Merge tag 'ptrace-cleanups-for-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

Pull ptrace cleanups from Eric Biederman:
 "This set of changes removes tracehook.h, moves modification of all of
  the ptrace fields inside of siglock to remove races, adds a missing
  permission check to ptrace.c

  The removal of tracehook.h is quite significant as it has been a major
  source of confusion in recent years. Much of that confusion was around
  task_work and TIF_NOTIFY_SIGNAL (which I have now decoupled making the
  semantics clearer).

  For people who don't know tracehook.h is a vestiage of an attempt to
  implement uprobes like functionality that was never fully merged, and
  was later superseeded by uprobes when uprobes was merged. For many
  years now we have been removing what tracehook functionaly a little
  bit at a time. To the point where anything left in tracehook.h was
  some weird strange thing that was difficult to understand"

* tag 'ptrace-cleanups-for-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  ptrace: Remove duplicated include in ptrace.c
  ptrace: Check PTRACE_O_SUSPEND_SECCOMP permission on PTRACE_SEIZE
  ptrace: Return the signal to continue with from ptrace_stop
  ptrace: Move setting/clearing ptrace_message into ptrace_stop
  tracehook: Remove tracehook.h
  resume_user_mode: Move to resume_user_mode.h
  resume_user_mode: Remove #ifdef TIF_NOTIFY_RESUME in set_notify_resume
  signal: Move set_notify_signal and clear_notify_signal into sched/signal.h
  task_work: Decouple TIF_NOTIFY_SIGNAL and task_work
  task_work: Call tracehook_notify_signal from get_signal on all architectures
  task_work: Introduce task_work_pending
  task_work: Remove unnecessary include from posix_timers.h
  ptrace: Remove tracehook_signal_handler
  ptrace: Remove arch_syscall_{enter,exit}_tracehook
  ptrace: Create ptrace_report_syscall_{entry,exit} in ptrace.h
  ptrace/arm: Rename tracehook_report_syscall report_syscall
  ptrace: Move ptrace_report_syscall into ptrace.h

10 files changed, 171 insertions, 276 deletions

diff --git a/include/asm-generic/syscall.h b/include/asm-generic/syscall.h
index 81695eb02a12..5a80fe728dc8 100644
--- a/include/asm-generic/syscall.h
+++ b/include/asm-generic/syscall.h
@@ -44,7 +44,7 @@ int syscall_get_nr(struct task_struct *task, struct pt_regs *regs);
  *
  * 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
diff --git a/include/linux/entry-common.h b/include/linux/entry-common.h
index 141952f4fee8..ab78bd4c2eb0 100644
--- a/include/linux/entry-common.h
+++ b/include/linux/entry-common.h
@@ -3,7 +3,7 @@
 #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>
@@ -80,26 +80,6 @@ static __always_inline void arch_check_user_regs(struct pt_regs *regs) {}
 #endif
 
 /**
- * arch_syscall_enter_tracehook - Wrapper around tracehook_report_syscall_entry()
- * @regs:	Pointer to currents pt_regs
- *
- * Returns: 0 on success or an error code to skip the syscall.
- *
- * Defaults to tracehook_report_syscall_entry(). Can be replaced by
- * architecture specific code.
- *
- * Invoked from syscall_enter_from_user_mode()
- */
-static inline __must_check int arch_syscall_enter_tracehook(struct pt_regs *regs);
-
-#ifndef arch_syscall_enter_tracehook
-static inline __must_check int arch_syscall_enter_tracehook(struct pt_regs *regs)
-{
-	return tracehook_report_syscall_entry(regs);
-}
-#endif
-
-/**
  * enter_from_user_mode - Establish state when coming from user mode
  *
  * Syscall/interrupt entry disables interrupts, but user mode is traced as
@@ -157,7 +137,7 @@ void syscall_enter_from_user_mode_prepare(struct pt_regs *regs);
  * It handles the following work items:
  *
  *  1) syscall_work flag dependent invocations of
- *     arch_syscall_enter_tracehook(), __secure_computing(), trace_sys_enter()
+ *     ptrace_report_syscall_entry(), __secure_computing(), trace_sys_enter()
  *  2) Invocation of audit_syscall_entry()
  */
 long syscall_enter_from_user_mode_work(struct pt_regs *regs, long syscall);
@@ -277,26 +257,7 @@ static __always_inline void arch_exit_to_user_mode(void) { }
  *
  * Invoked from exit_to_user_mode_loop().
  */
-void arch_do_signal_or_restart(struct pt_regs *regs, bool has_signal);
-
-/**
- * arch_syscall_exit_tracehook - Wrapper around tracehook_report_syscall_exit()
- * @regs:	Pointer to currents pt_regs
- * @step:	Indicator for single step
- *
- * Defaults to tracehook_report_syscall_exit(). Can be replaced by
- * architecture specific code.
- *
- * Invoked from syscall_exit_to_user_mode()
- */
-static inline void arch_syscall_exit_tracehook(struct pt_regs *regs, bool step);
-
-#ifndef arch_syscall_exit_tracehook
-static inline void arch_syscall_exit_tracehook(struct pt_regs *regs, bool step)
-{
-	tracehook_report_syscall_exit(regs, step);
-}
-#endif
+void arch_do_signal_or_restart(struct pt_regs *regs);
 
