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=-12.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 10120C4361B for ; Sat, 19 Dec 2020 19:35:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BF87A22D72 for ; Sat, 19 Dec 2020 19:35:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727440AbgLSTey (ORCPT ); Sat, 19 Dec 2020 14:34:54 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:30357 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725896AbgLSTey (ORCPT ); Sat, 19 Dec 2020 14:34:54 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1608406408; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=6z0RbAiLK9GTR+9ggjBwb/1gZHkBY9XWAFgiHpI1ZyE=; b=Q5F6XX8pspZFXiWIBHBd3jPYKCtwpJatxicI7Ld37xREc9GGoSq524lkhAJyF3aGvRDRGk EroVGStknnlC41YYPFLUUTNA296TM0OrQJap3xtTbwgBPVoiLX1DC/GHNc+SFUEMECm5KS rWYvCjvEoo6kJp+wd22mQ1sq6ZacdX0= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-140-bsrU9ddYNdOjEM0LL4A0Tg-1; Sat, 19 Dec 2020 14:33:26 -0500 X-MC-Unique: bsrU9ddYNdOjEM0LL4A0Tg-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id C1EA9800D53; Sat, 19 Dec 2020 19:33:24 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.40.192.46]) by smtp.corp.redhat.com (Postfix) with SMTP id B921E10016FF; Sat, 19 Dec 2020 19:33:15 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Sat, 19 Dec 2020 20:33:24 +0100 (CET) Date: Sat, 19 Dec 2020 20:33:14 +0100 From: Oleg Nesterov To: Pedro Alves Cc: "Eric W. Biederman" , Andrew Morton , Eugene Syromiatnikov , Jan Kratochvil , Linus Torvalds , Mathieu Desnoyers , Michael Kerrisk , Simon Marchi , linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH] ptrace: make ptrace() fail if the tracee changed its pid unexpectedly Message-ID: <20201219193313.GB9539@redhat.com> References: <20201217142931.GA8865@redhat.com> <875z50roia.fsf@x220.int.ebiederm.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/19, Pedro Alves wrote: > > BTW, the problem was discovered by Simon Marchi when he tried to write > a GDB testcase for a multi-threaded exec scenario: OOPS! Sorry Simon, yes I forgot to add reported-by. Andrew, or Eric, if you take this patch, could you also add Reported-by: Simon Marchi > I've went through GDB's code looking for potential issues with the change and whether > it would affect GDBs already in the wild. Tricky corner cases abound, but I think > we're good. Feel free to add my ack: > > Acked-by: Pedro Alves Thanks! Oleg.