From 8e2091f18f1c123e0af0a6db8adac7f8fc6378bc Mon Sep 17 00:00:00 2001
From: Jan Kotas <jkotas@microsoft.com>
Date: Mon, 4 Nov 2024 14:09:15 -0800
Subject: [PATCH] Disable GS cookie checks for LightUnwind

LightUnwind does not track sufficient context to compute GS cookie address

Fixes #109242
---
 src/coreclr/inc/eetwain.h                     |  2 ++
 src/coreclr/vm/eetwain.cpp                    |  9 ++++++++
 src/coreclr/vm/exceptionhandling.cpp          |  1 +
 src/coreclr/vm/stackwalk.cpp                  |  1 +
 .../coreclr/GitHub_109242/test109242.cs       | 21 +++++++++++++++++++
 .../coreclr/GitHub_109242/test109242.csproj   | 12 +++++++++++
 6 files changed, 46 insertions(+)
 create mode 100644 src/tests/Regressions/coreclr/GitHub_109242/test109242.cs
 create mode 100644 src/tests/Regressions/coreclr/GitHub_109242/test109242.csproj

diff --git a/src/coreclr/inc/eetwain.h b/src/coreclr/inc/eetwain.h
index c7b1be02e5c638..4ee7b9a7b84b6e 100644
--- a/src/coreclr/inc/eetwain.h
+++ b/src/coreclr/inc/eetwain.h
@@ -273,6 +273,7 @@ virtual GenericParamContextType GetParamContextType(PREGDISPLAY     pContext,
 */
 virtual void * GetGSCookieAddr(PREGDISPLAY     pContext,
                                EECodeInfo    * pCodeInfo,
+                               unsigned        flags,
                                CodeManState  * pState) = 0;
 
 #ifndef USE_GC_INFO_DECODER
@@ -541,6 +542,7 @@ PTR_VOID GetExactGenericsToken(SIZE_T          baseStackSlot,
 virtual
 void * GetGSCookieAddr(PREGDISPLAY     pContext,
                        EECodeInfo    * pCodeInfo,
+                       unsigned        flags,
                        CodeManState  * pState);
 
 
diff --git a/src/coreclr/vm/eetwain.cpp b/src/coreclr/vm/eetwain.cpp
index 5746c44de4a770..618077b1b105c7 100644
--- a/src/coreclr/vm/eetwain.cpp
+++ b/src/coreclr/vm/eetwain.cpp
@@ -1952,6 +1952,7 @@ PTR_VOID EECodeManager::GetExactGenericsToken(SIZE_T          baseStackSlot,
 
 void * EECodeManager::GetGSCookieAddr(PREGDISPLAY     pContext,
                                       EECodeInfo *    pCodeInfo,
+                                      unsigned        flags,
                                       CodeManState  * pState)
 {
     CONTRACTL {
@@ -1969,6 +1970,14 @@ void * EECodeManager::GetGSCookieAddr(PREGDISPLAY     pContext,
     }
 #endif
 
+#ifdef HAS_LIGHTUNWIND
+    // LightUnwind does not track sufficient context to compute GS cookie address
+    if (flags & LightUnwind)
+    {
+        return NULL;
+    }
+#endif
+
 #ifndef USE_GC_INFO_DECODER
     _ASSERTE(sizeof(CodeManStateBuf) <= sizeof(pState->stateBuf));
 
diff --git a/src/coreclr/vm/exceptionhandling.cpp b/src/coreclr/vm/exceptionhandling.cpp
index f9426d46f0029b..264a29d17bf32c 100644
--- a/src/coreclr/vm/exceptionhandling.cpp
+++ b/src/coreclr/vm/exceptionhandling.cpp
@@ -2054,6 +2054,7 @@ CLRUnwindStatus ExceptionTracker::ProcessOSExceptionNotification(
         {
             pGSCookie = (GSCookie*)cfThisFrame.GetCodeManager()->GetGSCookieAddr(cfThisFrame.pRD,
                                                                                           &cfThisFrame.codeInfo,
+                                                                                          0 /* CodeManFlags */,
                                                                                           &cfThisFrame.codeManState);
             if (pGSCookie)
             {
diff --git a/src/coreclr/vm/stackwalk.cpp b/src/coreclr/vm/stackwalk.cpp
index b333249637d37e..fcf0a2e7f64853 100644
--- a/src/coreclr/vm/stackwalk.cpp
+++ b/src/coreclr/vm/stackwalk.cpp
@@ -3185,6 +3185,7 @@ void StackFrameIterator::PreProcessingForManagedFrames(void)
     m_pCachedGSCookie = (GSCookie*)m_crawl.GetCodeManager()->GetGSCookieAddr(
                                                         m_crawl.pRD,
                                                         &m_crawl.codeInfo,
+                                                        m_codeManFlags,
                                                         &m_crawl.codeManState);
 #endif // !DACCESS_COMPILE
 
diff --git a/src/tests/Regressions/coreclr/GitHub_109242/test109242.cs b/src/tests/Regressions/coreclr/GitHub_109242/test109242.cs
new file mode 100644
index 00000000000000..080744316bdd73
--- /dev/null
+++ b/src/tests/Regressions/coreclr/GitHub_109242/test109242.cs
@@ -0,0 +1,21 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+using System;
+using System.Reflection;
+using Xunit;
+
+public class Test109242
+{
+    [Fact]
+    public static void TestEntryPoint()
+    {
+        unsafe
+        {
+            void* p = stackalloc byte[Random.Shared.Next(100)];
+            GC.KeepAlive(((IntPtr)p).ToString());
+        }
+
+        Assembly.Load("System.Runtime");
+    }
+}
+
diff --git a/src/tests/Regressions/coreclr/GitHub_109242/test109242.csproj b/src/tests/Regressions/coreclr/GitHub_109242/test109242.csproj
new file mode 100644
index 00000000000000..d087213b695b82
--- /dev/null
+++ b/src/tests/Regressions/coreclr/GitHub_109242/test109242.csproj
@@ -0,0 +1,12 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <CLRTestPriority>1</CLRTestPriority>
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+  </PropertyGroup>
+  <ItemGroup>
+    <Compile Include="test109242.cs" />
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="$(TestSourceDir)Common/CoreCLRTestLibrary/CoreCLRTestLibrary.csproj" />
+  </ItemGroup>
+</Project>