ptrace: Create ptrace_report_syscall_{entry,exit} in ptrace.h

Rename tracehook_report_syscall_{entry,exit} to
ptrace_report_syscall_{entry,exit} and place them in ptrace.h

There is no longer any generic tracehook infractructure so make
these ptrace specific functions ptrace specific.

Reviewed-by: Kees Cook <[e-mail]>
Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: "Eric W. Biederman" <[e-mail]>

arch/Kconfig

···
 #	asm/syscall.h		supplying asm-generic/syscall.h interface
 #	linux/regset.h		user_regset interfaces
 #	CORE_DUMP_USE_REGSET	#define'd in linux/elf.h
-#	TIF_SYSCALL_TRACE	calls tracehook_report_syscall_{entry,exit}
+#	TIF_SYSCALL_TRACE	calls ptrace_report_syscall_{entry,exit}
 #	TIF_NOTIFY_RESUME	calls tracehook_notify_resume()
 #	signal delivery		calls tracehook_signal_handler()
 #

arch/alpha/kernel/ptrace.c

···
 #include <linux/user.h>
 #include <linux/security.h>
 #include <linux/signal.h>
-#include <linux/tracehook.h>
 #include <linux/audit.h>
 
 #include <linux/uaccess.h>
···
 	unsigned long ret = 0;
 	struct pt_regs *regs = current_pt_regs();
 	if (test_thread_flag(TIF_SYSCALL_TRACE) &&
-	    tracehook_report_syscall_entry(current_pt_regs()))
+	    ptrace_report_syscall_entry(current_pt_regs()))
 		ret = -1UL;
 	audit_syscall_entry(regs->r0, regs->r16, regs->r17, regs->r18, regs->r19);
 	return ret ?: current_pt_regs()->r0;
···
 {
 	audit_syscall_exit(current_pt_regs());
 	if (test_thread_flag(TIF_SYSCALL_TRACE))
-		tracehook_report_syscall_exit(current_pt_regs(), 0);
+		ptrace_report_syscall_exit(current_pt_regs(), 0);
 }

arch/arc/kernel/ptrace.c

···
  */
 
 #include <linux/ptrace.h>
-#include <linux/tracehook.h>
 #include <linux/sched/task_stack.h>
 #include <linux/regset.h>
 #include <linux/unistd.h>
···
 
 asmlinkage int syscall_trace_entry(struct pt_regs *regs)
 {
-	if (tracehook_report_syscall_entry(regs))
+	if (ptrace_report_syscall_entry(regs))
 		return ULONG_MAX;
 
 	return regs->r8;
···
 
 asmlinkage void syscall_trace_exit(struct pt_regs *regs)
 {
-	tracehook_report_syscall_exit(regs, 0);
+	ptrace_report_syscall_exit(regs, 0);
 }

arch/arm/kernel/ptrace.c

···
 #include <linux/hw_breakpoint.h>
 #include <linux/regset.h>
 #include <linux/audit.h>
-#include <linux/tracehook.h>
 #include <linux/unistd.h>
 
 #include <asm/syscall.h>
···
 	regs->ARM_ip = dir;
 
 	if (dir == PTRACE_SYSCALL_EXIT)
-		tracehook_report_syscall_exit(regs, 0);
-	else if (tracehook_report_syscall_entry(regs))
+		ptrace_report_syscall_exit(regs, 0);
+	else if (ptrace_report_syscall_entry(regs))
 		current_thread_info()->abi_syscall = -1;
 
 	regs->ARM_ip = ip;

arch/arm64/kernel/ptrace.c

···
 #include <linux/perf_event.h>
 #include <linux/hw_breakpoint.h>
 #include <linux/regset.h>
-#include <linux/tracehook.h>
 #include <linux/elf.h>
 
