On 1/27/21 3:31 AM, Andrei Matei wrote:
On Tue, Jan 26, 2021 at 6:21 PM Daniel Borkmann <daniel@xxxxxxxxxxxxx> wrote:
On 1/24/21 8:05 PM, Andrei Matei 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 an accepted 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 ironically 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>
---
tools/testing/selftests/bpf/test_verifier.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index 59bfa6201d1d..69298bf8ee86 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -88,6 +88,9 @@ 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.
+ */
const char *errstr;
const char *errstr_unpriv;
uint32_t insn_processed;
@@ -995,9 +998,11 @@ 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.
+ */
static bool cmp_str_seq(const char *log, const char *exp)
{
- char needle[80];
+ char needle[200];
const char *p, *q;
int len;
@@ -1015,7 +1020,7 @@ 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 +1135,11 @@ 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) {
+ printf("FAIL\nTestcase bug; missing expected_err\n");
+ goto fail_log;
Do we have an in-tree case like this?
You're asking if there are tests with expected_res == REJECT and
expected_err == NULL?
There are no such test cases, and the intention of this "testcase bug"
check was to keep it that way.
I can simply fold it into the test failure below, as you're suggesting.
Yeah, I would just fold it given such issue would be visible there as well.
Given this would also be visible below with 'EXP:'
being (null), I might simplify and just replace the strstr() with cmp_str_seq().
Also, could you elaborate on which test cases need the cmp_str_seq() conversion?
There are VERBOSE_ACCEPT tests that you a tab-separated list of
expected messages; see precise.c.
There are no such REJECT tests yet. I was about to introduce one in
another patch that's inflight, but I ended
up not needing to. Still, I figured that unifying the capabilities of
.errstr between VERBOSE_ACCEPT and REJECT
is a good idea.
I think unifying seems reasonable, lets do then.
Thanks,
Daniel
