[PATCH 4/4] bpf:selftests: Add kfunc_call test for mixing 32-bit and 64-bit parameters

[Yang Jihong]

for function foo(u32 a, u64 b, u32 c) in 32-bit ARM: a is in r0, b is in
r2-r3, c is stored on the stack.
Because the AAPCS states:
"A double-word sized type is passed in two consecutive registers (e.g., r0
and r1, or r2 and r3). The content of the registers is as if the value had
been loaded from memory representation with a single LDM instruction."
Supplement the test cases in this case.

Signed-off-by: Yang Jihong <yangjihong1@xxxxxxxxxx>
---
 net/bpf/test_run.c                            |  6 +++++
 .../selftests/bpf/prog_tests/kfunc_call.c     |  1 +
 .../selftests/bpf/progs/kfunc_call_test.c     | 23 +++++++++++++++++++
 3 files changed, 30 insertions(+)

diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
index 13d578ce2a09..bdfb3081e1ce 100644
--- a/net/bpf/test_run.c
+++ b/net/bpf/test_run.c
@@ -551,6 +551,11 @@ struct sock * noinline bpf_kfunc_call_test3(struct sock *sk)
 	return sk;
 }
 
+u64 noinline bpf_kfunc_call_test4(struct sock *sk, u64 a, u64 b, u32 c, u32 d)
+{
+	return a + b + c + d;
+}
+
 struct prog_test_member1 {
 	int a;
 };
@@ -739,6 +744,7 @@ BTF_SET8_START(test_sk_check_kfunc_ids)
 BTF_ID_FLAGS(func, bpf_kfunc_call_test1)
 BTF_ID_FLAGS(func, bpf_kfunc_call_test2)
 BTF_ID_FLAGS(func, bpf_kfunc_call_test3)
+BTF_ID_FLAGS(func, bpf_kfunc_call_test4)
 BTF_ID_FLAGS(func, bpf_kfunc_call_test_acquire, KF_ACQUIRE | KF_RET_NULL)
 BTF_ID_FLAGS(func, bpf_kfunc_call_memb_acquire, KF_ACQUIRE | KF_RET_NULL)
 BTF_ID_FLAGS(func, bpf_kfunc_call_test_release, KF_RELEASE)
diff --git a/tools/testing/selftests/bpf/prog_tests/kfunc_call.c b/tools/testing/selftests/bpf/prog_tests/kfunc_call.c
index 5af1ee8f0e6e..13a105bb05ed 100644
--- a/tools/testing/selftests/bpf/prog_tests/kfunc_call.c
+++ b/tools/testing/selftests/bpf/prog_tests/kfunc_call.c
@@ -72,6 +72,7 @@ static struct kfunc_test_params kfunc_tests[] = {
 	/* success cases */
 	TC_TEST(kfunc_call_test1, 12),
 	TC_TEST(kfunc_call_test2, 3),
+	TC_TEST(kfunc_call_test4, 16),
 	TC_TEST(kfunc_call_test_ref_btf_id, 0),
 	TC_TEST(kfunc_call_test_get_mem, 42),
 	SYSCALL_TEST(kfunc_syscall_test, 0),
diff --git a/tools/testing/selftests/bpf/progs/kfunc_call_test.c b/tools/testing/selftests/bpf/progs/kfunc_call_test.c
index f636e50be259..7cccb014d26e 100644
--- a/tools/testing/selftests/bpf/progs/kfunc_call_test.c
+++ b/tools/testing/selftests/bpf/progs/kfunc_call_test.c
@@ -6,6 +6,8 @@
 extern int bpf_kfunc_call_test2(struct sock *sk, __u32 a, __u32 b) __ksym;
 extern __u64 bpf_kfunc_call_test1(struct sock *sk, __u32 a, __u64 b,
 				  __u32 c, __u64 d) __ksym;
+extern __u64 bpf_kfunc_call_test4(struct sock *sk, __u64 a, __u64 b,
+				  __u32 c, __u32 d) __ksym;
 
 extern struct prog_test_ref_kfunc *bpf_kfunc_call_test_acquire(unsigned long *sp) __ksym;
 extern void bpf_kfunc_call_test_release(struct prog_test_ref_kfunc *p) __ksym;
@@ -17,6 +19,27 @@ extern void bpf_kfunc_call_test_mem_len_fail2(__u64 *mem, int len) __ksym;
 extern int *bpf_kfunc_call_test_get_rdwr_mem(struct prog_test_ref_kfunc *p, const int rdwr_buf_size) __ksym;
 extern int *bpf_kfunc_call_test_get_rdonly_mem(struct prog_test_ref_kfunc *p, const int rdonly_buf_size) __ksym;
 
+SEC("tc")
+int kfunc_call_test4(struct __sk_buff *skb)
+{
+	struct bpf_sock *sk = skb->sk;
+	__u64 a = 1ULL << 32;
+	__u32 ret;
+
+	if (!sk)
+		return -1;
+
+	sk = bpf_sk_fullsock(sk);
+	if (!sk)
+		return -1;
+
+	a = bpf_kfunc_call_test4((struct sock *)sk, a | 2, a | 3, 4, 5);
+	ret = a >> 32;   /* ret should be 2 */
+	ret += (__u32)a; /* ret should be 16 */
+
+	return ret;
+}
+
 SEC("tc")
 int kfunc_call_test2(struct __sk_buff *skb)
 {
-- 
2.30.GIT