[ros-diffs] [ros-arm-bringup] 43507: - Implement ARM3 page fault handling. - Paged pool PTEs are demand zero PTEs while the memory hasn't been accessed -- this is the only type of fault supported. - Because paged pool PDEs are also demand-paged, added code to handle demand paging of PDEs as well. - Also, because paged pool is non-resident, but can be accessed from any process, we need a mechanism to sync up the kernel's page directory with the per-process one, on demand. This is done at startup, but other p

Author: ros-arm-bringup
Date: Fri Oct 16 00:08:26 2009
New Revision: 43507

URL: http://svn.reactos.org/svn/reactos?rev=43507&view=rev
Log:
- Implement ARM3 page fault handling.
- Paged pool PTEs are demand zero PTEs while the memory hasn't been accessed -- this
is the only type of fault supported.
- Because paged pool PDEs are also demand-paged, added code to handle demand paging of
PDEs as well.
- Also, because paged pool is non-resident, but can be accessed from any process, we need
a mechanism to sync up the kernel's page directory with the per-process one, on
demand. This is done at startup, but other processes may have paged in paged pool that
another process knows nothing about when he faults.
  - Similar to the hack ReactOS Mm uses, but done properly.
  - This is what that shadow system page directory is finally being used for.
- Assert if we get a user-mode fault, a transition fault, or a soft fault, since these
shouldn't happen.
- Disable APCs while dispatching faults, and pseudo-use the working set lock.
- Assert if we get write errors on read-only pages, since we don't use those in ARM3
yet.
- Assert if we have a paged out PTE, this shouldn't happen yet.
- Enable test to see if we can touch a paged pool allocation.


Added:
    trunk/reactos/ntoskrnl/mm/ARM3/pagfault.c   (with props)
Modified:
    trunk/reactos/ntoskrnl/mm/mmfault.c
    trunk/reactos/ntoskrnl/mm/mminit.c
    trunk/reactos/ntoskrnl/ntoskrnl-generic.rbuild

