December 2024 - Wine-Devel - list.winehq.org

[PATCH v7 13/30] ntsync: Introduce NTSYNC_IOC_MUTEX_READ.

by Elizabeth Figura

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(a)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 b2043412c5cd..0047b13b6ebd 100644 --- a/drivers/misc/ntsync.c +++ b/drivers/misc/ntsync.c @@ -605,6 +605,30 @@ 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_device *dev = mutex->dev; + struct ntsync_mutex_args args; + bool all; + int ret; + + if (mutex->type != NTSYNC_TYPE_MUTEX) + return -EINVAL; + + all = ntsync_lock_obj(dev, mutex); + + args.count = mutex->u.mutex.count; + args.owner = mutex->u.mutex.owner; + ret = mutex->u.mutex.ownerdead ? -EOWNERDEAD : 0; + + ntsync_unlock_obj(dev, mutex, all); + + 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; @@ -630,6 +654,8 @@ 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 e36b4cfb7d34..207646e63ef3 100644 --- a/include/uapi/linux/ntsync.h +++ b/include/uapi/linux/ntsync.h @@ -52,5 +52,6 @@ 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 -- 2.45.2

Dec. 13, 2024

[PATCH v7 12/30] ntsync: Introduce NTSYNC_IOC_SEM_READ.

by Elizabeth Figura

This corresponds to the NT syscall NtQuerySemaphore(). This returns the current count and maximum count of the semaphore. Signed-off-by: Elizabeth Figura <zfigura(a)codeweavers.com> --- drivers/misc/ntsync.c | 24 ++++++++++++++++++++++++ include/uapi/linux/ntsync.h | 1 + 2 files changed, 25 insertions(+) diff --git a/drivers/misc/ntsync.c b/drivers/misc/ntsync.c index 141ebe8a7d4f..b2043412c5cd 100644 --- a/drivers/misc/ntsync.c +++ b/drivers/misc/ntsync.c @@ -583,6 +583,28 @@ 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; + + 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 +624,8 @@ static long ntsync_obj_ioctl(struct file *file, unsigned int cmd, switch (cmd) { case NTSYNC_IOC_SEM_RELEASE: return ntsync_sem_release(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 9eab7666b8b9..e36b4cfb7d34 100644 --- a/include/uapi/linux/ntsync.h +++ b/include/uapi/linux/ntsync.h @@ -51,5 +51,6 @@ 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

Dec. 13, 2024

[PATCH v7 11/30] ntsync: Introduce NTSYNC_IOC_EVENT_PULSE.

by Elizabeth Figura

This corresponds to the NT syscall NtPulseEvent(). This wakes up any waiters as if the event had been set, but does not set the event, instead resetting it if it had been signalled. Thus, for a manual-reset event, all waiters are woken, whereas for an auto-reset event, at most one waiter is woken. Signed-off-by: Elizabeth Figura <zfigura(a)codeweavers.com> --- drivers/misc/ntsync.c | 8 ++++++-- include/uapi/linux/ntsync.h | 1 + 2 files changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/misc/ntsync.c b/drivers/misc/ntsync.c index b31443aa9692..141ebe8a7d4f 100644 --- a/drivers/misc/ntsync.c +++ b/drivers/misc/ntsync.c @@ -534,7 +534,7 @@ static int ntsync_mutex_kill(struct ntsync_obj *mutex, void __user *argp) return ret; } -static int ntsync_event_set(struct ntsync_obj *event, void __user *argp) +static int ntsync_event_set(struct ntsync_obj *event, void __user *argp, bool pulse) { struct ntsync_device *dev = event->dev; __u32 prev_state; @@ -550,6 +550,8 @@ static int ntsync_event_set(struct ntsync_obj *event, void __user *argp) if (all) try_wake_all_obj(dev, event); try_wake_any_event(event); + if (pulse) + event->u.event.signaled = false; ntsync_unlock_obj(dev, event, all); @@ -605,9 +607,11 @@ static long ntsync_obj_ioctl(struct file *file, unsigned int cmd, case NTSYNC_IOC_MUTEX_KILL: return ntsync_mutex_kill(obj, argp); case NTSYNC_IOC_EVENT_SET: - return ntsync_event_set(obj, argp); + return ntsync_event_set(obj, argp, false); case NTSYNC_IOC_EVENT_RESET: return ntsync_event_reset(obj, argp); + case NTSYNC_IOC_EVENT_PULSE: + return ntsync_event_set(obj, argp, true); default: return -ENOIOCTLCMD; } diff --git a/include/uapi/linux/ntsync.h b/include/uapi/linux/ntsync.h index d74c4e4f93d8..9eab7666b8b9 100644 --- a/include/uapi/linux/ntsync.h +++ b/include/uapi/linux/ntsync.h @@ -50,5 +50,6 @@ struct ntsync_wait_args { #define NTSYNC_IOC_MUTEX_KILL _IOW ('N', 0x86, __u32) #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) #endif -- 2.45.2

Dec. 13, 2024

[PATCH v7 10/30] ntsync: Introduce NTSYNC_IOC_EVENT_RESET.

