From patchwork Wed Dec 5 16:41:40 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steve Capper X-Patchwork-Id: 10714609 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 DCE57109C for ; Wed, 5 Dec 2018 16:42:28 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CCED02DE5C for ; Wed, 5 Dec 2018 16:42:28 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C15542DE5E; Wed, 5 Dec 2018 16:42:28 +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=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 45AD72DE5D for ; Wed, 5 Dec 2018 16:42:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=vKryr8D1u4tBORk82NfwB6l3ZTT0UuhIwwct71iNI4Q=; b=QklcOA1MA6x8qv gyq+lTKXe2kKe80Zdfu8QfZYW1oQ58C24k285vtakKItNn/icnp3yVx+da3eNB1IMqdOpzEHoVP/Y weQYdpt72m5rFbZqTTtcfq59NhWy08thll3+iMtBGmRcmQGIyUYheLhlyg6Q9yYA2pNM0f75Txyev zICcM+svsN6YAN8UKE0F/0mVBMRY5YhXGjm1y4HLrJrJx0anTasjbg3wg3SXCe/6GX/3wL8qV1mOE JOlDUZTLzAXwaKKL3GK+4UnbbJuWJvssKRL0SCBvaFKFexE0+7Reo6DDVw2EntYbc32WVRYXPak8T HJYihh4Jz1Ji2YtLLPjw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gUaFg-0000XM-89; Wed, 05 Dec 2018 16:42:20 +0000 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70] helo=foss.arm.com) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gUaFU-0000KZ-AG for linux-arm-kernel@lists.infradead.org; Wed, 05 Dec 2018 16:42:09 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 19F5315AD; Wed, 5 Dec 2018 08:42:00 -0800 (PST) Received: from capper-debian.emea.arm.com (C02R32KKFVH8.manchester.arm.com [10.32.102.139]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id A2EE03F5AF; Wed, 5 Dec 2018 08:41:58 -0800 (PST) From: Steve Capper To: linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH V4 1/6] mm: mmap: Allow for "high" userspace addresses Date: Wed, 5 Dec 2018 16:41:40 +0000 Message-Id: <20181205164145.24568-2-steve.capper@arm.com> X-Mailer: git-send-email 2.19.2 In-Reply-To: <20181205164145.24568-1-steve.capper@arm.com> References: <20181205164145.24568-1-steve.capper@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20181205_084208_395585_D9CEBB63 X-CRM114-Status: GOOD ( 16.60 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Steve Capper , catalin.marinas@arm.com, ard.biesheuvel@linaro.org, will.deacon@arm.com, jcm@redhat.com, Andrew Morton Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP This patch adds support for "high" userspace addresses that are optionally supported on the system and have to be requested via a hint mechanism ("high" addr parameter to mmap). Architectures such as powerpc and x86 achieve this by making changes to their architectural versions of arch_get_unmapped_* functions. However, on arm64 we use the generic versions of these functions. Rather than duplicate the generic arch_get_unmapped_* implementations for arm64, this patch instead introduces two architectural helper macros and applies them to arch_get_unmapped_*: arch_get_mmap_end(addr) - get mmap upper limit depending on addr hint arch_get_mmap_base(addr, base) - get mmap_base depending on addr hint If these macros are not defined in architectural code then they default to (TASK_SIZE) and (base) so should not introduce any behavioural changes to architectures that do not define them. Signed-off-by: Steve Capper Reviewed-by: Catalin Marinas Cc: Andrew Morton --- Changed in V4, added Catalin's reviewed by Changed in V3, commit log cleared up, explanation given for why core code change over just architectural change --- mm/mmap.c | 25 ++++++++++++++++++------- 1 file changed, 18 insertions(+), 7 deletions(-) diff --git a/mm/mmap.c b/mm/mmap.c index 6c04292e16a7..7bb64381e77c 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2066,6 +2066,15 @@ unsigned long unmapped_area_topdown(struct vm_unmapped_area_info *info) return gap_end; } + +#ifndef arch_get_mmap_end +#define arch_get_mmap_end(addr) (TASK_SIZE) +#endif + +#ifndef arch_get_mmap_base +#define arch_get_mmap_base(addr, base) (base) +#endif + /* Get an address range which is currently unmapped. * For shmat() with addr=0. * @@ -2085,8 +2094,9 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr, struct mm_struct *mm = current->mm; struct vm_area_struct *vma, *prev; struct vm_unmapped_area_info info; + const unsigned long mmap_end = arch_get_mmap_end(addr); - if (len > TASK_SIZE - mmap_min_addr) + if (len > mmap_end - mmap_min_addr) return -ENOMEM; if (flags & MAP_FIXED) @@ -2095,7 +2105,7 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr, if (addr) { addr = PAGE_ALIGN(addr); vma = find_vma_prev(mm, addr, &prev); - if (TASK_SIZE - len >= addr && addr >= mmap_min_addr && + if (mmap_end - len >= addr && addr >= mmap_min_addr && (!vma || addr + len <= vm_start_gap(vma)) && (!prev || addr >= vm_end_gap(prev))) return addr; @@ -2104,7 +2114,7 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr, info.flags = 0; info.length = len; info.low_limit = mm->mmap_base; - info.high_limit = TASK_SIZE; + info.high_limit = mmap_end; info.align_mask = 0; return vm_unmapped_area(&info); } @@ -2124,9 +2134,10 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, struct mm_struct *mm = current->mm; unsigned long addr = addr0; struct vm_unmapped_area_info info; + const unsigned long mmap_end = arch_get_mmap_end(addr); /* requested length too big for entire address space */ - if (len > TASK_SIZE - mmap_min_addr) + if (len > mmap_end - mmap_min_addr) return -ENOMEM; if (flags & MAP_FIXED) @@ -2136,7 +2147,7 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, if (addr) { addr = PAGE_ALIGN(addr); vma = find_vma_prev(mm, addr, &prev); - if (TASK_SIZE - len >= addr && addr >= mmap_min_addr && + if (mmap_end - len >= addr && addr >= mmap_min_addr && (!vma || addr + len <= vm_start_gap(vma)) && (!prev || addr >= vm_end_gap(prev))) return addr; @@ -2145,7 +2156,7 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, info.flags = VM_UNMAPPED_AREA_TOPDOWN; info.length = len; info.low_limit = max(PAGE_SIZE, mmap_min_addr); - info.high_limit = mm->mmap_base; + info.high_limit = arch_get_mmap_base(addr, mm->mmap_base); info.align_mask = 0; addr = vm_unmapped_area(&info); @@ -2159,7 +2170,7 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, VM_BUG_ON(addr != -ENOMEM); info.flags = 0; info.low_limit = TASK_UNMAPPED_BASE; - info.high_limit = TASK_SIZE; + info.high_limit = mmap_end; addr = vm_unmapped_area(&info); }