From a64c8d3205fa2771ee9223812ecf683a9880e214 Mon Sep 17 00:00:00 2001
From: nmzik <Nmzik@mail.ru>
Date: Tue, 8 Sep 2026 16:46:18 +0400
Subject: [PATCH] kernel: implement umtx wait/wake and reject malformed
 timeouts

---
 src/libs/libKernel.cpp | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/src/libs/libKernel.cpp b/src/libs/libKernel.cpp
index b00001642..8ae19a644 100644
--- a/src/libs/libKernel.cpp
+++ b/src/libs/libKernel.cpp
@@ -2112,6 +2112,33 @@ int KYTY_SYSV_ABI KernelSyncOnAddressWake(volatile void* address, int32_t count)
 	return LibKernel::SyncOnAddress::Wake(address, count);
 }
 
+int KYTY_SYSV_ABI UmtxOp(volatile void* address, int operation, uint64_t value,
+                           void* uaddr, const void* timeout) {
+	constexpr int UMTX_OP_WAIT = 2;
+	constexpr int UMTX_OP_WAKE = 3;
+
+	EXIT_NOT_IMPLEMENTED(uaddr != nullptr);
+
+	switch (operation) {
+		case UMTX_OP_WAIT:
+			if (timeout != nullptr) {
+				LibKernel::KernelTimespec duration {};
+				std::memcpy(&duration, timeout, sizeof(duration));
+				if (duration.tv_sec < 0 || duration.tv_nsec < 0 || duration.tv_nsec >= 1000000000) {
+					*GetErrorAddr() = POSIX_EINVAL;
+					return -1;
+				}
+				EXIT("Valid _umtx_op timed waits are not implemented\n");
+			}
+			return POSIX_CALL(LibKernel::SyncOnAddress::Wait64(
+			    static_cast<volatile uint64_t*>(address), value, nullptr,
+			    LibKernel::KernelDispatchPendingSignalForCurrentThread));
+		case UMTX_OP_WAKE:
+			return POSIX_CALL(LibKernel::SyncOnAddress::Wake(address, static_cast<int32_t>(value)));
+		default: EXIT("Unsupported _umtx_op operation: %d\n", operation);
+	}
+}
+
 LIB_DEFINE(InitLibKernel_1_Posix) {
 	LIB_FUNC("k+AXqu2-eBc", getpagesize);
 	LIB_FUNC("lLMT9vJAck0", clock_gettime);
@@ -3310,6 +3337,7 @@ static void AddLibkernelUnityFunc(Loader::SymbolDatabase* s, const char* nid, ui
 }
 
 LIB_DEFINE(InitLibKernel_1) {
+	LIB_FUNC("04AjkP0jO9U", Posix::UmtxOp);
 	InitLibKernel_1_FS(s);
 	InitLibKernel_1_Mem(s);
 	InitLibKernel_1_Equeue(s);