel
- * mode transitions only.
- */
-static __always_inline void __enter_from_kernel_mode(struct pt_regs *regs)
-{
-	regs->exit_rcu = false;
-
-	if (!IS_ENABLED(CONFIG_TINY_RCU) && is_idle_task(current)) {
-		lockdep_hardirqs_off(CALLER_ADDR0);
-		ct_irq_enter();
-		trace_hardirqs_off_finish();
-
-		regs->exit_rcu = true;
-		return;
-	}
-
-	lockdep_hardirqs_off(CALLER_ADDR0);
-	rcu_irq_enter_check_tick();
-	trace_hardirqs_off_finish();
-}
-
-static void noinstr enter_from_kernel_mode(struct pt_regs *regs)
+static __always_inline void exit_to_user_mode_wrapper(struct pt_regs *regs)
 {
-	__enter_from_kernel_mode(regs);
-	mte_check_tfsr_entry();
-	mte_disable_tco_entry(current);
-}
-
-/*
- * Handle IRQ/context state management when exiting to kernel mode.
- * After this function returns it is not safe to call regular kernel code,
- * instrumentable code, or any code which may trigger an exception.
- *
- * This is intended to match the logic in irqentry_exit(), handling the kernel
- * mode transitions only, and with preemption handled elsewhere.
- */
-static __always_inline void __exit_to_kernel_mode(struct pt_regs *regs)
-{
-	lockdep_assert_irqs_disabled();
-
-	if (interrupts_enabled(regs)) {
-		if (regs->exit_rcu) {
-			trace_hardirqs_on_prepare();
-			lockdep_hardirqs_on_prepare();
-			ct_irq_exit();
-			lockdep_hardirqs_on(CALLER_ADDR0);
-			return;
-		}
-
-		trace_hardirqs_on();
-	} else {
-		if (regs->exit_rcu)
-			ct_irq_exit();
-	}
-}
-
-static void noinstr exit_to_kernel_mode(struct pt_regs *regs)
-{
-	mte_check_tfsr_exit();
-	__exit_to_kernel_mode(regs);
-}
-
-/*
- * Handle IRQ/context state management when entering from user mode.
- * Before this function is called it is not safe to call regular kernel code,
- * instrumentable code, or any code which may trigger an exception.
- */
-static __always_inline void __enter_from_user_mode(void)
-{
-	lockdep_hardirqs_off(CALLER_ADDR0);
-	CT_WARN_ON(ct_state() != CONTEXT_USER);
-	user_exit_irqoff();
-	trace_hardirqs_off_finish();
-	mte_disable_tco_entry(current);
-}
-
-static __always_inline void enter_from_user_mode(struct pt_regs *regs)
-{
-	__enter_from_user_mode();
-}
-
-/*
- * Handle IRQ/context state management when exiting to user mode.
- * After this function returns it is not safe to call regular kernel code,
- * instrumentable code, or any code which may trigger an exception.
- */
-static __always_inline void __exit_to_user_mode(void)
-{
-	trace_hardirqs_on_prepare();
-	lockdep_hardirqs_on_prepare();
-	user_enter_irqoff();
-	lockdep_hardirqs_on(CALLER_ADDR0);
-}
-
-static void do_notify_resume(struct pt_regs *regs, unsigned long thread_flags)
-{
-	do {
-		local_irq_enable();
-
-		if (thread_flags & _TIF_NEED_RESCHED)
-			schedule();
-
-		if (thread_flags & _TIF_UPROBE)
-			uprobe_notify_resume(regs);
-
-		if (thread_flags & _TIF_MTE_ASYNC_FAULT) {
-			clear_thread_flag(TIF_MTE_ASYNC_FAULT);
-			send_sig_fault(SIGSEGV, SEGV_MTEAERR,
-				       (void __user *)NULL, current);
-		}
-
-		if (thread_flags & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL))
-			do_signal(regs);
-
-		if (thread_flags & _TIF_NOTIFY_RESUME)
-			resume_user_mode_work(regs);
-
-		if (thread_flags & _TIF_FOREIGN_FPSTATE)
-			fpsimd_restore_current_state();
-
-		local_irq_disable();
-		thread_flags = read_thread_flags();
-	} while (thread_flags & _TIF_WORK_MASK);
-}
-
-static __always_inline void exit_to_user_mode_prepare(struct pt_regs *regs)
-{
-	unsigned long flags;
-
 	local_irq_disable();
-
-	flags = read_thread_flags();
-	if (unlikely(flags & _TIF_WORK_MASK))
-		do_notify_resume(regs, flags);
-
-	local_daif_mask();
-
-	lockdep_sys_exit();
-}
-
-static __always_inline void exit_to_user_mode(struct pt_regs *regs)
-{
-	exit_to_user_mode_prepare(regs);
-	mte_check_tfsr_exit();
-	__exit_to_user_mode();
+	irqentry_exit_to_user_mode(regs);
 }
 
