From 0e2d0415c0e3f815d99ac5faf45b8e35ec202862 Mon Sep 17 00:00:00 2001
From: Anton Lapounov <antonl@microsoft.com>
Date: Mon, 1 Aug 2022 16:12:04 -0700
Subject: [PATCH] Fix handling process affinity mask on Windows 11 (#69548)

---
 src/coreclr/gc/windows/gcenv.windows.cpp                   | 3 ---
 src/coreclr/nativeaot/Runtime/windows/PalRedhawkMinWin.cpp | 1 -
 src/coreclr/utilcode/util.cpp                              | 2 --
 src/coreclr/vm/gcenv.os.cpp                                | 2 --
 4 files changed, 8 deletions(-)

diff --git a/src/coreclr/gc/windows/gcenv.windows.cpp b/src/coreclr/gc/windows/gcenv.windows.cpp
index 0e69219..d8675e5 100644
--- a/src/coreclr/gc/windows/gcenv.windows.cpp
+++ b/src/coreclr/gc/windows/gcenv.windows.cpp
@@ -234,7 +234,6 @@ void InitCPUGroupInfo()
     DWORD_PTR processAffinityMask, systemAffinityMask;
     if (::GetProcessAffinityMask(::GetCurrentProcess(), &processAffinityMask, &systemAffinityMask))
     {
-        processAffinityMask &= systemAffinityMask;
         if (processAffinityMask != 0 && // only one CPU group is involved
             (processAffinityMask & (processAffinityMask - 1)) == 0) // only one bit is set
         {
@@ -542,8 +541,6 @@ bool GCToOSInterface::Initialize()
         uintptr_t pmask, smask;
         if (!!::GetProcessAffinityMask(::GetCurrentProcess(), (PDWORD_PTR)&pmask, (PDWORD_PTR)&smask))
         {
-            pmask &= smask;
-
             for (size_t i = 0; i < 8 * sizeof(uintptr_t); i++)
             {
                 if ((pmask & ((uintptr_t)1 << i)) != 0)
diff --git a/src/coreclr/nativeaot/Runtime/windows/PalRedhawkMinWin.cpp b/src/coreclr/nativeaot/Runtime/windows/PalRedhawkMinWin.cpp
index e6195e5..32c072d 100644
--- a/src/coreclr/nativeaot/Runtime/windows/PalRedhawkMinWin.cpp
+++ b/src/coreclr/nativeaot/Runtime/windows/PalRedhawkMinWin.cpp
@@ -79,7 +79,6 @@ void InitializeCurrentProcessCpuCount()
         }
         else
         {
-            pmask &= smask;
             count = 0;
 
             while (pmask)
diff --git a/src/coreclr/utilcode/util.cpp b/src/coreclr/utilcode/util.cpp
index b4fec28..2d2d2d2 100644
--- a/src/coreclr/utilcode/util.cpp
+++ b/src/coreclr/utilcode/util.cpp
@@ -1071,7 +1071,6 @@ int GetCurrentProcessCpuCount()
             }
             else
             {
-                pmask &= smask;
                 count = 0;
 
                 while (pmask)
@@ -1150,7 +1149,6 @@ DWORD_PTR GetCurrentProcessCpuMask()
     if (!GetProcessAffinityMask(GetCurrentProcess(), &pmask, &smask))
         return 1;
 
-    pmask &= smask;
     return pmask;
 #else
     return 0;
diff --git a/src/coreclr/vm/gcenv.os.cpp b/src/coreclr/vm/gcenv.os.cpp
index 34346f4..18413ba 100644
--- a/src/coreclr/vm/gcenv.os.cpp
+++ b/src/coreclr/vm/gcenv.os.cpp
@@ -146,8 +146,6 @@ bool GCToOSInterface::Initialize()
         uintptr_t pmask, smask;
         if (!!::GetProcessAffinityMask(::GetCurrentProcess(), (PDWORD_PTR)&pmask, (PDWORD_PTR)&smask))
         {
-            pmask &= smask;
-
             for (size_t i = 0; i < 8 * sizeof(uintptr_t); i++)
             {
                 if ((pmask & ((uintptr_t)1 << i)) != 0)
-- 
2.7.4