AK+Kernel: Don't allow allocations in AK::Function in kernel mode

Refs #6369. Fixes #15053. Co-authored-by: Brian Gianforcaro <[email protected]>
SerenityOS · Nov 1, 2022 · e44ccdd · e44ccdd
1 parent 2a840a5
commit e44ccdd
Showing 1 changed file with 10 additions and 0 deletions.
diff --git a/AK/Function.h b/AK/Function.h
@@ -213,13 +213,18 @@ class Function<Out(In...)> {
  {
  VERIFY(m_call_nesting_level == 0);
  using WrapperType = CallableWrapper<Callable>;
+#ifndef KERNEL
  if constexpr (sizeof(WrapperType) > inline_capacity) {
  *bit_cast<CallableWrapperBase**>(&m_storage) = new WrapperType(forward<Callable>(callable));
  m_kind = FunctionKind::Outline;
  } else {
+#endif
+ static_assert(sizeof(WrapperType) <= inline_capacity);
  new (m_storage) WrapperType(forward<Callable>(callable));
  m_kind = FunctionKind::Inline;
+#ifndef KERNEL
  }
+#endif
  }
 
  void move_from(Function&& other)
@@ -246,8 +251,13 @@ class Function<Out(In...)> {
  FunctionKind m_kind { FunctionKind::NullPointer };
  bool m_deferred_clear { false };
  mutable Atomic<u16> m_call_nesting_level { 0 };
+#ifndef KERNEL
  // Empirically determined to fit most lambdas and functions.
  static constexpr size_t inline_capacity = 4 * sizeof(void*);
+#else
+ // FIXME: Try to decrease this.
+ static constexpr size_t inline_capacity = 6 * sizeof(void*);
+#endif
  alignas(max(alignof(CallableWrapperBase), alignof(CallableWrapperBase*))) u8 m_storage[inline_capacity];
 };