 asmlinkage void noinstr asm_exit_to_user_mode(struct pt_regs *regs)
 {
-	exit_to_user_mode(regs);
-}
-
-/*
- * Handle IRQ/context state management when entering an NMI from user/kernel
- * mode. Before this function is called it is not safe to call regular kernel
- * code, instrumentable code, or any code which may trigger an exception.
- */
-static void noinstr arm64_enter_nmi(struct pt_regs *regs)
-{
-	regs->lockdep_hardirqs = lockdep_hardirqs_enabled();
-
-	__nmi_enter();
-	lockdep_hardirqs_off(CALLER_ADDR0);
-	lockdep_hardirq_enter();
-	ct_nmi_enter();
-
-	trace_hardirqs_off_finish();
-	ftrace_nmi_enter();
-}
-
-/*
- * Handle IRQ/context state management when exiting an NMI from user/kernel
- * mode. After this function returns it is not safe to call regular kernel
- * code, instrumentable code, or any code which may trigger an exception.
- */
-static void noinstr arm64_exit_nmi(struct pt_regs *regs)
-{
-	bool restore = regs->lockdep_hardirqs;
-
-	ftrace_nmi_exit();
-	if (restore) {
-		trace_hardirqs_on_prepare();
-		lockdep_hardirqs_on_prepare();
-	}
-
-	ct_nmi_exit();
-	lockdep_hardirq_exit();
-	if (restore)
-		lockdep_hardirqs_on(CALLER_ADDR0);
-	__nmi_exit();
+	exit_to_user_mode_wrapper(regs);
 }
 
 /*
@@ -259,27 +74,8 @@ static void noinstr arm64_exit_el1_dbg(struct pt_regs *regs)
 		lockdep_hardirqs_on(CALLER_ADDR0);
 }
 
-#ifdef CONFIG_PREEMPT_DYNAMIC
-DEFINE_STATIC_KEY_TRUE(sk_dynamic_irqentry_exit_cond_resched);
-#define need_irq_preemption() \
-	(static_branch_unlikely(&sk_dynamic_irqentry_exit_cond_resched))
-#else
-#define need_irq_preemption()	(IS_ENABLED(CONFIG_PREEMPTION))
-#endif
-
-static void __sched arm64_preempt_schedule_irq(void)
+bool arch_irqentry_exit_need_resched(void)
 {
-	if (!need_irq_preemption())
-		return;
-
-	/*
-	 * Note: thread_info::preempt_count includes both thread_info::count
-	 * and thread_info::need_resched, and is not equivalent to
-	 * preempt_count().
-	 */
-	if (READ_ONCE(current_thread_info()->preempt_count) != 0)
-		return;
-
 	/*
 	 * DAIF.DA are cleared at the start of IRQ/FIQ handling, and when GIC
 	 * priority masking is used the GIC irqchip driver will clear DAIF.IF
@@ -287,7 +83,7 @@ static void __sched arm64_preempt_schedule_irq(void)
 	 * DAIF we must have handled an NMI, so skip preemption.
 	 */
 	if (system_uses_irq_prio_masking() && read_sysreg(daif))
-		return;
+		return false;
 
 	/*
 	 * Preempting a task from an IRQ means we leave copies of PSTATE
@@ -297,8 +93,10 @@ static void __sched arm64_preempt_schedule_irq(void)
 	 * Only allow a task to be preempted once cpufeatures have been
 	 * enabled.
 	 */
-	if (system_capabilities_finalized())
-		preempt_schedule_irq();
+	if (!system_capabilities_finalized())
+		return false;
+
+	return true;
 }
 
 static void do_interrupt_handler(struct pt_regs *regs,
@@ -320,7 +118,7 @@ extern void (*handle_arch_fiq)(struct pt_regs *);
 static void noinstr __panic_unhandled(struct pt_regs *regs, const char *vector,
 				      unsigned long esr)
 {
-	arm64_enter_nmi(regs);
+	irqentry_nmi_enter(regs);
 
 	console_verbose();
 
@@ -426,41 +224,43 @@ UNHANDLED(el1t, 64, error)
 static void noinstr el1_abort(struct pt_regs *regs, unsigned long esr)
 {
 	unsigned long far = read_sysreg(far_el1);
+	irqentry_state_t state = irqentry_enter(regs);
 
