From 610313d7d654e3671425024b154b89f5f8d45a4b Mon Sep 17 00:00:00 2001
From: ShirkNeko <109797057+ShirkNeko@users.noreply.github.com>
Date: Fri, 11 Apr 2025 03:46:21 +0800
Subject: [PATCH] Remove definition checking on get_cred_rcu and can_umount
 functions to simplify path unloading logic in kernel Makefile.

---
 kernel/Makefile | 54 -------------------------------------------------
 1 file changed, 54 deletions(-)

diff --git a/kernel/Makefile b/kernel/Makefile
index a7fca597..5e7c7c70 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -189,60 +189,6 @@ ifneq ($(shell grep -Eq "^int path_umount" $(srctree)/fs/internal.h; echo $$?),0
 $(shell sed -i '/^extern void __init mnt_init/a int path_umount(struct path *path, int flags);' $(srctree)/fs/internal.h;)
 endif
 
-ifneq ($(shell grep -Eq "get_cred_rcu" $(srctree)/include/linux/cred.h; echo $$?),0)
-GET_CRED_RCU = static inline const struct cred *get_cred_rcu(const struct cred *cred)\n\
-{\n\t\
-	struct cred *nonconst_cred = (struct cred *) cred;\n\t\
-	if (!cred)\n\t\t\
-		return NULL;\n\t\
-	if (!atomic_inc_not_zero(&nonconst_cred->usage))\n\t\t\
-		return NULL;\n\t\
-	validate_creds(cred);\n\t\
-	return cred;\n\
-}\n
-$(shell sed -i '/^static inline void put_cred/i $(GET_CRED_RCU)' $(srctree)/include/linux/cred.h;)
-endif
-
-ifneq ($(shell grep -Eq "^static int can_umount" $(srctree)/fs/namespace.c; echo $$?),0)
-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 $$?),0)
-PATH_UMOUNT = int path_umount(struct path *path, int flags)\n\
-{\n\t\
-        struct mount *mnt = real_mount(path->mnt);\n\t\
-        int ret;\n\t\
-        ret = can_umount(path, flags);\n\t\
-        if (!ret)\n\t\t\
-                ret = do_umount(mnt, flags);\n\t\
-        dput(path->dentry);\n\t\
-        mntput_no_expire(mnt);\n\t\
-        return ret;\n\
-}\n
-$(shell sed -i '/^static bool is_mnt_ns_file/i $(PATH_UMOUNT)' $(srctree)/fs/namespace.c;)
-endif
-
-ifneq ($(shell grep -Eq "^int path_umount" $(srctree)/fs/internal.h; echo $$?),0)
-$(shell sed -i '/^extern void __init mnt_init/a int path_umount(struct path *path, int flags);' $(srctree)/fs/internal.h;)
-endif
-
 # Do checks before compile
 ifneq ($(shell grep -q "int path_umount" $(srctree)/fs/namespace.c; echo $$?),0)
 $(error -- Backporting path_umount is mandatory !! Read: https://kernelsu.org/guide/how-to-integrate-for-non-gki.html#how-to-backport-path-umount)