On Fri, Oct 09, 2015 at 11:25:09AM +0100, Thomas Gleixner wrote: > Hans, > > On Fri, 9 Oct 2015, Hans Zuidam wrote: > > On 9 okt. 2015, at 11:06, Thomas Gleixner <t...@linutronix.de> wrote: > > > You cannot use an explicit 32bit read. We need an access which > > > handles the fault gracefully. > > > > The reason for the explicit read suggestion is to avoid the > > _builtin_constant_p() in __copy_from_user_nocheck(). The GCC manual > > says that there may be situations where it returns 0 even though the > > argument is a constant. > > That's insane at best.
Right, but I bet that is for cases where constant propagation completely fails, and this is a trivial case, I have no problem relying on it. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
