On Tue, Sep 15, 2020 at 02:59:19PM -0700, Nick Desaulniers wrote: > On Tue, Sep 15, 2020 at 2:50 PM Arvind Sankar <nived...@alum.mit.edu> wrote: > > > > On Tue, Sep 15, 2020 at 10:49:12PM +0200, Borislav Petkov wrote: > > > > > > (Btw, clang doesn't need to add that "xor %eax,%eax" - panic() should not > > > be > > > returning, ever. :-)) > > > > > > > I think this is because panic() is varargs, and clang doesn't support > > gcc's -mskip-rax-setup. The normal ABI requires the caller to set RAX to > > the number of arguments in vector registers. > > > > https://patchwork.ozlabs.org/project/gcc/patch/20141218131150.ga32...@intel.com/ > > Thanks for the report. Filed > https://bugs.llvm.org/show_bug.cgi?id=47538. Do you have an account > there Arvind so that I can CC you on them?
Nope, no bugzilla account. If you're adding flags, another set the kernel uses is the -falign-{jumps,labels,loops} to turn off alignment of jumps and loops. > > Yikes, it looks like gcc 5.0 supports that. We'd better get to > implementing that lest someone try to remove the cc-option on it soon. > -- > Thanks, > ~Nick Desaulniers