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Commit dddad862 authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Greg Kroah-Hartman
Browse files

UPSTREAM: futex: Simplify fixup_pi_state_owner() 



commit f2dac39d93987f7de1e20b3988c8685523247ae2 upstream

Too many gotos already and an upcoming fix would make it even more
unreadable.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit f2dac39d93987f7de1e20b3988c8685523247ae2)
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@google.com>
Change-Id: I5a97587c0f696d4f4b849f7f106990a5587fa402
parent d245cfa1

kernel/futex.c

+26 −27
Original line number Diff line number Diff line
@@ -2466,18 +2466,13 @@ static void unqueue_me_pi(struct futex_q *q) 
	spin_unlock(q->lock_ptr);

}



static int fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q,

static int __fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q,

				  struct task_struct *argowner)

{

	u32 uval, uninitialized_var(curval), newval, newtid;

	struct futex_pi_state *pi_state = q->pi_state;

	u32 uval, uninitialized_var(curval), newval;

	struct task_struct *oldowner, *newowner;

	u32 newtid;

	int ret, err = 0;



	lockdep_assert_held(q->lock_ptr);



	raw_spin_lock_irq(&pi_state->pi_mutex.wait_lock);

	int err = 0;



	oldowner = pi_state->owner;
@@ -2511,14 +2506,12 @@ static int fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q, 
			 * We raced against a concurrent self; things are

			 * already fixed up. Nothing to do.

			 */

			ret = 0;

			goto out_unlock;

			return 0;

		}



		if (__rt_mutex_futex_trylock(&pi_state->pi_mutex)) {

			/* We got the lock. pi_state is correct. Tell caller. */

			ret = 1;

			goto out_unlock;

			return 1;

		}



		/*
@@ -2545,8 +2538,7 @@ static int fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q, 
			 * We raced against a concurrent self; things are

			 * already fixed up. Nothing to do.

			 */

			ret = 1;

			goto out_unlock;

			return 1;

		}

		newowner = argowner;

	}
@@ -2577,7 +2569,6 @@ static int fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q, 
	 * itself.

	 */

	pi_state_update_owner(pi_state, newowner);

	raw_spin_unlock_irq(&pi_state->pi_mutex.wait_lock);



	return argowner == current;
@@ -2600,17 +2591,16 @@ static int fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q, 


	switch (err) {

	case -EFAULT:

		ret = fault_in_user_writeable(uaddr);

		err = fault_in_user_writeable(uaddr);

		break;



	case -EAGAIN:

		cond_resched();

		ret = 0;

		err = 0;

		break;



	default:

		WARN_ON_ONCE(1);

		ret = err;

		break;

	}
@@ -2620,17 +2610,26 @@ static int fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q, 
	/*

	 * Check if someone else fixed it for us:

	 */

	if (pi_state->owner != oldowner) {

		ret = argowner == current;

		goto out_unlock;

	if (pi_state->owner != oldowner)

		return argowner == current;



	/* Retry if err was -EAGAIN or the fault in succeeded */

	if (!err)

		goto retry;



	return err;

}



	if (ret)

		goto out_unlock;

static int fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q,

				struct task_struct *argowner)

{

	struct futex_pi_state *pi_state = q->pi_state;

	int ret;



	goto retry;

	lockdep_assert_held(q->lock_ptr);



out_unlock:

	raw_spin_lock_irq(&pi_state->pi_mutex.wait_lock);

	ret = __fixup_pi_state_owner(uaddr, q, argowner);

	raw_spin_unlock_irq(&pi_state->pi_mutex.wait_lock);

	return ret;

}