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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8081EC4332F for ; Tue, 18 Oct 2022 15:40:26 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A32056B0072; Tue, 18 Oct 2022 11:40:25 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 9E2256B0075; Tue, 18 Oct 2022 11:40:25 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8D0B16B0078; Tue, 18 Oct 2022 11:40:25 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 7D6B76B0072 for ; Tue, 18 Oct 2022 11:40:25 -0400 (EDT) Received: from smtpin08.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 2B00B140A40 for ; Tue, 18 Oct 2022 15:40:25 +0000 (UTC) X-FDA: 80034482010.08.0AED03A Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by imf14.hostedemail.com (Postfix) with ESMTP id 671C410002A for ; Tue, 18 Oct 2022 15:40:24 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id B4A3068C4E; Tue, 18 Oct 2022 17:40:20 +0200 (CEST) Date: Tue, 18 Oct 2022 17:40:20 +0200 From: Christoph Hellwig To: Song Liu Cc: Christoph Hellwig , Song Liu , Linux-MM , lkml , Andrew Morton , X86 ML , Peter Zijlstra , Kernel Team , "Edgecombe, Rick P" , "Hansen, Dave" , "urezki@gmail.com" Subject: Re: [RFC v2 0/4] vmalloc_exec for modules and BPF programs Message-ID: <20221018154020.GA24383@lst.de> References: <20221007234315.2877365-1-song@kernel.org> <20221017072607.GA30977@lst.de> <20221018145021.GC20131@lst.de> <9A9A2DFD-45FA-45EA-95FB-5FC0DC5A9E2E@fb.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <9A9A2DFD-45FA-45EA-95FB-5FC0DC5A9E2E@fb.com> User-Agent: Mutt/1.5.17 (2007-11-01) ARC-Authentication-Results: i=1; imf14.hostedemail.com; dkim=none; dmarc=none; spf=none (imf14.hostedemail.com: domain of hch@lst.de has no SPF policy when checking 213.95.11.211) smtp.mailfrom=hch@lst.de ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1666107624; a=rsa-sha256; cv=none; b=iyeHckRsY8iwutMq8oCi9BWPL2QKcEyUn6kmnvN1BojEB1S3XJ/3S36AavrPvyB5MzfIkq y/nBzolVtnVoSzUAcN7Dke5pInwLgH93L088eRGEvU+LzPCSpTQ/vZTkJY6T2HtTHTDsXe Xx68Y5C1iG9I28QSpqKvPKR8ec2iMuU= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1666107624; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=D7KwR0G7C25rPCDYFBi0hStratvs8dZqDCgQ7xk4jSg=; b=UrASxyRZS9Qhq+UlWMZe+Xd2tRYkQq9lMG9Sjx5ESnyFE4hY9mKuKSABdb42Tday0fFUxq +mJ98kn1DPgASdEEXNfEWjBRIwogug+l7fntvnybMxA9MnhNMo3KUVlMQRPk2BYN5s0nGL xv9YG4BbLgMfhlN2+o7YVfKRcjEyCs8= Authentication-Results: imf14.hostedemail.com; dkim=none; dmarc=none; spf=none (imf14.hostedemail.com: domain of hch@lst.de has no SPF policy when checking 213.95.11.211) smtp.mailfrom=hch@lst.de X-Rspam-User: X-Rspamd-Server: rspam06 X-Stat-Signature: 9iudd7hrai7hzxdp6nq1843fhrceff18 X-Rspamd-Queue-Id: 671C410002A X-HE-Tag: 1666107624-419988 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Oct 18, 2022 at 03:05:24PM +0000, Song Liu wrote: > Maybe we need something like vcopy_exec(x_mem, tmp_buf, size), where > we explicitly check the allowed memory of x_mem is bigger or equal to > size. And users of vmalloc_exec should only use vcopy_exec to update > memory from vmalloc_exec. > > Does this make sense? Did I understand your concern correctly? It sounds sensible. Make sure it iѕ properly documented and reviewed by people that actually know this area. I just know enough to ask stupid question, not to very something is actually correct :)