by Elizabeth Figura

This corresponds to the NT syscall NtResetEvent(). This sets the event to the unsignaled state, and returns its previous state. Signed-off-by: Elizabeth Figura <zfigura(a)codeweavers.com> --- drivers/misc/ntsync.c | 24 ++++++++++++++++++++++++ include/uapi/linux/ntsync.h | 1 + 2 files changed, 25 insertions(+) diff --git a/drivers/misc/ntsync.c b/drivers/misc/ntsync.c index 0a87f8ad5993..b31443aa9692 100644 --- a/drivers/misc/ntsync.c +++ b/drivers/misc/ntsync.c @@ -559,6 +559,28 @@ static int ntsync_event_set(struct ntsync_obj *event, void __user *argp) return 0; } +static int ntsync_event_reset(struct ntsync_obj *event, void __user *argp) +{ + struct ntsync_device *dev = event->dev; + __u32 prev_state; + bool all; + + if (event->type != NTSYNC_TYPE_EVENT) + return -EINVAL; + + all = ntsync_lock_obj(dev, event); + + prev_state = event->u.event.signaled; + event->u.event.signaled = false; + + ntsync_unlock_obj(dev, event, all); + + if (put_user(prev_state, (__u32 __user *)argp)) + return -EFAULT; + + return 0; +} + static int ntsync_obj_release(struct inode *inode, struct file *file) { struct ntsync_obj *obj = file->private_data; @@ -584,6 +606,8 @@ static long ntsync_obj_ioctl(struct file *file, unsigned int cmd, return ntsync_mutex_kill(obj, argp); case NTSYNC_IOC_EVENT_SET: return ntsync_event_set(obj, argp); + case NTSYNC_IOC_EVENT_RESET: + return ntsync_event_reset(obj, argp); default: return -ENOIOCTLCMD; } diff --git a/include/uapi/linux/ntsync.h b/include/uapi/linux/ntsync.h index db2512f6e3f4..d74c4e4f93d8 100644 --- a/include/uapi/linux/ntsync.h +++ b/include/uapi/linux/ntsync.h @@ -49,5 +49,6 @@ struct ntsync_wait_args { #define NTSYNC_IOC_MUTEX_UNLOCK _IOWR('N', 0x85, struct ntsync_mutex_args) #define NTSYNC_IOC_MUTEX_KILL _IOW ('N', 0x86, __u32) #define NTSYNC_IOC_EVENT_SET _IOR ('N', 0x88, __u32) +#define NTSYNC_IOC_EVENT_RESET _IOR ('N', 0x89, __u32) #endif -- 2.45.2

Dec. 13, 2024

[PATCH v7 09/30] ntsync: Introduce NTSYNC_IOC_EVENT_SET.

by Elizabeth Figura

This corresponds to the NT syscall NtSetEvent(). This sets the event to the signaled state, and returns its previous state. Signed-off-by: Elizabeth Figura <zfigura(a)codeweavers.com> --- drivers/misc/ntsync.c | 27 +++++++++++++++++++++++++++ include/uapi/linux/ntsync.h | 1 + 2 files changed, 28 insertions(+) diff --git a/drivers/misc/ntsync.c b/drivers/misc/ntsync.c index 3e8827b6f480..0a87f8ad5993 100644 --- a/drivers/misc/ntsync.c +++ b/drivers/misc/ntsync.c @@ -534,6 +534,31 @@ static int ntsync_mutex_kill(struct ntsync_obj *mutex, void __user *argp) return ret; } +static int ntsync_event_set(struct ntsync_obj *event, void __user *argp) +{ + struct ntsync_device *dev = event->dev; + __u32 prev_state; + bool all; + + if (event->type != NTSYNC_TYPE_EVENT) + return -EINVAL; + + all = ntsync_lock_obj(dev, event); + + prev_state = event->u.event.signaled; + event->u.event.signaled = true; + if (all) + try_wake_all_obj(dev, event); + try_wake_any_event(event); + + ntsync_unlock_obj(dev, event, all); + + if (put_user(prev_state, (__u32 __user *)argp)) + return -EFAULT; + + return 0; +} + static int ntsync_obj_release(struct inode *inode, struct file *file) { struct ntsync_obj *obj = file->private_data; @@ -557,6 +582,8 @@ 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_EVENT_SET: + return ntsync_event_set(obj, argp); default: return -ENOIOCTLCMD; } diff --git a/include/uapi/linux/ntsync.h b/include/uapi/linux/ntsync.h index e08aa02f4dcc..db2512f6e3f4 100644 --- a/include/uapi/linux/ntsync.h +++ b/include/uapi/linux/ntsync.h @@ -48,5 +48,6 @@ struct ntsync_wait_args { #define NTSYNC_IOC_SEM_RELEASE _IOWR('N', 0x81, __u32) #define NTSYNC_IOC_MUTEX_UNLOCK _IOWR('N', 0x85, struct ntsync_mutex_args) #define NTSYNC_IOC_MUTEX_KILL _IOW ('N', 0x86, __u32) +#define NTSYNC_IOC_EVENT_SET _IOR ('N', 0x88, __u32) #endif -- 2.45.2

Dec. 13, 2024

[PATCH v7 08/30] ntsync: Introduce NTSYNC_IOC_CREATE_EVENT.

