Merge tag 'v3.18.35' into linux-linaro-lsk-v3.18

 This is the 3.18.35 stable release

3 files changed, 68 insertions, 55 deletions

diff --git a/kernel/exit.c b/kernel/exit.c
index 2116aace6c85..654021d9f1b3 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -930,17 +930,28 @@ static int eligible_pid(struct wait_opts *wo, struct task_struct *p)
 		task_pid_type(p, wo->wo_type) == wo->wo_pid;
 }
 
-static int eligible_child(struct wait_opts *wo, struct task_struct *p)
+static int
+eligible_child(struct wait_opts *wo, bool ptrace, struct task_struct *p)
 {
 	if (!eligible_pid(wo, p))
 		return 0;
-	/* Wait for all children (clone and not) if __WALL is set;
-	 * otherwise, wait for clone children *only* if __WCLONE is
-	 * set; otherwise, wait for non-clone children *only*.  (Note:
-	 * A "clone" child here is one that reports to its parent
-	 * using a signal other than SIGCHLD.) */
-	if (((p->exit_signal != SIGCHLD) ^ !!(wo->wo_flags & __WCLONE))
-	    && !(wo->wo_flags & __WALL))
+
+	/*
+	 * Wait for all children (clone and not) if __WALL is set or
+	 * if it is traced by us.
+	 */
+	if (ptrace || (wo->wo_flags & __WALL))
+		return 1;
+
+	/*
+	 * Otherwise, wait for clone children *only* if __WCLONE is set;
+	 * otherwise, wait for non-clone children *only*.
+	 *
+	 * Note: a "clone" child here is one that reports to its parent
+	 * using a signal other than SIGCHLD, or a non-leader thread which
+	 * we can only see if it is traced by us.
+	 */
+	if ((p->exit_signal != SIGCHLD) ^ !!(wo->wo_flags & __WCLONE))
 		return 0;
 
 	return 1;
@@ -1313,7 +1324,7 @@ static int wait_consider_task(struct wait_opts *wo, int ptrace,
 	if (unlikely(exit_state == EXIT_DEAD))
 		return 0;
 
-	ret = eligible_child(wo, p);
+	ret = eligible_child(wo, ptrace, p);
 	if (!ret)
 		return ret;
 
diff --git a/kernel/sched/proc.c b/kernel/sched/proc.c
index 8ecd552fe4f2..09dfe51f89b5 100644
--- a/kernel/sched/proc.c
+++ b/kernel/sched/proc.c
@@ -97,10 +97,13 @@ long calc_load_fold_active(struct rq *this_rq)
 static unsigned long
 calc_load(unsigned long load, unsigned long exp, unsigned long active)
 {
-	load *= exp;
-	load += active * (FIXED_1 - exp);
-	load += 1UL << (FSHIFT - 1);
-	return load >> FSHIFT;
+	unsigned long newload;
+
+	newload = load * exp + active * (FIXED_1 - exp);
+	if (active >= load)
+		newload += FIXED_1-1;
+
+	return newload / FIXED_1;
 }
 
 #ifdef CONFIG_NO_HZ_COMMON
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 0fc5cfedcc8c..d4588b08e07a 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -466,7 +466,8 @@ struct ring_buffer_per_cpu {
 	raw_spinlock_t			reader_lock;	/* serialize readers */
 	arch_spinlock_t			lock;
 	struct lock_class_key		lock_key;
-	unsigned int			nr_pages;
+	unsigned long			nr_pages;
+	unsigned int			current_context;
 	struct list_head		*pages;
 	struct buffer_page		*head_page;	/* read from head */
 	struct buffer_page		*tail_page;	/* write to tail */
@@ -486,7 +487,7 @@ struct ring_buffer_per_cpu {
 	u64				write_stamp;
 	u64				read_stamp;
 	/* ring buffer pages to update, > 0 to add, < 0 to remove */
-	int				nr_pages_to_update;
+	long				nr_pages_to_update;
 	struct list_head		new_pages; /* new pages to add */
 	struct work_struct		update_pages_work;
 	struct completion		update_done;
@@ -1165,10 +1166,10 @@ static int rb_check_pages(struct ring_buffer_per_cpu *cpu_buffer)
 	return 0;
 }
 
