pci_ioremap_bar could fail. The fix captures the failure and
pass an error code upstream. This can avoid potential NULL
pointer dereferences in the future.
Signed-off-by: Aditya Pakki <[email protected]>
---
v1: Missed return by default in CONFIG_SERIAL_8250_DMA, suggested by
Jiri Slaby
---
drivers/tty/serial/8250/8250_lpss.c | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)
diff --git a/drivers/tty/serial/8250/8250_lpss.c b/drivers/tty/serial/8250/8250_lpss.c
index 53ca9ba6ab4b..1dc67897dcf8 100644
--- a/drivers/tty/serial/8250/8250_lpss.c
+++ b/drivers/tty/serial/8250/8250_lpss.c
@@ -161,7 +161,7 @@ static const struct dw_dma_platform_data qrk_serial_dma_pdata = {
.multi_block = {0},
};
-static void qrk_serial_setup_dma(struct lpss8250 *lpss, struct uart_port *port)
+static int qrk_serial_setup_dma(struct lpss8250 *lpss, struct uart_port *port)
{
struct uart_8250_dma *dma = &lpss->dma;
struct dw_dma_chip *chip = &lpss->dma_chip;
@@ -172,12 +172,14 @@ static void qrk_serial_setup_dma(struct lpss8250 *lpss, struct uart_port *port)
chip->dev = &pdev->dev;
chip->irq = pci_irq_vector(pdev, 0);
chip->regs = pci_ioremap_bar(pdev, 1);
+ if (!chip->regs)
+ return -EIO;
chip->pdata = &qrk_serial_dma_pdata;
/* Falling back to PIO mode if DMA probing fails */
ret = dw_dma_probe(chip);
if (ret)
- return;
+ return ret;
pci_try_set_mwi(pdev);
@@ -191,6 +193,7 @@ static void qrk_serial_setup_dma(struct lpss8250 *lpss, struct uart_port *port)
param->hs_polarity = true;
lpss->dma_maxburst = 8;
+ return 0;
}
static void qrk_serial_exit_dma(struct lpss8250 *lpss)
@@ -202,7 +205,11 @@ static void qrk_serial_exit_dma(struct lpss8250 *lpss)
dw_dma_remove(&lpss->dma_chip);
}
#else /* CONFIG_SERIAL_8250_DMA */
-static void qrk_serial_setup_dma(struct lpss8250 *lpss, struct uart_port *port) {}
+static int qrk_serial_setup_dma(struct lpss8250 *lpss, struct uart_port *port)
+{
+ return 0;
+}
+
static void qrk_serial_exit_dma(struct lpss8250 *lpss) {}
#endif /* !CONFIG_SERIAL_8250_DMA */
@@ -219,8 +226,7 @@ static int qrk_serial_setup(struct lpss8250 *lpss, struct uart_port *port)
port->irq = pci_irq_vector(pdev, 0);
- qrk_serial_setup_dma(lpss, port);
- return 0;
+ return qrk_serial_setup_dma(lpss, port);
}
static void qrk_serial_exit(struct lpss8250 *lpss)
--
2.17.1
On Sun, Mar 24, 2019 at 12:55 AM Aditya Pakki <[email protected]> wrote:
>
> pci_ioremap_bar could fail. The fix captures the failure and
> pass an error code upstream. This can avoid potential NULL
> pointer dereferences in the future.
>
NAK.
This will break non-DMA case.
> Signed-off-by: Aditya Pakki <[email protected]>
>
> ---
> v1: Missed return by default in CONFIG_SERIAL_8250_DMA, suggested by
> Jiri Slaby
> ---
> drivers/tty/serial/8250/8250_lpss.c | 16 +++++++++++-----
> 1 file changed, 11 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/tty/serial/8250/8250_lpss.c b/drivers/tty/serial/8250/8250_lpss.c
> index 53ca9ba6ab4b..1dc67897dcf8 100644
> --- a/drivers/tty/serial/8250/8250_lpss.c
> +++ b/drivers/tty/serial/8250/8250_lpss.c
> @@ -161,7 +161,7 @@ static const struct dw_dma_platform_data qrk_serial_dma_pdata = {
> .multi_block = {0},
> };
>
> -static void qrk_serial_setup_dma(struct lpss8250 *lpss, struct uart_port *port)
> +static int qrk_serial_setup_dma(struct lpss8250 *lpss, struct uart_port *port)
> {
> struct uart_8250_dma *dma = &lpss->dma;
> struct dw_dma_chip *chip = &lpss->dma_chip;
> @@ -172,12 +172,14 @@ static void qrk_serial_setup_dma(struct lpss8250 *lpss, struct uart_port *port)
> chip->dev = &pdev->dev;
> chip->irq = pci_irq_vector(pdev, 0);
> chip->regs = pci_ioremap_bar(pdev, 1);
> + if (!chip->regs)
> + return -EIO;
> chip->pdata = &qrk_serial_dma_pdata;
>
> /* Falling back to PIO mode if DMA probing fails */
> ret = dw_dma_probe(chip);
> if (ret)
> - return;
> + return ret;
>
> pci_try_set_mwi(pdev);
>
> @@ -191,6 +193,7 @@ static void qrk_serial_setup_dma(struct lpss8250 *lpss, struct uart_port *port)
> param->hs_polarity = true;
>
> lpss->dma_maxburst = 8;
> + return 0;
> }
>
> static void qrk_serial_exit_dma(struct lpss8250 *lpss)
> @@ -202,7 +205,11 @@ static void qrk_serial_exit_dma(struct lpss8250 *lpss)
> dw_dma_remove(&lpss->dma_chip);
> }
> #else /* CONFIG_SERIAL_8250_DMA */
> -static void qrk_serial_setup_dma(struct lpss8250 *lpss, struct uart_port *port) {}
> +static int qrk_serial_setup_dma(struct lpss8250 *lpss, struct uart_port *port)
> +{
> + return 0;
> +}
> +
> static void qrk_serial_exit_dma(struct lpss8250 *lpss) {}
> #endif /* !CONFIG_SERIAL_8250_DMA */
>
> @@ -219,8 +226,7 @@ static int qrk_serial_setup(struct lpss8250 *lpss, struct uart_port *port)
>
> port->irq = pci_irq_vector(pdev, 0);
>
> - qrk_serial_setup_dma(lpss, port);
> - return 0;
> + return qrk_serial_setup_dma(lpss, port);
> }
>
> static void qrk_serial_exit(struct lpss8250 *lpss)
> --
> 2.17.1
>
--
With Best Regards,
Andy Shevchenko
On Sun, Mar 24, 2019 at 2:05 PM Andy Shevchenko
<[email protected]> wrote:
> On Sun, Mar 24, 2019 at 12:55 AM Aditya Pakki <[email protected]> wrote:
> >
> > pci_ioremap_bar could fail. The fix captures the failure and
> > pass an error code upstream. This can avoid potential NULL
> > pointer dereferences in the future.
> >
>
> NAK.
> This will break non-DMA case.
> > @@ -172,12 +172,14 @@ static void qrk_serial_setup_dma(struct lpss8250 *lpss, struct uart_port *port)
Just to clarify, what you need is simple
void __iomem *regs;
chip->pdata = ... //move it here for better looking code
chip->irq = ...
chip->regs = pci_ioremap_bar(...);
if (!chip->regs)
return;
and thank you for pointing to this.
--
With Best Regards,
Andy Shevchenko
On Sun, Mar 24, 2019 at 2:26 PM Andy Shevchenko
<[email protected]> wrote:
> On Sun, Mar 24, 2019 at 2:05 PM Andy Shevchenko
> <[email protected]> wrote:
> > On Sun, Mar 24, 2019 at 12:55 AM Aditya Pakki <[email protected]> wrote:
> > >
> > > pci_ioremap_bar could fail. The fix captures the failure and
> > > pass an error code upstream. This can avoid potential NULL
> > > pointer dereferences in the future.
> > >
> >
> > NAK.
> > This will break non-DMA case.
>
> > > @@ -172,12 +172,14 @@ static void qrk_serial_setup_dma(struct lpss8250 *lpss, struct uart_port *port)
>
> Just to clarify, what you need is simple
>
> void __iomem *regs;
Sorry for leftover.
> chip->pdata = ... //move it here for better looking code
> chip->irq = ...
> chip->regs = pci_ioremap_bar(...);
And looking into the code it needs pci_iounmap() on exit one.
> if (!chip->regs)
> return;
>
> and thank you for pointing to this.
--
With Best Regards,
Andy Shevchenko