-	enter_from_kernel_mode(regs);
 	local_daif_inherit(regs);
 	do_mem_abort(far, esr, regs);
 	local_daif_mask();
-	exit_to_kernel_mode(regs);
+	irqentry_exit(regs, state);
 }
 
 static void noinstr el1_pc(struct pt_regs *regs, unsigned long esr)
 {
 	unsigned long far = read_sysreg(far_el1);
+	irqentry_state_t state = irqentry_enter(regs);
 
-	enter_from_kernel_mode(regs);
 	local_daif_inherit(regs);
 	do_sp_pc_abort(far, esr, regs);
 	local_daif_mask();
-	exit_to_kernel_mode(regs);
+	irqentry_exit(regs, state);
 }
 
 static void noinstr el1_undef(struct pt_regs *regs, unsigned long esr)
 {
-	enter_from_kernel_mode(regs);
+	irqentry_state_t state = irqentry_enter(regs);
+
 	local_daif_inherit(regs);
 	do_el1_undef(regs, esr);
 	local_daif_mask();
-	exit_to_kernel_mode(regs);
+	irqentry_exit(regs, state);
 }
 
 static void noinstr el1_bti(struct pt_regs *regs, unsigned long esr)
 {
-	enter_from_kernel_mode(regs);
+	irqentry_state_t state = irqentry_enter(regs);
+
 	local_daif_inherit(regs);
 	do_el1_bti(regs, esr);
 	local_daif_mask();
-	exit_to_kernel_mode(regs);
+	irqentry_exit(regs, state);
 }
 
 static void noinstr el1_dbg(struct pt_regs *regs, unsigned long esr)
@@ -475,11 +275,12 @@ static void noinstr el1_dbg(struct pt_regs *regs, unsigned long esr)
 
 static void noinstr el1_fpac(struct pt_regs *regs, unsigned long esr)
 {
-	enter_from_kernel_mode(regs);
+	irqentry_state_t state = irqentry_enter(regs);
+
 	local_daif_inherit(regs);
 	do_el1_fpac(regs, esr);
 	local_daif_mask();
-	exit_to_kernel_mode(regs);
+	irqentry_exit(regs, state);
 }
 
 asmlinkage void noinstr el1h_64_sync_handler(struct pt_regs *regs)
@@ -522,23 +323,22 @@ asmlinkage void noinstr el1h_64_sync_handler(struct pt_regs *regs)
 static __always_inline void __el1_pnmi(struct pt_regs *regs,
 				       void (*handler)(struct pt_regs *))
 {
-	arm64_enter_nmi(regs);
+	irqentry_state_t state = irqentry_nmi_enter(regs);
+
 	do_interrupt_handler(regs, handler);
-	arm64_exit_nmi(regs);
+	irqentry_nmi_exit(regs, state);
 }
 
 static __always_inline void __el1_irq(struct pt_regs *regs,
 				      void (*handler)(struct pt_regs *))
 {
-	enter_from_kernel_mode(regs);
+	irqentry_state_t state = irqentry_enter(regs);
 
 	irq_enter_rcu();
 	do_interrupt_handler(regs, handler);
 	irq_exit_rcu();
 
-	arm64_preempt_schedule_irq();
-
-	exit_to_kernel_mode(regs);
+	irqentry_exit(regs, state);
 }
 static void noinstr el1_interrupt(struct pt_regs *regs,
 				  void (*handler)(struct pt_regs *))
@@ -564,21 +364,22 @@ asmlinkage void noinstr el1h_64_fiq_handler(struct pt_regs *regs)
 asmlinkage void noinstr el1h_64_error_handler(struct pt_regs *regs)
 {
 	unsigned long esr = read_sysreg(esr_el1);
+	irqentry_state_t state;
 
 	local_daif_restore(DAIF_ERRCTX);
-	arm64_enter_nmi(regs);
+	state = irqentry_nmi_enter(regs);
 	do_serror(regs, esr);
-	arm64_exit_nmi(regs);
+	irqentry_nmi_exit(regs, state);
 }
 
 static void noinstr el0_da(struct pt_regs *regs, unsigned long esr)
 {
 	unsigned long far = read_sysreg(far_el1);
 
-	enter_from_user_mode(regs);
+	irqentry_enter_from_user_mode(regs);
 	local_daif_restore(DAIF_PROCCTX);
 	do_mem_abort(far, esr, regs);
-	exit_to_user_mode(regs);
+	exit_to_user_mode_wrapper(regs);
 }
 
 static void noinstr el0_ia(struct pt_regs *regs, unsigned long esr)
@@ -593,50 +394,50 @@ static void noinstr el0_ia(struct pt_regs *regs, unsigned long esr)
 	if (!is_ttbr0_addr(far))
 		arm64_apply_bp_hardening();
 
