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Date: Tue, 26 Mar 2024 11:20:57 +0300
From: Dan Carpenter <dan.carpenter@linaro.org>
To: Johannes Berg <johannes@sipsolutions.net>
Cc: Boqun Feng <boqun.feng@gmail.com>, rcu@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	"Paul E. McKenney" <paulmck@kernel.org>,
	Frederic Weisbecker <frederic@kernel.org>,
	Josh Triplett <josh@joshtriplett.org>,
	Peter Zijlstra <peterz@infradead.org>
Subject: Re: [PATCH] rcu: mollify sparse with RCU guard
Message-ID: <619df5e7-13bb-4cb4-9018-e4611a0bac8c@moroto.mountain>
References: <20240325101626.41584-2-johannes@sipsolutions.net>
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In-Reply-To: <0659e47eb33c4159168abe392764a1de44e9bc71.camel@sipsolutions.net>

On Tue, Mar 26, 2024 at 08:53:39AM +0100, Johannes Berg wrote:
> On Tue, 2024-03-26 at 10:39 +0300, Dan Carpenter wrote:
> > On Mon, Mar 25, 2024 at 07:43:18PM +0100, Johannes Berg wrote:
> > > On Mon, 2024-03-25 at 21:28 +0300, Dan Carpenter wrote:
> > > > On Mon, Mar 25, 2024 at 05:41:22PM +0100, Johannes Berg wrote:
> > > > > Also __acquire()/__release() are just empty macros without __CHECKER__.
> > > > > So not sure the indirection really is warranted for this special case.
> > > > > 
> > > > > I can add a comment in there, I guess, something like
> > > > > 
> > > > >  /* sparse doesn't actually "call" cleanup functions */
> > > > > 
> > > > > perhaps. That reminds me I forgot to CC Dan ...
> > > > > 
> > > > 
> > > > These are Sparse warnings, not Smatch warning... Smatch doesn't use any
> > > > of the Sparse locking annotations.
> > > 
> > > Sure, of course. I just saw that you added cleanup stuff to sparse to
> > > allow using it in smatch.
> > > 
> > > > Smatch handles cleanup basically correctly at this point.
> > > 
> > > Do you "run" / "emit" the cleanup function calls there?
> > 
> > Yes.
> 
> I see. I guess that doesn't work for sparse. You write:
> 
>    This shouldn't really have been needed if I had written the parse.c
>    code correctly to create new scopes for every __cleanup__.
> 
> Would that maybe be a way to handle it in sparse? Though not sure how to
> return then.

I think I was just wrong when I wrote that.  But I'm not really sure how
this is normally handled by the compiler.

regards,
dan carpenter