 #include <asm/compat.h>
···
 	regs->regs[regno] = dir;
 
 	if (dir == PTRACE_SYSCALL_ENTER) {
-		if (tracehook_report_syscall_entry(regs))
+		if (ptrace_report_syscall_entry(regs))
 			forget_syscall(regs);
 		regs->regs[regno] = saved_reg;
 	} else if (!test_thread_flag(TIF_SINGLESTEP)) {
-		tracehook_report_syscall_exit(regs, 0);
+		ptrace_report_syscall_exit(regs, 0);
 		regs->regs[regno] = saved_reg;
 	} else {
 		regs->regs[regno] = saved_reg;
···
 		 * tracer modifications to the registers may have rewound the
 		 * state machine.
 		 */
-		tracehook_report_syscall_exit(regs, 1);
+		ptrace_report_syscall_exit(regs, 1);
 	}
 }
 

arch/csky/kernel/ptrace.c

···
 #include <linux/sched/task_stack.h>
 #include <linux/signal.h>
 #include <linux/smp.h>
-#include <linux/tracehook.h>
 #include <linux/uaccess.h>
 #include <linux/user.h>
 
···
 asmlinkage int syscall_trace_enter(struct pt_regs *regs)
 {
 	if (test_thread_flag(TIF_SYSCALL_TRACE))
-		if (tracehook_report_syscall_entry(regs))
+		if (ptrace_report_syscall_entry(regs))
 			return -1;
 
 	if (secure_computing() == -1)
···
 	audit_syscall_exit(regs);
 
 	if (test_thread_flag(TIF_SYSCALL_TRACE))
-		tracehook_report_syscall_exit(regs, 0);
+		ptrace_report_syscall_exit(regs, 0);
 
 	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
 		trace_sys_exit(regs, syscall_get_return_value(current, regs));

arch/h8300/kernel/ptrace.c

···
 #include <linux/errno.h>
 #include <linux/ptrace.h>
 #include <linux/audit.h>
-#include <linux/tracehook.h>
 #include <linux/regset.h>
 #include <linux/elf.h>
 
···
 	long ret = 0;
 
 	if (test_thread_flag(TIF_SYSCALL_TRACE) &&
-	    tracehook_report_syscall_entry(regs))
+	    ptrace_report_syscall_entry(regs))
 		/*
 		 * Tracing decided this syscall should not happen.
 		 * We'll return a bogus call number to get an ENOSYS
···
 
 	step = test_thread_flag(TIF_SINGLESTEP);
 	if (step || test_thread_flag(TIF_SYSCALL_TRACE))
-		tracehook_report_syscall_exit(regs, step);
+		ptrace_report_syscall_exit(regs, step);
 }

arch/hexagon/kernel/traps.c

···
 #include <linux/kdebug.h>
 #include <linux/syscalls.h>
 #include <linux/signal.h>
-#include <linux/tracehook.h>
+#include <linux/ptrace.h>
 #include <asm/traps.h>
 #include <asm/vm_fault.h>
 #include <asm/syscall.h>
···
 
 		/* allow strace to catch syscall args  */
 		if (unlikely(test_thread_flag(TIF_SYSCALL_TRACE) &&
-			tracehook_report_syscall_entry(regs)))
+			ptrace_report_syscall_entry(regs)))
 			return;  /*  return -ENOSYS somewhere?  */
 
 		/* Interrupts should be re-enabled for syscall processing */
···
 
 		/* allow strace to get the syscall return state  */
 		if (unlikely(test_thread_flag(TIF_SYSCALL_TRACE)))
-			tracehook_report_syscall_exit(regs, 0);
+			ptrace_report_syscall_exit(regs, 0);
 
 		break;
 	case TRAP_DEBUG:

arch/ia64/kernel/ptrace.c

···
 		     struct pt_regs regs)
 {
 	if (test_thread_flag(TIF_SYSCALL_TRACE))
-		if (tracehook_report_syscall_entry(&regs))
+		if (ptrace_report_syscall_entry(&regs))
 			return -ENOSYS;
 
 	/* copy user rbs to kernel rbs */
···
 
 	step = test_thread_flag(TIF_SINGLESTEP);
 	if (step || test_thread_flag(TIF_SYSCALL_TRACE))
-		tracehook_report_syscall_exit(&regs, step);
+		ptrace_report_syscall_exit(&regs, step);
 