 /**
  * exit_to_user_mode - Fixup state when exiting to user mode
@@ -347,7 +308,7 @@ void syscall_exit_to_user_mode_work(struct pt_regs *regs);
  *	- rseq syscall exit
  *      - audit
  *	- syscall tracing
- *	- tracehook (single stepping)
+ *	- ptrace (single stepping)
  *
  *  2) Preparatory work
  *	- Exit to user mode loop (common TIF handling). Invokes
diff --git a/include/linux/entry-kvm.h b/include/linux/entry-kvm.h
index 07c878d6e323..6813171afccb 100644
--- a/include/linux/entry-kvm.h
+++ b/include/linux/entry-kvm.h
@@ -3,7 +3,7 @@
 #define __LINUX_ENTRYKVM_H
 
 #include <linux/static_call_types.h>
-#include <linux/tracehook.h>
+#include <linux/resume_user_mode.h>
 #include <linux/syscalls.h>
 #include <linux/seccomp.h>
 #include <linux/sched.h>
diff --git a/include/linux/posix-timers.h b/include/linux/posix-timers.h
index 9cf126c3b27f..2c6e99ca48af 100644
--- a/include/linux/posix-timers.h
+++ b/include/linux/posix-timers.h
@@ -6,7 +6,6 @@
 #include <linux/list.h>
 #include <linux/alarmtimer.h>
 #include <linux/timerqueue.h>
-#include <linux/task_work.h>
 
 struct kernel_siginfo;
 struct task_struct;
diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h
index 8aee2945ff08..15b3d176b6b4 100644
--- a/include/linux/ptrace.h
+++ b/include/linux/ptrace.h
@@ -60,7 +60,7 @@ extern int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned
 extern void ptrace_disable(struct task_struct *);
 extern int ptrace_request(struct task_struct *child, long request,
 			  unsigned long addr, unsigned long data);
-extern void ptrace_notify(int exit_code);
+extern int ptrace_notify(int exit_code, unsigned long message);
 extern void __ptrace_link(struct task_struct *child,
 			  struct task_struct *new_parent,
 			  const struct cred *ptracer_cred);
@@ -155,8 +155,7 @@ static inline bool ptrace_event_enabled(struct task_struct *task, int event)
 static inline void ptrace_event(int event, unsigned long message)
 {
 	if (unlikely(ptrace_event_enabled(current, event))) {
-		current->ptrace_message = message;
-		ptrace_notify((event << 8) | SIGTRAP);
+		ptrace_notify((event << 8) | SIGTRAP, message);
 	} else if (event == PTRACE_EVENT_EXEC) {
 		/* legacy EXEC report via SIGTRAP */
 		if ((current->ptrace & (PT_PTRACED|PT_SEIZED)) == PT_PTRACED)
@@ -413,4 +412,80 @@ static inline void user_single_step_report(struct pt_regs *regs)
 extern int task_current_syscall(struct task_struct *target, struct syscall_info *info);
 
