kernel/linux.git/include/uapi/linux/ntsync.h, branch v6.19.11

ntsync: Introduce alertable waits.

2025-01-08T12:18:11+00:00

NT waits can optionally be made "alertable". This is a special channel for thread wakeup that is mildly similar to SIGIO. A thread has an internal single bit of "alerted" state, and if a thread is alerted while an alertable wait, the wait will return a special value, consume the "alerted" state, and will not consume any of its objects. Alerts are implemented using events; the user-space NT emulator is expected to create an internal ntsync event for each thread and pass that event to wait functions. Signed-off-by: Elizabeth Figura Acked-by: Peter Zijlstra (Intel) Acked-by: Arnd Bergmann Link: https://lore.kernel.org/r/20241213193511.457338-16-zfigura@codeweavers.com Signed-off-by: Greg Kroah-Hartman

ntsync: Introduce NTSYNC_IOC_EVENT_READ.

2025-01-08T12:18:11+00:00

This corresponds to the NT syscall NtQueryEvent(). This returns the signaled state of the event and whether it is manual-reset. Signed-off-by: Elizabeth Figura Link: https://lore.kernel.org/r/20241213193511.457338-15-zfigura@codeweavers.com Signed-off-by: Greg Kroah-Hartman

ntsync: Introduce NTSYNC_IOC_MUTEX_READ.

2025-01-08T12:18:11+00:00

This corresponds to the NT syscall NtQueryMutant(). This returns the recursion count, owner, and abandoned state of the mutex. Signed-off-by: Elizabeth Figura Link: https://lore.kernel.org/r/20241213193511.457338-14-zfigura@codeweavers.com Signed-off-by: Greg Kroah-Hartman

ntsync: Introduce NTSYNC_IOC_SEM_READ.

2025-01-08T12:18:11+00:00

This corresponds to the NT syscall NtQuerySemaphore(). This returns the current count and maximum count of the semaphore. Signed-off-by: Elizabeth Figura Link: https://lore.kernel.org/r/20241213193511.457338-13-zfigura@codeweavers.com Signed-off-by: Greg Kroah-Hartman

ntsync: Introduce NTSYNC_IOC_EVENT_PULSE.

2025-01-08T12:18:11+00:00

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 Acked-by: Peter Zijlstra (Intel) Acked-by: Arnd Bergmann Link: https://lore.kernel.org/r/20241213193511.457338-12-zfigura@codeweavers.com Signed-off-by: Greg Kroah-Hartman

ntsync: Introduce NTSYNC_IOC_EVENT_RESET.

2025-01-08T12:18:11+00:00

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 Acked-by: Peter Zijlstra (Intel) Acked-by: Arnd Bergmann Link: https://lore.kernel.org/r/20241213193511.457338-11-zfigura@codeweavers.com Signed-off-by: Greg Kroah-Hartman

ntsync: Introduce NTSYNC_IOC_EVENT_SET.

2025-01-08T12:18:11+00:00

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 Link: https://lore.kernel.org/r/20241213193511.457338-10-zfigura@codeweavers.com Signed-off-by: Greg Kroah-Hartman

ntsync: Introduce NTSYNC_IOC_CREATE_EVENT.

2025-01-08T12:18:11+00:00

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 Link: https://lore.kernel.org/r/20241213193511.457338-9-zfigura@codeweavers.com Signed-off-by: Greg Kroah-Hartman

ntsync: Introduce NTSYNC_IOC_MUTEX_KILL.

2025-01-08T12:18:10+00:00

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 Link: https://lore.kernel.org/r/20241213193511.457338-8-zfigura@codeweavers.com Signed-off-by: Greg Kroah-Hartman

ntsync: Introduce NTSYNC_IOC_MUTEX_UNLOCK.

2025-01-08T12:18:10+00:00

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 Link: https://lore.kernel.org/r/20241213193511.457338-7-zfigura@codeweavers.com Signed-off-by: Greg Kroah-Hartman