From: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
Date: Thu, 16 Apr 2020 06:23:35 +0000 (+0530)
Subject: dmaengine: pch_dma.c: Avoid data race between probe and irq handler
X-Git-Tag: v4.9.224~42
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=87b49639e11c13dac42d3a2fdd85fc0a0d35143c;p=platform%2Fkernel%2Flinux-amlogic.git

dmaengine: pch_dma.c: Avoid data race between probe and irq handler

[ 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>
---

diff --git a/drivers/dma/pch_dma.c b/drivers/dma/pch_dma.c
index df95727dc2fb..8a0c70e4f727 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);