kernel/tools/testing/selftests/bpf/prog_tests/subprogs.c, branch linux-6.2.y

selftests/bpf: Test subprog jit when toggle bpf_jit_harden repeatedly

2022-03-16T22:13:36Z

When bpf_jit_harden is toggled between 0 and 2, subprog jit may fail due to inconsistent twice read values of bpf_jit_harden during jit. So add a test to ensure the problem is fixed. Signed-off-by: Hou Tao Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20220309123321.2400262-5-houtao1@huawei.com

libbpf: Don't attempt to load unused subprog as an entry-point BPF program

2020-11-09T21:15:23Z

If BPF code contains unused BPF subprogram and there are no other subprogram calls (which can realistically happen in real-world applications given sufficiently smart Clang code optimizations), libbpf will erroneously assume that subprograms are entry-point programs and will attempt to load them with UNSPEC program type. Fix by not relying on subcall instructions and rather detect it based on the structure of BPF object's sections. Fixes: 9a94f277c4fb ("tools: libbpf: restore the ability to load programs from .text section") Reported-by: Dmitrii Banshchikov Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20201107000251.256821-1-andrii@kernel.org

selftests/bpf: Add selftest for multi-prog sections and bpf-to-bpf calls

2020-09-04T00:14:40Z

Add a selftest excercising bpf-to-bpf subprogram calls, as well as multiple entry-point BPF programs per section. Also make sure that BPF CO-RE works for such set ups both for sub-programs and for multi-entry sections. Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200903203542.15944-8-andriin@fb.com