From patchwork Tue Sep 27 11:01:19 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 12990392 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 8B0D3C54EE9 for ; Tue, 27 Sep 2022 11:02:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231643AbiI0LC6 (ORCPT ); Tue, 27 Sep 2022 07:02:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53746 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231425AbiI0LCV (ORCPT ); Tue, 27 Sep 2022 07:02:21 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D4662D1E80 for ; Tue, 27 Sep 2022 04:01:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1664276507; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=a6ppzU8NrJ3mYSPxoJruC+SRfOuYeuv/ezC2v1fvuK4=; b=bCLMABtaJ2uUtZAl83P1n7Zq0P7fH4nAXMWHXaH/n4+1hiQEVje4XNjY/GCz06c7LTWmIS ynHGIgfksdRpb1z2YxBDEpdDR1VwimE8Xv58d3+ZSQ/fKv95G6CcEh2iZQnxSAggUx046Q O5oEbeNoQQJPak/WMdzLMavq52gUQWE= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-607-K67q5aYpPl6RfXIYoCfxYQ-1; Tue, 27 Sep 2022 07:01:45 -0400 X-MC-Unique: K67q5aYpPl6RfXIYoCfxYQ-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id DC6B63C01D86; Tue, 27 Sep 2022 11:01:44 +0000 (UTC) Received: from t480s.redhat.com (unknown [10.39.194.14]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2C77CC15E76; Tue, 27 Sep 2022 11:01:42 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, linux-kselftest@vger.kernel.org, David Hildenbrand , Andrew Morton , Shuah Khan , Jason Gunthorpe , John Hubbard , Nadav Amit , Peter Xu , Andrea Arcangeli , Vlastimil Babka , Mike Rapoport , Christoph von Recklinghausen , Don Dutile Subject: [PATCH v1 6/7] mm/gup_test: start/stop/read functionality for PIN LONGTERM test Date: Tue, 27 Sep 2022 13:01:19 +0200 Message-Id: <20220927110120.106906-7-david@redhat.com> In-Reply-To: <20220927110120.106906-1-david@redhat.com> References: <20220927110120.106906-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org We want an easy way to take a R/O or R/W longterm pin on a range and be able to observe the content of the pinned pages, so we can properly test how longterm puns interact with our COW logic. Signed-off-by: David Hildenbrand --- mm/gup_test.c | 140 ++++++++++++++++++++++++++++++++++++++++++++++++++ mm/gup_test.h | 12 +++++ 2 files changed, 152 insertions(+) diff --git a/mm/gup_test.c b/mm/gup_test.c index 12b0a91767d3..2bbfacd31f5a 100644 --- a/mm/gup_test.c +++ b/mm/gup_test.c @@ -203,6 +203,134 @@ static int __gup_test_ioctl(unsigned int cmd, return ret; } +static DEFINE_MUTEX(pin_longterm_test_mutex); +static struct page **pin_longterm_test_pages; +static unsigned long pin_longterm_test_nr_pages; + +static inline void pin_longterm_test_stop(void) +{ + if (pin_longterm_test_pages) { + if (pin_longterm_test_nr_pages) + unpin_user_pages(pin_longterm_test_pages, + pin_longterm_test_nr_pages); + kfree(pin_longterm_test_pages); + pin_longterm_test_pages = NULL; + pin_longterm_test_nr_pages = 0; + } +} + +static inline int pin_longterm_test_start(unsigned long arg) +{ + long nr_pages, cur_pages, addr, remaining_pages; + int gup_flags = FOLL_LONGTERM; + struct pin_longterm_test args; + struct page **pages; + int ret = 0; + bool fast; + + if (pin_longterm_test_pages) + return -EINVAL; + + if (copy_from_user(&args, (void __user *)arg, sizeof(args))) + return -EFAULT; + + if (args.flags & + ~(PIN_LONGTERM_TEST_FLAG_USE_WRITE|PIN_LONGTERM_TEST_FLAG_USE_FAST)) + return -EINVAL; + if (!IS_ALIGNED(args.addr | args.size, PAGE_SIZE)) + return -EINVAL; + if (args.size > LONG_MAX) + return -EINVAL; + nr_pages = args.size / PAGE_SIZE; + if (!nr_pages) + return -EINVAL; + + pages = kvcalloc(nr_pages, sizeof(void *), GFP_KERNEL); + if (!pages) + return -ENOMEM; + + if (args.flags & PIN_LONGTERM_TEST_FLAG_USE_WRITE) + gup_flags |= FOLL_WRITE; + fast = !!