by Elizabeth Figura

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 <zfigura(a)codeweavers.com> --- drivers/misc/ntsync.c | 59 +++++++++++++++++++++++++++++++++++++ include/uapi/linux/ntsync.h | 6 ++++ 2 files changed, 65 insertions(+) diff --git a/drivers/misc/ntsync.c b/drivers/misc/ntsync.c index 03768ac25425..3e8827b6f480 100644 --- a/drivers/misc/ntsync.c +++ b/drivers/misc/ntsync.c @@ -26,6 +26,7 @@ enum ntsync_type { NTSYNC_TYPE_SEM, NTSYNC_TYPE_MUTEX, + NTSYNC_TYPE_EVENT, }; /* @@ -61,6 +62,10 @@ struct ntsync_obj { pid_t owner; bool ownerdead; } mutex; + struct { + bool manual; + bool signaled; + } event; } u; /* @@ -233,6 +238,8 @@ 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); @@ -283,6 +290,10 @@ 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); @@ -353,6 +364,28 @@ 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; + + ntsync_assert_held(event); + lockdep_assert(event->type == NTSYNC_TYPE_EVENT); + + list_for_each_entry(entry, &event->any_waiters, node) { + struct ntsync_q *q = entry->q; + int signaled = -1; + + if (!event->u.event.signaled) + break; + + if (atomic_try_cmpxchg(&q->signaled, &signaled, entry->index)) { + 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. @@ -622,6 +655,27 @@ static int ntsync_create_mutex(struct ntsync_device *dev, void __user *argp) return fd; } +static int ntsync_create_event(struct ntsync_device *dev, void __user *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; +} + static struct ntsync_obj *get_obj(struct ntsync_device *dev, int fd) { struct file *file = fget(fd); @@ -752,6 +806,9 @@ 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; } } @@ -941,6 +998,8 @@ 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 633958d90be3..e08aa02f4dcc 100644 --- a/include/uapi/linux/ntsync.h +++ b/include/uapi/linux/ntsync.h @@ -20,6 +20,11 @@ struct ntsync_mutex_args { __u32 count; }; +struct ntsync_event_args { + __u32 manual; + __u32 signaled; +}; + #define NTSYNC_WAIT_REALTIME 0x1 struct ntsync_wait_args { @@ -38,6 +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 _IOW ('N', 0x84, struct ntsync_mutex_args) +#define NTSYNC_IOC_CREATE_EVENT _IOW ('N', 0x87, struct ntsync_event_args) #define NTSYNC_IOC_SEM_RELEASE _IOWR('N', 0x81, __u32) #define NTSYNC_IOC_MUTEX_UNLOCK _IOWR('N', 0x85, struct ntsync_mutex_args) -- 2.45.2

Dec. 13, 2024

[PATCH v7 07/30] ntsync: Introduce NTSYNC_IOC_MUTEX_KILL.

by Elizabeth Figura

This does not correspond to any NT syscall. Rather, when a thread dies, it should be called by the NT emulator for each mutex, with the TID of the dying thread. NT mutexes are robust (in the pthread sense). When an NT thread dies, any mutexes it owned are immediately released. Acquisition of those mutexes by other threads will return a special value indicating that the mutex was abandoned, like EOWNERDEAD returned from pthread_mutex_lock(), and EOWNERDEAD is indeed used here for that purpose. Signed-off-by: Elizabeth Figura <zfigura(a)codeweavers.com> --- drivers/misc/ntsync.c | 61 +++++++++++++++++++++++++++++++++++-- include/uapi/linux/ntsync.h | 1 + 2 files changed, 60 insertions(+), 2 deletions(-) diff --git a/drivers/misc/ntsync.c b/drivers/misc/ntsync.c index 33e26240d9e7..03768ac25425 100644 --- a/drivers/misc/ntsync.c +++ b/drivers/misc/ntsync.c @@ -59,6 +59,7 @@ struct ntsync_obj { struct { __u32 count; pid_t owner; + bool ownerdead; } mutex; } u; @@ -107,6 +108,7 @@ struct ntsync_q { atomic_t signaled; bool all; + bool ownerdead; __u32 count; struct ntsync_q_entry entries[]; }; @@ -275,6 +277,9 @@ static void try_wake_all(struct ntsync_device *dev, struct ntsync_q *q, obj->u.sem.count--; break; case NTSYNC_TYPE_MUTEX: + if (obj->u.mutex.ownerdead) + q->ownerdead = true; + obj->u.mutex.ownerdead = false; obj->u.mutex.count++; obj->u.mutex.owner = q->owner; break; @@ -338,6 +343,9 @@ static void try_wake_any_mutex(struct ntsync_obj *mutex) continue; if (atomic_try_cmpxchg(&q->signaled, &signaled, entry->index)) { + if (mutex->u.mutex.ownerdead) + q->ownerdead = true; + mutex->u.mutex.ownerdead = false; mutex->u.mutex.count++; mutex->u.mutex.owner = q->owner; wake_up_process(q->task); @@ -447,6 +455,52 @@ static int ntsync_mutex_unlock(struct ntsync_obj *mutex, void __user *argp) return ret; } +/* + * Actually change the mutex state to mark its owner as dead, + * returning -EPERM if not the owner. + */ +static int kill_mutex_state(struct ntsync_obj *mutex, __u32 owner) +{ + ntsync_assert_held(mutex); + + if (mutex->u.mutex.owner != owner) + return -EPERM; + + mutex->u.mutex.ownerdead = true; + mutex->u.mutex.owner = 0; + mutex->u.mutex.count = 0; + return 0; +} + +static int ntsync_mutex_kill(struct ntsync_obj *mutex, void __user *argp) +{ + struct ntsync_device *dev = mutex->dev; + __u32 owner; + bool all; + int ret; + + if (get_user(owner, (__u32 __user *)argp)) + return -EFAULT; + if (!owner) + return -EINVAL; + + if (mutex->type != NTSYNC_TYPE_MUTEX) + return -EINVAL; + + all = ntsync_lock_obj(dev, mutex); + + ret = kill_mutex_state(mutex, owner); + if (!ret) { + if (all) + try_wake_all_obj(dev, mutex); + try_wake_any_mutex(mutex); + } + + ntsync_unlock_obj(dev, mutex, all); + + return ret; +} + static int ntsync_obj_release(struct inode *inode, struct file *file) { struct ntsync_obj *obj = file->private_data; @@ -468,6 +522,8 @@ static long ntsync_obj_ioctl(struct file *file, unsigned int cmd, return ntsync_sem_release(obj, argp); case NTSYNC_IOC_MUTEX_UNLOCK: return ntsync_mutex_unlock(obj, argp); + case NTSYNC_IOC_MUTEX_KILL: + return ntsync_mutex_kill(obj, argp); default: return -ENOIOCTLCMD; } @@ -652,6 +708,7 @@ static int setup_wait(struct ntsync_device *dev, q->owner = args->owner; atomic_set(&q->signaled, -1); q->all = all; + q->ownerdead = false; q->count = count; for (i = 0; i < count; i++) { @@ -760,7 +817,7 @@ static int ntsync_wait_any(struct ntsync_device *dev, void __user *argp) struct ntsync_wait_args __user *user_args = argp; /* even if we caught a signal, we need to communicate success */ - ret = 0; + ret = q->ownerdead ? -EOWNERDEAD : 0; if (put_user(signaled, &user_args->index)) ret = -EFAULT; @@ -841,7 +898,7 @@ static int ntsync_wait_all(struct ntsync_device *dev, void __user *argp) struct ntsync_wait_args __user *user_args = argp; /* even if we caught a signal, we need to communicate success */ - ret = 0; + ret = q->ownerdead ? -EOWNERDEAD : 0; if (put_user(signaled, &user_args->index)) ret = -EFAULT; diff --git a/include/uapi/linux/ntsync.h b/include/uapi/linux/ntsync.h index 9186304b253c..633958d90be3 100644 --- a/include/uapi/linux/ntsync.h +++ b/include/uapi/linux/ntsync.h @@ -41,5 +41,6 @@ struct ntsync_wait_args { #define NTSYNC_IOC_SEM_RELEASE _IOWR('N', 0x81, __u32) #define NTSYNC_IOC_MUTEX_UNLOCK _IOWR('N', 0x85, struct ntsync_mutex_args) +#define NTSYNC_IOC_MUTEX_KILL _IOW ('N', 0x86, __u32) #endif -- 2.45.2

