Update to latest bit_field version

(cherry picked from commit 46100ba24b)

.travis.yml

@@ -15,5 +15,4 @@ addons:
     packages:
       - nasm
 
-script:
-    - make
+script: make

README.md

@@ -1,7 +1,7 @@
-# Blog OS (Catching Exceptions)
-[![Build Status](https://travis-ci.org/phil-opp/blog_os.svg?branch=catching_exceptions)](https://travis-ci.org/phil-opp/blog_os/branches)
+# Blog OS (Better Exception Messages)
+[![Build Status](https://travis-ci.org/phil-opp/blog_os.svg?branch=better_exception_messages)](https://travis-ci.org/phil-opp/blog_os/branches)
 
-This repository contains the source code for the [Catching Exceptions](http://os.phil-opp.com/catching-exceptions.html) post of the [Writing an OS in Rust](http://os.phil-opp.com) series.
+This repository contains the source code for the [Better Exception Messages](http://os.phil-opp.com/better-exception-messages.html) post of the [Writing an OS in Rust](http://os.phil-opp.com) series.
 
 **Check out the [master branch](https://github.com/phil-opp/blog_os) for more information.**
 

src/interrupts/idt.rs

@@ -101,11 +101,13 @@ impl EntryOptions {
         self
     }
 
+    #[allow(dead_code)]
     pub fn set_privilege_level(&mut self, dpl: u16) -> &mut Self {
         self.0.set_bits(13..15, dpl);
         self
     }
 
+    #[allow(dead_code)]
     pub fn set_stack_index(&mut self, index: u16) -> &mut Self {
         self.0.set_bits(0..3, index);
         self

src/interrupts/mod.rs

@@ -9,11 +9,50 @@
 
 mod idt;
 
+macro_rules! handler {
+    ($name: ident) => {{
+        #[naked]
+        extern "C" fn wrapper() -> ! {
+            unsafe {
+                asm!("mov rdi, rsp
+                      sub rsp, 8 // align the stack pointer
+                      call $0"
+                      :: "i"($name as extern "C" fn(
+                          &ExceptionStackFrame) -> !)
+                      : "rdi" : "intel");
+                ::core::intrinsics::unreachable();
+            }
+        }
+        wrapper
+    }}
+}
+
+macro_rules! handler_with_error_code {
+    ($name: ident) => {{
+        #[naked]
+        extern "C" fn wrapper() -> ! {
+            unsafe {
+                asm!("pop rsi // pop error code into rsi
+                      mov rdi, rsp
+                      sub rsp, 8 // align the stack pointer
+                      call $0"
+                      :: "i"($name as extern "C" fn(
+                          &ExceptionStackFrame, u64) -> !)
+                      : "rdi","rsi" : "intel");
+                ::core::intrinsics::unreachable();
+            }
+        }
+        wrapper
+    }}
+}
+
 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, handler!(divide_by_zero_handler));
+        idt.set_handler(6, handler!(invalid_opcode_handler));
+        idt.set_handler(14, handler_with_error_code!(page_fault_handler));
 
         idt
     };
@@ -23,7 +62,44 @@ pub fn init() {
     IDT.load();
 }
 
-extern "C" fn divide_by_zero_handler() -> ! {
-    println!("EXCEPTION: DIVIDE BY ZERO");
+#[derive(Debug)]
+#[repr(C)]
+struct ExceptionStackFrame {
+    instruction_pointer: u64,
+    code_segment: u64,
+    cpu_flags: u64,
+    stack_pointer: u64,
+    stack_segment: u64,
+}
+
+extern "C" fn divide_by_zero_handler(stack_frame: &ExceptionStackFrame) -> ! {
+    println!("\nEXCEPTION: DIVIDE BY ZERO\n{:#?}", stack_frame);
+    loop {}
+}
+
+extern "C" fn invalid_opcode_handler(stack_frame: &ExceptionStackFrame) -> ! {
+    println!("\nEXCEPTION: INVALID OPCODE at {:#x}\n{:#?}",
+             stack_frame.instruction_pointer,
+             stack_frame);
+    loop {}
+}
+
+bitflags! {
+    flags PageFaultErrorCode: u64 {
+        const PROTECTION_VIOLATION = 1 << 0,
+        const CAUSED_BY_WRITE = 1 << 1,
+        const USER_MODE = 1 << 2,
+        const MALFORMED_TABLE = 1 << 3,
+        const INSTRUCTION_FETCH = 1 << 4,
+    }
+}
+
+extern "C" fn page_fault_handler(stack_frame: &ExceptionStackFrame, error_code: u64) -> ! {
+    use x86::shared::control_regs;
+    println!("\nEXCEPTION: PAGE FAULT while accessing {:#x}\nerror code: \
+                                  {:?}\n{:#?}",
+             unsafe { control_regs::cr2() },
+             PageFaultErrorCode::from_bits(error_code).unwrap(),
+             stack_frame);
     loop {}
 }

