linux-kernel - Re: [PATCH V8 06/44] mm/pkeys: Add Kconfig options for PKS

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <f72b0e17-11bf-b12e-fe7a-d38b0833acdc@intel.com>
Date:   Fri, 28 Jan 2022 15:51:56 -0800
From:   Dave Hansen <dave.hansen@...el.com>
To:     Ira Weiny <ira.weiny@...el.com>
Cc:     Dave Hansen <dave.hansen@...ux.intel.com>,
        "H. Peter Anvin" <hpa@...or.com>,
        Dan Williams <dan.j.williams@...el.com>,
        Fenghua Yu <fenghua.yu@...el.com>,
        Rick Edgecombe <rick.p.edgecombe@...el.com>,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH V8 06/44] mm/pkeys: Add Kconfig options for PKS

On 1/28/22 15:10, Ira Weiny wrote:
> This issue is that because PKS users are in kernel only and are not part of the
> architecture specific code there needs to be 2 mechanisms within the Kconfig
> structure.  One to communicate an architectures support PKS such that the user
> who needs it can depend on that config as well as a second to allow that user
> to communicate back to the architecture to enable PKS.

I *think* the point here is to ensure that PKS isn't compiled in unless
it is supported *AND* needed.  You have to have architecture support
(ARCH_HAS_SUPERVISOR_PKEYS) to permit features that depend on PKS to be
enabled.  Then, once one ore more of *THOSE* is enabled,
ARCH_ENABLE_SUPERVISOR_PKEYS comes into play and actually compiles the
feature in.

In other words, there are two things that must happen before the code
gets compiled in:

1. Arch support
2. One or more features to use the arch support