[PATCH bpf-next 11/13] selftests/bpf: set BPF_F_TEST_SANITY_SCRIPT by default

Andrii Nakryiko
2023-11-03T00:08:49Z

Make sure to set BPF_F_TEST_SANITY_STRICT program flag by default across
most verifier tests (and a bunch of others that set custom prog flags).

There are currently two tests that do fail validation, if enforced
strictly: verifier_bounds/crossing_64_bit_signed_boundary_2 and
verifier_bounds/crossing_32_bit_signed_boundary_2. To accommodate them,
we teach test_loader a flag negation:

__flag(!<flagname>) will *clear* specified flag, allowing easy opt-out.

We apply __flag(!BPF_F_TEST_SANITY_STRICT) to these to tests.

Also sprinkle BPF_F_TEST_SANITY_STRICT everywhere where we already set
test-only BPF_F_TEST_RND_HI32 flag, for completeness.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
---
.../bpf/prog_tests/bpf_verif_scale.c | 2 +-
.../selftests/bpf/progs/verifier_bounds.c | 2 ++
tools/testing/selftests/bpf/test_loader.c | 35 ++++++++++++++-----
tools/testing/selftests/bpf/test_sock_addr.c | 1 +
tools/testing/selftests/bpf/test_verifier.c | 2 +-
tools/testing/selftests/bpf/testing_helpers.c | 4 +--
6 files changed, 33 insertions(+), 13 deletions(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_verif_scale.c b/tools/testing/selftests/bpf/prog_tests/bpf_verif_scale.c
index 731c343897d8..3f2d70831873 100644
--- a/tools/testing/selftests/bpf/prog_tests/bpf_verif_scale.c
+++ b/tools/testing/selftests/bpf/prog_tests/bpf_verif_scale.c
@@ -35,7 +35,7 @@ static int check_load(const char *file, enum bpf_prog_type type)
}

bpf_program__set_type(prog, type);
- bpf_program__set_flags(prog, BPF_F_TEST_RND_HI32);
+ bpf_program__set_flags(prog, BPF_F_TEST_RND_HI32 | BPF_F_TEST_SANITY_STRICT);
bpf_program__set_log_level(prog, 4 | extra_prog_load_log_flags);

err = bpf_object__load(obj);
diff --git a/tools/testing/selftests/bpf/progs/verifier_bounds.c b/tools/testing/selftests/bpf/progs/verifier_bounds.c
index c5588a14fe2e..0c1460936373 100644
--- a/tools/testing/selftests/bpf/progs/verifier_bounds.c
+++ b/tools/testing/selftests/bpf/progs/verifier_bounds.c
@@ -965,6 +965,7 @@ l0_%=: r0 = 0; \
SEC("xdp")
__description("bound check with JMP_JSLT for crossing 64-bit signed boundary")
__success __retval(0)
+__flag(!BPF_F_TEST_SANITY_STRICT) /* known sanity violation */
__naked void crossing_64_bit_signed_boundary_2(void)
{
asm volatile (" \
@@ -1046,6 +1047,7 @@ l0_%=: r0 = 0; \
SEC("xdp")
__description("bound check with JMP32_JSLT for crossing 32-bit signed boundary")
__success __retval(0)
+__flag(!BPF_F_TEST_SANITY_STRICT) /* known sanity violation */
__naked void crossing_32_bit_signed_boundary_2(void)
{
asm volatile (" \
diff --git a/tools/testing/selftests/bpf/test_loader.c b/tools/testing/selftests/bpf/test_loader.c
index 37ffa57f28a1..57e27b1a73a6 100644
--- a/tools/testing/selftests/bpf/test_loader.c
+++ b/tools/testing/selftests/bpf/test_loader.c
@@ -153,6 +153,14 @@ static int parse_retval(const char *str, int *val, const char *name)
return parse_int(str, val, name);
}

+static void update_flags(int *flags, int flag, bool clear)
+{
+ if (clear)
+ *flags &= ~flag;
+ else
+ *flags |= flag;
+}
+
/* Uses btf_decl_tag attributes to describe the expected test
* behavior, see bpf_misc.h for detailed description of each attribute
* and attribute combinations.
@@ -171,6 +179,7 @@ static int parse_test_spec(struct test_loader *tester,
memset(spec, 0, sizeof(*spec));

spec->prog_name = bpf_program__name(prog);
+ spec->prog_flags = BPF_F_TEST_SANITY_STRICT; /* by default be strict */

btf = bpf_object__btf(obj);
if (!btf) {
@@ -187,7 +196,8 @@ static int parse_test_spec(struct test_loader *tester,
for (i = 1; i < btf__type_cnt(btf); i++) {
const char *s, *val, *msg;
const struct btf_type *t;
- int tmp;
+ bool clear;
+ int flags;

