Messages in this thread |  | | Date | Tue, 29 Aug 2017 11:01:12 +0100 | From | Mark Rutland <> | Subject | Re: [PATCH 14/14] arm64: kexec_file: add vmlinux format support |
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On Thu, Aug 24, 2017 at 06:30:50PM +0100, Mark Rutland wrote: > On Thu, Aug 24, 2017 at 05:18:11PM +0900, AKASHI Takahiro wrote: > > The first PT_LOAD segment, which is assumed to be "text" code, in vmlinux > > will be loaded at the offset of TEXT_OFFSET from the begining of system > > memory. The other PT_LOAD segments are placed relative to the first one. > > I really don't like assuming things about the vmlinux ELF file. > > > Regarding kernel verification, since there is no standard way to contain > > a signature within elf binary, we follow PowerPC's (not yet upstreamed) > > approach, that is, appending a signature right after the kernel binary > > itself like module signing. > > I also *really* don't like this. It's a bizarre in-band mechanism, > without explcit information. It's not a nice ABI. > > If we can load an Image, why do we need to be able to load a vmlinux?
So IIUC, the whole point of this is to be able to kexec_file_load() a vmlinux + signature bundle, for !CONFIG_EFI kernels.
For that, I think that we actually need a new kexec_file_load${N} syscall, where we can pass the signature for the kernel as a separate file. Ideally also with a flags argument and perhaps the ability to sign the initrd too.
That way we don't ahve to come up with a magic vmlinux+signature format, as we can just pass a regular image and a signature for that image separately. That should work for PPC and others, too.
Thanks, Mark.
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