diff mbox series

[v3,13/30] ntsync: Introduce NTSYNC_IOC_SEM_READ.

Message ID 20240329000621.148791-14-zfigura@codeweavers.com (mailing list archive)
State New
Headers show
Series NT synchronization primitive driver | expand

Commit Message

Elizabeth Figura March 29, 2024, 12:06 a.m. UTC 
This corresponds to the NT syscall NtQuerySemaphore().

This returns the current count and maximum count of the semaphore.

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

Patch

diff --git a/drivers/misc/ntsync.c b/drivers/misc/ntsync.c
index adba4657bf26..961e8d241602 100644
--- a/drivers/misc/ntsync.c
+++ b/drivers/misc/ntsync.c
@@ -532,6 +532,25 @@  static int ntsync_event_reset(struct ntsync_obj *event, void __user *argp)
 	return 0;
 }
 
+static int ntsync_sem_read(struct ntsync_obj *sem, void __user *argp)
+{
+	struct ntsync_sem_args __user *user_args = argp;
+	struct ntsync_sem_args args;
+
+	if (sem->type != NTSYNC_TYPE_SEM)
+		return -EINVAL;
+
+	args.sem = 0;
+	spin_lock(&sem->lock);
+	args.count = sem->u.sem.count;
+	args.max = sem->u.sem.max;
+	spin_unlock(&sem->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;
@@ -551,6 +570,8 @@  static long ntsync_obj_ioctl(struct file *file, unsigned int cmd,
 	switch (cmd) {
 	case NTSYNC_IOC_SEM_POST:
 		return ntsync_sem_post(obj, argp);
+	case NTSYNC_IOC_SEM_READ:
+		return ntsync_sem_read(obj, argp);
 	case NTSYNC_IOC_MUTEX_UNLOCK:
 		return ntsync_mutex_unlock(obj, argp);
 	case NTSYNC_IOC_MUTEX_KILL:
diff --git a/include/uapi/linux/ntsync.h b/include/uapi/linux/ntsync.h
index 57721f5d31ba..e298400bf25a 100644
--- a/include/uapi/linux/ntsync.h
+++ b/include/uapi/linux/ntsync.h
@@ -55,5 +55,6 @@  struct ntsync_wait_args {
 #define NTSYNC_IOC_EVENT_SET		_IOR ('N', 0x88, __u32)
 #define NTSYNC_IOC_EVENT_RESET		_IOR ('N', 0x89, __u32)
 #define NTSYNC_IOC_EVENT_PULSE		_IOR ('N', 0x8a, __u32)
+#define NTSYNC_IOC_SEM_READ		_IOR ('N', 0x8b, struct ntsync_sem_args)
 
 #endif