#define FUTEX_HASHBITS (CONFIG_BASE_SMALL ? 4 : 8)
+/*
+ * Futex flags used to encode options to functions and preserve them across
+ * restarts.
+ */
+#define FLAGS_SHARED 0x01
+#define FLAGS_CLOCKRT 0x02
+#define FLAGS_HAS_TIMEOUT 0x04
+
/*
* Priority Inheritance state:
*/
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
return 0;
}
-static inline
-void put_futex_key(int fshared, union futex_key *key)
+static inline void put_futex_key(union futex_key *key)
{
drop_futex_key_refs(key);
}
/*
* Wake up waiters matching bitset queued on this futex (uaddr).
*/
-static int futex_wake(u32 __user *uaddr, int fshared, int nr_wake, u32 bitset)
+static int
+futex_wake(u32 __user *uaddr, unsigned int flags, int nr_wake, u32 bitset)
{
struct futex_hash_bucket *hb;
struct futex_q *this, *next;
if (!bitset)
return -EINVAL;
- ret = get_futex_key(uaddr, fshared, &key);
+ ret = get_futex_key(uaddr, flags & FLAGS_SHARED, &key);
if (unlikely(ret != 0))
goto out;
}
spin_unlock(&hb->lock);
- put_futex_key(fshared, &key);
+ put_futex_key(&key);
out:
return ret;
}
* to this virtual address:
*/
static int
-futex_wake_op(u32 __user *uaddr1, int fshared, u32 __user *uaddr2,
+futex_wake_op(u32 __user *uaddr1, unsigned int flags, u32 __user *uaddr2,
int nr_wake, int nr_wake2, int op)
{
union futex_key key1 = FUTEX_KEY_INIT, key2 = FUTEX_KEY_INIT;
int ret, op_ret;
retry:
- ret = get_futex_key(uaddr1, fshared, &key1);
+ ret = get_futex_key(uaddr1, flags & FLAGS_SHARED, &key1);
if (unlikely(ret != 0))
goto out;
- ret = get_futex_key(uaddr2, fshared, &key2);
+ ret = get_futex_key(uaddr2, flags & FLAGS_SHARED, &key2);
if (unlikely(ret != 0))
goto out_put_key1;
if (ret)
goto out_put_keys;
- if (!fshared)
+ if (!(flags & FLAGS_SHARED))
goto retry_private;
- put_futex_key(fshared, &key2);
- put_futex_key(fshared, &key1);
+ put_futex_key(&key2);
+ put_futex_key(&key1);
goto retry;
}
double_unlock_hb(hb1, hb2);
out_put_keys:
- put_futex_key(fshared, &key2);
+ put_futex_key(&key2);
out_put_key1:
- put_futex_key(fshared, &key1);
+ put_futex_key(&key1);
out:
return ret;
}
/**
* futex_requeue() - Requeue waiters from uaddr1 to uaddr2
* @uaddr1: source futex user address
- * @fshared: 0 for a PROCESS_PRIVATE futex, 1 for PROCESS_SHARED
+ * @flags: futex flags (FLAGS_SHARED, etc.)
* @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)
+ * pi futex (pi to pi requeue is not supported)
*
* Requeue waiters on uaddr1 to uaddr2. In the requeue_pi case, try to acquire
* uaddr2 atomically on behalf of the top waiter.
