diff -urN 2.4.18-ac3/arch/i386/kernel/Makefile 2.4.18-ac3-exceptions/arch/i386/kernel/Makefile
--- 2.4.18-ac3/arch/i386/kernel/Makefile	Sat Jan 19 10:22:58 2002
+++ 2.4.18-ac3-exceptions/arch/i386/kernel/Makefile	Fri Feb 22 20:09:09 2002
@@ -18,7 +18,8 @@
 
 obj-y	:= process.o semaphore.o signal.o entry.o traps.o irq.o vm86.o \
 		ptrace.o i8259.o ioport.o ldt.o setup.o time.o sys_i386.o \
-		pci-dma.o i386_ksyms.o i387.o bluesmoke.o dmi_scan.o
+		pci-dma.o i386_ksyms.o i387.o bluesmoke.o dmi_scan.o \
+		exception.o
 
 
 ifdef CONFIG_PCI
diff -urN 2.4.18-ac3/arch/i386/kernel/exception.S 2.4.18-ac3-exceptions/arch/i386/kernel/exception.S
--- 2.4.18-ac3/arch/i386/kernel/exception.S	Thu Jan  1 02:00:00 1970
+++ 2.4.18-ac3-exceptions/arch/i386/kernel/exception.S	Fri Feb 22 20:18:45 2002
@@ -0,0 +1,112 @@
+/*
+ *   linux/arch/i386/kernel/exception.S
+ *
+ *   2002, Dan Aloni <da-x@gmx.net>
+ *
+ *   i386-specific exceptions implementation
+ */
+
+/* 
+ * offsets of stuff in except_t 
+ */
+	
+#define VALUE_OFFSET 0x18
+#define PREV_OFFSET 0x1c
+
+/* 
+ * no data, define anyway
+ */
+	
+.data
+.align 4
+
+/*
+ * code section
+ */
+	
+.text	
+.align 4
+
+/*
+ * long try_exception(except_t **current_frame, *this_exception)
+ *
+ * This function is used in the beginning of the try block. The function
+ * saves the current state of execution, which is the stack pointers, IP
+ * to return to, and the registers that a reserved during function calls.
+ *
+ * This function returns *twice*. Once with return value 0, for the normal. 
+ * execution, and second when the exception is caught, throw_exception 
+ * restores the execution state and sets the return value to 1.
+ *
+ * current_frame is the per-process variable that stores a pointer to
+ * the current exception frame (except_t), i.e, the exception frame that 
+ * was created by the most recent 'try' block in the current execution.
+ *
+ * this_exception is the new exception frame to initialize.
+ */
+	
+.globl try_exception
+try_exception:
+	movl 0x4(%esp),%ecx /* current_frame */
+	movl 0x8(%esp),%eax /* this_exception */
+
+	/* this_exception->prev = current_frame */
+	/* current_frame = this_exception */
+	
+	movl (%ecx), %edx
+	movl %edx, PREV_OFFSET (%eax)
+	movl %eax, (%ecx)
+
+	/* save return address, ebp, esi, edi, ebx, esp */
+	movl (%esp), %ecx
+	movl %ecx, 0x0(%eax)
+	movl %ebp, 0x4(%eax)
+	movl %esi, 0x8(%eax)
+	movl %edi, 0xC(%eax) 
+	movl %ebx, 0x10(%eax)
+	movl %esp, 0x14(%eax)
+	xorl %eax, %eax
+	ret
+
+/*
+ * throw_exception(except_t *current_frame, unsigned long value)
+ *
+ * Throws an exception with the given value. This restores the state that
+ * was saved in the frame using try_exception, and jumps back to where
+ * try_exception was called, with return value of 1. current_frame points
+ * to the current exception. 
+ *
+ * If current_frame == NULL, there is no code to catch the exception!
