linux-kernel - Re: [PATCH RFC v5 3/6] srcu: Add notrace variant of srcu

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20180501110403.0b661039@gandalf.local.home>
Date:   Tue, 1 May 2018 11:04:03 -0400
From:   Steven Rostedt <rostedt@...dmis.org>
To:     "Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>
Cc:     Joel Fernandes <joelaf@...gle.com>, linux-kernel@...r.kernel.org,
        Peter Zilstra <peterz@...radead.org>,
        Ingo Molnar <mingo@...hat.com>,
        Mathieu Desnoyers <mathieu.desnoyers@...icios.com>,
        Tom Zanussi <tom.zanussi@...ux.intel.com>,
        Namhyung Kim <namhyung@...nel.org>,
        Thomas Glexiner <tglx@...utronix.de>,
        Boqun Feng <boqun.feng@...il.com>,
        Frederic Weisbecker <fweisbec@...il.com>,
        Randy Dunlap <rdunlap@...radead.org>,
        Masami Hiramatsu <mhiramat@...nel.org>,
        Fenguang Wu <fengguang.wu@...el.com>,
        Baohong Liu <baohong.liu@...el.com>,
        Vedang Patel <vedang.patel@...el.com>, kernel-team@...roid.com
Subject: Re: [PATCH RFC v5 3/6] srcu: Add notrace variant of
 srcu_dereference

On Tue, 1 May 2018 07:18:17 -0700
"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com> wrote:


> > diff --git a/include/linux/srcu.h b/include/linux/srcu.h
> > index 2ec618979b20..a1c4947be877 100644
> > --- a/include/linux/srcu.h
> > +++ b/include/linux/srcu.h
> > @@ -135,6 +135,11 @@ static inline int srcu_read_lock_held(const struct srcu_struct *sp)
> >   */
> >  #define srcu_dereference(p, sp) srcu_dereference_check((p), (sp), 0)
> > 
> > +/**
> > + * srcu_dereference_notrace - no tracing and no lockdep calls from here
> > + */
> > +#define srcu_dereference_notrace(p, sp) srcu_dereference_check((p), (sp), 1)  
> 
> Given that this is a one-liner, why not just use srcu_dereference_check()
> directly, with 1 as you do above to disable lockdep?

I prefer what Joel did. It documents why we are doing this. Open coding
the call directly will just confuse others that touch tracepoint code.

-- Steve