[reactos] 08/100: [NTOSKRNL] Embed a SECTION struct inside MM_ROS_SECTION_OBJECT

[Jérôme Gardou]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=25722e647e0f105d77ee2…

commit 25722e647e0f105d77ee28fa6d12999afe21cab8
Author:     Jérôme Gardou <jerome.gardou(a)reactos.org>
AuthorDate: Fri Oct 23 14:42:21 2020 +0200
Commit:     Jérôme Gardou <jerome.gardou(a)reactos.org>
CommitDate: Wed Feb 3 09:41:21 2021 +0100

    [NTOSKRNL] Embed a SECTION struct inside MM_ROS_SECTION_OBJECT
---
 ntoskrnl/include/internal/mm.h | 17 +++-------------
 ntoskrnl/mm/ARM3/miarm.h       |  3 +--
 ntoskrnl/mm/section.c          | 45 +++++++++++++++++++++++++-----------------
 3 files changed, 31 insertions(+), 34 deletions(-)

diff --git a/ntoskrnl/include/internal/mm.h b/ntoskrnl/include/internal/mm.h
index 5700ad8ff65..c118866d5b5 100644
--- a/ntoskrnl/include/internal/mm.h
+++ b/ntoskrnl/include/internal/mm.h
@@ -196,21 +196,10 @@ typedef struct _MM_IMAGE_SECTION_OBJECT
 
 typedef struct _ROS_SECTION_OBJECT
 {
-    CSHORT Type;
-    CSHORT Size;
-    LARGE_INTEGER SizeOfSection;
-    ULONG InitialPageProtection;
-    union
-    {
-        ULONG LongFlags;
-        MMSECTION_FLAGS Flags;
-    } u;
+    SECTION;
     PFILE_OBJECT FileObject;
-    union
-    {
-        PMM_IMAGE_SECTION_OBJECT ImageSection;
-        PMM_SECTION_SEGMENT Segment;
-    };
+
+    PMM_IMAGE_SECTION_OBJECT ImageSection;
 } ROS_SECTION_OBJECT, *PROS_SECTION_OBJECT;
 
 #define MA_GetStartingAddress(_MemoryArea) ((_MemoryArea)->VadNode.StartingVpn
<< PAGE_SHIFT)
diff --git a/ntoskrnl/mm/ARM3/miarm.h b/ntoskrnl/mm/ARM3/miarm.h
index b374e94ad75..ade2696cf1d 100644
--- a/ntoskrnl/mm/ARM3/miarm.h
+++ b/ntoskrnl/mm/ARM3/miarm.h
@@ -1072,8 +1072,7 @@ BOOLEAN
 MiIsRosSectionObject(IN PVOID Section)
 {
     PROS_SECTION_OBJECT RosSection = Section;
-    if ((RosSection->Type == 'SC') && (RosSection->Size ==
'TN')) return TRUE;
-    return FALSE;
+    return RosSection->u.Flags.filler;
 }
 
 #define MI_IS_ROS_PFN(x)     ((x)->u4.AweAllocation == TRUE)
diff --git a/ntoskrnl/mm/section.c b/ntoskrnl/mm/section.c
index 9920f36ddcf..fbf44868d90 100644
--- a/ntoskrnl/mm/section.c
+++ b/ntoskrnl/mm/section.c
@@ -2684,7 +2684,7 @@ MmpDeleteSection(PVOID ObjectBody)
         if (Section->Segment == NULL)
             return;
 
-        (void)InterlockedDecrementUL(&Section->Segment->ReferenceCount);
+       
(void)InterlockedDecrementUL(&((PMM_SECTION_SEGMENT)Section->Segment)->ReferenceCount);
     }
     if (Section->FileObject != NULL)
     {
@@ -2750,8 +2750,9 @@ MmCreatePhysicalMemorySection(VOID)
      * Initialize it
      */
     RtlZeroMemory(PhysSection, sizeof(ROS_SECTION_OBJECT));
-    PhysSection->Type = 'SC';
-    PhysSection->Size = 'TN';
+
+    /* Mark this as a "ROS Section" */
+    PhysSection->u.Flags.filler = 1;
     PhysSection->InitialPageProtection = PAGE_EXECUTE_READWRITE;
     PhysSection->u.Flags.PhysicalMemory = 1;
     PhysSection->SizeOfSection = SectionSize;
@@ -2763,7 +2764,7 @@ MmCreatePhysicalMemorySection(VOID)
         return(STATUS_NO_MEMORY);
     }
     RtlZeroMemory(Segment, sizeof(MM_SECTION_SEGMENT));
-    PhysSection->Segment = Segment;
+    PhysSection->Segment = (PSEGMENT)Segment;
     Segment->ReferenceCount = 1;
     ExInitializeFastMutex(&Segment->Lock);
     Segment->Image.FileOffset = 0;
@@ -2865,8 +2866,9 @@ MmCreateDataFileSection(PROS_SECTION_OBJECT *SectionObject,
      * Initialize it
      */
     RtlZeroMemory(Section, sizeof(ROS_SECTION_OBJECT));
-    Section->Type = 'SC';
-    Section->Size = 'TN';
+
+    /* Mark this as a "ROS" section */
+    Section->u.Flags.filler = 1;
     Section->InitialPageProtection = SectionPageProtection;
     Section->u.Flags.File = 1;
     if (AllocationAttributes & SEC_NO_CHANGE)
@@ -2958,7 +2960,7 @@ MmCreateDataFileSection(PROS_SECTION_OBJECT *SectionObject,
             ObDereferenceObject(FileObject);
             return(STATUS_NO_MEMORY);
         }
-        Section->Segment = Segment;
+        Section->Segment = (PSEGMENT)Segment;
         Segment->ReferenceCount = 1;
         ExInitializeFastMutex(&Segment->Lock);
         /*
@@ -2994,7 +2996,7 @@ MmCreateDataFileSection(PROS_SECTION_OBJECT *SectionObject,
         Segment =
             (PMM_SECTION_SEGMENT)FileObject->SectionObjectPointer->
             DataSectionObject;
-        Section->Segment = Segment;
+        Section->Segment = (PSEGMENT)Segment;
         (void)InterlockedIncrementUL(&Segment->ReferenceCount);
         MmLockSectionSegment(Segment);
 
