From patchwork Fri Apr 13 13:41:26 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Igor Stoppa X-Patchwork-Id: 10340091 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 5FF1C6039A for ; Fri, 13 Apr 2018 13:43:17 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5784F2883C for ; Fri, 13 Apr 2018 13:43:17 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4B9CA28845; Fri, 13 Apr 2018 13:43:17 +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 818022883C for ; Fri, 13 Apr 2018 13:43:16 +0000 (UTC) Received: (qmail 29741 invoked by uid 550); 13 Apr 2018 13:43:13 -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 28652 invoked from network); 13 Apr 2018 13:43:13 -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=iVVMelf7NkqFXe71Q4xmxixl1zp8a8xHufYCz0ERiVSwAjabV1EH+9+4hivzkWU9QL ypc3Zgc6NXV15/125d9MXR3JwGROT5vVjN2NM0ZbbZKXfPNxbcMSWeDUiRXLWRObX9yT uQtQI/UUOuyXval6s91W6Wg0VhRtgZAAqc3gLwqXi/BiUjeFGEVDtF2QmgIFnpIAbyGK Hvo4sfrpr/VL7xmgn1TzIQPF6x3RHlFeEQI9XNDxQrKHwnF1jRjFJOwl7Eb1buFIVtYM PqFgO8l+FhDyw6Sj/nZD8LesyL6UcdGRnge/xQiWj8ZRqnxOVlNv51k9juXRN41GIWql jonA== 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=VXajdFRcK0keoX2h66Cc4G5/7CYb59xYZgdd45r3WXCz9XLtjowUaZAQCThJ7Ekexk ta4Q07UM7nGRToBuEXmfUerQqppIK1xMrMMWqZPmb8NKf1p31t59cYWPp00F9GNZ+FkF RlnP0OqaOJwctbxvAAaQNY+Y7Q4fvRTmjH3WX0hrNR7ubqwf9R+4kiEvKDnjffv8zQtq XZBXp36B2ZruXLyoAYLmIC0gx2sr8SPRYFU+vh6psKoFAlU/00G4EqaQR7qQV6NebWIo rVOpkYZqk/dtuCXkU6EwuJXdvYlZb6zO9D2622I+fFOK+trP5U9Zmpxmf7fVkv5Havc6 ElEQ== X-Gm-Message-State: ALQs6tAd8cvkiL6TFMwNknHT/qN7bdZbxCvBIgnkTo97RtpYrrs9kLlJ 4bx+9JfhnTpjglfFbISCxDQ= X-Google-Smtp-Source: AIpwx49pzn3on7BJuSTd/qjxj/T0cgVir/Deq7afMXEPKiWVKwVI76Kh2/9oq4KIPqDt9W0ZJNFPMg== X-Received: by 10.46.65.210 with SMTP id d79mr3351001ljf.80.1523626982061; Fri, 13 Apr 2018 06:43:02 -0700 (PDT) From: Igor Stoppa X-Google-Original-From: Igor Stoppa To: willy@infradead.org, keescook@chromium.org, mhocko@kernel.org, corbet@lwn.net Cc: david@fromorbit.com, rppt@linux.vnet.ibm.com, labbott@redhat.com, linux-security-module@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-hardening@lists.openwall.com, Igor Stoppa Subject: [PATCH 1/6] struct page: add field for vm_struct Date: Fri, 13 Apr 2018 17:41:26 +0400 Message-Id: <20180413134131.4651-2-igor.stoppa@huawei.com> X-Mailer: git-send-email 2.14.1 In-Reply-To: <20180413134131.4651-1-igor.stoppa@huawei.com> References: <20180413134131.4651-1-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();