PM / Hibernate: Disable usermode helpers right before freezing tasks

[linux-flexiantxendom0-3.2.10.git] / kernel / capability.c

diff --git a/kernel/capability.c b/kernel/capability.c
index 9e9385f..3f1adb6 100644 (file)
--- a/kernel/capability.c
+++ b/kernel/capability.c
@@ -10,10 +10,11 @@
 #include <linux/audit.h>
 #include <linux/capability.h>
 #include <linux/mm.h>
-#include <linux/module.h>
+#include <linux/export.h>
 #include <linux/security.h>
 #include <linux/syscalls.h>
 #include <linux/pid_namespace.h>
+#include <linux/user_namespace.h>
 #include <asm/uaccess.h>
 
 /*
@@ -21,12 +22,8 @@
  */
 
 const kernel_cap_t __cap_empty_set = CAP_EMPTY_SET;
-const kernel_cap_t __cap_full_set = CAP_FULL_SET;
-const kernel_cap_t __cap_init_eff_set = CAP_INIT_EFF_SET;
 
 EXPORT_SYMBOL(__cap_empty_set);
-EXPORT_SYMBOL(__cap_full_set);
-EXPORT_SYMBOL(__cap_init_eff_set);
 
 int file_caps_enabled = 1;
 
@@ -290,7 +287,88 @@ error:
 }
 
 /**
- * capable - Determine if the current task has a superior capability in effect
+ * has_ns_capability - Does a task have a capability in a specific user ns
+ * @t: The task in question
+ * @ns: target user namespace
+ * @cap: The capability to be tested for
+ *
+ * Return true if the specified task has the given superior capability
+ * currently in effect to the specified user namespace, false if not.
+ *
+ * Note that this does not set PF_SUPERPRIV on the task.
+ */
+bool has_ns_capability(struct task_struct *t,
+                      struct user_namespace *ns, int cap)
+{
+       int ret;
+
+       rcu_read_lock();
+       ret = security_capable(__task_cred(t), ns, cap);
+       rcu_read_unlock();
+
+       return (ret == 0);
+}
+
+/**
+ * has_capability - Does a task have a capability in init_user_ns
+ * @t: The task in question
+ * @cap: The capability to be tested for
+ *
+ * Return true if the specified task has the given superior capability
+ * currently in effect to the initial user namespace, false if not.
+ *
+ * Note that this does not set PF_SUPERPRIV on the task.
+ */
+bool has_capability(struct task_struct *t, int cap)
+{
+       return has_ns_capability(t, &init_user_ns, cap);
+}
+
+/**
+ * has_ns_capability_noaudit - Does a task have a capability (unaudited)
+ * in a specific user ns.
+ * @t: The task in question
+ * @ns: target user namespace
+ * @cap: The capability to be tested for
+ *
+ * Return true if the specified task has the given superior capability
+ * currently in effect to the specified user namespace, false if not.
+ * Do not write an audit message for the check.
+ *
+ * Note that this does not set PF_SUPERPRIV on the task.
+ */
+bool has_ns_capability_noaudit(struct task_struct *t,
+                              struct user_namespace *ns, int cap)
+{
+       int ret;
+
+       rcu_read_lock();
+       ret = security_capable_noaudit(__task_cred(t), ns, cap);
+       rcu_read_unlock();
+
+       return (ret == 0);
+}
+
+/**
+ * has_capability_noaudit - Does a task have a capability (unaudited) in the
+ * initial user ns
+ * @t: The task in question
+ * @cap: The capability to be tested for
+ *
+ * Return true if the specified task has the given superior capability
+ * currently in effect to init_user_ns, false if not.  Don't write an
+ * audit message for the check.
+ *
+ * Note that this does not set PF_SUPERPRIV on the task.
+ */
+bool has_capability_noaudit(struct task_struct *t, int cap)
+{
+       return has_ns_capability_noaudit(t, &init_user_ns, cap);
+}
+
+/**
+ * ns_capable - Determine if the current task has a superior capability in effect
+ * @ns:  The usernamespace we want the capability in
  * @cap: The capability to be tested for
  *
  * Return true if the current task has the given superior capability currently
@@ -299,17 +377,45 @@ error:
  * This sets PF_SUPERPRIV on the task if the capability is available on the
  * assumption that it's about to be used.
  */
-int capable(int cap)
+bool ns_capable(struct user_namespace *ns, int cap)
 {
        if (unlikely(!cap_valid(cap))) {
                printk(KERN_CRIT "capable() called with invalid cap=%u\n", cap);
                BUG();
        }
 
-       if (security_capable(current_cred(), cap) == 0) {
+       if (security_capable(current_cred(), ns, cap) == 0) {
                current->flags |= PF_SUPERPRIV;
-               return 1;
+               return true;
        }
-       return 0;
+       return false;
+}
+EXPORT_SYMBOL(ns_capable);
+
+/**
+ * capable - Determine if the current task has a superior capability in effect
+ * @cap: The capability to be tested for
+ *
+ * Return true if the current task has the given superior capability currently
+ * available for use, false if not.
+ *
+ * This sets PF_SUPERPRIV on the task if the capability is available on the
+ * assumption that it's about to be used.
+ */
+bool capable(int cap)
+{
+       return ns_capable(&init_user_ns, cap);
 }
 EXPORT_SYMBOL(capable);
+
+/**
+ * nsown_capable - Check superior capability to one's own user_ns
+ * @cap: The capability in question
+ *
+ * Return true if the current task has the given superior capability
+ * targeted at its own user namespace.
+ */
+bool nsown_capable(int cap)
+{
+       return ns_capable(current_user_ns(), cap);
+}