fix(mod): probe searches for features built-in the kernel

internal/mod/probe_linux.go

@@ -1,12 +1,49 @@
 package mod
 
 import (
+	"errors"
 	"fmt"
 )
 
-// Probe loads the given kernel module and its dependencies.
+// Probe is a expanded version of modprobe, in which it checks if the Kernel
+// built-in features contain the given module name.
+// It first tries to locate the modules directory in [getModulesPath].
+// If it fails (like on WSL), it then only checks for the kernel feature
+// in /proc/config.gz with [checkProcConfig].
+// Otherwise, it first checks if the modules directory modules.builtin
+// file contains the given module name in [checkModulesBuiltin].
+// If the module is not found, it then runs the classic [modProbe] behavior,
+// trying to load the module in the kernel.
+// If this fails, it does one final try running [checkProcConfig].
 func Probe(moduleName string) error {
-	modulesInfo, err := getModulesInfo()
+	modulesPath, err := getModulesPath()
+	if err != nil {
+		if errors.Is(err, ErrModulesDirectoryNotFound) {
+			err = checkProcConfig(moduleName)
+			if err != nil {
+				return fmt.Errorf("checking /proc/config.gz: %w", err)
+			}
+			return nil
+		}
+		return fmt.Errorf("getting modules path: %w", err)
+	}
+
+	err = checkModulesBuiltin(modulesPath, moduleName)
+	if err != nil {
+		err = modProbe(modulesPath, moduleName)
+		if err != nil {
+			err = checkProcConfig(moduleName)
+			if err != nil {
+				return fmt.Errorf("checking /proc/config.gz: %w", err)
+			}
+		}
+	}
+	return nil
+}
+
+// modProbe is the classic modprobe behavior.
+func modProbe(modulesPath, moduleName string) error {
+	modulesInfo, err := getModulesInfo(modulesPath)
 	if err != nil {
 		return fmt.Errorf("getting modules information: %w", err)
 	}