* >=0 - on success, the number of tasks requeued or woken
* <0 - on error
*/
-static int futex_requeue(u32 __user *uaddr1, int fshared, u32 __user *uaddr2,
- int nr_wake, int nr_requeue, u32 *cmpval,
- int requeue_pi)
+static int futex_requeue(u32 __user *uaddr1, unsigned int flags,
+ u32 __user *uaddr2, int nr_wake, int nr_requeue,
+ u32 *cmpval, int requeue_pi)
{
union futex_key key1 = FUTEX_KEY_INIT, key2 = FUTEX_KEY_INIT;
int drop_count = 0, task_count = 0, ret;
pi_state = NULL;
}
- ret = get_futex_key(uaddr1, fshared, &key1);
+ ret = get_futex_key(uaddr1, flags & FLAGS_SHARED, &key1);
if (unlikely(ret != 0))
goto out;
- ret = get_futex_key(uaddr2, fshared, &key2);
+ ret = get_futex_key(uaddr2, flags & FLAGS_SHARED, &key2);
if (unlikely(ret != 0))
goto out_put_key1;
if (ret)
goto out_put_keys;
- if (!fshared)
+ if (!(flags & FLAGS_SHARED))
goto retry_private;
- put_futex_key(fshared, &key2);
- put_futex_key(fshared, &key1);
+ put_futex_key(&key2);
+ put_futex_key(&key1);
goto retry;
}
if (curval != *cmpval) {
break;
case -EFAULT:
double_unlock_hb(hb1, hb2);
- put_futex_key(fshared, &key2);
- put_futex_key(fshared, &key1);
+ put_futex_key(&key2);
+ put_futex_key(&key1);
ret = fault_in_user_writeable(uaddr2);
if (!ret)
goto retry;
case -EAGAIN:
/* The owner was exiting, try again. */
double_unlock_hb(hb1, hb2);
- put_futex_key(fshared, &key2);
- put_futex_key(fshared, &key1);
+ put_futex_key(&key2);
+ put_futex_key(&key1);
cond_resched();
goto retry;
default:
drop_futex_key_refs(&key1);
out_put_keys:
- put_futex_key(fshared, &key2);
+ put_futex_key(&key2);
out_put_key1:
- put_futex_key(fshared, &key1);
+ put_futex_key(&key1);
out:
if (pi_state != NULL)
free_pi_state(pi_state);
* private futexes.
*/
static int fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q,
- struct task_struct *newowner, int fshared)
+ struct task_struct *newowner)
{
u32 newtid = task_pid_vnr(newowner) | FUTEX_WAITERS;
struct futex_pi_state *pi_state = q->pi_state;
goto retry;
}
-/*
- * In case we must use restart_block to restart a futex_wait,
- * we encode in the 'flags' shared capability
- */
-#define FLAGS_SHARED 0x01
-#define FLAGS_CLOCKRT 0x02
-#define FLAGS_HAS_TIMEOUT 0x04
-
static long futex_wait_restart(struct restart_block *restart);
/**
* fixup_owner() - Post lock pi_state and corner case management
* @uaddr: user address of the futex
- * @fshared: whether the futex is shared (1) or not (0)
* @q: futex_q (contains pi_state and access to the rt_mutex)
* @locked: if the attempt to take the rt_mutex succeeded (1) or not (0)
*
* 0 - success, lock not taken
* <0 - on error (-EFAULT)
*/
-static int fixup_owner(u32 __user *uaddr, int fshared, struct futex_q *q,
- int locked)
+static int fixup_owner(u32 __user *uaddr, struct futex_q *q, int locked)
{
struct task_struct *owner;
int ret = 0;
* did a lock-steal - fix up the PI-state in that case:
*/
if (q->pi_state->owner != current)
- ret = fixup_pi_state_owner(uaddr, q, current, fshared);
+ ret = fixup_pi_state_owner(uaddr, q, current);
goto out;
}
* lock. Fix the state up.
*/
owner = rt_mutex_owner(&q->pi_state->pi_mutex);
- ret = fixup_pi_state_owner(uaddr, q, owner, fshared);
+ ret = fixup_pi_state_owner(uaddr, q, owner);
goto out;
}
* futex_wait_setup() - Prepare to wait on a futex
* @uaddr: the futex userspace address
* @val: the expected value
- * @fshared: whether the futex is shared (1) or not (0)
+ * @flags: futex flags (FLAGS_SHARED, etc.)
* @q: the associated futex_q
* @hb: storage for hash_bucket pointer to be returned to caller
*
* 0 - uaddr contains val and hb has been locked
* <1 - -EFAULT or -EWOULDBLOCK (uaddr does not contain val) and hb is unlcoked
*/
-static int futex_wait_setup(u32 __user *uaddr, u32 val, int fshared,
+static int futex_wait_setup(u32 __user *uaddr, u32 val, unsigned int flags,
struct futex_q *q, struct futex_hash_bucket **hb)
{
u32 uval;
* rare, but normal.
