aboutsummaryrefslogtreecommitdiffstatshomepage
path: root/tools/testing/selftests/bpf/progs/cpumask_success.c
diff options
context:
space:
mode:
Diffstat (limited to 'tools/testing/selftests/bpf/progs/cpumask_success.c')
-rw-r--r--tools/testing/selftests/bpf/progs/cpumask_success.c890
1 files changed, 890 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/cpumask_success.c b/tools/testing/selftests/bpf/progs/cpumask_success.c
new file mode 100644
index 000000000000..0e04c31b91c0
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/cpumask_success.c
@@ -0,0 +1,890 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2023 Meta Platforms, Inc. and affiliates. */
+
+#include <vmlinux.h>
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_helpers.h>
+
+#include "bpf_misc.h"
+#include "cpumask_common.h"
+
+char _license[] SEC("license") = "GPL";
+
+int pid, nr_cpus;
+
+struct kptr_nested {
+ struct bpf_cpumask __kptr * mask;
+};
+
+struct kptr_nested_pair {
+ struct bpf_cpumask __kptr * mask_1;
+ struct bpf_cpumask __kptr * mask_2;
+};
+
+struct kptr_nested_mid {
+ int dummy;
+ struct kptr_nested m;
+};
+
+struct kptr_nested_deep {
+ struct kptr_nested_mid ptrs[2];
+ struct kptr_nested_pair ptr_pairs[3];
+};
+
+struct kptr_nested_deep_array_1_2 {
+ int dummy;
+ struct bpf_cpumask __kptr * mask[CPUMASK_KPTR_FIELDS_MAX];
+};
+
+struct kptr_nested_deep_array_1_1 {
+ int dummy;
+ struct kptr_nested_deep_array_1_2 d_2;
+};
+
+struct kptr_nested_deep_array_1 {
+ long dummy;
+ struct kptr_nested_deep_array_1_1 d_1;
+};
+
+struct kptr_nested_deep_array_2_2 {
+ long dummy[2];
+ struct bpf_cpumask __kptr * mask;
+};
+
+struct kptr_nested_deep_array_2_1 {
+ int dummy;
+ struct kptr_nested_deep_array_2_2 d_2[CPUMASK_KPTR_FIELDS_MAX];
+};
+
+struct kptr_nested_deep_array_2 {
+ long dummy;
+ struct kptr_nested_deep_array_2_1 d_1;
+};
+
+struct kptr_nested_deep_array_3_2 {
+ long dummy[2];
+ struct bpf_cpumask __kptr * mask;
+};
+
+struct kptr_nested_deep_array_3_1 {
+ int dummy;
+ struct kptr_nested_deep_array_3_2 d_2;
+};
+
+struct kptr_nested_deep_array_3 {
+ long dummy;
+ struct kptr_nested_deep_array_3_1 d_1[CPUMASK_KPTR_FIELDS_MAX];
+};
+
+private(MASK) static struct bpf_cpumask __kptr * global_mask_array[2];
+private(MASK) static struct bpf_cpumask __kptr * global_mask_array_l2[2][1];
+private(MASK) static struct bpf_cpumask __kptr * global_mask_array_one[1];
+private(MASK) static struct kptr_nested global_mask_nested[2];
+private(MASK_DEEP) static struct kptr_nested_deep global_mask_nested_deep;
+private(MASK_1) static struct kptr_nested_deep_array_1 global_mask_nested_deep_array_1;
+private(MASK_2) static struct kptr_nested_deep_array_2 global_mask_nested_deep_array_2;
