MALI: utgard: upgrade DDK to r6p1-01rel0

[firefly-linux-kernel-4.4.55.git] / kernel / capability.c

diff --git a/kernel/capability.c b/kernel/capability.c
index 00411c82dac57c4cac0254c823f9adcb2a951549..4984e1f552ebfb97fa460b527b35c67ebd0f324d 100644 (file)
--- a/kernel/capability.c
+++ b/kernel/capability.c
@@ -456,6 +456,19 @@ bool file_ns_capable(const struct file *file, struct user_namespace *ns,
 }
 EXPORT_SYMBOL(file_ns_capable);
 
+/**
+ * privileged_wrt_inode_uidgid - Do capabilities in the namespace work over the inode?
+ * @ns: The user namespace in question
+ * @inode: The inode in question
+ *
+ * Return true if the inode uid and gid are within the namespace.
+ */
+bool privileged_wrt_inode_uidgid(struct user_namespace *ns, const struct inode *inode)
+{
+       return kuid_has_mapping(ns, inode->i_uid) &&
+               kgid_has_mapping(ns, inode->i_gid);
+}
+
 /**
  * capable_wrt_inode_uidgid - Check nsown_capable and uid and gid mapped
  * @inode: The inode in question
@@ -469,7 +482,26 @@ bool capable_wrt_inode_uidgid(const struct inode *inode, int cap)
 {
        struct user_namespace *ns = current_user_ns();
 
-       return ns_capable(ns, cap) && kuid_has_mapping(ns, inode->i_uid) &&
-               kgid_has_mapping(ns, inode->i_gid);
+       return ns_capable(ns, cap) && privileged_wrt_inode_uidgid(ns, inode);
 }
 EXPORT_SYMBOL(capable_wrt_inode_uidgid);
+
+/**
+ * ptracer_capable - Determine if the ptracer holds CAP_SYS_PTRACE in the namespace
+ * @tsk: The task that may be ptraced
+ * @ns: The user namespace to search for CAP_SYS_PTRACE in
+ *
+ * Return true if the task that is ptracing the current task had CAP_SYS_PTRACE
+ * in the specified user namespace.
+ */
+bool ptracer_capable(struct task_struct *tsk, struct user_namespace *ns)
+{
+       int ret = 0;  /* An absent tracer adds no restrictions */
+       const struct cred *cred;
+       rcu_read_lock();
+       cred = rcu_dereference(tsk->ptracer_cred);
+       if (cred)
+               ret = security_capable_noaudit(cred, ns, CAP_SYS_PTRACE);
+       rcu_read_unlock();
+       return (ret == 0);
+}