linux-kernel - Re: [PATCH] printk/console: Enable console kthreads only when there is no boot console left

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-=whBSrixcBVoWGnU0eoaksp82gnQ9_1jMNZsCzhLXEgEpw@mail.gmail.com>
Date:   Mon, 20 Jun 2022 14:10:20 -0500
From:   Linus Torvalds <torvalds@...ux-foundation.org>
To:     Petr Mladek <pmladek@...e.com>
Cc:     Marek Behún <kabel@...nel.org>,
        John Ogness <john.ogness@...utronix.de>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Sergey Senozhatsky <senozhatsky@...omium.org>,
        Steven Rostedt <rostedt@...dmis.org>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Rasmus Villemoes <linux@...musvillemoes.dk>,
        Jan Kara <jack@...e.cz>, Peter Zijlstra <peterz@...radead.org>
Subject: Re: [PATCH] printk/console: Enable console kthreads only when there
 is no boot console left

On Mon, Jun 20, 2022 at 10:14 AM Petr Mladek <pmladek@...e.com> wrote:
>
> The console kthreads uncovered several races in console drivers.

I really want to make it clear that this was NOT some kind of "races
in drivers".

Console drivers may very well  have intentionally avoided taking locks
for console output, since the printk output was supposed to be
serialized by printk.

Don't try to make this some kind of "buggy drivers" thing. This is on
printk, not on anything else.

Assuming this solves all issues, I'm ok with this approach, but I
really want this to be clearly about printk being buggy, no "blame the
drivers" garbage.

And if there are other issues coming up, we revert the whole thing entirely.

Because printk is too important to play games with, and too important
to try to blame drivers.

               Linus