+private(MASK_3) static struct kptr_nested_deep_array_3 global_mask_nested_deep_array_3;
+
+static bool is_test_task(void)
+{
+ int cur_pid = bpf_get_current_pid_tgid() >> 32;
+
+ return pid == cur_pid;
+}
+
+static bool create_cpumask_set(struct bpf_cpumask **out1,
+ struct bpf_cpumask **out2,
+ struct bpf_cpumask **out3,
+ struct bpf_cpumask **out4)
+{
+ struct bpf_cpumask *mask1, *mask2, *mask3, *mask4;
+
+ mask1 = create_cpumask();
+ if (!mask1)
+ return false;
+
+ mask2 = create_cpumask();
+ if (!mask2) {
+ bpf_cpumask_release(mask1);
+ err = 3;
+ return false;
+ }
+
+ mask3 = create_cpumask();
+ if (!mask3) {
+ bpf_cpumask_release(mask1);
+ bpf_cpumask_release(mask2);
+ err = 4;
+ return false;
+ }
+
+ mask4 = create_cpumask();
+ if (!mask4) {
+ bpf_cpumask_release(mask1);
+ bpf_cpumask_release(mask2);
+ bpf_cpumask_release(mask3);
+ err = 5;
+ return false;
+ }
+
+ *out1 = mask1;
+ *out2 = mask2;
+ *out3 = mask3;
+ *out4 = mask4;
+
+ return true;
+}
+
+SEC("tp_btf/task_newtask")
+int BPF_PROG(test_alloc_free_cpumask, struct task_struct *task, u64 clone_flags)
+{
+ struct bpf_cpumask *cpumask;
+
+ if (!is_test_task())
+ return 0;
+
+ cpumask = create_cpumask();
+ if (!cpumask)
+ return 0;
+
+ bpf_cpumask_release(cpumask);
+ return 0;
+}
+
+SEC("tp_btf/task_newtask")
+int BPF_PROG(test_set_clear_cpu, struct task_struct *task, u64 clone_flags)
+{
+ struct bpf_cpumask *cpumask;
+
+ if (!is_test_task())
+ return 0;
+
+ cpumask = create_cpumask();
+ if (!cpumask)
+ return 0;
+
+ bpf_cpumask_set_cpu(0, cpumask);
+ if (!bpf_cpumask_test_cpu(0, cast(cpumask))) {
+ err = 3;
+ goto release_exit;
+ }
+
+ bpf_cpumask_clear_cpu(0, cpumask);
+ if (bpf_cpumask_test_cpu(0, cast(cpumask))) {
+ err = 4;
+ goto release_exit;
+ }
+
+release_exit:
+ bpf_cpumask_release(cpumask);
+ return 0;
+}
+
+SEC("tp_btf/task_newtask")
+int BPF_PROG(test_setall_clear_cpu, struct task_struct *task, u64 clone_flags)
+{
+ struct bpf_cpumask *cpumask;
+
+ if (!is_test_task())
+ return 0;
+
+ cpumask = create_cpumask();
+ if (!cpumask)
+ return 0;
+
+ bpf_cpumask_setall(cpumask);
+ if (!bpf_cpumask_full(cast(cpumask))) {
+ err = 3;
+ goto release_exit;
+ }
+
+ bpf_cpumask_clear(cpumask);
+ if (!bpf_cpumask_empty(cast(cpumask))) {
+ err = 4;
+ goto release_exit;
+ }
+
+release_exit:
+ bpf_cpumask_release(cpumask);
+ return 0;
+}
+
+SEC("tp_btf/task_newtask")
+int BPF_PROG(test_first_firstzero_cpu, struct task_struct *task, u64 clone_flags)
+{
+ struct bpf_cpumask *cpumask;
+
+ if (!is_test_task())
+ return 0;
+
+ cpumask = create_cpumask();
+ if (!cpumask)
+ return 0;
+
+ if (bpf_cpumask_first(cast(cpumask)) < nr_cpus) {
+ err = 3;
+ goto release_exit;
+ }
+
+ if (bpf_cpumask_first_zero(cast(cpumask)) != 0) {
+ bpf_printk("first zero: %d", bpf_cpumask_first_zero(cast(cpumask)));
