remove some compats

kernel/Makefile

@@ -31,14 +31,6 @@ $(warning "KSU_GIT_VERSION not defined! It is better to make KernelSU a git subm
 ccflags-y += -DKSU_VERSION=16
 endif
 
-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
-
 ifndef KSU_EXPECTED_SIZE
 KSU_EXPECTED_SIZE := 0x033b
 endif
@@ -58,13 +50,6 @@ $(info -- KernelSU Manager signature hash: $(KSU_EXPECTED_HASH))
 ccflags-y += -DEXPECTED_SIZE=$(KSU_EXPECTED_SIZE)
 ccflags-y += -DEXPECTED_HASH=\"$(KSU_EXPECTED_HASH)\"
 
-ifeq ($(shell grep -q "int path_umount" $(srctree)/fs/namespace.c; echo $$?),0)
-ccflags-y += -DKSU_UMOUNT
-else
-$(info -- Did you know you can backport path_umount to fs/namespace.c from 5.9?)
-$(info -- Read: https://kernelsu.org/guide/how-to-integrate-for-non-gki.html#how-to-backport-path_umount)
-endif
-
 ccflags-y += -Wno-implicit-function-declaration -Wno-strict-prototypes -Wno-int-conversion -Wno-gcc-compat
 ccflags-y += -Wno-declaration-after-statement -Wno-unused-function
 

kernel/allowlist.c

@@ -8,9 +8,7 @@
 #include "linux/slab.h"
 #include "linux/types.h"
 #include "linux/version.h"
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 14, 0)
 #include "linux/compiler_types.h"
-#endif
 
 #include "klog.h" // IWYU pragma: keep
 #include "selinux/selinux.h"

kernel/arch.h

@@ -18,11 +18,7 @@
 #define __PT_SP_REG sp
 #define __PT_IP_REG pc
 
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 16, 0)
 #define PRCTL_SYMBOL "__arm64_sys_prctl"
-#else
-#define PRCTL_SYMBOL "sys_prctl"
-#endif
 
 #elif defined(__x86_64__)
 
@@ -39,11 +35,7 @@
 #define __PT_RC_REG ax
 #define __PT_SP_REG sp
 #define __PT_IP_REG ip
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 16, 0)
 #define PRCTL_SYMBOL "__x64_sys_prctl"
-#else
-#define PRCTL_SYMBOL "sys_prctl"
-#endif
 
 #else
 #error "Unsupported arch"

kernel/core_hook.c

@@ -98,11 +98,7 @@ static void setup_groups(struct root_profile *profile, struct cred *cred)
 			put_group_info(group_info);
 			return;
 		}
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 9, 0)
 		group_info->gid[i] = kgid;
-#else
-		GROUP_AT(group_info, i) = kgid;
-#endif
 	}
 
 	groups_sort(group_info);
@@ -521,14 +517,10 @@ static bool should_umount(struct path *path)
 
 static void ksu_umount_mnt(struct path *path, int flags)
 {
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 9, 0) || defined(KSU_UMOUNT)
 	int err = path_umount(path, flags);
 	if (err) {
 		pr_info("umount %s failed: %d\n", path->dentry->d_iname, err);
 	}
-#else
-	// TODO: umount for non GKI kernel
-#endif
 }
 
 static void try_umount(const char *mnt, bool check_mnt, int flags)
@@ -620,22 +612,12 @@ int ksu_handle_setuid(struct cred *new, const struct cred *old)
 
 static int handler_pre(struct kprobe *p, struct pt_regs *regs)
 {
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 16, 0)
 	struct pt_regs *real_regs = (struct pt_regs *)PT_REGS_PARM1(regs);
-#else
-	struct pt_regs *real_regs = regs;
-#endif
 	int option = (int)PT_REGS_PARM1(real_regs);
 	unsigned long arg2 = (unsigned long)PT_REGS_PARM2(real_regs);
 	unsigned long arg3 = (unsigned long)PT_REGS_PARM3(real_regs);
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 16, 0)
 	// PRCTL_SYMBOL is the arch-specificed one, which receive raw pt_regs from syscall
 	unsigned long arg4 = (unsigned long)PT_REGS_SYSCALL_PARM4(real_regs);
-#else
-	// PRCTL_SYMBOL is the common one, called by C convention in do_syscall_64
-	// https://elixir.bootlin.com/linux/v4.15.18/source/arch/x86/entry/common.c#L287
-	unsigned long arg4 = (unsigned long)PT_REGS_CCALL_PARM4(real_regs);
-#endif
 	unsigned long arg5 = (unsigned long)PT_REGS_PARM5(real_regs);
 
