Re: [PATCH] powerpc: 8xx: fix a return value error in mpc8xx_pic_init

[Michael Ellerman]

Hangyu Hua <hbh25y@xxxxxxxxx> writes:
> mpc8xx_pic_init() should return -ENOMEM instead of 0 when
> irq_domain_add_linear() return NULL. This cause mpc8xx_pics_init to continue
> executing even if mpc8xx_pic_host is NULL.
>
> Fixes: cc76404feaed ("powerpc/8xx: Fix possible device node reference leak")
> Signed-off-by: Hangyu Hua <hbh25y@xxxxxxxxx>
> ---
>  arch/powerpc/platforms/8xx/pic.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/arch/powerpc/platforms/8xx/pic.c b/arch/powerpc/platforms/8xx/pic.c
> index f2ba837249d6..04a6abf14c29 100644
> --- a/arch/powerpc/platforms/8xx/pic.c
> +++ b/arch/powerpc/platforms/8xx/pic.c
> @@ -153,6 +153,7 @@ int __init mpc8xx_pic_init(void)

Expanding the context:

	siu_reg = ioremap(res.start, resource_size(&res));
	if (siu_reg == NULL) {
		ret = -EINVAL;
		goto out;
	}

	mpc8xx_pic_host = irq_domain_add_linear(np, 64, &mpc8xx_pic_host_ops, NULL);
>  	if (mpc8xx_pic_host == NULL) {
>  		printk(KERN_ERR "MPC8xx PIC: failed to allocate irq host!\n");
>  		ret = -ENOMEM;
> +		goto out;
>  	}
>  
>  	ret = 0;
>  	
out:
	of_node_put(np);
	return ret;
}

Proper error cleanup should also undo the ioremap() if
irq_domain_add_linear() fails.

cheers