Added: trunk/reactos/ntoskrnl/mm/ARM3/pagfault.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/mm/ARM3/pagfault.…
==============================================================================
--- trunk/reactos/ntoskrnl/mm/ARM3/pagfault.c (added)
+++ trunk/reactos/ntoskrnl/mm/ARM3/pagfault.c [iso-8859-1] Fri Oct 16 00:08:26 2009
@@ -1,0 +1,391 @@
+/*
+ * PROJECT:         ReactOS Kernel
+ * LICENSE:         BSD - See COPYING.ARM in the top level directory
+ * FILE:            ntoskrnl/mm/ARM3/pagfault.c
+ * PURPOSE:         ARM Memory Manager Page Fault Handling
+ * PROGRAMMERS:     ReactOS Portable Systems Group
+ */
+
+/* INCLUDES *******************************************************************/
+
+#include <ntoskrnl.h>
+#define NDEBUG
+#include <debug.h>
+
+#line 15 "ARM³::PAGFAULT"
+#define MODULE_INVOLVED_IN_ARM3
+#include "../ARM3/miarm.h"
+
+/* GLOBALS ********************************************************************/
+
+/* PRIVATE FUNCTIONS **********************************************************/
+
+NTSTATUS
+FASTCALL
+MiCheckPdeForPagedPool(IN PVOID Address)
+{
+    PMMPTE PointerPde;
+    NTSTATUS Status = STATUS_SUCCESS;
+    
+    //
+    // Check if this is a fault while trying to access the page table itself
+    //
+    if ((Address >= (PVOID)MiAddressToPte(MmSystemRangeStart)) &&
+        (Address < (PVOID)PTE_TOP))
+    {
+        //
+        // Send a hint to the page fault handler that this is only a valid fault
+        // if we already detected this was access within the page table range
+        //
+        PointerPde = MiAddressToPte(Address);
+        Status = STATUS_WAIT_1;
+    }
+    else if (Address < MmSystemRangeStart)
+    {
+        //
+        // This is totally illegal
+        //
+        return STATUS_ACCESS_VIOLATION;   
+    }
+    else
+    {
+        //
+        // Get the PDE for the address
+        //
+        PointerPde = MiAddressToPde(Address);
+    }
+    
+    //
+    // Check if it's not valid
+    //
+    if (PointerPde->u.Hard.Valid == 0)
+    {
+        //
+        // Copy it from our double-mapped system page directory
+        //
+        InterlockedExchangePte(PointerPde,
+                               MmSystemPagePtes[((ULONG_PTR)PointerPde &
+                                                 (PAGE_SIZE - 1)) /
+                                                sizeof(MMPTE)].u.Long);
+    }
+    
+    //
+    // Return status
+    //
+    return Status;
+}
+
+NTSTATUS
+NTAPI
+MiResolveDemandZeroFault(IN PVOID Address,
+                         IN PMMPTE PointerPte,
+                         IN PEPROCESS Process,
+                         IN KIRQL OldIrql)
+{
+    PFN_NUMBER PageFrameNumber;
+    MMPTE TempPte;
+    DPRINT("ARM3 Demand Zero Page Fault Handler for address: %p in process:
%p\n",
+            Address,
+            Process);
+    
+    //
+    // Lock the PFN database
+    //
+    OldIrql = KeAcquireQueuedSpinLock(LockQueuePfnLock);
+    ASSERT(PointerPte->u.Hard.Valid == 0);
+    
+    //
+    // Get a page
+    //
+    PageFrameNumber = MmAllocPage(MC_PPOOL, 0);
+    DPRINT("New pool page: %lx\n", PageFrameNumber);
+    
+    //
+    // Release PFN lock
+    //
+    KeReleaseQueuedSpinLock(LockQueuePfnLock, OldIrql);
+    
+    //
+    // Increment demand zero faults
+    //
+    InterlockedIncrement(&KeGetCurrentPrcb()->MmDemandZeroCount);
+    
+    //
+    // Build the PTE
+    //
+    TempPte = HyperTemplatePte;
+    TempPte.u.Hard.PageFrameNumber = PageFrameNumber;
+    *PointerPte = TempPte;
+    ASSERT(PointerPte->u.Hard.Valid == 1);
+    
+    //
+    // It's all good now
+    //
+    DPRINT("Paged pool page has now been paged in\n");
+    return STATUS_PAGE_FAULT_DEMAND_ZERO;
+}
+
+NTSTATUS
+NTAPI
+MiDispatchFault(IN BOOLEAN StoreInstruction,
+                IN PVOID Address,
+                IN PMMPTE PointerPte,
+                IN PMMPTE PrototypePte,
+                IN BOOLEAN Recursive,
+                IN PEPROCESS Process,
+                IN PVOID TrapInformation,
+                IN PVOID Vad)
+{
+    MMPTE TempPte;
+    KIRQL OldIrql;
+    NTSTATUS Status;
+    DPRINT("ARM3 Page Fault Dispatcher for address: %p in process: %p\n",
+            Address,
+            Process);
+    
+    //
+    // Make sure APCs are off and we're not at dispatch
+    //
+    OldIrql = KeGetCurrentIrql ();
+    ASSERT(OldIrql <= APC_LEVEL);
+    ASSERT(KeAreAllApcsDisabled () == TRUE);
+    
+    //
+    // Grab a copy of the PTE
+    //
+    TempPte = *PointerPte;
+    
+    //
+    // The PTE must be invalid, but not totally blank
+    //
+    ASSERT(TempPte.u.Hard.Valid == 0);
+    ASSERT(TempPte.u.Long != 0);
+    
+    //
+    // No prototype, transition or page file software PTEs in ARM3 yet
+    //
+    ASSERT(TempPte.u.Soft.Prototype == 0);
+    ASSERT(TempPte.u.Soft.Transition == 0);
+    ASSERT(TempPte.u.Soft.PageFileHigh == 0);
+    
+    //
+    // If we got this far, the PTE can only be a demand zero PTE, which is what
+    // we want. Go handle it!
+    //
+    Status = MiResolveDemandZeroFault(Address,
+                                      PointerPte,
+                                      Process,
+                                      -1);
+    if (NT_SUCCESS(Status))
+    {
+        //
+        // Make sure we're returning in a sane state and pass the status down
+        //
+        ASSERT(OldIrql == KeGetCurrentIrql ());
+        ASSERT(KeGetCurrentIrql() <= APC_LEVEL);
+        return Status;
+    }
+
+    //
+    // Generate an access fault
+    //
+    return STATUS_ACCESS_VIOLATION;
+}
+
+NTSTATUS
+NTAPI
+MmArmAccessFault(IN BOOLEAN StoreInstruction,
+                 IN PVOID Address,
+                 IN KPROCESSOR_MODE Mode,
