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

[PATCH v5 00/28] NT synchronization primitive driver
by Elizabeth Figura Aug. 12, 2024

Aug. 12, 2024

This patch series implements a new char misc driver, /dev/ntsync, which is used to implement Windows NT synchronization primitives. NT synchronization primitives are unique in that the wait functions both are vectored, operate on multiple types of object with different behaviour (mutex, semaphore, event), and affect the state of the objects they wait on. This model is not compatible with existing kernel synchronization objects or interfaces, and therefore the ntsync driver implements its own wait queues and locking. This patch series is rebased against the "char-misc-next" branch of gregkh/char-misc.git. == Background == The Wine project emulates the Windows API in user space. One particular part of that API, namely the NT synchronization primitives, have historically been implemented via RPC to a dedicated "kernel" process. However, more recent applications use these APIs more strenuously, and the overhead of RPC has become a bottleneck. The NT synchronization APIs are too complex to implement on top of existing primitives without sacrificing correctness. Certain operations, such as NtPulseEvent() or the "wait-for-all" mode of NtWaitForMultipleObjects(), require direct control over the underlying wait queue, and implementing a wait queue sufficiently robust for Wine in user space is not possible. This proposed driver, therefore, implements the problematic interfaces directly in the Linux kernel. This driver was presented at Linux Plumbers Conference 2023. For those further interested in the history of synchronization in Wine and past attempts to solve this problem in user space, a recording of the presentation can be viewed here: https://www.youtube.com/watch?v=NjU4nyWyhU8 == Performance == The performance measurements described below are copied from earlier versions of the patch set. While some of the code has changed, I do not currently anticipate that it has changed drastically enough to affect those measurements. The gain in performance varies wildly depending on the application in question and the user's hardware. For some games NT synchronization is not a bottleneck and no change can be observed, but for others frame rate improvements of 50 to 150 percent are not atypical. The following table lists frame rate measurements from a variety of games on a variety of hardware, taken by users Dmitry Skvortsov, FuzzyQuils, OnMars, and myself: Game Upstream ntsync improvement =========================================================================== Anger Foot 69 99 43% Call of Juarez 99.8 224.1 125% Dirt 3 110.6 860.7 678% Forza Horizon 5 108 160 48% Lara Croft: Temple of Osiris 141 326 131% Metro 2033 164.4 199.2 21% Resident Evil 2 26 77 196% The Crew 26 51 96% Tiny Tina's Wonderlands 130 360 177% Total War Saga: Troy 109 146 34% =========================================================================== == Patches == The intended semantics of the patches are broadly intended to match those of the corresponding Windows functions. For those not already familiar with the Windows functions (or their undocumented behaviour), patch 27/28 provides a detailed specification, and individual patches also include a brief description of the API they are implementing. The patches making use of this driver in Wine can be retrieved or browsed here: https://repo.or.cz/wine/zf.git/shortlog/refs/heads/ntsync5 == Previous versions == Changes from v4: * Rework wait-all locking code to avoid taking more than one spinlock at a time, and also to fix a race where the wait-all lock would not be not correctly taken. The new locking mechanism involves taking a simple spinlock for normal "any" waits, and taking a device-wide mutex for "all" waits or when locking any object that is involved in an "all" wait. The mechanism was written by Peter Zijlstra. * Try to reword or clarify various parts of the documentation (patch 27), per Peter Zijlstra. * I did not rename NTSYNC_IOC_SEM_POST to RELEASE (like NT) although this was suggested by Peter Zijlstra, mostly because it's not clear to me that renaming an already committed ioctl would be fine. The API committed isn't actually usable yet, though, so if altering it would be fine on those grounds, I can revise this series to rename the function accordingly. * Similarly, I did not change the create ioctls to return the fd directly, although this was suggested and would be a bit simpler and cleaner, because NTSYNC_IOC_CREATE_SEM already exists upstream and returns the fd through a struct. I can make this change in the next revision if that'd be preferable. I also still would appreciate a clarification on the advice in [1]. [1] https://docs.kernel.org/driver-api/ioctl.html#return-code * Link to v4: https://lore.kernel.org/lkml/20240416010837.333694-1-zfigura(a)codeweavers.… * Link to v3: https://lore.kernel.org/lkml/20240329000621.148791-1-zfigura(a)codeweavers.… * Link to v2: https://lore.kernel.org/lkml/20240219223833.95710-1-zfigura(a)codeweavers.c… * Link to v1: https://lore.kernel.org/lkml/20240214233645.9273-1-zfigura(a)codeweavers.co… * Link to RFC v2: https://lore.kernel.org/lkml/20240131021356.10322-1-zfigura(a)codeweavers.c… * Link to RFC v1: https://lore.kernel.org/lkml/20240124004028.16826-1-zfigura(a)codeweavers.c… Elizabeth Figura (28): ntsync: Introduce NTSYNC_IOC_WAIT_ANY. ntsync: Introduce NTSYNC_IOC_WAIT_ALL. ntsync: Introduce NTSYNC_IOC_CREATE_MUTEX. ntsync: Introduce NTSYNC_IOC_MUTEX_UNLOCK. ntsync: Introduce NTSYNC_IOC_MUTEX_KILL. ntsync: Introduce NTSYNC_IOC_CREATE_EVENT. ntsync: Introduce NTSYNC_IOC_EVENT_SET. ntsync: Introduce NTSYNC_IOC_EVENT_RESET. ntsync: Introduce NTSYNC_IOC_EVENT_PULSE. ntsync: Introduce NTSYNC_IOC_SEM_READ. ntsync: Introduce NTSYNC_IOC_MUTEX_READ. ntsync: Introduce NTSYNC_IOC_EVENT_READ. ntsync: Introduce alertable waits. selftests: ntsync: Add some tests for semaphore state. selftests: ntsync: Add some tests for mutex state. selftests: ntsync: Add some tests for NTSYNC_IOC_WAIT_ANY. selftests: ntsync: Add some tests for NTSYNC_IOC_WAIT_ALL. selftests: ntsync: Add some tests for wakeup signaling with WINESYNC_IOC_WAIT_ANY. selftests: ntsync: Add some tests for wakeup signaling with WINESYNC_IOC_WAIT_ALL. selftests: ntsync: Add some tests for manual-reset event state. selftests: ntsync: Add some tests for auto-reset event state. selftests: ntsync: Add some tests for wakeup signaling with events. selftests: ntsync: Add tests for alertable waits. selftests: ntsync: Add some tests for wakeup signaling via alerts. selftests: ntsync: Add a stress test for contended waits. maintainers: Add an entry for ntsync. docs: ntsync: Add documentation for the ntsync uAPI. ntsync: No longer depend on BROKEN. Documentation/userspace-api/index.rst | 1 + Documentation/userspace-api/ntsync.rst | 398 +++++ MAINTAINERS | 9 + drivers/misc/Kconfig | 1 - drivers/misc/ntsync.c | 989 +++++++++++- include/uapi/linux/ntsync.h | 39 + tools/testing/selftests/Makefile | 1 + .../selftests/drivers/ntsync/.gitignore | 1 + .../testing/selftests/drivers/ntsync/Makefile | 7 + tools/testing/selftests/drivers/ntsync/config | 1 + .../testing/selftests/drivers/ntsync/ntsync.c | 1407 +++++++++++++++++ 11 files changed, 2850 insertions(+), 4 deletions(-) create mode 100644 Documentation/userspace-api/ntsync.rst create mode 100644 tools/testing/selftests/drivers/ntsync/.gitignore create mode 100644 tools/testing/selftests/drivers/ntsync/Makefile create mode 100644 tools/testing/selftests/drivers/ntsync/config create mode 100644 tools/testing/selftests/drivers/ntsync/ntsync.c base-commit: f5b335dc025cfee90957efa90dc72fada0d5abb4 -- 2.43.0

