Fix incorrect memory handling in ported functions

Details of the functions:
- ClSoftmax
- CpuSoftmax
- CpuPool2d

Change-Id: Icd2c14d5df010c3b2301e2693ce6f414d7c61916
Resolves: COMPMID-4404
Signed-off-by: Manuel Bottini <manuel.bottini@arm.com>
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/5797
Reviewed-by: Georgios Pinitas <georgios.pinitas@arm.com>
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
diff --git a/src/runtime/cpu/utils/CpuAuxTensorHandler.h b/src/runtime/cpu/utils/CpuAuxTensorHandler.h
new file mode 100644
index 0000000..644018a
--- /dev/null
+++ b/src/runtime/cpu/utils/CpuAuxTensorHandler.h
@@ -0,0 +1,101 @@
+/*
+ * Copyright (c) 2021 Arm Limited.
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#ifndef ARM_COMPUTE_CPU_UTILS_CPU_AUX_TENSOR_HANDLER_H
+#define ARM_COMPUTE_CPU_UTILS_CPU_AUX_TENSOR_HANDLER_H
+
+#include "arm_compute/core/ITensorPack.h"
+#include "arm_compute/core/TensorInfo.h"
+#include "arm_compute/runtime/Tensor.h"
+
+#include "support/Cast.h"
+
+namespace arm_compute
+{
+namespace cpu
+{
+/* Tensor handler to wrap and handle tensor allocations on workspace buffers */
+class CpuAuxTensorHandler
+{
+public:
+    CpuAuxTensorHandler(int slot_id, TensorInfo &info, ITensorPack &pack, bool pack_inject = false)
+        : _tensor()
+    {
+        _tensor.allocator()->soft_init(info);
+
+        ITensor *packed_tensor = utils::cast::polymorphic_downcast<ITensor *>(pack.get_tensor(slot_id));
+        if((packed_tensor == nullptr) || (info.total_size() > packed_tensor->info()->total_size()))
+        {
+            _tensor.allocator()->allocate();
+            if(pack_inject)
+            {
+                pack.add_tensor(slot_id, &_tensor);
+                _injected_tensor_pack = &pack;
+                _injected_slot_id     = slot_id;
+            }
+        }
+        else
+        {
+            _tensor.allocator()->import_memory(packed_tensor->buffer());
+        }
+    }
+
+    CpuAuxTensorHandler(TensorInfo &info, ITensor &tensor)
+        : _tensor()
+    {
+        _tensor.allocator()->soft_init(info);
+        if(info.total_size() <= tensor.info()->total_size())
+        {
+            _tensor.allocator()->import_memory(tensor.buffer());
+        }
+    }
+
+    CpuAuxTensorHandler(const CpuAuxTensorHandler &) = delete;
+    CpuAuxTensorHandler &operator=(const CpuAuxTensorHandler) = delete;
+
+    ~CpuAuxTensorHandler()
+    {
+        if(_injected_tensor_pack)
+        {
+            _injected_tensor_pack->remove_tensor(_injected_slot_id);
+        }
+    }
+
+    ITensor *get()
+    {
+        return &_tensor;
+    }
+
+    ITensor *operator()()
+    {
+        return &_tensor;
+    }
+
+private:
+    Tensor       _tensor{};
+    ITensorPack *_injected_tensor_pack{ nullptr };
+    int          _injected_slot_id{ TensorType::ACL_UNKNOWN };
+};
+} // namespace cpu
+} // namespace arm_compute
+#endif /* ARM_COMPUTE_CPU_UTILS_CPU_AUX_TENSOR_HANDLER_H */
\ No newline at end of file