On Fri, Nov 13, 2020 at 9:18 AM Dmitrii Banshchikov <me@xxxxxxxxxxxxx> wrote: > > Currently verifier enforces return code checks for subprograms in the > same manner as it does for program entry points. This prevents returning > arbitrary scalar values from subprograms. Scalar type of returned values > is checked by btf_prepare_func_args() and hence it should be safe to > allow only scalars for now. Relax return code checks for subprograms and > allow any correct scalar values. > > Signed-off-by: Dmitrii Banshchikov <me@xxxxxxxxxxxxx> > Fixes: 51c39bb1d5d10 (bpf: Introduce function-by-function verification) > --- LGTM! Acked-by: Andrii Nakryiko <andrii@xxxxxxxxxx> > v1 -> v2: > - Move is_subprog flag determination to check_return_code() > - Remove unneeded intermediate function from tests > - Use __noinline instead of __attribute__((noinline)) in tests > > kernel/bpf/verifier.c | 15 +++++++++++++-- > .../bpf/prog_tests/test_global_funcs.c | 1 + > .../selftests/bpf/progs/test_global_func8.c | 19 +++++++++++++++++++ > 3 files changed, 33 insertions(+), 2 deletions(-) > create mode 100644 tools/testing/selftests/bpf/progs/test_global_func8.c > [...]
