From patchwork Mon Apr 23 12:54:50 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Igor Stoppa X-Patchwork-Id: 10356953 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 1BF2E60388 for ; Mon, 23 Apr 2018 12:55:49 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0D7ED28AAF for ; Mon, 23 Apr 2018 12:55:49 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 01F1828AB8; Mon, 23 Apr 2018 12:55:48 +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=-5.3 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, FREEMAIL_FROM, MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.wl.linuxfoundation.org (Postfix) with SMTP id 462A228AAF for ; Mon, 23 Apr 2018 12:55:47 +0000 (UTC) Received: (qmail 20208 invoked by uid 550); 23 Apr 2018 12:55:37 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Delivered-To: mailing list kernel-hardening@lists.openwall.com Received: (qmail 20090 invoked from network); 23 Apr 2018 12:55:36 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=EibkUN8IJIqpJJK5IsXHteb/ZHMrTxt39Z45b4pq1jo=; b=KJhnLgxcdc71VEgRlCyL1DzLax2CrXcGSX06TycgRNdYwO+tDzDeZyareQw39wvj33 JwLqk1V3f+GaSWd/Ar0/zjrAQGm/5sh8efVHpcSghAkgRcTieWceMMnxYyxBmgeFbvTZ +DtOe6WXFWFwPIGhIBKv172UV8x6osk18AEhzf0qbGfgEE5qb+O/9SwkZT7YeIuluyXR WN0lTj/6rO+rP9Lmg/USEJhZW0lqpUS8lZpdaYZrsYRdKTMFLuqzKZq8Sf+8pzDAJoMX 0ivPNN0/Dbof8vy0W+TNnUhR5K504PA7gx+Wf7kHZu7bVBI83Hn4b0IANmRWpltDSRaB Slig== 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; bh=EibkUN8IJIqpJJK5IsXHteb/ZHMrTxt39Z45b4pq1jo=; b=diUCqDOB9qmBrMq7MfdLLwtLfcCR5M03+5a/tq8RbKN8fIKRwd2wJjqaLquMkLr9gf ykoyqlzRnjWZ2rJCSinCmjjbNIh2nlj6YFvkt72/tfTrvRWbuRDWSpz5roabEhO20I1L 7o9QkZiBv47fg5MA4FpsJ9OAQxfdIyjDDAlx2KjGzoct97Hjj40xzpQbExKTaa2Z7oEU PAZcvSoHYqS3cvcnqHY8EulgEWg606RQbkLuKhE7gCuRFpxnzEl74Fi+AW0O1oQvF6NC bWCaGN1+LZqzL1G/g9VQ3JSA65iOVdwjbjORz0h0Wjz9xXKpqlusL2Z5Mkxi7jJyZJ1B 0c6w== X-Gm-Message-State: ALQs6tAJMA2WYrPcneNq3m+crr94Id1YRP4RAET2gMiQi+YINYP3nuQO VtsSVaIv8iIwg9Z+khwHycI= X-Google-Smtp-Source: AIpwx4/aYPCsXfmyA8sQnRau5JQ26ERBnGMvFinGBtUmCSMPUwEkkFF2kekM8l+RgwOD/Je6lE6gTg== X-Received: by 2002:a6b:5109:: with SMTP id f9-v6mr491505iob.192.1524488124179; Mon, 23 Apr 2018 05:55:24 -0700 (PDT) From: Igor Stoppa X-Google-Original-From: Igor Stoppa To: willy@infradead.org, keescook@chromium.org, paul@paul-moore.com, sds@tycho.nsa.gov, mhocko@kernel.org, corbet@lwn.net Cc: labbott@redhat.com, linux-cc=david@fromorbit.com, --cc=rppt@linux.vnet.ibm.com, --security-module@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-hardening@lists.openwall.com, igor.stoppa@gmail.com, Igor Stoppa Subject: [PATCH 1/9] struct page: add field for vm_struct Date: Mon, 23 Apr 2018 16:54:50 +0400 Message-Id: <20180423125458.5338-2-igor.stoppa@huawei.com> X-Mailer: git-send-email 2.14.1 In-Reply-To: <20180423125458.5338-1-igor.stoppa@huawei.com> References: <20180423125458.5338-1-igor.stoppa@huawei.com> X-Virus-Scanned: ClamAV using ClamSMTP When a page is used for virtual memory, it is often necessary to obtain a handler to the corresponding vm_struct, which refers to the virtually continuous area generated when invoking vmalloc. The struct page has a "mapping" field, which can be re-used, to store a pointer to the parent area. This will avoid more expensive searches, later on. Signed-off-by: Igor Stoppa Reviewed-by: Jay Freyensee Reviewed-by: Matthew Wilcox --- include/linux/mm_types.h | 1 + mm/vmalloc.c | 2 ++ 2 files changed, 3 insertions(+) diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 21612347d311..c74e2aa9a48b 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -86,6 +86,7 @@ struct page { void *s_mem; /* slab first object */ atomic_t compound_mapcount; /* first tail page */ /* page_deferred_list().next -- second tail page */ + struct vm_struct *area; }; /* Second double word */ diff --git a/mm/vmalloc.c b/mm/vmalloc.c index ebff729cc956..61a1ca22b0f6 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1536,6 +1536,7 @@ static void __vunmap(const void *addr, int deallocate_pages) struct page *page = area->pages[i]; BUG_ON(!page); + page->area = NULL; __free_pages(page, 0); } @@ -1705,6 +1706,7 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, area->nr_pages = i; goto fail; } + page->area = area; area->pages[i] = page; if (gfpflags_allow_blocking(gfp_mask|highmem_mask)) cond_resched();