bpf_test: add tests for loading modules with pinning config

To cover the test case of loading modules with pinning config,
add more tests for loading module with specific parameters, and
checking for actual pinned object under `/sys/fs/bpf`.

Author: Dongsu Park

bpf_test.go

@@ -17,10 +17,13 @@
 package bpf
 
 import (
+	"os"
+	"path/filepath"
 	"testing"
 
 	"github.com/iovisor/gobpf/bcc"
 	"github.com/iovisor/gobpf/elf"
+	"github.com/iovisor/gobpf/pkg/bpffs"
 )
 
 var simple1 string = `
@@ -109,6 +112,7 @@ func checkMaps(t *testing.T, b *elf.Module) {
 		"dummy_array",
 		"dummy_prog_array",
 		"dummy_perf",
+		"dummy_array_custom",
 	}
 
 	if kernelVersion >= kernelVersion46 {
@@ -233,6 +237,22 @@ func checkSocketFilters(t *testing.T, b *elf.Module) {
 	}
 }
 
+func checkPinConfig(t *testing.T, expectedPaths []string) {
+	for _, p := range expectedPaths {
+		if fi, err := os.Stat(p); os.IsNotExist(err) || !fi.Mode().IsRegular() {
+			t.Fatalf("pinned object %q not found", p)
+		}
+	}
+}
+
+func checkPinConfigCleanup(t *testing.T, expectedPaths []string) {
+	for _, p := range expectedPaths {
+		if _, err := os.Stat(p); !os.IsNotExist(err) {
+			t.Fatalf("pinned object %q is not cleaned up", p)
+		}
+	}
+}
+
 func TestModuleLoadELF(t *testing.T) {
 	var err error
 	kernelVersion, err = elf.CurrentKernelVersion()
@@ -249,18 +269,40 @@ func TestModuleLoadELF(t *testing.T) {
 		dummyELF = "./tests/dummy-46.o"
 	}
 
+	var secParams = map[string]elf.SectionParams{
+		"maps/dummy_array_custom": elf.SectionParams{
+			PinPath: filepath.Join("gobpf-test", "testgroup1"),
+		},
+	}
+	var closeOptions = map[string]elf.CloseOptions{
+		"maps/dummy_array_custom": elf.CloseOptions{
+			Unpin:   true,
+			PinPath: filepath.Join("gobpf-test", "testgroup1"),
+		},
+	}
+
+	if err := bpffs.Mount(); err != nil {
+		t.Skipf("error mounting bpf fs, skipping test: %v", err)
+	}
+
 	b := elf.NewModule(dummyELF)
 	if b == nil {
 		t.Fatal("prog is nil")
 	}
-	if err := b.Load(nil); err != nil {
+	if err := b.Load(secParams); err != nil {
 		t.Fatal(err)
 	}
-	defer b.Close()
+	defer func() {
+		if err := b.CloseExt(closeOptions); err != nil {
+			t.Fatal(err)
+		}
+		checkPinConfigCleanup(t, []string{"/sys/fs/bpf/gobpf-test/testgroup1"})
+	}()
 
 	checkMaps(t, b)
 	checkProbes(t, b)
 	checkCgroupProgs(t, b)
 	checkSocketFilters(t, b)
 	checkTracepointProgs(t, b)
+	checkPinConfig(t, []string{"/sys/fs/bpf/gobpf-test/testgroup1"})
 }

elf/include/bpf.h

@@ -617,4 +617,11 @@ typedef struct bpf_map_def {
 	char namespace[BUF_SIZE_MAP_NS];
 } bpf_map_def;
 
+enum bpf_pin_type {
+	PIN_NONE = 0,
+	PIN_OBJECT_NS,
+	PIN_GLOBAL_NS,
+	PIN_CUSTOM_NS,
+};
+
 #endif /* _UAPI__LINUX_BPF_H__ */

tests/build

@@ -2,7 +2,10 @@
 
 set -euo pipefail
 
-clang -O2 -emit-llvm -c dummy.c -o - | llc -march=bpf -filetype=obj -o dummy.o
+DUMMY_SRC=dummy.c
+DUMMY_OBJ=dummy.o
+
+clang -O2 -emit-llvm -c ${DUMMY_SRC} -o - | llc -march=bpf -filetype=obj -o ${DUMMY_OBJ}
 for kernel in 46 48 410; do
-  clang -DKERNEL_VERSION="${kernel}" -O2 -emit-llvm -c dummy.c -o - | llc -march=bpf -filetype=obj -o "dummy-${kernel}.o"
+  clang -DKERNEL_VERSION="${kernel}" -O2 -emit-llvm -c ${DUMMY_SRC} -o - | llc -march=bpf -filetype=obj -o "dummy-${kernel}.o"
 done

tests/dummy-410.o

@@ -72,6 +72,13 @@ struct bpf_map_def SEC("maps/dummy_cgroup_array") dummy_cgroup_array = {
 };
 #endif
 
+struct bpf_map_def SEC("maps/dummy_array_custom") dummy_array_custom = {
+	.type = BPF_MAP_TYPE_ARRAY,
+	.key_size = sizeof(int),
+	.value_size = sizeof(unsigned int),
+	.max_entries = 128,
+	.pinning = PIN_CUSTOM_NS,
+};
 
 SEC("kprobe/dummy")
 int kprobe__dummy(struct pt_regs *ctx)