perf callchain: Move validate_callchain to callchain lib

Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c
index db628af..ac14861 100644
--- a/tools/perf/util/callchain.c
+++ b/tools/perf/util/callchain.c
@@ -17,6 +17,13 @@
 
 #include "callchain.h"
 
+bool ip_callchain__valid(struct ip_callchain *chain, event_t *event)
+{
+	unsigned int chain_size = event->header.size;
+	chain_size -= (unsigned long)&event->ip.__more_data - (unsigned long)event;
+	return chain->nr * sizeof(u64) <= chain_size;
+}
+
 #define chain_for_each_child(child, parent)	\
 	list_for_each_entry(child, &parent->children, brothers)
 
diff --git a/tools/perf/util/callchain.h b/tools/perf/util/callchain.h
index 8a7e8bb..0f4da09 100644
--- a/tools/perf/util/callchain.h
+++ b/tools/perf/util/callchain.h
@@ -4,6 +4,7 @@
 #include "../perf.h"
 #include <linux/list.h>
 #include <linux/rbtree.h>
+#include "event.h"
 #include "util.h"
 #include "symbol.h"
 
@@ -58,4 +59,6 @@
 int register_callchain_param(struct callchain_param *param);
 int append_chain(struct callchain_node *root, struct ip_callchain *chain,
 		 struct map_symbol *syms);
+
+bool ip_callchain__valid(struct ip_callchain *chain, event_t *event);
 #endif	/* __PERF_CALLCHAIN_H */