From 6ee558d52ade2b73bbed533e7820c0bedaa4fb27 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?YC=E9=85=B1luyancib?= <2058282593@qq.com>
Date: Sun, 18 May 2025 18:39:20 +0800
Subject: [PATCH] kernel:fix missing auto backport can_mount #85

---
 kernel/Makefile | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/kernel/Makefile b/kernel/Makefile
index 3c85245f..4705f073 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -125,6 +125,28 @@ endif
 
 ccflags-y += -DKSU_UMOUNT
 
+ifneq ($(shell grep -Eq "^static int can_umount" $(srctree)/fs/namespace.c; echo $$?),0)
+$(info -- SukiSU compat: adding function 'static int can_umount(const struct path *path, int flags);' to $(srctree)/fs/namespace.c)
+CAN_UMOUNT = static int can_umount(const struct path *path, int flags)\n\
+{\n\t\
+        struct mount *mnt = real_mount(path->mnt);\n\t\
+        if (flags & ~(MNT_FORCE | MNT_DETACH | MNT_EXPIRE | UMOUNT_NOFOLLOW))\n\t\t\
+                return -EINVAL;\n\t\
+        if (!may_mount())\n\t\t\
+                return -EPERM;\n\t\
+        if (path->dentry != path->mnt->mnt_root)\n\t\t\
+                return -EINVAL;\n\t\
+        if (!check_mnt(mnt))\n\t\t\
+                return -EINVAL;\n\t\
+        if (mnt->mnt.mnt_flags & MNT_LOCKED)\n\t\t\
+                return -EINVAL;\n\t\
+        if (flags & MNT_FORCE && !capable(CAP_SYS_ADMIN))\n\t\t\
+                return -EPERM;\n\t\
+        return 0;\n\
+}\n
+$(shell sed -i '/^static bool is_mnt_ns_file/i $(CAN_UMOUNT)' $(srctree)/fs/namespace.c;)
+endif
+
 ifneq ($(shell grep -Eq "^int path_umount" $(srctree)/fs/namespace.c; echo $$?),0)
 $(info -- SukiSU compat: adding function 'int path_umount(struct path *path, int flags);' to $(srctree)/fs/namespace.c)
 PATH_UMOUNT = int path_umount(struct path *path, int flags)\n\