From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932175AbaGNRDX (ORCPT ); Mon, 14 Jul 2014 13:03:23 -0400 Received: from cdptpa-outbound-snat.email.rr.com ([107.14.166.230]:4334 "EHLO cdptpa-oedge-vip.email.rr.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756275AbaGNRDH (ORCPT ); Mon, 14 Jul 2014 13:03:07 -0400 Date: Mon, 14 Jul 2014 13:03:02 -0400 From: Steven Rostedt To: Ard Biesheuvel Cc: linux-kernel@vger.kernel.org, paulmck@linux.vnet.ibm.com Subject: Re: [PATCH v3] rcu: define tracepoint strings only if CONFIG_TRACING is set Message-ID: <20140714130302.59644d42@gandalf.local.home> In-Reply-To: <1405184509-12601-1-git-send-email-ard.biesheuvel@linaro.org> References: <1405184509-12601-1-git-send-email-ard.biesheuvel@linaro.org> X-Mailer: Claws Mail 3.9.3 (GTK+ 2.24.23; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-RR-Connecting-IP: 107.14.168.142:25 X-Cloudmark-Score: 0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 12 Jul 2014 19:01:49 +0200 Ard Biesheuvel wrote: > Commit f7f7bac9cb1c ("rcu: Have the RCU tracepoints use the tracepoint_string > infrastructure") unconditionally populates the __tracepoint_str input section, > but this section is not assigned an output section if CONFIG_TRACING is not set. > This results in the __tracepoint_str turning up in unexpected places, i.e., > after _edata. > > Signed-off-by: Ard Biesheuvel > Cc: rostedt@goodmis.org > Cc: paulmck@linux.vnet.ibm.com > --- > v3: > - make definition of _varname conditional as well > v2: > - s/DEFINE_TPS/DEFINE_RCU_TPS/ > > kernel/rcu/tree.c | 15 ++++++++++++--- > 1 file changed, 12 insertions(+), 3 deletions(-) > Reviewed-by: Steven Rostedt -- Steve > diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c > index f1ba77363fbb..0756a4696007 100644 > --- a/kernel/rcu/tree.c > +++ b/kernel/rcu/tree.c > @@ -79,9 +79,18 @@ static struct lock_class_key rcu_fqs_class[RCU_NUM_LVLS]; > * the tracing userspace tools to be able to decipher the string > * address to the matching string. > */ > -#define RCU_STATE_INITIALIZER(sname, sabbr, cr) \ > +#ifdef CONFIG_TRACING > +# define DEFINE_RCU_TPS(sname) \ > static char sname##_varname[] = #sname; \ > -static const char *tp_##sname##_varname __used __tracepoint_string = sname##_varname; \ > +static const char *tp_##sname##_varname __used __tracepoint_string = sname##_varname; > +# define RCU_STATE_NAME(sname) sname##_varname > +#else > +# define DEFINE_RCU_TPS(sname) > +# define RCU_STATE_NAME(sname) __stringify(sname) > +#endif > + > +#define RCU_STATE_INITIALIZER(sname, sabbr, cr) \ > +DEFINE_RCU_TPS(sname) \ > struct rcu_state sname##_state = { \ > .level = { &sname##_state.node[0] }, \ > .call = cr, \ > @@ -93,7 +102,7 @@ struct rcu_state sname##_state = { \ > .orphan_donetail = &sname##_state.orphan_donelist, \ > .barrier_mutex = __MUTEX_INITIALIZER(sname##_state.barrier_mutex), \ > .onoff_mutex = __MUTEX_INITIALIZER(sname##_state.onoff_mutex), \ > - .name = sname##_varname, \ > + .name = RCU_STATE_NAME(sname), \ > .abbr = sabbr, \ > }; \ > DEFINE_PER_CPU(struct rcu_data, sname##_data)