restore: Move uffd setup out of sigreturn_restore

Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>
Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org>

criu/cr-restore.c

@@ -848,6 +848,9 @@ static int restore_one_alive_task(int pid, CoreEntry *core)
 	if (prepare_vmas(current, ta))
 		return -1;
 
+	if (setup_uffd(pid, ta))
+		return -1;
+
 	return sigreturn_restore(pid, ta, args_len, core);
 }
 
@@ -3205,12 +3208,6 @@ static int sigreturn_restore(pid_t pid, struct task_restore_args *task_args, uns
 
 	strncpy(task_args->comm, core->tc->comm, sizeof(task_args->comm));
 
-	if (!opts.lazy_pages)
-		task_args->uffd = -1;
-	else
-		if (setup_uffd(task_args, pid) != 0)
-			goto err;
-
 	/*
 	 * Fill up per-thread data.
 	 */

criu/include/uffd.h

@@ -2,6 +2,6 @@
 #define __CR_UFFD_H_
 
 struct task_restore_args;
-extern int setup_uffd(struct task_restore_args *task_args, int pid);
+extern int setup_uffd(int pid, struct task_restore_args *task_args);
 
 #endif /* __CR_UFFD_H_ */

criu/uffd.c

@@ -182,9 +182,15 @@ static int check_for_uffd()
 }
 
 /* This function is used by 'criu restore --lazy-pages' */
-int setup_uffd(struct task_restore_args *task_args, int pid)
+int setup_uffd(int pid, struct task_restore_args *task_args)
 {
 	struct uffdio_api uffdio_api;
+
+	if (!opts.lazy_pages) {
+		task_args->uffd = -1;
+		return 0;
+	}
+
 	if (check_for_uffd())
 		return -1;
 	/*