From patchwork Thu Nov 21 01:37:17 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Amirreza Zarrabi X-Patchwork-Id: 13881533 Received: from mx0b-0031df01.pphosted.com (mx0b-0031df01.pphosted.com [205.220.180.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1B70B433BE; Thu, 21 Nov 2024 01:37:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=205.220.180.131 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732153068; cv=none; b=D4wp8m7SdQb0JNEMALJGtAjEpFu0UBqwNSKS2JDNk0C1eqRi9keeL/KriiIW/EJwc2YO9Kqe5rLz9se9zCOvjfMO+Xc6hHOahy6wASz9bRbe0eYDGfzOj3207X7TMa48mowe1h2aiq/tfAvJ12tFmj0gLBNYXOJtcZuR+Khf3TM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732153068; c=relaxed/simple; bh=NfHFsdP+9dV6RDQWWyLEx13cuJiljaXKgSsqHOa4k3I=; h=From:Date:Subject:MIME-Version:Content-Type:Message-ID:References: In-Reply-To:To:CC; b=XGCVs/dtgtYcrAyncsiQILuzoghCvN5uRHpoIw4MK4EpPSrW45T/JTg3+B+5xXTWdEJDzN48YNtfy0xhh+W+kjD9EwCWA7KCLftcD48LEpGmRQrRhAZB8Iyin8ysUVfOcQuy7mUFwO3riwxzLeBkr6DlWv5kt7Lcx7AchTJb9HM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=quicinc.com; spf=pass smtp.mailfrom=quicinc.com; dkim=pass (2048-bit key) header.d=quicinc.com header.i=@quicinc.com header.b=FkmBflXS; arc=none smtp.client-ip=205.220.180.131 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=quicinc.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=quicinc.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=quicinc.com header.i=@quicinc.com header.b="FkmBflXS" Received: from pps.filterd (m0279868.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 4AKLHUDY014454; Thu, 21 Nov 2024 01:37:44 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h= cc:content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s=qcppdkim1; bh= qpqgOrcDk4qex7tag/zzuN4ZoiXMtOb8QXHf6BnAM9k=; b=FkmBflXSPg+F7q96 UuO2q/vQBi5duKVRBLw3K8DSNusLoT6DyWLmV6aQo7ulG44rLNA3UY/nIWlwVnnX 6TLKl6oD11MevCB1PZfUegsc6qqKHzROwc6aI8ZXwh7j7nc7JKd5NE7vF7ucyXjt DJjxEU5fPPo6j42/92zBP0vFob1lxFXlq2so+ZERdN1cAYVibA//pLOTVVNtLfWq Nq7kLZt92lGTL+MpRDzotJ4nsZHlExY8m4yEoNl3SfAbfzQxs5TN5Jm7Vhh7YILM oRDmHwjI5ropW39e+J44PkDAt9m6tOKI8S16AuVzD7Jr0D9LGfCLzzZXf4KDyxv/ Q+6dOQ== Received: from nasanppmta03.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 4308y97j53-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 21 Nov 2024 01:37:43 +0000 (GMT) Received: from nasanex01b.na.qualcomm.com (nasanex01b.na.qualcomm.com [10.46.141.250]) by NASANPPMTA03.qualcomm.com (8.18.1.2/8.18.1.2) with ESMTPS id 4AL1bge7026021 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 21 Nov 2024 01:37:42 GMT Received: from hu-azarrabi-lv.qualcomm.com (10.49.16.6) by nasanex01b.na.qualcomm.com (10.46.141.250) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.9; Wed, 20 Nov 2024 17:37:42 -0800 From: Amirreza Zarrabi Date: Wed, 20 Nov 2024 17:37:17 -0800 Subject: [PATCH RFC 3/3] tee: introduce orphan tee_shm and default context Precedence: bulk X-Mailing-List: linux-arm-msm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <20241120-fix-tee_shm-refcount-upstream-v1-3-5da97f584fcd@quicinc.com> References: <20241120-fix-tee_shm-refcount-upstream-v1-0-5da97f584fcd@quicinc.com> In-Reply-To: <20241120-fix-tee_shm-refcount-upstream-v1-0-5da97f584fcd@quicinc.com> To: Jens Wiklander , Sumit Garg CC: , , , Amirreza Zarrabi X-Mailer: b4 0.13.0 X-ClientProxiedBy: nalasex01b.na.qualcomm.com (10.47.209.197) To nasanex01b.na.qualcomm.com (10.46.141.250) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-GUID: Uh1jUINsclYJRpRXiJVjoPMUy196Wmhk X-Proofpoint-ORIG-GUID: Uh1jUINsclYJRpRXiJVjoPMUy196Wmhk X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1039,Hydra:6.0.680,FMLib:17.12.60.29 