From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9146FC433E2 for ; Fri, 28 Aug 2020 15:50:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7164A2075B for ; Fri, 28 Aug 2020 15:50:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728257AbgH1Pu3 (ORCPT ); Fri, 28 Aug 2020 11:50:29 -0400 Received: from brightrain.aerifal.cx ([216.12.86.13]:47682 "EHLO brightrain.aerifal.cx" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726379AbgH1Pu0 (ORCPT ); Fri, 28 Aug 2020 11:50:26 -0400 Date: Fri, 28 Aug 2020 11:50:25 -0400 From: Rich Felker To: Michael Karcher Cc: linux-sh@vger.kernel.org, linux-kernel@vger.kernel.org, Yoshinori Sato , Adrian Glaubitz Subject: Re: [PATCH 3/4] sh: Add SECCOMP_FILTER Message-ID: <20200828155024.GX3265@brightrain.aerifal.cx> References: <20200722231322.419642-1-kernel@mkarcher.dialup.fu-berlin.de> <20200722231322.419642-3-kernel@mkarcher.dialup.fu-berlin.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200722231322.419642-3-kernel@mkarcher.dialup.fu-berlin.de> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 23, 2020 at 01:13:21AM +0200, Michael Karcher wrote: > Port sh to use the new SECCOMP_FILTER code. > > Signed-off-by: Michael Karcher > --- > arch/sh/Kconfig | 1 + > arch/sh/kernel/entry-common.S | 2 ++ > arch/sh/kernel/ptrace_32.c | 5 +++-- > tools/testing/selftests/seccomp/seccomp_bpf.c | 8 +++++++- > 4 files changed, 13 insertions(+), 3 deletions(-) > > diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig > index 32d959849df9..10b510c16841 100644 > --- a/arch/sh/Kconfig > +++ b/arch/sh/Kconfig > @@ -27,6 +27,7 @@ config SUPERH > select GENERIC_SMP_IDLE_THREAD > select GUP_GET_PTE_LOW_HIGH if X2TLB > select HAVE_ARCH_AUDITSYSCALL > + select HAVE_ARCH_SECCOMP_FILTER > select HAVE_ARCH_KGDB > select HAVE_ARCH_TRACEHOOK > select HAVE_DEBUG_BUGVERBOSE > diff --git a/arch/sh/kernel/entry-common.S b/arch/sh/kernel/entry-common.S > index c4d88d61890d..ad963104d22d 100644 > --- a/arch/sh/kernel/entry-common.S > +++ b/arch/sh/kernel/entry-common.S > @@ -368,6 +368,8 @@ syscall_trace_entry: > mov.l 7f, r11 ! Call do_syscall_trace_enter which notifies > jsr @r11 ! superior (will chomp R[0-7]) > nop > + cmp/eq #-1, r0 > + bt syscall_exit > mov.l r0, @(OFF_R0,r15) ! Save return value > ! Reload R0-R4 from kernel stack, where the > ! parent may have modified them using > diff --git a/arch/sh/kernel/ptrace_32.c b/arch/sh/kernel/ptrace_32.c > index 64bfb714943e..25ccfbd02bfa 100644 > --- a/arch/sh/kernel/ptrace_32.c > +++ b/arch/sh/kernel/ptrace_32.c > @@ -485,8 +485,6 @@ asmlinkage long do_syscall_trace_enter(struct pt_regs *regs) > { > long ret = 0; > > - secure_computing_strict(regs->regs[0]); > - > if (test_thread_flag(TIF_SYSCALL_TRACE) && > tracehook_report_syscall_entry(regs)) > /* > @@ -496,6 +494,9 @@ asmlinkage long do_syscall_trace_enter(struct pt_regs *regs) > */ > ret = -1L; > > + if (secure_computing() == -1) > + return -1; > + > if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT))) > trace_sys_enter(regs, regs->regs[0]); > This patch broke strace - it spews out bogus syscalls and gets the tracee hung. I suspect the last hunk is wrong and breaks all non-seccomp tracing. I'll follow up with further analysis and possibly a fix if you don't find one sooner. Rich