I have noticed this message popping up when using `valgrind --smc-check=stack --tool=callgrind /path/to/app`: WARNING: unhandled amd64-linux syscall: 332 You may be able to write your own handler. Read the file README_MISSING_SYSCALL_OR_IOCTL. Nevertheless we consider this a bug. Please report it at http://valgrind.org/support/bug_reports.html. I tried it on a few applications such as: echo, emacs, kate, bc, as well as some of my own example projects. So far I have found that this warning appears only with Qt applications.
*** This bug has been marked as a duplicate of bug 392118 ***