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charset="UTF-8" Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Tue, Jun 16, 2020 at 3:06 AM Jiri Olsa wrote: > > Adding verifier test for attaching tracing program and > calling d_path helper from within and testing that it's > allowed for dentry_open function and denied for 'd_path' > function with appropriate error. > > Signed-off-by: Jiri Olsa > --- > tools/testing/selftests/bpf/test_verifier.c | 13 ++++++- > tools/testing/selftests/bpf/verifier/d_path.c | 38 +++++++++++++++++++ > 2 files changed, 50 insertions(+), 1 deletion(-) > create mode 100644 tools/testing/selftests/bpf/verifier/d_path.c > > diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c > index 78a6bae56ea6..3cce3dc766a2 100644 > --- a/tools/testing/selftests/bpf/test_verifier.c > +++ b/tools/testing/selftests/bpf/test_verifier.c > @@ -114,6 +114,7 @@ struct bpf_test { > bpf_testdata_struct_t retvals[MAX_TEST_RUNS]; > }; > enum bpf_attach_type expected_attach_type; > + const char *kfunc; > }; > > /* Note we want this to be 64 bit aligned so that the end of our array is > @@ -984,8 +985,18 @@ static void do_test_single(struct bpf_test *test, bool unpriv, > attr.log_level = 4; > attr.prog_flags = pflags; > > + if (prog_type == BPF_PROG_TYPE_TRACING && test->kfunc) { > + attr.attach_btf_id = libbpf_find_vmlinux_btf_id(test->kfunc, > + attr.expected_attach_type); if (!attr.attach_btf_id) emit more meaningful error, than later during load? > + } > + > fd_prog = bpf_load_program_xattr(&attr, bpf_vlog, sizeof(bpf_vlog)); > - if (fd_prog < 0 && !bpf_probe_prog_type(prog_type, 0)) { > + > + /* BPF_PROG_TYPE_TRACING requires more setup and > + * bpf_probe_prog_type won't give correct answer > + */ > + if (fd_prog < 0 && (prog_type != BPF_PROG_TYPE_TRACING) && nit: () are redundant > + !bpf_probe_prog_type(prog_type, 0)) { > printf("SKIP (unsupported program type %d)\n", prog_type); > skips++; > goto close_fds; > diff --git a/tools/testing/selftests/bpf/verifier/d_path.c b/tools/testing/selftests/bpf/verifier/d_path.c > new file mode 100644 > index 000000000000..e08181abc056 > --- /dev/null > +++ b/tools/testing/selftests/bpf/verifier/d_path.c > @@ -0,0 +1,38 @@ > +{ > + "d_path accept", > + .insns = { > + BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_1, 0), > + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), > + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), > + BPF_MOV64_IMM(BPF_REG_6, 0), > + BPF_STX_MEM(BPF_DW, BPF_REG_2, BPF_REG_6, 0), > + BPF_LD_IMM64(BPF_REG_3, 8), > + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_d_path), > + BPF_MOV64_IMM(BPF_REG_0, 0), > + BPF_EXIT_INSN(), > + }, > + .errstr = "R0 max value is outside of the array range", > + .result = ACCEPT, accept with error string expected? > + .prog_type = BPF_PROG_TYPE_TRACING, > + .expected_attach_type = BPF_TRACE_FENTRY, > + .kfunc = "dentry_open", > +}, > +{ > + "d_path reject", > + .insns = { > + BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_1, 0), > + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), > + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), > + BPF_MOV64_IMM(BPF_REG_6, 0), > + BPF_STX_MEM(BPF_DW, BPF_REG_2, BPF_REG_6, 0), > + BPF_LD_IMM64(BPF_REG_3, 8), > + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_d_path), > + BPF_MOV64_IMM(BPF_REG_0, 0), > + BPF_EXIT_INSN(), > + }, > + .errstr = "helper call is not allowed in probe", > + .result = REJECT, > + .prog_type = BPF_PROG_TYPE_TRACING, > + .expected_attach_type = BPF_TRACE_FENTRY, > + .kfunc = "d_path", > +}, > -- > 2.25.4 >