Re: [PATCH] printk: Let %pR handle NULL pointers

[Trent Piepho <xyzzy@speakeasy.org>]

On Sun, 4 Jan 2009, Benjamin Herrenschmidt wrote:
> On Sat, 2009-01-03 at 09:10 -0800, Linus Torvalds wrote:
> >
> > On Sat, 3 Jan 2009, Trent Piepho wrote:
> > >
> > > Have %pR print "[NULL]" for the resource range when passed a NULL pointer.
> >
> > Wouldn't it be much nicer to just do it for _all_ pointer types?
> >
> > IOW, a patch more like the appended.
>
> Agreed.

I thought of doing that too, but then all the various %pX formats would all
have to print the same for NULL pointers.  For instance a resource prints
out like "[0x1000-0x100f]", so I chose "[NULL]" for printing a null
resource pointer.  Maybe "[]" or "[-]" would be better?  A null MAC address
could be ":::::" or "x:x:x:x:x:x".  "N.U.L.L" or "x.x.x.x" for a null IP4
address.  And so on.  So the printout looks nicer when a NULL pointer isn't
a bug.