Messages in this thread | | | From | Andy Lutomirski <> | Subject | Re: [PATCH 23/62] x86/idt: Move IDT to data segment | Date | Wed, 12 Feb 2020 08:23:54 -0800 |
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> On Feb 12, 2020, at 3:55 AM, Joerg Roedel <joro@8bytes.org> wrote: > > On Tue, Feb 11, 2020 at 02:41:25PM -0800, Andy Lutomirski wrote: >>> On Tue, Feb 11, 2020 at 5:53 AM Joerg Roedel <joro@8bytes.org> wrote: >>> >>> From: Joerg Roedel <jroedel@suse.de> >>> >>> With SEV-ES, exception handling is needed very early, even before the >>> kernel has cleared the bss segment. In order to prevent clearing the >>> currently used IDT, move the IDT to the data segment. >> >> Ugh. At the very least this needs a comment in the code. > > Yes, right, added a comment for that. > >> I had a patch to fix the kernel ELF loader to clear BSS, which would >> fix this problem once and for all, but it didn't work due to the messy >> way that the decompressor handles memory. I never got around to >> fixing this, sadly. > > Aren't there other ways of booting (Xen-PV?) which don't use the kernel > ELF loader?
Dunno. I would hope the any sane loader would clear BSS before executing anything. This isn’t currently the case, though. Oh well.
> > Regards, > > Joerg
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