 	/* copy user rbs to kernel rbs */
 	if (test_thread_flag(TIF_RESTORE_RSE))

arch/m68k/kernel/ptrace.c

···
 #include <linux/ptrace.h>
 #include <linux/user.h>
 #include <linux/signal.h>
-#include <linux/tracehook.h>
+#include <linux/ptrace.h>
 
 #include <linux/uaccess.h>
 #include <asm/page.h>
···
 	int ret = 0;
 
 	if (test_thread_flag(TIF_SYSCALL_TRACE))
-		ret = tracehook_report_syscall_entry(task_pt_regs(current));
+		ret = ptrace_report_syscall_entry(task_pt_regs(current));
 	return ret;
 }
 
 asmlinkage void syscall_trace_leave(void)
 {
 	if (test_thread_flag(TIF_SYSCALL_TRACE))
-		tracehook_report_syscall_exit(task_pt_regs(current), 0);
+		ptrace_report_syscall_exit(task_pt_regs(current), 0);
 }
 #endif /* CONFIG_COLDFIRE */

arch/microblaze/kernel/ptrace.c

···
 #include <linux/elf.h>
 #include <linux/audit.h>
 #include <linux/seccomp.h>
-#include <linux/tracehook.h>
 
 #include <linux/errno.h>
 #include <asm/processor.h>
···
 	secure_computing_strict(regs->r12);
 
 	if (test_thread_flag(TIF_SYSCALL_TRACE) &&
-	    tracehook_report_syscall_entry(regs))
+	    ptrace_report_syscall_entry(regs))
 		/*
 		 * Tracing decided this syscall should not happen.
 		 * We'll return a bogus call number to get an ENOSYS
···
 
 	step = test_thread_flag(TIF_SINGLESTEP);
 	if (step || test_thread_flag(TIF_SYSCALL_TRACE))
-		tracehook_report_syscall_exit(regs, step);
+		ptrace_report_syscall_exit(regs, step);
 }
 
 void ptrace_disable(struct task_struct *child)

arch/mips/kernel/ptrace.c

···
 #include <linux/smp.h>
 #include <linux/security.h>
 #include <linux/stddef.h>
-#include <linux/tracehook.h>
 #include <linux/audit.h>
 #include <linux/seccomp.h>
 #include <linux/ftrace.h>
···
 	current_thread_info()->syscall = syscall;
 
 	if (test_thread_flag(TIF_SYSCALL_TRACE)) {
-		if (tracehook_report_syscall_entry(regs))
+		if (ptrace_report_syscall_entry(regs))
 			return -1;
 		syscall = current_thread_info()->syscall;
 	}
···
 		trace_sys_exit(regs, regs_return_value(regs));
 
 	if (test_thread_flag(TIF_SYSCALL_TRACE))
-		tracehook_report_syscall_exit(regs, 0);
+		ptrace_report_syscall_exit(regs, 0);
 
 	user_enter();
 }

arch/nds32/include/asm/syscall.h

···
  *
  * It's only valid to call this when @task is stopped for system
  * call exit tracing (due to TIF_SYSCALL_TRACE or TIF_SYSCALL_AUDIT),
- * after tracehook_report_syscall_entry() returned nonzero to prevent
+ * after ptrace_report_syscall_entry() returned nonzero to prevent
  * the system call from taking place.
  *
  * This rolls back the register state in @regs so it's as if the

arch/nds32/kernel/ptrace.c

···
 
 #include <linux/ptrace.h>
 #include <linux/regset.h>
-#include <linux/tracehook.h>
 #include <linux/elf.h>
 #include <linux/sched/task_stack.h>
 
···
 asmlinkage int syscall_trace_enter(struct pt_regs *regs)
 {
 	if (test_thread_flag(TIF_SYSCALL_TRACE)) {
-		if (tracehook_report_syscall_entry(regs))
+		if (ptrace_report_syscall_entry(regs))
 			forget_syscall(regs);
 	}
 	return regs->syscallno;
···
 {
 	int step = test_thread_flag(TIF_SINGLESTEP);
 	if (step || test_thread_flag(TIF_SYSCALL_TRACE))
-		tracehook_report_syscall_exit(regs, step);
+		ptrace_report_syscall_exit(regs, step);
 
