Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933666Ab3CSCbc (ORCPT ); Mon, 18 Mar 2013 22:31:32 -0400 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:46284 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933620Ab3CSCb2 (ORCPT ); Mon, 18 Mar 2013 22:31:28 -0400 From: HATAYAMA Daisuke Subject: [PATCH v3 15/21] elf: introduce NT_VMCORE_PAD type To: vgoyal@redhat.com, ebiederm@xmission.com, cpw@sgi.com, kumagai-atsushi@mxc.nes.nec.co.jp, lisa.mitchell@hp.com, heiko.carstens@de.ibm.com, akpm@linux-foundation.org Cc: kexec@lists.infradead.org, linux-kernel@vger.kernel.org, zhangyanfei@cn.fujitsu.com Date: Sat, 16 Mar 2013 13:02:11 +0900 Message-ID: <20130316040211.15064.1645.stgit@localhost6.localdomain6> In-Reply-To: <20130316040003.15064.62308.stgit@localhost6.localdomain6> References: <20130316040003.15064.62308.stgit@localhost6.localdomain6> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1948 Lines: 46 The NT_VMCORE_PAD type is introduced to make both crash_notes buffer and vmcoreinfo_note buffer satisfy mmap()'s page-size boundary requirement by filling them with this note type. The purpose of this type is just to align the buffer in page-size boundary; it has no meaning in contents, which are fully filled with zero. This note type belongs to "VMCOREINFO" name space and the type in this name space is 7. The reason why the numbers from 1 to 5 is not chosen is that for the ones from 1 to 4, there are the corresponding note types using the same number in "CORE" name space, and crash utility and makedumpfile don't distinguish note types by name space at all; for the remaining 5, this has somehow not been used since v2.4.0 kernel despite the fact that NT_AUXV is defined as 6. It looks that it avoids some dependency to 5. Here simply 5 is not chosen for conservative viewpoint. By this change, gdb and binutils work well without any change, but makedumpfile and crash utility need their changes to distinguish two note types in "VMCOREINFO" name space. Signed-off-by: HATAYAMA Daisuke --- include/uapi/linux/elf.h | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/include/uapi/linux/elf.h b/include/uapi/linux/elf.h index b869904..9753e4c 100644 --- a/include/uapi/linux/elf.h +++ b/include/uapi/linux/elf.h @@ -402,6 +402,7 @@ typedef struct elf64_shdr { * Notes exported from /proc/vmcore, belonging to "VMCOREINFO" name. */ #define NT_VMCORE_DEBUGINFO 0 /* vmcore system kernel's debuginfo */ +#define NT_VMCORE_PAD 7 /* vmcore padding of note segments */ /* Note header in a PT_NOTE section */ typedef struct elf32_note { -- 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/