On Thu, Mar 15, 2018 at 09:11:27PM +0100, Arnd Bergmann wrote: > Shouldn't the callers of sys_mount just call do_mount() instead? > > As I understand it, sys_mount is already a wrapper around do_mount() > that copies its arguments from user space, but we don't need that > when called from inside the kernel.
In general yes. do_mount.c has some really strange calling context where it tries to operate on kernel and user pointers interchangably, but even with that just switching to do_mount seems like the right thing to me. In fact once we do that and take care or chdir/chdoot we could probably get rid of the sparse disable hack in favour of a few __force casts in change_floppy and sort this mess out as well.
