Fix crossgen memory mappings (#13972)

This change removes executable memory mappings from crossgen. Now it
can be run on systems with PAX set to prevent executable mappings
without any marking using the paxctl.

3 files changed, 16 insertions, 2 deletions

diff --git a/src/utilcode/loaderheap.cpp b/src/utilcode/loaderheap.cpp
index 2603a8ec33..ca1ed666f4 100644
--- a/src/utilcode/loaderheap.cpp
+++ b/src/utilcode/loaderheap.cpp
@@ -944,8 +944,12 @@ UnlockedLoaderHeap::UnlockedLoaderHeap(DWORD dwReserveBlockSize,
     m_pPrivatePerfCounter_LoaderBytes = pPrivatePerfCounter_LoaderBytes;
 
     m_Options                    = 0;
+
+#ifndef CROSSGEN_COMPILE
     if (fMakeExecutable)
         m_Options                |= LHF_EXECUTABLE;
+#endif // CROSSGEN_COMPILE
+
     if (fZeroInit)
         m_Options                |= LHF_ZEROINIT;
 
diff --git a/src/vm/peimagelayout.cpp b/src/vm/peimagelayout.cpp
index 93ab77cc78..94810a0e61 100644
--- a/src/vm/peimagelayout.cpp
+++ b/src/vm/peimagelayout.cpp
@@ -195,14 +195,14 @@ void PEImageLayout::ApplyBaseRelocations()
             if (((pSection->Characteristics & VAL32(IMAGE_SCN_MEM_WRITE)) == 0))
             {
                 DWORD dwNewProtection = PAGE_READWRITE;
-#ifdef FEATURE_PAL
+#if defined(FEATURE_PAL) && !defined(CROSSGEN_COMPILE)
                 if (((pSection->Characteristics & VAL32(IMAGE_SCN_MEM_EXECUTE)) != 0))
                 {
                     // On SELinux, we cannot change protection that doesn't have execute access rights
                     // to one that has it, so we need to set the protection to RWX instead of RW
                     dwNewProtection = PAGE_EXECUTE_READWRITE;
                 }
-#endif // FEATURE_PAL
+#endif // FEATURE_PAL && !CROSSGEN_COMPILE
                 if (!ClrVirtualProtect(pWriteableRegion, cbWriteableRegion,
                                        dwNewProtection, &dwOldProtection))
                     ThrowLastError();
@@ -243,6 +243,7 @@ void PEImageLayout::ApplyBaseRelocations()
     }
     _ASSERTE(dirSize == dirPos);
 
+#ifndef CROSSGEN_COMPILE
     if (dwOldProtection != 0)
     {
         // Restore the protection
@@ -250,6 +251,7 @@ void PEImageLayout::ApplyBaseRelocations()
                                dwOldProtection, &dwOldProtection))
             ThrowLastError();
     }
+#endif // CROSSGEN_COMPILE
 }
 #endif // FEATURE_PREJIT
 
@@ -478,7 +480,9 @@ MappedImageLayout::MappedImageLayout(HANDLE hFile, PEImage* pOwner)
 
 #else //!FEATURE_PAL
 
+#ifndef CROSSGEN_COMPILE
     m_FileView = PAL_LOADLoadPEFile(hFile);
+
     if (m_FileView == NULL)
     {
         // For CoreCLR, try to load all files via LoadLibrary first. If LoadLibrary did not work, retry using 
@@ -507,6 +511,10 @@ MappedImageLayout::MappedImageLayout(HANDLE hFile, PEImage* pOwner)
         SetRelocated();
     }
 
+#else // !CROSSGEN_COMPILE
+    m_FileView = NULL;
+#endif // !CROSSGEN_COMPILE
+
 #endif // !FEATURE_PAL
 }
 
diff --git a/src/vm/stublink.cpp b/src/vm/stublink.cpp
index d1833260c5..631f51150b 100644
--- a/src/vm/stublink.cpp
+++ b/src/vm/stublink.cpp
@@ -888,7 +888,9 @@ Stub *StubLinker::Link(LoaderHeap *pHeap, DWORD flags)
     int globalsize = 0;
     int size = CalculateSize(&globalsize);
 
+#ifndef CROSSGEN_COMPILE
     _ASSERTE(!pHeap || pHeap->IsExecutable());
+#endif
 
     StubHolder<Stub> pStub;