t = btf__type_by_id(btf, i);
if (!btf_is_decl_tag(t))
@@ -253,23 +263,30 @@ static int parse_test_spec(struct test_loader *tester,
goto cleanup;
} else if (str_has_pfx(s, TEST_TAG_PROG_FLAGS_PFX)) {
val = s + sizeof(TEST_TAG_PROG_FLAGS_PFX) - 1;
+
+ clear = val[0] == '!';
+ if (clear)
+ val++;
+
if (strcmp(val, "BPF_F_STRICT_ALIGNMENT") == 0) {
- spec->prog_flags |= BPF_F_STRICT_ALIGNMENT;
+ update_flags(&spec->prog_flags, BPF_F_STRICT_ALIGNMENT, clear);
} else if (strcmp(val, "BPF_F_ANY_ALIGNMENT") == 0) {
- spec->prog_flags |= BPF_F_ANY_ALIGNMENT;
+ update_flags(&spec->prog_flags, BPF_F_ANY_ALIGNMENT, clear);
} else if (strcmp(val, "BPF_F_TEST_RND_HI32") == 0) {
- spec->prog_flags |= BPF_F_TEST_RND_HI32;
+ update_flags(&spec->prog_flags, BPF_F_TEST_RND_HI32, clear);
} else if (strcmp(val, "BPF_F_TEST_STATE_FREQ") == 0) {
- spec->prog_flags |= BPF_F_TEST_STATE_FREQ;
+ update_flags(&spec->prog_flags, BPF_F_TEST_STATE_FREQ, clear);
} else if (strcmp(val, "BPF_F_SLEEPABLE") == 0) {
- spec->prog_flags |= BPF_F_SLEEPABLE;
+ update_flags(&spec->prog_flags, BPF_F_SLEEPABLE, clear);
} else if (strcmp(val, "BPF_F_XDP_HAS_FRAGS") == 0) {
- spec->prog_flags |= BPF_F_XDP_HAS_FRAGS;
+ update_flags(&spec->prog_flags, BPF_F_XDP_HAS_FRAGS, clear);
+ } else if (strcmp(val, "BPF_F_TEST_SANITY_STRICT") == 0) {
+ update_flags(&spec->prog_flags, BPF_F_TEST_SANITY_STRICT, clear);
} else /* assume numeric value */ {
- err = parse_int(val, &tmp, "test prog flags");
+ err = parse_int(val, &flags, "test prog flags");
if (err)
goto cleanup;
- spec->prog_flags |= tmp;
+ update_flags(&spec->prog_flags, flags, clear);
}
}
}
diff --git a/tools/testing/selftests/bpf/test_sock_addr.c b/tools/testing/selftests/bpf/test_sock_addr.c
index 2c89674fc62c..878c077e0fa7 100644
--- a/tools/testing/selftests/bpf/test_sock_addr.c
+++ b/tools/testing/selftests/bpf/test_sock_addr.c
@@ -680,6 +680,7 @@ static int load_path(const struct sock_addr_test *test, const char *path)
bpf_program__set_type(prog, BPF_PROG_TYPE_CGROUP_SOCK_ADDR);
bpf_program__set_expected_attach_type(prog, test->expected_attach_type);
bpf_program__set_flags(prog, BPF_F_TEST_RND_HI32);
+ bpf_program__set_flags(prog, BPF_F_TEST_SANITY_STRICT);

err = bpf_object__load(obj);
if (err) {
diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index 98107e0452d3..4992022f3137 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -1588,7 +1588,7 @@ static void do_test_single(struct bpf_test *test, bool unpriv,
if (fixup_skips != skips)
return;

- pflags = BPF_F_TEST_RND_HI32;
+ pflags = BPF_F_TEST_RND_HI32 | BPF_F_TEST_SANITY_STRICT;
if (test->flags & F_LOAD_WITH_STRICT_ALIGNMENT)
pflags |= BPF_F_STRICT_ALIGNMENT;
if (test->flags & F_NEEDS_EFFICIENT_UNALIGNED_ACCESS)
diff --git a/tools/testing/selftests/bpf/testing_helpers.c b/tools/testing/selftests/bpf/testing_helpers.c
index 8d994884c7b4..9786a94a666c 100644
--- a/tools/testing/selftests/bpf/testing_helpers.c
+++ b/tools/testing/selftests/bpf/testing_helpers.c
@@ -276,7 +276,7 @@ int bpf_prog_test_load(const char *file, enum bpf_prog_type type,
if (type != BPF_PROG_TYPE_UNSPEC && bpf_program__type(prog) != type)
bpf_program__set_type(prog, type);

- flags = bpf_program__flags(prog) | BPF_F_TEST_RND_HI32;
+ flags = bpf_program__flags(prog) | BPF_F_TEST_RND_HI32 | BPF_F_TEST_SANITY_STRICT;
bpf_program__set_flags(prog, flags);

err = bpf_object__load(obj);
@@ -299,7 +299,7 @@ int bpf_test_load_program(enum bpf_prog_type type, const struct bpf_insn *insns,
{
LIBBPF_OPTS(bpf_prog_load_opts, opts,
.kern_version = kern_version,
- .prog_flags = BPF_F_TEST_RND_HI32,
+ .prog_flags = BPF_F_TEST_RND_HI32 | BPF_F_TEST_SANITY_STRICT,
.log_level = extra_prog_load_log_flags,
.log_buf = log_buf,
.log_size = log_buf_sz,
--
2.34.1