[RFC][PATCH 01/23 v4] tracing: Fix trace_seq_bitmask() to start at current position

[Steven Rostedt <rostedt@goodmis.org>]

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From: "Steven Rostedt (Red Hat)" <rostedt@goodmis.org>

In trace_seq_bitmask() it calls bitmap_scnprintf() not from the current
position of the trace_seq buffer (s->buffer + s->len), but instead from
the beginning of the buffer (s->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 <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/trace/trace_seq.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/trace/trace_seq.c b/kernel/trace/trace_seq.c
index 1f24ed99dca2..b100994a17fe 100644
--- 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;
-- 
2.1.1