From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754590AbaDPFnt (ORCPT ); Wed, 16 Apr 2014 01:43:49 -0400 Received: from mail-pb0-f41.google.com ([209.85.160.41]:40922 "EHLO mail-pb0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754408AbaDPFnr (ORCPT ); Wed, 16 Apr 2014 01:43:47 -0400 Message-ID: <534E187E.6050908@gmail.com> Date: Wed, 16 Apr 2014 13:43:26 +0800 From: Chen Gang User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.4.0 MIME-Version: 1.0 To: =?UTF-8?B?566h6Zuq5rab?= CC: Guan Xuetao , akpm@linux-foundation.org, liuj97@gmail.com, rientjes@google.com, dhowells@redhat.com, mhocko@suse.cz, mgorman@suse.de, linux-kernel@vger.kernel.org Subject: Re: =?UTF-8?B?5Zue5aSN77yaIFtQQVRDSCB2M10gYXJjaDp1bmljb3JlMzI6bW0=?= =?UTF-8?B?OiBhZGQgZGV2bWVtX2lzX2FsbG93ZWQoKSB0byBzdXBwb3J0IFNUUklDVF9ERVY=?= =?UTF-8?B?TUVN?= References: <1834032058.38902.1397625329658.JavaMail.root@bj-mail03.pku.edu.cn> In-Reply-To: <1834032058.38902.1397625329658.JavaMail.root@bj-mail03.pku.edu.cn> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/16/2014 01:15 PM, 管雪涛 wrote: > Acked-by: Xuetao Guan > OK, thanks. > ----- Chen Gang 写道： >> unicore32 supports STRICT_DEVMEM, so it needs devmem_is_allowed(), like >> some of other architectures have done (e.g. arm, powerpc, x86 ...). >> >> The related error with allmodconfig: >> >> CC drivers/char/mem.o >> drivers/char/mem.c: In function ‘range_is_allowed’: >> drivers/char/mem.c:69: error: implicit declaration of function ‘devmem_is_allowed’ >> make[2]: *** [drivers/char/mem.o] Error 1 >> make[1]: *** [drivers/char] Error 2 >> make: *** [drivers] Error 2 >> >> >> Signed-off-by: Chen Gang >> --- >> arch/unicore32/include/asm/io.h | 23 +++++++++++++++++++++++ >> 1 file changed, 23 insertions(+) >> >> diff --git a/arch/unicore32/include/asm/io.h b/arch/unicore32/include/asm/io.h >> index 39decb6..ae327e4 100644 >> --- a/arch/unicore32/include/asm/io.h >> +++ b/arch/unicore32/include/asm/io.h >> @@ -44,5 +44,28 @@ extern void __uc32_iounmap(volatile void __iomem *addr); >> #define PIO_MASK (unsigned int)(IO_SPACE_LIMIT) >> #define PIO_RESERVED (PIO_OFFSET + PIO_MASK + 1) >> >> +#ifdef CONFIG_STRICT_DEVMEM >> + >> +#include >> +#include >> + >> +/* >> + * devmem_is_allowed() checks to see if /dev/mem access to a certain >> + * address is valid. The argument is a physical page number. >> + * We mimic x86 here by disallowing access to system RAM as well as >> + * device-exclusive MMIO regions. This effectively disable read()/write() >> + * on /dev/mem. >> + */ >> +static inline int devmem_is_allowed(unsigned long pfn) >> +{ >> + if (iomem_is_exclusive(pfn << PAGE_SHIFT)) >> + return 0; >> + if (!page_is_ram(pfn)) >> + return 1; >> + return 0; >> +} >> + >> +#endif /* CONFIG_STRICT_DEVMEM */ >> + >> #endif /* __KERNEL__ */ >> #endif /* __UNICORE_IO_H__ */ >> -- >> 1.7.9.5 >> > -- Chen Gang Open, share, and attitude like air, water, and life which God blessed