ring-buffer: Do 8 byte alignment for 64 bit that can not handle 4 byte align

[firefly-linux-kernel-4.4.55.git] / kernel / trace / ring_buffer.c

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 05a9f83b8819c39dcc03c76f737eaaf5ae7bbfe7..d1187ef20caf914048fb897dc5c63f1b302edbf6 100644 (file)
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -207,6 +207,14 @@ EXPORT_SYMBOL_GPL(tracing_is_on);
 #define RB_MAX_SMALL_DATA      (RB_ALIGNMENT * RINGBUF_TYPE_DATA_TYPE_LEN_MAX)
 #define RB_EVNT_MIN_SIZE       8U      /* two 32bit words */
 
+#if !defined(CONFIG_64BIT) || defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
+# define RB_FORCE_8BYTE_ALIGNMENT      0
+# define RB_ARCH_ALIGNMENT             RB_ALIGNMENT
+#else
+# define RB_FORCE_8BYTE_ALIGNMENT      1
+# define RB_ARCH_ALIGNMENT             8U
+#endif
+
 /* define RINGBUF_TYPE_DATA for 'case RINGBUF_TYPE_DATA:' */
 #define RINGBUF_TYPE_DATA 0 ... RINGBUF_TYPE_DATA_TYPE_LEN_MAX
 
@@ -1547,7 +1555,7 @@ rb_update_event(struct ring_buffer_event *event,
 
        case 0:
                length -= RB_EVNT_HDR_SIZE;
-               if (length > RB_MAX_SMALL_DATA)
+               if (length > RB_MAX_SMALL_DATA || RB_FORCE_8BYTE_ALIGNMENT)
                        event->array[0] = length;
                else
                        event->type_len = DIV_ROUND_UP(length, RB_ALIGNMENT);
@@ -1722,11 +1730,11 @@ static unsigned rb_calculate_event_length(unsigned length)
        if (!length)
                length = 1;
 
-       if (length > RB_MAX_SMALL_DATA)
+       if (length > RB_MAX_SMALL_DATA || RB_FORCE_8BYTE_ALIGNMENT)
                length += sizeof(event.array[0]);
 
        length += RB_EVNT_HDR_SIZE;
-       length = ALIGN(length, RB_ALIGNMENT);
+       length = ALIGN(length, RB_ARCH_ALIGNMENT);
 
        return length;
 }