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Date:   Tue, 5 Oct 2021 12:42:09 -0400
From:   Steven Rostedt <rostedt@goodmis.org>
To:     Linus Torvalds <torvalds@linux-foundation.org>
Cc:     LKML <linux-kernel@vger.kernel.org>,
        "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
        Josh Triplett <josh@joshtriplett.org>,
        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
        Lai Jiangshan <jiangshanlai@gmail.com>,
        Joel Fernandes <joel@joelfernandes.org>,
        Pablo Neira Ayuso <pablo@netfilter.org>,
        Jozsef Kadlecsik <kadlec@netfilter.org>,
        Florian Westphal <fw@strlen.de>,
        David Miller <davem@davemloft.net>,
        Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
        David Ahern <dsahern@kernel.org>,
        Jakub Kicinski <kuba@kernel.org>, rcu <rcu@vger.kernel.org>,
        NetFilter <netfilter-devel@vger.kernel.org>,
        coreteam@netfilter.org, Netdev <netdev@vger.kernel.org>
Subject: Re: [RFC][PATCH] rcu: Use typeof(p) instead of typeof(*p) *
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On Tue, 5 Oct 2021 09:18:04 -0700
Linus Torvalds <torvalds@linux-foundation.org> wrote:

> On Tue, Oct 5, 2021 at 6:47 AM Steven Rostedt <rostedt@goodmis.org> wrote:
> >
> > Also had to update a lot of the function pointer initialization in the
> > networking code, as a function address must be passed as an argument in
> > RCU_INIT_POINTER() and not just the function name, otherwise the following
> > error occurs:  
> 
> Ugh.
> 
> I think this is a sign of why we did it the way we did with that odd
> "typeof(*p)*" thing in the first place.
> 

Oh, which was also compiler specific.

On my fedora box, which has:

  gcc version 10.3.1 20210422 (Red Hat 10.3.1-1) (GCC)

It compiled fine, with no errors.

But on my Debian box with:

  gcc version 10.2.1 20210110 (Debian 10.2.1-6)

The function pointers were an issue :-/


-- Steve