On 10/24/19 5:47 PM, Nayna Jain wrote:
+static ssize_t size_show(struct kobject *kobj, struct kobj_attribute *attr,
+ char *buf)
+{
+ uint64_t dsize;
+ int rc;
+
+ rc = secvar_ops->get(kobj->name, strlen(kobj->name) + 1, NULL, &dsize);
+ if (rc) {
+ pr_err("Error retrieving variable size %d\n", rc);
+ return rc;
+ }
+
+ rc = sprintf(buf, "%llu\n", dsize);
+
+ return rc;
+}
nit: change it to "return sprintf(buf, "%llu\n", dsize);" instead.
+
+static ssize_t data_read(struct file *filep, struct kobject *kobj,
+ struct bin_attribute *attr, char *buf, loff_t off,
+ size_t count)
+{
+ uint64_t dsize;
+ char *data;
+ int rc;
+
+ rc = secvar_ops->get(kobj->name, strlen(kobj->name) + 1, NULL, &dsize);
+ if (rc) {
+ pr_err("Error getting variable size %d\n", rc);
+ return rc;
+ }
+ pr_debug("dsize is %llu\n", dsize);
+
+ data = kzalloc(dsize, GFP_KERNEL);
Is there any MAX\MIN limit on dsize that can be returned by secvar_ops?
Is it ok to not validate the dsize
+
+static ssize_t update_write(struct file *filep, struct kobject *kobj,
+ struct bin_attribute *attr, char *buf, loff_t off,
+ size_t count)
+{
+ int rc;
+
+ pr_debug("count is %ld\n", count);
+ rc = secvar_ops->set(kobj->name, strlen(kobj->name)+1, buf, count);
+ if (rc) {
+ pr_err("Error setting the variable %s\n", kobj->name);
+ return rc;
+ }
+
+ return count;
+}
Return value from this function can be a count (of bytes in buf?) or
error code. Could cause confusion.
+
+static int secvar_sysfs_load(void)
+{
+ char *name;
+ uint64_t namesize = 0;
+ struct kobject *kobj;
+ int rc;
+
+ name = kzalloc(NAME_MAX_SIZE, GFP_KERNEL);
+ if (!name)
+ return -ENOMEM;
+
+ do {
+ rc = secvar_ops->get_next(name, &namesize, NAME_MAX_SIZE);
+ if (rc) {
+ if (rc != -ENOENT)
+ pr_err("error getting secvar from firmware
%d\n",
+ rc);
+ break;
+ }
+
+ kobj = kzalloc(sizeof(*kobj), GFP_KERNEL);
+ if (!kobj)
+ return -ENOMEM;
Memory allocated for "name" is leaked in this case.
+
+ kobject_init(kobj, &secvar_ktype);
+
+ rc = kobject_add(kobj, &secvar_kset->kobj, "%s", name);
+ if (rc) {
+ pr_warn("kobject_add error %d for attribute: %s\n", rc,
+ name);
+ kobject_put(kobj);
+ kobj = NULL;
+ }
+
+ if (kobj)
+ kobject_uevent(kobj, KOBJ_ADD);
+
+ } while (!rc);
+
+ kfree(name);
+ return rc;
+}
