Add a test case to exercise verifier logic where a global function that
may potentially throw an exception is invoked from the main subprog,
such that during exploration, the reference state is not visible when
the bpf_throw instruction is explored. Without the fixes in prior
commits, bpf_throw will not complain when unreleased resources are
lingering in the program when a possible exception may be thrown.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx>
---
.../selftests/bpf/progs/exceptions_fail.c | 21 +++++++++++++++++++
1 file changed, 21 insertions(+)
diff --git a/tools/testing/selftests/bpf/progs/exceptions_fail.c b/tools/testing/selftests/bpf/progs/exceptions_fail.c
index 9cceb6521143..28602f905d7d 100644
--- a/tools/testing/selftests/bpf/progs/exceptions_fail.c
+++ b/tools/testing/selftests/bpf/progs/exceptions_fail.c
@@ -146,6 +146,13 @@ __noinline static int throwing_subprog(struct __sk_buff *ctx)
return 0;
}
+__noinline int throwing_global_subprog(struct __sk_buff *ctx)
+{
+ if (ctx->len)
+ bpf_throw(0);
+ return 0;
+}
+
SEC("?tc")
__failure __msg("bpf_rcu_read_unlock is missing")
int reject_subprog_with_rcu_read_lock(void *ctx)
@@ -346,4 +353,18 @@ int reject_exception_throw_cb_diff(struct __sk_buff *ctx)
return 0;
}
+SEC("?tc")
+__failure __msg("exploring program path where exception is thrown")
+int reject_exception_throw_ref_call_throwing_global(struct __sk_buff *ctx)
+{
+ struct { long a; } *p = bpf_obj_new(typeof(*p));
+
+ if (!p)
+ return 0;
+ if (ctx->protocol)
+ throwing_global_subprog(ctx);
+ bpf_obj_drop(p);
+ return 0;
+}
+
char _license[] SEC("license") = "GPL";
--
2.40.1
