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 <20240124004028.16826-6-zfigura@codeweavers.com>
Date: Wed, 24 Jan 2024 08:56:52 +0100
From: "Arnd Bergmann" <arnd@arndb.de>
To: "Elizabeth Figura" <zfigura@codeweavers.com>,
 "Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
 linux-kernel@vger.kernel.org, linux-api@vger.kernel.org
Cc: wine-devel@winehq.org,
 =?UTF-8?Q?Andr=C3=A9_Almeida?= <andrealmeid@igalia.com>,
 "Wolfram Sang" <wsa@kernel.org>, "Arkadiusz Hiler" <ahiler@codeweavers.com>,
 "Peter Zijlstra" <peterz@infradead.org>
Subject: Re: [RFC PATCH 5/9] ntsync: Introduce NTSYNC_IOC_WAIT_ANY.
Content-Type: text/plain

On Wed, Jan 24, 2024, at 01:40, Elizabeth Figura wrote:

> +	if (args->timeout) {
> +		struct timespec64 to;
> +
> +		if (get_timespec64(&to, u64_to_user_ptr(args->timeout)))
> +			return -EFAULT;
> +		if (!timespec64_valid(&to))
> +			return -EINVAL;
> +
> +		timeout = timespec64_to_ns(&to);
> +	}

Have you considered just passing the nanosecond value here?
Since you do not appear to write it back, that would avoid
the complexities of dealing with timespec layout differences
and indirection.

> +	ids = kmalloc_array(count, sizeof(*ids), GFP_KERNEL);
> +	if (!ids)
> +		return -ENOMEM;
> +	if (copy_from_user(ids, u64_to_user_ptr(args->objs),
> +			   array_size(count, sizeof(*ids)))) {
> +		kfree(ids);
> +		return -EFAULT;
> +	}

This looks like memdup_user() would be slightly simpler.

      Arnd