linux-kernel - Re: [PATCH v2] printk_legacy_map: use LD_WAIT_CONFIG instead of LD_WAIT

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: <20251024110004.GF771@redhat.com>
Date: Fri, 24 Oct 2025 13:00:04 +0200
From: Oleg Nesterov <oleg@...hat.com>
To: Sebastian Andrzej Siewior <bigeasy@...utronix.de>
Cc: Petr Mladek <pmladek@...e.com>, John Ogness <john.ogness@...utronix.de>,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] printk_legacy_map: use LD_WAIT_CONFIG instead of
 LD_WAIT_SLEEP

On 10/24, Sebastian Andrzej Siewior wrote:
>
> On 2025-10-24 12:40:56 [+0200], Oleg Nesterov wrote:
> > On 10/23, Sebastian Andrzej Siewior wrote:
> > >
> > > On 2025-10-23 12:32:34 [+0200], Oleg Nesterov wrote:
> > > > printk_legacy_map is used on !PREEMPT_RT to avoid false positives from
> > > > CONFIG_PROVE_RAW_LOCK_NESTING about raw_spinlock/spinlock nesting.
> > >
> > > Could we please get rid of CONFIG_PROVE_RAW_LOCK_NESTING here? This is
> > > lockdep internal implementation and has nothing to do with printk or
> > > anything.
> >
> > OK, but let me ensure I didn't miss something (again ;).
> >
> > I mentioned CONFIG_PROVE_RAW_LOCK_NESTING in the changelog because if
> > CONFIG_PROVE_RAW_LOCK_NESTING=n, then LD_WAIT_CONFIG == LD_WAIT_SPIN
> > and lockdep will not complain if spinlock_t nests inside raw_spinlock_t.
> >
> > IOW, without CONFIG_PROVE_RAW_LOCK_NESTING printk_legacy_map is not
> > really needed.
>
> This is correct but CONFIG_PROVE_RAW_LOCK_NESTING is kind of a must and
> should not be an option.

Yes, I see your point. Just wanted to ensure I fully understand it.

Thanks,

Oleg.