[ros-diffs] [fireball] 32672: - Factor out physical pages allocation and creating a virtual mapping into a standalone function called MmMapMemoryArea (idea proposed by Art Yerkes). - As a result, removed one case of a potentially dangerous _alloca usage in the kernel, increased code readability.

Author: fireball
Date: Thu Mar 13 08:17:57 2008
New Revision: 32672

URL: http://svn.reactos.org/svn/reactos?rev=3D32672&view=3Drev
Log:
- Factor out physical pages allocation and creating a virtual mapping into =
a standalone function called MmMapMemoryArea (idea proposed by Art Yerkes).
- As a result, removed one case of a potentially dangerous _alloca usage in=
 the kernel, increased code readability.

Modified:
    trunk/reactos/ntoskrnl/cc/view.c
    trunk/reactos/ntoskrnl/include/internal/mm.h
    trunk/reactos/ntoskrnl/mm/marea.c
    trunk/reactos/ntoskrnl/mm/ncache.c
    trunk/reactos/ntoskrnl/mm/section.c

Modified: trunk/reactos/ntoskrnl/cc/view.c
URL: http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/cc/view.c?re=
v=3D32672&r1=3D32671&r2=3D32672&view=3Ddiff
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D
--- trunk/reactos/ntoskrnl/cc/view.c (original)
+++ trunk/reactos/ntoskrnl/cc/view.c Thu Mar 13 08:17:57 2008
@@ -561,16 +561,13 @@
    		ULONG FileOffset,
    		PCACHE_SEGMENT* CacheSeg)
 {
-  ULONG i;
   PCACHE_SEGMENT current;
   PCACHE_SEGMENT previous;
   PLIST_ENTRY current_entry;
   NTSTATUS Status;
   KIRQL oldIrql;
-  PPFN_TYPE Pfn;
 #ifdef CACHE_BITMAP
   ULONG StartingOffset;
-#else
 #endif
   PHYSICAL_ADDRESS BoundaryAddressMultiple;
 =

@@ -706,24 +703,10 @@
      KEBUGCHECKCC;
   }
 #endif
-  Pfn =3D alloca(sizeof(PFN_TYPE) * ((Bcb->CacheSegmentSize / PAGE_SIZE)));
-  for (i =3D 0; i < (Bcb->CacheSegmentSize / PAGE_SIZE); i++)
-  {
-     Status =3D MmRequestPageMemoryConsumer(MC_CACHE, TRUE, &Pfn[i]);
-     if (!NT_SUCCESS(Status))
-     {
-	KEBUGCHECKCC;
-     }
-  }
-  Status =3D MmCreateVirtualMapping(NULL,
-				  current->BaseAddress,
-				  PAGE_READWRITE,
-				  Pfn,
-				  Bcb->CacheSegmentSize / PAGE_SIZE);
-  if (!NT_SUCCESS(Status))
-  {
-    KEBUGCHECKCC;
-  }
+
+  /* Create a virtual mapping for this memory area */
+  MmMapMemoryArea(current->BaseAddress, Bcb->CacheSegmentSize,
+      MC_CACHE, PAGE_READWRITE);
 =

return(STATUS_SUCCESS);
 }

Modified: trunk/reactos/ntoskrnl/include/internal/mm.h
URL: http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/include/inte=
rnal/mm.h?rev=3D32672&r1=3D32671&r2=3D32672&view=3Ddiff
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D
--- trunk/reactos/ntoskrnl/include/internal/mm.h (original)
+++ trunk/reactos/ntoskrnl/include/internal/mm.h Thu Mar 13 08:17:57 2008
@@ -503,6 +503,13 @@
     PVOID BaseAddress
 );
 =

+VOID
+NTAPI
+MmMapMemoryArea(PVOID BaseAddress,
+                ULONG Length,
+                ULONG Consumer,
+                ULONG Protection);
+
 /* npool.c ***************************************************************=
****/
 =

VOID

Modified: trunk/reactos/ntoskrnl/mm/marea.c
URL: http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/mm/marea.c?r=
ev=3D32672&r1=3D32671&r2=3D32672&view=3Ddiff
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D
--- trunk/reactos/ntoskrnl/mm/marea.c (original)
+++ trunk/reactos/ntoskrnl/mm/marea.c Thu Mar 13 08:17:57 2008
@@ -1022,6 +1022,38 @@
    return STATUS_SUCCESS;
 }
 =

