[PATCH v4 07/27] ntsync: Introduce NTSYNC_IOC_EVENT_SET.

From: Elizabeth Figura
Date: Mon Apr 15 2024 - 21:14:59 EST


This corresponds to the NT syscall NtSetEvent().

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

Signed-off-by: Elizabeth Figura <zfigura@xxxxxxxxxxxxxxx>
---
drivers/misc/ntsync.c | 37 +++++++++++++++++++++++++++++++++++++
include/uapi/linux/ntsync.h | 1 +
2 files changed, 38 insertions(+)

diff --git a/drivers/misc/ntsync.c b/drivers/misc/ntsync.c
index 3e125c805c00..69f359241cf6 100644
--- a/drivers/misc/ntsync.c
+++ b/drivers/misc/ntsync.c
@@ -473,6 +473,41 @@ static int ntsync_mutex_kill(struct ntsync_obj *mutex, void __user *argp)
return ret;
}

+static int ntsync_event_set(struct ntsync_obj *event, void __user *argp)
+{
+ struct ntsync_device *dev = event->dev;
+ __u32 prev_state;
+
+ if (event->type != NTSYNC_TYPE_EVENT)
+ return -EINVAL;
+
+ if (atomic_read(&event->all_hint) > 0) {
+ spin_lock(&dev->wait_all_lock);
+ spin_lock_nest_lock(&event->lock, &dev->wait_all_lock);
+
+ prev_state = event->u.event.signaled;
+ event->u.event.signaled = true;
+ try_wake_all_obj(dev, event);
+ try_wake_any_event(event);
+
+ spin_unlock(&event->lock);
+ spin_unlock(&dev->wait_all_lock);
+ } else {
+ spin_lock(&event->lock);
+
+ prev_state = event->u.event.signaled;
+ event->u.event.signaled = true;
+ try_wake_any_event(event);
+
+ 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;
@@ -496,6 +531,8 @@ static long ntsync_obj_ioctl(struct file *file, unsigned int cmd,
return ntsync_mutex_unlock(obj, argp);
case NTSYNC_IOC_MUTEX_KILL:
return ntsync_mutex_kill(obj, argp);
+ case NTSYNC_IOC_EVENT_SET:
+ return ntsync_event_set(obj, argp);
default:
return -ENOIOCTLCMD;
}
diff --git a/include/uapi/linux/ntsync.h b/include/uapi/linux/ntsync.h
index 0d133f2eaf0b..65329d15a472 100644
--- a/include/uapi/linux/ntsync.h
+++ b/include/uapi/linux/ntsync.h
@@ -52,5 +52,6 @@ struct ntsync_wait_args {
#define NTSYNC_IOC_SEM_POST _IOWR('N', 0x81, __u32)
#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)

#endif
--
2.43.0