+ * in that case, throw_exception will return 1
+ *
+ */
+	
+.align 4
+.globl throw_exception
+throw_exception:
+	movl 0x4(%esp), %eax /* current_frame */
+	test %eax, %eax      /* return 1 if there's no handler */
+	jz no_handler
+	movl 0x8(%esp), %edx /* value */
+
+	/* restore execution state */
+	movl 0x0(%eax), %ecx
+	movl 0x4(%eax), %ebp
+	movl 0x8(%eax), %esi
+	movl 0xC(%eax), %edi 
+	movl 0x10(%eax), %ebx
+	movl 0x14(%eax), %esp
+
+	/* set the exception value */
+	addl $4, %esp
+	movl %edx, VALUE_OFFSET (%eax)
+
+	/* jump back to where try_exception returns */
+	movl $0x1, %eax
+	jmpl *%ecx
+
+no_handler:
+	xorl %eax, %eax
+	ret 
+	
+.align 4
diff -urN 2.4.18-ac3/include/asm-i386/exception.h 2.4.18-ac3-exceptions/include/asm-i386/exception.h
--- 2.4.18-ac3/include/asm-i386/exception.h	Thu Jan  1 02:00:00 1970
+++ 2.4.18-ac3-exceptions/include/asm-i386/exception.h	Fri Feb 22 21:08:21 2002
@@ -0,0 +1,13 @@
+#ifndef _I386_EXCEPTION_H
+#define _I386_EXCEPTION_H
+
+struct exception_arch_struct {
+	unsigned long eip; /* 0x0 */
+	unsigned long ebp; /* 0x4 */
+	unsigned long esi; /* 0x8 */
+	unsigned long edi; /* 0xC */
+	unsigned long ebx; /* 0x10 */
+	unsigned long esp; /* 0x14 */
+};
+
+#endif
diff -urN 2.4.18-ac3/include/linux/exception.h 2.4.18-ac3-exceptions/include/linux/exception.h
--- 2.4.18-ac3/include/linux/exception.h	Thu Jan  1 02:00:00 1970
+++ 2.4.18-ac3-exceptions/include/linux/exception.h	Fri Feb 22 21:12:40 2002
@@ -0,0 +1,83 @@
+#ifndef _LINUX_EXCEPTION_H
+#define _LINUX_EXCEPTION_H
+
+/*
+ * linux/include/linux/exception.h
+ *
+ * 2002, Dan Aloni <da-x@gmx.net>
+ *
+ * C exceptions for the Linux kernel.
+ */
+
+#include <asm/exception.h>
+#include <linux/sched.h>
+
+/* 
+ * struct exception_struct - an exception frame 
+ *
+ * These are linked together from the current->exception and down using the 'prev' field
+ * to the first exception in the current thread.
+ */
+
+struct exception_struct {
+	struct exception_arch_struct arch;  /* arch dependant stuff */
+	unsigned long value;                /* exception value */
+	struct exception_struct *prev;      /* previous frame */
+	unsigned char caught;               /* was this frame's catch ran already */
+};
+
+typedef struct exception_struct except_t;
+
+/* implementation can be found in arch/<arch>/kernel/exception.S */
+
+extern long try_exception(struct exception_struct **current_frame, struct exception_struct *e);
+extern void throw_exception(struct exception_struct *current_frame, unsigned long value);
+
+/*
+ * try, catch, throw, and yrt overlapping macros with current->exception as the
+ * current exception frame.
+ */
+
+#define try try__cur_frame(current->exception)
+#define catch(_type_, _dec_) catch__cur_frame(current->exception, _type_, _dec_)
+#define throw(_value_) throw__cur_frame(current->exception, _value_)
+#define yrt yrt__cur_frame(current->exception)
+
+
+/* 
+ * begin a try block:
+ */
+
+#define try__cur_frame(_cur_frame_) { \
+	struct exception_struct _exception_; \
+	if (!try_exception(&(_cur_frame_), &_exception_)) \
+
+/*
+ * begin a catch block:
+ */
+
+#define catch__cur_frame(_cur_frame_, _type_, _dec_) \
+        else { \
+		struct exception_struct *_this_frame_ = _cur_frame_; \
+		_type_ _dec_ = (_type_)_this_frame_->value; \
+		_exception_.caught = 1; \
+		_cur_frame_ = _this_frame_->prev; { 
+
+/*
+ * throw function: 
+ */
+
+#define throw__cur_frame(_cur_frame_, _value_) \
+		throw_exception(_cur_frame_, (unsigned long)_value_)
+
+/*
+ * yrt - this macro must end an exception frame declaration.
+ */
+
+#define yrt__cur_frame(_cur_frame_) } }; \
+	if (!_exception_.caught) \
+		_cur_frame_ = (_cur_frame_)->prev;  \
+}
+
+#endif
+
diff -urN 2.4.18-ac3/include/linux/sched.h 2.4.18-ac3-exceptions/include/linux/sched.h
--- 2.4.18-ac3/include/linux/sched.h	Fri Feb 22 11:51:15 2002
+++ 2.4.18-ac3-exceptions/include/linux/sched.h	Fri Feb 22 20:28:40 2002
@@ -385,6 +385,7 @@
 	struct sem_queue *semsleeping;
 /* CPU-specific state of this task */
 	struct thread_struct thread;
+	struct exception_struct *exception;
 /* filesystem information */
 	struct fs_struct *fs;
 /* open file information */