*/
retry:
- q->key = FUTEX_KEY_INIT;
- ret = get_futex_key(uaddr, fshared, &q->key);
+ ret = get_futex_key(uaddr, flags & FLAGS_SHARED, &q->key);
if (unlikely(ret != 0))
return ret;
if (ret)
goto out;
- if (!fshared)
+ if (!(flags & FLAGS_SHARED))
goto retry_private;
- put_futex_key(fshared, &q->key);
+ put_futex_key(&q->key);
goto retry;
}
out:
if (ret)
- put_futex_key(fshared, &q->key);
+ put_futex_key(&q->key);
return ret;
}
-static int futex_wait(u32 __user *uaddr, int fshared,
- u32 val, ktime_t *abs_time, u32 bitset, int clockrt)
+static int futex_wait(u32 __user *uaddr, unsigned int flags, u32 val,
+ ktime_t *abs_time, u32 bitset)
{
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;
- hrtimer_init_on_stack(&to->timer, clockrt ? CLOCK_REALTIME :
- CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
+ hrtimer_init_on_stack(&to->timer, (flags & FLAGS_CLOCKRT) ?
+ CLOCK_REALTIME : CLOCK_MONOTONIC,
+ HRTIMER_MODE_ABS);
hrtimer_init_sleeper(to, current);
hrtimer_set_expires_range_ns(&to->timer, *abs_time,
current->timer_slack_ns);
* Prepare to wait on uaddr. On success, holds hb lock and increments
* q.key refs.
*/
- ret = futex_wait_setup(uaddr, val, fshared, &q, &hb);
+ ret = futex_wait_setup(uaddr, val, flags, &q, &hb);
if (ret)
goto out;
restart->futex.val = val;
restart->futex.time = abs_time->tv64;
restart->futex.bitset = bitset;
- restart->futex.flags = FLAGS_HAS_TIMEOUT;
-
- if (fshared)
- restart->futex.flags |= FLAGS_SHARED;
- if (clockrt)
- restart->futex.flags |= FLAGS_CLOCKRT;
+ restart->futex.flags = flags;
ret = -ERESTART_RESTARTBLOCK;
static long futex_wait_restart(struct restart_block *restart)
{
u32 __user *uaddr = restart->futex.uaddr;
- int fshared = 0;
ktime_t t, *tp = NULL;
if (restart->futex.flags & FLAGS_HAS_TIMEOUT) {
tp = &t;
}
restart->fn = do_no_restart_syscall;
- if (restart->futex.flags & FLAGS_SHARED)
- fshared = 1;
- return (long)futex_wait(uaddr, fshared, restart->futex.val, tp,
- restart->futex.bitset,
- restart->futex.flags & FLAGS_CLOCKRT);
+
+ return (long)futex_wait(uaddr, restart->futex.flags,
+ restart->futex.val, tp, restart->futex.bitset);
}
* if there are waiters then it will block, it does PI, etc. (Due to
* races the kernel might see a 0 value of the futex too.)
*/
-static int futex_lock_pi(u32 __user *uaddr, int fshared,
- int detect, ktime_t *time, int trylock)
+static int futex_lock_pi(u32 __user *uaddr, unsigned int flags, int detect,
+ ktime_t *time, int trylock)
{
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())
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, fshared, &q.key);
+ ret = get_futex_key(uaddr, flags & FLAGS_SHARED, &q.key);
if (unlikely(ret != 0))
goto out;
* exit to complete.
*/
queue_unlock(&q, hb);
- put_futex_key(fshared, &q.key);
+ put_futex_key(&q.key);
cond_resched();
goto retry;
default:
* Fixup the pi_state owner and possibly acquire the lock if we
* haven't already.
