From patchwork Sat Jun 1 07:49:46 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 10971275 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C79461932 for ; Sat, 1 Jun 2019 07:51:50 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BD3CD28D23 for ; Sat, 1 Jun 2019 07:51:50 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B0DA728D34; Sat, 1 Jun 2019 07:51:50 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.7 required=2.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1A34528D49 for ; Sat, 1 Jun 2019 07:51:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726952AbfFAHuq (ORCPT ); Sat, 1 Jun 2019 03:50:46 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:50904 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726210AbfFAHup (ORCPT ); Sat, 1 Jun 2019 03:50:45 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From :Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=64aY9b4xFVCSoNTQbXTmr4fGKAtsk5F7+1Ma/JRJei4=; b=mkWRLr9J9mHC0wx40p7g15JOI9 MqOjScSPa9jeEaRm9X2mjxzwMKdjCd086mEGnPApg7IMDXb1c7CpovPAF6hXz2nMidmHuycA4jU0t uYlQ3KBMfUCPEMSbW9cc4MZnsg4vxER8u/iO/pt02EJS8C69A7HyF1u4YCsOwGF3WTfZVnDfmIvrY mjdmAE+SemqsVDC+nsAYctAGcsSTP2jyW9Tra0GOmnaRwgZjYuZsl6++JQlzm+y47NF8eU0MPkqi3 of1k7Chqe2bjQ8kairsqNJ+gtDw7yjrfcUA2WU5ac8yOVr2wiPgLS1f9WRR0fa69WyMUAbZ/uEtoY XAOpu9Dg==; Received: from 217-76-161-89.static.highway.a1.net ([217.76.161.89] helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1hWymL-0007l9-SJ; Sat, 01 Jun 2019 07:50:14 +0000 From: Christoph Hellwig To: Linus Torvalds , Paul Burton , James Hogan , Yoshinori Sato , Rich Felker , "David S. Miller" Cc: Nicholas Piggin , Khalid Aziz , Andrey Konovalov , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , linux-mips@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org, x86@kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 03/16] mm: simplify gup_fast_permitted Date: Sat, 1 Jun 2019 09:49:46 +0200 Message-Id: <20190601074959.14036-4-hch@lst.de> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190601074959.14036-1-hch@lst.de> References: <20190601074959.14036-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-sh-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sh@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Pass in the already calculated end value instead of recomputing it, and leave the end > start check in the callers instead of duplicating them in the arch code. Signed-off-by: Christoph Hellwig --- arch/s390/include/asm/pgtable.h | 8 +------- arch/x86/include/asm/pgtable_64.h | 8 +------- mm/gup.c | 17 +++++++---------- 3 files changed, 9 insertions(+), 24 deletions(-) diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h index 9f0195d5fa16..9b274fcaacb6 100644 --- a/arch/s390/include/asm/pgtable.h +++ b/arch/s390/include/asm/pgtable.h @@ -1270,14 +1270,8 @@ static inline pte_t *pte_offset(pmd_t *pmd, unsigned long address) #define pte_offset_map(pmd, address) pte_offset_kernel(pmd, address) #define pte_unmap(pte) do { } while (0) -static inline bool gup_fast_permitted(unsigned long start, int nr_pages) +static inline bool gup_fast_permitted(unsigned long start, unsigned long end) { - unsigned long len, end; - - len = (unsigned long) nr_pages << PAGE_SHIFT; - end = start + len; - if (end < start) - return false; return end <= current->mm->context.asce_limit; } #define gup_fast_permitted gup_fast_permitted diff --git a/arch/x86/include/asm/pgtable_64.h b/arch/x86/include/asm/pgtable_64.h index 0bb566315621..4990d26dfc73 100644 --- a/arch/x86/include/asm/pgtable_64.h +++ b/arch/x86/include/asm/pgtable_64.h @@ -259,14 +259,8 @@ extern void init_extra_mapping_uc(unsigned long phys, unsigned long size); extern void init_extra_mapping_wb(unsigned long phys, unsigned long size); #define gup_fast_permitted gup_fast_permitted -static inline bool gup_fast_permitted(unsigned long start, int nr_pages) +static inline bool gup_fast_permitted(unsigned long start, unsigned long end) { - unsigned long len, end; - - len = (unsigned long)nr_pages << PAGE_SHIFT; - end = start + len; - if (end < start) - return false; if (end >> __VIRTUAL_MASK_SHIFT) return false; return true; diff --git a/mm/gup.c b/mm/gup.c index 9775f7675653..e7566f5ff9cf 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -2122,13 +2122,9 @@ static void gup_pgd_range(unsigned long addr, unsigned long end, * Check if it's allowed to use __get_user_pages_fast() for the range, or * we need to fall back to the slow version: */ -bool gup_fast_permitted(unsigned long start, int nr_pages) +static bool gup_fast_permitted(unsigned long start, unsigned long end) { - unsigned long len, end; - - len = (unsigned long) nr_pages << PAGE_SHIFT; - end = start + len; - return end >= start; + return true; } #endif @@ -2149,6 +2145,8 @@ int __get_user_pages_fast(unsigned long start, int nr_pages, int write, len = (unsigned long) nr_pages << PAGE_SHIFT; end = start + len; + if (end < start) + return 0; if (unlikely(!access_ok((void __user *)start, len))) return 0; @@ -2164,7 +2162,7 @@ int __get_user_pages_fast(unsigned long start, int nr_pages, int write, * block IPIs that come from THPs splitting. */ - if (gup_fast_permitted(start, nr_pages)) { + if (gup_fast_permitted(start, end)) { local_irq_save(flags); gup_pgd_range(start, end, write ? FOLL_WRITE : 0, pages, &nr); local_irq_restore(flags); @@ -2223,13 +2221,12 @@ int get_user_pages_fast(unsigned long start, int nr_pages, len = (unsigned long) nr_pages << PAGE_SHIFT; end = start + len; - if (nr_pages <= 0) + if (end < start) return 0; - if (unlikely(!access_ok((void __user *)start, len))) return -EFAULT; - if (gup_fast_permitted(start, nr_pages)) { + if (gup_fast_permitted(start, end)) { local_irq_disable(); gup_pgd_range(addr, end, gup_flags, pages, &nr); local_irq_enable();