From patchwork Thu Jun 10 21:09:07 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tyler Hicks X-Patchwork-Id: 12313959 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=-26.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT, USER_IN_DEF_DKIM_WL 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 CEED5C48BE0 for ; Thu, 10 Jun 2021 21:09:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BACE0613E7 for ; Thu, 10 Jun 2021 21:09:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231145AbhFJVLr (ORCPT ); Thu, 10 Jun 2021 17:11:47 -0400 Received: from linux.microsoft.com ([13.77.154.182]:60446 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230059AbhFJVLn (ORCPT ); Thu, 10 Jun 2021 17:11:43 -0400 Received: from sequoia.work.tihix.com (162-237-133-238.lightspeed.rcsntx.sbcglobal.net [162.237.133.238]) by linux.microsoft.com (Postfix) with ESMTPSA id 7035520B7188; Thu, 10 Jun 2021 14:09:45 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 7035520B7188 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1623359386; bh=whfJfsHqMmmVau0YBJ0E1Ux41l/udPG1ewedmaTL4yg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FVGjl+t53lgQXqPR6g0jjW7lwVMXdsNOtAxIgaPMJxOgUx1WFMCQKy9gIhwfySh6j lU09YKVgUMn1tsy3Ym3hVEAqTbt8lsdFv99NCPvQHfnUFLpSclNnDvqNZQAckWxBh7 6yuIt6W76iC00q/Z9JtyITaWOcIPtCfTUCW6fABI= From: Tyler Hicks To: Jens Wiklander , Allen Pais , Sumit Garg , Peter Huewe , Jarkko Sakkinen , Jason Gunthorpe , Vikas Gupta Cc: Thirupathaiah Annapureddy , Pavel Tatashin , =?utf-8?b?UmFmYcWCIE1pxYJlY2tp?= , op-tee@lists.trustedfirmware.org, linux-integrity@vger.kernel.org, bcm-kernel-feedback-list@broadcom.com, linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 2/8] optee: Refuse to load the driver under the kdump kernel Date: Thu, 10 Jun 2021 16:09:07 -0500 Message-Id: <20210610210913.536081-3-tyhicks@linux.microsoft.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210610210913.536081-1-tyhicks@linux.microsoft.com> References: <20210610210913.536081-1-tyhicks@linux.microsoft.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org Fix a hung task issue, seen when booting the kdump kernel, that is caused by all of the secure world threads being in a permanent suspended state: INFO: task swapper/0:1 blocked for more than 120 seconds. Not tainted 5.4.83 #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. swapper/0 D 0 1 0 0x00000028 Call trace: __switch_to+0xc8/0x118 __schedule+0x2e0/0x700 schedule+0x38/0xb8 schedule_timeout+0x258/0x388 wait_for_completion+0x16c/0x4b8 optee_cq_wait_for_completion+0x28/0xa8 optee_disable_shm_cache+0xb8/0xf8 optee_probe+0x560/0x61c platform_drv_probe+0x58/0xa8 really_probe+0xe0/0x338 driver_probe_device+0x5c/0xf0 device_driver_attach+0x74/0x80 __driver_attach+0x64/0xe0 bus_for_each_dev+0x84/0xd8 driver_attach+0x30/0x40 bus_add_driver+0x188/0x1e8 driver_register+0x64/0x110 __platform_driver_register+0x54/0x60 optee_driver_init+0x20/0x28 do_one_initcall+0x54/0x24c kernel_init_freeable+0x1e8/0x2c0 kernel_init+0x18/0x118 ret_from_fork+0x10/0x18 The invoke_fn hook returned OPTEE_SMC_RETURN_ETHREAD_LIMIT, indicating that the secure world threads were all in a suspended state at the time of the kernel crash. This intermittently prevented the kdump kernel from booting, resulting in a failure to collect the kernel dump. Make kernel dump collection more reliable on systems utilizing OP-TEE by refusing to load the driver under the kdump kernel. Signed-off-by: Tyler Hicks Reviewed-by: Jens Wiklander --- drivers/tee/optee/core.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c index ddb8f9ecf307..5288cd767d82 100644 --- a/drivers/tee/optee/core.c +++ b/drivers/tee/optee/core.c @@ -6,6 +6,7 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include +#include #include #include #include @@ -612,6 +613,16 @@ static int optee_probe(struct platform_device *pdev) u32 sec_caps; int rc; + /* + * The kernel may have crashed at the same time that all available + * secure world threads were suspended and we cannot reschedule the + * suspended threads without access to the crashed kernel's wait_queue. + * Therefore, we cannot reliably initialize the OP-TEE driver in the + * kdump kernel. + */ + if (is_kdump_kernel()) + return -ENODEV; + invoke_fn = get_invoke_func(&pdev->dev); if (IS_ERR(invoke_fn)) return PTR_ERR(invoke_fn);