Commit 5fae054c authored by Dan Carpenter's avatar Dan Carpenter Committed by Greg Kroah-Hartman

goldfish: locking bugs in goldfish_pipe_read_write()

We recently messed up the error handling here.  We can return with the
pipe->lock held or sometimes we unlock twice by mistake.

Fixes: 2f3be882 ('goldfish_pipe: Pin pages to memory while copying and other cleanups')
Signed-off-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent d40a0946
...@@ -313,7 +313,7 @@ static ssize_t goldfish_pipe_read_write(struct file *filp, char __user *buffer, ...@@ -313,7 +313,7 @@ static ssize_t goldfish_pipe_read_write(struct file *filp, char __user *buffer,
!is_write, 0, &page, NULL); !is_write, 0, &page, NULL);
up_read(&current->mm->mmap_sem); up_read(&current->mm->mmap_sem);
if (ret < 0) if (ret < 0)
return ret; break;
if (dev->version) { if (dev->version) {
/* Device version 1 or newer (qemu-android) expects the /* Device version 1 or newer (qemu-android) expects the
...@@ -400,22 +400,16 @@ static ssize_t goldfish_pipe_read_write(struct file *filp, char __user *buffer, ...@@ -400,22 +400,16 @@ static ssize_t goldfish_pipe_read_write(struct file *filp, char __user *buffer,
while (test_bit(wakeBit, &pipe->flags)) { while (test_bit(wakeBit, &pipe->flags)) {
if (wait_event_interruptible( if (wait_event_interruptible(
pipe->wake_queue, pipe->wake_queue,
!test_bit(wakeBit, &pipe->flags))) { !test_bit(wakeBit, &pipe->flags)))
ret = -ERESTARTSYS; return -ERESTARTSYS;
break;
}
if (test_bit(BIT_CLOSED_ON_HOST, &pipe->flags)) { if (test_bit(BIT_CLOSED_ON_HOST, &pipe->flags))
ret = -EIO; return -EIO;
break;
}
} }
/* Try to re-acquire the lock */ /* Try to re-acquire the lock */
if (mutex_lock_interruptible(&pipe->lock)) { if (mutex_lock_interruptible(&pipe->lock))
ret = -ERESTARTSYS; return -ERESTARTSYS;
break;
}
} }
mutex_unlock(&pipe->lock); mutex_unlock(&pipe->lock);
......
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