[RFC PATCH v2 15/29] ntsync: Introduce NTSYNC_IOC_EVENT_READ.

From: Elizabeth Figura
Date: Tue Jan 30 2024 - 21:21:09 EST


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 <zfigura@xxxxxxxxxxxxxxx>
---
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 7f5f96ec7c69..5439c1c9e90f 100644
--- a/drivers/misc/ntsync.c
+++ b/drivers/misc/ntsync.c
@@ -546,6 +546,25 @@ 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;
@@ -579,6 +598,8 @@ 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 a1d0ef581212..582d33b0dcac 100644
--- a/include/uapi/linux/ntsync.h
+++ b/include/uapi/linux/ntsync.h
@@ -53,5 +53,6 @@ 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