selftests: mptcp: lib: skip if missing symbol

BugLink: https://bugs.launchpad.net/bugs/2033931
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@vger.kernel.org
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

diff --git a/tools/testing/selftests/net/mptcp/config b/tools/testing/selftests/net/mptcp/config
index 38021a0dd52762bfdd546ccc0c5b3a5cc0749f3a..6032f9b23c4c2f7de2c237b6bc3d81d13a3cec00 100644 (file)
--- 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

diff --git a/tools/testing/selftests/net/mptcp/mptcp_lib.sh b/tools/testing/selftests/net/mptcp/mptcp_lib.sh
index 3286536b79d55b2edb1743c9f2c52a559feb3a10..29b65f4b73b298306f952d5c3b431bdb0554bc6b 100644 (file)
--- 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"
+}