-	enter_from_user_mode(regs);
+	irqentry_enter_from_user_mode(regs);
 	local_daif_restore(DAIF_PROCCTX);
 	do_mem_abort(far, esr, regs);
-	exit_to_user_mode(regs);
+	exit_to_user_mode_wrapper(regs);
 }
 
 static void noinstr el0_fpsimd_acc(struct pt_regs *regs, unsigned long esr)
 {
-	enter_from_user_mode(regs);
+	irqentry_enter_from_user_mode(regs);
 	local_daif_restore(DAIF_PROCCTX);
 	do_fpsimd_acc(esr, regs);
-	exit_to_user_mode(regs);
+	exit_to_user_mode_wrapper(regs);
 }
 
 static void noinstr el0_sve_acc(struct pt_regs *regs, unsigned long esr)
 {
-	enter_from_user_mode(regs);
+	irqentry_enter_from_user_mode(regs);
 	local_daif_restore(DAIF_PROCCTX);
 	do_sve_acc(esr, regs);
-	exit_to_user_mode(regs);
+	exit_to_user_mode_wrapper(regs);
 }
 
 static void noinstr el0_sme_acc(struct pt_regs *regs, unsigned long esr)
 {
-	enter_from_user_mode(regs);
+	irqentry_enter_from_user_mode(regs);
 	local_daif_restore(DAIF_PROCCTX);
 	do_sme_acc(esr, regs);
-	exit_to_user_mode(regs);
+	exit_to_user_mode_wrapper(regs);
 }
 
 static void noinstr el0_fpsimd_exc(struct pt_regs *regs, unsigned long esr)
 {
-	enter_from_user_mode(regs);
+	irqentry_enter_from_user_mode(regs);
 	local_daif_restore(DAIF_PROCCTX);
 	do_fpsimd_exc(esr, regs);
-	exit_to_user_mode(regs);
+	exit_to_user_mode_wrapper(regs);
 }
 
 static void noinstr el0_sys(struct pt_regs *regs, unsigned long esr)
 {
-	enter_from_user_mode(regs);
+	irqentry_enter_from_user_mode(regs);
 	local_daif_restore(DAIF_PROCCTX);
 	do_el0_sys(esr, regs);
-	exit_to_user_mode(regs);
+	exit_to_user_mode_wrapper(regs);
 }
 
 static void noinstr el0_pc(struct pt_regs *regs, unsigned long esr)
@@ -646,50 +447,50 @@ static void noinstr el0_pc(struct pt_regs *regs, unsigned long esr)
 	if (!is_ttbr0_addr(instruction_pointer(regs)))
 		arm64_apply_bp_hardening();
 
-	enter_from_user_mode(regs);
+	irqentry_enter_from_user_mode(regs);
 	local_daif_restore(DAIF_PROCCTX);
 	do_sp_pc_abort(far, esr, regs);
-	exit_to_user_mode(regs);
+	exit_to_user_mode_wrapper(regs);
 }
 
 static void noinstr el0_sp(struct pt_regs *regs, unsigned long esr)
 {
-	enter_from_user_mode(regs);
+	irqentry_enter_from_user_mode(regs);
 	local_daif_restore(DAIF_PROCCTX);
 	do_sp_pc_abort(regs->sp, esr, regs);
-	exit_to_user_mode(regs);
+	exit_to_user_mode_wrapper(regs);
 }
 
 static void noinstr el0_undef(struct pt_regs *regs, unsigned long esr)
 {
-	enter_from_user_mode(regs);
+	irqentry_enter_from_user_mode(regs);
 	local_daif_restore(DAIF_PROCCTX);
 	do_el0_undef(regs, esr);
-	exit_to_user_mode(regs);
+	exit_to_user_mode_wrapper(regs);
 }
 
 static void noinstr el0_bti(struct pt_regs *regs)
 {
-	enter_from_user_mode(regs);
+	irqentry_enter_from_user_mode(regs);
 	local_daif_restore(DAIF_PROCCTX);
 	do_el0_bti(regs);
-	exit_to_user_mode(regs);
+	exit_to_user_mode_wrapper(regs);
 }
 
 static void noinstr el0_mops(struct pt_regs *regs, unsigned long esr)
 {
-	enter_from_user_mode(regs);
+	irqentry_enter_from_user_mode(regs);
 	local_daif_restore(DAIF_PROCCTX);
 	do_el0_mops(regs, esr);
-	exit_to_user_mode(regs);
+	exit_to_user_mode_wrapper(regs);
 }
 
 static void noinstr el0_inv(struct pt_regs *regs, unsigned long esr)
 {
-	enter_from_user_mode(regs);
+	irqentry_enter_from_user_mode(regs);
 	local_daif_restore(DAIF_PROCCTX);
 	bad_el0_sync(regs, 0, esr);
-	exit_to_user_mode(regs);
+	exit_to_user_mode_wrapper(regs);
 }
 
 static void noinstr el0_dbg(struct pt_regs *regs, unsigned long esr)
@@ -697,28 +498,28 @@ static void noinstr el0_dbg(struct pt_regs *regs, unsigned long esr)
 	/* Only watchpoints write FAR_EL1, otherwise its UNKNOWN */
 	unsigned long far = read_sysreg(far_el1);
 
