Kernel Self Protection Project: slub_debug=ZF

Hello,

The Kernel Self Protection Project, on their Recommended Settings [1] 
page, suggests the following:

# Enable SLUB redzoning and sanity checking (slow; requires 
CONFIG_SLUB_DEBUG=y above).
slub_debug=ZF

On recent kernels, I see the following in dmesg when this option is set:

**********************************************************
**   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **
**                                                      **
** This system shows unhashed kernel memory addresses   **
** via the console, logs, and other interfaces. This    **
** might reduce the security of your system.            **
**                                                      **
** If you see this message and you are not debugging    **
** the kernel, report this immediately to your system   **
** administrator!                                       **
**                                                      **
**   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **
**********************************************************

A bit of digging tells me that this is caused by "slub: force on 
no_hash_pointers when slub_debug is enabled" [2]. Assuming the 
performance impact is acceptable, is this option still recommend? Should 
there perhaps be a way to explicitly disable no_hash_pointers (e.g. via 
no_hash_pointers=off)?

Regards,

Peter

[1]: 
https://kernsec.org/wiki/index.php/Kernel_Self_Protection_Project/Recommended_Settings
[2]: 
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=792702911f581f7793962fbeb99d5c3a1b28f4c3