From patchwork Mon Oct 9 06:42:28 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Suren Baghdasaryan X-Patchwork-Id: 731267 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 E4103E95A8E for ; Mon, 9 Oct 2023 06:42:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345354AbjJIGmy (ORCPT ); Mon, 9 Oct 2023 02:42:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35266 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345336AbjJIGmv (ORCPT ); Mon, 9 Oct 2023 02:42:51 -0400 Received: from mail-yw1-x114a.google.com (mail-yw1-x114a.google.com [IPv6:2607:f8b0:4864:20::114a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 305C9E9 for ; Sun, 8 Oct 2023 23:42:42 -0700 (PDT) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-5a234ffeb90so63793407b3.3 for ; Sun, 08 Oct 2023 23:42:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1696833762; x=1697438562; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=50i/QdEI5D071LaRqB1M3KzWwtbx6nE7wmO2EXtVHvA=; b=lpP38/5JvlOaMlcq0JFOwzSjg6eLfiYW4s5QkK51KNbANf+OXr6w7n33JYk1zTj0rs pVM2v46jUSwZPq0Q2bVwvqSWkCdmx2vXjzTswb0gxENj9JDem5tgj20Y+Up0ceiHTyO2 OTVxvl7zKgj9Ll56qF3PgtNjcwYY04VD62qypBcELy+5khsnbbkhxrA8oKkUEcgJq6B0 irT+1WcXalDxbPyP+Z1ZVAcEqV1Pe+qum34WgnA1iNREWLR00x8bgoBO8BQ8FhxgV244 LoBl7HvZ+HN+jjnFGJlZqPOCFm/CIh9TiKZlomEL361vcNsiQXL3/7rNxKRD+sej3qAt NKLw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1696833762; x=1697438562; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=50i/QdEI5D071LaRqB1M3KzWwtbx6nE7wmO2EXtVHvA=; b=S/vxvzq4+AR+5dGaVInQSNCrq7846AkJExcwQbpxBQHZxr0Tx6FazAXUh6DsZr7a46 chHTdaIN1j43vwekMfDushyHs5i+G6jcC1BRwGCudWQ6BIqkNVYr6pwsUO4T1KJ10i7M F33CUtnS+fd3tN7vcp3glCeIaQNc3LBZIjHZG4YiIRbexwIPOLjLWTR2Eze5u4UQbMCx R9oWS0OGosz/ksPlAqJJ6ZxaTtC9qMtnq7vuSzlwbDbu6i/StSNv2+NSClZP/RSBGXFV SQByYQyF2hpmlnyeqmNHD3i4XixtTMRcZ+q1yLIgWSa+B83bpPbrb15DjiEWwjXsbehL e7Ng== X-Gm-Message-State: AOJu0Yz2Zq+nIk0+4dQKTmr8NCtd1H7AIpctBj3fuGcMyqEjUujL3IIu LIbwWSxLxY/XlPd8d64Piri/hJvUUYg= X-Google-Smtp-Source: AGHT+IE3ENVpgSSY9jHiu1FOcPq/GRVi/eysZgrxroKYd6Fm4a1cG8w7FQlArfhqzdMAUqw7rMWUDxE9tZI= X-Received: from surenb-desktop.mtv.corp.google.com ([2620:15c:211:201:3e83:601e:dc42:a455]) (user=surenb job=sendgmr) by 2002:a25:68ce:0:b0:d86:56bc:e289 with SMTP id d197-20020a2568ce000000b00d8656bce289mr225181ybc.4.1696833762182; Sun, 08 Oct 2023 23:42:42 -0700 (PDT) Date: Sun, 8 Oct 2023 23:42:28 -0700 In-Reply-To: <20231009064230.2952396-1-surenb@google.com> Mime-Version: 1.0 References: <20231009064230.2952396-1-surenb@google.com> X-Mailer: git-send-email 2.42.0.609.gbb76f46606-goog Message-ID: <20231009064230.2952396-4-surenb@google.com> Subject: [PATCH v3 3/3] selftests/mm: add UFFDIO_MOVE ioctl test From: Suren Baghdasaryan To: akpm@linux-foundation.org Cc: viro@zeniv.linux.org.uk, brauner@kernel.org, shuah@kernel.org, aarcange@redhat.com, lokeshgidra@google.com, peterx@redhat.com, david@redhat.com, hughd@google.com, mhocko@suse.com, axelrasmussen@google.com, rppt@kernel.org, willy@infradead.org, Liam.Howlett@oracle.com, jannh@google.com, zhangpeng362@huawei.com, bgeffon@google.com, kaleshsingh@google.com, ngeoffray@google.com, jdduke@google.com, surenb@google.com, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, kernel-team@android.com Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org