From patchwork Tue Jul 19 19:56:26 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Axel Rasmussen X-Patchwork-Id: 12922962 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 30035CCA47F for ; Tue, 19 Jul 2022 19:56:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239687AbiGST45 (ORCPT ); Tue, 19 Jul 2022 15:56:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44154 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239704AbiGST4o (ORCPT ); Tue, 19 Jul 2022 15:56:44 -0400 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C3D0B5B7BA for ; Tue, 19 Jul 2022 12:56:40 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id m5-20020a2598c5000000b0066faab590c5so11547651ybo.7 for ; Tue, 19 Jul 2022 12:56:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=kfHTJgvI1xhbc2HV5Dg5HLOm6jC5g70kHqbkIkuEdDY=; b=eATFJJjY0r2Ckp5HyJYF7nbsKpNr/n+bnVWTBX/qKJPuAEJFHTGGCBZXyp9cXnxBjg Ca1+y0xLR0qoBqtrlrNHYULBzMXCsc8caFlMWYdtEt52PUQhmCcZQT9ESXfI1teZEuWa IWUlbVDzn15ayl5FiIOdT8aMilcfI1uMjS5UpC1ymoVTyAuboD3MgfK8/r3RKHzKZmKP 8m5pTgYtqjZZkBSc+eWfj3+JIt1hCkNiSZnJ7k/w+No27VJ2bcyRAaOz1ogd6Mrde2Rr +tyNsenOxNV9jPukEvgPal2QfI5GQaafFY21IscEco8k3Vd5LNcprxRmuTztwvxV115+ 2EZw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=kfHTJgvI1xhbc2HV5Dg5HLOm6jC5g70kHqbkIkuEdDY=; b=sGLTeCKevH+vclK7IJPZFC5hKMImtutp+n6kkKIWtk2IWwafvZC81jqiPNHEFwl2ua ApR5PJXw4US5G+gGczSMMxBx5nsg+Wr2ODDlcUCDYstfQ21H4s2LfxWr3zeQcLhlgQtW 0KZK4/cGnHFNxjes+92XMrC4JSiLlqZMbfMRowDsDcSjfBT13S4PQnF78coLFJU46jV6 YuXkZJriP+AA5Zy485i5TbfjtFOfaQ1RqnBTEQ6rnqLs/b25b2/FipxEO/9L8n+rX+cp Vj/3Z+dAJKJhE1jUS/jJ9tlcuPTGz7GXMJxE8lhwLZXoY2bc8MKCs9a3VhBBdBBB8yEu PWSQ== X-Gm-Message-State: AJIora8Ols2hAmbMfwrPdpgfeoJSlXmdCt5nUw0M0YXo+MjtF2QT/khD lf5CJ5MA9PE5OldIEi9hClLD8fUa4jnMHhG9Pslv X-Google-Smtp-Source: AGRyM1vh6EyxVuVXbs2vKNFncUeOGmAA4GIWCwxEtu04z5gOe8ex1hyo5UKRpWnlw9uhvTBE62Bd9M97+L2VvA7rWmqs X-Received: from ajr0.svl.corp.google.com ([2620:15c:2d4:203:a065:9221:e40d:4fbe]) (user=axelrasmussen job=sendgmr) by 2002:a25:3b11:0:b0:66e:ccf2:76dc with SMTP id i17-20020a253b11000000b0066eccf276dcmr33549674yba.247.1658260600090; Tue, 19 Jul 2022 12:56:40 -0700 (PDT) Date: Tue, 19 Jul 2022 12:56:26 -0700 In-Reply-To: <20220719195628.3415852-1-axelrasmussen@google.com> Message-Id: <20220719195628.3415852-4-axelrasmussen@google.com> Mime-Version: 1.0 References: <20220719195628.3415852-1-axelrasmussen@google.com> X-Mailer: git-send-email 2.37.0.170.g444d1eabd0-goog Subject: [PATCH v4 3/5] userfaultfd: selftests: modify selftest to use /dev/userfaultfd From: Axel Rasmussen To: Alexander Viro , Andrew Morton , Dave Hansen , "Dmitry V . Levin" , Gleb Fotengauer-Malinovskiy , Hugh Dickins , Jan Kara , Jonathan Corbet , Mel Gorman , Mike Kravetz , Mike Rapoport , Nadav Amit , Peter Xu , Shuah Khan , Suren Baghdasaryan , Vlastimil Babka , zhangyi Cc: Axel Rasmussen , linux-doc@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org We clearly want to ensure both userfaultfd(2) and /dev/userfaultfd keep working into the future, so just run the test twice, using each interface. Instead of always testing both userfaultfd(2) and /dev/userfaultfd, let the user choose which to test. As with other test features, change the behavior based on a new command line flag. Introduce the idea of "test mods", which are generic (not specific to a test type) modifications to the behavior of the test. This is sort of borrowed from this RFC patch series [1], but simplified a bit. The benefit is, in "typical" configurations this test is somewhat slow (say, 30sec or something). Testing both clearly doubles it, so it may not always be desirable, as users are likely to use one or the other, but never both, in the "real world". [1]: https://patchwork.kernel.org/project/linux-mm/patch/20201129004548.1619714-14-namit@vmware.com/ Signed-off-by: Axel Rasmussen Acked-by: Peter Xu --- tools/testing/selftests/vm/userfaultfd.c | 69 ++++++++++++++++++++---- 1 file changed, 60 insertions(+), 9 deletions(-) diff --git a/tools/testing/selftests/vm/userfaultfd.c b/tools/testing/selftests/vm/userfaultfd.c index 0bdfc1955229..0a126c620bc0 