linux-kernel - Re: [PATCH 13/26] locking: Add non-fatal spin lock assert

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: <20140904051411.GA27350@gmail.com>
Date:	Thu, 4 Sep 2014 07:14:11 +0200
From:	Ingo Molnar <mingo@...nel.org>
To:	Peter Zijlstra <peterz@...radead.org>
Cc:	Peter Hurley <peter@...leysoftware.com>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Jiri Slaby <jslaby@...e.cz>,
	One Thousand Gnomes <gnomes@...rguk.ukuu.org.uk>,
	linux-serial@...r.kernel.org, linux-kernel@...r.kernel.org,
	Thomas Gleixner <tglx@...utronix.de>
Subject: Re: [PATCH 13/26] locking: Add non-fatal spin lock assert


* Peter Zijlstra <peterz@...radead.org> wrote:

> On Wed, Sep 03, 2014 at 10:50:01AM -0400, Peter Hurley wrote:
> > So a lockdep-only assert is unlikely to draw attention to existing bugs,
> > especially in established drivers.
> 
> By the same logic lockdep will not find locking errors in established
> drivers.

Indeed, this patch is ill-advised in several ways:

  - it extends an API variant that we want to phase

  - emits a warning even if say lockdep has already emitted a
    warning and locking state is not guaranteed to be consistent. 

  - makes the kernel more expensive once fully debugged, in that
    non-fatal checks are unconditional.

Also please submit locking related patches as standalone series 
to the locking subsystem, not embedded in an unrelated series.

Thanks,

	Ingo
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/