From patchwork Wed Nov 16 10:26:42 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 13044695 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 246EAC4332F for ; Wed, 16 Nov 2022 10:30:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; 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bh=1Pfa0qX/ZhOI50QqJ9JdOGuy2kwPxeAxaBCfxYoSW9g=; b=CdH04xSb92RbKIj8gShf4bn2j6ug09/h0btgl92byETeR7FRQ1mZZUlMDj6yJEKj2HODly FaeFo/Ag4q2yn67WyU0PbAtzz8iStsBL/9rsKBDf9fTr5tEJLcsqbyoXinJHVqYrfncft7 paUqHkXY4zxXGJ2dBCZB79rwEhnEcYg= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-387-mUeJQgfvOUWRJd96rWHDcg-1; Wed, 16 Nov 2022 05:27:47 -0500 X-MC-Unique: mUeJQgfvOUWRJd96rWHDcg-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 547AE86F13B; Wed, 16 Nov 2022 10:27:45 +0000 (UTC) Received: from t480s.fritz.box (unknown [10.39.193.216]) by smtp.corp.redhat.com (Postfix) with ESMTP id C5D9B20290A6; Wed, 16 Nov 2022 10:27:38 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: x86@kernel.org, linux-alpha@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, sparclinux@vger.kernel.org, linux-um@lists.infradead.org, etnaviv@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-samsung-soc@vger.kernel.org, linux-rdma@vger.kernel.org, linux-media@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-perf-users@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kselftest@vger.kernel.org, Linus Torvalds , Andrew Morton , Jason Gunthorpe , John Hubbard , Peter Xu , Greg Kroah-Hartman , Andrea Arcangeli , Hugh Dickins , Nadav Amit , Vlastimil Babka , Matthew Wilcox , Mike Kravetz , Muchun Song , Shuah Khan , Lucas Stach , David Airlie , Oded Gabbay , Arnd Bergmann , Christoph Hellwig , Alex Williamson , David Hildenbrand Subject: [PATCH mm-unstable v1 03/20] selftests/vm: cow: R/O long-term pinning reliability tests for non-anon pages Date: Wed, 16 Nov 2022 11:26:42 +0100 Message-Id: <20221116102659.70287-4-david@redhat.com> In-Reply-To: <20221116102659.70287-1-david@redhat.com> References: <20221116102659.70287-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.4 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221116_022749_687263_1C861192 X-CRM114-Status: GOOD ( 17.17 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Let's test whether R/O long-term pinning is reliable for non-anonymous memory: when R/O long-term pinning a page, the expectation is that we break COW early before pinning, such that actual write access via the page tables won't break COW later and end up replacing the R/O-pinned page in the page table. Consequently, R/O long-term pinning in private mappings would only target exclusive anonymous pages. For now, all tests fail: # [RUN] R/O longterm GUP pin ... with shared zeropage not ok 151 Longterm R/O pin is reliable # [RUN] R/O longterm GUP pin ... with memfd not ok 152 Longterm R/O pin is reliable # [RUN] R/O longterm GUP pin ... with tmpfile not ok 153 Longterm R/O pin is reliable # [RUN] R/O longterm GUP pin ... with huge zeropage not ok 154 Longterm R/O pin is reliable # [RUN] R/O longterm GUP pin ... with memfd hugetlb (2048 kB) not ok 155 Longterm R/O pin is reliable # [RUN] R/O longterm GUP pin ... with memfd hugetlb (1048576 kB) not ok 156 Longterm R/O pin is reliable # [RUN] R/O longterm GUP-fast pin ... with shared zeropage not ok 157 Longterm R/O pin is reliable # [RUN] R/O longterm GUP-fast pin ... with memfd not ok 158 Longterm R/O pin is reliable # [RUN] R/O longterm GUP-fast pin ... with tmpfile not ok 159 Longterm R/O pin is reliable # [RUN] R/O longterm GUP-fast pin ... with huge zeropage not ok 160 Longterm R/O pin is reliable # [RUN] R/O longterm GUP-fast pin ... with memfd hugetlb (2048 kB) not ok 161 Longterm R/O pin is reliable # [RUN] R/O longterm GUP-fast pin ... with memfd hugetlb (1048576 kB) not ok 162 Longterm R/O pin is reliable Signed-off-by: David Hildenbrand --- tools/testing/selftests/vm/cow.c | 28 +++++++++++++++++++++++++++- 1 file changed, 27 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/vm/cow.c b/tools/testing/selftests/vm/cow.c index fb07bd44529c..73e05b52c49e 100644 --- a/tools/testing/selftests/vm/cow.c +++ b/tools/testing/selftests/vm/cow.c @@ -561,6 +561,7 @@ static void test_iouring_fork(char *mem, size_t size) #endif /* LOCAL_CONFIG_HAVE_LIBURING */ enum ro_pin_test { + RO_PIN_TEST, RO_PIN_TEST_SHARED, RO_PIN_TEST_PREVIOUSLY_SHARED, RO_PIN_TEST_RO_EXCLUSIVE, @@ -593,6 +594,8 @@ static void do_test_ro_pin(char *mem, size_t size, enum ro_pin_test test, } switch (test) { + case RO_PIN_TEST: + break; case RO_PIN_TEST_SHARED: case RO_PIN_TEST_PREVIOUSLY_SHARED: /* @@ -1193,6 +1196,16 @@ static void test_cow(char *mem, const char *smem, size_t size) free(old); } +static void test_ro_pin(char *mem, const char *smem, size_t size) +{ + do_test_ro_pin(mem, size, RO_PIN_TEST, false); +} + +static void test_ro_fast_pin(char *mem, const char *smem, size_t size) +{ + do_test_ro_pin(mem, size, RO_PIN_TEST, true); +} + static void run_with_zeropage(non_anon_test_fn fn, const char *desc) { char *mem, *smem, tmp; @@ -1433,7 +1446,7 @@ struct non_anon_test_case { }; /* - * Test cases that target any pages in private mappings that are non anonymous: + * Test cases that target any pages in private mappings that are not anonymous: * pages that may get shared via COW ndependent of fork(). This includes * the shared zeropage(s), pagecache pages, ... */ @@ -1446,6 +1459,19 @@ static const struct non_anon_test_case non_anon_test_cases[] = { "Basic COW", test_cow, }, + /* + * Take a R/O longterm pin. When modifying the page via the page table, + * the page content change must be visible via the pin. + */ + { + "R/O longterm GUP pin", + test_ro_pin, + }, + /* Same as above, but using GUP-fast. */ + { + "R/O longterm GUP-fast pin", + test_ro_fast_pin, + }, }; static void run_non_anon_test_case(struct non_anon_test_case const *test_case)