Fixed spinlock halting caused by data misalignment

kernel/spinlock.c

@@ -8,12 +8,6 @@
 #include "proc.h"
 #include "defs.h"
 
-void initlock(struct spinlock *lk, char *name) {
-	lk->name = name;
-	lk->locked = 0;
-	lk->cpu = 0;
-}
-
 // Acquire the lock.
 // Loops (spins) until the lock is acquired.
 void acquire(struct spinlock *lk) {

theseus/src/spinlock.rs

@@ -1,9 +1,18 @@
+use core::ptr::null_mut;
+
 // Mutual exclusion lock.
 #[repr(C)]
 pub struct SpinLock {
 	// Is the lock held?
 	pub locked: u32, // C boolean
 	// For debugging:
-	pub name: Option<*mut ()>, // Name of lock.
-	pub cpu: Option<*mut ()>,  // The cpu holding the lock.
+	pub name: *const u8, // Name of lock.
+	pub cpu: *mut (),    // The cpu holding the lock.
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn initlock(lock: *mut SpinLock, name: *const u8) {
+	(*lock).name = name;
+	(*lock).locked = 0;
+	(*lock).cpu = null_mut();
 }

theseus/src/uart.rs

@@ -1,11 +1,13 @@
-use crate::{memlayout::UART0, spinlock::SpinLock};
-use core::ptr::addr_of_mut;
+use crate::{
+	memlayout::UART0,
+	spinlock::{initlock, SpinLock},
+};
+use core::ptr::{addr_of_mut, null, null_mut};
 
 extern "C" {
 	// spinlock.c
 	fn push_off();
 	fn pop_off();
-	fn initlock(spinlock: *mut SpinLock, name: *const u8);
 	fn acquire(spinlock: *mut SpinLock);
 	fn release(spinlock: *mut SpinLock);
 
@@ -60,12 +62,12 @@ pub fn WriteReg(reg: u8, v: u8) {
 // the transmit output buffer.
 static mut uart_tx_lock: crate::spinlock::SpinLock = crate::spinlock::SpinLock {
 	locked: 0,
-	cpu: None,
-	name: None,
+	cpu: null_mut(),
+	name: null(),
 };
 
 // NOTE: string 'uart\0' for c-implmentation of spinlock. Stupid but works.
-static UART_LOCK_NAME: [u8; 5] = [117, 97, 114, 116, 0];
+static UART_LOCK_NAME: [u8; 5] = [0x75, 0x61, 0x72, 0x74, 0];
 
 const UART_TX_BUF_SIZE: usize = 32;
 static mut uart_tx_buf: [u8; UART_TX_BUF_SIZE] = [0; UART_TX_BUF_SIZE];