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 X-Spam-Level: X-Spam-Status: No, score=-12.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 38765C433E1 for ; Fri, 21 Aug 2020 03:44:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0F653208B3 for ; Fri, 21 Aug 2020 03:44:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="isZUrOqs" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727093AbgHUDop (ORCPT ); Thu, 20 Aug 2020 23:44:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57082 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727090AbgHUDop (ORCPT ); Thu, 20 Aug 2020 23:44:45 -0400 Received: from mail-pl1-x642.google.com (mail-pl1-x642.google.com [IPv6:2607:f8b0:4864:20::642]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1ABEDC061385; Thu, 20 Aug 2020 20:44:45 -0700 (PDT) Received: by mail-pl1-x642.google.com with SMTP id v16so287530plo.1; Thu, 20 Aug 2020 20:44:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=wyIVjmGqTstjchVJqOQwrnaOjDzoFs+oUprn8zSTmnY=; b=isZUrOqsG/63XB4tWP2IwaGUbFUurZ4oY18SSWClUtvGV1RD7DhBaPPGd/Ww2XLMAn ZgT+SRonsJCO8fqqnRx098Y7ADJforV8DZeJcMylQH/R0cTn4yB2ORxxz0vEC99R6j1F sExxtN/AFIrh947Q4vAjS5MJF4ZJAb42EqawgP1AJ+agcXB0Qjm5W2MGErw2KuZSr6Kl o9qRaZtYiyYmmfzrX1jggDAHXaP6YM6CZqNBYZFKHGUnFHCz38w3BYc9wE8RoJyJ8418 VaNWPV0IYt0sR+zSBrzFzCmFczt0tVCUcc5c/u4LukCZQadKosm9JXT615rVih1iKokq 6qbA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=wyIVjmGqTstjchVJqOQwrnaOjDzoFs+oUprn8zSTmnY=; b=ghUqZ6nsEbzjmVhOZ/3LyXn/Ln2e9TxQraRMnEHTeT+fsRZ3Uxm2DTO7rwE152PAbE jPBNCeFiRcj4lrbmoXiHEqyzGQYR5Tz4vUShGMEL7FDwrytD8gVbAuLWrhA0kPhN42OW zsELreozbN8ypjIeeMHVudI0eT7PC+/Lwwdkpgt+XBIycxwrI05bLljAIDgt9ABFrFtJ jVKipY3DddcRRyUkVkpfUi91qPaShPdvImenn6AL0wDMWrGC7PEBxoOL4JnRVFOPUBbJ 5ohJDgaejptTLG73Enfv1pxykX17I7bb8MrGitoB7mTmhL1CWtaHszHAoIv01NRZLMDF eiTA== X-Gm-Message-State: AOAM531UBIfdadJQHtwM2MzL+RcIXDdugCudh+KKZgBFkbi6t+6vqDA4 Nz5mYQbgLtz2Hl70y47hHw== X-Google-Smtp-Source: ABdhPJzvXgDyygUBAVsUvY687NV+FhoagdzjUUXE14qWdVGU3IGqA98UMadI38IkKipvJyvWBKAxbQ== X-Received: by 2002:a17:90a:e64b:: with SMTP id ep11mr925111pjb.86.1597981484578; Thu, 20 Aug 2020 20:44:44 -0700 (PDT) Received: from localhost.localdomain ([2402:3a80:cfa:ca54:b051:6744:d734:a674]) by smtp.gmail.com with ESMTPSA id q17sm607755pfh.32.2020.08.20.20.44.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 20 Aug 2020 20:44:43 -0700 (PDT) From: madhuparnabhowmik10@gmail.com To: paul@crapouillou.net, vkoul@kernel.org, dan.j.williams@intel.com, lars@metafoo.de Cc: dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org, andrianov@ispras.ru, ldv-project@linuxtesting.org, Madhuparna Bhowmik Subject: [PATCH v2] drivers/dma/dma-jz4780: Fix race condition between probe and irq handler Date: Fri, 21 Aug 2020 09:14:23 +0530 Message-Id: <20200821034423.12713-1-madhuparnabhowmik10@gmail.com> X-Mailer: git-send-email 2.17.1 Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org From: Madhuparna Bhowmik In probe, IRQ is requested before zchan->id is initialized which can be read in the irq handler. Hence, shift request irq after other initializations complete. Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Madhuparna Bhowmik --- Changes since v1: Keep enable clock before request IRQ. --- drivers/dma/dma-jz4780.c | 38 +++++++++++++++++++------------------- 1 file changed, 19 insertions(+), 19 deletions(-) diff --git a/drivers/dma/dma-jz4780.c b/drivers/dma/dma-jz4780.c index 448f663da89c..8beed91428bd 100644 --- a/drivers/dma/dma-jz4780.c +++ b/drivers/dma/dma-jz4780.c @@ -879,24 +879,11 @@ static int jz4780_dma_probe(struct platform_device *pdev) return -EINVAL; } - ret = platform_get_irq(pdev, 0); - if (ret < 0) - return ret; - - jzdma->irq = ret; - - ret = request_irq(jzdma->irq, jz4780_dma_irq_handler, 0, dev_name(dev), - jzdma); - if (ret) { - dev_err(dev, "failed to request IRQ %u!\n", jzdma->irq); - return ret; - } - jzdma->clk = devm_clk_get(dev, NULL); if (IS_ERR(jzdma->clk)) { dev_err(dev, "failed to get clock\n"); ret = PTR_ERR(jzdma->clk); - goto err_free_irq; + return ret; } clk_prepare_enable(jzdma->clk); @@ -949,10 +936,23 @@ static int jz4780_dma_probe(struct platform_device *pdev) jzchan->vchan.desc_free = jz4780_dma_desc_free; } + ret = platform_get_irq(pdev, 0); + if (ret < 0) + goto err_disable_clk; + + jzdma->irq = ret; + + ret = request_irq(jzdma->irq, jz4780_dma_irq_handler, 0, dev_name(dev), + jzdma); + if (ret) { + dev_err(dev, "failed to request IRQ %u!\n", jzdma->irq); + goto err_disable_clk; + } + ret = dmaenginem_async_device_register(dd); if (ret) { dev_err(dev, "failed to register device\n"); - goto err_disable_clk; + goto err_free_irq; } /* Register with OF DMA helpers. */ @@ -960,17 +960,17 @@ static int jz4780_dma_probe(struct platform_device *pdev) jzdma); if (ret) { dev_err(dev, "failed to register OF DMA controller\n"); - goto err_disable_clk; + goto err_free_irq; } dev_info(dev, "JZ4780 DMA controller initialised\n"); return 0; -err_disable_clk: - clk_disable_unprepare(jzdma->clk); - err_free_irq: free_irq(jzdma->irq, jzdma); + +err_disable_clk: + clk_disable_unprepare(jzdma->clk); return ret; } -- 2.17.1