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| author | Paul Chaignon <paul.chaignon@orange.com> | 2019-04-24 21:51:26 +0200 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2019-04-25 17:20:06 -0700 |
| commit | 6dd7f14080473b655c247863e61b7c34424f0c83 (patch) | |
| tree | 4ab4ef6b132c7066ef4f4df74211707caf0b324b | |
| parent | c6a9efa1d8353d8960d152e7d469d952b01495c0 (diff) | |
| download | lwn-6dd7f14080473b655c247863e61b7c34424f0c83.tar.gz lwn-6dd7f14080473b655c247863e61b7c34424f0c83.zip | |
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>
| -rw-r--r-- | tools/testing/selftests/bpf/verifier/calls.c | 25 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/verifier/direct_packet_access.c | 22 |
2 files changed, 47 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/verifier/calls.c b/tools/testing/selftests/bpf/verifier/calls.c index fb11240b758b..9093a8f64dc6 100644 --- a/tools/testing/selftests/bpf/verifier/calls.c +++ b/tools/testing/selftests/bpf/verifier/calls.c @@ -375,6 +375,31 @@ .flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS, }, { + "calls: ptr null check in subprog", + .insns = { + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), + BPF_MOV64_REG(BPF_REG_6, BPF_REG_0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, 3), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_6, 0), + BPF_EXIT_INSN(), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 1), + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + .errstr_unpriv = "function calls to other bpf functions are allowed for root only", + .fixup_map_hash_48b = { 3 }, + .result_unpriv = REJECT, + .result = ACCEPT, + .retval = 0, +}, +{ "calls: two calls with args", .insns = { BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, 1), diff --git a/tools/testing/selftests/bpf/verifier/direct_packet_access.c b/tools/testing/selftests/bpf/verifier/direct_packet_access.c index e3fc22e672c2..d5c596fdc4b9 100644 --- a/tools/testing/selftests/bpf/verifier/direct_packet_access.c +++ b/tools/testing/selftests/bpf/verifier/direct_packet_access.c @@ -631,3 +631,25 @@ .errstr = "invalid access to packet", .prog_type = BPF_PROG_TYPE_SCHED_CLS, }, +{ + "direct packet access: test29 (reg > pkt_end in subprog)", + .insns = { + BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1, + offsetof(struct __sk_buff, data)), + BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, + offsetof(struct __sk_buff, data_end)), + BPF_MOV64_REG(BPF_REG_3, BPF_REG_6), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_3, 8), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, 4), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_6, 0), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_JMP_REG(BPF_JGT, BPF_REG_3, BPF_REG_2, 1), + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, +}, |