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Implementing NtGetSystemInformation(SystemProcessorIdleInformation)
by Niko Patterson May 31, 2024

May 31, 2024

Hello, for the past couple of days I've been trying to get a program to run under wine, everything seems to function correctly except for a CPU stats window that errors every time it updates. After a few hours of debugging I traced it to NtGetSystemInformation and have been trying to write patches for wine to implement it. My only issue is that the program only uses certain parts of the output, and I'm not sure how to put together the structure for it, should I just name the unknown fields "ReservedX"? I'm also not 100% sure where to put the structure afterwards, since it doesn't seem to show up anywhere in MSDN (I may be using the wrong name, I assumed the structure name is just the enum name in title case like the ones that are documented). I apologize if I sent this to the wrong list, this is my first time contributing to wine and I'm still trying to figure things out. ~Niko

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Missing macro in commctrl.h
by Michael Dluhosch May 31, 2024

May 31, 2024

Hi, is there a reason why this macro https://learn.microsoft.com/en-us/windows/win32/api/commctrl/nf-commctrl-tr… is not defined in the wine version of commctrl.h? I currently try to compile windows sources with winegcc which need this macro. Kind Regards Michael

2 4

Proposal: changing the default bug status (from 'UNCONFIRMED' to 'NEW')
by Austin English May 21, 2024

May 21, 2024

Howdy all, Currently, unprivileged users have their bugs set to 'UNCONFIRMED' by default (while privileged users have the option of 'UNCONFIRMED'/'NEW'/'ASSIGNED'). As a general rule, no one seems to care if a bug is confirmed ('NEW') or not. This often leads to confusion for users (for example recently, [1]), who think that because their bug is 'UNCONFIRMED', it won't get attention. Because this distinction is useless, I'd like to propose that we make a few changes to Bugzilla: * change the default status for newly submitted bugs to 'NEW' (here: https://bugs.winehq.org/editworkflow.cgi) * do a bulk status update of existing bugs from 'UNCONFIRMED' to 'NEW' * disable the 'UNCONFIRMED' status (here: https://bugs.winehq.org/editproducts.cgi?action=edit&product=Wine) Thoughts/concerns? [1] https://bugs.winehq.org/show_bug.cgi?id=50876 -- -Austin GPG: 267B CC1F 053F 0749 (expires 2026-03-03)

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Wine staging 9.9 release
by Alistair Leslie-Hughes May 17, 2024

May 17, 2024

Binary packages for various distributions will be available from: https://www.winehq.org/download Summary since last release * Rebased to current wine 9.9 (427 patches are applied to wine vanilla) Upstreamed (Either directly from staging or fixed with a similar patch). * None Removed (No longer required). * None Added: * None Updated: * vkd3d-latest * ntdll-Junction_Points Where can you help * Run Steam/Battle.net/GOG/UPlay/Epic * Test your favorite game. * Test your favorite applications. * Improve staging patches and get them accepted upstream. * Suggest patches to be included in staging. As always, if you find a bug, please report it via https://bugs.winehq.org Best Regards Alistair.

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Re: [PATCH v4 00/30] NT synchronization primitive driver
by Elizabeth Figura May 15, 2024

