title: How can I tell if a virtual address has valid mapping in ARM linux kernel?
body: <p>I want to check if a virtual address can be dereferenced without raising segmentation fault.
  the virtual address I am talking about is not just untrustworthy user space address. I want to check the kernel virtual address as well.</p>
  
  <p>In x86 Linux kernel, __virt_addr_valid() function can be used to check if the
  virtual address has valid mapping.</p>
  
  <p>Is there any equivalent in ARM linux kernel??</p>
  
  <p>Thank you in advance.</p>