From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELvY1UGUSVeDT4FhX2aJcg1qH5WtdS2+InjsP/sI1u8G+zlOCC+86XJMTJ9y+P4bo+rR/BH/ ARC-Seal: i=1; a=rsa-sha256; t=1520281898; cv=none; d=google.com; s=arc-20160816; b=jORwr+p+Z0QB+/GjlMEqOycTCKyXqgLiKmkjImp6z1UQjk1KewXKV3FbKSbnGRXrMT QhzsKVPNtStzcvLA7o1rYb66pvvSfyAytFBonXEeG0F56cafKSooM2+Lk3MsOtsNjMmA XhzHyGENzNaIqBLEdyvgh5Ye+xdSUOTrfEg7dMNLqv3gmyn93fVz6Hj6lUXQZU/7WLz0 xCMfb4ZcGc/l1gbnpjKzFnu9dCVONb9D05Q/0vt84lT1yhoaJEIN4zsxJ7Tc8vKnmPMm eF1RfDWJdB41i74sn57Q4VbbkjXr/Ri6y35pTuzh2wwaF1tksp38vB3/DOvjZZY3Y5yU JyLA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-language:content-transfer-encoding:in-reply-to:mime-version :user-agent:date:message-id:from:references:cc:to:subject :dkim-signature:delivered-to:list-id:list-subscribe:list-unsubscribe :list-help:list-post:precedence:mailing-list :arc-authentication-results; bh=VUrp/5iGo6Jn/cQLlgfCcg/sOhCebej0/Rk4FaO8zkU=; b=foWnAlooZEyfwokJNlqIRa+5zccVnAf7zLbrXch27zusDlyPSDcVXDWBTK9qk0UH9Q vk6kZg78yPnZiYVyfFCAKXU2Serlyg8WGXgJ+pHfAPnHKWw+R3SA4ByV8TptmIAjNjv+ WwTqjshr1FLVbwwDA3p281vt14kICmOKJGLAT01eaGk+qMsdLHuFnmKxhaigq9Q6Xlfe C89wbK0vYXZDY8FLJIA0Yph+RPVaMcWRLdnYhXT2KJWQjQO/RgDQy+xdztxJpR1P/eR3 IRAtltkuHifF4rjgfuXh1G2i0SsqepptNYhX5iXBOii0su1tbz1/R4Ifjrh6ZPb6sxC6 4m0A== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=iogGuQcV; spf=pass (google.com: domain of kernel-hardening-return-12125-gregkh=linuxfoundation.org@lists.openwall.com designates 195.42.179.200 as permitted sender) smtp.mailfrom=kernel-hardening-return-12125-gregkh=linuxfoundation.org@lists.openwall.com; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=iogGuQcV; spf=pass (google.com: domain of kernel-hardening-return-12125-gregkh=linuxfoundation.org@lists.openwall.com designates 195.42.179.200 as permitted sender) smtp.mailfrom=kernel-hardening-return-12125-gregkh=linuxfoundation.org@lists.openwall.com; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm List-Post: List-Help: List-Unsubscribe: List-Subscribe: Subject: Re: [PATCH 3/7] struct page: add field for vm_struct To: Igor Stoppa , 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 References: <20180228200620.30026-1-igor.stoppa@huawei.com> <20180228200620.30026-4-igor.stoppa@huawei.com> From: J Freyensee Message-ID: <2985e90a-5937-9432-c53e-f594b27e7afa@gmail.com> Date: Mon, 5 Mar 2018 12:31:14 -0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <20180228200620.30026-4-igor.stoppa@huawei.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1593676685422778336?= X-GMAIL-MSGID: =?utf-8?q?1594131111486443129?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: Reviewed-by: Jay Freyensee On 2/28/18 12:06 PM, Igor Stoppa wrote: > 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 | 2 ++ > 2 files changed, 3 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 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();