May 15, 2024

On Wednesday, 17 April 2024 05:01:32 CDT Peter Zijlstra wrote: > > > > =================================== > > NT synchronization primitive driver > > =================================== > > > > This page documents the user-space API for the ntsync driver. > > > > ntsync is a support driver for emulation of NT synchronization > > primitives by user-space NT emulators. It exists because implementation > > in user-space, using existing tools, cannot match Windows performance > > while offering accurate semantics. It is implemented entirely in > > software, and does not drive any hardware device. > > > > This interface is meant as a compatibility tool only, and should not > > be used for general synchronization. Instead use generic, versatile > > interfaces such as futex(2) and poll(2). > > > > Synchronization primitives > > ========================== > > > > The ntsync driver exposes three types of synchronization primitives: > > semaphores, mutexes, and events. > > > > A semaphore holds a single volatile 32-bit counter, and a static 32-bit > > integer denoting the maximum value. It is considered signaled when the > > counter is nonzero. The counter is decremented by one when a wait is > > satisfied. Both the initial and maximum count are established when the > > semaphore is created. > > > > A mutex holds a volatile 32-bit recursion count, and a volatile 32-bit > > identifier denoting its owner. A mutex is considered signaled when its > > owner is zero (indicating that it is not owned). The recursion count is > > incremented when a wait is satisfied, and ownership is set to the given > > identifier. > > 'signaled' is used twice now but not defined. For both Semaphore and > Mutex this seems to indicate uncontended? Edit: seems to be needs-wakeup > more than uncontended. Uncontended, yes, or needs-wakeup (I'm not sure what the difference between the two is?) > > A mutex also holds an internal flag denoting whether its previous owner > > has died; such a mutex is said to be abandoned. Owner death is not > > tracked automatically based on thread death, but rather must be > > communicated using NTSYNC_IOC_MUTEX_KILL. An abandoned mutex is > > inherently considered unowned. > > > > Except for the "unowned" semantics of zero, the actual value of the > > owner identifier is not interpreted by the ntsync driver at all. The > > intended use is to store a thread identifier; however, the ntsync > > driver does not actually validate that a calling thread provides > > consistent or unique identifiers. > > Why not verify it? Seems simple enough to put in a TID check, esp. if NT > mandates the same. I mostly figured it'd be simplest to leave the driver completely agnostic, but I don't think there's any reason we can't use the real TID for most calls. > > An event holds a volatile boolean state denoting whether it is signaled > > or not. There are two types of events, auto-reset and manual-reset. An > > auto-reset event is designaled when a wait is satisfied; a manual-reset > > event is not. The event type is specified when the event is created. > > But what is an event? I'm familiar with semaphores and mutexes, but less > so with events. It's what I'm trying to define there, a single bit of state that's either contended or not. It acts broadly like an eventfd, in that you can wake (write) or wait (read), but without the distinction of having different nonzero values in the internal counter. You could also think of it as a semaphore with a maximum count of one. However, unlike a semaphore it also supports the "pulse" operation, and you can also have "manual-reset" events that *don't* change state when you wait on them (no equivalent for regular semaphores). > > Unless specified otherwise, all operations on an object are atomic and > > totally ordered with respect to other operations on the same object. > > > > Objects are represented by files. When all file descriptors to an > > object are closed, that object is deleted. > > > > Char device > > =========== > > > > The ntsync driver creates a single char device /dev/ntsync. Each file > > description opened on the device represents a unique instance intended > > to back an individual NT virtual machine. Objects created by one ntsync > > instance may only be used with other objects created by the same > > instance. > > > > ioctl reference > > =============== > > > > All operations on the device are done through ioctls. There are four > > structures used in ioctl calls:: > > > > struct ntsync_sem_args { > > __u32 sem; > > __u32 count; > > __u32 max; > > }; > > > > struct ntsync_mutex_args { > > __u32 mutex; > > __u32 owner; > > __u32 count; > > }; > > > > struct ntsync_event_args { > > __u32 event; > > __u32 signaled; > > __u32 manual; > > }; > > > > struct ntsync_wait_args { > > __u64 timeout; > > __u64 objs; > > __u32 count; > > __u32 owner; > > __u32 index; > > __u32 alert; > > __u32 flags; > > __u32 pad; > > }; > > > > Depending on the ioctl, members of the structure may be used as input, > > output, or not at all. All ioctls return 0 on success. > > > > The ioctls on the device file are as follows: > > > > NTSYNC_IOC_CREATE_SEM > > > > Create a semaphore object. Takes a pointer to struct ntsync_sem_args, > > which is used as follows: > > > > * sem: On output, contains a file descriptor to the created semaphore. > > * count: Initial count of the semaphore. > > * max: Maximum count of the semaphore. > > > > Fails with EINVAL if `count` is greater than `max`. > > So the implication is that @count and @max are input argument and as > such should be set before calling the ioctl()? > > It would not have been weird to have the ioctl() return the fd on > success I suppose, instead of mixing input and output arguments like > this, but whatever, this works. I think that would have been fine, and I could still change it accordingly. The reason I didn't do that was that [1] advises against it (although I don't know why). [1] https://docs.kernel.org/driver-api/ioctl.html#return-code > > The ioctls on the individual objects are as follows: > > > > NTSYNC_IOC_SEM_POST > > > > Post to a semaphore object. Takes a pointer to a 32-bit integer, > > which on input holds the count to be added to the semaphore, and on > > output contains its previous count. > > > > If adding to the semaphore's current count would raise the latter > > past the semaphore's maximum count, the ioctl fails with > > EOVERFLOW and the semaphore is not affected. If raising the > > semaphore's count causes it to become signaled, eligible threads > > waiting on this semaphore will be woken and the semaphore's count > > decremented appropriately. > > Urg, so this is the traditional V (vrijgeven per Dijkstra, release in > English), but now 'conveniently' called POST, such that it can be > readily confused with the P operation (passering, or passing) which it > is not. > > Glorious :-/ > > You're of course going to tell me NT did this and you can't help this > naming foible. No, NT calls it "release" (and the operation on a mutex is also "release" rather than "unlock".) I called it "post" after POSIX semaphores, on the idea that it'd be more familiar to a Unix developer (and shorter). I see I was wrong, so I'll rename it to "release". > > NTSYNC_IOC_MUTEX_UNLOCK > > > > Release a mutex object. Takes a pointer to struct ntsync_mutex_args, > > which is used as follows: > > > > * mutex: Ignored. > > * owner: Specifies the owner trying to release this mutex. > > * count: On output, contains the previous recursion count. > > > > If "owner" is zero, the ioctl fails with EINVAL. If "owner" > > is not the current owner of the mutex, the ioctl fails with > > EPERM. > > ISTR you having written elsewhere that NT actually demands mutexes to be > strictly per thread, which for the above would mandate @owner to be > current, no? Right. We could replace owner with current everywhere except for NTSYNC_IOC_KILL_OWNER. > > The mutex's count will be decremented by one. If decrementing the > > mutex's count causes it to become zero, the mutex is marked as > > unowned and signaled, and eligible threads waiting on it will be > > woken as appropriate. > > > > NTSYNC_IOC_SET_EVENT > > > > Signal an event object. Takes a pointer to a 32-bit integer, which on > > output contains the previous state of the event. > > > > Eligible threads will be woken, and auto-reset events will be > > designaled appropriately. > > Hmm, so the event thing is like a simple wait-wake scheme? Where the > 'signaled' bit is used as the wakeup state? Yes, exactly. > > NTSYNC_IOC_RESET_EVENT > > > > Designal an event object. Takes a pointer to a 32-bit integer, which > > on output contains the previous state of the event. > > > > NTSYNC_IOC_PULSE_EVENT > > > > Wake threads waiting on an event object while leaving it in an > > unsignaled state. Takes a pointer to a 32-bit integer, which on > > output contains the previous state of the event. > > > > A pulse operation can be thought of as a set followed by a reset, > > performed as a single atomic operation. If two threads are waiting on > > an auto-reset event which is pulsed, only one will be woken. If two > > threads are waiting a manual-reset event which is pulsed, both will > > be woken. However, in both cases, the event will be unsignaled > > afterwards, and a simultaneous read operation will always report the > > event as unsignaled. > > *groan* Yep :D This one is terrible, and it's the only one that Microsoft has come out and explicitly said "don't use this". Supposedly their kernel is even coded such that if a waiting thread gets hit by an interrupt that the pulse will go unnoticed, although I've tried to reproduce this in practice and been unsuccessful. But of course it's terrible regardless, because you never know if your thread is waiting or not. In practice it seems to usually be used on a timer, though, so that part doesn't matter as much. > > NTSYNC_IOC_READ_SEM > > > > Read the current state of a semaphore object. Takes a pointer to > > struct ntsync_sem_args, which is used as follows: > > > > * sem: Ignored. > > * count: On output, contains the current count of the semaphore. > > * max: On output, contains the maximum count of the semaphore. > > This seems inherently racy -- what is the intended purpose of this > interface? > > Specifically the moment a value is returned, either P or V operations > can change it, rendering the (as yet unused) return value incorrect. I have no idea what it's intended for. Actually it's not even exposed as a documented API, only an undocumented one. But it does work, and applications use it. > > NTSYNC_IOC_READ_MUTEX > > > > Read the current state of a mutex object. Takes a pointer to struct > > ntsync_mutex_args, which is used as follows: > > > > * mutex: Ignored. > > * owner: On output, contains the current owner of the mutex, or zero > > if the mutex is not currently owned. > > * count: On output, contains the current recursion count of the mutex. > > > > If the mutex is marked as abandoned, the function fails with > > EOWNERDEAD. In this case, "count" and "owner" are set to zero. > > Another questionable interface. I suspect you're going to be telling me > NT has them so you have to have them, but urgh. Unfortunately yes. > > NTSYNC_IOC_READ_EVENT > > > > Read the current state of an event object. Takes a pointer to struct > > ntsync_event_args, which is used as follows: > > > > * event: Ignored. > > * signaled: On output, contains the current state of the event. > > * manual: On output, contains 1 if the event is a manual-reset event, > > and 0 otherwise. > > I can't help but notice all those @sem, @mutex, @event 'output' members > being unused except for create. Seems like a waste to have them. Yes, mostly so I could reuse the existing structures. On the other hand if there's no reason not to return fds from the create ioctls, then we could just remove those members. > > NTSYNC_IOC_KILL_OWNER > > > > Mark a mutex as unowned and abandoned if it is owned by