Add a test for new UFFDIO_MOVE ioctl which uses uffd to move source into destination buffer while checking the contents of both after remapping. After the operation the content of the destination buffer should match the original source buffer's content while the source buffer should be zeroed. Signed-off-by: Suren Baghdasaryan --- tools/testing/selftests/mm/uffd-common.c | 41 ++++++++++++- tools/testing/selftests/mm/uffd-common.h | 1 + tools/testing/selftests/mm/uffd-unit-tests.c | 62 ++++++++++++++++++++ 3 files changed, 102 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/mm/uffd-common.c b/tools/testing/selftests/mm/uffd-common.c index 02b89860e193..ecc1244f1c2b 100644 --- a/tools/testing/selftests/mm/uffd-common.c +++ b/tools/testing/selftests/mm/uffd-common.c @@ -52,6 +52,13 @@ static int anon_allocate_area(void **alloc_area, bool is_src) *alloc_area = NULL; return -errno; } + + /* Prevent source pages from collapsing into THPs */ + if (madvise(*alloc_area, nr_pages * page_size, MADV_NOHUGEPAGE)) { + *alloc_area = NULL; + return -errno; + } + return 0; } @@ -484,8 +491,14 @@ void uffd_handle_page_fault(struct uffd_msg *msg, struct uffd_args *args) offset = (char *)(unsigned long)msg->arg.pagefault.address - area_dst; offset &= ~(page_size-1); - if (copy_page(uffd, offset, args->apply_wp)) - args->missing_faults++; + /* UFFD_MOVE is supported for anon non-shared mappings. */ + if (uffd_test_ops == &anon_uffd_test_ops && !map_shared) { + if (move_page(uffd, offset)) + args->missing_faults++; + } else { + if (copy_page(uffd, offset, args->apply_wp)) + args->missing_faults++; + } } } @@ -620,6 +633,30 @@ int copy_page(int ufd, unsigned long offset, bool wp) return __copy_page(ufd, offset, false, wp); } +int move_page(int ufd, unsigned long offset) +{ + struct uffdio_move uffdio_move; + + if (offset >= nr_pages * page_size) + err("unexpected offset %lu\n", offset); + uffdio_move.dst = (unsigned long) area_dst + offset; + uffdio_move.src = (unsigned long) area_src + offset; + uffdio_move.len = page_size; + uffdio_move.mode = UFFDIO_MOVE_MODE_ALLOW_SRC_HOLES; + uffdio_move.move = 0; + if (ioctl(ufd, UFFDIO_MOVE, &uffdio_move)) { + /* real retval in uffdio_move.move */ + if (uffdio_move.move != -EEXIST) + err("UFFDIO_MOVE error: %"PRId64, + (int64_t)uffdio_move.move); + wake_range(ufd, uffdio_move.dst, page_size); + } else if (uffdio_move.move != page_size) { + err("UFFDIO_MOVE error: %"PRId64, (int64_t)uffdio_move.move); + } else + return 1; + return 0; +} + int uffd_open_dev(unsigned int flags) { int fd, uffd; diff --git a/tools/testing/selftests/mm/uffd-common.h b/tools/testing/selftests/mm/uffd-common.h index 7c4fa964c3b0..f4d79e169a3d 100644 --- a/tools/testing/selftests/mm/uffd-common.h +++ b/tools/testing/selftests/mm/uffd-common.h @@ -111,6 +111,7 @@ void