Merge branch 'linus' into stackprotector

Conflicts:
	arch/x86/include/asm/pda.h
	kernel/fork.c

1 files changed, 52 insertions, 45 deletions

diff --git a/kernel/kmod.c b/kernel/kmod.c
index 2456d1a0bef..b46dbb90866 100644
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -113,15 +113,15 @@ int request_module(const char *fmt, ...)
 	return ret;
 }
 EXPORT_SYMBOL(request_module);
-#endif /* CONFIG_KMOD */
+#endif /* CONFIG_MODULES */
 
 struct subprocess_info {
 	struct work_struct work;
 	struct completion *complete;
+	struct cred *cred;
 	char *path;
 	char **argv;
 	char **envp;
-	struct key *ring;
 	enum umh_wait wait;
 	int retval;
 	struct file *stdin;
@@ -134,19 +134,20 @@ struct subprocess_info {
 static int ____call_usermodehelper(void *data)
 {
 	struct subprocess_info *sub_info = data;
-	struct key *new_session, *old_session;
 	int retval;
 
-	/* Unblock all signals and set the session keyring. */
-	new_session = key_get(sub_info->ring);
+	BUG_ON(atomic_read(&sub_info->cred->usage) != 1);
+
+	/* Unblock all signals */
 	spin_lock_irq(&current->sighand->siglock);
-	old_session = __install_session_keyring(current, new_session);
 	flush_signal_handlers(current, 1);
 	sigemptyset(&current->blocked);
 	recalc_sigpending();
 	spin_unlock_irq(&current->sighand->siglock);
 
-	key_put(old_session);
+	/* Install the credentials */
+	commit_creds(sub_info->cred);
+	sub_info->cred = NULL;
 
 	/* Install input pipe when needed */
 	if (sub_info->stdin) {
@@ -185,6 +186,8 @@ void call_usermodehelper_freeinfo(struct subprocess_info *info)
 {
 	if (info->cleanup)
 		(*info->cleanup)(info->argv, info->envp);
+	if (info->cred)
+		put_cred(info->cred);
 	kfree(info);
 }
 EXPORT_SYMBOL(call_usermodehelper_freeinfo);
@@ -240,6 +243,8 @@ static void __call_usermodehelper(struct work_struct *work)
 	pid_t pid;
 	enum umh_wait wait = sub_info->wait;
 
+	BUG_ON(atomic_read(&sub_info->cred->usage) != 1);
+
 	/* CLONE_VFORK: wait until the usermode helper has execve'd
 	 * successfully We need the data structures to stay around
 	 * until that is done.  */
@@ -265,7 +270,7 @@ static void __call_usermodehelper(struct work_struct *work)
 	}
 }
 
-#ifdef CONFIG_PM
+#ifdef CONFIG_PM_SLEEP
 /*
  * If set, call_usermodehelper_exec() will exit immediately returning -EBUSY
  * (used for preventing user land processes from being created after the user
@@ -288,39 +293,37 @@ static DECLARE_WAIT_QUEUE_HEAD(running_helpers_waitq);
  */
 #define RUNNING_HELPERS_TIMEOUT	(5 * HZ)
 
-static int usermodehelper_pm_callback(struct notifier_block *nfb,
-					unsigned long action,
-					void *ignored)
+/**
+ * usermodehelper_disable - prevent new helpers from being started
+ */
+int usermodehelper_disable(void)
 {
 	long retval;
 
-	switch (action) {
-	case PM_HIBERNATION_PREPARE:
-	case PM_SUSPEND_PREPARE:
-		usermodehelper_disabled = 1;
-		smp_mb();
-		/*
-		 * From now on call_usermodehelper_exec() won't start any new
-		 * helpers, so it is sufficient if running_helpers turns out to
-		 * be zero at one point (it may be increased later, but that
-		 * doesn't matter).
-		 */
-		retval = wait_event_timeout(running_helpers_waitq,
+	usermodehelper_disabled = 1;
+	smp_mb();
+	/*
+	 * From now on call_usermodehelper_exec() won't start any new
+	 * helpers, so it is sufficient if running_helpers turns out to
+	 * be zero at one point (it may be increased later, but that
+	 * doesn't matter).
+	 */
+	retval = wait_event_timeout(running_helpers_waitq,
 					atomic_read(&running_helpers) == 0,
 					RUNNING_HELPERS_TIMEOUT);
-		if (retval) {
-			return NOTIFY_OK;
-		} else {
-			usermodehelper_disabled = 0;
-			return NOTIFY_BAD;
-		}
-	case PM_POST_HIBERNATION:
-	case PM_POST_SUSPEND:
-		usermodehelper_disabled = 0;
-		return NOTIFY_OK;
-	}
+	if (retval)
+		return 0;
 
-	return NOTIFY_DONE;
+	usermodehelper_disabled = 0;
+	return -EAGAIN;
+}
+
+/**
+ * usermodehelper_enable - allow new helpers to be started again
+ */
+void usermodehelper_enable(void)
+{
+	usermodehelper_disabled = 0;
 }
 
 static void helper_lock(void)
@@ -334,18 +337,12 @@ static void helper_unlock(void)
 	if (atomic_dec_and_test(&running_helpers))
 		wake_up(&running_helpers_waitq);
 }
-
-static void register_pm_notifier_callback(void)
-{
-	pm_notifier(usermodehelper_pm_callback, 0);
-}
-#else /* CONFIG_PM */
+#else /* CONFIG_PM_SLEEP */
 #define usermodehelper_disabled	0
 
 static inline void helper_lock(void) {}
 static inline void helper_unlock(void) {}
-static inline void register_pm_notifier_callback(void) {}
-#endif /* CONFIG_PM */
+#endif /* CONFIG_PM_SLEEP */
 
 /**
  * call_usermodehelper_setup - prepare to call a usermode helper
@@ -370,6 +367,9 @@ struct subprocess_info *call_usermodehelper_setup(char *path, char **argv,
 	sub_info->path = path;
 	sub_info->argv = argv;
 	sub_info->envp = envp;
+	sub_info->cred = prepare_usermodehelper_creds();
+	if (!sub_info->cred)
+		return NULL;
 
   out:
 	return sub_info;
@@ -384,7 +384,13 @@ EXPORT_SYMBOL(call_usermodehelper_setup);
 void call_usermodehelper_setkeys(struct subprocess_info *info,
 				 struct key *session_keyring)
 {
-	info->ring = session_keyring;
+#ifdef CONFIG_KEYS
+	struct thread_group_cred *tgcred = info->cred->tgcred;
+	key_put(tgcred->session_keyring);
+	tgcred->session_keyring = key_get(session_keyring);
+#else
+	BUG();
+#endif
 }
 EXPORT_SYMBOL(call_usermodehelper_setkeys);
 
@@ -452,6 +458,8 @@ int call_usermodehelper_exec(struct subprocess_info *sub_info,
 	DECLARE_COMPLETION_ONSTACK(done);
 	int retval = 0;
 
+	BUG_ON(atomic_read(&sub_info->cred->usage) != 1);
+
 	helper_lock();
 	if (sub_info->path[0] == '\0')
 		goto out;
@@ -515,5 +523,4 @@ void __init usermodehelper_init(void)
 {
 	khelper_wq = create_singlethread_workqueue("khelper");
 	BUG_ON(!khelper_wq);
-	register_pm_notifier_callback();
 }