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authorLinus Torvalds <torvalds@linux-foundation.org>2010-10-21 14:06:17 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-10-21 14:06:17 -0700
commitb61f6a57f1919ef8dbd33f864df9b8b361c65b11 (patch)
tree9341bc1a3f6a8fdcd19f97d5bcf1a658ab7fc92c /kernel/futex.c
parent0575db881d18a4791013fc93ba756ad08b18fb48 (diff)
parentfb62db2ba943b1683f1d7181bb2988fce4c60870 (diff)
Merge branch 'futexes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'futexes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: futex: Fix kernel-doc notation & typos futex: Add lock context annotations futex: Mark restart_block.futex.uaddr[2] __user futex: Change 3rd arg of fetch_robust_entry() to unsigned int*
Diffstat (limited to 'kernel/futex.c')
-rw-r--r--kernel/futex.c35
1 files changed, 21 insertions, 14 deletions
diff --git a/kernel/futex.c b/kernel/futex.c
index e328f574c97..a118bf160e0 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -91,6 +91,7 @@ struct futex_pi_state {
/**
* struct futex_q - The hashed futex queue entry, one per waiting task
+ * @list: priority-sorted list of tasks waiting on this futex
* @task: the task waiting on the futex
* @lock_ptr: the hash bucket lock
* @key: the key the futex is hashed on
@@ -104,7 +105,7 @@ struct futex_pi_state {
*
* A futex_q has a woken state, just like tasks have TASK_RUNNING.
* It is considered woken when plist_node_empty(&q->list) || q->lock_ptr == 0.
- * The order of wakup is always to make the first condition true, then
+ * The order of wakeup is always to make the first condition true, then
* the second.
*
* PI futexes are typically woken before they are removed from the hash list via
@@ -295,7 +296,7 @@ void put_futex_key(int fshared, union futex_key *key)
* Slow path to fixup the fault we just took in the atomic write
* access to @uaddr.
*
- * We have no generic implementation of a non destructive write to the
+ * We have no generic implementation of a non-destructive write to the
* user address. We know that we faulted in the atomic pagefault
* disabled section so we can as well avoid the #PF overhead by
* calling get_user_pages() right away.
@@ -515,7 +516,7 @@ lookup_pi_state(u32 uval, struct futex_hash_bucket *hb,
*/
pi_state = this->pi_state;
/*
- * Userspace might have messed up non PI and PI futexes
+ * Userspace might have messed up non-PI and PI futexes
*/
if (unlikely(!pi_state))
return -EINVAL;
@@ -736,8 +737,8 @@ static void wake_futex(struct futex_q *q)
/*
* We set q->lock_ptr = NULL _before_ we wake up the task. If
- * a non futex wake up happens on another CPU then the task
- * might exit and p would dereference a non existing task
+ * a non-futex wake up happens on another CPU then the task
+ * might exit and p would dereference a non-existing task
* struct. Prevent this by holding a reference on p across the
* wake up.
*/
@@ -1131,11 +1132,13 @@ static int futex_proxy_trylock_atomic(u32 __user *pifutex,
/**
* futex_requeue() - Requeue waiters from uaddr1 to uaddr2
- * uaddr1: source futex user address
- * uaddr2: target futex user address
- * nr_wake: number of waiters to wake (must be 1 for requeue_pi)
- * nr_requeue: number of waiters to requeue (0-INT_MAX)
- * requeue_pi: if we are attempting to requeue from a non-pi futex to a
+ * @uaddr1: source futex user address
+ * @fshared: 0 for a PROCESS_PRIVATE futex, 1 for PROCESS_SHARED
+ * @uaddr2: target futex user address
+ * @nr_wake: number of waiters to wake (must be 1 for requeue_pi)
+ * @nr_requeue: number of waiters to requeue (0-INT_MAX)
+ * @cmpval: @uaddr1 expected value (or %NULL)
+ * @requeue_pi: if we are attempting to requeue from a non-pi futex to a
* pi futex (pi to pi requeue is not supported)
*
* Requeue waiters on uaddr1 to uaddr2. In the requeue_pi case, try to acquire
@@ -1360,6 +1363,7 @@ out:
/* The key must be already stored in q->key. */
static inline struct futex_hash_bucket *queue_lock(struct futex_q *q)
+ __acquires(&hb->lock)
{
struct futex_hash_bucket *hb;
@@ -1372,6 +1376,7 @@ static inline struct futex_hash_bucket *queue_lock(struct futex_q *q)
static inline void
queue_unlock(struct futex_q *q, struct futex_hash_bucket *hb)
+ __releases(&hb->lock)
{
spin_unlock(&hb->lock);
}
@@ -1389,6 +1394,7 @@ queue_unlock(struct futex_q *q, struct futex_hash_bucket *hb)
* an example).
*/
static inline void queue_me(struct futex_q *q, struct futex_hash_bucket *hb)
+ __releases(&hb->lock)
{
int prio;
@@ -1469,6 +1475,7 @@ retry:
* and dropped here.
*/
static void unqueue_me_pi(struct futex_q *q)
+ __releases(q->lock_ptr)
{
WARN_ON(plist_node_empty(&q->list));
plist_del(&q->list, &q->list.plist);
@@ -1841,7 +1848,7 @@ retry:
restart = &current_thread_info()->restart_block;
restart->fn = futex_wait_restart;
- restart->futex.uaddr = (u32 *)uaddr;
+ restart->futex.uaddr = uaddr;
restart->futex.val = val;
restart->futex.time = abs_time->tv64;
restart->futex.bitset = bitset;
@@ -1865,7 +1872,7 @@ out:
static long futex_wait_restart(struct restart_block *restart)
{
- u32 __user *uaddr = (u32 __user *)restart->futex.uaddr;
+ u32 __user *uaddr = restart->futex.uaddr;
int fshared = 0;
ktime_t t, *tp = NULL;
@@ -2459,7 +2466,7 @@ retry:
*/
static inline int fetch_robust_entry(struct robust_list __user **entry,
struct robust_list __user * __user *head,
- int *pi)
+ unsigned int *pi)
{
unsigned long uentry;
@@ -2648,7 +2655,7 @@ static int __init futex_init(void)
* of the complex code paths. Also we want to prevent
* registration of robust lists in that case. NULL is
* guaranteed to fault and we get -EFAULT on functional
- * implementation, the non functional ones will return
+ * implementation, the non-functional ones will return
* -ENOSYS.
*/
curval = cmpxchg_futex_value_locked(NULL, 0, 0);