exercising current aarch64 kprobe support with systemtap

[William Cohen]

Hi all,

When running the current systemtap checked out from the git repository
and a locally built kernel with the kprobes64-v13 patches (the
test_upstream_arm64_devel branch of
https://github.com/pratyushanand/linux) on Fedora 23 machine one of
the kprobes_onthefly.exp tests is causing the machine to get in a
state that requires rebooting to fix.  This can be triggered by running a
portion of the systemtap tests with:

 make installcheck RUNTESTFLAGS="--debug systemtap.onthefly/kprobes_onthefly.exp"

When it gets to the kprobes_onthefly - otf_stress_max_iter_5000 test the
console starts spewing the following and needs to be rebooted:

[23394.036860] Unexpected kernel single-step exception at EL1
[23394.042434] Unexpected kernel single-step exception at EL1
[23394.048008] Unexpected kernel single-step exception at EL1
[23394.053541] Unexpected kernel single-step exception at EL1
[23394.059053] Unexpected kernel single-step exception at EL1
[23394.064545] Unexpected kernel single-step exception at EL1

Sorry I don't have the start of the failure it scrolled off the screen very quickly.

-Will