8250_lpss: check null return when calling pci_ioremap_bar

pci_ioremap_bar may return null. This is eventually de-referenced at
drivers/dma/dw/core.c:1154 and drivers/dma/dw/core.c:1168. A null check
is needed to prevent null de-reference. I am adding the check and in
case of failure. Thanks to Andy Shevchenko for the hint on the necessity
of pci_iounmap when exiting.

Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20190719174848.24216-1-navid.emamdoost@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Navid Emamdoost 2019-07-19 12:48:45 -05:00 committed by Greg Kroah-Hartman
parent f77ebb241c
commit ea5ab2e422

View File

@ -169,10 +169,12 @@ static void qrk_serial_setup_dma(struct lpss8250 *lpss, struct uart_port *port)
struct pci_dev *pdev = to_pci_dev(port->dev);
int ret;
chip->pdata = &qrk_serial_dma_pdata;
chip->dev = &pdev->dev;
chip->irq = pci_irq_vector(pdev, 0);
chip->regs = pci_ioremap_bar(pdev, 1);
chip->pdata = &qrk_serial_dma_pdata;
if (!chip->regs)
return;
/* Falling back to PIO mode if DMA probing fails */
ret = dw_dma_probe(chip);
@ -195,11 +197,15 @@ static void qrk_serial_setup_dma(struct lpss8250 *lpss, struct uart_port *port)
static void qrk_serial_exit_dma(struct lpss8250 *lpss)
{
struct dw_dma_chip *chip = &lpss->dma_chip;
struct dw_dma_slave *param = &lpss->dma_param;
if (!param->dma_dev)
return;
dw_dma_remove(&lpss->dma_chip);
dw_dma_remove(chip);
pci_iounmap(to_pci_dev(chip->dev), chip->regs);
}
#else /* CONFIG_SERIAL_8250_DMA */
static void qrk_serial_setup_dma(struct lpss8250 *lpss, struct uart_port *port) {}