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Date:   Fri, 11 Jun 2021 12:39:59 +0200
From:   Greg KH <gregkh@linuxfoundation.org>
To:     Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Cc:     valentina.manea.m@gmail.com, shuah@kernel.org,
        linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] usbip: tools: usbipd: use ARRAY_SIZE for sockfdlist
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References: <1623406510-50900-1-git-send-email-jiapeng.chong@linux.alibaba.com>
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On Fri, Jun 11, 2021 at 06:15:10PM +0800, Jiapeng Chong wrote:
> Use ARRAY_SIZE instead of dividing sizeof array with sizeof an
> element.
> 
> Clean up the following coccicheck warning:
> 
> ./tools/usb/usbip/src/usbipd.c:536:19-20: WARNING: Use ARRAY_SIZE.

Why are you assuming that coccicheck should be run on userspace code?

> 
> Reported-by: Abaci Robot <abaci@linux.alibaba.com>
> Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
> ---
> Changes in v2:
>   -Add ARRAY_SIZE definition to usbip_common.h file.
> 
>  tools/usb/usbip/libsrc/usbip_common.h | 2 ++
>  tools/usb/usbip/src/usbipd.c          | 3 +--
>  2 files changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/usb/usbip/libsrc/usbip_common.h b/tools/usb/usbip/libsrc/usbip_common.h
> index 73a367a..4e12dc4 100644
> --- a/tools/usb/usbip/libsrc/usbip_common.h
> +++ b/tools/usb/usbip/libsrc/usbip_common.h
> @@ -101,6 +101,8 @@
>  		abort();				\
>  	} while (0)
>  
> +#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))

Why is this needed?

And if it really really is, why not define it in a way that ALL tools
can use it.

And then fix it up be correct for cases when you might call this when it
is not an array.  This is a very naive implementation.

> +
>  struct usbip_usb_interface {
>  	uint8_t bInterfaceClass;
>  	uint8_t bInterfaceSubClass;
> diff --git a/tools/usb/usbip/src/usbipd.c b/tools/usb/usbip/src/usbipd.c
> index 48398a7..4826d13 100644
> --- a/tools/usb/usbip/src/usbipd.c
> +++ b/tools/usb/usbip/src/usbipd.c
> @@ -532,8 +532,7 @@ static int do_standalone_mode(int daemonize, int ipv4, int ipv6)
>  		usbip_driver_close(driver);
>  		return -1;
>  	}
> -	nsockfd = listen_all_addrinfo(ai_head, sockfdlist,
> -		sizeof(sockfdlist) / sizeof(*sockfdlist));
> +	nsockfd = listen_all_addrinfo(ai_head, sockfdlist, ARRAY_SIZE(sockfdlist));

The code here is correct, right?  So this is not necessary unless you do
this for all in-tree userspace tools at the same time.

thanks,

greg k-h