Do you have a CL for this?

yes: https://chromium-review.googlesource.com/c/chromiumos/third_party/autotest/+/1253195

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/third_party/autotest/+/453d3ce56473b2eff185d456cf8cb716a141e924

commit 453d3ce56473b2eff185d456cf8cb716a141e924
Author: Luis Hector Chavez <lhchavez@google.com>
Date: Tue Oct 02 12:19:49 2018

security_AltSyscall: Update this test

This change:

* Makes this test pylint-compliant.
* Adds the -Werror compile flag for the test binaries.
* Makes this suite run in the FYI suite in preparation to run it in the
  bvt-cq suite.

BUG= chromium:890647 
TEST=security_AltSyscall

Change-Id: I2ba9051de2847ef0b1fbd5e1e95a8ac85f01c19a
Reviewed-on: https://chromium-review.googlesource.com/1253195
Commit-Ready: Luis Hector Chavez <lhchavez@chromium.org>
Tested-by: Luis Hector Chavez <lhchavez@chromium.org>
Reviewed-by: Jorge Lucangeli Obes <jorgelo@chromium.org>

[modify] https://crrev.com/453d3ce56473b2eff185d456cf8cb716a141e924/client/site_tests/security_AltSyscall/security_AltSyscall.py
[modify] https://crrev.com/453d3ce56473b2eff185d456cf8cb716a141e924/client/site_tests/security_AltSyscall/control
[modify] https://crrev.com/453d3ce56473b2eff185d456cf8cb716a141e924/client/site_tests/security_AltSyscall/src/Makefile
[modify] https://crrev.com/453d3ce56473b2eff185d456cf8cb716a141e924/client/site_tests/security_AltSyscall/src/clock_adjtime.c

Alright, let's also give this a ~week of runs.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/third_party/autotest/+/7bb9c1955164fb7ffda68fbaa1158f6049708411

commit 7bb9c1955164fb7ffda68fbaa1158f6049708411
Author: Luis Hector Chavez <lhchavez@google.com>
Date: Wed Oct 03 20:59:05 2018

security_AltSyscall: Make this test's status TEST_NA when unsupported

This change makes this test mark its run as TEST_NA when alt_syscall is
not supported.

BUG= chromium:890647 
TEST=pre-cq

Change-Id: I466a102b9ed791037d0665dea671b6bacd35541c
Reviewed-on: https://chromium-review.googlesource.com/1258524
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Tested-by: Luis Hector Chavez <lhchavez@chromium.org>
Reviewed-by: Jorge Lucangeli Obes <jorgelo@chromium.org>

[modify] https://crrev.com/7bb9c1955164fb7ffda68fbaa1158f6049708411/client/site_tests/security_AltSyscall/security_AltSyscall.py

The NextAction date has arrived: 2018-10-05

Alright, just waiting for https://chromium-review.googlesource.com/c/chromiumos/third_party/autotest/+/1261958 to land.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/third_party/autotest/+/abca7a190b9d7c12618f0cfd00f80f58bdbf6056

commit abca7a190b9d7c12618f0cfd00f80f58bdbf6056
Author: Luis Hector Chavez <lhchavez@google.com>
Date: Fri Oct 05 22:43:44 2018

security_AltSyscall: Add this test to bvt-cq

This change adds security_AltSyscall to bvt-cq. This should prevent
regressions going forward.

BUG= chromium:890647 
TEST=R71-11125.0.0 has all-non-red runs for this test.

Change-Id: I40106cea3a853a437873150eb3f673bd3b9ffb39
Reviewed-on: https://chromium-review.googlesource.com/1261958
Commit-Ready: Luis Hector Chavez <lhchavez@chromium.org>
Tested-by: Luis Hector Chavez <lhchavez@chromium.org>
Reviewed-by: Jorge Lucangeli Obes <jorgelo@chromium.org>

[modify] https://crrev.com/abca7a190b9d7c12618f0cfd00f80f58bdbf6056/client/site_tests/security_AltSyscall/control

all right, hopefully once 4.19 is a thing, we won't accidentally this feature.