1 files changed, 31 insertions, 24 deletions

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index bd38c5c..b36d737 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -123,8 +123,7 @@ void ring_buffer_normalize_time_stamp(int cpu, u64 *ts)
 EXPORT_SYMBOL_GPL(ring_buffer_normalize_time_stamp);
 
 #define RB_EVNT_HDR_SIZE (sizeof(struct ring_buffer_event))
-#define RB_ALIGNMENT_SHIFT	2
-#define RB_ALIGNMENT		(1 << RB_ALIGNMENT_SHIFT)
+#define RB_ALIGNMENT		4U
 #define RB_MAX_SMALL_DATA	28
 
 enum {
@@ -133,7 +132,7 @@ enum {
 };
 
 /* inline for ring buffer fast paths */
-static inline unsigned
+static unsigned
 rb_event_length(struct ring_buffer_event *event)
 {
 	unsigned length;
@@ -151,7 +150,7 @@ rb_event_length(struct ring_buffer_event *event)
 
 	case RINGBUF_TYPE_DATA:
 		if (event->len)
-			length = event->len << RB_ALIGNMENT_SHIFT;
+			length = event->len * RB_ALIGNMENT;
 		else
 			length = event->array[0];
 		return length + RB_EVNT_HDR_SIZE;
@@ -179,7 +178,7 @@ unsigned ring_buffer_event_length(struct ring_buffer_event *event)
 EXPORT_SYMBOL_GPL(ring_buffer_event_length);
 
 /* inline for ring buffer fast paths */
-static inline void *
+static void *
 rb_event_data(struct ring_buffer_event *event)
 {
 	BUG_ON(event->type != RINGBUF_TYPE_DATA);
@@ -229,10 +228,9 @@ static void rb_init_page(struct buffer_data_page *bpage)
  * Also stolen from mm/slob.c. Thanks to Mathieu Desnoyers for pointing
  * this issue out.
  */
-static inline void free_buffer_page(struct buffer_page *bpage)
+static void free_buffer_page(struct buffer_page *bpage)
 {
-	if (bpage->page)
-		free_page((unsigned long)bpage->page);
+	free_page((unsigned long)bpage->page);
 	kfree(bpage);
 }
 
@@ -811,7 +809,7 @@ rb_event_index(struct ring_buffer_event *event)
 	return (addr & ~PAGE_MASK) - (PAGE_SIZE - BUF_PAGE_SIZE);
 }
 
-static inline int
+static int
 rb_is_commit(struct ring_buffer_per_cpu *cpu_buffer,
 	     struct ring_buffer_event *event)
 {
@@ -825,7 +823,7 @@ rb_is_commit(struct ring_buffer_per_cpu *cpu_buffer,
 		rb_commit_index(cpu_buffer) == index;
 }
 
-static inline void
+static void
 rb_set_commit_event(struct ring_buffer_per_cpu *cpu_buffer,
 		    struct ring_buffer_event *event)
 {
@@ -850,7 +848,7 @@ rb_set_commit_event(struct ring_buffer_per_cpu *cpu_buffer,
 	local_set(&cpu_buffer->commit_page->page->commit, index);
 }
 
-static inline void
+static void
 rb_set_commit_to_write(struct ring_buffer_per_cpu *cpu_buffer)
 {
 	/*
@@ -896,7 +894,7 @@ static void rb_reset_reader_page(struct ring_buffer_per_cpu *cpu_buffer)
 	cpu_buffer->reader_page->read = 0;
 }
 
-static inline void rb_inc_iter(struct ring_buffer_iter *iter)
+static void rb_inc_iter(struct ring_buffer_iter *iter)
 {
 	struct ring_buffer_per_cpu *cpu_buffer = iter->cpu_buffer;
 
@@ -926,7 +924,7 @@ static inline void rb_inc_iter(struct ring_buffer_iter *iter)
  * and with this, we can determine what to place into the
  * data field.
  */
-static inline void
+static void
 rb_update_event(struct ring_buffer_event *event,
 			 unsigned type, unsigned length)
 {
@@ -938,15 +936,11 @@ rb_update_event(struct ring_buffer_event *event,
 		break;
 
 	case RINGBUF_TYPE_TIME_EXTEND:
-		event->len =
-			(RB_LEN_TIME_EXTEND + (RB_ALIGNMENT-1))
-			>> RB_ALIGNMENT_SHIFT;
+		event->len = DIV_ROUND_UP(RB_LEN_TIME_EXTEND, RB_ALIGNMENT);
 		break;
 
 	case RINGBUF_TYPE_TIME_STAMP:
-		event->len =
-			(RB_LEN_TIME_STAMP + (RB_ALIGNMENT-1))
-			>> RB_ALIGNMENT_SHIFT;
+		event->len = DIV_ROUND_UP(RB_LEN_TIME_STAMP, RB_ALIGNMENT);
 		break;
 
 	case RINGBUF_TYPE_DATA:
@@ -955,16 +949,14 @@ rb_update_event(struct ring_buffer_event *event,
 			event->len = 0;
 			event->array[0] = length;
 		} else
-			event->len =
-				(length + (RB_ALIGNMENT-1))
-				>> RB_ALIGNMENT_SHIFT;
+			event->len = DIV_ROUND_UP(length, RB_ALIGNMENT);
 		break;
 	default:
 		BUG();
 	}
 }
 
-static inline unsigned rb_calculate_event_length(unsigned length)
+static unsigned rb_calculate_event_length(unsigned length)
 {
 	struct ring_buffer_event event; /* Used only for sizeof array */
 
@@ -1438,7 +1430,7 @@ int ring_buffer_write(struct ring_buffer *buffer,
 }
 EXPORT_SYMBOL_GPL(ring_buffer_write);
 
-static inline int rb_per_cpu_empty(struct ring_buffer_per_cpu *cpu_buffer)
+static int rb_per_cpu_empty(struct ring_buffer_per_cpu *cpu_buffer)
 {
 	struct buffer_page *reader = cpu_buffer->reader_page;
 	struct buffer_page *head = cpu_buffer->head_page;
@@ -2277,9 +2269,24 @@ int ring_buffer_swap_cpu(struct ring_buffer *buffer_a,
 	if (buffer_a->pages != buffer_b->pages)
 		return -EINVAL;
 
+	if (ring_buffer_flags != RB_BUFFERS_ON)
+		return -EAGAIN;
+
+	if (atomic_read(&buffer_a->record_disabled))
+		return -EAGAIN;
+
+	if (atomic_read(&buffer_b->record_disabled))
+		return -EAGAIN;
+
 	cpu_buffer_a = buffer_a->buffers[cpu];
 	cpu_buffer_b = buffer_b->buffers[cpu];
 
+	if (atomic_read(&cpu_buffer_a->record_disabled))
+		return -EAGAIN;
+
+	if (atomic_read(&cpu_buffer_b->record_disabled))
+		return -EAGAIN;
+
 	/*
 	 * We can't do a synchronize_sched here because this
 	 * function can be called in atomic context.