[ros-diffs] [reactos] 05/09: [NTOS:MM:X64] Simplify and fix x64 mapping code

[Timo Kreuzer]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=8980850d565c226ec064e…

commit 8980850d565c226ec064e6ee0613ebeace8c6b51
Author:     Timo Kreuzer <timo.kreuzer(a)reactos.org>
AuthorDate: Sun Feb 4 13:33:14 2018 +0100
Commit:     Timo Kreuzer <timo.kreuzer(a)reactos.org>
CommitDate: Sun Nov 1 09:32:27 2020 +0100

    [NTOS:MM:X64] Simplify and fix x64 mapping code
    
    - Use demand-zero-ptes in MiGetPteForProcess
    - Handle NoExecute in MiSetPteProtection
    - Fix MmIsPageSwapEntry
    - Fix MmGetPageFileMapping
    - remove obsolete functions.
---
 ntoskrnl/mm/amd64/page.c | 121 +++++++++++++++++------------------------------
 1 file changed, 44 insertions(+), 77 deletions(-)

diff --git a/ntoskrnl/mm/amd64/page.c b/ntoskrnl/mm/amd64/page.c
index afae9827191..0559de76b88 100644
--- a/ntoskrnl/mm/amd64/page.c
+++ b/ntoskrnl/mm/amd64/page.c
@@ -144,75 +144,65 @@ MiGetPteForProcess(
     PVOID Address,
     BOOLEAN Create)
 {
-    MMPTE TmplPte, *Pte;
+    PMMPTE Pte;
+    PMMPDE Pde;
+    PMMPPE Ppe;
+    PMMPXE Pxe;
 
-    /* Check if we need hypersapce mapping */
-    if (Address < MmSystemRangeStart &&
-        Process && Process != PsGetCurrentProcess())
+    /* Make sure the process is correct */
+    if (Address < MmSystemRangeStart)
     {
-        UNIMPLEMENTED;
-        __debugbreak();
-        return NULL;
+        ASSERT(Process == PsGetCurrentProcess());
     }
-    else if (Create)
+    else
     {
-        KIRQL OldIrql;
-        TmplPte.u.Long = 0;
-        TmplPte.u.Flush.Valid = 1;
-        TmplPte.u.Flush.Write = 1;
-
-        /* All page table levels of user pages are user owned */
-        TmplPte.u.Flush.Owner = (Address < MmHighestUserAddress) ? 1 : 0;
+        ASSERT((Process == NULL) || (Process == PsGetCurrentProcess()));
+    }
 
-        /* Lock the PFN database */
-        OldIrql = MiAcquirePfnLock();
+    Pxe = MiAddressToPxe(Address);
+    Ppe = MiAddressToPpe(Address);
+    Pde = MiAddressToPde(Address);
+    Pte = MiAddressToPte(Address);
 
-        /* Get the PXE */
-        Pte = MiAddressToPxe(Address);
-        if (!Pte->u.Hard.Valid)
+    if (Create)
+    {
+        /* Check the PXE */
+        if (Pxe->u.Long == 0)
         {
-            TmplPte.u.Hard.PageFrameNumber = MiRemoveZeroPage(0);
-            MI_WRITE_VALID_PTE(Pte, TmplPte);
+            /* Make it demand zero */
+            MI_WRITE_INVALID_PDE(Pxe, DemandZeroPde);
         }
 
-        /* Get the PPE */
-        Pte = MiAddressToPpe(Address);
-        if (!Pte->u.Hard.Valid)
+        /* Check the PPE */
+        if (Ppe->u.Long == 0)
         {
-            TmplPte.u.Hard.PageFrameNumber = MiRemoveZeroPage(1);
-            MI_WRITE_VALID_PTE(Pte, TmplPte);
+            /* Make it demand zero */
+            MI_WRITE_INVALID_PDE(Ppe, DemandZeroPde);
         }
 
