Messages in this thread | | | From | Linus Torvalds <> | Date | Sun, 10 Dec 2017 12:39:11 -0800 | Subject | Re: [PATCH tip/core/rcu 02/20] torture: Prepare scripting for shift from %p to %pK |
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On Sun, Dec 10, 2017 at 4:52 AM, Andy Shevchenko <andy.shevchenko@gmail.com> wrote: >> >>> Perhaps it should have printed a fixed, non-zero value for non-zero >>> pointers. >> >> I must leave this to the people who have a dog in that contest. ;-) > > Since there is an ongoing discussion with security people near to %pK > and alike, I added Kees and Linus to Cc list. > > The proposed change can be done easily, though I have no knowledge > about possible implications.
I'd rather make %pK act more like %p than have gratuitous differences.
I also think %pK is kind of pointless in general. It has not been a big success, and the whole "root or not" is kind of nasty anyway. Root in a container? Things like that.
So I think that if people worry about leaking pointers, they should primarily go for:
- just use %p and now get the hashed value
- if the hashed value is pointless, ask yourself whether the pointer itself is important. Maybe it should be removed?
- as a last option, if you really think the true pointer value is important, why is root so special, and maybe you should use %px and make sure you have proper sensible permissions.
..and %pK just isn't really the answer in any of those cases.
Linus
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