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=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 026F4C433DF for ; Tue, 26 May 2020 14:00:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CF94C20B80 for ; Tue, 26 May 2020 14:00:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="NUYWWu+f" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731792AbgEZOAh (ORCPT ); Tue, 26 May 2020 10:00:37 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:23666 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728558AbgEZOAh (ORCPT ); Tue, 26 May 2020 10:00:37 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1590501636; 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=86WQURgCqAHa0WXNLzZX28I5KUeKUOWQEKAQ4Gpwaf0=; b=NUYWWu+fDO93/EZYSH8HVplpoD0SlCYkH/vAqA7m5bYDAJs+h7SaNkowpkU559ZRj32OD5 u2jNY44XCBxcrePIuBQdz7XlCRmamchd3XamDE5PbkcAUPnXpHClOL3x4wEwp+hB+Q/6Lo CQ2EunuSYqZH4J+ZeVcBAz6jJAUJo1E= 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-160-OvaMsk5FP-u0DBdNEz45pQ-1; Tue, 26 May 2020 10:00:32 -0400 X-MC-Unique: OvaMsk5FP-u0DBdNEz45pQ-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B8357100CD14; Tue, 26 May 2020 14:00:30 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.40.193.170]) by smtp.corp.redhat.com (Postfix) with SMTP id 3210460E1C; Tue, 26 May 2020 14:00:29 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Tue, 26 May 2020 16:00:30 +0200 (CEST) Date: Tue, 26 May 2020 16:00:28 +0200 From: Oleg Nesterov To: Greentime Hu Cc: guoren@linux.alibaba.com, vincent.chen@sifive.com, paul.walmsley@sifive.com, palmerdabbelt@google.com, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH v4 01/13] ptrace: Use regset_size() for dynamic regset size. Message-ID: <20200526140027.GC24212@redhat.com> References: <3700190a602a6d30fcbf76e1eea667e29a65c4c9.1590474856.git.greentime.hu@sifive.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3700190a602a6d30fcbf76e1eea667e29a65c4c9.1590474856.git.greentime.hu@sifive.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/26, Greentime Hu wrote: > > @@ -882,13 +882,18 @@ static int ptrace_regset(struct task_struct *task, int req, unsigned int type, > const struct user_regset_view *view = task_user_regset_view(task); > const struct user_regset *regset = find_regset(view, type); > int regset_no; > + unsigned int size; > > - if (!regset || (kiov->iov_len % regset->size) != 0) > + if (!regset) > return -EINVAL; > > regset_no = regset - view->regsets; > - kiov->iov_len = min(kiov->iov_len, > - (__kernel_size_t) (regset->n * regset->size)); > + size = regset_size(task, regset); > + > + if ((kiov->iov_len % size) != 0) > + return -EINVAL; Hmm. this doesn't look right. Before this patch we check "iov_len % regset->size", this is not the same as "iov_len % regset_size()". IOW, currently you can read/write, say, only the 1st register, you patch breaks this? Oleg.