From: Michel Normand <normand@fr.ibm.com>
Date: Fri, 15 May 2009 08:43:51 +0000 (+0200)
Subject: properly handle va_list in log_append functions
X-Git-Tag: lxc_0_6_3~95
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5fd8380be601c9f82708096a90a554d37f07b949;p=thirdparty%2Flxc.git

properly handle va_list in log_append functions

the support of multiple appenders need to associate
one va_list per appender.
This is the purpose of this patch to copy the va_list
before to call the appender.

Signed-off-by: Michel Normand <normand@fr.ibm.com>
Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>
---

diff --git a/src/lxc/log.c b/src/lxc/log.c
index a5a43535d..af5566933 100644
--- a/src/lxc/log.c
+++ b/src/lxc/log.c
@@ -45,7 +45,7 @@ lxc_log_define(lxc_log, lxc);
 
 /*---------------------------------------------------------------------------*/
 static int log_append_logfile(const struct lxc_log_appender *appender,
-	const struct lxc_log_event *event)
+			      struct lxc_log_event *event)
 {
 	char buffer[LXC_LOG_BUFFER_SIZE];
 	int n;
@@ -62,10 +62,10 @@ static int log_append_logfile(const struct lxc_log_appender *appender,
 		     event->category);
 
 	n += vsnprintf(buffer + n, sizeof(buffer) - n, event->fmt,
-		       event->va);
+		       *event->vap);
 
 	if (n >= sizeof(buffer) - 1) {
-		WARN("truncated next event from %d to %d bytes", n,
+		WARN("truncated next event from %d to %zd bytes", n,
 		     sizeof(buffer));
 		n = sizeof(buffer) - 1;
 	}
diff --git a/src/lxc/log.h b/src/lxc/log.h
index a8a82b8ed..1443eb286 100644
--- a/src/lxc/log.h
+++ b/src/lxc/log.h
@@ -71,14 +71,13 @@ struct lxc_log_event {
 	struct timeval		timestamp;
 	struct lxc_log_locinfo	*locinfo;
 	const char		*fmt;
-	va_list 		va;
+	va_list			*vap;
 };
 
 /* log appender object */
 struct lxc_log_appender {
 	const char*	name;
-	int (*append)(const struct lxc_log_appender *,
-		      const struct lxc_log_event *);
+	int (*append)(const struct lxc_log_appender *, struct lxc_log_event *);
 
 	/*
 	 * appenders can be stacked
@@ -148,17 +147,23 @@ static inline int lxc_log_priority_to_int(const char* name)
 
 static inline void
 __lxc_log_append(const struct lxc_log_appender *appender,
-		const struct lxc_log_event* event)
+		struct lxc_log_event* event)
 {
+	va_list va, *va_keep;
+	va_keep = event->vap;
+
 	while (appender) {
+		va_copy(va, *va_keep);
+		event->vap = &va;
 		appender->append(appender, event);
 		appender = appender->next;
+		va_end(va);
 	}
 }
 
 static inline void
 __lxc_log(const struct lxc_log_category* category,
-	 const struct lxc_log_event* event)
+	  struct lxc_log_event* event)
 {
 	while (category) {
 		__lxc_log_append(category->appender, event);
@@ -185,12 +190,14 @@ static inline void LXC_##PRIORITY(struct lxc_log_locinfo* locinfo,	\
 			.fmt		= format,			\
 			.locinfo	= locinfo			\
 		};							\
+		va_list va_ref;						\
 									\
 		gettimeofday(&evt.timestamp, NULL);			\
 									\
-		va_start(evt.va, format);				\
+		va_start(va_ref, format);				\
+		evt.vap = &va_ref;					\
 		__lxc_log(acategory, &evt);				\
-		va_end(evt.va);						\
+		va_end(va_ref);						\
 	}								\
 }