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drivers/dma/dma-jz4780: Fix race condition between probe and irq handler 

[ Upstream commit 6d6018fc30 ]

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 <madhuparnabhowmik10@gmail.com>
Reviewed-by: Paul Cercueil <paul@crapouillou.net>
Link: https://lore.kernel.org/r/20200821034423.12713-1-madhuparnabhowmik10@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Madhuparna Bhowmik 2020-08-21 09:14:23 +05:30 committed by Greg Kroah-Hartman
parent bcdbb7c8c7
commit cb54984b79
1 changed files with 19 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

38
drivers/dma/dma-jz4780.c
View File

@ -885,24 +885,11 @@ 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);
@ -955,10 +942,23 @@ 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. */
@ -966,17 +966,17 @@ 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;
}