[PATCH 09/31] ntsync: Introduce NTSYNC_IOC_CREATE_EVENT.

This correspond to the NT syscall NtCreateEvent(). An NT event holds a single bit of state denoting whether it is signaled or unsignaled. There are two types of events: manual-reset and automatic-reset. When an automatic-reset event is acquired via a wait function, its state is reset to unsignaled. Manual-reset events are not affected by wait functions. Whether the event is manual-reset, and its initial state, are specified at creation time. Signed-off-by: Elizabeth Figura &lt;zfigura(a)codeweavers.com&gt; --- drivers/misc/ntsync.c | 60 +++++++++++++++++++++++++++++++++++++ include/uapi/linux/ntsync.h | 7 +++++ 2 files changed, 67 insertions(+) diff --git a/drivers/misc/ntsync.c b/drivers/misc/ntsync.c index 8cb951c76aca..2a21e7b0982a 100644 --- a/drivers/misc/ntsync.c +++ b/drivers/misc/ntsync.c @@ -25,6 +25,7 @@ enum ntsync_type { NTSYNC_TYPE_SEM, NTSYNC_TYPE_MUTEX, + NTSYNC_TYPE_EVENT, }; struct ntsync_obj { @@ -46,6 +47,10 @@ struct ntsync_obj { __u32 owner; bool ownerdead; } mutex; + struct { + bool manual; + bool signaled; + } event; } u; /* @@ -130,6 +135,8 @@ static bool is_signaled(struct ntsync_obj *obj, __u32 owner) if (obj->u.mutex.owner && obj->u.mutex.owner != owner) return false; return obj->u.mutex.count < UINT_MAX; + case NTSYNC_TYPE_EVENT: + return obj->u.event.signaled; } WARN(1, "bad object type %#x\n", obj->type); @@ -179,6 +186,10 @@ static void try_wake_all(struct ntsync_device *dev, struct ntsync_q *q, obj->u.mutex.count++; obj->u.mutex.owner = q->owner; break; + case NTSYNC_TYPE_EVENT: + if (!obj->u.event.manual) + obj->u.event.signaled = false; + break; } } wake_up_process(q->task); @@ -245,6 +256,26 @@ static void try_wake_any_mutex(struct ntsync_obj *mutex) } } +static void try_wake_any_event(struct ntsync_obj *event) +{ + struct ntsync_q_entry *entry; + + lockdep_assert_held(&event->lock); + + list_for_each_entry(entry, &event->any_waiters, node) { + struct ntsync_q *q = entry->q; + + if (!event->u.event.signaled) + break; + + if (atomic_cmpxchg(&q->signaled, -1, entry->index) == -1) { + if (!event->u.event.manual) + event->u.event.signaled = false; + wake_up_process(q->task); + } + } +} + /* * Actually change the semaphore state, returning -EOVERFLOW if it is made * invalid. @@ -553,6 +584,30 @@ static int ntsync_create_mutex(struct ntsync_device *dev, void __user *argp) return put_user(fd, &user_args->mutex); } +static int ntsync_create_event(struct ntsync_device *dev, void __user *argp) +{ + struct ntsync_event_args __user *user_args = argp; + struct ntsync_event_args args; + struct ntsync_obj *event; + int fd; + + if (copy_from_user(&args, argp, sizeof(args))) + return -EFAULT; + + event = ntsync_alloc_obj(dev, NTSYNC_TYPE_EVENT); + if (!event) + return -ENOMEM; + event->u.event.manual = args.manual; + event->u.event.signaled = args.signaled; + fd = ntsync_obj_get_fd(event); + if (fd < 0) { + kfree(event); + return fd; + } + + return put_user(fd, &user_args->event); +} + static struct ntsync_obj *get_obj(struct ntsync_device *dev, int fd) { struct file *file = fget(fd); @@ -676,6 +731,9 @@ static void try_wake_any_obj(struct ntsync_obj *obj) case NTSYNC_TYPE_MUTEX: try_wake_any_mutex(obj); break; + case NTSYNC_TYPE_EVENT: + try_wake_any_event(obj); + break; } } @@ -864,6 +922,8 @@ static long ntsync_char_ioctl(struct file *file, unsigned int cmd, void __user *argp = (void __user *)parm; switch (cmd) { + case NTSYNC_IOC_CREATE_EVENT: + return ntsync_create_event(dev, argp); case NTSYNC_IOC_CREATE_MUTEX: return ntsync_create_mutex(dev, argp); case NTSYNC_IOC_CREATE_SEM: diff --git a/include/uapi/linux/ntsync.h b/include/uapi/linux/ntsync.h index 3861397c6c2f..b8cf503365ef 100644 --- a/include/uapi/linux/ntsync.h +++ b/include/uapi/linux/ntsync.h @@ -22,6 +22,12 @@ struct ntsync_mutex_args { __u32 count; }; +struct ntsync_event_args { + __u32 event; + __u32 manual; + __u32 signaled; +}; + struct ntsync_wait_args { __u64 timeout; __u64 objs; @@ -37,6 +43,7 @@ struct ntsync_wait_args { #define NTSYNC_IOC_WAIT_ANY _IOWR('N', 0x82, struct ntsync_wait_args) #define NTSYNC_IOC_WAIT_ALL _IOWR('N', 0x83, struct ntsync_wait_args) #define NTSYNC_IOC_CREATE_MUTEX _IOWR('N', 0x84, struct ntsync_sem_args) +#define NTSYNC_IOC_CREATE_EVENT _IOWR('N', 0x87, struct ntsync_event_args) #define NTSYNC_IOC_SEM_POST _IOWR('N', 0x81, __u32) #define NTSYNC_IOC_MUTEX_UNLOCK _IOWR('N', 0x85, struct ntsync_mutex_args) -- 2.43.0