Messages in this thread Patch in this message |  | | | From | Darren Hart <> | | Subject | [PATCH 3/3] futex: add futex_q static initializer | | Date | Wed, 27 Oct 2010 14:54:26 -0700 |
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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.
Signed-off-by: Darren Hart <dvhltc@us.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@elte.hu> CC: Eric Dumazet <eric.dumazet@gmail.com> CC: John Kacur <jkacur@redhat.com> --- kernel/futex.c | 25 ++++++++++--------------- 1 files changed, 10 insertions(+), 15 deletions(-) diff --git a/kernel/futex.c b/kernel/futex.c index 8502498..4a10d44 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -131,6 +131,12 @@ struct futex_q { u32 bitset; }; +#define FUTEX_Q_INIT \ + { /* list gets initialized in queue_me()*/ \ + .task = NULL, NULL, FUTEX_KEY_INIT \ + , NULL, NULL, NULL, 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, 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, int flags, u32 val, ktime_t *abs_time, 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, 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, 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, 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, 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; -- 1.7.1
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