diff mbox series

[10/11] selftests/bpf: Add verifier test for d_path helper

Message ID 20200616100512.2168860-11-jolsa@kernel.org
State Changes Requested
Delegated to: BPF Maintainers
Headers show
Series bpf: Add d_path helper | expand

Commit Message

Jiri Olsa June 16, 2020, 10:05 a.m. UTC 
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 <jolsa@kernel.org>
---
 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

Comments

Andrii Nakryiko June 19, 2020, 4:38 a.m. UTC | #1 
On Tue, Jun 16, 2020 at 3:06 AM Jiri Olsa <jolsa@kernel.org> 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 <jolsa@kernel.org>
> ---
>  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
>
Jiri Olsa June 19, 2020, 1:32 p.m. UTC | #2 
On Thu, Jun 18, 2020 at 09:38:56PM -0700, Andrii Nakryiko wrote:
> On Tue, Jun 16, 2020 at 3:06 AM Jiri Olsa <jolsa@kernel.org> 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 <jolsa@kernel.org>
> > ---
> >  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?

ok

> 
> > +       }
> > +
> >         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

ok

> 
> > +           !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?

oops, probably lefover, will check

thanks,
jirka

> 
> 
> > +       .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
> >
>
diff mbox series

Patch

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);
+	}
+
 	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) &&
+	    !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,
+	.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",
+},