definitions=2024-09-06_09,2024-09-06_01,2024-09-02_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 impostorscore=0 mlxscore=0 phishscore=0 suspectscore=0 adultscore=0 clxscore=1015 priorityscore=1501 lowpriorityscore=0 spamscore=0 bulkscore=0 mlxlogscore=999 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2409260000 definitions=main-2411210011 The default context has a lifespan similar to the tee_device. It is used as a context for shared memory if the context to which the shared memory belongs is released, making the tee_shm an orphan. This allows the driver implementing shm_unregister to safely make subsequent calls, such as to a supplicant if needed. It also enables users to free the shared memory while the driver is blocked on unregister_tee_device safely. Preferably, this should be used for all driver internal uses, using teedev_get_def_context rather than calling teedev_open. Signed-off-by: Amirreza Zarrabi --- drivers/tee/optee/core.c | 2 +- drivers/tee/optee/ffa_abi.c | 2 +- drivers/tee/optee/smc_abi.c | 2 +- drivers/tee/tee_core.c | 83 +++++++++++++++++++++++++++++---------------- drivers/tee/tee_private.h | 3 -- drivers/tee/tee_shm.c | 18 ++-------- include/linux/tee_core.h | 15 ++++++++ include/linux/tee_drv.h | 7 ---- 8 files changed, 73 insertions(+), 59 deletions(-) diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c index c75fddc83576..78d43d0c8014 100644 --- a/drivers/tee/optee/core.c +++ b/drivers/tee/optee/core.c @@ -173,7 +173,7 @@ void optee_remove_common(struct optee *optee) optee_notif_uninit(optee); optee_shm_arg_cache_uninit(optee); - teedev_close_context(optee->ctx); + /* * The two devices have to be unregistered before we can free the * other resources. diff --git a/drivers/tee/optee/ffa_abi.c b/drivers/tee/optee/ffa_abi.c index f3af5666bb11..6ad94f0788ad 100644 --- a/drivers/tee/optee/ffa_abi.c +++ b/drivers/tee/optee/ffa_abi.c @@ -949,7 +949,7 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev) optee_shm_arg_cache_init(optee, arg_cache_flags); mutex_init(&optee->rpmb_dev_mutex); ffa_dev_set_drvdata(ffa_dev, optee); - ctx = teedev_open(optee->teedev); + ctx = teedev_get_def_context(optee->teedev); if (IS_ERR(ctx)) { rc = PTR_ERR(ctx); goto err_rhashtable_free; diff --git a/drivers/tee/optee/smc_abi.c b/drivers/tee/optee/smc_abi.c index e9456e3e74cc..c77a3e631d04 100644 --- a/drivers/tee/optee/smc_abi.c +++ b/drivers/tee/optee/smc_abi.c @@ -1722,7 +1722,7 @@ static int optee_probe(struct platform_device *pdev) mutex_init(&optee->rpmb_dev_mutex); platform_set_drvdata(pdev, optee); - ctx = teedev_open(optee->teedev); + ctx = teedev_get_def_context(optee->teedev); if (IS_ERR(ctx)) { rc = PTR_ERR(ctx); goto err_supp_uninit; diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c index 93f3b330aec8..805e1336089d 100644 --- a/drivers/tee/tee_core.c +++ b/drivers/tee/tee_core.c @@ -57,7 +57,6 @@ struct tee_context *teedev_open(struct tee_device *teedev) goto err; } - kref_init(&ctx->refcount); ctx->teedev = teedev; INIT_LIST_HEAD(&ctx->list_shm); rc = teedev->desc->ops->open(ctx); @@ -73,36 +72,43 @@ struct tee_context *teedev_open(struct tee_device *teedev) } EXPORT_SYMBOL_GPL(teedev_open); -void teedev_ctx_get(struct tee_context *ctx) +struct tee_context *teedev_get_def_context(struct tee_device *teedev) { - if (ctx->releasing) - return; + int rc; + struct tee_context *ctx = &teedev->def_ctx; - kref_get(&ctx->refcount); -} + ctx->teedev = teedev; + INIT_LIST_HEAD(&ctx->list_shm); + rc = teedev->desc->ops->open(ctx); + if (rc) + return ERR_PTR(rc); -static void teedev_ctx_release(struct kref *ref) -{ - struct tee_context *ctx = container_of(ref, struct