the given > > owner. Takes an input-only pointer to a 32-bit integer denoting the > > owner. If the owner is zero, the ioctl fails with EINVAL. If the > > owner does not own the mutex, the function fails with EPERM. > > > > Eligible threads waiting on the mutex will be woken as appropriate > > (and such waits will fail with EOWNERDEAD, as described below). > > Wine will use this when it detects a thread exit I suppose. Exactly. > > NTSYNC_IOC_WAIT_ANY > > > > Poll on any of a list of objects, atomically acquiring at most one. > > Takes a pointer to struct ntsync_wait_args, which is used as follows: > > > > * timeout: Absolute timeout in nanoseconds. If NTSYNC_WAIT_REALTIME > > is set, the timeout is measured against the REALTIME > > clock; otherwise it is measured against the MONOTONIC > > clock. If the timeout is equal to or earlier than the > > current time, the function returns immediately without > > sleeping. If "timeout" is U64_MAX, the function will > > sleep until an object is signaled, and will not fail > > with ETIMEDOUT. > > > > * objs: Pointer to an array of "count" file descriptors > > (specified as an integer so that the structure has the > > same size regardless of architecture). If any object is > > invalid, the function fails with EINVAL. > > > > * count: Number of objects specified in the "objs" array. If > > greater than NTSYNC_MAX_WAIT_COUNT, the function fails > > with EINVAL. > > > > * owner: Mutex owner identifier. If any object in "objs" is a > > mutex, the ioctl will attempt to acquire that mutex on > > behalf of "owner". If "owner" is zero, the ioctl > > fails with EINVAL. > > Again, should that not be current? That is, why not maintain the NT > invariant and mandates TIDs and avoid the arguments in both cases? I don't think there's any particular reason. > > * index: On success, contains the index (into "objs") of the > > object which was signaled. If "alert" was signaled > > instead, this contains "count". > > Could be the actual return value, no? Edit: no it cannot be because > -EOWNERDEAD case below. Yeah. Again the advice about "only return zero from an ioctl", too. Although we could also use a bit in the return value (which is also kind of what NT does). > > A semaphore is considered to be signaled if its count is nonzero, and > > is acquired by decrementing its count by one. A mutex is considered > > to be signaled if it is unowned or if its owner matches the "owner" > > argument, and is acquired by incrementing its recursion count by one > > and setting its owner to the "owner" argument. An auto-reset event > > is acquired by designaling it; a manual-reset event is not affected > > by acquisition. > > > > Acquisition is atomic and totally ordered with respect to other > > operations on the same object. If two wait operations (with different > > "owner" identifiers) are queued on the same mutex, only one is > > signaled. If two wait operations are queued on the same semaphore, > > and a value of one is posted to it, only one is signaled. The order > > in which threads are signaled is not specified. > > Note that you do list the lack of guarantee here, but not above. I > suspect both cases are similar and guarantee nothing. There's no documented guarantee in either case, but when testing in controlled well-ordered environments, NtWaitForMultipleObjects() always acquires the lowest index first, and I think wakes are FIFO. I'm not really sure why I specified the guarantee for the former but not the latter. > > The "alert" argument is an "extra" event which can terminate the > > wait, independently of all other objects. If members of "objs" and > > "alert" are both simultaneously signaled, a member of "objs" will > > always be given priority and acquired first. > > > > It is valid to pass the same object more than once, including by > > passing the same event in the "objs" array and in "alert". If a > > wakeup occurs due to that object being signaled, "index" is set to > > the lowest index corresponding to that object. > > Urgh, is this an actual guarantee? This almost seems to imply that at > [A] above we can indeed guarantee the lowest indexed object is acquired > first. It's definitely legal in NT to pass the same object more than once (in wait-for-any, not wait-for-all though), and it's definitely the case that (at least in controlled well-ordered environments) the lowest index is acquired first. I don't know of any application that definitely depends on either of these, and they're not documented behaviours, but Wine has implemented those behaviours and it would make me nervous to break them here. The part about passing the same event in "alert" and "objs" is not part of NT exactly (in NT the "alert" isn't even an event; it's a special bit of thread state; we just use an event for simplicity). I think I specified it just to avoid coding an extra check (since it should Just Work), while also making it clear that case was considered. > > The function may fail with EINTR if a signal is received. > > In which case @index must be disregarded since nothing will be acquired, > right? > > So far nothing really weird, and I'm thinking futexes should be able to > do all this, no? Even disregarding wait-for-all, futexes aren't really good enough. Wait operations need to consume state, and while we could put that state in user space (and in fact we *do* have an out of tree patch set that kind of does this) that requires all that state to be shared across processes, which is a problem since we want processes to be isolated unless they explicitly share objects with each other. There's not a scalable way to achieve this, especially since you can share objects lazily. You also cannot do NtPulseEvent() this way. The aforementioned patch set badly emulates it and it does in practice break any application that uses it. Similarly there are some applications that do a weird "fake pulse" where they set and then immediately reset an event from the same thread, and expect that to always wake.

