Re: [PATCH] MIPS: SGI-IP27: Fix use of unchecked pointer in shutdown_bridge_irq

[Mukesh Ojha]

On 3/28/2019 7:07 PM, Thomas Bogendoerfer wrote:
> smatch complaint:
>
>      arch/mips/sgi-ip27/ip27-irq.c:123 shutdown_bridge_irq()
>      warn: variable dereferenced before check 'hd' (see line 121)
>
> Fix it by removing local variable and use hd->pin directly.
>
> Fixes: 69a07a41d908 ("MIPS: SGI-IP27: rework HUB interrupts")
> Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@xxxxxxx>


Reviewed-by: Mukesh Ojha <mojha@xxxxxxxxxxxxxx>

-Mukesh

> ---
>   arch/mips/sgi-ip27/ip27-irq.c | 3 +--
>   1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/arch/mips/sgi-ip27/ip27-irq.c b/arch/mips/sgi-ip27/ip27-irq.c
> index 710a59764b01..a32f843cdbe0 100644
> --- a/arch/mips/sgi-ip27/ip27-irq.c
> +++ b/arch/mips/sgi-ip27/ip27-irq.c
> @@ -118,7 +118,6 @@ static void shutdown_bridge_irq(struct irq_data *d)
>   {
>   	struct hub_irq_data *hd = irq_data_get_irq_chip_data(d);
>   	struct bridge_controller *bc;
> -	int pin = hd->pin;
>   
>   	if (!hd)
>   		return;
> @@ -126,7 +125,7 @@ static void shutdown_bridge_irq(struct irq_data *d)
>   	disable_hub_irq(d);
>   
>   	bc = hd->bc;
> -	bridge_clr(bc, b_int_enable, (1 << pin));
> +	bridge_clr(bc, b_int_enable, (1 << hd->pin));
>   	bridge_read(bc, b_wid_tflush);
>   }
>