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 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id B052FC433F5 for ; Wed, 19 Jan 2022 13:43:45 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id BD8BC10E2F8; Wed, 19 Jan 2022 13:43:44 +0000 (UTC) Received: from mail-ed1-x52d.google.com (mail-ed1-x52d.google.com [IPv6:2a00:1450:4864:20::52d]) by gabe.freedesktop.org (Postfix) with ESMTPS id D67A610E29A for ; Wed, 19 Jan 2022 13:43:43 +0000 (UTC) Received: by mail-ed1-x52d.google.com with SMTP id f21so11710351eds.11 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=LT8X92g52yvxRJBQn0JktF/37GwyldzkcP4fF75Y/1J7sBumjkMSoHmJAJox/+Ei1l qu4YzmVOc0tlsGCQBtktMYFn3uaKeNZW4fZwTv8klsuyyklAQEyza3C0dftiofiVxAN3 2CA+uN/iU6lhYKty3w3QwygGl7VgGU1ItkpoTnL4dO6U9iR6NWXIHBZr789/zT3BI0Be 3WMFnj0jYSHr/s4txjoAFBar3gMsQu83Hsb10TLw2t5Ns04ALvUUSlzaMVqVXpePiPt7 K2+KCpjYaxgKKSiOg+NM60sjo0jqib6y8ZzxLrGxmmIlL71QgpudVV+RIeNpWhLOYr2s w2BA== X-Gm-Message-State: AOAM532MeWZW5Y/s76fyrj1lGI5NpNtjq6kKNpRv+durh7wREEE4nQdL fLDoCpeCE/YTvngn2jQ3C6o= 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=20K=C3=B6nig?=" X-Google-Original-From: =?UTF-8?q?Christian=20K=C3=B6nig?= To: sumit.semwal@linaro.org, gustavo@padovan.org, daniel.vetter@ffwll.ch 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 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linaro-mm-sig@lists.linaro.org, dri-devel@lists.freedesktop.org, linux-media@vger.kernel.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" 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 --- 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); -- 2.25.1