Merge branch 'akpm' (aka "Andrew's patch-bomb")

Andrew elucidates:
 - First installmeant of MM.  We have a HUGE number of MM patches this
   time.  It's crazy.
 - MAINTAINERS updates
 - backlight updates
 - leds
 - checkpatch updates
 - misc ELF stuff
 - rtc updates
 - reiserfs
 - procfs
 - some misc other bits

* akpm: (124 commits)
  user namespace: make signal.c respect user namespaces
  workqueue: make alloc_workqueue() take printf fmt and args for name
  procfs: add hidepid= and gid= mount options
  procfs: parse mount options
  procfs: introduce the /proc/<pid>/map_files/ directory
  procfs: make proc_get_link to use dentry instead of inode
  signal: add block_sigmask() for adding sigmask to current->blocked
  sparc: make SA_NOMASK a synonym of SA_NODEFER
  reiserfs: don't lock root inode searching
  reiserfs: don't lock journal_init()
  reiserfs: delay reiserfs lock until journal initialization
  reiserfs: delete comments referring to the BKL
  drivers/rtc/interface.c: fix alarm rollover when day or month is out-of-range
  drivers/rtc/rtc-twl.c: add DT support for RTC inside twl4030/twl6030
  drivers/rtc/: remove redundant spi driver bus initialization
  drivers/rtc/rtc-jz4740.c: make jz4740_rtc_driver static
  drivers/rtc/rtc-mc13xxx.c: make mc13xxx_rtc_idtable static
  rtc: convert drivers/rtc/* to use module_platform_driver()
  drivers/rtc/rtc-wm831x.c: convert to devm_kzalloc()
  drivers/rtc/rtc-wm831x.c: remove unused period IRQ handler
  ...

4 files changed, 95 insertions, 13 deletions

diff --git a/kernel/fork.c b/kernel/fork.c
index b00711ce7c1..5e1391b5ade 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -76,6 +76,9 @@
 
 #include <trace/events/sched.h>
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/task.h>
+
 /*
  * Protected counters by write_lock_irq(&tasklist_lock)
  */
@@ -1370,6 +1373,9 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 	if (clone_flags & CLONE_THREAD)
 		threadgroup_change_end(current);
 	perf_event_fork(p);
+
+	trace_task_newtask(p, clone_flags);
+
 	return p;
 
 bad_fork_free_pid:
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index cbe2c144139..1cf88900ec4 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -858,6 +858,9 @@ static struct page *saveable_highmem_page(struct zone *zone, unsigned long pfn)
 	    PageReserved(page))
 		return NULL;
 
+	if (page_is_guard(page))
+		return NULL;
+
 	return page;
 }
 
@@ -920,6 +923,9 @@ static struct page *saveable_page(struct zone *zone, unsigned long pfn)
 	    && (!kernel_page_present(page) || pfn_is_nosave(pfn)))
 		return NULL;
 
+	if (page_is_guard(page))
+		return NULL;
+
 	return page;
 }
 
diff --git a/kernel/signal.c b/kernel/signal.c
index bb0efa5705e..c73c4284160 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -28,6 +28,7 @@
 #include <linux/freezer.h>
 #include <linux/pid_namespace.h>
 #include <linux/nsproxy.h>
+#include <linux/user_namespace.h>
 #define CREATE_TRACE_POINTS
 #include <trace/events/signal.h>
 
@@ -1019,6 +1020,34 @@ static inline int legacy_queue(struct sigpending *signals, int sig)
 	return (sig < SIGRTMIN) && sigismember(&signals->signal, sig);
 }
 
+/*
+ * map the uid in struct cred into user namespace *ns
+ */
+static inline uid_t map_cred_ns(const struct cred *cred,
+				struct user_namespace *ns)
+{
+	return user_ns_map_uid(ns, cred, cred->uid);
+}
+
+#ifdef CONFIG_USER_NS
+static inline void userns_fixup_signal_uid(struct siginfo *info, struct task_struct *t)
+{
+	if (current_user_ns() == task_cred_xxx(t, user_ns))
+		return;
+
+	if (SI_FROMKERNEL(info))
+		return;
+
+	info->si_uid = user_ns_map_uid(task_cred_xxx(t, user_ns),
+					current_cred(), info->si_uid);
+}
+#else
+static inline void userns_fixup_signal_uid(struct siginfo *info, struct task_struct *t)
+{
+	return;
+}
+#endif
+
 static int __send_signal(int sig, struct siginfo *info, struct task_struct *t,
 			int group, int from_ancestor_ns)
 {
@@ -1088,6 +1117,9 @@ static int __send_signal(int sig, struct siginfo *info, struct task_struct *t,
 				q->info.si_pid = 0;
 			break;
 		}
+
+		userns_fixup_signal_uid(&q->info, t);
+
 	} else if (!is_si_special(info)) {
 		if (sig >= SIGRTMIN && info->si_code != SI_USER) {
 			/*
@@ -1626,7 +1658,8 @@ bool do_notify_parent(struct task_struct *tsk, int sig)
 	 */
 	rcu_read_lock();
 	info.si_pid = task_pid_nr_ns(tsk, tsk->parent->nsproxy->pid_ns);
-	info.si_uid = __task_cred(tsk)->uid;
+	info.si_uid = map_cred_ns(__task_cred(tsk),
+			task_cred_xxx(tsk->parent, user_ns));
 	rcu_read_unlock();
 
