From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yu-cheng Yu Subject: Re: [RFC PATCH v6 08/11] x86: Insert endbr32/endbr64 to vDSO Date: Mon, 19 Nov 2018 14:43:31 -0800 Message-ID: References: <20181119214934.6174-1-yu-cheng.yu@intel.com> <20181119214934.6174-9-yu-cheng.yu@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Andy Lutomirski Cc: X86 ML , "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , LKML , "open list:DOCUMENTATION" , Linux-MM , linux-arch , Linux API , Arnd Bergmann , Balbir Singh , Cyrill Gorcunov , Dave Hansen , Eugene Syromiatnikov , Florian Weimer , "H. J. Lu" , Jann Horn , Jonathan Corbet , Kees Cook , Mike Kravetz , Nadav Amit List-Id: linux-api@vger.kernel.org On Mon, 2018-11-19 at 14:17 -0800, Andy Lutomirski wrote: > On Mon, Nov 19, 2018 at 1:55 PM Yu-cheng Yu wrote: > > > > From: "H.J. Lu" > > > > When Intel indirect branch tracking is enabled, functions in vDSO which > > may be called indirectly must have endbr32 or endbr64 as the first > > instruction. Compiler must support -fcf-protection=branch so that it > > can be used to compile vDSO. > > > > Signed-off-by: H.J. Lu > > --- > > arch/x86/entry/vdso/.gitignore | 4 ++++ > > arch/x86/entry/vdso/Makefile | 12 +++++++++++- > > arch/x86/entry/vdso/vdso-layout.lds.S | 1 + > > 3 files changed, 16 insertions(+), 1 deletion(-) > > > > diff --git a/arch/x86/entry/vdso/.gitignore b/arch/x86/entry/vdso/.gitignore > > index aae8ffdd5880..552941fdfae0 100644 > > --- a/arch/x86/entry/vdso/.gitignore > > +++ b/arch/x86/entry/vdso/.gitignore > > @@ -5,3 +5,7 @@ vdso32-sysenter-syms.lds > > vdso32-int80-syms.lds > > vdso-image-*.c > > vdso2c > > +vclock_gettime.S > > +vgetcpu.S > > +vclock_gettime.asm > > +vgetcpu.asm > > > What's this hunk about? We used to allow using non-CET capable BINUTILS and the Makefile would create these. I will remove them from the patch. Yu-cheng