tracing/ftrace: add the printk-msg-only option

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

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 639344a4d3a2ddc1f4246fefbad9383e38e5f87f..1a3d6b329782de4587d2bacd544e07fa7cb7f2c8 100644 (file)
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -287,6 +287,7 @@ static const char *trace_options[] = {
        "annotate",
        "userstacktrace",
        "sym-userobj",
+       "printk-msg-only",
        NULL
 };
 
@@ -2265,6 +2266,25 @@ static enum print_line_t print_hex_fmt(struct trace_iterator *iter)
        return TRACE_TYPE_HANDLED;
 }
 
+static enum print_line_t print_printk_msg_only(struct trace_iterator *iter)
+{
+       struct trace_seq *s = &iter->seq;
+       struct trace_entry *entry = iter->ent;
+       struct print_entry *field;
+       int ret;
+
+       trace_assign_type(field, entry);
+
+       ret = trace_seq_printf(s, field->buf);
+       if (!ret)
+               return TRACE_TYPE_PARTIAL_LINE;
+
+       if (entry->flags & TRACE_FLAG_CONT)
+               trace_seq_print_cont(s, iter);
+
+       return TRACE_TYPE_HANDLED;
+}
+
 static enum print_line_t print_bin_fmt(struct trace_iterator *iter)
 {
        struct trace_seq *s = &iter->seq;
@@ -2345,6 +2365,11 @@ static enum print_line_t print_trace_line(struct trace_iterator *iter)
                        return ret;
        }
 
+       if (iter->ent->type == TRACE_PRINT &&
+                       trace_flags & TRACE_ITER_PRINTK &&
+                       trace_flags & TRACE_ITER_PRINTK_MSGONLY)
+               return print_printk_msg_only(iter);
+
        if (trace_flags & TRACE_ITER_BIN)
                return print_bin_fmt(iter);