hi, Q1: How to produce a page fault? Q2: How translate physical memory address into virtual memory address? Because phys addr is 64 bit and virtual addr is 32 bit. Q1 description:: I have succeed to add hook in vfs layer to encrypt file data before write and decrypt file data after read. Now, when I use cp command, system will reboot, it seem to caused by encrypt data whose addr is uio->uio_iov->iov_base. Is it ok if only I produce a page fault manually? Q2 description:: I try to decrypt file data when page fault. I find it's easy to get physical address from virtual address, but when page fault, kern will page in several pages including page we require, how can I get virtual memory address of these pages? May I access data in physical memory directly? If yes, how tranlate 64 bit phys addr into 32 bit virt addr? Thanks!!!! pine _________________________________________________________________ Help STOP SPAM with the new MSN 8 and get 2 months FREE* http://join.msn.com/?page=features/junkmail