From patchwork Wed Jan 19 13:43:37 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Christian_K=C3=B6nig?= X-Patchwork-Id: 80108 Received: from vger.kernel.org ([23.128.96.18]) by www.linuxtv.org with esmtp (Exim 4.92) (envelope-from ) id 1nABFh-00GJNO-6k; Wed, 19 Jan 2022 13:43:53 +0000 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1354881AbiASNnu (ORCPT + 1 other); Wed, 19 Jan 2022 08:43:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34482 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245443AbiASNno (ORCPT ); Wed, 19 Jan 2022 08:43:44 -0500 Received: from mail-ed1-x52d.google.com (mail-ed1-x52d.google.com [IPv6:2a00:1450:4864:20::52d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CAEF9C06161C for ; Wed, 19 Jan 2022 05:43:43 -0800 (PST) Received: by mail-ed1-x52d.google.com with SMTP id c71so11849741edf.6 for ; Wed, 19 Jan 2022 05:43:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=ZBnr8W3NhjErF+08iBcJ135fidhwJh6suv4msEwXqUY=; b=Xm6IWY1PeF5288tssLFaZn1by7Vu5JTy0T4ztY6KDjbHZC0M47grNGiEe/yIkQ3hob XsAw9Ag+Yj7/z8JbC0TJQ6TmTebV/YyVTwM3TQ0SIINgm7ZkXYNCSsOlyi/ov5NxQmf1 HLDO27OQb7OG4PgEQIxvqkmB/JDPgw/FzbXH2rUDzTbhIsfxN/GY10slrnxNTamYdIJN 9N1DvBxsOMBQZl3pKCSgSeqiz+d2NbMAP/IIKOwTmAQ6/HC4ra4egPhweB1qwiNteR4I 8CNhz/L/qDyqK1lP2g9y0QeAkEjCZNQnOrF8ninP8l95Ghxx6ZRO52Aac4IaHrEBCU/6 YQWw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=ZBnr8W3NhjErF+08iBcJ135fidhwJh6suv4msEwXqUY=; b=4XmCUAEke+p2OrsnYyCx9L4AnIT9ukqYUXy3EDwUEiN6abQzQA9WJYSa+oPHYUVTxI sF+kOIwu0dyJimqDe557WsF4dgdV+/o6DnZU0Cyr+sj4e7RWhoWTtACeuRSZuPN1TYBK wvT9hoZX++TFp6mM29uCYNxbAWzrTIaDgBq8J8ru+idXr49kHAAAQBMgsVghwQaSzzv0 sNqmRzjkRr1kLdxEM5LKWeeXJXDmiYiIN3j1wC8l+eoHxMRaaXbJXqygdfrbi2nk8ltW GDBgVUl2RHWf+DBa7c8Nv051IpJwe+kFW6S/PkjK9Z2/v2pgxUxwn5o4xSJDz2lFcins ytcA== X-Gm-Message-State: AOAM530idsSplZ7v4JfLRyygwuUnMrUyRXb3r/+jVBi/9HikFkLJ1Yrr mXKuzcF7dC3T4yUyInmFI7w= X-Google-Smtp-Source: ABdhPJwRKHZmp53LX3TFftfhKR37HscsIXg23NmT8Lxx/R9T/LsqBsK1KO902EToCEEBzlGRYFkCow== X-Received: by 2002:a5d:5745:: with SMTP id q5mr7199118wrw.160.1642599822463; Wed, 19 Jan 2022 05:43:42 -0800 (PST) Received: from abel.fritz.box (p57b0bff8.dip0.t-ipconnect.de. [87.176.191.248]) by smtp.gmail.com with ESMTPSA id g15sm19733583wrm.2.2022.01.19.05.43.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 19 Jan 2022 05:43:42 -0800 (PST) From: " =?utf-8?q?Christian_K=C3=B6nig?= " X-Google-Original-From: =?utf-8?q?Christian_K=C3=B6nig?= To: sumit.semwal@linaro.org, gustavo@padovan.org, daniel.vetter@ffwll.ch Cc: linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org Subject: [PATCH 2/4] dma-buf: warn about dma_fence_array container rules Date: Wed, 19 Jan 2022 14:43:37 +0100 Message-Id: <20220119134339.3102-2-christian.koenig@amd.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220119134339.3102-1-christian.koenig@amd.com> References: <20220119134339.3102-1-christian.koenig@amd.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-LSpam-Score: -7.5 (-------) X-LSpam-Report: No, score=-7.5 required=5.0 tests=BAYES_00=-1.9,DKIM_SIGNED=0.1,DKIM_VALID=-0.1,DKIM_VALID_AU=-0.1,FREEMAIL_FORGED_FROMDOMAIN=0.001,FREEMAIL_FROM=0.001,HEADER_FROM_DIFFERENT_DOMAINS=0.5,MAILING_LIST_MULTI=-1,RCVD_IN_DNSWL_HI=-5 autolearn=ham autolearn_force=no It's not allowed to nest another dma_fence container into a dma_fence_array or otherwise we can run into recursion. Warn about that when we create a dma_fence_array. Signed-off-by: Christian König Reviewed-by: Daniel Vetter --- drivers/dma-buf/dma-fence-array.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/dma-buf/dma-fence-array.c b/drivers/dma-buf/dma-fence-array.c index 3e07f961e2f3..4bfbcb885bbc 100644 --- a/drivers/dma-buf/dma-fence-array.c +++ b/drivers/dma-buf/dma-fence-array.c @@ -176,6 +176,19 @@ struct dma_fence_array *dma_fence_array_create(int num_fences, array->base.error = PENDING_ERROR; + /* dma_fence_array objects should never contain any other fence + * containers or otherwise we run into recursion and potential kernel + * stack overflow on operations on the dma_fence_array. + * + * The correct way of handling this is to flatten out the array by the + * caller instead. + * + * Enforce this here by checking that we don't create a dma_fence_array + * with any container inside. + */ + while (seqno--) + WARN_ON(dma_fence_is_container(fences[seqno])); + return array; } EXPORT_SYMBOL(dma_fence_array_create);