Fix incorrect default state and bit math for bitsets

kernel/ds/bitset.c

@@ -2,15 +2,22 @@
  * This file is part of ToaruOS and is released under the terms
  * of the NCSA / University of Illinois License - see LICENSE.md
  * Copyright (C) 2015 Dale Weiler
+ *               2015 Kevin Lange
  */
 #include "bitset.h"
 
 #define CEIL(NUMBER, BASE) \
 	(((NUMBER) + (BASE) - 1) & ~((BASE) - 1))
 
+#define iom \
+	size_t index  = bit >> 3; \
+	bit = bit >> index; \
+	size_t offset = bit & 7; \
+	size_t mask   = 1 << offset;
+
 void bitset_init(bitset_t *set, size_t size) {
 	set->size = CEIL(size, 8);
-	set->data = malloc(set->size);
+	set->data = calloc(set->size, 1);
 }
 
 void bitset_free(bitset_t *set) {
@@ -21,20 +28,17 @@ static void bitset_resize(bitset_t *set, size_t size) {
 	if (set->size >= size) {
 		return;
 	}
-	unsigned char *temp = malloc(size);
-	memcpy(temp, set->data, set->size);
-	free(set->data);
-	set->data = temp;
+
+	set->data = realloc(set->data, size);
+	memset(set->data + set->size, 0, size - set->size);
 	set->size = size;
 }
 
 void bitset_set(bitset_t *set, size_t bit) {
-	size_t index = bit >> 3;
+	iom;
 	if (set->size <= index) {
 		bitset_resize(set, set->size << 1);
 	}
-	size_t offset = index & 7;
-	size_t mask = 1 << offset;
 	set->data[index] |= mask;
 }
 
@@ -49,16 +53,12 @@ int bitset_ffub(bitset_t *set) {
 }
 
 void bitset_clear(bitset_t *set, size_t bit) {
-	size_t index = bit >> 3;
-	size_t offset = index & 7;
-	size_t mask = 1 << offset;
+	iom;
 	set->data[index] &= ~mask;
 }
 
 int bitset_test(bitset_t *set, size_t bit) {
-	size_t index = bit >> 3;
-	size_t offset = index & 7;
-	size_t mask = 1 << offset;
-	return mask & set->data[index];
+	iom;
+	return !!(mask & set->data[index]);
 }