[PATCH v6 0/2] MR4822: ntdll: Fix: Ignore alignment if MEM_REPLACE_PLACEHOLDER is set in flags of NtMapViewOfSection(Ex)

[Felix Münchhalfen (＠jfmu)]

I had a bugreport here: https://bugs.winehq.org/show_bug.cgi?id=56161

This pull req fixes the bug that programs that do VirtualAlloc(placeholder)/VirtualFree(keep placeholder)/MapViewOfFile3(replace placeholder), do not run. Like the dotnet pe loader in .net 7 for example.

It was not clear to me at first, because i didnt notice it on msdn, but the way that Dmitry Timoshkov
"hacked" it in https://bugs.winehq.org/show_bug.cgi?id=56122 is actually exactly how it is supposed to happen according to msdn.

From here: https://learn.microsoft.com/en-us/windows/win32/api/memoryapi/nf-memoryapi-m...
![image](/uploads/58614927d38c15d4c23517aa5dc09d77/image.png)

So thanks to Dmitry Timoshkov.
If you are interested you could also look into the thing i mentioned in the bug report, that MapViewOfFile3 doesn't round down to 64k, but, i don't think this is a serious problem yet.

--
  v6: kernelbase: Added a test for MapViewOfFile3 with MEM_REPLACE_PLACEHOLDER

https://gitlab.winehq.org/wine/wine/-/merge_requests/4822

[PATCH v6 1/2] ntdll: Fix: Ignore alignment if MEM_REPLACE_PLACEHOLDER is set in flags

[Felix Münchhalfen]

From: Felix Münchhalfen

---
 dlls/ntdll/unix/virtual.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/dlls/ntdll/unix/virtual.c b/dlls/ntdll/unix/virtual.c
index abe1b4dc4ec..2a53f56879e 100644
--- a/dlls/ntdll/unix/virtual.c
+++ b/dlls/ntdll/unix/virtual.c
@@ -5466,6 +5466,9 @@ NTSTATUS WINAPI NtMapViewOfSection( HANDLE handle, HANDLE process, PVOID *addr_p
     }
 #endif

+    if (alloc_type & MEM_REPLACE_PLACEHOLDER)
+        mask = page_mask;
+
     if ((offset.u.LowPart & mask) || (*addr_ptr && ((UINT_PTR)*addr_ptr & mask)))
         return STATUS_MAPPED_ALIGNMENT;

@@ -5535,6 +5538,9 @@ NTSTATUS WINAPI NtMapViewOfSectionEx( HANDLE handle, HANDLE process, PVOID *addr
     }
 #endif

+    if (alloc_type & MEM_REPLACE_PLACEHOLDER)
+        mask = page_mask;
+
     if ((offset.u.LowPart & mask) || (*addr_ptr && ((UINT_PTR)*addr_ptr & mask)))
         return STATUS_MAPPED_ALIGNMENT;

[PATCH v6 2/2] kernelbase: Added a test for MapViewOfFile3 with MEM_REPLACE_PLACEHOLDER

[Felix Münchhalfen]

