perf tools: Add memdup function

Adding memdup function to duplicate region of memory.

void *memdup(const void *src, size_t len)

Signed-off-by: Jiri Olsa <[e-mail]>
Cc: Frederic Weisbecker <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: Paul Mackerras <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/util/include/linux/string.h

···
 #include <string.h>
+
+void *memdup(const void *src, size_t len);

tools/perf/util/string.c

···
 #include "util.h"
-#include "string.h"
+#include "linux/string.h"
 
 #define K 1024LL
 /*
···
 	*(end + 1) = '\0';
 
 	return s;
+}
+
+/**
+ * memdup - duplicate region of memory
+ * @src: memory region to duplicate
+ * @len: memory region length
+ */
+void *memdup(const void *src, size_t len)
+{
+	void *p;
+
+	p = malloc(len);
+	if (p)
+		memcpy(p, src, len);
+
+	return p;
 }