From patchwork Thu Sep 14 15:26:13 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Suren Baghdasaryan X-Patchwork-Id: 13385619 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 C923DEEAA51 for ; Thu, 14 Sep 2023 15:26:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240986AbjINP0i (ORCPT ); Thu, 14 Sep 2023 11:26:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38350 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240965AbjINP0g (ORCPT ); Thu, 14 Sep 2023 11:26:36 -0400 Received: from mail-yw1-x1149.google.com (mail-yw1-x1149.google.com [IPv6:2607:f8b0:4864:20::1149]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 474481FD2 for ; Thu, 14 Sep 2023 08:26:32 -0700 (PDT) Received: by mail-yw1-x1149.google.com with SMTP id 00721157ae682-59b50b45481so14798677b3.1 for ; Thu, 14 Sep 2023 08:26:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1694705191; x=1695309991; 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=Mu1OGPWARKH9oRMfZEcpV5n3maR0zmAnXssCvh8qI9k=; b=SQb9k5tA0qUyySqshNePRlA2p9ujS673L82mvo09YoCVxby0xVIUm5s7+SMYhOtZ9A pK5ysDa0CNM2+droM8gynPxphCozcpPc5IdaWiv7cA+OzlpTWtCGtLnzGgvU731lViZD BngPn/oDOhVXmnlsAZig2adWy1yhmgZFDaxGVk6CAAKqNKWM3cdZ2uHvZTTFXWOzegMJ vMvxyy8fePM9Dh17fjO6ElbOj133csNcqM7y/6OHzGEt4OxXdeGL7sQg4gMzXsMkOMS6 FICqishDIl3hRUTyb1Z3+pmYFuRzrv1epRYSeQfJfepZ/QbLljY8Vcoq2J6961CHhrK2 E3OA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1694705191; x=1695309991; 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=Mu1OGPWARKH9oRMfZEcpV5n3maR0zmAnXssCvh8qI9k=; b=veaE+OIGfI/CLk8558XDUFca6PCU6fscAIxmF0SmEjBq7Hz8fYByQRMxrX0nKs/oNX rnxs0juKYiIKK0RXwCu/0iUnS3tigAs36HioenkdF1cmN2MDdHGQ2Eteih/Ht4ST+m78 BJ4bILmcqPh0A2cvH9drLcYLdGaDYNeHtqxxNlIZA5ALp8NJVhidaeVucF+1maN6D772 tUPEHUX+xK5X7vFfuaXfAMEwBV5xadaxkmdRR7QPjwlrY376pCe6N0DcnQb9uWRfg9jC 0N2RHoYwuQj22VV55A9UFlByorRoyIEmsnAwHn1JNnOtoybWLWbxq/qAn94DCeq+BY1W 0raA== X-Gm-Message-State: AOJu0YzhYVLFYfCCMHJNzpn2kdLFi5p/Rehboxas33lAd3GXJemucYtn Zt4UYgsY0E5QiMPitn6ufGP5W9Dh4CE= X-Google-Smtp-Source: AGHT+IFBVegGxf80f6tK8JTRTL2eDdZPWBJrMSOMFpp88sQURTGOGeLIWNKbAvxE88xxjjHdcadvLmZLUmU= X-Received: from surenb-desktop.mtv.corp.google.com ([2620:15c:211:201:405c:ba64:810f:5fee]) (user=surenb job=sendgmr) by 2002:a81:c94b:0:b0:59b:ba8a:97d0 with SMTP id c11-20020a81c94b000000b0059bba8a97d0mr154662ywl.3.1694705191508; Thu, 14 Sep 2023 08:26:31 -0700 (PDT) Date: Thu, 14 Sep 2023 08:26:13 -0700 In-Reply-To: <20230914152620.2743033-1-surenb@google.com> Mime-Version: 1.0 References: <20230914152620.2743033-1-surenb@google.com> X-Mailer: git-send-email 2.42.0.283.g2d96d420d3-goog Message-ID: <20230914152620.2743033-4-surenb@google.com> Subject: [PATCH 3/3] selftests/mm: add UFFDIO_REMAP 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_REMAP ioctl which uses uffd to remaps 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 | 34 ++++++++++- tools/testing/selftests/mm/uffd-common.h | 1 + tools/testing/selftests/mm/uffd-unit-tests.c | 62 ++++++++++++++++++++ 3 files changed, 95 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/mm/uffd-common.c b/tools/testing/selftests/mm/uffd-common.c index 02b89860e193..fb449abc46e2 100644 --- a/tools/testing/selftests/mm/uffd-common.c +++ b/tools/testing/selftests/mm/uffd-common.c @@ -484,8 +484,14 @@ 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_REMAP is supported for anon non-shared mappings. */ + if (uffd_test_ops == &anon_uffd_test_ops && !map_shared) { + if (remap_page(uffd, offset)) + args->missing_faults++; + } else { + if (copy_page(uffd, offset, args->apply_wp)) + args->missing_faults++; + } } } @@ -620,6 +626,30 @@ int copy_page(int ufd, unsigned long offset, bool wp) return __copy_page(ufd, offset, false, wp); } +int remap_page(int ufd, unsigned long offset) +{ + struct uffdio_remap uffdio_remap; + + if (offset >= nr_pages * page_size) + err("unexpected offset %lu\n", offset); + uffdio_remap.dst = (unsigned long) area_dst + offset; + uffdio_remap.src = (unsigned long) area_src + offset; + uffdio_remap.len = page_size; + uffdio_remap.mode = UFFDIO_REMAP_MODE_ALLOW_SRC_HOLES; + uffdio_remap.remap = 0; + if (ioctl(ufd, UFFDIO_REMAP, &uffdio_remap)) { + /* real retval in uffdio_remap.remap */ + if (uffdio_remap.remap != -EEXIST) + err("UFFDIO_REMAP error: %"PRId64, + (int64_t)uffdio_remap.remap); + wake_range(ufd, uffdio_remap.dst, page_size); + } else if (uffdio_remap.remap != page_size) { + err("UFFDIO_REMAP error: %"PRId64, (int64_t)uffdio_remap.remap); + } 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..2bbb15d1920c 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 remap_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..a33819639187 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_remap_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 remap 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 = "remap", + .uffd_fn = uffd_remap_test, + .mem_targets = MEM_ANON, + .uffd_feature_required = 0, + }, { .name = "wp-fork", .uffd_fn = uffd_wp_fork_test,