Re: [PATCH][RESEND] lib/vsprintf: make-printk-non-secret printks all addresses as unhashed

[Timur Tabi]

On 2/5/21 4:59 AM, Vlastimil Babka wrote:
> Thanks a lot. Should this also affect %pK though? IIUC, there's currently no way
> to achieve non-mangled %pK in all cases, even with the most permissive
> kptr_restrict=1 setting:
> - in IRQ, there's "pK-error" instead
> - in a context of non-CAP_SYSLOG process, nulls are printed

Hmmm..  I thought %pK prints an unhashed pointer when the user is root, 
at least in situations where the user can be known (e.g. during an ioctl 
call).

> Yes, neither should matter if %pK were only used for prints that generate
> content of some kind of /proc file read by a CAP_SYSLOG process, but that
> doesn't seem to be the case and there are %pK used for printing to dmesg too...

I thought about that.  On one hand, people who use %pK probably really 
wanted a hashed pointer printed.  On the other hand, I agree that %pK 
should not be used for dmesg prints.

I get the feeling that some (most?) people who use %pK don't really 
understand how it's supposed to be used.

I can extend make-printk-non-secret to %pK if everyone agrees.