 	return ksu_handle_prctl(option, arg2, arg3, arg4, arg5);
@@ -695,23 +677,7 @@ static int ksu_task_prctl(int option, unsigned long arg2, unsigned long arg3,
 	ksu_handle_prctl(option, arg2, arg3, arg4, arg5);
 	return -ENOSYS;
 }
-// kernel 4.4 and 4.9
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 10, 0)
-static int ksu_key_permission(key_ref_t key_ref, const struct cred *cred,
-			      unsigned perm)
-{
-	if (init_session_keyring != NULL) {
-		return 0;
-	}
-	if (strcmp(current->comm, "init")) {
-		// we are only interested in `init` process
-		return 0;
-	}
-	init_session_keyring = cred->session_keyring;
-	pr_info("kernel_compat: got init_session_keyring\n");
-	return 0;
-}
-#endif
+
 static int ksu_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
 			    struct inode *new_inode, struct dentry *new_dentry)
 {
@@ -728,19 +694,11 @@ static struct security_hook_list ksu_hooks[] = {
 	LSM_HOOK_INIT(task_prctl, ksu_task_prctl),
 	LSM_HOOK_INIT(inode_rename, ksu_inode_rename),
 	LSM_HOOK_INIT(task_fix_setuid, ksu_task_fix_setuid),
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 10, 0)
-	LSM_HOOK_INIT(key_permission, ksu_key_permission)
-#endif
 };
 
 void __init ksu_lsm_hook_init(void)
 {
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
 	security_add_hooks(ksu_hooks, ARRAY_SIZE(ksu_hooks), "ksu");
-#else
-	// https://elixir.bootlin.com/linux/v4.10.17/source/include/linux/lsm_hooks.h#L1892
-	security_add_hooks(ksu_hooks, ARRAY_SIZE(ksu_hooks));
-#endif
 }
 
 #ifdef MODULE

kernel/kernel_compat.c

@@ -1,39 +1,10 @@
 #include "linux/version.h"
 #include "linux/fs.h"
 #include "linux/nsproxy.h"
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 10, 0)
 #include "linux/sched/task.h"
-#else
-#include "linux/sched.h"
-#endif
 #include "linux/uaccess.h"
 #include "klog.h" // IWYU pragma: keep
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 10, 0)
-#include "linux/key.h"
-#include "linux/errno.h"
-#include "linux/cred.h"
-struct key *init_session_keyring = NULL;
-
-static inline int install_session_keyring(struct key *keyring)
-{
-	struct cred *new;
-	int ret;
-
-	new = prepare_creds();
-	if (!new)
-		return -ENOMEM;
-
-	ret = install_session_keyring_to_cred(new, keyring);
-	if (ret < 0) {
-		abort_creds(new);
-		return ret;
-	}
-
-	return commit_creds(new);
-}
-#endif
-
 extern struct task_struct init_task;
 
 // mnt_ns context switch for environment that android_init->nsproxy->mnt_ns != init_task.nsproxy->mnt_ns, such as WSA
@@ -78,13 +49,6 @@ void ksu_android_ns_fs_check()
 
 struct file *ksu_filp_open_compat(const char *filename, int flags, umode_t mode)
 {
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 10, 0)
-	if (init_session_keyring != NULL && !current_cred()->session_keyring &&
-	    (current->flags & PF_WQ_WORKER)) {
-		pr_info("installing init session keyring for older kernel\n");
-		install_session_keyring(init_session_keyring);
-	}
-#endif
 	// switch mnt_ns even if current is not wq_worker, to ensure what we open is the correct file in android mnt_ns, rather than user created mnt_ns
 	struct ksu_ns_fs_saved saved;
 	if (android_context_saved_enabled) {
@@ -107,69 +71,17 @@ struct file *ksu_filp_open_compat(const char *filename, int flags, umode_t mode)
 ssize_t ksu_kernel_read_compat(struct file *p, void *buf, size_t count,
 			       loff_t *pos)
 {
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 14, 0)
 	return kernel_read(p, buf, count, pos);
-#else
-	loff_t offset = pos ? *pos : 0;
-	ssize_t result = kernel_read(p, offset, (char *)buf, count);
-	if (pos && result > 0) {
-		*pos = offset + result;
-	}
-	return result;
-#endif
 }
 
