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=-10.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,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 B4C06C2BB85 for ; Fri, 10 Apr 2020 03:46:57 +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 8A44520B1F for ; Fri, 10 Apr 2020 03:46:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="PLttwA7B"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="KBI8znHO" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8A44520B1F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org 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:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: 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: List-Owner; bh=ESApDHAUPOS1Gax6mA9udastlX6WNAgCFNHe8tFwqjg=; b=PLttwA7BChZpj8 iJwomJ5/JGveoPM9gGeT5rbVNyM+Csan6NZ2iDeKu7TTh/dZd9wHnuNwn7vjqLi7Bx2i4QJPsNkE8 mnzDyVV5qdrs0/C+MikqEt/NJ0Fdv+mtl4CRQJ+3ukWIajZ2A8NBQcWSVcG1OMmlIMhct9bp6fDUi JPV8mjcwpRy9uwQ0YmtcOZylJNzWgGfZ8YMGLE+I8eBfI9cmHQos9t1jGLkKwemFIZRPHNysclWT1 fWHEFR0c7Fj6PEwDhvLxKvQNTs1xgCXlm0XgC9bmVzN+iNXVz4DIVhMOH7sybbM947GJSka5t81x2 Bqv0Cz9Uuc9VcrZ9I1GQ==; 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 1jMkd6-0002H8-UL; Fri, 10 Apr 2020 03:46:56 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jMkcy-0002AN-EE for linux-arm-kernel@lists.infradead.org; Fri, 10 Apr 2020 03:46:49 +0000 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 0F301215A4; Fri, 10 Apr 2020 03:46:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586490407; bh=YDlUlH9cxoPoePJ/BVt1VLVyGDJmuuZt3f/vtA5eHsQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KBI8znHO9SpKB8M/7w//kYSOEbZQSujUGMyS0EcZWbBWrjEZqsdpkHaVUjEGfEbvY sbS6wU1uH1ZDuRm2ndN6E0hJTiiMNdhXoUSLz2aUve3uTbvunzgWSEUvf6+fUsawDm xxjtHYB0lZSZmXTOfjCwEDduVSeuy+PdhxNcaqtc= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH AUTOSEL 5.6 10/68] firmware: arm_sdei: fix double-lock on hibernate with shared events Date: Thu, 9 Apr 2020 23:45:35 -0400 Message-Id: <20200410034634.7731-10-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200410034634.7731-1-sashal@kernel.org> References: <20200410034634.7731-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200409_204648_519700_BF7B0BD1 X-CRM114-Status: GOOD ( 12.53 ) 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: Sasha Levin , Catalin Marinas , Liguang Zhang , James Morse , linux-arm-kernel@lists.infradead.org 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 From: James Morse [ Upstream commit 6ded0b61cf638bf9f8efe60ab8ba23db60ea9763 ] SDEI has private events that must be registered on each CPU. When CPUs come and go they must re-register and re-enable their private events. Each event has flags to indicate whether this should happen to protect against an event being registered on a CPU coming online, while all the others are unregistering the event. These flags are protected by the sdei_list_lock spinlock, because the cpuhp callbacks can't take the mutex. Hibernate needs to unregister all events, but keep the in-memory re-register and re-enable as they are. sdei_unregister_shared() takes the spinlock to walk the list, then calls _sdei_event_unregister() on each shared event. _sdei_event_unregister() tries to take the same spinlock to update re-register and re-enable. This doesn't go so well. Push the re-register and re-enable updates out to their callers. sdei_unregister_shared() doesn't want these values updated, so doesn't need to do anything. This also fixes shared events getting lost over hibernate as this path made them look unregistered. Fixes: da351827240e ("firmware: arm_sdei: Add support for CPU and system power states") Reported-by: Liguang Zhang Signed-off-by: James Morse Signed-off-by: Catalin Marinas Signed-off-by: Sasha Levin --- drivers/firmware/arm_sdei.c | 32 +++++++++++++++----------------- 1 file changed, 15 insertions(+), 17 deletions(-) diff --git a/drivers/firmware/arm_sdei.c b/drivers/firmware/arm_sdei.c index a479023fa036e..77eaa9a2fd156 100644 --- a/drivers/firmware/arm_sdei.c +++ b/drivers/firmware/arm_sdei.c @@ -491,11 +491,6 @@ static int _sdei_event_unregister(struct sdei_event *event) { lockdep_assert_held(&sdei_events_lock); - spin_lock(&sdei_list_lock); - event->reregister = false; - event->reenable = false; - spin_unlock(&sdei_list_lock); - if (event->type == SDEI_EVENT_TYPE_SHARED) return sdei_api_event_unregister(event->event_num); @@ -518,6 +513,11 @@ int sdei_event_unregister(u32 event_num) break; } + spin_lock(&sdei_list_lock); + event->reregister = false; + event->reenable = false; + spin_unlock(&sdei_list_lock); + err = _sdei_event_unregister(event); if (err) break; @@ -585,26 +585,15 @@ static int _sdei_event_register(struct sdei_event *event) lockdep_assert_held(&sdei_events_lock); - spin_lock(&sdei_list_lock); - event->reregister = true; - spin_unlock(&sdei_list_lock); - if (event->type == SDEI_EVENT_TYPE_SHARED) return sdei_api_event_register(event->event_num, sdei_entry_point, event->registered, SDEI_EVENT_REGISTER_RM_ANY, 0); - err = sdei_do_cross_call(_local_event_register, event); - if (err) { - spin_lock(&sdei_list_lock); - event->reregister = false; - event->reenable = false; - spin_unlock(&sdei_list_lock); - + if (err) sdei_do_cross_call(_local_event_unregister, event); - } return err; } @@ -632,8 +621,17 @@ int sdei_event_register(u32 event_num, sdei_event_callback *cb, void *arg) break; } + spin_lock(&sdei_list_lock); + event->reregister = true; + spin_unlock(&sdei_list_lock); + err = _sdei_event_register(event); if (err) { + spin_lock(&sdei_list_lock); + event->reregister = false; + event->reenable = false; + spin_unlock(&sdei_list_lock); + sdei_event_destroy(event); pr_warn("Failed to register event %u: %d\n", event_num, err); -- 2.20.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel