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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 11837C43381 for ; Mon, 18 Mar 2019 14:26:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E11922085A for ; Mon, 18 Mar 2019 14:26:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727703AbfCRO0W (ORCPT ); Mon, 18 Mar 2019 10:26:22 -0400 Received: from vmicros1.altlinux.org ([194.107.17.57]:35800 "EHLO vmicros1.altlinux.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726813AbfCRO0V (ORCPT ); Mon, 18 Mar 2019 10:26:21 -0400 Received: from mua.local.altlinux.org (mua.local.altlinux.org [192.168.1.14]) by vmicros1.altlinux.org (Postfix) with ESMTP id 830F972CC53; Mon, 18 Mar 2019 17:26:18 +0300 (MSK) Received: by mua.local.altlinux.org (Postfix, from userid 508) id 5A5E57CC74C; Mon, 18 Mar 2019 17:26:18 +0300 (MSK) Date: Mon, 18 Mar 2019 17:26:18 +0300 From: "Dmitry V. Levin" To: Sudeep Holla Cc: x86@kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Catalin Marinas , Will Deacon , Oleg Nesterov , Paul Mackerras , Michael Ellerman , Thomas Gleixner , Ingo Molnar , Richard Weinberger , jdike@addtoit.com, Steve Capper , Haibo Xu , Bin Lu , Andy Lutomirski Subject: Re: [PATCH v2 4/6] powerpc: use common ptrace_syscall_enter hook to handle _TIF_SYSCALL_EMU Message-ID: <20190318142618.GA27941@altlinux.org> References: <20190318104925.16600-1-sudeep.holla@arm.com> <20190318104925.16600-5-sudeep.holla@arm.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="HcAYCG3uE/tztfnV" Content-Disposition: inline In-Reply-To: <20190318104925.16600-5-sudeep.holla@arm.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --HcAYCG3uE/tztfnV Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Mar 18, 2019 at 10:49:23AM +0000, Sudeep Holla wrote: > Now that we have a new hook ptrace_syscall_enter that can be called from > syscall entry code and it handles PTRACE_SYSEMU in generic code, we > can do some cleanup using the same in do_syscall_trace_enter. >=20 > Cc: Oleg Nesterov > Cc: Paul Mackerras > Cc: Michael Ellerman > Signed-off-by: Sudeep Holla > --- > arch/powerpc/kernel/ptrace.c | 48 ++++++++++++++++-------------------- > 1 file changed, 21 insertions(+), 27 deletions(-) >=20 > diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c > index 2e2183b800a8..05579a5dcb12 100644 > --- a/arch/powerpc/kernel/ptrace.c > +++ b/arch/powerpc/kernel/ptrace.c > @@ -3278,35 +3278,29 @@ long do_syscall_trace_enter(struct pt_regs *regs) > =20 > user_exit(); > =20 > - flags =3D READ_ONCE(current_thread_info()->flags) & > - (_TIF_SYSCALL_EMU | _TIF_SYSCALL_TRACE); > - > - if (flags) { > - int rc =3D tracehook_report_syscall_entry(regs); > + if (unlikely(ptrace_syscall_enter(regs))) { > + /* > + * A nonzero return code from tracehook_report_syscall_entry() > + * tells us to prevent the syscall execution, but we are not > + * going to execute it anyway. > + * > + * Returning -1 will skip the syscall execution. We want to > + * avoid clobbering any registers, so we don't goto the skip > + * label below. > + */ > + return -1; > + } This comment is out of sync with the changed code. --=20 ldv --HcAYCG3uE/tztfnV Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIcBAEBCAAGBQJcj6qKAAoJEAVFT+BVnCUIpOUP/j1ZfG80n/XTu6EimciHcs9e nhN3qmFqVCDXeuvQh8I/xncM25fHK+ftwsUQOij1bT2iecbY/yLxpFpfBcru1bho Gp0hMlMCEQcxJ/2ArUKjL3HWIaeh8/ut63nLEgGARp0C4Zd14vnjNEZsJBtnZDvZ /pKKGNKENgMzx/LH/8pouPQoLTLcTctLjpg7QCHhVgyf+cEjkcTPB2z7ityUXUGG 4WlGjWyo6qL9fMmUKrhQ+w1B2FyjsffRv0zKAyOG+p2edHGHEjfqw+Z4s2h8rJLL nol9SN00msn5wFH83YJmkKolNAIVdDC3seGM2tiX4HROIqKK13MBr4ZqX37mQP7r DClvWfuvCCH/NaIoyaq6f4YkkSboox2YDZVTjPQ9NPInoRUXZG3MuvL92eGh8wuZ 2sjwMWvBU1a+l+C8u0+U2Q/7FMWG8wYwkARiq5AqkNZmIV8dxhyXtY2+X8G3LIDe /W1yzi2cYAlMU1oisoA4uYwrFHvUvd2K2jQYHXWvTX6tV7QFdiJNRv9DHdlOqmSL cnMyjhOXPKL7bxsh39VvHQJHBP1hru9+IuGqGuLUgeF1nSDIbaFY5RsvwzTqzazJ 6z8f+gK+Odmt2B6n5zZnSFqCvzOiyQ3XYuRa9Xbfh8DSaDR5BwzqUp3MQZs6QbRI DsJJJSfcDOCFdWJIYv+6 =JQDW -----END PGP SIGNATURE----- --HcAYCG3uE/tztfnV--