On Wed, Sep 12, 2018 at 05:08:52PM +0200, Arnd Bergmann wrote: > The .ioctl and .compat_ioctl file operations have the same prototype so > they can both point to the same function, which works great almost all > the time when all the commands are compatible. > > One exception is the s390 architecture, where a compat pointer is only > 31 bit wide, and converting it into a 64-bit pointer requires calling > compat_ptr(). Most drivers here will ever run in s390, but since we now > have a generic helper for it, it's easy enough to use it consistently. > > I double-checked all these drivers to ensure that all ioctl arguments > are used as pointers or are ignored, but are not interpreted as integer > values. > > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> > --- > fs/btrfs/super.c | 2 +- Acked-by: David Sterba <dsterba@xxxxxxxx>