+                 IN PVOID TrapInformation)
+{
+    KIRQL OldIrql = KeGetCurrentIrql(), LockIrql;
+    PMMPTE PointerPde, PointerPte;
+    MMPTE TempPte;
+    PETHREAD CurrentThread;
+    NTSTATUS Status;
+    DPRINT("ARM3 FAULT AT: %p\n", Address);
+    
+    //
+    // Get the PTE and PDE
+    //
+    PointerPte = MiAddressToPte(Address);
+    PointerPde = MiAddressToPde(Address);
+    
+    //
+    // Check for dispatch-level snafu
+    //
+    if (OldIrql > APC_LEVEL)
+    {
+        //
+        // There are some special cases where this is okay, but not in ARM3 yet
+        //
+        DbgPrint("MM:***PAGE FAULT AT IRQL > 1  Va %p, IRQL %lx\n",
+                 Address,
+                 OldIrql);
+        ASSERT(OldIrql <= APC_LEVEL);
+    }
+    
+    //
+    // Check for kernel fault
+    //
+    if (Address >= MmSystemRangeStart)
+    {
+        //
+        // What are you even DOING here?
+        //
+        if (Mode == UserMode) return STATUS_ACCESS_VIOLATION;
+        
+        //
+        // Is the PDE valid?
+        //
+        if (!PointerPde->u.Hard.Valid == 0)
+        {
+            //
+            // Debug spew (eww!)
+            //
+            DPRINT("Invalid PDE\n");
+            
+            //
+            // Handle mapping in "Special" PDE directoreis
+            //
+            MiCheckPdeForPagedPool(Address);
+            
+            //
+            // Now we SHOULD be good
+            //
+            if (PointerPde->u.Hard.Valid == 0)
+            {
+                //
+                // FIXFIX: Do the S-LIST hack
+                //
+                
+                //
+                // Kill the system
+                //
+                KeBugCheckEx(PAGE_FAULT_IN_NONPAGED_AREA,
+                             (ULONG_PTR)Address,
+                             StoreInstruction,
+                             (ULONG_PTR)TrapInformation,
+                             2);
+            }
+        }
+        
+        //
+        // The PDE is valid, so read the PTE
+        //
+        TempPte = *PointerPte;
+        if (TempPte.u.Hard.Valid == 1)
+        {
+            //
+            // Only two things can go wrong here:
+            // Executing NX page (we couldn't care less)
+            // Writing to a read-only page (the stuff ARM3 works with is write,
+            // so again, moot point).
+            //
+            if (StoreInstruction)
+            {
+                DPRINT1("Should NEVER happen on ARM3!!!\n");
+                return STATUS_ACCESS_VIOLATION;
+            }
+            
+            //
+            // Otherwise, the PDE was probably invalid, and all is good now
+            //
+            return STATUS_SUCCESS;
+        }
+        
+        //
+        // Check for a fault on the page table or hyperspace itself
+        // FIXME: Use MmHyperSpaceEnd
+        //
+        if ((Address >= (PVOID)PTE_BASE) && (Address <=
(PVOID)0xC0800000))
+        {
+            //
+            // This might happen...not sure yet
+            //
+            DPRINT1("FAULT ON PAGE TABLES!\n");
+            return STATUS_ACCESS_VIOLATION;
+        }
+        
+        //
+        // Now we must raise to APC_LEVEL and mark the thread as owner
+        // We don't actually implement a working set pushlock, so this is only
+        // for internal consistency (and blocking APCs)
+        //
+        KeRaiseIrql(APC_LEVEL, &LockIrql);
+        CurrentThread = PsGetCurrentThread();
+        KeEnterGuardedRegion();
+        ASSERT((CurrentThread->OwnsSystemWorkingSetExclusive == 0) &&
+               (CurrentThread->OwnsSystemWorkingSetShared == 0));
+        CurrentThread->OwnsSystemWorkingSetExclusive = 1; 
+        
+        //
+        // Re-read PTE now that the IRQL has been raised
+        //
+        TempPte = *PointerPte;
+        if (TempPte.u.Hard.Valid == 1)
+        {
+            //
+            // Only two things can go wrong here:
+            // Executing NX page (we couldn't care less)
+            // Writing to a read-only page (the stuff ARM3 works with is write,
+            // so again, moot point.
+            //
+            if (StoreInstruction)
+            {
+                DPRINT1("Should NEVER happen on ARM3!!!\n");
+                return STATUS_ACCESS_VIOLATION;
+            }
+            
+            //
+            // Otherwise, the PDE was probably invalid, and all is good now
+            //
+            return STATUS_SUCCESS;
+        }
+        
+        //
+        // We don't implement prototype PTEs
+        //
+        ASSERT(TempPte.u.Soft.Prototype == 0);
+        
+        //
+        // We don't implement transition PTEs
+        //
+        ASSERT(TempPte.u.Soft.Transition == 0);
+        
+        //
+        // Now do the real fault handling
+        //
+        Status = MiDispatchFault(StoreInstruction,
+                                 Address,
+                                 PointerPte,
+                                 NULL,
+                                 FALSE,
+                                 NULL,
+                                 TrapInformation,
+                                 NULL);
+        
+        //
+        // Re-enable APCs
+        //
+        ASSERT(KeAreAllApcsDisabled() == TRUE);
+        CurrentThread->OwnsSystemWorkingSetExclusive = 0;
+        KeLeaveGuardedRegion();
+        KeLowerIrql(LockIrql);
+        
+        //
+        // We are done!
+        //
+        DPRINT("Fault resolved with status: %lx\n", Status);
+        return Status;
+    }
+    
+    //
+    // DIE DIE DIE
+    //
+    DPRINT1("WARNING: USER MODE FAULT IN ARM3???\n");
+    return STATUS_ACCESS_VIOLATION;
+}
+
+/* EOF */

