From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f200.google.com (mail-wr0-f200.google.com [209.85.128.200]) by kanga.kvack.org (Postfix) with ESMTP id 235546B000C for ; Fri, 23 Feb 2018 09:50:35 -0500 (EST) Received: by mail-wr0-f200.google.com with SMTP id v16so5679791wrv.14 for ; Fri, 23 Feb 2018 06:50:35 -0800 (PST) Received: from huawei.com (lhrrgout.huawei.com. [194.213.3.17]) by mx.google.com with ESMTPS id v131si1391937wme.276.2018.02.23.06.50.33 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 23 Feb 2018 06:50:33 -0800 (PST) From: Igor Stoppa Subject: [PATCH 3/7] struct page: add field for vm_struct Date: Fri, 23 Feb 2018 16:48:03 +0200 Message-ID: <20180223144807.1180-4-igor.stoppa@huawei.com> In-Reply-To: <20180223144807.1180-1-igor.stoppa@huawei.com> References: <20180223144807.1180-1-igor.stoppa@huawei.com> MIME-Version: 1.0 Content-Type: text/plain Sender: owner-linux-mm@kvack.org List-ID: To: david@fromorbit.com, willy@infradead.org, keescook@chromium.org, mhocko@kernel.org Cc: 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 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 --- include/linux/mm_types.h | 1 + mm/vmalloc.c | 5 +++++ 2 files changed, 6 insertions(+) diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index fd1af6b9591d..c3a4825e10c0 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -84,6 +84,7 @@ 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 673942094328..14d99ed22397 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); } @@ -1744,6 +1745,7 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align, const void *caller) { struct vm_struct *area; + unsigned int i; void *addr; unsigned long real_size = size; @@ -1769,6 +1771,9 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align, kmemleak_vmalloc(area, size, gfp_mask); + for (i = 0; i < area->nr_pages; i++) + area->pages[i]->area = area; + return addr; fail: -- 2.14.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org