- Don't use the stack in FASTCALL_PROLOG. It messes up NPX checks (this is a bug, it shouldn't happen... related to DPC stack bug.)

- Zero out the trap/npx frame for new user-mode threads.
- Use KeI386FxsrPresent and not KEI386XMMIPresent when setting up the context for a new thread.

svn path=/trunk/; revision=26141

reactos/ntoskrnl/include/internal/i386/asmmacro.S

@@ -700,8 +700,10 @@ Dr_&EndLabel:
 //
 .macro FASTCALL_PROLOG Label EndLabel
     /* Set FS to PCR */
-    push KGDT_R0_PCR
-    pop fs
+    //push KGDT_R0_PCR
+    //pop fs
+    mov ecx, KGDT_R0_PCR
+    mov fs, cx
 
     /* Set user selector */
     mov ecx, KGDT_R3_DATA | RPL_MASK

reactos/ntoskrnl/ke/i386/ctxswitch.S

@@ -364,11 +364,13 @@ GetSwapLock:
     jnz WmiTrace
 
 AfterTrace:
+#ifdef CONFIG_SMP
 #ifdef DBG
     /* Assert that we're on the right CPU */
     mov cl, [esi+KTHREAD_NEXT_PROCESSOR]
     cmp cl, [ebx+KPCR_PROCESSOR_NUMBER]
     jnz WrongCpu
+#endif
 #endif
 
     /* Get CR0 and save it */

reactos/ntoskrnl/ke/i386/thrdini.c

@@ -74,6 +74,10 @@ Ke386InitThreadWithContext(IN PKTHREAD Thread,
         Context = &LocalContext;
         ContextFlags = CONTEXT_CONTROL;
 
+        /* Zero out the trap frame and save area */
+        RtlZeroMemory(&InitFrame->TrapFrame,
+                      KTRAP_FRAME_LENGTH + sizeof(FX_SAVE_AREA));
+
         /* Setup the Fx Area */
         FxSaveArea = &InitFrame->FxSaveArea;
 
@@ -114,7 +118,7 @@ Ke386InitThreadWithContext(IN PKTHREAD Thread,
             FxSaveArea->NpxSavedCpu = 0;
 
             /* Now set the context flags depending on XMM support */
-            ContextFlags |= (KeI386XMMIPresent) ? CONTEXT_EXTENDED_REGISTERS :
+            ContextFlags |= (KeI386FxsrPresent) ? CONTEXT_EXTENDED_REGISTERS :
                                                   CONTEXT_FLOATING_POINT;
 
             /* Set the Thread's NPX State */
@@ -154,7 +158,7 @@ Ke386InitThreadWithContext(IN PKTHREAD Thread,
         TrapFrame->PreviousPreviousMode = UserMode;
 
         /* Terminate the Exception Handler List */
-        TrapFrame->ExceptionList = (PVOID)0xFFFFFFFF;
+        TrapFrame->ExceptionList = EXCEPTION_CHAIN_END;
 
         /* Setup the Stack for KiThreadStartup and Context Switching */
         StartFrame = &InitFrame->StartFrame;