selftests/bpf: Test bpf_map__set_autocreate() and related log fixup logic

Add a subtest that excercises bpf_map__set_autocreate() API and
validates that libbpf properly fixes up BPF verifier log with correct
map information.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220428041523.4089853-5-andrii@kernel.org
This commit is contained in:
Andrii Nakryiko 2022-04-27 21:15:23 -07:00 committed by Alexei Starovoitov
parent ec41817b4a
commit 68964e1556
2 changed files with 62 additions and 1 deletions

View File

@ -85,7 +85,6 @@ static void bad_core_relo_subprog(void)
if (!ASSERT_ERR(err, "load_fail"))
goto cleanup;
/* there should be no prog loading log because we specified per-prog log buf */
ASSERT_HAS_SUBSTR(log_buf,
": <invalid CO-RE relocation>\n"
"failed to resolve CO-RE relocation <byte_off> ",
@ -101,6 +100,40 @@ cleanup:
test_log_fixup__destroy(skel);
}
static void missing_map(void)
{
char log_buf[8 * 1024];
struct test_log_fixup* skel;
int err;
skel = test_log_fixup__open();
if (!ASSERT_OK_PTR(skel, "skel_open"))
return;
bpf_map__set_autocreate(skel->maps.missing_map, false);
bpf_program__set_autoload(skel->progs.use_missing_map, true);
bpf_program__set_log_buf(skel->progs.use_missing_map, log_buf, sizeof(log_buf));
err = test_log_fixup__load(skel);
if (!ASSERT_ERR(err, "load_fail"))
goto cleanup;
ASSERT_TRUE(bpf_map__autocreate(skel->maps.existing_map), "existing_map_autocreate");
ASSERT_FALSE(bpf_map__autocreate(skel->maps.missing_map), "missing_map_autocreate");
ASSERT_HAS_SUBSTR(log_buf,
"8: <invalid BPF map reference>\n"
"BPF map 'missing_map' is referenced but wasn't created\n",
"log_buf");
if (env.verbosity > VERBOSE_NONE)
printf("LOG: \n=================\n%s=================\n", log_buf);
cleanup:
test_log_fixup__destroy(skel);
}
void test_log_fixup(void)
{
if (test__start_subtest("bad_core_relo_trunc_none"))
@ -111,4 +144,6 @@ void test_log_fixup(void)
bad_core_relo(250, TRUNC_FULL /* truncate also libbpf's message patch */);
if (test__start_subtest("bad_core_relo_subprog"))
bad_core_relo_subprog();
if (test__start_subtest("missing_map"))
missing_map();
}

View File

@ -35,4 +35,30 @@ int bad_relo_subprog(const void *ctx)
return bad_subprog() + bpf_core_field_size(t->pid);
}
struct {
__uint(type, BPF_MAP_TYPE_ARRAY);
__uint(max_entries, 1);
__type(key, int);
__type(value, int);
} existing_map SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_ARRAY);
__uint(max_entries, 1);
__type(key, int);
__type(value, int);
} missing_map SEC(".maps");
SEC("?raw_tp/sys_enter")
int use_missing_map(const void *ctx)
{
int zero = 0, *value;
value = bpf_map_lookup_elem(&existing_map, &zero);
value = bpf_map_lookup_elem(&missing_map, &zero);
return value != NULL;
}
char _license[] SEC("license") = "GPL";