On Sat, Jan 30, 2021 at 2:10 PM Andrei Matei <andreimatei1@xxxxxxxxx> wrote:
>
> This patch adds support to verifier tests to check for a succession of
> verifier log messages on program load failure. This makes the
> errstr field work uniformly across REJECT and VERBOSE_ACCEPT checks.
>
> This patch also increases the maximum size of a message in the series of
> messages to test from 80 chars to 200 chars. This is in order to keep
> existing tests working, which sometimes test for messages larger than 80
> chars (which was accepted in the REJECT case, when testing for a single
> message, but not in the VERBOSE_ACCEPT case, when testing for possibly
> multiple messages).
> And example of such a long, checked message is in bounds.c:
> "R1 has unknown scalar with mixed signed bounds, pointer arithmetic with
> it prohibited for !root"
>
> Signed-off-by: Andrei Matei <andreimatei1@xxxxxxxxx>
Acked-by: Song Liu <songliubraving@xxxxxx>
> ---
> tools/testing/selftests/bpf/test_verifier.c | 16 +++++++++++++---
> 1 file changed, 13 insertions(+), 3 deletions(-)
>
> diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
> index 59bfa6201d1d..58b5a349d3ba 100644
> --- a/tools/testing/selftests/bpf/test_verifier.c
> +++ b/tools/testing/selftests/bpf/test_verifier.c
> @@ -88,6 +88,10 @@ struct bpf_test {
> int fixup_map_event_output[MAX_FIXUPS];
> int fixup_map_reuseport_array[MAX_FIXUPS];
> int fixup_map_ringbuf[MAX_FIXUPS];
> + /* Expected verifier log output for result REJECT or VERBOSE_ACCEPT.
> + * Can be a tab-separated sequence of expected strings. An empty string
> + * means no log verification.
> + */
> const char *errstr;
> const char *errstr_unpriv;
> uint32_t insn_processed;
> @@ -995,13 +999,19 @@ static int do_prog_test_run(int fd_prog, bool unpriv, uint32_t expected_val,
> return 0;
> }
>
> +/* Returns true if every part of exp (tab-separated) appears in log, in order.
> + *
> + * If exp is an empty string, returns true.
> + */
> static bool cmp_str_seq(const char *log, const char *exp)
> {
> - char needle[80];
> + char needle[200];
> const char *p, *q;
> int len;
>
> do {
> + if (!strlen(exp))
> + break;
> p = strchr(exp, '\t');
> if (!p)
> p = exp + strlen(exp);
> @@ -1015,7 +1025,7 @@ static bool cmp_str_seq(const char *log, const char *exp)
> needle[len] = 0;
> q = strstr(log, needle);
> if (!q) {
> - printf("FAIL\nUnexpected verifier log in successful load!\n"
> + printf("FAIL\nUnexpected verifier log!\n"
> "EXP: %s\nRES:\n", needle);
> return false;
> }
> @@ -1130,7 +1140,7 @@ static void do_test_single(struct bpf_test *test, bool unpriv,
> printf("FAIL\nUnexpected success to load!\n");
> goto fail_log;
> }
> - if (!expected_err || !strstr(bpf_vlog, expected_err)) {
> + if (!expected_err || !cmp_str_seq(bpf_vlog, expected_err)) {
> printf("FAIL\nUnexpected error message!\n\tEXP: %s\n\tRES: %s\n",
> expected_err, bpf_vlog);
> goto fail_log;
> --
> 2.27.0
>
