From patchwork Tue Sep 15 12:59:47 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Muchun Song X-Patchwork-Id: 11778481 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D38DD139F for ; Wed, 16 Sep 2020 00:40:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B521B2080C for ; Wed, 16 Sep 2020 00:40:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=bytedance-com.20150623.gappssmtp.com header.i=@bytedance-com.20150623.gappssmtp.com header.b="UCioyFq/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726781AbgIPAjv (ORCPT ); Tue, 15 Sep 2020 20:39:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48632 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726535AbgIONEs (ORCPT ); Tue, 15 Sep 2020 09:04:48 -0400 Received: from mail-pj1-x1043.google.com (mail-pj1-x1043.google.com [IPv6:2607:f8b0:4864:20::1043]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B92B0C061356 for ; Tue, 15 Sep 2020 06:04:03 -0700 (PDT) Received: by mail-pj1-x1043.google.com with SMTP id s14so2692277pju.1 for ; Tue, 15 Sep 2020 06:04:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=jiL3ii4AJU2Njj/y/vFrTYFZ6QNs3Srg45f1FwlIOSw=; b=UCioyFq/nMf2pfW7YzyCEcx4LL4/jL1jJUkht2xjt+BMHebuzK/UKImXusybczC6tr hTRa9/L+br3pbdNipbSH20dV6etCd7/zplLBClKqkOe4p99jl807aGZocuBegTAKWegT qW2M0vOxaqwVOFS01ltZ94MXkaAN3yu7UcDSaUKd6lyuAbXXcRx6JaBNLO4WCBHrONrQ mI/sHDT9Q2NI5W8AOCu7XWmJSS7/IKrSpKT5OJnmwubKGNTLD2TMr7GFNW3wXS1xr9xB kQBgwh1xu2xzg1c75B4nGCznnkOnVs7OKDaGcFSPjqv8srW2nRfVyrrMT3OMOu6XNeyH 5Zqw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=jiL3ii4AJU2Njj/y/vFrTYFZ6QNs3Srg45f1FwlIOSw=; b=o9LHq8C+WqkxowBczt57vwGFkrMgdFsB2dmpufsltXXGFLGbLFQKXQgvTbnNG5pzn9 vFgk8c301IYbEGpjHoBKBcfqPXTqzbi0IU422SgqzjdxRnoJjAAPdYRgblNojIetx5yh kOS5Cxz/+fp0ehGqLt6eIZ9G2lOcQ38YKW4NWDhCmHl2ovj0sjKngRTKIqtyYcrg5Sjx f05i0zJixBvd6JmxxOGCCq2LmQePrTPpmGDXEGHW4kaCMu77NOhukfgHUdpY34L8rJli Sy1ZBEf9vUFE9s/A3yqb4H7c5pl14h8qYRJwLtD4pBV44wUMby4+aceD2LOWO2SzTbSg s8IQ== X-Gm-Message-State: AOAM531Tm/KGp6tdtgcWdg4UUW/Ljx9SXWhD74KzaMP7yZGBR47GeKMb S4YdJJx+F3Hj1lcgebCsInMqZQ== X-Google-Smtp-Source: ABdhPJzDjZ5u/kFp3j7KzOYJwm3WjE591cWhOwkG8OQSFmLJnogu52u+8IhXbjfuzBZdoCwfGeOYwQ== X-Received: by 2002:a17:902:9887:b029:d1:e626:788d with SMTP id s7-20020a1709029887b02900d1e626788dmr1206774plp.53.1600175043242; Tue, 15 Sep 2020 06:04:03 -0700 (PDT) Received: from localhost.bytedance.net ([103.136.220.66]) by smtp.gmail.com with ESMTPSA id w185sm14269855pfc.36.2020.09.15.06.03.54 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 15 Sep 2020 06:04:02 -0700 (PDT) From: Muchun Song To: corbet@lwn.net, mike.kravetz@oracle.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, viro@zeniv.linux.org.uk, akpm@linux-foundation.org, paulmck@kernel.org, mchehab+huawei@kernel.org, pawan.kumar.gupta@linux.intel.com, rdunlap@infradead.org, oneukum@suse.com, anshuman.khandual@arm.com, jroedel@suse.de, almasrymina@google.com, rientjes@google.com Cc: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Muchun Song Subject: [RFC PATCH 24/24] mm/hugetlb: Add BUILD_BUG_ON to catch invalid usage of tail struct page Date: Tue, 15 Sep 2020 20:59:47 +0800 Message-Id: <20200915125947.26204-25-songmuchun@bytedance.com> X-Mailer: git-send-email 2.21.0 (Apple Git-122) In-Reply-To: <20200915125947.26204-1-songmuchun@bytedance.com> References: <20200915125947.26204-1-songmuchun@bytedance.com> MIME-Version: 1.0 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org There are only `RESERVE_VMEMMAP_SIZE / sizeof(struct page)` struct pages can be used when CONFIG_HUGETLB_PAGE_FREE_VMEMMAP, so add a BUILD_BUG_ON to catch this invalid usage of tail struct page. Signed-off-by: Muchun Song --- mm/hugetlb.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index e66c3f10c583..63995ba74b6b 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -3994,6 +3994,8 @@ static int __init hugetlb_init(void) #ifdef CONFIG_HUGETLB_PAGE_FREE_VMEMMAP BUILD_BUG_ON_NOT_POWER_OF_2(sizeof(struct page)); + BUILD_BUG_ON(NR_USED_SUBPAGE >= + RESERVE_VMEMMAP_SIZE / sizeof(struct page)); #endif if (!hugepages_supported()) {