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=-8.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT autolearn=unavailable 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 3C658C43381 for ; Mon, 18 Mar 2019 14:55:44 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0D94220872 for ; Mon, 18 Mar 2019 14:55:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="TL5LD4X5" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0D94220872 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=qYVvNRHRd0iOhGO33po1Mn7vpnYXx4nzrw+qvI+9RnY=; b=TL5LD4X5t8Jx/9 mnuGjUJ9VZBA1LE9BXU55iojbvLHBDhJoFvUsXykVhIt9uDknurdMJwJPvkvsonkD5tLYv0JyIVgB 77TtBjYoZroznq+KLLMNUDqWCMiIie2zlqrkrZsbQWuBXzbalbXWE7LXWRTYJIhykN3lQoP/s++uA aY+Xjd43VDuWHgtm6dw4qv2kYd9C+GAK74abS58sCW+iEnl6VntTwdEIYUdAYjaBWP2MFAwIP/l/+ NsqZodvOmTRP2GxjfMgifxB9G9WvqLytExneMl1fwPZ0vDAezqcSft/kOY+8lOnORSG0WtUgAKALL 6GSmDWDDHBVWzjX8hqsQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1h5tft-0008Bz-BA; Mon, 18 Mar 2019 14:55:37 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1h5tfp-0008BG-4J for linux-arm-kernel@lists.infradead.org; Mon, 18 Mar 2019 14:55:34 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 2E6301650; Mon, 18 Mar 2019 07:55:32 -0700 (PDT) Received: from e107155-lin (e107155-lin.cambridge.arm.com [10.1.196.42]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 3873D3F59C; Mon, 18 Mar 2019 07:55:29 -0700 (PDT) Date: Mon, 18 Mar 2019 14:55:23 +0000 From: Sudeep Holla To: "Dmitry V. Levin" Subject: Re: [PATCH v2 2/6] ptrace: introduce ptrace_syscall_enter to consolidate PTRACE_SYSEMU handling Message-ID: <20190318145523.GA18196@e107155-lin> References: <20190318104925.16600-1-sudeep.holla@arm.com> <20190318104925.16600-3-sudeep.holla@arm.com> <20190318143147.GB27941@altlinux.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190318143147.GB27941@altlinux.org> User-Agent: Mutt/1.9.4 (2018-02-28) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190318_075533_189332_20F6241E X-CRM114-Status: GOOD ( 20.51 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Haibo Xu , Steve Capper , Catalin Marinas , jdike@addtoit.com, x86@kernel.org, Will Deacon , linux-kernel@vger.kernel.org, Oleg Nesterov , Richard Weinberger , Ingo Molnar , Paul Mackerras , Andy Lutomirski , Michael Ellerman , Thomas Gleixner , Bin Lu , linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Mar 18, 2019 at 05:31:47PM +0300, Dmitry V. Levin wrote: > 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. > > > > Let's introduce a hook 'ptrace_syscall_enter' that arch specific syscall > > entry code can call. > > > > Cc: Oleg Nesterov > > Signed-off-by: Sudeep Holla > > --- > > include/linux/ptrace.h | 1 + > > kernel/ptrace.c | 22 ++++++++++++++++++++++ > > 2 files changed, 23 insertions(+) > > > > 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 > > > > +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 > > > > /* > > * Access another process' address space via ptrace. > > @@ -557,6 +558,27 @@ static int ptrace_detach(struct task_struct *child, unsigned int data) > > return 0; > > } > > > > +/* > > + * 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=empty-body, > see https://lore.kernel.org/lkml/20181218205305.26647-1-malat@debian.org/ > Thanks for the pointer, will update. -- Regards, Sudeep _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel