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 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 0BD6BC43381 for ; Mon, 18 Mar 2019 14:31:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DCE402085A for ; Mon, 18 Mar 2019 14:31:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727550AbfCRObz (ORCPT ); Mon, 18 Mar 2019 10:31:55 -0400 Received: from vmicros1.altlinux.org ([194.107.17.57]:42854 "EHLO vmicros1.altlinux.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727858AbfCRObv (ORCPT ); Mon, 18 Mar 2019 10:31:51 -0400 Received: from mua.local.altlinux.org (mua.local.altlinux.org [192.168.1.14]) by vmicros1.altlinux.org (Postfix) with ESMTP id EA69172CC8C; Mon, 18 Mar 2019 17:31:47 +0300 (MSK) Received: by mua.local.altlinux.org (Postfix, from userid 508) id C662E7CC74C; Mon, 18 Mar 2019 17:31:47 +0300 (MSK) Date: Mon, 18 Mar 2019 17:31:47 +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 2/6] ptrace: introduce ptrace_syscall_enter to consolidate PTRACE_SYSEMU handling Message-ID: <20190318143147.GB27941@altlinux.org> References: <20190318104925.16600-1-sudeep.holla@arm.com> <20190318104925.16600-3-sudeep.holla@arm.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="98e8jtXdkpgskNou" Content-Disposition: inline In-Reply-To: <20190318104925.16600-3-sudeep.holla@arm.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --98e8jtXdkpgskNou Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Mar 18, 2019 at 10:49:21AM +0000, Sudeep Holla wrote: > Currently each architecture handles PTRACE_SYSEMU in very similar way. > It's completely arch independent and can be handled in the code helping > to consolidate PTRACE_SYSEMU handling. >=20 > Let's introduce a hook 'ptrace_syscall_enter' that arch specific syscall > entry code can call. >=20 > Cc: Oleg Nesterov > Signed-off-by: Sudeep Holla > --- > include/linux/ptrace.h | 1 + > kernel/ptrace.c | 22 ++++++++++++++++++++++ > 2 files changed, 23 insertions(+) >=20 > diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h > index edb9b040c94c..e30f51e3363e 100644 > --- a/include/linux/ptrace.h > +++ b/include/linux/ptrace.h > @@ -407,6 +407,7 @@ static inline void user_single_step_report(struct pt_= regs *regs) > #define current_user_stack_pointer() user_stack_pointer(current_pt_regs(= )) > #endif > =20 > +extern long ptrace_syscall_enter(struct pt_regs *regs); > extern int task_current_syscall(struct task_struct *target, long *callno, > unsigned long args[6], unsigned int maxargs, > unsigned long *sp, unsigned long *pc); > diff --git a/kernel/ptrace.c b/kernel/ptrace.c > index 4fa3b7f4c3c7..c9c505c483df 100644 > --- a/kernel/ptrace.c > +++ b/kernel/ptrace.c > @@ -29,6 +29,7 @@ > #include > #include > #include > +#include > =20 > /* > * Access another process' address space via ptrace. > @@ -557,6 +558,27 @@ static int ptrace_detach(struct task_struct *child, = unsigned int data) > return 0; > } > =20 > +/* > + * Hook to check and report for PTRACE_SYSEMU, can be called from arch > + * arch syscall entry code > + */ > +long ptrace_syscall_enter(struct pt_regs *regs) > +{ > +#ifdef TIF_SYSCALL_EMU > + if (test_thread_flag(TIF_SYSCALL_EMU)) { > + if (tracehook_report_syscall_entry(regs)) > + /* > + * We can ignore the return code here as we need > + * return -1 always for syscall emulation irrespective > + * of whether the tracehook report fails or succeed. > + */ > + ; This is problematic as it causes build errors with -Werror=3Dempty-body, see https://lore.kernel.org/lkml/20181218205305.26647-1-malat@debian.org/ --=20 ldv --98e8jtXdkpgskNou Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIcBAEBCAAGBQJcj6vTAAoJEAVFT+BVnCUIZdoQAMNcDIAbaXHLJT0H192POtdF rRwlBaKZeLHo9YKsCNI0YJWD5L6mrw6pzKrIb+O7w3fkel4k/BYhKJj0VKMriGWv ZhB0qOsRMRj8ytIGzBP+g0EjB+OVO0KBDrR9aKa1Kh3lRIL95sECaoZkcI4xv3dw 5Gs46YNIHaKzXg/0kdAmKb6/FmTqC+0x7dB1KdvuIP8uKFNKOAaLwopTS6fmTVvd SZPBuzeOhTvSvm73avmwwsLf2agniq9nFRiw1Q/3JWPxoRcJToRSozwudkm64z7J OClyRZiOsFTvtXd/tiPZVPr17YhNR2f6XQYtqpWCMzSsbLpvO86cTFJcFIzpWfJr ly+oeURC24KQK2jPjVLBeisugW074Kva0CqGYu/tKAUScWcvoXs6miNYv5/VoiIe yZWr4WlJ5God4Tnk5Y/BFvm3fhwShy+u56VpLy1hX8QaEZUC+jSp0N9YrS5ufx7U WMhdEHfXwfuoMtyAUSINxINFabH15RfC9P818lXmBs4tbKJs51OUQZ5OsyPF0MQn +iPj1Ups+D+1m788lrQE6RsyC4/3piJNehIt7S+5K73UeMek/f2LA5rq+BSjjzBO iJD6xpWwvqLg5mpAAn7Jdq0Wzz7g16auC2m+6F5pXeTA/a5Ju7qrPh1i1Xwx6qqH osPsh+YtCIqvfsZn9TSQ =fKg4 -----END PGP SIGNATURE----- --98e8jtXdkpgskNou--