From patchwork Mon Aug 8 17:56:12 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Axel Rasmussen X-Patchwork-Id: 12938955 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 0406CC25B0D for ; Mon, 8 Aug 2022 17:56:30 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 919E58E0002; Mon, 8 Aug 2022 13:56:29 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8A1DB6B0075; Mon, 8 Aug 2022 13:56:29 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 743248E0002; Mon, 8 Aug 2022 13:56:29 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 63F086B0074 for ; Mon, 8 Aug 2022 13:56:29 -0400 (EDT) Received: from smtpin10.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id 412421A015A for ; Mon, 8 Aug 2022 17:56:29 +0000 (UTC) X-FDA: 79777180098.10.CF40CFD Received: from mail-yb1-f202.google.com (mail-yb1-f202.google.com [209.85.219.202]) by imf07.hostedemail.com (Postfix) with ESMTP id D48D240024 for ; Mon, 8 Aug 2022 17:56:28 +0000 (UTC) Received: by mail-yb1-f202.google.com with SMTP id y81-20020a253254000000b0067ba548d2a1so6308309yby.15 for ; Mon, 08 Aug 2022 10:56:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:references:mime-version:message-id:in-reply-to :date:from:to:cc; bh=XlgksS8fZomBMU6we0kRE5nSjV4DtoPIEs0s8v9e0Dk=; b=eV0w1ZYN780esWshwM0oQr+SMcM8X1ftPquQabqMDvmezQ0q1z2xKHKgDWX/yxeqc9 ozDUd669ncenrTTXZiSADu6HOBVVJ+hx8n1kxLTCTk97Omymh2R56EtzHiXWQ3aIW+KD 2k+KoHq5nBWEX8hgoiES2yl9f43ytrPEVoREK3tGhoY+w4usvBXzAtAleOgBr3FUZsMb 0saV5Fro8js0s6kRVa6wN3HVgaDKhirXO5QWULIWfIxTIArpnf/9nyn9MCvTUeL8rugB 1p612BVnCnDJF6UB4CkcsJiydss3klalfiJWZvzpzEhQL4Bzg78G9g9gN0FyVHuS5cTI CRcA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:references:mime-version:message-id:in-reply-to :date:x-gm-message-state:from:to:cc; bh=XlgksS8fZomBMU6we0kRE5nSjV4DtoPIEs0s8v9e0Dk=; b=jV1pMXc3D+HAeF1Xmh722EU30QGD05m83tc9ekFaWPxMO1W/YH5ByAdbjlpvnQMJWh ZcR9pfIiOdpFDR/0UtKZG2ncyjAjTQrPUPvOcyvOtQUyrqSy7KVP6XBYYKgjzLsG7jKP wYhb7OAFnSIKQhIbbBaGvAvTYnL/dB4xr0uSjR68GRaNXrvp6Be34G9lbuRhtFMjHmiD 83Hl4O83tRn1Ap26aE8TnbLH6+1xS5yO6LJV8aKlBlHfalR/K9fsDMlDcpen2xobrX1l jn+GumKyy/bF5+osEktezMSc92wgQeKR3r5IgHiRrEUI4RGHd7k8/PthZRN568Q3A4YI qb7Q== X-Gm-Message-State: ACgBeo1BSuFdffbmrJDVXHSr8njBVsKZdYUwBM4w0AZOcFGCVJpF84TP pHOX3RQ1ZLpIXjeznYWxkrD5DrK2oTXbR9NIlN6L X-Google-Smtp-Source: AA6agR6npeg0ptcuEpFjsffo8RCXbkNDOrCByOZCObVgrDxj7LPO76dCYQ9ymRjDrk6K+87ZEVPO8jVWMLgS4Kj7TBeU X-Received: from ajr0.svl.corp.google.com ([2620:15c:2d4:203:7a2a:3bb5:f3a0:3bbc]) (user=axelrasmussen job=sendgmr) by 2002:a25:3b4e:0:b0:67a:85fd:f24f with SMTP id i75-20020a253b4e000000b0067a85fdf24fmr16477068yba.51.1659981388099; Mon, 08 Aug 2022 10:56:28 -0700 (PDT) Date: Mon, 8 Aug 2022 10:56:12 -0700 In-Reply-To: <20220808175614.3885028-1-axelrasmussen@google.com> Message-Id: <20220808175614.3885028-4-axelrasmussen@google.com> Mime-Version: 1.0 References: <20220808175614.3885028-1-axelrasmussen@google.com> X-Mailer: git-send-email 2.37.1.559.g78731f0fdb-goog Subject: [PATCH v5 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-kselftest@vger.kernel.org, linux-mm@kvack.org, linux-security-module@vger.kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1659981388; a=rsa-sha256; cv=none; b=5XPjRvNEk86jbcb5+JKE+4/LI3tuWs8mRNuGyBpC6MbWwvk1kWEYV+MyJ3lW0L32iUAohx SmJq4SZM+YfzGfdtIg639eZaAlXRLoIZGFkpP65xBs4dk4LVK5rWpVQnm6Wai5tIcGtmPt WdLHS2lTKKWGuNQNnUDUnffw/tTnoPg= ARC-Authentication-Results: i=1; imf07.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=eV0w1ZYN; spf=pass (imf07.hostedemail.com: domain of 3TE7xYg0KCMsrEv28r93B99v4x55x2v.t532z4BE-331Crt1.58x@flex--axelrasmussen.bounces.google.com designates 209.85.219.202 as permitted sender) smtp.mailfrom=3TE7xYg0KCMsrEv28r93B99v4x55x2v.t532z4BE-331Crt1.58x@flex--axelrasmussen.bounces.google.com; dmarc=pass (policy=reject) header.from=google.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1659981388; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=XlgksS8fZomBMU6we0kRE5nSjV4DtoPIEs0s8v9e0Dk=; b=j4LRKCTEH0O3GrwCYc3B7iss0xUc7vceIcXP4HrHdClby40W+Xye9Uhf/FzZdG3KMqt9tD +f4Fdxt86m+JWuMN5177BH5bHb8YF8JAdN9GXEigKoyimZW+NG3cSkKijGO4tTvN0sb/lE 16clmUzh7tUhfKftLbCd1FePILOOTjs= X-Rspamd-Server: rspam06 X-Rspam-User: X-Stat-Signature: c8ojsjy98qkt1djntp4gxyx9rr86zkik X-Rspamd-Queue-Id: D48D240024 Authentication-Results: imf07.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=eV0w1ZYN; spf=pass (imf07.hostedemail.com: domain of 3TE7xYg0KCMsrEv28r93B99v4x55x2v.t532z4BE-331Crt1.58x@flex--axelrasmussen.bounces.google.com designates 209.85.219.202 as permitted sender) smtp.mailfrom=3TE7xYg0KCMsrEv28r93B99v4x55x2v.t532z4BE-331Crt1.58x@flex--axelrasmussen.bounces.google.com; dmarc=pass (policy=reject) header.from=google.com X-HE-Tag: 1659981388-680564 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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/ Acked-by: Peter Xu Signed-off-by: Axel Rasmussen Acked-by: Mike Rapoport --- 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 7c3f1b0ab468..cae72867c173 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 /