On Thu, Jan 04, 2007 at 11:30:22AM -0800, Linus Torvalds wrote: > > > On Thu, 4 Jan 2007, Al Viro wrote: > > > > How about "makes call graph analysis easier"? ;-) In principle, I have > > no problem with force-casting, but it'd better be cast to the right > > type... > > Do we really care in the kernel? We simply never use function pointer > casts like this for anything non-trivial, so if the graph analysis just > doesn't work for those cases, do we really even care?
Umm... Let me put it that way - amount of things that can be done to void * is much more than what can be done to function pointers. So keeping track of them gets easier if we never do casts to/from void *. What's more, very few places in the kernel try to do that _and_ most of those that do are simply too lazy to declare local variable with the right type. bad_inode.c covers most of what remains. IMO we ought to start checking for that kind of stuff; note that we _still_ have strugglers from pt_regs removal where interrupt handler still takes 3 arguments, but we don't notice since argument of request_irq() is cast to void * ;-/ That's local stuff; however, when trying to do non-local work (e.g. deduce that foo() may be called from BH, bar() is always called from process context, etc. _without_ fuckloads of annotations all over the place), the ban on mixing void * with function pointers helps a _lot_. So my main issue with fs/bad_inode.c is not even cast per se; it's that cast is to void *. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/