+ err = 4;
+ goto release_exit;
+ }
+
+ bpf_cpumask_set_cpu(0, cpumask);
+ if (bpf_cpumask_first(cast(cpumask)) != 0) {
+ err = 5;
+ goto release_exit;
+ }
+
+ if (bpf_cpumask_first_zero(cast(cpumask)) != 1) {
+ err = 6;
+ goto release_exit;
+ }
+
+release_exit:
+ bpf_cpumask_release(cpumask);
+ 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)
+{
+ struct bpf_cpumask *cpumask;
+
+ if (!is_test_task())
+ return 0;
+
+ cpumask = create_cpumask();
+ if (!cpumask)
+ return 0;
+
+ if (bpf_cpumask_test_and_set_cpu(0, cpumask)) {
+ err = 3;
+ goto release_exit;
+ }
+
+ if (!bpf_cpumask_test_and_set_cpu(0, cpumask)) {
+ err = 4;
+ goto release_exit;
+ }
+
+ if (!bpf_cpumask_test_and_clear_cpu(0, cpumask)) {
+ err = 5;
+ goto release_exit;
+ }
+
+release_exit:
+ bpf_cpumask_release(cpumask);
+ return 0;
+}
+
+SEC("tp_btf/task_newtask")
+int BPF_PROG(test_and_or_xor, struct task_struct *task, u64 clone_flags)
+{
+ struct bpf_cpumask *mask1, *mask2, *dst1, *dst2;
+
+ if (!is_test_task())
+ return 0;
+
+ if (!create_cpumask_set(&mask1, &mask2, &dst1, &dst2))
+ return 0;
+
+ bpf_cpumask_set_cpu(0, mask1);
+ bpf_cpumask_set_cpu(1, mask2);
+
+ if (bpf_cpumask_and(dst1, cast(mask1), cast(mask2))) {
+ err = 6;
+ goto release_exit;
+ }
+ if (!bpf_cpumask_empty(cast(dst1))) {
+ err = 7;
+ goto release_exit;
+ }
+
+ bpf_cpumask_or(dst1, cast(mask1), cast(mask2));
+ if (!bpf_cpumask_test_cpu(0, cast(dst1))) {
+ err = 8;
+ goto release_exit;
+ }
+ if (!bpf_cpumask_test_cpu(1, cast(dst1))) {
+ err = 9;
+ goto release_exit;
+ }
+
+ bpf_cpumask_xor(dst2, cast(mask1), cast(mask2));
+ if (!bpf_cpumask_equal(cast(dst1), cast(dst2))) {
+ err = 10;
+ goto release_exit;
+ }
+
+release_exit:
+ bpf_cpumask_release(mask1);
+ bpf_cpumask_release(mask2);
+ bpf_cpumask_release(dst1);
+ bpf_cpumask_release(dst2);
+ return 0;
+}
+
+SEC("tp_btf/task_newtask")
+int BPF_PROG(test_intersects_subset, struct task_struct *task, u64 clone_flags)
+{
+ struct bpf_cpumask *mask1, *mask2, *dst1, *dst2;
+
+ if (!is_test_task())
+ return 0;
+
+ if (!create_cpumask_set(&mask1, &mask2, &dst1, &dst2))
+ return 0;
+
+ bpf_cpumask_set_cpu(0, mask1);
+ bpf_cpumask_set_cpu(1, mask2);
+ if (bpf_cpumask_intersects(cast(mask1), cast(mask2))) {
+ err = 6;
+ goto release_exit;
+ }
+
+ bpf_cpumask_or(dst1, cast(mask1), cast(mask2));
+ if (!bpf_cpumask_subset(cast(mask1), cast(dst1))) {
+ err = 7;
+ goto release_exit;
+ }
+
+ if (!bpf_cpumask_subset(cast(mask2), cast(dst1))) {
+ err = 8;
+ goto release_exit;
+ }
+
+ if (bpf_cpumask_subset(cast(dst1), cast(mask1))) {
+ err = 9;
+ goto release_exit;
+ }
+
+release_exit:
+ bpf_cpumask_release(mask1);
+ bpf_cpumask_release(mask2);
+ bpf_cpumask_release(dst1);
+ bpf_cpumask_release(dst2);
+ return 0;
+}
+
+SEC("tp_btf/task_newtask")
