[PATCH bpf-next 2/5] selftests/bpf: Add test for new bpf_cpumask_first_and() kfunc

[David Vernet <void@xxxxxxxxxxxxx>]

A prior patch added a new kfunc called bpf_cpumask_first_and() which
wraps cpumask_first_and(). This patch adds a selftest to validate its
behavior.

Signed-off-by: David Vernet <void@xxxxxxxxxxxxx>
---
 .../selftests/bpf/prog_tests/cpumask.c        |  1 +
 .../selftests/bpf/progs/cpumask_common.h      |  2 ++
 .../selftests/bpf/progs/cpumask_success.c     | 32 +++++++++++++++++++
 3 files changed, 35 insertions(+)

diff --git a/tools/testing/selftests/bpf/prog_tests/cpumask.c b/tools/testing/selftests/bpf/prog_tests/cpumask.c
index d89191440fb1..756ea8b590b6 100644
--- a/tools/testing/selftests/bpf/prog_tests/cpumask.c
+++ b/tools/testing/selftests/bpf/prog_tests/cpumask.c
@@ -10,6 +10,7 @@ static const char * const cpumask_success_testcases[] = {
 	"test_set_clear_cpu",
 	"test_setall_clear_cpu",
 	"test_first_firstzero_cpu",
+	"test_firstand_nocpu",
 	"test_test_and_set_clear",
 	"test_and_or_xor",
 	"test_intersects_subset",
diff --git a/tools/testing/selftests/bpf/progs/cpumask_common.h b/tools/testing/selftests/bpf/progs/cpumask_common.h
index 0c5b785a93e4..b3493d5d263e 100644
--- a/tools/testing/selftests/bpf/progs/cpumask_common.h
+++ b/tools/testing/selftests/bpf/progs/cpumask_common.h
@@ -28,6 +28,8 @@ void bpf_cpumask_release(struct bpf_cpumask *cpumask) __ksym;
 struct bpf_cpumask *bpf_cpumask_acquire(struct bpf_cpumask *cpumask) __ksym;
 u32 bpf_cpumask_first(const struct cpumask *cpumask) __ksym;
 u32 bpf_cpumask_first_zero(const struct cpumask *cpumask) __ksym;
+u32 bpf_cpumask_first_and(const struct cpumask *src1,
+			  const struct cpumask *src2) __ksym;
 void bpf_cpumask_set_cpu(u32 cpu, struct bpf_cpumask *cpumask) __ksym;
 void bpf_cpumask_clear_cpu(u32 cpu, struct bpf_cpumask *cpumask) __ksym;
 bool bpf_cpumask_test_cpu(u32 cpu, const struct cpumask *cpumask) __ksym;
diff --git a/tools/testing/selftests/bpf/progs/cpumask_success.c b/tools/testing/selftests/bpf/progs/cpumask_success.c
index 602a88b03dbc..fbaf510f4ab5 100644
--- a/tools/testing/selftests/bpf/progs/cpumask_success.c
+++ b/tools/testing/selftests/bpf/progs/cpumask_success.c
@@ -175,6 +175,38 @@ int BPF_PROG(test_first_firstzero_cpu, struct task_struct *task, u64 clone_flags
 	return 0;
 }
 
+SEC("tp_btf/task_newtask")
+int BPF_PROG(test_firstand_nocpu, struct task_struct *task, u64 clone_flags)
+{
+	struct bpf_cpumask *mask1, *mask2;
+	u32 first;
+
+	if (!is_test_task())
+		return 0;
+
+	mask1 = create_cpumask();
+	if (!mask1)
+		return 0;
+
+	mask2 = create_cpumask();
+	if (!mask2)
+		goto release_exit;
+
+	bpf_cpumask_set_cpu(0, mask1);
+	bpf_cpumask_set_cpu(1, mask2);
+
+	first = bpf_cpumask_first_and(cast(mask1), cast(mask2));
+	if (first <= 1)
+		err = 3;
+
+release_exit:
+	if (mask1)
+		bpf_cpumask_release(mask1);
+	if (mask2)
+		bpf_cpumask_release(mask2);
+	return 0;
+}
+
 SEC("tp_btf/task_newtask")
 int BPF_PROG(test_test_and_set_clear, struct task_struct *task, u64 clone_flags)
 {
-- 
2.40.1