Merge branch 'next' (accumulated 3.16 merge window patches) into master

Now that 3.15 is released, this merges the 'next' branch into 'master',
bringing us to the normal situation where my 'master' branch is the
merge window.

* accumulated work in next: (6809 commits)
  ufs: sb mutex merge + mutex_destroy
  powerpc: update comments for generic idle conversion
  cris: update comments for generic idle conversion
  idle: remove cpu_idle() forward declarations
  nbd: zero from and len fields in NBD_CMD_DISCONNECT.
  mm: convert some level-less printks to pr_*
  MAINTAINERS: adi-buildroot-devel is moderated
  MAINTAINERS: add linux-api for review of API/ABI changes
  mm/kmemleak-test.c: use pr_fmt for logging
  fs/dlm/debug_fs.c: replace seq_printf by seq_puts
  fs/dlm/lockspace.c: convert simple_str to kstr
  fs/dlm/config.c: convert simple_str to kstr
  mm: mark remap_file_pages() syscall as deprecated
  mm: memcontrol: remove unnecessary memcg argument from soft limit functions
  mm: memcontrol: clean up memcg zoneinfo lookup
  mm/memblock.c: call kmemleak directly from memblock_(alloc|free)
  mm/mempool.c: update the kmemleak stack trace for mempool allocations
  lib/radix-tree.c: update the kmemleak stack trace for radix tree allocations
  mm: introduce kmemleak_update_trace()
  mm/kmemleak.c: use %u to print ->checksum
  ...

1 files changed, 45 insertions, 50 deletions

diff --git a/kernel/signal.c b/kernel/signal.c
index 6ea13c09ae56..a4077e90f19f 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -277,6 +277,7 @@ void task_clear_jobctl_trapping(struct task_struct *task)
 {
 	if (unlikely(task->jobctl & JOBCTL_TRAPPING)) {
 		task->jobctl &= ~JOBCTL_TRAPPING;
+		smp_mb();	/* advised by wake_up_bit() */
 		wake_up_bit(&task->jobctl, JOBCTL_TRAPPING_BIT);
 	}
 }
@@ -705,11 +706,8 @@ void signal_wake_up_state(struct task_struct *t, unsigned int state)
  * Returns 1 if any signals were found.
  *
  * All callers must be holding the siglock.
- *
- * This version takes a sigset mask and looks at all signals,
- * not just those in the first mask word.
  */
-static int rm_from_queue_full(sigset_t *mask, struct sigpending *s)
+static int flush_sigqueue_mask(sigset_t *mask, struct sigpending *s)
 {
 	struct sigqueue *q, *n;
 	sigset_t m;
@@ -727,29 +725,6 @@ static int rm_from_queue_full(sigset_t *mask, struct sigpending *s)
 	}
 	return 1;
 }
-/*
- * Remove signals in mask from the pending set and queue.
- * Returns 1 if any signals were found.
- *
- * All callers must be holding the siglock.
- */
-static int rm_from_queue(unsigned long mask, struct sigpending *s)
-{
-	struct sigqueue *q, *n;
-
-	if (!sigtestsetmask(&s->signal, mask))
-		return 0;
-
-	sigdelsetmask(&s->signal, mask);
-	list_for_each_entry_safe(q, n, &s->list, list) {
-		if (q->info.si_signo < SIGRTMIN &&
-		    (mask & sigmask(q->info.si_signo))) {
-			list_del_init(&q->list);
-			__sigqueue_free(q);
-		}
-	}
-	return 1;
-}
 
 static inline int is_si_special(const struct siginfo *info)
 {
@@ -861,6 +836,7 @@ static bool prepare_signal(int sig, struct task_struct *p, bool force)
 {
 	struct signal_struct *signal = p->signal;
 	struct task_struct *t;
+	sigset_t flush;
 
 	if (signal->flags & (SIGNAL_GROUP_EXIT | SIGNAL_GROUP_COREDUMP)) {
 		if (signal->flags & SIGNAL_GROUP_COREDUMP)
@@ -872,26 +848,25 @@ static bool prepare_signal(int sig, struct task_struct *p, bool force)
 		/*
 		 * This is a stop signal.  Remove SIGCONT from all queues.
 		 */
-		rm_from_queue(sigmask(SIGCONT), &signal->shared_pending);
-		t = p;
-		do {
-			rm_from_queue(sigmask(SIGCONT), &t->pending);
-		} while_each_thread(p, t);
+		siginitset(&flush, sigmask(SIGCONT));
+		flush_sigqueue_mask(&flush, &signal->shared_pending);
+		for_each_thread(p, t)
+			flush_sigqueue_mask(&flush, &t->pending);
 	} else if (sig == SIGCONT) {
 		unsigned int why;
 		/*
 		 * Remove all stop signals from all queues, wake all threads.
 		 */
-		rm_from_queue(SIG_KERNEL_STOP_MASK, &signal->shared_pending);
-		t = p;
-		do {
+		siginitset(&flush, SIG_KERNEL_STOP_MASK);
+		flush_sigqueue_mask(&flush, &signal->shared_pending);
+		for_each_thread(p, t) {
+			flush_sigqueue_mask(&flush, &t->pending);
 			task_clear_jobctl_pending(t, JOBCTL_STOP_PENDING);
-			rm_from_queue(SIG_KERNEL_STOP_MASK, &t->pending);
 			if (likely(!(t->ptrace & PT_SEIZED)))
 				wake_up_state(t, __TASK_STOPPED);
 			else
 				ptrace_trap_notify(t);
-		} while_each_thread(p, t);
+		}
 
