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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CB9CFC25B07 for ; Thu, 11 Aug 2022 00:42:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231434AbiHKAmq (ORCPT ); Wed, 10 Aug 2022 20:42:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53778 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232964AbiHKAmp (ORCPT ); Wed, 10 Aug 2022 20:42:45 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E3112844CB for ; Wed, 10 Aug 2022 17:42:44 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 7EF71610AA for ; Thu, 11 Aug 2022 00:42:44 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D2B80C433D7; Thu, 11 Aug 2022 00:42:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1660178563; bh=J0fSgxG1Nn1Vardcnoc4vmXheQdwaiDzmhYuDE3BPJ4=; h=Date:To:From:Subject:From; b=BgzaQHCu3czTC2cgd+7xAsejvFfAtOdNotSrcghBNs7aVpHRS0uWS6shmvrtqBnwE CfLGir8PcxJWT5kcx4ppjh/YAGf71abHJtfHaXlvDa5H8MHQL2kg+Sycww3J2texks DMBFGBEp7dQSewBmqtvt75gwlbYyoa6z+ny+buJY= Date: Wed, 10 Aug 2022 17:42:43 -0700 To: mm-commits@vger.kernel.org, yi.zhang@huawei.com, viro@zeniv.linux.org.uk, vbabka@suse.cz, surenb@google.com, skhan@linuxfoundation.org, shuah@kernel.org, rppt@kernel.org, peterx@redhat.com, mike.kravetz@oracle.com, mgorman@techsingularity.net, ldv@altlinux.org, jack@suse.cz, hughd@google.com, glebfm@altlinux.org, dave.hansen@linux.intel.com, corbet@lwn.net, axelrasmussen@google.com, akpm@linux-foundation.org From: Andrew Morton Subject: + userfaultfd-selftests-modify-selftest-to-use-dev-userfaultfd.patch added to mm-unstable branch Message-Id: <20220811004243.D2B80C433D7@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: userfaultfd: selftests: modify selftest to use /dev/userfaultfd has been added to the -mm mm-unstable branch. Its filename is userfaultfd-selftests-modify-selftest-to-use-dev-userfaultfd.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/userfaultfd-selftests-modify-selftest-to-use-dev-userfaultfd.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Axel Rasmussen Subject: userfaultfd: selftests: modify selftest to use /dev/userfaultfd Date: Mon, 8 Aug 2022 10:56:12 -0700 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/ Link: https://lkml.kernel.org/r/20220808175614.3885028-4-axelrasmussen@google.com Signed-off-by: Axel Rasmussen Acked-by: Peter Xu Cc: Al Viro Cc: Dave Hansen Cc: Dmitry V. Levin Cc: Gleb Fotengauer-Malinovskiy Cc: Hugh Dickins Cc: Jan Kara Cc: Jonathan Corbet Cc: Mel Gorman Cc: Mike Kravetz Cc: Mike Rapoport Cc: Shuah Khan Cc: Shuah Khan Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Zhang Yi Signed-off-by: Andrew Morton --- tools/testing/selftests/vm/userfaultfd.c | 69 ++++++++++++++++++--- 1 file changed, 60 insertions(+), 9 deletions(-) --- a/tools/testing/selftests/vm/userfaultfd.c~userfaultfd-selftests-modify-selftest-to-use-dev-userfaultfd +++ a/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_prese } } +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(voi 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 *ty 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 / _ Patches currently in -mm which might be from axelrasmussen@google.com are selftests-vm-add-hugetlb_shared-userfaultfd-test-to-run_vmtestssh.patch userfaultfd-add-dev-userfaultfd-for-fine-grained-access-control.patch userfaultfd-selftests-modify-selftest-to-use-dev-userfaultfd.patch userfaultfd-update-documentation-to-describe-dev-userfaultfd.patch selftests-vm-add-dev-userfaultfd-test-cases-to-run_vmtestssh.patch