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Date:   Fri, 13 Oct 2023 22:58:02 +0300
From:   Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To:     Hongren Zheng <i@zenithal.me>
Cc:     Shuah Khan <shuah@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Valentina Manea <valentina.manea.m@gmail.com>,
        linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
        sfr@canb.auug.org.au
Subject: Re: [PATCH -next] usb/usbip: fix wrong data added to platform device
Message-ID: <ZSmhSozvQfggY8Cg@smile.fi.intel.com>
References: <ZSkhWa5wmAGsAdCK@Sun>
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Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo
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On Fri, Oct 13, 2023 at 06:52:09PM +0800, Hongren Zheng wrote:
> .data of platform_device_info will be copied into .platform_data of
> struct device via platform_device_add_data.
> 
> However, vhcis[i] contains a spinlock, is dynamically allocated and
> used by other code, so it is not meant to be copied. The workaround
> was to use void *vhci as an agent, but it was removed in the commit
> suggested below.
> 
> This patch adds back the workaround and changes the way of using
> platform_data accordingly.

...


One more thing...

>  static int __init vhci_hcd_init(void)
>  {
>  	int i, ret;
> +	void *vhci;
>  
>  	if (usb_disabled())
>  		return -ENODEV;
> @@ -1522,10 +1522,11 @@ static int __init vhci_hcd_init(void)
>  		goto err_driver_register;
>  
>  	for (i = 0; i < vhci_num_controllers; i++) {

> +		vhci = &vhcis[i];

This should be

		void *vhci = &vhcis[i];

because otherwise we mix code and definitions which is not so good style. (Yet
we allow to do that in exceptional cases: 1) iterators in for-loops, and 2)
RAII allocations with __free() in use.)

>  		struct platform_device_info pdevinfo = {
>  			.name = driver_name,
>  			.id = i,
> -			.data = &vhcis[i],
> +			.data = &vhci,
>  			.size_data = sizeof(void *),
>  		};

-- 
With Best Regards,
Andy Shevchenko