From 03dd4cb26d967f9588437b0fc9cc0e8353322bb7 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Andr=C3=A9=20Fabian=20Silva=20Delgado?= Date: Fri, 25 Mar 2016 03:53:42 -0300 Subject: Linux-libre 4.5-gnu --- drivers/gpu/drm/drm_fops.c | 58 +++++++++++++++++++++++++++++----------------- 1 file changed, 37 insertions(+), 21 deletions(-) (limited to 'drivers/gpu/drm/drm_fops.c') diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c index 6b5625e66..1ea8790e5 100644 --- a/drivers/gpu/drm/drm_fops.c +++ b/drivers/gpu/drm/drm_fops.c @@ -226,6 +226,8 @@ static int drm_open_helper(struct file *filp, struct drm_minor *minor) init_waitqueue_head(&priv->event_wait); priv->event_space = 4096; /* set aside 4k for event buffer */ + mutex_init(&priv->event_read_lock); + if (drm_core_check_feature(dev, DRIVER_GEM)) drm_gem_open(dev, priv); @@ -511,14 +513,28 @@ ssize_t drm_read(struct file *filp, char __user *buffer, { struct drm_file *file_priv = filp->private_data; struct drm_device *dev = file_priv->minor->dev; - ssize_t ret = 0; + ssize_t ret; if (!access_ok(VERIFY_WRITE, buffer, count)) return -EFAULT; - spin_lock_irq(&dev->event_lock); + ret = mutex_lock_interruptible(&file_priv->event_read_lock); + if (ret) + return ret; + for (;;) { - if (list_empty(&file_priv->event_list)) { + struct drm_pending_event *e = NULL; + + spin_lock_irq(&dev->event_lock); + if (!list_empty(&file_priv->event_list)) { + e = list_first_entry(&file_priv->event_list, + struct drm_pending_event, link); + file_priv->event_space += e->event->length; + list_del(&e->link); + } + spin_unlock_irq(&dev->event_lock); + + if (e == NULL) { if (ret) break; @@ -527,36 +543,36 @@ ssize_t drm_read(struct file *filp, char __user *buffer, break; } - spin_unlock_irq(&dev->event_lock); + mutex_unlock(&file_priv->event_read_lock); ret = wait_event_interruptible(file_priv->event_wait, !list_empty(&file_priv->event_list)); - spin_lock_irq(&dev->event_lock); - if (ret < 0) - break; - - ret = 0; + if (ret >= 0) + ret = mutex_lock_interruptible(&file_priv->event_read_lock); + if (ret) + return ret; } else { - struct drm_pending_event *e; - - e = list_first_entry(&file_priv->event_list, - struct drm_pending_event, link); - if (e->event->length + ret > count) + unsigned length = e->event->length; + + if (length > count - ret) { +put_back_event: + spin_lock_irq(&dev->event_lock); + file_priv->event_space -= length; + list_add(&e->link, &file_priv->event_list); + spin_unlock_irq(&dev->event_lock); break; + } - if (__copy_to_user_inatomic(buffer + ret, - e->event, e->event->length)) { + if (copy_to_user(buffer + ret, e->event, length)) { if (ret == 0) ret = -EFAULT; - break; + goto put_back_event; } - file_priv->event_space += e->event->length; - ret += e->event->length; - list_del(&e->link); + ret += length; e->destroy(e); } } - spin_unlock_irq(&dev->event_lock); + mutex_unlock(&file_priv->event_read_lock); return ret; } -- cgit v1.2.3