llseek: automatically add .llseek fop

[mirror_ubuntu-zesty-kernel.git] / kernel / trace / ring_buffer.c

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 3632ce87674f88dfd6c4ce5c8ed09eb184ace1a3..3aea966d16de8c7f81b6fd7536b8a6a353b214fa 100644 (file)
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -2985,13 +2985,11 @@ static void rb_advance_reader(struct ring_buffer_per_cpu *cpu_buffer)
 
 static void rb_advance_iter(struct ring_buffer_iter *iter)
 {
-       struct ring_buffer *buffer;
        struct ring_buffer_per_cpu *cpu_buffer;
        struct ring_buffer_event *event;
        unsigned length;
 
        cpu_buffer = iter->cpu_buffer;
-       buffer = cpu_buffer->buffer;
 
        /*
         * Check if we are at the end of the buffer.
@@ -3846,6 +3844,9 @@ int ring_buffer_read_page(struct ring_buffer *buffer,
                        rpos = reader->read;
                        pos += size;
 
+                       if (rpos >= commit)
+                               break;
+
                        event = rb_reader_event(cpu_buffer);
                        size = rb_event_length(event);
                } while (len > size);
@@ -3964,6 +3965,7 @@ static const struct file_operations rb_simple_fops = {
        .open           = tracing_open_generic,
        .read           = rb_simple_read,
        .write          = rb_simple_write,
+       .llseek         = default_llseek,
 };