Dec. 13, 2024

[PATCH v7 06/30] ntsync: Introduce NTSYNC_IOC_MUTEX_UNLOCK.

by Elizabeth Figura

This corresponds to the NT syscall NtReleaseMutant(). This syscall decrements the mutex's recursion count by one, and returns the previous value. If the mutex is not owned by the current task, the function instead fails and returns -EPERM. Signed-off-by: Elizabeth Figura <zfigura(a)codeweavers.com> --- drivers/misc/ntsync.c | 53 +++++++++++++++++++++++++++++++++++++ include/uapi/linux/ntsync.h | 1 + 2 files changed, 54 insertions(+) diff --git a/drivers/misc/ntsync.c b/drivers/misc/ntsync.c index a2826dbff2f4..33e26240d9e7 100644 --- a/drivers/misc/ntsync.c +++ b/drivers/misc/ntsync.c @@ -396,6 +396,57 @@ static int ntsync_sem_release(struct ntsync_obj *sem, void __user *argp) return ret; } +/* + * Actually change the mutex state, returning -EPERM if not the owner. + */ +static int unlock_mutex_state(struct ntsync_obj *mutex, + const struct ntsync_mutex_args *args) +{ + ntsync_assert_held(mutex); + + if (mutex->u.mutex.owner != args->owner) + return -EPERM; + + if (!--mutex->u.mutex.count) + mutex->u.mutex.owner = 0; + return 0; +} + +static int ntsync_mutex_unlock(struct ntsync_obj *mutex, void __user *argp) +{ + struct ntsync_mutex_args __user *user_args = argp; + struct ntsync_device *dev = mutex->dev; + struct ntsync_mutex_args args; + __u32 prev_count; + bool all; + int ret; + + if (copy_from_user(&args, argp, sizeof(args))) + return -EFAULT; + if (!args.owner) + return -EINVAL; + + if (mutex->type != NTSYNC_TYPE_MUTEX) + return -EINVAL; + + all = ntsync_lock_obj(dev, mutex); + + prev_count = mutex->u.mutex.count; + ret = unlock_mutex_state(mutex, &args); + if (!ret) { + if (all) + try_wake_all_obj(dev, mutex); + try_wake_any_mutex(mutex); + } + + ntsync_unlock_obj(dev, mutex, all); + + if (!ret && put_user(prev_count, &user_args->count)) + ret = -EFAULT; + + return ret; +} + static int ntsync_obj_release(struct inode *inode, struct file *file) { struct ntsync_obj *obj = file->private_data; @@ -415,6 +466,8 @@ static long ntsync_obj_ioctl(struct file *file, unsigned int cmd, switch (cmd) { case NTSYNC_IOC_SEM_RELEASE: return ntsync_sem_release(obj, argp); + case NTSYNC_IOC_MUTEX_UNLOCK: + return ntsync_mutex_unlock(obj, argp); default: return -ENOIOCTLCMD; } diff --git a/include/uapi/linux/ntsync.h b/include/uapi/linux/ntsync.h index bb7fb94f5856..9186304b253c 100644 --- a/include/uapi/linux/ntsync.h +++ b/include/uapi/linux/ntsync.h @@ -40,5 +40,6 @@ struct ntsync_wait_args { #define NTSYNC_IOC_CREATE_MUTEX _IOW ('N', 0x84, struct ntsync_mutex_args) #define NTSYNC_IOC_SEM_RELEASE _IOWR('N', 0x81, __u32) +#define NTSYNC_IOC_MUTEX_UNLOCK _IOWR('N', 0x85, struct ntsync_mutex_args) #endif -- 2.45.2

Dec. 13, 2024

[PATCH v7 05/30] ntsync: Introduce NTSYNC_IOC_CREATE_MUTEX.

