[ros-arm-bringup] 34640: - Improve system call handler by adding more debugging checks to be used later. - Optimize and simplify trap handling by using a common exit just like on x86's Kei386EoiHelper - KiExceptionExit. This way the code isn't duplicated 6 times. - Do the same for system calls (KiServiceExit). - Save the previous trap frame and restore it during each system call.

Author: ros-arm-bringup
Date: Mon Jul 21 10:55:58 2008
New Revision: 34640

URL: http://svn.reactos.org/svn/reactos?rev=34640&view=rev
Log:
- Improve system call handler by adding more debugging checks to be used later.
- Optimize and simplify trap handling by using a common exit just like on x86's
Kei386EoiHelper - KiExceptionExit. This way the code isn't duplicated 6 times.
- Do the same for system calls (KiServiceExit).
- Save the previous trap frame and restore it during each system call.


Modified:
    trunk/reactos/ntoskrnl/include/internal/arm/ksarm.h
    trunk/reactos/ntoskrnl/ke/arm/trap.s
    trunk/reactos/ntoskrnl/ke/arm/trapc.c
    trunk/reactos/ntoskrnl/ke/arm/usercall.c

Modified: trunk/reactos/ntoskrnl/include/internal/arm/ksarm.h
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/include/internal/…
==============================================================================
--- trunk/reactos/ntoskrnl/include/internal/arm/ksarm.h [iso-8859-1] (original)
+++ trunk/reactos/ntoskrnl/include/internal/arm/ksarm.h [iso-8859-1] Mon Jul 21 10:55:58
2008
@@ -62,7 +62,7 @@
 .equ TrSvcLr,              0x44
 .equ TrPc,                 0x48
 .equ TrSpsr,               0x4C
-.equ TrapFrameLength,      (22 * 0x04)
+.equ TrapFrameLength,      (23 * 0x04)
 
 /*
  * Exception Frame offsets

Modified: trunk/reactos/ntoskrnl/ke/arm/trap.s
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/ke/arm/trap.s?rev…
==============================================================================
--- trunk/reactos/ntoskrnl/ke/arm/trap.s [iso-8859-1] (original)
+++ trunk/reactos/ntoskrnl/ke/arm/trap.s [iso-8859-1] Mon Jul 21 10:55:58 2008
@@ -31,7 +31,6 @@
     TEXTAREA
     NESTED_ENTRY KiUndefinedInstructionException
     PROLOG_END KiUndefinedInstructionException
-    
     //
     // Handle trap entry
     //
@@ -40,21 +39,14 @@
     //
     // Call the C handler
     //
-    adr lr, 1f
+    ldr lr, =KiExceptionExit
     mov r0, sp
     ldr pc, =KiUndefinedExceptionHandler
+    ENTRY_END KiUndefinedInstructionException
     
-1:
-    //
-    // Handle trap exit
-    // 
-    TRAP_EPILOG 0 // NotFromSystemCall
-    
-    ENTRY_END KiUndefinedInstructionException
     
     NESTED_ENTRY KiSoftwareInterruptException
     PROLOG_END KiSoftwareInterruptException
-
     //
     // Handle trap entry
     //
@@ -63,21 +55,14 @@
     //
     // Call the C handler
     //
-    adr lr, 1f
+    ldr lr, =KiServiceExit
     mov r0, sp
     ldr pc, =KiSoftwareInterruptHandler
-    
-1:
-    //
-    // Handle trap exit
-    // 
-    TRAP_EPILOG 1 // FromSystemCall
-    
     ENTRY_END KiSoftwareInterruptException
+
 
     NESTED_ENTRY KiPrefetchAbortException
     PROLOG_END KiPrefetchAbortException
-    
     //
     // Handle trap entry
     //
@@ -86,21 +71,14 @@
     //
     // Call the C handler
     //
-    adr lr, 1f
+    ldr lr, =KiExceptionExit
     mov r0, sp
     ldr pc, =KiPrefetchAbortHandler
-    
-1:
-    //
-    // Handle trap exit
-    // 
-    TRAP_EPILOG 0 // NotFromSystemCall
-    
     ENTRY_END KiPrefetchAbortException
+
 
     NESTED_ENTRY KiDataAbortException
     PROLOG_END KiDataAbortException
-    
     //
     // Handle trap entry
     //
@@ -109,21 +87,14 @@
     //
     // Call the C handler
     //
-    adr lr, 1f
+    ldr lr, =KiExceptionExit
     mov r0, sp
     ldr pc, =KiDataAbortHandler
+    ENTRY_END KiDataAbortException
 
-1:
-    //
-    // Handle trap exit
-    // 
-    TRAP_EPILOG 0 // NotFromSystemCall
-    
-    ENTRY_END KiDataAbortException
 
