From 98f5f932254b88ce828bc8e4d1642d14e5854caa Mon Sep 17 00:00:00 2001
From: Richard Genoud <richard.genoud@gmail.com>
Date: Tue, 27 Nov 2018 17:06:34 +0100
Subject: [PATCH 1/2] dmaengine: at_hdmac: fix memory leak in at_dma_xlate()
The leak was found when opening/closing a serial port a great number of
time, increasing kmalloc-32 in slabinfo.
Each time the port was opened, dma_request_slave_channel() was called.
Then, in at_dma_xlate(), atslave was allocated with devm_kzalloc() and
never freed. (Well, it was free at module unload, but that's not what we
want).
So, here, kzalloc is more suited for the job since it has to be freed in
atc_free_chan_resources().
Cc: stable@vger.kernel.org
Fixes: bbe89c8e3d59 ("at_hdmac: move to generic DMA binding")
Reported-by: Mario Forner <m.forner@be4energy.com>
Suggested-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
---
drivers/dma/at_hdmac.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index 7cbac6e8c113..1b7f0ca0d5cd 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -1641,6 +1641,12 @@ static void atc_free_chan_resources(struct dma_chan *chan)
atchan->descs_allocated = 0;
atchan->status = 0;
+ /*
+ * Free atslave allocated in at_dma_xlate()
+ */
+ kfree(chan->private);
+ chan->private = NULL;
+
dev_vdbg(chan2dev(chan), "free_chan_resources: done\n");
}
@@ -1675,7 +1681,7 @@ static struct dma_chan *at_dma_xlate(struct of_phandle_args *dma_spec,
dma_cap_zero(mask);
dma_cap_set(DMA_SLAVE, mask);
- atslave = devm_kzalloc(&dmac_pdev->dev, sizeof(*atslave), GFP_KERNEL);
+ atslave = kzalloc(sizeof(*atslave), GFP_KERNEL);
if (!atslave)
return NULL;
From 77e75fda94d2ebb86aa9d35fb1860f6395bf95de Mon Sep 17 00:00:00 2001
From: Richard Genoud <richard.genoud@gmail.com>
Date: Tue, 27 Nov 2018 17:06:35 +0100
Subject: [PATCH 2/2] dmaengine: at_hdmac: fix module unloading
of_dma_controller_free() was not called on module onloading.
This lead to a soft lockup:
watchdog: BUG: soft lockup - CPU#0 stuck for 23s!
Modules linked in: at_hdmac [last unloaded: at_hdmac]
when of_dma_request_slave_channel() tried to call ofdma->of_dma_xlate().
Cc: stable@vger.kernel.org
Fixes: bbe89c8e3d59 ("at_hdmac: move to generic DMA binding")
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
---
drivers/dma/at_hdmac.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index 1b7f0ca0d5cd..01d936c9fe89 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -2006,6 +2006,8 @@ static int at_dma_remove(struct platform_device *pdev)
struct resource *io;
at_dma_off(atdma);
+ if (pdev->dev.of_node)
+ of_dma_controller_free(pdev->dev.of_node);
dma_async_device_unregister(&atdma->dma_common);
dma_pool_destroy(atdma->memset_pool);