 extern void sigaction_compat_abi(struct k_sigaction *act, struct k_sigaction *oact);
+
+/*
+ * ptrace report for syscall entry and exit looks identical.
+ */
+static inline int ptrace_report_syscall(unsigned long message)
+{
+	int ptrace = current->ptrace;
+	int signr;
+
+	if (!(ptrace & PT_PTRACED))
+		return 0;
+
+	signr = ptrace_notify(SIGTRAP | ((ptrace & PT_TRACESYSGOOD) ? 0x80 : 0),
+			      message);
+
+	/*
+	 * this isn't the same as continuing with a signal, but it will do
+	 * for normal use.  strace only continues with a signal if the
+	 * stopping signal is not SIGTRAP.  -brl
+	 */
+	if (signr)
+		send_sig(signr, current, 1);
+
+	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
diff --git a/include/linux/resume_user_mode.h b/include/linux/resume_user_mode.h
new file mode 100644
index 000000000000..285189454449
--- /dev/null
+++ b/include/linux/resume_user_mode.h
@@ -0,0 +1,64 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef LINUX_RESUME_USER_MODE_H
+#define LINUX_RESUME_USER_MODE_H
+
+#include <linux/sched.h>
+#include <linux/task_work.h>
+#include <linux/memcontrol.h>
+#include <linux/blk-cgroup.h>
+
+/**
+ * set_notify_resume - cause resume_user_mode_work() to be called
+ * @task:		task that will call resume_user_mode_work()
+ *
+ * Calling this arranges that @task will call resume_user_mode_work()
+ * before returning to user mode.  If it's already running in user mode,
+ * it will enter the kernel and call resume_user_mode_work() soon.
+ * If it's blocked, it will not be woken.
+ */
+static inline void set_notify_resume(struct task_struct *task)
+{
+	if (!test_and_set_tsk_thread_flag(task, TIF_NOTIFY_RESUME))
+		kick_process(task);
+}
+
+
+/**
+ * resume_user_mode_work - Perform work before returning to user mode
+ * @regs:		user-mode registers of @current task
+ *
+ * This is called when %TIF_NOTIFY_RESUME has been set.  Now we are
+ * about to return to user mode, and the user state in @regs can be
+ * inspected or adjusted.  The caller in arch code has cleared
+ * %TIF_NOTIFY_RESUME before the call.  If the flag gets set again
+ * asynchronously, this will be called again before we return to
+ * user mode.
+ *
+ * Called without locks.
+ */
+static inline void resume_user_mode_work(struct pt_regs *regs)
+{
+	clear_thread_flag(TIF_NOTIFY_RESUME);
+	/*
+	 * This barrier pairs with task_work_add()->set_notify_resume() after
+	 * hlist_add_head(task->task_works);
+	 */
+	smp_mb__after_atomic();
+	if (unlikely(task_work_pending(current)))
+		task_work_run();
+
+#ifdef CONFIG_KEYS_REQUEST_CACHE
+	if (unlikely(current->cached_requested_key)) {
+		key_put(current->cached_requested_key);
+		current->cached_requested_key = NULL;
+	}
+#endif
+
+	mem_cgroup_handle_over_high();
+	blkcg_maybe_throttle_current();
+
+	rseq_handle_notify_resume(NULL, regs);
+}
+
+#endif /* LINUX_RESUME_USER_MODE_H */
diff --git a/include/linux/sched/signal.h b/include/linux/sched/signal.h
index b6ecb9fc4cd2..3c8b34876744 100644
--- a/include/linux/sched/signal.h
+++ b/include/linux/sched/signal.h
@@ -349,6 +349,23 @@ extern void sigqueue_free(struct sigqueue *);
 extern int send_sigqueue(struct sigqueue *, struct pid *, enum pid_type);
 extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *);
 
