[PATCH bpf-next v3 08/10] selftests: bpf: fix test_kfunc_dynptr_param

[Puranjay Mohan <puranjay@kernel.org>]

As verifier now assumes that all kfuncs only takes trusted pointer
arguments, passing 0 (NULL) to a kfunc that doesn't mark the argument as
__nullable or __opt will be rejected with a failure message of: Possibly
NULL pointer passed to trusted arg<n>

Pass a non-null value to the kfunc to test the expected failure mode.

Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
---
 tools/testing/selftests/bpf/progs/test_kfunc_dynptr_param.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/bpf/progs/test_kfunc_dynptr_param.c b/tools/testing/selftests/bpf/progs/test_kfunc_dynptr_param.c
index 061befb004c2..d249113ed657 100644
--- a/tools/testing/selftests/bpf/progs/test_kfunc_dynptr_param.c
+++ b/tools/testing/selftests/bpf/progs/test_kfunc_dynptr_param.c
@@ -48,10 +48,9 @@ SEC("?lsm.s/bpf")
 __failure __msg("arg#0 expected pointer to stack or const struct bpf_dynptr")
 int BPF_PROG(not_ptr_to_stack, int cmd, union bpf_attr *attr, unsigned int size, bool kernel)
 {
-	unsigned long val = 0;
+	static struct bpf_dynptr val;
 
-	return bpf_verify_pkcs7_signature((struct bpf_dynptr *)val,
-					  (struct bpf_dynptr *)val, NULL);
+	return bpf_verify_pkcs7_signature(&val, &val, NULL);
 }
 
 SEC("lsm.s/bpf")
-- 
2.47.3