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=-8.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham 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 A3165C43441 for ; Thu, 22 Nov 2018 23:21:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 57F7C20818 for ; Thu, 22 Nov 2018 23:21:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=joelfernandes.org header.i=@joelfernandes.org header.b="j0fvkVfr" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 57F7C20818 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=joelfernandes.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2439078AbeKWKDi (ORCPT ); Fri, 23 Nov 2018 05:03:38 -0500 Received: from mail-pl1-f194.google.com ([209.85.214.194]:33994 "EHLO mail-pl1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2392635AbeKWKDh (ORCPT ); Fri, 23 Nov 2018 05:03:37 -0500 Received: by mail-pl1-f194.google.com with SMTP id f12-v6so9802622plo.1 for ; Thu, 22 Nov 2018 15:21:55 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=joelfernandes.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=WGnK2W1fNMNjJUmjzBmpHixfeOx8rrinn/2HUMu/9ms=; b=j0fvkVfrNDaJKqlIhqgDQc1aP197LuKByPQV8a9DCZW1HRro7pTxuMIczzZQiG8oqh gNBaBd34G52KLw+pH1iyYtDWawdrUfxTOgOKM/H5qNieaLDn9eauJZtjtPVGRf9Javhh h5IDF+/WxrdZLwXhKMSQ9T5ci+fTguXrMiQL4= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=WGnK2W1fNMNjJUmjzBmpHixfeOx8rrinn/2HUMu/9ms=; b=QK96ylShZgdq3Tk5THKfgkvx1iuO35ucAiiAcQIao2f/+lDVj2hkU1uEfxYWTEifSK DNp2q4iHk3igEWOgXc7Yr75gkmgvJY351Upp+zpgSrWNeX/y4WZxX4l1hvS8HX0a0TcE Oy8f4fikQfUXHlLP79YD76nndYoayjFSLkN45JKJ2VEhAeBnhqc7GzhTVk+doTvaLzL1 x1lnIPXNxWjEoLPU3xcEkj4sVWOr43GGmz56p06sVNJ5jZTaMCiBpdCSSM/8Ika2Jn2F kKlztUE3HOTdVk7Mlcupd6zbCg9amhN6yPwvXKj0+k6pOCsfJHFhgNI+tRSfxnb8M1nI RRpA== X-Gm-Message-State: AA+aEWaszMuGCT2a1NhwgzN20587DEEoV/k/12cdFoxIeaCjfXkZHuTQ HhWw9VfChLnLuY1Opbu5am+00CgneYk= X-Google-Smtp-Source: AFSGD/XfEZTIpG//Te8YOdDUWEzHKhMIec+FJ4M9+kro35NtdeBr61zHDLD0zfeUeYgv2HLy1yYJ+g== X-Received: by 2002:a17:902:50e:: with SMTP id 14mr5074980plf.141.1542928914652; Thu, 22 Nov 2018 15:21:54 -0800 (PST) Received: from localhost ([2620:0:1000:1601:3aef:314f:b9ea:889f]) by smtp.gmail.com with ESMTPSA id d3sm73232160pgl.64.2018.11.22.15.21.53 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 22 Nov 2018 15:21:53 -0800 (PST) Date: Thu, 22 Nov 2018 15:21:52 -0800 From: Joel Fernandes To: linux-kernel@vger.kernel.org Cc: Jann Horn , Andrew Morton , Andy Lutomirski , Hugh Dickins , Khalid Aziz , linux-api@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, =?iso-8859-1?Q?Marc-Andr=E9?= Lureau , Matthew Wilcox , Mike Kravetz , Shuah Khan , Stephen Rothwell Subject: Re: [PATCH -next 2/2] selftests/memfd: modify tests for F_SEAL_FUTURE_WRITE seal Message-ID: <20181122232152.GA17060@google.com> References: <20181120052137.74317-1-joel@joelfernandes.org> <20181120052137.74317-2-joel@joelfernandes.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181120052137.74317-2-joel@joelfernandes.