[PATCH v3 14/30] ntsync: Introduce NTSYNC_IOC_MUTEX_READ.
From: Elizabeth Figura <zfigura@codeweavers.com>
Date: 2024-03-29 00:24:23
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 NtQueryMutant(). This returns the recursion count, owner, and abandoned state of the mutex. Signed-off-by: Elizabeth Figura <zfigura@codeweavers.com> --- drivers/misc/ntsync.c | 23 +++++++++++++++++++++++ include/uapi/linux/ntsync.h | 1 + 2 files changed, 24 insertions(+)
diff --git a/drivers/misc/ntsync.c b/drivers/misc/ntsync.c
index 961e8d241602..bd043dccc9fa 100644
--- a/drivers/misc/ntsync.c
+++ b/drivers/misc/ntsync.c@@ -551,6 +551,27 @@ static int ntsync_sem_read(struct ntsync_obj *sem, void __user *argp) return 0; } +static int ntsync_mutex_read(struct ntsync_obj *mutex, void __user *argp) +{ + struct ntsync_mutex_args __user *user_args = argp; + struct ntsync_mutex_args args; + int ret; + + if (mutex->type != NTSYNC_TYPE_MUTEX) + return -EINVAL; + + args.mutex = 0; + spin_lock(&mutex->lock); + args.count = mutex->u.mutex.count; + args.owner = mutex->u.mutex.owner; + ret = mutex->u.mutex.ownerdead ? -EOWNERDEAD : 0; + spin_unlock(&mutex->lock); + + if (copy_to_user(user_args, &args, sizeof(args))) + return -EFAULT; + return ret; +} + static int ntsync_obj_release(struct inode *inode, struct file *file) { struct ntsync_obj *obj = file->private_data;
@@ -576,6 +597,8 @@ 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_MUTEX_READ: + return ntsync_mutex_read(obj, argp); case NTSYNC_IOC_EVENT_SET: return ntsync_event_set(obj, argp, false); case NTSYNC_IOC_EVENT_RESET:
diff --git a/include/uapi/linux/ntsync.h b/include/uapi/linux/ntsync.h
index e298400bf25a..797e8df10a3a 100644
--- a/include/uapi/linux/ntsync.h
+++ b/include/uapi/linux/ntsync.h@@ -56,5 +56,6 @@ struct ntsync_wait_args { #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) +#define NTSYNC_IOC_MUTEX_READ _IOR ('N', 0x8c, struct ntsync_mutex_args) #endif
--
2.43.0