[PATCH v4 08/27] ntsync: Introduce NTSYNC_IOC_EVENT_RESET.

[Elizabeth Figura]

This corresponds to the NT syscall NtResetEvent().

This sets the event to the unsignaled state, and returns its previous state.

Signed-off-by: Elizabeth Figura <zfig...@codeweavers.com>
---
 drivers/misc/ntsync.c       | 22 ++++++++++++++++++++++
 include/uapi/linux/ntsync.h |  1 +
 2 files changed, 23 insertions(+)

diff --git a/drivers/misc/ntsync.c b/drivers/misc/ntsync.c
index 69f359241cf6..ae78425c87d1 100644
--- a/drivers/misc/ntsync.c
+++ b/drivers/misc/ntsync.c
@@ -508,6 +508,26 @@ static int ntsync_event_set(struct ntsync_obj *event, void 
__user *argp)
        return 0;
 }
 
+static int ntsync_event_reset(struct ntsync_obj *event, void __user *argp)
+{
+       __u32 prev_state;
+
+       if (event->type != NTSYNC_TYPE_EVENT)
+               return -EINVAL;
+
+       spin_lock(&event->lock);
+
+       prev_state = event->u.event.signaled;
+       event->u.event.signaled = false;
+
+       spin_unlock(&event->lock);
+
+       if (put_user(prev_state, (__u32 __user *)argp))
+               return -EFAULT;
+
+       return 0;
+}
+
 static int ntsync_obj_release(struct inode *inode, struct file *file)
 {
        struct ntsync_obj *obj = file->private_data;
@@ -533,6 +553,8 @@ static long ntsync_obj_ioctl(struct file *file, unsigned 
int cmd,
                return ntsync_mutex_kill(obj, argp);
        case NTSYNC_IOC_EVENT_SET:
                return ntsync_event_set(obj, argp);
+       case NTSYNC_IOC_EVENT_RESET:
+               return ntsync_event_reset(obj, argp);
        default:
                return -ENOIOCTLCMD;
        }
diff --git a/include/uapi/linux/ntsync.h b/include/uapi/linux/ntsync.h
index 65329d15a472..657542107328 100644
--- a/include/uapi/linux/ntsync.h
+++ b/include/uapi/linux/ntsync.h
@@ -53,5 +53,6 @@ struct ntsync_wait_args {
 #define NTSYNC_IOC_MUTEX_UNLOCK                _IOWR('N', 0x85, struct 
ntsync_mutex_args)
 #define NTSYNC_IOC_MUTEX_KILL          _IOW ('N', 0x86, __u32)
 #define NTSYNC_IOC_EVENT_SET           _IOR ('N', 0x88, __u32)
+#define NTSYNC_IOC_EVENT_RESET         _IOR ('N', 0x89, __u32)
 
 #endif
-- 
2.43.0