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[79.19.52.27]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-37d081f7035sm1705056f8f.23.2024.10.03.10.34.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 03 Oct 2024 10:34:39 -0700 (PDT) From: Matteo Martelli Date: Thu, 03 Oct 2024 19:34:06 +0200 Subject: [PATCH 1/7] iio: core: add read_avail_release_resource callback to fix race Precedence: bulk X-Mailing-List: linux-iio@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20241003-iio-read-avail-release-v1-1-c70cc7d9c2e0@gmail.com> References: <20241003-iio-read-avail-release-v1-0-c70cc7d9c2e0@gmail.com> In-Reply-To: <20241003-iio-read-avail-release-v1-0-c70cc7d9c2e0@gmail.com> To: Jonathan Cameron , Lars-Peter Clausen , Michael Hennerich , Alisa-Dariana Roman , Christian Eggers , Peter Rosin , Paul Cercueil , Sebastian Reichel Cc: linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, linux-pm@vger.kernel.org, Matteo Martelli X-Mailer: b4 0.14.2 Some iio drivers currently share an available info buffer that might be changed while iio core prints it to sysfs. To avoid the buffer corruption, add a release callback to let iio drivers allocate a copy of the available info buffer and later free it in the release callback. Such control is kept in the driver logic so that some driver that needs a big available info buffer might also perform some check to keep the copied buffer around in case no race has occurred. Signed-off-by: Matteo Martelli --- drivers/iio/industrialio-core.c | 14 +++++++++++--- include/linux/iio/iio.h | 4 ++++ 2 files changed, 15 insertions(+), 3 deletions(-) diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c index 6a6568d4a2cb3a3f63381d5a6f25a2881b3ba2ed..4aea9de9f15a4d70f9d02fb3d47df49eef8c8423 100644 --- a/drivers/iio/industrialio-core.c +++ b/drivers/iio/industrialio-core.c @@ -859,12 +859,20 @@ static ssize_t iio_read_channel_info_avail(struct device *dev, return ret; switch (ret) { case IIO_AVAIL_LIST: - return iio_format_avail_list(buf, vals, type, length); + ret = iio_format_avail_list(buf, vals, type, length); + break; case IIO_AVAIL_RANGE: - return iio_format_avail_range(buf, vals, type); + ret = iio_format_avail_range(buf, vals, type); + break; default: - return -EINVAL; + ret = -EINVAL; } + + if (indio_dev->info->read_avail_release_resource) + indio_dev->info->read_avail_release_resource( + indio_dev, this_attr->c, vals, this_attr->address); + + return ret; } /** diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h index 18779b631e9071801958fc9d50b941b548fab940..55326f0310b2e9b3fa561c4728e7eabe1d7a5e78 100644 --- a/include/linux/iio/iio.h +++ b/include/linux/iio/iio.h @@ -491,6 +491,10 @@ struct iio_info { int *length, long mask); + void (*read_avail_release_resource)(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + const int *vals, long mask); + int (*write_raw)(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int val,