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;
@@ -51,12 +53,9 @@ pub extern "C" fn rust_main(multiboot_information_address: usize) {
     // initialize our IDT
     interrupts::init();
 
-    fn divide_by_zero() {
-        unsafe { asm!("mov dx, 0; div dx" ::: "ax", "dx" : "volatile", "intel") }
-    }
+    // provoke a page fault
+    unsafe { *(0xdeadbeaf as *mut u64) = 42 };
 
-    // provoke a divide by zero fault inside println
-    println!("{:?}", divide_by_zero());
 
     println!("It did not crash!");
     loop {}

src/memory/area_frame_allocator.rs

@@ -47,13 +47,12 @@ impl AreaFrameAllocator {
 
     fn choose_next_area(&mut self) {
         self.current_area = self.areas
-                                .clone()
-                                .filter(|area| {
-                                    let address = area.base_addr + area.length - 1;
-                                    Frame::containing_address(address as usize) >=
-                                    self.next_free_frame
-                                })
-                                .min_by_key(|area| area.base_addr);
+            .clone()
+            .filter(|area| {
+                let address = area.base_addr + area.length - 1;
+                Frame::containing_address(address as usize) >= self.next_free_frame
+            })
+            .min_by_key(|area| area.base_addr);
 
         if let Some(area) = self.current_area {
             let start_frame = Frame::containing_address(area.base_addr as usize);

src/memory/mod.rs

@@ -24,15 +24,15 @@ pub fn init(boot_info: &BootInformation) {
     let elf_sections_tag = boot_info.elf_sections_tag().expect("Elf sections tag required");
 
     let kernel_start = elf_sections_tag.sections()
-                                       .filter(|s| s.is_allocated())
-                                       .map(|s| s.addr)
-                                       .min()
-                                       .unwrap();
+        .filter(|s| s.is_allocated())
+        .map(|s| s.addr)
+        .min()
+        .unwrap();
     let kernel_end = elf_sections_tag.sections()
-                                     .filter(|s| s.is_allocated())
-                                     .map(|s| s.addr + s.size)
-                                     .max()
-                                     .unwrap();
+        .filter(|s| s.is_allocated())
+        .map(|s| s.addr + s.size)
+        .max()
+        .unwrap();
 
     println!("kernel start: {:#x}, kernel end: {:#x}",
              kernel_start,

src/memory/paging/mapper.rs

@@ -69,9 +69,9 @@ impl Mapper {
         };
 
         p3.and_then(|p3| p3.next_table(page.p3_index()))
-          .and_then(|p2| p2.next_table(page.p2_index()))
-          .and_then(|p1| p1[page.p1_index()].pointed_frame())
-          .or_else(huge_page)
+            .and_then(|p2| p2.next_table(page.p2_index()))
+            .and_then(|p1| p1[page.p1_index()].pointed_frame())
+            .or_else(huge_page)
     }
 
     pub fn map_to<A>(&mut self, page: Page, frame: Frame, flags: EntryFlags, allocator: &mut A)
@@ -105,10 +105,10 @@ impl Mapper {
         assert!(self.translate(page.start_address()).is_some());
 
         let p1 = self.p4_mut()
-                     .next_table_mut(page.p4_index())
-                     .and_then(|p3| p3.next_table_mut(page.p3_index()))
-                     .and_then(|p2| p2.next_table_mut(page.p2_index()))
-                     .expect("mapping code does not support huge pages");
+            .next_table_mut(page.p4_index())
+            .and_then(|p3| p3.next_table_mut(page.p3_index()))
+            .and_then(|p2| p2.next_table_mut(page.p2_index()))
+            .expect("mapping code does not support huge pages");
         let frame = p1[page.p1_index()].pointed_frame().unwrap();
         p1[page.p1_index()].set_unused();
         unsafe { ::x86::shared::tlb::flush(page.start_address()) };

src/memory/paging/mod.rs

@@ -180,7 +180,7 @@ pub fn remap_the_kernel<A>(allocator: &mut A, boot_info: &BootInformation) -> Ac
 
     active_table.with(&mut new_table, &mut temporary_page, |mapper| {
         let elf_sections_tag = boot_info.elf_sections_tag()
-                                        .expect("Memory map tag required");
+            .expect("Memory map tag required");
 
         // identity map the allocated kernel sections
         for section in elf_sections_tag.sections() {