Hijack a weak syscall

[NISHANTHA]

Hi,
I'm trying to implement kexec as a module. When I do "cat /proc/kallsyms |
grep kexec" it gives a out output like this

c01b3478 W compat_sys_kexec_load
c01b3478 W sys_kexec_load

my sys_call_table page is not write protected. So I did

*syscall_table[__NR_kexec_load] = (void *)my_kexec;

but when I run kexec, It still says "kexec_load function not implimented"

When if dig more, The W above means it's a weak symbol. Can I hijack those
or, will I have to find another way?
Thank you
-madushan
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