From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2E160BE6C; Sun, 6 Oct 2024 14:18:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728224301; cv=none; b=T472JhidskYRfgP7mvc/HDC6EPMXAJ0C8VZxEXqlFvbgvELH6wb+66nSlhui8avgVzXgajBzMNtrd4l/siDO9de4cU52OtmOs+GBjcesOnKcQPzJQjGxZdHLDzVD8fwU+ByNbkoVh6/1tYduBMscsTf3G9ynd0FLG1W7KXltmF4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728224301; c=relaxed/simple; bh=E8zE0FPsM+NzL95TqGQap5qX0jjVRpxwP9HfacedVHs=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=BHpTcw1zOd10m7gWLyvYEv/JdOod8SyFjNFZvGgQlKeSpxsihU78NnEE8atyc5qVAytYV5CZ+Kmth4uq+x8DGjRFo8i5lSDBN0TQFlLtDW/tTFw93dg31k3WWOdx1BOEoX0/91E/sxXQN7KL3olg3cyoc6hB8vstc0/YNHP2yQg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=MDh93Va/; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="MDh93Va/" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AEA9FC4CEC5; Sun, 6 Oct 2024 14:18:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1728224299; bh=E8zE0FPsM+NzL95TqGQap5qX0jjVRpxwP9HfacedVHs=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=MDh93Va/uuUFTCyNQX2nqRgg4FYnJRThIyMxO1hQRC7ZogUl0PNDI7Dh1bjlhO64K wCDC1kYCle7KZrj50znm5xcbUTgzb1piH9WjRoj37UFFb5i+JLwAwODcJfLSn6bSj0 7Ho+lrhbHdTVGFsbM1bz6C1CjUI9L/VMahBmmSQDyfi/kzidZNaQUHZGrvch0I03Jf 2+OTnym5wCqNrFMlglRaXBDGiuw3oFFj8bB6pjxRyjVyc7knc5tVuO1ETEknCUq9zH cWyInpnjWkX+EUaqAiEKIog7uQaIXp0LrYG66TfkdypoWKfMdDpk1SkdPMylCvhtQr hCkuF02Y1+jEQ== Date: Sun, 6 Oct 2024 15:18:08 +0100 From: Jonathan Cameron To: Matteo Martelli Cc: Lars-Peter Clausen , Michael Hennerich , Alisa-Dariana Roman , Christian Eggers , Peter Rosin , Paul Cercueil , Sebastian Reichel , linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, linux-pm@vger.kernel.org Subject: Re: [PATCH 4/7] iio: as73211: copy/release available integration times to fix race Message-ID: <20241006151808.1310db7d@jic23-huawei> In-Reply-To: <20241003-iio-read-avail-release-v1-4-c70cc7d9c2e0@gmail.com> References: <20241003-iio-read-avail-release-v1-0-c70cc7d9c2e0@gmail.com> <20241003-iio-read-avail-release-v1-4-c70cc7d9c2e0@gmail.com> X-Mailer: Claws Mail 4.3.0 (GTK 3.24.43; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-mips@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Thu, 03 Oct 2024 19:34:09 +0200 Matteo Martelli wrote: > While available integration times are being printed to sysfs by iio core > (iio_read_channel_info_avail), the sampling frequency might be changed. > This could cause the buffer shared with iio core to be corrupted. To > prevent it, make a copy of the integration times buffer and free it in > the read_avail_release_resource callback. > > Signed-off-by: Matteo Martelli > --- > drivers/iio/light/as73211.c | 23 ++++++++++++++++++++--- > 1 file changed, 20 insertions(+), 3 deletions(-) > > diff --git a/drivers/iio/light/as73211.c b/drivers/iio/light/as73211.c > index be0068081ebbbb37fdfb252b67a77b302ff725f6..520c898e0ff9c530b4fdd45589559f9014d7992c 100644 > --- a/drivers/iio/light/as73211.c > +++ b/drivers/iio/light/as73211.c > @@ -493,17 +493,33 @@ static int as73211_read_avail(struct iio_dev *indio_dev, struct iio_chan_spec co > *type = IIO_VAL_INT; > return IIO_AVAIL_LIST; > > - case IIO_CHAN_INFO_INT_TIME: > + case IIO_CHAN_INFO_INT_TIME: { > *length = ARRAY_SIZE(data->int_time_avail); > - *vals = data->int_time_avail; > *type = IIO_VAL_INT_PLUS_MICRO; > - return IIO_AVAIL_LIST; > > + guard(mutex)(&data->mutex); > + > + *vals = kmemdup_array(data->int_time_avail, *length, > + sizeof(int), GFP_KERNEL); > + if (!*vals) > + return -ENOMEM; > + > + return IIO_AVAIL_LIST; > + } > default: > return -EINVAL; > } > } > > +static void as73211_read_avail_release_res(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + const int *vals, long mask) > +{ > + if (mask == IIO_CHAN_INFO_INT_TIME) > + kfree(vals); > +} > + Trivial but one blank line is enough. If there is no other feedback on the series I can tidy this up whilst applying. > + > static int _as73211_write_raw(struct iio_dev *indio_dev, > struct iio_chan_spec const *chan __always_unused, > int val, int val2, long mask) > @@ -699,6 +715,7 @@ static irqreturn_t as73211_trigger_handler(int irq __always_unused, void *p) > static const struct iio_info as73211_info = { > .read_raw = as73211_read_raw, > .read_avail = as73211_read_avail, > + .read_avail_release_resource = as73211_read_avail_release_res, > .write_raw = as73211_write_raw, > }; > >