On Mon, 5 Nov 2012, Jiri Kosina wrote: > Do I understand you correctly that by the 'glue' stuff you actually mean > the division of the kexec image into segments? > > Of course, when we are dividing the image into segments and then passing > those individually (even more so if some transformations are performed on > those segments, which I don't know whether that's the case or not), then > we can't do any signature verification of the image any more. > > But I still don't fully understand what is so magical about taking the > kernel image as is, and passing the whole lot to the running kernel as-is, > allowing for signature verification. > > Yes, it couldn't be sys_kexec_load(), as that would be ABI breakage, so > it'd mean sys_kexec_raw_load(), or whatever ... but I fail to see why that > would be problem in principle. > > If you can point me to the code where all the magic that prevents this > easy handling is happening, I'd appreciate it.
OK, so after wandering through kexec-tools sources for a while, I am starting to get your point. I wasn't actually aware of the fact that it supports such a wide variety of binary formats etc. (multiboot, nbi, etc). I had a naive idea of just putting in-kernel verification of a complete ELF binary passed to kernel by userspace, and if the signature matches, jumping to it. Would work for elf-x86_64 nicely I guess, but we'd lose a lot of other functionality currently being provided by kexec-tools. Bah. This is a real pandora's box. -- Jiri Kosina SUSE Labs -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
