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 BC17EC636D6 for ; Wed, 22 Feb 2023 12:49:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231764AbjBVMte (ORCPT ); Wed, 22 Feb 2023 07:49:34 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44714 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231774AbjBVMtb (ORCPT ); Wed, 22 Feb 2023 07:49:31 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 82DEC29E34 for ; Wed, 22 Feb 2023 04:48:51 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1677070130; 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=Pwhafy9c9OVklvOu8fWr7CpmYP0sg2Cj0LDnB+q0JdQ=; b=MKlzp5MMrddKyDCiClF81dnGgh2GQniJQNvATqrPORj5p0dRre24EF1thvZ8dRKzvaCbv1 MtpCVvJsYT5PeRxVpfsMFwHiHuuPG7O0w7sgffMIz49nGkQBEhgUzy3dCxOeNRroEqdG6J kn1QHv+R7QhYMuBR3KrLOCEiWICb/Q8= 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-136-yC4_3_61NByzTdmNpn1GFA-1; Wed, 22 Feb 2023 07:48:44 -0500 X-MC-Unique: yC4_3_61NByzTdmNpn1GFA-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id B11E73C10690; Wed, 22 Feb 2023 12:48:43 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.45.227.52]) by smtp.corp.redhat.com (Postfix) with SMTP id 24BD82026D38; Wed, 22 Feb 2023 12:48:40 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Wed, 22 Feb 2023 13:48:38 +0100 (CET) Date: Wed, 22 Feb 2023 13:48:35 +0100 From: Oleg Nesterov To: Gregory Price Cc: linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, avagin@gmail.com, peterz@infradead.org, luto@kernel.org, krisman@collabora.com, tglx@linutronix.de, corbet@lwn.net, shuah@kernel.org, Gregory Price Subject: Re: [PATCH v11 2/2] ptrace,syscall_user_dispatch: checkpoint/restore support for SUD Message-ID: <20230222124834.GA15591@redhat.com> References: <20230221201740.2236-1-gregory.price@memverge.com> <20230221201740.2236-3-gregory.price@memverge.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230221201740.2236-3-gregory.price@memverge.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 3.1 on 10.11.54.4 Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On 02/21, Gregory Price wrote: > > +struct ptrace_sud_config { > + __u8 mode; > + __u8 pad[7]; ^^^^^^ Why? > +int syscall_user_dispatch_get_config(struct task_struct *task, unsigned long size, > + void __user *data) > +{ > + struct syscall_user_dispatch *sd = &task->syscall_dispatch; > + struct ptrace_sud_config config; > + if (size != sizeof(struct ptrace_sud_config)) > + return -EINVAL; Andrei, do we really need this check? > + > + if (test_task_syscall_work(task, SYSCALL_USER_DISPATCH)) > + config.mode = PR_SYS_DISPATCH_ON; > + else > + config.mode = PR_SYS_DISPATCH_OFF; > + > + config.offset = sd->offset; > + config.len = sd->len; > + config.selector = (__u64)sd->selector; As the kernel test robot reports, this is not -Wpointer-to-int-cast friendly. Please use uintptr_t. See for example ptrace_get_rseq_configuration(). Same for syscall_user_dispatch_set_config(). > + if (copy_to_user(data, &config, sizeof(config))) { This leaks info in (uninitialized) config.pad[]. You can probably simply make config.mode __u64 as well. Minor, but sizeof(struct ptrace_sud_config) above vs this sizeof(config)) doesn't look consistent to me... > +static int sys_ptrace(int request, pid_t pid, void *addr, void *data) > +{ > + return syscall(SYS_ptrace, request, pid, addr, data); > +} Why can't you simply use ptrace() ? Oleg.