From patchwork Thu Jun 10 21:09:13 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tyler Hicks X-Patchwork-Id: 12313973 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 D88A7C48BE8 for ; Thu, 10 Jun 2021 21:09:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BB70E61412 for ; Thu, 10 Jun 2021 21:09:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231231AbhFJVLz (ORCPT ); Thu, 10 Jun 2021 17:11:55 -0400 Received: from linux.microsoft.com ([13.77.154.182]:60598 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231143AbhFJVLw (ORCPT ); Thu, 10 Jun 2021 17:11:52 -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 CCE8720B7188; Thu, 10 Jun 2021 14:09:54 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com CCE8720B7188 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1623359395; bh=3AkzjPDle5pDg2xwxx73EHJTuFLG/FBLbuCVbDMwXys=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JNUuI/mdWDJ1NMEp1b6ythmOtQDckHJlMtuCE0pv0xNPxGMsXQMvw1GNIbuAtUX5A JcqEZ0tg2K19EKEkTc/Gaqg/zvam7nPhrytPoORlMbDLIkYoNpBYVtGiDzQQPwc+jm X6cxan64tV76eWmX646Fz2dV4Q/ofREsv/jXYtKE= 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 8/8] firmware: tee_bnxt: Release TEE shm, session, and context during kexec Date: Thu, 10 Jun 2021 16:09:13 -0500 Message-Id: <20210610210913.536081-9-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 From: Allen Pais Implement a .shutdown hook that will be called during a kexec operation so that the TEE shared memory, session, and context that were set up during .probe can be properly freed/closed. Additionally, don't use dma-buf backed shared memory for the fw_shm_pool. dma-buf backed shared memory cannot be reliably freed and unregistered during a kexec operation even when tee_shm_free() is called on the shm from a .shutdown hook. The problem occurs because dma_buf_put() calls fput() which then uses task_work_add(), with the TWA_RESUME parameter, to queue tee_shm_release() to be called before the current task returns to user mode. However, the current task never returns to user mode before the kexec completes so the memory is never freed nor unregistered. Use tee_shm_alloc_kernel_buf() to avoid dma-buf backed shared memory allocation so that tee_shm_free() can directly call tee_shm_release(). This will ensure that the shm can be freed and unregistered during a kexec operation. Fixes: 246880958ac9 ("firmware: broadcom: add OP-TEE based BNXT f/w manager") Signed-off-by: Allen Pais Co-developed-by: Tyler Hicks Signed-off-by: Tyler Hicks --- drivers/firmware/broadcom/tee_bnxt_fw.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/drivers/firmware/broadcom/tee_bnxt_fw.c b/drivers/firmware/broadcom/tee_bnxt_fw.c index ed10da5313e8..a5bf4c3f6dc7 100644 --- a/drivers/firmware/broadcom/tee_bnxt_fw.c +++ b/drivers/firmware/broadcom/tee_bnxt_fw.c @@ -212,10 +212,9 @@ static int tee_bnxt_fw_probe(struct device *dev) pvt_data.dev = dev; - fw_shm_pool = tee_shm_alloc(pvt_data.ctx, MAX_SHM_MEM_SZ, - TEE_SHM_MAPPED | TEE_SHM_DMA_BUF); + fw_shm_pool = tee_shm_alloc_kernel_buf(pvt_data.ctx, MAX_SHM_MEM_SZ); if (IS_ERR(fw_shm_pool)) { - dev_err(pvt_data.dev, "tee_shm_alloc failed\n"); + dev_err(pvt_data.dev, "tee_shm_alloc_kernel_buf failed\n"); err = PTR_ERR(fw_shm_pool); goto out_sess; } @@ -242,6 +241,14 @@ static int tee_bnxt_fw_remove(struct device *dev) return 0; } +static void tee_bnxt_fw_shutdown(struct device *dev) +{ + tee_shm_free(pvt_data.fw_shm_pool); + tee_client_close_session(pvt_data.ctx, pvt_data.session_id); + tee_client_close_context(pvt_data.ctx); + pvt_data.ctx = NULL; +} + static const struct tee_client_device_id tee_bnxt_fw_id_table[] = { {UUID_INIT(0x6272636D, 0x2019, 0x0716, 0x42, 0x43, 0x4D, 0x5F, 0x53, 0x43, 0x48, 0x49)}, @@ -257,6 +264,7 @@ static struct tee_client_driver tee_bnxt_fw_driver = { .bus = &tee_bus_type, .probe = tee_bnxt_fw_probe, .remove = tee_bnxt_fw_remove, + .shutdown = tee_bnxt_fw_shutdown, }, };