-        /* Get the PDE */
-        Pte = MiAddressToPde(Address);
-        if (!Pte->u.Hard.Valid)
+        /* Check the PDE */
+        if (Pde->u.Long == 0)
         {
-            TmplPte.u.Hard.PageFrameNumber = MiRemoveZeroPage(2);
-            MI_WRITE_VALID_PTE(Pte, TmplPte);
+            /* Make it demand zero */
+            MI_WRITE_INVALID_PDE(Pde, DemandZeroPde);
         }
-
-        /* Unlock PFN database */
-        MiReleasePfnLock(OldIrql);
     }
     else
     {
-        /* Get the PXE */
-        Pte = MiAddressToPxe(Address);
-        if (!Pte->u.Hard.Valid)
+        /* Check the PXE */
+        if (!Pxe->u.Hard.Valid)
             return NULL;
 
-        /* Get the PPE */
-        Pte = MiAddressToPpe(Address);
-        if (!Pte->u.Hard.Valid)
+        /* Check the PPE */
+        if (!Ppe->u.Hard.Valid)
             return NULL;
 
-        /* Get the PDE */
-        Pte = MiAddressToPde(Address);
-        if (!Pte->u.Hard.Valid)
+        /* Check the PDE */
+        if (!Pde->u.Hard.Valid)
             return NULL;
     }
 
-    return MiAddressToPte(Address);
+    return Pte;
 }
 
 static
@@ -272,8 +262,8 @@ MiGetPteProtection(MMPTE Pte)
     return Protect;
 }
 
+static
 VOID
-NTAPI
 MiSetPteProtection(PMMPTE Pte, ULONG Protection)
 {
     Pte->u.Flush.CopyOnWrite = (Protection & PAGE_WRITECOPY_ANY) ? 1 : 0;
@@ -282,7 +272,7 @@ MiSetPteProtection(PMMPTE Pte, ULONG Protection)
     Pte->u.Flush.WriteThrough = (Protection & PAGE_WRITETHROUGH) ? 1 : 0;
 
     // FIXME: This doesn't work. Why?
-//    Pte->u.Flush.NoExecute = (Protection & PAGE_EXECUTE_ANY) ? 0 : 1;
+    Pte->u.Flush.NoExecute = (Protection & PAGE_EXECUTE_ANY) ? 0 : 1;
 }
 
 /* FUNCTIONS ***************************************************************/
@@ -324,34 +314,7 @@ MmIsPageSwapEntry(PEPROCESS Process, PVOID Address)
 {
     MMPTE Pte;
     Pte.u.Long = MiGetPteValueForProcess(Process, Address);
-    return Pte.u.Hard.Valid && Pte.u.Soft.Transition;
-}
-
-static PMMPTE
-MmGetPageTableForProcess(PEPROCESS Process, PVOID Address, BOOLEAN Create)
-{
-    __debugbreak();
-    return 0;
-}
-
-BOOLEAN MmUnmapPageTable(PMMPTE Pt)
-{
-    ASSERT(FALSE);
-    return 0;
-}
-
-static ULONG64 MmGetPageEntryForProcess(PEPROCESS Process, PVOID Address)
-{
-    MMPTE Pte, *PointerPte;
-
-    PointerPte = MmGetPageTableForProcess(Process, Address, FALSE);
-    if (PointerPte)
-    {
-        Pte = *PointerPte;
-        MmUnmapPageTable(PointerPte);
-        return Pte.u.Long;
-    }
-    return 0;
+    return !Pte.u.Hard.Valid && Pte.u.Soft.Transition;
 }
 
 VOID
@@ -361,8 +324,12 @@ MmGetPageFileMapping(
     PVOID Address,
     SWAPENTRY* SwapEntry)
 {
-	ULONG64 Entry = MmGetPageEntryForProcess(Process, Address);
-	*SwapEntry = Entry >> 1;
+    PMMPTE PointerPte;
+
+    ASSERT(Process == PsGetCurrentProcess());
+
+    PointerPte = MiAddressToPte(Address);
+    *SwapEntry = PointerPte->u.Long >> 1;
 }
 
 BOOLEAN