From nobody Fri Oct 17 10:32:19 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4D54DC4332F for ; Wed, 19 Oct 2022 09:10:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232467AbiJSJKn (ORCPT ); Wed, 19 Oct 2022 05:10:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34262 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232427AbiJSJH2 (ORCPT ); Wed, 19 Oct 2022 05:07:28 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3EFC23C8E7; Wed, 19 Oct 2022 01:59:54 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 5933C61866; Wed, 19 Oct 2022 08:58:40 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6800EC433D6; Wed, 19 Oct 2022 08:58:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1666169919; bh=L322BFkuLIvqiR/Get1l0XbzU8LuDpj1WX+7zRzp758=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nNLulaaacM0rT4Q2dJ9lH5LwiAdrzgT/sb/0WCR35c/5RvVPtWt1SFMwB8nRNV+4Y FLl5xYm4NcKKcRz248VSdrhAzlMxN1Sqh3Y5MKrUBpqj6x0A7b1I71UtQe3QU6VZZL e9cK4NzdPT6iQYn9n17qwEFcL4/yf6ZvwlyBZWHM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Claudiu Beznea , Jonathan Cameron , Sasha Levin Subject: [PATCH 6.0 459/862] iio: adc: at91-sama5d2_adc: lock around oversampling and sample freq Date: Wed, 19 Oct 2022 10:29:06 +0200 Message-Id: <20221019083310.272084498@linuxfoundation.org> X-Mailer: git-send-email 2.38.0 In-Reply-To: <20221019083249.951566199@linuxfoundation.org> References: <20221019083249.951566199@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Claudiu Beznea [ Upstream commit 9780a23ed5a0a0a63683e078f576719a98d4fb70 ] .read_raw()/.write_raw() could be called asynchronously from user space or other in kernel drivers. Without locking on st->lock these could be called asynchronously while there is a conversion in progress. Read will be harmless but changing registers while conversion is in progress may lead to inconsistent results. Thus, to avoid this lock st->lock. Fixes: 27e177190891 ("iio:adc:at91_adc8xx: introduce new atmel adc driver") Fixes: 6794e23fa3fe ("iio: adc: at91-sama5d2_adc: add support for oversampl= ing resolution") Signed-off-by: Claudiu Beznea Link: https://lore.kernel.org/r/20220803102855.2191070-4-claudiu.beznea@mic= rochip.com Signed-off-by: Jonathan Cameron Signed-off-by: Sasha Levin --- drivers/iio/adc/at91-sama5d2_adc.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama= 5d2_adc.c index 08d1f806c839..3734ddc82952 100644 --- a/drivers/iio/adc/at91-sama5d2_adc.c +++ b/drivers/iio/adc/at91-sama5d2_adc.c @@ -1542,10 +1542,10 @@ static int at91_adc_read_info_raw(struct iio_dev *i= ndio_dev, ret =3D at91_adc_read_position(st, chan->channel, &tmp_val); *val =3D tmp_val; - mutex_unlock(&st->lock); - iio_device_release_direct_mode(indio_dev); if (ret > 0) ret =3D at91_adc_adjust_val_osr(st, val); + mutex_unlock(&st->lock); + iio_device_release_direct_mode(indio_dev); =20 return ret; } @@ -1558,10 +1558,10 @@ static int at91_adc_read_info_raw(struct iio_dev *i= ndio_dev, ret =3D at91_adc_read_pressure(st, chan->channel, &tmp_val); *val =3D tmp_val; - mutex_unlock(&st->lock); - iio_device_release_direct_mode(indio_dev); if (ret > 0) ret =3D at91_adc_adjust_val_osr(st, val); + mutex_unlock(&st->lock); + iio_device_release_direct_mode(indio_dev); =20 return ret; } @@ -1650,16 +1650,20 @@ static int at91_adc_write_raw(struct iio_dev *indio= _dev, /* if no change, optimize out */ if (val =3D=3D st->oversampling_ratio) return 0; + mutex_lock(&st->lock); st->oversampling_ratio =3D val; /* update ratio */ at91_adc_config_emr(st); + mutex_unlock(&st->lock); return 0; case IIO_CHAN_INFO_SAMP_FREQ: if (val < st->soc_info.min_sample_rate || val > st->soc_info.max_sample_rate) return -EINVAL; =20 + mutex_lock(&st->lock); at91_adc_setup_samp_freq(indio_dev, val); + mutex_unlock(&st->lock); return 0; default: return -EINVAL; --=20 2.35.1