From patchwork Thu Feb 25 19:38:56 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Bottomley X-Patchwork-Id: 8426271 Return-Path: X-Original-To: patchwork-linux-fsdevel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 8B384C0553 for ; Thu, 25 Feb 2016 19:39:09 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id CA7822037C for ; Thu, 25 Feb 2016 19:39:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B217F20394 for ; Thu, 25 Feb 2016 19:39:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933661AbcBYTjE (ORCPT ); Thu, 25 Feb 2016 14:39:04 -0500 Received: from bedivere.hansenpartnership.com ([66.63.167.143]:35424 "EHLO bedivere.hansenpartnership.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933377AbcBYTjD (ORCPT ); Thu, 25 Feb 2016 14:39:03 -0500 Received: from localhost (localhost [127.0.0.1]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id 9F33D8EE457; Thu, 25 Feb 2016 11:38:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=hansenpartnership.com; s=20151216; t=1456429137; bh=qBORGzmwBBnVVPfAfB+TkQT85WUN1jZAPTJZj+b3b+Q=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=grOB6WH2GTZ9z9hcif4uOXSGStFM85oGAGzf6GHe1tNoRDgfhTChEcEpd/MjTXPTc X/sSfAvf8J7S/i2MIMO7sIZZM6uudgI5jcHoPi4qGVV20AdpIL+SD7UlBBLqErGCr5 P7jYgLfXst3eOi8Y4EJLq7h3j+aiejMVuYl0XoLw= Received: from bedivere.hansenpartnership.com ([127.0.0.1]) by localhost (bedivere.hansenpartnership.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id hpWeVYWyeVwJ; Thu, 25 Feb 2016 11:38:57 -0800 (PST) Received: from [153.66.254.194] (unknown [184.11.141.41]) by bedivere.hansenpartnership.com (Postfix) with ESMTPSA id 2EFE78EE07D; Thu, 25 Feb 2016 11:38:57 -0800 (PST) Message-ID: <1456429136.2377.7.camel@HansenPartnership.com> Subject: [Patch v2 3/3] binfmt_misc: add F option description to documentation From: James Bottomley To: containers@lists.linux-foundation.org, linux-fsdevel Cc: Al Viro Date: Thu, 25 Feb 2016 11:38:56 -0800 In-Reply-To: <1456428890.2377.2.camel@HansenPartnership.com> References: <1456428890.2377.2.camel@HansenPartnership.com> X-Mailer: Evolution 3.16.5 Mime-Version: 1.0 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Spam-Status: No, score=-1.8 required=5.0 tests=BAYES_00,DKIM_SIGNED, UNPARSEABLE_RELAY autolearn=no version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Signed-off-by: James Bottomley --- Documentation/binfmt_misc.txt | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/Documentation/binfmt_misc.txt b/Documentation/binfmt_misc.txt index 6b1de70..a22eb69 100644 --- a/Documentation/binfmt_misc.txt +++ b/Documentation/binfmt_misc.txt @@ -66,6 +66,13 @@ Here is what the fields mean: This feature should be used with care as the interpreter will run with root permissions when a setuid binary owned by root is run with binfmt_misc. + 'F' - fix binary. The usual behaviour of binfmt_misc is to spawn the + binary lazily when the misc format file is invoked. However, + this doesn't work very well in the face of mount namespaces and + changeroots, so the F mode opens the binary as soon as the + emultation is installed and uses the opened image to spawn the + emulator, meaning it is always available once installed, + regardless of how the environment changes. There are some restrictions: