Commit c363b7ed authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Ingo Molnar
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futex: Clean up stale comments 



The futex key reference mechanism is long gone. Clean up the stale comments
which still mention it.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211305.249178312@linutronix.de
parent dc7109aa

kernel/futex.c

+7 −11
Original line number Diff line number Diff line
@@ -1354,7 +1354,7 @@ static int lock_pi_update_atomic(u32 __user *uaddr, u32 uval, u32 newval) 
 *  -  1 - acquired the lock;

 *  - <0 - error

 *

 * The hb->lock and futex_key refs shall be held by the caller.

 * The hb->lock must be held by the caller.

 *

 * @exiting is only set when the return value is -EBUSY. If so, this holds

 * a refcount on the exiting task on return and the caller needs to drop it
@@ -2621,8 +2621,7 @@ static void futex_wait_queue_me(struct futex_hash_bucket *hb, struct futex_q *q, 
 *

 * Setup the futex_q and locate the hash_bucket.  Get the futex value and

 * compare it with the expected value.  Handle atomic faults internally.

 * Return with the hb lock held and a q.key reference on success, and unlocked

 * with no q.key reference on failure.

 * Return with the hb lock held on success, and unlocked on failure.

 *

 * Return:

 *  -  0 - uaddr contains val and hb has been locked;
@@ -2700,8 +2699,8 @@ static int futex_wait(u32 __user *uaddr, unsigned int flags, u32 val, 
			       current->timer_slack_ns);

retry:

	/*

	 * Prepare to wait on uaddr. On success, holds hb lock and increments

	 * q.key refs.

	 * Prepare to wait on uaddr. On success, it holds hb->lock and q

	 * is initialized.

	 */

	ret = futex_wait_setup(uaddr, val, flags, &q, &hb);

	if (ret)
@@ -2712,7 +2711,6 @@ static int futex_wait(u32 __user *uaddr, unsigned int flags, u32 val, 


	/* If we were woken (and unqueued), we succeeded, whatever. */

	ret = 0;

	/* unqueue_me() drops q.key ref */

	if (!unqueue_me(&q))

		goto out;

	ret = -ETIMEDOUT;
@@ -3205,8 +3203,8 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, 
	q.requeue_pi_key = &key2;



	/*

	 * Prepare to wait on uaddr. On success, increments q.key (key1) ref

	 * count.

	 * Prepare to wait on uaddr. On success, it holds hb->lock and q

	 * is initialized.

	 */

	ret = futex_wait_setup(uaddr, val, flags, &q, &hb);

	if (ret)
@@ -3235,9 +3233,7 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, 
	 * In order for us to be here, we know our q.key == key2, and since

	 * we took the hb->lock above, we also know that futex_requeue() has

	 * completed and we no longer have to concern ourselves with a wakeup

	 * race with the atomic proxy lock acquisition by the requeue code. The

	 * futex_requeue dropped our key1 reference and incremented our key2

	 * reference count.

	 * race with the atomic proxy lock acquisition by the requeue code.

	 */



	/*