 }

arch/nios2/kernel/ptrace.c

···
 #include <linux/regset.h>
 #include <linux/sched.h>
 #include <linux/sched/task_stack.h>
-#include <linux/tracehook.h>
 #include <linux/uaccess.h>
 #include <linux/user.h>
 
···
 	int ret = 0;
 
 	if (test_thread_flag(TIF_SYSCALL_TRACE))
-		ret = tracehook_report_syscall_entry(task_pt_regs(current));
+		ret = ptrace_report_syscall_entry(task_pt_regs(current));
 
 	return ret;
 }
···
 asmlinkage void do_syscall_trace_exit(void)
 {
 	if (test_thread_flag(TIF_SYSCALL_TRACE))
-		tracehook_report_syscall_exit(task_pt_regs(current), 0);
+		ptrace_report_syscall_exit(task_pt_regs(current), 0);
 }

arch/openrisc/kernel/ptrace.c

···
 #include <linux/ptrace.h>
 #include <linux/audit.h>
 #include <linux/regset.h>
-#include <linux/tracehook.h>
 #include <linux/elf.h>
 
 #include <asm/thread_info.h>
···
 	long ret = 0;
 
 	if (test_thread_flag(TIF_SYSCALL_TRACE) &&
-	    tracehook_report_syscall_entry(regs))
+	    ptrace_report_syscall_entry(regs))
 		/*
 		 * Tracing decided this syscall should not happen.
 		 * We'll return a bogus call number to get an ENOSYS
···
 
 	step = test_thread_flag(TIF_SINGLESTEP);
 	if (step || test_thread_flag(TIF_SYSCALL_TRACE))
-		tracehook_report_syscall_exit(regs, step);
+		ptrace_report_syscall_exit(regs, step);
 }

arch/parisc/kernel/ptrace.c

···
 #include <linux/elf.h>
 #include <linux/errno.h>
 #include <linux/ptrace.h>
-#include <linux/tracehook.h>
 #include <linux/user.h>
 #include <linux/personality.h>
 #include <linux/regset.h>
···
 long do_syscall_trace_enter(struct pt_regs *regs)
 {
 	if (test_thread_flag(TIF_SYSCALL_TRACE)) {
-		int rc = tracehook_report_syscall_entry(regs);
+		int rc = ptrace_report_syscall_entry(regs);
 
 		/*
 		 * As tracesys_next does not set %r28 to -ENOSYS
···
 		if (rc) {
 			/*
 			 * A nonzero return code from
-			 * tracehook_report_syscall_entry() tells us
+			 * ptrace_report_syscall_entry() tells us
 			 * to prevent the syscall execution.  Skip
 			 * the syscall call and the syscall restart handling.
 			 *
···
 #endif
 
 	if (stepping || test_thread_flag(TIF_SYSCALL_TRACE))
-		tracehook_report_syscall_exit(regs, stepping);
+		ptrace_report_syscall_exit(regs, stepping);
 }
 
 

arch/powerpc/kernel/ptrace/ptrace.c

···
  */
 
 #include <linux/regset.h>
-#include <linux/tracehook.h>
+#include <linux/ptrace.h>
 #include <linux/audit.h>
 #include <linux/context_tracking.h>
 #include <linux/syscalls.h>
···
 	flags = read_thread_flags() & (_TIF_SYSCALL_EMU | _TIF_SYSCALL_TRACE);
 
 	if (flags) {
-		int rc = tracehook_report_syscall_entry(regs);
+		int rc = ptrace_report_syscall_entry(regs);
 
 		if (unlikely(flags & _TIF_SYSCALL_EMU)) {
 			/*
 			 * A nonzero return code from
-			 * tracehook_report_syscall_entry() tells us to prevent
+			 * ptrace_report_syscall_entry() tells us to prevent
 			 * the syscall execution, but we are not going to
 			 * execute it anyway.
 			 *
···
 
