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-rw-r--r--kernel/futex/waitwake.c129
1 files changed, 77 insertions, 52 deletions
diff --git a/kernel/futex/waitwake.c b/kernel/futex/waitwake.c
index ba01b94082..61b112897a 100644
--- a/kernel/futex/waitwake.c
+++ b/kernel/futex/waitwake.c
@@ -106,20 +106,11 @@
* double_lock_hb() and double_unlock_hb(), respectively.
*/
-/*
- * The hash bucket lock must be held when this is called.
- * Afterwards, the futex_q must not be accessed. Callers
- * must ensure to later call wake_up_q() for the actual
- * wakeups to occur.
- */
-void futex_wake_mark(struct wake_q_head *wake_q, struct futex_q *q)
+bool __futex_wake_mark(struct futex_q *q)
{
- struct task_struct *p = q->task;
-
if (WARN(q->pi_state || q->rt_waiter, "refusing to wake PI futex\n"))
- return;
+ return false;
- get_task_struct(p);
__futex_unqueue(q);
/*
* The waiting task can free the futex_q as soon as q->lock_ptr = NULL
@@ -130,6 +121,26 @@ void futex_wake_mark(struct wake_q_head *wake_q, struct futex_q *q)
*/
smp_store_release(&q->lock_ptr, NULL);
+ return true;
+}
+
+/*
+ * The hash bucket lock must be held when this is called.
+ * Afterwards, the futex_q must not be accessed. Callers
+ * must ensure to later call wake_up_q() for the actual
+ * wakeups to occur.
+ */
+void futex_wake_mark(struct wake_q_head *wake_q, struct futex_q *q)
+{
+ struct task_struct *p = q->task;
+
+ get_task_struct(p);
+
+ if (!__futex_wake_mark(q)) {
+ put_task_struct(p);
+ return;
+ }
+
/*
* Queue the task for later wakeup for after we've released
* the hb->lock.
@@ -145,16 +156,19 @@ int futex_wake(u32 __user *uaddr, unsigned int flags, int nr_wake, u32 bitset)
struct futex_hash_bucket *hb;
struct futex_q *this, *next;
union futex_key key = FUTEX_KEY_INIT;
- int ret;
DEFINE_WAKE_Q(wake_q);
+ int ret;
if (!bitset)
return -EINVAL;
- ret = get_futex_key(uaddr, flags & FLAGS_SHARED, &key, FUTEX_READ);
+ ret = get_futex_key(uaddr, flags, &key, FUTEX_READ);
if (unlikely(ret != 0))
return ret;
+ if ((flags & FLAGS_STRICT) && !nr_wake)
+ return 0;
+
hb = futex_hash(&key);
/* Make sure we really have tasks to wakeup */
@@ -174,7 +188,7 @@ int futex_wake(u32 __user *uaddr, unsigned int flags, int nr_wake, u32 bitset)
if (!(this->bitset & bitset))
continue;
- futex_wake_mark(&wake_q, this);
+ this->wake(&wake_q, this);
if (++ret >= nr_wake)
break;
}
@@ -245,10 +259,10 @@ int futex_wake_op(u32 __user *uaddr1, unsigned int flags, u32 __user *uaddr2,
DEFINE_WAKE_Q(wake_q);
retry:
- ret = get_futex_key(uaddr1, flags & FLAGS_SHARED, &key1, FUTEX_READ);
+ ret = get_futex_key(uaddr1, flags, &key1, FUTEX_READ);
if (unlikely(ret != 0))
return ret;
- ret = get_futex_key(uaddr2, flags & FLAGS_SHARED, &key2, FUTEX_WRITE);
+ ret = get_futex_key(uaddr2, flags, &key2, FUTEX_WRITE);
if (unlikely(ret != 0))
return ret;
@@ -289,7 +303,7 @@ retry_private:
ret = -EINVAL;
goto out_unlock;
}
- futex_wake_mark(&wake_q, this);
+ this->wake(&wake_q, this);
if (++ret >= nr_wake)
break;
}
@@ -303,7 +317,7 @@ retry_private:
ret = -EINVAL;
goto out_unlock;
}
- futex_wake_mark(&wake_q, this);
+ this->wake(&wake_q, this);
if (++op_ret >= nr_wake2)
break;
}
@@ -358,7 +372,7 @@ void futex_wait_queue(struct futex_hash_bucket *hb, struct futex_q *q,
}
/**
- * unqueue_multiple - Remove various futexes from their hash bucket
+ * futex_unqueue_multiple - Remove various futexes from their hash bucket
* @v: The list of futexes to unqueue
* @count: Number of futexes in the list
*
@@ -368,7 +382,7 @@ void futex_wait_queue(struct futex_hash_bucket *hb, struct futex_q *q,
* - >=0 - Index of the last futex that was awoken;
* - -1 - No futex was awoken
*/
-static int unqueue_multiple(struct futex_vector *v, int count)
+int futex_unqueue_multiple(struct futex_vector *v, int count)
{
int ret = -1, i;
@@ -396,7 +410,7 @@ static int unqueue_multiple(struct futex_vector *v, int count)
* - 0 - Success
* - <0 - -EFAULT, -EWOULDBLOCK or -EINVAL
*/
-static int futex_wait_multiple_setup(struct futex_vector *vs, int count, int *woken)
