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 --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