Received-SPF: pass (google.com: domain of linux-kernel+bounces-193442-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:4601:e00::3 as permitted sender) client-ip=2604:1380:4601:e00::3;
Date: Wed, 29 May 2024 06:25:43 +0100
From: Al Viro <viro@zeniv.linux.org.uk>
To: Nick Bowler <nbowler@draconx.ca>
Cc: linux-kernel@vger.kernel.org,
	Linux regressions mailing list <regressions@lists.linux.dev>,
	Alexey Gladkov <legion@kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: PROBLEM: kbd busted in linux 6.10-rc1 (regression)
Message-ID: <20240529052543.GL2118490@ZenIV>
References: <ad4e561c-1d49-4f25-882c-7a36c6b1b5c0@draconx.ca>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <ad4e561c-1d49-4f25-882c-7a36c6b1b5c0@draconx.ca>
Sender: Al Viro <viro@ftp.linux.org.uk>

On Wed, May 29, 2024 at 12:45:56AM -0400, Nick Bowler quoted:

>        All other headers use _IOC() macros to describe ioctls for a long time
>        now. This header is stuck in the last century.
>    
>        Simply use the _IO() macro. No other changes.

.. are needed, since _IO() is arch-dependent; this is quite enough to fuck
alpha and sparc over.  _IO(x,y) is (1<<29) + 256*x + y there; both ports
got started with compat userland support, so _IO...() family there is
modelled after OSF/1 and Solaris resp.

kbd ioctls predate all of that.

Please, revert 8c467f330059 - commit in question breaks userland on alpha
and on sparc for no reason whatsoever.  Might be worth adding a comment
to those definitions at some point, but that can go on top of revert.

Folks, 0xXYZW is *not* an uncool way to spell _IO(0xXY,0xZW) - if there's
any chance that those definitions are seen on all architectures, they
should be left alone.