linux-kernel - Re: [PATCH 1/2] moduleparams: Add hex type parameter

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: <CAHk-=wimBucBdC+tzFEuFJU5X1UFTVWo+AHMvQTSkCcVnTT-ww@mail.gmail.com>
Date:   Thu, 2 Jul 2020 12:42:37 -0700
From:   Linus Torvalds <torvalds@...ux-foundation.org>
To:     Christian König <christian.koenig@....com>
Cc:     Paul Menzel <pmenzel@...gen.mpg.de>,
        Alex Deucher <alexander.deucher@....com>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        amd-gfx@...ts.freedesktop.org
Subject: Re: [PATCH 1/2] moduleparams: Add hex type parameter

On Thu, Jul 2, 2020 at 7:42 AM Christian König <christian.koenig@....com> wrote:
>
> I'm just not sure how well this is received upstream because it only
> covers u32
>
> On the other hand that is probably also the most used.

Not necessarily true. I'd argue that "unsigned long"  is equally
possible for some bit mask (or other hex-likely) type.

So don't call it just "hex". Call it "hexint" (the hex does imply
"unsigned", I feel - showing hex numbers with a sign sounds insane).

That way, if somebody ends up wanting it for unsigned long values,
we're not stuck.

Another option is to just say that hex values always have bit _sizes_.
So "hex32" and "hex64" would also make sense as names to me.

While at it, should the hex numbers always be padded out to the size?
The example Paul used doesn't have that issue (high bit being set).

Bbut often it may make sense to show a 32-bit hex number as "%#08x"
because it really makes things clearer when you're looking at high
bits, say.

It's really hard to tell the difference between "just bit 27 set" and
"just bit 31" set otherwise, and that's not all that uncommon when the
bitmasks are sparse.

             Linus