root/tools/testing/selftests/bpf/progs/struct_ops_kptr_return_fail__invalid_scalar.c
#include <vmlinux.h>
#include <bpf/bpf_tracing.h>
#include "../test_kmods/bpf_testmod.h"
#include "bpf_misc.h"

char _license[] SEC("license") = "GPL";

struct cgroup *bpf_cgroup_acquire(struct cgroup *p) __ksym;
void bpf_task_release(struct task_struct *p) __ksym;

/* This test struct_ops BPF programs returning referenced kptr. The verifier should
 * reject programs returning a non-zero scalar value.
 */
SEC("struct_ops/test_return_ref_kptr")
__failure __msg("At program exit the register R0 has smin=1 smax=1 should have been in [0, 0]")
struct task_struct *BPF_PROG(kptr_return_fail__invalid_scalar, int dummy,
                             struct task_struct *task, struct cgroup *cgrp)
{
        bpf_task_release(task);
        return (struct task_struct *)1;
}

SEC(".struct_ops.link")
struct bpf_testmod_ops testmod_kptr_return = {
        .test_return_ref_kptr = (void *)kptr_return_fail__invalid_scalar,
};