From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.1 required=3.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID, USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DA676C433F5 for ; Thu, 6 Sep 2018 09:01:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8775D2077C for ; Thu, 6 Sep 2018 09:01:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="hCOxYuzc" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8775D2077C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728139AbeIFNgX (ORCPT ); Thu, 6 Sep 2018 09:36:23 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:50566 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727629AbeIFNgX (ORCPT ); Thu, 6 Sep 2018 09:36:23 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=CxURDXOJ/bVBK6vwIiHDWdbFBP5azd04fxM73FjDmWM=; b=hCOxYuzc+VXxzxJhst7nzr0gZ 9RrO+Ym9tGR7Z8Yv7eQ+UEI+TqgpSNdjZRcEtgVUcefy+S6/1ClDeDH7jMkCPI8Fq4yhjZe+ZiPpk Pk2LFaw6Qm/vvYmsNYPYypnSK08jy76Jn38rQDMgFN1lYTPTIEt+yGtodkhu2nUp65G0mQCMT4/l6 vcsQaLbfv9KzdDBYUJLW625K5DPI3XVb54fQ0ffURNJAEMudvTcb4P7ko9hDn79EUsbI3vBcGRgfq Fkwpzx2m1yD7intMdcdYVt3F/FdB1TI2n+7Q6wfbNUab8gFlGgBicyGCb6TICkifJIu/b7F1HeZs5 rxEo9bD0w==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1fxqAa-00033G-Er; Thu, 06 Sep 2018 09:01:44 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id C285D20210309; Thu, 6 Sep 2018 11:01:42 +0200 (CEST) Date: Thu, 6 Sep 2018 11:01:42 +0200 From: Peter Zijlstra To: Nadav Amit Cc: Thomas Gleixner , linux-kernel@vger.kernel.org, Ingo Molnar , x86@kernel.org, Arnd Bergmann , linux-arch@vger.kernel.org, Dave Hansen , Nadav Amit , Kees Cook , Dave Hansen Subject: Re: [PATCH v2 4/6] x86/alternatives: initializing temporary mm for patching Message-ID: <20180906090142.GG24082@hirez.programming.kicks-ass.net> References: <20180902173224.30606-1-namit@vmware.com> <20180902173224.30606-5-namit@vmware.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180902173224.30606-5-namit@vmware.com> User-Agent: Mutt/1.10.0 (2018-05-17) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Sep 02, 2018 at 10:32:22AM -0700, Nadav Amit wrote: > +void __init poking_init(void) > +{ > + unsigned long poking_addr; > + > + poking_mm = copy_init_mm(); > + if (!poking_mm) { > + pr_err("x86/mm: error setting a separate poking address space"); > + return; > + } > + > + /* > + * Randomize the poking address, but make sure that the following page > + * will be mapped at the same PMD. We need 2 pages, so find space for 3, > + * and adjust the address if the PMD ends after the first one. > + */ > + poking_addr = TASK_UNMAPPED_BASE + > + (kaslr_get_random_long("Poking") & PAGE_MASK) % > + (TASK_SIZE - TASK_UNMAPPED_BASE - 3 * PAGE_SIZE); > + > + if (((poking_addr + PAGE_SIZE) & ~PMD_MASK) == 0) > + poking_addr += PAGE_SIZE; > +} This fails to compile for me.. I don't have kaslr_get_random_long().