+int BPF_PROG(test_copy_any_anyand, struct task_struct *task, u64 clone_flags)
+{
+ struct bpf_cpumask *mask1, *mask2, *dst1, *dst2;
+ int cpu;
+
+ if (!is_test_task())
+ return 0;
+
+ if (!create_cpumask_set(&mask1, &mask2, &dst1, &dst2))
+ return 0;
+
+ bpf_cpumask_set_cpu(0, mask1);
+ bpf_cpumask_set_cpu(1, mask2);
+ bpf_cpumask_or(dst1, cast(mask1), cast(mask2));
+
+ cpu = bpf_cpumask_any_distribute(cast(mask1));
+ if (cpu != 0) {
+ err = 6;
+ goto release_exit;
+ }
+
+ cpu = bpf_cpumask_any_distribute(cast(dst2));
+ if (cpu < nr_cpus) {
+ err = 7;
+ goto release_exit;
+ }
+
+ bpf_cpumask_copy(dst2, cast(dst1));
+ if (!bpf_cpumask_equal(cast(dst1), cast(dst2))) {
+ err = 8;
+ goto release_exit;
+ }
+
+ cpu = bpf_cpumask_any_distribute(cast(dst2));
+ if (cpu > 1) {
+ err = 9;
+ goto release_exit;
+ }
+
+ cpu = bpf_cpumask_any_and_distribute(cast(mask1), cast(mask2));
+ if (cpu < nr_cpus) {
+ err = 10;
+ goto release_exit;
+ }
+
+release_exit:
+ bpf_cpumask_release(mask1);
+ bpf_cpumask_release(mask2);
+ bpf_cpumask_release(dst1);
+ bpf_cpumask_release(dst2);
+ return 0;
+}
+
+SEC("tp_btf/task_newtask")
+int BPF_PROG(test_insert_leave, struct task_struct *task, u64 clone_flags)
+{
+ struct bpf_cpumask *cpumask;
+
+ cpumask = create_cpumask();
+ if (!cpumask)
+ return 0;
+
+ if (cpumask_map_insert(cpumask))
+ err = 3;
+
+ return 0;
+}
+
+SEC("tp_btf/task_newtask")
+int BPF_PROG(test_insert_remove_release, struct task_struct *task, u64 clone_flags)
+{
+ struct bpf_cpumask *cpumask;
+ struct __cpumask_map_value *v;
+
+ cpumask = create_cpumask();
+ if (!cpumask)
+ return 0;
+
+ if (cpumask_map_insert(cpumask)) {
+ err = 3;
+ return 0;
+ }
+
+ v = cpumask_map_value_lookup();
+ if (!v) {
+ err = 4;
+ return 0;
+ }
+
+ cpumask = bpf_kptr_xchg(&v->cpumask, NULL);
+ if (cpumask)
+ bpf_cpumask_release(cpumask);
+ else
+ err = 5;
+
+ return 0;
+}
+
+SEC("tp_btf/task_newtask")
+int BPF_PROG(test_global_mask_rcu, struct task_struct *task, u64 clone_flags)
+{
+ struct bpf_cpumask *local, *prev;
+
+ if (!is_test_task())
+ return 0;
+
+ local = create_cpumask();
+ if (!local)
+ return 0;
+
+ prev = bpf_kptr_xchg(&global_mask, local);
+ if (prev) {
+ bpf_cpumask_release(prev);
+ err = 3;
+ return 0;
+ }
+
+ bpf_rcu_read_lock();
+ local = global_mask;
+ if (!local) {
+ err = 4;
+ bpf_rcu_read_unlock();
+ return 0;
+ }
+
+ bpf_cpumask_test_cpu(0, (const struct cpumask *)local);
+ bpf_rcu_read_unlock();
+
+ return 0;
+}
+
+SEC("tp_btf/task_newtask")
+int BPF_PROG(test_global_mask_array_one_rcu, struct task_struct *task, u64 clone_flags)
+{
+ struct bpf_cpumask *local, *prev;
+
+ if (!is_test_task())
+ return 0;
+
+ /* Kptr arrays with one element are special cased, being treated
+ * just like a single pointer.