*/
- res = fixup_owner(uaddr, fshared, &q, !ret);
+ res = fixup_owner(uaddr, &q, !ret);
/*
* If fixup_owner() returned an error, proprogate that. If it acquired
* the lock, clear our -ETIMEDOUT or -EINTR.
queue_unlock(&q, hb);
out_put_key:
- put_futex_key(fshared, &q.key);
+ put_futex_key(&q.key);
out:
if (to)
destroy_hrtimer_on_stack(&to->timer);
if (ret)
goto out_put_key;
- if (!fshared)
+ if (!(flags & FLAGS_SHARED))
goto retry_private;
- put_futex_key(fshared, &q.key);
+ put_futex_key(&q.key);
goto retry;
}
* This is the in-kernel slowpath: we look up the PI state (if any),
* and do the rt-mutex unlock.
*/
-static int futex_unlock_pi(u32 __user *uaddr, int fshared)
+static int futex_unlock_pi(u32 __user *uaddr, unsigned int flags)
{
struct futex_hash_bucket *hb;
struct futex_q *this, *next;
if ((uval & FUTEX_TID_MASK) != task_pid_vnr(current))
return -EPERM;
- ret = get_futex_key(uaddr, fshared, &key);
+ ret = get_futex_key(uaddr, flags & FLAGS_SHARED, &key);
if (unlikely(ret != 0))
goto out;
out_unlock:
spin_unlock(&hb->lock);
- put_futex_key(fshared, &key);
+ put_futex_key(&key);
out:
return ret;
pi_faulted:
spin_unlock(&hb->lock);
- put_futex_key(fshared, &key);
+ put_futex_key(&key);
ret = fault_in_user_writeable(uaddr);
if (!ret)
/**
* futex_wait_requeue_pi() - Wait on uaddr and take uaddr2
* @uaddr: the futex we initially wait on (non-pi)
- * @fshared: whether the futexes are shared (1) or not (0). They must be
+ * @flags: futex flags (FLAGS_SHARED, FLAGS_CLOCKRT, etc.), they must be
* the same type, no requeueing from private to shared, etc.
* @val: the expected value of uaddr
* @abs_time: absolute timeout
* 0 - On success
* <0 - On error
*/
-static int futex_wait_requeue_pi(u32 __user *uaddr, int fshared,
+static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags,
u32 val, ktime_t *abs_time, u32 bitset,
- int clockrt, u32 __user *uaddr2)
+ u32 __user *uaddr2)
{
struct hrtimer_sleeper timeout, *to = NULL;
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)
if (abs_time) {
to = &timeout;
- hrtimer_init_on_stack(&to->timer, clockrt ? CLOCK_REALTIME :
- CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
+ hrtimer_init_on_stack(&to->timer, (flags & FLAGS_CLOCKRT) ?
+ CLOCK_REALTIME : CLOCK_MONOTONIC,
+ HRTIMER_MODE_ABS);
hrtimer_init_sleeper(to, current);
hrtimer_set_expires_range_ns(&to->timer, *abs_time,
current->timer_slack_ns);
debug_rt_mutex_init_waiter(&rt_waiter);
rt_waiter.task = NULL;
- key2 = FUTEX_KEY_INIT;
- ret = get_futex_key(uaddr2, fshared, &key2);
+ 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;
* Prepare to wait on uaddr. On success, increments q.key (key1) ref
* count.
*/
- ret = futex_wait_setup(uaddr, val, fshared, &q, &hb);
+ ret = futex_wait_setup(uaddr, val, flags, &q, &hb);
if (ret)
goto out_key2;
*/
if (q.pi_state && (q.pi_state->owner != current)) {
spin_lock(q.lock_ptr);
- ret = fixup_pi_state_owner(uaddr2, &q, current,
- fshared);
+ ret = fixup_pi_state_owner(uaddr2, &q, current);
spin_unlock(q.lock_ptr);
}
} else {
* Fixup the pi_state owner and possibly acquire the lock if we
* haven't already.
*/
- res = fixup_owner(uaddr2, fshared, &q, !ret);
+ res = fixup_owner(uaddr2, &q, !ret);
/*
* If fixup_owner() returned an error, proprogate that. If it
* acquired the lock, clear -ETIMEDOUT or -EINTR.
