On Wed, Oct 16, 2019 at 02:41:35AM +0200, Christian Brauner 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. > > Thanks! > Christian > > /* v1 */ > Link: https://lore.kernel.org/r/20191009160907.10981-1-christian.brauner@xxxxxxxxxx > > /* v2 */ > - rebase onto bpf-next > > /* Reference */ > [1]: f5a1a536fa14 ("lib: introduce copy_struct_from_user() helper") Alexei, instead of applying the series you can also just pull from me: The following changes since commit 5bc60de50dfea235634fdf38cbc992fb968d113b: selftests: bpf: Don't try to read files without read permission (2019-10-15 16:27:25 -0700) are available in the Git repository at: git@xxxxxxxxxxxxxxxxxxx:pub/scm/linux/kernel/git/brauner/linux tags/bpf-copy-struct-from-user for you to fetch changes up to da1699b959d182bb161be3ffc17eab063b2aedd2: bpf: use copy_struct_from_user() in bpf() syscall (2019-10-16 02:35:11 +0200) ---------------------------------------------------------------- bpf-copy-struct-from-user ---------------------------------------------------------------- Christian Brauner (3): bpf: use check_zeroed_user() in bpf_check_uarg_tail_zero() bpf: use copy_struct_from_user() in bpf_prog_get_info_by_fd() bpf: use copy_struct_from_user() in bpf() syscall kernel/bpf/syscall.c | 46 ++++++++++++++++++---------------------------- 1 file changed, 18 insertions(+), 28 deletions(-)
