On Wed, Oct 09, 2019 at 04:06:18PM -0700, Alexei Starovoitov wrote: > On Wed, Oct 9, 2019 at 9:09 AM Christian Brauner > <christian.brauner@xxxxxxxxxx> wrote: > > > > Hey everyone, > > > > In v5.4-rc2 we added two new helpers check_zeroed_user() and > > copy_struct_from_user() including selftests (cf. [1]). It is a generic > > interface designed to copy a struct from userspace. The helpers will be > > especially useful for structs versioned by size of which we have quite a > > few. > > > > The most obvious benefit is that this helper lets us get rid of > > duplicate code. We've already switched over sched_setattr(), perf_event_open(), > > and clone3(). More importantly it will also help to ensure that users > > implementing versioning-by-size end up with the same core semantics. > > > > This point is especially crucial since we have at least one case where > > versioning-by-size is used but with slighly different semantics: > > sched_setattr(), perf_event_open(), and clone3() all do do similar > > checks to copy_struct_from_user() while rt_sigprocmask(2) always rejects > > differently-sized struct arguments. > > > > This little series switches over bpf codepaths that have hand-rolled > > implementations of these helpers. > > check_zeroed_user() is not in bpf-next. > we will let this set sit in patchworks for some time until bpf-next > is merged back into net-next and we fast forward it. > Then we can apply it (assuming no conflicts). Sounds good to me. Just ping me when you need me to resend rebase onto bpf-next. Christian