From f49974968c9d19563a00c6a21f2219e834b40431 Mon Sep 17 00:00:00 2001
From: cisc7310x <cisc7310x@localhost.localdomain>
Date: Fri, 9 Feb 2018 19:07:53 -0500
Subject: [PATCH] reversed syscall for the 4.14 kernel

---
 4.14.8/examples/syscall.c | 25 +++++++++++--------------
 1 file changed, 11 insertions(+), 14 deletions(-)

diff --git a/4.14.8/examples/syscall.c b/4.14.8/examples/syscall.c
index ccb901c..16222c5 100644
--- a/4.14.8/examples/syscall.c
+++ b/4.14.8/examples/syscall.c
@@ -25,7 +25,7 @@
 #include <linux/sched.h>
 #include <linux/uaccess.h>
 
-sys_call_ptr_t *sys_call_table_ptr;
+unsigned long **sys_call_table;
 unsigned long original_cr0;
 
 /*
@@ -87,18 +87,15 @@ asmlinkage int our_sys_open(const char *filename, int flags, int mode)
     return original_call(filename, flags, mode);
 }
 
-static sys_call_ptr_t *aquire_sys_call_table(void)
+static unsigned long **aquire_sys_call_table(void)
 {
     unsigned long int offset = PAGE_OFFSET;
-    /* unsigned long **sct; */
-    sys_call_ptr_t *sct;
+    unsigned long **sct;
 
     while (offset < ULLONG_MAX) {
-        /* sct = (unsigned long **)offset; */
-        sct = (sys_call_ptr_t *)offset;
+        sct = (unsigned long **)offset;
 
-        /* if (sct[__NR_close] == (unsigned long *) sys_close) */
-        if (sct[__NR_close] == (sys_call_ptr_t) sys_close)
+        if (sct[__NR_close] == (unsigned long *) sys_close)
             return sct;
 
         offset += sizeof(void *);
@@ -109,7 +106,7 @@ static sys_call_ptr_t *aquire_sys_call_table(void)
 
 static int __init syscall_start(void)
 {
-    if(!(sys_call_table_ptr = aquire_sys_call_table()))
+    if(!(sys_call_table = aquire_sys_call_table()))
         return -1;
 
     original_cr0 = read_cr0();
@@ -117,10 +114,10 @@ static int __init syscall_start(void)
     write_cr0(original_cr0 & ~0x00010000);
 
     /* keep track of the original open function */
-    original_call = (void*)sys_call_table_ptr[__NR_open];
+    original_call = (void*)sys_call_table[__NR_open];
 
     /* use our open function instead */
-    sys_call_table_ptr[__NR_open] = (sys_call_ptr_t)our_sys_open;
+    sys_call_table[__NR_open] = (unsigned long *)our_sys_open;
 
     write_cr0(original_cr0);
 
@@ -131,14 +128,14 @@ static int __init syscall_start(void)
 
 static void __exit syscall_end(void)
 {
-    if(!sys_call_table_ptr) {
+    if(!sys_call_table) {
         return;
     }
 
     /*
      * Return the system call back to normal
      */
-    if (sys_call_table_ptr[__NR_open] != (sys_call_ptr_t) our_sys_open) {
+    if (sys_call_table[__NR_open] != (unsigned long *)our_sys_open) {
         pr_alert("Somebody else also played with the ");
         pr_alert("open system call\n");
         pr_alert("The system may be left in ");
@@ -146,7 +143,7 @@ static void __exit syscall_end(void)
     }
 
     write_cr0(original_cr0 & ~0x00010000);
-    sys_call_table_ptr[__NR_open] = (sys_call_ptr_t)original_call;
+    sys_call_table[__NR_open] = (unsigned long *)original_call;
     write_cr0(original_cr0);
 
     msleep(2000);