kernel: Fix compilation for non-gki kernels (#593)

kernel/allowlist.c

@@ -19,6 +19,7 @@
 
 #include "klog.h" // IWYU pragma: keep
 #include "ksud.h"
+#include "kernel_compat.h"
 #include "selinux/selinux.h"
 #include "allowlist.h"
 #include "manager.h"
@@ -431,11 +432,7 @@ void persistent_allow_list()
         goto put_task;
     }
     cb->func = do_persistent_allow_list;
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 7, 0)
     task_work_add(tsk, cb, TWA_RESUME);
-#else
-    task_work_add(tsk, cb, true);
-#endif
 
 put_task:
     put_task_struct(tsk);

kernel/file_wrapper.c

@@ -279,7 +279,7 @@ static int ksu_wrapper_fadvise(struct file *fp, loff_t off1, loff_t off2, int fl
 static int ksu_wrapper_clone_file_range(struct file *file_in, loff_t pos_in,
 				struct file *file_out, loff_t pos_out, u64 len) {
 	// TODO: determine which file to use
-	struct ksu_file_proxy* data = file_in->private_data;
+	struct ksu_file_wrapper* data = file_in->private_data;
 	struct file* orig = data->orig;
 	if (orig->f_op->clone_file_range) {
 		return orig->f_op->clone_file_range(orig, pos_in, file_out, pos_out, len);
@@ -290,7 +290,7 @@ static int ksu_wrapper_clone_file_range(struct file *file_in, loff_t pos_in,
 static ssize_t ksu_wrapper_dedupe_file_range(struct file *src_file, u64 loff,
 				u64 len, struct file *dst_file, u64 dst_loff) {
 	// TODO: determine which file to use
-	struct ksu_file_proxy* data = src_file->private_data;
+	struct ksu_file_wrapper* data = src_file->private_data;
 	struct file* orig = data->orig;
 	if (orig->f_op->dedupe_file_range) {
 		return orig->f_op->dedupe_file_range(orig, loff, len, dst_file, dst_loff);

kernel/kernel_compat.c

@@ -78,57 +78,3 @@ long ksu_strncpy_from_user_nofault(char *dst, const void __user *unsafe_addr,
     return ret;
 }
 #endif
-
-long ksu_strncpy_from_user_retry(char *dst, const void __user *unsafe_addr,
-                   long count)
-{
-    long ret;
-
-    ret = ksu_strncpy_from_user_nofault(dst, unsafe_addr, count);
-    if (likely(ret >= 0))
-        return ret;
-
-    // we faulted! fallback to slow path
-    if (unlikely(!ksu_access_ok(unsafe_addr, count))) {
-#ifdef CONFIG_KSU_DEBUG
-        pr_err("%s: faulted!\n", __func__);
-#endif
-        return -EFAULT;
-    }
-
-    // why we don't do like how strncpy_from_user_nofault?
-    ret = strncpy_from_user(dst, unsafe_addr, count);
-
-    if (ret >= count) {
-        ret = count;
-        dst[ret - 1] = '\0';
-    } else if (likely(ret >= 0)) {
-        ret++;
-    }
-
-    return ret;
-}
-
-long ksu_copy_from_user_nofault(void *dst, const void __user *src, size_t size)
-{
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 8, 0)
-    return copy_from_user_nofault(dst, src, size);
-#else
-    // https://elixir.bootlin.com/linux/v5.8/source/mm/maccess.c#L205
-    long ret = -EFAULT;
-    mm_segment_t old_fs = get_fs();
-
-    set_fs(USER_DS);
-    // tweaked to use ksu_access_ok
-    if (ksu_access_ok(src, size)) {
-        pagefault_disable();
-        ret = __copy_from_user_inatomic(dst, src, size);
-        pagefault_enable();
-    }
-    set_fs(old_fs);
-
-    if (ret)
-        return -EFAULT;
-    return 0;
-#endif
-}

kernel/kernel_compat.h

@@ -15,32 +15,12 @@
 extern long ksu_strncpy_from_user_nofault(char *dst,
                       const void __user *unsafe_addr,
                       long count);
-extern long ksu_strncpy_from_user_retry(char *dst,
-                      const void __user *unsafe_addr,
-                      long count);
 
 #if LINUX_VERSION_CODE < KERNEL_VERSION(4, 10, 0) ||    \
     defined(CONFIG_IS_HW_HISI) ||    \
     defined(CONFIG_KSU_ALLOWLIST_WORKAROUND)
 extern struct key *init_session_keyring;
 #endif
-/*
- * ksu_copy_from_user_retry
- * try nofault copy first, if it fails, try with plain
- * paramters are the same as copy_from_user
- * 0 = success
- */
-extern long ksu_copy_from_user_nofault(void *dst, const void __user *src, size_t size);
-static long ksu_copy_from_user_retry(void *to, 
-        const void __user *from, unsigned long count)
-{
-    long ret = ksu_copy_from_user_nofault(to, from, count);
-    if (likely(!ret))
-        return ret;
-
-    // we faulted! fallback to slow path
-    return copy_from_user(to, from, count);
-}
 
