This is to discuss the problems I am facing with porting a driver from a 2.6.18 kernel to 3.8.3 kernel. Apart from the APIs and functions that have changed(which I have more or less replaced), the system call implementation has changed. http://lxr.linux.no/linux+v2.6.18/arch/i386/kernel/syscall_table.S#L41 http://lxr.linux.no/linux+v3.8.3/arch/x86/syscalls/syscall_64.tbl#L92 Now due to this, some unnecessary warnings and errors are coming. To explain this I am providing the compiler error which is not coming on 2.6.18 kernel but is coming on 3.8.3 kernel. the below line is generating https://github.com/HeisSpiter/hepunion/blob/master/fs/hepunion/helpers.c#L49... mode &= ~current->fs->umask; the following error- ERROR:Derefencing pointer to incomplete type This has nothing to do with any APIs or change in the structure in the newer kernel. This just the importation of mkdir code from the linux kernel. Likely to be sys_mkdir, IIRC. Talking of which, I'd think that I must sync ALL the importations from the Linux kernel with mine. Regards, Saket Sinha