Re: [PATCH v2] selftests/lkdtm: Use "comm" instead of "diff" for dmesg

From: Shuah Khan
Date: Wed Sep 09 2020 - 17:35:10 EST

On 9/9/20 3:17 PM, Kees Cook wrote:
Instead of full GNU diff (which smaller boot environments may not have),
use "comm" which is more available.

Reported-by: Naresh Kamboju <naresh.kamboju@xxxxxxxxxx>
Cc: Shuah Khan <shuah@xxxxxxxxxx>
Cc: linux-kselftest@xxxxxxxxxxxxxxx
Fixes: f131d9edc29d ("selftests/lkdtm: Don't clear dmesg when running tests")
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
v2: add --nocheck-order, thanks to Joe Lawrence
tools/testing/selftests/lkdtm/ | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/lkdtm/ b/tools/testing/selftests/lkdtm/
index 8383eb89d88a..bb7a1775307b 100755
--- a/tools/testing/selftests/lkdtm/
+++ b/tools/testing/selftests/lkdtm/
@@ -82,7 +82,7 @@ dmesg > "$DMESG"
($SHELL -c 'cat <(echo '"$test"') >'"$TRIGGER" 2>/dev/null) || true
# Record and dump the results
-dmesg | diff --changed-group-format='%>' --unchanged-group-format='' "$DMESG" - > "$LOG" || true
+dmesg | comm --nocheck-order -13 "$DMESG" - > "$LOG" || true
cat "$LOG"
# Check for expected output


Would you like me to take this through kselftest tree?

If you want to take it through lkdtm tree, here is my Ack:

Acked-by: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>

-- Shuah