[PATCH v6 10/28] ntsync: Introduce NTSYNC_IOC_SEM_READ.
From: Elizabeth Figura <zfigura@codeweavers.com>
Date: 2024-12-09 19:03:04
Also in:
linux-doc, linux-kselftest, lkml
Subsystem:
char and misc drivers, ntsync synchronization primitive driver, the rest · Maintainers:
Arnd Bergmann, Greg Kroah-Hartman, Elizabeth Figura, Linus Torvalds
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 | 26 ++++++++++++++++++++++++++ include/uapi/linux/ntsync.h | 1 + 2 files changed, 27 insertions(+)
diff --git a/drivers/misc/ntsync.c b/drivers/misc/ntsync.c
index 6b8352270874..d6e8a4bde1d0 100644
--- a/drivers/misc/ntsync.c
+++ b/drivers/misc/ntsync.c@@ -583,6 +583,30 @@ 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_device *dev = sem->dev; + struct ntsync_sem_args args; + bool all; + + if (sem->type != NTSYNC_TYPE_SEM) + return -EINVAL; + + args.sem = 0; + + all = ntsync_lock_obj(dev, sem); + + args.count = sem->u.sem.count; + args.max = sem->u.sem.max; + + ntsync_unlock_obj(dev, sem, all); + + 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;
@@ -602,6 +626,8 @@ 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 5586fadd9bdd..5e922703686f 100644
--- a/include/uapi/linux/ntsync.h
+++ b/include/uapi/linux/ntsync.h@@ -54,5 +54,6 @@ 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
--
2.45.2