-	enter_from_user_mode(regs);
+	irqentry_enter_from_user_mode(regs);
 	do_debug_exception(far, esr, regs);
 	local_daif_restore(DAIF_PROCCTX);
-	exit_to_user_mode(regs);
+	exit_to_user_mode_wrapper(regs);
 }
 
 static void noinstr el0_svc(struct pt_regs *regs)
 {
-	enter_from_user_mode(regs);
+	irqentry_enter_from_user_mode(regs);
 	cortex_a76_erratum_1463225_svc_handler();
 	fp_user_discard();
 	local_daif_restore(DAIF_PROCCTX);
 	do_el0_svc(regs);
-	exit_to_user_mode(regs);
+	exit_to_user_mode_wrapper(regs);
 }
 
 static void noinstr el0_fpac(struct pt_regs *regs, unsigned long esr)
 {
-	enter_from_user_mode(regs);
+	irqentry_enter_from_user_mode(regs);
 	local_daif_restore(DAIF_PROCCTX);
 	do_el0_fpac(regs, esr);
-	exit_to_user_mode(regs);
+	exit_to_user_mode_wrapper(regs);
 }
 
 asmlinkage void noinstr el0t_64_sync_handler(struct pt_regs *regs)
@@ -783,7 +584,7 @@ asmlinkage void noinstr el0t_64_sync_handler(struct pt_regs *regs)
 static void noinstr el0_interrupt(struct pt_regs *regs,
 				  void (*handler)(struct pt_regs *))
 {
-	enter_from_user_mode(regs);
+	irqentry_enter_from_user_mode(regs);
 
 	write_sysreg(DAIF_PROCCTX_NOIRQ, daif);
 
@@ -794,7 +595,7 @@ static void noinstr el0_interrupt(struct pt_regs *regs,
 	do_interrupt_handler(regs, handler);
 	irq_exit_rcu();
 
-	exit_to_user_mode(regs);
+	exit_to_user_mode_wrapper(regs);
 }
 
 static void noinstr __el0_irq_handler_common(struct pt_regs *regs)
@@ -820,14 +621,15 @@ asmlinkage void noinstr el0t_64_fiq_handler(struct pt_regs *regs)
 static void noinstr __el0_error_handler_common(struct pt_regs *regs)
 {
 	unsigned long esr = read_sysreg(esr_el1);
+	irqentry_state_t state_nmi;
 
-	enter_from_user_mode(regs);
+	irqentry_enter_from_user_mode(regs);
 	local_daif_restore(DAIF_ERRCTX);
-	arm64_enter_nmi(regs);
+	state_nmi = irqentry_nmi_enter(regs);
 	do_serror(regs, esr);
-	arm64_exit_nmi(regs);
+	irqentry_nmi_exit(regs, state_nmi);
 	local_daif_restore(DAIF_PROCCTX);
-	exit_to_user_mode(regs);
+	exit_to_user_mode_wrapper(regs);
 }
 
 asmlinkage void noinstr el0t_64_error_handler(struct pt_regs *regs)
@@ -838,19 +640,19 @@ asmlinkage void noinstr el0t_64_error_handler(struct pt_regs *regs)
 #ifdef CONFIG_COMPAT
 static void noinstr el0_cp15(struct pt_regs *regs, unsigned long esr)
 {
-	enter_from_user_mode(regs);
+	irqentry_enter_from_user_mode(regs);
 	local_daif_restore(DAIF_PROCCTX);
 	do_el0_cp15(esr, regs);
-	exit_to_user_mode(regs);
+	exit_to_user_mode_wrapper(regs);
 }
 
 static void noinstr el0_svc_compat(struct pt_regs *regs)
 {
-	enter_from_user_mode(regs);
+	irqentry_enter_from_user_mode(regs);
 	cortex_a76_erratum_1463225_svc_handler();
 	local_daif_restore(DAIF_PROCCTX);
 	do_el0_svc_compat(regs);
-	exit_to_user_mode(regs);
+	exit_to_user_mode_wrapper(regs);
 }
 
 asmlinkage void noinstr el0t_32_sync_handler(struct pt_regs *regs)
@@ -924,7 +726,7 @@ asmlinkage void noinstr __noreturn handle_bad_stack(struct pt_regs *regs)
 	unsigned long esr = read_sysreg(esr_el1);
 	unsigned long far = read_sysreg(far_el1);
 
