selftests/bpf: test cases for pkt/null checks in subprogs
The first test case, for pointer null checks, is equivalent to the
following pseudo-code. It checks that the verifier does not complain on
line 6 and recognizes that ptr isn't null.
1: ptr = bpf_map_lookup_elem(map, &key);
2: ret = subprog(ptr) {
3: return ptr != NULL;
4: }
5: if (ret)
6: value = *ptr;
The second test case, for packet bound checks, is equivalent to the
following pseudo-code. It checks that the verifier does not complain on
line 7 and recognizes that the packet is at least 1 byte long.
1: pkt_end = ctx.pkt_end;
2: ptr = ctx.pkt + 8;
3: ret = subprog(ptr, pkt_end) {
4: return ptr <= pkt_end;
5: }
6: if (ret)
7: value = *(u8 *)ctx.pkt;
Signed-off-by: Paul Chaignon <paul.chaignon@orange.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2 files changed