linux-kernel - Re: [PATCH] x86, olpc: Avoid leak OF node on error

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Message-ID: <74b7b668-a1f6-596f-8000-041f9ca7b181@redhat.com>
Date:   Mon, 23 May 2022 13:53:18 +0200
From:   Hans de Goede <hdegoede@...hat.com>
To:     cgel.zte@...il.com, dvhart@...radead.org
Cc:     andy@...radead.org, tglx@...utronix.de,
        platform-driver-x86@...r.kernel.org, linux-kernel@...r.kernel.org,
        Minghao Chi <chi.minghao@....com.cn>,
        Zeal Robot <zealci@....com.cn>
Subject: Re: [PATCH] x86, olpc: Avoid leak OF node on error

Hi,

On 5/23/22 13:12, cgel.zte@...il.com wrote:
> From: Minghao Chi <chi.minghao@....com.cn>
> 
> The OF node should be put before returning error in xo1_rtc_init(),
> otherwise node's refcount will be leaked.
> 
> Reported-by: Zeal Robot <zealci@....com.cn>
> Signed-off-by: Minghao Chi <chi.minghao@....com.cn>
> ---
>  arch/x86/platform/olpc/olpc-xo1-rtc.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/x86/platform/olpc/olpc-xo1-rtc.c b/arch/x86/platform/olpc/olpc-xo1-rtc.c
> index 57f210cda761..dc5ac56cd9dd 100644
> --- a/arch/x86/platform/olpc/olpc-xo1-rtc.c
> +++ b/arch/x86/platform/olpc/olpc-xo1-rtc.c
> @@ -59,9 +59,9 @@ static int __init xo1_rtc_init(void)
>  	struct device_node *node;
>  
>  	node = of_find_compatible_node(NULL, NULL, "olpc,xo1-rtc");
> +	of_node_put(node);
>  	if (!node)
>  		return 0;
> -	of_node_put(node);
>  
>  	pr_info("olpc-xo1-rtc: Initializing OLPC XO-1 RTC\n");
>  	rdmsrl(MSR_RTC_DOMA_OFFSET, rtc_info.rtc_day_alarm);

of_node_put on a NULL node is a no-op, so this patch
does not make any functional difference and it makes the
code harder to read.

nack.

Regards,

Hans