[RFC] ntdll: Force allocations to be aligned to 64K.

[Derek Lesho]

Microsoft Powerpoint expects that free spaces be at-least 64K bytes in size, so
internally allocating at a higher granularity can cause trouble with this assertion.
This patch does exhaust a bit more of the address space, which is a problem on 32-bit, so
I'm curious about what you guys think we could do instead.

Signed-off-by: Derek Lesho <dlesho at codeweavers.com>
---
 dlls/ntdll/directory.c | 4 ++--
 dlls/ntdll/heap.c      | 4 ++--
 dlls/ntdll/thread.c    | 2 +-
 dlls/ntdll/virtual.c   | 3 +--
 4 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/dlls/ntdll/directory.c b/dlls/ntdll/directory.c
index 7554934701..f04348a40f 100644
--- a/dlls/ntdll/directory.c
+++ b/dlls/ntdll/directory.c
@@ -1743,14 +1743,14 @@ static KERNEL_DIRENT *start_vfat_ioctl( int fd )
         SIZE_T size = 2 * sizeof(*de) + page_size;
         void *addr = NULL;
 
-        if (virtual_alloc_aligned( &addr, 0, &size, MEM_RESERVE, PAGE_READWRITE, 1 ))
+        if (virtual_alloc_aligned( &addr, 0, &size, MEM_RESERVE, PAGE_READWRITE, 0 ))
             return NULL;
         /* commit only the size needed for the dir entries */
         /* this leaves an extra unaccessible page, which should make the kernel */
         /* fail with -EFAULT before it stomps all over our memory */
         de = addr;
         size = 2 * sizeof(*de);
-        virtual_alloc_aligned( &addr, 0, &size, MEM_COMMIT, PAGE_READWRITE, 1 );
+        virtual_alloc_aligned( &addr, 0, &size, MEM_COMMIT, PAGE_READWRITE, 0 );
     }
 
     /* set d_reclen to 65535 to work around an AFS kernel bug */
diff --git a/dlls/ntdll/heap.c b/dlls/ntdll/heap.c
index e8ac1ffa7a..8bbf4f2262 100644
--- a/dlls/ntdll/heap.c
+++ b/dlls/ntdll/heap.c
@@ -726,7 +726,7 @@ static void *allocate_large_block( HEAP *heap, DWORD flags, SIZE_T size )
     LPVOID address = NULL;
 
     if (block_size < size) return NULL;  /* overflow */
-    if (virtual_alloc_aligned( &address, 0, &block_size, MEM_COMMIT, get_protection_type( flags ), 5 ))
+    if (virtual_alloc_aligned( &address, 0, &block_size, MEM_COMMIT, get_protection_type( flags ), 0 ))
     {
         WARN("Could not allocate block for %08lx bytes\n", size );
         return NULL;
@@ -1520,7 +1520,7 @@ void heap_set_debug_flags( HANDLE handle )
         void *ptr = NULL;
         SIZE_T size = MAX_FREE_PENDING * sizeof(*heap->pending_free);
 
-        if (!virtual_alloc_aligned( &ptr, 0, &size, MEM_COMMIT, PAGE_READWRITE, 4 ))
+        if (!virtual_alloc_aligned( &ptr, 0, &size, MEM_COMMIT, PAGE_READWRITE, 0 ))
         {
             heap->pending_free = ptr;
             heap->pending_pos = 0;
diff --git a/dlls/ntdll/thread.c b/dlls/ntdll/thread.c
index be54f89082..aaa19ee69e 100644
--- a/dlls/ntdll/thread.c
+++ b/dlls/ntdll/thread.c
@@ -250,7 +250,7 @@ void thread_init(void)
 
     addr = NULL;
     size = sizeof(*peb);
-    virtual_alloc_aligned( &addr, 0, &size, MEM_COMMIT | MEM_TOP_DOWN, PAGE_READWRITE, 1 );
+    virtual_alloc_aligned( &addr, 0, &size, MEM_COMMIT | MEM_TOP_DOWN, PAGE_READWRITE, 0 );
     peb = addr;
 
     peb->FastPebLock        = &peb_lock;
diff --git a/dlls/ntdll/virtual.c b/dlls/ntdll/virtual.c
index d15b49f6fd..27b7e3fab7 100644
--- a/dlls/ntdll/virtual.c
+++ b/dlls/ntdll/virtual.c
@@ -411,8 +411,7 @@ static struct file_view *VIRTUAL_FindView( const void *addr, size_t size )
  */
 static inline UINT_PTR get_mask( ULONG alignment )
 {
-    if (!alignment) return 0xffff;  /* allocations are aligned to 64K by default */
-    if (alignment < page_shift) alignment = page_shift;
+    if (alignment <= 16) return 0xffff;  /* allocations must be aligned to 64K */
     if (alignment > 21) return 0;
     return (1 << alignment) - 1;
 }
-- 
2.23.0