From d923021c2ce12acb50dc7086a1bf66eed82adf6a Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Tue, 30 Jun 2020 10:12:41 -0700 Subject: bpf: Add tests for PTR_TO_BTF_ID vs. null comparison Add two tests for PTR_TO_BTF_ID vs. null ptr comparison, one for PTR_TO_BTF_ID in the ctx structure and the other for PTR_TO_BTF_ID after one level pointer chasing. In both cases, the test ensures condition is not removed. For example, for this test struct bpf_fentry_test_t { struct bpf_fentry_test_t *a; }; int BPF_PROG(test7, struct bpf_fentry_test_t *arg) { if (arg == 0) test7_result = 1; return 0; } Before the previous verifier change, we have xlated codes: int test7(long long unsigned int * ctx): ; int BPF_PROG(test7, struct bpf_fentry_test_t *arg) 0: (79) r1 = *(u64 *)(r1 +0) ; int BPF_PROG(test7, struct bpf_fentry_test_t *arg) 1: (b4) w0 = 0 2: (95) exit After the previous verifier change, we have: int test7(long long unsigned int * ctx): ; int BPF_PROG(test7, struct bpf_fentry_test_t *arg) 0: (79) r1 = *(u64 *)(r1 +0) ; if (arg == 0) 1: (55) if r1 != 0x0 goto pc+4 ; test7_result = 1; 2: (18) r1 = map[id:6][0]+48 4: (b7) r2 = 1 5: (7b) *(u64 *)(r1 +0) = r2 ; int BPF_PROG(test7, struct bpf_fentry_test_t *arg) 6: (b4) w0 = 0 7: (95) exit Signed-off-by: Yonghong Song Signed-off-by: Daniel Borkmann Acked-by: John Fastabend Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20200630171241.2523875-1-yhs@fb.com --- .../selftests/bpf/prog_tests/fentry_fexit.c | 2 +- tools/testing/selftests/bpf/progs/fentry_test.c | 22 ++++++++++++++++++++++ tools/testing/selftests/bpf/progs/fexit_test.c | 22 ++++++++++++++++++++++ 3 files changed, 45 insertions(+), 1 deletion(-) (limited to 'tools') diff --git a/tools/testing/selftests/bpf/prog_tests/fentry_fexit.c b/tools/testing/selftests/bpf/prog_tests/fentry_fexit.c index 83493bd5745c..109d0345a2be 100644 --- a/tools/testing/selftests/bpf/prog_tests/fentry_fexit.c +++ b/tools/testing/selftests/bpf/prog_tests/fentry_fexit.c @@ -36,7 +36,7 @@ void test_fentry_fexit(void) fentry_res = (__u64 *)fentry_skel->bss; fexit_res = (__u64 *)fexit_skel->bss; printf("%lld\n", fentry_skel->bss->test1_result); - for (i = 0; i < 6; i++) { + for (i = 0; i < 8; i++) { CHECK(fentry_res[i] != 1, "result", "fentry_test%d failed err %lld\n", i + 1, fentry_res[i]); CHECK(fexit_res[i] != 1, "result", diff --git a/tools/testing/selftests/bpf/progs/fentry_test.c b/tools/testing/selftests/bpf/progs/fentry_test.c index 9365b686f84b..5f645fdaba6f 100644 --- a/tools/testing/selftests/bpf/progs/fentry_test.c +++ b/tools/testing/selftests/bpf/progs/fentry_test.c @@ -55,3 +55,25 @@ int BPF_PROG(test6, __u64 a, void *b, short c, int d, void * e, __u64 f) e == (void *)20 && f == 21; return 0; } + +struct bpf_fentry_test_t { + struct bpf_fentry_test_t *a; +}; + +__u64 test7_result = 0; +SEC("fentry/bpf_fentry_test7") +int BPF_PROG(test7, struct bpf_fentry_test_t *arg) +{ + if (arg == 0) + test7_result = 1; + return 0; +} + +__u64 test8_result = 0; +SEC("fentry/bpf_fentry_test8") +int BPF_PROG(test8, struct bpf_fentry_test_t *arg) +{ + if (arg->a == 0) + test8_result = 1; + return 0; +} diff --git a/tools/testing/selftests/bpf/progs/fexit_test.c b/tools/testing/selftests/bpf/progs/fexit_test.c index bd1e17d8024c..0952affb22a6 100644 --- a/tools/testing/selftests/bpf/progs/fexit_test.c +++ b/tools/testing/selftests/bpf/progs/fexit_test.c @@ -56,3 +56,25 @@ int BPF_PROG(test6, __u64 a, void *b, short c, int d, void *e, __u64 f, int ret) e == (void *)20 && f == 21 && ret == 111; return 0; } + +struct bpf_fentry_test_t { + struct bpf_fentry_test *a; +}; + +__u64 test7_result = 0; +SEC("fexit/bpf_fentry_test7") +int BPF_PROG(test7, struct bpf_fentry_test_t *arg) +{ + if (arg == 0) + test7_result = 1; + return 0; +} + +__u64 test8_result = 0; +SEC("fexit/bpf_fentry_test8") +int BPF_PROG(test8, struct bpf_fentry_test_t *arg) +{ + if (arg->a == 0) + test8_result = 1; + return 0; +} -- cgit v1.2.3