by Elizabeth Figura

This corresponds to the NT syscall NtCreateMutant(). An NT mutex is recursive, with a 32-bit recursion counter. When acquired via NtWaitForMultipleObjects(), the recursion counter is incremented by one. The OS records the thread which acquired it. The OS records the thread which acquired it. However, in order to keep this driver self-contained, the owning thread ID is managed by user-space, and passed as a parameter to all relevant ioctls. The initial owner and recursion count, if any, are specified when the mutex is created. Signed-off-by: Elizabeth Figura <zfigura(a)codeweavers.com> --- drivers/misc/ntsync.c | 74 +++++++++++++++++++++++++++++++++++-- include/uapi/linux/ntsync.h | 9 ++++- 2 files changed, 79 insertions(+), 4 deletions(-) diff --git a/drivers/misc/ntsync.c b/drivers/misc/ntsync.c index c8beb5504bcc..a2826dbff2f4 100644 --- a/drivers/misc/ntsync.c +++ b/drivers/misc/ntsync.c @@ -25,6 +25,7 @@ enum ntsync_type { NTSYNC_TYPE_SEM, + NTSYNC_TYPE_MUTEX, }; /* @@ -55,6 +56,10 @@ struct ntsync_obj { __u32 count; __u32 max; } sem; + struct { + __u32 count; + pid_t owner; + } mutex; } u; /* @@ -92,6 +97,7 @@ struct ntsync_q_entry { struct ntsync_q { struct task_struct *task; + __u32 owner; /* * Protected via atomic_try_cmpxchg(). Only the thread that wins the @@ -214,13 +220,17 @@ static void ntsync_unlock_obj(struct ntsync_device *dev, struct ntsync_obj *obj, ((lockdep_is_held(&(obj)->dev->wait_all_lock) != LOCK_STATE_NOT_HELD) && \ (obj)->dev_locked)) -static bool is_signaled(struct ntsync_obj *obj) +static bool is_signaled(struct ntsync_obj *obj, __u32 owner) { ntsync_assert_held(obj); switch (obj->type) { case NTSYNC_TYPE_SEM: return !!obj->u.sem.count; + case NTSYNC_TYPE_MUTEX: + if (obj->u.mutex.owner && obj->u.mutex.owner != owner) + return false; + return obj->u.mutex.count < UINT_MAX; } WARN(1, "bad object type %#x\n", obj->type); @@ -250,7 +260,7 @@ static void try_wake_all(struct ntsync_device *dev, struct ntsync_q *q, } for (i = 0; i < count; i++) { - if (!is_signaled(q->entries[i].obj)) { + if (!is_signaled(q->entries[i].obj, q->owner)) { can_wake = false; break; } @@ -264,6 +274,10 @@ static void try_wake_all(struct ntsync_device *dev, struct ntsync_q *q, case NTSYNC_TYPE_SEM: obj->u.sem.count--; break; + case NTSYNC_TYPE_MUTEX: + obj->u.mutex.count++; + obj->u.mutex.owner = q->owner; + break; } } wake_up_process(q->task); @@ -307,6 +321,30 @@ static void try_wake_any_sem(struct ntsync_obj *sem) } } +static void try_wake_any_mutex(struct ntsync_obj *mutex) +{ + struct ntsync_q_entry *entry; + + ntsync_assert_held(mutex); + lockdep_assert(mutex->type == NTSYNC_TYPE_MUTEX); + + list_for_each_entry(entry, &mutex->any_waiters, node) { + struct ntsync_q *q = entry->q; + int signaled = -1; + + if (mutex->u.mutex.count == UINT_MAX) + break; + if (mutex->u.mutex.owner && mutex->u.mutex.owner != q->owner) + continue; + + if (atomic_try_cmpxchg(&q->signaled, &signaled, entry->index)) { + mutex->u.mutex.count++; + mutex->u.mutex.owner = q->owner; + wake_up_process(q->task); + } + } +} + /* * Actually change the semaphore state, returning -EOVERFLOW if it is made * invalid. @@ -451,6 +489,30 @@ static int ntsync_create_sem(struct ntsync_device *dev, void __user *argp) return fd; } +static int ntsync_create_mutex(struct ntsync_device *dev, void __user *argp) +{ + struct ntsync_mutex_args args; + struct ntsync_obj *mutex; + int fd; + + if (copy_from_user(&args, argp, sizeof(args))) + return -EFAULT; + + if (!args.owner != !args.count) + return -EINVAL; + + mutex = ntsync_alloc_obj(dev, NTSYNC_TYPE_MUTEX); + if (!mutex) + return -ENOMEM; + mutex->u.mutex.count = args.count; + mutex->u.mutex.owner = args.owner; + fd = ntsync_obj_get_fd(mutex); + if (fd < 0) + kfree(mutex); + + return fd; +} + static struct ntsync_obj *get_obj(struct ntsync_device *dev, int fd) { struct file *file = fget(fd); @@ -520,7 +582,7 @@ static int setup_wait(struct ntsync_device *dev, struct ntsync_q *q; __u32 i, j; - if (args->pad[0] || args->pad[1] || args->pad[2] || (args->flags & ~NTSYNC_WAIT_REALTIME)) + if (args->pad[0] || args->pad[1] || (args->flags & ~NTSYNC_WAIT_REALTIME)) return -EINVAL; if (args->count > NTSYNC_MAX_WAIT_COUNT) @@ -534,6 +596,7 @@ static int setup_wait(struct ntsync_device *dev, if (!q) return -ENOMEM; q->task = current; + q->owner = args->owner; atomic_set(&q->signaled, -1); q->all = all; q->count = count; @@ -576,6 +639,9 @@ static void try_wake_any_obj(struct ntsync_obj *obj) case NTSYNC_TYPE_SEM: try_wake_any_sem(obj); break; + case NTSYNC_TYPE_MUTEX: + try_wake_any_mutex(obj); + break; } } @@ -765,6 +831,8 @@ static long ntsync_char_ioctl(struct file *file, unsigned int cmd, void __user *argp = (void __user *)parm; switch (cmd) { + case NTSYNC_IOC_CREATE_MUTEX: + return ntsync_create_mutex(dev, argp); case NTSYNC_IOC_CREATE_SEM: return ntsync_create_sem(dev, argp); case NTSYNC_IOC_WAIT_ALL: diff --git a/include/uapi/linux/ntsync.h b/include/uapi/linux/ntsync.h index d64420ffbcd7..bb7fb94f5856 100644 --- a/include/uapi/linux/ntsync.h +++ b/include/uapi/linux/ntsync.h @@ -15,6 +15,11 @@ struct ntsync_sem_args { __u32 max; }; +struct ntsync_mutex_args { + __u32 owner; + __u32 count; +}; + #define NTSYNC_WAIT_REALTIME 0x1 struct ntsync_wait_args { @@ -23,7 +28,8 @@ struct ntsync_wait_args { __u32 count; __u32 index; __u32 flags; - __u32 pad[3]; + __u32 owner; + __u32 pad[2]; }; #define NTSYNC_MAX_WAIT_COUNT 64 @@ -31,6 +37,7 @@ struct ntsync_wait_args { #define NTSYNC_IOC_CREATE_SEM _IOW ('N', 0x80, struct ntsync_sem_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 _IOW ('N', 0x84, struct ntsync_mutex_args) #define NTSYNC_IOC_SEM_RELEASE _IOWR('N', 0x81, __u32) -- 2.45.2