-	arm64_enter_nmi(regs);
+	irqentry_nmi_enter(regs);
 	panic_bad_stack(regs, esr, far);
 }
 #endif /* CONFIG_VMAP_STACK */
@@ -933,6 +735,7 @@ asmlinkage void noinstr __noreturn handle_bad_stack(struct pt_regs *regs)
 asmlinkage noinstr unsigned long
 __sdei_handler(struct pt_regs *regs, struct sdei_registered_event *arg)
 {
+	irqentry_state_t state;
 	unsigned long ret;
 
 	/*
@@ -957,9 +760,9 @@ __sdei_handler(struct pt_regs *regs, struct sdei_registered_event *arg)
 	else if (cpu_has_pan())
 		set_pstate_pan(0);
 
-	arm64_enter_nmi(regs);
+	state = irqentry_nmi_enter(regs);
 	ret = do_sdei_event(regs, arg);
-	arm64_exit_nmi(regs);
+	irqentry_nmi_exit(regs, state);
 
 	return ret;
 }
diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index 0d022599eb61..fb2662cf9357 100644
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -29,6 +29,7 @@
 #include <linux/regset.h>
 #include <linux/elf.h>
 #include <linux/rseq.h>
+#include <linux/entry-common.h>
 
 #include <asm/compat.h>
 #include <asm/cpufeature.h>
@@ -42,7 +43,6 @@
 #include <asm/system_misc.h>
 
 #define CREATE_TRACE_POINTS
-#include <trace/events/syscalls.h>
 
 struct pt_regs_offset {
 	const char *name;
@@ -2184,10 +2184,10 @@ enum ptrace_syscall_dir {
 	PTRACE_SYSCALL_EXIT,
 };
 
-static void report_syscall(struct pt_regs *regs, enum ptrace_syscall_dir dir)
+unsigned long arch_prepare_report_syscall_entry(struct pt_regs *regs)
 {
-	int regno;
 	unsigned long saved_reg;
+	int regno;
 
 	/*
 	 * We have some ABI weirdness here in the way that we handle syscall
@@ -2207,63 +2207,51 @@ static void report_syscall(struct pt_regs *regs, enum ptrace_syscall_dir dir)
 	 */
 	regno = (is_compat_task() ? 12 : 7);
 	saved_reg = regs->regs[regno];
-	regs->regs[regno] = dir;
+	regs->regs[regno] = PTRACE_SYSCALL_ENTER;
 
-	if (dir == PTRACE_SYSCALL_ENTER) {
-		if (ptrace_report_syscall_entry(regs))
-			forget_syscall(regs);
-		regs->regs[regno] = saved_reg;
-	} else if (!test_thread_flag(TIF_SINGLESTEP)) {
-		ptrace_report_syscall_exit(regs, 0);
-		regs->regs[regno] = saved_reg;
-	} else {
-		regs->regs[regno] = saved_reg;
+	return saved_reg;
+}
+
+void arch_post_report_syscall_entry(struct pt_regs *regs, unsigned long saved_reg)
+{
+	int regno = (is_compat_task() ? 12 : 7);
+
+	regs->regs[regno] = saved_reg;
+}
+
+unsigned long arch_prepare_report_syscall_exit(struct pt_regs *regs, unsigned long work)
+{
+	unsigned long saved_reg;
+	int regno;
 
+	regno = (is_compat_task() ? 12 : 7);
+	saved_reg = regs->regs[regno];
+	regs->regs[regno] = PTRACE_SYSCALL_EXIT;
+
+	if (report_single_step(work)) {
 		/*
 		 * Signal a pseudo-step exception since we are stepping but
 		 * tracer modifications to the registers may have rewound the
 		 * state machine.
 		 */
-		ptrace_report_syscall_exit(regs, 1);
+		regs->regs[regno] = saved_reg;
 	}
+
+	return saved_reg;
 }
 
-int syscall_trace_enter(struct pt_regs *regs)
+void arch_post_report_syscall_exit(struct pt_regs *regs, unsigned long saved_reg,
+				   unsigned long work)
 {
-	unsigned long flags = read_thread_flags();
-
-	if (flags & (_TIF_SYSCALL_EMU | _TIF_SYSCALL_TRACE)) {
-		report_syscall(regs, PTRACE_SYSCALL_ENTER);
-		if (flags & _TIF_SYSCALL_EMU)
-			return NO_SYSCALL;
-	}
-
-	/* Do the secure computing after ptrace; failures should be fast. */
-	if (secure_computing() == -1)
-		return NO_SYSCALL;
+	int regno = (is_compat_task() ? 12 : 7);
 