 	step = test_thread_flag(TIF_SINGLESTEP);
 	if (step || test_thread_flag(TIF_SYSCALL_TRACE))
-		tracehook_report_syscall_exit(regs, step);
+		ptrace_report_syscall_exit(regs, step);
 }
 
 void __init pt_regs_check(void);

arch/riscv/kernel/ptrace.c

···
 #include <linux/regset.h>
 #include <linux/sched.h>
 #include <linux/sched/task_stack.h>
-#include <linux/tracehook.h>
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/syscalls.h>
···
 __visible int do_syscall_trace_enter(struct pt_regs *regs)
 {
 	if (test_thread_flag(TIF_SYSCALL_TRACE))
-		if (tracehook_report_syscall_entry(regs))
+		if (ptrace_report_syscall_entry(regs))
 			return -1;
 
 	/*
···
 	audit_syscall_exit(regs);
 
 	if (test_thread_flag(TIF_SYSCALL_TRACE))
-		tracehook_report_syscall_exit(regs, 0);
+		ptrace_report_syscall_exit(regs, 0);
 
 #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
 	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))

arch/sh/kernel/ptrace_32.c

···
 #include <linux/io.h>
 #include <linux/audit.h>
 #include <linux/seccomp.h>
-#include <linux/tracehook.h>
 #include <linux/elf.h>
 #include <linux/regset.h>
 #include <linux/hw_breakpoint.h>
···
 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 {
 	if (test_thread_flag(TIF_SYSCALL_TRACE) &&
-	    tracehook_report_syscall_entry(regs)) {
+	    ptrace_report_syscall_entry(regs)) {
 		regs->regs[0] = -ENOSYS;
 		return -1;
 	}
···
 
 	step = test_thread_flag(TIF_SINGLESTEP);
 	if (step || test_thread_flag(TIF_SYSCALL_TRACE))
-		tracehook_report_syscall_exit(regs, step);
+		ptrace_report_syscall_exit(regs, step);
 }

arch/sparc/kernel/ptrace_32.c

···
 #include <linux/signal.h>
 #include <linux/regset.h>
 #include <linux/elf.h>
-#include <linux/tracehook.h>
 
 #include <linux/uaccess.h>
 #include <asm/cacheflush.h>
···
 
 	if (test_thread_flag(TIF_SYSCALL_TRACE)) {
 		if (syscall_exit_p)
-			tracehook_report_syscall_exit(regs, 0);
+			ptrace_report_syscall_exit(regs, 0);
 		else
-			ret = tracehook_report_syscall_entry(regs);
+			ret = ptrace_report_syscall_entry(regs);
 	}
 
 	return ret;

arch/sparc/kernel/ptrace_64.c

···
 #include <linux/audit.h>
 #include <linux/signal.h>
 #include <linux/regset.h>
-#include <linux/tracehook.h>
 #include <trace/syscall.h>
 #include <linux/compat.h>
 #include <linux/elf.h>
···
 		user_exit();
 
 	if (test_thread_flag(TIF_SYSCALL_TRACE))
-		ret = tracehook_report_syscall_entry(regs);
+		ret = ptrace_report_syscall_entry(regs);
 
 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 		trace_sys_enter(regs, regs->u_regs[UREG_G1]);
···
 		trace_sys_exit(regs, regs->u_regs[UREG_I0]);
 
 	if (test_thread_flag(TIF_SYSCALL_TRACE))
-		tracehook_report_syscall_exit(regs, 0);
+		ptrace_report_syscall_exit(regs, 0);
 
 	if (test_thread_flag(TIF_NOHZ))
 		user_enter();

arch/um/kernel/ptrace.c

···
 #include <linux/audit.h>
 #include <linux/ptrace.h>
 #include <linux/sched.h>
-#include <linux/tracehook.h>
 #include <linux/uaccess.h>
 #include <asm/ptrace-abi.h>
 
···
 	if (!test_thread_flag(TIF_SYSCALL_TRACE))
 		return 0;
 
