From: Andrii Nakryiko <andrii@kernel.org>
Date: Wed, 27 Apr 2022 21:15:23 -0700
Subject: selftests/bpf: Test bpf_map__set_autocreate() and related log fixup
logic
Patch-mainline: v5.19-rc1
Git-commit: 68964e155677ab6eca21784a248b8e65fb745660
References: jsc#PED-1377
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
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
---
tools/testing/selftests/bpf/prog_tests/log_fixup.c | 37 ++++++++++++++++++++-
tools/testing/selftests/bpf/progs/test_log_fixup.c | 26 ++++++++++++++
2 files changed, 62 insertions(+), 1 deletion(-)
--- a/tools/testing/selftests/bpf/prog_tests/log_fixup.c
+++ b/tools/testing/selftests/bpf/prog_tests/log_fixup.c
@@ -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();
}
--- a/tools/testing/selftests/bpf/progs/test_log_fixup.c
+++ b/tools/testing/selftests/bpf/progs/test_log_fixup.c
@@ -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";