kernel/src/memory/KernelVM.cpp

@@ -21,6 +21,7 @@ namespace KernelVM
     void init()
     {
         g_kernelvm_bitmap.initialize(bitmap_memory, sizeof(bitmap_memory));
+        g_kernelvm_bitmap.clear(false);
     }
 
     Result<u64> alloc_one_page()
@@ -36,7 +37,7 @@ namespace KernelVM
         return err(ENOMEM);
     }
 
-    Result<u64> alloc_several_pages(usize count)
+    bool find_several_pages_impl(usize count, u64& start_index)
     {
         u64 first_free_index = 0;
         u64 free_contiguous_pages = 0;
@@ -56,12 +57,24 @@ namespace KernelVM
             // Found enough contiguous free pages!!
             if (free_contiguous_pages == count)
             {
-                g_used_vm += ARCH_PAGE_SIZE * count;
-                g_kernelvm_bitmap.clear_region(first_free_index, count, true);
-                return KERNEL_VM_RANGE_START + (first_free_index * ARCH_PAGE_SIZE);
+                start_index = first_free_index;
+                return true;
             }
         }
 
+        return false;
+    }
+
+    Result<u64> alloc_several_pages(const usize count)
+    {
+        u64 start_index;
+        if (find_several_pages_impl(count, start_index))
+        {
+            g_kernelvm_bitmap.clear_region(start_index, count, true);
+            g_used_vm += ARCH_PAGE_SIZE * count;
+            return KERNEL_VM_RANGE_START + (start_index * ARCH_PAGE_SIZE);
+        }
+
         return err(ENOMEM);
     }