tetragon: Add tests for other (not owner) maps

Adding tests for 'other' maps to cover following scenarios:

  - other map gets properly created from pinned map
  - other map fails to be loaded if the pinned map is missing
  - other map fails to be loaded if the pinned map has different
    max entries setup
  - other map fails to be loaded if the pinned map is not compatible

Signed-off-by: Jiri Olsa <jolsa@kernel.org>

bpf/Makefile

@@ -31,7 +31,7 @@ PROCESS = bpf_execve_event.o bpf_execve_event_v53.o bpf_fork.o bpf_exit.o bpf_ge
 	  bpf_loader.o \
 	  bpf_cgroup.o \
 	  bpf_enforcer.o bpf_multi_enforcer.o bpf_fmodret_enforcer.o \
-	  bpf_map_test_p1.o bpf_map_test_p2.o
+	  bpf_map_test_p1.o bpf_map_test_p2.o bpf_map_test_p3.o
 
 CGROUP = bpf_cgroup_mkdir.o bpf_cgroup_rmdir.o bpf_cgroup_release.o
 BPFTEST = bpf_lseek.o

bpf/process/bpf_map_test_p3.c

@@ -0,0 +1,22 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+/* Copyright Authors of Cilium */
+
+#include "vmlinux.h"
+#include "api.h"
+#include "bpf_tracing.h"
+#include "bpf_helpers.h"
+#include "compiler.h"
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__uint(max_entries, 1);
+	__type(key, int);
+	__type(value, unsigned long);
+} m1 SEC(".maps");
+
+__attribute__((section("kprobe/wake_up_new_task"), used)) int
+BPF_KPROBE(p2)
+{
+	map_lookup_elem(&m1, &(unsigned long){ 0 });
+	return 0;
+}

pkg/sensors/test/sensors_test.go

@@ -197,6 +197,154 @@ func TestMapMultipleSensors(t *testing.T) {
 	assert.Equal(t, m12.PinPath, m22.PinPath)
 }
 
+func TestMapOther(t *testing.T) {
+	p1 := program.Builder(
+		"bpf_map_test_p1.o",
+		"wake_up_new_task",
+		"kprobe/wake_up_new_task",
+		"p1",
+		"kprobe",
+	)
+	p2 := program.Builder(
+		"bpf_map_test_p2.o",
+		"wake_up_new_task",
+		"kprobe/wake_up_new_task",
+		"p2",
+		"kprobe",
+	)
+	p3 := program.Builder(
+		"bpf_map_test_p3.o",
+		"wake_up_new_task",
+		"kprobe/wake_up_new_task",
+		"p3",
+		"kprobe",
+	)
+	opts := program.MapOpts{
+		Type:  program.MapTypeGlobal,
+		Owner: program.MapOwnerOther,
+	}
+
+	var err error
+
+	// Create sensor with other map and make sure it's properly loaded
+	t.Run("ok", func(t *testing.T) {
+		m1 := program.MapBuilder("m1", p1)
+		m2 := program.MapBuilder("m2", p2)
+
+		s1 := &sensors.Sensor{
+			Name:   "sensor1",
+			Progs:  []*program.Program{p1},
+			Maps:   []*program.Map{m1, m2},
+			Policy: "policy",
+		}
+
+		// other-owner map
+		m1Other := program.MapBuilderOpts("m1", opts, p2)
+
+		s2 := &sensors.Sensor{
+			Name:   "sensor2",
+			Progs:  []*program.Program{p2},
+			Maps:   []*program.Map{m1Other},
+			Policy: "policy",
+		}
+
+		err = s1.Load(bpf.MapPrefixPath())
+		defer s1.Unload()
+		assert.NoError(t, err)
+
+		err = s2.Load(bpf.MapPrefixPath())
+		defer s2.Unload()
+		assert.NoError(t, err)
+	})
+
+	// Create sensor with other map with wrong name (no existing pinned
+	// map file) and make sure the sensor fails to load
+	t.Run("fail_name", func(t *testing.T) {
+		m1 := program.MapBuilder("m1", p1, p2)
+
+		// other-owner map with wrong name
+		m2 := program.MapBuilderOpts("non-existing", opts, p1, p2)
+
+		s1 := &sensors.Sensor{
+			Name:   "sensor1",
+			Progs:  []*program.Program{p1},
+			Maps:   []*program.Map{m1, m2},
+			Policy: "policy",
+		}
+
+		err = s1.Load(bpf.MapPrefixPath())
+		assert.Error(t, err)
+		if err == nil {
+			defer s1.Unload()
+		}
+	})
+
+	// Create sensor with other map with different max entries setup
+	// from real owner map and make sure the sensor fails to load
+	t.Run("fail_max", func(t *testing.T) {
+		m1 := program.MapBuilder("m1", p1)
+		m1.SetMaxEntries(10)
+
+		s1 := &sensors.Sensor{
+			Name:   "sensor1",
+			Progs:  []*program.Program{p1},
+			Maps:   []*program.Map{m1},
+			Policy: "policy",
+		}
+
+		// other-owner map with extra max setup
+		m1Other := program.MapBuilderOpts("m1", opts, p2)
+		m1Other.SetMaxEntries(100)
+
+		s2 := &sensors.Sensor{
+			Name:   "sensor2",
+			Progs:  []*program.Program{p2},
+			Maps:   []*program.Map{m1Other},
+			Policy: "policy",
+		}
+
+		err = s1.Load(bpf.MapPrefixPath())
+		defer s1.Unload()
+		assert.NoError(t, err)
+
+		err = s2.Load(bpf.MapPrefixPath())
+		defer s2.Unload()
+		assert.Error(t, err)
+	})
+
+	// Create sensor with other map with different spec from real owner
+	// map and make sure the sensor fails to load
+	t.Run("fail_spec", func(t *testing.T) {
+		m1 := program.MapBuilder("m1", p1)
+
+		s1 := &sensors.Sensor{
+			Name:   "sensor1",
+			Progs:  []*program.Program{p1},
+			Maps:   []*program.Map{m1},
+			Policy: "policy",
+		}
+
+		// The bpf_map_test_p3 has map with same name and different
+		// value type, so we should fail to load it.
+		m1Other := program.MapBuilderOpts("m1", opts, p3)
+
+		s3 := &sensors.Sensor{
+			Name:   "sensor3",
+			Progs:  []*program.Program{p3},
+			Maps:   []*program.Map{m1Other},
+			Policy: "policy",
+		}
+
+		err = s1.Load(bpf.MapPrefixPath())
+		defer s1.Unload()
+		assert.NoError(t, err)
+
+		err = s3.Load(bpf.MapPrefixPath())
+		defer s3.Unload()
+		assert.Error(t, err)
+	})
+}
+
 func TestPolicyMapPath(t *testing.T) {
 	option.Config.HubbleLib = tus.Conf().TetragonLib
 	option.Config.Verbosity = 5