use map for module BTF

btf/core_reloc_test.go

@@ -37,7 +37,7 @@ func TestCORERelocationLoad(t *testing.T) {
 				}
 
 				prog, err := ebpf.NewProgramWithOptions(progSpec, ebpf.ProgramOptions{
-					KernelTypes: []*btf.Spec{spec.Types},
+					KernelTypes: spec.Types,
 				})
 				testutils.SkipIfNotSupported(t, err)
 
@@ -89,7 +89,7 @@ func TestCORERelocationRead(t *testing.T) {
 		for _, progSpec := range spec.Programs {
 			t.Run(progSpec.Name, func(t *testing.T) {
 				prog, err := ebpf.NewProgramWithOptions(progSpec, ebpf.ProgramOptions{
-					KernelTypes: []*btf.Spec{targetSpec},
+					KernelTypes: targetSpec,
 				})
 				testutils.SkipIfNotSupported(t, err)
 				if err != nil {

elf_reader_test.go

@@ -1121,7 +1121,7 @@ func TestLibBPFCompat(t *testing.T) {
 				}
 
 				opts := opts // copy
-				opts.Programs.KernelTypes = []*btf.Spec{btfSpec}
+				opts.Programs.KernelTypes = btfSpec
 				load(t, spec, opts, valid)
 			})
 		}

prog.go

@@ -80,7 +80,15 @@ type ProgramOptions struct {
 	// This is useful in environments where the kernel BTF is not available
 	// (containers) or where it is in a non-standard location. Defaults to
 	// use the kernel BTF from a well-known location if nil.
-	KernelTypes []*btf.Spec
+	KernelTypes *btf.Spec
+
+	// Type information used for CO-RE relocations of kernel modules,
+	// indexed by module name.
+	//
+	// This is useful in environments where the kernel BTF is not available
+	// (containers) or where it is in a non-standard location. Defaults to
+	// use the kernel module BTF from a well-known location if nil.
+	KernelModuleTypes map[string]*btf.Spec
 }
 
 // ProgramSpec defines a Program.
@@ -248,8 +256,18 @@ func newProgramWithOptions(spec *ProgramSpec, opts ProgramOptions) (*Program, er
 		return nil, fmt.Errorf("kernel module search: %w", err)
 	}
 
+	var targets []*btf.Spec
+	if opts.KernelTypes != nil {
+		targets = append(targets, opts.KernelTypes)
+	}
+	if kmodName != "" && opts.KernelModuleTypes != nil {
+		if modBTF, ok := opts.KernelModuleTypes[kmodName]; ok {
+			targets = append(targets, modBTF)
+		}
+	}
+
 	var b btf.Builder
-	if err := applyRelocations(insns, opts.KernelTypes, kmodName, spec.ByteOrder, &b); err != nil {
+	if err := applyRelocations(insns, targets, kmodName, spec.ByteOrder, &b); err != nil {
 		return nil, fmt.Errorf("apply CO-RE relocations: %w", err)
 	}
 

prog_test.go

@@ -880,7 +880,7 @@ func TestProgramKernelTypes(t *testing.T) {
 		},
 		License: "MIT",
 	}, ProgramOptions{
-		KernelTypes: []*btf.Spec{btfSpec},
+		KernelTypes: btfSpec,
 	})
 	testutils.SkipIfNotSupported(t, err)
 	if err != nil {