Revert "combine kernel spec structs"

This reverts commit 80f49f8.

btf/btf.go

@@ -54,7 +54,7 @@ type Spec struct {
 }
 
 func init() {
-	kernelBTF.kmods = make(map[string]*Spec)
+	kernelModuleBTF.spec = make(map[string]*Spec)
 }
 
 // LoadSpec opens file and calls LoadSpecFromReader on it.
@@ -280,19 +280,25 @@ func LoadKernelModuleSpec(module string) (*Spec, error) {
 
 var kernelBTF struct {
 	sync.RWMutex
-	spec  *Spec
-	kmods map[string]*Spec
+	spec *Spec
 	// True if the spec was read from an ELF instead of raw BTF in /sys.
 	fallback bool
 }
 
+var kernelModuleBTF struct {
+	sync.RWMutex
+	spec map[string]*Spec
+}
+
 // FlushKernelSpec removes any cached kernel type information.
 func FlushKernelSpec() {
 	kernelBTF.Lock()
+	kernelModuleBTF.Lock()
 	defer kernelBTF.Unlock()
+	defer kernelModuleBTF.Unlock()
 
 	kernelBTF.spec, kernelBTF.fallback = nil, false
-	kernelBTF.kmods = make(map[string]*Spec)
+	kernelModuleBTF.spec = make(map[string]*Spec)
 }
 
 func kernelSpec() (*Spec, bool, error) {
@@ -321,15 +327,15 @@ func kernelSpec() (*Spec, bool, error) {
 }
 
 func kernelModuleSpec(module string) (*Spec, error) {
-	kernelBTF.RLock()
-	spec := kernelBTF.kmods[module]
-	kernelBTF.RUnlock()
+	kernelModuleBTF.RLock()
+	spec := kernelModuleBTF.spec[module]
+	kernelModuleBTF.RUnlock()
 
 	if spec == nil {
-		kernelBTF.Lock()
-		defer kernelBTF.Unlock()
+		kernelModuleBTF.Lock()
+		defer kernelModuleBTF.Unlock()
 
-		spec = kernelBTF.kmods[module]
+		spec = kernelModuleBTF.spec[module]
 	}
 
 	if spec != nil {
@@ -341,7 +347,7 @@ func kernelModuleSpec(module string) (*Spec, error) {
 		return nil, err
 	}
 
-	kernelBTF.kmods[module] = spec
+	kernelModuleBTF.spec[module] = spec
 	return spec, nil
 }