wp_range(int ufd, __u64 start, __u64 len, bool wp); void uffd_handle_page_fault(struct uffd_msg *msg, struct uffd_args *args); int __copy_page(int ufd, unsigned long offset, bool retry, bool wp); int copy_page(int ufd, unsigned long offset, bool wp); +int move_page(int ufd, unsigned long offset); void *uffd_poll_thread(void *arg); int uffd_open_dev(unsigned int flags); diff --git a/tools/testing/selftests/mm/uffd-unit-tests.c b/tools/testing/selftests/mm/uffd-unit-tests.c index 2709a34a39c5..f0ded3b34367 100644 --- a/tools/testing/selftests/mm/uffd-unit-tests.c +++ b/tools/testing/selftests/mm/uffd-unit-tests.c @@ -824,6 +824,10 @@ static void uffd_events_test_common(bool wp) char c; struct uffd_args args = { 0 }; + /* Prevent source pages from being mapped more than once */ + if (madvise(area_src, nr_pages * page_size, MADV_DONTFORK)) + err("madvise(MADV_DONTFORK) failed"); + fcntl(uffd, F_SETFL, uffd_flags | O_NONBLOCK); if (uffd_register(uffd, area_dst, nr_pages * page_size, true, wp, false)) @@ -1062,6 +1066,58 @@ static void uffd_poison_test(uffd_test_args_t *targs) uffd_test_pass(); } +static void uffd_move_test(uffd_test_args_t *targs) +{ + unsigned long nr; + pthread_t uffd_mon; + char c; + unsigned long long count; + struct uffd_args args = { 0 }; + + if (uffd_register(uffd, area_dst, nr_pages * page_size, + true, false, false)) + err("register failure"); + + if (pthread_create(&uffd_mon, NULL, uffd_poll_thread, &args)) + err("uffd_poll_thread create"); + + /* + * Read each of the pages back using the UFFD-registered mapping. We + * expect that the first time we touch a page, it will result in a missing + * fault. uffd_poll_thread will resolve the fault by remapping source + * page to destination. + */ + for (nr = 0; nr < nr_pages; nr++) { + /* Check area_src content */ + count = *area_count(area_src, nr); + if (count != count_verify[nr]) + err("nr %lu source memory invalid %llu %llu\n", + nr, count, count_verify[nr]); + + /* Faulting into area_dst should remap the page */ + count = *area_count(area_dst, nr); + if (count != count_verify[nr]) + err("nr %lu memory corruption %llu %llu\n", + nr, count, count_verify[nr]); + + /* Re-check area_src content which should be empty */ + count = *area_count(area_src, nr); + if (count != 0) + err("nr %lu move failed %llu %llu\n", + nr, count, count_verify[nr]); + } + + if (write(pipefd[1], &c, sizeof(c)) != sizeof(c)) + err("pipe write"); + if (pthread_join(uffd_mon, NULL)) + err("join() failed"); + + if (args.missing_faults != nr_pages || args.minor_faults != 0) + uffd_test_fail("stats check error"); + else + uffd_test_pass(); +} + /* * Test the returned uffdio_register.ioctls with different register modes. * Note that _UFFDIO_ZEROPAGE is tested separately in the zeropage test. @@ -1139,6 +1195,12 @@ uffd_test_case_t uffd_tests[] = { .mem_targets = MEM_ALL, .uffd_feature_required = 0, }, + { + .name = "move", + .uffd_fn = uffd_move_test, + .mem_targets = MEM_ANON, + .uffd_feature_required = UFFD_FEATURE_MOVE, + }, { .name = "wp-fork", .uffd_fn = uffd_wp_fork_test,