3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Loic Poulain <loic.poulain@xxxxxxxxx> commit f8fd1b0350d3a4581125f5eda6528f5a2c5f9183 upstream. __dma_tx_complete is not protected against concurrent call of serial8250_tx_dma. it can lead to circular tail index corruption or parallel call of serial_tx_dma on the same data portion. This patch fixes this issue by holding the port lock. Signed-off-by: Loic Poulain <loic.poulain@xxxxxxxxx> Reviewed-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/tty/serial/8250/8250_dma.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) --- a/drivers/tty/serial/8250/8250_dma.c +++ b/drivers/tty/serial/8250/8250_dma.c @@ -20,12 +20,15 @@ static void __dma_tx_complete(void *para struct uart_8250_port *p = param; struct uart_8250_dma *dma = p->dma; struct circ_buf *xmit = &p->port.state->xmit; - - dma->tx_running = 0; + unsigned long flags; dma_sync_single_for_cpu(dma->txchan->device->dev, dma->tx_addr, UART_XMIT_SIZE, DMA_TO_DEVICE); + spin_lock_irqsave(&p->port.lock, flags); + + dma->tx_running = 0; + xmit->tail += dma->tx_size; xmit->tail &= UART_XMIT_SIZE - 1; p->port.icount.tx += dma->tx_size; @@ -35,6 +38,8 @@ static void __dma_tx_complete(void *para if (!uart_circ_empty(xmit) && !uart_tx_stopped(&p->port)) serial8250_tx_dma(p); + + spin_unlock_irqrestore(&p->port.lock, flags); } static void __dma_rx_complete(void *param) -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html