From: Felix Münchhalfen

---
 dlls/kernelbase/tests/process.c | 34 +++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/dlls/kernelbase/tests/process.c b/dlls/kernelbase/tests/process.c
index 88a527c45d5..6045d04e3bc 100644
--- a/dlls/kernelbase/tests/process.c
+++ b/dlls/kernelbase/tests/process.c
@@ -38,6 +38,7 @@ static LPVOID (WINAPI *pMapViewOfFile3)(HANDLE, HANDLE, PVOID, ULONG64 offset, S
 static LPVOID (WINAPI *pVirtualAlloc2)(HANDLE, void *, SIZE_T, DWORD, DWORD, MEM_EXTENDED_PARAMETER *, ULONG);
 static LPVOID (WINAPI *pVirtualAlloc2FromApp)(HANDLE, void *, SIZE_T, DWORD, DWORD, MEM_EXTENDED_PARAMETER *, ULONG);
 static PVOID (WINAPI *pVirtualAllocFromApp)(PVOID, SIZE_T, DWORD, DWORD);
+static BOOL (WINAPI *pVirtualFree)(LPVOID,SIZE_T,DWORD);
 static HANDLE (WINAPI *pOpenFileMappingFromApp)( ULONG, BOOL, LPCWSTR);
 static HANDLE (WINAPI *pCreateFileMappingFromApp)(HANDLE, PSECURITY_ATTRIBUTES, ULONG, ULONG64, PCWSTR);
 static LPVOID (WINAPI *pMapViewOfFileFromApp)(HANDLE, ULONG, ULONG64, SIZE_T);
@@ -134,6 +135,37 @@ static void test_MapViewOfFile3(void)
     ok(ret, "Failed to delete a test file.\n");
 }

+static void test_MapViewOfFileReplacePlaceholder(void)
+{
+    SYSTEM_INFO si;
+    size_t szFile = 1024UL*1024; // 1M
+    HANDLE hFileMapping;
+    PVOID pAllocation;
+    PVOID pMapStart;
+    PVOID pMapEnd;
+    BOOL bVirtualFree;
+    PVOID pMappedFileView;
+
+    GetSystemInfo(&si);
+
+    hFileMapping = CreateFileMappingA(NULL, NULL, PAGE_READWRITE, 0, (DWORD)szFile, NULL);
+    ok(hFileMapping != NULL, "CreateFileMapping did not return a handle\n");
+
+    pAllocation = pVirtualAlloc2(GetCurrentProcess(), NULL, szFile, MEM_RESERVE | MEM_RESERVE_PLACEHOLDER, PAGE_NOACCESS, NULL, 0);
+    ok(pAllocation != NULL, "VirtualAlloc2 returned NULL\n");
+
+    pMapStart = (void*)(((unsigned long long)pAllocation + si.dwPageSize) & ~(si.dwPageSize-1)); // advance forward to align with pagesize
+    pMapEnd = (void*)(((unsigned long long)pAllocation + 2*si.dwPageSize) & ~(si.dwPageSize-1));
+    bVirtualFree = pVirtualFree(pMapStart, si.dwPageSize, MEM_RELEASE | MEM_PRESERVE_PLACEHOLDER); // split the region into two placeholders
+    ok(bVirtualFree, "VirtualFree failed to split the placeholder\n");
+    pMappedFileView = pMapViewOfFile3(hFileMapping, GetCurrentProcess(), pMapStart, si.dwPageSize, si.dwPageSize, MEM_REPLACE_PLACEHOLDER, PAGE_READWRITE, NULL, 0);
+    ok(pMappedFileView != NULL, "MapViewOfFile3 did not map the FileMapping\n");
+
+    bVirtualFree = pVirtualFree(pMapEnd, szFile - 2*si.dwPageSize, MEM_RELEASE);
+    ok(bVirtualFree, "VirtualFree failed to free the remaining placeholder\n");
+    ok(CloseHandle(hFileMapping), "CloseHandle failed on hFileMapping\n");
+}
+
 #define check_region_size(p, s) check_region_size_(p, s, __LINE__)
 static void check_region_size_(void *p, SIZE_T s, unsigned int line)
 {
@@ -519,6 +551,7 @@ static void init_funcs(void)
     X(VirtualAlloc2);
     X(VirtualAlloc2FromApp);
     X(VirtualAllocFromApp);
+    X(VirtualFree);
     X(UnmapViewOfFile2);

hmod = GetModuleHandleA("ntdll.dll");
@@ -533,6 +566,7 @@ START_TEST(process)

test_CompareObjectHandles();
     test_MapViewOfFile3();
+    test_MapViewOfFileReplacePlaceholder();
     test_VirtualAlloc2();
     test_VirtualAllocFromApp();
     test_VirtualAlloc2FromApp();