Add a selftest to ensure BPF for loops within critical sections are
accepted by the verifier.
Signed-off-by: Emil Tsalapatis (Meta) <emil@xxxxxxxxxxxxxxx>
Acked-by: Eduard Zingerman <eddyz87@xxxxxxxxx>
---
.../selftests/bpf/progs/verifier_spin_lock.c | 26 +++++++++++++++++++
1 file changed, 26 insertions(+)
diff --git a/tools/testing/selftests/bpf/progs/verifier_spin_lock.c b/tools/testing/selftests/bpf/progs/verifier_spin_lock.c
index 25599eac9a70..d9d7b05cf6d2 100644
--- a/tools/testing/selftests/bpf/progs/verifier_spin_lock.c
+++ b/tools/testing/selftests/bpf/progs/verifier_spin_lock.c
@@ -530,4 +530,30 @@ l1_%=: exit; \
: __clobber_all);
}
+SEC("tc")
+__description("spin_lock: loop within a locked region")
+__success __failure_unpriv __msg_unpriv("")
+__retval(0)
+int bpf_loop_inside_locked_region(void)
+{
+ const int zero = 0;
+ struct val *val;
+ int i, j = 0;
+
+ val = bpf_map_lookup_elem(&map_spin_lock, &zero);
+ if (!val)
+ return -1;
+
+ bpf_spin_lock(&val->l);
+ bpf_for(i, 0, 10) {
+ j++;
+ /* Silence "unused variable" warnings. */
+ if (j == 10)
+ break;
+ }
+ bpf_spin_unlock(&val->l);
+
+ return 0;
+}
+
char _license[] SEC("license") = "GPL";
--
2.47.1
