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

From: Elizabeth Figura
Date: Mon Apr 15 2024 - 21:12:57 EST


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 <zfigura@xxxxxxxxxxxxxxx>
---
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