Hi Andrey, On 16/03/18 13:49, Andrey Konovalov wrote: > Hi! > > I've recently tried to boot clang built kernel on real hardware > (Odroid C2 board) instead of using a VM. The issue that I stumbled > upon is that arm64 kvm built with clang doesn't boot. > > Adding -fno-jump-tables compiler flag to arch/arm64/kvm/* helps. There > was a patch some time ago that did exactly that > (https://patchwork.kernel.org/patch/10060381/), but it wasn't accepted > AFAICT (see the discussion on that thread). I wasn't aware of that discussion, but this is indeed quite annoying. Note that you should be able to restrict this to arch/arm64/kvm/hyp/* and virt/kvm/arm/hyp/*. > What would be the best way to get this fixed? Ideally, I'd like to see is a way to stick to PC-relative addressing within a compilation unit. > I've also had to disable CONFIG_JUMP_LABEL to get the kernel boot > (even without kvm enabled), but that might be a different (though > related) issue. That's quite bizarre. Does clang has the equivalent of "asm goto"? Or do you rely on reading a variable to decide whether or not to branch? Thanks, M. -- Jazz is not dead. It just smells funny... _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
