Re: how do you call userspace syscalls (e.g. sys_rename) from inside kernel

[Luke Kenneth Casson Leighton <lkcl@lkcl.net>]

On Fri, Oct 08, 2004 at 05:18:40PM +0200, Brice Goglin wrote:
> > call sys_rename, sys_pread, sys_create, sys_mknod, sys_rmdir
> > etc. - everything that does file access.
> 
> If you ever actually call sys_this or sys_that ... from
> the kernel, you'll have to do something like this to avoid
> copy_from/to_user to fail because the target buffer is not
> in kernel space:
> 
> mm_segment_t old_fs;
> old_fs = get_fs();
> set_fs(KERNEL_DS);
> <do you stuff here>
> set_fs(old_fs);
 
 that's it!  that's what i was looking for.  thank you.

 l.