From: Alexei Starovoitov <ast@xxxxxxxxxx>
Add recursive non-sleepable fentry program as a test.
All attach points where sleepable progs can execute are non recursive so far.
The recursion protection mechanism for sleepable cannot be activated yet.
Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx>
---
.../selftests/bpf/prog_tests/recursion.c | 33 +++++++++++++
tools/testing/selftests/bpf/progs/recursion.c | 46 +++++++++++++++++++
2 files changed, 79 insertions(+)
create mode 100644 tools/testing/selftests/bpf/prog_tests/recursion.c
create mode 100644 tools/testing/selftests/bpf/progs/recursion.c
diff --git a/tools/testing/selftests/bpf/prog_tests/recursion.c b/tools/testing/selftests/bpf/prog_tests/recursion.c
new file mode 100644
index 000000000000..16e8eab5a29d
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/recursion.c
@@ -0,0 +1,33 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2021 Facebook */
+#include <test_progs.h>
+#include "recursion.skel.h"
+
+void test_recursion(void)
+{
+ struct recursion *skel;
+ int key = 0;
+ int err;
+
+ skel = recursion__open_and_load();
+ if (!ASSERT_OK_PTR(skel, "skel_open_and_load"))
+ return;
+
+ err = recursion__attach(skel);
+ if (!ASSERT_OK(err, "skel_attach"))
+ goto out;
+
+ ASSERT_EQ(skel->bss->pass1, 0, "pass1 == 0");
+ bpf_map_lookup_elem(bpf_map__fd(skel->maps.hash1), &key, 0);
+ ASSERT_EQ(skel->bss->pass1, 1, "pass1 == 1");
+ bpf_map_lookup_elem(bpf_map__fd(skel->maps.hash1), &key, 0);
+ ASSERT_EQ(skel->bss->pass1, 2, "pass1 == 2");
+
+ ASSERT_EQ(skel->bss->pass2, 0, "pass2 == 0");
+ bpf_map_lookup_elem(bpf_map__fd(skel->maps.hash2), &key, 0);
+ ASSERT_EQ(skel->bss->pass2, 1, "pass2 == 1");
+ bpf_map_lookup_elem(bpf_map__fd(skel->maps.hash2), &key, 0);
+ ASSERT_EQ(skel->bss->pass2, 2, "pass2 == 2");
+out:
+ recursion__destroy(skel);
+}
diff --git a/tools/testing/selftests/bpf/progs/recursion.c b/tools/testing/selftests/bpf/progs/recursion.c
new file mode 100644
index 000000000000..49f679375b9d
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/recursion.c
@@ -0,0 +1,46 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2021 Facebook */
+
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+char _license[] SEC("license") = "GPL";
+
+struct {
+ __uint(type, BPF_MAP_TYPE_HASH);
+ __uint(max_entries, 1);
+ __type(key, int);
+ __type(value, long);
+} hash1 SEC(".maps");
+
+struct {
+ __uint(type, BPF_MAP_TYPE_HASH);
+ __uint(max_entries, 1);
+ __type(key, int);
+ __type(value, long);
+} hash2 SEC(".maps");
+
+int pass1 = 0;
+int pass2 = 0;
+
+SEC("fentry/__htab_map_lookup_elem")
+int BPF_PROG(on_lookup, struct bpf_map *map)
+{
+ int key = 0;
+
+ if (map == (void *)&hash1) {
+ pass1++;
+ return 0;
+ }
+ if (map == (void *)&hash2) {
+ pass2++;
+ /* htab_map_gen_lookup() will inline below call
+ * into direct call to __htab_map_lookup_elem()
+ */
+ bpf_map_lookup_elem(&hash2, &key);
+ return 0;
+ }
+
+ return 0;
+}
--
2.24.1
