From patchwork Sat Apr 15 09:08:42 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lorenzo Stoakes X-Patchwork-Id: 13212342 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 27D71C7619A for ; Sat, 15 Apr 2023 09:08:50 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B633D6B007B; Sat, 15 Apr 2023 05:08:49 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B138C6B007D; Sat, 15 Apr 2023 05:08:49 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9DB276B007E; Sat, 15 Apr 2023 05:08:49 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 913C86B007B for ; Sat, 15 Apr 2023 05:08:49 -0400 (EDT) Received: from smtpin09.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 69DC51C5ACA for ; Sat, 15 Apr 2023 09:08:49 +0000 (UTC) X-FDA: 80683050378.09.EF4FF24 Received: from mail-wm1-f53.google.com (mail-wm1-f53.google.com [209.85.128.53]) by imf21.hostedemail.com (Postfix) with ESMTP id 8F2EB1C0002 for ; Sat, 15 Apr 2023 09:08:47 +0000 (UTC) Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=gmail.com header.s=20221208 header.b="b454/ADS"; spf=pass (imf21.hostedemail.com: domain of lstoakes@gmail.com designates 209.85.128.53 as permitted sender) smtp.mailfrom=lstoakes@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1681549727; 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-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=8GS8ed+C9TZSDKqE7yJs3rXmG1XU+tjMZxFV1EPCP0I=; b=upzHpuFdbbu8HHyyo0vsgEeGySWzY/jsZhn+I/inWkRF0639gKJ6h8zrq1/HlbhvRAAep+ QVrpIVBOx9lCPFVqJ3+x2rWvJZc//AHI135lj/lz68bxTDQxiUsLR0GeuKEwXUrDLk7aCA 1E9m6g4jMsvDlOaciCMy362gLUbUv3w= ARC-Authentication-Results: i=1; imf21.hostedemail.com; dkim=pass header.d=gmail.com header.s=20221208 header.b="b454/ADS"; spf=pass (imf21.hostedemail.com: domain of lstoakes@gmail.com designates 209.85.128.53 as permitted sender) smtp.mailfrom=lstoakes@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1681549727; a=rsa-sha256; cv=none; b=NPAU++hooLMu3PhFG7FRpxLBQUY9RSIjRMIR5WJYiM68jTZona1WQdjEi8m1mOl72kQola cN5VoC0tAUxz+JHwLANQe6FF3XOtR/m6k3XU7zd/kPuH2vQNSbBKcCUjpAe+ieNVTWURb4 UWqWANYobD9wC+S0NGGi9tWWDtII868= Received: by mail-wm1-f53.google.com with SMTP id q5so11439663wmo.4 for ; Sat, 15 Apr 2023 02:08:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1681549726; x=1684141726; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=8GS8ed+C9TZSDKqE7yJs3rXmG1XU+tjMZxFV1EPCP0I=; b=b454/ADSubR+UtZwD/vd9/bxU7eI6S5iNJ+h+0UiN9FgDora+ApBhUaT3SSlJPj557 Wr3AFdfbJaL+aizieInN5iM4WcDgKnRveo/2NyepsbPQmZF74KcuE7RuIOiyD6ggtXa6 ALOo/15uJ0W2QbV3lcS061wfIQnR61bEBb8pnD6aBXrCXX96Kdxx2HQDKFGkGZpb7EpW OmTyhghPGusO7/l9glNJkiPfr2rNIQjHZklmjuE1K1RDy4jndjREXz5eqSeEihKFhXsA LyQ/OMWU+Dr0qQaxFDPpttO2bKIZFUYKcoe8bc2bHU7zWvT8dbv3t9Daba//frSBg37T 2SgA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1681549726; x=1684141726; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=8GS8ed+C9TZSDKqE7yJs3rXmG1XU+tjMZxFV1EPCP0I=; b=iywVgFS+QFV5iSneTb3IneilSGo56qQR5Wg2LlXK5e/u8KQ7PxemWHk4uhu2gOUVGU Uiosd//P1a5fus+CKvAe70EqRWReG/KK3DIgLalD5mKP8lXTpYyQi/BZNJta5H7LvpaO Wskfe9aHI5LJ1/5HaZN7+KbtaC4YHDjzUQh/Hj6V9IPlVqacc7NIjBKmNJVn5TpaWby5 0nWRhsoWzgX2rRRpTC7FucSBXRFCBrR7qasTr0NFuxqwmD4Ya04rATWvMIPh6G62whvW yxKBL/GaLPpnrEsbFiAzWUwZEUqpyAPbTdbWa1YhB0Eu9/dIQwADdwtQH+Sq6qJ144eq ff3Q== X-Gm-Message-State: AAQBX9e4kDpbo2Z8bJ+1KXHf6lbnRp5CekaR6xbdON5dHPILoRCEjs8x ID1LDnuI6Fr89F+ehTSiB2DQUYHHYjcWeg== X-Google-Smtp-Source: AKy350aou3ekqdEv1AmYmuJIzUpY9augs9/NpgSD9Hdfv4oTmMl+FDy9Ovq+2DeTaldPP79lxq+pcg== X-Received: by 2002:a7b:c7c8:0:b0:3ed:b094:3c93 with SMTP id z8-20020a7bc7c8000000b003edb0943c93mr5887766wmk.23.1681549725732; Sat, 15 Apr 2023 02:08:45 -0700 (PDT) Received: from lucifer.home ([2a00:23c5:dc8c:8701:1663:9a35:5a7b:1d76]) by smtp.googlemail.com with ESMTPSA id c8-20020a05600c0a4800b003ee5fa61f45sm9990707wmq.3.2023.04.15.02.08.