[PATCH] tracing/syscalls: ignore numbers outside NR_syscalls' range

[Christoph Hellwig]

On Wed, Oct 29, 2014 at 11:06:58PM +0100, Rabin Vincent wrote:
> ARM has some private syscalls (for example, set_tls(2)) which lie
> outside the range of NR_syscalls.  If any of these are called while
> syscall tracing is being performed, out-of-bounds array access will
> occur in the ftrace and perf sys_{enter,exit} handlers.

While this patch looks like good caution, having syscalls outside of
NR_syscalls seems like a receipe for a disaster.  Can you try to fix
that issue as ell, please?