Heap: Log more details of blocks

kernel/src/memory/Heap.cpp

@@ -125,8 +125,14 @@ static Option<HeapBlock*> split(HeapBlock* block, usize size)
 
 static Result<void> combine_forward(HeapBlock* block)
 {
+    // This block ends a memory range, cannot be combined with blocks outside its range.
+    if (block->status & BLOCK_END_MEM) return {};
+
     // The caller needs to ensure there is a next block.
     HeapBlock* const next = heap.next(block).value();
+    // This block starts a memory range, cannot be combined with blocks outside its range.
+    if (next->status & BLOCK_START_MEM) return {};
+
     heap.remove(next);
     next->magic = BLOCK_DEAD;
 
@@ -134,7 +140,8 @@ static Result<void> combine_forward(HeapBlock* block)
     {
         if (next->status & BLOCK_START_MEM)
         {
-            TRY(release_pages(next, get_blocks_from_size(next->full_size + sizeof(HeapBlock), ARCH_PAGE_SIZE)));
+            const usize pages = get_blocks_from_size(next->full_size + sizeof(HeapBlock), ARCH_PAGE_SIZE);
+            TRY(release_pages(next, pages));
             return {};
         }
         else
@@ -148,8 +155,13 @@ static Result<void> combine_forward(HeapBlock* block)
 
 static Result<HeapBlock*> combine_backward(HeapBlock* block)
 {
+    // This block starts a memory range, cannot be combined with blocks outside its range.
+    if (block->status & BLOCK_START_MEM) return block;
+
     // The caller needs to ensure there is a last block.
     HeapBlock* const last = heap.previous(block).value();
+    // This block ends a memory range, cannot be combined with blocks outside its range.
+    if (last->status & BLOCK_END_MEM) return block;
     heap.remove(block);
     block->magic = BLOCK_DEAD;
 
@@ -157,7 +169,8 @@ static Result<HeapBlock*> combine_backward(HeapBlock* block)
     {
         if (block->status & BLOCK_START_MEM)
         {
-            TRY(release_pages(block, get_blocks_from_size(block->full_size + sizeof(HeapBlock), ARCH_PAGE_SIZE)));
+            const usize pages = get_blocks_from_size(block->full_size + sizeof(HeapBlock), ARCH_PAGE_SIZE);
+            TRY(release_pages(block, pages));
             return last;
         }
         else
@@ -273,7 +286,8 @@ Result<void> kfree(void* ptr)
     if ((block->status & BLOCK_START_MEM) && (block->status & BLOCK_END_MEM))
     {
         heap.remove(block);
-        TRY(release_pages(block, get_blocks_from_size(block->full_size + sizeof(HeapBlock), ARCH_PAGE_SIZE)));
+        const usize pages = get_blocks_from_size(block->full_size + sizeof(HeapBlock), ARCH_PAGE_SIZE);
+        TRY(release_pages(block, pages));
     }
 
     return {};
@@ -352,12 +366,15 @@ void dump_heap_usage()
     {
         if (is_block_free(block))
         {
-            kdbgln("- Available block, of size %zu", block->full_size);
+            kdbgln("- Available block (%p), of size %zu (%s%s)", (void*)block, block->full_size,
+                   block->status & BLOCK_START_MEM ? "b" : "-", block->status & BLOCK_END_MEM ? "e" : "-");
             alloc_total += block->full_size + sizeof(HeapBlock);
         }
         else
         {
-            kdbgln("- Used block, of size %zu, of which %zu bytes are being used", block->full_size, block->req_size);
+            kdbgln("- Used block (%p), of size %zu, of which %zu bytes are being used (%s%s)", (void*)block,
+                   block->full_size, block->req_size, block->status & BLOCK_START_MEM ? "b" : "-",
+                   block->status & BLOCK_END_MEM ? "e" : "-");
             alloc_total += block->full_size + sizeof(HeapBlock);
             alloc_used += block->req_size;
         }

luna/include/luna/LinkedList.h

@@ -49,12 +49,14 @@ template <typename T> class LinkedListNode
     {
         end_node->m_next_node = this;
         this->m_last_node = end_node;
+        this->m_next_node = nullptr;
     }
 
     void prepend_to_list(SelfType* start_node)
     {
         start_node->m_last_node = this;
         this->m_next_node = start_node;
+        this->m_last_node = nullptr;
     }
 
     friend class LinkedList<T>;
@@ -104,6 +106,8 @@ template <typename T> class LinkedList
 
         if (m_end_node == base_node) m_end_node = new_node;
 
+        if (base_node->get_next()) base_node->get_next()->set_last(new_node);
+
         new_node->set_next(base_node->get_next());
         base_node->set_next(new_node);
         new_node->set_last(base_node);