[PATCH v4 12/27] ntsync: Introduce NTSYNC_IOC_EVENT_READ.

[Elizabeth Figura]

This corresponds to the NT syscall NtQueryEvent().

This returns the signaled state of the event and whether it is manual-reset.

Signed-off-by: Elizabeth Figura <zfig...@codeweavers.com>
---
 drivers/misc/ntsync.c       | 21 +++++++++++++++++++++
 include/uapi/linux/ntsync.h |  1 +
 2 files changed, 22 insertions(+)

diff --git a/drivers/misc/ntsync.c b/drivers/misc/ntsync.c
index bd043dccc9fa..a03c6fceb518 100644
--- a/drivers/misc/ntsync.c
+++ b/drivers/misc/ntsync.c
@@ -572,6 +572,25 @@ static int ntsync_mutex_read(struct ntsync_obj *mutex, 
void __user *argp)
        return ret;
 }
 
+static int ntsync_event_read(struct ntsync_obj *event, void __user *argp)
+{
+       struct ntsync_event_args __user *user_args = argp;
+       struct ntsync_event_args args;
+
+       if (event->type != NTSYNC_TYPE_EVENT)
+               return -EINVAL;
+
+       args.event = 0;
+       spin_lock(&event->lock);
+       args.manual = event->u.event.manual;
+       args.signaled = event->u.event.signaled;
+       spin_unlock(&event->lock);
+
+       if (copy_to_user(user_args, &args, sizeof(args)))
+               return -EFAULT;
+       return 0;
+}
+
 static int ntsync_obj_release(struct inode *inode, struct file *file)
 {
        struct ntsync_obj *obj = file->private_data;
@@ -605,6 +624,8 @@ static long ntsync_obj_ioctl(struct file *file, unsigned 
int cmd,
                return ntsync_event_reset(obj, argp);
        case NTSYNC_IOC_EVENT_PULSE:
                return ntsync_event_set(obj, argp, true);
+       case NTSYNC_IOC_EVENT_READ:
+               return ntsync_event_read(obj, argp);
        default:
                return -ENOIOCTLCMD;
        }
diff --git a/include/uapi/linux/ntsync.h b/include/uapi/linux/ntsync.h
index 797e8df10a3a..80f36de46a75 100644
--- a/include/uapi/linux/ntsync.h
+++ b/include/uapi/linux/ntsync.h
@@ -57,5 +57,6 @@ struct ntsync_wait_args {
 #define NTSYNC_IOC_EVENT_PULSE         _IOR ('N', 0x8a, __u32)
 #define NTSYNC_IOC_SEM_READ            _IOR ('N', 0x8b, struct ntsync_sem_args)
 #define NTSYNC_IOC_MUTEX_READ          _IOR ('N', 0x8c, struct 
ntsync_mutex_args)
+#define NTSYNC_IOC_EVENT_READ          _IOR ('N', 0x8d, struct 
ntsync_event_args)
 
 #endif
-- 
2.43.0