linux-kernel - Re: [PATCH] vc_screen: don't clobber return value in vcs

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Message-ID: <58af4510-13cd-4f4c-9199-b6b59b2f2bff@t-8ch.de>
Date:   Sat, 4 Mar 2023 22:33:37 +0000
From:   Thomas Weißschuh <linux@...ssschuh.net>
To:     Storm Dragon <stormdragon2976@...il.com>
Cc:     George Kennedy <george.kennedy@...cle.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Jiri Slaby <jirislaby@...nel.org>,
        linux-kernel@...r.kernel.org, Randy Dunlap <rdunlap@...radead.org>
Subject: Re: [PATCH] vc_screen: don't clobber return value in vcs_read

On Sat, Mar 04, 2023 at 02:58:46PM -0500, Storm Dragon wrote:
> On Fri, Mar 03, 2023 at 11:25:00PM +0000, Thomas Weißschuh wrote:
> 
> > Does this mean the screenreader now works correctly or is it still
> > broken somehow?
> > 
> > Thomas
> 
> I have still been testing this kernel. Most things work as expected, but
> the pasting functionality for Fenrir's clipboard is broken. After
> checking into the problem, it seems that tiocsti is disabled, and that
> is causing the problem. Was that something done in this test kernel
> only, or will that be the default for all new Arch kernels? If it is the
> default, is there a way to turn it back on?

By now this package has been promoted to [core] so it is in fact the
default ArchLinux kernel.

As a workaround you can use the "linux-lts" package that now also
carries the fix for your original problem but not the code responsible
for the new issue.

pacman -Sy linux-lts

> I tried the following:
> 
> [storm@...llnir ~] $ sudo sysctl dev.tty.legacy_tiocsti=1
> sysctl: setting key "dev.tty.legacy_tiocsti": Invalid argument

This is indeed the correct way to enable the feature again.

It seems that the commit that introduced this sysctl[0] depends on
another commit [1] to be applied. But the 6.2.2 stable kernel is missing
the requirement.

I'll validate that this indeed is the issue and will then send a formal
request for backporting.

[0] 83efeeeb3d04 ("tty: Allow TIOCSTI to be disabled")
[1] f1aa2eb5ea05 ("sysctl: fix proc_dobool() usability")