From 308b033ea9ba7768d75add7fea402d4ef66edf7f Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Wed, 3 Aug 2016 16:22:59 +0200
Subject: [PATCH] Add a wrapper function and print the exception stack frame

---
 src/interrupts/mod.rs | 33 ++++++++++++++++++++++++++++++---
 src/lib.rs            |  2 ++
 2 files changed, 32 insertions(+), 3 deletions(-)

diff --git a/src/interrupts/mod.rs b/src/interrupts/mod.rs
index 07d19874..b41db333 100644
--- a/src/interrupts/mod.rs
+++ b/src/interrupts/mod.rs
@@ -4,7 +4,7 @@ lazy_static! {
     static ref IDT: idt::Idt = {
         let mut idt = idt::Idt::new();
 
-        idt.set_handler(0, divide_by_zero_handler);
+        idt.set_handler(0, divide_by_zero_wrapper);
 
         idt
     };
@@ -14,9 +14,36 @@ pub fn init() {
     IDT.load();
 }
 
+#[derive(Debug)]
+#[repr(C)]
+struct ExceptionStackFrame {
+    instruction_pointer: u64,
+    code_segment: u64,
+    cpu_flags: u64,
+    stack_pointer: u64,
+    stack_segment: u64,
+}
+
 use vga_buffer::print_error;
 
-extern "C" fn divide_by_zero_handler() -> ! {
-    unsafe { print_error(format_args!("EXCEPTION: DIVIDE BY ZERO")) };
+#[naked]
+extern "C" fn divide_by_zero_wrapper() -> ! {
+    unsafe {
+        asm!("mov rdi, rsp
+              sub rsp, 8 // align the stack pointer
+              call $0"
+              :: "i"(divide_by_zero_handler as extern "C" fn(_) -> !)
+              : "rdi" : "intel");
+        ::core::intrinsics::unreachable();
+    }
+}
+
+extern "C" fn divide_by_zero_handler(stack_frame: *const ExceptionStackFrame)
+    -> !
+{
+    unsafe {
+        print_error(format_args!("EXCEPTION: DIVIDE BY ZERO\n{:#?}",
+            *stack_frame));
+    }
     loop {}
 }
diff --git a/src/lib.rs b/src/lib.rs
index 7a35129e..37df865e 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -11,6 +11,8 @@
 #![feature(const_fn, unique)]
 #![feature(alloc, collections)]
 #![feature(asm)]
+#![feature(naked_functions)]
+#![feature(core_intrinsics)]
 #![no_std]
 
 extern crate rlibc;