}
out_put_keys:
- put_futex_key(fshared, &q.key);
+ put_futex_key(&q.key);
out_key2:
- put_futex_key(fshared, &key2);
+ put_futex_key(&key2);
out:
if (to) {
{
struct robust_list_head __user *head = curr->robust_list;
struct robust_list __user *entry, *next_entry, *pending;
- unsigned int limit = ROBUST_LIST_LIMIT, pi, next_pi, pip;
+ unsigned int limit = ROBUST_LIST_LIMIT, pi, pip;
+ unsigned int uninitialized_var(next_pi);
unsigned long futex_offset;
int rc;
long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout,
u32 __user *uaddr2, u32 val2, u32 val3)
{
- int clockrt, ret = -ENOSYS;
- int cmd = op & FUTEX_CMD_MASK;
- int fshared = 0;
+ int ret = -ENOSYS, cmd = op & FUTEX_CMD_MASK;
+ unsigned int flags = 0;
if (!(op & FUTEX_PRIVATE_FLAG))
- fshared = 1;
+ flags |= FLAGS_SHARED;
- clockrt = op & FUTEX_CLOCK_REALTIME;
- if (clockrt && cmd != FUTEX_WAIT_BITSET && cmd != FUTEX_WAIT_REQUEUE_PI)
- return -ENOSYS;
+ if (op & FUTEX_CLOCK_REALTIME) {
+ flags |= FLAGS_CLOCKRT;
+ if (cmd != FUTEX_WAIT_BITSET && cmd != FUTEX_WAIT_REQUEUE_PI)
+ return -ENOSYS;
+ }
switch (cmd) {
case FUTEX_WAIT:
val3 = FUTEX_BITSET_MATCH_ANY;
case FUTEX_WAIT_BITSET:
- ret = futex_wait(uaddr, fshared, val, timeout, val3, clockrt);
+ ret = futex_wait(uaddr, flags, val, timeout, val3);
break;
case FUTEX_WAKE:
val3 = FUTEX_BITSET_MATCH_ANY;
case FUTEX_WAKE_BITSET:
- ret = futex_wake(uaddr, fshared, val, val3);
+ ret = futex_wake(uaddr, flags, val, val3);
break;
case FUTEX_REQUEUE:
- ret = futex_requeue(uaddr, fshared, uaddr2, val, val2, NULL, 0);
+ ret = futex_requeue(uaddr, flags, uaddr2, val, val2, NULL, 0);
break;
case FUTEX_CMP_REQUEUE:
- ret = futex_requeue(uaddr, fshared, uaddr2, val, val2, &val3,
- 0);
+ ret = futex_requeue(uaddr, flags, uaddr2, val, val2, &val3, 0);
break;
case FUTEX_WAKE_OP:
- ret = futex_wake_op(uaddr, fshared, uaddr2, val, val2, val3);
+ ret = futex_wake_op(uaddr, flags, uaddr2, val, val2, val3);
break;
case FUTEX_LOCK_PI:
if (futex_cmpxchg_enabled)
- ret = futex_lock_pi(uaddr, fshared, val, timeout, 0);
+ ret = futex_lock_pi(uaddr, flags, val, timeout, 0);
break;
case FUTEX_UNLOCK_PI:
if (futex_cmpxchg_enabled)
- ret = futex_unlock_pi(uaddr, fshared);
+ ret = futex_unlock_pi(uaddr, flags);
break;
case FUTEX_TRYLOCK_PI:
if (futex_cmpxchg_enabled)
- ret = futex_lock_pi(uaddr, fshared, 0, timeout, 1);
+ ret = futex_lock_pi(uaddr, flags, 0, timeout, 1);
break;
case FUTEX_WAIT_REQUEUE_PI:
val3 = FUTEX_BITSET_MATCH_ANY;
- ret = futex_wait_requeue_pi(uaddr, fshared, val, timeout, val3,
- clockrt, uaddr2);
+ ret = futex_wait_requeue_pi(uaddr, flags, val, timeout, val3,
+ uaddr2);
break;
case FUTEX_CMP_REQUEUE_PI:
- ret = futex_requeue(uaddr, fshared, uaddr2, val, val2, &val3,
- 1);
+ ret = futex_requeue(uaddr, flags, uaddr2, val, val2, &val3, 1);
break;
default:
ret = -ENOSYS;
git.openpandora.org / pandora-kernel.git / blobdiff