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Re: [PATCH v4 02/27] ntsync: Introduce NTSYNC_IOC_WAIT_ALL.
by Elizabeth Figura May 13, 2024

May 13, 2024

On Friday, April 19, 2024 11:28:14 AM CDT Peter Zijlstra wrote: > On Thu, Apr 18, 2024 at 11:35:11AM +0200, Peter Zijlstra wrote: > > On Wed, Apr 17, 2024 at 03:03:05PM -0500, Elizabeth Figura wrote: > > > Ach. I wrote this with the idea that the race isn't meaningful, but > > > looking at it again you're right—there is a harmful race here. > > > > > > I think it should be fixable by moving the atomic_read inside the lock, > > > though. > > > > Right, I've ended up with the (as yet untested) below. I'll see if I can > > find time later to actually test things. > > Latest hackery... I tried testing this but I'm not having luck using the > patched wine as per the other email. > I converted the rest of the direct uses of spin_lock() using the below patch and tested it myself, and it passes Wine tests. As far as I can tell the logic is correct, too; I couldn't find any races. I'll incorporate these changes into the next revision, unless there's a good reason not to. --- --- a/drivers/misc/ntsync.c +++ b/drivers/misc/ntsync.c @@ -569,17 +569,19 @@ static int ntsync_event_set(struct ntsync_obj *event, void __user *argp, bool pu 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; - spin_lock(&event->lock); + all = ntsync_lock_obj(dev, event); prev_state = event->u.event.signaled; event->u.event.signaled = false; - spin_unlock(&event->lock); + ntsync_unlock_obj(dev, event, all); if (put_user(prev_state, (__u32 __user *)argp)) return -EFAULT; @@ -590,16 +592,21 @@ static int ntsync_event_reset(struct ntsync_obj *event, void __user *argp) 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; - spin_lock(&sem->lock); + + all = ntsync_lock_obj(dev, sem); + args.count = sem->u.sem.count; args.max = sem->u.sem.max; - spin_unlock(&sem->lock); + + ntsync_unlock_obj(dev, sem, all); if (copy_to_user(user_args, &args, sizeof(args))) return -EFAULT; @@ -609,18 +616,23 @@ static int ntsync_sem_read(struct ntsync_obj *sem, void __user *argp) 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; args.mutex = 0; - spin_lock(&mutex->lock); + + 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; - spin_unlock(&mutex->lock); + + ntsync_unlock_obj(dev, mutex, all); if (copy_to_user(user_args, &args, sizeof(args))) return -EFAULT; @@ -630,16 +642,21 @@ static int ntsync_mutex_read(struct ntsync_obj *mutex, void __user *argp) static int ntsync_event_read(struct ntsync_obj *event, void __user *argp) { struct ntsync_event_args __user *user_args = argp; + struct ntsync_device *dev = event->dev; struct ntsync_event_args args; + bool all; if (event->type != NTSYNC_TYPE_EVENT) return -EINVAL; args.event = 0; - spin_lock(&event->lock); + + all = ntsync_lock_obj(dev, event); + args.manual = event->u.event.manual; args.signaled = event->u.event.signaled; - spin_unlock(&event->lock); + + ntsync_unlock_obj(dev, event, all); if (copy_to_user(user_args, &args, sizeof(args))) return -EFAULT; @@ -962,6 +979,7 @@ static int ntsync_wait_any(struct ntsync_device *dev, void __user *argp) __u32 i, total_count; struct ntsync_q *q; int signaled; + bool all; int ret; if (copy_from_user(&args, argp, sizeof(args))) @@ -981,9 +999,9 @@ 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); } /* @@ -1000,9 +1018,9 @@ 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 */ @@ -1015,9 +1033,9 @@ 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); } @@ -1075,9 +1093,9 @@ static int ntsync_wait_all(struct ntsync_device *dev, void __user *argp) struct ntsync_q_entry *entry = &q->entries[args.count]; struct ntsync_obj *obj = entry->obj; - spin_lock_nest_lock(&obj->lock, &dev->wait_all_lock); + dev_lock_obj(dev, obj); list_add_tail(&entry->node, &obj->any_waiters); - spin_unlock(&obj->lock); + dev_unlock_obj(dev, obj); } /* check if we are already signaled */ @@ -1095,9 +1113,9 @@ static int ntsync_wait_all(struct ntsync_device *dev, void __user *argp) struct ntsync_obj *obj = q->entries[args.count].obj; if (atomic_read(&q->signaled) == -1) { - spin_lock(&obj->lock); + dev_lock_obj(dev, obj); try_wake_any_obj(obj); - spin_unlock(&obj->lock); + dev_unlock_obj(dev, obj); } } @@ -1127,9 +1145,9 @@ static int ntsync_wait_all(struct ntsync_device *dev, void __user *argp) struct ntsync_q_entry *entry = &q->entries[args.count]; struct ntsync_obj *obj = entry->obj; - spin_lock_nest_lock(&obj->lock, &dev->wait_all_lock); + dev_lock_obj(dev, obj); list_del(&entry->node); - spin_unlock(&obj->lock); + dev_unlock_obj(dev, obj); put_obj(obj); }

