Re: [PATCH V11 3/5] printk: hash addresses printed with %p

[Linus Torvalds]

On Wed, Dec 6, 2017 at 3:21 PM, Kees Cook <keescook@xxxxxxxxxxxx> wrote:
> On Wed, Dec 6, 2017 at 2:31 AM, David Laight <David.Laight@xxxxxxxxxx> wrote:
>>
>> I can also image issues where you want to know whether 2 pointers point
>> into the same structure (like an skb).
>
> This is already retained due to the hashing. i.e. the same pointer
> value will produce the same hash value, so that kind of direct
> comparison still works.

DavidL isn't talking about the _same_ pointer, he's talking about it
being offset from the same base.

But realistically, I don't think we ever hash things like that anyway.

Things like that do show up in register dumps etc during oopses, but
those aren't hashed.

            Linus