Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755500Ab1EXJuJ (ORCPT ); Tue, 24 May 2011 05:50:09 -0400 Received: from mail.codesourcery.com ([38.113.113.100]:57182 "EHLO mail.codesourcery.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751580Ab1EXJuH (ORCPT ); Tue, 24 May 2011 05:50:07 -0400 From: Pedro Alves Organization: CodeSourcery To: Tejun Heo Subject: Re: [PATCH 03/10] ptrace: implement PTRACE_SEIZE Date: Tue, 24 May 2011 10:49:58 +0100 User-Agent: KMail/1.13.5 (Linux/2.6.35-28-generic; KDE/4.6.2; x86_64; ; ) Cc: Denys Vlasenko , oleg@redhat.com, jan.kratochvil@redhat.com, linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, indan@nul.nu, bdonlan@gmail.com References: <1305569849-10448-1-git-send-email-tj@kernel.org> <201105201027.36688.pedro@codesourcery.com> <20110520093111.GG31426@htj.dyndns.org> In-Reply-To: <20110520093111.GG31426@htj.dyndns.org> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201105241049.58921.pedro@codesourcery.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1258 Lines: 33 On Friday 20 May 2011 10:31:11, Tejun Heo wrote: > On Fri, May 20, 2011 at 10:27:35AM +0100, Pedro Alves wrote: > > Okay, good to hear that. Looks like the tracer can do: > > > > SEIZE,execve,SETOPTS,'readlink /proc/pid/exe' > > > > and pretend it SEIZED after the execve. > > Yeap, and I was trying to say that if tracer and tracee are running on > different CPUs, the order between SEIZE and execve isn't even well > defined (sans the nasty automatic SIGTRAP). I see, indeed, thanks. A couple interface questions that just crossed my mind: - on a fork/vfork/clone, if PTRACE_EVENT_FORK|VFORK|CLONE have been enabled, will the tracer still see the new child stop with a SIGSTOP, or will it see a PTRACE_EVENT_INTERRUPT? - is PTRACE_INTERRUPT on PTRACE_TRACEME-traced-child planed to be allowed (for convenience)? A PTRACE_O_TRACEINTERRUPT, or some such PTRACE_SETOPTIONS option might be necessary to get PTRACE_EVENT_INTERRUPT instead of SIGSTOP in the point above. -- Pedro Alves -- 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/