Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752288AbaKLLN6 (ORCPT ); Wed, 12 Nov 2014 06:13:58 -0500 Received: from foss-mx-na.foss.arm.com ([217.140.108.86]:56716 "EHLO foss-mx-na.foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751412AbaKLLN5 (ORCPT ); Wed, 12 Nov 2014 06:13:57 -0500 Date: Wed, 12 Nov 2014 11:13:52 +0000 From: Will Deacon To: AKASHI Takahiro Cc: Oleg Nesterov , "roland@hack.frob.com" , "linux@arm.linux.org.uk" , "dsaxena@linaro.org" , "keescook@chromium.org" , "linux-arm-kernel@lists.infradead.org" , "linaro-kernel@lists.linaro.org" , "linux-kernel@vger.kernel.org" Subject: Re: [RFC] ptrace: add generic SET_SYSCALL request Message-ID: <20141112111352.GC26437@arm.com> References: <1415346443-28915-1-git-send-email-takahiro.akashi@linaro.org> <20141107140405.GA30156@redhat.com> <54633A69.6090202@linaro.org> <20141112110047.GB26437@arm.com> <54633F53.8020507@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <54633F53.8020507@linaro.org> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 12, 2014 at 11:06:59AM +0000, AKASHI Takahiro wrote: > On 11/12/2014 08:00 PM, Will Deacon wrote: > > On Wed, Nov 12, 2014 at 10:46:01AM +0000, AKASHI Takahiro wrote: > >> On 11/07/2014 11:04 PM, Oleg Nesterov wrote: > >>> To me the fact that PTRACE_SET_SYSCALL can be undefined and syscall_set_nr() > >>> is very much arch-dependant (but most probably trivial) means that this code > >>> should live in arch_ptrace(). > >> > >> Thinking of Oleg's comment above, it doesn't make sense neither to define generic > >> NT_SYSTEM_CALL (user_regset) in uapi/linux/elf.h and implement it in ptrace_regset() > >> in kernel/ptrace.c with arch-defined syscall_(g)set_nr(). > >> > >> Since we should have the same interface on arm and arm64, we'd better implement > >> ptrace(PTRACE_SET_SYSCALL) locally on arm64 for now (as I originally submitted). > > > > I think the regset approach is cleaner. We already do something similar for > > TLS. That would be implemented under arch/arm64/ with it's own NT type. > > Okey, so arm64 goes its own way :) > Or do you want to have a similar regset on arm, too? > (In this case, NT_ARM_SYSTEM_CALL can be shared in uapi/linux/elf.h) Just do arm64. We already have the dedicated request for arch/arm/. Will -- 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/