Architectures lacks MMU doesn't support fork(2) syscall and only vfork(2) is available with limitations. Thus, we cannot run kselftest on nommu architecture as is.
This commit addresses this issue with the following changes: - on test run stage, avoid calling timeout command when NOMMU=1 variable added to environmental variable, since timeout command uses fork syscall which nommu platform doesn't support. - describe the difference of nommu tests in the document. So command line to build/execute tests for nommu should be like below: $ make ARCH=um NOMMU=1 O=build kselftest-all TARGETS=nommu $ make ARCH=um NOMMU=1 O=build kselftest-install TARGETS=nommu $ NOMMU=1 ./build/kselftest/kselftest_install/run_kselftest.sh -p \ -c nommu Cc: Shuah Khan <[email protected]> Cc: Jonathan Corbet <[email protected]> Cc: Kees Cook <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Will Drewry <[email protected]> Cc: Mark Brown <[email protected]> Cc: Brendan Jackman <[email protected]> Cc: Hangbin Liu <[email protected]> Cc: "Ricardo B. Marliere" <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Closes: https://sashiko.dev/#/patchset/20260813063401.1786548-1-thehajime%40gmail.com Signed-off-by: Hajime Tazaki <[email protected]> -- v2 => v3 - remove unnecessary modification - new target is moved from TARGETS=mm/nommu to TARGETS=nommu - rename CONFIG_NOMMU to NOMMU to avoid confusion to kernel config rfc => v2 - reformat ktap header, reported by Sashiko review - https://lore.kernel.org/linux-mm/[email protected]/ rfc: https://lore.kernel.org/linux-mm/[email protected]/ --- Documentation/dev-tools/kselftest.rst | 14 ++++++++++++++ tools/testing/selftests/kselftest/runner.sh | 6 +++++- 2 files changed, 19 insertions(+), 1 deletion(-) diff --git a/Documentation/dev-tools/kselftest.rst b/Documentation/dev-tools/kselftest.rst index 64c0ec7428a2..c35b819947b7 100644 --- a/Documentation/dev-tools/kselftest.rst +++ b/Documentation/dev-tools/kselftest.rst @@ -230,6 +230,20 @@ section:: .. _tar's auto-compress: https://www.gnu.org/software/tar/manual/html_node/gzip.html#auto_002dcompress +Build and test on nommu target +============================== + +If you (cross-)build kselftests for nommu targets, or run tests on nommu targets, use +``NOMMU=1`` as a make variable/environment setting to tell build system to do the additional +checks. These nommu targets may differ in several ways, such as not supporting fork(2) or +using musl or another libc. Set this variable to apply the necessary build and test adjustments. + +:: + + $ make ARCH=um NOMMU=1 O=build kselftest-all TARGETS=nommu # <= build-only + $ make ARCH=um NOMMU=1 O=build kselftest-install TARGETS=nommu + $ NOMMU=1 ./build/kselftest/kselftest_install/run_kselftest.sh -p -c nommu + Contributing new tests ====================== diff --git a/tools/testing/selftests/kselftest/runner.sh b/tools/testing/selftests/kselftest/runner.sh index 8fc1018d6fec..95b5ebb8bbb9 100644 --- a/tools/testing/selftests/kselftest/runner.sh +++ b/tools/testing/selftests/kselftest/runner.sh @@ -38,8 +38,12 @@ tap_prefix() tap_timeout() { + # nommu doesn't support timeout command (missing fork(2)) + if [ "$NOMMU" = "1" ] ; then + echo "timeout isn't supported for NOMMU" + $1 # Make sure tests will time out if utility is available. - if [ -x /usr/bin/timeout ] ; then + elif [ -x /usr/bin/timeout ] ; then /usr/bin/timeout --foreground "$kselftest_timeout" \ /usr/bin/timeout "$kselftest_timeout" $1 else -- 2.43.0