+ */
+
+ local = create_cpumask();
+ if (!local)
+ return 0;
+
+ prev = bpf_kptr_xchg(&global_mask_array_one[0], local);
+ if (prev) {
+ bpf_cpumask_release(prev);
+ err = 3;
+ return 0;
+ }
+
+ bpf_rcu_read_lock();
+ local = global_mask_array_one[0];
+ if (!local) {
+ err = 4;
+ bpf_rcu_read_unlock();
+ return 0;
+ }
+
+ bpf_rcu_read_unlock();
+
+ return 0;
+}
+
+static int _global_mask_array_rcu(struct bpf_cpumask **mask0,
+ struct bpf_cpumask **mask1)
+{
+ struct bpf_cpumask *local;
+
+ if (!is_test_task())
+ return 0;
+
+ /* Check if two kptrs in the array work and independently */
+
+ local = create_cpumask();
+ if (!local)
+ return 0;
+
+ bpf_rcu_read_lock();
+
+ local = bpf_kptr_xchg(mask0, local);
+ if (local) {
+ err = 1;
+ goto err_exit;
+ }
+
+ /* [<mask 0>, *] */
+ if (!*mask0) {
+ err = 2;
+ goto err_exit;
+ }
+
+ if (!mask1)
+ goto err_exit;
+
+ /* [*, NULL] */
+ if (*mask1) {
+ err = 3;
+ goto err_exit;
+ }
+
+ local = create_cpumask();
+ if (!local) {
+ err = 9;
+ goto err_exit;
+ }
+
+ local = bpf_kptr_xchg(mask1, local);
+ if (local) {
+ err = 10;
+ goto err_exit;
+ }
+
+ /* [<mask 0>, <mask 1>] */
+ if (!*mask0 || !*mask1 || *mask0 == *mask1) {
+ err = 11;
+ goto err_exit;
+ }
+
+err_exit:
+ if (local)
+ bpf_cpumask_release(local);
+ bpf_rcu_read_unlock();
+ return 0;
+}
+
+SEC("tp_btf/task_newtask")
+int BPF_PROG(test_global_mask_array_rcu, struct task_struct *task, u64 clone_flags)
+{
+ return _global_mask_array_rcu(&global_mask_array[0], &global_mask_array[1]);
+}
+
+SEC("tp_btf/task_newtask")
+int BPF_PROG(test_global_mask_array_l2_rcu, struct task_struct *task, u64 clone_flags)
+{
+ return _global_mask_array_rcu(&global_mask_array_l2[0][0], &global_mask_array_l2[1][0]);
+}
+
+SEC("tp_btf/task_newtask")
+int BPF_PROG(test_global_mask_nested_rcu, struct task_struct *task, u64 clone_flags)
+{
+ return _global_mask_array_rcu(&global_mask_nested[0].mask, &global_mask_nested[1].mask);
+}
+
+/* Ensure that the field->offset has been correctly advanced from one
+ * nested struct or array sub-tree to another. In the case of
+ * kptr_nested_deep, it comprises two sub-trees: ktpr_1 and kptr_2. By
+ * calling bpf_kptr_xchg() on every single kptr in both nested sub-trees,
+ * the verifier should reject the program if the field->offset of any kptr
+ * is incorrect.