-	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
-		trace_sys_enter(regs, regs->syscallno);
-
-	audit_syscall_entry(regs->syscallno, regs->orig_x0, regs->regs[1],
-			    regs->regs[2], regs->regs[3]);
-
-	return regs->syscallno;
+	if (!report_single_step(work))
+		regs->regs[regno] = saved_reg;
 }
 
-void syscall_trace_exit(struct pt_regs *regs)
+void arch_forget_syscall(struct pt_regs *regs)
 {
-	unsigned long flags = read_thread_flags();
-
-	audit_syscall_exit(regs);
-
-	if (flags & _TIF_SYSCALL_TRACEPOINT)
-		trace_sys_exit(regs, syscall_get_return_value(current, regs));
-
-	if (flags & (_TIF_SYSCALL_TRACE | _TIF_SINGLESTEP))
-		report_syscall(regs, PTRACE_SYSCALL_EXIT);
-
-	rseq_syscall(regs);
+	forget_syscall(regs);
 }
 
 /*
diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c
index 4a77f4976e11..2982f6db6d96 100644
--- a/arch/arm64/kernel/signal.c
+++ b/arch/arm64/kernel/signal.c
@@ -19,6 +19,7 @@
 #include <linux/ratelimit.h>
 #include <linux/rseq.h>
 #include <linux/syscalls.h>
+#include <linux/entry-common.h>
 
 #include <asm/daifflags.h>
 #include <asm/debug-monitors.h>
@@ -1266,7 +1267,7 @@ static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
  * the kernel can handle, and then we build all the user-level signal handling
  * stack-frames in one go after that.
  */
-void do_signal(struct pt_regs *regs)
+void arch_do_signal_or_restart(struct pt_regs *regs)
 {
 	unsigned long continue_addr = 0, restart_addr = 0;
 	int retval = 0;
diff --git a/arch/arm64/kernel/syscall.c b/arch/arm64/kernel/syscall.c
index ad198262b981..160ac9d15c27 100644
--- a/arch/arm64/kernel/syscall.c
+++ b/arch/arm64/kernel/syscall.c
@@ -7,6 +7,7 @@
 #include <linux/ptrace.h>
 #include <linux/randomize_kstack.h>
 #include <linux/syscalls.h>
+#include <linux/entry-common.h>
 
 #include <asm/debug-monitors.h>
 #include <asm/exception.h>
@@ -66,14 +67,15 @@ static void invoke_syscall(struct pt_regs *regs, unsigned int scno,
 	choose_random_kstack_offset(get_random_u16() & 0x1FF);
 }
 
-static inline bool has_syscall_work(unsigned long flags)
+static inline bool has_syscall_work(unsigned long work)
 {
-	return unlikely(flags & _TIF_SYSCALL_WORK);
+	return unlikely(work & SYSCALL_WORK_ENTER);
 }
 
 static void el0_svc_common(struct pt_regs *regs, int scno, int sc_nr,
 			   const syscall_fn_t syscall_table[])
 {
+	unsigned long work = READ_ONCE(current_thread_info()->syscall_work);
 	unsigned long flags = read_thread_flags();
 
 	regs->orig_x0 = regs->regs[0];
@@ -107,7 +109,7 @@ static void el0_svc_common(struct pt_regs *regs, int scno, int sc_nr,
 		return;
 	}
 
-	if (has_syscall_work(flags)) {
+	if (has_syscall_work(work)) {
 		/*
 		 * The de-facto standard way to skip a system call using ptrace
 		 * is to set the system call to -1 (NO_SYSCALL) and set x0 to a
@@ -125,7 +127,7 @@ static void el0_svc_common(struct pt_regs *regs, int scno, int sc_nr,
 		 */
 		if (scno == NO_SYSCALL)
 			syscall_set_return_value(current, regs, -ENOSYS, 0);
-		scno = syscall_trace_enter(regs);
+		scno = syscall_trace_enter(regs, regs->syscallno, work);
 		if (scno == NO_SYSCALL)
 			goto trace_exit;
 	}
@@ -137,14 +139,14 @@ static void el0_svc_common(struct pt_regs *regs, int scno, int sc_nr,
 	 * check again. However, if we were tracing entry, then we always trace
 	 * exit regardless, as the old entry assembly did.
 	 */
-	if (!has_syscall_work(flags) && !IS_ENABLED(CONFIG_DEBUG_RSEQ)) {
-		flags = read_thread_flags();
-		if (!has_syscall_work(flags) && !(flags & _TIF_SINGLESTEP))
+	if (!has_syscall_work(work) && !IS_ENABLED(CONFIG_DEBUG_RSEQ)) {
+		work = READ_ONCE(current_thread_info()->syscall_work);
+		if (!has_syscall_work(work) && !report_single_step(work))
 			return;
 	}
 