+int futex_wait_multiple_setup(struct futex_vector *vs, int count, int *woken)
{
struct futex_hash_bucket *hb;
bool retry = false;
@@ -419,11 +433,11 @@ static int futex_wait_multiple_setup(struct futex_vector *vs, int count, int *wo
*/
retry:
for (i = 0; i < count; i++) {
- if ((vs[i].w.flags & FUTEX_PRIVATE_FLAG) && retry)
+ if (!(vs[i].w.flags & FLAGS_SHARED) && retry)
continue;
ret = get_futex_key(u64_to_user_ptr(vs[i].w.uaddr),
- !(vs[i].w.flags & FUTEX_PRIVATE_FLAG),
+ vs[i].w.flags,
&vs[i].q.key, FUTEX_READ);
if (unlikely(ret))
@@ -435,7 +449,7 @@ retry:
for (i = 0; i < count; i++) {
u32 __user *uaddr = (u32 __user *)(unsigned long)vs[i].w.uaddr;
struct futex_q *q = &vs[i].q;
- u32 val = (u32)vs[i].w.val;
+ u32 val = vs[i].w.val;
hb = futex_q_lock(q);
ret = futex_get_value_locked(&uval, uaddr);
@@ -458,7 +472,7 @@ retry:
* was woken, we don't return error and return this index to
* userspace
*/
- *woken = unqueue_multiple(vs, i);
+ *woken = futex_unqueue_multiple(vs, i);
if (*woken >= 0)
return 1;
@@ -543,7 +557,7 @@ int futex_wait_multiple(struct futex_vector *vs, unsigned int count,
__set_current_state(TASK_RUNNING);
- ret = unqueue_multiple(vs, count);
+ ret = futex_unqueue_multiple(vs, count);
if (ret >= 0)
return ret;
@@ -599,7 +613,7 @@ int futex_wait_setup(u32 __user *uaddr, u32 val, unsigned int flags,
* while the syscall executes.
*/
retry:
- ret = get_futex_key(uaddr, flags & FLAGS_SHARED, &q->key, FUTEX_READ);
+ ret = get_futex_key(uaddr, flags, &q->key, FUTEX_READ);
if (unlikely(ret != 0))
return ret;
@@ -629,20 +643,18 @@ retry_private:
return ret;
}
-int futex_wait(u32 __user *uaddr, unsigned int flags, u32 val, ktime_t *abs_time, u32 bitset)
+int __futex_wait(u32 __user *uaddr, unsigned int flags, u32 val,
+ struct hrtimer_sleeper *to, u32 bitset)
{
- struct hrtimer_sleeper timeout, *to;
- struct restart_block *restart;
- struct futex_hash_bucket *hb;
struct futex_q q = futex_q_init;
+ struct futex_hash_bucket *hb;
int ret;
if (!bitset)
return -EINVAL;
+
q.bitset = bitset;
- to = futex_setup_timer(abs_time, &timeout, flags,
- current->timer_slack_ns);
retry:
/*
* Prepare to wait on uaddr. On success, it holds hb->lock and q
@@ -650,18 +662,17 @@ retry:
*/
ret = futex_wait_setup(uaddr, val, flags, &q, &hb);
if (ret)
- goto out;
+ return ret;
/* futex_queue and wait for wakeup, timeout, or a signal. */
futex_wait_queue(hb, &q, to);
/* If we were woken (and unqueued), we succeeded, whatever. */
- ret = 0;
if (!futex_unqueue(&q))
- goto out;
- ret = -ETIMEDOUT;
+ return 0;
+
if (to && !to->task)
- goto out;
+ return -ETIMEDOUT;
/*
* We expect signal_pending(current), but we might be the
@@ -670,24 +681,38 @@ retry:
if (!signal_pending(current))
goto retry;
- ret = -ERESTARTSYS;
- if (!abs_time)
- goto out;
+ return -ERESTARTSYS;
+}
- restart = &current->restart_block;
- restart->futex.uaddr = uaddr;
- restart->futex.val = val;
- restart->futex.time = *abs_time;
- restart->futex.bitset = bitset;
- restart->futex.flags = flags | FLAGS_HAS_TIMEOUT;
+int futex_wait(u32 __user *uaddr, unsigned int flags, u32 val, ktime_t *abs_time, u32 bitset)
+{
+ struct hrtimer_sleeper timeout, *to;
+ struct restart_block *restart;
+ int ret;
- ret = set_restart_fn(restart, futex_wait_restart);
+ to = futex_setup_timer(abs_time, &timeout, flags,
+ current->timer_slack_ns);
-out:
- if (to) {
- hrtimer_cancel(&to->timer);
- destroy_hrtimer_on_stack(&to->timer);
+ ret = __futex_wait(uaddr, flags, val, to, bitset);
+
+ /* No timeout, nothing to clean up. */
+ if (!to)
+ return ret;
+
+ hrtimer_cancel(&to->timer);
+ destroy_hrtimer_on_stack(&to->timer);
+
+ if (ret == -ERESTARTSYS) {
+ restart = &current->restart_block;
+ restart->futex.uaddr = uaddr;
+ restart->futex.val = val;
+ restart->futex.time = *abs_time;
+ restart->futex.bitset = bitset;
+ restart->futex.flags = flags | FLAGS_HAS_TIMEOUT;
+
+ return set_restart_fn(restart, futex_wait_restart);
}
+
return ret;
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-01 02:15:35 +0000