Dec. 13, 2024

[PATCH v7 04/30] ntsync: Introduce NTSYNC_IOC_WAIT_ALL.

by Elizabeth Figura

This is similar to NTSYNC_IOC_WAIT_ANY, but waits until all of the objects are simultaneously signaled, and then acquires all of them as a single atomic operation. Because acquisition of multiple objects is atomic, some complex locking is required. We cannot simply spin-lock multiple objects simultaneously, as that may disable preëmption for a problematically long time. Instead, modifying any object which may be involved in a wait-all operation takes a device-wide sleeping mutex, "wait_all_lock", instead of the normal object spinlock. Because wait-for-all is a rare operation, in order to optimize wait-for-any, this lock is only taken when necessary. "all_hint" is used to mark objects which are involved in a wait-for-all operation, and if an object is not, only its spinlock is taken. The locking scheme used here was written by Peter Zijlstra. Signed-off-by: Elizabeth Figura <zfigura(a)codeweavers.com> --- drivers/misc/ntsync.c | 336 ++++++++++++++++++++++++++++++++++-- include/uapi/linux/ntsync.h | 1 + 2 files changed, 323 insertions(+), 14 deletions(-) diff --git a/drivers/misc/ntsync.c b/drivers/misc/ntsync.c index 900cc5ce5761..c8beb5504bcc 100644 --- a/drivers/misc/ntsync.c +++ b/drivers/misc/ntsync.c @@ -13,6 +13,7 @@ #include <linux/ktime.h> #include <linux/miscdevice.h> #include <linux/module.h> +#include <linux/mutex.h> #include <linux/overflow.h> #include <linux/sched.h> #include <linux/sched/signal.h> @@ -41,6 +42,7 @@ enum ntsync_type { struct ntsync_obj { spinlock_t lock; + int dev_locked; enum ntsync_type type; @@ -55,7 +57,30 @@ struct ntsync_obj { } sem; } u; + /* + * any_waiters is protected by the object lock, but all_waiters is + * protected by the device wait_all_lock. + */ struct list_head any_waiters; + struct list_head all_waiters; + + /* + * Hint describing how many tasks are queued on this object in a + * wait-all operation. + * + * Any time we do a wake, we may need to wake "all" waiters as well as + * "any" waiters. In order to atomically wake "all" waiters, we must + * lock all of the objects, and that means grabbing the wait_all_lock + * below (and, due to lock ordering rules, before locking this object). + * However, wait-all is a rare operation, and grabbing the wait-all + * lock for every wake would create unnecessary contention. + * Therefore we first check whether all_hint is zero, and, if it is, + * we skip trying to wake "all" waiters. + * + * Since wait requests must originate from user-space threads, we're + * limited here by PID_MAX_LIMIT, so there's no risk of overflow. + */ + atomic_t all_hint; }; struct ntsync_q_entry { @@ -75,19 +100,198 @@ struct ntsync_q { */ atomic_t signaled; + bool all; __u32 count; struct ntsync_q_entry entries[]; }; struct ntsync_device { + /* + * Wait-all operations must atomically grab all objects, and be totally + * ordered with respect to each other and wait-any operations. + * If one thread is trying to acquire several objects, another thread + * cannot touch the object at the same time. + * + * This device-wide lock is used to serialize wait-for-all + * operations, and operations on an object that is involved in a + * wait-for-all. + */ + struct mutex wait_all_lock; + struct file *file; }; +/* + * Single objects are locked using obj->lock. + * + * Multiple objects are 'locked' while holding dev->wait_all_lock. + * In this case however, individual objects are not locked by holding + * obj->lock, but by setting obj->dev_locked. + * + * This means that in order to lock a single object, the sequence is slightly + * more complicated than usual. Specifically it needs to check obj->dev_locked + * after acquiring obj->lock, if set, it needs to drop the lock and acquire + * dev->wait_all_lock in order to serialize against the multi-object operation. + */ + +static void dev_lock_obj(struct ntsync_device *dev, struct ntsync_obj *obj) +{ + lockdep_assert_held(&dev->wait_all_lock); + lockdep_assert(obj->dev == dev); + spin_lock(&obj->lock); + /* + * By setting obj->dev_locked inside obj->lock, it is ensured that + * anyone holding obj->lock must see the value. + */ + obj->dev_locked = 1; + spin_unlock(&obj->lock); +} + +static void dev_unlock_obj(struct ntsync_device *dev, struct ntsync_obj *obj) +{ + lockdep_assert_held(&dev->wait_all_lock); + lockdep_assert(obj->dev == dev); + spin_lock(&obj->lock); + obj->dev_locked = 0; + spin_unlock(&obj->lock); +} + +static void obj_lock(struct ntsync_obj *obj) +{ + struct ntsync_device *dev = obj->dev; + + for (;;) { + spin_lock(&obj->lock); + if (likely(!obj->dev_locked)) + break; + + spin_unlock(&obj->lock); + mutex_lock(&dev->wait_all_lock); + spin_lock(&obj->lock); + /* + * obj->dev_locked