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 BD378C4828E for ; Fri, 2 Feb 2024 19:32:20 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 4DC4E8D0002; Fri, 2 Feb 2024 14:32:20 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 48BAD8D0001; Fri, 2 Feb 2024 14:32:20 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 37B6B8D0002; Fri, 2 Feb 2024 14:32:20 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 277818D0001 for ; Fri, 2 Feb 2024 14:32:20 -0500 (EST) Received: from smtpin08.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id EFE1614101A for ; Fri, 2 Feb 2024 19:32:19 +0000 (UTC) X-FDA: 81747859998.08.6730718 Received: from cvs.openbsd.org (cvs.openbsd.org [199.185.137.3]) by imf25.hostedemail.com (Postfix) with ESMTP id 23B69A001A for ; Fri, 2 Feb 2024 19:32:17 +0000 (UTC) Authentication-Results: imf25.hostedemail.com; dkim=pass header.d=openbsd.org header.s=selector1 header.b=ZdHsQtxZ; spf=pass (imf25.hostedemail.com: domain of deraadt@openbsd.org designates 199.185.137.3 as permitted sender) smtp.mailfrom=deraadt@openbsd.org; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1706902338; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=iMuvp02SyYoj4JF2gtN2+jkpvA/AUkOFWxEPuAq/IjM=; b=Mlcjpnjo1uKdjEuLtOlnE3HqQ5D9j/D4YtNjrMwjl1X4izEKhCIfb9rzj/S5QmD/w//aR/ YyLwNfSFiW3KYymUFszYxs9FKXgYguruZUyxLkU75cRRP4YmeVLurAoHMYKY80gG9dfguo KMJDDkZmpjfWmbVw+0TMVRzw6z3tgos= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1706902338; a=rsa-sha256; cv=none; b=ZcFtvBFjgavzHHmJS6V2qoaOYQiikH+DJd5A+WPy+faqUa7HOQojuyFMcAEQMZx8iBuAoX ATg5mO2yp1Ll8aQA04HLkVXzFv5ZottLmyWzL8Y7wpLlpKV0onsCtrHWonGPzbIjQenCIP 1LfSslC61duTzzdzQRnmqBJ1M9dCjJM= ARC-Authentication-Results: i=1; imf25.hostedemail.com; dkim=pass header.d=openbsd.org header.s=selector1 header.b=ZdHsQtxZ; spf=pass (imf25.hostedemail.com: domain of deraadt@openbsd.org designates 199.185.137.3 as permitted sender) smtp.mailfrom=deraadt@openbsd.org; dmarc=none DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; s=selector1; bh=ekn8zZyh2S J/K4/UbZI/dsGbE82SD/gtWKgnDxS+Csg=; h=date:references:in-reply-to: subject:to:from; d=openbsd.org; b=ZdHsQtxZd7zV7xxA41DRY2ESVMUbSAnvR1xc AlK7ecM9Ucc9edCmBIKnSpBApeWQwf3odD6e7TBICtNVqhp2Zva5TXONs0ssS378pCBvkM 4lyOWSpIn7akT2yQnl1fhqedjWlWt2K7DRAapspanK04WySI/fAE7WB4yp1ASTvAcVJv76 dOREtdXKhniP8HAbBjy9NG4YE4EhcjBPAESBMP3Yu43xtw8YvyKPC3muuRLI2uNjjRC1mB 4cz9yJYYcle46GXKmS9Z4NPB4cVl9QFhxzXe68UB5hOodzmyCJfxFaqihHUt55frwCB07R gkgopKTD0GkEtx/ZgDrPzaJwnw== Received: from cvs.openbsd.org (localhost [127.0.0.1]) by cvs.openbsd.org (OpenSMTPD) with ESMTP id 78374f08; Fri, 2 Feb 2024 12:32:16 -0700 (MST) From: "Theo de Raadt" To: "Liam R. Howlett" , Jeff Xu , Jeff Xu , Jonathan Corbet , akpm@linux-foundation.org, keescook@chromium.org, jannh@google.com, sroettger@google.com, willy@infradead.org, gregkh@linuxfoundation.org, torvalds@linux-foundation.org, usama.anjum@collabora.com, rdunlap@infradead.org, jorgelo@chromium.org, groeck@chromium.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, pedro.falcato@gmail.com, dave.hansen@intel.com, linux-hardening@vger.kernel.org Mail-Followup-To: "Liam R. Howlett" , Jeff Xu , Jeff Xu , Jonathan Corbet , akpm@linux-foundation.org, keescook@chromium.org, jannh@google.com, sroettger@google.com, willy@infradead.org, gregkh@linuxfoundation.org, torvalds@linux-foundation.org, usama.anjum@collabora.com, rdunlap@infradead.org, jorgelo@chromium.org, groeck@chromium.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, pedro.falcato@gmail.com, dave.hansen@intel.com, linux-hardening@vger.kernel.org Subject: Re: [PATCH v8 0/4] Introduce mseal In-reply-to: <20240202192137.6lupguvhtdt72rbr@revolver> References: <20240131175027.3287009-1-jeffxu@chromium.org> <20240131193411.opisg5yoyxkwoyil@revolver> <20240201204512.ht3e33yj77kkxi4q@revolver> <20240202151345.kj4nhb5uog4aknsp@revolver> <20240202192137.6lupguvhtdt72rbr@revolver> Comments: In-reply-to "Liam R. Howlett" message dated "Fri, 02 Feb 2024 14:21:37 -0500." MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <98845.1706902336.1@cvs.openbsd.org> Date: Fri, 02 Feb 2024 12:32:16 -0700 Message-ID: <85714.1706902336@cvs.openbsd.org> X-Rspamd-Queue-Id: 23B69A001A X-Rspam-User: X-Rspamd-Server: rspam11 X-Stat-Signature: gqnd4q6q7kdy88ypg6hxgtx8uanswcgr X-HE-Tag: 1706902337-667090 X-HE-Meta: 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 8bLnSO/r T+nevr8p73avmrQIo7HZm1lEjFboSY/Z9oYztU3mfMziq2/uu0Xt91fus6ejVNlwVzx9r0mA1d5EyUyAaHmtccU5QjndtaBiudZ11+WytLGuuXbCdwK9yV9+9Pg0Wiz8Dp8XJrYMaRnCTizgDC3He37jyz2UOXide8TJ9uvMIfZYeyPxlirYMA3B/PRNNGME5cn0tIuyQLJW13miyD5/8QxCQGA== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000028, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: > What I'm more concerned about is what happens if you call mseal() on a > range and it can mseal a portion. Like, what happens to the first vma > in your test_seal_unmapped_middle case? I see it returns an error, but > is the first VMA mseal()'ed? (no it's not, but test that) That is correct, Liam. Unix system calls must be atomic. They either return an error, and that is a promise they made no changes. Or they do the work required, and then return success. In OpenBSD, all mimmutable() aspects were carefully studied to gaurantee this behaviour. I am not an expert in the Linux kernel to make the assessment; someone who is qualified must make that assessment. Fuzzing with tests is a good way to judge it simpler.