From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Wed, 16 Dec 2020 21:23:53 +0000 (-0500)
Subject: Fix: incorrect parameters passed to vtracelog
X-Git-Tag: v2.13.0-rc1~402
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=49faeca7301c4081d16ef360636bc79077c9943f;p=lttng-ust.git

Fix: incorrect parameters passed to vtracelog

The vtracelog APIs should be called from the vtracelog instrumentation
rather than the "tracelog" APIs, because it passes a va_list rather than
a variable argument list (...).

This can be verified by tracing the demo program doc/examples/demo-tracelog/demo-vtracelog:

Issue (corrupted trace output):

16:17:26.686073539] (+0.000000530) thinkos lttng_ust_tracelog:TRACE_ERR: { cpu_id = 2 }, { line = 31, file = "demo-vtracelog.c", func = "print_err", _msg_length = 49, msg = "This is a \"\b\" formatted 638975520 error event d68" }

Fixed:

[16:23:33.538189343] (+0.000000600) thinkos lttng_ust_tracelog:TRACE_ERR: { cpu_id = 3 }, { line = 31, file = "demo-vtracelog.c", func = "print_err", _msg_length = 52, msg = "This is a \"mystring test\" formatted 4 error event 42" }

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I330e339a3bf68fb8d9779bbc71b08c3bc033ac4e
---

diff --git a/include/lttng/tracelog.h b/include/lttng/tracelog.h
index 7aa86809..d4406a43 100644
--- a/include/lttng/tracelog.h
+++ b/include/lttng/tracelog.h
@@ -29,9 +29,11 @@
 extern "C" {
 #endif
 
-#define TP_TRACELOG_CB_TEMPLATE(level) \
-	extern void _lttng_ust_tracelog_##level(const char *file, \
-		int line, const char *func, const char *fmt, ...)
+#define TP_TRACELOG_CB_TEMPLATE(level)					\
+	extern void _lttng_ust_tracelog_##level(const char *file,	\
+		int line, const char *func, const char *fmt, ...);	\
+	extern void _lttng_ust_vtracelog_##level(const char *file,	\
+		int line, const char *func, const char *fmt, va_list ap);
 
 TP_TRACELOG_CB_TEMPLATE(TRACE_EMERG);
 TP_TRACELOG_CB_TEMPLATE(TRACE_ALERT);
@@ -56,14 +58,14 @@ TP_TRACELOG_CB_TEMPLATE(TRACE_DEBUG);
 		LTTNG_STAP_PROBEV(tracepoint_lttng_ust_tracelog, level, ## __VA_ARGS__); \
 		if (caa_unlikely(__tracepoint_lttng_ust_tracelog___##level.state)) \
 			_lttng_ust_tracelog_##level(__FILE__, __LINE__, __func__, \
-				fmt, ## __VA_ARGS__); \
+				fmt, ## __VA_ARGS__);			\
 	} while (0)
 
 #define vtracelog(level, fmt, ap)					\
 	do {								\
 		if (caa_unlikely(__tracepoint_lttng_ust_tracelog___##level.state)) \
-			_lttng_ust_tracelog_##level(__FILE__, __LINE__, __func__, \
-				fmt, ap); \
+			_lttng_ust_vtracelog_##level(__FILE__, __LINE__, __func__, \
+				fmt, ap);				\
 	} while (0)
 
 #ifdef __cplusplus