(args.flags & PIN_LONGTERM_TEST_FLAG_USE_FAST); + + if (!fast && mmap_read_lock_killable(current->mm)) { + kfree(pages); + return -EINTR; + } + + pin_longterm_test_pages = pages; + pin_longterm_test_nr_pages = 0; + + while (nr_pages - pin_longterm_test_nr_pages) { + remaining_pages = nr_pages - pin_longterm_test_nr_pages; + addr = args.addr + pin_longterm_test_nr_pages * PAGE_SIZE; + + if (fast) + cur_pages = pin_user_pages_fast(addr, remaining_pages, + gup_flags, pages); + else + cur_pages = pin_user_pages(addr, remaining_pages, + gup_flags, pages, NULL); + if (cur_pages < 0) { + pin_longterm_test_stop(); + ret = cur_pages; + break; + } + pin_longterm_test_nr_pages += cur_pages; + pages += cur_pages; + }; + + if (!fast) + mmap_read_unlock(current->mm); + return ret; +} + +static inline int pin_longterm_test_read(unsigned long arg) +{ + __u64 user_addr; + unsigned long i; + + if (!pin_longterm_test_pages) + return -EINVAL; + + if (copy_from_user(&user_addr, (void __user *)arg, sizeof(user_addr))) + return -EFAULT; + + for (i = 0; i < pin_longterm_test_nr_pages; i++) { + void *addr = page_to_virt(pin_longterm_test_pages[i]); + + if (copy_to_user((void __user *)user_addr, addr, PAGE_SIZE)) + return -EFAULT; + user_addr += PAGE_SIZE; + } + return 0; +} + +static long pin_longterm_test_ioctl(struct file *filep, unsigned int cmd, + unsigned long arg) +{ + int ret = -EINVAL; + + if (mutex_lock_killable(&pin_longterm_test_mutex)) + return -EINTR; + + switch (cmd) { + case PIN_LONGTERM_TEST_START: + ret = pin_longterm_test_start(arg); + break; + case PIN_LONGTERM_TEST_STOP: + pin_longterm_test_stop(); + ret = 0; + break; + case PIN_LONGTERM_TEST_READ: + ret = pin_longterm_test_read(arg); + break; + } + + mutex_unlock(&pin_longterm_test_mutex); + return ret; +} + static long gup_test_ioctl(struct file *filep, unsigned int cmd, unsigned long arg) { @@ -217,6 +345,10 @@ static long gup_test_ioctl(struct file *filep, unsigned int cmd, case PIN_BASIC_TEST: case DUMP_USER_PAGES_TEST: break; + case PIN_LONGTERM_TEST_START: + case PIN_LONGTERM_TEST_STOP: + case PIN_LONGTERM_TEST_READ: + return pin_longterm_test_ioctl(filep, cmd, arg); default: return -EINVAL; } @@ -234,9 +366,17 @@ static long gup_test_ioctl(struct file *filep, unsigned int cmd, return 0; } +static int gup_test_release(struct inode *inode, struct file *file) +{ + pin_longterm_test_stop(); + + return 0; +} + static const struct file_operations gup_test_fops = { .open = nonseekable_open, .unlocked_ioctl = gup_test_ioctl, + .release = gup_test_release, }; static int __init gup_test_init(void) diff --git a/mm/gup_test.h b/mm/gup_test.h index 887ac1d5f5bc..5b37b54e8bea 100644 --- a/mm/gup_test.h +++ b/mm/gup_test.h @@ -10,6 +10,9 @@ #define GUP_BASIC_TEST _IOWR('g', 4, struct gup_test) #define PIN_BASIC_TEST _IOWR('g', 5, struct gup_test) #define DUMP_USER_PAGES_TEST _IOWR('g', 6, struct gup_test) +#define PIN_LONGTERM_TEST_START _IOW('g', 7, struct pin_longterm_test) +#define PIN_LONGTERM_TEST_STOP _IO('g', 8) +#define PIN_LONGTERM_TEST_READ _IOW('g', 9, __u64) #define GUP_TEST_MAX_PAGES_TO_DUMP 8 @@ -30,4 +33,13 @@ struct gup_test { __u32 which_pages[GUP_TEST_MAX_PAGES_TO_DUMP]; }; +#define PIN_LONGTERM_TEST_FLAG_USE_WRITE 1 +#define PIN_LONGTERM_TEST_FLAG_USE_FAST 2 + +struct pin_longterm_test { + __u64 addr; + __u64 size; + __u32 flags; +}; + #endif /* __GUP_TEST_H */