100644 --- a/tools/testing/selftests/vm/userfaultfd.c +++ b/tools/testing/selftests/vm/userfaultfd.c @@ -77,6 +77,11 @@ static int bounces; #define TEST_SHMEM 3 static int test_type; +#define UFFD_FLAGS (O_CLOEXEC | O_NONBLOCK | UFFD_USER_MODE_ONLY) + +/* test using /dev/userfaultfd, instead of userfaultfd(2) */ +static bool test_dev_userfaultfd; + /* exercise the test_uffdio_*_eexist every ALARM_INTERVAL_SECS */ #define ALARM_INTERVAL_SECS 10 static volatile bool test_uffdio_copy_eexist = true; @@ -125,6 +130,8 @@ struct uffd_stats { const char *examples = "# Run anonymous memory test on 100MiB region with 99999 bounces:\n" "./userfaultfd anon 100 99999\n\n" + "# Run the same anonymous memory test, but using /dev/userfaultfd:\n" + "./userfaultfd anon:dev 100 99999\n\n" "# Run share memory test on 1GiB region with 99 bounces:\n" "./userfaultfd shmem 1000 99\n\n" "# Run hugetlb memory test on 256MiB region with 50 bounces:\n" @@ -141,6 +148,14 @@ static void usage(void) "[hugetlbfs_file]\n\n"); fprintf(stderr, "Supported : anon, hugetlb, " "hugetlb_shared, shmem\n\n"); + fprintf(stderr, "'Test mods' can be joined to the test type string with a ':'. " + "Supported mods:\n"); + fprintf(stderr, "\tsyscall - Use userfaultfd(2) (default)\n"); + fprintf(stderr, "\tdev - Use /dev/userfaultfd instead of userfaultfd(2)\n"); + fprintf(stderr, "\nExample test mod usage:\n"); + fprintf(stderr, "# Run anonymous memory test with /dev/userfaultfd:\n"); + fprintf(stderr, "./userfaultfd anon:dev 100 99999\n\n"); + fprintf(stderr, "Examples:\n\n"); fprintf(stderr, "%s", examples); exit(1); @@ -154,12 +169,14 @@ static void usage(void) ret, __LINE__); \ } while (0) -#define err(fmt, ...) \ +#define errexit(exitcode, fmt, ...) \ do { \ _err(fmt, ##__VA_ARGS__); \ - exit(1); \ + exit(exitcode); \ } while (0) +#define err(fmt, ...) errexit(1, fmt, ##__VA_ARGS__) + static void uffd_stats_reset(struct uffd_stats *uffd_stats, unsigned long n_cpus) { @@ -383,13 +400,29 @@ static void assert_expected_ioctls_present(uint64_t mode, uint64_t ioctls) } } +static int __userfaultfd_open_dev(void) +{ + int fd, _uffd = -1; + + fd = open("/dev/userfaultfd", O_RDWR | O_CLOEXEC); + if (fd < 0) + return -1; + + _uffd = ioctl(fd, USERFAULTFD_IOC_NEW, UFFD_FLAGS); + close(fd); + return _uffd; +} + static void userfaultfd_open(uint64_t *features) { struct uffdio_api uffdio_api; - uffd = syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLOCK | UFFD_USER_MODE_ONLY); + if (test_dev_userfaultfd) + uffd = __userfaultfd_open_dev(); + else + uffd = syscall(__NR_userfaultfd, UFFD_FLAGS); if (uffd < 0) - err("userfaultfd syscall not available in this kernel"); + errexit(KSFT_SKIP, "creating userfaultfd failed"); uffd_flags = fcntl(uffd, F_GETFD, NULL); uffdio_api.api = UFFD_API; @@ -1584,8 +1617,6 @@ unsigned long default_huge_page_size(void) static void set_test_type(const char *type) { - uint64_t features = UFFD_API_FEATURES; - if (!strcmp(type, "anon")) { test_type = TEST_ANON; uffd_test_ops = &anon_uffd_test_ops; @@ -1603,9 +1634,29 @@ static void set_test_type(const char *type) test_type = TEST_SHMEM; uffd_test_ops = &shmem_uffd_test_ops; test_uffdio_minor = true; - } else { - err("Unknown test type: %s", type); } +} + +static void parse_test_type_arg(const char *raw_type) +{ + char *buf = strdup(raw_type); + uint64_t features = UFFD_API_FEATURES; + + while (buf) { + const char *token = strsep(&buf, ":"); + + if (!test_type) + set_test_type(token); + else if (!strcmp(token, "dev")) + test_dev_userfaultfd = true; + else if (!strcmp(token, "syscall")) + test_dev_userfaultfd = false; + else + err("unrecognized test mod '%s'", token); + } + + if (!test_type) + err("failed to parse test type argument: '%s'", raw_type); if (test_type == TEST_HUGETLB) page_size = default_huge_page_size(); @@ -1653,7 +1704,7 @@ int main(int argc, char **argv) err("failed to arm SIGALRM"); alarm(ALARM_INTERVAL_SECS); - set_test_type(argv[1]); + parse_test_type_arg(argv[1]); nr_cpus = sysconf(_SC_NPROCESSORS_ONLN); nr_pages_per_cpu = atol(argv[2]) * 1024*1024 / page_size /