tee_context, - refcount); - ctx->releasing = true; - ctx->teedev->desc->ops->release(ctx); - kfree(ctx); + return ctx; } +EXPORT_SYMBOL_GPL(teedev_get_def_context); -void teedev_ctx_put(struct tee_context *ctx) +void teedev_close_context(struct tee_context *ctx) { - if (ctx->releasing) + struct tee_device *teedev = ctx->teedev; + struct tee_shm *shm; + + if (ctx == &teedev->def_ctx) return; - kref_put(&ctx->refcount, teedev_ctx_release); -} + teedev->desc->ops->release(ctx); -void teedev_close_context(struct tee_context *ctx) -{ - struct tee_device *teedev = ctx->teedev; + mutex_lock(&teedev->mutex); + list_for_each_entry(shm, &ctx->list_shm, link) { + /* Context released. However, shm still holding a teedev reference. + * Replace shm->ctx with the default context so that tee_shm_get_from_id() + * fails (i.e. it is not accessible from userspace) but shm still + * holds a valid context for further clean up, e.g. shm_unregister(). + */ + shm->ctx = &teedev->def_ctx; + } + mutex_unlock(&teedev->mutex); - teedev_ctx_put(ctx); + kfree(ctx); tee_device_put(teedev); } EXPORT_SYMBOL_GPL(teedev_close_context); @@ -946,6 +952,8 @@ struct tee_device *tee_device_alloc(const struct tee_desc *teedesc, teedev->desc = teedesc; teedev->pool = pool; + /* Only open default context when teedev_get_def_context() called. */ + teedev->def_ctx.teedev = NULL; return teedev; err_devt: @@ -1027,16 +1035,31 @@ EXPORT_SYMBOL_GPL(tee_device_register); void tee_device_put(struct tee_device *teedev) { - mutex_lock(&teedev->mutex); - /* Shouldn't put in this state */ - if (!WARN_ON(!teedev->desc)) { - teedev->num_users--; - if (!teedev->num_users) { - teedev->desc = NULL; - complete(&teedev->c_no_users); - } + const struct tee_desc *desc; + + scoped_guard(mutex, &teedev->mutex) { + desc = teedev->desc; + + /* Shouldn't put in this state */ + if (WARN_ON(!desc)) + return; + + /* If there is still users for teedev */ + if (--teedev->num_users) + return; + + /* tee_device_unregister() has been called and there is no + * user in userspace or kernel, including orphan shm for teedev. + * Set teedev->desc to NULL, so that teedev can not be reused. + */ + teedev->desc = NULL; } - mutex_unlock(&teedev->mutex); + + /* Release the default context */ + desc->ops->release(&teedev->def_ctx); + teedev->def_ctx.teedev = NULL; + + complete(&teedev->c_no_users); } bool tee_device_get(struct tee_device *teedev) diff --git a/drivers/tee/tee_private.h b/drivers/tee/tee_private.h index 9bc50605227c..6c7bcc308958 100644 --- a/drivers/tee/tee_private.h +++ b/drivers/tee/tee_private.h @@ -17,9 +17,6 @@ int tee_shm_get_fd(struct tee_shm *shm); bool tee_device_get(struct tee_device *teedev); void tee_device_put(struct tee_device *teedev); -void teedev_ctx_get(struct tee_context *ctx); -void teedev_ctx_put(struct tee_context *ctx); - struct tee_shm *tee_shm_alloc_user_buf(struct tee_context *ctx, size_t size); struct tee_shm *tee_shm_register_user_buf(struct tee_context *ctx, unsigned long addr, size_t length); diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c index c0164c0f4a01..f07274291edf 100644 --- a/drivers/tee/tee_shm.c +++ b/drivers/tee/tee_shm.c @@ -59,8 +59,6 @@ static void tee_shm_release(struct tee_shm *shm) release_registered_pages(shm); } - teedev_ctx_put(shm->ctx); - kfree(shm); tee_device_put(teedev); @@ -93,13 +91,6 @@ static struct tee_shm *shm_alloc_helper(struct tee_context *ctx, size_t size, shm->flags = flags; shm->teedev = teedev; shm->id = id; - - /* - * We're assigning this as it is needed if the shm is to be - * registered. If this function returns OK then the caller expected - * to call teedev_ctx_get() or clear shm->ctx in case it's not - * needed