A module written to modify the system call always reports a segment error!

A module written to modify the system call always reports a segment error! -- Linux general technology-Linux programming and kernel information. The following is a detailed description. Recently I wrote an LKM for modifying system calls. My kernel is 2.6.24 and is from fedora8. The source code is as follows:
# Ifndef _ KERNEL __
# Define _ KERNEL __
# Endif

# Ifndef MODULE
# Define MODULE
# Endif

# Ifdef CONFIG_MODVERSIONS
# Define MODVERSIONS
# Include
# Endif

# Include
# Include
# Include
# Include
MODULE_LICENSE ("GPL ");
// Because sys_call_table is not exposed in the 2.6 kernel, I checked the address of sys_call_table in/boot/System. map.
Void ** sys_call_table = (void **) 0xc06357a0;


Int (* orig_open) (const char * filename, int flags, int mode );

Int new_open (const char * filename, int flags, int mode)
{
// It's just a test.
Printk ("this is a test \ n ");
Return orig_open (filename, flags, mode );
}
Int init_module (void)
{
Orig_open = sys_call_table [_ NR_open];
Sys_call_table [_ NR_open] = new_open;
Printk ("init_module exe \ n ");
Return 0;
}

Void cleanup_module (void)
{
Sys_call_table [_ NR_open] = orig_open;
Printk ("cleanup_module exe \ n ");
}
Compilation is normal, but when insmod test2.ko is used, a segment error occurs.
When the system reported a segment error, I used dmesg to view the error message as follows:
<1> BUG: unable to handle kernel paging request at virtual address c06357b4
Printing eip: d0aac056 * PVDF = 0e9dd163 * pte = 00635161
Oops: 0003 [#1] SMP
Modules linked in: test2 (U) addsym (U) using autofs4 fuse rfcomm l2cap bluetooth sunrpc when using xt_state when using iptable_filter when x_tables loop dm_multipath ipv6 when gameport snd_rawmidi when using commandid parport snd_seq floppy when using snd_pcm when ac button pcnet32 snd unzip pcspkr soundcore mii unzip i2c_core sr_mod sg cdrom BusLogic dm_snapshot dm_zero dm_mirror dm_mod ata_piix pata_acpi ata_generic libata sd_mod scsi_mod ext3 jbd mbcache uhci_hcd extends

Pid: 3793, comm: insmod Not tainted (2.6.24.7-92. fc8 #1)
EIPs: 0060 :[ ] EFLAGS: 00010286 CPU: 0
EIP is at init_module + 0x13/0x29 [test2]
EAX: c0487967 EBX: c3c05268 ECX: 00000000 EDX: c06357b4
ESI: c3c05240 EDI: 00000001 EBP: d0aac1_esp: ced43ebc
DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
Process insmod (pid: 3793, ti = ced43000 task = c92d0690 task. ti = ced43000)
Stack: 00000000 c044d064 00000000 00000000 c1025520 00000200 2017001b 00000000
C3d9b990 00000438 describe03 c91ea004 00000000 00000000 00000000
00000000 00000000 00000000 00000000 00000000 00000000 00000000
Call Trace:
[ ] Sys_init_module + 0x14d6/0x15f9
[ ] Printk + 0x0/0x1f
[ ] Syscall_call + 0x7/0xb
======================================
Code: aa d0 a1 2c c4 aa d0 89 50 14 c7 04 24 04 c1 aa d0 e8 69 37 98 ef 58 c3 83 ec 04 8b 15 2c c4 aa d0 83 c2 14 8b 02 a3 0c d6 aa d0 02 6c c0 aa d0 c7 04 24 18 c1 aa d0 e8 42 37 98 ef 31 c0 5a
EIP :[ ] Init_module + 0x13/0x29 [test2] SS: ESP 0068: ced43ebc


By adding printk to the code, I found that after orig_open = sys_call_table [_ NR_open] is executed, orig_open has been correctly assigned the sys_open value, which is consistent with the sys_open VALUE IN System. map.
The error occurs in the init_module's value assignment to sys_call_table [_ NR_open]: sys_call_table [_ NR_open] = new_open;
The error message is unable to handle kernel paging request at virtual address c06357b4. The system call number of sys_open is 5. The address of my sys_call_table is c06357a0. C06357b4 is just c06357a0 + 5*4.
Therefore, I guess that a new value cannot be written to sys_call_table [_ NR_open. But the moudle I read on the Internet and in my book that modifies the system call is written in this way. Why is this error reported when I load the module? Isn't there any new changes to my 2.6.24 kernel?
You are in urgent need of expert help. Thank you !!