Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756230AbaDHDUe (ORCPT ); Mon, 7 Apr 2014 23:20:34 -0400 Received: from mx9.pku.edu.cn ([162.105.129.172]:47618 "EHLO mail.pku.edu.cn" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755964AbaDHDUc convert rfc822-to-8bit (ORCPT ); Mon, 7 Apr 2014 23:20:32 -0400 X-Spam-Flag: NO X-Spam-Score: -307.252 Date: Tue, 8 Apr 2014 11:20:16 +0800 (CST) From: =?utf-8?B?566h6Zuq5rab?= To: Chen Gang 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 Message-ID: <629583968.18592.1396927216694.JavaMail.root@bj-mail03.pku.edu.cn> In-Reply-To: <53428BC9.3070001@gmail.com> Subject: =?utf-8?Q?=E5=9B=9E=E5=A4=8D=EF=BC=9A_[PATCH]_arch:unicore32:mm:_add_devm?= =?utf-8?Q?em=5Fis=5Fallowed()_to_support_STRICT=5FDEVMEM?= MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT X-Originating-IP: [162.105.129.95] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I'd like to put the code into asm/io.h, and make it static. > +#ifdef CONFIG_STRICT_DEVMEM > +/* > + * 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 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 */ Thanks, Acked-by: Xuetao Guan ----- 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/page.h | 4 ++++ > arch/unicore32/mm/init.c | 18 ++++++++++++++++++ > 2 files changed, 22 insertions(+) > > diff --git a/arch/unicore32/include/asm/page.h b/arch/unicore32/include/asm/page.h > index 594b322..231cb89 100644 > --- a/arch/unicore32/include/asm/page.h > +++ b/arch/unicore32/include/asm/page.h > @@ -68,6 +68,10 @@ typedef struct page *pgtable_t; > > extern int pfn_valid(unsigned long); > > +#ifdef CONFIG_STRICT_DEVMEM > +extern int devmem_is_allowed(unsigned long pfn); > +#endif /* CONFIG_STRICT_DEVMEM */ > + > #include > > #endif /* !__ASSEMBLY__ */ > diff --git a/arch/unicore32/mm/init.c b/arch/unicore32/mm/init.c > index be2bde9..3bc3a59 100644 > --- a/arch/unicore32/mm/init.c > +++ b/arch/unicore32/mm/init.c > @@ -449,3 +449,21 @@ static int __init keepinitrd_setup(char *__unused) > > __setup("keepinitrd", keepinitrd_setup); > #endif > + > +#ifdef CONFIG_STRICT_DEVMEM > +/* > + * 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. > + */ > +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 */ > -- > 1.7.9.5 -- 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/