On Fri, Apr 20, 2018 at 10:13 AM, Marc Zyngier <marc.zyngier@xxxxxxx> wrote: >> The issue is that >> clang doesn't know about the "S" asm constraint. I reported this to >> clang [2], and hopefully this will get fixed. In the meantime, would >> it possible to work around using the "S" constraint in the kernel? > > I have no idea, I've never used clang to build the kernel. Clang isn't > really supported to build the arm64 kernel anyway (as you mention > below), and working around clang deficiencies would mean that we leave > with the workaround forever. I'd rather enable clang once it is at > feature parity with GCC. The fact that there are some existing issues with building arm64 kernel with clang doesn't sound like a good justification for adding new issues :) However in this case I do believe that this is more of a bug in clang that should be fixed. >> While we're here, regarding the other issue with kvm [3], I didn't >> receive any comments as to whether it makes sense to send the fix that >> adds -fno-jump-tables flag when building kvm with clang. > > Is that the only thing missing? Are you sure that there is no other way > for clang to generate absolute addresses that will then lead to a crash? > Again, I'd rather make sure we have the full picture. Well, I have tried applying that patch and running kvm tests that I could find [1], and they passed (actually I think there was an issue with one of them, but I saw the same thing when I tried running them on a kernel built with GCC). [1] https://www.linux-kvm.org/page/KVM-unit-tests _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
