Received: by 2002:ac0:a582:0:0:0:0:0 with SMTP id m2-v6csp2370027imm; Sat, 13 Oct 2018 17:11:58 -0700 (PDT) X-Google-Smtp-Source: ACcGV60AdDNthxvxENY1i4zKBGbR4Nc8WN/drP/XsoO998U2sOFLBF8JO2kryAMakX4QPpBYRHCV X-Received: by 2002:a63:5922:: with SMTP id n34-v6mr10936970pgb.134.1539475918177; Sat, 13 Oct 2018 17:11:58 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1539475918; cv=none; d=google.com; s=arc-20160816; b=g6+Afk2e4ve+W1aSCw+aS47DIrUYqdvmMLEGJR9M87P9YY9KmhNSZQUugHQPWUTFqX 6BO7KWesqTb1m8BNJaN/c+PQUzC1nWqiS1O755E3qGOhufbj3oyUSbIGbLlFIJiie/11 l67tqbsAFN9wbEvunCARGp/Buw2wJxngqSv2V1CVX62tQaHhDWfSLjtfkyH/fpgWhUwC +iNnzUJ1GRxwEzqOBfEzVgWd6p0EQa6UUDjrDieTRDwvuPlzRPGCdQChg3EaAeyMZqz5 nKKhGe6hRfriSujvKiM2phgtbjKopo90ge6oZZagbwxnLAjhLTX73ddwqOnZWXUG3723 LTkw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-disposition:mime-version:references:message-id:subject:cc :to:from:date; bh=rFDmUqwYDztIZ6TXXkCw3xqr1h85NZkB1ZFmu68uxLE=; b=pjAUYvpMngUU14Ps7T8z6POB34PKHB7m8v0yoWX0Zup+Bg17Bpa+TY2SQWzw/47+YI +fw2+XlZ1SsvqT6e8zoGGLw4YPWgdidAgXxHl0OX5unyNz++DLfNQxas8XNFkgJQBxzK ifr9XetkD/71nbKiT9RoucopQdXEPS+zth+hnSQ26379LAWoG7qjLhYz2yPYTaw0pAfF dW8WNZVZBwYut8pC44mLccBf1mgjInwFynpBYR+f+XF4fHOgWY3NInfy/qNmFD7tF8H3 9xZ/Z1Pz6RcHlvuoTTLrVDW1EGPW/R9kWFYC6lrJs6i1GLfiKoaw3S/bRJ9enmRIsUSf DD9A== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=redhat.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id h8-v6si5914449pgj.352.2018.10.13.17.11.43; Sat, 13 Oct 2018 17:11:58 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=redhat.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726400AbeJNHuE (ORCPT + 99 others); Sun, 14 Oct 2018 03:50:04 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48358 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726042AbeJNHuD (ORCPT ); Sun, 14 Oct 2018 03:50:03 -0400 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 77C5EC05D3FF; Sun, 14 Oct 2018 00:11:06 +0000 (UTC) Received: from asgard.redhat.com (ovpn-200-28.brq.redhat.com [10.40.200.28]) by smtp.corp.redhat.com (Postfix) with ESMTPS id E93F95EB18; Sun, 14 Oct 2018 00:11:04 +0000 (UTC) Date: Sun, 14 Oct 2018 02:11:26 +0200 From: Eugene Syromiatnikov To: tbhardwa@codeaurora.org Cc: "'Zhang, Ning A'" , linux-kernel@vger.kernel.org, linux-media@vger.kernel.org Subject: Re: question about V4L2_MEMORY_USERPTR on 64bit applications Message-ID: <20181014001126.GA717@asgard.redhat.com> References: <1539313441.21249.3.camel@intel.com> <1539318782.21249.7.camel@intel.com> <000601d461eb$a1f7afc0$e5e70f40$@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <000601d461eb$a1f7afc0$e5e70f40$@codeaurora.org> User-Agent: Mutt/1.5.23 (2014-03-12) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Sun, 14 Oct 2018 00:11:06 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Oct 12, 2018 at 10:52:51AM +0530, tbhardwa@codeaurora.org wrote: > (in 64 bit userspace long is 32-bit) Not on Linux. $ cat /tmp/c.c int main(void) { return sizeof(long); } $ gcc /tmp/c.c $ ./a.out; echo $? 8 $ file ./a.out ./a.out: ELF 64-bit LSB pie executable, 64-bit PowerPC or cisco 7500, version 1 (SYSV), dynamically linked, interpreter /lib64/ld64.so.2, for GNU/Linux 3.10.0, BuildID[sha1]=dad78822e741b7900dc7568222822d5d63c31a6c, not stripped