diff --git a/kern/libkern/endian.h b/kern/libkern/endian.h
index 13f0f3b..3f9132f 100644
--- a/kern/libkern/endian.h
+++ b/kern/libkern/endian.h
@@ -1,7 +1,7 @@
 #ifndef ENDIAN_KERNEL_H
 #define ENDIAN_KERNEL_H
 
-#include <types.h>
+#include <stdint.h>
 
 /** Swap byte order of 16-bit value */
 static inline u16 swap16(u16 x) {
diff --git a/kern/libkern/spinlock.c b/kern/libkern/spinlock.c
index 7dc6658..b9ccd8b 100644
--- a/kern/libkern/spinlock.c
+++ b/kern/libkern/spinlock.c
@@ -67,7 +67,7 @@ uint32_t pop_off(void) {
         PANIC("pop_off - interruptible");
 
     if (cpu->noff < 1)
-        PANIC("pop_off");
+        PANIC("pop_off when cpu->noff < 1");
 
     cpu->noff -= 1;
 
@@ -89,8 +89,8 @@ __attribute__((warn_unused_result)) bool spin_trylock(spinlock_t *l) {
 }
 
 void spin_unlock(spinlock_t *l) {
-    // if (!spin_is_holding(l))
-    //     panic("spin_unlock");
+    if (!spin_is_holding(l))
+        PANIC("Unlocking a spinlock that is not held by the locking cpu!");
 
     l->cpu = 0;
 
@@ -98,10 +98,10 @@ void spin_unlock(spinlock_t *l) {
     uint32_t dummy;
     __asm__ volatile("amoswap.w.rl %0, %2, (%1)\n" : "=&r"(dummy) : "r"(&l->v), "r"(0u) : "memory");
 
-    // __sync_synchronize();             // No loads/stores after this point
+    __sync_synchronize(); // No loads/stores after this point
     // __sync_lock_release(&lk->locked); // Essentially lk->locked = 0
 
-    // pop_off();
+    pop_off();
 }
 
 /**
@@ -110,8 +110,11 @@ void spin_unlock(spinlock_t *l) {
 void spin_lock(spinlock_t *l) {
     uint32_t backoff = 1;
     for (;;) {
-        if (spin_trylock(l))
+        if (spin_trylock(l)) {
+            l->cpu = mycpu();
+            push_off();
             return;
+        }
 
         while (__atomic_load_n(&l->v, __ATOMIC_RELAXED) != 0) {
             for (uint32_t i = 0; i < backoff; ++i)
@@ -120,8 +123,6 @@ void spin_lock(spinlock_t *l) {
                 backoff <<= 1;
         }
     }
-
-    l->cpu = mycpu();
 }
 
 /**
diff --git a/kern/libkern/string.c b/kern/libkern/string.c
index e6c0000..308292f 100644
--- a/kern/libkern/string.c
+++ b/kern/libkern/string.c
@@ -114,18 +114,6 @@ void *memset(void *dest, int c, size_t n) {
     return dest;
 }
 
-// int memcmp(const void *s1, const void *s2, size_t n) {
-//     if (n != 0) {
-//         const unsigned char *p1 = s1, *p2 = s2;
-//
-//         do {
-//             if (*p1++ != *p2++)
-//                 return (*--p1 - *--p2);
-//         } while (--n != 0);
-//     }
-//     return (0);
-// }
-
 char *itoa(int value, char *str, int base) {
     char        *p = str;
     char        *p1, *p2;
@@ -166,39 +154,6 @@ char *itoa(int value, char *str, int base) {
     return str;
 }
 
-// void *memset(void *dst, int c, size_t length) {
-//     u8      *ptr = (u8 *)dst;
-//     const u8 value = (u8)c;
-//
-//     while (length--) *(ptr++) = value;
-//
-//     return dst;
-// }
-
-// void *memcpy(void *dst, const void *src, size_t len) {
-//     u8       *d = (u8 *)dst;
-//     const u8 *s = (const u8 *)src;
-//     for (size_t i = 0; i < len; i++) {
-//         d[i] = s[i];
-//     }
-//     return dst;
-// }
-
-// void *memmove(void *dst, const void *src, size_t len) {
-//     u8       *d = (u8 *)dst;
-//     const u8 *s = (const u8 *)src;
-//     if (d < s) {
-//         for (size_t i = 0; i < len; i++) {
-//             d[i] = s[i];
-//         }
-//     } else if (d > s) {
-//         for (size_t i = len; i > 0; i--) {
-//             d[i - 1] = s[i - 1];
-//         }
-//     }
-//     return dst;
-// }
-
 int memcmp(const void *s1, const void *s2, size_t len) {
     const u8 *a = (const u8 *)s1;
     const u8 *b = (const u8 *)s2;