Add more debugging to run_host_test

If a host test fails, record the execution state of the EC host process.

This is an attempt to provide a hint whether the test was blocked on
I/O, if so it might be in 'D' state (but it might have recovered too
late too).

Signed-off-by: Vincent Palatin <vpalatin@chromium.org>

BRANCH=none
BUG=chromium:715011
TEST=run 'make runtests -j', then run it again with TIMEOUT reduced to 1
see it fail on 'kb_scan' and 'interrupt' tests with the trace containing
'*** test [...] in state Ssl+ ***'

Change-Id: I4590a4b84a2aba8d385d3ef911d5d0186e8ce2e3
Reviewed-on: https://chromium-review.googlesource.com/859771
Commit-Ready: Vincent Palatin <vpalatin@chromium.org>
Tested-by: Vincent Palatin <vpalatin@chromium.org>
Reviewed-by: Randall Spangler <rspangler@chromium.org>

util/run_host_test

@@ -7,6 +7,7 @@
 from cStringIO import StringIO
 import pexpect
 import signal
+import subprocess
 import sys
 import time
 
@@ -19,6 +20,8 @@ RESULT_ID_EOF = 3
 
 EXPECT_LIST = [pexpect.TIMEOUT, 'Pass!', 'Fail!', pexpect.EOF]
 
+PS_ARGS = ['ps', '--no-headers', '-o', 'stat', '--pid']
+
 class Tee(object):
   def __init__(self, target):
     self._target = target
@@ -39,6 +42,10 @@ def RunOnce(test_name, log):
     return child.expect(EXPECT_LIST)
   finally:
     if child.isalive():
+      ps_cmd = PS_ARGS + ['%d' % (child.pid)]
+      ps_stat = subprocess.check_output(ps_cmd).strip()
+      log.write('\n*** test %s process %d in state %s ***\n' %
+                (test_name, child.pid, ps_stat))
       child.kill(signal.SIGTERM)
     child.read()