any longer. - */ shm->ctx = ctx; rc = teedev->pool->ops->alloc(teedev->pool, shm, size, align); @@ -112,7 +103,6 @@ static struct tee_shm *shm_alloc_helper(struct tee_context *ctx, size_t size, list_add_tail(&shm->link, &ctx->list_shm); mutex_unlock(&teedev->mutex); - teedev_ctx_get(ctx); return shm; err_kfree: kfree(shm); @@ -295,12 +285,10 @@ register_shm_helper(struct tee_context *ctx, struct iov_iter *iter, u32 flags, goto err_dev_put; } - teedev_ctx_get(ctx); - shm = kzalloc(sizeof(*shm), GFP_KERNEL); if (!shm) { ret = ERR_PTR(-ENOMEM); - goto err_ctx_put; + goto err_dev_put; } refcount_set(&shm->refcount, 1); @@ -313,7 +301,7 @@ register_shm_helper(struct tee_context *ctx, struct iov_iter *iter, u32 flags, num_pages = iov_iter_npages(iter, INT_MAX); if (!num_pages) { ret = ERR_PTR(-ENOMEM); - goto err_ctx_put; + goto err_dev_put; } shm->pages = kcalloc(num_pages, sizeof(*shm->pages), GFP_KERNEL); @@ -361,8 +349,6 @@ register_shm_helper(struct tee_context *ctx, struct iov_iter *iter, u32 flags, kfree(shm->pages); err_free_shm: kfree(shm); -err_ctx_put: - teedev_ctx_put(ctx); err_dev_put: tee_device_put(teedev); return ret; diff --git a/include/linux/tee_core.h b/include/linux/tee_core.h index a38494d6b5f4..13393ddac530 100644 --- a/include/linux/tee_core.h +++ b/include/linux/tee_core.h @@ -44,6 +44,7 @@ * @idr: register of user space shared memory objects allocated or * registered on this device * @pool: shared memory pool + * @def_ctx: default context used if there is no context available, e.g. internal driver calls. */ struct tee_device { char name[TEE_MAX_DEV_NAME_LEN]; @@ -60,6 +61,7 @@ struct tee_device { struct idr idr; struct tee_shm_pool *pool; + struct tee_context def_ctx; }; /** @@ -309,6 +311,19 @@ static inline bool tee_param_is_memref(struct tee_param *param) */ struct tee_context *teedev_open(struct tee_device *teedev); +/** + * teedev_get_def_context() - Get default context for a struct tee_device + * @teedev: Device to open + * + * Unlike a context that returned from teedev_open(), the default context is static + * and available as long as @teedev has a user ''other then this context''. This context + * can be used for driver internal operation and clean up where a context should be + * available, while tee_device_unregister() is waiting for other users to go away. + * + * @return a pointer to struct tee_context on success or an ERR_PTR on failure. + */ +struct tee_context *teedev_get_def_context(struct tee_device *teedev); + /** * teedev_close_context() - closes a struct tee_context * @ctx: The struct tee_context to close diff --git a/include/linux/tee_drv.h b/include/linux/tee_drv.h index 1b57cddfecc8..9633e14ba484 100644 --- a/include/linux/tee_drv.h +++ b/include/linux/tee_drv.h @@ -7,7 +7,6 @@ #define __TEE_DRV_H #include -#include #include #include #include @@ -25,10 +24,6 @@ struct tee_device; * @teedev: pointer to this drivers struct tee_device * @list_shm: List of shared memory object owned by this context * @data: driver specific context data, managed by the driver - * @refcount: reference counter for this structure - * @releasing: flag that indicates if context is being released right now. - * It is needed to break circular dependency on context during - * shared memory release. * @supp_nowait: flag that indicates that requests in this context should not * wait for tee-supplicant daemon to be started if not present * and just return with an error code. It is needed for requests @@ -41,8 +36,6 @@ struct tee_context { struct tee_device *teedev; struct list_head list_shm; void *data; - struct kref refcount; - bool releasing; bool supp_nowait; bool cap_memref_null; };