-	return tracehook_report_syscall_entry(regs);
+	return ptrace_report_syscall_entry(regs);
 }
 
 void syscall_trace_leave(struct pt_regs *regs)
···
 	if (!test_thread_flag(TIF_SYSCALL_TRACE))
 		return;
 
-	tracehook_report_syscall_exit(regs, 0);
+	ptrace_report_syscall_exit(regs, 0);
 	/* force do_signal() --> is_syscall() */
 	if (ptraced & PT_PTRACED)
 		set_thread_flag(TIF_SIGPENDING);

arch/xtensa/kernel/ptrace.c

···
 #include <linux/security.h>
 #include <linux/signal.h>
 #include <linux/smp.h>
-#include <linux/tracehook.h>
 #include <linux/uaccess.h>
 
 #define CREATE_TRACE_POINTS
···
 		regs->areg[2] = -ENOSYS;
 
 	if (test_thread_flag(TIF_SYSCALL_TRACE) &&
-	    tracehook_report_syscall_entry(regs)) {
+	    ptrace_report_syscall_entry(regs)) {
 		regs->areg[2] = -ENOSYS;
 		regs->syscall = NO_SYSCALL;
 		return 0;
···
 	step = test_thread_flag(TIF_SINGLESTEP);
 
 	if (step || test_thread_flag(TIF_SYSCALL_TRACE))
-		tracehook_report_syscall_exit(regs, step);
+		ptrace_report_syscall_exit(regs, step);
 }

include/asm-generic/syscall.h

···
  *
  * It's only valid to call this when @task is stopped for system
  * call exit tracing (due to %SYSCALL_WORK_SYSCALL_TRACE or
- * %SYSCALL_WORK_SYSCALL_AUDIT), after tracehook_report_syscall_entry()
+ * %SYSCALL_WORK_SYSCALL_AUDIT), after ptrace_report_syscall_entry()
  * returned nonzero to prevent the system call from taking place.
  *
  * This rolls back the register state in @regs so it's as if the

include/linux/entry-common.h

···
 #define __LINUX_ENTRYCOMMON_H
 
 #include <linux/static_call_types.h>
-#include <linux/tracehook.h>
+#include <linux/ptrace.h>
 #include <linux/syscalls.h>
 #include <linux/seccomp.h>
 #include <linux/sched.h>
···
 #ifndef arch_syscall_enter_tracehook
 static inline __must_check int arch_syscall_enter_tracehook(struct pt_regs *regs)
 {
-	return tracehook_report_syscall_entry(regs);
+	return ptrace_report_syscall_entry(regs);
 }
 #endif
 
···
 #ifndef arch_syscall_exit_tracehook
 static inline void arch_syscall_exit_tracehook(struct pt_regs *regs, bool step)
 {
-	tracehook_report_syscall_exit(regs, step);
+	ptrace_report_syscall_exit(regs, step);
 }
 #endif
 

include/linux/ptrace.h

···
 	current->ptrace_message = 0;
 	return fatal_signal_pending(current);
 }
+
+/**
+ * ptrace_report_syscall_entry - task is about to attempt a system call
+ * @regs:		user register state of current task
+ *
+ * This will be called if %SYSCALL_WORK_SYSCALL_TRACE or
+ * %SYSCALL_WORK_SYSCALL_EMU have been set, when the current task has just
+ * entered the kernel for a system call.  Full user register state is
+ * available here.  Changing the values in @regs can affect the system
+ * call number and arguments to be tried.  It is safe to block here,
+ * preventing the system call from beginning.
+ *
+ * Returns zero normally, or nonzero if the calling arch code should abort
+ * the system call.  That must prevent normal entry so no system call is
+ * made.  If @task ever returns to user mode after this, its register state
+ * is unspecified, but should be something harmless like an %ENOSYS error
+ * return.  It should preserve enough information so that syscall_rollback()
+ * can work (see asm-generic/syscall.h).
+ *
+ * Called without locks, just after entering kernel mode.
+ */
+static inline __must_check int ptrace_report_syscall_entry(
+	struct pt_regs *regs)
+{
+	return ptrace_report_syscall(PTRACE_EVENTMSG_SYSCALL_ENTRY);
+}
+
+/**
+ * ptrace_report_syscall_exit - task has just finished a system call
+ * @regs:		user register state of current task
+ * @step:		nonzero if simulating single-step or block-step
+ *
+ * This will be called if %SYSCALL_WORK_SYSCALL_TRACE has been set, when
+ * the current task has just finished an attempted system call.  Full
+ * user register state is available here.  It is safe to block here,
+ * preventing signals from being processed.
+ *
+ * If @step is nonzero, this report is also in lieu of the normal
+ * trap that would follow the system call instruction because
+ * user_enable_block_step() or user_enable_single_step() was used.
+ * In this case, %SYSCALL_WORK_SYSCALL_TRACE might not be set.
+ *
+ * Called without locks, just before checking for pending signals.
+ */
+static inline void ptrace_report_syscall_exit(struct pt_regs *regs, int step)
+{
+	if (step)
+		user_single_step_report(regs);
+	else
+		ptrace_report_syscall(PTRACE_EVENTMSG_SYSCALL_EXIT);
+}
 #endif

