Date: Wed, 2 Mar 2016 13:12:16 -0800
From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Davidlohr Bueso <dave@stgolabs.net>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>, linux-kernel@vger.kernel.org,
        peterz@infradead.org, mingo@redhat.com,
        Josh Triplett <josh@joshtriplett.org>,
        "Guohanjun (Hanjun Guo)" <guohanjun@huawei.com>
Subject: Re: [PATCH v2] locktorture: Fix NULL pointer when torture_type is
 invalid
Message-ID: <20160302211216.GC3577@linux.vnet.ibm.com>
Reply-To: paulmck@linux.vnet.ibm.com
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 <20160131002721.GI6719@linux.vnet.ibm.com>
 <20160131221736.GB16147@linux-uzut.site>
 <56AEC21A.5010107@huawei.com>
 <20160201030235.GC16147@linux-uzut.site>
 <56AED0C7.7050505@huawei.com>
 <20160202064635.GH6719@linux.vnet.ibm.com>
 <20160203002331.GA3385@linux-uzut.site>
 <20160302195543.GA12593@linux-uzut.site>
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On Wed, Mar 02, 2016 at 11:55:43AM -0800, Davidlohr Bueso wrote:
> On Tue, 02 Feb 2016, Davidlohr Bueso wrote:
> 
> I've just hit this issue myself and remembered this thread :)
> 
> Paul, folks, does the below patch look reasonable to you? If so
> I can properly resend. thanks.

If it works for Kefeng Wang, I would be happy to take it.

							Thanx, Paul

> >On Mon, 01 Feb 2016, Paul E. McKenney wrote:
> >
> >>On Mon, Feb 01, 2016 at 11:28:07AM +0800, Kefeng Wang wrote:
> >
> >>>Just like I mentioned before, keep consistent with rcutorture???
> >
> >Because rcutorture does it doesn't mean locktorture has to do it ;)
> >In any case, I'd suggest the same be done for rcutorture.
> >
> >[...]
> >
> >>
> >>Hmmm...   If nothing happened, then I agree that it makes sense not to
> >>print any statistics.  But if some testing actually was carried out, then
> >>we really need to print the statistics.
> >
> >Right, so how about the following? It introduces an early cleanup helper
> >that all it does is do torture specific cleanups. I don't really love the
> >begin/end calls there, but it's not the end of the world and it seems better
> >than a more messier refactoring. ie, I had also considered adding an 'early'
> >flag to lock_torture_cleanup() such that we can enable it for this bogus param
> >scenario, but seems over complicating things and we also call it for such a
> >small issue.
> >
> >Thanks,
> >Davidlohr
> >
> >
> >diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c
> >index 8ef1919..05e2649 100644
> >--- a/kernel/locking/locktorture.c
> >+++ b/kernel/locking/locktorture.c
> >@@ -741,6 +741,19 @@ lock_torture_print_module_parms(struct lock_torture_ops *cur_ops,
> >		 onoff_interval, onoff_holdoff);
> >}
> >+/*
> >+ * Indicates early cleanup, meaning that the test has not run,
> >+ * such as when passing bogus args when loading the module. As
> >+ * such, only perform the underlying torture-specific cleanups,
> >+ * and avoid anything related to locktorture.
> >+ */
> >+static inline void lock_torture_early_cleanup(void)
> >+{
> >+	if (torture_cleanup_begin())
> >+		return;
> >+	torture_cleanup_end();
> >+}
> >+
> >static void lock_torture_cleanup(void)
> >{
> >	int i;
> >@@ -811,8 +824,10 @@ static int __init lock_torture_init(void)
> >		for (i = 0; i < ARRAY_SIZE(torture_ops); i++)
> >			pr_alert(" %s", torture_ops[i]->name);
> >		pr_alert("\n");
> >-		firsterr = -EINVAL;
> >-		goto unwind;
> >+
> >+		torture_init_end();
> >+		lock_torture_early_cleanup();
> >+		return -EINVAL;
> >	}
> >	if (cxt.cur_ops->init)
> >		cxt.cur_ops->init();
>