From: Frederic Weisbecker <fweisbec@gmail.com>
To: Ingo Molnar <mingo@elte.hu>
Cc: Greg KH <gregkh@suse.de>, LKML <linux-kernel@vger.kernel.org>,
LTP <ltp-list@lists.sourceforge.net>,
Peter Zijlstra <peterz@infradead.org>
Subject: Re: [PATCH 2/2] lockdep: choose to continue lock debugging despite taint
Date: Sat, 11 Apr 2009 03:15:06 +0200 [thread overview]
Message-ID: <20090411011505.GA5992@nowhere> (raw)
In-Reply-To: <20090410134520.GC17878@elte.hu>
On Fri, Apr 10, 2009 at 03:45:20PM +0200, Ingo Molnar wrote:
>
> * Frederic Weisbecker <fweisbec@gmail.com> wrote:
>
> > On Fri, Apr 10, 2009 at 02:15:15PM +0200, Ingo Molnar wrote:
> > >
> > > * Frederic Weisbecker <fweisbec@gmail.com> wrote:
> > >
> > > > Lockdep is disabled after any kernel taints. This might be
> > > > convenient to ignore bad locking issues which sources come from
> > > > outside the kernel tree. Nevertheless, it might be a frustrating
> > > > experience for the staging developers or anyone who might develop
> > > > a kernel that happens to be tainted.
> > >
> > > Good point. Not having lockdep coverage for drivers/staging/ just
> > > prolongs their transition - not good.
> > >
> > > But instead of this:
> > >
> > > > void add_taint(unsigned flag)
> > > > {
> > > > +#ifndef CONFIG_LOCKDEP_IGNORE_TAINT
> > > > /*
> > > > * Can't trust the integrity of the kernel anymore.
> > > > * We don't call directly debug_locks_off() because the issue
> > > > @@ -220,6 +221,7 @@ void add_taint(unsigned flag)
> > > > */
> > > > if (xchg(&debug_locks, 0))
> > > > printk(KERN_WARNING "Disabling lockdep due to kernel taint\n");
> > > > +#endif
> > >
> > > I'd suggest to not do the debug_locks_off() call if TAINT_CRAP. I.e.
> > > something like:
> > >
> > > if (!(flag & TAINT_CRAP) && debug_locks_off())
> > > printk(...);
> > >
> > > will do the trick.
> > >
> > > Ingo
> >
> >
> > Ok, but this is not only about staging. It's also about
> > TAINT_WARN. Just imagine that you report a warning to a
> > maintainer, and while you are waiting for it to be fixed, you
> > can't use lockdep for your own needs.
> >
> > Hm?
>
> We can exclude TAINT_WARN too - i.e. (TAINT_CRAP|TAINT_WARN).
>
> Ingo
Fine :-)
See the v2 on further mails in this thread.
Side request: do you think you could merge them on kill-the-BKL tree?
Thanks!
next prev parent reply other threads:[~2009-04-11 1:15 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-04-09 21:27 [PATCH 1/2] lockdep: warn about lockdep disabling after kernel taint Frederic Weisbecker
2009-04-09 21:27 ` [PATCH 2/2] lockdep: choose to continue lock debugging despite taint Frederic Weisbecker
2009-04-10 12:15 ` Ingo Molnar
2009-04-10 13:38 ` Frederic Weisbecker
2009-04-10 13:45 ` Ingo Molnar
2009-04-11 1:15 ` Frederic Weisbecker [this message]
2009-04-11 1:37 ` Frederic Weisbecker
2009-04-12 14:09 ` Ingo Molnar
2009-04-11 1:17 ` [PATCH 1/2 v2] lockdep: warn about lockdep disabling after kernel taint Frederic Weisbecker
2009-04-12 14:45 ` [tip:core/urgent] " Frederic Weisbecker
2009-04-11 1:17 ` [PATCH 2/2 v2] lockdep: continue lock debugging despite some taints Frederic Weisbecker
2009-04-12 14:45 ` [tip:core/urgent] " Frederic Weisbecker
2009-04-10 12:12 ` [PATCH 1/2] lockdep: warn about lockdep disabling after kernel taint Ingo Molnar
2009-04-10 13:34 ` Frederic Weisbecker
2009-04-10 13:38 ` Ingo Molnar
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20090411011505.GA5992@nowhere \
--to=fweisbec@gmail.com \
--cc=gregkh@suse.de \
--cc=linux-kernel@vger.kernel.org \
--cc=ltp-list@lists.sourceforge.net \
--cc=mingo@elte.hu \
--cc=peterz@infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).