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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 2A357C28EB9 for ; Thu, 6 Jun 2019 22:52:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 020B62089E for ; Thu, 6 Jun 2019 22:52:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726976AbfFFWwy convert rfc822-to-8bit (ORCPT ); Thu, 6 Jun 2019 18:52:54 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58754 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726352AbfFFWwy (ORCPT ); Thu, 6 Jun 2019 18:52:54 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 0889F30821DF; Thu, 6 Jun 2019 22:52:54 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-120-173.rdu2.redhat.com [10.10.120.173]) by smtp.corp.redhat.com (Postfix) with ESMTP id B61CD78569; Thu, 6 Jun 2019 22:52:51 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: <20190606212140.GA25664@vmlxhi-102.adit-jv.com> References: <20190606212140.GA25664@vmlxhi-102.adit-jv.com> <155981411940.17513.7137844619951358374.stgit@warthog.procyon.org.uk> <155981421379.17513.13158528501056454772.stgit@warthog.procyon.org.uk> To: Eugeniu Rosca Cc: dhowells@redhat.com, viro@zeniv.linux.org.uk, raven@themaw.net, linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org, linux-block@vger.kernel.org, keyrings@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, Eugeniu Rosca Subject: Re: [PATCH 10/10] Add sample notification program [ver #3] MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <31574.1559861570.1@warthog.procyon.org.uk> Content-Transfer-Encoding: 8BIT Date: Thu, 06 Jun 2019 23:52:50 +0100 Message-ID: <31575.1559861570@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.47]); Thu, 06 Jun 2019 22:52:54 +0000 (UTC) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Eugeniu Rosca wrote: > How about arm64? Do you intend to enable cross-compilation? There's no guarantee that a cross-compiler can actually build userspace apps, though I haven't intended to encode anything against that in the Makefile. > > + asm ("lfence" : : : "memory" ); > [..] > > + asm("mfence" ::: "memory"); > > FWIW, trying to cross-compile it returned: > > aarch64-linux-gnu-gcc -I../../usr/include -I../../include watch_test.c -o watch_test > /tmp/ccDXYynm.s: Assembler messages: > /tmp/ccDXYynm.s:471: Error: unknown mnemonic `lfence' -- `lfence' > /tmp/ccDXYynm.s:568: Error: unknown mnemonic `mfence' -- `mfence' Yeah. I need to use C-standard __atomic_* stuff. David