Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755319AbbHNO1q (ORCPT ); Fri, 14 Aug 2015 10:27:46 -0400 Received: from mail-ob0-f172.google.com ([209.85.214.172]:36054 "EHLO mail-ob0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754153AbbHNO1o (ORCPT ); Fri, 14 Aug 2015 10:27:44 -0400 MIME-Version: 1.0 In-Reply-To: <55CDD7CE.5070503@redhat.com> References: <55CCB510.3060807@redhat.com> <55CD0DAC.9080809@redhat.com> <55CDD7CE.5070503@redhat.com> From: Andy Lutomirski Date: Fri, 14 Aug 2015 07:27:24 -0700 Message-ID: Subject: Re: [Regression v4.2 ?] 32-bit seccomp-BPF returned errno values wrong in VM? To: Denys Vlasenko Cc: Kees Cook , Linus Torvalds , David Drysdale , "linux-kernel@vger.kernel.org" , Will Drewry , Ingo Molnar , Alok Kataria , Borislav Petkov , Alexei Starovoitov , Frederic Weisbecker , "H. Peter Anvin" , Oleg Nesterov , Steven Rostedt , X86 ML Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1528 Lines: 38 On Fri, Aug 14, 2015 at 4:58 AM, Denys Vlasenko wrote: > On 08/14/2015 12:59 AM, Andy Lutomirski wrote: >> On Thu, Aug 13, 2015 at 3:56 PM, Kees Cook wrote: >>> On Thu, Aug 13, 2015 at 3:54 PM, Linus Torvalds >>> wrote: >>>> On Thu, Aug 13, 2015 at 3:49 PM, Linus Torvalds >>>> wrote: >>>>> >>>>> Does the attached patch make sense and work? >>>> >>>> Btw, I'm not all that happy with it anyway. >>>> >>>> I still think Denys' patch also potentially changed what audit and >>>> strace see for %rax in the pt_regs to -ENOSYS, which I'm not convinced >>>> is a good change. >>>> >>>> But maybe that three-liner patch fixes the immediate problem that >>>> David sees. David? >>> >>> Your patch fixes it for me. The seccomp compat selftests pass again >>> with audit enabled. >> >> Kees, would it be straightforward to rig up the seccomp tests to >> automatically test compat? The x86 selftests automatically test both >> native and compat, and that might be usable as a model. I did that >> because it's extremely easy to regress one and not the other. > > BTW, why 64-bt code doesn't need this RAX read-back? > It's hiding inside of RESTORE_C_REGS_EXCEPT_RCX_R11. --Andy -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/