+ *
+ * For instance, if we have 10 kptrs in a nested struct and a program that
+ * accesses each kptr individually with bpf_kptr_xchg(), the compiler
+ * should emit instructions to access 10 different offsets if it works
+ * correctly. If the field->offset values of any pair of them are
+ * incorrectly the same, the number of unique offsets in btf_record for
+ * this nested struct should be less than 10. The verifier should fail to
+ * discover some of the offsets emitted by the compiler.
+ *
+ * Even if the field->offset values of kptrs are not duplicated, the
+ * verifier should fail to find a btf_field for the instruction accessing a
+ * kptr if the corresponding field->offset is pointing to a random
+ * incorrect offset.
+ */
+SEC("tp_btf/task_newtask")
+int BPF_PROG(test_global_mask_nested_deep_rcu, struct task_struct *task, u64 clone_flags)
+{
+ int r, i;
+
+ r = _global_mask_array_rcu(&global_mask_nested_deep.ptrs[0].m.mask,
+ &global_mask_nested_deep.ptrs[1].m.mask);
+ if (r)
+ return r;
+
+ for (i = 0; i < 3; i++) {
+ r = _global_mask_array_rcu(&global_mask_nested_deep.ptr_pairs[i].mask_1,
+ &global_mask_nested_deep.ptr_pairs[i].mask_2);
+ if (r)
+ return r;
+ }
+ return 0;
+}
+
+SEC("tp_btf/task_newtask")
+int BPF_PROG(test_global_mask_nested_deep_array_rcu, struct task_struct *task, u64 clone_flags)
+{
+ int i;
+
+ for (i = 0; i < CPUMASK_KPTR_FIELDS_MAX; i++)
+ _global_mask_array_rcu(&global_mask_nested_deep_array_1.d_1.d_2.mask[i], NULL);
+
+ for (i = 0; i < CPUMASK_KPTR_FIELDS_MAX; i++)
+ _global_mask_array_rcu(&global_mask_nested_deep_array_2.d_1.d_2[i].mask, NULL);
+
+ for (i = 0; i < CPUMASK_KPTR_FIELDS_MAX; i++)
+ _global_mask_array_rcu(&global_mask_nested_deep_array_3.d_1[i].d_2.mask, NULL);
+
+ return 0;
+}
+
+SEC("tp_btf/task_newtask")
+int BPF_PROG(test_cpumask_weight, struct task_struct *task, u64 clone_flags)
+{
+ struct bpf_cpumask *local;
+
+ if (!is_test_task())
+ return 0;
+
+ local = create_cpumask();
+ if (!local)
+ return 0;
+
+ if (bpf_cpumask_weight(cast(local)) != 0) {
+ err = 3;
+ goto out;
+ }
+
+ bpf_cpumask_set_cpu(0, local);
+ if (bpf_cpumask_weight(cast(local)) != 1) {
+ err = 4;
+ goto out;
+ }
+
+ /*
+ * Make sure that adding additional CPUs changes the weight. Test to
+ * see whether the CPU was set to account for running on UP machines.
