2022-03-12 18:07:01

by Krzysztof Kozlowski

Subject: [PATCH v4 08/11] vdpa: Use helper for safer setting of driver_override

Use a helper to set driver_override to reduce amount of duplicated code.

Signed-off-by: Krzysztof Kozlowski <[email protected]>
---
drivers/vdpa/vdpa.c | 29 ++++-------------------------
include/linux/vdpa.h | 4 +++-
2 files changed, 7 insertions(+), 26 deletions(-)

diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
index 1ea525433a5c..2dabed1df35c 100644
--- a/drivers/vdpa/vdpa.c
+++ b/drivers/vdpa/vdpa.c
@@ -77,32 +77,11 @@ static ssize_t driver_override_store(struct device *dev,
const char *buf, size_t count)
{
struct vdpa_device *vdev = dev_to_vdpa(dev);
- const char *driver_override, *old;
- char *cp;
+ int ret;

- /* We need to keep extra room for a newline */
- if (count >= (PAGE_SIZE - 1))
- return -EINVAL;
-
- driver_override = kstrndup(buf, count, GFP_KERNEL);
- if (!driver_override)
- return -ENOMEM;
-
- cp = strchr(driver_override, '\n');
- if (cp)
- *cp = '\0';
-
- device_lock(dev);
- old = vdev->driver_override;
- if (strlen(driver_override)) {
- vdev->driver_override = driver_override;
- } else {
- kfree(driver_override);
- vdev->driver_override = NULL;
- }
- device_unlock(dev);
-
- kfree(old);
+ ret = driver_set_override(dev, &vdev->driver_override, buf, count);
+ if (ret)
+ return ret;

return count;
}
diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
index 721089bb4c84..37117404660e 100644
--- a/include/linux/vdpa.h
+++ b/include/linux/vdpa.h
@@ -64,7 +64,9 @@ struct vdpa_mgmt_dev;
* struct vdpa_device - representation of a vDPA device
* @dev: underlying device
* @dma_dev: the actual device that is performing DMA
- * @driver_override: driver name to force a match
+ * @driver_override: driver name to force a match; do not set directly,
+ * because core frees it; use driver_set_override() to
+ * set or clear it.
* @config: the configuration ops for this device.
* @cf_mutex: Protects get and set access to configuration layout.
* @index: device index
--
2.32.0

2022-03-15 14:55:44

by Michael S. Tsirkin

Subject: Re: [PATCH v4 08/11] vdpa: Use helper for safer setting of driver_override

On Sat, Mar 12, 2022 at 02:28:53PM +0100, Krzysztof Kozlowski wrote:
> Use a helper to set driver_override to reduce amount of duplicated code.
>
> Signed-off-by: Krzysztof Kozlowski <[email protected]>

Acked-by: Michael S. Tsirkin <[email protected]>

> ---
> drivers/vdpa/vdpa.c | 29 ++++-------------------------
> include/linux/vdpa.h | 4 +++-
> 2 files changed, 7 insertions(+), 26 deletions(-)
>
> diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
> index 1ea525433a5c..2dabed1df35c 100644
> --- a/drivers/vdpa/vdpa.c
> +++ b/drivers/vdpa/vdpa.c
> @@ -77,32 +77,11 @@ static ssize_t driver_override_store(struct device *dev,
> const char *buf, size_t count)
> {
> struct vdpa_device *vdev = dev_to_vdpa(dev);
> - const char *driver_override, *old;
> - char *cp;
> + int ret;
>
> - /* We need to keep extra room for a newline */
> - if (count >= (PAGE_SIZE - 1))
> - return -EINVAL;
> -
> - driver_override = kstrndup(buf, count, GFP_KERNEL);
> - if (!driver_override)
> - return -ENOMEM;
> -
> - cp = strchr(driver_override, '\n');
> - if (cp)
> - *cp = '\0';
> -
> - device_lock(dev);
> - old = vdev->driver_override;
> - if (strlen(driver_override)) {
> - vdev->driver_override = driver_override;
> - } else {
> - kfree(driver_override);
> - vdev->driver_override = NULL;
> - }
> - device_unlock(dev);
> -
> - kfree(old);
> + ret = driver_set_override(dev, &vdev->driver_override, buf, count);
> + if (ret)
> + return ret;
>
> return count;
> }
> diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
> index 721089bb4c84..37117404660e 100644
> --- a/include/linux/vdpa.h
> +++ b/include/linux/vdpa.h
> @@ -64,7 +64,9 @@ struct vdpa_mgmt_dev;
> * struct vdpa_device - representation of a vDPA device
> * @dev: underlying device
> * @dma_dev: the actual device that is performing DMA
> - * @driver_override: driver name to force a match
> + * @driver_override: driver name to force a match; do not set directly,
> + * because core frees it; use driver_set_override() to
> + * set or clear it.
> * @config: the configuration ops for this device.
> * @cf_mutex: Protects get and set access to configuration layout.
> * @index: device index
> --
> 2.32.0

2022-03-17 01:25:25

by Michael S. Tsirkin

Subject: Re: [PATCH v4 08/11] vdpa: Use helper for safer setting of driver_override

On Sat, Mar 12, 2022 at 02:28:53PM +0100, Krzysztof Kozlowski wrote:
> Use a helper to set driver_override to reduce amount of duplicated code.
>
> Signed-off-by: Krzysztof Kozlowski <[email protected]>

Acked-by: Michael S. Tsirkin <[email protected]>

feel free to merge with the rest of the patchset.

> ---
> drivers/vdpa/vdpa.c | 29 ++++-------------------------
> include/linux/vdpa.h | 4 +++-
> 2 files changed, 7 insertions(+), 26 deletions(-)
>
> diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
> index 1ea525433a5c..2dabed1df35c 100644
> --- a/drivers/vdpa/vdpa.c
> +++ b/drivers/vdpa/vdpa.c
> @@ -77,32 +77,11 @@ static ssize_t driver_override_store(struct device *dev,
> const char *buf, size_t count)
> {
> struct vdpa_device *vdev = dev_to_vdpa(dev);
> - const char *driver_override, *old;
> - char *cp;
> + int ret;
>
> - /* We need to keep extra room for a newline */
> - if (count >= (PAGE_SIZE - 1))
> - return -EINVAL;
> -
> - driver_override = kstrndup(buf, count, GFP_KERNEL);
> - if (!driver_override)
> - return -ENOMEM;
> -
> - cp = strchr(driver_override, '\n');
> - if (cp)
> - *cp = '\0';
> -
> - device_lock(dev);
> - old = vdev->driver_override;
> - if (strlen(driver_override)) {
> - vdev->driver_override = driver_override;
> - } else {
> - kfree(driver_override);
> - vdev->driver_override = NULL;
> - }
> - device_unlock(dev);
> -
> - kfree(old);
> + ret = driver_set_override(dev, &vdev->driver_override, buf, count);
> + if (ret)
> + return ret;
>
> return count;
> }
> diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
> index 721089bb4c84..37117404660e 100644
> --- a/include/linux/vdpa.h
> +++ b/include/linux/vdpa.h
> @@ -64,7 +64,9 @@ struct vdpa_mgmt_dev;
> * struct vdpa_device - representation of a vDPA device
> * @dev: underlying device
> * @dma_dev: the actual device that is performing DMA
> - * @driver_override: driver name to force a match
> + * @driver_override: driver name to force a match; do not set directly,
> + * because core frees it; use driver_set_override() to
> + * set or clear it.
> * @config: the configuration ops for this device.
> * @cf_mutex: Protects get and set access to configuration layout.
> * @index: device index
> --
> 2.32.0