<html><body><div style="color:#000; background-color:#fff; font-family:times new roman, new york, times, serif;font-size:12pt"><div>Hi all,</div><div><br></div><div>In a kernel module is there a way to test if an address range has </div><div>been already mapped by the kernel or not. </div><div><br></div><div>Ex: (on a PC with the latest kernel)</div><div><span class="Apple-tab-span" style="white-space: pre; "> </span>- an access to physical 0xC0000000 will return the value at this address</div><div><span class="Apple-tab-span" style="white-space: pre; "> </span>- an access to physical 0x00100000 will have the kernel kill the module/application </div><div> using the module. Dmesg: BUG: unable to handle kernel paging request at 00100000.<br></div><div><br></div><div>How can I test this condition before dereferencing the
address. </div><div><br></div><div>Thanks,</div><div>Stephan.</div><div><br></div></div></body></html>