From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-14.3 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BA2F8C433E1 for ; Tue, 7 Jul 2020 16:43:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 91D3E20708 for ; Tue, 7 Jul 2020 16:43:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Ip4JCRO9" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728184AbgGGQnc (ORCPT ); Tue, 7 Jul 2020 12:43:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45132 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728029AbgGGQnb (ORCPT ); Tue, 7 Jul 2020 12:43:31 -0400 Received: from mail-pl1-x641.google.com (mail-pl1-x641.google.com [IPv6:2607:f8b0:4864:20::641]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ADB78C061755 for ; Tue, 7 Jul 2020 09:43:31 -0700 (PDT) Received: by mail-pl1-x641.google.com with SMTP id x11so16959738plo.7 for ; Tue, 07 Jul 2020 09:43:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=0CvFCRMGyH8ng1oyUVoBZbdUNhkgtcfr8Mw5rYPl6rU=; b=Ip4JCRO9Uih6Knc+6wGL010irBJegJQlega20oXZD3gAVz3Gd96yQRvs7kaA3fNjV/ z/ZAGWVhhJjrmk34h9KVXeuOIaYj72kuKRWPEmYv0R0iY8LFuVS0z7DbSvF+HjQ08l8A oUg6MlEKkSCh78v9cDkJ55Qm4t2hysgVyhapX2iKObx3m4a9jLTUV4GbWVHNpjEBVQ7g AoodoW9ix66XSZBcf3u0ldo/kMtkd+FX2uNLw0LKtcOLgt3rvi3VrFUbKkw7DCoVNXDV LQ8I03Yti0ZM6SiXfhQ91ml5lPQYcGroauyF+5ECCGLjPgQWmZo3E521xeqU+AadU+jf ckLw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=0CvFCRMGyH8ng1oyUVoBZbdUNhkgtcfr8Mw5rYPl6rU=; b=QFx309dNhmG+ENihJA161hONSlFdS0e5SRVyiJrN8Nvdrcvmxda/lr1lQY3s6lQNUh xT2fAKA5v1HByvjsztrIYWtmULMhZQvK7PfM6lHYxhwGAjTQTL7QEo5Tq0/VVZ+TZQAm Vp0OmCYaS4kbcSdhU69aeskCgpCZco0BHpqO3Juxw2jpihG8xQBcKggXVVn1beyhC+sq zAGldiGP2r8uurQwIuJTFU0obclhztBia7xf80Jraur2pwruTrg+SyDM5qHydb9PZEWc UwTrTzQedfUSnIOcadX+8HtLdW++qIOuiveV5Wv2oLbeOqKvrHytYyNYeC5g05BpksoE i6bw== X-Gm-Message-State: AOAM530kM2V09kvzc4KlIshjdSNPFDvdwStBwUz+oIYrtZbN9ldOpb2g PTHRUWeIF7UZnfwJtEoYl9nU+w== X-Google-Smtp-Source: ABdhPJwwBLoiCnrjwRhFJQYWj+jTUZqOBr3HuHyo0/STACqPViLc8hndgtf6CrLI/HtLg7tjT5bZ0A== X-Received: by 2002:a17:90a:1089:: with SMTP id c9mr5346227pja.180.1594140210827; Tue, 07 Jul 2020 09:43:30 -0700 (PDT) Received: from google.com ([2620:15c:201:2:f693:9fff:fef4:1b6d]) by smtp.gmail.com with ESMTPSA id n12sm1392859pgr.88.2020.07.07.09.43.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 07 Jul 2020 09:43:29 -0700 (PDT) Date: Tue, 7 Jul 2020 09:43:25 -0700 From: Sami Tolvanen To: Neal Liu Cc: "Rafael J. Wysocki" , Len Brown , Daniel Lezcano , Thierry Reding , Jonathan Hunter , Jacob Pan , Matthias Brugger , linux-acpi@vger.kernel.org, linux-pm@vger.kernel.org, linux-tegra@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, lkml , wsd_upstream@mediatek.com Subject: Re: [PATCH v2] cpuidle: change enter_s2idle() prototype Message-ID: <20200707164325.GA2525978@google.com> References: <1594005196-16327-1-git-send-email-neal.liu@mediatek.com> <1594005196-16327-2-git-send-email-neal.liu@mediatek.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1594005196-16327-2-git-send-email-neal.liu@mediatek.com> Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org On Mon, Jul 06, 2020 at 11:13:16AM +0800, Neal Liu wrote: > Control Flow Integrity(CFI) is a security mechanism that disallows > changes to the original control flow graph of a compiled binary, > making it significantly harder to perform such attacks. > > init_state_node() assign same function callback to different > function pointer declarations. > > static int init_state_node(struct cpuidle_state *idle_state, > const struct of_device_id *matches, > struct device_node *state_node) { ... > idle_state->enter = match_id->data; ... > idle_state->enter_s2idle = match_id->data; } > > Function declarations: > > struct cpuidle_state { ... > int (*enter) (struct cpuidle_device *dev, > struct cpuidle_driver *drv, > int index); > > void (*enter_s2idle) (struct cpuidle_device *dev, > struct cpuidle_driver *drv, > int index); }; > > In this case, either enter() or enter_s2idle() would cause CFI check > failed since they use same callee. > > Align function prototype of enter() since it needs return value for > some use cases. The return value of enter_s2idle() is no > need currently. > > Signed-off-by: Neal Liu > --- > drivers/acpi/processor_idle.c | 6 ++++-- > drivers/cpuidle/cpuidle-tegra.c | 8 +++++--- > drivers/idle/intel_idle.c | 6 ++++-- > include/linux/cpuidle.h | 6 +++--- > 4 files changed, 16 insertions(+), 10 deletions(-) > > diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c > index 75534c5..6ffb6c9 100644 > --- a/drivers/acpi/processor_idle.c > +++ b/drivers/acpi/processor_idle.c > @@ -655,8 +655,8 @@ static int acpi_idle_enter(struct cpuidle_device *dev, > return index; > } > > -static void acpi_idle_enter_s2idle(struct cpuidle_device *dev, > - struct cpuidle_driver *drv, int index) > +static int acpi_idle_enter_s2idle(struct cpuidle_device *dev, > + struct cpuidle_driver *drv, int index) > { > struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); > > @@ -674,6 +674,8 @@ static void acpi_idle_enter_s2idle(struct cpuidle_device *dev, > } > } > acpi_idle_do_entry(cx); > + > + return 0; > } > > static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr, > diff --git a/drivers/cpuidle/cpuidle-tegra.c b/drivers/cpuidle/cpuidle-tegra.c > index 1500458..a12fb14 100644 > --- a/drivers/cpuidle/cpuidle-tegra.c > +++ b/drivers/cpuidle/cpuidle-tegra.c > @@ -253,11 +253,13 @@ static int tegra_cpuidle_enter(struct cpuidle_device *dev, > return err ? -1 : index; > } > > -static void tegra114_enter_s2idle(struct cpuidle_device *dev, > - struct cpuidle_driver *drv, > - int index) > +static int tegra114_enter_s2idle(struct cpuidle_device *dev, > + struct cpuidle_driver *drv, > + int index) > { > tegra_cpuidle_enter(dev, drv, index); > + > + return 0; > } > > /* > diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c > index f449584..b178da3 100644 > --- a/drivers/idle/intel_idle.c > +++ b/drivers/idle/intel_idle.c > @@ -175,13 +175,15 @@ static __cpuidle int intel_idle(struct cpuidle_device *dev, > * Invoked as a suspend-to-idle callback routine with frozen user space, frozen > * scheduler tick and suspended scheduler clock on the target CPU. > */ > -static __cpuidle void intel_idle_s2idle(struct cpuidle_device *dev, > - struct cpuidle_driver *drv, int index) > +static __cpuidle int intel_idle_s2idle(struct cpuidle_device *dev, > + struct cpuidle_driver *drv, int index) > { > unsigned long eax = flg2MWAIT(drv->states[index].flags); > unsigned long ecx = 1; /* break on interrupt flag */ > > mwait_idle_with_hints(eax, ecx); > + > + return 0; > } > > /* > diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h > index ec2ef63..bee10c0 100644 > --- a/include/linux/cpuidle.h > +++ b/include/linux/cpuidle.h > @@ -66,9 +66,9 @@ struct cpuidle_state { > * suspended, so it must not re-enable interrupts at any point (even > * temporarily) or attempt to change states of clock event devices. > */ > - void (*enter_s2idle) (struct cpuidle_device *dev, > - struct cpuidle_driver *drv, > - int index); > + int (*enter_s2idle)(struct cpuidle_device *dev, > + struct cpuidle_driver *drv, > + int index); > }; > > /* Idle State Flags */ > -- > 1.7.9.5 This looks good to me, thank you for sending the patch! Please feel free to add: Reviewed-by: Sami Tolvanen Sami