tracing: Fix trace_seq_bitmask() to start at current position

rostedt · rostedt · commit e400a40cffa7 · 2014-11-19T15:25:38.000-05:00
In trace_seq_bitmask() it calls bitmap_scnprintf() not from the current
position of the trace_seq buffer (s-&gt;buffer + s-&gt;len), but instead from
the beginning of the buffer (s-&gt;buffer).

Luckily, the only user of this "ipi_raise tracepoint" uses it as the
first parameter, and as such, the start of the temp buffer in
include/trace/ftrace.h (see __get_bitmask()).

Reported-by: Petr Mladek &lt;pmladek@suse.cz&gt;
Reviewed-by: Petr Mladek &lt;pmladek@suse.cz&gt;
Signed-off-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
diff --git a/kernel/trace/trace_seq.c b/kernel/trace/trace_seq.c
@@ -122,7 +122,7 @@ int trace_seq_bitmask(struct trace_seq *s, const unsigned long *maskp,
 	if (s->full || !len)
 		return 0;
 
-	ret = bitmap_scnprintf(s->buffer, len, maskp, nmaskbits);
+	ret = bitmap_scnprintf(s->buffer + s->len, len, maskp, nmaskbits);
 	s->len += ret;
 
 	return 1;
