On Fri, May 13, 2022 at 11:38 PM Luis Chamberlain <mcgrof@xxxxxxxxxx> wrote: > > On Fri, May 13, 2022 at 04:32:13PM +0800, David Gow wrote: > > Make any kselftest test module (using the kselftest_module framework) > > taint the kernel with TAINT_TEST on module load. > > > > Note that several selftests use kernel modules which are not based on > > the kselftest_module framework, and so will not automatically taint the > > kernel. These modules will have to be manually modified if they should > > taint the kernel this way. > > > > Similarly, selftests which do not load modules into the kernel generally > > should not taint the kernel (or possibly should only do so on failure), > > as it's assumed that testing from user-space should be safe. Regardless, > > they can write to /proc/sys/kernel/tainted if required. > > > > Signed-off-by: David Gow <davidgow@xxxxxxxxxx> > > Not all selftest modules use KSTM_MODULE_LOADERS() so I'd like to see a > modpost target as well, otherwise this just covers a sliver of > selftests. > My personal feeling is that the ideal way of solving this is actually to port those modules which aren't using KSTM_MODULE_LOADERS() (or KUnit, or some other system) to do so, or to otherwise manually tag them as selftests and/or make them taint the kernel. That being said, we can gain a bit my making the module-loading helpers in kselftest/module.sh manually taint the kernel with /proc/sys/kernel/tainted, which will catch quite a few of them (even if tainting from userspace before they're loaded is suboptimal). I've also started experimenting with a "test" MODULE_INFO field, which modpost would add with the -t option. That still requires sprinkling MODULE_INFO() everwhere, or the '-t' option to a bunch of makefiles, or doing something more drastic to set it automatically for modules in a given directory / makefile. Or the staging thing of checking the directory / prefix in modpost. I'll play around some more and have something to show in v4. (If we have a MODULE_INFO field, we should use it for KUnit modules, but we'd still have to taint the kernel manually for built-in tests anyway, so it'd be redundant...) -- David
