From: Dmitry Osipenko <digetx@gmail.com>
To: Laxman Dewangan <ldewangan@nvidia.com>,
Vinod Koul <vkoul@kernel.org>,
Dan Williams <dan.j.williams@intel.com>,
Thierry Reding <thierry.reding@gmail.com>,
Jonathan Hunter <jonathanh@nvidia.com>
Cc: dmaengine@vger.kernel.org, linux-tegra@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: [PATCH v2 03/12] dmaengine: tegra-apb: Prevent race conditions on channel's freeing
Date: Sun, 29 Dec 2019 17:55:16 +0300 [thread overview]
Message-ID: <20191229145525.533-4-digetx@gmail.com> (raw)
In-Reply-To: <20191229145525.533-1-digetx@gmail.com>
It's unsafe to check the channel's "busy" state without taking a lock,
it is also unsafe to assume that tasklet isn't in-fly.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
drivers/dma/tegra20-apb-dma.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c
index 664e9c5df3ba..28aff0b9763e 100644
--- a/drivers/dma/tegra20-apb-dma.c
+++ b/drivers/dma/tegra20-apb-dma.c
@@ -1294,8 +1294,8 @@ static void tegra_dma_free_chan_resources(struct dma_chan *dc)
dev_dbg(tdc2dev(tdc), "Freeing channel %d\n", tdc->id);
- if (tdc->busy)
- tegra_dma_terminate_all(dc);
+ tegra_dma_terminate_all(dc);
+ tasklet_kill(&tdc->tasklet);
spin_lock_irqsave(&tdc->lock, flags);
list_splice_init(&tdc->pending_sg_req, &sg_req_list);
@@ -1543,7 +1543,6 @@ static int tegra_dma_probe(struct platform_device *pdev)
struct tegra_dma_channel *tdc = &tdma->channels[i];
free_irq(tdc->irq, tdc);
- tasklet_kill(&tdc->tasklet);
}
pm_runtime_disable(&pdev->dev);
@@ -1563,7 +1562,6 @@ static int tegra_dma_remove(struct platform_device *pdev)
for (i = 0; i < tdma->chip_data->nr_channels; ++i) {
tdc = &tdma->channels[i];
free_irq(tdc->irq, tdc);
- tasklet_kill(&tdc->tasklet);
}
pm_runtime_disable(&pdev->dev);
--
2.24.0
next prev parent reply other threads:[~2019-12-29 14:57 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-29 14:55 [PATCH v2 00/12] NVIDIA Tegra APB DMA driver fixes and improvements Dmitry Osipenko
2019-12-29 14:55 ` [PATCH v2 01/12] dmaengine: tegra-apb: Fix use-after-free Dmitry Osipenko
2019-12-29 14:55 ` [PATCH v2 02/12] dmaengine: tegra-apb: Implement synchronization callback Dmitry Osipenko
2019-12-29 14:55 ` Dmitry Osipenko [this message]
2019-12-29 14:55 ` [PATCH v2 04/12] dmaengine: tegra-apb: Prevent race conditions of tasklet vs free list Dmitry Osipenko
2019-12-29 14:55 ` [PATCH v2 05/12] dmaengine: tegra-apb: Use devm_platform_ioremap_resource Dmitry Osipenko
2019-12-29 14:55 ` [PATCH v2 06/12] dmaengine: tegra-apb: Use devm_request_irq Dmitry Osipenko
2019-12-29 14:55 ` [PATCH v2 07/12] dmaengine: tegra-apb: Fix coding style problems Dmitry Osipenko
2019-12-29 14:55 ` [PATCH v2 08/12] dmaengine: tegra-apb: Remove runtime PM usage Dmitry Osipenko
2019-12-29 14:55 ` [PATCH v2 09/12] dmaengine: tegra-apb: Clean up suspend-resume Dmitry Osipenko
2019-12-29 14:55 ` [PATCH v2 10/12] dmaengine: tegra-apb: Add missing of_dma_controller_free Dmitry Osipenko
2019-12-29 14:55 ` [PATCH v2 11/12] dmaengine: tegra-apb: Allow to compile as a loadable kernel module Dmitry Osipenko
2019-12-29 14:55 ` [PATCH v2 12/12] dmaengine: tegra-apb: Remove MODULE_ALIAS Dmitry Osipenko
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