BusyBox's 'cmp' command doesn't support the '--bytes' parameter.
Some CIs -- i.e. LKFT -- use BusyBox and have the mptcp_join.sh test failing [1] because their 'cmp' command doesn't support this '--bytes' option:
cmp: unrecognized option '--bytes=1024' BusyBox v1.35.0 () multi-call binary.
Usage: cmp [-ls] [-n NUM] FILE1 [FILE2]
Instead, 'head --bytes' can be used as this option is supported by BusyBox. A temporary file is needed for this operation.
Because it is apparently quite common to use BusyBox, it is certainly better to backport this fix to impacted kernels.
Fixes: 6bf41020b72b ("selftests: mptcp: update and extend fastclose test-cases") Cc: stable@vger.kernel.org Link: https://qa-reports.linaro.org/lkft/linux-mainline-master/build/v6.3-rc5-5-g1... [1] Suggested-by: Paolo Abeni pabeni@redhat.com Reviewed-by: Mat Martineau martineau@kernel.org Signed-off-by: Matthieu Baerts matthieu.baerts@tessares.net --- tools/testing/selftests/net/mptcp/mptcp_join.sh | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh index 26310c17b4c6..4f3fe45f8f71 100755 --- a/tools/testing/selftests/net/mptcp/mptcp_join.sh +++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh @@ -17,6 +17,7 @@ sout="" cin="" cinfail="" cinsent="" +tmpfile="" cout="" capout="" ns1="" @@ -175,6 +176,7 @@ cleanup() { rm -f "$cin" "$cout" "$sinfail" rm -f "$sin" "$sout" "$cinsent" "$cinfail" + rm -f "$tmpfile" rm -rf $evts_ns1 $evts_ns2 cleanup_partial } @@ -383,9 +385,16 @@ check_transfer() fail_test return 1 fi - bytes="--bytes=${bytes}" + + # note: BusyBox's "cmp" command doesn't support --bytes + tmpfile=$(mktemp) + head --bytes="$bytes" "$in" > "$tmpfile" + mv "$tmpfile" "$in" + head --bytes="$bytes" "$out" > "$tmpfile" + mv "$tmpfile" "$out" + tmpfile="" fi - cmp -l "$in" "$out" ${bytes} | while read -r i a b; do + cmp -l "$in" "$out" | while read -r i a b; do local sum=$((0${a} + 0${b})) if [ $check_invert -eq 0 ] || [ $sum -ne $((0xff)) ]; then echo "[ FAIL ] $what does not match (in, out):"