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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>,
        Vinod Koul <vkoul@kernel.org>, Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.9 49/90] dmaengine: pch_dma.c: Avoid data race between probe and irq handler
Date:   Mon, 18 May 2020 19:36:27 +0200
Message-Id: <20200518173501.186923601@linuxfoundation.org>
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From: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>

[ Upstream commit 2e45676a4d33af47259fa186ea039122ce263ba9 ]

pd->dma.dev is read in irq handler pd_irq().
However, it is set to pdev->dev after request_irq().
Therefore, set pd->dma.dev to pdev->dev before request_irq() to
avoid data race between pch_dma_probe() and pd_irq().

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
Link: https://lore.kernel.org/r/20200416062335.29223-1-madhuparnabhowmik10@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/dma/pch_dma.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma/pch_dma.c b/drivers/dma/pch_dma.c
index df95727dc2fba..8a0c70e4f7277 100644
--- a/drivers/dma/pch_dma.c
+++ b/drivers/dma/pch_dma.c
@@ -876,6 +876,7 @@ static int pch_dma_probe(struct pci_dev *pdev,
 	}
 
 	pci_set_master(pdev);
+	pd->dma.dev = &pdev->dev;
 
 	err = request_irq(pdev->irq, pd_irq, IRQF_SHARED, DRV_NAME, pd);
 	if (err) {
@@ -891,7 +892,6 @@ static int pch_dma_probe(struct pci_dev *pdev,
 		goto err_free_irq;
 	}
 
-	pd->dma.dev = &pdev->dev;
 
 	INIT_LIST_HEAD(&pd->dma.channels);
 
-- 
2.20.1