+static inline void clear_notify_signal(void)
+{
+	clear_thread_flag(TIF_NOTIFY_SIGNAL);
+	smp_mb__after_atomic();
+}
+
+/*
+ * Called to break out of interruptible wait loops, and enter the
+ * exit_to_user_mode_loop().
+ */
+static inline void set_notify_signal(struct task_struct *task)
+{
+	if (!test_and_set_tsk_thread_flag(task, TIF_NOTIFY_SIGNAL) &&
+	    !wake_up_state(task, TASK_INTERRUPTIBLE))
+		kick_process(task);
+}
+
 static inline int restart_syscall(void)
 {
 	set_tsk_thread_flag(current, TIF_SIGPENDING);
diff --git a/include/linux/task_work.h b/include/linux/task_work.h
index 5b8a93f288bb..897494b597ba 100644
--- a/include/linux/task_work.h
+++ b/include/linux/task_work.h
@@ -19,6 +19,11 @@ enum task_work_notify_mode {
 	TWA_SIGNAL,
 };
 
+static inline bool task_work_pending(struct task_struct *task)
+{
+	return READ_ONCE(task->task_works);
+}
+
 int task_work_add(struct task_struct *task, struct callback_head *twork,
 			enum task_work_notify_mode mode);
 
diff --git a/include/linux/tracehook.h b/include/linux/tracehook.h
deleted file mode 100644
index 88c007ab5ebc..000000000000
--- a/include/linux/tracehook.h
+++ /dev/null
@@ -1,226 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * Tracing hooks
- *
- * Copyright (C) 2008-2009 Red Hat, Inc.  All rights reserved.
- *
- * This file defines hook entry points called by core code where
- * user tracing/debugging support might need to do something.  These
- * entry points are called tracehook_*().  Each hook declared below
- * has a detailed kerneldoc comment giving the context (locking et
- * al) from which it is called, and the meaning of its return value.
- *
- * Each function here typically has only one call site, so it is ok
- * to have some nontrivial tracehook_*() inlines.  In all cases, the
- * fast path when no tracing is enabled should be very short.
- *
- * The purpose of this file and the tracehook_* layer is to consolidate
- * the interface that the kernel core and arch code uses to enable any
- * user debugging or tracing facility (such as ptrace).  The interfaces
- * here are carefully documented so that maintainers of core and arch
- * code do not need to think about the implementation details of the
- * tracing facilities.  Likewise, maintainers of the tracing code do not
- * need to understand all the calling core or arch code in detail, just
- * documented circumstances of each call, such as locking conditions.
- *
- * If the calling core code changes so that locking is different, then
- * it is ok to change the interface documented here.  The maintainer of
- * core code changing should notify the maintainers of the tracing code
- * that they need to work out the change.
- *
- * Some tracehook_*() inlines take arguments that the current tracing
- * implementations might not necessarily use.  These function signatures
- * are chosen to pass in all the information that is on hand in the
- * caller and might conceivably be relevant to a tracer, so that the
- * core code won't have to be updated when tracing adds more features.
- * If a call site changes so that some of those parameters are no longer
- * already on hand without extra work, then the tracehook_* interface
- * can change so there is no make-work burden on the core code.  The
- * maintainer of core code changing should notify the maintainers of the
- * tracing code that they need to work out the change.
- */
-
-#ifndef _LINUX_TRACEHOOK_H
-#define _LINUX_TRACEHOOK_H	1
-
-#include <linux/sched.h>
-#include <linux/ptrace.h>
-#include <linux/security.h>
-#include <linux/task_work.h>
-#include <linux/memcontrol.h>
-#include <linux/blk-cgroup.h>
-struct linux_binprm;
-
-/*
- * ptrace report for syscall entry and exit looks identical.
- */
-static inline int ptrace_report_syscall(unsigned long message)
-{
-	int ptrace = current->ptrace;
-
-	if (!(ptrace & PT_PTRACED))
-		return 0;
