Re: [PATCH] powerpc/xive: Fix unsigned comparison with less than zero

[Christophe Leroy <christophe.leroy@csgroup.eu>]

Le 07/05/2021 à 12:20, Jiapeng Chong a écrit :
> The return from the call to irq_domain_alloc_irqs() is int, it can be
> a negative error code, however this is being assigned to an unsigned
> int variable 'irq', this may lead to invalid if statement detection,
> so that kfree execution is invalid. So making 'irq' an int.
> 
> Clean up the following coccicheck warning:
> 
> ./arch/powerpc/sysdev/xive/common.c:1157:6-14: WARNING: Unsigned
> expression compared with zero: xid -> irq < 0.
> 
> Reported-by: Abaci Robot <abaci@linux.alibaba.com>
> Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>

This was fixed by 
https://github.com/linuxppc/linux/commit/3f601608b71c3ca1e199898cd16f09d707fedb56

> ---
>   arch/powerpc/sysdev/xive/common.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/sysdev/xive/common.c b/arch/powerpc/sysdev/xive/common.c
> index a830432..a5fd45a 100644
> --- a/arch/powerpc/sysdev/xive/common.c
> +++ b/arch/powerpc/sysdev/xive/common.c
> @@ -65,7 +65,7 @@
>   #ifdef CONFIG_SMP
>   /* The IPIs use the same logical irq number when on the same chip */
>   static struct xive_ipi_desc {
> -	unsigned int irq;
> +	int irq;
>   	char name[16];
>   } *xive_ipis;
>