Re: [PATCH] selftests/livepatch: Do not check order when using "comm" for dmesg checking
From: Joe Lawrence <joe.lawrence@redhat.com>
Date: 2020-08-27 13:31:22
Also in:
linux-kselftest, lkml
On Thu, Aug 27, 2020 at 01:07:09PM +0200, Miroslav Benes wrote:
check_result() uses "comm" to check expected results of selftests output in dmesg. Everything works fine if timestamps in dmesg are unique. If not, like in this example [ 86.844422] test_klp_callbacks_demo: pre_unpatch_callback: test_klp_callbacks_mod -> [MODULE_STATE_LIVE] Normal state [ 86.844422] livepatch: 'test_klp_callbacks_demo': starting unpatching transition
Heh, our assumption that the timestamps would provide sorting wasn't true after all.
, "comm" fails with "comm: file 2 is not in sorted order". Suppress the order checking with --nocheck-order option. Signed-off-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Joe Lawrence <joe.lawrence@redhat.com>
And not so important for selftests, but helpful for backporting efforts:
Fixes: 2f3f651f3756 ("selftests/livepatch: Use "comm" instead of "diff" for dmesg")
--- The strange thing is, I can reproduce the issue easily and reliably on older codestreams (4.12) but not on current upstream in my testing environment. I think the change makes sense regardless though.
We haven't backported v5.8 changes just yet, so thanks for finding this one and posting a fix. -- Joe
quoted hunk ↗ jump to hunk
tools/testing/selftests/livepatch/functions.sh | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)diff --git a/tools/testing/selftests/livepatch/functions.sh b/tools/testing/selftests/livepatch/functions.sh index 1aba83c87ad3..846c7ed71556 100644 --- a/tools/testing/selftests/livepatch/functions.sh +++ b/tools/testing/selftests/livepatch/functions.sh@@ -278,7 +278,7 @@ function check_result { # help differentiate repeated testing runs. Remove them with a # post-comparison sed filter. - result=$(dmesg | comm -13 "$SAVED_DMESG" - | \ + result=$(dmesg | comm --nocheck-order -13 "$SAVED_DMESG" - | \ grep -e 'livepatch:' -e 'test_klp' | \ grep -v '\(tainting\|taints\) kernel' | \ sed 's/^\[[ 0-9.]*\] //')-- 2.28.0