-
-	current->ptrace_message = message;
-	ptrace_notify(SIGTRAP | ((ptrace & PT_TRACESYSGOOD) ? 0x80 : 0));
-
-	/*
-	 * this isn't the same as continuing with a signal, but it will do
-	 * for normal use.  strace only continues with a signal if the
-	 * stopping signal is not SIGTRAP.  -brl
-	 */
-	if (current->exit_code) {
-		send_sig(current->exit_code, current, 1);
-		current->exit_code = 0;
-	}
-
-	current->ptrace_message = 0;
-	return fatal_signal_pending(current);
-}
-
-/**
- * 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
- *
- * Called by the arch code after a signal handler has been set up.
- * Register and stack state reflects the user handler about to run.
- * Signal mask changes have already been made.
- *
- * Called without locks, shortly before returning to user mode
- * (or handling more signals).
- */
-static inline void tracehook_signal_handler(int stepping)
-{
-	if (stepping)
-		ptrace_notify(SIGTRAP);
-}
-
-/**
- * set_notify_resume - cause tracehook_notify_resume() to be called
- * @task:		task that will call tracehook_notify_resume()
- *
- * Calling this arranges that @task will call tracehook_notify_resume()
- * before returning to user mode.  If it's already running in user mode,
- * it will enter the kernel and call tracehook_notify_resume() soon.
- * If it's blocked, it will not be woken.
- */
-static inline void set_notify_resume(struct task_struct *task)
-{
-#ifdef TIF_NOTIFY_RESUME
-	if (!test_and_set_tsk_thread_flag(task, TIF_NOTIFY_RESUME))
-		kick_process(task);
-#endif
-}
-
-/**
- * tracehook_notify_resume - report when about to return to user mode
- * @regs:		user-mode registers of @current task
- *
- * This is called when %TIF_NOTIFY_RESUME has been set.  Now we are
- * about to return to user mode, and the user state in @regs can be
- * inspected or adjusted.  The caller in arch code has cleared
- * %TIF_NOTIFY_RESUME before the call.  If the flag gets set again
- * asynchronously, this will be called again before we return to
- * user mode.
- *
- * Called without locks.
- */
-static inline void tracehook_notify_resume(struct pt_regs *regs)
-{
-	clear_thread_flag(TIF_NOTIFY_RESUME);
-	/*
-	 * This barrier pairs with task_work_add()->set_notify_resume() after
-	 * hlist_add_head(task->task_works);
-	 */
-	smp_mb__after_atomic();
-	if (unlikely(current->task_works))
-		task_work_run();
-
-#ifdef CONFIG_KEYS_REQUEST_CACHE
-	if (unlikely(current->cached_requested_key)) {
-		key_put(current->cached_requested_key);
-		current->cached_requested_key = NULL;
-	}
-#endif
-
-	mem_cgroup_handle_over_high();
-	blkcg_maybe_throttle_current();
-
-	rseq_handle_notify_resume(NULL, regs);
-}
-
-/*
- * called by exit_to_user_mode_loop() if ti_work & _TIF_NOTIFY_SIGNAL. This
- * is currently used by TWA_SIGNAL based task_work, which requires breaking
- * wait loops to ensure that task_work is noticed and run.
- */
-static inline void tracehook_notify_signal(void)
-{
-	clear_thread_flag(TIF_NOTIFY_SIGNAL);
-	smp_mb__after_atomic();
-	if (current->task_works)
-		task_work_run();
-}
-
-/*
- * Called when we have work to process from exit_to_user_mode_loop()
- */
-static inline void set_notify_signal(struct task_struct *task)
-{
-	if (!test_and_set_tsk_thread_flag(task, TIF_NOTIFY_SIGNAL) &&
-	    !wake_up_state(task, TASK_INTERRUPTIBLE))
-		kick_process(task);
-}
-
-#endif	/* <linux/tracehook.h> */
diff --git a/include/uapi/linux/ptrace.h b/include/uapi/linux/ptrace.h
index 3747bf816f9a..195ae64a8c87 100644
--- a/include/uapi/linux/ptrace.h
+++ b/include/uapi/linux/ptrace.h
@@ -114,7 +114,7 @@ struct ptrace_rseq_configuration {
 
 /*
  * These values are stored in task->ptrace_message
- * by tracehook_report_syscall_* to describe the current syscall-stop.
+ * by ptrace_stop to describe the current syscall-stop.
  */
 #define PTRACE_EVENTMSG_SYSCALL_ENTRY	1
 #define PTRACE_EVENTMSG_SYSCALL_EXIT	2