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 0, 0)
 #define ksu_access_ok(addr, size)    access_ok(addr, size)
@@ -48,4 +28,14 @@ static long ksu_copy_from_user_retry(void *to,
 #define ksu_access_ok(addr, size)    access_ok(VERIFY_READ, addr, size)
 #endif
 
+#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 7, 0)
+#define TWA_RESUME true
+#endif
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 2, 0)
+#define ksu_force_sig(sig)      force_sig(sig);
+#else
+#define ksu_force_sig(sig)      force_sig(sig, current);
+#endif
+
 #endif

kernel/kernel_umount.c

@@ -10,10 +10,12 @@
 #include <linux/path.h>
 #include <linux/printk.h>
 #include <linux/types.h>
+#include <linux/uaccess.h>
 
 #include "manager.h"
 #include "kernel_umount.h"
 #include "klog.h" // IWYU pragma: keep
+#include "kernel_compat.h"
 #include "allowlist.h"
 #include "selinux/selinux.h"
 #include "feature.h"
@@ -245,11 +247,7 @@ int ksu_handle_umount(uid_t old_uid, uid_t new_uid)
     tw->old_cred = get_current_cred();
     tw->cb.func = umount_tw_func;
 
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 9, 0)
     int err = task_work_add(current, &tw->cb, TWA_RESUME);
-#else
-    int err = task_work_add(current, &tw->cb, true);
-#endif
     if (err) {
         if (tw->old_cred) {
             put_cred(tw->old_cred);

kernel/ksud.c

@@ -32,6 +32,7 @@
 #include "arch.h"
 #include "klog.h" // IWYU pragma: keep
 #include "ksud.h"
+#include "kernel_compat.h"
 #include "selinux/selinux.h"
 #include "throne_tracker.h"
 
@@ -254,7 +255,7 @@ int ksu_handle_execveat_ksud(int *fd, struct filename **filename_ptr,
             const char __user *p = get_user_arg_ptr(*argv, 1);
             if (p && !IS_ERR(p)) {
                 char first_arg[16];
-                strncpy_from_user_nofault(first_arg, p, sizeof(first_arg));
+                ksu_strncpy_from_user_nofault(first_arg, p, sizeof(first_arg));
                 pr_info("/system/bin/init first arg: %s\n", first_arg);
                 if (!strcmp(first_arg, "second_stage")) {
                     pr_info("/system/bin/init second_stage executed\n");
@@ -276,7 +277,7 @@ int ksu_handle_execveat_ksud(int *fd, struct filename **filename_ptr,
             const char __user *p = get_user_arg_ptr(*argv, 1);
             if (p && !IS_ERR(p)) {
                 char first_arg[16];
-                strncpy_from_user_nofault(first_arg, p, sizeof(first_arg));
+                ksu_strncpy_from_user_nofault(first_arg, p, sizeof(first_arg));
                 pr_info("/init first arg: %s\n", first_arg);
                 if (!strcmp(first_arg, "--second-stage")) {
                     pr_info("/init second_stage executed\n");
@@ -298,7 +299,7 @@ int ksu_handle_execveat_ksud(int *fd, struct filename **filename_ptr,
                     }
                     char env[256];
                     // Reading environment variable strings from user space
-                    if (strncpy_from_user_nofault(env, p, sizeof(env)) < 0)
+                    if (ksu_strncpy_from_user_nofault(env, p, sizeof(env)) < 0)
                         continue;
                     // Parsing environment variable names and values
                     char *env_name = env;
@@ -543,7 +544,7 @@ static int sys_execve_handler_pre(struct kprobe *p, struct pt_regs *regs)
         return 0;
 
     memset(path, 0, sizeof(path));
-    strncpy_from_user_nofault(path, *filename_user, 32);
+    ksu_strncpy_from_user_nofault(path, *filename_user, 32);
     filename_in.name = path;
 
     filename_p = &filename_in;

kernel/setuid_hook.c

@@ -52,6 +52,7 @@
 #include "setuid_hook.h"
 #include "feature.h"
 #include "klog.h" // IWYU pragma: keep
+#include "kernel_compat.h"
 #include "ksu.h"
 #include "manager.h"
 #include "selinux/selinux.h"
@@ -147,7 +148,7 @@ int ksu_handle_setresuid(uid_t ruid, uid_t euid, uid_t suid)
             if (!is_ksu_domain()) {
                 pr_warn("find suspicious EoP: %d %s, from %d to %d\n", 
                     current->pid, current->comm, old_uid, new_uid);
-                force_sig(SIGKILL);
+                ksu_force_sig(SIGKILL);
                 return 0;
             }
         }
@@ -156,7 +157,7 @@ int ksu_handle_setresuid(uid_t ruid, uid_t euid, uid_t suid)
             if (euid < current_euid().val && !ksu_is_allow_uid_for_current(old_uid)) {
                 pr_warn("find suspicious EoP: %d %s, from %d to %d\n", 
                     current->pid, current->comm, old_uid, new_uid);
-                force_sig(SIGKILL);
+                ksu_force_sig(SIGKILL);
                 return 0;
             }
         }
@@ -227,7 +228,7 @@ int ksu_handle_setresuid(uid_t ruid, uid_t euid, uid_t suid){
             if (!is_ksu_domain()) {
                 pr_warn("find suspicious EoP: %d %s, from %d to %d\n", 
                     current->pid, current->comm, old_uid, new_uid);
-                force_sig(SIGKILL);
+                ksu_force_sig(SIGKILL);
                 return 0;
             }
         }
@@ -236,7 +237,7 @@ int ksu_handle_setresuid(uid_t ruid, uid_t euid, uid_t suid){
             if (euid < current_euid().val && !ksu_is_allow_uid_for_current(old_uid)) {
                 pr_warn("find suspicious EoP: %d %s, from %d to %d\n", 
                     current->pid, current->comm, old_uid, new_uid);
-                force_sig(SIGKILL);
+                ksu_force_sig(SIGKILL);
                 return 0;
             }
         }

