This test exposes the issue of being unable to call kfuncs within a
normal tracepoint program. The program will be rejected by the verifier
as not allowed.
Signed-off-by: JP Kobryn <inwardvessel@xxxxxxxxx>
---
.../selftests/bpf/prog_tests/kfunc_in_tp.c | 34 ++++++++++++++++++
.../selftests/bpf/progs/test_kfunc_in_tp.c | 35 +++++++++++++++++++
2 files changed, 69 insertions(+)
create mode 100644 tools/testing/selftests/bpf/prog_tests/kfunc_in_tp.c
create mode 100644 tools/testing/selftests/bpf/progs/test_kfunc_in_tp.c
diff --git a/tools/testing/selftests/bpf/prog_tests/kfunc_in_tp.c b/tools/testing/selftests/bpf/prog_tests/kfunc_in_tp.c
new file mode 100644
index 000000000000..bef1d192fc00
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/kfunc_in_tp.c
@@ -0,0 +1,34 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */
+
+#include <errno.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+
+#include "test_kfunc_in_tp.skel.h"
+#include "test_progs.h"
+
+static void run_tp(void)
+{
+ (void)syscall(__NR_getpid);
+}
+
+void test_kfunc_in_tp(void)
+{
+ struct test_kfunc_in_tp *skel;
+ int err;
+
+ skel = test_kfunc_in_tp__open();
+ ASSERT_OK_PTR(skel, "test_kfunc_in_tp__open");
+
+ err = test_kfunc_in_tp__load(skel);
+ ASSERT_OK(err, "test_kfunc_in_tp__load");
+
+ err = test_kfunc_in_tp__attach(skel);
+ ASSERT_OK(err, "test_kfunc_in_tp__attach");
+
+ run_tp();
+ ASSERT_OK(skel->data->result, "complete");
+
+ test_kfunc_in_tp__destroy(skel);
+}
diff --git a/tools/testing/selftests/bpf/progs/test_kfunc_in_tp.c b/tools/testing/selftests/bpf/progs/test_kfunc_in_tp.c
new file mode 100644
index 000000000000..5a3f1ff930af
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_kfunc_in_tp.c
@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */
+
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+
+char _license[] SEC("license") = "GPL";
+
+extern struct bpf_cpumask *bpf_cpumask_create(void) __ksym;
+extern void bpf_cpumask_set_cpu(u32 cpu, struct bpf_cpumask *cpumask) __ksym;
+extern bool bpf_cpumask_test_cpu(u32 cpu, const struct cpumask *cpumask) __ksym;
+extern void bpf_cpumask_release(struct bpf_cpumask *cpumask) __ksym;
+
+int result = -1;
+
+/* call arbitrary kfuncs within a tracepoint program */
+SEC("tp/syscalls/sys_enter_getpid")
+int handle_tp(struct trace_event_raw_ipi_send_cpumask *ctx)
+{
+ struct bpf_cpumask *cpumask;
+ const u32 cpu = bpf_get_smp_processor_id();
+
+ cpumask = bpf_cpumask_create();
+ if (!cpumask)
+ return 0;
+
+ bpf_cpumask_set_cpu(cpu, cpumask);
+ if (bpf_cpumask_test_cpu(cpu, (struct cpumask *)cpumask))
+ bpf_printk("match\n");
+
+ bpf_cpumask_release(cpumask);
+ result = 0;
+
+ return 0;
+}
--
2.46.0
