link: add test for uprobe multi link

This commit adds test for uprobe multi link.

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

link/uprobe_multi_test.go

@@ -0,0 +1,129 @@
+package link
+
+import (
+	"errors"
+	"os/exec"
+	"testing"
+
+	"github.com/cilium/ebpf"
+	"github.com/cilium/ebpf/internal/testutils"
+	"github.com/go-quicktest/qt"
+)
+
+func TestUprobeMulti(t *testing.T) {
+	testutils.SkipIfNotSupported(t, haveBPFLinkUprobeMulti())
+
+	prog := mustLoadProgram(t, ebpf.Kprobe, ebpf.AttachTraceUprobeMulti, "")
+
+	um, err := bashEx.UprobeMulti([]string{"bash_logout", "main"}, prog, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer um.Close()
+
+	testLink(t, um, prog)
+}
+
+func TestUprobeMultiInput(t *testing.T) {
+	testutils.SkipIfNotSupported(t, haveBPFLinkUprobeMulti())
+
+	prog := mustLoadProgram(t, ebpf.Kprobe, ebpf.AttachTraceUprobeMulti, "")
+
+	// One of symbols or offsets must be given.
+	_, err := bashEx.UprobeMulti([]string{}, prog, nil)
+	qt.Assert(t, qt.ErrorIs(err, errInvalidInput))
+
+	// One offset, two cookies.
+	_, err = bashEx.UprobeMulti([]string{}, prog, &UprobeMultiOptions{
+		Offsets: []uint64{1},
+		Cookies: []uint64{2, 3},
+	})
+	qt.Assert(t, qt.ErrorIs(err, errInvalidInput))
+
+	// Two offset, ont refctr offset.
+	_, err = bashEx.UprobeMulti([]string{}, prog, &UprobeMultiOptions{
+		Offsets:       []uint64{1, 2},
+		RefCtrOffsets: []uint64{4},
+	})
+	qt.Assert(t, qt.ErrorIs(err, errInvalidInput))
+
+	// It's either symbols or opts.Offsets.
+	_, err = bashEx.UprobeMulti([]string{"main"}, prog, &UprobeMultiOptions{
+		Offsets: []uint64{1},
+	})
+	qt.Assert(t, qt.ErrorIs(err, errInvalidInput))
+}
+
+func TestUprobeMultiCookie(t *testing.T) {
+	testutils.SkipIfNotSupported(t, haveBPFLinkUprobeMulti())
+
+	prog := mustLoadProgram(t, ebpf.Kprobe, ebpf.AttachTraceUprobeMulti, "")
+
+	um, err := bashEx.UprobeMulti([]string{"bash_logout", "main"}, prog,
+		&UprobeMultiOptions{
+			Cookies: []uint64{1, 2},
+		})
+	if err != nil {
+		t.Fatal(err)
+	}
+	_ = um.Close()
+}
+
+func TestUprobeMultiProgramCall(t *testing.T) {
+	testutils.SkipIfNotSupported(t, haveBPFLinkUprobeMulti())
+
+	args := []string{"--help"}
+	elf := "/bin/bash"
+
+	m, p := newUpdaterMapProg(t, ebpf.Kprobe, ebpf.AttachTraceUprobeMulti)
+
+	// Load the executable.
+	ex, err := OpenExecutable(elf)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// Open UprobeMulti on the executable for the given symbol
+	// and attach it to the ebpf program created above.
+	um, err := ex.UprobeMulti([]string{"main", "_start"}, p, nil)
+	if errors.Is(err, ErrNoSymbol) {
+		// Assume bash::main and go::main.main always exists
+		// and skip the test if the symbol can't be found as
+		// certain OS (eg. Debian) strip binaries.
+		t.Skipf("executable %s appear to be stripped, skipping", elf)
+	}
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// Trigger ebpf program call.
+	trigger := func(t *testing.T) {
+		if err := exec.Command(elf, args...).Run(); err != nil {
+			t.Fatal(err)
+		}
+	}
+	trigger(t)
+
+	// Assert that the value at index 0 has been updated to 2.
+	assertMapValueGE(t, m, 0, 2)
+
+	// Detach the Uprobe.
+	if err := um.Close(); err != nil {
+		t.Fatal(err)
+	}
+
+	// Reset map value to 0 at index 0.
+	if err := m.Update(uint32(0), uint32(0), ebpf.UpdateExist); err != nil {
+		t.Fatal(err)
+	}
+
+	// Retrigger the ebpf program call.
+	trigger(t)
+
+	// Assert that this time the value has not been updated.
+	assertMapValue(t, m, 0, 0)
+}
+
+func TestHaveBPFLinkUprobeMulti(t *testing.T) {
+	testutils.CheckFeatureTest(t, haveBPFLinkUprobeMulti)
+}