include/linux/tracehook.h

···
 
 
 /**
- * tracehook_report_syscall_entry - task is about to attempt a system call
- * @regs:		user register state of current task
- *
- * This will be called if %SYSCALL_WORK_SYSCALL_TRACE or
- * %SYSCALL_WORK_SYSCALL_EMU have been set, when the current task has just
- * entered the kernel for a system call.  Full user register state is
- * available here.  Changing the values in @regs can affect the system
- * call number and arguments to be tried.  It is safe to block here,
- * preventing the system call from beginning.
- *
- * Returns zero normally, or nonzero if the calling arch code should abort
- * the system call.  That must prevent normal entry so no system call is
- * made.  If @task ever returns to user mode after this, its register state
- * is unspecified, but should be something harmless like an %ENOSYS error
- * return.  It should preserve enough information so that syscall_rollback()
- * can work (see asm-generic/syscall.h).
- *
- * Called without locks, just after entering kernel mode.
- */
-static inline __must_check int tracehook_report_syscall_entry(
-	struct pt_regs *regs)
-{
-	return ptrace_report_syscall(PTRACE_EVENTMSG_SYSCALL_ENTRY);
-}
-
-/**
- * tracehook_report_syscall_exit - task has just finished a system call
- * @regs:		user register state of current task
- * @step:		nonzero if simulating single-step or block-step
- *
- * This will be called if %SYSCALL_WORK_SYSCALL_TRACE has been set, when
- * the current task has just finished an attempted system call.  Full
- * user register state is available here.  It is safe to block here,
- * preventing signals from being processed.
- *
- * If @step is nonzero, this report is also in lieu of the normal
- * trap that would follow the system call instruction because
- * user_enable_block_step() or user_enable_single_step() was used.
- * In this case, %SYSCALL_WORK_SYSCALL_TRACE might not be set.
- *
- * Called without locks, just before checking for pending signals.
- */
-static inline void tracehook_report_syscall_exit(struct pt_regs *regs, int step)
-{
-	if (step)
-		user_single_step_report(regs);
-	else
-		ptrace_report_syscall(PTRACE_EVENTMSG_SYSCALL_EXIT);
-}
-
-/**
  * tracehook_signal_handler - signal handler setup is complete
  * @stepping:		nonzero if debugger single-step or block-step in use
  *

include/uapi/linux/ptrace.h

···
 
 /*
  * These values are stored in task->ptrace_message
- * by tracehook_report_syscall_* to describe the current syscall-stop.
+ * by ptrace_report_syscall_* to describe the current syscall-stop.
  */
 #define PTRACE_EVENTMSG_SYSCALL_ENTRY	1
 #define PTRACE_EVENTMSG_SYSCALL_EXIT	2

kernel/entry/common.c

···
 
 #include <linux/context_tracking.h>
 #include <linux/entry-common.h>
+#include <linux/tracehook.h>
 #include <linux/highmem.h>
 #include <linux/livepatch.h>
 #include <linux/audit.h>