From: Nicholas Mc Guire <der.herr@hofr.at>
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: linux-rt-users@vger.kernel.org
Subject: Re: bad return value in __mutex_lock_check_stamp
Date: Sun, 15 Dec 2013 17:18:29 +0100 [thread overview]
Message-ID: <20131215161829.GA18302@opentech.at> (raw)
In-Reply-To: <52ADC653.7090005@linutronix.de>
On Sun, 15 Dec 2013, Sebastian Andrzej Siewior wrote:
> On 12/15/2013 03:40 PM, Nicholas Mc Guire wrote:
> >
> > Bad return value in _mutex_lock_check_stamp - this problem only would show
> > up with 3.12.1 rt4 applied but CONFIG_PREEMPT_RT_FULL not enabled
> > currently it would be returning what ever vprintk_emit ended up with
> > (atleast on x86), which probably is not the intended behavior. Added a
> > return 0; as in the case with CONFIG_PREEMPT_RT_FULL enabled.
>
> Interesting. How do you trigger this? This BUG()-only function should
> get completely removed by gcc because
> - ctx argument should be always NULL
> - BUG() has unreachable() so gcc knows it does not return.
>
poped up with randconfig seed 0xBE96A834
Don't get it - why could gcc optimize it out ? it gets called
in the mutex slowpath (kernel/mutex.c) if CONFIG_PREEMPT_RT_FULL
is not set ?
Am I confusing some ifdefs ?
thx!
hofrat
next prev parent reply other threads:[~2013-12-15 16:18 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-12-15 14:40 bad return value in __mutex_lock_check_stamp Nicholas Mc Guire
2013-12-15 15:10 ` Sebastian Andrzej Siewior
2013-12-15 16:18 ` Nicholas Mc Guire [this message]
2013-12-15 16:48 ` Sebastian Andrzej Siewior
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=20131215161829.GA18302@opentech.at \
--to=der.herr@hofr.at \
--cc=bigeasy@linutronix.de \
--cc=linux-rt-users@vger.kernel.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.