-static int __rb_allocate_pages(int nr_pages, struct list_head *pages, int cpu)
+static int __rb_allocate_pages(long nr_pages, struct list_head *pages, int cpu)
 {
-	int i;
 	struct buffer_page *bpage, *tmp;
+	long i;
 
 	for (i = 0; i < nr_pages; i++) {
 		struct page *page;
@@ -1205,7 +1206,7 @@ free_pages:
 }
 
 static int rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer,
-			     unsigned nr_pages)
+			     unsigned long nr_pages)
 {
 	LIST_HEAD(pages);
 
@@ -1230,7 +1231,7 @@ static int rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer,
 }
 
 static struct ring_buffer_per_cpu *
-rb_allocate_cpu_buffer(struct ring_buffer *buffer, int nr_pages, int cpu)
+rb_allocate_cpu_buffer(struct ring_buffer *buffer, long nr_pages, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	struct buffer_page *bpage;
@@ -1330,8 +1331,9 @@ struct ring_buffer *__ring_buffer_alloc(unsigned long size, unsigned flags,
 					struct lock_class_key *key)
 {
 	struct ring_buffer *buffer;
+	long nr_pages;
 	int bsize;
-	int cpu, nr_pages;
+	int cpu;
 
 	/* keep it in its own cache line */
 	buffer = kzalloc(ALIGN(sizeof(*buffer), cache_line_size()),
@@ -1457,12 +1459,12 @@ static inline unsigned long rb_page_write(struct buffer_page *bpage)
 }
 
 static int
-rb_remove_pages(struct ring_buffer_per_cpu *cpu_buffer, unsigned int nr_pages)
+rb_remove_pages(struct ring_buffer_per_cpu *cpu_buffer, unsigned long nr_pages)
 {
 	struct list_head *tail_page, *to_remove, *next_page;
 	struct buffer_page *to_remove_page, *tmp_iter_page;
 	struct buffer_page *last_page, *first_page;
-	unsigned int nr_removed;
+	unsigned long nr_removed;
 	unsigned long head_bit;
 	int page_entries;
 
@@ -1679,7 +1681,7 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size,
 			int cpu_id)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
-	unsigned nr_pages;
+	unsigned long nr_pages;
 	int cpu, err = 0;
 
 	/*
@@ -1693,14 +1695,13 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size,
 	    !cpumask_test_cpu(cpu_id, buffer->cpumask))
 		return size;
 
-	size = DIV_ROUND_UP(size, BUF_PAGE_SIZE);
-	size *= BUF_PAGE_SIZE;
+	nr_pages = DIV_ROUND_UP(size, BUF_PAGE_SIZE);
 
 	/* we need a minimum of two pages */
-	if (size < BUF_PAGE_SIZE * 2)
-		size = BUF_PAGE_SIZE * 2;
+	if (nr_pages < 2)
+		nr_pages = 2;
 
-	nr_pages = DIV_ROUND_UP(size, BUF_PAGE_SIZE);
+	size = nr_pages * BUF_PAGE_SIZE;
 
 	/*
 	 * Don't succeed if resizing is disabled, as a reader might be
@@ -2680,11 +2681,11 @@ rb_reserve_next_event(struct ring_buffer *buffer,
  * just so happens that it is the same bit corresponding to
  * the current context.
  */
-static DEFINE_PER_CPU(unsigned int, current_context);
 
-static __always_inline int trace_recursive_lock(void)
+static __always_inline int
+trace_recursive_lock(struct ring_buffer_per_cpu *cpu_buffer)
 {
-	unsigned int val = __this_cpu_read(current_context);
+	unsigned int val = cpu_buffer->current_context;
 	int bit;
 
 	if (in_interrupt()) {
@@ -2701,23 +2702,21 @@ static __always_inline int trace_recursive_lock(void)
 		return 1;
 
 	val |= (1 << bit);
-	__this_cpu_write(current_context, val);
+	cpu_buffer->current_context = val;
 
 	return 0;
 }
 
-static __always_inline void trace_recursive_unlock(void)
+static __always_inline void
+trace_recursive_unlock(struct ring_buffer_per_cpu *cpu_buffer)
 {
-	unsigned int val = __this_cpu_read(current_context);
-
-	val &= val & (val - 1);
-	__this_cpu_write(current_context, val);
+	cpu_buffer->current_context &= cpu_buffer->current_context - 1;
 }
 
 #else
 
-#define trace_recursive_lock()		(0)
-#define trace_recursive_unlock()	do { } while (0)
+#define trace_recursive_lock(cpu_buffer)	(0)
+#define trace_recursive_unlock(cpu_buffer)	do { } while (0)
 
 #endif
 
@@ -2749,35 +2748,34 @@ ring_buffer_lock_reserve(struct ring_buffer *buffer, unsigned long length)
 	/* If we are tracing schedule, we don't want to recurse */
 	preempt_disable_notrace();
 
-	if (atomic_read(&buffer->record_disabled))
-		goto out_nocheck;
-
-	if (trace_recursive_lock())
-		goto out_nocheck;
+	if (unlikely(atomic_read(&buffer->record_disabled)))
+		goto out;
 
 	cpu = raw_smp_processor_id();
 
-	if (!cpumask_test_cpu(cpu, buffer->cpumask))
+	if (unlikely(!cpumask_test_cpu(cpu, buffer->cpumask)))
 		goto out;
 
 	cpu_buffer = buffer->buffers[cpu];
 
-	if (atomic_read(&cpu_buffer->record_disabled))
+	if (unlikely(atomic_read(&cpu_buffer->record_disabled)))
 		goto out;
 
-	if (length > BUF_MAX_DATA_SIZE)
+	if (unlikely(length > BUF_MAX_DATA_SIZE))
+		goto out;
+
+	if (unlikely(trace_recursive_lock(cpu_buffer)))
 		goto out;
 
 	event = rb_reserve_next_event(buffer, cpu_buffer, length);
 	if (!event)
-		goto out;
+		goto out_unlock;
 
 	return event;
 
+ out_unlock:
+	trace_recursive_unlock(cpu_buffer);
  out:
-	trace_recursive_unlock();
-
- out_nocheck:
 	preempt_enable_notrace();
 	return NULL;
 }
@@ -2867,7 +2865,7 @@ int ring_buffer_unlock_commit(struct ring_buffer *buffer,
 
 	rb_wakeups(buffer, cpu_buffer);
 
-	trace_recursive_unlock();
+	trace_recursive_unlock(cpu_buffer);
 
 	preempt_enable_notrace();
 
@@ -2978,7 +2976,7 @@ void ring_buffer_discard_commit(struct ring_buffer *buffer,
  out:
 	rb_end_commit(cpu_buffer);
 
-	trace_recursive_unlock();
+	trace_recursive_unlock(cpu_buffer);
 
 	preempt_enable_notrace();
 
@@ -4655,8 +4653,9 @@ static int rb_cpu_notify(struct notifier_block *self,
 	struct ring_buffer *buffer =
 		container_of(self, struct ring_buffer, cpu_notify);
 	long cpu = (long)hcpu;
-	int cpu_i, nr_pages_same;
-	unsigned int nr_pages;
+	long nr_pages_same;
+	int cpu_i;
+	unsigned long nr_pages;
 
 	switch (action) {
 	case CPU_UP_PREPARE: