Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754160AbYG1HGS (ORCPT ); Mon, 28 Jul 2008 03:06:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752188AbYG1HGI (ORCPT ); Mon, 28 Jul 2008 03:06:08 -0400 Received: from araneidae.co.uk ([62.3.233.233]:2447 "EHLO mail.araneidae.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752018AbYG1HGH (ORCPT ); Mon, 28 Jul 2008 03:06:07 -0400 X-Greylist: delayed 1029 seconds by postgrey-1.27 at vger.kernel.org; Mon, 28 Jul 2008 03:06:07 EDT Date: Mon, 28 Jul 2008 06:48:52 +0000 (GMT) From: Michael Abbott To: linux-kernel@vger.kernel.org Subject: [PATCH]: Make ioctl.h compatible with userland Message-ID: <20080728063957.J72435@saturn.araneidae.co.uk> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1869 Lines: 48 The attached patch seems to already exist in a number of branches -- it keeps popping up on Google for me, and is certainly already in Debian -- but is strangely absent from mainstream. The problem appears to be that the patched file ends up as part of the target toolchain, but unfortunately the gcc constant folding doesn't appear to eliminate the __invalid_size_argument_for_IOC value early enough. Certainly compiling C++ programs which use _IO... macros as constants fails without this patch. No doubt this has been pushed upstream before: this problem seems to date from the very early days of 2.6 ... but here it is again. It makes sense to do it. commit 0df6f37b4e4534f219b5e40cb49ffd9311eb6195 Author: Michael Abbott Date: Mon Jul 28 07:32:05 2008 +0100 Add long established but strangely absent patch to allow ioctl.h to work smoothly with userspace program optimisations. diff --git a/include/asm-generic/ioctl.h b/include/asm-generic/ioctl.h index 8641813..15828b2 100644 --- a/include/asm-generic/ioctl.h +++ b/include/asm-generic/ioctl.h @@ -68,12 +68,16 @@ ((nr) << _IOC_NRSHIFT) | \ ((size) << _IOC_SIZESHIFT)) +#ifdef __KERNEL__ /* provoke compile error for invalid uses of size argument */ extern unsigned int __invalid_size_argument_for_IOC; #define _IOC_TYPECHECK(t) \ ((sizeof(t) == sizeof(t[1]) && \ sizeof(t) < (1 << _IOC_SIZEBITS)) ? \ sizeof(t) : __invalid_size_argument_for_IOC) +#else +#define _IOC_TYPECHECK(t) (sizeof(t)) +#endif /* used to create numbers */ #define _IO(type,nr) _IOC(_IOC_NONE,(type),(nr),0) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/