This is a note to let you know that I've just added the patch titled
serial: sh-sci: protect invalidating RXDMA on shutdown
to the 6.8-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
serial-sh-sci-protect-invalidating-rxdma-on-shutdown.patch
and it can be found in the queue-6.8 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit dfcef6c66f51777c06cd53d6ce5742868c6776e7
Author: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
Date: Mon May 6 13:40:17 2024 +0200
serial: sh-sci: protect invalidating RXDMA on shutdown
[ Upstream commit aae20f6e34cd0cbd67a1d0e5877561c40109a81b ]
The to-be-fixed commit removed locking when invalidating the DMA RX
descriptors on shutdown. It overlooked that there is still a rx_timer
running which may still access the protected data. So, re-add the
locking.
Reported-by: Dirk Behme <dirk.behme@xxxxxxxxxxxx>
Closes: https://lore.kernel.org/r/ee6c9e16-9f29-450e-81da-4a8dceaa8fc7@xxxxxxxxxxxx
Fixes: 2c4ee23530ff ("serial: sh-sci: Postpone DMA release when falling back to PIO")
Signed-off-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20240506114016.30498-7-wsa+renesas@xxxxxxxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index a85e7b9a2e492..0d9eab56747cc 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -1272,9 +1272,14 @@ static void sci_dma_rx_chan_invalidate(struct sci_port *s)
static void sci_dma_rx_release(struct sci_port *s)
{
struct dma_chan *chan = s->chan_rx_saved;
+ struct uart_port *port = &s->port;
+ unsigned long flags;
+ uart_port_lock_irqsave(port, &flags);
s->chan_rx_saved = NULL;
sci_dma_rx_chan_invalidate(s);
+ uart_port_unlock_irqrestore(port, flags);
+
dmaengine_terminate_sync(chan);
dma_free_coherent(chan->device->dev, s->buf_len_rx * 2, s->rx_buf[0],
sg_dma_address(&s->sg_rx[0]));
