Merge pull request #1293 from iovisor/tools_fixes

Couple minor tools fixes

src/cc/usdt.cc

@@ -356,6 +356,9 @@ const char *bcc_usdt_genargs(void **usdt_array, int len) {
   static std::string storage_;
   std::ostringstream stream;
 
+  if (!len)
+    return "";
+
   stream << USDT::USDT_PROGRAM_HEADER;
   // Generate genargs codes for an array of USDT Contexts.
   //

tools/dcstat.py

@@ -49,7 +49,7 @@ enum stats {
     S_MAXSTAT
 };
 
-BPF_ARRAY(stats, u64, S_MAXSTAT + 1);
+BPF_ARRAY(stats, u64, S_MAXSTAT);
 
 /*
  * How this is instrumented, and how to interpret the statistics, is very much

tools/pidpersec.py

@@ -26,7 +26,7 @@ enum stat_types {
     S_MAXSTAT
 };
 
-BPF_ARRAY(stats, u64, S_MAXSTAT + 1);
+BPF_ARRAY(stats, u64, S_MAXSTAT);
 
 static void stats_increment(int key) {
     u64 *leaf = stats.lookup(&key);

tools/vfsstat.py

@@ -49,7 +49,7 @@ enum stat_types {
     S_MAXSTAT
 };
 
-BPF_ARRAY(stats, u64, S_MAXSTAT + 1);
+BPF_ARRAY(stats, u64, S_MAXSTAT);
 
 static void stats_increment(int key) {
     u64 *leaf = stats.lookup(&key);