kernel/sucompat.c

@@ -97,7 +97,7 @@ int ksu_handle_faccessat(int *dfd, const char __user **filename_user, int *mode,
 
     char path[sizeof(su) + 1];
     memset(path, 0, sizeof(path));
-    strncpy_from_user_nofault(path, *filename_user, sizeof(path));
+    ksu_strncpy_from_user_nofault(path, *filename_user, sizeof(path));
 
     if (unlikely(!memcmp(path, su, sizeof(su)))) {
 #if __SULOG_GATE
@@ -144,7 +144,7 @@ int ksu_handle_stat(int *dfd, const char __user **filename_user, int *flags)
     pr_info("vfs_statx su->sh!\n");
     memcpy((void *)filename->name, sh, sizeof(sh));
 #else
-    strncpy_from_user_nofault(path, *filename_user, sizeof(path));
+    ksu_strncpy_from_user_nofault(path, *filename_user, sizeof(path));
 
     if (unlikely(!memcmp(path, su, sizeof(su)))) {
 #if __SULOG_GATE
@@ -174,7 +174,7 @@ int ksu_handle_execve_sucompat(const char __user **filename_user,
         return 0;
 
     memset(path, 0, sizeof(path));
-    strncpy_from_user_nofault(path, *filename_user, sizeof(path));
+    ksu_strncpy_from_user_nofault(path, *filename_user, sizeof(path));
 
     if (likely(memcmp(path, su, sizeof(su))))
         return 0;
@@ -260,7 +260,7 @@ int ksu_handle_faccessat(int *dfd, const char __user **filename_user, int *mode,
         return 0;
     }
 
-    strncpy_from_user_nofault(path, *filename_user, sizeof(path));
+    ksu_strncpy_from_user_nofault(path, *filename_user, sizeof(path));
 
     if (unlikely(!memcmp(path, su_path, sizeof(su_path)))) {
 #if __SULOG_GATE
@@ -316,7 +316,7 @@ int ksu_handle_stat(int *dfd, const char __user **filename_user, int *flags)
     pr_info("ksu_handle_stat: su->sh!\n");
     memcpy((void *)filename->name, sh_path, sizeof(sh_path));
 #else
-    strncpy_from_user_nofault(path, *filename_user, sizeof(path));
+    ksu_strncpy_from_user_nofault(path, *filename_user, sizeof(path));
 
     if (unlikely(!memcmp(path, su_path, sizeof(su_path)))) {
 #if __SULOG_GATE

kernel/supercalls.c

@@ -19,6 +19,7 @@
 #include "feature.h"
 #include "klog.h" // IWYU pragma: keep
 #include "ksud.h"
+#include "kernel_compat.h"
 #include "manager.h"
 #include "sulog.h"
 #include "selinux/selinux.h"
@@ -812,10 +813,10 @@ static void ksu_install_fd_tw_func(struct callback_head *cb)
 
     if (copy_to_user(tw->outp, &fd, sizeof(fd))) {
         pr_err("install ksu fd reply err\n");
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 11, 0)
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 10, 0)
         close_fd(fd);
 #else
-        ksys_close(fd);
+        __close_fd(current->files, fd);
 #endif
     }
 

kernel/syscall_hook_manager.c

@@ -235,7 +235,9 @@ static inline bool check_syscall_fastpath(int nr)
     case __NR_execve:
     case __NR_setresuid:
     case __NR_clone:
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 2, 0)
     case __NR_clone3:
+#endif
         return true;
     default:
         return false;
@@ -251,7 +253,7 @@ int ksu_handle_init_mark_tracker(const char __user **filename_user)
         return 0;
 
     memset(path, 0, sizeof(path));
-    strncpy_from_user_nofault(path, *filename_user, sizeof(path));
+    ksu_strncpy_from_user_nofault(path, *filename_user, sizeof(path));
 
     if (likely(strstr(path, "/app_process") == NULL && strstr(path, "/adbd") == NULL && strstr(path, "/ksud") == NULL)) {
 		pr_info("hook_manager: unmark %d exec %s", current->pid, path);