Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752673AbdF2Qp1 (ORCPT ); Thu, 29 Jun 2017 12:45:27 -0400 Received: from mail-qk0-f173.google.com ([209.85.220.173]:35033 "EHLO mail-qk0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751797AbdF2QpV (ORCPT ); Thu, 29 Jun 2017 12:45:21 -0400 Subject: Re: [RFC PATCH 1/4] Provide linux/set_memory.h To: Michael Ellerman , kernel-hardening@lists.openwall.com Cc: keescook@chromium.org, akpm@linux-foundation.org, linux-kernel@vger.kernel.org References: <1498717781-29151-1-git-send-email-mpe@ellerman.id.au> From: Laura Abbott Message-ID: <0ebcc89e-8230-defa-8c15-0d673505db29@redhat.com> Date: Thu, 29 Jun 2017 09:45:16 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.1.0 MIME-Version: 1.0 In-Reply-To: <1498717781-29151-1-git-send-email-mpe@ellerman.id.au> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2034 Lines: 55 On 06/28/2017 11:29 PM, Michael Ellerman wrote: > Currently code that wants to use set_memory_ro() etc, needs to include > asm/set_memory.h, which doesn't exist on all arches. Some code knows > it only builds on arches which have the header, other code guards the > inclusion with an #ifdef, neither is ideal. > > So create linux/set_memory.h. This always exists, so users don't need > an #ifdef just to include the header. > > When CONFIG_ARCH_HAS_SET_MEMORY=y it includes asm/set_memory.h, > otherwise it provides empty non-failing implementations. > > Signed-off-by: Michael Ellerman > --- > include/linux/set_memory.h | 20 ++++++++++++++++++++ > 1 file changed, 20 insertions(+) > create mode 100644 include/linux/set_memory.h > > > Does this look OK to people? If so it would be great if someone, Kees?, > Andrew?, could pick up patch 1 (it's a nop by itself) and then we can send the > conversions separately later in the merge window? > Acked-by: Laura Abbott > cheers > > diff --git a/include/linux/set_memory.h b/include/linux/set_memory.h > new file mode 100644 > index 000000000000..e5140648f638 > --- /dev/null > +++ b/include/linux/set_memory.h > @@ -0,0 +1,20 @@ > +/* > + * Copyright 2017, Michael Ellerman, IBM Corporation. > + * > + * This program is free software; you can redistribute it and/or > + * modify it under the terms of the GNU General Public License version > + * 2 as published by the Free Software Foundation; > + */ > +#ifndef _LINUX_SET_MEMORY_H_ > +#define _LINUX_SET_MEMORY_H_ > + > +#ifdef CONFIG_ARCH_HAS_SET_MEMORY > +#include > +#else > +static inline int set_memory_ro(unsigned long addr, int numpages) { return 0; } > +static inline int set_memory_rw(unsigned long addr, int numpages) { return 0; } > +static inline int set_memory_x(unsigned long addr, int numpages) { return 0; } > +static inline int set_memory_nx(unsigned long addr, int numpages) { return 0; } > +#endif > + > +#endif /* _LINUX_SET_MEMORY_H_ */ >