 ssize_t ksu_kernel_write_compat(struct file *p, const void *buf, size_t count,
 				loff_t *pos)
 {
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 14, 0)
 	return kernel_write(p, buf, count, pos);
-#else
-	loff_t offset = pos ? *pos : 0;
-	ssize_t result = kernel_write(p, buf, count, offset);
-	if (pos && result > 0) {
-		*pos = offset + result;
-	}
-	return result;
-#endif
 }
 
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 8, 0)
 long ksu_strncpy_from_user_nofault(char *dst, const void __user *unsafe_addr,
 				   long count)
 {
 	return strncpy_from_user_nofault(dst, unsafe_addr, count);
 }
-#elif LINUX_VERSION_CODE >= KERNEL_VERSION(5, 3, 0)
-long ksu_strncpy_from_user_nofault(char *dst, const void __user *unsafe_addr,
-				   long count)
-{
-	return strncpy_from_unsafe_user(dst, unsafe_addr, count);
-}
-#else
-// Copied from: https://elixir.bootlin.com/linux/v4.9.337/source/mm/maccess.c#L201
-long ksu_strncpy_from_user_nofault(char *dst, const void __user *unsafe_addr,
-				   long count)
-{
-	mm_segment_t old_fs = get_fs();
-	long ret;
-
-	if (unlikely(count <= 0))
-		return 0;
-
-	set_fs(USER_DS);
-	pagefault_disable();
-	ret = strncpy_from_user(dst, unsafe_addr, count);
-	pagefault_enable();
-	set_fs(old_fs);
-
-	if (ret >= count) {
-		ret = count;
-		dst[ret - 1] = '\0';
-	} else if (ret > 0) {
-		ret++;
-	}
-
-	return ret;
-}
-#endif

kernel/kernel_compat.h

@@ -9,10 +9,6 @@ extern long ksu_strncpy_from_user_nofault(char *dst,
 					  const void __user *unsafe_addr,
 					  long count);
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 10, 0)
-extern struct key *init_session_keyring;
-#endif
-
 extern void ksu_android_ns_fs_check();
 extern struct file *ksu_filp_open_compat(const char *filename, int flags,
 					 umode_t mode);

kernel/ksu.c

@@ -87,7 +87,4 @@ module_exit(kernelsu_exit);
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("weishu");
 MODULE_DESCRIPTION("Android KernelSU");
-
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 0, 0)
 MODULE_IMPORT_NS(VFS_internal_I_am_really_a_filesystem_and_am_NOT_a_driver);
-#endif

kernel/ksud.c

@@ -4,14 +4,7 @@
 #include "linux/err.h"
 #include "linux/fs.h"
 #include "linux/version.h"
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 4, 0)
 #include "linux/input-event-codes.h"
-#else
-#include "uapi/linux/input.h"
-#endif
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 1, 0)
-#include "linux/aio.h"
-#endif
 #include "linux/kprobes.h"
 #include "linux/printk.h"
 #include "linux/types.h"
@@ -479,13 +472,7 @@ static int input_handle_event_handler_pre(struct kprobe *p,
 }
 
 static struct kprobe execve_kp = {
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 9, 0)
 	.symbol_name = "do_execveat_common",
-#elif LINUX_VERSION_CODE >= KERNEL_VERSION(4, 19, 0)
-	.symbol_name = "__do_execve_file",
-#elif LINUX_VERSION_CODE >= KERNEL_VERSION(3, 19, 0)
-	.symbol_name = "do_execveat_common",
-#endif
 	.pre_handler = execve_handler_pre,
 };
 

kernel/selinux/selinux.h

@@ -4,10 +4,6 @@
 #include "linux/types.h"
 #include "linux/version.h"
 
-#if (LINUX_VERSION_CODE >= KERNEL_VERSION(5, 10, 0)) || defined(KSU_COMPAT_HAS_SELINUX_STATE)
-#define KSU_COMPAT_USE_SELINUX_STATE
-#endif
-
 void setup_selinux(const char *);
 
 void setenforce(bool);