mfc: silence enum conversion warning

[GitHub/exynos8895/android_kernel_samsung_universal8895.git] / kernel / cgroup_freezer.c

diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c
index 2d3df82c54f2dd84484e0b4d739551cb69861e4e..1314c0908852ad02e642fd54d65e897839f71807 100644 (file)
--- a/kernel/cgroup_freezer.c
+++ b/kernel/cgroup_freezer.c
@@ -450,6 +450,40 @@ static u64 freezer_parent_freezing_read(struct cgroup_subsys_state *css,
        return (bool)(freezer->state & CGROUP_FREEZING_PARENT);
 }
 
+#ifdef CONFIG_SAMSUNG_FREECESS
+/**
+ * Check if the task is allowed to be added to the freezer group
+ * only the admin can add the task to the freezer group.
+ */
+static int freezer_can_attach(struct cgroup_taskset *tset)
+{
+       const struct cred *cred = current_cred(), *tcred;
+       struct task_struct *task;
+       struct cgroup_subsys_state *css;
+
+       cgroup_taskset_for_each(task, css, tset) {
+               tcred = __task_cred(task);
+
+               //Only system process and root have the permission.
+               if ((current != task) && !(cred->euid.val == 1000 || capable(CAP_SYS_ADMIN))) {
+                       pr_err("Permission problem\n");
+                       return -EACCES;
+               }
+       }
+
+       return 0;
+}
+
+/**
+ * Cancel the attach action when it failed. It's usually used to restore the attach action.
+ * But freezer attach just sends the signal, it will always success.
+ * So, it doesn't need to restore any action.
+ */
+static void freezer_cancel_attach(struct cgroup_taskset *tset)
+{
+}
+#endif
+
 static struct cftype files[] = {
        {
                .name = "state",
@@ -478,4 +512,8 @@ struct cgroup_subsys freezer_cgrp_subsys = {
        .attach         = freezer_attach,
        .fork           = freezer_fork,
        .legacy_cftypes = files,
+#ifdef CONFIG_SAMSUNG_FREECESS
+       .can_attach   = freezer_can_attach,
+       .cancel_attach  = freezer_cancel_attach,
+#endif
 };