Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752054AbbEFWLw (ORCPT ); Wed, 6 May 2015 18:11:52 -0400 Received: from mail-lb0-f169.google.com ([209.85.217.169]:33875 "EHLO mail-lb0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751871AbbEFWLu (ORCPT ); Wed, 6 May 2015 18:11:50 -0400 MIME-Version: 1.0 In-Reply-To: <2043095.ifDvYKem54@vostro.rjw.lan> References: <1430938267-14951-1-git-send-email-jinqian@android.com> <2043095.ifDvYKem54@vostro.rjw.lan> Date: Wed, 6 May 2015 15:11:48 -0700 Message-ID: Subject: Re: [PATCH v2 1/3] power: validate wakeup source before activating it. From: Jin Qian To: "Rafael J. Wysocki" Cc: Pavel Machek , Len Brown , Greg Kroah-Hartman , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2657 Lines: 76 Hi Rafael, I kept braces since checkpatch.pl didn't report error or warning. The if condition has two lines, a brace make the statement more clear I think. I removed the format string since ws->name can be random strings if the wakeup_source is not registered (i.e. using prepare functions). It's not very useful to print name if we have stack dump from WARN_ONCE. Thanks, jin On Wed, May 6, 2015 at 3:00 PM, Rafael J. Wysocki wrote: > On Wednesday, May 06, 2015 11:51:07 AM Jin Qian wrote: >> A rogue wakeup source not registered in wakeup_sources list is not visible >> from wakeup_sources_stats_show. Check if the wakeup source is registered >> properly by looking at the timer struct. >> >> Signed-off-by: Jin Qian >> --- >> drivers/base/power/wakeup.c | 19 +++++++++++++++++++ >> 1 file changed, 19 insertions(+) >> >> diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c >> index 7726200..aead738 100644 >> --- a/drivers/base/power/wakeup.c >> +++ b/drivers/base/power/wakeup.c >> @@ -351,6 +351,20 @@ int device_set_wakeup_enable(struct device *dev, bool enable) >> } >> EXPORT_SYMBOL_GPL(device_set_wakeup_enable); >> >> +/** >> + * wakeup_source_not_registered - validate the given wakeup source. >> + * @ws: Wakeup source to be validated. >> + */ >> +static bool wakeup_source_not_registered(struct wakeup_source *ws) >> +{ >> + /* >> + * Use timer struct to check if the given source is initialized >> + * by wakeup_source_add. >> + */ >> + return ws->timer.function != pm_wakeup_timer_fn || >> + ws->timer.data != (unsigned long)ws; >> +} >> + >> /* >> * The functions below use the observation that each wakeup event starts a >> * period in which the system should not be suspended. The moment this period >> @@ -391,6 +405,11 @@ static void wakeup_source_activate(struct wakeup_source *ws) >> { >> unsigned int cec; >> >> + if (WARN_ONCE(wakeup_source_not_registered(ws), >> + "unregistered wakeup source\n")) { >> + return; >> + } > > The braces are not necessary and you can use format strings with WARN_ONCE() > too IIRC. > >> + >> /* >> * active wakeup source should bring the system >> * out of PM_SUSPEND_FREEZE state >> > > -- > I speak only for myself. > Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/