__prober

 Determines whether read access to the virtual address specified by
 __address bits {60:0} and the region register indexed by __address
 bits {63:61} is permitted at the privilege level given by __mode
 bits {1:0}.  It returns 1 if the access is permitted, and 0
 otherwise.

 This function can probe only with equal or lower privilege levels.
 If the specified privilege level is higher (lower number), then the
 probe is performed with the current privilege level.

 This function is the same as the Intel __probe_r function.

 Syntax:

      int __prober (__int64 __address, unsigned int __mode);