From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759691Ab3BNKNl (ORCPT ); Thu, 14 Feb 2013 05:13:41 -0500 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:48742 "EHLO fgwmail6.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752772Ab3BNKMv (ORCPT ); Thu, 14 Feb 2013 05:12:51 -0500 From: HATAYAMA Daisuke Subject: [PATCH 12/13] vmcore: copy non page-size aligned head and tail pages in 2nd kernel To: ebiederm@xmission.com, vgoyal@redhat.com, cpw@sgi.com, kumagai-atsushi@mxc.nes.nec.co.jp, lisa.mitchell@hp.com Cc: kexec@lists.infradead.org, linux-kernel@vger.kernel.org Date: Thu, 14 Feb 2013 19:12:48 +0900 Message-ID: <20130214101248.22466.53004.stgit@localhost6.localdomain6> In-Reply-To: <20130214100945.22466.4172.stgit@localhost6.localdomain6> References: <20130214100945.22466.4172.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 Due to mmap() requirement, we need to copy pages not starting or ending with page-size aligned address in 2nd kernel and to map them to user-space. For example, see the map below: 00000000-0001ffff : reserved 00010000-0009f7ff : System RAM 0009f800-0009ffff : reserved where the System RAM ends with 0x9f800 that is not page-size aligned. This map is divided into two parts: 00010000-0009dfff 0009f000-0009f7ff and the first one is kept in old memory and the 2nd one is copied into buffer on 2nd kernel. This kind of non-page-size-aligned area can always occur since any part of System RAM can be converted into reserved area at runtime. If not doing copying like this and if remapping non page-size aligned pages on old memory directly, mmap() had to export memory which is not dump target to user-space. In the above example this is reserved 0x9f800-0xa0000. Signed-off-by: HATAYAMA Daisuke --- fs/proc/vmcore.c | 97 ++++++++++++++++++++++++++++++++++++++++++++++++------ 1 files changed, 87 insertions(+), 10 deletions(-) diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c index 2968e5a..99f5673 100644 --- a/fs/proc/vmcore.c +++ b/fs/proc/vmcore.c @@ -446,11 +446,10 @@ static int __init process_ptload_program_headers_elf64(char *elfptr, size_t elfsz, struct list_head *vc_list) { - int i; + int i, rc; Elf64_Ehdr *ehdr_ptr; Elf64_Phdr *phdr_ptr; loff_t vmcore_off; - struct vmcore *new; ehdr_ptr = (Elf64_Ehdr *)elfptr; phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr)); /* PT_NOTE hdr */ @@ -460,20 +459,98 @@ static int __init process_ptload_program_headers_elf64(char *elfptr, PAGE_SIZE); for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { + u64 start, end, rest; + if (phdr_ptr->p_type != PT_LOAD) continue; - /* 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; - list_add_tail(&new->list, vc_list); + start = phdr_ptr->p_offset; + end = phdr_ptr->p_offset + phdr_ptr->p_memsz; + rest = phdr_ptr->p_memsz; + + if (start & ~PAGE_MASK) { + u64 paddr, len; + char *buf; + struct vmcore *new; + + paddr = start; + len = min(roundup(start,PAGE_SIZE), end) - start; + + buf = (char *)get_zeroed_page(GFP_KERNEL); + if (!buf) + return -ENOMEM; + rc = read_from_oldmem(buf + (start & ~PAGE_MASK), len, + &paddr, 0); + if (rc < 0) { + free_pages((unsigned long)buf, 0); + return rc; + } + + new = get_new_element(); + if (!new) { + free_pages((unsigned long)buf, 0); + return -ENOMEM; + } + new->type = VMCORE_2ND_KERNEL; + new->size = PAGE_SIZE; + new->buf = buf; + list_add_tail(&new->list, vc_list); + + rest -= len; + } + + if (rest > 0 && + roundup(start, PAGE_SIZE) < rounddown(end, PAGE_SIZE)) { + u64 paddr, len; + struct vmcore *new; + + paddr = roundup(start, PAGE_SIZE); + len =rounddown(end,PAGE_SIZE)-roundup(start,PAGE_SIZE); + + new = get_new_element(); + if (!new) + return -ENOMEM; + new->type = VMCORE_OLD_MEMORY; + new->paddr = paddr; + new->size = len; + list_add_tail(&new->list, vc_list); + + rest -= new->size; + } + + if (rest > 0) { + u64 paddr, len; + char *buf; + struct vmcore *new; + + paddr = rounddown(end, PAGE_SIZE); + len = end - rounddown(end, PAGE_SIZE); + + buf = (char *)get_zeroed_page(GFP_KERNEL); + if (!buf) + return -ENOMEM; + rc = read_from_oldmem(buf, len, &paddr, 0); + if (rc < 0) { + free_pages((unsigned long)buf, 0); + return rc; + } + + new = get_new_element(); + if (!new) { + free_pages((unsigned long)buf, 0); + return -ENOMEM; + } + new->type = VMCORE_2ND_KERNEL; + new->size = PAGE_SIZE; + new->buf = buf; + list_add_tail(&new->list, vc_list); + + rest -= len; + } /* Update the program header offset. */ phdr_ptr->p_offset = vmcore_off; - vmcore_off = vmcore_off + phdr_ptr->p_memsz; + vmcore_off +=roundup(end,PAGE_SIZE)-rounddown(start,PAGE_SIZE); } return 0; } From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1U5voB-0003IL-N7 for kexec@lists.infradead.org; Thu, 14 Feb 2013 10:12:52 +0000 Received: from m4.gw.fujitsu.co.jp (unknown [10.0.50.74]) by fgwmail6.fujitsu.co.jp (Postfix) with ESMTP id 342403EE0C1 for ; Thu, 14 Feb 2013 19:12:50 +0900 (JST) Received: from smail (m4 [127.0.0.1]) by outgoing.m4.gw.fujitsu.co.jp (Postfix) with ESMTP id 0957645DE51 for ; Thu, 14 Feb 2013 19:12:50 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (s4.gw.fujitsu.co.jp [10.0.50.94]) by m4.gw.fujitsu.co.jp (Postfix) with ESMTP id E43C145DE4E for ; Thu, 14 Feb 2013 19:12:49 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id D891D1DB803F for ; Thu, 14 Feb 2013 19:12:49 +0900 (JST) Received: from m1000.s.css.fujitsu.com (m1000.s.css.fujitsu.com [10.240.81.136]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id 7D4841DB803E for ; Thu, 14 Feb 2013 19:12:49 +0900 (JST) From: HATAYAMA Daisuke Subject: [PATCH 12/13] vmcore: copy non page-size aligned head and tail pages in 2nd kernel Date: Thu, 14 Feb 2013 19:12:48 +0900 Message-ID: <20130214101248.22466.53004.stgit@localhost6.localdomain6> In-Reply-To: <20130214100945.22466.4172.stgit@localhost6.localdomain6> References: <20130214100945.22466.4172.stgit@localhost6.localdomain6> MIME-Version: 1.0 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-bounces@lists.infradead.org Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: ebiederm@xmission.com, vgoyal@redhat.com, cpw@sgi.com, kumagai-atsushi@mxc.nes.nec.co.jp, lisa.mitchell@hp.com Cc: kexec@lists.infradead.org, linux-kernel@vger.kernel.org Due to mmap() requirement, we need to copy pages not starting or ending with page-size aligned address in 2nd kernel and to map them to user-space. For example, see the map below: 00000000-0001ffff : reserved 00010000-0009f7ff : System RAM 0009f800-0009ffff : reserved where the System RAM ends with 0x9f800 that is not page-size aligned. This map is divided into two parts: 00010000-0009dfff 0009f000-0009f7ff and the first one is kept in old memory and the 2nd