add a few error messages

cr-restore.c

@@ -2271,8 +2271,10 @@ static int prepare_creds(int pid, struct task_restore_args *args, char **lsm_pro
 		return -1;
 	}
 
-	if (!may_restore(ce))
+	if (!may_restore(ce)) {
+		pr_err("Operation not permitted\n");
 		return -1;
+	}
 
 	args->creds = *ce;
 	args->creds.cap_inh = args->cap_inh;
@@ -2800,8 +2802,10 @@ static int sigreturn_restore(pid_t pid, CoreEntry *core)
 	thread_args	= (struct thread_restore_args *)(task_args + 1);
 
 	ret = prepare_creds(pid, task_args, &lsm);
-	if (ret < 0)
+	if (ret < 0) {
+		pr_err("Unable to restore credentials\n");
 		goto err;
+	}
 
 	if (lsm) {
 		char *rendered;
@@ -2810,6 +2814,7 @@ static int sigreturn_restore(pid_t pid, CoreEntry *core)
 		ret = render_lsm_profile(lsm, &rendered);
 		xfree(lsm);
 		if (ret < 0) {
+			pr_err("Unable to render lsm profile\n");
 			goto err_nv;
 		}
 

lsm.c

@@ -199,6 +199,7 @@ int render_lsm_profile(char *profile, char **val)
 		}
 		break;
 	default:
+		pr_err("Unknown LSM type: %d\n", lsmtype);
 		return -1;
 	}