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

[Paul Moore]

On Wed, Apr 15, 2020 at 11:34 AM Richard Guy Briggs <rgb@xxxxxxxxxx> 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@xxxxxxxxxxxxxxxxx>
> >
> > 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.

  commit cb5172d96d16df72db8b55146b0ec00bfd97f079
  Author: Amol Grover <frextrite@xxxxxxxxx>
  Date:   Mon Dec 2 00:03:48 2019 +0530

   audit: Add __rcu annotation to RCU pointer

   Add __rcu annotation to RCU-protected global pointer auditd_conn.

   auditd_conn is an RCU-protected global pointer,i.e., accessed
   via RCU methods rcu_dereference() and rcu_assign_pointer(),
   hence it must be annotated with __rcu for sparse to report
   warnings/errors correctly.

   Fix multiple instances of the sparse error:
   error: incompatible types in comparison expression
   (different address spaces)

   Reviewed-by: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx>
   Signed-off-by: Amol Grover <frextrite@xxxxxxxxx>
   [PM: tweak subject line]
   Signed-off-by: Paul Moore <paul@xxxxxxxxxxxxxx>

-- 
paul moore
www.paul-moore.com