+ */
+ bpf_cpumask_set_cpu(1, local);
+ if (bpf_cpumask_test_cpu(1, cast(local)) && bpf_cpumask_weight(cast(local)) != 2) {
+ err = 5;
+ goto out;
+ }
+
+ bpf_cpumask_clear(local);
+ if (bpf_cpumask_weight(cast(local)) != 0) {
+ err = 6;
+ goto out;
+ }
+out:
+ bpf_cpumask_release(local);
+ return 0;
+}
+
+SEC("tp_btf/task_newtask")
+int BPF_PROG(test_refcount_null_tracking, struct task_struct *task, u64 clone_flags)
+{
+ struct bpf_cpumask *mask1, *mask2;
+
+ mask1 = bpf_cpumask_create();
+ mask2 = bpf_cpumask_create();
+
+ if (!mask1 || !mask2)
+ goto free_masks_return;
+
+ bpf_cpumask_test_cpu(0, (const struct cpumask *)mask1);
+ bpf_cpumask_test_cpu(0, (const struct cpumask *)mask2);
+
+free_masks_return:
+ if (mask1)
+ bpf_cpumask_release(mask1);
+ if (mask2)
+ bpf_cpumask_release(mask2);
+ return 0;
+}
+
+SEC("tp_btf/task_newtask")
+int BPF_PROG(test_populate_reject_small_mask, struct task_struct *task, u64 clone_flags)
+{
+ struct bpf_cpumask *local;
+ u8 toofewbits;
+ int ret;
+
+ if (!is_test_task())
+ return 0;
+
+ local = create_cpumask();
+ if (!local)
+ return 0;
+
+ /* The kfunc should prevent this operation */
+ ret = bpf_cpumask_populate((struct cpumask *)local, &toofewbits, sizeof(toofewbits));
+ if (ret != -EACCES)
+ err = 2;
+
+ bpf_cpumask_release(local);
+
+ return 0;
+}
+
+/* Mask is guaranteed to be large enough for bpf_cpumask_t. */
+#define CPUMASK_TEST_MASKLEN (sizeof(cpumask_t))
+
+/* Add an extra word for the test_populate_reject_unaligned test. */
+u64 bits[CPUMASK_TEST_MASKLEN / 8 + 1];
+extern bool CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS __kconfig __weak;
+
+SEC("tp_btf/task_newtask")
+int BPF_PROG(test_populate_reject_unaligned, struct task_struct *task, u64 clone_flags)
+{
+ struct bpf_cpumask *mask;
+ char *src;
+ int ret;
+
+ if (!is_test_task())
+ return 0;
+
+ /* Skip if unaligned accesses are fine for this arch. */
+ if (CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
+ return 0;
+
+ mask = bpf_cpumask_create();
+ if (!mask) {
+ err = 1;
+ return 0;
+ }
+
+ /* Misalign the source array by a byte. */
+ src = &((char *)bits)[1];
+
+ ret = bpf_cpumask_populate((struct cpumask *)mask, src, CPUMASK_TEST_MASKLEN);
+ if (ret != -EINVAL)
+ err = 2;
+
+ bpf_cpumask_release(mask);
+
+ return 0;
+}
+
+
+SEC("tp_btf/task_newtask")
+int BPF_PROG(test_populate, struct task_struct *task, u64 clone_flags)
+{
+ struct bpf_cpumask *mask;
+ bool bit;
+ int ret;
+ int i;
+
+ if (!is_test_task())
+ return 0;
+
+ /* Set only odd bits. */
+ __builtin_memset(bits, 0xaa, CPUMASK_TEST_MASKLEN);
+
+ mask = bpf_cpumask_create();
+ if (!mask) {
+ err = 1;
+ return 0;
+ }
+
+ /* Pass the entire bits array, the kfunc will only copy the valid bits. */
+ ret = bpf_cpumask_populate((struct cpumask *)mask, bits, CPUMASK_TEST_MASKLEN);
+ if (ret) {
+ err = 2;
+ goto out;
+ }
+
+ /*
+ * Test is there to appease the verifier. We cannot directly
+ * access NR_CPUS, the upper bound for nr_cpus, so we infer
+ * it from the size of cpumask_t.
+ */
+ if (nr_cpus < 0 || nr_cpus >= CPUMASK_TEST_MASKLEN * 8) {
+ err = 3;
+ goto out;
+ }
+
+ bpf_for(i, 0, nr_cpus) {
+ /* Odd-numbered bits should be set, even ones unset. */
+ bit = bpf_cpumask_test_cpu(i, (const struct cpumask *)mask);
+ if (bit == (i % 2 != 0))
+ continue;
+
+ err = 4;
+ break;
+ }
+
+out:
+ bpf_cpumask_release(mask);
+
+ return 0;
+}
+
+#undef CPUMASK_TEST_MASKLEN