Re: [PATCH] binder: Use %p for pointer formatting

[Carlos Llamas]

On Fri, Sep 18, 2026 at 12:30:08PM +0200, Sebastian Andrzej Siewior wrote:
> Commit 8ca86f1639ec5 ("binder: replace "%p" with "%pK"") introduced the
> %pK modifier in order not to leak kernel pointer.
> Since commit ad67b74d2469d ("printk: hash addresses printed with %p")
> pointers are hashed by default and the behaviour can be controller by
> `hash_pointers' boot argument.
> Commit 57483a362741e ("binder: Create safe versions of binder log
> files") introduced a hashed version while preserving the other interface
> where pointers are returned. This interface is for debugging of memory
> leaks. Ideally it would provide just one interface without leaking
> pointers.

These binder_log files is a different thing. These are userspace
pointers.

> 
> The policy on %p is to not introduce new ones. Rather then removing the
> pointer output make it use %p.

IIUC, the policy is to use %pK for seq_printf() files exposed to users.
This is the relevant section from printk-formats.rst:

 | If (and only if) you are printing addresses as a content of a virtual file in
 | e.g. procfs or sysfs (using e.g. seq_printf(), not printk()) read by a
 | userspace process, use the %pK modifier described below instead of %p or %px.

Has this changed?

> 
> Cc: Tiffany Y. Yang <ynaffit@xxxxxxxxxx>
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
> ---
>  drivers/android/binder.c | 4 ++--

This file is now deleted anyway.


Cheers,
--
Carlos Llamas