- fix some cases where we are using uninitialized memory

runtime/vm/os_linux.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"
 #if defined(TARGET_OS_LINUX)
 
 #include "vm/os.h"
 
 #include <errno.h>  // NOLINT
 #include <limits.h>  // NOLINT
 #include <malloc.h>  // NOLINT
 #include <time.h>  // NOLINT
 #include <sys/resource.h>  // NOLINT
 #include <sys/time.h>  // NOLINT
 #include <sys/types.h>  // NOLINT
 #include <sys/syscall.h>  // NOLINT
 #include <sys/stat.h>  // NOLINT
 #include <fcntl.h>  // NOLINT
 #include <unistd.h>  // NOLINT
 
+#include "platform/memory_sanitizer.h"
 #include "platform/utils.h"
 #include "vm/code_observers.h"
 #include "vm/dart.h"
 #include "vm/flags.h"
 #include "vm/isolate.h"
 #include "vm/lockers.h"
 #include "vm/os_thread.h"
 #include "vm/zone.h"
 
 
@@ skipping 282 matching lines @@
 int OS::SNPrint(char* str, size_t size, const char* format, ...) {
   va_list args;
   va_start(args, format);
   int retval = VSNPrint(str, size, format, args);
   va_end(args);
   return retval;
 }
 
 
 int OS::VSNPrint(char* str, size_t size, const char* format, va_list args) {
+  MSAN_UNPOISON(str, size);
   int retval = vsnprintf(str, size, format, args);
   if (retval < 0) {
     FATAL1("Fatal error in OS::VSNPrint with format '%s'", format);
   }
   return retval;
 }
 
 
 char* OS::SCreate(Zone* zone, const char* format, ...) {
   va_list args;
@@ skipping 83 matching lines @@
 }
 
 
 void OS::Exit(int code) {
   exit(code);
 }
 
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_LINUX)