Add security_ptraceRestriction test

This adds tests for the ptrace restrictions introduced by the Yama LSM
in the kernel.

BUG=chromium-os:22137
TEST=passes on x86-alex when Yama is enabled (using patch series from
 https://gerrit.chromium.org/gerrit/12409)

Signed-off-by: Kees Cook <keescook@chromium.org>

Change-Id: I70787ebb1899028cc86d922a3d361479c836bf23
Reviewed-on: https://gerrit.chromium.org/gerrit/12873
Tested-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Jim Hebert <jimhebert@chromium.org>
Commit-Ready: Kees Cook <keescook@chromium.org>
6 files changed