From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933631AbaDINyS (ORCPT ); Wed, 9 Apr 2014 09:54:18 -0400 Received: from cdptpa-outbound-snat.email.rr.com ([107.14.166.229]:37539 "EHLO cdptpa-oedge-vip.email.rr.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S933143AbaDINyP convert rfc822-to-8bit (ORCPT ); Wed, 9 Apr 2014 09:54:15 -0400 Date: Wed, 9 Apr 2014 09:54:12 -0400 From: Steven Rostedt To: Mathieu Desnoyers Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH] Fix: sparse warnings in tracepoint.c Message-ID: <20140409095412.74c4d3de@gandalf.local.home> In-Reply-To: <1397049883-28692-1-git-send-email-mathieu.desnoyers@efficios.com> References: <1397049883-28692-1-git-send-email-mathieu.desnoyers@efficios.com> X-Mailer: Claws Mail 3.9.3 (GTK+ 2.24.22; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT X-RR-Connecting-IP: 107.14.168.118:25 X-Cloudmark-Score: 0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 9 Apr 2014 09:24:43 -0400 Mathieu Desnoyers wrote: > Fix the following sparse warnings: > > CHECK kernel/tracepoint.c > kernel/tracepoint.c:184:18: warning: incorrect type in assignment (different address spaces) > kernel/tracepoint.c:184:18: expected struct tracepoint_func *tp_funcs > kernel/tracepoint.c:184:18: got struct tracepoint_func [noderef] *funcs > kernel/tracepoint.c:216:18: warning: incorrect type in assignment (different address spaces) > kernel/tracepoint.c:216:18: expected struct tracepoint_func *tp_funcs > kernel/tracepoint.c:216:18: got struct tracepoint_func [noderef] *funcs > kernel/tracepoint.c:392:24: error: return expression in void function > CC kernel/tracepoint.o > kernel/tracepoint.c: In function ‘tracepoint_module_going’: > kernel/tracepoint.c:392:3: warning: ‘return’ with a value, in function returning void [enabled by default] > kernel/tracepoint.c:491:6: warning: symbol 'syscall_regfunc' was not declared. Should it be static? > kernel/tracepoint.c:508:6: warning: symbol 'syscall_unregfunc' was not declared. Should it be static? Hmm, I push yesterday and haven't seen any sparse warnings yet. > > Signed-off-by: Mathieu Desnoyers > CC: Steven Rostedt > --- > include/linux/tracepoint.h | 5 +++++ > include/trace/events/syscalls.h | 3 --- > kernel/tracepoint.c | 8 +++++--- > 3 files changed, 10 insertions(+), 6 deletions(-) > > diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h > index 08150e2..abab285 100644 > --- a/include/linux/tracepoint.h > +++ b/include/linux/tracepoint.h > @@ -81,6 +81,11 @@ static inline void tracepoint_synchronize_unregister(void) > synchronize_sched(); > } > > +#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS > +extern void syscall_regfunc(void); > +extern void syscall_unregfunc(void); > +#endif /* CONFIG_HAVE_SYSCALL_TRACEPOINTS */ > + > #define PARAMS(args...) args > > #endif /* _LINUX_TRACEPOINT_H */ > diff --git a/include/trace/events/syscalls.h b/include/trace/events/syscalls.h > index 5a4c04a..14e49c7 100644 > --- a/include/trace/events/syscalls.h > +++ b/include/trace/events/syscalls.h > @@ -13,9 +13,6 @@ > > #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS > > -extern void syscall_regfunc(void); > -extern void syscall_unregfunc(void); > - > TRACE_EVENT_FN(sys_enter, > > TP_PROTO(struct pt_regs *regs, long id), > diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c > index 8c4f2f4..f39bb79 100644 > --- a/kernel/tracepoint.c > +++ b/kernel/tracepoint.c > @@ -181,7 +181,8 @@ static int tracepoint_add_func(struct tracepoint *tp, > if (tp->regfunc && !static_key_enabled(&tp->key)) > tp->regfunc(); > > - tp_funcs = tp->funcs; > + tp_funcs = rcu_dereference_protected(tp->funcs, > + lockdep_is_held(&tracepoints_mutex)); > old = func_add(&tp_funcs, func); > if (IS_ERR(old)) { > WARN_ON_ONCE(1); > @@ -213,7 +214,8 @@ static int tracepoint_remove_func(struct tracepoint *tp, > { > struct tracepoint_func *old, *tp_funcs; > > - tp_funcs = tp->funcs; > + tp_funcs = rcu_dereference_protected(tp->funcs, > + lockdep_is_held(&tracepoints_mutex)); > old = func_remove(&tp_funcs, func); > if (IS_ERR(old)) { > WARN_ON_ONCE(1); > @@ -389,7 +391,7 @@ static void tracepoint_module_going(struct module *mod) > struct tp_module *tp_mod; > > if (!mod->num_tracepoints) > - return 0; > + return; My tests caught this, and fixed it manually (noting I did so in the change log). I wanted to get this finished, and such a slight change didn't require asking you to resubmit again ;-) I'll pull in the rest of this and start testing it. I'll push what I have to Linux next now. -- Steve > > mutex_lock(&tracepoint_module_list_mutex); > list_for_each_entry(tp_mod, &tracepoint_module_list, list) {