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Commit 499f5aca authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Thomas Gleixner
Browse files

futex: Cleanup variable names for futex_top_waiter() 



futex_top_waiter() returns the top-waiter on the pi_mutex. Assinging
this to a variable 'match' totally obscures the code.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: juri.lelli@arm.com
Cc: bigeasy@linutronix.de
Cc: xlpang@redhat.com
Cc: rostedt@goodmis.org
Cc: mathieu.desnoyers@efficios.com
Cc: jdesfossez@efficios.com
Cc: dvhart@infradead.org
Cc: bristot@redhat.com
Link: http://lkml.kernel.org/r/20170322104151.554710645@infradead.org


Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent e6790e4b

kernel/futex.c

+15 −15
Original line number Diff line number Diff line
@@ -1122,14 +1122,14 @@ static int attach_to_pi_owner(u32 uval, union futex_key *key, 
static int lookup_pi_state(u32 uval, struct futex_hash_bucket *hb,

			   union futex_key *key, struct futex_pi_state **ps)

{

	struct futex_q *match = futex_top_waiter(hb, key);

	struct futex_q *top_waiter = futex_top_waiter(hb, key);



	/*

	 * If there is a waiter on that futex, validate it and

	 * attach to the pi_state when the validation succeeds.

	 */

	if (match)

		return attach_to_pi_state(uval, match->pi_state, ps);

	if (top_waiter)

		return attach_to_pi_state(uval, top_waiter->pi_state, ps);



	/*

	 * We are the first waiter - try to look up the owner based on
@@ -1176,7 +1176,7 @@ static int futex_lock_pi_atomic(u32 __user *uaddr, struct futex_hash_bucket *hb, 
				struct task_struct *task, int set_waiters)

{

	u32 uval, newval, vpid = task_pid_vnr(task);

	struct futex_q *match;

	struct futex_q *top_waiter;

	int ret;



	/*
@@ -1202,9 +1202,9 @@ static int futex_lock_pi_atomic(u32 __user *uaddr, struct futex_hash_bucket *hb, 
	 * Lookup existing state first. If it exists, try to attach to

	 * its pi_state.

	 */

	match = futex_top_waiter(hb, key);

	if (match)

		return attach_to_pi_state(uval, match->pi_state, ps);

	top_waiter = futex_top_waiter(hb, key);

	if (top_waiter)

		return attach_to_pi_state(uval, top_waiter->pi_state, ps);



	/*

	 * No waiter and user TID is 0. We are here because the
@@ -1294,11 +1294,11 @@ static void mark_wake_futex(struct wake_q_head *wake_q, struct futex_q *q) 
	q->lock_ptr = NULL;

}



static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_q *this,

static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_q *top_waiter,

			 struct futex_hash_bucket *hb)

{

	struct task_struct *new_owner;

	struct futex_pi_state *pi_state = this->pi_state;

	struct futex_pi_state *pi_state = top_waiter->pi_state;

	u32 uninitialized_var(curval), newval;

	DEFINE_WAKE_Q(wake_q);

	bool deboost;
@@ -1319,11 +1319,11 @@ static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_q *this, 


	/*

	 * It is possible that the next waiter (the one that brought

	 * this owner to the kernel) timed out and is no longer

	 * top_waiter owner to the kernel) timed out and is no longer

	 * waiting on the lock.

	 */

	if (!new_owner)

		new_owner = this->task;

		new_owner = top_waiter->task;



	/*

	 * We pass it to the next owner. The WAITERS bit is always
@@ -2633,7 +2633,7 @@ static int futex_unlock_pi(u32 __user *uaddr, unsigned int flags) 
	u32 uninitialized_var(curval), uval, vpid = task_pid_vnr(current);

	union futex_key key = FUTEX_KEY_INIT;

	struct futex_hash_bucket *hb;

	struct futex_q *match;

	struct futex_q *top_waiter;

	int ret;



retry:
@@ -2657,9 +2657,9 @@ static int futex_unlock_pi(u32 __user *uaddr, unsigned int flags) 
	 * all and we at least want to know if user space fiddled

	 * with the futex value instead of blindly unlocking.

	 */

	match = futex_top_waiter(hb, &key);

	if (match) {

		ret = wake_futex_pi(uaddr, uval, match, hb);

	top_waiter = futex_top_waiter(hb, &key);

	if (top_waiter) {

		ret = wake_futex_pi(uaddr, uval, top_waiter, hb);

		/*

		 * In case of success wake_futex_pi dropped the hash

		 * bucket lock.