Check if the kernel is patched against Meltdown

[davidebeatrici]

Linux 4.14.0-3 is patched against Meltdown, resulting in my CPU not being marked as vulnerable anymore.

NOT VULNERABLE ON
4.14.0-3-amd64 #1 SMP Debian 4.14.13-1 (2018-01-14) unknown
processor       : 0
vendor_id       : GenuineIntel
cpu family      : 6
model           : 60
model name      : Intel(R) Core(TM) i5-4690 CPU @ 3.50GHz
stepping        : 3
microcode       : 0x23
cpu MHz         : 3171.998
cache size      : 6144 KB
physical id     : 0

I think that the program should check the kernel version and eventually inform the user that it's impossible to know if the CPU is really not vulnerable.

This would be useful especially because there are a lot of vulnerable CPUs reported in #22.

[dshmgh]

How about using this checker on the kernel first: https://raw.githubusercontent.com/speed47/spectre-meltdown-checker/master/spectre-meltdown-checker.sh

Then if your kernel is NOT patched, check the CPU itself.