An example of no invalid memory access message from valgrind,
==150659== Memcheck, a memory error detector
==150659== Copyright (C) 2002-2015, and GNU GPLd, by Julian Seward et al.
==150659== Using Valgrind-3.12.0 and LibVEX; rerun with -h for copyright info
==150659== Command: ./Work/pthread/sim.out
==150659==
INFO: Reading options file './Work/options/x86sim.options'.
date
==150659==
==150659== HEAP SUMMARY:
==150659== in use at exit: 184,181 bytes in 716 blocks
==150659== total heap usage: 2,239,062 allocs, 2,238,346 frees, 141,993,399 bytes allocated
==150659==
==150659== For a detailed leak analysis, rerun with: --leak-check=full
==150659==
==150659== For counts of detected and suppressed errors, rerun with: -v
==150659== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)