Il 13/06/2013 07:56, Anthony Liguori ha scritto: > Markus Armbruster <arm...@redhat.com> writes: > >> Peter Lieven <p...@kamp.de> writes: >> >>> On 13.06.2013 10:40, Stefan Hajnoczi wrote: >>>> On Thu, Jun 13, 2013 at 08:09:09AM +0200, Peter Lieven wrote: >>>>> I was thinking if it would be a good idea to zeroize all memory >>>>> resources on system reset and >>>>> madvise dontneed them afterwards. This would avoid system reset >>>>> attacks in case the attacker >>>>> has only access to the console of a vServer but not on the physical >>>>> host and it would shrink >>>>> RSS size of the vServer siginificantly. >>>> I wonder if you'll hit weird OS installers or PXE clients that rely on >>>> stashing stuff in memory across reset. >>> One point: >>> Wouldn't a memory test which some systems do at startup break these as well? >> >> Systems that distinguish between warm and cold boot (such as PCs) >> generally run POST only on cold boot. >> >> I'm not saying triggering warm reboot and expecting memory contents to >> survive is a good idea, but it has been done. > > Doesn't kexec do a warm reboot stashing the new kernel somewhere in > memory?
No, it undoes most of the hardware setup and jumps to the new kernel. It never goes through the BIOS. Paolo
