[patch V4 56/68] futex: Cleanup stale comments

From: Thomas Gleixner
Date: Wed Aug 11 2021 - 08:27:09 EST


From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

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

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
V2: Cleanup more key ref comments - Andre
---
kernel/futex.c | 18 +++++++-----------
1 file changed, 7 insertions(+), 11 deletions(-)
---
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -1354,7 +1354,7 @@ static int lock_pi_update_atomic(u32 __u
* - 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 f
*
* 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,
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,

/* 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 __u
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 __u
* 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.
*/

/*