From: John Hodge <tpg@prelude.mutabah.net>
Date: Sat, 1 May 2010 04:20:12 +0000 (+0800)
Subject: Improved user error handling, now a user DIV0 doesn't cause a kernel
X-Git-Tag: rel0.06~203
X-Git-Url: https://git.ucc.asn.au/?a=commitdiff_plain;h=5beb98670f040b2d4e697e4d8690cd46d2d30cf3;p=tpg%2Facess2.git

Improved user error handling, now a user DIV0 doesn't cause a kernel
 panic.
---

diff --git a/Kernel/arch/x86/errors.c b/Kernel/arch/x86/errors.c
index ac54bc11..d1d9cb72 100644
--- a/Kernel/arch/x86/errors.c
+++ b/Kernel/arch/x86/errors.c
@@ -12,7 +12,8 @@
 // === IMPORTS ===
 extern void	MM_PageFault(Uint Addr, Uint ErrorCode, tRegs *Regs);
 extern void	VM8086_GPF(tRegs *Regs);
-extern void Threads_Dump();
+extern void Threads_Dump(void);
+extern void	Threads_Fault(int Num);
 
 // === PROTOTYPES ===
 void	Error_Backtrace(Uint eip, Uint ebp);
@@ -66,6 +67,28 @@ void ErrorHandler(tRegs *Regs)
 		return ;
 	}
 	
+	// Check if it's a user mode fault
+	if( Regs->eip < KERNEL_BASE || (Regs->cs & 3) == 3 ) {
+		Log_Warning("Arch", "User Fault -  %s, Code: 0x%x",
+			csaERROR_NAMES[Regs->int_num], Regs->err_code);
+		Log_Warning("Arch", "at CS:EIP %04x:%08x",
+			Regs->cs, Regs->eip);
+		switch( Regs->int_num )
+		{
+		// Division by Zero
+		case  0:	Threads_Fault(FAULT_DIV0);	break;
+		// Invalid opcode
+		case  6:	Threads_Fault(FAULT_OPCODE);	break;
+		// GPF
+		case 13:	Threads_Fault(FAULT_ACCESS);	break;
+		// Floating Point Exception
+		case 16:	Threads_Fault(FAULT_FLOAT);	break;
+		
+		default:	Threads_Fault(FAULT_MISC);	break;
+		}
+		return ;
+	}
+	
 	Debug_KernelPanic();
 	Warning("CPU Error %i - %s, Code: 0x%x",
 		Regs->int_num, csaERROR_NAMES[Regs->int_num], Regs->err_code);
diff --git a/Kernel/include/threads.h b/Kernel/include/threads.h
index 28d669d2..2b066d9f 100644
--- a/Kernel/include/threads.h
+++ b/Kernel/include/threads.h
@@ -67,6 +67,16 @@ enum {
 	THREAD_STAT_DEAD
 };
 
+enum eFaultNumbers
+{
+	FAULT_MISC,
+	FAULT_PAGE,
+	FAULT_ACCESS,
+	FAULT_DIV0,
+	FAULT_OPCODE,
+	FAULT_FLOAT
+};
+
 // === FUNCTIONS ===
 extern tThread	*Proc_GetCurThread();
 extern tThread	*Threads_GetThread(Uint TID);
diff --git a/Kernel/threads.c b/Kernel/threads.c
index 0a9ab372..c62f7268 100644
--- a/Kernel/threads.c
+++ b/Kernel/threads.c
@@ -565,7 +565,7 @@ void Threads_AddActive(tThread *Thread)
 }
 
 /**
- * \fn void Threads_SetSignalHandler(Uint Handler)
+ * \fn void Threads_SetFaultHandler(Uint Handler)
  * \brief Sets the signal handler for a signal
  */
 void Threads_SetFaultHandler(Uint Handler)
@@ -606,6 +606,8 @@ void Threads_Fault(int Num)
 		HALT();
 	}
 	
+	thread->CurFaultNum = Num;
+	
 	Proc_CallFaultHandler(thread);
 }