one is copied into buffer on 2nd kernel. This kind of non-page-size-aligned area can always occur since any part of System RAM can be converted into reserved area at runtime. If not doing copying like this and if remapping non page-size aligned pages on old memory directly, mmap() had to export memory which is not dump target to user-space. In the above example this is reserved 0x9f800-0xa0000. Signed-off-by: HATAYAMA Daisuke --- fs/proc/vmcore.c | 97 ++++++++++++++++++++++++++++++++++++++++++++++++------ 1 files changed, 87 insertions(+), 10 deletions(-) diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c index 2968e5a..99f5673 100644 --- a/fs/proc/vmcore.c +++ b/fs/proc/vmcore.c @@ -446,11 +446,10 @@ static int __init process_ptload_program_headers_elf64(char *elfptr, size_t elfsz, struct list_head *vc_list) { - int i; + int i, rc; Elf64_Ehdr *ehdr_ptr; Elf64_Phdr *phdr_ptr; loff_t vmcore_off; - struct vmcore *new; ehdr_ptr = (Elf64_Ehdr *)elfptr; phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr)); /* PT_NOTE hdr */ @@ -460,20 +459,98 @@ static int __init process_ptload_program_headers_elf64(char *elfptr, PAGE_SIZE); for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { + u64 start, end, rest; + if (phdr_ptr->p_type != PT_LOAD) continue; - /* 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; - list_add_tail(&new->list, vc_list); + start = phdr_ptr->p_offset; + end = phdr_ptr->p_offset + phdr_ptr->p_memsz; + rest = phdr_ptr->p_memsz; + + if (start & ~PAGE_MASK) { + u64 paddr, len; + char *buf; + struct vmcore *new; + + paddr = start; + len = min(roundup(start,PAGE_SIZE), end) - start; + + buf = (char *)get_zeroed_page(GFP_KERNEL); + if (!buf) + return -ENOMEM; + rc = read_from_oldmem(buf + (start & ~PAGE_MASK), len, + &paddr, 0); + if (rc < 0) { + free_pages((unsigned long)buf, 0); + return rc; + } + + new = get_new_element(); + if (!new) { + free_pages((unsigned long)buf, 0); + return -ENOMEM; + } + new->type = VMCORE_2ND_KERNEL; + new->size = PAGE_SIZE; + new->buf = buf; + list_add_tail(&new->list, vc_list); + + rest -= len; + } + + if (rest > 0 && + roundup(start, PAGE_SIZE) < rounddown(end, PAGE_SIZE)) { + u64 paddr, len; + struct vmcore *new; + + paddr = roundup(start, PAGE_SIZE); + len =rounddown(end,PAGE_SIZE)-roundup(start,PAGE_SIZE); + + new = get_new_element(); + if (!new) + return -ENOMEM; + new->type = VMCORE_OLD_MEMORY; + new->paddr = paddr; + new->size = len; + list_add_tail(&new->list, vc_list); + + rest -= new->size; + } + + if (rest > 0) { + u64 paddr, len; + char *buf; + struct vmcore *new; + + paddr = rounddown(end, PAGE_SIZE); + len = end - rounddown(end, PAGE_SIZE); + + buf = (char *)get_zeroed_page(GFP_KERNEL); + if (!buf) + return -ENOMEM; + rc = read_from_oldmem(buf, len, &paddr, 0); + if (rc < 0) { + free_pages((unsigned long)buf, 0); + return rc; + } + + new = get_new_element(); + if (!new) { + free_pages((unsigned long)buf, 0); + return -ENOMEM; + } + new->type = VMCORE_2ND_KERNEL; + new->size = PAGE_SIZE; + new->buf = buf; + list_add_tail(&new->list, vc_list); + + rest -= len; + } /* Update the program header offset. */ phdr_ptr->p_offset = vmcore_off; - vmcore_off = vmcore_off + phdr_ptr->p_memsz; + vmcore_off +=roundup(end,PAGE_SIZE)-rounddown(start,PAGE_SIZE); } return 0; } _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec