Difference in values of addresses in System.map and /proc/kallsyms

From: Ajay Garg
Date: Sat Jun 22 2019 - 11:28:44 EST


Hi All.

My system is

ajay@latitude-3480:~$ uname -a
Linux latitude-3480 4.13.0-38-generic #43~16.04.1-Ubuntu SMP Wed Mar
14 17:48:43 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux


When I see the address for a symbol, say linux_banner, in
/boot/System.map-4.13.0-38-generic, it shows
ffffffff81e00120 R linux_banner

However, when I see it in /proc/kallsyms, it shows
ffffffffa7000120 R linux_banner


Also, I note that /proc/kallsyms addresses vary upon reboots, so I am
a little confused as to what the entries in /proc/kallsyms really
mean.
So, will be grateful for some pointers from the experts :)


Thanks and Regards,
Ajay