Hi all,

In a kernel module is there a way to test if an address range has 

been already mapped by the kernel or not. 

Ex:  (on a PC with the latest kernel)

- an access to physical 0xC0000000 will return the value at this address

- an access to physical 0x00100000 will have the kernel kill the module/application 

           using the module. Dmesg: BUG: unable to handle kernel paging request at 00100000.

How can I test this condition before dereferencing the address. 

Thanks,

Stephan.