+VOID NTAPI
+MmMapMemoryArea(PVOID BaseAddress,
+                ULONG Length,
+                ULONG Consumer,
+                ULONG Protection)
+{
+   ULONG i;
+   NTSTATUS Status;
+
+   for (i =3D 0; i < PAGE_ROUND_UP(Length) / PAGE_SIZE; i++)
+   {
+      PFN_TYPE Page;
+
+      Status =3D MmRequestPageMemoryConsumer(Consumer, TRUE, &Page);
+      if (!NT_SUCCESS(Status))
+      {
+         DPRINT1("Unable to allocate page\n");
+         KEBUGCHECK(0);
+      }
+      Status =3D MmCreateVirtualMapping (NULL,
+                                       (PVOID)((ULONG_PTR)BaseAddress + (i=
 * PAGE_SIZE)),
+                                       Protection,
+                                       &Page,
+                                       1);
+      if (!NT_SUCCESS(Status))
+      {
+         DPRINT1("Unable to create virtual mapping\n");
+         KEBUGCHECK(0);
+      }
+   }
+}
+
 =

VOID STDCALL
 MmReleaseMemoryAreaIfDecommitted(PEPROCESS Process,

Modified: trunk/reactos/ntoskrnl/mm/ncache.c
URL: http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/mm/ncache.c?=
rev=3D32672&r1=3D32671&r2=3D32672&view=3Ddiff
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D
--- trunk/reactos/ntoskrnl/mm/ncache.c (original)
+++ trunk/reactos/ntoskrnl/mm/ncache.c Thu Mar 13 08:17:57 2008
@@ -46,7 +46,6 @@
    PVOID Result;
    MEMORY_AREA* marea;
    NTSTATUS Status;
-   ULONG i;
    ULONG Protect =3D PAGE_READWRITE|PAGE_SYSTEM|PAGE_NOCACHE|PAGE_WRITETHR=
OUGH;
    PHYSICAL_ADDRESS BoundaryAddressMultiple;
 =

@@ -66,20 +65,14 @@
 =

if (!NT_SUCCESS(Status))
    {
+      DPRINT1("Allocating marea for noncached mem failed with Status "
+          "0x%08X\n", Status);
       return (NULL);
    }
 =

-   for (i =3D 0; i < (PAGE_ROUND_UP(NumberOfBytes) / PAGE_SIZE); i++)
-   {
-      PFN_TYPE NPage;
+   /* Create a virtual mapping for this memory area */
+   MmMapMemoryArea(Result, NumberOfBytes, MC_NPPOOL, Protect);
 =

-      Status =3D MmRequestPageMemoryConsumer(MC_NPPOOL, TRUE, &NPage);
-      MmCreateVirtualMapping (NULL,
-                              (char*)Result + (i * PAGE_SIZE),
-                              Protect,
-                              &NPage,
-                              1);
-   }
    return ((PVOID)Result);
 }
 =

Modified: trunk/reactos/ntoskrnl/mm/section.c
URL: http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/mm/section.c=
?rev=3D32672&r1=3D32671&r2=3D32672&view=3Ddiff
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D
--- trunk/reactos/ntoskrnl/mm/section.c (original)
+++ trunk/reactos/ntoskrnl/mm/section.c Thu Mar 13 08:17:57 2008
@@ -4391,7 +4391,6 @@
    PVOID Result;
    MEMORY_AREA* marea;
    NTSTATUS Status;
-   ULONG i;
    PMADDRESS_SPACE AddressSpace;
    PHYSICAL_ADDRESS BoundaryAddressMultiple;
 =

@@ -4418,27 +4417,10 @@
       return (NULL);
    }
    DPRINT("Result %p\n",Result);
-   for (i =3D 0; i < PAGE_ROUND_UP(Length) / PAGE_SIZE; i++)
-   {
-      PFN_TYPE Page;
-
-      Status =3D MmRequestPageMemoryConsumer(MC_NPPOOL, TRUE, &Page);
-      if (!NT_SUCCESS(Status))
-      {
-         DPRINT1("Unable to allocate page\n");
-         KEBUGCHECK(0);
-      }
-      Status =3D MmCreateVirtualMapping (NULL,
-                                       (PVOID)((ULONG_PTR)Result + (i * PA=
GE_SIZE)),
-                                       PAGE_READWRITE,
-                                       &Page,
-                                       1);
-      if (!NT_SUCCESS(Status))
-      {
-         DPRINT1("Unable to create virtual mapping\n");
-         KEBUGCHECK(0);
-      }
-   }
+
+   /* Create a virtual mapping for this memory area */
+   MmMapMemoryArea(Result, Length, MC_NPPOOL, PAGE_READWRITE);
+
    return ((PVOID)Result);
 }
 =