From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756280Ab3ENB5p (ORCPT ); Mon, 13 May 2013 21:57:45 -0400 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:39048 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755967Ab3ENB5n (ORCPT ); Mon, 13 May 2013 21:57:43 -0400 From: HATAYAMA Daisuke Subject: [PATCH v5 6/8] vmcore: treat memory chunks referenced by PT_LOAD program header entries in page-size boundary in vmcore_list To: vgoyal@redhat.com, ebiederm@xmission.com, akpm@linux-foundation.org Cc: 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 Date: Tue, 14 May 2013 10:57:40 +0900 Message-ID: <20130514015740.18697.67638.stgit@localhost6.localdomain6> In-Reply-To: <20130514015622.18697.77191.stgit@localhost6.localdomain6> References: <20130514015622.18697.77191.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 Treat memory chunks referenced by PT_LOAD program header entries in page-size boundary in vmcore_list. Formally, for each range [start, end], we set up the corresponding vmcore object in vmcore_list to [rounddown(start, PAGE_SIZE), roundup(end, PAGE_SIZE)]. This change affects layout of /proc/vmcore. The gaps generated by the rearrangement are newly made visible to applications as holes. Concretely, they are two ranges [rounddown(start, PAGE_SIZE), start] and [end, roundup(end, PAGE_SIZE)]. Suppose variable m points at a vmcore object in vmcore_list, and variable phdr points at the program header of PT_LOAD type the variable m corresponds to. Then, pictorially: m->offset +---------------+ | hole | phdr->p_offset = +---------------+ m->offset + (paddr - start) | |\ | kernel memory | phdr->p_memsz | |/ +---------------+ | hole | m->offset + m->size +---------------+ where m->offset and m->offset + m->size are always page-size aligned. Signed-off-by: HATAYAMA Daisuke --- fs/proc/vmcore.c | 30 ++++++++++++++++++++++-------- 1 files changed, 22 insertions(+), 8 deletions(-) diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c index 795efd2..eb7ff29 100644 --- a/fs/proc/vmcore.c +++ b/fs/proc/vmcore.c @@ -504,20 +504,27 @@ static int __init process_ptload_program_headers_elf64(char *elfptr, vmcore_off = elfsz + elfnotesegsz; for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { + u64 paddr, start, end, size; + if (phdr_ptr->p_type != PT_LOAD) continue; + paddr = phdr_ptr->p_offset; + start = rounddown(paddr, PAGE_SIZE); + end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE); + size = end - start; + /* Add this contiguous chunk of memory to vmcore list.*/ new = get_new_element(); if (!new) return -ENOMEM; - new->paddr = phdr_ptr->p_offset; - new->size = phdr_ptr->p_memsz; + new->paddr = start; + new->size = size; list_add_tail(&new->list, vc_list); /* Update the program header offset. */ - phdr_ptr->p_offset = vmcore_off; - vmcore_off = vmcore_off + phdr_ptr->p_memsz; + phdr_ptr->p_offset = vmcore_off + (paddr - start); + vmcore_off = vmcore_off + size; } return 0; } @@ -540,20 +547,27 @@ static int __init process_ptload_program_headers_elf32(char *elfptr, vmcore_off = elfsz + elfnotesegsz; for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { + u64 paddr, start, end, size; + if (phdr_ptr->p_type != PT_LOAD) continue; + paddr = phdr_ptr->p_offset; + start = rounddown(paddr, PAGE_SIZE); + end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE); + size = end - start; + /* Add this contiguous chunk of memory to vmcore list.*/ new = get_new_element(); if (!new) return -ENOMEM; - new->paddr = phdr_ptr->p_offset; - new->size = phdr_ptr->p_memsz; + new->paddr = start; + new->size = size; list_add_tail(&new->list, vc_list); /* Update the program header offset */ - phdr_ptr->p_offset = vmcore_off; - vmcore_off = vmcore_off + phdr_ptr->p_memsz; + phdr_ptr->p_offset = vmcore_off + (paddr - start); + vmcore_off = vmcore_off + size; } return 0; }