Revert "features: tolerate EPERM in haveObjName and objNameAllowsDot"

This reverts commit cfd8515.

Now that the ELF reader doesn't rely on feature tests anymore we can
undo the change to treat EPERM specially.

Signed-off-by: Lorenz Bauer <[email protected]>

Author: lmb

syscalls.go

@@ -206,17 +206,9 @@ var haveObjName = internal.NewFeatureTest("object names", func() error {
 		MapName:    sys.NewObjName("feature_test"),
 	}
 
-	// Tolerate EPERM as this runs during ELF loading which is potentially
-	// unprivileged. Only EINVAL is conclusive, thrown from CHECK_ATTR.
 	fd, err := sys.MapCreate(&attr)
-	if errors.Is(err, unix.EPERM) {
-		return nil
-	}
-	if errors.Is(err, unix.EINVAL) {
-		return internal.ErrNotSupported
-	}
 	if err != nil {
-		return err
+		return internal.ErrNotSupported
 	}
 
 	_ = fd.Close()
@@ -241,18 +233,9 @@ var objNameAllowsDot = internal.NewFeatureTest("dot in object names", func() err
 		MapName:    sys.NewObjName(".test"),
 	}
 
-	// Tolerate EPERM, otherwise MapSpec.Name has its dots removed when run by
-	// unprivileged tools. (bpf2go, other code gen). Only EINVAL is conclusive,
-	// thrown from bpf_obj_name_cpy().
 	fd, err := sys.MapCreate(&attr)
-	if errors.Is(err, unix.EPERM) {
-		return nil
-	}
-	if errors.Is(err, unix.EINVAL) {
-		return internal.ErrNotSupported
-	}
 	if err != nil {
-		return err
+		return internal.ErrNotSupported
 	}
 
 	_ = fd.Close()