linux-kernel - Re: [patch RFC 06/29] printk: Protect [un]register

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: <YzMUe5soxMrsFM8V@alley>
Date:   Tue, 27 Sep 2022 17:19:23 +0200
From:   Petr Mladek <pmladek@...e.com>
To:     Thomas Gleixner <tglx@...utronix.de>
Cc:     LKML <linux-kernel@...r.kernel.org>,
        John Ogness <john.ogness@...utronix.de>,
        Sergey Senozhatsky <senozhatsky@...omium.org>,
        Steven Rostedt <rostedt@...dmis.org>,
        Linus Torvalds <torvalds@...uxfoundation.org>,
        Peter Zijlstra <peterz@...radead.org>,
        "Paul E. McKenney" <paulmck@...nel.org>,
        Daniel Vetter <daniel@...ll.ch>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Helge Deller <deller@....de>,
        Jason Wessel <jason.wessel@...driver.com>,
        Daniel Thompson <daniel.thompson@...aro.org>
Subject: Re: [patch RFC 06/29] printk: Protect [un]register_console() with a
 mutex

On Tue 2022-09-27 11:56:30, Petr Mladek wrote:
> On Sun 2022-09-11 00:27:41, Thomas Gleixner wrote:
> > Unprotected list walks are a brilliant idea. Especially in the context of
> > hotpluggable consoles.
> 
> Yeah, it is crazy. And it is there probably since the beginning.
> 
> > @@ -3107,13 +3143,14 @@ void register_console(struct console *ne
> >  	bool realcon_enabled = false;
> >  	int err;
> >  
> > -	for_each_console(con) {
> > +	console_list_lock();
> 
> Hmm, the new mutex is really nasty. It has very strange semantic.
> It makes the locking even more complicated.

Please, continue the discussion in the reply to the v1 patchset,
see https://lore.kernel.org/r/YzMT27FVllY3u05k@alley

I send it to this RFC by mistake.

I am sorry for the mess.

Best Regards,
Petr