     NESTED_ENTRY KiInterruptException
     PROLOG_END KiInterruptException
-        
     //
     // Handle trap entry
     //
@@ -132,25 +103,35 @@
     //
     // Call the C handler
     //
-    adr lr, 1f
+    ldr lr, =KiExceptionExit
     mov r0, sp
     mov r1, #0
     ldr pc, =KiInterruptHandler
+    ENTRY_END KiInterruptException
+
+
+    NESTED_ENTRY KiFastInterruptException
+    PROLOG_END KiFastInterruptException
+    //
+    // FIXME-PERF: Implement FIQ exception
+    //
+    b .
+    ENTRY_END KiFastInterruptException
     
-1:
+    
+    NESTED_ENTRY KiExceptionExit
+    PROLOG_END KiExceptionExit
     //
     // Handle trap exit
     // 
     TRAP_EPILOG 0 // NotFromSystemCall
-    
-    ENTRY_END KiInterruptException
+    ENTRY_END KiExceptionExit
 
-    NESTED_ENTRY KiFastInterruptException
-    PROLOG_END KiFastInterruptException
-    
+
+    NESTED_ENTRY KiServiceExit
+    PROLOG_END KiServiceExit
     //
-    // FIXME-PERF: Implement FIQ exception
-    //
-    b .
-    
-    ENTRY_END KiFastInterruptException
+    // Handle trap exit
+    // 
+    TRAP_EPILOG 1 // FromSystemCall
+    ENTRY_END KiServiceExit

Modified: trunk/reactos/ntoskrnl/ke/arm/trapc.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/ke/arm/trapc.c?re…
==============================================================================
--- trunk/reactos/ntoskrnl/ke/arm/trapc.c [iso-8859-1] (original)
+++ trunk/reactos/ntoskrnl/ke/arm/trapc.c [iso-8859-1] Mon Jul 21 10:55:58 2008
@@ -457,7 +457,6 @@
     //
     // Unhandled
     //
-    while (TRUE);
     DPRINT1("[PREFETCH ABORT] (%x) @ %p/%p/%p\n",
             KeArmInstructionFaultStatusRegisterGet(), Address, TrapFrame->SvcLr,
TrapFrame->Pc);
     UNIMPLEMENTED;
@@ -516,6 +515,7 @@
     // Save old previous mode
     //
     TrapFrame->PreviousMode = PreviousMode;
+    TrapFrame->PreviousTrapFrame = (ULONG_PTR)Thread->TrapFrame;
     
     //
     // Save previous mode and trap frame

Modified: trunk/reactos/ntoskrnl/ke/arm/usercall.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/ke/arm/usercall.c…
==============================================================================
--- trunk/reactos/ntoskrnl/ke/arm/usercall.c [iso-8859-1] (original)
+++ trunk/reactos/ntoskrnl/ke/arm/usercall.c [iso-8859-1] Mon Jul 21 10:55:58 2008
@@ -9,6 +9,7 @@
 /* INCLUDES *******************************************************************/
 
 #include <ntoskrnl.h>
+#include <internal/arm/ksarm.h>
 #define NDEBUG
 #include <debug.h>
 
@@ -90,6 +91,7 @@
     PVOID SystemCall;
     PVOID* Argument;
     PVOID Arguments[0x11]; // Maximum 17 arguments
+    KIRQL OldIrql;
     ASSERT(TrapFrame->DbgArgMark == 0xBADB0D00);
     
     //
@@ -209,4 +211,53 @@
     //
     TrapFrame->R0 = KiSyscallHandlers[ArgumentCount]((PVOID)SystemCall,
                                                      (PVOID)Arguments);
+                                                     
+    //
+    // Check if this was a user call
+    //
+    if (KiGetPreviousMode(TrapFrame) == UserMode)
+    {
+        //
+        // Make sure we didn't return at elevated IRQL
+        //
+        OldIrql = KeGetCurrentIrql();
+        if (OldIrql != PASSIVE_LEVEL)
+        {
+            //
+            // Forcibly put us in a sane state
+            //
+            KeGetPcr()->CurrentIrql = 0;
+            _disable();
+            
+            //
+            // Fail
+            //
+            KeBugCheckEx(IRQL_GT_ZERO_AT_SYSTEM_SERVICE,
+                         (ULONG_PTR)SystemCall,
+                         OldIrql,
+                         0,
+                         0);
+        }
+        
+        //
+        // Make sure we're not attached and that APCs are not disabled
+        //
+        if ((KeGetCurrentThread()->ApcStateIndex != CurrentApcEnvironment) ||
+            (KeGetCurrentThread()->CombinedApcDisable != 0))
+        {
+            //
+            // Fail
+            //
+            KeBugCheckEx(APC_INDEX_MISMATCH,
+                         (ULONG_PTR)SystemCall,
+                         KeGetCurrentThread()->ApcStateIndex,
+                         KeGetCurrentThread()->CombinedApcDisable,
+                         0);
+        }
+    }
+    
+    //
+    // Restore the old trap frame
+    //
+    Thread->TrapFrame = (PKTRAP_FRAME)TrapFrame->PreviousTrapFrame;
 }