 	info.si_utime = cputime_to_clock_t(tsk->utime + tsk->signal->utime);
@@ -1709,7 +1742,8 @@ static void do_notify_parent_cldstop(struct task_struct *tsk,
 	 */
 	rcu_read_lock();
 	info.si_pid = task_pid_nr_ns(tsk, parent->nsproxy->pid_ns);
-	info.si_uid = __task_cred(tsk)->uid;
+	info.si_uid = map_cred_ns(__task_cred(tsk),
+			task_cred_xxx(parent, user_ns));
 	rcu_read_unlock();
 
 	info.si_utime = cputime_to_clock_t(tsk->utime);
@@ -2125,8 +2159,11 @@ static int ptrace_signal(int signr, siginfo_t *info,
 		info->si_signo = signr;
 		info->si_errno = 0;
 		info->si_code = SI_USER;
+		rcu_read_lock();
 		info->si_pid = task_pid_vnr(current->parent);
-		info->si_uid = task_uid(current->parent);
+		info->si_uid = map_cred_ns(__task_cred(current->parent),
+				current_user_ns());
+		rcu_read_unlock();
 	}
 
 	/* If the (new) signal is now blocked, requeue it.  */
@@ -2318,6 +2355,27 @@ relock:
 	return signr;
 }
 
+/**
+ * block_sigmask - add @ka's signal mask to current->blocked
+ * @ka: action for @signr
+ * @signr: signal that has been successfully delivered
+ *
+ * This function should be called when a signal has succesfully been
+ * delivered. It adds the mask of signals for @ka to current->blocked
+ * so that they are blocked during the execution of the signal
+ * handler. In addition, @signr will be blocked unless %SA_NODEFER is
+ * set in @ka->sa.sa_flags.
+ */
+void block_sigmask(struct k_sigaction *ka, int signr)
+{
+	sigset_t blocked;
+
+	sigorsets(&blocked, &current->blocked, &ka->sa.sa_mask);
+	if (!(ka->sa.sa_flags & SA_NODEFER))
+		sigaddset(&blocked, signr);
+	set_current_blocked(&blocked);
+}
+
 /*
  * It could be that complete_signal() picked us to notify about the
  * group-wide signal. Other threads should be notified now to take
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 42fa9ad0a81..bec7b5b53e0 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -242,10 +242,10 @@ struct workqueue_struct {
 
 	int			nr_drainers;	/* W: drain in progress */
 	int			saved_max_active; /* W: saved cwq max_active */
-	const char		*name;		/* I: workqueue name */
 #ifdef CONFIG_LOCKDEP
 	struct lockdep_map	lockdep_map;
 #endif
+	char			name[];		/* I: workqueue name */
 };
 
 struct workqueue_struct *system_wq __read_mostly;
@@ -2954,14 +2954,29 @@ static int wq_clamp_max_active(int max_active, unsigned int flags,
 	return clamp_val(max_active, 1, lim);
 }
 
-struct workqueue_struct *__alloc_workqueue_key(const char *name,
+struct workqueue_struct *__alloc_workqueue_key(const char *fmt,
 					       unsigned int flags,
 					       int max_active,
 					       struct lock_class_key *key,
-					       const char *lock_name)
+					       const char *lock_name, ...)
 {
+	va_list args, args1;
 	struct workqueue_struct *wq;
 	unsigned int cpu;
+	size_t namelen;
+
+	/* determine namelen, allocate wq and format name */
+	va_start(args, lock_name);
+	va_copy(args1, args);
+	namelen = vsnprintf(NULL, 0, fmt, args) + 1;
+
+	wq = kzalloc(sizeof(*wq) + namelen, GFP_KERNEL);
+	if (!wq)
+		goto err;
+
+	vsnprintf(wq->name, namelen, fmt, args1);
+	va_end(args);
+	va_end(args1);
 
 	/*
 	 * Workqueues which may be used during memory reclaim should
@@ -2978,12 +2993,9 @@ struct workqueue_struct *__alloc_workqueue_key(const char *name,
 		flags |= WQ_HIGHPRI;
 
 	max_active = max_active ?: WQ_DFL_ACTIVE;
-	max_active = wq_clamp_max_active(max_active, flags, name);
-
-	wq = kzalloc(sizeof(*wq), GFP_KERNEL);
-	if (!wq)
-		goto err;
+	max_active = wq_clamp_max_active(max_active, flags, wq->name);
 
+	/* init wq */
 	wq->flags = flags;
 	wq->saved_max_active = max_active;
 	mutex_init(&wq->flush_mutex);
@@ -2991,7 +3003,6 @@ struct workqueue_struct *__alloc_workqueue_key(const char *name,
 	INIT_LIST_HEAD(&wq->flusher_queue);
 	INIT_LIST_HEAD(&wq->flusher_overflow);
 
-	wq->name = name;
 	lockdep_init_map(&wq->lockdep_map, lock_name, key, 0);
 	INIT_LIST_HEAD(&wq->list);
 
@@ -3020,7 +3031,8 @@ struct workqueue_struct *__alloc_workqueue_key(const char *name,
 		if (!rescuer)
 			goto err;
 
-		rescuer->task = kthread_create(rescuer_thread, wq, "%s", name);
+		rescuer->task = kthread_create(rescuer_thread, wq, "%s",
+					       wq->name);
 		if (IS_ERR(rescuer->task))
 			goto err;