tetragon: Add max entries test

wip

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

pkg/sensors/tracing/kprobe_maxentries_test.go

@@ -0,0 +1,125 @@
+// SPDX-License-Identifier: Apache-2.0
+// Copyright Authors of Tetragon
+
+package tracing
+
+import (
+	"os"
+	"testing"
+
+	"github.com/cilium/ebpf"
+	"github.com/cilium/tetragon/pkg/observer/observertesthelper"
+	"github.com/cilium/tetragon/pkg/sensors"
+	tus "github.com/cilium/tetragon/pkg/testutils/sensors"
+	"github.com/stretchr/testify/assert"
+)
+
+func runConfig(t *testing.T, config string, fn func(string, int)) {
+
+	var err error
+	err = os.WriteFile(testConfigFile, []byte(config), 0644)
+	if err != nil {
+		t.Fatalf("writeFile(%s): err %s", testConfigFile, err)
+	}
+	sens, err := observertesthelper.GetDefaultSensorsWithFile(t, testConfigFile,
+		tus.Conf().TetragonLib)
+	if err != nil {
+		t.Fatalf("GetDefaultObserverWithFile error: %s", err)
+	}
+
+	for _, sensor := range sens {
+		for _, load := range sensor.Progs {
+			c := load.LC
+			for _, p := range c.Programs {
+				for _, id := range p.MapIDs {
+					m, err := ebpf.NewMapFromID(id)
+					if err != nil {
+						t.Fatalf("can't open map id %d: %s\n", id, err)
+					}
+					info, err := m.Info()
+					if err != nil {
+						t.Fatalf("can't get map info: %s\n", err)
+					}
+					fn(info.Name, int(info.MaxEntries))
+				}
+			}
+		}
+	}
+
+	sensi := make([]sensors.SensorIface, 0, len(sens))
+	for _, s := range sens {
+		sensi = append(sensi, s)
+	}
+	sensors.UnloadSensors(sensi)
+}
+
+func TestMaxEntries(t *testing.T) {
+
+	t.Run("fdinstall_1", func(t *testing.T) {
+		config := `
+apiVersion: cilium.io/v1alpha1
+kind: TracingPolicy
+metadata:
+  name: "sys-read"
+spec:
+  kprobes:
+  - call: "sys_read"
+    syscall: true
+    return: true
+    args:
+    - index: 0
+      type: "int"
+    - index: 1
+      type: "char_buf"
+      returnCopy: true
+    - index: 2
+      type: "size_t"
+    returnArg:
+      type: "size_t"
+`
+
+		runConfig(t, config, func(name string, entries int) {
+			if name == "fdinstall_map" {
+				assert.Equal(t, 1, entries)
+			}
+		})
+	})
+
+	t.Run("fdinstall_32000", func(t *testing.T) {
+		config := `
+apiVersion: cilium.io/v1alpha1
+kind: TracingPolicy
+metadata:
+  name: "syswritefollowfdpsswd"
+spec:
+  kprobes:
+  - call: "fd_install"
+    syscall: false
+    args:
+    - index: 0
+      type: int
+    - index: 1
+      type: "file"
+    selectors:
+    - matchArgs:
+      - index: 1
+        operator: "Equal"
+        values:
+        - "/tmp/test"
+      matchBinaries:
+      - operator: "In"
+        values:
+        - "/usr/bin/vim"
+      matchActions:
+      - action: FollowFD
+        argFd: 0
+        argName: 1
+`
+
+		runConfig(t, config, func(name string, entries int) {
+			if name == "fdinstall_map" {
+				assert.Equal(t, 32000, entries)
+			}
+		})
+	})
+}