more work on elf header

emulator/Loader/Elf.cpp

@@ -98,6 +98,12 @@ void Elf::Open(const std::string& file_name)
 
     m_elf_header = load_elf_header(*m_f);
 
+    if (!isElfFile())
+    {
+        delete m_elf_header;
+        m_elf_header = nullptr;
+    }
+
     DebugDump();
 }
 
@@ -134,6 +140,27 @@ bool Elf::isSelfFile() const
     return true;
 }
 
+bool Elf::isElfFile() const
+{
+    if (m_f == nullptr)
+    {
+        return false;
+    }
+
+    if (m_elf_header == nullptr)
+    {
+        return false;
+    }
+    if (m_elf_header->e_ident[0] != '\x7f' || m_elf_header->e_ident[1] != '\x45' || m_elf_header->e_ident[2] != '\x4c' ||
+        m_elf_header->e_ident[3] != '\x46')
+    {
+        printf("Not an ELF file magic is wrong!\n");
+        return false;
+    }
+
+    return true;
+}
+
 void Elf::DebugDump() {
     printf("SELF header:\n");
     printf("  magic ..............: 0x%08" PRIx32 "\n", m_self->magic);

emulator/Loader/Elf.h

@@ -95,6 +95,7 @@ public:
 
     void Open(const std::string & file_name);
     bool isSelfFile() const;
+    bool isElfFile() const;
     void DebugDump();
 private: