| Message ID | 20220505114750.45423-1-Indan.Zupancic@mep-info.com |
|---|---|
| State | New |
| Headers | show |
| Series | fsl_lpuart: Don't enable interrupts too early | expand |
> -----Original Message----- > From: Indan Zupancic <Indan.Zupancic@mep-info.com> > Sent: 2022年5月5日 19:48 > To: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > Cc: Sherry Sun <sherry.sun@nxp.com>; dl-linux-imx <linux-imx@nxp.com>; > linux-serial@vger.kernel.org; jirislaby@kernel.org; Indan Zupancic > <Indan.Zupancic@mep-info.com> > Subject: [PATCH] fsl_lpuart: Don't enable interrupts too early > > If an irq is pending when devm_request_irq() is called, the irq handler will > cause a NULL pointer access because initialisation is not done yet. > > Fixes: 9d7ee0e28da59 ("tty: serial: lpuart: avoid report NULL interrupt") > Signed-off-by: Indan Zupancic <Indan.Zupancic@mep-info.com> Reviewed-by: Sherry Sun <sherry.sun@nxp.com> Best regards Sherry > --- > drivers/tty/serial/fsl_lpuart.c | 18 +++++++++--------- > 1 file changed, 9 insertions(+), 9 deletions(-) > > diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c > index 75b3c36c13bc..7b46b97a6ddd 100644 > --- a/drivers/tty/serial/fsl_lpuart.c > +++ b/drivers/tty/serial/fsl_lpuart.c > @@ -2629,6 +2629,7 @@ static int lpuart_probe(struct platform_device > *pdev) > struct device_node *np = pdev->dev.of_node; > struct lpuart_port *sport; > struct resource *res; > + irq_handler_t handler; > int ret; > > sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL); @@ > -2701,17 +2702,11 @@ static int lpuart_probe(struct platform_device *pdev) > > if (lpuart_is_32(sport)) { > lpuart_reg.cons = LPUART32_CONSOLE; > - ret = devm_request_irq(&pdev->dev, sport->port.irq, > lpuart32_int, 0, > - DRIVER_NAME, sport); > + handler = lpuart32_int; > } else { > lpuart_reg.cons = LPUART_CONSOLE; > - ret = devm_request_irq(&pdev->dev, sport->port.irq, > lpuart_int, 0, > - DRIVER_NAME, sport); > + handler = lpuart_int; > } > - > - if (ret) > - goto failed_irq_request; > - > ret = uart_add_one_port(&lpuart_reg, &sport->port); > if (ret) > goto failed_attach_port; > @@ -2733,13 +2728,18 @@ static int lpuart_probe(struct platform_device > *pdev) > > sport->port.rs485_config(&sport->port, &sport->port.rs485); > > + ret = devm_request_irq(&pdev->dev, sport->port.irq, handler, 0, > + DRIVER_NAME, sport); > + if (ret) > + goto failed_irq_request; > + > return 0; > > +failed_irq_request: > failed_get_rs485: > failed_reset: > uart_remove_one_port(&lpuart_reg, &sport->port); > failed_attach_port: > -failed_irq_request: > lpuart_disable_clks(sport); > return ret; > } > -- > 2.30.2
On 05. 05. 22, 13:47, Indan Zupancic wrote: > If an irq is pending when devm_request_irq() is called, the irq > handler will cause a NULL pointer access because initialisation > is not done yet. Sounds about right. But could you be a bit more specific? Like appending the BUG and its stack trace? > Fixes: 9d7ee0e28da59 ("tty: serial: lpuart: avoid report NULL interrupt") > Signed-off-by: Indan Zupancic <Indan.Zupancic@mep-info.com> > --- > drivers/tty/serial/fsl_lpuart.c | 18 +++++++++--------- > 1 file changed, 9 insertions(+), 9 deletions(-) > > diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c > index 75b3c36c13bc..7b46b97a6ddd 100644 > --- a/drivers/tty/serial/fsl_lpuart.c > +++ b/drivers/tty/serial/fsl_lpuart.c > @@ -2629,6 +2629,7 @@ static int lpuart_probe(struct platform_device *pdev) > struct device_node *np = pdev->dev.of_node; > struct lpuart_port *sport; > struct resource *res; > + irq_handler_t handler; > int ret; > > sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL); > @@ -2701,17 +2702,11 @@ static int lpuart_probe(struct platform_device *pdev) > > if (lpuart_is_32(sport)) { > lpuart_reg.cons = LPUART32_CONSOLE; > - ret = devm_request_irq(&pdev->dev, sport->port.irq, lpuart32_int, 0, > - DRIVER_NAME, sport); > + handler = lpuart32_int; > } else { > lpuart_reg.cons = LPUART_CONSOLE; > - ret = devm_request_irq(&pdev->dev, sport->port.irq, lpuart_int, 0, > - DRIVER_NAME, sport); > + handler = lpuart_int; > } > - > - if (ret) > - goto failed_irq_request; > - > ret = uart_add_one_port(&lpuart_reg, &sport->port); > if (ret) > goto failed_attach_port; > @@ -2733,13 +2728,18 @@ static int lpuart_probe(struct platform_device *pdev) > > sport->port.rs485_config(&sport->port, &sport->port.rs485); > > + ret = devm_request_irq(&pdev->dev, sport->port.irq, handler, 0, > + DRIVER_NAME, sport); > + if (ret) > + goto failed_irq_request; > + > return 0; > > +failed_irq_request: > failed_get_rs485: > failed_reset: > uart_remove_one_port(&lpuart_reg, &sport->port); > failed_attach_port: > -failed_irq_request: > lpuart_disable_clks(sport); > return ret; > }
diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c index 75b3c36c13bc..7b46b97a6ddd 100644 --- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -2629,6 +2629,7 @@ static int lpuart_probe(struct platform_device *pdev) struct device_node *np = pdev->dev.of_node; struct lpuart_port *sport; struct resource *res; + irq_handler_t handler; int ret; sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL); @@ -2701,17 +2702,11 @@ static int lpuart_probe(struct platform_device *pdev) if (lpuart_is_32(sport)) { lpuart_reg.cons = LPUART32_CONSOLE; - ret = devm_request_irq(&pdev->dev, sport->port.irq, lpuart32_int, 0, - DRIVER_NAME, sport); + handler = lpuart32_int; } else { lpuart_reg.cons = LPUART_CONSOLE; - ret = devm_request_irq(&pdev->dev, sport->port.irq, lpuart_int, 0, - DRIVER_NAME, sport); + handler = lpuart_int; } - - if (ret) - goto failed_irq_request; - ret = uart_add_one_port(&lpuart_reg, &sport->port); if (ret) goto failed_attach_port; @@ -2733,13 +2728,18 @@ static int lpuart_probe(struct platform_device *pdev) sport->port.rs485_config(&sport->port, &sport->port.rs485); + ret = devm_request_irq(&pdev->dev, sport->port.irq, handler, 0, + DRIVER_NAME, sport); + if (ret) + goto failed_irq_request; + return 0; +failed_irq_request: failed_get_rs485: failed_reset: uart_remove_one_port(&lpuart_reg, &sport->port); failed_attach_port: -failed_irq_request: lpuart_disable_clks(sport); return ret; }
If an irq is pending when devm_request_irq() is called, the irq handler will cause a NULL pointer access because initialisation is not done yet. Fixes: 9d7ee0e28da59 ("tty: serial: lpuart: avoid report NULL interrupt") Signed-off-by: Indan Zupancic <Indan.Zupancic@mep-info.com> --- drivers/tty/serial/fsl_lpuart.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-)