Re: [Linux-kernel-mentees] [PATCH v2] kernel: audit.c: Add __rcu notation to RCU pointer

From: Richard Guy Briggs <rgb@redhat.com>
To: Ondrej Mosnacek <omosnace@redhat.com>
Cc: Paul Moore <paul@paul-moore.com>,
	Linux kernel mailing list <linux-kernel@vger.kernel.org>,
	Linux-Audit Mailing List <linux-audit@redhat.com>,
	Joel Fernandes <joel@joelfernandes.org>,
	linux-kernel-mentees@lists.linuxfoundation.org
Subject: Re: [Linux-kernel-mentees] [PATCH v2] kernel: audit.c: Add __rcu notation to RCU pointer
Date: Wed, 15 Apr 2020 15:27:23 -0400	[thread overview]
Message-ID: <20200415192723.rrdwtitiu3f2cd67@madcap2.tricolour.ca> (raw)
In-Reply-To: <CAFqZXNuYnvru+pMhPwNTBn1+uB=MfYh1yWWBeAn+J-=LXrFgcg@mail.gmail.com>

On 2020-04-15 18:53, Ondrej Mosnacek wrote:
> On Wed, Apr 15, 2020 at 6:15 PM Richard Guy Briggs <rgb@redhat.com> wrote:
> > On 2020-04-15 12:06, Paul Moore wrote:
> > > On Wed, Apr 15, 2020 at 11:34 AM Richard Guy Briggs <rgb@redhat.com> wrote:
> > > > On 2019-11-29 21:07, Joel Fernandes wrote:
> > > > > On Thu, Nov 28, 2019 at 09:02:03PM +0530, Amol Grover wrote:
> > > > > > add __rcu notation to RCU protected global pointer auditd_conn
> > > > >
> > > > > Again, please use proper punctuation and captilization. This is unacceptable.
> > > > > Please put more effort into changelog.
> > > > >
> > > > > Otherwise the patch diff itself looks good to me, with the above nit
> > > > > corrected, you could add my tag to the next revision:
> > > > >
> > > > > Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
> > > > >
> > > > > thanks,
> > > > >
> > > > >  - Joel
> > > > >
> > > > > >
> > > > > > Fixes multiple instances of sparse error:
> > > > > > error: incompatible types in comparison expression
> > > > > > (different address spaces)
> > > >
> > > > Amol or Joel: Is there a reproducer recipe for this?
> > >
> > > The commit which was merged has a slightly better description which may help.
> >
> > I've already seen this.  Perhaps I should have replied to this message
> > instead to make that evident.  What really needed was Amol's original
> > message sent to this list, but it was Joel who included this list in his
> > reply (all 3 versions).
> >
> > I'm looking for the specific setup and commands that produced this error.
> 
> You can run make with "C=1", which will run sparse on all files that
> are rebuilt during that make run. For example, if I fully build the
> kernel and then revert commit
> cb5172d96d16df72db8b55146b0ec00bfd97f079, I get:
> 
> $ make [...] C=1
> [...]
>   CHECK   [...]/kernel/audit.c
> [...]/kernel/audit.c:218:14: error: incompatible types in comparison
> expression (different address spaces):
> [...]/kernel/audit.c:218:14:    struct auditd_connection [noderef] <asn:4> *
> [...]/kernel/audit.c:218:14:    struct auditd_connection *
> (...and a lot more errors like this + 2 different warnings)
> 
> And when I un-revert it again, I get only the 2 warnings.

Perfect, thanks Ondrej.

> Ondrej Mosnacek <omosnace at redhat dot com>

- RGB

--
Richard Guy Briggs <rgb@redhat.com>
Sr. S/W Engineer, Kernel Security, Base Operating Systems
Remote, Ottawa, Red Hat Canada
IRC: rgb, SunRaycer
Voice: +1.647.777.2635, Internal: (81) 32635

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