Re: [PATCH v2 1/2] vsprintf: Don't leak pointers for %ps without KALLSYMS enabled

[Sebastian Andrzej Siewior <bigeasy@linutronix.de>]

On 2026-08-27 11:51:00 [+0200], Petr Mladek wrote:
> 
> I think that it is a matter of taste. I could understand that
> "(unknown)" might look more obvious to some people.
> 
> I would still prefer the hashed pointer. It make it consistent with
> %p handling. Both print addresses in this case.

For %p expect a pointer, for %pS you expect a name.

> The motivation for the hash in %p is that it is slightly more useful
> than a static string, e.g. "(address)" or "(pointer)". The hash allows
> to match the same addresses. It is not 100% reliable but better
> than nothing.

but is this helpful?

> Also the hash makes it more obvious the connection with "no_hash_pointer"
> option.

Assuming you know about the no_hash_pointer. And then you get a
randomized pointer. Enabling kallsym would be a _bigger_ help than
rebooting with no_hash_pointer.

> IMHO, the only drawback is that people might confuse the hash with
> a real value. But it is easier on 64-bit systems because the higher
> 32-bits are zeros.

That, too. Do you continue to insist on this hashed pointer output here?

> Best Regards,
> Petr

Sebastian