[PATCH v3] driver-staging: vsoc.c: Add sysfs support for examining the permissions of regions.
dan.carpenter at oracle.com
Fri Nov 9 17:15:58 UTC 2018
On Wed, Nov 07, 2018 at 10:30:43AM +0800, Jerry Lin wrote:
> Add a attribute called permissions under vsoc device node for examining
> current granted permissions in vsoc_device.
> This file will display permissions in following format:
> begin_offset end_offset owner_offset owned_value
> %x %x %x %x
(I'm not totally an expert on sysfs rules).
Sysfs are supposed to be one value per file, so instead of doing this
you would create a directory with four files like
vsoc_device/begin_offset vsoc_device/end_offset etc. And each would
just hae a %x output.
> +static ssize_t permissions_show(struct device *dev,
> + struct device_attribute *attr,
> + char *buffer)
> + struct fd_scoped_permission_node *node;
> + char *row;
> + int ret;
> + ssize_t written = 0;
> + row = kzalloc(sizeof(char) * 128, GFP_KERNEL);
> + if (!row)
> + return 0;
Don't allocate this, just snprintf() directly into the buffer.
More information about the devel