From: Matthieu Baerts <matthieu.baerts@xxxxxxxxxxxx> commit 673004821ab98c6645bd21af56a290854e88f533 upstream. Selftests are supposed to run on any kernels, including the old ones not supporting all MPTCP features. New functions are now available to easily detect if a certain feature is missing by looking at kallsyms. These new helpers are going to be used in the following commits. In order to ease the backport of such future patches, it would be good if this patch is backported up to the introduction of MPTCP selftests, hence the Fixes tag below: this type of check was supposed to be done from the beginning. Link: https://github.com/multipath-tcp/mptcp_net-next/issues/368 Fixes: 048d19d444be ("mptcp: add basic kselftest for mptcp") Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Matthieu Baerts <matthieu.baerts@xxxxxxxxxxxx> Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- tools/testing/selftests/net/mptcp/config | 1 tools/testing/selftests/net/mptcp/mptcp_lib.sh | 38 +++++++++++++++++++++++++ 2 files changed, 39 insertions(+) --- a/tools/testing/selftests/net/mptcp/config +++ b/tools/testing/selftests/net/mptcp/config @@ -1,3 +1,4 @@ +CONFIG_KALLSYMS=y CONFIG_MPTCP=y CONFIG_IPV6=y CONFIG_MPTCP_IPV6=y --- a/tools/testing/selftests/net/mptcp/mptcp_lib.sh +++ b/tools/testing/selftests/net/mptcp/mptcp_lib.sh @@ -38,3 +38,41 @@ mptcp_lib_check_mptcp() { exit ${KSFT_SKIP} fi } + +mptcp_lib_check_kallsyms() { + if ! mptcp_lib_has_file "/proc/kallsyms"; then + echo "SKIP: CONFIG_KALLSYMS is missing" + exit ${KSFT_SKIP} + fi +} + +# Internal: use mptcp_lib_kallsyms_has() instead +__mptcp_lib_kallsyms_has() { + local sym="${1}" + + mptcp_lib_check_kallsyms + + grep -q " ${sym}" /proc/kallsyms +} + +# $1: part of a symbol to look at, add '$' at the end for full name +mptcp_lib_kallsyms_has() { + local sym="${1}" + + if __mptcp_lib_kallsyms_has "${sym}"; then + return 0 + fi + + mptcp_lib_fail_if_expected_feature "${sym} symbol not found" +} + +# $1: part of a symbol to look at, add '$' at the end for full name +mptcp_lib_kallsyms_doesnt_have() { + local sym="${1}" + + if ! __mptcp_lib_kallsyms_has "${sym}"; then + return 0 + fi + + mptcp_lib_fail_if_expected_feature "${sym} symbol has been found" +}