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Re: [PATCH v4 00/30] NT synchronization primitive driver
by Elizabeth Figura May 6, 2024

May 6, 2024

On Friday, 19 April 2024 11:16:11 CDT Peter Zijlstra wrote: > On Tue, Apr 16, 2024 at 05:18:56PM -0500, Elizabeth Figura wrote: > > On Tuesday, 16 April 2024 16:18:24 CDT Elizabeth Figura wrote: > > > On Tuesday, 16 April 2024 03:14:21 CDT Peter Zijlstra wrote: > > > > I don't support GE has it in his builds? Last time I tried, building > > > > Wine was a bit of a pain. > > > > > > It doesn't seem so. I tried to build a GE-compatible ntsync build, uploaded > > > here (thanks Arek for hosting): > > > > > > https://f002.backblazeb2.com/file/wine-ntsync/ntsync-wine.tar.xz > > > > Oops, the initial version I uploaded had broken paths. Should be fixed now. > > > > (It's also broken on an unpatched kernel unless explicitly disabled with > > WINE_DISABLE_FAST_SYNC=1. Not sure what I messed up there—it should fall back > > cleanly—but hopefully shouldn't be too important for testing.) > > So I've tried using that wine build with lutris, and I can't get it to > start EGS or anything else. > > I even added a printk to the ntsync driver for every open, to see if it > gets that far, but I'm not even getting that :/ That's odd, it works for me, both as a standalone build and with lutris... Does /dev/ntsync exist (module is loaded) and have nonzero permissions? I forgot to mention that's necessary, sorry. Otherwise I can try to look at an strace, or a Wine debug log. I don't think there's an easy way to get the latter with Lutris, but something like `WINEDEBUG=+all ./wine winecfg 2>log` should work.

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Wine staging 9.8 release
by Alistair Leslie-Hughes May 4, 2024

May 4, 2024

Binary packages for various distributions will be available from: https://www.winehq.org/download Summary since last release * Rebased to current wine 9.8 (430 patches are applied to wine vanilla) Upstreamed (Either directly from staging or fixed with a similar patch). * widl: Make automatic dispid generation scheme better match what midl does. * widl: Create library block index right after the CompObj one. * widl: Set the lowest bit in the param name to indicate whether type description follows the name. * widl: Add support for function parameter flags to SLTG typelib generator. * widl: Avoid relying on side effects when marking function index as the last one. * stdole32.tlb: Compile typelib with --oldtlb. Removed (No longer required). * ntdll-CriticalSection * Pipelight * winex11-XEMBED Added: * [46012] d3d9: Implement ID3DXEffect::SetRawValue. Updated: * vkd3d-latest * odbc-remove-unixodbc * ddraw-GetPickRecords Where can you help * Run Steam/Battle.net/GOG/UPlay/Epic * Test your favorite game. * Test your favorite applications. * Improve staging patches and get them accepted upstream. * Suggest patches to be included in staging. As always, if you find a bug, please report it via https://bugs.winehq.org Best Regards Alistair.

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