From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753898AbYIEUrO (ORCPT ); Fri, 5 Sep 2008 16:47:14 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751564AbYIEUq7 (ORCPT ); Fri, 5 Sep 2008 16:46:59 -0400 Received: from saraswathi.solana.com ([198.99.130.12]:43260 "EHLO saraswathi.solana.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751465AbYIEUq6 (ORCPT ); Fri, 5 Sep 2008 16:46:58 -0400 Date: Fri, 5 Sep 2008 12:37:18 -0400 From: Jeff Dike To: Steve VanDeBogart Cc: linux-kernel@vger.kernel.org, user-mode-linux-devel@lists.sourceforge.net, jiayingz@google.com, dkegel@google.com Subject: Re: [uml-devel] [PATCH 2/6] UML: Don't valgrind userspace Message-ID: <20080905163718.GA11455@c2.user-mode-linux.org> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Aug 29, 2008 at 04:15:24PM -0700, Steve VanDeBogart wrote: > Add a flag to tell Valgrind to run the forked child natively. Necessary > because Valgrind makes additional system calls to instrumented processes, > which confuse UML. > +#ifdef UML_CONFIG_VALGRIND_SUPPORT > + flags |= VALGRIND_CLONE_LETGO; > +#endif > + } I keep forgetting that I have a really bad feeling about this: +#define VALGRIND_CLONE_LETGO 0x80000000 /* do not track fork like childr en*/ This is effectively appropriating part of the kernel's ABI for valgrind's use. Not to mention that that bit is already taken: #define CLONE_IO 0x80000000 /* Clone io context */ Could you do this with an annotation that says "let the next clone run untraced"? Jeff -- Work email - jdike at linux dot intel dot com