On Tue, Oct 23, 2018 at 11:13:36AM -0600, Shuah Khan wrote: > On 10/23/2018 11:05 AM, Michal Hocko wrote: > > On Tue 23-10-18 08:26:40, Matthew Wilcox wrote: > >> On Tue, Oct 23, 2018 at 09:02:56AM -0600, Shuah Khan wrote: > > [...] > >>> The way it can be handled is by adding a test module under lib. test_kmod, > >>> test_sysctl, test_user_copy etc. > >> > >> The problem is that said module can only invoke functions which are > >> exported using EXPORT_SYMBOL. And there's a cost to exporting them, > >> which I don't think we're willing to pay, purely to get test coverage. > > > > Yes, I think we do not want to export internal functionality which might > > be still interesting for the testing coverage. Maybe we want something > > like EXPORT_SYMBOL_KSELFTEST which would allow to link within the > > kselftest machinery but it wouldn't allow the same for general modules > > and will not give any API promisses. > > > > I like this proposal. I think we will open up lot of test opportunities with > this approach. > > Maybe we can use this stress test as a pilot and see where it takes us. I am a bit worried that such an EXPORT_SYMBOL_KSELFTEST mechanism can be abused by out-of-tree module writers to call internal functionality. How would you prevent that? thanks, - Joel
