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-rw-r--r--samples/kobject/kset-example.c44
1 files changed, 30 insertions, 14 deletions
diff --git a/samples/kobject/kset-example.c b/samples/kobject/kset-example.c
index 579ce150217c..d0103904e5dd 100644
--- a/samples/kobject/kset-example.c
+++ b/samples/kobject/kset-example.c
@@ -37,10 +37,11 @@ struct foo_obj {
/* a custom attribute that works just for a struct foo_obj. */
struct foo_attribute {
struct attribute attr;
- ssize_t (*show)(struct foo_obj *foo, struct foo_attribute *attr, char *buf);
- ssize_t (*store)(struct foo_obj *foo, struct foo_attribute *attr, const char *buf, size_t count);
+ ssize_t (*show)(struct foo_obj *foo, const struct foo_attribute *attr, char *buf);
+ ssize_t (*store)(struct foo_obj *foo, const struct foo_attribute *attr,
+ const char *buf, size_t count);
};
-#define to_foo_attr(x) container_of(x, struct foo_attribute, attr)
+#define to_foo_attr(x) container_of_const(x, struct foo_attribute, attr)
/*
* The default show function that must be passed to sysfs. This will be
@@ -53,7 +54,7 @@ static ssize_t foo_attr_show(struct kobject *kobj,
struct attribute *attr,
char *buf)
{
- struct foo_attribute *attribute;
+ const struct foo_attribute *attribute;
struct foo_obj *foo;
attribute = to_foo_attr(attr);
@@ -73,7 +74,7 @@ static ssize_t foo_attr_store(struct kobject *kobj,
struct attribute *attr,
const char *buf, size_t len)
{
- struct foo_attribute *attribute;
+ const struct foo_attribute *attribute;
struct foo_obj *foo;
attribute = to_foo_attr(attr);
@@ -109,13 +110,13 @@ static void foo_release(struct kobject *kobj)
/*
* The "foo" file where the .foo variable is read from and written to.
*/
-static ssize_t foo_show(struct foo_obj *foo_obj, struct foo_attribute *attr,
+static ssize_t foo_show(struct foo_obj *foo_obj, const struct foo_attribute *attr,
char *buf)
{
return sysfs_emit(buf, "%d\n", foo_obj->foo);
}
-static ssize_t foo_store(struct foo_obj *foo_obj, struct foo_attribute *attr,
+static ssize_t foo_store(struct foo_obj *foo_obj, const struct foo_attribute *attr,
const char *buf, size_t count)
{
int ret;
@@ -128,14 +129,14 @@ static ssize_t foo_store(struct foo_obj *foo_obj, struct foo_attribute *attr,
}
/* Sysfs attributes cannot be world-writable. */
-static struct foo_attribute foo_attribute =
+static const struct foo_attribute foo_attribute =
__ATTR(foo, 0664, foo_show, foo_store);
/*
* More complex function where we determine which variable is being accessed by
* looking at the attribute for the "baz" and "bar" files.
*/
-static ssize_t b_show(struct foo_obj *foo_obj, struct foo_attribute *attr,
+static ssize_t b_show(struct foo_obj *foo_obj, const struct foo_attribute *attr,
char *buf)
{
int var;
@@ -147,7 +148,7 @@ static ssize_t b_show(struct foo_obj *foo_obj, struct foo_attribute *attr,
return sysfs_emit(buf, "%d\n", var);
}
-static ssize_t b_store(struct foo_obj *foo_obj, struct foo_attribute *attr,
+static ssize_t b_store(struct foo_obj *foo_obj, const struct foo_attribute *attr,
const char *buf, size_t count)
{
int var, ret;
@@ -163,22 +164,37 @@ static ssize_t b_store(struct foo_obj *foo_obj, struct foo_attribute *attr,
return count;
}
-static struct foo_attribute baz_attribute =
+static const struct foo_attribute baz_attribute =
__ATTR(baz, 0664, b_show, b_store);
-static struct foo_attribute bar_attribute =
+static const struct foo_attribute bar_attribute =
__ATTR(bar, 0664, b_show, b_store);
/*
* Create a group of attributes so that we can create and destroy them all
* at once.
*/
-static struct attribute *foo_default_attrs[] = {
+static const struct attribute *const foo_default_attrs[] = {
&foo_attribute.attr,
&baz_attribute.attr,
&bar_attribute.attr,
NULL, /* need to NULL terminate the list of attributes */
};
-ATTRIBUTE_GROUPS(foo_default);
+
+static umode_t foo_default_attrs_is_visible(struct kobject *kobj,
+ const struct attribute *attr,
+ int n)
+{
+ /* Hide attributes with the same name as the kobject. */
+ if (strcmp(kobject_name(kobj), attr->name) == 0)
+ return 0;
+ return attr->mode;
+}
+
+static const struct attribute_group foo_default_group = {
+ .attrs_const = foo_default_attrs,
+ .is_visible_const = foo_default_attrs_is_visible,
+};
+__ATTRIBUTE_GROUPS(foo_default);
/*
* Our own ktype for our kobjects. Here we specify our sysfs ops, the