 trace_exit:
-	syscall_trace_exit(regs);
+	syscall_exit_work(regs, work);
 }
 
 void do_el0_svc(struct pt_regs *regs)
-- 
2.34.1

Re: [PATCH 0/3] arm64: entry: Convert to generic entry

[Kees Cook]

On Tue, Jun 25, 2024 at 05:27:56PM +0800, Jinjie Ruan wrote:
> Currently, x86, Riscv, Loongarch use the generic entry. Convert arm64
> to use the generic entry infrastructure from kernel/entry/*. The generic
> entry makes maintainers' work easier and codes more elegant, which aslo
> removed a lot of duplicate code.
> 
> Jinjie Ruan (3):
>   entry: Add some arch funcs to support arm64 to use generic entry
>   arm64: Prepare to switch to generic entry
>   arm64: entry: Convert to generic entry
> 
>  arch/arm64/Kconfig                    |   1 +
>  arch/arm64/include/asm/entry-common.h |  60 +++++
>  arch/arm64/include/asm/ptrace.h       |   5 +
>  arch/arm64/include/asm/stacktrace.h   |   5 +-
>  arch/arm64/include/asm/syscall.h      |   6 +-
>  arch/arm64/include/asm/thread_info.h  |  23 +-
>  arch/arm64/kernel/entry-common.c      | 355 ++++++--------------------
>  arch/arm64/kernel/ptrace.c            |  78 +++---
>  arch/arm64/kernel/signal.c            |   3 +-
>  arch/arm64/kernel/syscall.c           |  18 +-
>  include/linux/entry-common.h          |  51 ++++
>  kernel/entry/common.c                 |  49 +++-
>  12 files changed, 294 insertions(+), 360 deletions(-)
>  create mode 100644 arch/arm64/include/asm/entry-common.h

This is very cool! While the arm64 maintainers need to review it, I at
least built and ran tests using the seccomp selftests which tends to be
pretty sensitive to corner cases around syscall exit/entry things, and
it passed just fine.

Tested-by: Kees Cook <kees@kernel.org>

-- 
Kees Cook

Re: [PATCH 0/3] arm64: entry: Convert to generic entry

[Jinjie Ruan]

On 2024/6/27 6:52, Kees Cook wrote:
> On Tue, Jun 25, 2024 at 05:27:56PM +0800, Jinjie Ruan wrote:
>> Currently, x86, Riscv, Loongarch use the generic entry. Convert arm64
>> to use the generic entry infrastructure from kernel/entry/*. The generic
>> entry makes maintainers' work easier and codes more elegant, which aslo
>> removed a lot of duplicate code.
>>
>> Jinjie Ruan (3):
>>   entry: Add some arch funcs to support arm64 to use generic entry
>>   arm64: Prepare to switch to generic entry
>>   arm64: entry: Convert to generic entry
>>
>>  arch/arm64/Kconfig                    |   1 +
>>  arch/arm64/include/asm/entry-common.h |  60 +++++
>>  arch/arm64/include/asm/ptrace.h       |   5 +
>>  arch/arm64/include/asm/stacktrace.h   |   5 +-
>>  arch/arm64/include/asm/syscall.h      |   6 +-
>>  arch/arm64/include/asm/thread_info.h  |  23 +-
>>  arch/arm64/kernel/entry-common.c      | 355 ++++++--------------------
>>  arch/arm64/kernel/ptrace.c            |  78 +++---
>>  arch/arm64/kernel/signal.c            |   3 +-
>>  arch/arm64/kernel/syscall.c           |  18 +-
>>  include/linux/entry-common.h          |  51 ++++
>>  kernel/entry/common.c                 |  49 +++-
>>  12 files changed, 294 insertions(+), 360 deletions(-)
>>  create mode 100644 arch/arm64/include/asm/entry-common.h
> 
> This is very cool! While the arm64 maintainers need to review it, I at
> least built and ran tests using the seccomp selftests which tends to be
> pretty sensitive to corner cases around syscall exit/entry things, and
> it passed just fine.

Kees, thank you for helping to test the code.

> 
> Tested-by: Kees Cook <kees@kernel.org>
>