Linux syscall table from C re-written to assembly - linux

Question

So, from this code, a kernel module, there is a get_system_call function to get the x86_64 system call table.
#define IA32_LSTAR 0xc0000082
void *get_system_call(void)
{
void *system_call;
unsigned char *ptr;
int i, low, high;
asm volatile("rdmsr" : "=a" (low), "=d" (high) : "c" (IA32_LSTAR));
system_call = (void*)(((long)high<<32) | low);
printk(KERN_INFO "system_call: 0x%p\n", system_call);
for (ptr=system_call, i=0; i<500; i++) {
if (ptr[0] == 0xff && ptr[1] == 0x14 && ptr[2] == 0xc5)
return (void*)(0xffffffff00000000 | *((unsigned int*)(ptr+3)));
ptr++;
}
return NULL;
}
I try to rewrite the x86 assembly version like this:
global _start
section .text
_start:
mov ecx, 0xc0000082
rdmsr
mov edx, 32
mov ecx, edx
sal edx, cl
or eax, edx
.loop_init:
mov ecx, eax
add ecx, 500
jmp .loop_body
.loop:
add eax, 1
cmp ecx, eax
je .fail
.loop_body:
cmp byte [eax], 0xff
jne .loop
cmp byte [eax+1], 0x14
jne .loop
cmp byte [eax+2], 0xc5
jne .loop
.success:
mov ecx, 0xffffffff
mov eax, dword [eax+3]
or eax, ecx
ret
.fail:
xor eax, eax
ret
My question is: Is that correct or I'm totally wrong ?