feat(libkernel): implement sceKernelGetEventError

core/libs/prx/libkernel/Equeue/src/EventAccessors.cpp

@@ -4,6 +4,7 @@
 #include <string>
 #include "SceTypes.hpp"
 #include "prx/libc/include/General.hpp"
+#include "prx/libkernel/Equeue/Equeue.hpp"
 
 static const KernelEvent& requireEvent(const KernelEvent* ev, const char* caller) {
     if (ev == nullptr) {
@@ -19,9 +20,8 @@ intptr_t APS5_VABI sceKernelGetEventData(const KernelEvent* ev) {
 }
 
 int APS5_VABI sceKernelGetEventError(const KernelEvent* ev) {
- (void)ev;
- NotImplemented_nid_no_patch(__func__);
- return 0;
+    const KernelEvent& event = requireEvent(ev, __func__);
+    return (event.flags & EV_ERROR) != 0 ? static_cast<int>(event.data) : 0;
 }
 
 intptr_t APS5_VABI sceKernelGetEventFflags(const KernelEvent* ev) {

core/libs/tests/GuestEqueueEvents.cpp

@@ -20,6 +20,7 @@ int APS5_VABI sceKernelAddHRTimerEvent(KernelEqueue eq, int id, const KernelTime
 int APS5_VABI sceKernelAddTimerEvent(KernelEqueue eq, int id, KernelUseconds usec, void* udata);
 int APS5_VABI sceKernelDeleteTimerEvent(KernelEqueue eq, int id);
 intptr_t APS5_VABI sceKernelGetEventData(const KernelEvent* ev);
+int APS5_VABI sceKernelGetEventError(const KernelEvent* ev);
 intptr_t APS5_VABI sceKernelGetEventFflags(const KernelEvent* ev);
 int APS5_VABI sceKernelGetEventFilter(const KernelEvent* ev);
 uintptr_t APS5_VABI sceKernelGetEventId(const KernelEvent* ev);
@@ -34,6 +35,7 @@ static constexpr int EVFILT_TIMER = -7;
 static constexpr int EVFILT_USER = -11;
 static constexpr int EVFILT_HRTIMER = -15;
 static constexpr int EVFILT_AMPR = -25;
+static constexpr std::uint16_t EV_ERROR = 0x4000;
 
 static void Require(bool value) { if (!value) std::abort(); }
 
@@ -77,6 +79,7 @@ static void VerifyPeriodicTimer() {
     Require(sceKernelGetEventFilter(&events[0]) == EVFILT_TIMER);
     Require(sceKernelGetEventData(&events[0]) >= 5);
     Require(sceKernelGetEventUserData(&events[0]) == &first);
+    Require(sceKernelGetEventError(&events[0]) == 0);
     Require(sceKernelWaitEqueue(eq, events, 2, &count, &wait) == SCE_OK);
     Require(count == 1 && sceKernelGetEventData(&events[0]) >= 1);
 
@@ -288,8 +291,15 @@ int main() {
     Require(sceKernelGetEventFflags(&rawEvent) == static_cast<intptr_t>(0x80000001LL));
     Require(sceKernelGetEventData(&rawEvent) == -5);
     Require(sceKernelGetEventUserData(&rawEvent) == nullptr);
+    Require(sceKernelGetEventError(&rawEvent) == 0);
+    rawEvent.flags = static_cast<std::uint16_t>(~EV_ERROR);
+    Require(sceKernelGetEventError(&rawEvent) == 0);
+    rawEvent.flags = EV_ERROR;
+    rawEvent.data = 22;
+    Require(sceKernelGetEventError(&rawEvent) == 22);
 
     Require(RejectsNull(sceKernelGetEventData));
+    Require(RejectsNull(sceKernelGetEventError));
     Require(RejectsNull(sceKernelGetEventFflags));
     Require(RejectsNull(sceKernelGetEventFilter));
     Require(RejectsNull(sceKernelGetEventId));

