updated malloc and extended heap

main.c

@@ -4,6 +4,7 @@
 
 #define ALIGN4(s) (((((s)-1)>>2)<<2)+4)
 #define BLOCK_SIZE sizeof(struct block)
+#define MINIMUM_BLOCK_SIZE  16
 
 /// The memory block's header.
 struct block
@@ -24,6 +25,11 @@ struct block* extend_heap(size_t s)
 {
     struct block* b = sbrk(0);
 
+    // Ensure the allocated size is at least the minimum block size
+    if (s < MINIMUM_BLOCK_SIZE) {
+        s = MINIMUM_BLOCK_SIZE;
+    }
+
     if (sbrk(BLOCK_SIZE + s) == (void*)-1)
         return NULL;
 
@@ -77,6 +83,11 @@ void* malloc(size_t size)
 
     size_t alignedSize = ALIGN4(size);
 
+    // Enforce the minimum block size
+    if (alignedSize < MINIMUM_BLOCK_SIZE) {
+        alignedSize = MINIMUM_BLOCK_SIZE;
+    }
+
     if (first)
     {
         b = find_first(alignedSize);
@@ -97,6 +108,7 @@ void* malloc(size_t size)
     return b +  1;
 }
 
+
 /// Will flag the provided memory as free and will defragment other blocks adjacent to it.
 /// @param [in] ptr The memory to flag as free.
 /// @note If all data after the provided memory is free, it will reduce the heap size.