Propchange: trunk/reactos/ntoskrnl/mm/ARM3/pagfault.c
------------------------------------------------------------------------------
    svn:eol-style = native

Propchange: trunk/reactos/ntoskrnl/mm/ARM3/pagfault.c
------------------------------------------------------------------------------
    svn:mime-type = text/plain

Modified: trunk/reactos/ntoskrnl/mm/mmfault.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/mm/mmfault.c?rev=…
==============================================================================
--- trunk/reactos/ntoskrnl/mm/mmfault.c [iso-8859-1] (original)
+++ trunk/reactos/ntoskrnl/mm/mmfault.c [iso-8859-1] Fri Oct 16 00:08:26 2009
@@ -283,9 +283,7 @@
         //
         // Hand it off to more competent hands...
         //
-        UNIMPLEMENTED;
-        KeBugCheckEx(MEMORY_AREA_OWNED_BY_ARM3, Mode, (ULONG_PTR)Address, 0, 0);
-        //return MmArmAccessFault(StoreInstruction, Address, Mode, TrapInformation);
+        return MmArmAccessFault(StoreInstruction, Address, Mode, TrapInformation);
     }   
 
     /* Keep same old ReactOS Behaviour */

Modified: trunk/reactos/ntoskrnl/mm/mminit.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/mm/mminit.c?rev=4…
==============================================================================
--- trunk/reactos/ntoskrnl/mm/mminit.c [iso-8859-1] (original)
+++ trunk/reactos/ntoskrnl/mm/mminit.c [iso-8859-1] Fri Oct 16 00:08:26 2009
@@ -403,12 +403,12 @@
         // STEP 3: Allocate a page and touch it.
         // We should get an ARM3 page fault and it should handle the fault
         //
-        if (0) // NOT YET IMPLEMENTED
+        if (1)
         {
             PULONG Test;
             
             Test = MiAllocatePoolPages(PagedPool, PAGE_SIZE);
-            DPRINT1("Value: %lx", *Test);
+            ASSERT(*Test == 0);
             MiFreePoolPages(Test);
         }
         

Modified: trunk/reactos/ntoskrnl/ntoskrnl-generic.rbuild
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/ntoskrnl-generic.…
==============================================================================
--- trunk/reactos/ntoskrnl/ntoskrnl-generic.rbuild [iso-8859-1] (original)
+++ trunk/reactos/ntoskrnl/ntoskrnl-generic.rbuild [iso-8859-1] Fri Oct 16 00:08:26 2009
@@ -392,6 +392,7 @@
 			<file>mdlsup.c</file>
 			<file>mmsup.c</file>
 			<file>ncache.c</file>
+			<file>pagfault.c</file>
 			<file>pool.c</file>
 			<file>procsup.c</file>
 			<file>syspte.c</file>