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: Peter 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: Thomas Gleixner <tglx@linutronix.de>

diff --git a/kernel/futex.c b/kernel/futex.c
index 45858ec739411f5741667e560552757697441e6b..1531cc405270a5f4ac026769b3085510c74f1388 100644 (file)
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -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 @@ retry:
         * 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.