From 68964e155677ab6eca21784a248b8e65fb745660 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Wed, 27 Apr 2022 21:15:23 -0700 Subject: [PATCH] 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 Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20220428041523.4089853-5-andrii@kernel.org --- .../selftests/bpf/prog_tests/log_fixup.c | 37 ++++++++++++++++++- .../selftests/bpf/progs/test_log_fixup.c | 26 +++++++++++++ 2 files changed, 62 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/bpf/prog_tests/log_fixup.c b/tools/testing/selftests/bpf/prog_tests/log_fixup.c index be3a956cb3a5..f4ffdcabf4e4 100644 --- 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, ": \n" "failed to resolve CO-RE relocation ", @@ -101,6 +100,40 @@ static void bad_core_relo_subprog(void) 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: \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(); } diff --git a/tools/testing/selftests/bpf/progs/test_log_fixup.c b/tools/testing/selftests/bpf/progs/test_log_fixup.c index a78980d897b3..60450cb0e72e 100644 --- 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";