Revert "clk: rockchip: rk3368: Add CLK_IGNORE_UNUSED flag for mipi phy refclk"

[firefly-linux-kernel-4.4.55.git] / kernel / futex.c

diff --git a/kernel/futex.c b/kernel/futex.c
index 461c72b2dac2c4d316e66b38b5b7d73d980ab347..af29863f33495eb68dcbad7fa4b3f8d4ac319cb9 100644 (file)
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -681,7 +681,7 @@ static int get_futex_value_locked(u32 *dest, u32 __user *from)
        int ret;
 
        pagefault_disable();
-       ret = __copy_from_user_inatomic(dest, from, sizeof(u32));
+       ret = __get_user(*dest, from);
        pagefault_enable();
 
        return ret ? -EFAULT : 0;
@@ -1244,10 +1244,20 @@ static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_q *this,
        if (unlikely(should_fail_futex(true)))
                ret = -EFAULT;
 
-       if (cmpxchg_futex_value_locked(&curval, uaddr, uval, newval))
+       if (cmpxchg_futex_value_locked(&curval, uaddr, uval, newval)) {
                ret = -EFAULT;
-       else if (curval != uval)
-               ret = -EINVAL;
+       } else if (curval != uval) {
+               /*
+                * If a unconditional UNLOCK_PI operation (user space did not
+                * try the TID->0 transition) raced with a waiter setting the
+                * FUTEX_WAITERS flag between get_user() and locking the hash
+                * bucket lock, retry the operation.
+                */
+               if ((FUTEX_TID_MASK & curval) == uval)
+                       ret = -EAGAIN;
+               else
+                       ret = -EINVAL;
+       }
        if (ret) {
                raw_spin_unlock(&pi_state->pi_mutex.wait_lock);
                return ret;
@@ -1474,8 +1484,8 @@ void requeue_futex(struct futex_q *q, struct futex_hash_bucket *hb1,
        if (likely(&hb1->chain != &hb2->chain)) {
                plist_del(&q->list, &hb1->chain);
                hb_waiters_dec(hb1);
-               plist_add(&q->list, &hb2->chain);
                hb_waiters_inc(hb2);
+               plist_add(&q->list, &hb2->chain);
                q->lock_ptr = &hb2->lock;
        }
        get_futex_key_refs(key2);
@@ -2537,6 +2547,15 @@ retry:
                 */
                if (ret == -EFAULT)
                        goto pi_faulted;
+               /*
+                * A unconditional UNLOCK_PI op raced against a waiter
+                * setting the FUTEX_WAITERS bit. Try again.
+                */
+               if (ret == -EAGAIN) {
+                       spin_unlock(&hb->lock);
+                       put_futex_key(&key);
+                       goto retry;
+               }
                /*
                 * wake_futex_pi has detected invalid state. Tell user
                 * space.
@@ -2671,7 +2690,6 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags,
 {
        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 = FUTEX_KEY_INIT;
        struct futex_q q = futex_q_init;
@@ -2755,6 +2773,8 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags,
                if (q.pi_state && (q.pi_state->owner != current)) {
                        spin_lock(q.lock_ptr);
                        ret = fixup_pi_state_owner(uaddr2, &q, current);
+                       if (ret && rt_mutex_owner(&q.pi_state->pi_mutex) == current)
+                               rt_mutex_unlock(&q.pi_state->pi_mutex);
                        /*
                         * Drop the reference to the pi state which
                         * the requeue_pi() code acquired for us.
@@ -2763,6 +2783,8 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags,
                        spin_unlock(q.lock_ptr);
                }
        } else {
+               struct rt_mutex *pi_mutex;
+
                /*
                 * We have been woken up by futex_unlock_pi(), a timeout, or a
                 * signal.  futex_unlock_pi() will not destroy the lock_ptr nor
@@ -2786,18 +2808,19 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags,
                if (res)
                        ret = (res < 0) ? res : 0;
 
+               /*
+                * If fixup_pi_state_owner() faulted and was unable to handle
+                * the fault, unlock the rt_mutex and return the fault to
+                * userspace.
+                */
+               if (ret && rt_mutex_owner(pi_mutex) == current)
+                       rt_mutex_unlock(pi_mutex);
+
                /* Unqueue and drop the lock. */
                unqueue_me_pi(&q);
        }
 
-       /*
-        * If fixup_pi_state_owner() faulted and was unable to handle the
-        * fault, unlock the rt_mutex and return the fault to userspace.
-        */
-       if (ret == -EFAULT) {
-               if (pi_mutex && rt_mutex_owner(pi_mutex) == current)
-                       rt_mutex_unlock(pi_mutex);
-       } else if (ret == -EINTR) {
+       if (ret == -EINTR) {
                /*
                 * We've already been requeued, but cannot restart by calling
                 * futex_lock_pi() directly. We could restart this syscall, but
@@ -3180,4 +3203,4 @@ static int __init futex_init(void)
 
        return 0;
 }
-__initcall(futex_init);
+core_initcall(futex_init);