Commit d9ae90ac authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Linus Torvalds
Browse files

use __set_task_state() for TRACED/STOPPED tasks 



1. It is much easier to grep for ->state change if __set_task_state() is used
   instead of the direct assignment.

2. ptrace_stop() and handle_group_stop() use set_task_state() which adds the
   unneeded mb() (btw even if we use mb() it is still possible that do_wait()
   sees the new ->state but not ->exit_code, but this is ok).

Signed-off-by: default avatarOleg Nesterov <oleg@tv-sign.ru>
Acked-by: default avatarRoland McGrath <roland@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 06b8e878

kernel/fork.c

+1 −1
Original line number Diff line number Diff line
@@ -1510,7 +1510,7 @@ long do_fork(unsigned long clone_flags, 
		if (!(clone_flags & CLONE_STOPPED))

			wake_up_new_task(p, clone_flags);

		else

			p->state = TASK_STOPPED;

			__set_task_state(p, TASK_STOPPED);



		if (unlikely (trace)) {

			current->ptrace_message = nr;

kernel/ptrace.c

+4 −6
Original line number Diff line number Diff line
@@ -53,7 +53,7 @@ void ptrace_untrace(struct task_struct *child) 
	spin_lock(&child->sighand->siglock);

	if (task_is_traced(child)) {

		if (child->signal->flags & SIGNAL_STOP_STOPPED) {

			child->state = TASK_STOPPED;

			__set_task_state(child, TASK_STOPPED);

		} else {

			signal_wake_up(child, 1);

		}
@@ -103,18 +103,16 @@ int ptrace_check_attach(struct task_struct *child, int kill) 
	    && child->signal != NULL) {

		ret = 0;

		spin_lock_irq(&child->sighand->siglock);

		if (task_is_stopped(child)) {

		if (task_is_stopped(child))

			child->state = TASK_TRACED;

		} else if (!task_is_traced(child) && !kill) {

		else if (!task_is_traced(child) && !kill)

			ret = -ESRCH;

		}

		spin_unlock_irq(&child->sighand->siglock);

	}

	read_unlock(&tasklist_lock);



	if (!ret && !kill) {

	if (!ret && !kill)

		wait_task_inactive(child);

	}



	/* All systems go.. */

	return ret;

kernel/signal.c

+1 −1
Original line number Diff line number Diff line
@@ -1601,7 +1601,7 @@ static void ptrace_stop(int exit_code, int nostop_code, siginfo_t *info) 
	current->exit_code = exit_code;



	/* Let the debugger run.  */

	set_current_state(TASK_TRACED);

	__set_current_state(TASK_TRACED);

	spin_unlock_irq(&current->sighand->siglock);

	try_to_freeze();

	read_lock(&tasklist_lock);

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