[SOLVED] Problem with 4.4.6 kernel and Kexec

[Nicolas]

Hi everyone,

I can't run kexec with the grsecurity patch:

Your selection: 1
Staging Debian GNU/Linux
kexec unload failed: Function not implemented
kexec_load failed: Function not implemented
entry = 0x847ff47f0 flags = 0x3e0000
nr_segments = 4
segment[0].buf = 0x3b72b75f010
segment[0].bufsz = 0xe1926e
segment[0].mem = 0x8455e6000
segment[0].memsz = 0xe1a000
segment[1].buf = 0x3b72c57d410
segment[1].bufsz = 0x34c550
segment[1].mem = 0x846400000
segment[1].memsz = 0x18e8000
segment[2].buf = 0x36adbb0
segment[2].bufsz = 0x4479
segment[2].mem = 0x847fef000
segment[2].memsz = 0x5000
segment[3].buf = 0x36a4a70
segment[3].bufsz = 0x9100
segment[3].mem = 0x847ff4000
segment[3].memsz = 0xb000

I use a Hp proliant servers for my labs and as you may know, the boot time of these things is frustrating

Someone as a workaround to make kexec working?

Have a good day.
Best regards,
Nicolas

[PaX Team]

do you have KEXEC in your .config at all? GRKERNSEC_KMEM automatically disables it.

[Nicolas]

Hi,

What do you mean by having kexec in my .config?

I don't have kexec installed on the VM where I build my kernel, is that the problem?


Edit: I've tried disable this option "Deny writing to /dev/kmem, /dev/mem, and /dev/port" in my last build but I still have the problem. And I want to make an exception only for kexec, is that possible?

Best regards

[PaX Team]

KEXEC is a configurable kernel option and you must have it enabled if you want to be able to use it.

[Nicolas]

That was the problem, many thanks