From f39d4f0f38d438c9ec22ed11339bed9a63b9cba5 Mon Sep 17 00:00:00 2001
From: Shadichy <60534636+shadichy@users.noreply.github.com>
Date: Fri, 7 Nov 2025 21:18:05 +0700
Subject: [PATCH] kernel: Refactor selinux/selinux.c (#2881)

Signed-off-by: shadichy <shadichy@blisslabs.org>
Co-authored-by: Wang Han <416810799@qq.com>
---
 kernel/Makefile          |  8 -----
 kernel/selinux/selinux.c | 64 ++++++++++++----------------------------
 2 files changed, 19 insertions(+), 53 deletions(-)

diff --git a/kernel/Makefile b/kernel/Makefile
index 93978ea0..701a9e02 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -118,14 +118,6 @@ else
 $(info -- KPM is disabled)
 endif
 
-# SELinux drivers check
-ifeq ($(shell grep -q "current_sid(void)" $(srctree)/security/selinux/include/objsec.h; echo $$?),0)
-ccflags-y += -DKSU_COMPAT_HAS_CURRENT_SID
-endif
-ifeq ($(shell grep -q "struct selinux_state " $(srctree)/security/selinux/include/security.h; echo $$?),0)
-ccflags-y += -DKSU_COMPAT_HAS_SELINUX_STATE
-endif
-
 # Handle optional backports
 ifeq ($(shell grep -q "strncpy_from_user_nofault" $(srctree)/include/linux/uaccess.h; echo $$?),0)
 ccflags-y += -DKSU_OPTIONAL_STRNCPY
diff --git a/kernel/selinux/selinux.c b/kernel/selinux/selinux.c
index 051384a7..57c2be1b 100644
--- a/kernel/selinux/selinux.c
+++ b/kernel/selinux/selinux.c
@@ -90,27 +90,28 @@ bool getenforce(void)
     return __is_selinux_enforcing();
 }
 
-#if (LINUX_VERSION_CODE < KERNEL_VERSION(5, 10, 0)) &&                         \
-    !defined(KSU_COMPAT_HAS_CURRENT_SID)
-/*
- * get the subjective security ID of the current task
- */
-static inline u32 current_sid(void)
-{
-    const struct task_security_struct *tsec = current_security();
+#if LINUX_VERSION_CODE < KERNEL_VERSION(6, 14, 0)
+struct lsm_context {
+    char *context;
+    u32 len;
+};
 
-    return tsec->sid;
+static int __security_secid_to_secctx(u32 secid, struct lsm_context *cp)
+{
+    return security_secid_to_secctx(secid, &cp->context, &cp->len);
 }
+static void __security_release_secctx(struct lsm_context *cp)
+{
+    return security_release_secctx(cp->context, cp->len);
+}
+#else
+#define __security_secid_to_secctx security_secid_to_secctx
+#define __security_release_secctx security_release_secctx
 #endif
 
 bool is_task_ksu_domain(const struct cred* cred)
 {
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 14, 0)
     struct lsm_context ctx;
-#else
-    char *domain;
-    u32 seclen;
-#endif
     bool result;
     if (!cred) {
         return false;
@@ -119,23 +120,12 @@ bool is_task_ksu_domain(const struct cred* cred)
     if (!tsec) {
         return false;
     }
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 14, 0)
-    int err = security_secid_to_secctx(tsec->sid, &ctx);
-#else
-    int err = security_secid_to_secctx(tsec->sid, &domain, &seclen);
-#endif
-
+    int err = __security_secid_to_secctx(tsec->sid, &ctx);
     if (err) {
         return false;
     }
-
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 14, 0)
     result = strncmp(KERNEL_SU_DOMAIN, ctx.context, ctx.len) == 0;
-    security_release_secctx(&ctx);
-#else
-    result = strncmp(KERNEL_SU_DOMAIN, domain, seclen) == 0;
-    security_release_secctx(domain, seclen);
-#endif
+    __security_release_secctx(&ctx);
     return result;
 }
 
@@ -154,30 +144,14 @@ bool is_zygote(const struct cred* cred)
     if (!tsec) {
         return false;
     }
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 14, 0)
     struct lsm_context ctx;
-#else
-    char *domain;
-    u32 seclen;
-#endif
     bool result;
-
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 14, 0)
-    int err = security_secid_to_secctx(tsec->sid, &ctx);
-#else
-    int err = security_secid_to_secctx(tsec->sid, &domain, &seclen);
-#endif
+    int err = __security_secid_to_secctx(tsec->sid, &ctx);
     if (err) {
         return false;
     }
-
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 14, 0)
     result = strncmp("u:r:zygote:s0", ctx.context, ctx.len) == 0;
-    security_release_secctx(&ctx);
-#else
-    result = strncmp("u:r:zygote:s0", domain, seclen) == 0;
-    security_release_secctx(domain, seclen);
-#endif
+    __security_release_secctx(&ctx);
     return result;
 }