[PATCH 0/1] 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.

[PATCH 1/1] 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, 4 insertions(+), 2 deletions(-)

diff --git a/dlls/ntdll/unix/virtual.c b/dlls/ntdll/unix/virtual.c
index abe1b4dc4ec..fb4fa6f1439 100644
--- a/dlls/ntdll/unix/virtual.c
+++ b/dlls/ntdll/unix/virtual.c
@@ -5466,7 +5466,8 @@ NTSTATUS WINAPI NtMapViewOfSection( HANDLE handle, HANDLE process, PVOID *addr_p
     }
 #endif

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

if (process != NtCurrentProcess())
@@ -5535,7 +5536,8 @@ NTSTATUS WINAPI NtMapViewOfSectionEx( HANDLE handle, HANDLE process, PVOID *addr
     }
 #endif

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

if (process != NtCurrentProcess())

[Nikolay Sivov (＠nsivov)]

Thank you for the MR. We'll definitely need a test for this, preferably for both the syscall and user wrapper in kernel32.

[Alex Henrie (＠alexhenrie)]

Alex Henrie (@alexhenrie) commented about dlls/ntdll/unix/virtual.c:
>  }
>
> #endif
> - if ((offset.u.LowPart & mask) || (*addr_ptr && ((UINT_PTR)*addr_ptr & mask)))
> - if (!(alloc_type & MEM_REPLACE_PLACEHOLDER) &&

Please don't leave a space at the end of the line. Trailing whitespace causes warnings in Git.

[Alex Henrie (＠alexhenrie)]

Alex Henrie (@alexhenrie) commented about dlls/ntdll/unix/virtual.c:
>  }
>
> #endif
> - if ((offset.u.LowPart & mask) || (*addr_ptr && ((UINT_PTR)*addr_ptr & mask)))
> - if (!(alloc_type & MEM_REPLACE_PLACEHOLDER) &&

Same here