Re: [PATCH] rcuscale: Constify struct rcu_scale_ops

[Paul E. McKenney]

On Mon, Nov 09, 2026 at 06:32:15PM +0100, Christophe JAILLET wrote:
> Le 09/11/2026 à 00:06, Joel Fernandes a écrit :
> > On Sat, Nov 07, 2026 at 10:02:25PM +0100, Christophe JAILLET wrote:
> > > 'struct rcu_scale_ops' is not modified in this driver.
> > > 
> > > Constifying these structures moves some data to a read-only section, so
> > > increases overall security, especially when the structure holds some
> > > function pointers.
> > > 
> > > On a x86_64, with allmodconfig:
> > > Before:
> > > ======
> > >     text	   data	    bss	    dec	    hex	filename
> > >    45585	  24946	   2816	  73347	  11e83	kernel/rcu/rcuscale.o
> > > 
> > > After:
> > > =====
> > >     text	   data	    bss	    dec	    hex	filename
> > >    46545	  23986	   2816	  73347	  11e83	kernel/rcu/rcuscale.o
> > > 
> > > Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
> > > ---
> > > Compile tested only.
> > 
> > rcuscale is a test kernel module, is it worth adding boilerplate for
> > non-production code sighting security reasons?
> 
> Oups, now I better understand Bradley Morgan comments.
> 
> I didn't notice it was a test module.
> My patch makes no more sense, as it is not hardening runtime, so feel free
> to just drop it.
> 
> Sorry for the noise and not seeing it by myself.

Although the header comment does say "Read-Copy Update module-based
scalability-test facility", maybe there is something that should be
done to more clearly mark code that is not to be used in production.
And maybe to inform the LLM review bots of this.

But this is bigger than just RCU.

Thoughts?

							Thanx, Paul

> CJ
> 
> > 
> > Do you mind runtime testing it too if you still feel we should do it (and
> > provide reasons why)?
> > 
> > thanks,
> > 
> > Joel Fernandes
> >