From f28d4b9f3933e24880880e97e2d36a232a67246c Mon Sep 17 00:00:00 2001
From: Rissu <90097027+rsuntk@users.noreply.github.com>
Date: Tue, 25 Mar 2025 13:41:48 +0000
Subject: [PATCH] kernel: fix prebuilt get_cred_rcu on certain linux version

Previously, i think non_rcu not available on 4.4.186 and below
but, apparently 4.9 too.

Fix: https://github.com/luyanci/KernelSU/commit/33d2961b057d87909887c49f80358e8bfd328e72

Signed-off-by: Rissu <90097027+rsuntk@users.noreply.github.com>
---
 kernel/Makefile        |  7 +++----
 kernel/kernel_compat.h | 38 ++++++++++++++++++++------------------
 2 files changed, 23 insertions(+), 22 deletions(-)

diff --git a/kernel/Makefile b/kernel/Makefile
index 5d4c5852..7b6effb9 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -80,12 +80,11 @@ endif
 ifeq ($(shell grep -q "get_cred_rcu" $(srctree)/include/linux/cred.h; echo $$?),0)
 ccflags-y += -DKSU_COMPAT_HAS_GET_CRED_RCU
 else
-# https://github.com/gregkh/linux/commit/123e44b9a49a42ff5313ec65256f1540d7c52fa0
 ifeq ($(shell grep -q "atomic_long_t\s\+\usage" $(srctree)/include/linux/cred.h; echo $$?),0)
-$(info -- KernelSU compat: atomic_long_t detected.)
 ccflags-y += -DKSU_COMPAT_ATOMIC_LONG
-else
-$(info -- KernelSU compat: atomic_t detected.)
+endif
+ifeq ($(shell grep -q "int\s\+\non_rcu" $(srctree)/include/linux/cred.h; echo $$?),0)
+ccflags-y += -DKSU_COMPAT_HAS_NONCONST_CRED
 endif
 endif
 
diff --git a/kernel/kernel_compat.h b/kernel/kernel_compat.h
index d4170355..36501246 100644
--- a/kernel/kernel_compat.h
+++ b/kernel/kernel_compat.h
@@ -8,24 +8,26 @@
 #include "linux/key.h"
 
 // for kernel without get_cred_rcu
- #ifndef KSU_COMPAT_HAS_GET_CRED_RCU
- static inline const struct cred *get_cred_rcu(const struct cred *cred)
- {
- 	struct cred *nonconst_cred = (struct cred *) cred;
- 	if (!cred)
- 		return NULL;
- #ifdef KSU_COMPAT_ATOMIC_LONG
- 	if (!atomic_long_inc_not_zero(&nonconst_cred->usage))
- #else
- 	if (!atomic_inc_not_zero(&nonconst_cred->usage))
- #endif		
- 		return NULL;
- 	validate_creds(cred);
- 	nonconst_cred->non_rcu = 0;
- 	return cred;
- }
- #endif
- 
+#ifndef KSU_COMPAT_HAS_GET_CRED_RCU
+static inline const struct cred *get_cred_rcu(const struct cred *cred)
+{
+	struct cred *nonconst_cred = (struct cred *) cred;
+	if (!cred)
+		return NULL;
+#ifdef KSU_COMPAT_ATOMIC_LONG
+	if (!atomic_long_inc_not_zero(&nonconst_cred->usage))
+#else
+	if (!atomic_inc_not_zero(&nonconst_cred->usage))
+#endif		
+		return NULL;
+	validate_creds(cred);
+#ifdef KSU_COMPAT_HAS_NONCONST_CRED
+	nonconst_cred->non_rcu = 0;
+#endif
+	return cred;
+}
+#endif
+
 /*
  * Adapt to Huawei HISI kernel without affecting other kernels ,
  * Huawei Hisi Kernel EBITMAP Enable or Disable Flag ,