 		/*
 		 * Notify the parent with CLD_CONTINUED if we were stopped.
@@ -2854,7 +2829,7 @@ int do_sigtimedwait(const sigset_t *which, siginfo_t *info,
 
 		spin_lock_irq(&tsk->sighand->siglock);
 		__set_task_blocked(tsk, &tsk->real_blocked);
-		siginitset(&tsk->real_blocked, 0);
+		sigemptyset(&tsk->real_blocked);
 		sig = dequeue_signal(tsk, &mask, info);
 	}
 	spin_unlock_irq(&tsk->sighand->siglock);
@@ -3091,18 +3066,39 @@ COMPAT_SYSCALL_DEFINE4(rt_tgsigqueueinfo,
 }
 #endif
 
+/*
+ * For kthreads only, must not be used if cloned with CLONE_SIGHAND
+ */
+void kernel_sigaction(int sig, __sighandler_t action)
+{
+	spin_lock_irq(&current->sighand->siglock);
+	current->sighand->action[sig - 1].sa.sa_handler = action;
+	if (action == SIG_IGN) {
+		sigset_t mask;
+
+		sigemptyset(&mask);
+		sigaddset(&mask, sig);
+
+		flush_sigqueue_mask(&mask, &current->signal->shared_pending);
+		flush_sigqueue_mask(&mask, &current->pending);
+		recalc_sigpending();
+	}
+	spin_unlock_irq(&current->sighand->siglock);
+}
+EXPORT_SYMBOL(kernel_sigaction);
+
 int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact)
 {
-	struct task_struct *t = current;
+	struct task_struct *p = current, *t;
 	struct k_sigaction *k;
 	sigset_t mask;
 
 	if (!valid_signal(sig) || sig < 1 || (act && sig_kernel_only(sig)))
 		return -EINVAL;
 
-	k = &t->sighand->action[sig-1];
+	k = &p->sighand->action[sig-1];
 
-	spin_lock_irq(&current->sighand->siglock);
+	spin_lock_irq(&p->sighand->siglock);
 	if (oact)
 		*oact = *k;
 
@@ -3121,21 +3117,20 @@ int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact)
 		 *   (for example, SIGCHLD), shall cause the pending signal to
 		 *   be discarded, whether or not it is blocked"
 		 */
-		if (sig_handler_ignored(sig_handler(t, sig), sig)) {
+		if (sig_handler_ignored(sig_handler(p, sig), sig)) {
 			sigemptyset(&mask);
 			sigaddset(&mask, sig);
-			rm_from_queue_full(&mask, &t->signal->shared_pending);
-			do {
-				rm_from_queue_full(&mask, &t->pending);
-			} while_each_thread(current, t);
+			flush_sigqueue_mask(&mask, &p->signal->shared_pending);
+			for_each_thread(p, t)
+				flush_sigqueue_mask(&mask, &t->pending);
 		}
 	}
 
-	spin_unlock_irq(&current->sighand->siglock);
+	spin_unlock_irq(&p->sighand->siglock);
 	return 0;
 }
 
-static int 
+static int
 do_sigaltstack (const stack_t __user *uss, stack_t __user *uoss, unsigned long sp)
 {
 	stack_t oss;
@@ -3496,7 +3491,7 @@ COMPAT_SYSCALL_DEFINE3(sigaction, int, sig,
 }
 #endif
 
-#ifdef __ARCH_WANT_SYS_SGETMASK
+#ifdef CONFIG_SGETMASK_SYSCALL
 
 /*
  * For backwards compatibility.  Functionality superseded by sigprocmask.
@@ -3517,7 +3512,7 @@ SYSCALL_DEFINE1(ssetmask, int, newmask)
 
 	return old;
 }
-#endif /* __ARCH_WANT_SGETMASK */
+#endif /* CONFIG_SGETMASK_SYSCALL */
 
 #ifdef __ARCH_WANT_SYS_SIGNAL
 /*