From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from moutng.kundenserver.de ([212.227.126.171]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1Ul1Vc-0004NW-6X for kexec@lists.infradead.org; Fri, 07 Jun 2013 18:35:32 +0000 From: Arnd Bergmann Subject: Re: [PATCH v8 9/9] vmcore: support mmap() on /proc/vmcore Date: Fri, 7 Jun 2013 20:34:58 +0200 References: <20130523052421.13864.83978.stgit@localhost6.localdomain6> <10307835.fkACLi6FUD@wuerfel> <51B130F9.8070408@jp.fujitsu.com> In-Reply-To: <51B130F9.8070408@jp.fujitsu.com> MIME-Version: 1.0 Message-Id: <201306072034.58817.arnd@arndb.de> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=twosheds.infradead.org@lists.infradead.org To: HATAYAMA Daisuke Cc: riel@redhat.com, hughd@google.com, jingbai.ma@hp.com, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, lisa.mitchell@hp.com, linux-mm@kvack.org, kumagai-atsushi@mxc.nes.nec.co.jp, ebiederm@xmission.com, kosaki.motohiro@jp.fujitsu.com, zhangyanfei@cn.fujitsu.com, akpm@linux-foundation.org, walken@google.com, cpw@sgi.com, vgoyal@redhat.com On Friday 07 June 2013, HATAYAMA Daisuke wrote: > Thanks for trying the build and your report! > > OTOH, I don't have no-MMU architectures; x86 box only. I cannot reproduce this build error. > Could you give me your build log? I want to use it to detect what part depends on CONFIG_MMU. What I get is a link-time error: fs/built-in.o: In function `mmap_vmcore': :(.text+0x4bc18): undefined reference to `remap_vmalloc_range_partial' fs/built-in.o: In function `merge_note_headers_elf32.constprop.4': :(.init.text+0x142c): undefined reference to `find_vm_area' and I used this patch to temporarily work around the problem, effectively disabling all of /proc/vmcore on non-MMU kernels. diff --git a/include/linux/crash_dump.h b/include/linux/crash_dump.h index 37e4f8d..9a078ef 100644 --- a/include/linux/crash_dump.h +++ b/include/linux/crash_dump.h @@ -55,7 +55,7 @@ static inline int is_kdump_kernel(void) static inline int is_vmcore_usable(void) { - return is_kdump_kernel() && elfcorehdr_addr != ELFCORE_ADDR_ERR ? 1 : 0; + return IS_ENABLED(CONFIG_MMU) && is_kdump_kernel() && elfcorehdr_addr != ELFCORE_ADDR_ERR ? 1 : 0; } /* vmcore_unusable() marks the vmcore as unusable, For testing, I used ARM at91x40_defconfig and manually turned on VMCORE support in menuconfig, but it happened before using "randconfig". On most distros you can these days install an arm cross compiler using yum or apt-get and build the kernel yourself with 'make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi-' Arnd _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx159.postini.com [74.125.245.159]) by kanga.kvack.org (Postfix) with SMTP id 9CD876B0031 for ; Fri, 7 Jun 2013 14:35:57 -0400 (EDT) From: Arnd Bergmann Subject: Re: [PATCH v8 9/9] vmcore: support mmap() on /proc/vmcore Date: Fri, 7 Jun 2013 20:34:58 +0200 References: <20130523052421.13864.83978.stgit@localhost6.localdomain6> <10307835.fkACLi6FUD@wuerfel> <51B130F9.8070408@jp.fujitsu.com> In-Reply-To: <51B130F9.8070408@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201306072034.58817.arnd@arndb.de> Sender: owner-linux-mm@kvack.org List-ID: To: HATAYAMA Daisuke Cc: vgoyal@redhat.com, ebiederm@xmission.com, akpm@linux-foundation.org, cpw@sgi.com, kumagai-atsushi@mxc.nes.nec.co.jp, lisa.mitchell@hp.com, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, zhangyanfei@cn.fujitsu.com, jingbai.ma@hp.com, linux-mm@kvack.org, riel@redhat.com, walken@google.com, hughd@google.com, kosaki.motohiro@jp.fujitsu.com On Friday 07 June 2013, HATAYAMA Daisuke wrote: > Thanks for trying the build and your report! > > OTOH, I don't have no-MMU architectures; x86 box only. I cannot reproduce this build error. > Could you give me your build log? I want to use it to detect what part depends on CONFIG_MMU. What I get is a link-time error: fs/built-in.o: In function `mmap_vmcore': :(.text+0x4bc18): undefined reference to `remap_vmalloc_range_partial' fs/built-in.o: In function `merge_note_headers_elf32.constprop.4': :(.init.text+0x142c): undefined reference to `find_vm_area' and I used this patch to temporarily work around the problem, effectively disabling all of /proc/vmcore on non-MMU kernels. diff --git a/include/linux/crash_dump.h b/include/linux/crash_dump.h index 37e4f8d..9a078ef 100644 --- a/include/linux/crash_dump.h +++ b/include/linux/crash_dump.h @@ -55,7 +55,7 @@ static inline int is_kdump_kernel(void) static inline int is_vmcore_usable(void) { - return is_kdump_kernel() && elfcorehdr_addr != ELFCORE_ADDR_ERR ? 1 : 0; + return IS_ENABLED(CONFIG_MMU) && is_kdump_kernel() && elfcorehdr_addr != ELFCORE_ADDR_ERR ? 1 : 0; } /* vmcore_unusable() marks the vmcore as unusable, For testing, I used ARM at91x40_defconfig and manually turned on VMCORE support in menuconfig, but it happened before using "randconfig". On most distros you can these days install an arm cross compiler using yum or apt-get and build the kernel yourself with 'make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi-' Arnd -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932099Ab3FGSfM (ORCPT ); Fri, 7 Jun 2013 14:35:12 -0400 Received: from moutng.kundenserver.de ([212.227.126.171]:59858 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756580Ab3FGSfK (ORCPT ); Fri, 7 Jun 2013 14:35:10 -0400 From: Arnd Bergmann To: HATAYAMA Daisuke Subject: Re: [PATCH v8 9/9] vmcore: support mmap() on /proc/vmcore Date: Fri, 7 Jun 2013 20:34:58 +0200 User-Agent: KMail/1.12.2 (Linux/3.8.0-22-generic; KDE/4.3.2; x86_64; ; ) Cc: vgoyal@redhat.com, ebiederm@xmission.com, akpm@linux-foundation.org, cpw@sgi.com, kumagai-atsushi@mxc.nes.nec.co.jp, lisa.mitchell@hp.com, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, zhangyanfei@cn.fujitsu.com, jingbai.ma@hp.com, linux-mm@kvack.org, riel@redhat.com, walken@google.com, hughd@google.com, kosaki.motohiro@jp.fujitsu.com References: <20130523052421.13864.83978.stgit@localhost6.localdomain6> <10307835.fkACLi6FUD@wuerfel> <51B130F9.8070408@jp.fujitsu.com> In-Reply-To: <51B130F9.8070408@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201306072034.58817.arnd@arndb.de> X-Provags-ID: V02:K0:t7XQZOlOdxVd3i/OFhdgdgLFbsySqV28jlWVwG4bU17 I+TA/SrtTmKrJ0/A4Fs0z7cU5rDI3d5rkPOu+pR8DZCKikuON7 KoH+4qk3af6W48Fj//aWPirtpuIIHIpta5hxXAhp/4MsNgC7Sb jq6VeBozWMYVFwgrdUosO9m7Snj0if0gEFUKT4rSV8GNhhx7G7 sMs/AyyeO/fMAN2oRroA9oy5Th+v4nFMG/FRUiWx9cu8EnAuVt oU+k6JqXq9AQoAALr/GWaCSsz5YVqDtXDH0tVZLUUra2DilwZF u4LhB44/q8VSVAKiYYgcmpMViyGPn/MRJTq/obqwvE9UPSF0Kz 8vvLDZPtV9xcNSp9ZjU4= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Friday 07 June 2013, HATAYAMA Daisuke wrote: > Thanks for trying the build and your report! > > OTOH, I don't have no-MMU architectures; x86 box only. I cannot reproduce this build error. > Could you give me your build log? I want to use it to detect what part depends on CONFIG_MMU. What I get is a link-time error: fs/built-in.o: In function `mmap_vmcore': :(.text+0x4bc18): undefined reference to `remap_vmalloc_range_partial' fs/built-in.o: In function `merge_note_headers_elf32.constprop.4': :(.init.text+0x142c): undefined reference to `find_vm_area' and I used this patch to temporarily work around the problem, effectively disabling all of /proc/vmcore on non-MMU kernels. diff --git a/include/linux/crash_dump.h b/include/linux/crash_dump.h index 37e4f8d..9a078ef 100644 --- a/include/linux/crash_dump.h +++ b/include/linux/crash_dump.h @@ -55,7 +55,7 @@ static inline int is_kdump_kernel(void) static inline int is_vmcore_usable(void) { - return is_kdump_kernel() && elfcorehdr_addr != ELFCORE_ADDR_ERR ? 1 : 0; + return IS_ENABLED(CONFIG_MMU) && is_kdump_kernel() && elfcorehdr_addr != ELFCORE_ADDR_ERR ? 1 : 0; } /* vmcore_unusable() marks the vmcore as unusable, For testing, I used ARM at91x40_defconfig and manually turned on VMCORE support in menuconfig, but it happened before using "randconfig". On most distros you can these days install an arm cross compiler using yum or apt-get and build the kernel yourself with 'make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi-' Arnd