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Date: Thu, 06 Jun 2024 12:34:12 +0200
From: "Arnd Bergmann" <arnd@arndb.de>
To: "He Zhe" <zhe.he@windriver.com>, "Clemens Ladisch" <clemens@ladisch.de>,
 "Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
 linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] hpet: Support 32-bit userspace
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On Thu, Jun 6, 2024, at 11:46, He Zhe wrote:
> v2:
> - Use in_compat_syscall to determine if we're handling 32-bit or 64-bit
> - Drop unnecessary compat_ptr for hpet_ioctl_common
> - Add comment for COMPAT_HPET_INFO and COMPAT_HPET_IRQFREQ

Thanks, this version looks correct to me,

Reviewed-by: Arnd Bergmann <arnd@arndb.de>

I would suggest one simplification though:

> +#ifdef CONFIG_COMPAT
> +	if (in_compat_syscall()) {
> +		if (count < sizeof(compat_ulong_t))
> +			return -EINVAL;
> +	} else {
> +		if (count < sizeof(unsigned long))
> +			return -EINVAL;
> +	}
> +#else
>  	if (count < sizeof(unsigned long))
>  		return -EINVAL;
> +#endif

The #ifdef/#else is not really required here, since
in_compat_syscall() is defined to return false when
this is unset. For both cases, it should be sufficient
to keep the part inside of the #ifdef block.

     Arnd