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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B9B7BC433F5 for ; Tue, 24 May 2022 15:28:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238881AbiEXP15 (ORCPT ); Tue, 24 May 2022 11:27:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50528 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238878AbiEXP1z (ORCPT ); Tue, 24 May 2022 11:27:55 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id A69F95FF0D for ; Tue, 24 May 2022 08:27:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1653406073; 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=0dpLkRs1d/f4IvFC0kcR0J1iYghGd/WbywlFV5pQCIw=; b=ilxgQ6U8GlBMouQlFtovYTXM67zgxZVH/c42YJBzDXFoxkUcyUDu4BNQS2loManxhvBDMK zM9Vrlv8rqmbSqCnv7o7DzCBL6t1uclplZaT7ZgKI2M2nhtMLlAM6f278mbNfnIZ4WJhIU hC12Qro0TEMUulO2E4ATCRY04s3wsJE= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-586-StCUA6iqOkemmeQYbKoalw-1; Tue, 24 May 2022 11:27:48 -0400 X-MC-Unique: StCUA6iqOkemmeQYbKoalw-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id D2ABC3810D25; Tue, 24 May 2022 15:27:46 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.40.195.109]) by smtp.corp.redhat.com (Postfix) with SMTP id EB1312166B29; Tue, 24 May 2022 15:27:26 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Tue, 24 May 2022 17:27:46 +0200 (CEST) Date: Tue, 24 May 2022 17:27:25 +0200 From: Oleg Nesterov To: "Eric W. Biederman" Cc: linux-kernel@vger.kernel.org, rjw@rjwysocki.net, mingo@kernel.org, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, mgorman@suse.de, bigeasy@linutronix.de, Will Deacon , tj@kernel.org, linux-pm@vger.kernel.org, Peter Zijlstra , Richard Weinberger , Anton Ivanov , Johannes Berg , linux-um@lists.infradead.org, Chris Zankel , Max Filippov , linux-xtensa@linux-xtensa.org, Kees Cook , Jann Horn , linux-ia64@vger.kernel.org, Robert OCallahan , Kyle Huey , Richard Henderson , Ivan Kokshaysky , Matt Turner , Jason Wessel , Daniel Thompson , Douglas Anderson , Douglas Miller , Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras Subject: Re: [PATCH 08/16] ptrace: Only populate last_siginfo from ptrace Message-ID: <20220524152725.GE14347@redhat.com> References: <871qwq5ucx.fsf_-_@email.froward.int.ebiederm.org> <20220518225355.784371-8-ebiederm@xmission.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220518225355.784371-8-ebiederm@xmission.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On 05/18, Eric W. Biederman wrote: > > The code in ptrace_signal to populate siginfo if the signal number > changed is buggy. If the tracer contined the tracee using > ptrace_detach it is guaranteed to use the real_parent (or possibly a > new tracer) but definitely not the origional tracer to populate si_pid > and si_uid. I guess nobody cares. As the comment says If the debugger wanted something specific in the siginfo structure then it should have updated *info via PTRACE_SETSIGINFO. otherwise I don't think si_pid/si_uid have any value. However the patch looks fine to me, just the word "buggy" looks a bit too strong imo. Oleg.