should be set and released under the same + * wait_all_lock section, since we now own this lock, it should + * be clear. + */ + lockdep_assert(!obj->dev_locked); + spin_unlock(&obj->lock); + mutex_unlock(&dev->wait_all_lock); + } +} + +static void obj_unlock(struct ntsync_obj *obj) +{ + spin_unlock(&obj->lock); +} + +static bool ntsync_lock_obj(struct ntsync_device *dev, struct ntsync_obj *obj) +{ + bool all; + + obj_lock(obj); + all = atomic_read(&obj->all_hint); + if (unlikely(all)) { + obj_unlock(obj); + mutex_lock(&dev->wait_all_lock); + dev_lock_obj(dev, obj); + } + + return all; +} + +static void ntsync_unlock_obj(struct ntsync_device *dev, struct ntsync_obj *obj, bool all) +{ + if (all) { + dev_unlock_obj(dev, obj); + mutex_unlock(&dev->wait_all_lock); + } else { + obj_unlock(obj); + } +} + +#define ntsync_assert_held(obj) \ + lockdep_assert((lockdep_is_held(&(obj)->lock) != LOCK_STATE_NOT_HELD) || \ + ((lockdep_is_held(&(obj)->dev->wait_all_lock) != LOCK_STATE_NOT_HELD) && \ + (obj)->dev_locked)) + +static bool is_signaled(struct ntsync_obj *obj) +{ + ntsync_assert_held(obj); + + switch (obj->type) { + case NTSYNC_TYPE_SEM: + return !!obj->u.sem.count; + } + + WARN(1, "bad object type %#x\n", obj->type); + return false; +} + +/* + * "locked_obj" is an optional pointer to an object which is already locked and + * should not be locked again. This is necessary so that changing an object's + * state and waking it can be a single atomic operation. + */ +static void try_wake_all(struct ntsync_device *dev, struct ntsync_q *q, + struct ntsync_obj *locked_obj) +{ + __u32 count = q->count; + bool can_wake = true; + int signaled = -1; + __u32 i; + + lockdep_assert_held(&dev->wait_all_lock); + if (locked_obj) + lockdep_assert(locked_obj->dev_locked); + + for (i = 0; i < count; i++) { + if (q->entries[i].obj != locked_obj) + dev_lock_obj(dev, q->entries[i].obj); + } + + for (i = 0; i < count; i++) { + if (!is_signaled(q->entries[i].obj)) { + can_wake = false; + break; + } + } + + if (can_wake && atomic_try_cmpxchg(&q->signaled, &signaled, 0)) { + for (i = 0; i < count; i++) { + struct ntsync_obj *obj = q->entries[i].obj; + + switch (obj->type) { + case NTSYNC_TYPE_SEM: + obj->u.sem.count--; + break; + } + } + wake_up_process(q->task); + } + + for (i = 0; i < count; i++) { + if (q->entries[i].obj != locked_obj) + dev_unlock_obj(dev, q->entries[i].obj); + } +} + +static void try_wake_all_obj(struct ntsync_device *dev, struct ntsync_obj *obj) +{ + struct ntsync_q_entry *entry; + + lockdep_assert_held(&dev->wait_all_lock); + lockdep_assert(obj->dev_locked); + + list_for_each_entry(entry, &obj->all_waiters, node) + try_wake_all(dev, entry->q, obj); +} + static void try_wake_any_sem(struct ntsync_obj *sem) { struct ntsync_q_entry *entry; - lockdep_assert_held(&sem->lock); + ntsync_assert_held(sem); + lockdep_assert(sem->type == NTSYNC_TYPE_SEM); list_for_each_entry(entry, &sem->any_waiters, node) { struct ntsync_q *q = entry->q; @@ -111,7 +315,7 @@ static int release_sem_state(struct ntsync_obj *sem, __u32 count) { __u32 sum; - lockdep_assert_held(&sem->lock); + ntsync_assert_held(sem); if (check_add_overflow(sem->u.sem.count, count, &sum) || sum > sem->u.sem.max) @@ -123,9 +327,11 @@ static int release_sem_state(struct ntsync_obj *sem, __u32 count) static int ntsync_sem_release(struct ntsync_obj *sem, void __user *argp) { + struct ntsync_device *dev = sem->dev; __u32 __user *user_args = argp; __u32 prev_count; __u32 args; + bool all; int ret; if (copy_from_user(&args, argp, sizeof(args))) @@ -134,14 +340,17 @@ static int ntsync_sem_release(struct ntsync_obj *sem, void __user *argp) if (sem->type != NTSYNC_TYPE_SEM) return -EINVAL; - spin_lock(&sem->lock); + all = ntsync_lock_obj(dev, sem); prev_count = sem->u.sem.count; - ret = post_sem_state(sem, args); - if (!ret) + ret = release_sem_state(sem, args); + if (!ret) { + if (all) + try_wake_all_obj(dev, sem); try_wake_any_sem(sem); + } - spin_unlock(&sem->lock); + ntsync_unlock_obj(dev, sem, all); if (!ret && put_user(prev_count, user_args)) ret = -EFAULT; @@ -193,6 +402,8 @@ static struct ntsync_obj *ntsync_alloc_obj(struct ntsync_device *dev, get_file(dev->file); spin_lock_init(&obj->lock); INIT_LIST_HEAD(&obj->any_waiters); + INIT_LIST_HEAD(&obj->all_waiters); + atomic_set(&obj->all_hint, 0); return obj; } @@ -301,7 +512,7 @@ static int ntsync_schedule(const struct ntsync_q *q, const struct ntsync_wait_ar * Allocate and initialize the ntsync_q structure, but do not queue us yet. */ static int setup_wait(struct ntsync_device *dev, - const struct ntsync_wait_args *args, + const struct ntsync_wait_args *args, bool all, struct ntsync_q **ret_q) { const __u32 count = args->count; @@ -324,6 +535,7 @@ static int setup_wait(struct ntsync_device *dev, return -ENOMEM; q->task = current; atomic_set(&q->signaled, -1); + q->all = all; q->count = count; for (i = 0; i < count; i++) { @@ -333,6 +545,16 @@ static int setup_wait(struct ntsync_device *dev, if (!obj) goto err; + if (all) { + /* Check that the objects are all distinct. */ + for (j = 0; j < i; j++) { + if (obj == q->entries[j].obj) { + put_obj(obj); + goto err; + } + } + } + entry->obj = obj; entry->q = q; entry->index = i; @@ -362,13 +584,14 @@ static int ntsync_wait_any(struct ntsync_device *dev, void __user *argp) struct ntsync_wait_args args; struct ntsync_q *q; int signaled; + bool all; __u32 i; int ret; if (copy_from_user(&args, argp, sizeof(args))) return -EFAULT; - ret = setup_wait(dev, &args, &q); + ret = setup_wait(dev, &args, false, &q); if (ret < 0) return ret; @@ -378,9 +601,9 @@ static int ntsync_wait_any(struct ntsync_device *dev, void __user *argp) struct ntsync_q_entry *entry = &q->entries[i]; struct ntsync_obj *obj = entry->obj; - spin_lock(&obj->lock); + all = ntsync_lock_obj(dev, obj); list_add_tail(&entry->node, &obj->any_waiters); - spin_unlock(&obj->lock); + ntsync_unlock_obj(dev, obj, all); } /* check if we are already signaled */ @@ -391,9 +614,9 @@ static int ntsync_wait_any(struct ntsync_device *dev, void __user *argp) if (atomic_read(&q->signaled) != -1) break; - spin_lock(&obj->lock); + all = ntsync_lock_obj(dev, obj); try_wake_any_obj(obj); - spin_unlock(&obj->lock); + ntsync_unlock_obj(dev, obj, all); } /* sleep */ @@ -406,9 +629,9 @@ static int ntsync_wait_any(struct ntsync_device *dev, void __user *argp) struct ntsync_q_entry *entry = &q->entries[i]; struct ntsync_obj *obj = entry->obj; - spin_lock(&obj->lock); + all = ntsync_lock_obj(dev, obj); list_del(&entry->node); - spin_unlock(&obj->lock); + ntsync_unlock_obj(dev, obj, all); put_obj(obj); } @@ -430,6 +653,87 @@ static int ntsync_wait_any(struct ntsync_device *dev, void __user *argp) return ret; } +static int ntsync_wait_all(struct ntsync_device *dev, void __user *argp) +{ + struct ntsync_wait_args args; + struct ntsync_q *q; + int signaled; + __u32 i; + int ret; + + if (copy_from_user(&args, argp, sizeof(args))) + return -EFAULT; + + ret = setup_wait(dev, &args, true, &q); + if (ret < 0) + return ret; + + /* queue ourselves */ + + mutex_lock(&dev->wait_all_lock); + + for (i = 0; i < args.count; i++) { + struct ntsync_q_entry *entry = &q->entries[i]; + struct ntsync_obj *obj = entry->obj; + + atomic_inc(&obj->all_hint); + + /* + * obj->all_waiters is protected by dev->wait_all_lock rather + * than obj->lock, so there is no need to acquire obj->lock + * here. + */ + list_add_tail(&entry->node, &obj->all_waiters); + } + + /* check if we are already signaled */ + + try_wake_all(dev, q, NULL); + + mutex_unlock(&dev->wait_all_lock); + + /* sleep */ + + ret = ntsync_schedule(q, &args); + + /* and finally, unqueue */ + + mutex_lock(&dev->wait_all_lock); + + for (i = 0; i < args.count; i++) { + struct ntsync_q_entry *entry = &q->entries[i]; + struct ntsync_obj *obj = entry->obj; + + /* + * obj->all_waiters is protected by dev->wait_all_lock rather + * than obj->lock, so there is no need to acquire it here. + */ + list_del(&entry->node); + + atomic_dec(&obj->all_hint); + + put_obj(obj); + } + + mutex_unlock(&dev->wait_all_lock); + + signaled = atomic_read(&q->signaled); + if (signaled != -1) { + struct ntsync_wait_args __user *user_args = argp; + + /* even if we caught a signal, we need to communicate success */ + ret = 0; + + if (put_user(signaled, &user_args->index)) + ret = -EFAULT; + } else if (!ret) { + ret = -ETIMEDOUT; + } + + kfree(q); + return ret; +} + static int ntsync_char_open(struct inode *inode, struct file *file) { struct ntsync_device *dev; @@ -438,6 +742,8 @@ static int ntsync_char_open(struct inode *inode, struct file *file) if (!dev) return -ENOMEM; + mutex_init(&dev->wait_all_lock); + file->private_data = dev; dev->file = file; return nonseekable_open(inode, file); @@ -461,6 +767,8 @@ static long ntsync_char_ioctl(struct file *file, unsigned int cmd, switch (cmd) { case NTSYNC_IOC_CREATE_SEM: return ntsync_create_sem(dev, argp); + case NTSYNC_IOC_WAIT_ALL: + return ntsync_wait_all(dev, argp); case NTSYNC_IOC_WAIT_ANY: return ntsync_wait_any(dev, argp); default: diff --git a/include/uapi/linux/ntsync.h b/include/uapi/linux/ntsync.h index 40ffdc41d5bb..d64420ffbcd7 100644 --- a/include/uapi/linux/ntsync.h +++ b/include/uapi/linux/ntsync.h @@ -30,6 +30,7 @@ struct ntsync_wait_args { #define NTSYNC_IOC_CREATE_SEM _IOW ('N', 0x80, struct ntsync_sem_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_SEM_RELEASE _IOWR('N', 0x81, __u32) -- 2.45.2

Dec. 13, 2024