docs/dev/debt/libkernel.md

@@ -156,6 +156,7 @@
 - [select](../../../core/libs/prx/libkernel/Socket/src/Socket.cpp) (libkernel) validates `tv_usec` but saturates a valid timeout beyond the remaining `steady_clock` range at `time_point::max()`, so the wait can continue effectively indefinitely. The console's behavior for a valid timeout outside the host clock's range is unknown.
 - [_fstatfs](../../../core/libs/prx/libkernel/File/src/Stdio.cpp) (libkernel) fills the FreeBSD 11 `struct statfs` of the PS5 payload SDK with the host volume that holds the file: block size, transfer size, total, free and available blocks, maximum name length and the read-only, `nosuid` and `noexec` flags (on Windows only read-only, and `f_files` and `f_ffree` are 0, as NTFS has no fixed number of files). The filesystem type number and name, mount paths, owner, filesystem id and I/O counters are left 0 or empty, since they would describe a host mount, not a console one. Sockets and pipes return `EINVAL`, as FreeBSD's `getvnode` does; a Windows descriptor that is neither a file nor a pipe throws. Stremio Plus (PPSA74126) reads the free space before a download and only logs the other fields
 - [pthread_spin_init, pthread_spin_destroy, pthread_spin_lock, pthread_spin_trylock, pthread_spin_unlock](../../../core/libs/prx/libkernel/Pthread/Posix/Spinlock.cpp) (libkernel) follow FreeBSD 11.4 libthr [`thr_pspinlock.c`](https://github.com/freebsd/freebsd-src/blob/8c639945a44588f6cfdddfb057bb5aad88735da0/lib/libthr/thread/thr_pspinlock.c) and the owner checks of its [`thr_umtx.h`](https://github.com/freebsd/freebsd-src/blob/8c639945a44588f6cfdddfb057bb5aad88735da0/lib/libthr/thread/thr_umtx.h#L80-L175), unverified on the console: `EINVAL` for a null or destroyed lock and a `pshared` other than 0 or 1, `EBUSY` from `trylock` while any thread holds it, `EPERM` from `unlock` by a thread that does not hold it. `PTHREAD_PROCESS_SHARED` allocates a private lock, as guest code runs in one process. libthr spins forever when the holder locks again; here that call throws
+- [sceKernelGetEventError](../../../core/libs/prx/libkernel/Equeue/src/EventAccessors.cpp) (libkernel) returns the event's `data` as an `int` when `EV_ERROR` (0x4000) is set in `flags` and 0 otherwise, as [KytyPS5](https://github.com/KytyPS5/KytyPS5/blob/947627d10d4ef4b68ba3c0189aab6c368e70a8d2/src/kernel/eventQueue.cpp#L663) does and as FreeBSD 11's [kevent](https://github.com/freebsd/freebsd-src/blob/release/11.0.0/sys/kern/kern_event.c#L1005) reports a failed change (`flags = EV_ERROR`, errno in `data`). [fpPS4](https://github.com/red-prig/fpPS4/blob/04cefd43e6fddd1ab033e7980cd356d14c964905/kernel/ps4_queue.pas#L643) instead returns `fflags` plus `0x80020000` when `fflags` is nonzero. Whether the console reads `data` or `fflags` and returns the raw errno or an SCE error code is unverified. No event delivered by the equeue here carries `EV_ERROR`, so the call returns 0 for every event `sceKernelWaitEqueue` reports
 - [pthread_cond_reltimedwait_np](../../../core/libs/prx/libkernel/Pthread/Posix/Cond.cpp) (libkernel) takes `(cond, mutex, usec)`, a relative timeout in microseconds, and is `scePthreadCondTimedwait` with POSIX error numbers. FreeBSD 11.4 has no such function; the signature comes only from shadPS4, which registers one function for this NID and for `scePthreadCondTimedwait` ([`condvar.cpp`](https://github.com/shadps4-emu/shadPS4/blob/3a9f57265d28975658f1ca941daa5c879c7a74bd/src/core/libraries/kernel/threads/condvar.cpp#L229-L234)). shadPS4 reads a 64-bit count; here it is the 32-bit `SceKernelUseconds` of the SCE twin, as for `sem_reltimedwait_np`. Unverified on the console
 - [sysctl kern.arandom](../../../core/libs/prx/libkernel/System/src/SystemConfiguration.cpp) (libkernel) serves FreeBSD 11's MIB {1, 37} (CTL_KERN, KERN_ARANDOM) and the "kern.arandom" sysctlbyname lookup through std::random_device, returning min(*oldLength, 256) random bytes. Following FreeBSD's sysctl_kern_arnd, a null buffer reports min(*oldLength, 256) without writing, a null length returns 0 without writing, and requests with a new value return EPERM (1) as the node is read-only. Cryptographic quality depends on the host's random device implementation.
 - [sceKernelGetPageTableStats](../../../core/libs/prx/libkernel/DirectMemory/Export.cpp) (libkernel) - reports 2048 page-table entries on each side (a 4 GiB pool of 2 MiB entries, the constants of [KytyPS5](https://github.com/KytyPS5/KytyPS5/blob/main/src/kernel/memory.cpp)) and all of them available: no entries are counted as used, so a title never sees page-table pressure. KytyPS5 counts the 2 MiB entries of the committed CPU- or GPU-accessible ranges as used, which this port does not do. The four `int*` arguments follow OpenOrbis' `libkernel.h`, the Orbital type database and SharpProspero; a null pointer returns `SCE_KERNEL_ERROR_EFAULT` as in KytyPS5. None of the values is measured on a console. PPSA30601 (Resonance) calls it during start-up