RE: [PATCH V11 4/5] vsprintf: add printk specifier %px

David Laight
2017-11-29T10:07:37Z

From: Linus Torvalds
> Sent: 29 November 2017 02:29
>
> On Tue, Nov 28, 2017 at 6:05 PM, Tobin C. Harding <me@tobin.cc> wrote:
> >
> > Let's add specifier %px as a
> > clear, opt-in, way to print a pointer and maintain some level of
> > isolation from all the other hex integer output within the Kernel.
>
> Yes, I like this model. It's easy and it's obvious ("'x' for hex"),
> and it gives people a good way to say "yes, I really want the actual
> address as hex" for if/when the hashed pointer doesn't work for some
> reason.

Remind me to change every %p to %px on kernels that support it.

Although the absolute values of pointers may not be useful, knowing
that two pointer differ by a small amount is useful.
It is also useful to know whether pointers are to stack, code, static
data or heap.

This change to %p is going to make debugging a nightmare.

David