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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_GIT autolearn=unavailable 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 0E93CC33CAF for ; Thu, 16 Jan 2020 03:29:08 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id DB02D222C3 for ; Thu, 16 Jan 2020 03:29:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="scp1CjL4" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DB02D222C3 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:Message-Id:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To: References:List-Owner; bh=yStSyH6FAZRFzrId1ww4ZnshAavv7+enOldbQnt9Qc0=; b=scp 1CjL4F/QI2f5yn/4TWfkBbMv3JIbr5p3vYyU34CHKVowjH00bnHcR2CkLKfWvBTKgGSLy4vN+8vCV 90eZ6LxR24qKMuJC8qQPVZemp8YrrWKJEg8OGQit8uHhXsdQpoZtMHl3vcCBuHNvZHplIPIxLc+9X gv6mYcq1mVApue/cDCKQFI65qWOUqWHhVW0qnpm3mQpUb5BkXodl8+9ZYJE46syMtM4oHchCbUnxJ gAvll7tAy4zgdKbreFA5p17BM3l6KOtX7FX5J4WmLnirxAqrt+ILEJyMJ/8sP71sInGCXXsdon/3Q OJ2S8VCiFU/j3WijbWXlf2YO//NOcew==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1irvqF-0006p0-IG; Thu, 16 Jan 2020 03:29:07 +0000 Received: from out30-44.freemail.mail.aliyun.com ([115.124.30.44]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1irvqC-0006oA-ED for linux-arm-kernel@lists.infradead.org; Thu, 16 Jan 2020 03:29:05 +0000 X-Alimail-AntiSpam: AC=PASS; BC=-1|-1; BR=01201311R121e4; CH=green; DM=||false|; DS=||; FP=0|-1|-1|-1|0|-1|-1|-1; HT=e01f04452; MF=zhangliguang@linux.alibaba.com; NM=1; PH=DS; RN=3; SR=0; TI=SMTPD_---0TnrNuc._1579145331; Received: from localhost(mailfrom:zhangliguang@linux.alibaba.com fp:SMTPD_---0TnrNuc._1579145331) by smtp.aliyun-inc.com(127.0.0.1); Thu, 16 Jan 2020 11:29:00 +0800 From: luanshi To: james.morse@arm.com Subject: [V2 1/3] firmware: arm_sdei: fix possible deadlock Date: Thu, 16 Jan 2020 11:28:49 +0800 Message-Id: <1579145331-78633-1-git-send-email-zhangliguang@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200115_192904_667309_519B81E0 X-CRM114-Status: UNSURE ( 9.25 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org We call sdei_reregister_event() with sdei_list_lock held but _sdei_event_register() and sdei_event_destroy() also acquires sdei_list_lock thus creating A-A deadlock. Fixes: da351827240e ("firmware: arm_sdei: Add support for CPU and system power states") Signed-off-by: Liguang Zhang --- drivers/firmware/arm_sdei.c | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-) diff --git a/drivers/firmware/arm_sdei.c b/drivers/firmware/arm_sdei.c index a479023..37e9bf0 100644 --- a/drivers/firmware/arm_sdei.c +++ b/drivers/firmware/arm_sdei.c @@ -45,8 +45,11 @@ static asmlinkage void (*sdei_firmware_call)(unsigned long function_id, static unsigned long sdei_entry_point; struct sdei_event { - /* These three are protected by the sdei_list_lock */ + /* protected by the sdei_list_lock */ struct list_head list; + + spinlock_t sdei_event_lock; + /* These two are protected by the sdei_event_lock */ bool reregister; bool reenable; @@ -214,6 +217,7 @@ static struct sdei_event *sdei_event_create(u32 event_num, return ERR_PTR(-ENOMEM); INIT_LIST_HEAD(&event->list); + spin_lock_init(&event->sdei_event_lock); event->event_num = event_num; err = sdei_api_event_get_info(event_num, SDEI_EVENT_INFO_EV_PRIORITY, @@ -412,9 +416,9 @@ int sdei_event_enable(u32 event_num) return -ENOENT; } - spin_lock(&sdei_list_lock); + spin_lock(&event->sdei_event_lock); event->reenable = true; - spin_unlock(&sdei_list_lock); + spin_unlock(&event->sdei_event_lock); if (event->type == SDEI_EVENT_TYPE_SHARED) err = sdei_api_event_enable(event->event_num); @@ -491,10 +495,10 @@ static int _sdei_event_unregister(struct sdei_event *event) { lockdep_assert_held(&sdei_events_lock); - spin_lock(&sdei_list_lock); + spin_lock(&event->sdei_event_lock); event->reregister = false; event->reenable = false; - spin_unlock(&sdei_list_lock); + spin_unlock(&event->sdei_event_lock); if (event->type == SDEI_EVENT_TYPE_SHARED) return sdei_api_event_unregister(event->event_num); @@ -585,9 +589,9 @@ static int _sdei_event_register(struct sdei_event *event) lockdep_assert_held(&sdei_events_lock); - spin_lock(&sdei_list_lock); + spin_lock(&event->sdei_event_lock); event->reregister = true; - spin_unlock(&sdei_list_lock); + spin_unlock(&event->sdei_event_lock); if (event->type == SDEI_EVENT_TYPE_SHARED) return sdei_api_event_register(event->event_num, @@ -598,10 +602,10 @@ static int _sdei_event_register(struct sdei_event *event) err = sdei_do_cross_call(_local_event_register, event); if (err) { - spin_lock(&sdei_list_lock); + spin_lock(&event->sdei_event_lock); event->reregister = false; event->reenable = false; - spin_unlock(&sdei_list_lock); + spin_unlock(&event->sdei_event_lock); sdei_do_cross_call(_local_event_unregister, event); } -- 1.8.3.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel