[PATCH v3 07/11] spi: Use helper for safer setting of driver_override

Krzysztof Kozlowski
2022-02-27T13:53:43Z

Use a helper for seting driver_override to reduce amount of duplicated
code.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
---
drivers/spi/spi.c | 26 ++++----------------------
include/linux/spi/spi.h | 2 ++
2 files changed, 6 insertions(+), 22 deletions(-)

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 4599b121d744..9d0b11017741 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -72,29 +72,11 @@ static ssize_t driver_override_store(struct device *dev,
const char *buf, size_t count)
{
struct spi_device *spi = to_spi_device(dev);
- const char *end = memchr(buf, '\n', count);
- const size_t len = end ? end - buf : count;
- const char *driver_override, *old;
-
- /* We need to keep extra room for a newline when displaying value */
- if (len >= (PAGE_SIZE - 1))
- return -EINVAL;
-
- driver_override = kstrndup(buf, len, GFP_KERNEL);
- if (!driver_override)
- return -ENOMEM;
+ int ret;

- device_lock(dev);
- old = spi->driver_override;
- if (len) {
- spi->driver_override = driver_override;
- } else {
- /* Empty string, disable driver override */
- spi->driver_override = NULL;
- kfree(driver_override);
- }
- device_unlock(dev);
- kfree(old);
+ ret = driver_set_override(dev, &spi->driver_override, buf, count);
+ if (ret)
+ return ret;

return count;
}
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index 7ab3fed7b804..f99bbb20dd4b 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -136,6 +136,8 @@ extern int spi_delay_exec(struct spi_delay *_delay, struct spi_transfer *xfer);
* for driver coldplugging, and in uevents used for hotplugging
* @driver_override: If the name of a driver is written to this attribute, then
* the device will bind to the named driver and only the named driver.
+ * Do not set directly, because core frees it; use driver_set_override() to
+ * set or clear it.
* @cs_gpio: LEGACY: gpio number of the chipselect line (optional, -ENOENT when
* not using a GPIO line) use cs_gpiod in new drivers by opting in on
* the spi_master.
--
2.32.0