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[198.145.64.163]) by smtp.gmail.com with ESMTPSA id a18sm88751pjq.0.2019.06.25.13.09.38 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 25 Jun 2019 13:09:38 -0700 (PDT) Date: Tue, 25 Jun 2019 13:09:38 -0700 From: Kees Cook To: Nathan Chancellor Cc: Peter Zijlstra , Miguel Ojeda , "Gustavo A. R. Silva" , Joe Perches , Ingo Molnar , Arnaldo Carvalho de Melo , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Thomas Gleixner , Borislav Petkov , "H. Peter Anvin" , "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" , Kan Liang , linux-kernel , Shawn Landden Subject: Re: [PATCH] perf/x86/intel: Mark expected switch fall-throughs Message-ID: <201906251309.BBB7D17@keescook> References: <20190624161913.GA32270@embeddedor> <20190624193123.GI3436@hirez.programming.kicks-ass.net> <20190624203737.GL3436@hirez.programming.kicks-ass.net> <3dc75cd4-9a8d-f454-b5fb-64c3e6d1f416@embeddedor.com> <20190625071846.GN3436@hirez.programming.kicks-ass.net> <201906251009.BCB7438@keescook> <20190625180525.GA119831@archlinux-epyc> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190625180525.GA119831@archlinux-epyc> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jun 25, 2019 at 11:05:25AM -0700, Nathan Chancellor wrote: > On Tue, Jun 25, 2019 at 10:12:42AM -0700, Kees Cook wrote: > > On Tue, Jun 25, 2019 at 09:18:46AM +0200, Peter Zijlstra wrote: > > > Can it build a kernel without patches yet? That is, why should I care > > > what LLVM does? > > > > Yes. LLVM trunk builds and boots x86 now. As for distro availability, > > AIUI, the asm-goto feature missed the 9.0 LLVM branch point, so it'll > > appear in the following release. > > > > -- > > Kees Cook > > I don't think that's right. LLVM 9 hasn't been branched yet so it should > make it in. > > http://lists.llvm.org/pipermail/llvm-dev/2019-June/133155.html > > If anyone wants to play around with it before then, we wrote a > self-contained script that will build an LLVM toolchain suitable for > kernel development: > > https://github.com/ClangBuiltLinux/tc-build Ah! That's good news. :) I thought the branch happened just before asm-goto landed. Wheee! -- Kees Cook