From patchwork Mon Oct 5 15:26:40 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 268155 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=-13.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT 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 46917C4727D for ; Mon, 5 Oct 2020 15:33:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 13D6B2074F for ; Mon, 5 Oct 2020 15:33:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601912039; bh=gnFsBKMWFbEWtrezR3gQjFqKb7oCLp1fI/Myh8q4kV8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=SPwFOr5ra5P2UGtqLaz/g0i/Xqn6nfQe/dro/EP9htCC4/Bxb1dmG45m0IRMjURCk sw0SoazTAY+yw4KEtVbO0/+IFtV484xzLnRn4wcU8nK4mg/znv4r1fVr/HRdC0r4wB FfWKN4/6YAVGGIWQhmH1LSNydqTFRmNsA4KwDI3k= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727293AbgJEPd6 (ORCPT ); Mon, 5 Oct 2020 11:33:58 -0400 Received: from mail.kernel.org ([198.145.29.99]:34208 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728210AbgJEPdx (ORCPT ); Mon, 5 Oct 2020 11:33:53 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 6D107207BC; Mon, 5 Oct 2020 15:33:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601912033; bh=gnFsBKMWFbEWtrezR3gQjFqKb7oCLp1fI/Myh8q4kV8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=yGhfidbldlG5ytfoBFPx06SsH/JPTqexrt3v0LtTaVtmv4xKUVuKwexeg8crZId9B w296axZFlZ5i5gvxlmei0hi7K3Gjv4TeqHyKnLiooJF4JxR9AF1QO9hSeoUNeazy4C 9vJL0F3Pp9gf1k9JVffLUuakbo0qlWEG4fgM3d+I= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Naresh Kamboju , Ulf Hansson , "Paul E. McKenney" , "Rafael J. Wysocki" , Sasha Levin Subject: [PATCH 5.8 44/85] cpuidle: psci: Fix suspicious RCU usage Date: Mon, 5 Oct 2020 17:26:40 +0200 Message-Id: <20201005142116.844451153@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201005142114.732094228@linuxfoundation.org> References: <20201005142114.732094228@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Ulf Hansson [ Upstream commit 36050d8984ab743f9990a2eb97a0062fdc3d7bbd ] The commit eb1f00237aca ("lockdep,trace: Expose tracepoints"), started to expose us for tracepoints. This lead to the following RCU splat on an ARM64 Qcom board. [ 5.529634] WARNING: suspicious RCU usage [ 5.537307] sdhci-pltfm: SDHCI platform and OF driver helper [ 5.541092] 5.9.0-rc3 #86 Not tainted [ 5.541098] ----------------------------- [ 5.541105] ../include/trace/events/lock.h:37 suspicious rcu_dereference_check() usage! [ 5.541110] [ 5.541110] other info that might help us debug this: [ 5.541110] [ 5.541116] [ 5.541116] rcu_scheduler_active = 2, debug_locks = 1 [ 5.541122] RCU used illegally from extended quiescent state! [ 5.541129] no locks held by swapper/0/0. [ 5.541134] [ 5.541134] stack backtrace: [ 5.541143] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.9.0-rc3 #86 [ 5.541149] Hardware name: Qualcomm Technologies, Inc. APQ 8016 SBC (DT) [ 5.541157] Call trace: [ 5.568185] sdhci_msm 7864900.sdhci: Got CD GPIO [ 5.574186] dump_backtrace+0x0/0x1c8 [ 5.574206] show_stack+0x14/0x20 [ 5.574229] dump_stack+0xe8/0x154 [ 5.574250] lockdep_rcu_suspicious+0xd4/0xf8 [ 5.574269] lock_acquire+0x3f0/0x460 [ 5.574292] _raw_spin_lock_irqsave+0x80/0xb0 [ 5.574314] __pm_runtime_suspend+0x4c/0x188 [ 5.574341] psci_enter_domain_idle_state+0x40/0xa0 [ 5.574362] cpuidle_enter_state+0xc0/0x610 [ 5.646487] cpuidle_enter+0x38/0x50 [ 5.650651] call_cpuidle+0x18/0x40 [ 5.654467] do_idle+0x228/0x278 [ 5.657678] cpu_startup_entry+0x24/0x70 [ 5.661153] rest_init+0x1a4/0x278 [ 5.665061] arch_call_rest_init+0xc/0x14 [ 5.668272] start_kernel+0x508/0x540 Following the path in pm_runtime_put_sync_suspend() from psci_enter_domain_idle_state(), it seems like we end up using the RCU. Therefore, let's simply silence the splat by informing the RCU about it with RCU_NONIDLE. Note that, this is a temporary solution. Instead we should strive to avoid using RCU_NONIDLE (and similar), but rather push rcu_idle_enter|exit() further down, closer to the arch specific code. However, as the CPU PM notifiers are also using the RCU, additional rework is needed. Reported-by: Naresh Kamboju Signed-off-by: Ulf Hansson Acked-by: Paul E. McKenney Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin --- drivers/cpuidle/cpuidle-psci.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/cpuidle/cpuidle-psci.c b/drivers/cpuidle/cpuidle-psci.c index 3806f911b61c0..915172e3ec906 100644 --- a/drivers/cpuidle/cpuidle-psci.c +++ b/drivers/cpuidle/cpuidle-psci.c @@ -64,7 +64,7 @@ static int psci_enter_domain_idle_state(struct cpuidle_device *dev, return -1; /* Do runtime PM to manage a hierarchical CPU toplogy. */ - pm_runtime_put_sync_suspend(pd_dev); + RCU_NONIDLE(pm_runtime_put_sync_suspend(pd_dev)); state = psci_get_domain_state(); if (!state) @@ -72,7 +72,7 @@ static int psci_enter_domain_idle_state(struct cpuidle_device *dev, ret = psci_cpu_suspend_enter(state) ? -1 : idx; - pm_runtime_get_sync(pd_dev); + RCU_NONIDLE(pm_runtime_get_sync(pd_dev)); cpu_pm_exit();