[PATCH 01/10] dmaengine: fsldma: kill tasklet before removing channel

[Rosen Penev <rosenp@gmail.com>]

Add tasklet_kill() in fsl_dma_chan_remove() to prevent a race
where the tasklet, scheduled by the IRQ handler, runs after
the channel has been torn down. With the recent devm conversions
the channel struct is no longer freed in the remove path, so
this is not a use-after-free crash fix, but rather correct
shutdown sequencing to avoid the tasklet operating on a
logically-removed channel.

Assisted-by: opencode:big-pickle
Signed-off-by: Rosen Penev <rosenp@gmail.com>
---
 drivers/dma/fsldma.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c
index 22d62d958abd..0e2f84862261 100644
--- a/drivers/dma/fsldma.c
+++ b/drivers/dma/fsldma.c
@@ -1205,6 +1205,7 @@ static int fsl_dma_chan_probe(struct fsldma_device *fdev,
 
 static void fsl_dma_chan_remove(struct fsldma_chan *chan)
 {
+	tasklet_kill(&chan->tasklet);
 	irq_dispose_mapping(chan->irq);
 	list_del(&chan->common.device_node);
 	iounmap(chan->regs);
-- 
2.54.0