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Commit 47e452fc authored by Lee Jones's avatar Lee Jones Committed by Greg Kroah-Hartman
Browse files

futex: Simplify fixup_pi_state_owner() 



From: Thomas Gleixner <tglx@linutronix.de>

[ Upstream commit f2dac39d93987f7de1e20b3988c8685523247ae2 ]

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 avatarLee Jones <lee.jones@linaro.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent f08a4af5

kernel/futex.c

+27 −14
Original line number Diff line number Diff line
@@ -2237,18 +2237,16 @@ 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)

{

	struct futex_pi_state *pi_state = q->pi_state;

	u32 uval, uninitialized_var(curval), newval;

	struct task_struct *oldowner, *newowner;

	u32 newtid;

	int ret;



	lockdep_assert_held(q->lock_ptr);

	u32 uval, curval, newval, newtid;

	int err = 0;



	oldowner = pi_state->owner;



	/* Owner died? */

	if (!pi_state->owner)

		newtid |= FUTEX_OWNER_DIED;
@@ -2289,7 +2287,7 @@ retry: 


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

			/* We got the lock after all, nothing to fix. */

			return 0;

			return 1;

		}



		/*
@@ -2304,7 +2302,7 @@ retry: 
			 * We raced against a concurrent self; things are

			 * already fixed up. Nothing to do.

			 */

			return 0;

			return 1;

		}

		newowner = argowner;

	}
@@ -2345,7 +2343,7 @@ retry: 
handle_fault:

	spin_unlock(q->lock_ptr);



	ret = fault_in_user_writeable(uaddr);

	err = fault_in_user_writeable(uaddr);



	spin_lock(q->lock_ptr);
@@ -2353,12 +2351,27 @@ handle_fault: 
	 * Check if someone else fixed it for us:

	 */

	if (pi_state->owner != oldowner)

		return 0;



	if (ret)

		return ret;

		return argowner == current;



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

	if (!err)

		goto retry;



	return err;

}



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;



	lockdep_assert_held(q->lock_ptr);



	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;

}



static long futex_wait_restart(struct restart_block *restart);