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authorDarren Hart <dvhart@linux.intel.com>2010-11-08 13:40:28 -0800
committerThomas Gleixner <tglx@linutronix.de>2010-11-10 15:01:34 +0100
commit5bdb05f91b27b9361c4f348a4e05999f597df72e (patch)
tree23d68ff7cdd469a6138b95aff37e6990b395eae9 /kernel
parentb41277dc7a18ee332d9e8078e978bacdf6e76157 (diff)
futex: Add futex_q static initializer
The futex_q struct has grown considerably over the last couple years. I believe it now merits a static initializer to avoid uninitialized data errors (having spent more time than I care to admit debugging an uninitialized q.bitset in an experimental new op code). With the key initializer built in, several of the FUTEX_KEY_INIT calls can be removed. V2: use a static variable instead of an init macro. use a C99 initializer and don't rely on variable ordering in the struct. V3: make futex_q_init const Signed-off-by: Darren Hart <dvhart@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: John Kacur <jkacur@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> LKML-Reference: <1289252428-18383-1-git-send-email-dvhart@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/futex.c25
1 files changed, 10 insertions, 15 deletions
diff --git a/kernel/futex.c b/kernel/futex.c
index 87ad28746e17..3019b92e6917 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -131,6 +131,12 @@ struct futex_q {
u32 bitset;
};
+static const struct futex_q futex_q_init = {
+ /* list gets initialized in queue_me()*/
+ .key = FUTEX_KEY_INIT,
+ .bitset = FUTEX_BITSET_MATCH_ANY
+};
+
/*
* Hash buckets are shared by all the futex_keys that hash to the same
* location. Each key may have multiple futex_q structures, one for each task
@@ -1750,7 +1756,6 @@ static int futex_wait_setup(u32 __user *uaddr, u32 val, unsigned int flags,
* rare, but normal.
*/
retry:
- q->key = FUTEX_KEY_INIT;
ret = get_futex_key(uaddr, flags & FLAGS_SHARED, &q->key);
if (unlikely(ret != 0))
return ret;
@@ -1791,16 +1796,12 @@ static int futex_wait(u32 __user *uaddr, unsigned int flags, u32 val,
struct hrtimer_sleeper timeout, *to = NULL;
struct restart_block *restart;
struct futex_hash_bucket *hb;
- struct futex_q q;
+ struct futex_q q = futex_q_init;
int ret;
if (!bitset)
return -EINVAL;
-
- q.pi_state = NULL;
q.bitset = bitset;
- q.rt_waiter = NULL;
- q.requeue_pi_key = NULL;
if (abs_time) {
to = &timeout;
@@ -1891,7 +1892,7 @@ static int futex_lock_pi(u32 __user *uaddr, unsigned int flags, int detect,
{
struct hrtimer_sleeper timeout, *to = NULL;
struct futex_hash_bucket *hb;
- struct futex_q q;
+ struct futex_q q = futex_q_init;
int res, ret;
if (refill_pi_state_cache())
@@ -1905,11 +1906,7 @@ static int futex_lock_pi(u32 __user *uaddr, unsigned int flags, int detect,
hrtimer_set_expires(&to->timer, *time);
}
- q.pi_state = NULL;
- q.rt_waiter = NULL;
- q.requeue_pi_key = NULL;
retry:
- q.key = FUTEX_KEY_INIT;
ret = get_futex_key(uaddr, flags & FLAGS_SHARED, &q.key);
if (unlikely(ret != 0))
goto out;
@@ -2197,8 +2194,8 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags,
struct rt_mutex_waiter rt_waiter;
struct rt_mutex *pi_mutex = NULL;
struct futex_hash_bucket *hb;
- union futex_key key2;
- struct futex_q q;
+ union futex_key key2 = FUTEX_KEY_INIT;
+ struct futex_q q = futex_q_init;
int res, ret;
if (!bitset)
@@ -2221,12 +2218,10 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags,
debug_rt_mutex_init_waiter(&rt_waiter);
rt_waiter.task = NULL;
- key2 = FUTEX_KEY_INIT;
ret = get_futex_key(uaddr2, flags & FLAGS_SHARED, &key2);
if (unlikely(ret != 0))
goto out;
- q.pi_state = NULL;
q.bitset = bitset;
q.rt_waiter = &rt_waiter;
q.requeue_pi_key = &key2;