@@ -3692,8 +3694,10 @@ MmCreateImageSection(PROS_SECTION_OBJECT *SectionObject,
      * Initialize it
      */
     RtlZeroMemory(Section, sizeof(ROS_SECTION_OBJECT));
-    Section->Type = 'SC';
-    Section->Size = 'TN';
+
+    /* Mark this as a "ROS" Section */
+    Section->u.Flags.filler = 1;
+
     Section->InitialPageProtection = SectionPageProtection;
     Section->u.Flags.File = 1;
     Section->u.Flags.Image = 1;
@@ -4256,8 +4260,8 @@ NtQuerySection(
                     }
                     else
                     {
-                        Sbi->BaseAddress =
(PVOID)RosSection->Segment->Image.VirtualAddress;
-                        Sbi->Size.QuadPart =
RosSection->Segment->Length.QuadPart;
+                        Sbi->BaseAddress =
(PVOID)((PMM_SECTION_SEGMENT)RosSection->Segment)->Image.VirtualAddress;
+                        Sbi->Size.QuadPart =
((PMM_SECTION_SEGMENT)RosSection->Segment)->Length.QuadPart;
                     }
 
                     if (ResultLength != NULL)
@@ -4557,6 +4561,8 @@ MmMapViewOfSection(IN PVOID SectionObject,
     }
     else
     {
+        PMM_SECTION_SEGMENT Segment = (PMM_SECTION_SEGMENT)Section->Segment;
+
         /* check for write access */
         if ((Protect & (PAGE_READWRITE|PAGE_EXECUTE_READWRITE)) &&
                 !(Section->InitialPageProtection &
(PAGE_READWRITE|PAGE_EXECUTE_READWRITE)))
@@ -4605,16 +4611,16 @@ MmMapViewOfSection(IN PVOID SectionObject,
 
         *ViewSize = PAGE_ROUND_UP(*ViewSize);
 
-        MmLockSectionSegment(Section->Segment);
+        MmLockSectionSegment(Segment);
         Status = MmMapViewOfSegment(AddressSpace,
                                     Section,
-                                    Section->Segment,
+                                    Segment,
                                     BaseAddress,
                                     *ViewSize,
                                     Protect,
                                     ViewOffset,
                                     AllocationType & (MEM_TOP_DOWN|SEC_NO_CHANGE));
-        MmUnlockSectionSegment(Section->Segment);
+        MmUnlockSectionSegment(Segment);
         if (!NT_SUCCESS(Status))
         {
             MmUnlockAddressSpace(AddressSpace);
@@ -4765,6 +4771,7 @@ MmMapViewInSystemSpace (IN PVOID SectionObject,
                         IN OUT PSIZE_T ViewSize)
 {
     PROS_SECTION_OBJECT Section;
+    PMM_SECTION_SEGMENT Segment;
     PMMSUPPORT AddressSpace;
     NTSTATUS Status;
     PAGED_CODE();
@@ -4780,6 +4787,8 @@ MmMapViewInSystemSpace (IN PVOID SectionObject,
     DPRINT("MmMapViewInSystemSpace() called\n");
 
     Section = (PROS_SECTION_OBJECT)SectionObject;
+    Segment = (PMM_SECTION_SEGMENT)Section->Segment;
+
     AddressSpace = MmGetKernelAddressSpace();
 
     MmLockAddressSpace(AddressSpace);
@@ -4794,19 +4803,19 @@ MmMapViewInSystemSpace (IN PVOID SectionObject,
         (*ViewSize) = Section->SizeOfSection.u.LowPart;
     }
 
-    MmLockSectionSegment(Section->Segment);
+    MmLockSectionSegment(Segment);
 
 
     Status = MmMapViewOfSegment(AddressSpace,
                                 Section,
-                                Section->Segment,
+                                Segment,
                                 MappedBase,
                                 *ViewSize,
                                 PAGE_READWRITE,
                                 0,
                                 0);
 
-    MmUnlockSectionSegment(Section->Segment);
+    MmUnlockSectionSegment(Segment);
     MmUnlockAddressSpace(AddressSpace);
 
     return Status;