From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756319AbbICBHh (ORCPT ); Wed, 2 Sep 2015 21:07:37 -0400 Received: from v094114.home.net.pl ([79.96.170.134]:56473 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1756298AbbICBHc (ORCPT ); Wed, 2 Sep 2015 21:07:32 -0400 From: "Rafael J. Wysocki" To: Xunlei Pang Cc: linux-kernel@vger.kernel.org, Daniel Lezcano , linux-pm@vger.kernel.org, Xunlei Pang Subject: Re: [PATCH v3] cpuidle/coupled: Add sanity check for safe_state_index Date: Thu, 03 Sep 2015 03:35:15 +0200 Message-ID: <2730874.lxGIcz4Q5K@vostro.rjw.lan> User-Agent: KMail/4.11.5 (Linux/4.1.0-rc5+; KDE/4.11.5; x86_64; ; ) In-Reply-To: <1440992045-17464-1-git-send-email-xlpang@126.com> References: <1440992045-17464-1-git-send-email-xlpang@126.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Monday, August 31, 2015 11:34:05 AM Xunlei Pang wrote: > From: Xunlei Pang > > Since we are using cpuidle_driver::safe_state_index directly as the > target state index, it is better to add the sanity check at the point > of registering the driver. > > Signed-off-by: Xunlei Pang I'm queuing this one up for the next PM pull request, thanks! > --- > v2->v3: > Move the code to a new cpuidle_coupled_state_verify() depending on > CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED, to avoid using #ifdef in function > bodies. Thanks Rafael's comments on this. > > drivers/cpuidle/coupled.c | 22 ++++++++++++++++++++++ > drivers/cpuidle/cpuidle.h | 6 ++++++ > drivers/cpuidle/driver.c | 4 ++++ > 3 files changed, 32 insertions(+) > > diff --git a/drivers/cpuidle/coupled.c b/drivers/cpuidle/coupled.c > index 1523e2d..344058f 100644 > --- a/drivers/cpuidle/coupled.c > +++ b/drivers/cpuidle/coupled.c > @@ -187,6 +187,28 @@ bool cpuidle_state_is_coupled(struct cpuidle_driver *drv, int state) > } > > /** > + * cpuidle_coupled_state_verify - check if the coupled states are correctly set. > + * @drv: struct cpuidle_driver for the platform > + * > + * Returns 0 for valid state values, a negative error code otherwise: > + * * -EINVAL if any coupled state(safe_state_index) is wrongly set. > + */ > +int cpuidle_coupled_state_verify(struct cpuidle_driver *drv) > +{ > + int i; > + > + for (i = drv->state_count - 1; i >= 0; i--) { > + if (cpuidle_state_is_coupled(drv, i) && > + (drv->safe_state_index == i || > + drv->safe_state_index < 0 || > + drv->safe_state_index >= drv->state_count)) > + return -EINVAL; > + } > + > + return 0; > +} > + > +/** > * cpuidle_coupled_set_ready - mark a cpu as ready > * @coupled: the struct coupled that contains the current cpu > */ > diff --git a/drivers/cpuidle/cpuidle.h b/drivers/cpuidle/cpuidle.h > index 178c5ad..f87f399 100644 > --- a/drivers/cpuidle/cpuidle.h > +++ b/drivers/cpuidle/cpuidle.h > @@ -35,6 +35,7 @@ extern void cpuidle_remove_sysfs(struct cpuidle_device *dev); > > #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED > bool cpuidle_state_is_coupled(struct cpuidle_driver *drv, int state); > +int cpuidle_coupled_state_verify(struct cpuidle_driver *drv); > int cpuidle_enter_state_coupled(struct cpuidle_device *dev, > struct cpuidle_driver *drv, int next_state); > int cpuidle_coupled_register_device(struct cpuidle_device *dev); > @@ -46,6 +47,11 @@ bool cpuidle_state_is_coupled(struct cpuidle_driver *drv, int state) > return false; > } > > +static inline int cpuidle_coupled_state_verify(struct cpuidle_driver *drv) > +{ > + return 0; > +} > + > static inline int cpuidle_enter_state_coupled(struct cpuidle_device *dev, > struct cpuidle_driver *drv, int next_state) > { > diff --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c > index 5db1478..389ade4 100644 > --- a/drivers/cpuidle/driver.c > +++ b/drivers/cpuidle/driver.c > @@ -227,6 +227,10 @@ static int __cpuidle_register_driver(struct cpuidle_driver *drv) > if (!drv || !drv->state_count) > return -EINVAL; > > + ret = cpuidle_coupled_state_verify(drv); > + if (ret) > + return ret; > + > if (cpuidle_disabled()) > return -ENODEV; > > -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.