On Thu, Jun 7, 2018 at 1:50 PM, Andy Lutomirski <luto@xxxxxxxxxx> wrote: > On Thu, Jun 7, 2018 at 7:42 AM Yu-cheng Yu <yu-cheng.yu@xxxxxxxxx> wrote: >> >> From: "H.J. Lu" <hjl.tools@xxxxxxxxx> >> >> When Intel indirect branch tracking is enabled, functions in vDSO which >> may be called indirectly should have endbr32 or endbr64 as the first >> instruction. We try to compile vDSO with -fcf-protection=branch -mibt >> if possible. Otherwise, we insert endbr32 or endbr64 by hand to assembly >> codes generated by the compiler. > > Wow, that's... a genuine abomination. Do we really need to support > CET on kernels built with old toolchains? > Yes. GCC 7 should be able to build CET kernel. -- H.J.