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 19, 2018 at 09:21:37PM -0800, Joel Fernandes (Google) wrote: > Modify the tests for F_SEAL_FUTURE_WRITE based on the changes > introduced in previous patch. > > Also add a test to make sure the reopen issue pointed by Jann Horn [1] > is fixed. > > [1] https://lore.kernel.org/lkml/CAG48ez1h=v-JYnDw81HaYJzOfrNhwYksxmc2r=cJvdQVgYM+NA@mail.gmail.com/ > > Cc: Jann Horn > Signed-off-by: Joel Fernandes (Google) > --- > tools/testing/selftests/memfd/memfd_test.c | 88 +++++++++++----------- > 1 file changed, 44 insertions(+), 44 deletions(-) Since we squashed [1] the mm/memfd patch modifications suggested by Andy into the original patch, I also squashed the selftests modifications and appended the patch inline below if you want to take this instead: [1] https://lore.kernel.org/lkml/20181122230906.GA198127@google.com/T/#m8ba68f67f3ec24913a977b62bcaeafc4b194b8c8 ---8<----------------------- From: "Joel Fernandes (Google)" Subject: [PATCH v4] selftests/memfd: add tests for F_SEAL_FUTURE_WRITE seal Add tests to verify sealing memfds with the F_SEAL_FUTURE_WRITE works as expected. Signed-off-by: Joel Fernandes (Google) --- tools/testing/selftests/memfd/memfd_test.c | 74 ++++++++++++++++++++++ 1 file changed, 74 insertions(+) diff --git a/tools/testing/selftests/memfd/memfd_test.c b/tools/testing/selftests/memfd/memfd_test.c index 10baa1652fc2..c67d32eeb668 100644 --- a/tools/testing/selftests/memfd/memfd_test.c +++ b/tools/testing/selftests/memfd/memfd_test.c @@ -54,6 +54,22 @@ static int mfd_assert_new(const char *name, loff_t sz, unsigned int flags) return fd; } +static int mfd_assert_reopen_fd(int fd_in) +{ + int r, fd; + char path[100]; + + sprintf(path, "/proc/self/fd/%d", fd_in); + + fd = open(path, O_RDWR); + if (fd < 0) { + printf("re-open of existing fd %d failed\n", fd_in); + abort(); + } + + return fd; +} + static void mfd_fail_new(const char *name, unsigned int flags) { int r; @@ -255,6 +271,25 @@ static void mfd_assert_read(int fd) munmap(p, mfd_def_size); } +/* Test that PROT_READ + MAP_SHARED mappings work. */ +static void mfd_assert_read_shared(int fd) +{ + void *p; + + /* verify PROT_READ and MAP_SHARED *is* allowed */ + p = mmap(NULL, + mfd_def_size, + PROT_READ, + MAP_SHARED, + fd, + 0); + if (p == MAP_FAILED) { + printf("mmap() failed: %m\n"); + abort(); + } + munmap(p, mfd_def_size); +} + static void mfd_assert_write(int fd) { ssize_t l; @@ -692,6 +727,44 @@ static void test_seal_write(void) close(fd); } +/* + * Test SEAL_FUTURE_WRITE + * Test whether SEAL_FUTURE_WRITE actually prevents modifications. + */ +static void test_seal_future_write(void) +{ + int fd, fd2; + void *p; + + printf("%s SEAL-FUTURE-WRITE\n", memfd_str); + + fd = mfd_assert_new("kern_memfd_seal_future_write", + mfd_def_size, + MFD_CLOEXEC | MFD_ALLOW_SEALING); + + p = mfd_assert_mmap_shared(fd); + + mfd_assert_has_seals(fd, 0); + + mfd_assert_add_seals(fd, F_SEAL_FUTURE_WRITE); + mfd_assert_has_seals(fd, F_SEAL_FUTURE_WRITE); + + /* read should pass, writes should fail */ + mfd_assert_read(fd); + mfd_assert_read_shared(fd); + mfd_fail_write(fd); + + fd2 = mfd_assert_reopen_fd(fd); + /* read should pass, writes should still fail */ + mfd_assert_read(fd2); + mfd_assert_read_shared(fd2); + mfd_fail_write(fd2); + + munmap(p, mfd_def_size); + close(fd2); + close(fd); +} + /* * Test SEAL_SHRINK * Test whether SEAL_SHRINK actually prevents shrinking @@ -945,6 +1018,7 @@ int main(int argc, char **argv) test_basic(); test_seal_write(); + test_seal_future_write(); test_seal_shrink(); test_seal_grow(); test_seal_resize(); -- 2.19.1.1215.g8438c0b245-goog