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 15 Apr 2023 02:08:45 -0700 (PDT) From: Lorenzo Stoakes To: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton Cc: Matthew Wilcox , David Hildenbrand , Jens Axboe , Pavel Begunkov , io-uring@vger.kernel.org, Lorenzo Stoakes Subject: [PATCH v2 5/7] io_uring: rsrc: use FOLL_SAME_FILE on pin_user_pages() Date: Sat, 15 Apr 2023 10:08:42 +0100 Message-Id: <362e96284273ef0781df0116b6491ce97b0fe073.1681547405.git.lstoakes@gmail.com> X-Mailer: git-send-email 2.40.0 In-Reply-To: References: MIME-Version: 1.0 X-Rspam-User: X-Rspamd-Server: rspam03 X-Stat-Signature: oj9k7zpeco1as4w7m9y4jwbaruqa5gtf X-Rspamd-Queue-Id: 8F2EB1C0002 X-HE-Tag: 1681549727-242143 X-HE-Meta: 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 MO+QrMN3 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 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: Commit edd478269640 ("io_uring/rsrc: disallow multi-source reg buffers") prevents io_pin_pages() from pinning pages spanning multiple VMAs with permitted characteristics (anon/huge), requiring that all VMAs share the same vm_file. The newly introduced FOLL_SAME_FILE flag permits this to be expressed as a GUP flag rather than having to retrieve VMAs to perform the check. We then only need to perform a VMA lookup for the first VMA to assert the anon/hugepage requirement as we know the rest of the VMAs will possess the same characteristics. Doing this eliminates the one instance of vmas being used by pin_user_pages(). Signed-off-by: Lorenzo Stoakes Suggested-by: Matthew Wilcox (Oracle) --- io_uring/rsrc.c | 39 ++++++++++++++++----------------------- 1 file changed, 16 insertions(+), 23 deletions(-) diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c index 7a43aed8e395..adc860bcbd4f 100644 --- a/io_uring/rsrc.c +++ b/io_uring/rsrc.c @@ -1141,9 +1141,8 @@ static int io_buffer_account_pin(struct io_ring_ctx *ctx, struct page **pages, struct page **io_pin_pages(unsigned long ubuf, unsigned long len, int *npages) { unsigned long start, end, nr_pages; - struct vm_area_struct **vmas = NULL; struct page **pages = NULL; - int i, pret, ret = -ENOMEM; + int pret, ret = -ENOMEM; end = (ubuf + len + PAGE_SIZE - 1) >> PAGE_SHIFT; start = ubuf >> PAGE_SHIFT; @@ -1153,31 +1152,26 @@ struct page **io_pin_pages(unsigned long ubuf, unsigned long len, int *npages) if (!pages) goto done; - vmas = kvmalloc_array(nr_pages, sizeof(struct vm_area_struct *), - GFP_KERNEL); - if (!vmas) - goto done; - ret = 0; mmap_read_lock(current->mm); - pret = pin_user_pages(ubuf, nr_pages, FOLL_WRITE | FOLL_LONGTERM, - pages, vmas); + + pret = pin_user_pages(ubuf, nr_pages, + FOLL_WRITE | FOLL_LONGTERM | FOLL_SAME_FILE, + pages, NULL); if (pret == nr_pages) { - struct file *file = vmas[0]->vm_file; + /* + * lookup the first VMA, we require that all VMAs in range + * maintain the same file characteristics, as enforced by + * FOLL_SAME_FILE + */ + struct vm_area_struct *vma = vma_lookup(current->mm, ubuf); + struct file *file; /* don't support file backed memory */ - for (i = 0; i < nr_pages; i++) { - if (vmas[i]->vm_file != file) { - ret = -EINVAL; - break; - } - if (!file) - continue; - if (!vma_is_shmem(vmas[i]) && !is_file_hugepages(file)) { - ret = -EOPNOTSUPP; - break; - } - } + file = vma->vm_file; + if (file && !vma_is_shmem(vma) && !is_file_hugepages(file)) + ret = -EOPNOTSUPP; + *npages = nr_pages; } else { ret = pret < 0 ? pret : -EFAULT; @@ -1194,7 +1188,6 @@ struct page **io_pin_pages(unsigned long ubuf, unsigned long len, int *npages) } ret = 0; done: - kvfree(vmas); if (ret < 0) { kvfree(pages); pages = ERR_PTR(ret);