On Thu, 19 May 2022 at 15:08, David Gow <davidgow@xxxxxxxxxx> wrote: > > On Wed, May 18, 2022 at 5:21 PM Marco Elver <elver@xxxxxxxxxx> wrote: > > > > On Wed, May 18, 2022 at 03:32PM +0800, David Gow wrote: > > > Add a .kunitconfig file, which provides a default, working config for > > > running the KCSAN tests. Note that it needs to run on an SMP machine, so > > > to run under kunit_tool, the x86_64-smp qemu-based setup should be used: > > > ./tools/testing/kunit/kunit.py run --arch=x86_64-smp --kunitconfig=kernel/kcsan > > > > > > Signed-off-by: David Gow <davidgow@xxxxxxxxxx> > > > > Reviewed-by: Marco Elver <elver@xxxxxxxxxx> > > > > Thanks for adding this. > > > > > --- > > > kernel/kcsan/.kunitconfig | 20 ++++++++++++++++++++ > > > 1 file changed, 20 insertions(+) > > > create mode 100644 kernel/kcsan/.kunitconfig > > > > > > diff --git a/kernel/kcsan/.kunitconfig b/kernel/kcsan/.kunitconfig > > > new file mode 100644 > > > index 000000000000..a8a815b1eb73 > > > --- /dev/null > > > +++ b/kernel/kcsan/.kunitconfig > > > @@ -0,0 +1,20 @@ > > > +# Note that the KCSAN tests need to run on an SMP setup. > > > +# Under kunit_tool, this can be done by using the x86_64-smp > > > +# qemu-based architecture: > > > +# ./tools/testing/kunit/kunit.py run --kunitconfig=kernel/kcsan --arch=x86_64-smp > > > + > > > +CONFIG_KUNIT=y > > > + > > > +CONFIG_DEBUG_KERNEL=y > > > + > > > +CONFIG_KCSAN=y > > > +CONFIG_KCSAN_KUNIT_TEST=y > > > + > > > +# Needed for test_barrier_nothreads > > > +CONFIG_KCSAN_STRICT=y > > > +CONFIG_KCSAN_WEAK_MEMORY=y > > > > Note, KCSAN_STRICT implies KCSAN_WEAK_MEMORY. > > > > Also, a bunch of the test cases' outcomes depend on KCSAN's > > "strictness". I think to cover the various combinations would be too > > complex, but we can just settle on testing KCSAN_STRICT=y. > > It's definitely possible to either have multiple .kunitconfigs, each > of which could have slightly different setups, e.g.: > - kernel/kcsan/.kunitconfig (defualt) > - kernel/kcsan/strict.kunitconfig (passed explicitly when desired) > > Equally, if we got rid of KCSAN_STRICT in the .kunitconfig, you could > override it with --kconfig_add, e.g. > - ./tools/testing/kunit/kunit.py run --kunitconfig=kernel/kcsan > --arch=x86_64-smp > - ./tools/testing/kunit/kunit.py run --kunitconfig=kernel/kcsan > --arch=x86_64-smp --kconfig_add CONFIG_KSCAN_STRICT=y > > > The end result is the same, but you could drop the > > CONFIG_KCSAN_WEAK_MEMORY=y line, and let the latest KCSAN_STRICT > > defaults decide (I don't expect them to change any time soon). > > > > If you want it to be more explicit, it's also fine leaving the > > CONFIG_KCSAN_WEAK_MEMORY=y line in. > > Do you have a preference here? Or to get rid of both and default to > the non-strict version mentioned above? I'd keep it simple for now, and remove both lines i.e. make non-strict the default. It's easy to just run with --kconfig_add CONFIG_KCSAN_STRICT=y, along with other variations. I know that rcutoruture uses KCSAN_STRICT=y by default, so it's already getting coverage there. ;-) Thanks, -- Marco
